Minimum Energy Control of In-Wheel Motors with Real Time Road Adaption(I)
|關鍵字:||電動車;輪胎摩擦力估測;車輛運動控制;Electric Vehicle;Tire Force Estimation;Vehicle Motion Control|
The lack of petroleum in the near future inspires the study of electric vehicles. In addition to its efficient and clean power usage, the electric vehicle has many other advantages over the internal combustion engine vehicle. Firstly, the four wheels of the electric vehicle are driven directly and independently by individual motors; therefore the angular velocities and torques of each wheel are known exactly. The tire force as well as the road adhesion coefficient can then be estimated with high accuracy. Besides, motors respond much faster than internal combustion engines; hence the electric vehicle can move more agilely provided that the motion control system is designed properly. This project is going to develop an efficient and robust estimation algorithm for the tire force and the road adhesion coefficient. Taking advantage of the rich information about each wheel and the novel tire dynamic model developed recently (the so-called DDT model), we can enhance the accuracy of the estimation, especially in the low-speed and low slip ratio regions. The estimated tire-road information will then be incorporated into the vehicle motion control system (e.g. the traction control or the yaw-moment control system) such that the controller becomes “road-adaptive,” i.e. the motor outputs are self-tuning in accordance with the road condition. Moreover, the energy consumption will also be taken into account in the design of the control system in order for the electric vehicle to be stable, safe and power efficient.