A methodology for analysing lateral coupled behavior of high speed railway vehicles and structures

International Nuclear Information System (INIS)

AntolIn, P; Goicolea, J M; Astiz, M A; Alonso, A

2010-01-01

Continuous increment of the speed of high speed trains entails the increment of kinetic energy of the trains. The main goal of this article is to study the coupled lateral behavior of vehicle-structure systems for high speed trains. Non linear finite element methods are used for structures whereas multibody dynamics methods are employed for vehicles. Special attention must be paid when dealing with contact rolling constraints for coupling bridge decks and train wheels. The dynamic models must include mixed variables (displacements and creepages). Additionally special attention must be paid to the contact algorithms adequate to wheel-rail contact. The coupled vehicle-structure system is studied in a implicit dynamic framework. Due to the presence of very different systems (trains and bridges), different frequencies are involved in the problem leading to stiff systems. Regarding to contact methods, a main branch is studied in normal contact between train wheels and bridge decks: penalty method. According to tangential contact FastSim algorithm solves the tangential contact at each time step solving a differential equation involving relative displacements and creepage variables. Integration for computing the total forces in the contact ellipse domain is performed for each train wheel and each solver iteration. Coupling between trains and bridges requires a special treatment according to the kinetic constraints imposed in the wheel-rail pair and the load transmission. A numerical example is performed.

A methodology for analysing lateral coupled behavior of high speed railway vehicles and structures

Science.gov (United States)

Antolín, P.; Goicolea, J. M.; Astiz, M. A.; Alonso, A.

2010-06-01

Continuous increment of the speed of high speed trains entails the increment of kinetic energy of the trains. The main goal of this article is to study the coupled lateral behavior of vehicle-structure systems for high speed trains. Non linear finite element methods are used for structures whereas multibody dynamics methods are employed for vehicles. Special attention must be paid when dealing with contact rolling constraints for coupling bridge decks and train wheels. The dynamic models must include mixed variables (displacements and creepages). Additionally special attention must be paid to the contact algorithms adequate to wheel-rail contact. The coupled vehicle-structure system is studied in a implicit dynamic framework. Due to the presence of very different systems (trains and bridges), different frequencies are involved in the problem leading to stiff systems. Regarding to contact methods, a main branch is studied in normal contact between train wheels and bridge decks: penalty method. According to tangential contact FastSim algorithm solves the tangential contact at each time step solving a differential equation involving relative displacements and creepage variables. Integration for computing the total forces in the contact ellipse domain is performed for each train wheel and each solver iteration. Coupling between trains and bridges requires a special treatment according to the kinetic constraints imposed in the wheel-rail pair and the load transmission. A numerical example is performed.

Vehicle Speed Estimation and Forecasting Methods Based on Cellular Floating Vehicle Data

Directory of Open Access Journals (Sweden)

Wei-Kuang Lai

2016-02-01

Full Text Available Traffic information estimation and forecasting methods based on cellular floating vehicle data (CFVD are proposed to analyze the signals (e.g., handovers (HOs, call arrivals (CAs, normal location updates (NLUs and periodic location updates (PLUs from cellular networks. For traffic information estimation, analytic models are proposed to estimate the traffic flow in accordance with the amounts of HOs and NLUs and to estimate the traffic density in accordance with the amounts of CAs and PLUs. Then, the vehicle speeds can be estimated in accordance with the estimated traffic flows and estimated traffic densities. For vehicle speed forecasting, a back-propagation neural network algorithm is considered to predict the future vehicle speed in accordance with the current traffic information (i.e., the estimated vehicle speeds from CFVD. In the experimental environment, this study adopted the practical traffic information (i.e., traffic flow and vehicle speed from Taiwan Area National Freeway Bureau as the input characteristics of the traffic simulation program and referred to the mobile station (MS communication behaviors from Chunghwa Telecom to simulate the traffic information and communication records. The experimental results illustrated that the average accuracy of the vehicle speed forecasting method is 95.72%. Therefore, the proposed methods based on CFVD are suitable for an intelligent transportation system.

Side-suspended High- Tc Superconducting Maglev Prototype Vehicle Running at a High Speed in an Evacuated Circular Test Track

International Nuclear Information System (INIS)

Zhou, Dajin; Zhao, Lifeng; Cui, Chenyu; Zhang, Yong; Guo, Jianqiang; Zhao, Yong

2017-01-01

High- T c superconductor (HTS) and permanent magnetic guideway (PMG) based maglev train is intensively studied in China, Japan, Germany and Brazil, mainly through static or vibration test. Amongst these studies, only a few of reports are available for the direct and effective assessment on the dynamic performance of the HTS maglev vehicle by running on a straight or circular PMG track. The highest running speed of these experiments is lower than 50 km/h. In this paper, a side-suspended HTS permanent magnetic guideway maglev system was proposed and constructed in order to increase the running speed in a circular track. By optimizing the arrangement of YBCO bulks besides the PMG, the side-suspended HTS maglev prototype vehicle was successfully running stably at a speed as high as 150 km/h in a circular test track with 6.5 m in diameter, and in an evacuated tube environment, in which the pressure is 5 × 10 3 Pa. (paper)

Side-suspended High-Tc Superconducting Maglev Prototype Vehicle Running at a High Speed in an Evacuated Circular Test Track

Science.gov (United States)

Zhou, Dajin; Zhao, Lifeng; Cui, Chenyu; Zhang, Yong; Guo, Jianqiang; Zhao, Yong

2017-07-01

High-T c superconductor (HTS) and permanent magnetic guideway (PMG) based maglev train is intensively studied in China, Japan, Germany and Brazil, mainly through static or vibration test. Amongst these studies, only a few of reports are available for the direct and effective assessment on the dynamic performance of the HTS maglev vehicle by running on a straight or circular PMG track. The highest running speed of these experiments is lower than 50 km/h. In this paper, a side-suspended HTS permanent magnetic guideway maglev system was proposed and constructed in order to increase the running speed in a circular track. By optimizing the arrangement of YBCO bulks besides the PMG, the side-suspended HTS maglev prototype vehicle was successfully running stably at a speed as high as 150 km/h in a circular test track with 6.5 m in diameter, and in an evacuated tube environment, in which the pressure is 5 × 103 Pa.

An RFID-Based Intelligent Vehicle Speed Controller Using Active Traffic Signals

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Joshué Pérez

2010-06-01

Full Text Available These days, mass-produced vehicles benefit from research on Intelligent Transportation System (ITS. One prime example of ITS is vehicle Cruise Control (CC, which allows it to maintain a pre-defined reference speed, to economize on fuel or energy consumption, to avoid speeding fines, or to focus all of the driver’s attention on the steering of the vehicle. However, achieving efficient Cruise Control is not easy in roads or urban streets where sudden changes of the speed limit can happen, due to the presence of unexpected obstacles or maintenance work, causing, in inattentive drivers, traffic accidents. In this communication we present a new Infrastructure to Vehicles (I2V communication and control system for intelligent speed control, which is based upon Radio Frequency Identification (RFID technology for identification of traffic signals on the road, and high accuracy vehicle speed measurement with a Hall effect-based sensor. A fuzzy logic controller, based on sensor fusion of the information provided by the I2V infrastructure, allows the efficient adaptation of the speed of the vehicle to the circumstances of the road. The performance of the system is checked empirically, with promising results.

An RFID-Based Intelligent Vehicle Speed Controller Using Active Traffic Signals

Science.gov (United States)

Pérez, Joshué; Seco, Fernando; Milanés, Vicente; Jiménez, Antonio; Díaz, Julio C.; de Pedro, Teresa

2010-01-01

These days, mass-produced vehicles benefit from research on Intelligent Transportation System (ITS). One prime example of ITS is vehicle Cruise Control (CC), which allows it to maintain a pre-defined reference speed, to economize on fuel or energy consumption, to avoid speeding fines, or to focus all of the driver’s attention on the steering of the vehicle. However, achieving efficient Cruise Control is not easy in roads or urban streets where sudden changes of the speed limit can happen, due to the presence of unexpected obstacles or maintenance work, causing, in inattentive drivers, traffic accidents. In this communication we present a new Infrastructure to Vehicles (I2V) communication and control system for intelligent speed control, which is based upon Radio Frequency Identification (RFID) technology for identification of traffic signals on the road, and high accuracy vehicle speed measurement with a Hall effect-based sensor. A fuzzy logic controller, based on sensor fusion of the information provided by the I2V infrastructure, allows the efficient adaptation of the speed of the vehicle to the circumstances of the road. The performance of the system is checked empirically, with promising results. PMID:22219692

An RFID-based intelligent vehicle speed controller using active traffic signals.

Science.gov (United States)

Pérez, Joshué; Seco, Fernando; Milanés, Vicente; Jiménez, Antonio; Díaz, Julio C; de Pedro, Teresa

2010-01-01

These days, mass-produced vehicles benefit from research on Intelligent Transportation System (ITS). One prime example of ITS is vehicle Cruise Control (CC), which allows it to maintain a pre-defined reference speed, to economize on fuel or energy consumption, to avoid speeding fines, or to focus all of the driver's attention on the steering of the vehicle. However, achieving efficient Cruise Control is not easy in roads or urban streets where sudden changes of the speed limit can happen, due to the presence of unexpected obstacles or maintenance work, causing, in inattentive drivers, traffic accidents. In this communication we present a new Infrastructure to Vehicles (I2V) communication and control system for intelligent speed control, which is based upon Radio Frequency Identification (RFID) technology for identification of traffic signals on the road, and high accuracy vehicle speed measurement with a Hall effect-based sensor. A fuzzy logic controller, based on sensor fusion of the information provided by the I2V infrastructure, allows the efficient adaptation of the speed of the vehicle to the circumstances of the road. The performance of the system is checked empirically, with promising results.

Vehicle speed guidance strategy at signalized intersection based on cooperative vehicle infrastructure system

Directory of Open Access Journals (Sweden)

Fengyuan JIA

2017-10-01

Full Text Available In order to reduce stopping time of vehicle at a signalized intersection, aiming at the difficulty, even the impossibility to obtain real-time queue length of intersection in third and fourth-tier cities in China sometimes, a speed guidance strategy based on cooperative vehicle infrastructure system is put forward and studied. For validating the strategy, the traffic signal timing data of the intersection at Hengshan Road and North Fengming Lake Road in Wuhu is collected by a vehicular traffic signal reminder system which is designed. The simulation experiments using the acquired data are done by software VISSIM. The simulation results demonstrate that the strategy under high and low traffic flow can effectively decrease the link travel-time, reducing average ratio is 9.2 % and 13.0 %, respectively, and the effect under low traffic flow is better than that under high traffic flow. The strategy improves efficiency of traffic at a signalized intersection and provides an idea for the application of vehicle speed guidance based on cooperative vehicle infrastructure system.

Hydrogen tube vehicle for supersonic transport: 2. Speed and energy

Energy Technology Data Exchange (ETDEWEB)

Miller, Arnold R. [Vehicle Projects Inc and Supersonic Tubevehicle LLC, 200 Violet St, Suite 100, Golden, CO 80401 (United States)

2010-06-15

The central concept of a new idea in high-speed transport is that operation of a vehicle in a hydrogen atmosphere, because of the low density of hydrogen, would increase sonic speed by a factor of 3.8 and decrease drag by 15 relative to air. A hydrogen atmosphere requires that the vehicle operate within a hydrogen-filled tube or pipeline, which serves as a phase separator. The supersonic tube vehicle (STV) can be supersonic with respect to air outside the tube while remaining subsonic inside. It breathes hydrogen fuel for its propulsion fuel cells from the tube itself. This paper, second in a series on the scientific foundations of the supersonic tube vehicle, tests the hypothesis that the STV will be simultaneously fast and energy efficient by comparing its predicted speed and energy consumption with that of four long-haul passenger transport modes: road, rail, maglev, and air. The study establishes the speed ranking STV >> airplane > maglev > train > coach (intercity bus) and the normalized energy consumption ranking Airplane >> coach > maglev > train > STV. Consistent with the hypothesis, the concept vehicle is both the fastest and lowest energy consuming mode. In theory, the vehicle can cruise at Mach 2.8 while consuming less than half the energy per passenger of a Boeing 747 at a cruise speed of Mach 0.81. (author)

Raising the speed limit from 75 to 80mph on Utah rural interstates: Effects on vehicle speeds and speed variance.

Science.gov (United States)

Hu, Wen

2017-06-01

In November 2010 and October 2013, Utah increased speed limits on sections of rural interstates from 75 to 80mph. Effects on vehicle speeds and speed variance were examined. Speeds were measured in May 2010 and May 2014 within the new 80mph zones, and at a nearby spillover site and at more distant control sites where speed limits remained 75mph. Log-linear regression models estimated percentage changes in speed variance and mean speeds for passenger vehicles and large trucks associated with the speed limit increase. Logistic regression models estimated effects on the probability of passenger vehicles exceeding 80, 85, or 90mph and large trucks exceeding 80mph. Within the 80mph zones and at the spillover location in 2014, mean passenger vehicle speeds were significantly higher (4.1% and 3.5%, respectively), as were the probabilities that passenger vehicles exceeded 80mph (122.3% and 88.5%, respectively), than would have been expected without the speed limit increase. Probabilities that passenger vehicles exceeded 85 and 90mph were non-significantly higher than expected within the 80mph zones. For large trucks, the mean speed and probability of exceeding 80mph were higher than expected within the 80mph zones. Only the increase in mean speed was significant. Raising the speed limit was associated with non-significant increases in speed variance. The study adds to the wealth of evidence that increasing speed limits leads to higher travel speeds and an increased probability of exceeding the new speed limit. Results moreover contradict the claim that increasing speed limits reduces speed variance. Although the estimated increases in mean vehicle speeds may appear modest, prior research suggests such increases would be associated with substantial increases in fatal or injury crashes. This should be considered by lawmakers considering increasing speed limits. Copyright © 2017 Elsevier Ltd and National Safety Council. All rights reserved.

Maglev vehicles and superconductor technology: Integration of high-speed ground transportation into the air travel system

Energy Technology Data Exchange (ETDEWEB)

Johnson, L.R.; Rote, D.M.; Hull, J.R.; Coffey, H.T.; Daley, J.G.; Giese, R.F.

1989-04-01

This study was undertaken to (1) evaluate the potential contribution of high-temperature superconductors (HTSCs) to the technical and economic feasibility of magnetically levitated (maglev) vehicles, (2) determine the status of maglev transportation research in the United States and abroad, (3) identify the likelihood of a significant transportation market for high-speed maglev vehicles, and (4) provide a preliminary assessment of the potential energy and economic benefits of maglev systems. HTSCs should be considered as an enhancing, rather than an enabling, development for maglev transportation because they should improve reliability and reduce energy and maintenance costs. Superconducting maglev transportation technologies were developed in the United States in the late 1960s and early 1970s. Federal support was withdrawn in 1975, but major maglev transportation programs were continued in Japan and West Germany, where full-scale prototypes now carry passengers at speeds of 250 mi/h in demonstration runs. Maglev systems are generally viewed as very-high-speed train systems, but this study shows that the potential market for maglev technology as a train system, e.g., from one downtown to another, is limited. Rather, aircraft and maglev vehicles should be seen as complementing rather than competing transportation systems. If maglev systems were integrated into major hub airport operations, they could become economical in many relatively high-density US corridors. Air traffic congestion and associated noise and pollutant emissions around airports would also be reduced. 68 refs., 26 figs., 16 tabs.

Changes in speed distribution: Applying aggregated safety effect models to individual vehicle speeds.

Science.gov (United States)

Vadeby, Anna; Forsman, Åsa

2017-06-01

This study investigated the effect of applying two aggregated models (the Power model and the Exponential model) to individual vehicle speeds instead of mean speeds. This is of particular interest when the measure introduced affects different parts of the speed distribution differently. The aim was to examine how the estimated overall risk was affected when assuming the models are valid on an individual vehicle level. Speed data from two applications of speed measurements were used in the study: an evaluation of movable speed cameras and a national evaluation of new speed limits in Sweden. The results showed that when applied on individual vehicle speed level compared with aggregated level, there was essentially no difference between these for the Power model in the case of injury accidents. However, for fatalities the difference was greater, especially for roads with new cameras where those driving fastest reduced their speed the most. For the case with new speed limits, the individual approach estimated a somewhat smaller effect, reflecting that changes in the 15th percentile (P15) were somewhat larger than changes in P85 in this case. For the Exponential model there was also a clear, although small, difference between applying the model to mean speed changes and individual vehicle speed changes when speed cameras were used. This applied both for injury accidents and fatalities. There were also larger effects for the Exponential model than for the Power model, especially for injury accidents. In conclusion, applying the Power or Exponential model to individual vehicle speeds is an alternative that provides reasonable results in relation to the original Power and Exponential models, but more research is needed to clarify the shape of the individual risk curve. It is not surprising that the impact on severe traffic crashes was larger in situations where those driving fastest reduced their speed the most. Further investigations on use of the Power and/or the

The wheel-rail contact friction influence on high speed vehicle model stability

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Mirosław DUSZA

2015-09-01

Full Text Available Right estimating of the coefficient of friction between the wheel and rail is essential in modelling rail vehicle dynamics. Constant value of coefficient of friction is the typical assumption in theoretical studies. But it is obvious that in real circumstances a few factors may have significant influence on the rails surface condition and this way on the coefficient of friction value. For example the weather condition, the railway location etc. Influence of the coefficient of friction changes on high speed rail vehicle model dynamics is presented in this paper. Four axle rail vehicle model were built. The FASTSIM code is employed for calculation of the tangential contact forces between wheel and rail. One coefficient of friction value is adopted in the particular simulation process. To check the vehicle model properties under the influence of wheel-rail coefficient of friction changes, twenty four series of simulations were performed. For three curved tracks of radii R = 3000m, 6000m and  (straight track, the coefficient of friction was changed from 0.1 to 0.8. The results are presented in form of bifurcation diagrams.

Influence of Suspended Equipment on the Carbody Vertical Vibration Behaviour of High-Speed Railway Vehicles

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Dumitriu Mădălina

2016-03-01

Full Text Available The equipment mounted on the carbody chassis of the railway vehicles is a critical component of the vehicle in terms of ride comfort. The reason for that is their large mass, able to visibly influence the vibrations mode of the carbody. The paper examines the influence of the equipment upon the mode of vertical vibrations of the carbody in the high-speed vehicles, reached on the basis of the frequency response functions of the acceleration in three carbody reference points - at the centre and above the bogies. These functions are derived from the numerical simulations developed on a rigid-flexible coupled model, with seven degrees of freedom. As a rule, the results herein prove the influence of the equipment mounting mode (rigid or elastic, along with the speed regime, upon the level of vibrations in the carbody reference points, at the resonance frequency of the symmetrical bending mode. Similarly, it is also demonstrated how the equipment mass and the damping degree of the suspension system affect the level of the vibrations in the carbody.

Vehicle Classification and Speed Estimation Using Combined Passive Infrared/Ultrasonic Sensors

KAUST Repository

Odat, Enas M.

2017-09-18

In this paper, a new sensing device that can simultaneously monitor traffic congestion and urban flash floods is presented. This sensing device is based on the combination of passive infrared sensors (PIRs) and ultrasonic rangefinder, and is used for real-time vehicle detection, classification, and speed estimation in the context of wireless sensor networks. This framework relies on dynamic Bayesian Networks to fuse heterogeneous data both spatially and temporally for vehicle detection. To estimate the speed of the incoming vehicles, we first use cross correlation and wavelet transform-based methods to estimate the time delay between the signals of different sensors. We then propose a calibration and self-correction model based on Bayesian Networks to make a joint inference by all sensors about the speed and the length of the detected vehicle. Furthermore, we use the measurements of the ultrasonic and the PIR sensors to perform vehicle classification. Validation data (using an experimental dual infrared and ultrasonic traffic sensor) show a 99% accuracy in vehicle detection, a mean error of 5 kph in vehicle speed estimation, a mean error of 0.7m in vehicle length estimation, and a high accuracy in vehicle classification. Finally, we discuss the computational performance of the algorithm, and show that this framework can be implemented on low-power computational devices within a wireless sensor network setting. Such decentralized processing greatly improves the energy consumption of the system and minimizes bandwidth usage.

A model predictive speed tracking control approach for autonomous ground vehicles

Science.gov (United States)

Zhu, Min; Chen, Huiyan; Xiong, Guangming

2017-03-01

This paper presents a novel speed tracking control approach based on a model predictive control (MPC) framework for autonomous ground vehicles. A switching algorithm without calibration is proposed to determine the drive or brake control. Combined with a simple inverse longitudinal vehicle model and adaptive regulation of MPC, this algorithm can make use of the engine brake torque for various driving conditions and avoid high frequency oscillations automatically. A simplified quadratic program (QP) solving algorithm is used to reduce the computational time, and the approach has been applied in a 16-bit microcontroller. The performance of the proposed approach is evaluated via simulations and vehicle tests, which were carried out in a range of speed-profile tracking tasks. With a well-designed system structure, high-precision speed control is achieved. The system can robustly model uncertainty and external disturbances, and yields a faster response with less overshoot than a PI controller.

Ride performance of a high speed rail vehicle using controlled semi active suspension system

Science.gov (United States)

Sharma, Sunil Kumar; Kumar, Anil

2017-05-01

The rail-wheel interaction in a rail vehicle running at high speed results in large amplitude vibration of carbody that deteriorates the ride comfort of travellers. The role of suspension system is crucial to provide an acceptable level of ride performance. In this context, an existing rail vehicle is modelled in vertical, pitch and roll motions of carbody and bogies. Additionally, nonlinear stiffness and damping parameters of passive suspension system are defined based on experimental data. In the secondary vertical suspension system, a magneto-rheological (MR) damper is included to improve the ride quality and comfort. The parameters of MR damper depend on the current, amplitude and frequency of excitations. At different running speeds, three semi-active suspension strategies with MR damper are analysed for periodic track irregularity and the resulting performance indices are juxtaposed with the nonlinear passive suspension system. The disturbance rejection and force tracking damper controller algorithms are applied to control the desired force of MR damper. This study reveals that the vertical vibrations of a vehicle can be reduced significantly by using the proposed semi-active suspension strategies. Moreover, it naturally results in improved ride quality and passenger’s comfort in comparison to the existing passive system.

Scaling model for a speed-dependent vehicle noise spectrum

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Giovanni Zambon

2017-06-01

Full Text Available Considering the well-known features of the noise emitted by moving sources, a number of vehicle characteristics such as speed, unladen mass, engine size, year of registration, power and fuel were recorded in a dedicated monitoring campaign performed in three different places, each characterized by different number of lanes and the presence of nearby reflective surfaces. A full database of 144 vehicles (cars was used to identify statistically relevant features. In order to compare the vehicle transit noise in different environmental condition, all 1/3-octave band spectra were normalized and analysed. Unsupervised clustering algorithms were employed to group together spectrum levels with similar profiles. Our results corroborate the well-known fact that speed is the most relevant characteristic to discriminate between different vehicle noise spectrum. In keeping with this fact, we present a new approach to predict analytically noise spectra for a given vehicle speed. A set of speed-dependent analytical functions are suggested in order to fit the normalized average spectrum profile at different speeds. This approach can be useful for predicting vehicle speed based purely on its noise spectrum pattern. The present work is complementary to the accurate analysis of noise sources based on the beamforming technique.

Comprehensive analysis of the carbon impacts of vehicle intelligent speed control

Science.gov (United States)

Carslaw, David C.; Goodman, Paul S.; Lai, Frank C. H.; Carsten, Oliver M. J.

2010-07-01

In recent years sophisticated technologies have been developed to control vehicle speed based on the type of road the vehicle is driven on using Global Positioning Systems and in-car technology that can alter the speed of the vehicle. While reducing the speed of road vehicles is primarily of interest from a safety perspective, vehicle speed is also an important determinant of vehicle emissions and thus these technologies can be expected to have impacts on a range of exhaust emissions. This work analyses the results from a very large, comprehensive field trial that used 20 instrumented vehicles with and without speed control driven almost 500,000 km measuring vehicle speed at 10 Hz. We develop individual vehicle modal emissions models for CO 2 for 30 Euro III and Euro IV cars at a 1-Hz time resolution. Generalized Additive Models were used to describe how emissions from individual vehicles vary depending on their driving conditions, taking account of variable interactions and time-lag effects. We quantify the impact that vehicle speed control has on-vehicle emissions of CO 2 by road type, fuel type and driver behaviour. Savings in CO 2 of ≈6% were found on average for motorway-type roads when mandatory speed control was used compared with base case conditions. For most other types of road, speed control has very little effect on emissions of CO 2 and in some cases can result in increased emissions for low-speed limit urban roads. We also find that there is on average a 20% difference in CO 2 emission between the lowest and highest emitting driver, which highlights the importance of driver behaviour in general as a means of reducing emissions of CO 2.

EVALUATION METHOD OF FUEL-EFFICIENT DRIVING IN DUMP TRUCK USING VEHICLE SPEED AND ENGINE ROTATIONAL SPEED

Science.gov (United States)

Hirata, Masafumi; Yamamoto, Tatsuo; Yasui, Toshiaki; Hayashi, Mayu; Takebe, Atsuji; Funahashi, Masashi

In the construction site, the light oil that the construction vehicle such as dump trucks uses accounts for 70 percent of the amount of the energy use. Therefore, the eco-driving education of the construction vehicle is effective in the fuel cost improvement and the CO2 reduction. The eco-driving education can be executed cheap and easily, and a high effect can be expected. However, it is necessary to evaluate the eco-driving situation of the construction vehicle exactly to maintain the educative effect for a long term. In this paper, the method for evaluating the effect of the fuel cost improvement was examined by using the vehicle speed and the engine rotational speed of the dump truck. In this method, "Ideal eco-driving model" that considers the difference between the vehicle model and the running condition (traffic jam etc.) is made. As a result, it is possible to evaluate the fuel consumption improvement effect of a dump truck by the same index.

Estimation of longitudinal force, lateral vehicle speed and yaw rate for four-wheel independent driven electric vehicles

Science.gov (United States)

Chen, Te; Xu, Xing; Chen, Long; Jiang, Haobing; Cai, Yingfeng; Li, Yong

2018-02-01

Accurate estimation of longitudinal force, lateral vehicle speed and yaw rate is of great significance to torque allocation and stability control for four-wheel independent driven electric vehicle (4WID-EVs). A fusion method is proposed to estimate the longitudinal force, lateral vehicle speed and yaw rate for 4WID-EVs. The electric driving wheel model (EDWM) is introduced into the longitudinal force estimation, the longitudinal force observer (LFO) is designed firstly based on the adaptive high-order sliding mode observer (HSMO), and the convergence of LFO is analyzed and proved. Based on the estimated longitudinal force, an estimation strategy is then presented in which the strong tracking filter (STF) is used to estimate lateral vehicle speed and yaw rate simultaneously. Finally, co-simulation via Carsim and Matlab/Simulink is carried out to demonstrate the effectiveness of the proposed method. The performance of LFO in practice is verified by the experiment on chassis dynamometer bench.

Literature review on vehicle travel speeds and pedestrian injuries

Science.gov (United States)

1999-10-01

The relationship between vehicle travel speeds and resulting pedestrian injury was reviewed in the literature and in existing data sets. Results indicated that higher vehicle speeds are strongly associated with both a greater likelihood of pedestrian...

The Effects of a Rectangular Rapid-Flashing Beacon on Vehicle Speed

Science.gov (United States)

VanWagner, Michelle; Van Houten, Ron; Betts, Brian

2011-01-01

In 2008, nearly 31% of vehicle fatalities were related to failure to adhere to safe vehicle speeds (National Highway Traffic Safety Administration [NHTSA], 2009). The current study evaluated the effect of a rectangular rapid-flashing beacon (RRFB) triggered by excessive speed on vehicle speed using a combined alternating treatments and reversal…

Experimental study of the vehicle dynamics behavior during lane changing in different speeds

Science.gov (United States)

Heerwan, P. M.; Asyraf, S. M.; Efistein, A. N.; Seah, C. H.; Zikri, J. M.; Syawahieda, J. N.

2017-10-01

During lane changing, the speed of the vehicle is related to the stability of the vehicle. If the driver changes the lane at a high speed, the vehicle will lose its stability and it can increase the possibility of an accident. In this study, the experiment has been developed to analyse how the speed of the vehicle can affect the vehicle dynamics behavior. To achieve this objective, the UMP Test Car which employed with global positioning system (GPS), steering torque and angle sensor, displacement sensor and gyro sensor is used in the experiment. The experiment is run at the UMP test track and the track has 2 lanes which can allows the vehicle to change the position from the left to the right. In the experiment, when the GPS monitor shows 30 km/h, the driver will maintain the speed and start to turn the steering just after the test car reaches to the first skittle. Then, the driver will turn again the steering when the test car reaches to the second skittle. This method is repeated two times and the same methods is used for the speed 50 km/h. The data from the sensors is recorded in the Dewetron software and the graph is plotted. From the experimental results, the steering angle, steering torque, yaw rate and displacement for the speed 30 km/h is smaller than 50 km/h. It means that during lane changing, the speed 30 km/h is more stable compared with 50 km/h.

HIGH SPEED RAILWAY LINES – FUTURE PART OF CZECH RAILWAY NETWORK?

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Lukáš Týfa

2017-08-01

Full Text Available The paper first describes high speed rail generally and explains the relationship between high speed and conventional railway networks (according to the vehicle types in operation on the network. The core of the paper is comprised of the methodology for choosing the best route for a railway line and its application to the high speed railway connection Praha – Brno. The Algorithm used assumes the existence of more route proposals, which could be different in terms of the operational conception, line routing or types of vehicles used. The optimal variant is the one with the lowest daily cost, which includes infrastructure and vehicle costs; investment and operational costs. The results from applying this model confirmed the assumption, that a dedicated high speed railway line, only for high speed trains, has the same or lower investment costs than a line for both high speed and conventional trains. Furthermore, a dedicated high line also has a lower cost for infrastructure maintenance but a higher cost for buying high speed multiple units.

Vision based speed breaker detection for autonomous vehicle

Science.gov (United States)

C. S., Arvind; Mishra, Ritesh; Vishal, Kumar; Gundimeda, Venugopal

2018-04-01

In this paper, we are presenting a robust and real-time, vision-based approach to detect speed breaker in urban environments for autonomous vehicle. Our method is designed to detect the speed breaker using visual inputs obtained from a camera mounted on top of a vehicle. The method performs inverse perspective mapping to generate top view of the road and segment out region of interest based on difference of Gaussian and median filter images. Furthermore, the algorithm performs RANSAC line fitting to identify the possible speed breaker candidate region. This initial guessed region via RANSAC, is validated using support vector machine. Our algorithm can detect different categories of speed breakers on cement, asphalt and interlock roads at various conditions and have achieved a recall of 0.98.

Effects of weather conditions, light conditions, and road lighting on vehicle speed.

Science.gov (United States)

Jägerbrand, Annika K; Sjöbergh, Jonas

2016-01-01

Light conditions are known to affect the number of vehicle accidents and fatalities but the relationship between light conditions and vehicle speed is not fully understood. This study examined whether vehicle speed on roads is higher in daylight and under road lighting than in darkness, and determined the combined effects of light conditions, posted speed limit and weather conditions on driving speed. The vehicle speed of passenger cars in different light conditions (daylight, twilight, darkness, artificial light) and different weather conditions (clear weather, rain, snow) was determined using traffic and weather data collected on an hourly basis for approximately 2 years (1 September 2012-31 May 2014) at 25 locations in Sweden (17 with road lighting and eight without). In total, the data included almost 60 million vehicle passes. The data were cleaned by removing June, July, and August, which have different traffic patterns than the rest of the year. Only data from the periods 10:00 A.M.-04:00 P.M. and 06:00 P.M.-10:00 P.M. were used, to remove traffic during rush hour and at night. Multivariate adaptive regression splines was used to evaluate the overall influence of independent variables on vehicle speed and nonparametric statistical testing was applied to test for speed differences between dark-daylight, dark-twilight, and twilight-daylight, on roads with and without road lighting. The results show that vehicle speed in general depends on several independent variables. Analyses of vehicle speed and speed differences between daylight, twilight and darkness, with and without road lighting, did not reveal any differences attributable to light conditions. However, vehicle speed decreased due to rain or snow and the decrease was higher on roads without road lighting than on roads with lighting. These results suggest that the strong association between traffic accidents and darkness or low light conditions could be explained by drivers failing to adjust their

Vision-Based Steering Control, Speed Assistance and Localization for Inner-City Vehicles

Directory of Open Access Journals (Sweden)

Miguel Angel Olivares-Mendez

2016-03-01

Full Text Available Autonomous route following with road vehicles has gained popularity in the last few decades. In order to provide highly automated driver assistance systems, different types and combinations of sensors have been presented in the literature. However, most of these approaches apply quite sophisticated and expensive sensors, and hence, the development of a cost-efficient solution still remains a challenging problem. This work proposes the use of a single monocular camera sensor for an automatic steering control, speed assistance for the driver and localization of the vehicle on a road. Herein, we assume that the vehicle is mainly traveling along a predefined path, such as in public transport. A computer vision approach is presented to detect a line painted on the road, which defines the path to follow. Visual markers with a special design painted on the road provide information to localize the vehicle and to assist in its speed control. Furthermore, a vision-based control system, which keeps the vehicle on the predefined path under inner-city speed constraints, is also presented. Real driving tests with a commercial car on a closed circuit finally prove the applicability of the derived approach. In these tests, the car reached a maximum speed of 48 km/h and successfully traveled a distance of 7 km without the intervention of a human driver and any interruption.

Vision-Based Steering Control, Speed Assistance and Localization for Inner-City Vehicles.

Science.gov (United States)

Olivares-Mendez, Miguel Angel; Sanchez-Lopez, Jose Luis; Jimenez, Felipe; Campoy, Pascual; Sajadi-Alamdari, Seyed Amin; Voos, Holger

2016-03-11

Autonomous route following with road vehicles has gained popularity in the last few decades. In order to provide highly automated driver assistance systems, different types and combinations of sensors have been presented in the literature. However, most of these approaches apply quite sophisticated and expensive sensors, and hence, the development of a cost-efficient solution still remains a challenging problem. This work proposes the use of a single monocular camera sensor for an automatic steering control, speed assistance for the driver and localization of the vehicle on a road. Herein, we assume that the vehicle is mainly traveling along a predefined path, such as in public transport. A computer vision approach is presented to detect a line painted on the road, which defines the path to follow. Visual markers with a special design painted on the road provide information to localize the vehicle and to assist in its speed control. Furthermore, a vision-based control system, which keeps the vehicle on the predefined path under inner-city speed constraints, is also presented. Real driving tests with a commercial car on a closed circuit finally prove the applicability of the derived approach. In these tests, the car reached a maximum speed of 48 km/h and successfully traveled a distance of 7 km without the intervention of a human driver and any interruption.

Vision-Based Steering Control, Speed Assistance and Localization for Inner-City Vehicles

Science.gov (United States)

Olivares-Mendez, Miguel Angel; Sanchez-Lopez, Jose Luis; Jimenez, Felipe; Campoy, Pascual; Sajadi-Alamdari, Seyed Amin; Voos, Holger

2016-01-01

Autonomous route following with road vehicles has gained popularity in the last few decades. In order to provide highly automated driver assistance systems, different types and combinations of sensors have been presented in the literature. However, most of these approaches apply quite sophisticated and expensive sensors, and hence, the development of a cost-efficient solution still remains a challenging problem. This work proposes the use of a single monocular camera sensor for an automatic steering control, speed assistance for the driver and localization of the vehicle on a road. Herein, we assume that the vehicle is mainly traveling along a predefined path, such as in public transport. A computer vision approach is presented to detect a line painted on the road, which defines the path to follow. Visual markers with a special design painted on the road provide information to localize the vehicle and to assist in its speed control. Furthermore, a vision-based control system, which keeps the vehicle on the predefined path under inner-city speed constraints, is also presented. Real driving tests with a commercial car on a closed circuit finally prove the applicability of the derived approach. In these tests, the car reached a maximum speed of 48 km/h and successfully traveled a distance of 7 km without the intervention of a human driver and any interruption. PMID:26978365

High-speed ground transportation development outside United States

Energy Technology Data Exchange (ETDEWEB)

Eastham, T.R. [Queen`s Univ., Kingston, Ontario (United Kingdom)

1995-09-01

This paper surveys the state of high-speed (in excess of 200 km/h) ground-transportation developments outside the United States. Both high-speed rail and Maglev systems are covered. Many vehicle systems capable of providing intercity service in the speed range 200--500 km/h are or will soon be available. The current state of various technologies, their implementation, and the near-term plans of countries that are most active in high-speed ground transportation development are reported.

Nonlinear Output Feedback Control of Underwater Vehicle Propellers using Advance Speed Feedback

DEFF Research Database (Denmark)

Fossen, T.I.; Blanke, M.

1999-01-01

More accurate propeller shaft speed controllers can be designed by using nonlinear control theory. In this paper, an output feedback controller reconstructing the advance speed (speed of water going into the propeller) from vehicle speed measurements is derived. For this purpose a three-state model...... minimizes thruster losses due to variations in propeller axial inlet flow which is a major problem when applying conventional vehicle-propeller control systems. The proposed controller is simulated for an underwater vehicle equipped with a single propeller. From the simulations it can be concluded...... of propeller shaft speed, forward (surge) speed of the vehicle and axial inlet flow of the propeller is applied. A nonlinear observer in combination with an output feedback integral controller are derived by applying Lyapunov stability theory and exponential stability is proven. The output feedback controller...

High-speed Maglev studies in Canada

International Nuclear Information System (INIS)

Atherton, D.L.; Eastham, A.R.

1974-01-01

This paper reports on Canadian studies of superconducting magnetic levitation and variable-speed linear synchronous motor propulsion for high-speed inter-city guided ground transport. Levitation is obtained by the interaction of vehicle-mounted superconducting magnets and the eddy currents induced in aluminium strip conductors on the guideway. Non-contact propulsion by linear synchronous motor (LSM) is obtained by using vehicle-borne superconducting magnets and powered guideway coils. A suggested guidance scheme uses a flat guideway with 'null-flux' loops overlying the LSM windings. The propulsion magnets interact with the loops and the edges of the levitation strips to provide lateral stabilization. The test facility is a 7.6m wheel, rotating with a peripheral speed of 33m/s. (author)

Considering Variable Road Geometry in Adaptive Vehicle Speed Control

Directory of Open Access Journals (Sweden)

Xinping Yan

2013-01-01

Full Text Available Adaptive vehicle speed control is critical for developing Advanced Driver Assistance Systems (ADAS. Vehicle speed control considering variable road geometry has become a hotspot in ADAS research. In this paper, first, an exploration of intrinsic relationship between vehicle operation and road geometry is made. Secondly, a collaborative vehicle coupling model, a road geometry model, and an AVSC, which can respond to variable road geometry in advance, are developed. Then, based on H∞ control method and the minimum energy principle, a performance index is specified by a cost function for the proposed AVSC, which can explicitly consider variable road geometry in its optimization process. The proposed AVSC is designed by the Hamilton-Jacobi Inequality (HJI. Finally, simulations are carried out by combining the vehicle model with the road geometry model, in an aim of minimizing the performance index of the AVSC. Analyses of the simulation results indicate that the proposed AVSC can automatically and effectively regulate speed according to variable road geometry. It is believed that the proposed AVSC can be used to improve the economy, comfort, and safety effects of current ADAS.

Adaptive Neuro-Fuzzy Determination of the Effect of Experimental Parameters on Vehicle Agent Speed Relative to Vehicle Intruder.

Directory of Open Access Journals (Sweden)

Shahaboddin Shamshirband

Full Text Available Intelligent Transportation Systems rely on understanding, predicting and affecting the interactions between vehicles. The goal of this paper is to choose a small subset from the larger set so that the resulting regression model is simple, yet have good predictive ability for Vehicle agent speed relative to Vehicle intruder. The method of ANFIS (adaptive neuro fuzzy inference system was applied to the data resulting from these measurements. The ANFIS process for variable selection was implemented in order to detect the predominant variables affecting the prediction of agent speed relative to intruder. This process includes several ways to discover a subset of the total set of recorded parameters, showing good predictive capability. The ANFIS network was used to perform a variable search. Then, it was used to determine how 9 parameters (Intruder Front sensors active (boolean, Intruder Rear sensors active (boolean, Agent Front sensors active (boolean, Agent Rear sensors active (boolean, RSSI signal intensity/strength (integer, Elapsed time (in seconds, Distance between Agent and Intruder (m, Angle of Agent relative to Intruder (angle between vehicles °, Altitude difference between Agent and Intruder (m influence prediction of agent speed relative to intruder. The results indicated that distance between Vehicle agent and Vehicle intruder (m and angle of Vehicle agent relative to Vehicle Intruder (angle between vehicles ° is the most influential parameters to Vehicle agent speed relative to Vehicle intruder.

Adaptive Neuro-Fuzzy Determination of the Effect of Experimental Parameters on Vehicle Agent Speed Relative to Vehicle Intruder.

Science.gov (United States)

Shamshirband, Shahaboddin; Banjanovic-Mehmedovic, Lejla; Bosankic, Ivan; Kasapovic, Suad; Abdul Wahab, Ainuddin Wahid Bin

2016-01-01

Intelligent Transportation Systems rely on understanding, predicting and affecting the interactions between vehicles. The goal of this paper is to choose a small subset from the larger set so that the resulting regression model is simple, yet have good predictive ability for Vehicle agent speed relative to Vehicle intruder. The method of ANFIS (adaptive neuro fuzzy inference system) was applied to the data resulting from these measurements. The ANFIS process for variable selection was implemented in order to detect the predominant variables affecting the prediction of agent speed relative to intruder. This process includes several ways to discover a subset of the total set of recorded parameters, showing good predictive capability. The ANFIS network was used to perform a variable search. Then, it was used to determine how 9 parameters (Intruder Front sensors active (boolean), Intruder Rear sensors active (boolean), Agent Front sensors active (boolean), Agent Rear sensors active (boolean), RSSI signal intensity/strength (integer), Elapsed time (in seconds), Distance between Agent and Intruder (m), Angle of Agent relative to Intruder (angle between vehicles °), Altitude difference between Agent and Intruder (m)) influence prediction of agent speed relative to intruder. The results indicated that distance between Vehicle agent and Vehicle intruder (m) and angle of Vehicle agent relative to Vehicle Intruder (angle between vehicles °) is the most influential parameters to Vehicle agent speed relative to Vehicle intruder.

Appending High-Resolution Elevation Data to GPS Speed Traces for Vehicle Energy Modeling and Simulation

Energy Technology Data Exchange (ETDEWEB)

Wood, E.; Burton, E.; Duran, A.; Gonder, J.

2014-06-01

Accurate and reliable global positioning system (GPS)-based vehicle use data are highly valuable for many transportation, analysis, and automotive considerations. Model-based design, real-world fuel economy analysis, and the growing field of autonomous and connected technologies (including predictive powertrain control and self-driving cars) all have a vested interest in high-fidelity estimation of powertrain loads and vehicle usage profiles. Unfortunately, road grade can be a difficult property to extract from GPS data with consistency. In this report, we present a methodology for appending high-resolution elevation data to GPS speed traces via a static digital elevation model. Anomalous data points in the digital elevation model are addressed during a filtration/smoothing routine, resulting in an elevation profile that can be used to calculate road grade. This process is evaluated against a large, commercially available height/slope dataset from the Navteq/Nokia/HERE Advanced Driver Assistance Systems product. Results will show good agreement with the Advanced Driver Assistance Systems data in the ability to estimate road grade between any two consecutive points in the contiguous United States.

Vehicle Routing Problems with Fuel Consumption and Stochastic Travel Speeds

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Yanling Feng

2017-01-01

Full Text Available Conventional vehicle routing problems (VRP always assume that the vehicle travel speed is fixed or time-dependent on arcs. However, due to the uncertainty of weather, traffic conditions, and other random factors, it is not appropriate to set travel speeds to fixed constants in advance. Consequently, we propose a mathematic model for calculating expected fuel consumption and fixed vehicle cost where average speed is assumed to obey normal distribution on each arc which is more realistic than the existing model. For small-scaled problems, we make a linear transformation and solve them by existing solver CPLEX, while, for large-scaled problems, an improved simulated annealing (ISA algorithm is constructed. Finally, instances from real road networks of England are performed with the ISA algorithm. Computational results show that our ISA algorithm performs well in a reasonable amount of time. We also find that when taking stochastic speeds into consideration, the fuel consumption is always larger than that with fixed speed model.

