四辊卷板机侧辊位移线性自抗扰控制

Linear Active Disturbance Rejection Control for the Side Roller Displacement of Four-roller Plate Bending Machine

侧辊位移的精确控制对实现四辊卷板机高效加工至关重要,其核心问题是提高阀控非对称缸电液伺服系统的抗扰能力。由于电液伺服系统具有高度非线性和时变不确定性,传统非线性控制方法很难有效处理包含未知动态、外部扰动以及参数变化等的多源不确定扰动。提出一种四辊卷板机侧辊位移线性自抗扰控制方法。综合考虑各种不确定扰动因素的影响,设计了线性扩张状态观测器进行实时估计,采用状态误差反馈控制律给予主动补偿,并消除跟踪误差,证明了线性扩张状态观测器状态观测误差的收敛性和电液伺服系统的闭环稳定性。试验结果表明,所设计的线性自抗扰控制器能有效抑制电液伺服系统中多源不确定性扰动,实现侧辊位移的快速、精确轨迹跟踪。

Precision control of the side roller displacement is of great importance for the high efficient processing of four-roller plate bending machine, in which the key problem is how to improve the disturbance rejection ability of the electro-hydraulic servo system(EHSS) of the valve-controlled asymmetric cylinder. Because EHSS has the characteristics of strong nonlinear and time-varying uncertainty, multiple uncertain disturbances involving unknown dynamics, external disturbance and parameter variations is very difficult to be effectively dealt with traditional nonlinear control methods. A kind of linear active disturbance rejection control(LADRC) strategy for the side roller displacement of four-roller plate bending machine is proposed. Comprehensively considering the influence of the multiple uncertain disturbances of EHSS, a linear extended state observer(LESO) is designed to estimate the disturbances in real time. The state error feedback control law is employed to actively compensate the total disturbance and eliminate the tracking errors. The convergence of the state observation error of the LESO and the closed loop stability of the EHSS has been verified. Experimental results show that the multiple uncertain disturbances of the EHSS can be effectively suppressed with the designed LADRC, and fast and accurate trajectory tracking of the side roller displacement can be realized.