针对阀控电液起竖系统同时存在匹配与不匹配未知干扰的问题,考虑液压阀的死区非线性特性,提出一种新型非线性控制器。首先,基于系统的机电液耦合动力学与液压阀死区特性,建立了考虑阀死区的系统非线性数学模型。其次,基于全状态反馈条件,对数学模型进行改写并设计了自适应扩张状态观测器与干扰观测器,实现了对匹配与不匹配干扰的估计,抑制了观测峰值现象。再次,基于前述的观测器,设计了自抗扰控制器,实现了干扰的前馈补偿。同时,为解决传统反步法控制器设计框架所固有的“微分爆炸”问题,引入了一种非线性指令滤波器。最后,通过Lyapunov理论分析,证明了系统运动误差、观测器估计误差以及滤波误差的有界性,验证了控制器的稳定性。为检验该控制器的性能,搭建了仿真平台。仿真结果表明:相比常用的PID控制器,所设计的控制器可提高系统的运动跟踪精度。

Considering the coexistence of both matched and unmatched unknown disturbances in electro-hydraulic valve-controlled erection systems and the inherent dead-zone nonlinearity in hydraulic valves, a novel nonlinear controller is proposed. First, a nonlinear mathematical model of the electro-hydraulic erection system is established based on the electromechanical-hydraulic coupled dynamics of the system and the dead-zone characteristics of the hydraulic valve. Second, based on the full-state feedback condition, the aforementioned mathematical model is reformulated, and an adaptive extended state observer (AESO) along with a disturbance observer (DO) is designed to estimate both matched and unmatched disturbances, and effectively suppress the observation peaking phenomenon. Third, a novel active disturbance rejection controller is developed leveraging the aforementioned AESO and DO to achieve feedforward compensation for disturbances. Simultaneously, to address the inherent "differential explosion" issue in the conventional backstepping-based controller design framework, a nonlinear command filter is incorporated. At last, through rigorous analysis based on Lyapunov's theory, it demonstrates the boundedness of the motion errors of the system, observer estimation errors and filter error, and verifies the stability of the controller. A simulation platform is developed to validate the performance of the proposed controller. Comparative results with conventional industrial PID controller demonstrate that the proposed controller significantly enhances motion tracking accuracy of the electro-hydraulic erection system.