Abstract
This paper gives a general procedure for the analysis of a feedback system with a nonlinear control function. Taking the actuating signal as the dependent variable, a single nonlinear differential equation is obtained, the order of which depends upon the complexity of the linear transfer functions. This high-order nonlinear differential equation is then solvable by the phase-space method developed by the author and detailed in his previous papers (1, 2, 3). The method is further extended to the analysis of a system with one nonlinear controller in the forward branch and another nonlinear controller in the feedback branch. The two phase-plane equations obtained from the simultaneous differential equations are then solvable by the method given in reference (4).
