On the control design of a gyro test table

An important aspect of linear controller design is to clarify whether the design reaches the performance limit, which is highly significant to the practice of control system design. Based on an industrial project of a high-precision gyro test table (servo system), a paradigm is presented to demonstrate that the performance limit of the disturbance attenuation design of the servo system can be reached in a systematic way by using μ synthesis. A gyro test table is a servo system employed to measure the drift of a gyro. In contrast with general sensitivity theory, which generally considers the output disturbance rejection, the main concern in gyro test table design is the input disturbance attenuation. The uncertainty caused by the neglected dynamics in this servo design implies a limitation on the bandwidth of the gyro test table, i.e. the bandwidth is limited by the robust stability requirement. Furthermore, it is manifested that the multiplicative uncertainty description plays a leading role in the H_∞/μ design. This paper reveals that the performance limit is determined by the bandwidth. This finding will help the designer to judge whether any given performance specification is achievable and illustrates the design idea of giving priority to the bandwidth.