Quantitative feedback theory (QFT) for chattering reduction and improved tracking. in sliding mode control

Sliding mode control is a robust control technique with chattering as a major drawback. Chattering is undesirable because it can excite unmodeled high frequency dynamics of the system. One way to reduce chattering is to introduce a boundary layer around the sliding surface and keep the boundary layer attractive. However, the introduction of the boundary layer does not make the sliding surface to converge to zero but rather to oscillate around zero or on the boundary layer. In this paper, we design a QFT controller to reduce the oscillations within the boundary and make the sliding surface converge to zero. An example is provided to illustrate the proposed method