Advanced Sliding Mode Control for Nonlinear Systems with Partially Unknown Parameters

Professor Liu Jinkun's sliding mode control program represents an advanced control methodology capable of handling nonlinear system control. The algorithm employs a sliding surface design approach that enables effective control not only for systems with fully known parameters but also for systems with partially unknown parameters through parameter adaptation mechanisms. The implementation typically involves defining a sliding variable, establishing reachability conditions, and incorporating switching control laws with boundary layer techniques to reduce chattering. Furthermore, the program exhibits robust disturbance rejection capabilities by utilizing high-frequency switching control to maintain system stability against various external disturbances. This makes the algorithm widely applicable in control systems and a preferred control method among engineers for its implementation efficiency using saturation functions or sigmoid approximation to replace sign functions, thereby improving practical performance while maintaining theoretical robustness.