Robust control design for stiffness measurement of flexible joint

Flexible joint, one kind of force-sensing element, is a key part of flexible gyro. Its stiffness is very small such that it is easily disturbed by noises in working environment. During the development of the instrument of its stiffness measuring, instability is the main factor affecting the measuring precision. This paper firstly presents a model for stiffness measuring system subjected to disturbance. Based on the model, robust H/sub /spl infin// control design for stiffness measurement of flexible joint is proposed by using a complete parametric approach of eigenstructure assignment to stabilize the stiffness measuring system and guarantee the specified H/sub /spl infin//-norm upper-bound constraint. Finally, the results of simulation show the effect of the proposed approach.