基于双幂次趋近律的电动汽车定速巡航滑模控制研究

Study on Constant Speed Cruise Sliding Mode Control of Electric Vehicle Based on Power Approach Law

针对传统滑模趋近律在电动汽车定速巡航控制中存在收敛速度慢、时间长和抖振严重等不足,提出一种新型双幂次趋近律提高系统状态收敛速度的设计方案。首先,采用输入-输出反馈线性化方法,解决多变量之间的耦合关系,从而建立电动汽车纵向动力学模型;其次,针对外界扰动和电动汽车的不确定参数,利用干扰观测器逼近未知干扰;最后,引入改进的幂次趋近律,结合滑模控制理论设计新型滑模控制器。选取北汽新能源汽车-北汽E150EV为被控对象,仿真结果表明,设计的新型控制器与指数趋近律、传统幂次趋近律相比,具有更快的收敛速度和更好的运动品质。

A new two-power approach law is proposed to improve the state convergence speed of the system.Firstly,the input-output feedback linearization method is adopted to solve the coupling relationship between multiple variables,so as to establish the longitudinal dynamics model of electric vehicles.Secondly,the disturbance observer is used to approach the unknown disturbance to the uncertain parameters of external disturbances and electric vehicles.Finally,an improved power approaching law is introduced and a new sliding mode controller is designed with the theory of sliding mode control.