A new approach to the digital redesign of continuous-time control systems with multiple loops

The paper is concerned with an approach, called the multi-loop plant input mapping (MLPIM) method, for redesigning a continuous-time control system with multiple loops into a multi-loop digital control system. The digital controllers are synthesized by matching the discrete-time transfer function from the reference input to the control input to be applied to the plant and that of the continuous-time counterpart. Each control loop is redesigned, taking into account the characteristics of inner loops and plant. The proposed technique is implemented on a ball-on-beam control system and the results thus obtained are compared with those obtained by the Tustin method