Optimal sliding-mode controller design based on state observer

The sliding-mode control could make a system unstable because of some unexpected external disturbance and model uncertainty. This paper suggests an optimal sliding-mode control algorithm, which can be applied to a linear system with unmodeled dynamic errors. To reduce the chattering effect, the proposed control algorithm uses an optimal state feedback controller with an augmented system, which includes additional state variables such as control input, estimated state variable. To test the robustness of the proposed control system, time maximum disturbance is designed and applied. Through simulation comparison with an optimal control algorithm (LQR), the suggested control algorithm shows an improved stability and robustness while it manifests fast tracking capability.