Guang Yao Zhao

Jackknife Control on Tractor Semi-Trailer during Emergency Braking

Emergency braking on a low coefficient of friction or split-mu road surface, the semi-trailer may push the tractor from behind until it spins round and faces backwards, and a jackknife accident occurs. In this paper, the tractor semi-trailer kinematics was analyzed and a 3-dof of tractor semi-trailer model was used to design a state observer to estimate the articulation angle. To avoid a jackknife, the four-channel ABS which can produce maximum braking force will be switch to three-channel ABS according the estimated articulation angle. The virtual prototyping simulation results show that the jackknife control system can improve the tractor semi-trailer lateral stability under emergency braking and shorten the stop distance dramatically on split-mu road surface at high speed.

Fuzzy Control Strategy and Simulation for Dual Electric Tracked Vehicle Motion Control

Based on tracked vehicle dynamics analysis, a fuzzy control strategy is proposed in this paper for the dual electric tracked vehicle motion control. The inputs of fuzzy system are driver acceleration, braking and steering signals besides vehicle velocity feedback signal, while outputs are dual motors’ torque commands and mechanical braker’s target force. Control strategy contains two fuzzy logics, one is for steering and straight-line running control, the other is for braking control section. Simulation results show that the fuzzy control strategy presented here is correct and effective for electric tracked vehicle motion control.

Stability Control on Tractor Semi-Trailer during Split-Mu Braking

Handling behaviour of articulated vehicles combination is more complex and less predictable than that of non-articulated vehicles. It is usually difficult for drivers to maneuver a tractor semi-trailer during high speed emergency braking on split-mu road surface. Braking on this type of road surface, the conventional anti-lock braking systems will cause the vehicle deviate from the desired direction, or overmuch stopping distance. In this paper, a 3-dof of tractor semi-trailer model was used to produce desired yaw rates which were compared with actual yaw rates. An active front steering control and four-channel ABS were integrated to improve the tractor semi-trailer lateral stability while braking on split-mu road surface, which will produce maximum braking force. A full function tractor semi-trailer model was built and assembled in multi-body dynamics software, and the dynamic analysis was performed on split-mu road surface. The simulation results show that the integrated system can improve the tractor semi-trailer lateral stability under braking on split-mu road surface.

Research on Active Suspension System Based on BP and RBF Network Algorithm

A six degrees of freedom half body vehicle suspension system is presented in the paper .The Back Propagation neural network algorithm and the Radial-Basis Function network algorithm is adopted to control the suspension system. With the aid of software Matlab/Simulink , the simulation model is obtained. A great deal of simulation work is done. Simulation results demonstrate that both the designed radius basis function neural network and the back propagation neural network work well for the proposed vehicle suspension model in the paper .

The Body Structural Optimization Based on Safe Side Impact

In view of analyzing the whole side crashworthiness, based on C-NCAP side impact regulations, this study has analyzed the structural characteristics influencing the side impact of car, and proposed the corresponding structural optimization case. According to FEM, the body optimization case has been simulated and contrasted with the real results. As a result, a good side crashworthiness of the car has been obtained, which helps reduce the cost and the quality of the car. Besides, the study has also done simulation work of the rigidity and modal of the body-in-white and compared it with the real results, which has further tested the correctness of optimization model and helped achieve effective approaches to the design of the car side crashworthiness.

Analysis of Statics and Transient Responses on Automotive Gearbox Casing

The three-dimensional solid modeling is built based on some Automobile gearbox Product, the dangerous working conditions of static load are analyzed. On the basis of ADAMS, transient dynamic loads of gearbox at different working gears are found out. The finite element analysis modeling of gearbox casing is built. The static displacement and the stress distribution of gearbox casing are obtained, and the static strength and stiffness are evaluated. The eigenvalues of vibration of gearbox casing are solved, the coupling relationship of the excitation frequency and the gearbox casing natural frequency is analyzed. Based on the transient dynamic analysis of gearbox casing at the first gear and the reverse gear, the evaluations of the dynamic strength and dynamic stiffness are obtained and the weak position of structure is found out, which provides the beneficial information for the further study on the design of the fatigue and reliability of gearbox casing.

D2P Real-Time Simulation of Energy Management Strategy for Parallel Hybrid Electric Vehicle

For investigating the feasibility of control strategy used in parallel hybrid electric vehicle, a D2P real-time simulation is introduced. A new multi-mode rule-based control strategy is proposed. The strategy is based on splitting the torque from the motor and engine so that these power sources can be operated at high efficiency. A real-time simulation platform is built based on D2P system. Real driver inputs and controller are applied while controlled objects are simulated using the model of parallel hybrid electric system computed in D2P module. Strategy is validated by D2P real-time simulation, which results show that the presented strategy is feasible and effective.

Acceleration Control for a Plug-in Series Hybrid Electric Vehicle

Acceleration control using fuzzy logic is investigated in this paper for a plug-in series hybrid electric vehicle in order to improve the vehicle response to drivers demand. The transient process of acceleration is mainly considered in this research. Fuzzy logic is used for motor transient torque control according to drivers input and vehicle velocity, outputting a regulatory factor to increase motor torque transiently when drivers acceleration pedal is pushed down deeply and to reduce the torque increment when acceleration process is close to over. Performance of fuzzy control is tested by MATLAB simulation. Simulation results indicate that the presented fuzzy algorithm is feasible and effective for improving vehicle acceleration ability without damaging stable velocity control characteristic; in simulation, vehicle acceleration time of 0-100km/h has been reduced by 2.4 seconds.

The Study of Simulation and Optimization on Car Ride Comfort

Based on the ADMAS software environment, the study designed a simulation model of the whole car virtual prototype for a certain type of car; then random road was created, and the movements and forces of the car in different working conditions were simulated; the originally designed type of car was simulated for its ride comfort evaluation. Then through the analysis of sensitivity, the important factors influencing the whole car ride comfort were found. In order to improve the whole car ride comfort, the suspension spring stiffness and shock-absorbing damper of the original design were optimized, which effectively improved the riding comfort of this type of car. The paper aims at improving the designing method of car ride comfort.

Research on Suspension System Based on Radial-Basis Function Algorithm

In this paper, a four degrees of freedom half body vehicle suspension system is developed .The Radial-Basis Function network algorithm is used to control the suspension system. With the aid of software Matlab/Simulink , the simulation model is achieved. A lot of simulation work is done. Simulation results demonstrate that the proposed active suspension system proves to be effective in vibration reduction of the suspension system.