Robust feedback design with optimized diagnostic performance

This paper is concerned with the design of reconfigurable control laws that also effectively facilitate the acquisition of information used for diagnostic purposes in fault tolerant control systems. A control performance index and a diagnostic performance index are chosen to indicate the overall performance. A simple relationship between the two indexes is established that elucidates the control/diagnostic tradeoff. A control design method is developed that first finds a set of controllers achieving a certain control performance level and then uses the remaining degrees of freedom in the controller set to achieve an optimized diagnostic performance level.