变量泵控制变量马达系统变结构控制算法

变量泵控制变量马达系统的速度调节过程相当于变量泵控制定量马达或定量泵控制变量马达,存在系统溢流损失大、调节速度慢和没有发挥系统潜能等缺点.为了克服这些不足,提出基于反馈线性化理论的变量泵变量马达系统变结构控制算法.建立变量泵控制变量马达系统数学模型,并针对系统的相乘非线性,运用精确反馈线性化理论将其线性化;根据该闭式液压系统双变量调速的特点,利用变量马达期望转速和马达排量计算变量泵排量;运用变结构算法进行变量马达转速控制,并进行算法的Lyapunov稳定性证明.仿真表明,基于本控制策略可有效地提高系统的响应速度、减小超调量,而且算法具有较强的鲁棒性.

Variable structure control for variable pump controlling variable motor

Variable structure control for variable pump controlling variable motor (VPCVM) systems based on feedback linearization was presented to overcome the defects, such as huge overflow losses, slow speed regulating and poor full capacity utilization, arisen from the conventional independent control of variable pump or variable motor in the systems. The mathematical model of VPCVM was established, and the multiplicative nonlinear property existing in the system caused trouble for the motor speed controlling. To improve the VPCVM performance, the VPCVM nonlinear model was transformed into a linear system by feedback linearization. For the closed hydraulic speed controlling system with double-variable, the variable pump displacement can be deduced from motor expected speed and variable motor displacement. The variable structure controller was designed to control variable motor speed and its stability was proved according to Lyapunov theory. Simulations show that our approach has the capacity for speeding up system response and reducing overshoot of VPCVM system, and features with robust performance.