阀控非对称缸系统鲁棒反馈线性化控制

Robust feedback linearization control of valve controlled asymmetric cylinder system

针对阀控非对称缸液压系统存在不确定性和干扰问题,提出综合滑模变结构控制与反馈线性化控制的鲁棒反馈线性化控制策略.利用反馈线性化控制提高非线性系统控制精度,利用变结构控制补偿外界干扰与系统不确定性,并采用边界层法减少滑模变结构控制可能导致系统高频抖动.针对位移信号直接微分得到的加速度信号存在高频噪声问题,提出利用改进二阶滑模算法抑制干扰的影响.通过建立统一的阀控非对称缸液压伺服系统非线性数学模型,以时变负载力扰动为例对系统的动态特性进行了研究,结果表明:鲁棒反馈线性化策略能有效抑制外界的干扰和负载力扰动对液压位置追踪精度的影响,提高了液压控制系统的精度和鲁棒性.

Considering the uncertainty and disturbance of asymmetric cylinder hydraulic system ,a ro-bust feedback linearization control strategy was presented ,based on both sliding mode variable struc-ture control （SMC） and feedback linearization .By using feedback linearization to improve the system control precision and SMC to compensate disturbance and uncertainty ,the boundary layer method was used to reduce vibration .A improved second order sliding mode control algorithm was designed to solve the problem of high-frequency disturbance in the acceleration signal in direct differentiation of displacement .The dynamic characteristics of the hydraulic system was researched by establishing a unified nonlinear mathematical model of asymmetric cylinder hydraulic servo system under the condition of time-varying load .T he results show that the robust feedback linearization can effectively restrain the outside disturbance and improve hydraulic position on tracking accuracy ,in w hich the ac-curacy and robustness of the hydraulic control system is improved .