For a distributed drive electric vehicle（DDEV） driven by four in-wheel motors, advanced vehicle dynamic control methods can be realized easily because motors can be controlled independently, quickly and precisely. A...For a distributed drive electric vehicle（DDEV） driven by four in-wheel motors, advanced vehicle dynamic control methods can be realized easily because motors can be controlled independently, quickly and precisely. And direct yaw-moment control（DYC） has been widely studied and applied to vehicle stability control. Good vehicle handling performance： quick yaw rate transient response, small overshoot, high steady yaw rate gain, etc, is required by drivers under normal conditions, which is less concerned, however. Based on the hierarchical control methodology, a novel control system using direct yaw moment control for improving handling performance of a distributed drive electric vehicle especially under normal driving conditions has been proposed. The upper-loop control system consists of two parts： a state feedback controller, which aims to realize the ideal transient response of yaw rate, with a vehicle sideslip angle observer; and a steering wheel angle feedforward controller designed to achieve a desired yaw rate steady gain. Under the restriction of the effect of poles and zeros in the closed-loop transfer function on the system response and the capacity of in-wheel motors, the integrated time and absolute error（ITAE） function is utilized as the cost function in the optimal control to calculate the ideal eigen frequency and damper coefficient of the system and obtain optimal feedback matrix and feedforward matrix. Simulations and experiments with a DDEV under multiple maneuvers are carried out and show the effectiveness of the proposed method： yaw rate rising time is reduced, steady yaw rate gain is increased, vehicle steering characteristic is close to neutral steer and drivers burdens are also reduced. The control system improves vehicle handling performance under normal conditions in both transient and steady response. State feedback control instead of model following control is introduced in the control system so that the sense of control intervention to drivers is relieved.展开更多
针对传统控制器在永磁直驱风力发电机中进行最大功率跟踪时响应速度慢、追踪精度低等问题,提出了一种基于改进指数趋近律和非线性扩张状态观测器(non-linear extended state observer,NLESO)的滑模控制方法。该方法使用连续函数代替符...针对传统控制器在永磁直驱风力发电机中进行最大功率跟踪时响应速度慢、追踪精度低等问题,提出了一种基于改进指数趋近律和非线性扩张状态观测器(non-linear extended state observer,NLESO)的滑模控制方法。该方法使用连续函数代替符号函数sign(s),引入增益函数设计改进指数趋近律以加快系统响应速度;将传统扩张状态观测器(extended state observer,ESO)中fal函数替换成一种非线性函数,并基于此设计NLESO以提升系统抗扰动能力,结合二者设计改进滑模控制器取代传统PI控制器。在MATLAB/Simulink上构建模型,结果表明,渐变风突变过程无超调,风速突变后再次平衡时间从0.054 s减少到0.028 s,自然风过程中系统能精准追踪上额定转速,证明了该控制方法具有超调量小、响应速度快、追踪精度高等特点。展开更多
基金Supported by National Basic Research Program of China(973 Program,Grant No.2011CB711200)National Science and Technology Support Program of China(Grant No.2015BAG17B00)National Natural Science Foundation of China(Grant No.51475333)
文摘For a distributed drive electric vehicle（DDEV） driven by four in-wheel motors, advanced vehicle dynamic control methods can be realized easily because motors can be controlled independently, quickly and precisely. And direct yaw-moment control（DYC） has been widely studied and applied to vehicle stability control. Good vehicle handling performance： quick yaw rate transient response, small overshoot, high steady yaw rate gain, etc, is required by drivers under normal conditions, which is less concerned, however. Based on the hierarchical control methodology, a novel control system using direct yaw moment control for improving handling performance of a distributed drive electric vehicle especially under normal driving conditions has been proposed. The upper-loop control system consists of two parts： a state feedback controller, which aims to realize the ideal transient response of yaw rate, with a vehicle sideslip angle observer; and a steering wheel angle feedforward controller designed to achieve a desired yaw rate steady gain. Under the restriction of the effect of poles and zeros in the closed-loop transfer function on the system response and the capacity of in-wheel motors, the integrated time and absolute error（ITAE） function is utilized as the cost function in the optimal control to calculate the ideal eigen frequency and damper coefficient of the system and obtain optimal feedback matrix and feedforward matrix. Simulations and experiments with a DDEV under multiple maneuvers are carried out and show the effectiveness of the proposed method： yaw rate rising time is reduced, steady yaw rate gain is increased, vehicle steering characteristic is close to neutral steer and drivers burdens are also reduced. The control system improves vehicle handling performance under normal conditions in both transient and steady response. State feedback control instead of model following control is introduced in the control system so that the sense of control intervention to drivers is relieved.
文摘针对传统控制器在永磁直驱风力发电机中进行最大功率跟踪时响应速度慢、追踪精度低等问题,提出了一种基于改进指数趋近律和非线性扩张状态观测器(non-linear extended state observer,NLESO)的滑模控制方法。该方法使用连续函数代替符号函数sign(s),引入增益函数设计改进指数趋近律以加快系统响应速度;将传统扩张状态观测器(extended state observer,ESO)中fal函数替换成一种非线性函数,并基于此设计NLESO以提升系统抗扰动能力,结合二者设计改进滑模控制器取代传统PI控制器。在MATLAB/Simulink上构建模型,结果表明,渐变风突变过程无超调,风速突变后再次平衡时间从0.054 s减少到0.028 s,自然风过程中系统能精准追踪上额定转速,证明了该控制方法具有超调量小、响应速度快、追踪精度高等特点。
