Applied Mechanics and Materials Vols. 321-324

Abstract: An approximation method for calculating inverter power loss is proposed for SVPWM widely used in the electric vehicle drive system. Losses in the different vector sectors are calculated separately according to the characteristics and parameters of the IGBT in the loss approximation method. After that, for id=0 control and MTPA control of the permanent magnet synchronous motor, the power losses are calculated respectively and compared. This approximation method provides a theoretical basis for the selection of the appropriate power module and the rational design of cooling devices for the inverter

Abstract: GSP module of new intelligent electric automobile chassis navigation system. GPS positioning system mainly uses the technology is very mature GPS module with single- chip microcomputer interface communication completed, use more convenient, more accurate positioning. The design of the electric navigation system with global positioning, automatic control, good real-time performance and so on various advantages for an organic whole, used in today's car has a good development prospect.

Abstract: The bus drivers have to suffer from very high labor intensity every day. Driving fatigue among the bus drivers is very common and has very dangerous risk for traffic safety. Fourteen male bus drivers, divided into two groups according to two kinds of work schedules, participated in a control experiment. The driving session was performed in the real road scene. Each driver was asked to finish a five-laps driving task. The Stanford Sleepiness Scale score was recorded to measure the subjective fatigue feelings of the bus drivers. Choice reaction time and PECLOS indicators were used to assess the driving performance. One-way ANOVA was used to examine significance of data variations with SPSS. Person’s correlation coefficient was employed to explore the correlations among the three indicators. The results reveal that driving duration has a significant effect on the vigilance level of the bus drivers. There are evident positive correlations between the three indicators. And the two kinds of work schedules have different effect on the bus drivers’ prevention of driving fatigue.

Abstract: Rear-end collision is one kind of traffic accident with extreme danger. Peoples security and property are serious threatened by this kind of accidents. Based on morphological research of real-world collisions, this paper makes quantitative analysis of minimum safe distance under complex traffic situations. A novel mathematics model and corresponding collision avoidance algorithms are proposed. To verify feasibility of this algorithm, this paper performs accident emulation and data analysis with Visual Basic 6.0. Experimental results show that this approach is capable of reducing occurrence possibility of rear-end collisions.

Abstract: The delay in trains generated by an incident often occurs in urban rail transit scheduling, and how to faster and more accurate estimates the delay time of the trains will determine whether or not the influence can provide at the top speed. In this paper, we analysis the working process of the primary delay and the secondary delay, present the methods to calculate the delay time of the trains in case of non-overtaking and overtaking. We adopted the simulation technique to analysis the delay time of the trains. These methods have been inserted the Urban Rail Transit Trains Operation Control Simulation System as an analytical tool.

Abstract: In this paper, firstly, the function of test-bed of motor-wheel-drive Electric Vehicle has been clarified, the frame structures of test-bed has been designed and built. Secondly, control algorithm of motor-wheel-drive Electric Vehicle has been established, including vector control algorithm model, digital PID algorithm model and electronic differential control algorithm model, the control system of test-bed has been designed. Lastly, based on the test bed, the control algorithm of motor-wheel-drive Electric Vehicle has been verified by bench test. The bench test results show that, the control algorithm of motor-wheel-drive Electric Vehicle can achieve straight-ahead control and steering control, which laid the foundation for the future of the real vehicle tests.

Abstract: Power management of hybrid electric vehicle (HEV) is an important operational factor for HEV to enhance fuel economy and reduce emissions. Optimal control for HEV requires the knowledge of entire driving cycle and elevation profile to obtain the optimal control strategy over fixed driving cycle. In this paper, the traffic knowledge extracted from intelligent transportation systems (ITSs),global positioning systems (GPSs) and geographical information systems (GISs) is used for predicting the knowledge of the future driving cycle, and the real-time optimal control strategy based on dynamic programming in a moving window is investigated in order to minimize fuel consumption. A simulation study was conducted for two driving cycles, and the results showed significant improvement in fuel economy compared with a rule-based control. Furthermore, the results showed that the distance of the moving window has obvious effect on the fuel economy.

Abstract: Electronic Stability Program (ESP) is an advanced initiative system for car security. As an integration of subsystems such as ABS, TCS, ESC, etc., this new control system is designed to accurately manipulate the dynamics behaviors of vehicles under critical adhesive conditions, allowing maximum cooperation of vehicles responses to the driver's operation within physical limits. This research has firstly established a dynamical model of an entire vehicle as the controlled object in this study of ESP. Then, the paper moved on to the design of ESP control algorithm strategy, discussing the selection problem of which wheels should the longitudinal control force apply to, and finally proposing an effective improvement on operational stability control of ESP system.

Abstract: In the late-stage of designing an airbag control system, a lot of collision experiments should be done to verify the performance of the system, but collision experiments cost a lot of time and money. In this paper, we design a new development and testing platform that can generate multi-channel acceleration analog signals and provide multi-channel airbag ignition interfaces. The platform receives the acceleration data customized on PC via a USB interface, then, the PC issues a command to start the output of the acceleration waveforms. The airbag ignition interface has the same electrical characteristics with real airbag, when it receives an ignition current, the platform will ignite the virtual airbag, and record the time. The experimental results show that the platform designed in this paper can precisely simulate the acceleration waveforms collected in collision experiments.

Abstract: A new hybrid power train using variable displacement pump/motor was developed for electric vehicle. It mainly includes engine, brake, clutch, variable displacement pump/motor, hydraulic accumulator, output gear, planetary gear set, controller. The planetary gear set, brake, clutch, output gear, power output shaft are integrated to form power split and coupling mechanism. In this new power train, the hydraulic variable displacement pump/motor is used instead of the electric generator/motor with different operation modes, which are pure hydraulic motor driving, pure engine driving, parallel hybrid driving, and compound hybrid driving.