Performance improvement of a dynamically tuned gyroscope using an input compensator

Abstract

An improved rebalance loop of a dynamically tuned gyroscope that has annexed an input compensator to the conventional rebalance loop is proposed in this paper. The input compensator is a simple estimator of input rates to the gyro, which is to be subtracted from torquing command. The improved rebalance loop significantly reduces transient torquing error, which allows higher gain and wider bandwidth loop as well as smaller tilt angle over transient state. Thus, it contributes to the accuracy improvement and widening dynamic range of the gyroscope. It is also shown that the stability robustness of the rebalance loop combined with the input compensator can be recovered by adjusting the bandwidth of the input compensator. Closed-loop frequency response analysis shows an improvement of the rebalance loop with the use of the input compensator, compared with a conventional one, in that the ratio between input and output torque has unity magnitude as well as low phase shift in wider range. The improved rebalance loop has been fabricated with analog devices and connected to a real gyroscope. The experiment result is compared with that of simulation. Both of them have demonstrated that the responses of output torque and rotor's tilt angle are considerably improved.