Research ArticleSmooth integral sliding mode controller for the position control of Stewart platform

- Super twisting observer is used to estimate the leg velocity knowing the leg lengths.
- The existing integral sliding mode control algorithm is modified using the twisting algorithm based control.
- The performance of the controller is evaluated by applying the position control of a Stewart platform.

This paper proposes the application of a new algorithm for the position control of a Stewart platform. The conventional integral sliding mode controller is a combination of nominal control and discontinuous feedback control hence the overall control is discontinuous in nature. The discontinuity in the feedback control is undesirable for practical applications due to chattering which causes the wear and tear of the mechanical actuators. In this paper the existing integral sliding mode control law for systems with matched disturbances is modified by replacing the discontinuous part by a continuous modified twisting control. This proposed controller is continuous in nature due to the combinations of two continuous controls. The desired position of the platform has been achieved using the proposed controller even in the presence of matched disturbances. The effectiveness of the proposed controller has been proved with the simulation results.