Improving Dynamic Surface Control with a Sliding Mode Differentiator

In addition, to address the characteristics of slow convergence speed of the first-order low-pass filter in traditional dynamic surface and the impact of filtering error on control accuracy and system stability, an improved first-order sliding mode differentiator is used instead of the first-order low-pass filter to obtain an approximate differential signal for the virtual control signal. At the same time, the error variable is constructed directly using the virtual control signal, which improves the performance of dynamic surface control.