Control of Linear Systems by Output Proportional Plus Derivative Feedback

This paper presents a control design procedure for linear time invariant systems using output proportional plus derivative feedback. The traditional linear quadratic performance index is used with additional terms to penalize disturbance and noise response and eigenvalue and response sensitivities. The sensitivity terms represent measures of stability robustness. It is shown that the derivative feedback improves the measure of performance. This design procedure has been applied to obtain an improved autopilot for the lateral dynamics of an L1011 aircraft.