流量控制式ECHPS系统的自适应动态面控制策略

针对商用车普遍采用的液压动力转向系统(HPS)助力特性不可变的缺点,提出了一种旁通流量控制式电控液压转向系统。设计了这种转向系统的助力控制策略,研究其核心部件电液比例阀的结构原理和数学模型,采用动态面控制方法设计了一个鲁棒自适应动态面控制器。理论推导证明所设计的控制器不仅能够保证闭环系统半全局渐近稳定,输出渐近跟踪期望轨迹,而且对于系统不确定参数和外界干扰具有较强的鲁棒性。仿真结果表明,所设计的自适应动态面控制器不仅响应快、跟踪效果好、控制精度高,而且能够实现汽车低速时的转向轻便性和高速时的良好路感要求。

Adaptive Dynamic Surface Control Strategy for Flow Control Type Electrical Controlled Hydraulic Power Steering System

Aimed at the shortcoming of the characteristic of unalterable power of commercial vehicles commonly used hydraulic power steering system (HPS), a bypass flow control type of electrical controlled hydraulic power steering (ECHPS) system was introduced. The power control strategy of the steering system was designed, the structure principle and mathematical model of its core component of electro hydraulic proportional valve was studied, and a robust adaptive dynamic surface controller was designed by dynamic surface control method. The theory proves that the designed controller not only can guarantee the closed loop semi globally asymptotically stable ,and output asymptotic tracking expected trajectory, but also the controller has strong robustness for the uncertain parameters and external disturbances. The simulation results indicate that the designed adaptive dynamic surface controller has not only fast response, good tracking performance and high control accuracy, but also can achieve the requirements of low speed light and high speed good road sense when the vehicle steering.