Experimental Platform for Evaluation of On-Board Real-Time Motion Controllers for Electric Vehicles

Electric vehicles are considered to be a greener and safer means of transport thanks to the distinguished advantages of electric motors. Studies on this object require experimental platforms for control validation purpose. Under the pressure of research, the development of these platforms must be reliable, safe, fast, and cost effective. To practically validate the control system, the controllers should be implemented in an on-board micro-controller platform; whereas, the vehicle model should be realized in a real-time emulator that behaves like the real vehicle. In this paper, we propose a signal hardware-in-the-loop simulation system for electric vehicles that are driven by four independent electric motors installed in wheels (in-wheel motor). The system is elaborately built on the basis of longitudinal, lateral, and yaw dynamics, as well as kinematic and position models, of which the characteristics are complete and comprehensive. The performance of the signal hardware-in-the-loop system is evaluated by various open-loop testing scenarios and by validation of a representative closed-loop optimal force distribution control. The proposed system can be applied for researches on active safety system of electric vehicles, including traction, braking control, force/torque distribution strategy, and electronic stability program.

Stability Control for Vehicle Dynamic Management with Multi-Objective Fuzzy Continuous Damping Control

Vehicle dynamic management (VDM) is a vehicle chassis integrated control system based on electronic stability program (ESP) and continuous damping control (CDC) that has been developed in recent years. In this work, the ideal yaw angle rate and sideslip angle of the mass center are calculated deriving an ideal monorail model with two degrees of freedom. Then, a direct yaw moment proportional-integral-differential control strategy for ESP is proposed as the foundation of VDM. In addition, a multi-objective fuzzy continuous damping control (MFCDC) is proposed to achieve comfort, handling stability, and rollover prevention. The effect of the MFCDC strategy is analyzed and verified through a sine wave steer input test, double line change test, and fishhook test. The results indicate that MFCDC-ESP has a significant advantage in preventing rollover. MFCDC-ESP can maintain the optimized distribution of damping force through its own compensation under possible instability and predict the critical stable state to some extent. MFCDC-ESP exhibits strong real-time sensitivity to the control state of the damping force of each wheel. Hence, it can ensure the comfort of passengers under good driving conditions and exert strong adaptability and control effects under extreme working conditions.

A Fuzzy-PID Scheme for Low Speed Control of a Vehicle While Going on a Downhill Road

We explored a vehicle hill descent control (HDC) system based on an electronic stability program (ESP) and applied this system to brake cars. The experimental results reveal that our system can effectively reduce the workload of a driver during a downhill journey. In the first phase of our work, the control strategy of the HDC system based on fuzzy-PID (Proportion Integral Differential) was built by MATLAB/Simulink. Then, the co-simulation based on MATLAB/Simulink, CarSim and AMESim was carried out. Finally, a real vehicle test was conducted to further verify the feasibility of the strategy. A series of simulation experiments and real vehicle tests show that the HDC system can assist the driver to control the vehicle while driving downhill at low speed, thus effectively improving the safety of the vehicle and reducing the workload of driver.

Research on coordinated control of electronic stability program and active suspension system based on function allocation and multi-objective fuzzy decision

The stabilities of the handling and rollover are the two important performance of the vehicle and play an important role in vehicle safe driving. Focusing on improving the handling and rollover stabilities, a new approach to realize the coordinated control of the electronic stability program and the active suspension system is proposed. The vehicle model including the active suspension system has been built. The distance between vehicle centroid and the front and rear axles is estimated by the forgetting factor recursion least squares method on the basis of the vertical motion of the vehicle. The parameter self-tuning fuzzy proportional–integral–derivative control of the electronic stability program is adopted and the 2-degree-of-freedom vehicle model considering the changes of the distance between vehicle centroid and the front and rear axles is treated as the reference model. The active suspension system controller is designed according to the different functions of the active suspension system in different vehicle status areas. The function allocation controller is also designed using multi-objective fuzzy decision, which is used to realize the allocation control of the active suspension system and electronic stability program. Under the double-lane change conditions, the function allocation control has been simulated based on MATLAB/Simulink software, which results indicate that the function allocation control strategy of electronic stability program and active suspension system can significantly improve the manipulation and rollover stability of the vehicle at a high speed under emergency steering. Finally, the function allocation controller is installed to the active suspension system and electronic stability program hardware-in-loop test platform, and the hardware-in-loop test has been done, which results are consistent with the results of simulation.