Modeling speed and width parameters of vehicle tires for prediction of the reduction in vehicle noise pollution

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Amir Esmael Forouhid

2016-06-01

Full Text Available Introduction: Safe driving requires the ability of the driver to receive the messages and complying with them. The most significant consequences of noise pollution are on the human auditory system. Disorders in the auditory system can have harmful side effects for human health. By reducing this kind of pollution in large cities, the quality of life, which is one of the biggest goals of the governments, can be considerably increased. Hence, in the present research, some parameters of vehicle tires were examined as a source of noise pollution, and the results can be taken into consideration in noise pollution reduction. Material and Method: Several vehicles with different tire width were selected for measuring sound level. The sound levels were measured for moving vehicles with the use of the Statistical Pass By Method (SPB, ISO 11819-1. Following sound level measurements for moving vehicles and by considering tire width, mathematical model of noise level was predicted on the basis of the obtained information and by usage of SPSS program and considering vehicle tire parameters. Result: The result of this study showed that the vehicle speed and tire width can affect different sound levels emitted by moving tire on road surface. The average speed of vehicles can play an important role in the noise pollution. By increasing speed, rotation of the the tires on the asphalt is increased, as it is a known factors for noise pollution. Moreover, changing the speed of vehicles is accompanied with abnormal sounds of vehicle engine. According to regression model analysis, the obtained value of R2 for the model is 0.8367 which represents the coefficient of determination. Conclusion: The results suggest the main role of the vehicle speed and tire width in increasing the noise reaches to the drivers and consequent noise pollution, which demonstrates the necessity for noise control measures. According to the obtained model, it is understood that changes in noise

Multivariable Techniques for High-Speed Research Flight Control Systems

Science.gov (United States)

Newman, Brett A.

1999-01-01

This report describes the activities and findings conducted under contract with NASA Langley Research Center. Subject matter is the investigation of suitable multivariable flight control design methodologies and solutions for large, flexible high-speed vehicles. Specifically, methodologies are to address the inner control loops used for stabilization and augmentation of a highly coupled airframe system possibly involving rigid-body motion, structural vibrations, unsteady aerodynamics, and actuator dynamics. Design and analysis techniques considered in this body of work are both conventional-based and contemporary-based, and the vehicle of interest is the High-Speed Civil Transport (HSCT). Major findings include: (1) control architectures based on aft tail only are not well suited for highly flexible, high-speed vehicles, (2) theoretical underpinnings of the Wykes structural mode control logic is based on several assumptions concerning vehicle dynamic characteristics, and if not satisfied, the control logic can break down leading to mode destabilization, (3) two-loop control architectures that utilize small forward vanes with the aft tail provide highly attractive and feasible solutions to the longitudinal axis control challenges, and (4) closed-loop simulation sizing analyses indicate the baseline vane model utilized in this report is most likely oversized for normal loading conditions.

Reduction Vehicle Speed Using GPS Android Smart Phone Programming

Directory of Open Access Journals (Sweden)

Sameer Sami Hassan

2017-07-01

Full Text Available Today the new generation of smart phone such as Samsung galaxy, Sony, Motorola, HTC is used to build smart applications that made the human life more comfortable and safe. The Android open source operating system with java programming language can be used to develop such applications. In this paper a new software application has been developed using Samsung, galaxy note smart phone to control the speed of vehicle using GPS and Android programming for such smart phone. By collecting the speed and location information from Global Position System (GPS receiver and using the global map application programming interface to determine the location nearby university, school and hospital in Baghdad city. The application will be check the speed of vehicle in zone of school, hospital and university using GPS information. If the speed over the limit the application produce sound alarm to reduce the speed to set up limit.

Investigation on a Power Coupling Steering System for Dual-Motor Drive Tracked Vehicles Based on Speed Control

Directory of Open Access Journals (Sweden)

Li Zhai

2017-08-01

Full Text Available Double-motor drive tracked vehicles (2MDTV are widely used in the tracked vehicle industry due to the development of electric vehicle drive systems. The aim of this paper is to solve the problem of insufficient propulsion motor torque in low-speed, small-radius steering and insufficient power in high-speed large-radius steering. In order to do this a new type of steering system with a coupling device is designed and a closed-loop control strategy based on speed is adopted to improve the lateral stability of the vehicle. The work done entails modeling and simulating the 2MDTV and the proposed control strategy in RecurDyn and Matlab/Simulink. The simulation results show that the 2MDTV with the coupling device outputs more torque and power in both steering cases compared to the 2MDTV without the coupling device, and the steering stability of the vehicle is improved by using the strategy based on speed.

A Review of Vehicles Speed on School Safety Zone Areas in Pekanbaru City

Science.gov (United States)

Dwi Putri, Lusi; Soehardi, Fitridawati; Saleh, Alfian

2017-12-01

School Safety Zone is a location or region on particular roads that are time-based speed zone to set the speed of the vehicle in the school environment. The maximum speed limit permits entering a School Safety Zone, especially in Pekanbaru City is 25 km / h and an outline of the speed limit permit vehicles that pass through the School Safety Zone in Indonesia is generally 20-30 km / h. However, the vehicles speeds that pass School Safety Zone are higher than permit speeds.To ensure the level of vehicle offense across the territory of the School Safety Zone so it is necessary a primary data which is taken randomly based on field survey for 3 days at schools that has that facility ie SDN 3 Jalan Kesehatan Pekanbaru City, SDN 68 Jalan Balam Ujung Kota Pekanbaru and SDN 143 Jalan Taskurun Kota Pekanbaru. Furthermore, the data were taken in good condition that is at 6:30 to 7:30 am and at 12:00 to 13:00 pm. In addition, the data obtained is mileage and travel time of the vehicle. Both of these data can generate good speed value that passes through the area of School Safety Zone. Based on the research findings, the vehicle speed passing through the area of School Safety Zone is incompatible with speed permit at 35 km / h with a maximum average percentage of the rate of offense in the area of the school zone is 91.7%. This indicates that the vehicle passes School Safety Zone not following the rules of the maximum limit area and can be potentially harmful to elementary school students.

Cognitive radio networks efficient resource allocation in cooperative sensing, cellular communications, high-speed vehicles, and smart grid

CERN Document Server

Jiang, Tao; Cao, Yang

2015-01-01

PrefaceAcknowledgmentsAbout the AuthorsIntroductionCognitive Radio-Based NetworksOpportunistic Spectrum Access NetworksCognitive Radio Networks with Cooperative SensingCognitive Radio Networks for Cellular CommunicationsCognitive Radio Networks for High-Speed VehiclesCognitive Radio Networks for a Smart GridContent and OrganizationTransmission Slot Allocation in an Opportunistic Spectrum Access NetworkSingle-User Single-Channel System ModelProbabilistic Slot Allocation SchemeOptimal Probabilistic Slot AllocationBaseline PerformanceExponential DistributionHyper-Erlang DistributionPerformance An

Studying the Effect of Roughness of Wet Road on Critical speed of Vehicle

Directory of Open Access Journals (Sweden)

Ali K. Mohammed

2018-01-01

Full Text Available Hydroplaning is one the most dangerous phenomena which effect on the safety of driving cars on wet roads, then, the critical speed of slipping cars is an important parameter in the hydroplaning ,and depends on the properties of  the following three  parameters: tires, water layer and  road surface. The road texture is the main property of road specifications which affect directly on the critical speed of the vehicle. In the present work, the properties of road roughness and influence of surface texture on critical speed of vehicle are studied with variation of the following parameters: thickness and dynamic viscosity of water on the road surface and the vehicle load. The results showed that increasing the road surface roughness and the vehicle load both has a appositive influence on the critical speed (increaseof the vehicle, while increasing the dynamic viscosity and thickness of the water layer on the road surface has a negative influence on the critical speed (decrease of the vehicle. DOI: http://dx.doi.org/10.25130/tjes.24.2017.24

A study on model fidelity for model predictive control-based obstacle avoidance in high-speed autonomous ground vehicles

Science.gov (United States)

Liu, Jiechao; Jayakumar, Paramsothy; Stein, Jeffrey L.; Ersal, Tulga

2016-11-01

This paper investigates the level of model fidelity needed in order for a model predictive control (MPC)-based obstacle avoidance algorithm to be able to safely and quickly avoid obstacles even when the vehicle is close to its dynamic limits. The context of this work is large autonomous ground vehicles that manoeuvre at high speed within unknown, unstructured, flat environments and have significant vehicle dynamics-related constraints. Five different representations of vehicle dynamics models are considered: four variations of the two degrees-of-freedom (DoF) representation as lower fidelity models and a fourteen DoF representation with combined-slip Magic Formula tyre model as a higher fidelity model. It is concluded that the two DoF representation that accounts for tyre nonlinearities and longitudinal load transfer is necessary for the MPC-based obstacle avoidance algorithm in order to operate the vehicle at its limits within an environment that includes large obstacles. For less challenging environments, however, the two DoF representation with linear tyre model and constant axle loads is sufficient.

Modeling and predicting low-speed vehicle emissions as a function of driving kinematics.

Science.gov (United States)

Hao, Lijun; Chen, Wei; Li, Lei; Tan, Jianwei; Wang, Xin; Yin, Hang; Ding, Yan; Ge, Yunshan

2017-05-01

An instantaneous emission model was developed to model and predict the real driving emissions of the low-speed vehicles. The emission database used in the model was measured by using portable emission measurement system (PEMS) under actual traffic conditions in the rural area, and the characteristics of the emission data were determined in relation to the driving kinematics (speed and acceleration) of the low-speed vehicle. The input of the emission model is driving cycle, and the model requires instantaneous vehicle speed and acceleration levels as input variables and uses them to interpolate the pollutant emission rate maps to calculate the transient pollutant emission rates, which will be accumulated to calculate the total emissions released during the whole driving cycle. And the vehicle fuel consumption was determined through the carbon balance method. The model predicted the emissions and fuel consumption of an in-use low-speed vehicle type model, which agreed well with the measured data. Copyright © 2016. Published by Elsevier B.V.

Design And Analysis Of Doppler Radar-Based Vehicle Speed Detection

Directory of Open Access Journals (Sweden)

Su Myat Paing

2015-08-01

Full Text Available The most unwanted thing to happen to a road user is road accident. Most of the fatal accidents occur due to over speeding. Faster vehicles are more prone to accident than the slower one. Among the various methods for detecting speed of the vehicle object detection systems based on Radar have been replaced for about a century for various purposes like detection of aircrafts spacecraft ships navigation reading weather formations and terrain mapping. The essential feature in adaptive vehicle activated sign systems is the accurate measurement of a vehicles velocity. The velocities of the vehicles are acquired from a continuous wave Doppler radar. A very low amount of power is consumed in this system and only batteries can use to operate. The system works on the principle of Doppler Effect by detecting the Doppler shift in microwaves reflected from a moving object. Since the output of the sensor is sinusoidal wave with very small amplitude and needs to be amplified with the help of the amplifier before further processing. The purpose to calculate and display the speed on LCD is performed by the microcontroller.

Embedded Vehicle Speed Estimation System Using an Asynchronous Temporal Contrast Vision Sensor

Directory of Open Access Journals (Sweden)

D. Bauer

2007-01-01

Full Text Available This article presents an embedded multilane traffic data acquisition system based on an asynchronous temporal contrast vision sensor, and algorithms for vehicle speed estimation developed to make efficient use of the asynchronous high-precision timing information delivered by this sensor. The vision sensor features high temporal resolution with a latency of less than 100 μs, wide dynamic range of 120 dB of illumination, and zero-redundancy, asynchronous data output. For data collection, processing and interfacing, a low-cost digital signal processor is used. The speed of the detected vehicles is calculated from the vision sensor's asynchronous temporal contrast event data. We present three different algorithms for velocity estimation and evaluate their accuracy by means of calibrated reference measurements. The error of the speed estimation of all algorithms is near zero mean and has a standard deviation better than 3% for both traffic flow directions. The results and the accuracy limitations as well as the combined use of the algorithms in the system are discussed.

Vehicle speed detection based on gaussian mixture model using sequential of images

Science.gov (United States)

Setiyono, Budi; Ratna Sulistyaningrum, Dwi; Soetrisno; Fajriyah, Farah; Wahyu Wicaksono, Danang

2017-09-01

Intelligent Transportation System is one of the important components in the development of smart cities. Detection of vehicle speed on the highway is supporting the management of traffic engineering. The purpose of this study is to detect the speed of the moving vehicles using digital image processing. Our approach is as follows: The inputs are a sequence of frames, frame rate (fps) and ROI. The steps are following: First we separate foreground and background using Gaussian Mixture Model (GMM) in each frames. Then in each frame, we calculate the location of object and its centroid. Next we determine the speed by computing the movement of centroid in sequence of frames. In the calculation of speed, we only consider frames when the centroid is inside the predefined region of interest (ROI). Finally we transform the pixel displacement into a time unit of km/hour. Validation of the system is done by comparing the speed calculated manually and obtained by the system. The results of software testing can detect the speed of vehicles with the highest accuracy is 97.52% and the lowest accuracy is 77.41%. And the detection results of testing by using real video footage on the road is included with real speed of the vehicle.

Design And Implementation Of Pc Based Over Speed Violation Management For Vehicles On Highway

Directory of Open Access Journals (Sweden)

Ni Ni Hlaing

2015-07-01

Full Text Available Abstract In the present day scenario traffic rules are frequently violated by the drivers and over speeding occur due to bad driving behavior. So a driver assistance system is provided to prevent over speeding violation of road rules also to display alert messages and gives alerts like road works steep slope school zone in the form of acoustical messages and also in LCD. The proposed system has a reporting displaying and database systemfor over speed violation management. This designed system has the ability to detect the speed of the vehicle in the roads and the main highways and the places where the drivers can use of more speed while driving. The laser transmitter senses the load entered by the vehicle and then the receiver unit sends to the microcontroller. The receiver unit is used by Light Dependent Resistor LDR. If the speed of vehicle exceeds the permissible speed for the highway this information will sent to PC which starts the camera to capture the vehicle. And all the information of vehicle are sent to database system. Then also shows the speed information on LCD.

High-speed surface transportation corridor : a conceptual framework, final report.

Science.gov (United States)

2009-10-08

Efficient transportation is indispensable for economic growth and prosperity. In this study we propose the development of a high-speed surface corridor and compatible vehicles. We present a conceptual framework for this corridor and vehicle. This pro...

Numerical Modelling of the Dynamic Response of High-Speed Railway Bridges Considering Vehicle-Structure and Structure-Soil-Structure Interaction

DEFF Research Database (Denmark)

Bucinskas, Paulius; Agapii, L.; Sneideris, J.

2015-01-01

is idealized as a multi-degree-of-freedom system, modelled with two layers of spring-dashpot suspension systems. Coupling the vehicle system and railway track is realized through interaction forces between the wheels and the rail, where the irregularities of the track are implemented as a random stationary......The aim of this paper is the dynamic analysis of a multi-support bridge structure exposed to high-speed railway traffic. The proposed computational model has a unified approach for simultaneously accounting for the bridge structure response, soil response and forces induced by the vehicle....... The bridge structure is modelled in three dimensions based on the finite element method using two-noded three-dimensional beam elements. The track structure is composed of three layers: rail, sleepers and deck which are connected through spring-dashpot systems. The vehicle travelling along a bridge...

Two wheel speed robust sliding mode control for electric vehicle drive

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Abdelfatah Nasri

2008-01-01

Full Text Available Nowadays the uses of electrical power resources are integrated in the modern vehicle motion traction chain so new technologies allow the development of electric vehicles (EV by means of static converters-related electric motors. All mechanical transmission devices are eliminated and vehicle wheel motion can be controlled by means of power electronics. The proposed propulsing system consists of two induction motors (IM that ensure the drive of the two back driving wheels. The proposed control structure-called independent machines- for speed control permit the achievement of an electronic differential. The electronic differential system ensures the robust control of the vehicle behavior on the road. It also allows controlling independently, every driving wheel to turn at different speeds in any curve. This paper presents the study and the sliding mode control strategy of the electric vehicle driving wheels.

In pedestrian crashes, it's vehicle speed that matters the most

Science.gov (United States)

2000-05-13

A recently prepared report on pedestrian injuries provides these two main findings: 1) regardless of age, pedestrians involved in crashes are more likely to be killed as vehicle speeds increase; and 2) in crashes at any speed, older pedestrians are m...

Regardless-of-Speed Superconducting LSM Controlled-Repulsive MAGLEV Vehicle

Science.gov (United States)

Yoshida, Kinjiro; Egashira, Tatsuya; Hirai, Ryuichi

1996-01-01

This paper proposes a new repulsive Maglev vehicle which a superconducting linear synchronous motor (LSM) can levitate and propel simultaneously, independently of the vehicle speeds. The combined levitation and propulsion control is carried out by controlling mechanical-load angle and armature-current. Dynamic simulations show successful operations with good ride-quality by using a compact control method proposed here.

Vibrational Comfort on Board the Vehicle: Influence of Speed Bumps and Comparison between Different Categories of Vehicle

Directory of Open Access Journals (Sweden)

Vincenzo Barone

2016-01-01

Full Text Available This paper shows the results of a study conducted on five different categories of vehicles in a specific test site. The aim was to investigate how the effect of the test site discontinuity determines variations of comfort related to the increase in speed and to the five selected road vehicles of different classes. Measurements were obtained by combining data relating to vibrations in the three reference axes, detected through a vibration dosimeter (VIB-008, and geolocation data (latitude, longitude, and speed identified by the GPS inside a smartphone. This procedure, through the synchronization between dosimeter and GPS location, has been helpful in postprocessing to eliminate any measurement anomalies generated by the operator. After the survey campaign it was determined that a formulation allows defining a Comfort Index (CI depending on velocity and five vehicles of different classes. This study showed that the presence of speed bumps, in the test site investigated, appears to be uncomfortable even at speeds well below those required by the Highway Code.

High-Speed Data Recorder for Space, Geodesy, and Other High-Speed Recording Applications

Science.gov (United States)

Taveniku, Mikael

2013-01-01

A high-speed data recorder and replay equipment has been developed for reliable high-data-rate recording to disk media. It solves problems with slow or faulty disks, multiple disk insertions, high-altitude operation, reliable performance using COTS hardware, and long-term maintenance and upgrade path challenges. The current generation data recor - ders used within the VLBI community are aging, special-purpose machines that are both slow (do not meet today's requirements) and are very expensive to maintain and operate. Furthermore, they are not easily upgraded to take advantage of commercial technology development, and are not scalable to multiple 10s of Gbit/s data rates required by new applications. The innovation provides a softwaredefined, high-speed data recorder that is scalable with technology advances in the commercial space. It maximally utilizes current technologies without being locked to a particular hardware platform. The innovation also provides a cost-effective way of streaming large amounts of data from sensors to disk, enabling many applications to store raw sensor data and perform post and signal processing offline. This recording system will be applicable to many applications needing realworld, high-speed data collection, including electronic warfare, softwaredefined radar, signal history storage of multispectral sensors, development of autonomous vehicles, and more.

Investigation of Inner Loop Flight Control Strategies for High-Speed Research

Science.gov (United States)

Newman, Brett; Kassem, Ayman

1999-01-01

This report describes the activities and findings conducted under contract NAS1-19858 with NASA Langley Research Center. Subject matter is the investigation of suitable flight control design methodologies and solutions for large, flexible high-speed vehicles. Specifically, methodologies are to address the inner control loops used for stabilization and augmentation of a highly coupled airframe system possibly involving rigid-body motion, structural vibrations, unsteady aerodynamics, and actuator dynamics. Techniques considered in this body of work are primarily conventional-based, and the vehicle of interest is the High-Speed Civil Transport (HSCT). Major findings include 1) current aeroelastic vehicle modeling procedures require further emphasis and refinement, 2) traditional and nontraditional inner loop flight control strategies employing a single feedback loop do not appear sufficient for highly flexible HSCT class vehicles, 3) inner loop flight control systems will, in all likelihood, require multiple interacting feedback loops, and 4) Ref. H HSCT configuration presents major challenges to designing acceptable closed-loop flight dynamics.

A Vehicle Active Safety Model: Vehicle Speed Control Based on Driver Vigilance Detection Using Wearable EEG and Sparse Representation.

Science.gov (United States)

Zhang, Zutao; Luo, Dianyuan; Rasim, Yagubov; Li, Yanjun; Meng, Guanjun; Xu, Jian; Wang, Chunbai

2016-02-19

In this paper, we present a vehicle active safety model for vehicle speed control based on driver vigilance detection using low-cost, comfortable, wearable electroencephalographic (EEG) sensors and sparse representation. The proposed system consists of three main steps, namely wireless wearable EEG collection, driver vigilance detection, and vehicle speed control strategy. First of all, a homemade low-cost comfortable wearable brain-computer interface (BCI) system with eight channels is designed for collecting the driver's EEG signal. Second, wavelet de-noising and down-sample algorithms are utilized to enhance the quality of EEG data, and Fast Fourier Transformation (FFT) is adopted to extract the EEG power spectrum density (PSD). In this step, sparse representation classification combined with k-singular value decomposition (KSVD) is firstly introduced in PSD to estimate the driver's vigilance level. Finally, a novel safety strategy of vehicle speed control, which controls the electronic throttle opening and automatic braking after driver fatigue detection using the above method, is presented to avoid serious collisions and traffic accidents. The simulation and practical testing results demonstrate the feasibility of the vehicle active safety model.

A Vehicle Active Safety Model: Vehicle Speed Control Based on Driver Vigilance Detection Using Wearable EEG and Sparse Representation

Directory of Open Access Journals (Sweden)

Zutao Zhang

2016-02-01

Full Text Available In this paper, we present a vehicle active safety model for vehicle speed control based on driver vigilance detection using low-cost, comfortable, wearable electroencephalographic (EEG sensors and sparse representation. The proposed system consists of three main steps, namely wireless wearable EEG collection, driver vigilance detection, and vehicle speed control strategy. First of all, a homemade low-cost comfortable wearable brain-computer interface (BCI system with eight channels is designed for collecting the driver’s EEG signal. Second, wavelet de-noising and down-sample algorithms are utilized to enhance the quality of EEG data, and Fast Fourier Transformation (FFT is adopted to extract the EEG power spectrum density (PSD. In this step, sparse representation classification combined with k-singular value decomposition (KSVD is firstly introduced in PSD to estimate the driver’s vigilance level. Finally, a novel safety strategy of vehicle speed control, which controls the electronic throttle opening and automatic braking after driver fatigue detection using the above method, is presented to avoid serious collisions and traffic accidents. The simulation and practical testing results demonstrate the feasibility of the vehicle active safety model.

Predicting Light-Duty Vehicle Fuel Economy as a Function of Highway Speed

Energy Technology Data Exchange (ETDEWEB)

Thomas, John [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Hwang, Ho-Ling [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); West, Brian [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Huff, Shean [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

2013-04-08

The www.fueleconomy.gov website offers information such as window label fuel economy for city, highway, and combined driving for all U.S.-legal light-duty vehicles from 1984 to the present. The site is jointly maintained by the U.S. Department of Energy and the U.S. Environmental Protection Agency (EPA), and also offers a considerable amount of consumer information and advice pertaining to vehicle fuel economy and energy related issues. Included with advice pertaining to driving styles and habits is information concerning the trend that as highway cruising speed is increased, fuel economy will degrade. An effort was undertaken to quantify this conventional wisdom through analysis of dynamometer testing results for 74 vehicles at steady state speeds from 50 to 80 mph. Using this experimental data, several simple models were developed to predict individual vehicle fuel economy and its rate of change over the 50-80 mph speed range interval. The models presented require a minimal number of vehicle attributes. The simplest model requires only the EPA window label highway mpg value (based on the EPA specified estimation method for 2008 and beyond). The most complex of these simple model uses vehicle coast-down test coefficients (from testing prescribed by SAE Standard J2263) known as the vehicle Target Coefficients, and the raw fuel economy result from the federal highway test. Statistical comparisons of these models and discussions of their expected usefulness and limitations are offered.

Market penetration speed and effects on CO2 reduction of electric vehicles and plug-in hybrid electric vehicles in Japan

International Nuclear Information System (INIS)

Yabe, Kuniaki; Shinoda, Yukio; Seki, Tomomichi; Tanaka, Hideo; Akisawa, Atsushi

2012-01-01

Abstarct: In order to reduce CO 2 emissions in the passenger vehicle sector, mass introduction of electric vehicles (EVs) and plug-in hybrid electric vehicles (PHEVs) is required despite their high battery costs. This paper forecasts the rate at which EV/PHEV will penetrate into the market in the future and the effects of that spread on CO 2 reduction by using a learning curve for lithium-ion batteries, distribution of daily travel distance for each vehicle, and an optimal power generation planning model for charging vehicles. Taking into consideration each driver's economical viewpoint, the speed at which the EV/PHEV share of the new passenger vehicle market grows is fairly slow. The optimum calculation in our base case shows that the share of EV/PHEV is only a quarter even in 2050. However, the initial price and progress rate of batteries have a great effect on this share. Therefore, long-term economic support from the government and significant R and D innovation are required to reduce CO 2 drastically through cutting down battery price. The results also show how much the CO 2 emission intensity of power generation affects the CO 2 reduction rate by introducing EV/PHEV. - Highlights: ► Authors minimized the total cost of vehicle and power supply sectors until 2050. ► Simulation results show the penetration speed of PHEVs/EVs is not so fast. ► To accelerate it and reduce CO 2 , subsidies and innovations are required. ► The introduction of PHEVs/EVs is still reasonable even after the nuclear accident.

Sampling optimization for high-speed weigh-in-motion measurements using in-pavement strain-based sensors

International Nuclear Information System (INIS)

Zhang, Zhiming; Huang, Ying; Bridgelall, Raj; Palek, Leonard; Strommen, Robert

2015-01-01

Weigh-in-motion (WIM) measurement has been widely used for weight enforcement, pavement design, freight management, and intelligent transportation systems to monitor traffic in real-time. However, to use such sensors effectively, vehicles must exit the traffic stream and slow down to match their current capabilities. Hence, agencies need devices with higher vehicle passing speed capabilities to enable continuous weight measurements at mainline speeds. The current practices for data acquisition at such high speeds are fragmented. Deployment configurations and settings depend mainly on the experiences of operation engineers. To assure adequate data, most practitioners use very high frequency measurements that result in redundant samples, thereby diminishing the potential for real-time processing. The larger data memory requirements from higher sample rates also increase storage and processing costs. The field lacks a sampling design or standard to guide appropriate data acquisition of high-speed WIM measurements. This study develops the appropriate sample rate requirements as a function of the vehicle speed. Simulations and field experiments validate the methods developed. The results will serve as guidelines for future high-speed WIM measurements using in-pavement strain-based sensors. (paper)

Sampling optimization for high-speed weigh-in-motion measurements using in-pavement strain-based sensors

Science.gov (United States)

Zhang, Zhiming; Huang, Ying; Bridgelall, Raj; Palek, Leonard; Strommen, Robert

2015-06-01

Weigh-in-motion (WIM) measurement has been widely used for weight enforcement, pavement design, freight management, and intelligent transportation systems to monitor traffic in real-time. However, to use such sensors effectively, vehicles must exit the traffic stream and slow down to match their current capabilities. Hence, agencies need devices with higher vehicle passing speed capabilities to enable continuous weight measurements at mainline speeds. The current practices for data acquisition at such high speeds are fragmented. Deployment configurations and settings depend mainly on the experiences of operation engineers. To assure adequate data, most practitioners use very high frequency measurements that result in redundant samples, thereby diminishing the potential for real-time processing. The larger data memory requirements from higher sample rates also increase storage and processing costs. The field lacks a sampling design or standard to guide appropriate data acquisition of high-speed WIM measurements. This study develops the appropriate sample rate requirements as a function of the vehicle speed. Simulations and field experiments validate the methods developed. The results will serve as guidelines for future high-speed WIM measurements using in-pavement strain-based sensors.

Dual motor drive vehicle speed synchronization and coordination control strategy

Science.gov (United States)

Huang, Hao; Tu, Qunzhang; Jiang, Chenming; Ma, Limin; Li, Pei; Zhang, Hongxing

2018-04-01

Multi-motor driven systems are more and more widely used in the field of electric engineering vehicles, as a result of the road conditions and the variable load of engineering vehicles, makes multi-motors synchronization coordinated control system as a key point of the development of the electric vehicle drive system. This paper based on electrical machinery transmission speed in the process of engineering vehicles headed for coordinated control problem, summarized control strategies at home and abroad in recent years, made analysis and comparison of the characteristics, finally discussed the trend of development of the multi-motor coordination control, provided a reference for synchronized control system research of electric drive engineering vehicles.

A comparison of high-speed flywheels, batteries, and ultracapacitors on the bases of cost and fuel economy as the energy storage system in a fuel cell based hybrid electric vehicle

Energy Technology Data Exchange (ETDEWEB)

Doucette, Reed T.; McCulloch, Malcolm D. [Department of Engineering Science, University of Oxford, Thom Building, Parks Road, Oxford, OX1 3PJ (United Kingdom)

2011-02-01

Fuel cells aboard hybrid electric vehicles (HEVs) are often hybridized with an energy storage system (ESS). Batteries and ultracapacitors are the most common technologies used in ESSs aboard HEVs. High-speed flywheels are an emerging technology with traits that have the potential to make them competitive with more established battery and ultracapacitor technologies in certain vehicular applications. This study compares high-speed flywheels, ultracapacitors, and batteries functioning as the ESS in a fuel cell based HEV on the bases of cost and fuel economy. In this study, computer models were built to simulate the powertrain of a fuel cell based HEV where high-speed flywheels, batteries, and ultracapacitors of a range of sizes were used as the ESS. A simulated vehicle with a powertrain using each of these technologies was run over two different drive cycles in order to see how the different ESSs performed under different driving patterns. The results showed that when cost and fuel economy were both considered, high-speed flywheels were competitive with batteries and ultracapacitors. (author)

Research on motor rotational speed measurement in regenerative braking system of electric vehicle

Science.gov (United States)

Pan, Chaofeng; Chen, Liao; Chen, Long; Jiang, Haobin; Li, Zhongxing; Wang, Shaohua

2016-01-01

Rotational speed signals acquisition and processing techniques are widely used in rotational machinery. In order to realized precise and real-time control of motor drive and regenerative braking process, rotational speed measurement techniques are needed in electric vehicles. Obtaining accurate motor rotational speed signal will contribute to the regenerative braking force control steadily and realized higher energy recovery rate. This paper aims to develop a method that provides instantaneous speed information in the form of motor rotation. It addresses principles of motor rotational speed measurement in the regenerative braking systems of electric vehicle firstly. The paper then presents ideal and actual Hall position sensor signals characteristics, the relation between the motor rotational speed and the Hall position sensor signals is revealed. Finally, Hall position sensor signals conditioning and processing circuit and program for motor rotational speed measurement have been carried out based on measurement error analysis.

36 CFR 1192.175 - High-speed rail cars, monorails and systems.

Science.gov (United States)

2010-07-01

..., monorails and systems. 1192.175 Section 1192.175 Parks, Forests, and Public Property ARCHITECTURAL AND... TRANSPORTATION VEHICLES Other Vehicles and Systems § 1192.175 High-speed rail cars, monorails and systems. (a... steel-wheel-on-steel-rail technology, and monorail systems operating primarily on dedicated rail (i.e...

Life-cycle assessment of high-speed rail: the case of California

International Nuclear Information System (INIS)

Chester, Mikhail; Horvath, Arpad

2010-01-01

The state of California is expected to have significant population growth in the next half-century resulting in additional passenger transportation demand. Planning for a high-speed rail system connecting San Diego, Los Angeles, San Francisco, and Sacramento as well as many population centers between is now underway. The considerable investment in California high-speed rail has been debated for some time and now includes the energy and environmental tradeoffs. The per-trip energy consumption, greenhouse gas emissions, and other emissions are often compared against the alternatives (automobiles, heavy rail, and aircraft), but typically only considering vehicle operation. An environmental life-cycle assessment of the four modes was created to compare both direct effects of vehicle operation and indirect effects from vehicle, infrastructure, and fuel components. Energy consumption, greenhouse gas emissions, and SO 2 , CO, NO X , VOC, and PM 10 emissions were evaluated. The energy and emission intensities of each mode were normalized per passenger kilometer traveled by using high and low occupancies to illustrate the range in modal environmental performance at potential ridership levels. While high-speed rail has the potential to be the lowest energy consumer and greenhouse gas emitter, appropriate planning and continued investment would be needed to ensure sustained high occupancy. The time to environmental payback is discussed highlighting the ridership conditions where high-speed rail will or will not produce fewer environmental burdens than existing modes. Furthermore, environmental tradeoffs may occur. High-speed rail may lower energy consumption and greenhouse gas emissions per trip but can create more SO 2 emissions (given the current electricity mix) leading to environmental acidification and human health issues. The significance of life-cycle inventorying is discussed as well as the potential of increasing occupancy on mass transit modes.

78 FR 16051 - Vehicle/Track Interaction Safety Standards; High-Speed and High Cant Deficiency Operations

Science.gov (United States)

2013-03-13

..., without the need for obtaining a waiver. In order to take advantage of high cant deficiency operations and... attention. In addition, to improve the process for analyzing data while vehicles are negotiating spiral... the last few decades, computer models of rail vehicles interacting with track have become practical...

Evaluation of uncertainty of vehicle speed when autotechnical examination of traffic accidents

Directory of Open Access Journals (Sweden)

Kashkanov А.А.

2016-08-01

Full Text Available The existing methods and ways to measure vehicle speed, which can be used in autotechnical examination of road accidents, in order to identify ways to improve the peer review mechanism of emergencies are analyzed. To achieve the goal we propose to take measurement errors vehicle speed into account. Modern automated technology (GPS, EDR and ACN can reduce these errors, and with sufficient accuracy to determine the speed of the vehicle and other motion parameters and technical data that helps to quicken research in various stages of examination, but there are a number of objective problems hindering their widespread use in Ukraine. To solve these problems need to develop and improve existing methods of expert investigation of the circumstances of accidents based process automation capabilities fixing mechanism and the scene, measurements and calculations options vehicular traffic. This will increase the effectiveness of traditional methods and to minimize the influence of subjective factors.

Evaluation of sounds for hybrid and electric vehicles operating at low speed

Science.gov (United States)

2012-10-22

Electric vehicles (EV) and hybrid electric vehicles (HEVs), operated at low speeds may reduce auditory cues used by pedestrians to assess the state of nearby traffic creating a safety issue. This field study compares the auditory detectability of num...

Antisideslip and Antirollover Safety Speed Controller Design for Vehicle on Curved Road

Directory of Open Access Journals (Sweden)

Guo Lie

2014-01-01

Full Text Available When the drivers cannot be aware of the existing of forthcoming curved roads and fail to regulate their safety speeds accordingly, sideslip or rollover may occur with high probability. The antisideslip and antirollover control of vehicle on curved road in automatic highway systems is studied. The safety speed warning system is set before entering the curved road firstly. The speed adhesion control is adopted to shorten the braking distance while decelerating and to guarantee the safety speed. The velocity controller when decelerating on the straight path and the posture controller when driving on curved road are designed, respectively, utilizing integral backstepping technology. Simulation results demonstrate that this control system is characterized by quick and precise tracking and global stability. Consequently, it is able to avoid the dangerous operating conditions, such as sideslip and rollover, and guarantee the safety and directional stability when driving on curved road.

Motion Planning of Autonomous Vehicles on a Dual Carriageway without Speed Lanes

Directory of Open Access Journals (Sweden)

Rahul Kala

2015-01-01

Full Text Available The problem of motion planning of an autonomous vehicle amidst other vehicles on a straight road is considered. Traffic in a number of countries is unorganized, where the vehicles do not move within predefined speed lanes. In this paper, we formulate a mechanism wherein an autonomous vehicle may travel on the “wrong” side in order to overtake a vehicle. Challenges include assessing a possible overtaking opportunity, cooperating with other vehicles, partial driving on the “wrong” side of the road and safely going to and returning from the “wrong” side. The experimental results presented show vehicles cooperating to accomplish overtaking manoeuvres.

The present status of the high temperature superconducting Maglev vehicle in China

International Nuclear Information System (INIS)

Wang, J S; Wang, S Y; Zeng, Y W; Deng, C Y; Ren, Z Y; Wang, X R; Song, H H; Wang, X Z; Zheng, J; Zhao, Y

2005-01-01

Since the first successful running of the people-carrying high temperature superconducting (HTS) Maglev test vehicle on 31 December 2000, about 27,000 people have taken it, and the accumulated running distance is about 400 km. The levitation force of the onboard HTS equipment is measured periodically, and new experimental results measured on 5 March 2003 show that the performance of the onboard HTS Maglev equipment is almost the same as that of two years ago. Experimental results indicate that the long-term stability of the HTS Maglev vehicle is good. This further proves the feasibility of the HTS Maglev vehicle for practical transportation. It is worth mentioning that all the results are measured at a low speed; however, investigations of the dynamic performance of the HTS Maglev vehicle at high speed are necessary for practical application. Research on the dynamic performance of the HTS Maglev vehicle is ongoing

The present status of the high temperature superconducting Maglev vehicle in China

Energy Technology Data Exchange (ETDEWEB)

Wang, J S; Wang, S Y; Zeng, Y W; Deng, C Y; Ren, Z Y; Wang, X R; Song, H H; Wang, X Z; Zheng, J; Zhao, Y [Superconductivity R and D Center, Mail Stop: 152, Southwest Jiaotong University, Chengdu 610031, Sichuan (China)

2005-02-01

Since the first successful running of the people-carrying high temperature superconducting (HTS) Maglev test vehicle on 31 December 2000, about 27,000 people have taken it, and the accumulated running distance is about 400 km. The levitation force of the onboard HTS equipment is measured periodically, and new experimental results measured on 5 March 2003 show that the performance of the onboard HTS Maglev equipment is almost the same as that of two years ago. Experimental results indicate that the long-term stability of the HTS Maglev vehicle is good. This further proves the feasibility of the HTS Maglev vehicle for practical transportation. It is worth mentioning that all the results are measured at a low speed; however, investigations of the dynamic performance of the HTS Maglev vehicle at high speed are necessary for practical application. Research on the dynamic performance of the HTS Maglev vehicle is ongoing.

Advances on Propulsion Technology for High-Speed Aircraft. Volume 1

National Research Council Canada - National Science Library

2007-01-01

.... The demand for supersonic vehicles is believed to boost in the incoming years. This VKI/RTO lecture series will review the current state of the art of high speed propulsion for both airplanes and space launchers...

Advances on Propulsion Technology for High-Speed Aircraft. Volume 2

National Research Council Canada - National Science Library

2007-01-01

.... The demand for supersonic vehicles is believed to boost in the incoming years. This VKI/RTO lecture series will review the current state of the art of high speed propulsion for both airplanes and space launchers...

Distributed and self-adaptive vehicle speed estimation in the composite braking case for four-wheel drive hybrid electric car

Science.gov (United States)

Zhao, Z.-G.; Zhou, L.-J.; Zhang, J.-T.; Zhu, Q.; Hedrick, J.-K.

2017-05-01

Considering the controllability and observability of the braking torques of the hub motor, Integrated Starter Generator (ISG), and hydraulic brake for four-wheel drive (4WD) hybrid electric cars, a distributed and self-adaptive vehicle speed estimation algorithm for different braking situations has been proposed by fully utilising the Electronic Stability Program (ESP) sensor signals and multiple powersource signals. Firstly, the simulation platform of a 4WD hybrid electric car was established, which integrates an electronic-hydraulic composited braking system model and its control strategy, a nonlinear seven degrees-of-freedom vehicle dynamics model, and the Burckhardt tyre model. Secondly, combining the braking torque signals with the ESP signals, self-adaptive unscented Kalman sub-filter and main-filter adaptable to the observation noise were, respectively, designed. Thirdly, the fusion rules for the sub-filters and master filter were proposed herein, and the estimation results were compared with the simulated value of a real vehicle speed. Finally, based on the hardware in-the-loop platform and by picking up the regenerative motor torque signals and wheel cylinder pressure signals, the proposed speed estimation algorithm was tested under the case of moderate braking on the highly adhesive road, and the case of Antilock Braking System (ABS) action on the slippery road, as well as the case of ABS action on the icy road. Test results show that the presented vehicle speed estimation algorithm has not only a high precision but also a strong adaptability in the composite braking case.

Advanced Range Safety System for High Energy Vehicles

Science.gov (United States)

Claxton, Jeffrey S.; Linton, Donald F.

2002-01-01

The advanced range safety system project is a collaboration between the National Aeronautics and Space Administration and the United States Air Force to develop systems that would reduce costs and schedule for safety approval for new classes of unmanned high-energy vehicles. The mission-planning feature for this system would yield flight profiles that satisfy the mission requirements for the user while providing an increased quality of risk assessment, enhancing public safety. By improving the speed and accuracy of predicting risks to the public, mission planners would be able to expand flight envelopes significantly. Once in place, this system is expected to offer the flexibility of handling real-time risk management for the high-energy capabilities of hypersonic vehicles including autonomous return-from-orbit vehicles and extended flight profiles over land. Users of this system would include mission planners of Space Launch Initiative vehicles, space planes, and other high-energy vehicles. The real-time features of the system could make extended flight of a malfunctioning vehicle possible, in lieu of an immediate terminate decision. With this improved capability, the user would have more time for anomaly resolution and potential recovery of a malfunctioning vehicle.

Joint optimization of green vehicle scheduling and routing problem with time-varying speeds

Science.gov (United States)

Zhang, Dezhi; Wang, Xin; Ni, Nan; Zhang, Zhuo

2018-01-01

Based on an analysis of the congestion effect and changes in the speed of vehicle flow during morning and evening peaks in a large- or medium-sized city, the piecewise function is used to capture the rules of the time-varying speed of vehicles, which are very important in modelling their fuel consumption and CO2 emission. A joint optimization model of the green vehicle scheduling and routing problem with time-varying speeds is presented in this study. Extra wages during nonworking periods and soft time-window constraints are considered. A heuristic algorithm based on the adaptive large neighborhood search algorithm is also presented. Finally, a numerical simulation example is provided to illustrate the optimization model and its algorithm. Results show that, (1) the shortest route is not necessarily the route that consumes the least energy, (2) the departure time influences the vehicle fuel consumption and CO2 emissions and the optimal departure time saves on fuel consumption and reduces CO2 emissions by up to 5.4%, and (3) extra driver wages have significant effects on routing and departure time slot decisions. PMID:29466370

Factors affecting speed in human-powered vehicles.

Science.gov (United States)

White, A P

1994-10-01

It is shown how to derive the appropriate cubic equation relating power and the effects of friction, gradient and wind resistance on the speed of a human-powered vehicle (HPV). The effects of gradient and wind resistance are explored for parameters representing a typical racing cyclist. The principal conclusion may be summarized as follows: for optimum performance in a time trial, there should be no wind and the course should be level. Any deviation from these conditions will produce a decrement in performance.

Acoustic and Emission Characteristics of Small, High-Speed Internal Combustion Engines

Science.gov (United States)

1981-07-01

The intent of this study is to obtain information on small high-speed engines so that their effect on the urban environment may be assessed, and if necessary, programs devised to reduce the noise and other emissions from vehicles using these highly d...

Time optimal paths for high speed maneuvering

Energy Technology Data Exchange (ETDEWEB)

Reister, D.B.; Lenhart, S.M.

1993-01-01

Recent theoretical results have completely solved the problem of determining the minimum length path for a vehicle with a minimum turning radius moving from an initial configuration to a final configuration. Time optimal paths for a constant speed vehicle are a subset of the minimum length paths. This paper uses the Pontryagin maximum principle to find time optimal paths for a constant speed vehicle. The time optimal paths consist of sequences of axes of circles and straight lines. The maximum principle introduces concepts (dual variables, bang-bang solutions, singular solutions, and transversality conditions) that provide important insight into the nature of the time optimal paths. We explore the properties of the optimal paths and present some experimental results for a mobile robot following an optimal path.

The Seismic Response of High-Speed Railway Bridges Subjected to Near-Fault Forward Directivity Ground Motions Using a Vehicle-Track-Bridge Element

Directory of Open Access Journals (Sweden)

Chen Ling-kun

2014-01-01

Full Text Available Based on the Next Generation Attenuation (NGA project ground motion library, the finite element model of the high-speed railway vehicle-bridge system is established. The model was specifically developed for such system that is subjected to near-fault ground motions. In addition, it accounted for the influence of the rail irregularities. The vehicle-track-bridge (VTB element is presented to simulate the interaction between train and bridge, in which a train can be modeled as a series of sprung masses concentrated at the axle positions. For the short period railway bridge, the results from the case study demonstrate that directivity pulse effect tends to increase the seismic responses of the bridge compared with far-fault ground motions or nonpulse-like motions and the directivity pulse effect and high values of the vertical acceleration component can notably influence the hysteretic behaviour of piers.

76 FR 78 - Federal Motor Vehicle Safety Standard; Engine Control Module Speed Limiter Device

Science.gov (United States)

2011-01-03

... [Docket No. NHTSA-2007-26851] Federal Motor Vehicle Safety Standard; Engine Control Module Speed Limiter... occupants. IIHS stated that on-board electronic engine control modules (ECM) will maintain the desired speed... be equipped with an electronic control module (ECM) that is capable of limiting the maximum speed of...

