A nonlinear compensation technique for systems involving hysteresis

This paper presents a simple procedure using a non-linear compensator for eliminating limit cycles in control systems arising due to hysteresis in contactors or due to backlash. The method consists of 1) the insertion of an element of gain or , and 2) the switching of this element by simple processing of the input and output signals of the original nonlinearity. For a contactor, the technique effectively removes the hysteresis but does not alter the dead zone (which, it is pointed out in one instance, might be an advantage) or, of more importance, the bang-bang characteristic of the element. Furthermore, for the contactors, the compensation technique is found effective irrespective of the waveshape at the nonlinearity input and, therefore, is of some general consequence in design.