Pressure ripples in electric power steering （EPS） systems can be caused by the phase lag between the driver s steering torque and steer angle, the nonlinear frictions, and the disturbances from road and sensor noise...Pressure ripples in electric power steering （EPS） systems can be caused by the phase lag between the driver s steering torque and steer angle, the nonlinear frictions, and the disturbances from road and sensor noise especially during high-frequency maneuvers. This paper investigates the use of the robust fuzzy control method for actively reducing pressure ripples for EPS systems. Remarkable progress on steering maneuverability is achieved. The EPS dynamics is described with an eight-order nonlinear state-space model and approximated by a Takagi-Sugeno （T-S） fuzzy model with time-varying delays and external disturbances. A stabilization approach is then presented for nonlinear time-delay systems through fuzzy state feedback controller in parallel distributed compensation （PDC） structure. The closed-loop stability conditions of EPS system with the fuzzy controller are parameterized in terms of the linear matrix inequality （LMI） problem. Simulations and experiments using the proposed robust fuzzy controller and traditional PID controller have been carried out for EPS systems. Both the simulation and experiment results show that the proposed fuzzy controller can reduce the torque ripples and allow us to have a good steering feeling and stable driving.展开更多
电动助力转向(electric power steering,EPS)系统具有非线性和时变性,采用常系数补偿无法实现对转矩的准确跟踪,影响驾驶员手感。文章采用滑模控制器准确跟踪电流,并设计补偿算法,利用带遗忘因子的递推最小二乘(recursive least squares...电动助力转向(electric power steering,EPS)系统具有非线性和时变性,采用常系数补偿无法实现对转矩的准确跟踪,影响驾驶员手感。文章采用滑模控制器准确跟踪电流,并设计补偿算法,利用带遗忘因子的递推最小二乘(recursive least squares,RLS)算法对助力装置进行在线参数辨识,并将辨识得到的结果进行补偿控制,在参数缓慢变化的条件下实现EPS对转矩的准确跟踪。展开更多
文章从电动助力转向(electric power steering,EPS)系统多模式切换的平稳性角度出发,建立EPS模型和整车二自由度动力学模型,提出了一种EPS模糊切换控制策略,设计相应的模糊切换控制器;在模糊切换控制的基础上进而提出可拓模糊切换控制策...文章从电动助力转向(electric power steering,EPS)系统多模式切换的平稳性角度出发,建立EPS模型和整车二自由度动力学模型,提出了一种EPS模糊切换控制策略,设计相应的模糊切换控制器;在模糊切换控制的基础上进而提出可拓模糊切换控制策略;在不同测度模式内分别设计对应的控制算法,构建基于EPS多模式切换的可拓控制器;对提出的2种控制策略进行仿真和试验研究。结果表明:模糊切换控制对EPS性能有较大提高,大大改善了EPS各模式切换过程的不稳定性;可拓模糊切换控制相比于模糊切换控制对切换过程中的EPS性能有了进一步的提高,实现了EPS多模式的平滑切换。展开更多
为了解决电动助力转向(electric power steering,EPS)系统回正控制中快速性与准确性之间的矛盾,提升回正控制的稳定性,文章针对PID控制中积分环节的不利影响及滑模变结构控制(sliding mode control,SMC)较为依赖精确数学模型的问题,采...为了解决电动助力转向(electric power steering,EPS)系统回正控制中快速性与准确性之间的矛盾,提升回正控制的稳定性,文章针对PID控制中积分环节的不利影响及滑模变结构控制(sliding mode control,SMC)较为依赖精确数学模型的问题,采用了非线性状态误差反馈(nonlinear state error feedback,NLSEF)的EPS回正控制策略;对NLSEF的参数采用模糊化控制调节,以转向盘的转角及角速度作为输入变量,建立回正控制策略模型。台架试验结果对比表明,参数模糊化控制的NLSEF方案明显改善了EPS的回正性能,同一车速条件下,不论转向盘初始状态如何,都能快速、准确地操纵汽车回正。展开更多
基金supported Foundation of National Development and Reform Commission of China (No. 2040)
文摘Pressure ripples in electric power steering （EPS） systems can be caused by the phase lag between the driver s steering torque and steer angle, the nonlinear frictions, and the disturbances from road and sensor noise especially during high-frequency maneuvers. This paper investigates the use of the robust fuzzy control method for actively reducing pressure ripples for EPS systems. Remarkable progress on steering maneuverability is achieved. The EPS dynamics is described with an eight-order nonlinear state-space model and approximated by a Takagi-Sugeno （T-S） fuzzy model with time-varying delays and external disturbances. A stabilization approach is then presented for nonlinear time-delay systems through fuzzy state feedback controller in parallel distributed compensation （PDC） structure. The closed-loop stability conditions of EPS system with the fuzzy controller are parameterized in terms of the linear matrix inequality （LMI） problem. Simulations and experiments using the proposed robust fuzzy controller and traditional PID controller have been carried out for EPS systems. Both the simulation and experiment results show that the proposed fuzzy controller can reduce the torque ripples and allow us to have a good steering feeling and stable driving.
文摘电动助力转向(electric power steering,EPS)系统具有非线性和时变性,采用常系数补偿无法实现对转矩的准确跟踪,影响驾驶员手感。文章采用滑模控制器准确跟踪电流,并设计补偿算法,利用带遗忘因子的递推最小二乘(recursive least squares,RLS)算法对助力装置进行在线参数辨识,并将辨识得到的结果进行补偿控制,在参数缓慢变化的条件下实现EPS对转矩的准确跟踪。
文摘文章从电动助力转向(electric power steering,EPS)系统多模式切换的平稳性角度出发,建立EPS模型和整车二自由度动力学模型,提出了一种EPS模糊切换控制策略,设计相应的模糊切换控制器;在模糊切换控制的基础上进而提出可拓模糊切换控制策略;在不同测度模式内分别设计对应的控制算法,构建基于EPS多模式切换的可拓控制器;对提出的2种控制策略进行仿真和试验研究。结果表明:模糊切换控制对EPS性能有较大提高,大大改善了EPS各模式切换过程的不稳定性;可拓模糊切换控制相比于模糊切换控制对切换过程中的EPS性能有了进一步的提高,实现了EPS多模式的平滑切换。
文摘为了解决电动助力转向(electric power steering,EPS)系统回正控制中快速性与准确性之间的矛盾,提升回正控制的稳定性,文章针对PID控制中积分环节的不利影响及滑模变结构控制(sliding mode control,SMC)较为依赖精确数学模型的问题,采用了非线性状态误差反馈(nonlinear state error feedback,NLSEF)的EPS回正控制策略;对NLSEF的参数采用模糊化控制调节,以转向盘的转角及角速度作为输入变量,建立回正控制策略模型。台架试验结果对比表明,参数模糊化控制的NLSEF方案明显改善了EPS的回正性能,同一车速条件下,不论转向盘初始状态如何,都能快速、准确地操纵汽车回正。