Super high-speed magnetically levitated system approaches: practical use

Energy Technology Data Exchange (ETDEWEB)

Matsuda, S; Nakao, H; Takemasa, H

1988-01-01

The JR-MAGLEV, utilizing superconducting magnets, has been under development since 1970 with the manufacturing of a succession of trial vehicles such as the LSM 200, ML 100, ML 500 and MLU 001. In 1979, the ML 500 trial vehicle achieved a world-record speed of 517 km/h. This was followed by the MLU 001, which recorded a speed of 350 km/h as a 3-car formation in 1986 and 400 km/h as a 2-car formation with passengers in 1987. As a result of the satisfactory results obtained by the MLU 001, a prototype vehicle for commercial service, the MLU 002, was manufactured in March 1988 and is now under testing at the Miyazaki test track, with the aim of achieving a target operational speed of 420 km/h.

Superconducting magnet suspensions in high speed ground transport

Energy Technology Data Exchange (ETDEWEB)

Alston, I A

1973-08-01

A technical and economic definition of high speed ground transport systems using magnetic suspensions is given. The full range of common superconducting suspensions and of propulsions are covered with designs produced for speeds ranging from 100 m/s (225 miles/hr) to 250 m/s (560 mile/hr). Technical descriptions of the vehicles, their suspensions, propulsions and tracks are given in some detail and operating costs are presented for all the systems together with details of the breakdown of costs and the capital costs involved. The design assumptions, the costing procedure and a cost sensitivity study are presented. It is concluded that the systems are technically feasible; that they are suited to existing duorail track for low speed running and that, in these circumstances, they would be economically viable over many routes.

Modeling the Turning Speed and Car Following Behaviors of Autonomous Vehicles in a Virtual World

Directory of Open Access Journals (Sweden)

Carrillo-González José Gerardo

2015-07-01

Full Text Available This article deals with mathematical models for controlling vehicles behavior in a virtual world, where two behaviors are considered: 1 curve turning and 2 car following situations, in this last is essential to provide a safety distance between the leader and the follower and at the same time keep the follower not delayed with respect to the leader, and in a curve turning the complexity is to provide a safety speed inside the curve and keep the car inside the lane. Using basic information as vehicles position, mathematical models can be developed for explaining the heading angle and the autonomous vehicles speed on curves, i.e. the controlled by the models. A model that predicts the autonomous vehicle speed on curves is developed considering previous data in other curves. Two models that control the acceleration/deceleration behavior of autonomous vehicles in a car following situation are proposed. In the first model, the parameters are calibrated with a proposed algorithm which enables accuracy in order to imitate the human behavior for accelerating and braking, and the second model provides a safety distance between the follower and the leader at sudden stops of the latter and employs the acceleration/deceleration top capabilities to follow the leader car similar to the human behavior.

Super high-speed magnetically levitated system approaches practical use

Energy Technology Data Exchange (ETDEWEB)

Matsuda, Shoji; Nakao, Hiroyuki; Takemasa, Hisashi

1988-10-01

The JR-MAGLEV, a super high-speed magnetically levitated system, has been under development since the inauguration with the manufacturing of a succession of trial vehicles. In 1987, the trial vehicle recorded a speed of 400 km/hr as a 2-car formation with passengers. As a participant in the Maglev project, Toshiba has been contributing to the development of superconducting magnets, the main element of the system, as well as auxiliary power sources and the cycloconverter to be used in the substations. A prototype vehicle for commercial service, MLU 002, was manufactured in March 1988 and is now under testing with the aim of achieving a target speed of 420km/hr. The main parameters of superconducting magnet are as follows; magnetomotive force of 700 kA and number of coils of 3 poles/2 trains/ 2 cars, and the magnets are light weight which is almost the limits with the weight ratio to rolling stock of 0.25. As measures to protect vaporization loss of helium for coil-cooling, a relicfaction process of the helium vapor by use of Claude cycle refrigerator was adopted. A circulating current cycloconverter with 16 MVA was developed for the travel motion. The cycloconverter enabled to receive power directly from an electric power company, the output current becomes complete sine wave, and the problems on traveling control were solved. 6 references, 8 figures, 3 tables.

Structural concepts and experimental considerations for a versatile high-speed research airplane

Science.gov (United States)

Jackson, L. R.; Kirkham, F. S.; Weidner, J. P.

1978-01-01

Future aircraft may be hydrogen fueled and fly at hypersonic speeds. The resulting environments will require new structural concepts to satisfy performance goals. Large representative structures will have to be flight tested prior to commitment to a costly vehicle fleet. To perform flight tests, a versatile, economical, high-speed research airplane is defined. Results of this study including experimental considerations for a hypersonic research airplane are reported.

Network Provisioning for High Speed Vehicles Moving along Predictable Routes - Part 1: Spiderman Handover

OpenAIRE

Maureira , Juan-Carlos; Dujovne , Diego; Dalle , Olivier

2009-01-01

This report presents our on-going work on a new system designed to provide a continuous network connectivity to communicating devices located on-board a vehicle moving at ”high speed” with a predictable trajectory such as trains, subways or buses. The devices on-board the vehicle form a sub-network called the ”in-motion network”. This system we propose is composed of two parts. The mobile part, called Spiderman Device (SD), installed on the roof of the vehicle, and the fixed part is composed ...

Perils of using speed zone data to assess real-world compliance to speed limits.

Science.gov (United States)

Chevalier, Anna; Clarke, Elizabeth; Chevalier, Aran John; Brown, Julie; Coxon, Kristy; Ivers, Rebecca; Keay, Lisa

2017-11-17

Real-world driving studies, including those involving speeding alert devices and autonomous vehicles, can gauge an individual vehicle's speeding behavior by comparing measured speed with mapped speed zone data. However, there are complexities with developing and maintaining a database of mapped speed zones over a large geographic area that may lead to inaccuracies within the data set. When this approach is applied to large-scale real-world driving data or speeding alert device data to determine speeding behavior, these inaccuracies may result in invalid identification of speeding. We investigated speeding events based on service provider speed zone data. We compared service provider speed zone data (Speed Alert by Smart Car Technologies Pty Ltd., Ultimo, NSW, Australia) against a second set of speed zone data (Google Maps Application Programming Interface [API] mapped speed zones). We found a systematic error in the zones where speed limits of 50-60 km/h, typical of local roads, were allocated to high-speed motorways, which produced false speed limits in the speed zone database. The result was detection of false-positive high-range speeding. Through comparison of the service provider speed zone data against a second set of speed zone data, we were able to identify and eliminate data most affected by this systematic error, thereby establishing a data set of speeding events with a high level of sensitivity (a true positive rate of 92% or 6,412/6,960). Mapped speed zones can be a source of error in real-world driving when examining vehicle speed. We explored the types of inaccuracies found within speed zone data and recommend that a second set of speed zone data be utilized when investigating speeding behavior or developing mapped speed zone data to minimize inaccuracy in estimates of speeding.

Low Speed Longitudinal Control Algorithms for Automated Vehicles in Simulation and Real Platforms

Directory of Open Access Journals (Sweden)

Mauricio Marcano

2018-01-01

Full Text Available Advanced Driver Assistance Systems (ADAS acting over throttle and brake are already available in level 2 automated vehicles. In order to increase the level of automation new systems need to be tested in an extensive set of complex scenarios, ensuring safety under all circumstances. Validation of these systems using real vehicles presents important drawbacks: the time needed to drive millions of kilometers, the risk associated with some situations, and the high cost involved. Simulation platforms emerge as a feasible solution. Therefore, robust and reliable virtual environments to test automated driving maneuvers and control techniques are needed. In that sense, this paper presents a use case where three longitudinal low speed control techniques are designed, tuned, and validated using an in-house simulation framework and later applied in a real vehicle. Control algorithms include a classical PID, an adaptive network fuzzy inference system (ANFIS, and a Model Predictive Control (MPC. The simulated dynamics are calculated using a multibody vehicle model. In addition, longitudinal actuators of a Renault Twizy are characterized through empirical tests. A comparative analysis of results between simulated and real platform shows the effectiveness of the proposed framework for designing and validating longitudinal controllers for real automated vehicles.

MAINTAINING VEHICLE SPEED USING A MECHANICAL CRUISE CONTROL

Directory of Open Access Journals (Sweden)

Peter GIROVSKÝ

2017-06-01

Full Text Available In this article we would like to present cruise control realization. This cruise control is presented as mechanical device for vehicle speed maintenance and has been proposed as a low cost solution. Principle of function in mechanical cruise control is based on a position control of throttle. For the right action of mechanical cruise control it was need to solve some particular tasks related with speed sensing, construct of device for control of throttle position and design of control system of whole mechanical cruise control. Information about car velocity we have gained using Hall sensor attached on a magnetic ring of car tachometer. For control of the throttle was used a small servo drive and as the control unit was used Arduino. The designed solution of mechanical cruise control have been realized for car Škoda Felicia.

Impacts of Bus-stops on the Speed of Motorized Vehicles under Heterogeneous Traffic Conditions: A Case-Study of Delhi, India

Directory of Open Access Journals (Sweden)

Prateek Bansal

2014-06-01

Full Text Available The presence of friction generators1 such as bus-stops, intersections, petrol pumps and pedestrian crossings, etc. significantly influences the speed of traffic stream. Among all the friction generators, understanding the impact of bus-stops is particularly important from planning and modeling perspective in the Indian context. Therefore, this study presents a methodology to quantify the impact of bus-stops on the speed of other motorized vehicles (the total motorized vehicle fleet minus the buses under heterogeneous traffic conditions. The methodology was validated on the typical urban arterials in Delhi, India. Two types of data, location of bus-stops and speed profiles of motorized vehicles, were collected by GPS and V-box respectively. These two data sets were mapped and merged using ArcGIS. To understand the nature of traffic stream near bus-stops, ‘influence regions’ of bus-stops were extracted. Later, characteristic parameters such as lengths of the influence regions and average speeds in the influence regions were computed. Finally, 95% confidence intervals of these characteristic parameters were obtained and regression analysis was performed to quantify the impact of bus-stops on the speed of motorized vehicles. The results of study suggest that the influence region of bus-stops on the corridors investigated varies from 140–170 meters and average speed of motorized vehicles in the influence region is reduced by 26–38% of the free flow speed. These findings can better inform planners about the speeds used in traffic flow and travel demand modeling under heterogeneous conditions by helping them in accounting for the speed-reducing impacts of bus-stops. Moreover, transit planners may also consider the magnitudes and characteristics of the influence regions of bus-stops while determining their locations along the corridor to minimize their adverse impacts on the speed of other motorized vehicles.

Modeling vehicle operating speed on urban roads in Montreal: a panel mixed ordered probit fractional split model.

Science.gov (United States)

Eluru, Naveen; Chakour, Vincent; Chamberlain, Morgan; Miranda-Moreno, Luis F

2013-10-01

Vehicle operating speed measured on roadways is a critical component for a host of analysis in the transportation field including transportation safety, traffic flow modeling, roadway geometric design, vehicle emissions modeling, and road user route decisions. The current research effort contributes to the literature on examining vehicle speed on urban roads methodologically and substantively. In terms of methodology, we formulate a new econometric model framework for examining speed profiles. The proposed model is an ordered response formulation of a fractional split model. The ordered nature of the speed variable allows us to propose an ordered variant of the fractional split model in the literature. The proposed formulation allows us to model the proportion of vehicles traveling in each speed interval for the entire segment of roadway. We extend the model to allow the influence of exogenous variables to vary across the population. Further, we develop a panel mixed version of the fractional split model to account for the influence of site-specific unobserved effects. The paper contributes substantively by estimating the proposed model using a unique dataset from Montreal consisting of weekly speed data (collected in hourly intervals) for about 50 local roads and 70 arterial roads. We estimate separate models for local roads and arterial roads. The model estimation exercise considers a whole host of variables including geometric design attributes, roadway attributes, traffic characteristics and environmental factors. The model results highlight the role of various street characteristics including number of lanes, presence of parking, presence of sidewalks, vertical grade, and bicycle route on vehicle speed proportions. The results also highlight the presence of site-specific unobserved effects influencing the speed distribution. The parameters from the modeling exercise are validated using a hold-out sample not considered for model estimation. The results indicate

Assessment of capacity support and scattering in experimental high speed vehicle to vehicle MIMO links

DEFF Research Database (Denmark)

Eggers, Patrick Claus F.; Brown, Tim; Olesen, Kim

2007-01-01

Preliminary results on the use of the vehicle to vehicle MIMO channel in a rural highway environment are presented. This is looked at both in terms of the available spatial multiplexing through singular value decomposition and also angular distribution within the channel. Results indicate a strong...... predominant line of sight link in general while instances of scattering from other vehicles will cause changes in the Doppler spectrum as well as beamforming jitter....

Motion stability of high-speed maglev systems in consideration of aerodynamic effects: a study of a single magnetic suspension system

Science.gov (United States)

Wu, Han; Zeng, Xiao-Hui; Yu, Yang

2017-12-01

In this study, the intrinsic mechanism of aerodynamic effects on the motion stability of a high-speed maglev system was investigated. The concept of a critical speed for maglev vehicles considering the aerodynamic effect is proposed. The study was carried out based on a single magnetic suspension system, which is convenient for proposing relevant concepts and obtaining explicit expressions. This study shows that the motion stability of the suspension system is closely related to the vehicle speed when aerodynamic effects are considered. With increases of the vehicle speed, the stability behavior of the system changes. At a certain vehicle speed, the stability of the system reaches a critical state, followed by instability. The speed corresponding to the critical state is the critical speed. Analysis reveals that when the system reaches the critical state, it takes two forms, with two critical speeds, and thus two expressions for the critical speed are obtained. The conditions of the existence of the critical speed were determined, and the effects of the control parameters and the lift coefficient on the critical speed were analyzed by numerical analysis. The results show that the first critical speed appears when the aerodynamic force is upward, and the second critical speed appears when the aerodynamic force is downward. Moreover, both critical speeds decrease with the increase of the lift coefficient.

Dynamic Speed Adaptation for Path Tracking Based on Curvature Information and Speed Limits.

Science.gov (United States)

Gámez Serna, Citlalli; Ruichek, Yassine

2017-06-14

A critical concern of autonomous vehicles is safety. Different approaches have tried to enhance driving safety to reduce the number of fatal crashes and severe injuries. As an example, Intelligent Speed Adaptation (ISA) systems warn the driver when the vehicle exceeds the recommended speed limit. However, these systems only take into account fixed speed limits without considering factors like road geometry. In this paper, we consider road curvature with speed limits to automatically adjust vehicle's speed with the ideal one through our proposed Dynamic Speed Adaptation (DSA) method. Furthermore, 'curve analysis extraction' and 'speed limits database creation' are also part of our contribution. An algorithm that analyzes GPS information off-line identifies high curvature segments and estimates the speed for each curve. The speed limit database contains information about the different speed limit zones for each traveled path. Our DSA senses speed limits and curves of the road using GPS information and ensures smooth speed transitions between current and ideal speeds. Through experimental simulations with different control algorithms on real and simulated datasets, we prove that our method is able to significantly reduce lateral errors on sharp curves, to respect speed limits and consequently increase safety and comfort for the passenger.

Influence of Vehicle Speed on the Characteristics of Driver's Eye Movement at a Highway Tunnel Entrance during Day and Night Conditions: A Pilot Study.

Science.gov (United States)

Qin, Li; Dong, Li-Li; Xu, Wen-Hai; Zhang, Li-Dong; Leon, Arturo S

2018-04-02

The aim of this study was to investigate how vehicle speed influences the characteristics of driver's eye movement at highway tunnel entrances during day and night. In this study, six drivers' eye movement data (from 200 m before tunnel entrance to 200 m inside tunnel entrance) under five predetermined vehicle speeds (40, 50, 60, 70 and 80 km/h) in the daytime and three predetermined vehicle speeds (40, 60 and 80 km/h) in the nighttime were recorded using the non-intrusive Dikablis Professional eye-tracking system. Pupil size, the average fixation duration time and the average number of fixation were analyzed and then the influence of the vehicle speed on these parameters was evaluated by means of IBM SPSS Statistics 20.0. The results for pupil size in daytime increased when approaching the tunnel entrance, while as for nighttime, pupil size decreased when approaching the tunnel entrance and then increased after entering the tunnel. The pupil size in daytime has a significant negative correlation with vehicle speed, while the pupil size in nighttime did not show a significant association with vehicle speed. Furthermore, the average fixation duration in daytime increased when entering the tunnel, and had a significant negative correlation with vehicle speed. Also, the average number of fixations in daytime decreased when entering the tunnel and has a significant negative correlation with vehicle speed. However, the average fixation duration and the average number of fixations in nighttime did not show any significant association with vehicle speed. Moreover, limitations and future directions of the study are discussed for the further investigation.

Analysis of Electromagnetics Forces on Magnetically Suspended High-Speed Trains

Directory of Open Access Journals (Sweden)

Daniel Mayer

2004-01-01

Full Text Available High-speed superexpresses (HSST developed by Japanese airlines (JAL are based on the electrodynamics principle of magnetic suspension. The track contains short-circuited coils and interaction between them and superconductive coils in the vehicle produces its suspension. The paper includes a mathematical model for traction electrodynamics suspension device HSST represented by a system of linear differential equations with coefficients varying in time. Numerical analysis of this model fields the velocity-dependent lift and drag forces acting on the system. The time distribution of the lift force exhibits certain oscillations that may be suppressed by suitable placement of several superconductive levitation wings in the vehicle. The results obtained are in a good agreement with the knowledge found by various authors on prototype vehicles.

Research on Correlation between Vehicle Cycle and Engine Cycle in Heavy-duty commercial vehicle

Science.gov (United States)

lin, Chen; Zhong, Wang; Shuai, Liu

2017-12-01

In order to study the correlation between vehicle cycle and engine cycle in heavy commercial vehicles, the conversion model of vehicle cycle to engine cycle is constructed based on the vehicle power system theory and shift strategy, which considers the verification on diesel truck. The results show that the model has high rationality and reliability in engine operation. In the acceleration process of high speed, the difference of model gear selection leads to the actual deviation. Compared with the drum test, the engine speed distribution obtained by the model deviates to right, which fits to the lower grade. The grade selection has high influence on the model.

Vehicle Speed Determination in Case of Road Accident by Software Method and Comparing of Results with the Mathematical Model

OpenAIRE

Hoxha Gezim; Shala Ahmet; Likaj Rame

2017-01-01

The paper addresses the problem to vehicle speed calculation at road accidents. To determine the speed are used the PC Crash software and Virtual Crash. With both methods are analysed concrete cases of road accidents. Calculation methods and comparing results are present for analyse. These methods consider several factors such are: the front part of the vehicle, the technical feature of the vehicle, car angle, remote relocation after the crash, road conditions etc. Expected results with PC Cr...

Reliability analysis of high-speed tracked vehicles in the polish army

Directory of Open Access Journals (Sweden)

Kończak Jarosław

2017-06-01

Full Text Available The Polish Armed Forces use tracked vehicles that serve as a core element of the ground combat forces. These vehicles are capable of fighting in all kinds of terrain conditions, in any season of the year. Combat missions are often fought in areas where even no dirt roads are available. The present paper assesses the reliability of tracked vehicles in the context of their irregular operation, as well as service- and maintenance-related vulnerability.

Sleep-related vehicle crashes on low speed roads.

Science.gov (United States)

Filtness, A J; Armstrong, K A; Watson, A; Smith, S S

2017-02-01

Very little is known about the characteristics of sleep related (SR) crashes occurring on low speed roads compared with current understanding of the role of sleep in crashes occurring on high speed roads e.g. motorways. To address this gap, analyses were undertaken to identify the differences and similarities between (1) SR crashes occurring on roads with low (≤60km/h) and high (≥100km/h) speed limits, and (2) SR crashes and not-SR crashes occurring on roads with low speed limits. Police reports of all crashes occurring on low and high speed roads over a ten year period between 2000 and 2009 were examined for Queensland, Australia. Attending police officers identified all crash attributes, including 'fatigue/fell asleep', which indicates that the police believe the crash to have a causal factor relating to falling asleep, sleepiness due to sleep loss, time of day, or fatigue. Driver or rider involvement in crashes was classified as SR or not-SR. All crash-associated variables were compared using Chi-square tests (Cramer's V=effect size). A series of logistic regression was performed, with driver and crash characteristics as predictors of crash category. A conservative alpha level of 0.001 determined statistical significance. There were 440,855 drivers or riders involved in a crash during this time; 6923 (1.6%) were attributed as SR. SR crashes on low speed roads have similar characteristics to those on high speed roads with young (16-24y) males consistently over represented. SR crashes on low speed roads are noticeably different to not-SR crashes in the same speed zone in that male and young novice drivers are over represented and outcomes are more severe. Of all the SR crashes identified, 41% occurred on low speed roads. SR crashes are not confined to high speed roads. Low speed SR crashes warrant specific investigation because they occur in densely populated areas, exposing a greater number of people to risk and have more severe outcomes than not-SR crashes

High speed atom source

International Nuclear Information System (INIS)

Hoshino, Hitoshi.

1990-01-01

In a high speed atom source, since the speed is not identical between ions and electrons, no sufficient neutralizing effect for ionic rays due to the mixing of the ionic rays and the electron rays can be obtained failing to obtain high speed atomic rays at high density. In view of the above, a speed control means is disposed for equalizing the speed of ions forming ionic rays and the speed of electrons forming electron rays. Further, incident angle of the electron rays and/or ionic rays to a magnet or an electrode is made variable. As a result, the relative speed between the ions and the electrons to the processing direction is reduced to zero, in which the probability of association between the ions and the electrons due to the coulomb force is increased to improve the neutralizing efficiency to easily obtain fine and high density high speed electron rays. Further, by varying the incident angle, a track capable of obtaining an ideal mixing depending on the energy of the neutralized ionic rays is formed. Since the high speed electron rays has such high density, they can be irradiated easily to the minute region of the specimen. (N.H.)

Energetic optimization of regenerative braking for high speed railway systems

International Nuclear Information System (INIS)

Frilli, Amedeo; Meli, Enrico; Nocciolini, Daniele; Pugi, Luca; Rindi, Andrea

2016-01-01

Highlights: • A model of longitudinal dynamics of the High-speed train ETR1000 is presented. • The model includes on board traction and braking subsystems. • Interactions between overhead line and power line are modelled. • The model is validated on real experimental data. • An energy storage strategy for a high-speed line is proposed. - Abstract: The current development trend in the railway field has led to an ever increasing interest for the energetic optimization of railway systems (especially considering the braking phases), with a strong attention to the mutual interactions between the loads represented by railway vehicles and the electrical infrastructure, including all the sub-systems related to distribution and smart energy management such as energy storage systems. In this research work, the authors developed an innovative coupled modelling approach suitable for the analysis of the energetic optimization of railway systems and based on the use of the new object oriented language Matlab-Simscape™, which presents several advantages with respect to conventional modelling tools. The proposed model has been validated considering an Italian Direct Current High-speed line and the High-speed train ETR 1000. Furthermore, the model has been used to perform an efficiency analysis, considering the use of energy storage devices. The results obtained with the developed model show that the use of energy recovery systems in high-speed railway can provide great opportunities of energy savings.

Instability of a vehicle moving on an elastic structure

NARCIS (Netherlands)

Veritchev, S.N.

2002-01-01

Vibrations of a vehicle that moves on a long elastic structure can become unstable because of elastic waves that the vehicle generates in the structure. A typical example of the vehicle that can experience such instability is a high-speed train. Moving with a sufficiently high speed, this train

Vehicle Speed Determination in Case of Road Accident by Software Method and Comparing of Results with the Mathematical Model

Directory of Open Access Journals (Sweden)

Hoxha Gezim

2017-11-01

Full Text Available The paper addresses the problem to vehicle speed calculation at road accidents. To determine the speed are used the PC Crash software and Virtual Crash. With both methods are analysed concrete cases of road accidents. Calculation methods and comparing results are present for analyse. These methods consider several factors such are: the front part of the vehicle, the technical feature of the vehicle, car angle, remote relocation after the crash, road conditions etc. Expected results with PC Crash software and Virtual Crash are shown in tabular graphics and compared in mathematical methods.

Cooperative Intelligence in Roundabout Intersections Using Hierarchical Fuzzy Behavior Calculation of Vehicle Speed Profile

Directory of Open Access Journals (Sweden)

Bosankić Ivan

2016-01-01

Full Text Available In this paper, a new fuzzy-behavior-based algorithm for roundabout intersection management is presented. The algorithm employs cooperative intelligence and includes intelligent vehicles and infrastructure to calculate speed profiles for different vehicles, in order to achieve more comfortable driving profiles, as well to reduce congestion and CO2 emissions. The algorithm uses adaptive spatio-temporal reservation technique and was tested in MATLAB/Simulink environment. The algorithm is designed to function in different scenarios with both cooperative and non-cooperative vehicles, as well as optional intersection infrastructure. Results have show that using the proposed algorithm different vehicle communication types can be successfully combined in order to increase traffic flow through roundabout intersections.

High-speed rail with emerging automobiles and aircraft can reduce environmental impacts in California’s future

International Nuclear Information System (INIS)

Chester, Mikhail; Horvath, Arpad

2012-01-01

Sustainable mobility policy for long-distance transportation services should consider emerging automobiles and aircraft as well as infrastructure and supply chain life-cycle effects in the assessment of new high-speed rail systems. Using the California corridor, future automobiles, high-speed rail and aircraft long-distance travel are evaluated, considering emerging fuel-efficient vehicles, new train designs and the possibility that the region will meet renewable electricity goals. An attributional per passenger-kilometer-traveled life-cycle inventory is first developed including vehicle, infrastructure and energy production components. A consequential life-cycle impact assessment is then established to evaluate existing infrastructure expansion against the construction of a new high-speed rail system. The results show that when using the life-cycle assessment framework, greenhouse gas footprints increase significantly and human health and environmental damage potentials may be dominated by indirect and supply chain components. The environmental payback is most sensitive to the number of automobile trips shifted to high-speed rail, and for greenhouse gases is likely to occur in 20–30 years. A high-speed rail system that is deployed with state-of-the-art trains, electricity that has met renewable goals, and in a configuration that endorses high ridership will provide significant environmental benefits over existing modes. Opportunities exist for reducing the long-distance transportation footprint by incentivizing large automobile trip shifts, meeting clean electricity goals and reducing material production effects. (letter)

Estimation of Road Vehicle Speed Using Two Omnidirectional Microphones: A Maximum Likelihood Approach

Directory of Open Access Journals (Sweden)

López-Valcarce Roberto

2004-01-01

Full Text Available We address the problem of estimating the speed of a road vehicle from its acoustic signature, recorded by a pair of omnidirectional microphones located next to the road. This choice of sensors is motivated by their nonintrusive nature as well as low installation and maintenance costs. A novel estimation technique is proposed, which is based on the maximum likelihood principle. It directly estimates car speed without any assumptions on the acoustic signal emitted by the vehicle. This has the advantages of bypassing troublesome intermediate delay estimation steps as well as eliminating the need for an accurate yet general enough acoustic traffic model. An analysis of the estimate for narrowband and broadband sources is provided and verified with computer simulations. The estimation algorithm uses a bank of modified crosscorrelators and therefore it is well suited to DSP implementation, performing well with preliminary field data.

Robust/optimal temperature profile control of a high-speed aerospace vehicle using neural networks.

Science.gov (United States)

Yadav, Vivek; Padhi, Radhakant; Balakrishnan, S N

2007-07-01

An approximate dynamic programming (ADP)-based suboptimal neurocontroller to obtain desired temperature for a high-speed aerospace vehicle is synthesized in this paper. A 1-D distributed parameter model of a fin is developed from basic thermal physics principles. "Snapshot" solutions of the dynamics are generated with a simple dynamic inversion-based feedback controller. Empirical basis functions are designed using the "proper orthogonal decomposition" (POD) technique and the snapshot solutions. A low-order nonlinear lumped parameter system to characterize the infinite dimensional system is obtained by carrying out a Galerkin projection. An ADP-based neurocontroller with a dual heuristic programming (DHP) formulation is obtained with a single-network-adaptive-critic (SNAC) controller for this approximate nonlinear model. Actual control in the original domain is calculated with the same POD basis functions through a reverse mapping. Further contribution of this paper includes development of an online robust neurocontroller to account for unmodeled dynamics and parametric uncertainties inherent in such a complex dynamic system. A neural network (NN) weight update rule that guarantees boundedness of the weights and relaxes the need for persistence of excitation (PE) condition is presented. Simulation studies show that in a fairly extensive but compact domain, any desired temperature profile can be achieved starting from any initial temperature profile. Therefore, the ADP and NN-based controllers appear to have the potential to become controller synthesis tools for nonlinear distributed parameter systems.

Effects of automated speed enforcement in Montgomery County, Maryland, on vehicle speeds, public opinion, and crashes.

Science.gov (United States)

Hu, Wen; McCartt, Anne T

2016-09-01

In May 2007, Montgomery County, Maryland, implemented an automated speed enforcement program, with cameras allowed on residential streets with speed limits of 35 mph or lower and in school zones. In 2009, the state speed camera law increased the enforcement threshold from 11 to 12 mph over the speed limit and restricted school zone enforcement hours. In 2012, the county began using a corridor approach, in which cameras were periodically moved along the length of a roadway segment. The long-term effects of the speed camera program on travel speeds, public attitudes, and crashes were evaluated. Changes in travel speeds at camera sites from 6 months before the program began to 7½ years after were compared with changes in speeds at control sites in the nearby Virginia counties of Fairfax and Arlington. A telephone survey of Montgomery County drivers was conducted in Fall 2014 to examine attitudes and experiences related to automated speed enforcement. Using data on crashes during 2004-2013, logistic regression models examined the program's effects on the likelihood that a crash involved an incapacitating or fatal injury on camera-eligible roads and on potential spillover roads in Montgomery County, using crashes in Fairfax County on similar roads as controls. About 7½ years after the program began, speed cameras were associated with a 10% reduction in mean speeds and a 62% reduction in the likelihood that a vehicle was traveling more than 10 mph above the speed limit at camera sites. When interviewed in Fall 2014, 95% of drivers were aware of the camera program, 62% favored it, and most had received a camera ticket or knew someone else who had. The overall effect of the camera program in its modified form, including both the law change and the corridor approach, was a 39% reduction in the likelihood that a crash resulted in an incapacitating or fatal injury. Speed cameras alone were associated with a 19% reduction in the likelihood that a crash resulted in an

Complete de-Dopplerization and acoustic holography for external noise of a high-speed train.

Science.gov (United States)

Yang, Diange; Wen, Junjie; Miao, Feng; Wang, Ziteng; Gu, Xiaoan; Lian, Xiaomin

2016-09-01

Identification and measurement of moving sound sources are the bases for vehicle noise control. Acoustic holography has been applied in successfully identifying the moving sound source since the 1990s. However, due to the high demand for the accuracy of holographic data, currently the maximum velocity achieved by acoustic holography is just above 100 km/h. The objective of this study was to establish a method based on the complete Morse acoustic model to restore the measured signal in high-speed situations, and to propose a far-field acoustic holography method applicable for high-speed moving sound sources. Simulated comparisons of the proposed far-field acoustic holography with complete Morse model, the acoustic holography with simplified Morse model and traditional delay-and-sum beamforming were conducted. Experiments with a high-speed train running at the speed of 278 km/h validated the proposed far-field acoustic holography. This study extended the applications of acoustic holography to high-speed situations and established the basis for quantitative measurements of far-field acoustic holography.

Parameter design and performance analysis of shift actuator for a two-speed automatic mechanical transmission for pure electric vehicles

Directory of Open Access Journals (Sweden)

Jianjun Hu

2016-08-01

Full Text Available Recent developments of pure electric vehicles have shown that pure electric vehicles equipped with two-speed or multi-speed gearbox possess higher energy efficiency by ensuring the drive motor operates at its peak performance range. This article presents the design, analysis, and control of a two-speed automatic mechanical transmission for pure electric vehicles. The shift actuator is based on a motor-controlled camshaft where a special geometric groove is machined, and the camshaft realizes the axial positions of the synchronizer sleeve for gear engaging, disengaging, and speed control of the drive motor. Based on the force analysis of shift process, the parameters of shift actuator and shift motor are designed. The drive motor’s torque control strategy before shifting, speed governing control strategy before engaging, shift actuator’s control strategy during gear engaging, and drive motor’s torque recovery strategy after shift process are proposed and implemented with a prototype. To validate the performance of the two-speed gearbox, a test bed was developed based on dSPACE that emulates various operation conditions. The experimental results indicate that the shift process with the proposed shift actuator and control strategy could be accomplished within 1 s under various operation conditions, with shift smoothness up to passenger car standard.

Effects of major-road vehicle speed and driver age and gender on left-turn gap acceptance.

Science.gov (United States)

Yan, Xuedong; Radwan, Essam; Guo, Dahai

2007-07-01

Because the driver's gap-acceptance maneuver is a complex and risky driving behavior, it is a highly concerned topic for traffic safety and operation. Previous studies have mainly focused on the driver's gap acceptance decision itself but did not pay attention to the maneuver process and driving behaviors. Using a driving simulator experiment for left-turn gap acceptance at a stop-controlled intersection, this study evaluated the effects of major traffic speed and driver age and gender on gap acceptance behaviors. The experiment results illustrate relationships among drivers' left-turn gap decision, driver's acceleration rate, steering action, and the influence of the gap-acceptance maneuver on the vehicles in the major traffic stream. The experiment results identified an association between high crash risk and high traffic speed at stop-controlled intersections. The older drivers, especially older female drivers, displayed a conservative driving attitude as a compensation for reduced driving ability, but also showed to be the most vulnerable group for the relatively complex driving maneuvers.

Numerical analysis of flow induced noise propagation in supercavitating vehicles at subsonic speeds.

Science.gov (United States)

Ramesh, Sai Sudha; Lim, Kian Meng; Zheng, Jianguo; Khoo, Boo Cheong

2014-04-01

Flow supercavitation begins when fluid is accelerated over a sharp edge, usually at the nose of an underwater vehicle, where phase change occurs and causes low density gaseous cavity to gradually envelop the whole object (supercavity) and thereby enabling higher speeds of underwater vehicles. The process of supercavity inception/development by means of "natural cavitation" and its sustainment through ventilated cavitation result in turbulence and fluctuations at the water-vapor interface that manifest themselves as major sources of hydrodynamic noise. Therefore in the present context, three main sources are investigated, namely, (1) flow generated noise due to turbulent pressure fluctuations around the supercavity, (2) small scale pressure fluctuations at the vapor-water interface, and (3) pressure fluctuations due to direct impingement of ventilated gas-jets on the supercavity wall. An understanding of their relative contributions toward self-noise is very crucial for the efficient operation of high frequency acoustic sensors that facilitate the vehicle's guidance system. Qualitative comparisons of acoustic pressure distribution resulting from aforementioned sound sources are presented by employing a recently developed boundary integral method. By using flow data from a specially developed unsteady computational fluid dynamics solver for simulating supercavitating flows, the boundary-element method based acoustic solver was developed for computing flow generated sound.

Validation of temporal and spatial consistency of facility- and speed-specific vehicle-specific power distributions for emission estimation: A case study in Beijing, China.

Science.gov (United States)

Zhai, Zhiqiang; Song, Guohua; Lu, Hongyu; He, Weinan; Yu, Lei

2017-09-01

Vehicle-specific power (VSP) has been found to be highly correlated with vehicle emissions. It is used in many studies on emission modeling such as the MOVES (Motor Vehicle Emissions Simulator) model. The existing studies develop specific VSP distributions (or OpMode distribution in MOVES) for different road types and various average speeds to represent the vehicle operating modes on road. However, it is still not clear if the facility- and speed-specific VSP distributions are consistent temporally and spatially. For instance, is it necessary to update periodically the database of the VSP distributions in the emission model? Are the VSP distributions developed in the city central business district (CBD) area applicable to its suburb area? In this context, this study examined the temporal and spatial consistency of the facility- and speed-specific VSP distributions in Beijing. The VSP distributions in different years and in different areas are developed, based on real-world vehicle activity data. The root mean square error (RMSE) is employed to quantify the difference between the VSP distributions. The maximum differences of the VSP distributions between different years and between different areas are approximately 20% of that between different road types. The analysis of the carbon dioxide (CO 2 ) emission factor indicates that the temporal and spatial differences of the VSP distributions have no significant impact on vehicle emission estimation, with relative error of less than 3%. The temporal and spatial differences have no significant impact on the development of the facility- and speed-specific VSP distributions for the vehicle emission estimation. The database of the specific VSP distributions in the VSP-based emission models can maintain in terms of time. Thus, it is unnecessary to update the database regularly, and it is reliable to use the history vehicle activity data to forecast the emissions in the future. In one city, the areas with less data can still

Tyre influences on untripped vehicle rollover

NARCIS (Netherlands)

Jansen, S.T.H.; Lupker, H.A.; Koppenaal, C.J.P.

2002-01-01

Vehicle rollover can be initiated by steering actions that occur at vehicle evasive manoeuvres or high speed cornering of commercial vehicles. This untripped vehicle rollover is more difficult to reproduce for passenger cars then for commercial vehicles. For passenger cars it occurs closer to the

Effect Of Platooning on Fuel Consumption of Class 8 Vehicles Over a Range of Speeds, Following Distances, and Mass

Energy Technology Data Exchange (ETDEWEB)

Lammert, M. P.; Duran, A.; Diez, J.; Burton, K.; Nicholson, A.

2014-10-01

This research project evaluates fuel consumption results of two Class 8 tractor-trailer combinations platooned together compared to their standalone fuel consumption. A series of ten modified SAE Type II J1321 fuel consumption track tests were performed to document fuel consumption of two platooned vehicles and a control vehicle at varying steady-state speeds, following distances, and gross vehicle weights (GVWs). The steady-state speeds ranged from 55 mph to 70 mph, the following distances ranged from a 20-ft following distance to a 75-ft following distance, and the GVWs were 65K lbs and 80K lbs. All tractors involved had U.S. Environmental Protection Agency (EPA) SmartWay-compliant aerodynamics packages installed, and the trailers were equipped with side skirts. Effects of vehicle speed, following distance, and GVW on fuel consumption were observed and analyzed. The platooning demonstration system used in this study consisted of radar systems, Dedicated Short-Range Communication (DSRC) vehicle-to-vehicle (V2V) communications, vehicle braking and torque control interface, cameras and driver displays. The lead tractor consistently demonstrated an improvement in average fuel consumption reduction as following distance decreased, with results showing 2.7% to 5.3% fuel savings at a GVW of 65k. The trailing vehicle achieved fuel consumption savings ranging from 2.8% to 9.7%; tests during which the engine cooling fan did not operate achieved savings of 8.4% to 9.7%. 'Team' fuel savings, considering the platooned vehicles as one, ranged from 3.7% to 6.4%, with the best combined result being for 55 mph, 30-ft following distance, and 65k GVW.

Heel and toe driving on fuel cell vehicle

Science.gov (United States)

Choi, Tayoung; Chen, Dongmei

2012-12-11

A system and method for providing nearly instantaneous power in a fuel cell vehicle. The method includes monitoring the brake pedal angle and the accelerator pedal angle of the vehicle, and if the vehicle driver is pressing both the brake pedal and the accelerator pedal at the same time and the vehicle is in a drive gear, activating a heel and toe mode. When the heel and toe mode is activated, the speed of a cathode compressor is increased to a predetermined speed set-point, which is higher than the normal compressor speed for the pedal position. Thus, when the vehicle brake is removed, the compressor speed is high enough to provide enough air to the cathode, so that the stack can generate nearly immediate power.

Advancement and Application of Multi-Phase CFD Modeling to High Speed Supercavitating Flows

Science.gov (United States)

2013-08-13

October 2008 - December 2013 4. TITLE AND SUBTITLE Advancement and Application of Multi-Phase CFD Modeling to High Speed Supercavitating Flows...influence cavity hysteresis behavior. These observations are used to guide improved supercavitating -vehicle analyses including numerical predictions...experiments, and modeling 15. SUBJECT TERMS supercavitation , computational fluid dynamics, multiphase flow 16. SECURITY CLASSIFICATION OF: a

Supercavitating Vehicle Control

Science.gov (United States)

2008-10-10

401) 832-1511. DISTRIBUTION STATEMENT Approved for Public Release Distribution is unlimited 20081027289 Attorney Docket No. 96674 SUPERCAVITATING ...methods and more specifically to systems and methods for controlling a trajectory of a supercavitating vehicle. (2) Description of the Prior Art [0004...1 [0005) Some investigations into reducing the drag of high-speed, underwater vehicles have focused attention on supercavitating underwater vehicles

South African performance based standards (PBS) vehicle to transport steel pipes

CSIR Research Space (South Africa)

Dessein, T

2010-03-01

Full Text Available measures the vehicle?s rollover stability. Rearward Amplification (RA) ? Measures the degree to which the lateral accelerations experienced by trailing units are amplified in comparison to that of the towing unit in a high speed evasive single lane...-speed 90? turn high-speed travel along a 1.0km long straight road with uneven road surface a pulse-steer test HVTT11: A South African PBS Vehicle to Transport Pipes 10 a constant radius turn at slowly increasing speed an evasive lane change...

Nonlinear Adaptive Rotational Speed Control Design and Experiment of the Propeller of an Electric Micro Air Vehicle

Directory of Open Access Journals (Sweden)

Shouzhao Sheng

2016-01-01

Full Text Available Micro Air Vehicles (MAVs driven by electric propellers are of interest for military and civilian applications. The rotational speed control of such electric propellers is an important factor for improving the flight performance of the vehicles, such as their positioning accuracy and stability. Therefore, this paper presents a nonlinear adaptive control scheme for the electric propulsion system of a certain MAV, which can not only speed up the convergence rates of adjustable parameters, but can also ensure the overall stability of the adjustable parameters. The significant improvement of the dynamic tracking accuracy of the rotational speed can be easily achieved through the combination of the proposed control algorithm and linear control methods. The experimental test results have also demonstrated the positive effect of the nonlinear adaptive control scheme on the flight performance of the MAV.

Speed support through the intelligent vehicle : perspective, estimated effects and implementation aspects.[Deliverable of the Intelligent Vehicles project, part of the Traffic Management project within TRANSUMO (TRANsition to SUstainable MObility).

NARCIS (Netherlands)

Morsink, P. Goldenbeld, C. Dragutinovic, N. Marchau, V. Walta, L. & Brookhuis, K.

2008-01-01

Speed management is a central theme in traffic management, aiming to optimize traffic in terms of safety, efficiency and the environment, by reducing speeding and speed differences in traffic. Intelligent vehicles can perform tasks that conventional measures cannot do at all, or do less efficiently.

Speed, speed variation and crash relationships for urban arterials.

Science.gov (United States)

Wang, Xuesong; Zhou, Qingya; Quddus, Mohammed; Fan, Tianxiang; Fang, Shou'en

2018-04-01

Speed and speed variation are closely associated with traffic safety. There is, however, a dearth of research on this subject for the case of urban arterials in general, and in the context of developing nations. In downtown Shanghai, the traffic conditions in each direction are very different by time of day, and speed characteristics during peak hours are also greatly different from those during off-peak hours. Considering that traffic demand changes with time and in different directions, arterials in this study were divided into one-way segments by the direction of flow, and time of day was differentiated and controlled for. In terms of data collection, traditional fixed-based methods have been widely used in previous studies, but they fail to capture the spatio-temporal distributions of speed along a road. A new approach is introduced to estimate speed variation by integrating spatio-temporal speed fluctuation of a single vehicle with speed differences between vehicles using taxi-based high frequency GPS data. With this approach, this paper aims to comprehensively establish a relationship between mean speed, speed variation and traffic crashes for the purpose of formulating effective speed management measures, specifically using an urban dataset. From a total of 234 one-way road segments from eight arterials in Shanghai, mean speed, speed variation, geometric design features, traffic volume, and crash data were collected. Because the safety effects of mean speed and speed variation may vary at different segment lengths, arterials with similar signal spacing density were grouped together. To account for potential correlations among these segments, a hierarchical Poisson log-normal model with random effects was developed. Results show that a 1% increase in mean speed on urban arterials was associated with a 0.7% increase in total crashes, and larger speed variation was also associated with increased crash frequency. Copyright © 2018 Elsevier Ltd. All rights

Vehicle speed prediction via a sliding-window time series analysis and an evolutionary least learning machine: A case study on San Francisco urban roads

Directory of Open Access Journals (Sweden)

Ladan Mozaffari

2015-06-01

Full Text Available The main goal of the current study is to take advantage of advanced numerical and intelligent tools to predict the speed of a vehicle using time series. It is clear that the uncertainty caused by temporal behavior of the driver as well as various external disturbances on the road will affect the vehicle speed, and thus, the vehicle power demands. The prediction of upcoming power demands can be employed by the vehicle powertrain control systems to improve significantly the fuel economy and emission performance. Therefore, it is important to systems design engineers and automotive industrialists to develop efficient numerical tools to overcome the risk of unpredictability associated with the vehicle speed profile on roads. In this study, the authors propose an intelligent tool called evolutionary least learning machine (E-LLM to forecast the vehicle speed sequence. To have a practical evaluation regarding the efficacy of E-LLM, the authors use the driving data collected on the San Francisco urban roads by a private Honda Insight vehicle. The concept of sliding window time series (SWTS analysis is used to prepare the database for the speed forecasting process. To evaluate the performance of the proposed technique, a number of well-known approaches, such as auto regressive (AR method, back-propagation neural network (BPNN, evolutionary extreme learning machine (E-ELM, extreme learning machine (ELM, and radial basis function neural network (RBFNN, are considered. The performances of the rival methods are then compared in terms of the mean square error (MSE, root mean square error (RMSE, mean absolute percentage error (MAPE, median absolute percentage error (MDAPE, and absolute fraction of variances (R2 metrics. Through an exhaustive comparative study, the authors observed that E-LLM is a powerful tool for predicting the vehicle speed profiles. The outcomes of the current study can be of use for the engineers of automotive industry who have been

Electronic differential control of 2WD electric vehicle considering steering stability

Science.gov (United States)

Hua, Yiding; Jiang, Haobin; Geng, Guoqing

2017-03-01

Aiming at the steering wheel differential steering control technology of rear wheel independent driving electric wheel, considering the assisting effect of electronic differential control on vehicle steering, based on the high speed steering characteristic of electric wheel car, the electronic differential speed of auxiliary wheel steering is also studied. A yaw moment control strategy is applied to the vehicle at high speed. Based on the vehicle stability reference value, yaw rate is used to design the fuzzy controller to distribute the driving wheel torque. The simulation results show that the basic electronic differential speed function is realized based on the yaw moment control strategy, while the vehicle stability control is improved and the driving safety is enhanced. On the other hand, the torque control strategy can also assist steering of vehicle.

