具通信功能之車用功率系統晶片---子計畫二：具有即時路況適應能力與最小耗能之輪內馬達驅動控制(I)

Abstract

由於石油即將用罄，使得電動車的研究日益受到重視。比起內燃機引擎車輛，電動車除了能源使用效率高以及零污染之外，還有許多其他的優點。首先，電動車使用馬達獨立驅動四個輪子，因此每個輪子的轉動速度與轉矩皆可量測得到，因此輪胎受力與路面摩擦係數的估測可以更準確。此外，馬達響應比內燃機還快，所以電動車的行駛會更加靈活。 本計畫目的在發展一套估測輪胎受力與路面摩擦係數的演算法。利用輪胎轉速與轉矩的資訊，以及最新的輪胎動態模型(即所謂的DDT模型)，可以提升演算法的準確性，特別是在低速與低滑動比的區域。 輪胎受力與路面摩擦係數的估測值將與車輛運動控制系統整合，使得控制器具有路況適應的能力，亦即馬達輸出功率會因路況而自行調節。而在設計控制器時，亦需將能量損耗納入考量，使得電動車可以兼顧穩定、安全與低耗能。

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.