Drive Control of Electric Vehicle based on Non-linear H infinity control theory

汽车的驱动力是通过轮胎与路面之间的摩擦力传递的。摩擦力是车体重量和轮胎与路面摩擦系数μ的函数。摩擦系数μ也是以下参数的函数：由车身速度和车轮速度决定的滑移率λ以及路面状况。汽车在加速和制动过程中经常发生打滑，造成很大的损坏。在本研究中，提出了一种新的驱动控制系统，它对加速和制动都有影响。在驱动控制系统中，采用了李雅普诺夫函数设计的非线性控制器。该非线性控制器具有两种功能：一种是移动车身的μ控制，另一种是λ控制。控制器被设计成μ和λ分别工作于防滑和带滑。采用扰动观测器作为另一种控制器，对难以测量的车身速度进行估计。然后，证明了由非线性控制器和扰动观测器两个控制器组成的组合系统的稳定性条件。最后，通过两个实例的仿真和实验结果验证了该控制系统的有效性。

The driving force of automobiles is transmitted by the frictional force between the tires and the road surface. This frictional force is a function of the weight of the car-body and the friction coefficient μ between the tires and the road surface. The friction coefficient μ is also a function of the following parameters: the slip ratio λ determined by the car-body speed and the wheel speed, and the condition of the road surface.Slippage of automobiles which causes much damage often occurs during accelerating and braking. In this research, a new drive control system is proposed, which has an effect on acceleration and braking. In the drive control system, a non-linear controller designed by using a Lyapunov function is used. This non-linear controller has two functions: first one is μ control which moves the car-body, another one is λ control. The controller is designed in order that μ and λ work at non-slip and with slip respectively. As another controller, a disturbance observer is used for estimating the car-body speed which is difficult to be measured. Then, this lead to the proof of the stability condition of the combined system which consists of two controllers: the non-linear controller and the disturbance observer.Finally, the effectiveness of this control system is proved by the very satisfactory simulation and experimental results for two cases.