Modeling pedestrian crossing speed profiles considering speed change behavior for the safety assessment of signalized intersections.

Science.gov (United States)

Iryo-Asano, Miho; Alhajyaseen, Wael K M

2017-11-01

Pedestrian safety is one of the most challenging issues in road networks. Understanding how pedestrians maneuver across an intersection is the key to applying countermeasures against traffic crashes. It is known that the behaviors of pedestrians at signalized crosswalks are significantly different from those in ordinary walking spaces, and they are highly influenced by signal indication, potential conflicts with vehicles, and intersection geometries. One of the most important characteristics of pedestrian behavior at crosswalks is the possible sudden speed change while crossing. Such sudden behavioral change may not be expected by conflicting vehicles, which may lead to hazardous situations. This study aims to quantitatively model the sudden speed changes of pedestrians as they cross signalized crosswalks under uncongested conditions. Pedestrian speed profiles are collected from empirical data and speed change events are extracted assuming that the speed profiles are stepwise functions. The occurrence of speed change events is described by a discrete choice model as a function of the necessary walking speed to complete crossing before the red interval ends, current speed, and the presence of turning vehicles in the conflict area. The amount of speed change before and after the event is modeled using regression analysis. A Monte Carlo simulation is applied for the entire speed profile of the pedestrians. The results show that the model can represent the pedestrian travel time distribution more accurately than the constant speed model. Copyright © 2017 Elsevier Ltd. All rights reserved.

Future Vehicle Technologies : high performance transportation innovations

Energy Technology Data Exchange (ETDEWEB)

Pratt, T. [Future Vehicle Technologies Inc., Maple Ridge, BC (Canada)

2010-07-01

Battery management systems (BMS) were discussed in this presentation, with particular reference to the basic BMS design considerations; safety; undisclosed information about BMS; the essence of BMS; and Future Vehicle Technologies' BMS solution. Basic BMS design considerations that were presented included the balancing methodology; prismatic/cylindrical cells; cell protection; accuracy; PCB design, size and components; communications protocol; cost of manufacture; and expandability. In terms of safety, the presentation addressed lithium fires; high voltage; high voltage ground detection; crash/rollover shutdown; complete pack shutdown capability; and heat shields, casings, and impact protection. BMS bus bar engineering considerations were discussed along with good chip design. It was concluded that FVTs advantage is a unique skillset in automotive technology and the development of speed and cost effectiveness. tabs., figs.

Effect of In-Vehicle Audio Warning System on Driver’s Speed Control Performance in Transition Zones from Rural Areas to Urban Areas

Directory of Open Access Journals (Sweden)

Xuedong Yan

2016-06-01

Full Text Available Speeding is a major contributing factor to traffic crashes and frequently happens in areas where there is a mutation in speed limits, such as the transition zones that connect urban areas from rural areas. The purpose of this study is to investigate the effects of an in-vehicle audio warning system and lit speed limit sign on preventing drivers’ speeding behavior in transition zones. A high-fidelity driving simulator was used to establish a roadway network with the transition zone. A total of 41 participants were recruited for this experiment, and the driving speed performance data were collected from the simulator. The experimental results display that the implementation of the audio warning system could significantly reduce drivers’ operating speed before they entered the urban area, while the lit speed limit sign had a minimal effect on improving the drivers’ speed control performance. Without consideration of different types of speed limit signs, it is found that male drivers generally had a higher operating speed both upstream and in the transition zones and have a larger maximum deceleration for speed reduction than female drivers. Moreover, the drivers who had medium-level driving experience had the higher operating speed and were more likely to have speeding behaviors in the transition zones than those who had low-level and high-level driving experience in the transition zones.

A Minimization of Speed Ripple of Sensorless DTC for controlled Induction Motors used in Electric Vehicles

OpenAIRE

Khoucha , Farid; Marouani , Khoudir; Kheloui , Abdelaziz; Benbouzid , Mohamed

2006-01-01

International audience; The main theme of this paper is to present different switching techniques in DTC induction motor drives for electric vehicle applications, witch insert zero-voltage vector and/or more non zero-voltage vectors to the conventional switching table associated to full adaptive flux and speed observer. Those techniques are quite effective in reducing the torque pulsation and the speed ripples of the motors, as demonstrated in experimental results.

Dynamic model tracking design for low inertia, high speed permanent magnet ac motors.

Science.gov (United States)

Stewart, P; Kadirkamanathan, V

2004-01-01

Permanent magnet ac (PMAC) motors have existed in various configurations for many years. The advent of rare-earth magnets and their associated highly elevated levels of magnetic flux makes the permanent magnet motor attractive for many high performance applications from computer disk drives to all electric racing cars. The use of batteries as a prime storage element carries a cost penalty in terms of the unladen weight of the vehicle. Minimizing this cost function requires the minimum electric motor size and weight to be specified, while still retaining acceptable levels of output torque. This tradeoff can be achieved by applying a technique known as flux weakening which will be investigated in this paper. The technique allows the speed range of a PMAC motor to be greatly increased, giving a constant power range of more than 4:1. A dynamic model reference controller is presented which has advantages in ease of implementation, and is particularly suited to dynamic low inertia applications such as clutchless gear changing in high performance electric vehicles. The benefits of this approach are to maximize the torque speed envelope of the motor, particularly advantageous when considering low inertia operation. The controller is examined experimentally, confirming the predicted performance.

Using endemic road features to create self-explaining roads and reduce vehicle speeds.

Science.gov (United States)

Charlton, Samuel G; Mackie, Hamish W; Baas, Peter H; Hay, Karen; Menezes, Miguel; Dixon, Claire

2010-11-01

This paper describes a project undertaken to establish a self-explaining roads (SER) design programme on existing streets in an urban area. The methodology focussed on developing a process to identify functional road categories and designs based on endemic road characteristics taken from functional exemplars in the study area. The study area was divided into two sections, one to receive SER treatments designed to maximise visual differences between road categories, and a matched control area to remain untreated for purposes of comparison. The SER design for local roads included increased landscaping and community islands to limit forward visibility, and removal of road markings to create a visually distinct road environment. In comparison, roads categorised as collectors received increased delineation, addition of cycle lanes, and improved amenity for pedestrians. Speed data collected 3 months after implementation showed a significant reduction in vehicle speeds on local roads and increased homogeneity of speeds on both local and collector roads. The objective speed data, combined with residents' speed choice ratings, indicated that the project was successful in creating two discriminably different road categories. 2010 Elsevier Ltd. All rights reserved.

Magnetically suspended experimental vehicle-strength of structure and dynamic analysis

Energy Technology Data Exchange (ETDEWEB)

Nagahiro, T; Terada, K; Kasai, Y; Motonaga, M

1973-06-01

To cope with rapid increase in demand for railroad transportation, studies in magnetically suspended high speed trains are being pushed forward at the Japanese National Railways. Recently a special experimental vehiclc was completed which will be used by JNR in experiments concerning magnetic propulsion and suspension of magnetically suspended high speed trains. This test vehicle is provided with reaction plates of linear induction motor under the floor at about the center of the vehicle, with superconducting magnets for suspension on both sides. The vehicle body is made mainly of high tensile strengthened aluminium (duralumin) for weight reduction, but its strength was checked by the vibration analysis and load tests carried out in the suspended condition. Remote-operated from the control tower, this unmanned test vehicle will provide a key to the completion of a super-high speed magnetically suspended train.

Applications of a saving method with max-min ant system to a vehicle routing problem with time windows and speed limits

Directory of Open Access Journals (Sweden)

Suphan Sodsoon

2014-06-01

Full Text Available This study aims to solve a Vehicle Routing Problem with Time Windows and Speed Limits (VRPTWSL, which has received considerable attention in recent years. The vehicle routing problem with time windows is an extension of the well-known Vehicle Routing Problem (VRP and involves a fleet of vehicles set of from a depot to serve a number of customers at different geographic locations with various demands within specific time and speed limits before returning to the depot eventually. To solve the problem, an efficient Saving Method-Max Min Ant System (Saving-MMAS with Local Search algorithm is applied. Using minimization of the total transportation costs as the objective of the extension VRPTWSL, a mathematic model is constructed. Finally, the Saving-MMAS algorithms indicated the good quality of the method in this problem.

Drag reduction of a rapid vehicle in supercavitating flow

Directory of Open Access Journals (Sweden)

D. Yang

2017-01-01

Full Text Available Supercavitation is one of the most attractive technologies to achieve high speed for underwater vehicles. However, the multiphase flow with high-speed around the supercavitating vehicle (SCV is difficult to simulate accurately. In this paper, we use modified the turbulent viscosity formula in the Standard K-Epsilon (SKE turbulent model to simulate the supercavitating flow. The numerical results of flow over several typical cavitators are in agreement with the experimental data and theoretical prediction. In the last part, a flying SCV was studied by unsteady numerical simulation. The selected computation setup corresponds to an outdoor supercavitating experiment. Only very limited experimental data was recorded due to the difficulties under the circumstance of high-speed underwater condition. However, the numerical simulation recovers the whole scenario, the results are qualitatively reasonable by comparing to the experimental observations. The drag reduction capacity of supercavitation is evaluated by comparing with a moving vehicle launching at the same speed but without supercavitation. The results show that the supercavitation reduces the drag of the vehicle dramatically.

Electric Vehicles at Kennedy Space Center

Science.gov (United States)

Chesson, Bruce E.

2007-01-01

The story of how the transportation office began by introducing low speed electric cars (LSEV) to the fleet managers and employees. This sparked and interest in purchasing some of these LSEV and the usage on KSC. Transportation was approached by a vender of High Speed Electric Vehicle (HSEV) we decided to test the HSEV to see if they would meet our fleet vehicle needs. Transportation wrote a Space Act Agreement (SAA) for the loan of three Lithium Powered Electric vehicles for a one year test. The vehicles have worked very well and we have extended the test for another year. The use of HSEV has pushed for an independent Electric Vehicle Study to be performed to consider ways to effectively optimize the use of electric vehicles in replacement of gasoline vehicles in the KSC vehicle fleet. This will help the center to move closer to meeting the Executive Order 13423.

Applications of endothermic research technology to the high speed civil transport

Science.gov (United States)

Glickstein, M. R.; Spadaccini, L. J.

1997-01-01

The success of strategies for controlling emissions and enhancing performance in High Speed Research applications may be increased by more effective utilization of the heat sink afforded by the fuel in the vehicle thermal management system. This study quantifies the potential benefits associated with the use of supercritical preheating and endothermic cracking of jet fuel prior to combustion to enhance the thermal management capabilities of the propulsion systems in the High Speed Civil Transport (HSCT). A fuel-cooled thermal management system, consisting of plate-fin heat exchangers and a small auxiliary compressor, is defined for the HSCT, integrated with the engine, and an assessment of the effect on engine performance, weight, and operating cost is performed. The analysis indicates significant savings due a projected improvement in fuel economy, and the potential for additional benefit if the cycle is modified to take full advantage of all the heat sink available in the fuel.

Influence of long-wavelength track irregularities on the motion of a high-speed train

Science.gov (United States)

Hung, C. F.; Hsu, W. L.

2018-01-01

Vertical track irregularities over viaducts in high-speed rail systems could be possibly caused by concrete creep if pre-stressed concrete bridges are used. For bridge spans that are almost uniformly distributed, track irregularity exhibits a near-regular wave profile that excites car bodies as a high-speed train moves over the bridge system. A long-wavelength irregularity induces low-frequency excitation that may be close to the natural frequencies of the train suspension system, thereby causing significant vibration of the car body. This paper investigates the relationship between the levels of car vibration, bridge vibration, track irregularity, and the train speed. First, this study investigates the vibration levels of a high-speed train and bridge system using 3D finite-element (FE) transient dynamic analysis, before and after adjustment of vertical track irregularities by means of installing shimming plates under rail pads. The analysis models are validated by in situ measurements and on-board measurement. Parametric studies of car body vibration and bridge vibration under three different levels of track irregularity at five train speeds and over two bridge span lengths are conducted using the FE model. Finally, a discontinuous shimming pattern is proposed to avoid vehicle suspension resonance.

Simulation and experimental research on trans-media vehicle water-entry motion characteristics at low speed.

Science.gov (United States)

Yang, Jian; Li, Yongli; Feng, Jinfu; Hu, Junhua; Liu, An

2017-01-01

The motion characteristics of trans-media vehicles during the water-entry process were explored in this study in an effort to obtain the optimal water-entry condition of the vehicle for developing a novel, single control strategy integrating underwater non-control and in-air control. A water-entry dynamics model is established by combining the water-entry motion characteristics of the vehicle in uncontrolled conditions at low speed with time-varying parameters (e.g. buoyancy, added mass). A water-entry experiment is designed to confirm the effectiveness of the established model. After that, by comparing the experimental results with the simulated results, the model is further modified to more accurately reflect water-entry motion. The change laws of the vehicle's attitude and position during the water-entry process are also obtained by analyzing the simulation of the modified model under different velocity, angle, and angle of attack conditions. The results presented here have guiding significance for the future realization of reaching the stable underwater navigation state of the vehicle after water-entry process.

Simulation and experimental research on trans-media vehicle water-entry motion characteristics at low speed.

Directory of Open Access Journals (Sweden)

Jian Yang

Full Text Available The motion characteristics of trans-media vehicles during the water-entry process were explored in this study in an effort to obtain the optimal water-entry condition of the vehicle for developing a novel, single control strategy integrating underwater non-control and in-air control. A water-entry dynamics model is established by combining the water-entry motion characteristics of the vehicle in uncontrolled conditions at low speed with time-varying parameters (e.g. buoyancy, added mass. A water-entry experiment is designed to confirm the effectiveness of the established model. After that, by comparing the experimental results with the simulated results, the model is further modified to more accurately reflect water-entry motion. The change laws of the vehicle's attitude and position during the water-entry process are also obtained by analyzing the simulation of the modified model under different velocity, angle, and angle of attack conditions. The results presented here have guiding significance for the future realization of reaching the stable underwater navigation state of the vehicle after water-entry process.

High-speed AC motors

Energy Technology Data Exchange (ETDEWEB)

Jokinen, T.; Arkkio, A. [Helsinki University of Technology Laboratory of Electromechanics, Otaniemi (Finland)

1997-12-31

The paper deals with various types of highspeed electric motors, and their limiting powers. Standard machines with laminated rotors can be utilised if the speed is moderate. The solid rotor construction makes it possible to reach higher power and speed levels than those of laminated rotors. The development work on high-speed motors done at Helsinki University of Technology is presented, too. (orig.) 12 refs.

Coupled vibration analysis of Maglev vehicle-guideway while standing still or moving at low speeds

Science.gov (United States)

Kim, Ki-Jung; Han, Jong-Boo; Han, Hyung-Suk; Yang, Seok-Jo

2015-04-01

Dynamic instability, that is, resonance, may occur on an electromagnetic suspension-type Maglev that runs over the elevated guideway, particularly at very low speeds, due to the flexibility of the guideway. An analysis of the dynamic interaction between the vehicle and guideway is required at the design stage to investigate such instability, setting slender guideway in design direction for reducing construction costs. In addition, it is essential to design an effective control algorithm to solve the problem of instability. In this article, a more detailed model for the dynamic interaction of vehicle/guideway is proposed. The proposed model incorporates a 3D full vehicle model based on virtual prototyping, flexible guideway by a modal superposition method and levitation electromagnets including feedback controller into an integrated model. By applying the proposed model to an urban Maglev vehicle newly developed for commercial application, an analysis of the instability phenomenon and an investigation of air gap control performance are carried out through a simulation.

Modelling and design optimization of low speed fuel cell - battery hybrid electric vehicles. Paper no. IGEC-1-125

International Nuclear Information System (INIS)

Guenther, M.; Dong, Z.

2005-01-01

A push for electric vehicles has occurred in the past several decades due to various concerns about air pollution and the contribution of emissions to global climate change. Although electric cars and buses have been the focus of much of electric vehicle development, smaller vehicles are used extensively for transportation and utility purposes in many countries. In order to explore the viability of fuel cell - battery hybrid electric vehicles, empirical fuel cell system data has been incorporated into the NREL's vehicle design and simulation tool, ADVISOR (ADvanced Vehicle SimulatOR), to predict the performance of a low-speed, fuel cell - battery electric vehicle through MATLAB Simulink. The modelling and simulation provide valuable feedback to the design optimization of the fuel cell power system. A sampling based optimization algorithm was used to explore the viability and options of a low cost design for urban use. (author)

A magneto rheological hybrid damper for railway vehicles suspensions

Directory of Open Access Journals (Sweden)

Gheorghe GHITA

2012-09-01

Full Text Available High speed railway vehicles features a specific lateral oscillation resulting from the coupled lateral displacement and yaw of the wheelset which leads to a sinusoid movement of the wheelset along the track, transferred to the entire vehicle. The amplitude of this oscillation is strongly dependant on vehicle’s velocity. Over a certain value, namely the critical speed, the instability phenomenon so-called hunting occurs. To raise the vehicle’s critical speed different designs of the suspension all leading to a much stiffer vehicle can be envisaged. Different simulations prove that a stiffer central suspension will decrease the passenger’s comfort in terms of lateral accelerations of the carboy. The authors propose a semi-active magneto rheological suspension to improve the vehicle’s comfort at high speeds. The suspension has as executive elements hybrid magneto rheological dampers operating under sequential control strategy type balance logic. Using an original mathematical model for the lateral dynamics of the vehicle the responses of the system with passive and semi-active suspensions are simulated. It is shown that the semi-active suspension can improve the vehicle performances.

Vehicle dynamic effects in the course of passing over turnouts

Directory of Open Access Journals (Sweden)

Zelenka J.

2007-11-01

Full Text Available For the quantification of vehicle dynamic effects at passing over turnouts at a higher speed there was developed a methodology for evaluating of acceleration measured on vehicle axle boxes in the year 2003. The methodology is based on statistical evaluation of lateral and vertical acceleration measured values at passing over both critical parts of a turnout (tongue, frog. The created methodology was used for investigation of vehicle dynamic effects by running at speed up to 230 km/h in the year 2004 in terms of high speed tests of tilting-body unit class 680 CD. There was found relatively high values of dynamic effects already at a speed 160 km/h. In terms of tilting-body unit class 680 tests at a higher speed in curves of chosen track lines of 1st and 2nd corridor of Czech Railways there was carried out also verification of curved turnouts state according to methodology mentioned above with a view to possibility of speed increasing at curved throats of chosen stations. Lateral vehicle dynamic effects at passing over a curved turnout frog area were evaluated. There were carried out simulation calculations of vehicle passing over a turnout based on measured geometric parameters of wheelset as well as chosen turnouts. Results of the calculations were compared with measurements. The increased vehicle dynamic effects found in pulsed beats character influence negatively the turnouts part (not only wheel contacting parts as well as operating life all unsuspended parts of vehicles.

Real-Time Vehicle Speed Estimation Based on License Plate Tracking in Monocular Video Sequences

Directory of Open Access Journals (Sweden)

Aleksej MAKAROV

2016-02-01

Full Text Available A method of estimating the vehicle speed from images obtained by a fixed over-the-road monocular camera is presented. The method is based on detecting and tracking vehicle license plates. The contrast between the license plate and its surroundings is enhanced using infrared light emitting diodes and infrared camera filters. A range of the license plate height values is assumed a priori. The camera vertical angle of view is measured prior to installation. The camera tilt is continuously measured by a micro-electromechanical sensor. The distance of the license plate from the camera is theoretically derived in terms of its pixel coordinates. Inaccuracies due to the frame rate drift, to the tilt and the angle of view measurement errors, to edge pixel detection and to a coarse assumption of the vehicle license plate height are analyzed and theoretically formulated. The resulting system is computationally efficient, inexpensive and easy to install and maintain along with the existing ALPR cameras.

A New Vibration Absorber Design for Under-Chassis Device of a High-Speed Train

Directory of Open Access Journals (Sweden)

Yu Sun

2017-01-01

Full Text Available To realize the separation of vertical and lateral stiffness of the under-chassis device, a new type of vibration absorber is designed by using the negative stiffness of the disc spring in parallel with the rubber component. To solve its transmission characteristics, harmonic transfer method was used. A rigid-flexible coupling multibody dynamic model of a high-speed train with an elastic car body is established, and the vertical and lateral optimal stiffness of the under-chassis device are calculated. The Sperling index and acceleration PSD of the vehicle with the new vibration absorber and the vehicle with traditional rubber absorber are compared and analyzed. The results show that, with the new vibration absorber, vehicle’s running stability and vibration of the car body are more effective than the vehicle with the traditional rubber absorber.

Fall from a car driving at high speed: A case report.

Science.gov (United States)

Maujean, Géraldine; Guinet, Tiphaine; Malicier, Daniel

2016-04-01

In cases of falls, the key issue for forensic scientists is to determine the manner of death. They must distinguish between accidental falls, suicidal falls, falls including blows and falls caused by a blow. Several strategies have been proposed in the literature to help explain injury patterns. Here, we report an original case of a man who died after jumping from a car moving at high speed. A mathematical and modeling approach was developed to reconstruct the trajectory of the body in order to understand the injury pattern and apparent discrepancy between the high speed of the car from which the victim jumped and the topography of the bone fractures, which were limited to the skull. To define the initial values of the model's parameters, a technical vehicle evaluation and several test jumps at low speed were carried out. We studied in greater detail the trajectory of three characteristic points corresponding to the dummy's center of gravity, head and right foot. Calculations were made with and without the air friction effect to show its influence. Finally, we were successful in modeling the initial trajectory of the body and the variation of its head energy over time, which were consistent with the injuries observed. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Drag reduction of a rapid vehicle in supercavitating flow

OpenAIRE

D. Yang; Y.L. Xiong; X.F. Guo

2017-01-01

Supercavitation is one of the most attractive technologies to achieve high speed for underwater vehicles. However, the multiphase flow with high-speed around the supercavitating vehicle (SCV) is difficult to simulate accurately. In this paper, we use modified the turbulent viscosity formula in the Standard K-Epsilon (SKE) turbulent model to simulate the supercavitating flow. The numerical results of flow over several typical cavitators are in agreement with the experimental data and theoretic...

High speed heterostructure devices

CERN Document Server

Beer, Albert C; Willardson, R K; Kiehl, Richard A; Sollner, T C L Gerhard

1994-01-01

Volume 41 includes an in-depth review of the most important, high-speed switches made with heterojunction technology. This volume is aimed at the graduate student or working researcher who needs a broad overview andan introduction to current literature. Key Features * The first complete review of InP-based HFETs and complementary HFETs, which promise very low power and high speed * Offers a complete, three-chapter review of resonant tunneling * Provides an emphasis on circuits as well as devices.

The injection equipment of future high-speed DI diesel engines with respect to power and pollution requirements

Energy Technology Data Exchange (ETDEWEB)

Dolenc, A. (Monobloc Dieselmotoren GmbH, Vienna (AT))

1990-01-01

The development of high specific output DI diesel engines started at the low-speed end some 50 years ago primarily for marine and traction applications. Movement towards the high-speed end has been slow but steady with the majority of truck engines being very conservatively rated. There has been recent major effort on the automotive car and light commercial vehicle diesel application leading to lightweight DI diesel engines with an engine speed of 4000-5000 r/min and a rated power of 50 kW/litre displacement. These are expected to be on the market in a short period of time. The key point of this development has been the injection equipment including combustion control. In this area the use of modulated injection has the possibility of solving power and pollution requirements. (author).

Rapid road repair vehicle

Science.gov (United States)

Mara, Leo M.

1998-01-01

Disclosed is a rapid road repair vehicle capable of moving over a surface to be repaired at near normal posted traffic speeds to scan for and find an the high rate of speed, imperfections in the pavement surface, prepare the surface imperfection for repair by air pressure and vacuum cleaning, applying a correct amount of the correct patching material to effect the repair, smooth the resulting repaired surface, and catalog the location and quality of the repairs for maintenance records of the road surface. The rapid road repair vehicle can repair surface imperfections at lower cost, improved quality, at a higher rate of speed than was was heretofor possible, with significantly reduced exposure to safety and health hazards associated with this kind of road repair activities in the past.

Fuzzy logic speed control for the engine of an air-powered vehicle

Directory of Open Access Journals (Sweden)

Qihui Yu

2016-03-01

Full Text Available To improve the condition of air and eliminate exhaust gas pollution, this article proposes a compressed air power system. Instead of an internal combustion engine, the automobile is equipped with a compressed air engine, which transforms the energy of compressed air into mechanical motion energy. A prototype was built, and the compressed air engine was tested on an experimental platform. The output torque and energy efficiency were obtained from experimental results. When the supply pressure was set at 2 MPa and the speed was 420 r min−1, the output torque, the output power, and the energy efficiency were 56 N m, 1.93 kW, and 25%, respectively. To improve the efficiency of the system, a fuzzy logic speed control strategy is proposed and simulated. The experimental study verified that the theoretical evaluation of the system was reasonable, and this research can be referred to as the design and control of air-powered vehicles.

Dazzle camouflage affects speed perception.

Directory of Open Access Journals (Sweden)

Nicholas E Scott-Samuel

Full Text Available Movement is the enemy of camouflage: most attempts at concealment are disrupted by motion of the target. Faced with this problem, navies in both World Wars in the twentieth century painted their warships with high contrast geometric patterns: so-called "dazzle camouflage". Rather than attempting to hide individual units, it was claimed that this patterning would disrupt the perception of their range, heading, size, shape and speed, and hence reduce losses from, in particular, torpedo attacks by submarines. Similar arguments had been advanced earlier for biological camouflage. Whilst there are good reasons to believe that most of these perceptual distortions may have occurred, there is no evidence for the last claim: changing perceived speed. Here we show that dazzle patterns can distort speed perception, and that this effect is greatest at high speeds. The effect should obtain in predators launching ballistic attacks against rapidly moving prey, or modern, low-tech battlefields where handheld weapons are fired from short ranges against moving vehicles. In the latter case, we demonstrate that in a typical situation involving an RPG7 attack on a Land Rover the reduction in perceived speed is sufficient to make the grenade miss where it was aimed by about a metre, which could be the difference between survival or not for the occupants of the vehicle.

Broadband vehicle-to-vehicle communication using an extended autonomous cruise control sensor

Science.gov (United States)

Heddebaut, M.; Rioult, J.; Ghys, J. P.; Gransart, Ch; Ambellouis, S.

2005-06-01

For several years road vehicle autonomous cruise control (ACC) systems as well as anti-collision radar have been developed. Several manufacturers currently sell this equipment. The current generation of ACC sensors only track the first preceding vehicle to deduce its speed and position. These data are then used to compute, manage and optimize a safety distance between vehicles, thus providing some assistance to car drivers. However, in real conditions, to elaborate and update a real time driving solution, car drivers use information about speed and position of preceding and following vehicles. This information is essentially perceived using the driver's eyes, binocular stereoscopic vision performed through the windscreens and rear-view mirrors. Furthermore, within a line of vehicles, the frontal road perception of the first vehicle is very particular and highly significant. Currently, all these available data remain strictly on-board the vehicle that has captured the perception information and performed these measurements. To get the maximum effectiveness of all these approaches, we propose that this information be shared in real time with the following vehicles, within the convoy. On the basis of these considerations, this paper technically explores a cost-effective solution to extend the basic ACC sensor function in order to simultaneously provide a vehicle-to-vehicle radio link. This millimetre wave radio link transmits relevant broadband perception data (video, localization...) to following vehicles, along the line of vehicles. The propagation path between the vehicles uses essentially grazing angles of incidence of signals over the road surface including millimetre wave paths beneath the cars.

Comparative field evaluation of vehicle cruise speed and acceleration level impacts on hot stabilized emissions

International Nuclear Information System (INIS)

El-Shawarby, Ihab; Ahn, Kyoungho; Rakha, Hesham

2005-01-01

The main objectives of this paper are two fold. First, the paper evaluates the impact of vehicle cruise speed and acceleration levels on vehicle fuel-consumption and emission rates using field data gathered under real-world driving conditions. Second, it validates the VT-Micro model for the modeling of real-world conditions. Specifically, an on-board emission-measurement device was used to collect emissions of oxides of nitrogen, hydrocarbons, carbon monoxide, and carbon dioxide using a light-duty test vehicle. The analysis demonstrates that vehicle fuel-consumption and emission rates per-unit distance are optimum in the range of 60-90 km/h, with considerable increase outside this optimum range. The study demonstrates that as the level of aggressiveness for acceleration maneuvers increases, the fuel-consumption and emission rates per maneuver decrease because the vehicle spends less time accelerating. However, when emissions are gathered over a sufficiently long fixed distance, fuel-consumption and mobile-source emission rates per-unit distance increase as the level of acceleration increases because of the history effects that accompany rich-mode engine operations. In addition, the paper demonstrates the validity of the VT-Micro framework for modeling steady-state vehicle fuel-consumption and emission behavior. Finally, the research demonstrates that the VT-Micro framework requires further refinement to capture non-steady-state history behavior when the engine operates in rich mode. (Author)

Research and new technologies in transportation. Vol. 1. High-speed railway systems: Maglev technology. Forschung und neue Technologien im Verkehr. Bd. 1. Schnellbahnsysteme: Magnetbandtechnolgie

Energy Technology Data Exchange (ETDEWEB)

1988-01-01

High-speed magnetic levitation technology opens up a new dimension for long-distance passenger transport with speeds ranging between ground travel and flying. The status of development and test results of the German TRANSRAPID magnetic levitation system and corresponding activities abroad will be reported on. Both the new vehicle technology of the TRANSRAPID 07 and results of application studies at home and abroad will be presented. High-speed magnetic railway technology - status and development perspectives; readiness for service, safety and reliability, application studies. The book comprises 11 papers read at the symposium on the subject of high-speed trains. 14 papers have been recorded separately in this database. (orig./HW).

In-Vehicle Dynamic Curve-Speed Warnings at High-Risk Rural Curves

Science.gov (United States)

2018-03-01

Lane-departure crashes at horizontal curves represent a significant portion of fatal crashes on rural Minnesota roads. Because of this, solutions are needed to aid drivers in identifying upcoming curves and inform them of a safe speed at which they s...

14 CFR 23.253 - High speed characteristics.

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false High speed characteristics. 23.253 Section... Requirements § 23.253 High speed characteristics. If a maximum operating speed VMO/MMO is established under § 23.1505(c), the following speed increase and recovery characteristics must be met: (a) Operating...

Improving the Efficiency of a High Speed Catamaran Through the Replacement of the Propulsion System

Directory of Open Access Journals (Sweden)

German de Melo Rodriguez

2015-12-01

Full Text Available The high speed vessels are primarily designed for short distances services as public transport of passengers and vehicles. The range of high speed, according to the Code of high-speed vessels begins at 20 knots, which depends on the cruise speed you desire for your vessel; you will have to use the most appropriate type of propellant. In general, in the past 20 years, they have been building high-speed vessels with speeds above 33 knots, which meant installing water jet propellants coupled to powerful engines and therefore of high consumption of fuel, increasing operating costs and causing increased air pollution. Although the prices of fuel have been reduced to half, due to the sharp fall in oil prices, the consumption of fuel and the air pollution remains high at these speeds and powers used, in addition to that the reduction of the time spent on each trip is not excessive, mainly in short routes that are less than an hour . This article is about adapting a ship of high-speed service, with a maximum speed in tests of 34 knots and to reduce its operating costs (fuel, maintenance, etc. and make it economically viable; before the transformation, this vessel was operating with a service speed of 22 knots, and with a consumption per mile of 135 litters of MGO. The transformation process has consisted by: – Replacement of the two original water jet with four shaft lines with fix pitch propeller. – Replacement of the two original main engines (2 x 6500 kW = 13000 kW by four engines (4 x 1380kW = 5.520 kW. – Changing the underwater hull shape to fit the new propellers and maximize its efficiency. – Relocation of auxiliary engines, to achieve the most efficient trim. – Installation of two lateral propellers to improve maneuverability and shorten the total time of journey. After the reform and the return to service of the vessel with a service speed of over 22 knots, it has been verified that the consumption per mile is of 45 litters MGO

Modified Motor Vehicles Travel Speed Models on the Basis of Curb Parking Setting under Mixed Traffic Flow

Directory of Open Access Journals (Sweden)

Zhenyu Mei

2012-01-01

Full Text Available The ongoing controversy about in what condition should we set the curb parking has few definitive answers because comprehensive research in this area has been lacking. Our goal is to present a set of heuristic urban street speed functions under mixed traffic flow by taking into account impacts of curb parking. Two impacts have been defined to classify and quantify the phenomena of motor vehicles' speed dynamics in terms of curb parking. The first impact is called Space impact, which is caused by the curb parking types. The other one is the Time impact, which results from the driver maneuvering in or out of parking space. In this paper, based on the empirical data collected from six typical urban streets in Nanjing, China, two models have been proposed to describe these phenomena for one-way traffic and two-way traffic, respectively. An intensive experiment has been conducted in order to calibrate and validate these proposed models, by taking into account the complexity of the model parameters. We also provide guidelines in terms of how to cluster and calculate those models' parameters. Results from these models demonstrated promising performance of modeling motor vehicles' speed for mixed traffic flow under the influence of curb parking.

Semi-active H∞ control of high-speed railway vehicle suspension with magnetorheological dampers

Science.gov (United States)

Zong, Lu-Hang; Gong, Xing-Long; Xuan, Shou-Hu; Guo, Chao-Yang

2013-05-01

In this paper, semi-active H∞ control with magnetorheological (MR) dampers for railway vehicle suspension systems to improve the lateral ride quality is investigated. The proposed semi-active controller is composed of a H∞ controller as the system controller and an adaptive neuro-fuzzy inference system (ANFIS) inverse MR damper model as the damper controller. First, a 17-degree-of-freedom model for a full-scale railway vehicle is developed and the random track irregularities are modelled. Then a modified Bouc-Wen model is built to characterise the forward dynamic characteristics of the MR damper and an inverse MR damper model is built with the ANFIS technique. Furthermore, a H∞ controller composed of a yaw motion controller and a rolling pendulum motion (lateral motion+roll motion) controller is established. By integrating the H∞ controller with the ANFIS inverse model, a semi-active H∞ controller for the railway vehicle is finally proposed. Simulation results indicate that the proposed semi-active suspension system possesses better attenuation ability for the vibrations of the car body than the passive suspension system.

High-Speed Photography

International Nuclear Information System (INIS)

Paisley, D.L.; Schelev, M.Y.

1998-01-01

The applications of high-speed photography to a diverse set of subjects including inertial confinement fusion, laser surgical procedures, communications, automotive airbags, lightning etc. are briefly discussed. (AIP) copyright 1998 Society of Photo-Optical Instrumentation Engineers

Thermal analysis and temperature characteristics of a braking resistor for high-speed trains for changes in the braking current

Science.gov (United States)

Lee, Dae-Dong; Kang, Hyun-Il; Shim, Jae-Myung

2015-09-01

Electric brake systems are used in high-speed trains to brake trains by converting the kinetic energy of a railway vehicle to electric energy. The electric brake system consists of a regenerative braking system and a dynamic braking system. When the electric energy generated during the dynamic braking process is changed to heat through the braking resistor, the braking resistor can overheat; thus, failures can occur to the motor block. In this paper, a braking resistor for a high-speed train was used to perform thermal analyses and tests, and the results were analyzed. The analyzed data were used to estimate the dependence of the brake currents and the temperature rises on speed changes up to 300 km/h, at which a test could not be performed.

SEAL FOR HIGH SPEED CENTRIFUGE

Science.gov (United States)

Skarstrom, C.W.

1957-12-17

A seal is described for a high speed centrifuge wherein the centrifugal force of rotation acts on the gasket to form a tight seal. The cylindrical rotating bowl of the centrifuge contains a closure member resting on a shoulder in the bowl wall having a lower surface containing bands of gasket material, parallel and adjacent to the cylinder wall. As the centrifuge speed increases, centrifugal force acts on the bands of gasket material forcing them in to a sealing contact against the cylinder wall. This arrangememt forms a simple and effective seal for high speed centrifuges, replacing more costly methods such as welding a closure in place.

Integrated vehicle control and guidance systems in unmanned ground vehicles for commercial applications

Science.gov (United States)

Kenyon, Chase H.

1995-01-01

While there is a lot of recent development in the entire IVHS field, very few have had the opportunity to combine the many areas of development into a single integrated `intelligent' unmanned vehicle. One of our systems was developed specifically to serve a major automobile manufacturer's need for an automated vehicle chassis durability test facility. Due to the severity of the road surface human drivers could not be used. A totally automated robotic vehicle driver and guidance system was necessary. In order to deliver fixed price commercial projects now, it was apparent system and component costs were of paramount importance. Cyplex has developed a robust, cost effective single wire guidance system. This system has inherent advantages in system simplicity. Multi-signal (per vehicle lane) systems complicate path planning and layout when multiple lanes and lane changes are required, as on actual highways. The system has demonstrated high enough immunity to rain and light snow cover that normal safety reductions in speed are adequate to stay within the required system performance envelope. This system and it's antenna interface have shown the ability to guide the vehicle at slow speeds (10 MPH) with a tracking repeatability of plus or minus 1/8 of an inch. The basic guide and antenna system has been tested at speeds up to 80 mph. The system has inherently superior abilities for lane changes and precision vehicle placement. The operation of this system will be described and the impact of a system that is commercially viable now for highway and off road use will be discussed.

The high speed civil transport and NASA's High Speed Research (HSR) program

Science.gov (United States)

Shaw, Robert J.

1994-01-01

Ongoing studies being conducted not only in this country but in Europe and Asia suggest that a second generation supersonic transport, or High-Speed Civil Transport (HSCT), could become an important part of the 21st century international air transportation system. However, major environmental compatibility and economic viability issues must be resolved if the HSCT is to become a reality. This talk will overview the NASA High-Speed Research (HSR) program which is aimed at providing the U.S. industry with a technology base to allow them to consider launching an HSCT program early in the next century. The talk will also discuss some of the comparable activities going on within Europe and Japan.

Using a High-Speed Camera to Measure the Speed of Sound

Science.gov (United States)

Hack, William Nathan; Baird, William H.

2012-01-01

The speed of sound is a physical property that can be measured easily in the lab. However, finding an inexpensive and intuitive way for students to determine this speed has been more involved. The introduction of affordable consumer-grade high-speed cameras (such as the Exilim EX-FC100) makes conceptually simple experiments feasible. Since the…

The eco-driving effect of electric vehicles compared to conventional gasoline vehicles

Directory of Open Access Journals (Sweden)

Hideki Kato

2016-10-01

Full Text Available Eco-driving is attractive to the public, not only users of internal-combustion-engine vehicles (ICEVs including hybrid electric vehicles (HEVs but also users of electric vehicles (EVs have interest in eco-driving. In this context, a quantitative evaluation of eco-driving effect of EVs was conducted using a chassis dynamometer (C/D with an “eco-driving test mode.” This mode comprised four speed patterns selected from fifty-two real-world driving datasets collected during an eco-driving test-ride event. The four patterns had the same travel distance (5.2 km, but showed varying eco-driving achievement levels. Three ICEVs, one HEV and two EVs were tested using a C/D. Good linear relationships were found between the eco-driving achievement level and electric or fuel consumption rate of all vehicles. The reduction of CO2 emissions was also estimated. The CO2-reduction rates of the four conventional (including hybrid vehicles were 10.9%–12.6%, while those of two types of EVs were 11.7%–18.4%. These results indicate that the eco-driving tips for conventional vehicles are effective to not only ICEVs and HEVs but also EVs. Furthermore, EVs have a higher potential of eco-driving effect than ICEVs and HEVs if EVs could maintain high energy conversion efficiency at low load range. This study is intended to support the importance of the dissemination of tools like the intelligent speed adaptation (ISA to obey the regulation speed in real time. In the future, also in the development and dissemination of automated driving systems, the viewpoint of achieving the traveling purpose with less kinetic energy would be important.

Analysis and design of a speed and position system for maglev vehicles.

Science.gov (United States)

Dai, Chunhui; Dou, Fengshan; Song, Xianglei; Long, Zhiqiang

2012-01-01

This paper mainly researches one method of speed and location detection for maglev vehicles. As the maglev train doesn't have any physical contact with the rails, it has to use non-contact measuring methods. The technology based on the inductive loop-cable could fulfill the requirement by using an on-board antenna which could detect the alternating magnetic field produced by the loop-cable on rails. This paper introduces the structure of a speed and position system, and analyses the electromagnetic field produced by the loop-cable. The equivalent model of the loop-cable is given and the most suitable component of the magnetic flux density is selected. Then the paper also compares the alternating current (AC) resistance and the quality factor between two kinds of coils which the antenna is composed of. The effect of the rails to the signal receiving is also researched and then the structure of the coils is improved. Finally, considering the common-mode interference, 8-word coils are designed and analyzed.

Analysis and Design of a Speed and Position System for Maglev Vehicles

Directory of Open Access Journals (Sweden)

Zhiqiang Long

2012-06-01

Full Text Available This paper mainly researches one method of speed and location detection for maglev vehicles. As the maglev train doesn’t have any physical contact with the rails, it has to use non-contact measuring methods. The technology based on the inductive loop-cable could fulfill the requirement by using an on-board antenna which could detect the alternating magnetic field produced by the loop-cable on rails. This paper introduces the structure of a speed and position system, and analyses the electromagnetic field produced by the loop-cable. The equivalent model of the loop-cable is given and the most suitable component of the magnetic flux density is selected. Then the paper also compares the alternating current (AC resistance and the quality factor between two kinds of coils which the antenna is composed of. The effect of the rails to the signal receiving is also researched and then the structure of the coils is improved. Finally, considering the common-mode interference, 8-word coils are designed and analyzed.

Safety of high speed ground transportation systems: X2000 US demonstration vehicle dynamics trials, preliminary test report. Report for October 1992-January 1993

Energy Technology Data Exchange (ETDEWEB)

Whitten, B.T.; Kesler, J.K.

1993-01-01

The report documents the procedures, events, and results of vehicle dynamic tests carried out on the ASEA-Brown Boveri (ABB) X2000 tilt body trainset in the US between October 1992 and January 1993. These tests, sponsored by Amtrak and supported by the FRA, were conducted to assess the suitability of the X2000 trainset for safe operation at elevated cant deficiencies and speeds in Amtrak's Northeast Corridor under existing track conditions in a revenue service demonstration. The report describes the safety criteria against which the performance of the X2000 test train was examined, the instrumentation used, the test locations, and the track conditions. Preliminary results are presented from tests conducted on Amtrak lines between Philadelphia and Harrisburg, PA, and between Washington DC and New York NY, in which cant deficiencies of 12.5 inches and speeds of 154 mph were reached in a safe and controlled manner. The significance of the results is discussed, and preliminary conclusions and recommendations are presented.

33 CFR 84.24 - High-speed craft.

Science.gov (United States)

2010-07-01

... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false High-speed craft. 84.24 Section... RULES ANNEX I: POSITIONING AND TECHNICAL DETAILS OF LIGHTS AND SHAPES § 84.24 High-speed craft. (a) The masthead light of high-speed craft with a length to breadth ratio of less than 3.0 may be placed at a...

Modern trends in designing high-speed trains

Directory of Open Access Journals (Sweden)

Golubović Snežana D.

