Computer aided control system-compensator desing via third order models

Chen and Shieh have developed a model simplification method for linear systems based on the continuous fraction expansion (7) and applied the method algebraically of the design of closed loop control systems via sonse second order reference models. Their design method is very suitable for computer usage (8). It sssas observed that the success of their design method depended on the initial design specifications as well as the effectiveness of their model simplica- tion method (10). In this study, the second order reference model they employed is normalized and graphs shoeing the relationship between the design specifications are developed. These graphs indi cate that the design specifications can not be selected at random and must be somewhat compatible with each other. The design examples solved for explaining the usage of their method (8). has been re-solved but now employing a reference model of third order. Analysis of the redesigns carried out in this study, clearly indicate that the modified design method has become clearly more effective and generates solutions which realize the initial design specifications more closely; due to using reference model of third order instead of second order. Also, as it would be expected ( 5 )f the designed systems time responses are definitely closer to those of the third order models-