不确定离散变结构控制系统的趋近律方法

分析了不确定离散变结构控制系统的常用设计方法的优缺点, 借助s型函数提出了一种改进的离散趋近律.应用该趋近律设计的变结构控制系统, 其原点稳定性和系统平稳性都优于指数趋近律和变速趋近律, 该设计方案保证了系统状态在趋近过程中能够保持某一趋近特性, 加快了系统状态的趋近速度, 同时降低了抖振, 易于变结构控制设计. 仿真结果验证了该设计方案的可行性和有效性.

A reaching-law method for uncertain discrete variable-structure control systems

Existing design methods for uncertain discrete variable-structure control systems(UDVSCS) are discussed.An improved reaching-law for UDVSCS is proposed based on the sigmoid function. By applying the proposed reachinglaw to UDVSCS, the stability of origin and the smoothness of the converging process of the system are better than those obtained by using the exponential rate reaching-law and the variable rate reaching-law; the system states are kept in a single converging pattern during the process of reaching the origin. With this design method, the sliding surface can be reached quickly and the system chattering can be reduced at the same time, facilitating the design of variable-structure control. Simulation results show that the proposed method is feasible and effective.