2015-01-01

Full Text Available Increased advantages of railway transportation systems over other types of transportation systems in the past sixty years have been a result of an intensive development of the new generations of high-speed trains. Not only do these types of trains comply with the need for increased speed of transportation and make the duration of the journey shorter, but they also meet the demands for increased reliability, safety and direct application of energy efficiency to the transportation system itself. Along with increased train speed, the motion resistance is increased as well, whereby at speeds over 200 km/h the proportion of air resistance becomes the most dominant member. One of the most efficient measures for reducing air resistance, as well as other negative consequences of high-speed motion, is the development of the aerodynamic shape of the train. This paper presents some construction solutions that affect the aerodynamic properties of high-speed trains, first and foremost, the nose shape, as well as the similarities and differences of individual subsystems necessary for the functioning of modern high-speed rail systems. We analysed two approaches to solving the problem of the aerodynamic shape of the train and the appropriate infrastructure using the examples of Japan and France. Two models of high-speed trains, Shinkansen (Japan and TGV, i.e. AGV (France, have been discussed.

High Power Orbit Transfer Vehicle

National Research Council Canada - National Science Library

Gulczinski, Frank

2003-01-01

... from Virginia Tech University and Aerophysics, Inc. to examine propulsion requirements for a high-power orbit transfer vehicle using thin-film voltaic solar array technologies under development by the Space Vehicles Directorate (dubbed PowerSail...

Changes of indicators of high-speed and high-speed and power preparedness at volleyball players of 12–13 years old

Directory of Open Access Journals (Sweden)

Oleg Shevchenko

2016-04-01

Full Text Available Purpose: to define changes of indicators of high-speed and high-speed and power preparedness of volleyball players of 12–13 years old. Material & Methods: the test exercises, which are recommended by the training program of CYSS on volleyball, were used for the definition of the level of development of high-speed and high-speed and power abilities of volleyball players. 25 young volleyball players from the group of the previous basic preparation took part in the experiment. Sports experience of sportsmen is 3–4 years. The analysis of scientifically-methodical literature, pedagogical testing, pedagogical experiment, methods of mathematical statistics were carried out. Results: the analyzed level of high-speed and high-speed and power abilities of volleyball players. Conclusions: the results had reliable changes (t=2,2–2,4 at р<0,05 of the level of high-speed and high-speed and power abilities of volleyball players of 12–13years old in the experimental group at the end of the experiment, except run on 30 m that demonstrates a positive influence of application of special exercises in the educational-training process.

Reducing Heating In High-Speed Cinematography

Science.gov (United States)

Slater, Howard A.

1989-01-01

Infrared-absorbing and infrared-reflecting glass filters simple and effective means for reducing rise in temperature during high-speed motion-picture photography. "Hot-mirror" and "cold-mirror" configurations, employed in projection of images, helps prevent excessive heating of scenes by powerful lamps used in high-speed photography.

On-board emission measurement of high-loaded light-duty vehicles in Algeria.

Science.gov (United States)

Boughedaoui, Ménouèr; Kerbachi, Rabah; Joumard, Robert

2008-01-01

A sample of eight private gasoline and diesel conventional light-duty vehicles (LDVs) in use with various ages, carrying a load of 460 kg, were tested on a representative trip in the traffic flow of the city of Blida to obtain emission factors representing the actual use conditions of Algerian LDVs. The gas sampling system (mini-constant volume sampling) as well as the analyzers are carried on-board the vehicle. Around 55 tests were conducted during 3 months covering more than 480 km under various real driving conditions. The mean speed downtown is about 16.1 km/hr with a rather low acceleration, an average of 0.60 m/sec2. For each test, kinematics are recorded as well as the analysis of the four emitted pollutants carbon dioxide, carbon monoxide, oxides of nitrogen, and total hydrocarbons. Emission factors were evaluated according to speed for each category of gasoline and diesel engines. The influence of some parameters such as cold/hot start, age of vehicle and its state of maintenance are discussed. Results are compared with the European database ARTEMIS for comparable vehicles. These measurements contribute to the development of unit emission of the vehicles used in Algeria, which are necessary for the calculation of emission inventory of pollutants and greenhouse gases from the road transportation sector. The unit emissions constitute a tool of decisionmaking aid regarding the conception of new regulations of vehicle control and inspection in Algeria and even in similar developing countries.

High speed data acquisition

International Nuclear Information System (INIS)

Cooper, P.S.

1997-07-01

A general introduction to high speed data acquisition system techniques in modern particle physics experiments is given. Examples are drawn from the SELEX(E78 1) high statistics charmed baryon production and decay experiment now taking data at Fermilab

Visual Analysis of Speeding Bumps Using Floating Car Dataset

DEFF Research Database (Denmark)

Kveladze, Irma; Agerholm, Niels

2018-01-01

measures, and also their influence on the driving behaviour of vehicles from a temporal perspective. To fill this gap and understand these aspects, in this research we propose visual analytics techniques. To explore the influence of the bumps on speed change behavior of vehicles, several use case studies...... in three different cities were selected with close cooperation of a traffic domain expert. The aim was first to study influence of the bumps on vehicle volume and speeding from a time perspective. And then, establish any connection between speed bump intervals and vehicle speeding in the selected use cases...

Wake flow characteristics at high wind speed

DEFF Research Database (Denmark)

Aagaard Madsen, Helge; Larsen, Torben J.; Larsen, Gunner Chr.

2016-01-01

Wake flow characteristic at high wind speeds is the main subject of this paper. Although the wake losses decrease at high wind speeds it has been found in a recent study that for multiple wake inflow the increase in loading due to wake effects are substantial even at wind speeds well above rated ...

Vehicle test report: Electric Vehicle Associates electric conversion of an AMC Pacer

Science.gov (United States)

Price, T. W.; Wirth, V. A., Jr.; Pompa, M. F.

1981-01-01

Tests were performed to characterize certain parameters of the EVA Pacer and to provide baseline data that can be used for the comparison of improved batteries that may be incorporated into the vehicle at a later time. The vehicle tests were concentrated on the electrical drive subsystem; i.e., the batteries, controller and motor. The tests included coastdowns to characterize the road load, and range evaluations for both cyclic and constant speed conditions. A qualitative evaluation of the vehicle's performance was made by comparing its constant speed range performance with other electric and hybrid vehicles. The Pacer performance was approximately equal to the majority of those vehicles assessed in 1977.

14 CFR 25.253 - High-speed characteristics.

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false High-speed characteristics. 25.253 Section...-speed characteristics. (a) Speed increase and recovery characteristics. The following speed increase and recovery characteristics must be met: (1) Operating conditions and characteristics likely to cause...

Capacitated Vehicle Routing with Nonuniform Speeds

DEFF Research Database (Denmark)

Gørtz, Inge Li; Molinaro, Marco; Nagarajan, Viswanath

2016-01-01

is the distance traveled divided by its speed.Our algorithm relies on a new approximate minimum spanning tree construction called Level-Prim, which is related to but different from Light Approximate Shortest-path Trees. We also extend the widely used tour-splitting technique to nonuniform speeds, using ideas from...

Chicago-St. Louis high speed rail plan

International Nuclear Information System (INIS)

Stead, M.E.

1994-01-01

The Illinois Department of Transportation (IDOT), in cooperation with Amtrak, undertook the Chicago-St. Louis High Speed Rail Financial and Implementation Plan study in order to develop a realistic and achievable blueprint for implementation of high speed rail in the Chicago-St. Louis corridor. This report presents a summary of the Price Waterhouse Project Team's analysis and the Financial and Implementation Plan for implementing high speed rail service in the Chicago-St. Louis corridor

Chicago-St. Louis high speed rail plan

Energy Technology Data Exchange (ETDEWEB)

Stead, M.E.

1994-12-31

The Illinois Department of Transportation (IDOT), in cooperation with Amtrak, undertook the Chicago-St. Louis High Speed Rail Financial and Implementation Plan study in order to develop a realistic and achievable blueprint for implementation of high speed rail in the Chicago-St. Louis corridor. This report presents a summary of the Price Waterhouse Project Team`s analysis and the Financial and Implementation Plan for implementing high speed rail service in the Chicago-St. Louis corridor.

Effectiveness of Motorcycle speed controlled by speed hump

Directory of Open Access Journals (Sweden)

Pornsiri Urapa

2014-09-01

Full Text Available Speed humps are one of the traffic calming measures widely accepted to control vehicle speed in the local road. Humps standards from the western countries are designed mainly for the passenger car. This study, therefore, aims to reveal the effectiveness of speed hump to control the motorcycle speed. This study observes the free-flow speed of the riders at the total of 20 speed bumps and humps. They are 0.3-14.8 meter in width and 5-18 centimeter in height. The results reveal that the 85th percentile speeds reduce 15-65 percent when crossing the speed bumps and speed humps. Besides, this study develops the speed model to predict the motorcycle mean speed and 85th percentile speed. It is found that speed humps follow the ITE standard can control motorcycle crossing speeds to be 25-30 Kph which are suitable to travel on the local road.

Lubrication and cooling for high speed gears

Science.gov (United States)

Townsend, D. P.

1985-01-01

The problems and failures occurring with the operation of high speed gears are discussed. The gearing losses associated with high speed gearing such as tooth mesh friction, bearing friction, churning, and windage are discussed with various ways shown to help reduce these losses and thereby improve efficiency. Several different methods of oil jet lubrication for high speed gearing are given such as into mesh, out of mesh, and radial jet lubrication. The experiments and analytical results for the various methods of oil jet lubrication are shown with the strengths and weaknesses of each method discussed. The analytical and experimental results of gear lubrication and cooling at various test conditions are presented. These results show the very definite need of improved methods of gear cooling at high speed and high load conditions.

Low speed hybrid generalized predictive control of a gasoline-propelled car.

Science.gov (United States)

Romero, M; de Madrid, A P; Mañoso, C; Milanés, V

2015-07-01

Low-speed driving in traffic jams causes significant pollution and wasted time for commuters. Additionally, from the passengers׳ standpoint, this is an uncomfortable, stressful and tedious scene that is suitable to be automated. The highly nonlinear dynamics of car engines at low-speed turn its automation in a complex problem that still remains as unsolved. Considering the hybrid nature of the vehicle longitudinal control at low-speed, constantly switching between throttle and brake pedal actions, hybrid control is a good candidate to solve this problem. This work presents the analytical formulation of a hybrid predictive controller for automated low-speed driving. It takes advantage of valuable characteristics supplied by predictive control strategies both for compensating un-modeled dynamics and for keeping passengers security and comfort analytically by means of the treatment of constraints. The proposed controller was implemented in a gas-propelled vehicle to experimentally validate the adopted solution. To this end, different scenarios were analyzed varying road layouts and vehicle speeds within a private test track. The production vehicle is a commercial Citroën C3 Pluriel which has been modified to automatically act over its throttle and brake pedals. Copyright © 2015 ISA. Published by Elsevier Ltd. All rights reserved.

On-board measurement of particle numbers and their size distribution from a light-duty diesel vehicle: Influences of VSP and altitude.

Science.gov (United States)

Liu, Jia; Ge, Yunshan; Wang, Xin; Hao, Lijun; Tan, Jianwei; Peng, Zihang; Zhang, Chuanzhen; Gong, Huiming; Huang, Ying

2017-07-01

In this study, the particle size-resolved distribution from a China-3 certificated light-duty diesel vehicle was measured by using a portable emission measurement system (PEMS). In order to examine the influences of vehicle specific power (VSP) and high-altitude operation, measurements were conducted at 8 constant speeds, which ranged from 10 to 80km/hr at 10km/hr intervals, and two different high altitudes, namely 2200 and 3200m. The results demonstrated that the numbers of particles in all size ranges decreased significantly as VSP increased when the test vehicle was running at lower speeds (vehicle resulted in increased particle number emissions at low and high driving speeds; however, particle numbers obtained at moderate speeds decreased as altitude rose. When the test vehicle was running at moderate speeds, particle numbers measured at the two altitudes were very close, except for comparatively higher number concentrations of nanoparticles measured at 2200m. Copyright © 2017. Published by Elsevier B.V.

X-36 Tailless Fighter Agility Research Aircraft on lakebed during high-speed taxi tests

Science.gov (United States)

1996-01-01

The NASA/McDonnell Douglas Corporation (MDC) X-36 Tailless Fighter Agility Research Aircraft undergoes high-speed taxi tests on Rogers Dry Lake at NASA Dryden Flight Research Center, Edwards, California, on October 17, 1996. The aircraft was tested at speeds up to 85 knots. Normal takeoff speed would be 110 knots. The NASA/Boeing X-36 Tailless Fighter Agility Research Aircraft program successfully demonstrated the tailless fighter design using advanced technologies to improve the maneuverability and survivability of possible future fighter aircraft. The program met or exceeded all project goals. For 31 flights during 1997 at the Dryden Flight Research Center, Edwards, California, the project team examined the aircraft's agility at low speed / high angles of attack and at high speed / low angles of attack. The aircraft's speed envelope reached up to 206 knots (234 mph). This aircraft was very stable and maneuverable. It handled very well. The X-36 vehicle was designed to fly without the traditional tail surfaces common on most aircraft. Instead, a canard forward of the wing was used as well as split ailerons and an advanced thrust-vectoring nozzle for directional control. The X-36 was unstable in both pitch and yaw axes, so an advanced, single-channel digital fly-by-wire control system (developed with some commercially available components) was put in place to stabilize the aircraft. Using a video camera mounted in the nose of the aircraft and an onboard microphone, the X-36 was remotely controlled by a pilot in a ground station virtual cockpit. A standard fighter-type head-up display (HUD) and a moving-map representation of the vehicle's position within the range in which it flew provided excellent situational awareness for the pilot. This pilot-in-the-loop approach eliminated the need for expensive and complex autonomous flight control systems and the risks associated with their inability to deal with unknown or unforeseen phenomena in flight. Fully fueled the X

The use of high-speed imaging in education

Science.gov (United States)

Kleine, H.; McNamara, G.; Rayner, J.

2017-02-01

Recent improvements in camera technology and the associated improved access to high-speed camera equipment have made it possible to use high-speed imaging not only in a research environment but also specifically for educational purposes. This includes high-speed sequences that are created both with and for a target audience of students in high schools and universities. The primary goal is to engage students in scientific exploration by providing them with a tool that allows them to see and measure otherwise inaccessible phenomena. High-speed imaging has the potential to stimulate students' curiosity as the results are often surprising or may contradict initial assumptions. "Live" demonstrations in class or student- run experiments are highly suitable to have a profound influence on student learning. Another aspect is the production of high-speed images for demonstration purposes. While some of the approaches known from the application of high speed imaging in a research environment can simply be transferred, additional techniques must often be developed to make the results more easily accessible for the targeted audience. This paper describes a range of student-centered activities that can be undertaken which demonstrate how student engagement and learning can be enhanced through the use of high speed imaging using readily available technologies.

Innovation Analysis Approach to Design Parameters of High Speed Train Carriage and Their Intrinsic Complexity Relationships

Science.gov (United States)

Xiao, Shou-Ne; Wang, Ming-Meng; Hu, Guang-Zhong; Yang, Guang-Wu

2017-09-01

In view of the problem that it's difficult to accurately grasp the influence range and transmission path of the vehicle top design requirements on the underlying design parameters. Applying directed-weighted complex network to product parameter model is an important method that can clarify the relationships between product parameters and establish the top-down design of a product. The relationships of the product parameters of each node are calculated via a simple path searching algorithm, and the main design parameters are extracted by analysis and comparison. A uniform definition of the index formula for out-in degree can be provided based on the analysis of out-in-degree width and depth and control strength of train carriage body parameters. Vehicle gauge, axle load, crosswind and other parameters with higher values of the out-degree index are the most important boundary conditions; the most considerable performance indices are the parameters that have higher values of the out-in-degree index including torsional stiffness, maximum testing speed, service life of the vehicle, and so on; the main design parameters contain train carriage body weight, train weight per extended metre, train height and other parameters with higher values of the in-degree index. The network not only provides theoretical guidance for exploring the relationship of design parameters, but also further enriches the application of forward design method to high-speed trains.

Effect of interactions between vehicles and pedestrians on fuel consumption and emissions

Science.gov (United States)

Li, Xiang; Sun, Jian-Qiao

2014-12-01

This paper presents a study of variations of fuel consumption and emissions of vehicles due to random street crossings of pedestrians. The pedestrian and vehicle movement models as well as the interaction model between the two entities are presented. Extensive numerical simulations of single and multiple cars are carried out to investigate the traffic flow rate, vehicle average speed, fuel consumption, CO, HC and NOx emissions. Generally more noncompliant road-crossings of pedestrians lead to higher level of fuel consumptions and emissions of vehicles, and the traffic situation can be improved by imposing higher vehicle speed limit to some extent. Different traffic characteristics in low and high vehicle density regions are studied. The traffic flow is more influenced by crossing pedestrians in the low vehicle density region, while in the high vehicle density region, the interactions among vehicles dominate. The main contribution of this paper lies in the qualitative analysis of the impact of the interactions between pedestrians and vehicles on the traffic, its energy economy and emissions.

High-speed elevators controlled by inverters

Energy Technology Data Exchange (ETDEWEB)

Sakai, Yoshio; Takahashi, Hideaki; Nakamura, Kiyoshi; Kinoshita, Hiroshi

1988-10-25

The super-high-speed elevator with superiority to 300m/min of speed, requires both the large capacity power and wide range speed controls. Therefore, in order to materialize the smooth and quiet operation characteristics, by applying the inverter control, the low torque ripple control in the low frequency range and high frequency large capacity inverting for lowering the motor in noise are necessary with their being assured of reliability. To satisfy the above necessary items, together with the development of a sine wave pulse width and frequency modulation (PWM/PFM) control system, to more precisely enable the sine wave electric current control, and 3kHz switching power converter, using a 800A power transistor module, a supervoltage control circuit under the extraordinary condition was designed. As a result of commercializing a 360m/min super-high speed inverter elevator, the power source unit, due to the effect of high power factor, could be reduced by 30% in capacity and also the higher harmonic wave including ratio could be considerably lowered to the inferiority to 5%. 2 references, 7 figures, 1 table.

High - speed steel for precise cased tools

International Nuclear Information System (INIS)

Karwiarz, J.; Mazur, A.

2001-01-01

The test results of high-vanadium high - speed steel (SWV9) for precise casted tools are presented. The face -milling cutters of NFCa80A type have been tested in industrial operating conditions. An average life - time of SWV9 steel tools was 3-10 times longer compare to the conventional high - speed milling cutters. Metallography of SWB9 precise casted steel revealed beneficial for tool properties distribution of primary vanadium carbides in the steel matrix. Presented results should be a good argument for wide application of high - vanadium high - speed steel for precise casted tools. (author)

Reusable Launch Vehicle Technology Program

Science.gov (United States)

Freeman, Delma C., Jr.; Talay, Theodore A.; Austin, R. Eugene

1997-01-01

Industry/NASA reusable launch vehicle (RLV) technology program efforts are underway to design, test, and develop technologies and concepts for viable commercial launch systems that also satisfy national needs at acceptable recurring costs. Significant progress has been made in understanding the technical challenges of fully reusable launch systems and the accompanying management and operational approaches for achieving a low cost program. This paper reviews the current status of the RLV technology program including the DC-XA, X-33 and X-34 flight systems and associated technology programs. It addresses the specific technologies being tested that address the technical and operability challenges of reusable launch systems including reusable cryogenic propellant tanks, composite structures, thermal protection systems, improved propulsion and subsystem operability enhancements. The recently concluded DC-XA test program demonstrated some of these technologies in ground and flight test. Contracts were awarded recently for both the X-33 and X-34 flight demonstrator systems. The Orbital Sciences Corporation X-34 flight test vehicle will demonstrate an air-launched reusable vehicle capable of flight to speeds of Mach 8. The Lockheed-Martin X-33 flight test vehicle will expand the test envelope for critical technologies to flight speeds of Mach 15. A propulsion program to test the X-33 linear aerospike rocket engine using a NASA SR-71 high speed aircraft as a test bed is also discussed. The paper also describes the management and operational approaches that address the challenge of new cost effective, reusable launch vehicle systems.

Dynamic response analysis of single-span guideway caused by high speed maglev train

Directory of Open Access Journals (Sweden)

Jin Shi

Full Text Available High speed maglev is one of the most important reformations in the ground transportation systems because of its no physical contact nature. This paper intends to study the dynamic response of the single-span guideway induced by moving maglev train. The dynamic model of the maglev train-guideway system is established. In this model, a maglev train consists of three vehicles and each vehicle is regarded as a multibody system with 34 degrees-of-freedom. The guideway is modeled as a simply supported beam. Considering the motion-dependent nature of electromagnetic forces in the maglev system, an iterative approach is presented to compute the dynamic response of a maglev train-guideway system. The histories of the train traversing the guideways are simulated and the dynamic responses of the guideway and the train vehicles are calculated. A field experiment is carried out to verify the results of the analysis. The resonant conditions of single-span guideway are analyzed. The results show that all the dynamic indexes of train-guideway system are far less than permissive values of railway and maglev system, the vertical resonant of guideways caused by periodical excitations of the train will not happen.

Hybrid Turbine Electric Vehicle

Science.gov (United States)

Viterna, Larry A.

1997-01-01

Hybrid electric power trains may revolutionize today's ground passenger vehicles by significantly improving fuel economy and decreasing emissions. The NASA Lewis Research Center is working with industry, universities, and Government to develop and demonstrate a hybrid electric vehicle. Our partners include Bowling Green State University, the Cleveland Regional Transit Authority, Lincoln Electric Motor Division, the State of Ohio's Department of Development, and Teledyne Ryan Aeronautical. The vehicle will be a heavy class urban transit bus offering double the fuel economy of today's buses and emissions that are reduced to 1/10th of the Environmental Protection Agency's standards. At the heart of the vehicle's drive train is a natural-gas-fueled engine. Initially, a small automotive engine will be tested as a baseline. This will be followed by the introduction of an advanced gas turbine developed from an aircraft jet engine. The engine turns a high-speed generator, producing electricity. Power from both the generator and an onboard energy storage system is then provided to a variable-speed electric motor attached to the rear drive axle. An intelligent power-control system determines the most efficient operation of the engine and energy storage system.

Aerodynamic design on high-speed trains

Science.gov (United States)

Ding, San-San; Li, Qiang; Tian, Ai-Qin; Du, Jian; Liu, Jia-Li

2016-04-01

Compared with the traditional train, the operational speed of the high-speed train has largely improved, and the dynamic environment of the train has changed from one of mechanical domination to one of aerodynamic domination. The aerodynamic problem has become the key technological challenge of high-speed trains and significantly affects the economy, environment, safety, and comfort. In this paper, the relationships among the aerodynamic design principle, aerodynamic performance indexes, and design variables are first studied, and the research methods of train aerodynamics are proposed, including numerical simulation, a reduced-scale test, and a full-scale test. Technological schemes of train aerodynamics involve the optimization design of the streamlined head and the smooth design of the body surface. Optimization design of the streamlined head includes conception design, project design, numerical simulation, and a reduced-scale test. Smooth design of the body surface is mainly used for the key parts, such as electric-current collecting system, wheel truck compartment, and windshield. The aerodynamic design method established in this paper has been successfully applied to various high-speed trains (CRH380A, CRH380AM, CRH6, CRH2G, and the Standard electric multiple unit (EMU)) that have met expected design objectives. The research results can provide an effective guideline for the aerodynamic design of high-speed trains.

Vehicle fault diagnostics and management system

Science.gov (United States)

Gopal, Jagadeesh; Gowthamsachin

2017-11-01

This project is a kind of advanced automatic identification technology, and is more and more widely used in the fields of transportation and logistics. It looks over the main functions with like Vehicle management, Vehicle Speed limit and Control. This system starts with authentication process to keep itself secure. Here we connect sensors to the STM32 board which in turn is connected to the car through Ethernet cable, as Ethernet in capable of sending large amounts of data at high speeds. This technology involved clearly shows how a careful combination of software and hardware can produce an extremely cost-effective solution to a problem.

Combining chemical and electric-nuclear propulsion for high speed flight

International Nuclear Information System (INIS)

Murthy, S.N.B.; Froning, H.D.

1991-01-01

In the development of propulsion for the high speed (greater than Mach 8) regime of a SSTO vehicle, an alternative to a combination of scramjets and conventional chemical rockets is a nuclear system such as the dense plasma fusion engine operated with aneutronic fuels. Several variants are then possible in the manner of energizing the working fluid. An attempt has been made to compare the effectiveness of nuclear and scramjet engines with respect to weights and utilization of energy availability. It is shown that nuclear engines can be as effective as the optimized combustion engines, and will yield a considerable reduction in GTOW in earth-based missions, and have a special use in other planetary atmospheres in which combustion may be difficult but collection and processing of working fluid is feasible. 9 refs

Toward an Effective Long-Term Strategy for Preventing Motor Vehicle Crashes and Injuries

Directory of Open Access Journals (Sweden)

Anthony R. Mawson

2014-08-01

Full Text Available Casualties due to motor vehicle crashes (MVCs include some 40,000 deaths each year in the United States and one million deaths worldwide. One strategy that has been recommended for improving automobile safety is to lower speed limits and enforce them with speed cameras. However, motor vehicles can be hazardous even at low speeds whereas properly protected human beings can survive high-speed crashes without injury. Emphasis on changing driver behavior as the focus for road safety improvements has been largely unsuccessful; moreover, drivers today are increasingly distracted by secondary tasks such as cell phone use and texting. Indeed, the true limiting factor in vehicular safety is the capacity of human beings to sense and process information and to make rapid decisions. Given that dramatic reductions in injuries and deaths from MVCs have occurred over the past century due to improvements in safety technology, despite increases in the number of vehicles on the road and miles driven per vehicle, we propose that an effective long-term strategy for reducing MVC-related injury would be continued technological innovation in vehicle design, aimed at progressively removing the driver from routine operational decision-making. Once this is achieved, high rates of speed could be achieved on open highways, with minimal risk of crashes and injury to occupants and pedestrians.

Toward an effective long-term strategy for preventing motor vehicle crashes and injuries.

Science.gov (United States)

Mawson, Anthony R; Walley, E Kenneth

2014-08-11

Casualties due to motor vehicle crashes (MVCs) include some 40,000 deaths each year in the United States and one million deaths worldwide. One strategy that has been recommended for improving automobile safety is to lower speed limits and enforce them with speed cameras. However, motor vehicles can be hazardous even at low speeds whereas properly protected human beings can survive high-speed crashes without injury. Emphasis on changing driver behavior as the focus for road safety improvements has been largely unsuccessful; moreover, drivers today are increasingly distracted by secondary tasks such as cell phone use and texting. Indeed, the true limiting factor in vehicular safety is the capacity of human beings to sense and process information and to make rapid decisions. Given that dramatic reductions in injuries and deaths from MVCs have occurred over the past century due to improvements in safety technology, despite increases in the number of vehicles on the road and miles driven per vehicle, we propose that an effective long-term strategy for reducing MVC-related injury would be continued technological innovation in vehicle design, aimed at progressively removing the driver from routine operational decision-making. Once this is achieved, high rates of speed could be achieved on open highways, with minimal risk of crashes and injury to occupants and pedestrians.

High-speed Imaging of Global Surface Temperature Distributions on Hypersonic Ballistic-Range Projectiles

Science.gov (United States)

Wilder, Michael C.; Reda, Daniel C.

2004-01-01

The NASA-Ames ballistic range provides a unique capability for aerothermodynamic testing of configurations in hypersonic, real-gas, free-flight environments. The facility can closely simulate conditions at any point along practically any trajectory of interest experienced by a spacecraft entering an atmosphere. Sub-scale models of blunt atmospheric entry vehicles are accelerated by a two-stage light-gas gun to speeds as high as 20 times the speed of sound to fly ballistic trajectories through an 24 m long vacuum-rated test section. The test-section pressure (effective altitude), the launch velocity of the model (flight Mach number), and the test-section working gas (planetary atmosphere) are independently variable. The model travels at hypersonic speeds through a quiescent test gas, creating a strong bow-shock wave and real-gas effects that closely match conditions achieved during actual atmospheric entry. The challenge with ballistic range experiments is to obtain quantitative surface measurements from a model traveling at hypersonic speeds. The models are relatively small (less than 3.8 cm in diameter), which limits the spatial resolution possible with surface mounted sensors. Furthermore, since the model is in flight, surface-mounted sensors require some form of on-board telemetry, which must survive the massive acceleration loads experienced during launch (up to 500,000 gravities). Finally, the model and any on-board instrumentation will be destroyed at the terminal wall of the range. For these reasons, optical measurement techniques are the most practical means of acquiring data. High-speed thermal imaging has been employed in the Ames ballistic range to measure global surface temperature distributions and to visualize the onset of transition to turbulent-flow on the forward regions of hypersonic blunt bodies. Both visible wavelength and infrared high-speed cameras are in use. The visible wavelength cameras are intensified CCD imagers capable of integration

Thermostructural applications of heat pipes for cooling leading edges of high-speed aerospace vehicles

Science.gov (United States)

Camarda, Charles J.; Glass, David E.

1992-01-01

Heat pipes have been considered for use on wing leading edge for over 20 years. Early concepts envisioned metal heat pipes cooling a metallic leading edge. Several superalloy/sodium heat pipes were fabricated and successfully tested for wing leading edge cooling. Results of radiant heat and aerothermal testing indicate the feasibility of using heat pipes to cool the stagnation region of shuttle-type space transportation systems. The test model withstood a total seven radiant heating tests, eight aerothermal tests, and twenty-seven supplemental radiant heating tests. Cold-wall heating rates ranged from 21 to 57 Btu/sq ft-s and maximum operating temperatures ranged from 1090 to 1520 F. Follow-on studies investigated the application of heat pipes to cool the stagnation regions of single-stage-to-orbit and advanced shuttle vehicles. Results of those studies indicate that a 'D-shaped' structural design can reduce the mass of the heat-pipe concept by over 44 percent compared to a circular heat-pipe geometry. Simple analytical models for heat-pipe startup from the frozen state (working fluid initially frozen) were adequate to approximate transient, startup, and steady-state heat-pipe performance. Improvement in analysis methods has resulted in the development of a finite-element analysis technique to predict heat-pipe startup from the frozen state. However, current requirements of light-weight design and reliability suggest that metallic heat pipes embedded in a refractory composite material should be used. This concept is the concept presently being evaluated for NASP. A refractory-composite/heat-pipe-cooled wing leading edge is currently being considered for the National Aero-Space Plane (NASP). This concept uses high-temperature refractory-metal/lithium heat pipes embedded within a refractory-composite structure and is significantly lighter than an actively cooled wing leading edge because it eliminates the need for active cooling during ascent and descent. Since the

75 FR 25927 - Vehicle/Track Interaction Safety Standards; High-Speed and High Cant Deficiency Operations

Science.gov (United States)

2010-05-10

... Transporte;* Sheet Metal Workers International Association (SMWIA); Tourist Railway Association, Inc... over their intended service routes using instrumented wheelsets to directly measure forces between the... Carbody Acceleration Events During route testing of the MARC-III multi-level car at speeds to 125 m.p.h...

Benefits associated with advanced technologies applied to a high-speed civil transport concept

Science.gov (United States)

Ozoroski, L. P.; Shields, E. W.; Fenbert, J. W.; Mcelroy, M. O.

1993-01-01

Results of a first-order assessment of the mission performance benefits associated with the technology improvements and goals of the Phase II High-Speed Research (HSR) Program are presented. A breakdown of the four major disciplines resulted in the following estimated TOGW savings from the 1990 vehicle: propulsion at 14.3 percent, structures at 11.7 percent, flight-deck systems at 4.0 percent, and aerodynamics at 15.0 percent. Based on 100 percent success of the HSR Phase II proposed technology advancements, the overall combined impact is estimated to result in a 45 percent reduction in TOGW from a 1990 entry-into-service (EIS) date, which could result in a viable 2005 EIS vehicle with an acceptable TOGW that meets Stage III community noise restrictions. Through supersonic laminar flow control and the possible reduction in reserve fuel requirements resulting from synthetic vision capability, the potential exists for an additional 9.6 percent reduction in TOGW.

Risk Factors Associated with Injury and Mortality from Paediatric Low Speed Vehicle Incidents: A Systematic Review

Directory of Open Access Journals (Sweden)

Anne Paul Anthikkat

2013-01-01

Full Text Available Objective. This study reviews modifiable risk factors associated with fatal and nonfatal injury from low-speed vehicle runover (LSVRO incidents involving children aged 0–15 years. Data Sources. Electronic searches for child pedestrian and driveway injuries from the peer-reviewed literature and transport-related websites from 1955 to 2012. Study Selection. 41 studies met the study inclusion criteria. Data Extraction. A systematic narrative summary was conducted that included study design, methodology, risk factors, and other study variables. Results. The most commonly reported risk factors for LSVRO incidents included age under 5 years, male gender, and reversing vehicles. The majority of reported incidents involved residential driveways, but several studies identified other traffic and nontraffic locations. Low socioeconomic status and rental accommodation were also associated with LSVRO injury. Vehicles were most commonly driven by a family member, predominantly a parent. Conclusion. There are a number of modifiable vehicular, environmental, and behavioural factors associated with LSVRO injuries in young children that have been identified in the literature to date. Strategies relating to vehicle design (devices for increased rearward visibility and crash avoidance systems, housing design (physical separation of driveway and play areas, and behaviour (driver behaviour, supervision of young children are discussed.

Full-frame, high-speed 3D shape and deformation measurements using stereo-digital image correlation and a single color high-speed camera

Science.gov (United States)

Yu, Liping; Pan, Bing

2017-08-01

Full-frame, high-speed 3D shape and deformation measurement using stereo-digital image correlation (stereo-DIC) technique and a single high-speed color camera is proposed. With the aid of a skillfully designed pseudo stereo-imaging apparatus, color images of a test object surface, composed of blue and red channel images from two different optical paths, are recorded by a high-speed color CMOS camera. The recorded color images can be separated into red and blue channel sub-images using a simple but effective color crosstalk correction method. These separated blue and red channel sub-images are processed by regular stereo-DIC method to retrieve full-field 3D shape and deformation on the test object surface. Compared with existing two-camera high-speed stereo-DIC or four-mirror-adapter-assisted singe-camera high-speed stereo-DIC, the proposed single-camera high-speed stereo-DIC technique offers prominent advantages of full-frame measurements using a single high-speed camera but without sacrificing its spatial resolution. Two real experiments, including shape measurement of a curved surface and vibration measurement of a Chinese double-side drum, demonstrated the effectiveness and accuracy of the proposed technique.

High speed VLSI neural network for high energy physics

NARCIS (Netherlands)

Masa, P.; Masa, P.; Hoen, K.; Hoen, Klaas; Wallinga, Hans

1994-01-01

A CMOS neural network IC is discussed which was designed for very high speed applications. The parallel architecture, analog computing and digital weight storage provides unprecedented computing speed combined with ease of use. The circuit classifies up to 70 dimensional vectors within 20

Thrust Reduction of Magnetic Levitation Vehicle Driven by Long Stator Linear Synchronous Motor

Directory of Open Access Journals (Sweden)

Wan-Tsun Tseng

2013-01-01

Full Text Available The propulsion technology of long stator linear synchronous motors is used to drive high-speed maglev trains. The linear synchronous motor stator is divided into sections placed on guideway. The electric power supplies to stator sections in which the train just passes in change-step mode for long-distance operation. However, a thrust drop will be caused by change-step machinery for driving magnetic vehicle. According to the train speed and vehicle data, the change-step mode has three types of operation, namely premature commutation, simultaneous commutation, and late commutation. Each type of operation has a different thrust drop which can be affected by several parameters such as jerk, running speed, motor section length, and vehicle data. This paper focuses on determining the thrust drop of the change-step mode. The study results of this paper can be used to improve the operation system of high-speed maglev trains.

Efficient Numerical Simulation of Aerothermoelastic Hypersonic Vehicles

Science.gov (United States)

Klock, Ryan J.

Hypersonic vehicles operate in a high-energy flight environment characterized by high dynamic pressures, high thermal loads, and non-equilibrium flow dynamics. This environment induces strong fluid, thermal, and structural dynamics interactions that are unique to this flight regime. If these vehicles are to be effectively designed and controlled, then a robust and intuitive understanding of each of these disciplines must be developed not only in isolation, but also when coupled. Limitations on scaling and the availability of adequate test facilities mean that physical investigation is infeasible. Ever growing computational power offers the ability to perform elaborate numerical simulations, but also has its own limitations. The state of the art in numerical simulation is either to create ever more high-fidelity physics models that do not couple well and require too much processing power to consider more than a few seconds of flight, or to use low-fidelity analytical models that can be tightly coupled and processed quickly, but do not represent realistic systems due to their simplifying assumptions. Reduced-order models offer a middle ground by distilling the dominant trends of high-fidelity training solutions into a form that can be quickly processed and more tightly coupled. This thesis presents a variably coupled, variable-fidelity, aerothermoelastic framework for the simulation and analysis of high-speed vehicle systems using analytical, reduced-order, and surrogate modeling techniques. Full launch-to-landing flights of complete vehicles are considered and used to define flight envelopes with aeroelastic, aerothermal, and thermoelastic limits, tune in-the-loop flight controllers, and inform future design considerations. A partitioned approach to vehicle simulation is considered in which regions dominated by particular combinations of processes are made separate from the overall solution and simulated by a specialized set of models to improve overall processing

Hybrid Electric Vehicle Experimental Model with CAN Network Real Time Control

Directory of Open Access Journals (Sweden)

RATOI, M.

2010-05-01

Full Text Available In this paper an experimental model with a distributed control system of a hybrid electrical vehicle is presented. A communication CAN network of high speed (1 Mbps assures a distributed control of the all components. The modeling and the control of different operating regimes are realized on an experimental test-bench of a hybrid electrical vehicle. The experimental results concerning the variations of the mains variables (currents, torques, speeds are presented.

Full-Scale Passive Earth Entry Vehicle Landing Tests: Methods and Measurements

Science.gov (United States)

Littell, Justin D.; Kellas, Sotiris

2018-01-01

During the summer of 2016, a series of drop tests were conducted on two passive earth entry vehicle (EEV) test articles at the Utah Test and Training Range (UTTR). The tests were conducted to evaluate the structural integrity of a realistic EEV vehicle under anticipated landing loads. The test vehicles were lifted to an altitude of approximately 400m via a helicopter and released via release hook into a predesignated 61 m landing zone. Onboard accelerometers were capable of measuring vehicle free flight and impact loads. High-speed cameras on the ground tracked the free-falling vehicles and data was used to calculate critical impact parameters during the final seconds of flight. Additional sets of high definition and ultra-high definition cameras were able to supplement the high-speed data by capturing the release and free flight of the test articles. Three tests were successfully completed and showed that the passive vehicle design was able to withstand the impact loads from nominal and off-nominal impacts at landing velocities of approximately 29 m/s. Two out of three test resulted in off-nominal impacts due to a combination of high winds at altitude and the method used to suspend the vehicle from the helicopter. Both the video and acceleration data captured is examined and discussed. Finally, recommendations for improved release and instrumentation methods are presented.

High spatio-temporal resolution pollutant measurements of on-board vehicle emissions using ultra-fast response gas analyzers

Directory of Open Access Journals (Sweden)

M. Irwin

2018-06-01

Full Text Available Existing ultra-fast response engine exhaust emissions analyzers have been adapted for on-board vehicle use combined with GPS data. We present, for the first time, how high spatio-temporal resolution data products allow transient features associated with internal combustion engines to be examined in detail during on-road driving. Such data are both useful to examine the circumstances leading to high emissions, and reveals the accurate position of urban air quality hot spots as deposited by the candidate vehicle, useful for source attribution and dispersion modelling. The fast response time of the analyzers, which results in 100 Hz data, makes accurate time-alignment with the vehicle's engine control unit (ECU signals possible. This enables correlation with transient air fuel ratio, engine speed, load, and other engine parameters, which helps to explain the causes of the emissions spikes that portable emissions measurement systems (PEMS and conventional slow response analyzers would miss or smooth out due to mixing within their sampling systems. The data presented is from NO and NOx analyzers, but other fast analyzers (e.g. total hydrocarbons (THC, CO and CO2 can be used similarly. The high levels of NOx pollution associated with accelerating on entry ramps to motorways, driving over speed bumps, accelerating away from traffic lights, are explored in detail. The time-aligned ultra-fast analyzers offer unique insight allowing more accurate quantification and better interpretation of engine and driver activity and the associated emissions impact on local air quality.

The Harmonoise/IMAGINE model for traction noise of powered railway vehicles

NARCIS (Netherlands)

Dittrich, M.G.; Zhang, X.

2006-01-01

Traction noise is one of the noise sources of powered railway vehicles such as locomotives, electric- and diesel-powered multiple unit trains and high-speed trains. Especially at speeds below 60 km/h and at idling, but also at acceleration conditions for a wide range of speeds, traction noise can be

Piecewise affine control for fast unmanned ground vehicles

OpenAIRE

Benine Neto , André; Grand , Christophe

2012-01-01

International audience; Unmanned ground vehicles (UGV) may experience skidding when moving at high speeds, and therefore have its safety jeopardized. For this reason the nonlinear dynamics of lateral tire forces must be taken into account into the design of steering controllers for autonomous vehicles. This paper presents the design of a state feedback piecewise affine controller applied to an UGV to coordinate the steering and torque distribution inputs in order to reduce vehicle skidding on...

Automated mixed traffic vehicle control and scheduling study

Science.gov (United States)

Peng, T. K. C.; Chon, K.

1976-01-01

The operation and the expected performance of a proposed automatic guideway transit system which uses low speed automated mixed traffic vehicles (AMTVs) were analyzed. Vehicle scheduling and headway control policies were evaluated with a transit system simulation model. The effect of mixed traffic interference on the average vehicle speed was examined with a vehicle pedestrian interface model. Control parameters regulating vehicle speed were evaluated for safe stopping and passenger comfort. Some preliminary data on the cost and operation of an experimental AMTV system are included. These data were the result of a separate task conducted at JPL, and were included as background information.

Multi-Speed Transmission For Commercial Delivery Medium Duty PEDVs

Energy Technology Data Exchange (ETDEWEB)

Chavdar, Bulent [Eaton Corp., Menomonee Falls, WI (United States)

2017-12-31

Successful completion of the proposed project will set a course for improving quality of life by overcoming key challenges in the gearbox for commercial-delivery, medium-duty, plug-in electric drive vehicles: It will reduce US dependency on foreign oil through the use of electric driven propulsion instead of fuel driven. It will reduce health risks by replacing tailpipe emissions in densely populated city centers. Finally, it will improve the performance-cost basis to meet or exceed the expectations of the targeted medium duty vehicle fleet owners and the independent customers. The proposed multi-speed transmission will narrow motor operation to the peak efficiency region, thereby increasing the electric powertrain efficiency to help close the range gap. Further, it will enhance customer satisfaction by improving vehicle acceleration, top speed and gradeability over the baseline. The project was conducted in three budget periods: In BP1: Technology Development, High-level vehicle powertrain models were used to optimize candidate transmission architectures and ratios along with a variety of traction motor characteristics for concept selection. The detailed driveline designs and component dynamics were investigated to meet medium-duty EV requirements; In BP2: Technology Development and Prototype Demonstration, The modeling and simulations with multi-speed transmissions were extended to other MD and HD EV platforms. Clean sheet design of a compact, lightweight, flexible, and modular, four-speed transmission was completed. Development of novel shifting and controls strategies were started and procurement of the prototype transmission and the controller hardware was begun; In BP3: Technology Integration, Testing, and Demonstration, Prototyping the four-speed automated mechanical transmission was completed. The transmission controls system and software development and preliminary gearbox dyno tests were done at Eaton. ORNL conducted integrated powertrain HIL tests. One

A High-Speed Design of Montgomery Multiplier

Science.gov (United States)

Fan, Yibo; Ikenaga, Takeshi; Goto, Satoshi

With the increase of key length used in public cryptographic algorithms such as RSA and ECC, the speed of Montgomery multiplication becomes a bottleneck. This paper proposes a high speed design of Montgomery multiplier. Firstly, a modified scalable high-radix Montgomery algorithm is proposed to reduce critical path. Secondly, a high-radix clock-saving dataflow is proposed to support high-radix operation and one clock cycle delay in dataflow. Finally, a hardware-reused architecture is proposed to reduce the hardware cost and a parallel radix-16 design of data path is proposed to accelerate the speed. By using HHNEC 0.25μm standard cell library, the implementation results show that the total cost of Montgomery multiplier is 130 KGates, the clock frequency is 180MHz and the throughput of 1024-bit RSA encryption is 352kbps. This design is suitable to be used in high speed RSA or ECC encryption/decryption. As a scalable design, it supports any key-length encryption/decryption up to the size of on-chip memory.

Electric vehicles, magnetic levitation and superconductive levitation in Japan

International Nuclear Information System (INIS)

Wyczalek, F.A.

