Skip to Main Content
The investigated nonlinear control system consists of a linear member with an ensemble of possible discrete combinations of proportional and derivative feedback around the linear member. The particular combination of proportional and derivative feedback employed at any instant is determined by a feedback switching circuit which is in turn operated by sensed binary information obtained from the output, output derivative, error and error derivative [namely, the signs (sgn) of these variables] . Techniques that are common to the digital computer field are used to implement this switching circuit. For a linear member of second order the feedback circuit is comprised of four discrete values of proportional feedback and four discrete values of derivative feedback. Simulation techniques have been used to study and evaluate the performance of the nonlinear control system and to compare it with a linear system for a wide variety of inputs. A sample of these experimental results is presented. The experiments show that the nonlinear system performance is much better than that of a linear system of comparable power handling capability. Preliminary studies of a nonlinear control system of third order show that the basic idea can be extended to higher order systems.