轧机液压伺服位置系统的自适应反步滑模控制

摘要

针对轧机液压伺服位置系统存在非线性特性、参数不确定性以及控制输入前具有不确定系数的问题,提出了一种自适应反步滑模控制方法.通过对系统非线性模型的等价变换和选择合适的Lyapunov函数,有效解决了由于控制输入前具有不确定系数导致的所设计的控制量与自适应律互相嵌套的难题.把自适应反步法和滑模控制方法相结合,有效克服了系统非线性与参数不确定性的影响,提高了系统的鲁棒性.在自适应反步滑模控制器设计时,给出了不确定参数的自适应律,并对系统跟踪误差的收敛性进行了证明.仿真研究结果表明,所设计的自适应反步滑模控制器能实现快速准确的跟踪,并且对参数变化具有较强的鲁棒性,与PID控制器相比,系统跟踪误差小,响应速度快,跟踪性能好.%An adaptive backstepping sliding mode control method is proposed for rolling mill hydraulic servo position system, which contains nonlinear characteristics, parametric uncertainty and the control input with uncertain coefficient. By using the equivalent transformation of. The nonlinear model and selecting a proper Lyapunov function, the nesting problem caused by the mutual inclusion of parameter adaptive law and control input was effectively solved. By combining the adaptive backstepping and the sliding mode method, it can effectively overcome the influence caused by the nonlinear characteristics and para-.metric uncertainty and improve the robustness of the system. In the adaptive backstepping sliding mode controller design, adaptive law of the uncertain parameters was given and the convergence of the system tracking error was also proved. Simulation results show that the designed controller can achieve fast and accurate tracking, and has stronger robustness for the parameter variations. Compared with the PID controller, it has small system tracking error, fast response and good tracking performance.