含有非线性不确定参数的电液系统滑模自适应控制

针对含有非线性不确定参数的电液控制系统, 提出了一种滑模自适应控制方法. 该控制方法主要是为了解决由于初始控制容积的不确定性而引起的, 非线性不确定参数自适应律设计的难题. 其主要特点为, 通过定义一个新型的特Lyapunov 函数, 进而构建系统的自适应控制器及参数自适应律, 并结合滑模控制方法及一种简单的鲁棒设计方法, 给出整个电液系统的滑模自适应控制器, 及所有不确定参数的自适应律. 试验结果表明, 采用该控制方法能够取得良好的性能, 尤其可以补偿非线性不确定参数对系统的影响.

Sliding mode adaptive control of electro-hydraulic system with nonlinear unknown parameters

An adaptive sliding control method is proposed for an electro-hydraulic system with nonlinear unknown parameters. The proposed control method is for designing a nonlinear adaptive controller with adaptation laws to compensate the nonlinear uncertain parameters due to the uncertainty of the original controlled volumes. Firstly, we developed a novel type Lyapunov function to construct an asymptotically stable adaptive controller and present the adaptation laws of nonlinear uncertain parameters. Then, by combining sliding mode control with a simple robust method, the sliding mode adaptive controller with parameters update laws of the electro-hydraulic system is designed, which can compensate the system for uncertain nonlinearities, linear uncertain parameters and especially nonlinear uncertain parameters resulted from the uncertainty of the original controlled volumes. Finally, the experimental results show that the nonlinear control algorithm, together with the adaptation scheme, gives a good performance for the specified tracking task in the presence of unknown nonlinear parameters.