1988-01-01

This is a technological assessment of electric automotive vehicles, high speed magnetic levitation trains and hyperspeed superconductive magnetic levitation trains in Japan. It includes conventional battery electric vehicles for the automotive application, conventional magnetic levitation trains with peak speeds of 300 km/h and superconductive levitation trains capable of speeds over 500 km/h in transcontinental service. These electric vehicles have been under development since 1971 and are now considered ready for introduction into intercity commercial service. Conventional magnetic levitation trains are targeted to connect New Chitose International Airport with Sapporo and shorter connections in LasVegas, Philadelphia and Miami. The first superconductive train is planned for the Osaka to Tokyo link by the year 2000, a distance of 515 km. The initial step has been taken with approval of funding for the first five year phase of construction beginning with the Kansai project near Osaka

How does speed affect the rebound effect in car travel? Conceptual issues explored in case study of 900 Formula 1 Grand Prix speed trials

International Nuclear Information System (INIS)

Galvin, Ray

2017-01-01

The “rebound effect” occurs when reductions in energy consumption following energy efficiency increases are lower than engineering estimates. In cars this happens when drivers increase their distance travelled or average speed, as a behavioural response to cheaper travel. Rebound effects due to increased distance travelled have been extensively studied, but only one existing study attempts to quantify rebound effects due to increased average speed. This paper builds on that study, using a much larger empirical base and offering more generalised and more widely applicable mathematical modelling. It uses data from 30 Formula 1 Grand Prix time trial sessions of 10 vehicles doing 3 trials each, in 2014 and 2015. The heavily regulated Formula 1 regime, with its precisely measured data, provides a highly controlled framework for developing mathematics of average speed rebounds. The study thereby shows how speed and distance rebounds can be coherently combined in road vehicle travel to produce total rebound figures. It then shows how even small increases in average speed can nullify all the energy savings that are expected from energy efficiency increases. It also raises critical questions on the adequacy of proposed new road vehicle fuel efficiency testing procedures. - Highlights: • Rebound effects in car travel have been well studied for distance but not speed. • But speed rebound effects reduce fuel savings from energy efficiency upgrades. • A mathematical model is developed for dealing with average speed rebounds. • This model is tested with precise data from 900 Formula 1 Grand Prix time trials. • It is shown how speed and distance rebounds can be combined in everyday car travel.

High-speed and high-fidelity system and method for collecting network traffic

Science.gov (United States)

Weigle, Eric H [Los Alamos, NM

2010-08-24

A system is provided for the high-speed and high-fidelity collection of network traffic. The system can collect traffic at gigabit-per-second (Gbps) speeds, scale to terabit-per-second (Tbps) speeds, and support additional functions such as real-time network intrusion detection. The present system uses a dedicated operating system for traffic collection to maximize efficiency, scalability, and performance. A scalable infrastructure and apparatus for the present system is provided by splitting the work performed on one host onto multiple hosts. The present system simultaneously addresses the issues of scalability, performance, cost, and adaptability with respect to network monitoring, collection, and other network tasks. In addition to high-speed and high-fidelity network collection, the present system provides a flexible infrastructure to perform virtually any function at high speeds such as real-time network intrusion detection and wide-area network emulation for research purposes.

System Analyses of Pneumatic Technology for High Speed Civil Transport Aircraft

Science.gov (United States)

Mavris, Dimitri N.; Tai, Jimmy C.; Kirby, Michelle M.; Roth, Bryce A.

1999-01-01

The primary aspiration of this study was to objectively assess the feasibility of the application of a low speed pneumatic technology, in particular Circulation Control (CC) to an HSCT concept. Circulation Control has been chosen as an enabling technology to be applied on a generic High Speed Civil Transport (HSCT). This technology has been proven for various subsonic vehicles including flight tests on a Navy A-6 and computational application on a Boeing 737. Yet, CC has not been widely accepted for general commercial fixed-wing use but its potential has been extensively investigated for decades in wind tunnels across the globe for application to rotorcraft. More recently, an experimental investigation was performed at Georgia Tech Research Institute (GTRI) with application to an HSCT-type configuration. The data from those experiments was to be applied to a full-scale vehicle to assess the impact from a system level point of view. Hence, this study attempted to quantitatively assess the impact of this technology to an HSCT. The study objective was achieved in three primary steps: 1) Defining the need for CC technology; 2) Wind tunnel data reduction; 3) Detailed takeoff/landing performance assessment. Defining the need for the CC technology application to an HSCT encompassed a preliminary system level analysis. This was accomplished through the utilization of recent developments in modern aircraft design theory at Aerospace Systems Design Laboratory (ASDL). These developments include the creation of techniques and methods needed for the identification of technical feasibility show stoppers. These techniques and methods allow the designer to rapidly assess a design space and disciplinary metric enhancements to enlarge or improve the design space. The takeoff and landing field lengths were identified as the concept "show-stoppers". Once the need for CC was established, the actual application of data and trends was assessed. This assessment entailed a reduction of the

High-resolution simulation of link-level vehicle emissions and concentrations for air pollutants in a traffic-populated eastern Asian city

Directory of Open Access Journals (Sweden)

S. Zhang

2016-08-01

Full Text Available Vehicle emissions containing air pollutants created substantial environmental impacts on air quality for many traffic-populated cities in eastern Asia. A high-resolution emission inventory is a useful tool compared with traditional tools (e.g. registration data-based approach to accurately evaluate real-world traffic dynamics and their environmental burden. In this study, Macau, one of the most populated cities in the world, is selected to demonstrate a high-resolution simulation of vehicular emissions and their contribution to air pollutant concentrations by coupling multimodels. First, traffic volumes by vehicle category on 47 typical roads were investigated during weekdays in 2010 and further applied in a networking demand simulation with the TransCAD model to establish hourly profiles of link-level vehicle counts. Local vehicle driving speed and vehicle age distribution data were also collected in Macau. Second, based on a localized vehicle emission model (e.g. the emission factor model for the Beijing vehicle fleet – Macau, EMBEV–Macau, this study established a link-based vehicle emission inventory in Macau with high resolution meshed in a temporal and spatial framework. Furthermore, we employed the AERMOD (AMS/EPA Regulatory Model model to map concentrations of CO and primary PM2.5 contributed by local vehicle emissions during weekdays in November 2010. This study has discerned the strong impact of traffic flow dynamics on the temporal and spatial patterns of vehicle emissions, such as a geographic discrepancy of spatial allocation up to 26 % between THC and PM2.5 emissions owing to spatially heterogeneous vehicle-use intensity between motorcycles and diesel fleets. We also identified that the estimated CO2 emissions from gasoline vehicles agreed well with the statistical fuel consumption in Macau. Therefore, this paper provides a case study and a solid framework for developing high-resolution environment assessment tools for other

Potential scenarios of concern for high speed rail operations

Science.gov (United States)

2011-03-16

Currently, multiple operating authorities are proposing the : introduction of high-speed rail service in the United States. : While high-speed rail service shares a number of basic : principles with conventional-speed rail service, the operational : ...

Regional on-road vehicle running emissions modeling and evaluation for conventional and alternative vehicle technologies.

Science.gov (United States)

Frey, H Christopher; Zhai, Haibo; Rouphail, Nagui M

2009-11-01

This study presents a methodology for estimating high-resolution, regional on-road vehicle emissions and the associated reductions in air pollutant emissions from vehicles that utilize alternative fuels or propulsion technologies. The fuels considered are gasoline, diesel, ethanol, biodiesel, compressed natural gas, hydrogen, and electricity. The technologies considered are internal combustion or compression engines, hybrids, fuel cell, and electric. Road link-based emission models are developed using modal fuel use and emission rates applied to facility- and speed-specific driving cycles. For an urban case study, passenger cars were found to be the largest sources of HC, CO, and CO(2) emissions, whereas trucks contributed the largest share of NO(x) emissions. When alternative fuel and propulsion technologies were introduced in the fleet at a modest market penetration level of 27%, their emission reductions were found to be 3-14%. Emissions for all pollutants generally decreased with an increase in the market share of alternative vehicle technologies. Turnover of the light duty fleet to newer Tier 2 vehicles reduced emissions of HC, CO, and NO(x) substantially. However, modest improvements in fuel economy may be offset by VMT growth and reductions in overall average speed.

Dynamics and Control of Non-Smooth Systems with Applications to Supercavitating Vehicles

Science.gov (United States)

2011-01-01

ABSTRACT Title of dissertation: Dynamics and Control of Non-Smooth Systems with Applications to Supercavitating Vehicles Vincent Nguyen, Doctor of...relates to the dynamics of non-smooth vehicle systems, and in particular, supercavitating vehicles. These high-speed under- water vehicles are...Applications to Supercavitating Vehicles 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER 5e. TASK

The dynamic behaviour of a railway mine vehicle

Energy Technology Data Exchange (ETDEWEB)

van Manen, P.; Brickle, B.V.

1983-06-01

The paper describes a mathematical model of a railway mine vehicle which is capable of predicting its dynamic behaviour in response to track inputs. The predictions of the model have been compared with the results of tests carried out on a new high speed mine vehicle and the correlation shown is good. The model yields frequency response information for the vehicle and may be used to simulate dynamic behaviour in response to track irregularities. (4 refs.)

High-Speed Non-Volatile Optical Memory: Achievements and Challenges

Directory of Open Access Journals (Sweden)

Vadym Zayets

2017-01-01

Full Text Available We have proposed, fabricated, and studied a new design of a high-speed optical non-volatile memory. The recoding mechanism of the proposed memory utilizes a magnetization reversal of a nanomagnet by a spin-polarized photocurrent. It was shown experimentally that the operational speed of this memory may be extremely fast above 1 TBit/s. The challenges to realize both a high-speed recording and a high-speed reading are discussed. The memory is compact, integratable, and compatible with present semiconductor technology. If realized, it will advance data processing and computing technology towards a faster operation speed.

A Study on BC Emission from Vehicles using Different Types of Fuel

Science.gov (United States)

Kim, K.; Son, J.; Kim, J.; Kim, S.; Park, G.; Sung, K.; Kim, I.; Chung, T.; Park, T.; Kang, S.; Ban, J.; Kim, J.; Hong, Y. D.; Woo, J. H.; Lee, T.

2017-12-01

Black carbon (BC) is an anthropogenic aerosol from fossil fuels, and biomass burning. It absorbs solar radiation, and heats the atmosphere leading 0.4W m-2 radiative forcing. BC is a particle that can cause serious effects on human body as well. Toxicological studies of black carbon suggests that BC may be an important carrier of toxic chemicals to human body. The recent researches show that one of the main precursor of BC is vehicle emission, but the inventory of BC emission rate from vehicle is inadequate in South Korea. This study tries to find differences of BC emission from different sizes of vehicles using different types of fuels. Fuels used in vehicles are gasoline, liquefied petroleum gas (LPG), and diesel. BC was directly measured from the tail pipe of vehicles using Aethalometer (AE33, Magee Scientific Corporation). This study was conducted in Transport Pollutant Research Center, National Institute of Environmental Research, South Korea. Measurement was progressed with the five different test modes of speeds. Speed modes includes 4.7, 17.3, 34.1, 65.4, and 97.3 km h-1. Emission rate of BC was high in the slowest speed mode, and showed decrease with increase of the speed of vehicles. Gasoline vehicles had the relatively higher emission rate of BC than the LPG vehicle, while the emission rate of BC for Diesel with DPF (Diesel Particle Filter) was observed to be the lowest.

High speed laser tomography system

Science.gov (United States)

Samsonov, D.; Elsaesser, A.; Edwards, A.; Thomas, H. M.; Morfill, G. E.

2008-03-01

A high speed laser tomography system was developed capable of acquiring three-dimensional (3D) images of optically thin clouds of moving micron-sized particles. It operates by parallel-shifting an illuminating laser sheet with a pair of galvanometer-driven mirrors and synchronously recording two-dimensional (2D) images of thin slices of the imaged volume. The maximum scanning speed achieved was 120000slices/s, sequences of 24 volume scans (up to 256 slices each) have been obtained. The 2D slices were stacked to form 3D images of the volume, then the positions of the particles were identified and followed in the consecutive scans. The system was used to image a complex plasma with particles moving at speeds up to cm/s.

Air change rates of motor vehicles and in-vehicle pollutant concentrations from secondhand smoke.

Science.gov (United States)

Ott, Wayne; Klepeis, Neil; Switzer, Paul

2008-05-01

The air change rates of motor vehicles are relevant to the sheltering effect from air pollutants entering from outside a vehicle and also to the interior concentrations from any sources inside its passenger compartment. We made more than 100 air change rate measurements on four motor vehicles under moving and stationary conditions; we also measured the carbon monoxide (CO) and fine particle (PM(2.5)) decay rates from 14 cigarettes smoked inside the vehicle. With the vehicle stationary and the fan off, the ventilation rate in air changes per hour (ACH) was less than 1 h(-1) with the windows closed and increased to 6.5 h(-1) with one window fully opened. The vehicle speed, window position, ventilation system, and air conditioner setting was found to affect the ACH. For closed windows and passive ventilation (fan off and no recirculation), the ACH was linearly related to the vehicle speed over the range from 15 to 72 mph (25 to 116 km h(-1)). With a vehicle moving, windows closed, and the ventilation system off (or the air conditioner set to AC Max), the ACH was less than 6.6 h(-1) for speeds ranging from 20 to 72 mph (32 to 116 km h(-1)). Opening a single window by 3'' (7.6 cm) increased the ACH by 8-16 times. For the 14 cigarettes smoked in vehicles, the deposition rate k and the air change rate a were correlated, following the equation k=1.3a (R(2)=82%; n=14). With recirculation on (or AC Max) and closed windows, the interior PM(2.5) concentration exceeded 2000 microg m(-3) momentarily for all cigarettes tested, regardless of speed. The concentration time series measured inside the vehicle followed the mathematical solutions of the indoor mass balance model, and the 24-h average personal exposure to PM(2.5) could exceed 35 microg m(-3) for just two cigarettes smoked inside the vehicle.

A Historical Review of High Speed Metal Forming

OpenAIRE

Zittel, G.

2010-01-01

This paper will present a Historical Review of High Speed Metal Forming beginning with the first thought of forming metal by using an electromagnetic impulse to today, whereby High Speed Metal Forming is an accepted production process. Although this paper will briefly cover the basic physics of the process, it will not dwell on it. It will rather show how the industrial acceptance of High Speed Metal Forming is tightly connected to the knowledge acquired from many applications studies. These ...

Design of power steering systems for heavy-duty long-haul vehicles

NARCIS (Netherlands)

Silvas, E.; Backx, E.A.; Hofman, T.; Voets, H.; Steinbuch, M.

2014-01-01

Conventionally, all auxiliaries present in a heavy-duty vehicle (e.g., power-steering pump, air-conditioning compressor) are engine-driven systems, which put high constraints on their performance. Outputs (e.g., speed, temperature) and energy consumption are dictated by engine speed, while most

New Integrated Testing System for the Validation of Vehicle-Snow Interaction Models

Science.gov (United States)

2010-08-06

are individual wheel speeds, accelerator pedal position, vehicle speed, yaw rate, lateral acceleration, steering wheel angle and brake ...forces and moments at each wheel center, vehicle body slip angle , speed, acceleration, yaw rate, roll, and pitch. The profilometer has a 3-D scanning...Stability Program. The test vehicle provides measurements that include three forces and moments at each wheel center, vehicle body slip angle , speed

High-speed photography. Technique and evolution

International Nuclear Information System (INIS)

Sanchez-Tembleque, R.

1981-01-01

It is intended to present some general considerations about ''Higg-speed photography'' as a tool of work common in mos research laboratories in the world. ''High-speed photography'' relies on the principles of photography of actions, that change rapidly with the time. The evolution of this technique goes along with the discovering of new phenomena in wich higher speeds are involved. At present is normal to deal with changing rates involving picoseconds times (10 -12 s) and new developments on the field of femtosecond (10 -15 s) theoretically are contemplated. (author)

Review of High-Speed Fiber Optic Grating Sensors Systems

Energy Technology Data Exchange (ETDEWEB)

Udd, E; Benterou, J; May, C; Mihailov, S J; Lu, P

2010-03-24

Fiber grating sensors can be used to support a wide variety of high speed measurement applications. This includes measurements of vibrations on bridges, traffic monitoring on freeways, ultrasonic detection to support non-destructive tests on metal plates and providing details of detonation events. This paper provides a brief overview of some of the techniques that have been used to support high speed measurements using fiber grating sensors over frequency ranges from 10s of kHz, to MHZ and finally toward frequencies approaching the GHz regime. Very early in the development of fiber grating sensor systems it was realized that a high speed fiber grating sensor system could be realized by placing an optical filter that might be a fiber grating in front of a detector so that spectral changes in the reflection from a fiber grating were amplitude modulated. In principal the only limitation on this type of system involved the speed of the output detector which with the development of high speed communication links moved from the regime of 10s of MHz toward 10s of GHz. The earliest deployed systems involved civil structures including measurements of the strain fields on composite utility poles and missile bodies during break tests, bridges and freeways. This was followed by a series of developments that included high speed fiber grating sensors to support nondestructive testing via ultrasonic wave detection, high speed machining and monitoring ship hulls. Each of these applications involved monitoring mechanical motion of structures and thus interest was in speeds up to a few 10s of MHz. Most recently there has been interest in using fiber grating to monitor the very high speed events such as detonations and this has led to utilization of fiber gratings that are consumed during an event that may require detection speeds of hundreds of MHz and in the future multiple GHz.

High-Speed Videography Instrumentation And Procedures

Science.gov (United States)

Miller, C. E.

1982-02-01

High-speed videography has been an electronic analog of low-speed film cameras, but having the advantages of instant-replay and simplicity of operation. Recent advances have pushed frame-rates into the realm of the rotating prism camera. Some characteristics of videography systems are discussed in conjunction with applications in sports analysis, and with sports equipment testing.

Two laboratory methods for the calibration of GPS speed meters

International Nuclear Information System (INIS)

Bai, Yin; Sun, Qiao; Du, Lei; Yu, Mei; Bai, Jie

2015-01-01

The set-ups of two calibration systems are presented to investigate calibration methods of GPS speed meters. The GPS speed meter calibrated is a special type of high accuracy speed meter for vehicles which uses Doppler demodulation of GPS signals to calculate the measured speed of a moving target. Three experiments are performed: including simulated calibration, field-test signal replay calibration, and in-field test comparison with an optical speed meter. The experiments are conducted at specific speeds in the range of 40–180 km h −1 with the same GPS speed meter as the device under calibration. The evaluation of measurement results validates both methods for calibrating GPS speed meters. The relative deviations between the measurement results of the GPS-based high accuracy speed meter and those of the optical speed meter are analyzed, and the equivalent uncertainty of the comparison is evaluated. The comparison results justify the utilization of GPS speed meters as reference equipment if no fewer than seven satellites are available. This study contributes to the widespread use of GPS-based high accuracy speed meters as legal reference equipment in traffic speed metrology. (paper)

Vehicle test report: Battronic pickup truck

Science.gov (United States)

Price, T. W.; Shain, T. W.; Freeman, R. J.; Pompa, M. F.

1982-01-01

An electric pickup truck was tested to characterize certain parameters and to provide baseline data that can be used for the comparison of improved batteries that may be incorporated into the vehicle at a later time. The vehicle tests were concentrated on the electrical drive subsystem; i.e., the batteries, controller, and motor. The tests included coastdowns to characterize the road load and range evaluations for both cyclic and constant speed conditions. A qualitative evaluation of the vehicle's performance was made by comparing its constant speed range performance with other vehicles.

Integrated computer network high-speed parallel interface

International Nuclear Information System (INIS)

Frank, R.B.

1979-03-01

As the number and variety of computers within Los Alamos Scientific Laboratory's Central Computer Facility grows, the need for a standard, high-speed intercomputer interface has become more apparent. This report details the development of a High-Speed Parallel Interface from conceptual through implementation stages to meet current and future needs for large-scle network computing within the Integrated Computer Network. 4 figures

High-speed and intercity passenger rail testing strategy.

Science.gov (United States)

2013-05-01

This high-speed and intercity passenger rail (HSIPR) testing strategy addresses the requirements for testing of high-speed train sets and technology before introduction to the North American railroad system. The report documents the results of a surv...

Application of high-speed photography to hydrodynamic instability research

International Nuclear Information System (INIS)

Chang Lihua; Li Zuoyou; Xiao Zhengfei; Zou Liyong; Liu Jinhong; Xiong Xueshi

2012-01-01

High-speed photography is used to study the Rayleigh-Taylor instability of air-water interface driven by high- pressure exploding gas. Clear images illustrating the instability are obtained, along with the air bubble peak speed and turbulent mixing speed. The RM (Richtmyer-Meshkov) instability of air/SF 6 interface driven by shock wave is also researched by using high-speed Schlieren technique on the horizontal shock tube and primary experimental results are obtained, which show the change of the turbulent mixing region clearly. (authors)

Development of high-speed video cameras

Science.gov (United States)

Etoh, Takeharu G.; Takehara, Kohsei; Okinaka, Tomoo; Takano, Yasuhide; Ruckelshausen, Arno; Poggemann, Dirk

2001-04-01

Presented in this paper is an outline of the R and D activities on high-speed video cameras, which have been done in Kinki University since more than ten years ago, and are currently proceeded as an international cooperative project with University of Applied Sciences Osnabruck and other organizations. Extensive marketing researches have been done, (1) on user's requirements on high-speed multi-framing and video cameras by questionnaires and hearings, and (2) on current availability of the cameras of this sort by search of journals and websites. Both of them support necessity of development of a high-speed video camera of more than 1 million fps. A video camera of 4,500 fps with parallel readout was developed in 1991. A video camera with triple sensors was developed in 1996. The sensor is the same one as developed for the previous camera. The frame rate is 50 million fps for triple-framing and 4,500 fps for triple-light-wave framing, including color image capturing. Idea on a video camera of 1 million fps with an ISIS, In-situ Storage Image Sensor, was proposed in 1993 at first, and has been continuously improved. A test sensor was developed in early 2000, and successfully captured images at 62,500 fps. Currently, design of a prototype ISIS is going on, and, hopefully, will be fabricated in near future. Epoch-making cameras in history of development of high-speed video cameras by other persons are also briefly reviewed.

Modeling real-world fuel consumption and carbon dioxide emissions with high resolution for light-duty passenger vehicles in a traffic populated city

International Nuclear Information System (INIS)

Zhang, Shaojun; Wu, Ye; Un, Puikei; Fu, Lixin; Hao, Jiming

2016-01-01

Modeling fuel consumption of light-duty passenger vehicles has created substantial concerns due to the uncertainty from real-world operating conditions. Macao is world-renowned for its tourism industry and high population density. An empirical model is developed to estimate real-world fuel consumption and carbon dioxide emissions for gasoline-powered light-duty passenger vehicles in Macao by considering local fleet configuration and operating conditions. Thanks to increasingly stringent fuel consumption limits in vehicle manufacturing countries, estimated type-approval fuel consumption for light-duty passenger vehicles in Macao by model year was reduced from 7.4 L/100 km in 1995 to 5.9 L/100 km in 2012, although a significant upsizing trend has considerably offset potential energy-saving benefit. However, lower driving speed and the air-conditioning usage tend to raise fleet-average fuel consumption and carbon dioxide emission factors, which are estimated to be 10.1 L/100 km and 240 g/km in 2010. Fleet-total fuel consumption and carbon dioxide emissions are modeled through registered vehicle population-based and link-level traffic demand approaches and the results satisfactorily coincide with the historical record of fuel sales in Macao. Temporal and spatial variations in fuel consumption and carbon dioxide emissions from light-duty passenger vehicles further highlight the importance of effective traffic management in congested areas of Macao. - Highlights: • A fuel consumption model is developed for Macao's light-duty passenger cars. • Increased vehicle size partially offset energy benefit from tightened fuel consumption standard. • Lower speed and use of air-conditioning greatly increase fuel use of Macao light-duty passenger cars. • A high resolution inventory of fuel use and carbon dioxide emissions is built with link-level traffic data. • Policy suggestions are provided to mitigate fuel use in a traffic populated city.

High-speed AFM of human chromosomes in liquid

Energy Technology Data Exchange (ETDEWEB)

Picco, L M; Dunton, P G; Ulcinas, A; Engledew, D J; Miles, M J [H H Wills Physics Laboratory and IRC in Nanotechnology, University of Bristol, Tyndall Avenue, Bristol BS8 1TL (United Kingdom); Hoshi, O; Ushiki, T [Division of Microscopic Anatomy and Bio-Imaging, Department of Cellular Function, Niigata University Graduate School of Medical and Dental Sciences, Asahimachi-Dori 1, Niigata, 951-8150 (Japan)], E-mail: m.j.miles@bristol.ac.uk

2008-09-24

Further developments of the previously reported high-speed contact-mode AFM are described. The technique is applied to the imaging of human chromosomes at video rate both in air and in water. These are the largest structures to have been imaged with high-speed AFM and the first imaging in liquid to be reported. A possible mechanism that allows such high-speed contact-mode imaging without significant damage to the sample is discussed in the context of the velocity dependence of the measured lateral force on the AFM tip.

Characterizing speed-independence of high-level designs

DEFF Research Database (Denmark)

Kishinevsky, Michael; Staunstrup, Jørgen

1994-01-01

This paper characterizes the speed-independence of high-level designs. The characterization is a condition on the design description ensuring that the behavior of the design is independent of the speeds of its components. The behavior of a circuit is modeled as a transition system, that allows data...... types, and internal as well as external non-determinism. This makes it possible to verify the speed-independence of a design without providing an explicit realization of the environment. The verification can be done mechanically. A number of experimental designs have been verified including a speed-independent...

Development of ultra high speed photographic system using high repetition rate visible laser

International Nuclear Information System (INIS)

Lee, Jong Min; Cha, Byung Hun; Kim, Sung Ho; Kim, Jung Bog; Lim, Chang Hwan; Cha, Hyung Ki; Song, Kyu Seok; Lee, Byung Deok; Rhi, Jong Hoon; Baik, Dae Hyun; Han, Jae Min; Rho, Si Pyo; Lee, Byung Cheol; Jeong, Do Yung; Choi, An Seong; Jeong, Chan Ik; Park, Dae Ung; Jeong, Sung Min; Lee, Sang Kil; Kim, Heon Jun; Jang, Rae gak; Jo, Do Hun; Park, Min Young

1992-12-01

The goal of this project is to develop and commercialize a high speed photographic system equipped with a high repetition rate visible laser. The developed system provides the characteristics of high time resolution and large number of frames. The system consists of 10 W air cooled CVL or a 30 W water cooled CVL, a rotating drum-type high speed camera with the framing rate of 35,000 fps, and a automatic control device. The system has the performance of 10 nsec time resolution, 35,000 fps framing rate, and 250 picture frames. The high speed photographic systems are widely applied to the fields such as high-efficient engine development, high-speed vibration analysis, shock wave propagation study, flow visualization analysis, weapon development, etc. (Author)

Connect & Drive - On the use of vehicle-to-vehicle communications to increase Traffic Stability and Efficiency

NARCIS (Netherlands)

Heijenk, Geert

2009-01-01

At moderate to high traffic densities, road traffic exhibits an unstable behavior, resulting in decrease traffic efficiency. One of the phenomena that can be observed at these densities is the propagation of shock waves against the flow of traffic, which seriously reduce the speed of vehicles. The

Enabling high speed friction stir welding of aluminum tailor welded blanks

Science.gov (United States)

Hovanski, Yuri

Current welding technologies for production of aluminum tailor-welded blanks (TWBs) are utilized in low-volume and niche applications, and have yet to be scaled for the high-volume vehicle market. This study targeted further weight reduction, part reduction, and cost savings by enabling tailor-welded blank technology for aluminum alloys at high-volumes. While friction stir welding (FSW) has traditionally been applied at linear velocities less than one meter per minute, high volume production applications demand the process be extended to higher velocities more amenable to cost sensitive production environments. Unfortunately, weld parameters and performance developed and characterized at low to moderate welding velocities do not directly translate to high speed linear friction stir welding. Therefore, in order to facilitate production of high volume aluminum FSW components, parameters were developed with a minimum welding velocity of three meters per minute. With an emphasis on weld quality, welded blanks were evaluated for post-weld formability using a combination of numerical and experimental methods. Evaluation across scales was ultimately validated by stamping full-size production door inner panels made from dissimilar thickness aluminum tailor-welded blanks, which provided validation of the numerical and experimental analysis of laboratory scale tests.

High-Speed Friction-Stir Welding to Enable Aluminum Tailor-Welded Blanks

Science.gov (United States)

Hovanski, Yuri; Upadhyay, Piyush; Carsley, John; Luzanski, Tom; Carlson, Blair; Eisenmenger, Mark; Soulami, Ayoub; Marshall, Dustin; Landino, Brandon; Hartfield-Wunsch, Susan

2015-05-01

Current welding technologies for production of aluminum tailor-welded blanks (TWBs) are utilized in low-volume and niche applications, and they have yet to be scaled for the high-volume vehicle market. This study targeted further weight reduction, part reduction, and cost savings by enabling tailor-welded blank technology for aluminum alloys at high volumes. While friction-stir welding (FSW) has been traditionally applied at linear velocities less than 1 m/min, high-volume production applications demand the process be extended to higher velocities more amenable to cost-sensitive production environments. Unfortunately, weld parameters and performance developed and characterized at low-to-moderate welding velocities do not directly translate to high-speed linear FSW. Therefore, to facilitate production of high-volume aluminum FSW components, parameters were developed with a minimum welding velocity of 3 m/min. With an emphasis on weld quality, welded blanks were evaluated for postweld formability using a combination of numerical and experimental methods. An evaluation across scales was ultimately validated by stamping full-size production door inner panels made from dissimilar thickness aluminum TWBs, which provided validation of the numerical and experimental analysis of laboratory-scale tests.

High speed maglev design

Science.gov (United States)

Rote, Donald M.; He, Jianliang; Coffey, Howard

1993-01-01

A propulsion and stabilization system for an inductive repulsion type magnetically levitated vehicle which is propelled and suspended by a system which includes dividing the superconducting magnets into two types: a strong field magnet which is located vertically below the vehicle for propulsion and guidance and a weak field superconducting magnet located at the ends of the vehicle for levitation and added guidance. Several proposed embodiments exist for the placement of the magnetic field shielding: locating the shielding on the vehicle, locating the shielding on the guideway, and locating the shielding on the guideway and adding shielding to the vertical undercarriage. In addition, the separation between the vehicle and the guideway can be controlled to reduce the exposure of the passenger cabin to magnetic fields.

High speed maglev design

Science.gov (United States)

Rote, D.M.; Jianliang He; Coffey, H.

1993-10-19

A propulsion and stabilization system for an inductive repulsion type magnetically levitated vehicle which is propelled and suspended by a system which includes dividing the superconducting magnets into two types: a strong field magnet which is located vertically below the vehicle for propulsion and guidance and a weak field superconducting magnet located at the ends of the vehicle for levitation and added guidance. Several proposed embodiments exist for the placement of the magnetic field shielding: locating the shielding on the vehicle, locating the shielding on the guideway, and locating the shielding on the guideway and adding shielding to the vertical undercarriage. In addition, the separation between the vehicle and the guideway can be controlled to reduce the exposure of the passenger cabin to magnetic fields. 4 figures.

Model Reduction of Computational Aerothermodynamics for Multi-Discipline Analysis in High Speed Flows

Science.gov (United States)

Crowell, Andrew Rippetoe

This dissertation describes model reduction techniques for the computation of aerodynamic heat flux and pressure loads for multi-disciplinary analysis of hypersonic vehicles. NASA and the Department of Defense have expressed renewed interest in the development of responsive, reusable hypersonic cruise vehicles capable of sustained high-speed flight and access to space. However, an extensive set of technical challenges have obstructed the development of such vehicles. These technical challenges are partially due to both the inability to accurately test scaled vehicles in wind tunnels and to the time intensive nature of high-fidelity computational modeling, particularly for the fluid using Computational Fluid Dynamics (CFD). The aim of this dissertation is to develop efficient and accurate models for the aerodynamic heat flux and pressure loads to replace the need for computationally expensive, high-fidelity CFD during coupled analysis. Furthermore, aerodynamic heating and pressure loads are systematically evaluated for a number of different operating conditions, including: simple two-dimensional flow over flat surfaces up to three-dimensional flows over deformed surfaces with shock-shock interaction and shock-boundary layer interaction. An additional focus of this dissertation is on the implementation and computation of results using the developed aerodynamic heating and pressure models in complex fluid-thermal-structural simulations. Model reduction is achieved using a two-pronged approach. One prong focuses on developing analytical corrections to isothermal, steady-state CFD flow solutions in order to capture flow effects associated with transient spatially-varying surface temperatures and surface pressures (e.g., surface deformation, surface vibration, shock impingements, etc.). The second prong is focused on minimizing the computational expense of computing the steady-state CFD solutions by developing an efficient surrogate CFD model. The developed two

Prediction on the charging demand for electric vehicles in Chengdu

Science.gov (United States)

yun, Cai; wanquan, Zhang; wei, You; pan, Mao

2018-03-01

The development of the electric vehicle charging station facilities speed directly affect the development of electric vehicle speed. And the charging demand of electric vehicles is one of the main factors influencing the electric vehicle charging facilities. The paper collected and collated car ownership in recent years, the use of elastic coefficient to predict Chengdu electric vehicle ownership, further modeling to give electric vehicle charging demand.

Minimum Plate Thickness in High-Speed Craft

DEFF Research Database (Denmark)

Pedersen, Preben Terndrup; Zhang, Shengming

1998-01-01

The minimum plate thickness requirements specified by the classification societies for high-speed craft are supposed to ensure adequate resistance to impact loads such as collision with floating objects and objects falling on the deck. The paper presents analytical methods of describing such impact...... phenomena and proposes performance requirements instead of thickness requirements for hull panels in high-speed craft made of different building materials....

The large scale and long term evolution of the solar wind speed distribution and high speed streams

International Nuclear Information System (INIS)

Intriligator, D.S.

1977-01-01

The spatial and temporal evolution of the solar wind speed distribution and of high speed streams in the solar wind are examined. Comparisons of the solar wind streaming speeds measured at Earth, Pioneer 11, and Pioneer 10 indicate that between 1 AU and 6.4 AU the solar wind speed distributions are narrower (i.e. the 95% value minus the 5% value of the solar wind streaming speed is less) at extended heliocentric distances. These observations are consistent with one exchange of momentum in the solar wind between high speed streams and low speed streams as they propagate outward from the Sun. Analyses of solar wind observations at 1 AU from mid 1964 through 1973 confirm the earlier results reported by Intriligator (1974) that there are statistically significant variations in the solar wind in 1968 and 1969, years of solar maximum. High speed stream parameters show that the number of high speed streams in the solar wind in 1968 and 1969 is considerably more than the predicted yearly average, and in 1965 and 1972 less. Histograms of solar wind speed from 1964 through 1973 indicate that in 1968 there was the highest percentage of elevated solar wind speeds and in 1965 and 1972 the lowest. Studies by others also confirm these results although the respective authors did not indicate this fact. The duration of the streams and the histograms for 1973 imply a shifting in the primary stream source. (Auth.)

Effectiveness of a Program Using a Vehicle Tracking System, Incentives, and Disincentives to Reduce the Speeding Behavior of Drivers with ADHD

Science.gov (United States)

Markham, Paula T.; Porter, Bryan E.; Ball, J. D.

2013-01-01

Objective: In this article, the authors investigated the effectiveness of a behavior modification program using global positioning system (GPS) vehicle tracking devices with contingency incentives and disincentives to reduce the speeding behavior of drivers with ADHD. Method: Using an AB multiple-baseline design, six participants drove a 5-mile…

A novel dual motor drive system for three wheel electric vehicles

Science.gov (United States)

Panmuang, Piyapat; Thongsan, Taweesak; Suwapaet, Nuchida; Laohavanich, Juckamass; Photong, Chonlatee

2018-03-01

This paper presents a novel dual motor drive system used for three wheel electric vehicles that have one free wheel at the front and two wheels with a drive system at the end of the vehicles. A novel dual motor drive system consists of two identical DC motors that are independently controlled by its speed-torque controller. Under light load conditions, only one of the DC motors will operate around it rated whilst under hard load conditions both of the DC motors will operate. With this drive system, the motors will operate only at its high performance at rated or else no operate to retain longer lifetime. The simulated results for the Skylab three wheel electric vehicle prototype with 8kW at full load (high torque, low speed) and around 4kW at light/normal operating loads (regular speed-torque) showed that the proposed system provides better dynamic responses with faster overshoot current/voltage recovery time, has lower investment costs, has longer lifetime of the motors and allows the motors to always operate at their high performance and thus achieve more cost effective system compared to a single motor drive system with 8kW DC motors.

Blind haste: As light decreases, speeding increases.

Science.gov (United States)

de Bellis, Emanuel; Schulte-Mecklenbeck, Michael; Brucks, Wernher; Herrmann, Andreas; Hertwig, Ralph

2018-01-01

Worldwide, more than one million people die on the roads each year. A third of these fatal accidents are attributed to speeding, with properties of the individual driver and the environment regarded as key contributing factors. We examine real-world speeding behavior and its interaction with illuminance, an environmental property defined as the luminous flux incident on a surface. Drawing on an analysis of 1.2 million vehicle movements, we show that reduced illuminance levels are associated with increased speeding. This relationship persists when we control for factors known to influence speeding (e.g., fluctuations in traffic volume) and consider proxies of illuminance (e.g., sight distance). Our findings add to a long-standing debate about how the quality of visual conditions affects drivers' speed perception and driving speed. Policy makers can intervene by educating drivers about the inverse illuminance‒speeding relationship and by testing how improved vehicle headlights and smart road lighting can attenuate speeding.

Blind haste: As light decreases, speeding increases.

Directory of Open Access Journals (Sweden)

Emanuel de Bellis

Full Text Available Worldwide, more than one million people die on the roads each year. A third of these fatal accidents are attributed to speeding, with properties of the individual driver and the environment regarded as key contributing factors. We examine real-world speeding behavior and its interaction with illuminance, an environmental property defined as the luminous flux incident on a surface. Drawing on an analysis of 1.2 million vehicle movements, we show that reduced illuminance levels are associated with increased speeding. This relationship persists when we control for factors known to influence speeding (e.g., fluctuations in traffic volume and consider proxies of illuminance (e.g., sight distance. Our findings add to a long-standing debate about how the quality of visual conditions affects drivers' speed perception and driving speed. Policy makers can intervene by educating drivers about the inverse illuminance‒speeding relationship and by testing how improved vehicle headlights and smart road lighting can attenuate speeding.

Long-range high-speed visible light communication system over 100-m outdoor transmission utilizing receiver diversity technology

Science.gov (United States)

Wang, Yiguang; Huang, Xingxing; Shi, Jianyang; Wang, Yuan-quan; Chi, Nan

2016-05-01

Visible light communication (VLC) has no doubt become a promising candidate for future wireless communications due to the increasing trends in the usage of light-emitting diodes (LEDs). In addition to indoor high-speed wireless access and positioning applications, VLC usage in outdoor scenarios, such as vehicle networks and intelligent transportation systems, are also attracting significant interest. However, the complex outdoor environment and ambient noise are the key challenges for long-range high-speed VLC outdoor applications. To improve system performance and transmission distance, we propose to use receiver diversity technology in an outdoor VLC system. Maximal ratio combining-based receiver diversity technology is utilized in two receivers to achieve the maximal signal-to-noise ratio. A 400-Mb/s VLC transmission using a phosphor-based white LED and a 1-Gb/s wavelength division multiplexing VLC transmission using a red-green-blue LED are both successfully achieved over a 100-m outdoor distance with the bit error rate below the 7% forward error correction limit of 3.8×10-3. To the best of our knowledge, this is the highest data rate at 100-m outdoor VLC transmission ever achieved. The experimental results clearly prove the benefit and feasibility of receiver diversity technology for long-range high-speed outdoor VLC systems.

Rat muscle blood flows during high-speed locomotion

International Nuclear Information System (INIS)

Armstrong, R.B.; Laughlin, M.H.

1985-01-01

We previously studied blood flow distribution within and among rat muscles as a function of speed from walking (15 m/min) through galloping (75 m/min) on a motor-driven treadmill. The results showed that muscle blood flows continued to increase as a function of speed through 75 m/min. The purpose of the present study was to have rats run up to maximal treadmill speeds to determine if blood flows in the muscles reach a plateau as a function of running speed over the animals normal range of locomotory speeds. Muscle blood flows were measured with radiolabeled microspheres at 1 min of running at 75, 90, and 105 m/min in male Sprague-Dawley rats. The data indicate that even at these relatively high treadmill speeds there was still no clear evidence of a plateau in blood flow in most of the hindlimb muscles. Flows in most muscles continued to increase as a function of speed. These observed patterns of blood flow vs. running speed may have resulted from the rigorous selection of rats that were capable of performing the high-intensity exercise and thus only be representative of a highly specific population of animals. On the other hand, the data could be interpreted to indicate that the cardiovascular potential during exercise is considerably higher in laboratory rats than has normally been assumed and that inadequate blood flow delivery to the muscles does not serve as a major limitation to their locomotory performance

Tactical Decision Aids High Bandwidth Links Using Autonomous Vehicles

Science.gov (United States)

2004-01-01

1 Tactical Decision Aids (High Bandwidth Links Using Autonomous Vehicles ) A. J. Healey, D. P. Horner, Center for Autonomous Underwater Vehicle...SUBTITLE Tactical Decision Aids (High Bandwidth Links Using Autonomous Vehicles ) 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6

New Intelligent Transmission Concept for Hybrid Mobile Robot Speed Control

Directory of Open Access Journals (Sweden)

Nazim Mir-Nasiri

2008-11-01

Full Text Available This paper presents a new concept of a mobile robot speed control by using two degree of freedom gear transmission. The developed intelligent speed controller utilizes a gear box which comprises of epicyclic gear train with two inputs, one coupled with the engine shaft and another with the shaft of a variable speed dc motor. The net output speed is a combination of the two input speeds and is governed by the transmission ratio of the planetary gear train. This new approach eliminates the use of a torque converter which is otherwise an indispensable part of all available automatic transmissions, thereby reducing the power loss that occurs in the box during the fluid coupling. By gradually varying the speed of the dc motor a stepless transmission has been achieved. The other advantages of the developed controller are pulling over and reversing the vehicle, implemented by intelligent mixing of the dc motor and engine speeds. This approach eliminates traditional braking system in entire vehicle design. The use of two power sources, IC engine and battery driven DC motor, utilizes the modern idea of hybrid vehicles. The new mobile robot speed controller is capable of driving the vehicle even in extreme case of IC engine failure, for example, due to gas depletion..

New Intelligent Transmission Concept for Hybrid Mobile Robot Speed Control

Directory of Open Access Journals (Sweden)

Nazim Mir-Nasiri

2005-09-01

Full Text Available This paper presents a new concept of a mobile robot speed control by using two degree of freedom gear transmission. The developed intelligent speed controller utilizes a gear box which comprises of epicyclic gear train with two inputs, one coupled with the engine shaft and another with the shaft of a variable speed dc motor. The net output speed is a combination of the two input speeds and is governed by the transmission ratio of the planetary gear train. This new approach eliminates the use of a torque converter which is otherwise an indispensable part of all available automatic transmissions, thereby reducing the power loss that occurs in the box during the fluid coupling. By gradually varying the speed of the dc motor a stepless transmission has been achieved. The other advantages of the developed controller are pulling over and reversing the vehicle, implemented by intelligent mixing of the dc motor and engine speeds. This approach eliminates traditional braking system in entire vehicle design. The use of two power sources, IC engine and battery driven DC motor, utilizes the modern idea of hybrid vehicles. The new mobile robot speed controller is capable of driving the vehicle even in extreme case of IC engine failure, for example, due to gas depletion.

High-Speed Photo-Polarimetry of Magnetic Cataclysmic Variables

Directory of Open Access Journals (Sweden)

S. B. Potter

2015-02-01

Full Text Available I review recent highlights of the SAAO High-speed Photo-POlarimeter (HIPPO on the study of magnetic Cataclysmic Variables. Its high-speed capabilities are demonstrated with example observations made of the intermediate polar NY Lup and the polar IGRJ14536-5522.

Novel Aerodynamic Design for Formula SAE Vehicles

Science.gov (United States)

Sentongo, Samuel; Carter, Austin; Cecil, Christopher; Feier, Ioan

2017-11-01

This paper identifies and evaluates the design characteristics of a novel airfoil that harnesses the Magnus Effect, applying a moving-surface boundary-layer control (MSBC) method to a Formula SAE Vehicle. The MSBC minimizes adverse pressure gradient and delays boundary layer separation through the use of a conveyor belt that interacts with the airfoil boundary layer. The MSBC allows dynamic control of the aerodynamic coefficients by variation of the belt speed, minimizing drag in high speed straights and maximizing downforce during vehicle cornering. A conveyer belt wing measuring approximately 0.9 x 0.9m in planform was designed and built to test the mechanical setup for such a MSBC wing. This study follows the relationship between inputted power and outputted surface velocity, with the goal being to maximize speed output vs. power input. The greatest hindrance to maximizing speed output is friction among belts, rollers, and stationary members. The maximum belt speed achieved during testing was 5.9 m/s with a power input of 48.8 W, which corresponds to 45.8 N of downforce based on 2D CFD results. Ongoing progress on this project is presented. United States Air Force Academy.

