基于输出约束的电液伺服系统非线性方法研究

针对于电液伺服系统的输出约束问题,提出了将反步控制和障碍李雅普诺夫函数相结合的控制方法来设计控制律。障碍李雅普诺夫函数在解决非线性系统中的状态和输出约束上有较为突出的贡献,当状态或者输出约束达到一定的约束限制的时候,整个函数就会趋于无穷大,确保了在系统运动过程中约束限制被破坏的可能。通过构造关于状态变量和期望值误差的方法,得到了确保系统能够渐进稳定跟踪期望的3个控制律,并保证系统在李雅普诺夫议意义下是稳定的。最后,通过数字仿真验证了该方法的可行性。

Nonlinear Method with Output Tracking Error Constraint for Electro-hydraulic Systems

 In this paper, the backstepping control and the barrier Lyapunov function is proposed to control the output tracking error constraint for electro-hydraulic systems. Barrier Lyapunov function has prominent contribution to solving state or output constraints in nonlinear systems, barrier Lyapunov function approaches infinity whenever some limits are to be exceed, which ensures that violation of constraints is prevented along the system trajectories. In this paper, three control laws ensuring the asymptotic stability of references tracking are obtained by constructing barrier Lyapunov function on the errors concerning the state variables and theirs desired values ,and ensure that the system is stable in the sense of Lyapunov. The simulation results have verified the effectiveness of the proposed approach.