在分析电动助力转向(Electric Power Steering,简称EPS)的基本原理和工作特点的基础之上,比较三种常见的助力特性,针对EPS上层目标电流的决策提出一种基于车速权重的曲线型助力特性,针对EPS上层目标电流的决策提出一种基于车速权重的曲线型助力特性,下层电机电流的跟踪控制采用鲁棒性能较好的PID控制器。仿真结果表明,设计的曲线型助力特性是有效的,解决了助力突变的问题,能够使驾驶员获得适宜的转向助力。
电池荷电状态(state of charge,SOC)是电池管理系统的重要参数,也是混合动力汽车动力系统分配的重要依据,准确地估算电池荷电状态具有重要意义。按照传统电量状态定义电池SOC的估算方法不能满足蓄电池变电流放电工况的需求,为了解决这一问题,采用能量守恒原理对电池SOC重新定义,基于修正的Thevenin等效电路,在Matlab/simulink环境下,建立了电池的动态充、放电模型,通过仿真分析,证明新的SOC估算策略能够满足蓄电池在大电流和变电流放电工况下SOC的估算,提高了电池SOC估算的精度。
为提高并联式混合动力汽车(Parallel Hybrid Electric Vehicle,PHEV)再生制动能量的回收率,该文对PHEV制动力进行了分析,提出了再生制动控制策略。该策略不但能够合理分配前后轮制动力,而且能够合理分配后轮液压制动力、电机制动力和发动机反拖制动力,在保证制动性能的前提下,使电机能够最大限度的回收制动能量。仿真结果表明了所提方法的有效性。
This paper is concerned with the stabilization problem for a class of nonlinear systems with disturbance. The disturbance model is unknown and the first derivative of disturbance is bounded. Firstly, a general disturbance observer is proposed to estimate disturbance approximatively. Secondly, since the bound of the disturbance observer error is unknown, an adaptive sliding mode controller is designed to guarantee that the state of system asymptotically converges to zero and the unknown bound can be adjusted by an adaptive law. Finally, an example is given to illustrate the effectiveness of the proposed method.
Lei-Po Liu Zhu-Mu Fu Xiao-Na Song College of Electric and Information Engineering, Henan University of Science and Technology, Luoyang 471003, China