A Microcontroller Based Car-Safety System Implementing Drowsiness Detection And Vehicle-Vehicle Distance Detection In Parallel.

Directory of Open Access Journals (Sweden)

Pragyaditya Das.

2015-08-01

Full Text Available Abstract Accidents due to drowsiness can be controlled and prevented with the help of eye blink sensor using IR rays. It consists of IR transmitter and an IR receiver. The transmitter transmits IR rays into the eye. If the eye is shut then the output is high. If the eye is open then the output is low. This output is interfaced with an alarm inside and outside the vehicle. This module can be connected to the braking system of the vehicle and can be used to reduce the speed of the vehicle. The alarm inside the vehicle will go on for a period of time until the driver is back to his senses. If the driver is unable to take control of the vehicle after that stipulated amount of time then the alarm outside the vehicle will go on to warn and tell others to help the driver.

Trend on High-speed Power Line Communication Technology

Science.gov (United States)

Ogawa, Osamu

High-speed power line communication (PLC) is useful technology to easily build the communication networks, because construction of new infrastructure is not necessary. In Europe and America, PLC has been used for broadband networks since the beginning of 21th century. In Japan, high-speed PLC was deregulated only indoor usage in 2006. Afterward it has been widely used for home area network, LAN in hotels and school buildings and so on. And recently, PLC is greatly concerned as communication technology for smart grid network. In this paper, the author surveys the high-speed PLC technology and its current status.

A high speed digital noise generator

Science.gov (United States)

Obrien, J.; Gaffney, B.; Liu, B.

In testing of digital signal processing hardware, a high speed pseudo-random noise generator is often required to simulate an input noise source to the hardware. This allows the hardware to be exercised in a manner analogous to actual operating conditions. In certain radar and communication environments, a noise generator operating at speeds in excess of 60 MHz may be required. In this paper, a method of generating high speed pseudo-random numbers from an arbitrarily specified distribution (Gaussian, Log-Normal, etc.) using a transformation from a uniform noise source is described. A noise generator operating at 80 MHz has been constructed. Different distributions can be readily obtained by simply changing the ROM set. The hardware and test results will be described. Using this approach, the generation of pseudo-random sequences with arbitrary distributions at word rates in excess of 200 MHz can be readily achieved.

Compressibility, turbulence and high speed flow

CERN Document Server

Gatski, Thomas B

2013-01-01

Compressibility, Turbulence and High Speed Flow introduces the reader to the field of compressible turbulence and compressible turbulent flows across a broad speed range, through a unique complimentary treatment of both the theoretical foundations and the measurement and analysis tools currently used. The book provides the reader with the necessary background and current trends in the theoretical and experimental aspects of compressible turbulent flows and compressible turbulence. Detailed derivations of the pertinent equations describing the motion of such turbulent flows is provided and an extensive discussion of the various approaches used in predicting both free shear and wall bounded flows is presented. Experimental measurement techniques common to the compressible flow regime are introduced with particular emphasis on the unique challenges presented by high speed flows. Both experimental and numerical simulation work is supplied throughout to provide the reader with an overall perspective of current tre...

High-speed solar wind flow parameters at 1 AU

International Nuclear Information System (INIS)

Feldman, W.C.; Asbridge, J.R.; Bame, S.J.; Gosling, J.T.

1976-01-01

To develop a set of constraints for theories of solar wind high-speed streams, a detailed study was made of the fastest streams observed at 1 AU during the time period spanning March 1971 through July 1974. Streams were accepted for study only if (1) the maximum speed exceeded 650 km s -1 ; (2) effects of stream-stream dynamical interaction on the flow parameters could be safely separated from the intrinsic characteristics of the high-speed regions; (3) the full width at half maximum (FWHM) of the stream when mapped back to 20 solar radii by using a constant speed approximation was greater than 45degree in Carrington longitude; and (4) there were no obvious solar-activity-induced contaminating effects. Nineteen streams during this time interval satisfied these criteria. Average parameters at 1 AU for those portions of these streams above V=650 km s -1 are given.Not only is it not presently known why electrons are significantly cooler than the protons within high-speed regions, but also observed particle fluxes and convected energy fluxes for speed greater than 650 km s -1 are substantially larger than those values predicted by any of the existing theories of solar wind high-speed streams. More work is therefore needed in refining present solar wind models to see whether suitable modifications and/or combinations of existing theories based on reasonable coronal conditions can accommodate the above high-speed flow parameters

On-road emission characteristics of heavy-duty diesel vehicles in Shanghai

Science.gov (United States)

Chen, Changhong; Huang, Cheng; Jing, Qiguo; Wang, Haikun; Pan, Hansheng; Li, Li; Zhao, Jing; Dai, Yi; Huang, Haiying; Schipper, Lee; Streets, David G.

On-road vehicle tests of nine heavy-duty diesel trucks were conducted using SEMTECH-D, an emissions measuring instrument provided by Sensors, Inc. The total length of roads for the tests was 186 km. Data were obtained for 37,255 effective driving cycles, including 17,216 on arterial roads, 15,444 on residential roads, and 4595 on highways. The impacts of speed and acceleration on fuel consumption and emissions were analyzed. Results show that trucks spend an average of 16.5% of the time in idling mode, 25.5% in acceleration mode, 27.9% in deceleration mode, and only 30.0% at cruise speed. The average emission factors of CO, total hydrocarbons (THC), and NO x for the selected vehicles are (4.96±2.90), (1.88±1.03) and (6.54±1.90) g km -1, respectively. The vehicle emission rates vary significantly with factors like speed and acceleration. The test results reflect the actual traffic situation and the current emission status of diesel trucks in Shanghai. The measurements show that low-speed conditions with frequent acceleration and deceleration, particularly in congestion conditions, are the main factors that aggravate vehicle emissions and cause high emissions of CO and THC. Alleviating congestion would significantly improve vehicle fuel economy and reduce CO and THC emissions.

California statewide model for high-speed rail

OpenAIRE

Outwater, Maren; Tierney, Kevin; Bradley, Mark; Sall, Elizabeth; Kuppam, Arun; Modugala, Vamsee

2010-01-01

The California High Speed Rail Authority (CHSRA) and the Metropolitan Transportation Commission (MTC) have developed a new statewide model to support evaluation of high-speed rail alternatives in the State of California. This statewide model will also support future planning activities of the California Department of Transportation (Caltrans). The approach to this statewide model explicitly recognizes the unique characteristics of intraregional travel demand and interregional travel demand. A...

Effect of joint mechanism on vehicle redirectional capability of water-filled road safety barrier systems.

Science.gov (United States)

Thiyahuddin, M I; Thambiratnam, D P; Gu, Y T

2014-10-01

Portable water-filled barriers (PWFBs) are roadside appurtenances that prevent vehicles from penetrating into temporary construction zones on roadways. PWFBs are required to satisfy the strict regulations for vehicle re-direction in tests. However, many of the current PWFBs fail to re-direct the vehicle at high speeds due to the inability of the joints to provide appropriate stiffness. The joint mechanism hence plays a crucial role in the performance of a PWFB system at high speed impacts. This paper investigates the desired features of the joint mechanism in a PWFB system that can re-direct vehicles at high speeds, while limiting the lateral displacement to acceptable limits. A rectangular "wall" representative of a 30m long barrier system was modeled and a novel method of joining adjacent road barriers was introduced through appropriate pin-joint connections. The impact response of the barrier "wall" and the vehicle was obtained and the results show that a rotational stiffness of 3000kNm/rad at the joints seems to provide the desired features of the PWFB system to re-direct impacting vehicles and restrict the lateral deflection. These research findings will be useful to safety engineers and road barrier designers in developing a new generation of PWFBs for increased road safety. Copyright © 2014 Elsevier Ltd. All rights reserved.

Design of a Path-Tracking Steering Controller for Autonomous Vehicles

Directory of Open Access Journals (Sweden)

Chuanyang Sun

2018-06-01

Full Text Available This paper presents a linearization method for the vehicle and tire models under the model predictive control (MPC scheme, and proposes a linear model-based MPC path-tracking steering controller for autonomous vehicles. The steering controller is designed to minimize lateral path-tracking deviation at high speeds. The vehicle model is linearized by a sequence of supposed steering angles, which are obtained by assuming the vehicle can reach the desired path at the end of the MPC prediction horizon and stay in a steady-state condition. The lateral force of the front tire is directly used as the control input of the model, and the rear tire’s lateral force is linearized by an equivalent cornering stiffness. The course-direction deviation, which is the angle between the velocity vector and the path heading, is chosen as a control reference state. The linearization model is validated through the simulation, and the results show high prediction accuracy even in regions of large steering angle. This steering controller is tested through simulations on the CarSim-Simulink platform (R2013b, MathWorks, Natick, MA, USA, showing the improved performance of the present controller at high speeds.

A system methodology for optimization design of the structural crashworthiness of a vehicle subjected to a high-speed frontal crash

Science.gov (United States)

Xia, Liang; Liu, Weiguo; Lv, Xiaojiang; Gu, Xianguang

2018-04-01

The structural crashworthiness design of vehicles has become an important research direction to ensure the safety of the occupants. To effectively improve the structural safety of a vehicle in a frontal crash, a system methodology is presented in this study. The surrogate model of Online support vector regression (Online-SVR) is adopted to approximate crashworthiness criteria and different kernel functions are selected to enhance the accuracy of the model. The Online-SVR model is demonstrated to have the advantages of solving highly nonlinear problems and saving training costs, and can effectively be applied for vehicle structural crashworthiness design. By combining the non-dominated sorting genetic algorithm II and Monte Carlo simulation, both deterministic optimization and reliability-based design optimization (RBDO) are conducted. The optimization solutions are further validated by finite element analysis, which shows the effectiveness of the RBDO solution in the structural crashworthiness design process. The results demonstrate the advantages of using RBDO, resulting in not only increased energy absorption and decreased structural weight from a baseline design, but also a significant improvement in the reliability of the design.

Research on Aerodynamic Noise Reduction for High-Speed Trains

OpenAIRE

Zhang, Yadong; Zhang, Jiye; Li, Tian; Zhang, Liang; Zhang, Weihua

2016-01-01

A broadband noise source model based on Lighthill’s acoustic theory was used to perform numerical simulations of the aerodynamic noise sources for a high-speed train. The near-field unsteady flow around a high-speed train was analysed based on a delayed detached-eddy simulation (DDES) using the finite volume method with high-order difference schemes. The far-field aerodynamic noise from a high-speed train was predicted using a computational fluid dynamics (CFD)/Ffowcs Williams-Hawkings (FW-H)...

Non-linear vehicle-bridge-wind interaction model for running safety assessment of high-speed trains over a high-pier viaduct

Science.gov (United States)

Olmos, José M.; Astiz, Miguel Á.

2018-04-01

In order to properly study the high-speed traffic safety on a high-pier viaduct subject to episodes of lateral turbulent winds, an efficient dynamic interaction train-bridge-wind model has been developed and experimentally validated. This model considers the full wheel and rail profiles, the friction between these two bodies in contact, and the piers P-Delta effect. The model has been used to determine the critical train and wind velocities from which the trains cannot travel safely over the O'Eixo Bridge. The dynamic simulations carried out and the results obtained in the time domain show that traffic safety rates exceed the allowed limits for turbulent winds with mean velocities at the deck higher than 25 m/s.

Dynamic Eco-Driving Speed Guidance at Signalized Intersections: Multivehicle Driving Simulator Based Experimental Study

Directory of Open Access Journals (Sweden)

Peng Chen

2018-01-01

Full Text Available Variations in vehicle fuel consumption and gas emissions are usually associated with changes in cruise speed and the aggressiveness of drivers’ acceleration/deceleration, especially at traffic signals. In an attempt to enhance vehicle fuel efficiency on arterials, this study developed a dynamic eco-driving speed guidance strategy (DESGS using real-time signal timing and vehicle positioning information in a connected vehicle (CV environment. DESGS mainly aims to optimize the fuel/emission speed profiles for vehicles approaching signalized intersections. An optimization-based rolling horizon and a dynamic programming approach were proposed to track the optimal guided velocity for individual vehicles along the travel segment. In addition, a vehicle specific power (VSP based approach was integrated into DESGS to estimate the fuel consumption and CO2 emissions. To evaluate the effectiveness of the overall strategy, 15 experienced drivers were recruited to participate in interactive speed guidance experiments using multivehicle driving simulators. It was found that compared to vehicles without speed guidance, those with DESGS had a significantly reduced number of stops and approximately 25% less fuel consumption and CO2 emissions.

Performance of an Automated-Mixed-Traffic-Vehicle /AMTV/ System. [urban people mover

Science.gov (United States)

Peng, T. K. C.; Chon, K.

1978-01-01

This study analyzes the operation and evaluates the expected performance of a proposed automatic guideway transit system which uses low-speed Automated Mixed Traffic Vehicles (AMTV's). Vehicle scheduling and headway control policies are evaluated with a transit system simulation model. The effect of mixed-traffic interference on the average vehicle speed is examined with a vehicle-pedestrian interface model. Control parameters regulating vehicle speed are evaluated for safe stopping and passenger comfort.

Nugget Structure Evolution with Rotation Speed for High-Rotation-Speed Friction-Stir-Welded 6061 Aluminum Alloy

Science.gov (United States)

Zhang, H. J.; Wang, M.; Zhu, Z.; Zhang, X.; Yu, T.; Wu, Z. Q.

2018-03-01

High-rotation-speed friction stir welding (HRS-FSW) is a promising technique to reduce the welding loads during FSW and thus facilitates the application of FSW for in situ fabrication and repair. In this study, 6061 aluminum alloy was friction stir welded at high-rotation speeds ranging from 3000 to 7000 rpm at a fixed welding speed of 50 mm/min, and the effects of rotation speed on the nugget zone macro- and microstructures were investigated in detail in order to illuminate the process features. Temperature measurements during HRS-FSW indicated that the peak temperature did not increase consistently with rotation speed; instead, it dropped remarkably at 5000 rpm because of the lowering of material shear stress. The nugget size first increased with rotation speed until 5000 rpm and then decreased due to the change of the dominant tool/workpiece contact condition from sticking to sliding. At the rotation speed of 5000 rpm, where the weld material experienced weaker thermal effect and higher-strain-rate plastic deformation, the nugget exhibited relatively small grain size, large textural intensity, and high dislocation density. Consequently, the joint showed superior nugget hardness and simultaneously a slightly low tensile ductility.

Balancing High-Speed Rotors at Low Speed

Science.gov (United States)

Giordano, J.; Zorzi, E.

1986-01-01

Flexible balancing reduces vibrations at operating speeds. Highspeed rotors in turbomachines dynamically balanced at fraction of operating rotor speed. New method takes into account rotor flexible rather than rigid.

High-speed holographic camera

International Nuclear Information System (INIS)

Novaro, Marc

The high-speed holographic camera is a disgnostic instrument using holography as an information storing support. It allows us to take 10 holograms, of an object, with exposures times of 1,5ns, separated in time by 1 or 2ns. In order to get these results easily, no mobile part is used in the set-up [fr

Experimental investigation of a quad-rotor biplane micro air vehicle

Science.gov (United States)

Bogdanowicz, Christopher Michael

Micro air vehicles are expected to perform demanding missions requiring efficient operation in both hover and forward flight. This thesis discusses the development of a hybrid air vehicle which seamlessly combines both flight capabilities: hover and high-speed forward flight. It is the quad-rotor biplane, which weighs 240 grams and consists of four propellers with wings arranged in a biplane configuration. The performance of the vehicle system was investigated in conditions representative of flight through a series of wind tunnel experiments. These studies provided an understanding of propeller-wing interaction effects and system trim analysis. This showed that the maximum speed of 11 m/s and a cruise speed of 4 m/s were achievable and that the cruise power is approximately one-third of the hover power. Free flight testing of the vehicle successfully highlighted its ability to achieve equilibrium transition flight. Key design parameters were experimentally investigated to understand their effect on overall performance. It was found that a trade-off between efficiency and compactness affects the final choice of the design. Design improvements have allowed for decreases in vehicle weight and ground footprint, while increasing structural soundness. Numerous vehicle designs, models, and flight tests have proven system scalability as well as versatility, including an upscaled model to be utilized in an extensive commercial package delivery system. Overall, the quad-rotor biplane is proven to be an efficient and effective multi-role vehicle.

Recent progress on high-speed optical transmission

Directory of Open Access Journals (Sweden)

Jianjun Yu

2016-05-01

Full Text Available The recently reported high spectral efficiency (SE and high-baud-rate signal transmission are all based on digital coherent optical communications and digital signal processing (DSP. DSP simplifies the reception of advanced modulation formats and also enables the major electrical and optical impairments to be processed and compensated in the digital domain, at the transmitter or receiver side. In this paper, we summarize the research progress on high-speed signal generation and detection and also show the progress on DSP for high-speed signal detection. We also report the latest progress on multi-core and multi-mode multiplexing.

Designing Sustainable Public Transportation: Integrated Optimization of Bus Speed and Holding Time in a Connected Vehicle Environment

Directory of Open Access Journals (Sweden)

Wei Wu

2016-11-01

Full Text Available Developing public transportation and giving priority to buses is a feasible solution for improving the level of public transportation service, which facilitates congestion alleviation and prevention, and contributes to urban development and city sustainability. This paper presents a novel bus operation control strategy including both holding control and speed control to improve the level of service of transit systems within a connected vehicle environment. Most previous work focuses on optimization of signal timing to decrease the bus signal delay by assuming that holding control is not applied; the speed of buses is given as a constant input and the acceleration and deceleration processes of buses can be neglected. This paper explores the benefits of a bus operation control strategy to minimize the total cost, which includes bus signal delay, bus holding delay, bus travel delay, acceleration cost due to frequent stops and intense driving. A set of formulations are developed to explicitly capture the interaction between bus holding control and speed control. Experimental analysisand simulation tests have shown that the proposed integrated operational model outperforms the traditional control, speed control only, or holding control only strategies in terms of reducing the total cost of buses. The sensitivity analysis has further demonstrated the potential effectiveness of the proposed approach to be applied in a real-time bus operation control system under different levels of traffic demand, bus stop locations, and speed limits.

Demand for alternative-fuel vehicles when registration taxes are high

DEFF Research Database (Denmark)

Mabit, Stefan Lindhard; Fosgerau, Mogens

2011-01-01

This paper investigates the potential futures for alternative-fuel vehicles in Denmark, where the vehicle registration tax is very high and large tax rebates can be given. A large stated choice dataset has been collected concerning vehicle choice among conventional, hydrogen, hybrid, bio......-diesel, and electric vehicles. We estimate a mixed logit model that improves on previous contributions by controlling for reference dependence and allowing for correlation of random effects. Both improvements are found to be important. An application of the model shows that alternative-fuel vehicles with present...... technology could obtain fairly high market shares given tax regulations possible in the present high-tax vehicle market....

Single-Photon Tracking for High-Speed Vision

Directory of Open Access Journals (Sweden)

Istvan Gyongy

2018-01-01

Full Text Available Quanta Imager Sensors provide photon detections at high frame rates, with negligible read-out noise, making them ideal for high-speed optical tracking. At the basic level of bit-planes or binary maps of photon detections, objects may present limited detail. However, through motion estimation and spatial reassignment of photon detections, the objects can be reconstructed with minimal motion artefacts. We here present the first demonstration of high-speed two-dimensional (2D tracking and reconstruction of rigid, planar objects with a Quanta Image Sensor, including a demonstration of depth-resolved tracking.

A high-speed interface for multi-channel analyzer

International Nuclear Information System (INIS)

Shen Ji; Zheng Zhong; Qiao Chong; Chen Ziyu; Ye Yunxiu; Ye Zhenyu

2003-01-01

This paper presents a high-speed computer interface for multi-channel analyzer based on DMA technique. Its essential principle and operating procedure are introduced. By the detecting of γ spectrum of 137 Cs with the interface, it's proved that the interface can meet the requirements of high-speed data acquisition

High-speed readout of high-Z pixel detectors with the LAMBDA detector

International Nuclear Information System (INIS)

Pennicard, D.; Smoljanin, S.; Sheviakov, I.; Xia, Q.; Rothkirch, A.; Yu, Y.; Struth, B.; Hirsemann, H.; Graafsma, H.

2014-01-01

High-frame-rate X-ray pixel detectors make it possible to perform time-resolved experiments at synchrotron beamlines, and to make better use of these sources by shortening experiment times. LAMBDA is a photon-counting hybrid pixel detector based on the Medipix3 chip, designed to combine a small pixel size of 55 μm, a large tileable module design, high speed, and compatibility with ''high-Z'' sensors for hard X-ray detection. This technical paper focuses on LAMBDA's high-speed-readout functionality, which allows a frame rate of 2000 frames per second with no deadtime between successive images. This takes advantage of the Medipix3 chip's ''continuous read-write'' function and highly parallelised readout. The readout electronics serialise this data and send it back to a server PC over two 10 Gigabit Ethernet links. The server PC controls the detector and receives, processes and stores the data using software designed for the Tango control system. As a demonstration of high-speed readout of a high-Z sensor, a GaAs LAMBDA detector was used to make a high-speed X-ray video of a computer fan

Analysis and Test Correlation of Proof of Concept Box for Blended Wing Body-Low Speed Vehicle

Science.gov (United States)

Spellman, Regina L.

2003-01-01

The Low Speed Vehicle (LSV) is a 14.2% scale remotely piloted vehicle of the revolutionary Blended Wing Body concept. The design of the LSV includes an all composite airframe. Due to internal manufacturing capability restrictions, room temperature layups were necessary. An extensive materials testing and manufacturing process development effort was underwent to establish a process that would achieve the high modulus/low weight properties required to meet the design requirements. The analysis process involved a loads development effort that incorporated aero loads to determine internal forces that could be applied to a traditional FEM of the vehicle and to conduct detailed component analyses. A new tool, Hypersizer, was added to the design process to address various composite failure modes and to optimize the skin panel thickness of the upper and lower skins for the vehicle. The analysis required an iterative approach as material properties were continually changing. As a part of the material characterization effort, test articles, including a proof of concept wing box and a full-scale wing, were fabricated. The proof of concept box was fabricated based on very preliminary material studies and tested in bending, torsion, and shear. The box was then tested to failure under shear. The proof of concept box was also analyzed using Nastran and Hypersizer. The results of both analyses were scaled to determine the predicted failure load. The test results were compared to both the Nastran and Hypersizer analytical predictions. The actual failure occurred at 899 lbs. The failure was predicted at 1167 lbs based on the Nastran analysis. The Hypersizer analysis predicted a lower failure load of 960 lbs. The Nastran analysis alone was not sufficient to predict the failure load because it does not identify local composite failure modes. This analysis has traditionally been done using closed form solutions. Although Hypersizer is typically used as an optimizer for the design

High Speed Magnetostrictive MEMS Actuated Mirror Deflectors, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — The main goal of this proposal is to develop high speed magnetostrictive and MEMS actuators for rapidly deflecting or deforming mirrors. High speed, light-weight,...

Design of high-speed turnouts and crossings

Science.gov (United States)

Raif, Lukáš; Puda, Bohuslav; Havlík, Jiří; Smolka, Marek

2017-09-01

Recently, the new ways to improve the railway switches and crossings have been sought, as the railway transport increases its operating speed. The expectation of these adjustments is to decrease the dynamic load, which usually increases together with velocity, and this influences the comfort of the vehicle passage, the wear of the structural parts and the cost of maintenance. These adjustments are primarily the turnout elements such as the optimized geometry of the turnout branch line by means of transition curves application, which minimizes the lateral acceleration during the vehicle passage through the track curve. The rail inclination is solved either by means of inclination in fastening system, or by machining of the rail head shape, because this ways of adjustment retain the wheel-rail interaction characteristics along the whole length of the turnout. Secondly, it is the crossing with movable part, which excludes the interruption of the running surface and optimization of the railway stiffness throughout the whole turnout length as well. We can see that the different stiffness along the turnout influences the dynamic load and it is necessary to optimize the discontinuities in the stiffness along the whole length of the turnout. For this purpose, the numeric modeling is carried out to seek the areas with the highest stiffness and subsequently, the system of stiffness optimization will be designed.

Cadence® High High-Speed PCB Design Flow Workshop

CERN Document Server

2006-01-01

Last release of Cadence High-Speed PCB Design methodology (PE142) based on Concept-HDL schematic editor, Constraint Manager, SPECCTRAQuest signal integrity analysis tool and ALLEGRO layout associated with SPECCTRA auto router tools, is now enough developed and stable to be taken into account for high-speed board designs at CERN. The implementation of this methodology, build around the new Constraint Manager program, is essential when you have to develop a board having a lot of high-speed design rules such as terminated lines, large bus structures, maximum length, timing, crosstalk etc.. that could not be under control by traditional method. On more conventional designs, formal aspect of the methodology could avoid misunderstanding between hardware and ALLEGRO layout designers, minimizing prototype iteration, development time and price. The capability to keep trace of the original digital designer intents in schematic or board layout, loading formal constraints in EDMS, could also be considered for LHC electro...

High-speed LWR transients simulation for optimizing emergency response

International Nuclear Information System (INIS)

Wulff, W.; Cheng, H.S.; Lekach, S.V.; Mallen, A.N.; Stritar, A.

1984-01-01

The purpose of computer-assisted emergency response in nuclear power plants, and the requirements for achieving such a response, are presented. An important requirement is the attainment of realistic high-speed plant simulations at the reactor site. Currently pursued development programs for plant simulations are reviewed. Five modeling principles are established and a criterion is presented for selecting numerical procedures and efficient computer hardware to achieve high-speed simulations. A newly developed technology for high-speed power plant simulation is described and results are presented. It is shown that simulation speeds ten times greater than real-time process-speeds are possible, and that plant instrumentation can be made part of the computational loop in a small, on-site minicomputer. Additional technical issues are presented which must still be resolved before the newly developed technology can be implemented in a nuclear power plant

Development of autonomous controller system of high speed UAV from simulation to ready to fly condition

Science.gov (United States)

Yudhi Irwanto, Herma

2018-02-01

The development of autonomous controller system that is specially used in our high speed UAV, it’s call RKX-200EDF/TJ controlled vehicle needs to be continued as a step to mastery and to developt control system of LAPAN’s satellite launching rocket. The weakness of the existing control system in this high speed UAV needs to be repaired and replaced using the autonomous controller system. Conversion steps for ready-to-fly system involved controlling X tail fin, adjusting auto take off procedure by adding X axis sensor, procedure of way points reading and process of measuring distance and heading to the nearest way point, developing user-friendly ground station, and adding tools for safety landing. The development of this autonomous controller system also covered a real flying test in Pandanwangi, Lumajang in November 2016. Unfortunately, the flying test was not successful because the booster rocket was blown right after burning. However, the system could record the event and demonstrated that the controller system had worked according to plan.

Overview of Variable-Speed Power-Turbine Research

Science.gov (United States)

Welch, Gerard E.

2011-01-01

The vertical take-off and landing (VTOL) and high-speed cruise capability of the NASA Large Civil Tilt-Rotor (LCTR) notional vehicle is envisaged to enable increased throughput in the national airspace. A key challenge of the LCTR is the requirement to vary the main rotor speeds from 100% at take-off to near 50% at cruise as required to minimize mission fuel burn. The variable-speed power-turbine (VSPT), driving a fixed gear-ratio transmission, provides one approach for effecting this wide speed variation. The key aerodynamic and rotordynamic challenges of the VSPT were described in the FAP Conference presentation. The challenges include maintaining high turbine efficiency at high work factor, wide (60 deg.) of incidence variation in all blade rows due to the speed variation, and operation at low Reynolds numbers (with transitional flow). The PT -shaft of the VSPT must be designed for safe operation in the wide speed range required, and therefore poses challenges associated with rotordynamics. The technical challenges drive research activities underway at NASA. An overview of the NASA SRW VSPT research activities was provided. These activities included conceptual and preliminary aero and mechanical (rotordynamics) design of the VSPT for the LCTR application, experimental and computational research supporting the development of incidence tolerant blading, and steps toward component-level testing of a variable-speed power-turbine of relevance to the LCTR application.

Intersection Management Using In-Vehicle Speed Advisory/Adaptation

OpenAIRE

Rakha, Hesham; Bichiou, Youssef; Hassan, Abdallah; Zohdy, Ismail

2016-01-01

In recent years, connected vehicles (CVs) and automated vehicles (AVs) have emerged as a realistic and viable transportation option. Research centers and companies have dedicated substantial efforts to the technology, motivated largely by the potential safety benefits that can be realized through the elimination of human error, the enhancement of mobility via reduction of congestion and optimization of trips, and the associated positive environmental impacts. Both sensors and control mechanis...

Current front stiffness of European vehicles with regard to compatibility

NARCIS (Netherlands)

Huibers, J.; Beer, E. de

2001-01-01

EuroNCAP tests are carried out since 1997. The test procedure in general is comparable to the EC Directive 96/79 with a test speed of 64 km/h. This increased test speed implies a higher frontal stiffness for new vehicle designs in order to achieve a high ranking. This frontal stiffness is one of the

Preface to the special section on human factors and automation in vehicles: designing highly automated vehicles with the driver in mind.

Science.gov (United States)

Merat, Natasha; Lee, John D

2012-10-01

This special section brings together diverse research regarding driver interaction with advanced automotive technology to guide design of increasingly automated vehicles. Rapidly evolving vehicle automation will likely change cars and trucks more in the next 5 years than the preceding 50, radically redefining what it means to drive. This special section includes 10 articles from European and North American researchers reporting simulator and naturalistic driving studies. Little research has considered the consequences of fully automated driving, with most focusing on lane-keeping and speed control systems individually. The studies reveal two underlying design philosophies: automate driving versus support driving. Results of several studies, consistent with previous research in other domains, suggest that the automate philosophy can delay driver responses to incidents in which the driver has to intervene and take control from the automation. Understanding how to orchestrate the transfer or sharing of control between the system and the driver, particularly in critical incidents, emerges as a central challenge. Designers should not assume that automation can substitute seamlessly for a human driver, nor can they assume that the driver can safely accommodate the limitations of automation. Designers, policy makers, and researchers must give careful consideration to what role the person should have in highly automated vehicles and how to support the driver if the driver is to be responsible for vehicle control. As in other domains, driving safety increasingly depends on the combined performance of the human and automation, and successful designs will depend on recognizing and supporting the new roles of the driver.

Cutting force model for high speed machining process

International Nuclear Information System (INIS)

Haber, R. E.; Jimenez, J. E.; Jimenez, A.; Lopez-Coronado, J.

2004-01-01

This paper presents cutting force-based models able to describe a high speed machining process. The model considers the cutting force as output variable, essential for the physical processes that are taking place in high speed machining. Moreover, this paper shows the mathematical development to derive the integral-differential equations, and the algorithms implemented in MATLAB to predict the cutting force in real time MATLAB is a software tool for doing numerical computations with matrices and vectors. It can also display information graphically and includes many toolboxes for several research and applications areas. Two end mill shapes are considered (i. e. cylindrical and ball end mill) for real-time implementation of the developed algorithms. the developed models are validated in slot milling operations. The results corroborate the importance of the cutting force variable for predicting tool wear in high speed machining operations. The developed models are the starting point for future work related with vibration analysis, process stability and dimensional surface finish in high speed machining processes. (Author) 19 refs

MODELLING OF DYNAMIC SPEED LIMITS USING THE MODEL PREDICTIVE CONTROL

Directory of Open Access Journals (Sweden)

Andrey Borisovich Nikolaev

2017-09-01

Full Text Available The article considers the issues of traffic management using intelligent system “Car-Road” (IVHS, which consist of interacting intelligent vehicles (IV and intelligent roadside controllers. Vehicles are organized in convoy with small distances between them. All vehicles are assumed to be fully automated (throttle control, braking, steering. Proposed approaches for determining speed limits for traffic cars on the motorway using a model predictive control (MPC. The article proposes an approach to dynamic speed limit to minimize the downtime of vehicles in traffic.

A semi-active control suspension system for railway vehicles with magnetorheological fluid dampers

Science.gov (United States)

Wei, Xiukun; Zhu, Ming; Jia, Limin

2016-07-01

The high-speed train has achieved great progress in the last decades. It is one of the most important modes of transportation between cities. With the rapid development of the high-speed train, its safety issue is paid much more attention than ever before. To improve the stability of the vehicle with high speed, extra dampers (i.e. anti-hunting damper) are used in the traditional bogies with passive suspension system. However, the curving performance of the vehicle is undermined due to the extra lateral force generated by the dampers. The active suspension systems proposed in the last decades attempt to solve the vehicle steering issue. However, the active suspension systems need extra actuators driven by electrical power or hydraulic power. There are some implementation and even safety issues which are not easy to be overcome. In this paper, an innovative semi-active controlled lateral suspension system for railway vehicles is proposed. Four magnetorheological fluid dampers are fixed to the primary suspension system of each bogie. They are controlled by online controllers for enhancing the running stability on the straight track line on the one hand and further improving the curving performance by controlling the damper force on the other hand. Two control strategies are proposed in the light of the pure rolling concept. The effectiveness of the proposed strategies is demonstrated by SIMPACK and Matlab co-simulation for a full railway vehicle with two conventional bogies.

Research on the tool holder mode in high speed machining

Science.gov (United States)

Zhenyu, Zhao; Yongquan, Zhou; Houming, Zhou; Xiaomei, Xu; Haibin, Xiao

2018-03-01

High speed machining technology can improve the processing efficiency and precision, but also reduce the processing cost. Therefore, the technology is widely regarded in the industry. With the extensive application of high-speed machining technology, high-speed tool system has higher and higher requirements on the tool chuck. At present, in high speed precision machining, several new kinds of clip heads are as long as there are heat shrinkage tool-holder, high-precision spring chuck, hydraulic tool-holder, and the three-rib deformation chuck. Among them, the heat shrinkage tool-holder has the advantages of high precision, high clamping force, high bending rigidity and dynamic balance, etc., which are widely used. Therefore, it is of great significance to research the new requirements of the machining tool system. In order to adapt to the requirement of high speed machining precision machining technology, this paper expounds the common tool holder technology of high precision machining, and proposes how to select correctly tool clamping system in practice. The characteristics and existing problems are analyzed in the tool clamping system.

High-speed photodetectors in optical communication system

Science.gov (United States)

Zhao, Zeping; Liu, Jianguo; Liu, Yu; Zhu, Ninghua

2017-12-01

This paper presents a review and discussion for high-speed photodetectors and their applications on optical communications and microwave photonics. A detailed and comprehensive demonstration of high-speed photodetectors from development history, research hotspots to packaging technologies is provided to the best of our knowledge. A few typical applications based on photodetectors are also illustrated, such as free-space optical communications, radio over fiber and millimeter terahertz signal generation systems. Project supported by the Preeminence Youth Fund of China (No. 61625504).

CORRELATION ANALYSIS OF DRIVING CONDITIONS AND ON-ROAD EMISSIONS TRENDS FOR VEHICLES

Directory of Open Access Journals (Sweden)

Jawad H. Al-rifai

2017-01-01

Full Text Available This paper presents the impact of road grade, vehicle speed, nu mber of vehicles and vehicle type on vehicle emissions. ANOVA analyses were conducte d among different driving conditions and vehicle emissions to discover the signif icant effects of driving conditions on measured emission rates. This study is intended t o improve the understanding of vehicle emission levels in Jordan. Gas emissio ns in real-world driving conditions were measured by a por table emissions measurement un it over six sections of an urban road. The road grade, speed, type and number of veh icles were found to have a significant influence on the rate of gas emissions. Road grade and diesel-fueled vehicles were positively correlate d with average emission rates . The average emission rates were higher at speeds ranging between 60–69 km/h than at three other speed ranges. The results of ANOVA showed a strong and consistent reg ression between rates of emissions measured and grade, speed and diesel vehicle parameters. The grade parameter contributed the most to the rate of emissions compare d to other parameters. Gasoline vehicles contributed the least.

Analysis and topology optimization design of high-speed driving spindle

Science.gov (United States)

Wang, Zhilin; Yang, Hai

2018-04-01

The three-dimensional model of high-speed driving spindle is established by using SOLIDWORKS. The model is imported through the interface of ABAQUS, A finite element analysis model of high-speed driving spindle was established by using spring element to simulate bearing boundary condition. High-speed driving spindle for the static analysis, the spindle of the stress, strain and displacement nephogram, and on the basis of the results of the analysis on spindle for topology optimization, completed the lightweight design of high-speed driving spindle. The design scheme provides guidance for the design of axial parts of similar structures.

Proposal of a high rigidity and high speed rotating mechanism using a new concept hydrodynamic bearing in X-ray tube for high speed computed tomography

International Nuclear Information System (INIS)

Hattori, Hitoshi; Fukushima, Harunobu; Yoshii, Yasuo; Nakamuta, Hironori; Iwase, Mitsuo; Kitade, Koichi

2009-01-01

In this paper, a high rigidity and high speed rotating mechanism using a new concept hydrodynamic bearing in X-ray tube for high speed computed tomography is proposed. In order to obtain both the stability and the high load carrying capacity, the hydrodynamic bearing lubricated by liquid metal (Gallium alloy), named as the hybrid hydrodynamic bearing generates the lubricating film by wedge effect on the plane region between the spiral grooves under high loading condition. The parallelism between the bearing and the rotating body can be secured by optimizing the rigidity distribution of stationary shaft in the proposed rotating mechanism. By carrying out the fundamental design by numerical analyses, it has been made clear that the hybrid hydrodynamic bearing and the rotating mechanism are suitable for the X-ray tube used in the CT with ever-increasingly scanning speed. (author)

Application of Fabry-Perot velocimeter to high-speed experiments

International Nuclear Information System (INIS)

Chaw, H.H.; McMillan, C.F.; Osher, J.E.

1988-01-01

The Fabry-Perot (F-P) velocimeter is a useful instrument for measuring the velocity of objects at speeds ranging from fractions of a kilometer per second to a few tens of kilometers per second and up. Because of its immunity to electromagnetic interference and its velocity resolution, it has become the prime diagnostic tool in our electric-gun facility. Examples of its application to high speed experiments are discussed, including: electric-gun flyer studies, spallation of materials under high-speed impact, momentum-transfer studies, pressure pulse created by high-velocity impact, and detonation-wave studies in high-explosive experiments

Application of polarization in high speed, high contrast inspection

Science.gov (United States)

Novak, Matthew J.

2017-08-01

Industrial optical inspection often requires high speed and high throughput of materials. Engineers use a variety of techniques to handle these inspection needs. Some examples include line scan cameras, high speed multi-spectral and laser-based systems. High-volume manufacturing presents different challenges for inspection engineers. For example, manufacturers produce some components in quantities of millions per month, per week or even per day. Quality control of so many parts requires creativity to achieve the measurement needs. At times, traditional vision systems lack the contrast to provide the data required. In this paper, we show how dynamic polarization imaging captures high contrast images. These images are useful for engineers to perform inspection tasks in some cases where optical contrast is low. We will cover basic theory of polarization. We show how to exploit polarization as a contrast enhancement technique. We also show results of modeling for a polarization inspection application. Specifically, we explore polarization techniques for inspection of adhesives on glass.

High speed network sampling

OpenAIRE

Rindalsholt, Ole Arild

2005-01-01

Master i nettverks- og systemadministrasjon Classical Sampling methods play an important role in the current practice of Internet measurement. With today’s high speed networks, routers cannot manage to generate complete Netflow data for every packet. They have to perform restricted sampling. This thesis summarizes some of the most important sampling schemes and their applications before diving into an analysis on the effect of sampling Netflow records.

Speed-dependent emission of air pollutants from gasoline-powered passenger cars.

Science.gov (United States)

Jung, Sungwoon; Lee, Meehye; Kim, Jongchoon; Lyu, Youngsook; Park, Junhong

2011-01-01

In Korea emissions from motor vehicles are a major source of air pollution in metropolitan cities, and in Seoul a large proportion of the vehicle fleet is made up of gasoline-powered passenger cars. The carbon monoxide (CO), hydrocarbons (HC), oxides of nitrogen (NOx) and carbon dioxide (CO2) contained in the exhaust emissions from 76 gasoline-powered passenger cars equipped with three-way catalysts has been assessed by vehicle speed, vehicle mileage and model year. The results show that CO, HC, NOx and CO2 emissions remained almost unchanged at higher speeds but decreased rapidly at lower speeds. While a reduction in CO, HC and NOx emissions was noticeable in vehicles of recent manufacture and lower mileage, CO2 emissions were found to be insensitive to vehicle mileage, but strongly dependent on gross vehicle weight. Lower emissions from more recent gasoline-powered vehicles arose mainly from improvements in three-way catalytic converter technology following strengthened emission regulations. The correlation between CO2 emission and fuel consumption has been investigated with a view to establishing national CO2 emission standards for Korea.

High Speed On-Wafer Characterization Laboratory

Data.gov (United States)

Federal Laboratory Consortium — At the High Speed On-Wafer Characterization Laboratory, researchers characterize and model devices operating at terahertz (THz) and millimeter-wave frequencies. The...

High-speed nonvolatile CMOS/MNOS RAM

International Nuclear Information System (INIS)

Derbenwick, G.F.; Dodson, W.D.; Sokel, R.J.

1979-01-01

A bulk silicon technology for a high-speed static CMOS/MNOS RAM has been developed. Radiation-hardened, high voltage CMOS circuits have been fabricated for the memory array driving circuits and the enhancement-mode p-channel MNOS memory transistors have been fabricated using a native tunneling oxide with a 45 nm CVD Si 3 N 4 insulator deposited at 750 0 C. Read cycle times less than 350 ns and write cycle times of 1 μs are projected for the final 1Kx1 design. The CMOS circuits provide adequate speed for the write and read cycles and minimize the standby power dissipation. Retention times well in excess of 30 min are projected

High-speed cryptography and cryptanalysis

NARCIS (Netherlands)

Schwabe, P.

2011-01-01

Modern digital communication relies heavily on cryptographic protection to ensure data integrity and privacy. In order to deploy state-of-the art cryptographic primitives and protocols in real-world scenarios, one needs to highly optimize software for both speed and security. This requires careful

Advancing high-speed rail policy in the United States.

Science.gov (United States)

2012-06-01

This report builds on a review of international experience with high-speed rail projects to develop recommendations for a High-speed rail policy framework for the United States. The international review looked at the experience of Korea, Taiwan, Chin...

Empirical Analysis and Modeling of Stop-Line Crossing Time and Speed at Signalized Intersections

Directory of Open Access Journals (Sweden)

Keshuang Tang

2016-12-01

Full Text Available In China, a flashing green (FG indication of 3 s followed by a yellow (Y indication of 3 s is commonly applied to end the green phase at signalized intersections. Stop-line crossing behavior of drivers during such a phase transition period significantly influences safety performance of signalized intersections. The objective of this study is thus to empirically analyze and model drivers’ stop-line crossing time and speed in response to the specific phase transition period of FG and Y. High-resolution trajectories for 1465 vehicles were collected at three rural high-speed intersections with a speed limit of 80 km/h and two urban intersections with a speed limit of 50 km/h in Shanghai. With the vehicle trajectory data, statistical analyses were performed to look into the general characteristics of stop-line crossing time and speed at the two types of intersections. A multinomial logit model and a multiple linear regression model were then developed to predict the stop-line crossing patterns and speeds respectively. It was found that the percentage of stop-line crossings during the Y interval is remarkably higher and the stop-line crossing time is approximately 0.7 s longer at the urban intersections, as compared with the rural intersections. In addition, approaching speed and distance to the stop-line at the onset of FG as well as area type significantly affect the percentages of stop-line crossings during the FG and Y intervals. Vehicle type and stop-line crossing pattern were found to significantly influence the stop-line crossing speed, in addition to the above factors. The red-light-running seems to occur more frequently at the large intersections with a long cycle length.

Design and applications of a pneumatic accelerator for high speed punching

International Nuclear Information System (INIS)

Yaldiz, Sueleyman; Saglam, Haci; Unsacar, Faruk; Isik, Hakan

2007-01-01

High speed forming is an important production method that requires specially designed HERF (high energy rate forming) machines. Most of the HERF machines are devices that consist of a system in which energy is stored and a differential piston mechanism is used to release the energy at high rate. In order to eliminate the usage of specially designed HERF machines and to obtain the high speed forming benefits, the accelerator which can be adapted easily onto conventional presses has been designed and manufactured in this study. The designed energy accelerator can be incorporated into mechanical press to convert the low speed operation into high-speed operation of a hammer. Expectations from this work are reduced distortion rates, increased surface quality and precise dimensions in metal forming operations. From the performance test, the accelerator is able to achieve high speed and energy which require for high speed blanking of thick sheet metals

Assessment of rural soundscapes with high-speed train noise.

