FURTHER DEVELOPMENT OF AN APPROXIMATE LOOP TRANSFER RECOVERY METHODOLOGY FOR FIXED ORDER DYNAMIC COMPENSATOR DESIGN

This paper further develops a methodology for designing fixed order co mpensators. The formulation uses an approximate loop transfer recovery (LTR) method to achieve performance and stability subject to a distur bance and unstructured uncertainty at either the plant input or the pl ant output. The approximate LTR methodology has the advantage that the quadratic performance index weighting matrices are uniquely defined. To reduce sensitivity to real parameter uncertainty, the performance i ndex is modified to include a penalty on the closed-loop sensitivity d ynamics. The formulation avoids the explicit introduction of sensitivi ty states into the performance index and thus does not increase the ov erall dimension of the problem. An example design for the coupled mass benchmark control problem is provided to demonstrate this methodology .