基于滑模控制的汽车电子助力转向系统性能研究

Research on the Power Assisted Control Performance of Automobile Electric Power Steering Based on Slide Mode Control

考虑汽车电子助力转向系统性能受外部扰动和机械传动环节摩擦力的影响,提出了一种新型滑模控制算法,通过理论分析研究算法的稳定性,并通过实验验证算法对电子助力转向系统稳态精度和动态响应特性的影响。首先,针对典型的电子助力转向系统,构建其运动学和动力学方程,确定助力电机与执行机构间机电系统的数学关系。其次,为提升电子助力转向系统的控制性能,提出一种新型滑模控制算法,并通过李雅普诺夫判据证明此控制器的稳定性。再次,说明电子助力转向系统控制结构,利用Microchip公司生产的dsPIC30F6012作为系统运算处理微控制器,在其控制器中嵌入所提控制算法。最后,采用PID控制算法、传统滑模控制算法和新型滑模控制算法3种方法跟踪阶跃指令和正弦转矩指令,实验表明新型滑模控制方法动态响应速度快,稳态精度高,在跟踪正弦转矩指令时,其动态跟踪精度较PID和传统滑模控制方法分别提升71.7%和45.8%。

Considering that the performance of automobile electronic power steering system is affected by external disturbance and friction of mechanical transmission,a new type of sliding mode control algorithm is proposed.Firstly,the kinematics and dynamics equations are constructed,and the mathematical relationship of the electro-mechanical system between the power motor and the actuator is determined.Secondly,a new sliding mode control algorithm is proposed,and the stability of the controller is proved by Lyapunov criterion.Thirdly,the control structure of the electronic power steering system is explained.dsPIC30 f6012 produced by Microchip company is used as the system operation micro controller.Finally,PID control algorithm,traditional slide mode control algorithm and new slide mode control algorithm are used to track step command and sinusoidal torque command.The test shows that the new slide mode control method has fast dynamic response speed and high steady-state accuracy.When tracking sinusoidal torque command,its dynamic tracking accuracy is 71.7% and 45.8% higher than PID and traditional slide mode control method respectively.