tailieunhanh - Electric Vehicles Modelling and Simulations Part 4

Tham khảo tài liệu 'electric vehicles modelling and simulations part 4', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Vehicle Dynamic Control of 4 In-Wheel-Motor Drived Electric Vehicle 79 According to results from and we can get that the combined control method has better robustness to the input signal s disturb. This point is very important to the usage of the control method. 3. Anti-lock brake control For electric vehicles the motor inside each wheel is able to provide braking torque during deceleration by working as a generator. Moreover the torque response of an electric motor is much faster than that of a hydraulic system. Thanks to the synergy of electric and hydraulic brake system the performance of the ABS Anti-lock Brake System on board is considerably improved. In this section a new anti-skidding method based on the model following control method is proposed. With the new feedback function and control parameter the braking performance especially the phase-delay of the electric motor s torque is according to the result of the simulation improved. Combined with the advantage of the origin MFC the improved MFC can be widely applied in anti-skidding brake control. Furthermore a braking torque dynamic distributor based on the adjustable hybrid braking system is designed so that the output torque can track the input torque accurately. Meanwhile a sliding mode controller is constructed which doesn t perform with the slip ratio value as the main control parameter. Accordingly the total torque is regulated in order to prevent the skidding of the wheel so that the braking safety can be guaranteed. Model following controller One wheel model When braking slip ratio 2 is generally given by V V 2 V Where V is the vehicle longitudinal velocity and Vw is the wheel velocity. Vw Rw where R w are the wheel radius and angular velocity respectively. Fig. . One wheel model dynamic analysis 80 Electric Vehicles - Modelling and Simulations In the light of Fig. the motion equations of one wheel model can be represented as dw w dt IwdVw R dt Fd R - Tb .