An application of computer aided parameter tuning of a super-twisting sliding mode controller

A tuning procedure of the super-twisting algorithm is exploited in order to operate a thermal plant within predefined specifications. The configuration consisting of the chosen control algorithm and the thermal plant results in a limit cycle, i.e. the solutions of the closed-loop system are periodic functions of time. The tuning algorithm is based on the pre-specified amplitude and frequency of the variable to be controlled. The computation of the constant controller gains is based on the equation of harmonic balance. A possibly needed dynamical filter is introduced to guarantee that every desired amplitude and frequency of the limit cycle can be adjusted. The tuning procedure is extended such that the controller parameters can be calculated directly without using any graphical aids. Real world experiments demonstrate the achieved accuracy of the tuning algorithm.