THE DIGITAL LQG LTR CONTROLLER WITH A COMPENSATED OBSERVER FOR A TETHERED REFLECTOR/ANTENNA SYSTEM/

The purpose of this paper is to develop a practical method of robustne ss recovery for discrete-time systems. It has been proven that the rob ustness recovery method for the LQG control with the filtering observe r is also valid for discrete-time systems, but it is not valid for the control with the predicting observer. In engineering practice, howeve r, due to the data transmission and computation delay the use of the f iltering observer is not practical. One of the main contributions of t his paper is to make the LQG/LTR methodology practicable in engineerin g implementation. The strategy here is to use the predicting observer at the beginning of every sampling period and then modified by the lat er data coming from the sensors; the error is compensated by resistor- capacitor circuits. The parameters of the compensator depend on the so lution of a set of multi-element high powered equations. This methodol ogy has been successfully applied to the reduced order controller for the orbiting tethered reflector/antenna system. Copyright (C) 1996 Els evier Science Ltd