Science.gov (United States)

Lee, Pyoung Jik; Hong, Joo Young; Jeon, Jin Yong

2014-06-01

In the present study, rural soundscapes with high-speed train noise were assessed through laboratory experiments. A total of ten sites with varying landscape metrics were chosen for audio-visual recording. The acoustical characteristics of the high-speed train noise were analyzed using various noise level indices. Landscape metrics such as the percentage of natural features (NF) and Shannon's diversity index (SHDI) were adopted to evaluate the landscape features of the ten sites. Laboratory experiments were then performed with 20 well-trained listeners to investigate the perception of high-speed train noise in rural areas. The experiments consisted of three parts: 1) visual-only condition, 2) audio-only condition, and 3) combined audio-visual condition. The results showed that subjects' preference for visual images was significantly related to NF, the number of land types, and the A-weighted equivalent sound pressure level (LAeq). In addition, the visual images significantly influenced the noise annoyance, and LAeq and NF were the dominant factors affecting the annoyance from high-speed train noise in the combined audio-visual condition. In addition, Zwicker's loudness (N) was highly correlated with the annoyance from high-speed train noise in both the audio-only and audio-visual conditions. © 2013.

Performance Evaluation of an In-Wheel Motor Cooling System in an Electric Vehicle/Hybrid Electric Vehicle

Directory of Open Access Journals (Sweden)

Dong Hyun Lim

2014-02-01

Full Text Available High power and miniaturization of motors in an in-wheel drive system, which is installed inside the wheels of a vehicle, are required for directly driving the wheels. In addition, an efficient cooling system is required to ensure high driving performance and durability. This study experimentally evaluated the heat dissipation performance of a 35-kW-class large-capacity in-wheel motor equipped with an internal-circulation-type oil-cooling system that exhibits high cooling performance and can be easily miniaturized to this motor. Temperatures of the coil and stator core of cooling systems with and without a radiator were measured in real time under in-wheel motor driving conditions. It was found that operating the cooling system at a continuous-rating maximum speed without the radiator was difficult. We confirmed that under continuous-rating base speed and continuous-rating maximum speed driving conditions, the cooling system with the radiator showed thermally stable operation. Furthermore, under maximum-rating base speed and maximum-rating maximum speed driving conditions, the cooling system with the radiator provided additional driving times of approximately 22 s and 2 s, respectively.

High-speed imaging of explosive eruptions: applications and perspectives

Science.gov (United States)

Taddeucci, Jacopo; Scarlato, Piergiorgio; Gaudin, Damien; Capponi, Antonio; Alatorre-Ibarguengoitia, Miguel-Angel; Moroni, Monica

2013-04-01

Explosive eruptions, being by definition highly dynamic over short time scales, necessarily call for observational systems capable of relatively high sampling rates. "Traditional" tools, like as seismic and acoustic networks, have recently been joined by Doppler radar and electric sensors. Recent developments in high-speed camera systems now allow direct visual information of eruptions to be obtained with a spatial and temporal resolution suitable for the analysis of several key eruption processes. Here we summarize the methods employed to gather and process high-speed videos of explosive eruptions, and provide an overview of the several applications of these new type of data in understanding different aspects of explosive volcanism. Our most recent set up for high-speed imaging of explosive eruptions (FAMoUS - FAst, MUltiparametric Set-up,) includes: 1) a monochrome high speed camera, capable of 500 frames per second (fps) at high-definition (1280x1024 pixel) resolution and up to 200000 fps at reduced resolution; 2) a thermal camera capable of 50-200 fps at 480-120x640 pixel resolution; and 3) two acoustic to infrasonic sensors. All instruments are time-synchronized via a data logging system, a hand- or software-operated trigger, and via GPS, allowing signals from other instruments or networks to be directly recorded by the same logging unit or to be readily synchronized for comparison. FAMoUS weights less than 20 kg, easily fits into four, hand-luggage-sized backpacks, and can be deployed in less than 20' (and removed in less than 2', if needed). So far, explosive eruptions have been recorded in high-speed at several active volcanoes, including Fuego and Santiaguito (Guatemala), Stromboli (Italy), Yasur (Vanuatu), and Eyjafiallajokull (Iceland). Image processing and analysis from these eruptions helped illuminate several eruptive processes, including: 1) Pyroclasts ejection. High-speed videos reveal multiple, discrete ejection pulses within a single Strombolian

Motorcycle and scooter speeds approaching urban intersections.

Science.gov (United States)

Walton, D; Buchanan, J

2012-09-01

Five urban, uncontrolled T-intersections known to be motorcycle crash 'black spots' were monitored using instrumentation and a roadside observer. Two sets of twelve-hour observations were collected for each site (N≈100,000). Instrumentation recorded the 'events' of vehicles passing to measure, speed, direction, lane position, vehicle type (broadly characterised) and headway. Observers further recorded times of bicycle events, type of motorcycle (scooters or motorcycles), the behaviour of motorcycles and the use of 'high conspicuity' gear such as clothing or helmets. Results establish that motorcycles travel around 10% faster than the other traffic (car mean speed=34.97 km/h), with motorcycles travelling on average 3.3 km/h faster than cars. Motorcycles were 3.4 times more likely to be exceeding the speed limit than cars. Similar results are described for scooters. Also examined are the influences on mean speeds such as the time of day, the presence of a car at the t-intersection, and the influence of free headway. The results are compared for robustness across locations and days. It is concluded that in urban areas motorcycles are travelling significantly faster than other traffic. These findings are discussed against a concern to reduce motorcycle crashes by improving conspicuity and previous research that implicates a 'looked-but-failed-to-see' effect for car drivers. Copyright © 2012 Elsevier Ltd. All rights reserved.

High-speed microjet generation using laser-induced vapor bubbles

Science.gov (United States)

Oudalov, Nikolai; Tagawa, Yoshiyuki; Peters, Ivo; Visser, Claas-Willem; van der Meer, Devaraj; Prosperetti, Andrea; Sun, Chao; Lohse, Detlef

2011-11-01

The generation and evolution of microjets are studied both experimentally and numerically. The jets are generated by focusing a laser pulse into a microscopic capillary tube (~50 μm) filled with water-based red dye. A vapor bubble is created instantly after shooting the laser (<1 μs), sending out a shockwave towards the curved free surface at which the high-speed microjet forms. The process of jet formation is captured using high-speed recordings at 1.0 × 106 fps. The velocity of the microjets can reach speeds of ~850 m/s while maintaining a very sharp geometry. The high-speed recordings enable us to study the effect of several parameters on the jet velocity, e.g. the absorbed energy and the distance between the laser spot and the free surface.The results show a clear dependence on these variables, even for supersonic speeds. Comparisons with numerical simulations confirm the nature of these dependencies.

Vehicle classification using mobile sensors.

Science.gov (United States)

2013-04-01

In this research, the feasibility of using mobile traffic sensors for binary vehicle classification on arterial roads is investigated. Features (e.g. : speed related, acceleration/deceleration related, etc.) are extracted from vehicle traces (passeng...

Adaptive magnetorheological seat suspension for the expeditionary fighting vehicle

International Nuclear Information System (INIS)

Hiemenz, G J; Hu, W; Wereley, N M

2009-01-01

The Expeditionary Fighting Vehicle (EFV) is an amphibious vehicle designed to operate through harsh conditions and at much higher speeds than its predecessors. These unique capabilities and broadly varying operational conditions lead to a complex design and human factors scenario for the forward seating positions that cannot be solved using conventional passive seat suspension systems. Injurious shock loads transmitted to the occupants when traversing over water in high sea states and/or at high speeds, as well as harmful shock and vibration transmitted to the occupants when the vehicle is travelling over land, pose a threat to occupant health and significantly limit mission duration. In this study, a semi-active magnetorheological (MR) seat suspension is developed which adapts to broadly varying operational conditions, as well as occupant weight, to provide optimal protection of EFV occupants. It is shown that this MR seat suspension system will reduce the shock and vibration transmitted to the occupant by up to 33% and 65%, respectively, as compared to the existing passive suspension.

Adaptive magnetorheological seat suspension for the expeditionary fighting vehicle

Energy Technology Data Exchange (ETDEWEB)

Hiemenz, G J [Techno-Sciences, Inc., 11750 Beltsville Dr. Ste. 300, Beltsville, MD 20705 (United States); Hu, W; Wereley, N M [Aerospace Engineering, University of Maryland, College Park, MD 20712 (United States)], E-mail: greg@technosci.com, E-mail: wereley@umd.edu

2009-02-01

The Expeditionary Fighting Vehicle (EFV) is an amphibious vehicle designed to operate through harsh conditions and at much higher speeds than its predecessors. These unique capabilities and broadly varying operational conditions lead to a complex design and human factors scenario for the forward seating positions that cannot be solved using conventional passive seat suspension systems. Injurious shock loads transmitted to the occupants when traversing over water in high sea states and/or at high speeds, as well as harmful shock and vibration transmitted to the occupants when the vehicle is travelling over land, pose a threat to occupant health and significantly limit mission duration. In this study, a semi-active magnetorheological (MR) seat suspension is developed which adapts to broadly varying operational conditions, as well as occupant weight, to provide optimal protection of EFV occupants. It is shown that this MR seat suspension system will reduce the shock and vibration transmitted to the occupant by up to 33% and 65%, respectively, as compared to the existing passive suspension.

High Accuracy Piezoelectric Kinemometer; Cinemometro piezoelectrico de alta exactitud (VUAE)

Energy Technology Data Exchange (ETDEWEB)

Jimenez Martinez, F. J.; Frutos, J. de; Pastor, C.; Vazquez Rodriguez, M.

2012-07-01

We have developed a portable computerized and low consumption, our system is called High Accuracy Piezoelectric Kinemometer measurement, herein VUAE. By the high accuracy obtained by VUAE it make able to use the VUAE to obtain references measurements of system for measuring Speeds in Vehicles. Therefore VUAE could be used how reference equipment to estimate the error of installed kinemometers. The VUAE was created with n (n=2) pairs of ultrasonic transmitter-receiver, herein E-Rult. The transmitters used in the n couples E-Rult generate n ultrasonic barriers and receivers receive the echoes when the vehicle crosses the barriers. Digital processing of the echoes signals let us to obtain acceptable signals. Later, by mean of cross correlation technics is possible make a highly exact estimation of speed of the vehicle. The log of the moments of interception and the distance between each of the n ultrasounds allows for a highly exact estimation of speed of the vehicle. VUAE speed measurements were compared to a speed reference system based on piezoelectric cables. (Author) 11 refs.

Analysis of Non-Tactical Vehicle Utilization at Fort Carson

Science.gov (United States)

2012-03-30

regenerative braking energy recovery. The mass of the vehicles monitored in this study was not known. However, some useful information may be...regeneration to add braking action when the driver demand for deceleration rate exceeds the power absorption capability of the regenerative energy...recovery system (for instance, at the beginning of a hard brake from high speeds and as the vehicle comes to rest). This action decreases the overall

Map Matching for Intelligent Speed Adaptation

DEFF Research Database (Denmark)

Tradisauskas, Nerius; Juhl, Jens; Lahrmann, Harry

2007-01-01

The availability of Global Navigation Satellite Systems enables sophisticated vehicle guidance and advisory systems such as Intelligent Speed Adaptation (ISA) systems. In ISA systems, it is essential to be able to position vehicles within a road network. Because digital road networks as well as G...

Operation analysis of AC traction motors in terms of electromagnetic torque capability on sustainable railway vehicles

OpenAIRE

Bulucea Cornelia A.; Nicola Doru A.; Rosen Marc A.; Mastorakis Nikos E.; Bulucea Carmen A.

2016-01-01

Sustainable operation of electric railway systems represents a significant purpose nowadays in the development of high power and high speed locomotives and trains. At present, high speed electric vehicles mostly work with three-phase induction motors or three-phase synchronous motors as traction motors. The two electric machine types have different efficiencies at different operation points, and experience differences with respect to safety, speed and power, energy use and exergy efficiency. ...

Combat vehicle crew helmet-mounted display: next generation high-resolution head-mounted display

Science.gov (United States)

Nelson, Scott A.

1994-06-01

The Combat Vehicle Crew Head-Mounted Display (CVC HMD) program is an ARPA-funded, US Army Natick Research, Development, and Engineering Center monitored effort to develop a high resolution, flat panel HMD for the M1 A2 Abrams main battle tank. CVC HMD is part of the ARPA High Definition Systems (HDS) thrust to develop and integrate small (24 micrometers square pels), high resolution (1280 X 1024 X 6-bit grey scale at 60 frame/sec) active matrix electroluminescent (AMEL) and active matrix liquid crystal displays (AMLCD) for head mounted and projection applications. The Honeywell designed CVC HMD is a next generation head-mounted display system that includes advanced flat panel image sources, advanced digital display driver electronics, high speed (> 1 Gbps) digital interconnect electronics, and light weight, high performance optical and mechanical designs. The resulting dramatic improvements in size, weight, power, and cost have already led to program spin offs for both military and commercial applications.

Increasing accuracy of vehicle detection from conventional vehicle detectors - counts, speeds, classification, and travel time.

Science.gov (United States)

2014-09-01

Vehicle classification is an important traffic parameter for transportation planning and infrastructure : management. Length-based vehicle classification from dual loop detectors is among the lowest cost : technologies commonly used for collecting th...

A high capability teleoperated vehicle for hazardous applications

International Nuclear Information System (INIS)

Dudar, A.M.; Witherspoon, R.L.

1995-01-01

The Robotics Development Group at the Savannah River Site is developing a high performance teleoperated vehicle for use in radioactive and hazardous environments. The three-wheeled vehicle incorporates a highly dexterous 6 degree-of-freedom (DOF), hydraulically-powered manipulator made by Schilling Development, Inc. The teleoperator is called Little MoRT (MObile Radio-controlled Teleoperator) and is a modified version of a commercially available, battery-powered, warehouse vehicle. Little MoRT is controlled remotely by a universal robot controller either through a radio frequency link or a tethered cable. Six video cameras and a microphone provide the operator with audio-visual feedback of the vehicle and its surrounding environment. The vehicle also incorporates a hydraulic power unit consisting of a propane-driven engine for powering the Schilling manipulator. Little MoRT is capable of operating in outdoor as well as indoor environments and is well suited for decontamination and decommissioning activities such as dismantling, sorting, and surveying of radioactive waste

High speed railway track dynamics models, algorithms and applications

CERN Document Server

Lei, Xiaoyan

2017-01-01

This book systematically summarizes the latest research findings on high-speed railway track dynamics, made by the author and his research team over the past decade. It explores cutting-edge issues concerning the basic theory of high-speed railways, covering the dynamic theories, models, algorithms and engineering applications of the high-speed train and track coupling system. Presenting original concepts, systematic theories and advanced algorithms, the book places great emphasis on the precision and completeness of its content. The chapters are interrelated yet largely self-contained, allowing readers to either read through the book as a whole or focus on specific topics. It also combines theories with practice to effectively introduce readers to the latest research findings and developments in high-speed railway track dynamics. It offers a valuable resource for researchers, postgraduates and engineers in the fields of civil engineering, transportation, highway & railway engineering.

Plasma-Assisted Chemistry in High-Speed Flow

International Nuclear Information System (INIS)

Leonov, Sergey B.; Yarantsev, Dmitry A.; Napartovich, Anatoly P.; Kochetov, Igor V.

2007-01-01

Fundamental problems related to the high-speed combustion are analyzed. The result of plasma-chemical modeling is presented as a motivation of experimental activity. Numerical simulations of the effect of uniform non-equilibrium discharge on the premixed hydrogen and ethylene-air mixture in supersonic flow demonstrate an advantage of such a technique over a heating. Experimental results on multi-electrode non-uniform discharge maintenance behind wallstep and in cavity of supersonic flow are presented. The model test on hydrogen and ethylene ignition is demonstrated at direct fuel injection to low-temperature high-speed airflow

Thermomechanical simulations and experimental validation for high speed incremental forming

Science.gov (United States)

Ambrogio, Giuseppina; Gagliardi, Francesco; Filice, Luigino; Romero, Natalia

2016-10-01

Incremental sheet forming (ISF) consists in deforming only a small region of the workspace through a punch driven by a NC machine. The drawback of this process is its slowness. In this study, a high speed variant has been investigated from both numerical and experimental points of view. The aim has been the design of a FEM model able to perform the material behavior during the high speed process by defining a thermomechanical model. An experimental campaign has been performed by a CNC lathe with high speed to test process feasibility. The first results have shown how the material presents the same performance than in conventional speed ISF and, in some cases, better material behavior due to the temperature increment. An accurate numerical simulation has been performed to investigate the material behavior during the high speed process confirming substantially experimental evidence.

High Speed Photomicrography

Science.gov (United States)

Hyzer, William G.

1983-03-01

One of the most challenging areas in applying high-speed photography and videography in the plant and laboratory is in the recording of rapid events at macro and microscopic scales. Depth of field, exposure efficiency, working distance, and required exposure time are all reduced as optical magnification is increased, which severely taxes the skill and ingenuity of workers interested in recording any fast moving phenomena through the microscope or with magnifying lenses. This paper defines the problems inherent in photographing within macro and microscopic ranges and offers a systematic approach to optimizing the selection of equipment and choice of applicable techniques.

Material requirements for the High Speed Civil Transport

Science.gov (United States)

Stephens, Joseph R.; Hecht, Ralph J.; Johnson, Andrew M.

1993-01-01

Under NASA-sponsored High Speed Research (HSR) programs, the materials and processing requirements have been identified for overcoming the environmental and economic barriers of the next generation High Speed Civil Transport (HSCT) propulsion system. The long (2 to 5 hours) supersonic cruise portion of the HSCT cycle will place additional durability requirements on all hot section engine components. Low emissions combustor designs will require high temperature ceramic matrix composite liners to meet an emission goal of less than 5g NO(x) per Kg fuel burned. Large axisymmetric and two-dimensional exhaust nozzle designs are now under development to meet or exceed FAR 36 Stage III noise requirements, and will require lightweight, high temperature metallic, intermetallic, and ceramic matrix composites to reduce nozzle weight and meet structural and acoustic component performance goals. This paper describes and discusses the turbomachinery, combustor, and exhaust nozzle requirements of the High Speed Civil Transport propulsion system.

[Dynamic road vehicle emission inventory simulation study based on real time traffic information].

Science.gov (United States)

Huang, Cheng; Liu, Juan; Chen, Chang-Hong; Zhang, Jian; Liu, Deng-Guo; Zhu, Jing-Yu; Huang, Wei-Ming; Chao, Yuan

2012-11-01

The vehicle activity survey, including traffic flow distribution, driving condition, and vehicle technologies, were conducted in Shanghai. The databases of vehicle flow, VSP distribution and vehicle categories were established according to the surveyed data. Based on this, a dynamic vehicle emission inventory simulation method was designed by using the real time traffic information data, such as traffic flow and average speed. Some roads in Shanghai city were selected to conduct the hourly vehicle emission simulation as a case study. The survey results show that light duty passenger car and taxi are major vehicles on the roads of Shanghai city, accounting for 48% - 72% and 15% - 43% of the total flow in each hour, respectively. VSP distribution has a good relationship with the average speed. The peak of VSP distribution tends to move to high load section and become lower with the increase of average speed. Vehicles achieved Euro 2 and Euro 3 standards are majorities of current vehicle population in Shanghai. Based on the calibration of vehicle travel mileage data, the proportions of Euro 2 and Euro 3 standard vehicles take up 11% - 70% and 17% - 51% in the real-world situation, respectively. The emission simulation results indicate that the ratios of emission peak and valley for the pollutants of CO, VOC, NO(x) and PM are 3.7, 4.6, 9.6 and 19.8, respectively. CO and VOC emissions mainly come from light-duty passenger car and taxi, which has a good relationship with the traffic flow. NO(x) and PM emissions are mainly from heavy-duty bus and public buses and mainly concentrate in the morning and evening peak hours. The established dynamic vehicle emission simulation method can reflect the change of actual road emission and output high emission road sectors and hours in real time. The method can provide an important technical means and decision-making basis for transportation environment management.

High-Speed Sealift Technology Development Plan

National Research Council Canada - National Science Library

2002-01-01

.... The purpose of the project was to define the technology investments required to enable development of the high-speed commercial and military ships needed to provide realistic future mission capabilities...

Diagnostics of high-speed streams and coronal holes using geomagnetic pulsations

International Nuclear Information System (INIS)

Bol'shakova, O.V.; Troitskaya, V.A.

1980-01-01

In order to study the relations of high-speed solar wind streams and coronal holes analyzed are the parameters of geomagnetic pulsations of the Rs3 type and of high-speed streams at the decrease branch and in the minimum of solar activity. On the basis of the analysis of exciting pulsation regime determined are the differences in characteristics of high-speed stream properties. Presented are the graphical distributions of a number of occurrances of high-speed streams, coronal holes and pure regimes of Rs3R pulsations in several sections of 1973 in the Sun rotations of N1903-1919 and of the change of solar wind velocity while passing through the high-speed streams. It is found that Rs3R occurrance can serve an indicator of the high-speed flux connection with the large equatorial coronal hole. On the basis of the analysis of exciting pulsation properties determined are the differences in the stream characteristics. However the preliminary estimates permit to adopt neither the first nor the second of the existing hypotheses on the sourse of formation of high-speed streams

Benefits of high aerodynamic efficiency to orbital transfer vehicles

Science.gov (United States)

Andrews, D. G.; Norris, R. B.; Paris, S. W.

1984-01-01

The benefits and costs of high aerodynamic efficiency on aeroassisted orbital transfer vehicles (AOTV) are analyzed. Results show that a high lift to drag (L/D) AOTV can achieve significant velocity savings relative to low L/D aerobraked OTV's when traveling round trip between low Earth orbits (LEO) and alternate orbits as high as geosynchronous Earth orbit (GEO). Trajectory analysis is used to show the impact of thermal protection system technology and the importance of lift loading coefficient on vehicle performance. The possible improvements in AOTV subsystem technologies are assessed and their impact on vehicle inert weight and performance noted. Finally, the performance of high L/D AOTV concepts is compared with the performances of low L/D aeroassisted and all propulsive OTV concepts to assess the benefits of aerodynamic efficiency on this class of vehicle.

Optimal design of high-speed loading spindle based on ABAQUS

Science.gov (United States)

Yang, Xudong; Dong, Yu; Ge, Qingkuan; Yang, Hai

2017-12-01

The three-dimensional model of high-speed loading spindle is established by using ABAQUS’s modeling module. A finite element analysis model of high-speed loading spindle was established by using spring element to simulate bearing boundary condition. The static and dynamic performance of the spindle structure with different specifications of the rectangular spline and the different diameter neck of axle are studied in depth, and the influence of different spindle span on the static and dynamic performance of the high-speed loading spindle is studied. Finally, the optimal structure of the high-speed loading spindle is obtained. The results provide a theoretical basis for improving the overall performance of the test-bed

A Study of Torque Vectoring and Traction Control for an All-Wheel Drive Electric Vehicle

Directory of Open Access Journals (Sweden)

Maharun Mui’nuddin

2014-07-01

Full Text Available Common vehicle always experience energy loss during cornering manoeuver. Thus, to ensure it did not happened especially at high speed, a study of torque vectoring and traction control need to be made since it can increase the traction control of tyres during cornering at high speed. The study of torque vectoring and traction control for an all-wheel drive electric vehicle was conducted by modelling an all-wheel drive electric vehicle (EV in ADAMS/Car software. In addition, an optimal control algorithm will be developed for best performance to minimize energy losses using MATLAB/Simulink software. Furthermore, to prove the effectiveness of the all-wheel drive electric, the torque and traction control simulation of the all-wheel drive electric vehicle will be compared with uncontrolled electric vehicle model. According to the result, torque vectoring and traction control of in-wheel motor in all wheel drive EV can help to increase the performance of the electric vehicle during cornering manoeuver. In conclusion, this study of torque vectoring and traction control for an all-wheel drive electric vehicle will help researchers to improve the design of the future electric vehicle in term of the vehicle performance during cornering manoeuvre.

Vehicle-based road dust emission measurement (III):. effect of speed, traffic volume, location, and season on PM 10 road dust emissions in the Treasure Valley, ID

Science.gov (United States)

Etyemezian, V.; Kuhns, H.; Gillies, J.; Chow, J.; Hendrickson, K.; McGown, M.; Pitchford, M.

The testing re-entrained aerosol kinetic emissions from roads (TRAKER) road dust measurement system was used to survey more than 400 km of paved roads in southwestern Idaho during 3-week sampling campaigns in winter and summer, 2001. Each data point, consisting of a 1-s measurement of particle light scattering sampled behind the front tire, was associated with a link (section of road) in the traffic demand model network for the Treasure Valley, ID. Each link was in turn associated with a number of characteristics including posted speed limit, vehicle kilometers traveled (vkt), road class (local/residential, collector, arterial, and interstate), county, and land use (urban vs. rural). Overall, the TRAKER-based emission factors based on location, setting, season, and speed spanned a narrow range from 3.6 to 8.0 g/vkt. Emission factors were higher in winter compared to summer, higher in urban areas compared to rural, and lower for roads with fast travel speeds compared to slower roads. The inherent covariance between traffic volume and traffic speed obscured the assessment of the effect of traffic volume on emission potentials. Distance-based emission factors expressed in grams per kilometer traveled (g/vkt) for roads with low travel speeds (˜11 m/s residential roads) compared to those with high travel speeds (˜25 m/s interstates) were higher (5.2 vs. 3.0 g/vkt in summer and 5.9 vs. 4.9 g/vkt in winter). However, emission potentials which characterize the amount of suspendable material on a road were substantially higher on roads with low travel speeds (0.71 vs. 0.13 g/vkt/(m/s) in summer and 0.78 vs. 0.21 g/vkt/(m/s) in winter). This suggested that while high speed roads are much cleaner (factor of 5.4 in summer), on a vehicle kilometer traveled basis, emissions from high and low speed roads are of the same order. Emission inventories based on the TRAKER method, silt loadings obtained during the field study, and US EPA's AP-42 default values of silt loading were

Vehicle State Information Estimation with the Unscented Kalman Filter

Directory of Open Access Journals (Sweden)

Hongbin Ren

2014-01-01

Full Text Available The vehicle state information plays an important role in the vehicle active safety systems; this paper proposed a new concept to estimate the instantaneous vehicle speed, yaw rate, tire forces, and tire kinemics information in real time. The estimator is based on the 3DoF vehicle model combined with the piecewise linear tire model. The estimator is realized using the unscented Kalman filter (UKF, since it is based on the unscented transfer technique and considers high order terms during the measurement and update stage. The numerical simulations are carried out to further investigate the performance of the estimator under high friction and low friction road conditions in the MATLAB/Simulink combined with the Carsim environment. The simulation results are compared with the numerical results from Carsim software, which indicate that UKF can estimate the vehicle state information accurately and in real time; the proposed estimation will provide the necessary and reliable state information to the vehicle controller in the future.

Comprehensive surface treatment of high-speed steel tool

Science.gov (United States)

Fedorov, Sergey V.; Aleshin, Sergey V.; Swe, Min Htet; Abdirova, Raushan D.; Kapitanov, Alexey V.; Egorov, Sergey B.

2018-03-01

One of the promising directions of hardening of high-speed steel tool is the creation on their surface of the layered structures with the gradient of physic-chemical properties between the wear-resistant coatings to the base material. Among the methods of such surface modification, a special process takes place based on the use of pulsed high-intensity charged particle beams. The high speed of heating and cooling allows structural-phase transformations in the surface layer, which cannot be realized in a stationary mode. The treatment was conducted in a RITM-SP unit, which constitutes a combination of a source of low-energy high-current electron beams "RITM" and two magnetron spraying systems on a single vacuum chamber. The unit enables deposition of films on the surface of the desired product and subsequent liquid-phase mixing of materials of the film and the substrate by an intense pulse electron beam. The article discusses features of the structure of the subsurface layer of high-speed steel M2, modified by surface alloying of a low-energy high-current electron beam, and its effect on the wear resistance of the tool when dry cutting hard to machine Nickel alloy. A significant decrease of intensity of wear of high-speed steel with combined treatment happens due to the displacement of the zone of wear and decrease the radius of rounding of the cutting edge because of changes in conditions of interaction with the material being treated.

32 CFR 634.27 - Speed-measuring devices.

Science.gov (United States)

2010-07-01

... 32 National Defense 4 2010-07-01 2010-07-01 true Speed-measuring devices. 634.27 Section 634.27 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY (CONTINUED) LAW ENFORCEMENT AND CRIMINAL INVESTIGATIONS MOTOR VEHICLE TRAFFIC SUPERVISION Traffic Supervision § 634.27 Speed-measuring devices. Speed-measuring devices will be...

High-speed railway signal trackside equipment patrol inspection system

Science.gov (United States)

Wu, Nan

2018-03-01

High-speed railway signal trackside equipment patrol inspection system comprehensively applies TDI (time delay integration), high-speed and highly responsive CMOS architecture, low illumination photosensitive technique, image data compression technique, machine vision technique and so on, installed on high-speed railway inspection train, and achieves the collection, management and analysis of the images of signal trackside equipment appearance while the train is running. The system will automatically filter out the signal trackside equipment images from a large number of the background image, and identify of the equipment changes by comparing the original image data. Combining with ledger data and train location information, the system accurately locate the trackside equipment, conscientiously guiding maintenance.

Emission rates of regulated pollutants from on-road heavy-duty diesel vehicles

Science.gov (United States)

Shah, Sandip D.; Johnson, Kent C.; Wayne Miller, J.; Cocker, David R.

Emissions from heavy-duty diesel (HDD) vehicles are affected by many factors. Changes in engine technology, operating mode, fuel properties, vehicle speed and ambient conditions can have significant effects on emission rates of regulated species. This paper presents the results of on-road emissions testing of 11 HDD vehicles (model years 1996-2000) over the ARB Four Phase driving schedule and the urban dynamometer driving schedule (UDDS). Emission rates were found to be highly dependent on vehicle operating mode. Per mile NO x emission rates for vehicle operation at low speeds, in simulated congested traffic, were three times higher per mile emissions then while cruising on the freeway. Comparisons of NO x emission factors to EMFAC baseline emission factors were within 5-40% for vehicles of various model years tested over the UDDS. A comparison of NO x emission factors for a weighted average of the ARB four phase driving schedule yielded values within 17-57% of EMFAC values. Generally, particulate matter (PM) emission rates were lower than EMFAC values.

An extended heterogeneous car-following model accounting for anticipation driving behavior and mixed maximum speeds

Science.gov (United States)

Sun, Fengxin; Wang, Jufeng; Cheng, Rongjun; Ge, Hongxia

2018-02-01

The optimal driving speeds of the different vehicles may be different for the same headway. In the optimal velocity function of the optimal velocity (OV) model, the maximum speed vmax is an important parameter determining the optimal driving speed. A vehicle with higher maximum speed is more willing to drive faster than that with lower maximum speed in similar situation. By incorporating the anticipation driving behavior of relative velocity and mixed maximum speeds of different percentages into optimal velocity function, an extended heterogeneous car-following model is presented in this paper. The analytical linear stable condition for this extended heterogeneous traffic model is obtained by using linear stability theory. Numerical simulations are carried out to explore the complex phenomenon resulted from the cooperation between anticipation driving behavior and heterogeneous maximum speeds in the optimal velocity function. The analytical and numerical results all demonstrate that strengthening driver's anticipation effect can improve the stability of heterogeneous traffic flow, and increasing the lowest value in the mixed maximum speeds will result in more instability, but increasing the value or proportion of the part already having higher maximum speed will cause different stabilities at high or low traffic densities.

Pulse-burst PIV in a high-speed wind tunnel

International Nuclear Information System (INIS)

Beresh, Steven; Kearney, Sean; Wagner, Justin; Guildenbecher, Daniel; Henfling, John; Spillers, Russell; Pruett, Brian; Jiang, Naibo; Slipchenko, Mikhail; Mance, Jason; Roy, Sukesh

2015-01-01

Time-resolved particle image velocimetry (TR-PIV) has been achieved in a high-speed wind tunnel, providing velocity field movies of compressible turbulence events. The requirements of high-speed flows demand greater energy at faster pulse rates than possible with the TR-PIV systems developed for low-speed flows. This has been realized using a pulse-burst laser to obtain movies at up to 50 kHz, with higher speeds possible at the cost of spatial resolution. The constraints imposed by use of a pulse-burst laser are limited burst duration of 10.2 ms and a low duty cycle for data acquisition. Pulse-burst PIV has been demonstrated in a supersonic jet exhausting into a transonic crossflow and in transonic flow over a rectangular cavity. The velocity field sequences reveal the passage of turbulent structures and can be used to find velocity power spectra at every point in the field, providing spatial distributions of acoustic modes. The present work represents the first use of TR-PIV in a high-speed ground-test facility. (paper)

The Diesel as a Vehicle Engine

Science.gov (United States)

Neumann, Kurt

1928-01-01

The thorough investigation of a Dorner four-cylinder, four-stroke-cycle Diesel engine with mechanical injection led me to investigate more thoroughly the operation of the Diesel as a vehicle engine. Aside from the obvious need of reliability of functioning, a high rotative speed, light weight and economy in heat consumption per horsepower are also indispensable requirements.

High temperature superconducting Maglev equipment on vehicle

Science.gov (United States)

Wang, S. Y.; Wang, J. S.; Ren, Z. Y.; Zhu, M.; Jiang, H.; Wang, X. R.; Shen, X. M.; Song, H. H.

2003-04-01

Onboard high temperature superconducting (HTS) Maglev equipment is a heart part of a HTS Maglev vehicle, which is composed of YBaCuO bulks and rectangle-shape liquid nitrogen vessel and used successfully in the first manned HTS Maglev test vehicle. Arrangement of YBaCuO bulks in liquid nitrogen vessel, structure of the vessel, levitation forces of a single vessel and two vessels, and total levitation force are reported. The first manned HTS Maglev test vehicle in the world has operated well more than one year after it was born on Dec. 31, 2000, and more than 23,000 passengers have taken the vehicle till now. Well operation of more than one year proves the reliability of the onboard HTS Maglev equipment.

Application of a distributed systems architecture for increased speed in image processing on an autonomous ground vehicle

Science.gov (United States)

Wright, Adam A.; Momin, Orko; Shin, Young Ho; Shakya, Rahul; Nepal, Kumud; Ahlgren, David J.

2010-01-01

was established as the most reliable protocol after testing various options. Improvement can be made to the system by migrating more algorithms to the hardware based FPGA to further speed up the operations of the vehicle.

Development of high electrical resistance persistent current switch for high speed energization system

International Nuclear Information System (INIS)

Jizo, Y.; Furuta, Y.; Nakashima, H.

1986-01-01

Japanese National Railways is now developing a superconducting magnetically-levitated train system. A persistent current switch is incorporated in the super-conducting magnet used in the magnetically-levitated train. In recent years, the switch has been required to have higher electrical resistance during its off-state in order to realize the high speed energization/de-energization system of the superconducting magnets. The system aims to decrease evaporation volume of liquid helium during the energization/de-energization of the magnet, by means of energizing the superconducting magnet with high current increasing/decreasing rate. Consequently, it would be possible to decrease the dependence of the on-board magnet system upon the ground cooling system. Through the development of a stable superconductive wire material and a coil structure for the persistent current switch using many small model switches which were produced in order to improve their current carrying capacities, the authors have succeeded in manufacturing the high electrical resistance persistent current switch whose electrical resistance was 5 ohms. The switch, of cylindrical shape, has a diameter of about 100mm, a length of about 100mm. These 5 ohm PCSs are now functioning in stable conditions being incorporated in the superconducting magnets of No.2 vehicle of MLU001 at the JNR's Miyazaki test track. Further, the authors are now developing the PCS of still higher resistance values, such as 50 ohms, through studies for stabilization in structural aspects of the winding and obtaining results therefrom

49 CFR 38.175 - High-speed rail cars, monorails and systems.

Science.gov (United States)

2010-10-01

... 49 Transportation 1 2010-10-01 2010-10-01 false High-speed rail cars, monorails and systems. 38....175 High-speed rail cars, monorails and systems. (a) All cars for high-speed rail systems, including... monorail systems operating primarily on dedicated rail (i.e., not used by freight trains) or guideway, in...

Noise in the passenger cars of high-speed trains.

Science.gov (United States)

Hong, Joo Young; Cha, Yongwon; Jeon, Jin Yong

2015-12-01

The aim of this study is to investigate the effects of both room acoustic conditions and spectral characteristics of noises on acoustic discomfort in a high-speed train's passenger car. Measurement of interior noises in a high-speed train was performed when the train was operating at speeds of 100 km/h and 300 km/h. Acoustic discomfort caused by interior noises was evaluated by paired comparison methods based on the variation of reverberation time (RT) in a passenger car and the spectral differences in interior noises. The effect of RT on acoustic discomfort was not significant, whereas acoustic discomfort significantly varied depending on spectral differences in noise. Acoustic discomfort increased with increment of the sound pressure level (SPL) ratio at high frequencies, and variation in high-frequency noise components were described using sharpness. Just noticeable differences of SPL with low- and high-frequency components were determined to be 3.7 and 2.9 dB, respectively. This indicates that subjects were more sensitive to differences in SPLs at the high-frequency range than differences at the low-frequency range. These results support that, for interior noises, reduction in SPLs at high frequencies would significantly contribute to improved acoustic quality in passenger cars of high-speed trains.

High Speed Rail (HSR) in the United States

Science.gov (United States)

2009-12-08

announced that it will expand the capacity on its aging high speed line between Tokyo and Osaka, the most heavily traveled intercity rail segment in the...United States, in most of these countries intercity rail travel (including both conventional and high speed rail) represents less than 10% of all...that is sometimes mentioned by its advocates. Intercity passenger rail transport is relatively safe, at least compared with highway travel . And HSR in

High-speed optical signal processing using time lenses

DEFF Research Database (Denmark)

Galili, Michael; Hu, Hao; Guan, Pengyu

2015-01-01

This paper will discuss time lenses and their broad range of applications. A number of recent demonstrations of complex high-speed optical signal processing using time lenses will be outlined with focus on the operating principle.......This paper will discuss time lenses and their broad range of applications. A number of recent demonstrations of complex high-speed optical signal processing using time lenses will be outlined with focus on the operating principle....

Improved high speed maglev design

Science.gov (United States)

Rote, D.M.; He, Jianliang; Coffey, H.T.

1992-01-01

This report discusses a propulsion and stabilization system for an inductive repulsion type magnetically levitated vehicle which is propelled and suspended by a system which includes dividing the superconducting magnets into two types: a strong field magnet which is located vertically below the vehicle for propulsion and guidance and a weak field superconducting magnet located at the ends of the vehicle for levitation and added guidance. Several proposed embodiments exist for the placement of the magnetic field shielding: locating the shielding on the vehicle, locating the shielding on the guideway, and locating the shielding on the guideway and adding shielding to the vertical undercarriage. In addition, the separation between the be vehicle and the guideway can be controlled to reduce the exposure of the passenger cabin to magnetic fields.

NET in-vessel vehicle system

International Nuclear Information System (INIS)

Jones, H.

1991-02-01

The CFFTP/Spar In-vessel Vehicle System concept for in-vessel remote maintenance of the NET/ITER machine is described. It comprises a curved deployable boom, a vehicle which can travel on the boom and an end effector or work unit mounted on the vehicle. The stowed boom, vehicle, and work unit are inserted via the equatorial access port of the torus. Following insertion the boom is deployed and locked in place. The vehicle may then travel along the boom to transport the work unit to any desired location. A novel feature of the concept is the deployable boom. When fully deployed, it closely resembles a conventional curved truss structure in configuration and characteristics. However, the joints of the truss structure are hinged so that it can fold into a compact package, of less than 20% of deployed volume for storage, transportation and insertion into the torus. A full-scale 2-metre long section of this boom was produced for demonstration purposes. As part of the concept definition the work unit for divertor handling was studied to demonstrate that large payloads could be manipulated within the confines of the torus using the in-vessel vehicle system. Principal advantages of the IVVS are its high load capacity and rigidity, low weight and stowed volume, simplicity of control and operation, and its relatively high speed of transportation

High-speed parallel counter

International Nuclear Information System (INIS)

Gus'kov, B.N.; Kalinnikov, V.A.; Krastev, V.R.; Maksimov, A.N.; Nikityuk, N.M.

1985-01-01

This paper describes a high-speed parallel counter that contains 31 inputs and 15 outputs and is implemented by integrated circuits of series 500. The counter is designed for fast sampling of events according to the number of particles that pass simultaneously through the hodoscopic plane of the detector. The minimum delay of the output signals relative to the input is 43 nsec. The duration of the output signals can be varied from 75 to 120 nsec

Influence of “J”-Curve Spring Stiffness on Running Speeds of Segmented Legs during High-Speed Locomotion

Directory of Open Access Journals (Sweden)

Runxiao Wang

2016-01-01

Full Text Available Both the linear leg spring model and the two-segment leg model with constant spring stiffness have been broadly used as template models to investigate bouncing gaits for legged robots with compliant legs. In addition to these two models, the other stiffness leg spring models developed using inspiration from biological characteristic have the potential to improve high-speed running capacity of spring-legged robots. In this paper, we investigate the effects of “J”-curve spring stiffness inspired by biological materials on running speeds of segmented legs during high-speed locomotion. Mathematical formulation of the relationship between the virtual leg force and the virtual leg compression is established. When the SLIP model and the two-segment leg model with constant spring stiffness and with “J”-curve spring stiffness have the same dimensionless reference stiffness, the two-segment leg model with “J”-curve spring stiffness reveals that (1 both the largest tolerated range of running speeds and the tolerated maximum running speed are found and (2 at fast running speed from 25 to 40/92 m s−1 both the tolerated range of landing angle and the stability region are the largest. It is suggested that the two-segment leg model with “J”-curve spring stiffness is more advantageous for high-speed running compared with the SLIP model and with constant spring stiffness.

High speed rotary drum

Energy Technology Data Exchange (ETDEWEB)

Sagara, H

1970-03-25

A high speed rotary drum is disclosed in which the rotor vessel is a double-wall structure comprising an inner wave-shaped pipe inserted coaxially within an outer straight pipe, the object being to provide a strengthened composite light-weight structure. Since force induced axial deformation of the straight pipe and radial deformation of the corrugated pipe are small, the composite effectively resists external forces and, if the waves of the inner pipe are given a sufficient amplitude, the thickness of both pipes may be reduced to lower the overall weight. Thus high angular velocities can be obtained to separate U/sup 235/ from gaseous UF/sub 6/.

System and method of vehicle operating condition management

Science.gov (United States)

Sujan, Vivek A.; Vajapeyazula, Phani; Follen, Kenneth; Wu, An; Moffett, Barty L.

2015-10-20

A vehicle operating condition profile can be determined over a given route while also considering imposed constraints such as deviation from time targets, deviation from maximum governed speed limits, etc. Given current vehicle speed, engine state and transmission state, the present disclosure optimally manages the engine map and transmission to provide a recommended vehicle operating condition that optimizes fuel consumption in transitioning from one vehicle state to a target state. Exemplary embodiments provide for offline and online optimizations relative to fuel consumption. The benefit is increased freight efficiency in transporting cargo from source to destination by minimizing fuel consumption and maintaining drivability.

Coronal holes and high-speed wind streams

International Nuclear Information System (INIS)

Zirker, J.B.

1977-01-01

Coronal holes low have been identified as Bartel's M regions, i.e., sources of high-speed wind streams that produce recurrent geomagnetic variations. Throughout the Skylab period the polar caps of the Sun were coronal holes, and at lower latitudes the most persistent and recurrent holes were equatorial extensions of the polar caps. The holes rotated 'rigidly' at the equatorial synodic rate. They formed in regions of unipolar photospheric magnetic field, and their internal magnetic fields diverged rapidly with increasing distance from the sun. The geometry of the magnetic field in the inner corona seems to control both the physical properties of the holes and the global distribution of high-speed wind streams in the heliosphere. The latitude variation of the divergence of the coronal magnetic field lines produces corresponding variations in wind speed.During the years of declining solar activity the global field of the corona approximates a perturbed dipole. The divergence of field lines in each hemisphere produces a high-speed wind near the poles and low-speed wind in a narrow belt that coincides with the magnetic neutral sheet. The analysis of electron density measurements within a polar hole indicates that solar wind is accelerated principally in the region between 2 and 5 R/sub s/ and that mechanical wave pressure (possibly Alfven wave) may be responsible for the accleration of the wind. Phenomenological models for the birth and decay of coronal holes have been proposed. Attempts to explain the birth and rigid rotation of holes through dynamo action have been only partially successful. The 11-year variation of cosmic ray intensities at the earth may result from cyclic variation of open field regions associated with coronal holes