Design of digital rebalance loop for a dynamically tuned gyroscope using LQG/LTR method

This paper presents the results of a study on the design of a digital rebalance loop for a dynamically tuned gyroscope (DTG). The dynamic model for a DTG is explained briefly. A digital rebalance loop is designed using an LQG/LTR (linear quadratic Gaussian/loop transfer recovery) methodology. It is important that the output of a rebalance loop should follow exactly the angular rate given externally, as well as the the angles of a DTG should be kept small during the transient state. The performance of the digital LQG/LTR rebalance loop is compared with that of a conventional PID rebalance loop through frequency response, simulation, and experiment. The simulation and experimental results show that the performance of the LQG/LTR rebalance loop is better in that the output of the rebalance loop follows external angular rate more quickly, as well as keeping the angle smaller, compared with the conventional PID rebalance loop. The frequency response also shows that the bandwidth of the proposed rebalance loop is wider than that of the PID loop, which also contributes to the performance improvement.