Optimal non-fragile controller realization algorithm and application to control problems

• 作 者: Mian Ashfaq Ahmad WANG Dao-bo
• 机 构: College of Automation Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 21001
• 出 处: 哈尔滨工业大学学报（英文版）
• 发表日期: 2010年1期
• 关键词: controller fragility eigenstructure decomposition controller realizations

To reduce the fragility encountered in controller implementation, which is a measure of extent to describe small perturbations in controller parameters caused by rounding-off errors or component tolerances, and keep the system stability and performance, approaches of weighted eigenvalue sensitivity and stability radii comparison were used for computation and reduction of controller fragility. An algorithm has been derived for the efficient reduction of controller fragility, which used eigenstructure decomposition to obtain the suboptimal solution. The algorithm was tested for different control problems through reducing their fragility by a large margin.Different canonical forms were analyzed for fragility, including controllable canonical form, observable canonical form, modal canonical form, balanced realization and optimal (non-fragile) form. Different realizations were implemented through C language Matlab EXecutable (CMEX) S-function discrete state space block. Double precision calculations were performed. Open and closed loop controller realizations were compared with simulink state space (optimal) block. Results of comparison indicate that the optimal non-fragile controller realization shows better results beth in open loop and closed loop realization.