ナノモーションアクチュエータに対するPID制御器の設計(機械力学,計測,自動制御)  [in Japanese] PID Controller Design for Nano Motion Actuator(Mechanical Systems)  [in Japanese]

A conventional spin-stand system which used to evaluate read-write performance of magnetic recording heads and media can not allow thermal drift of its mechanism and NRRO (non-repeatable run out) of its air spindle motor. Therefore, we proposed a precise track following actuator which applied the spin-stand to construct a piggyback system. The actuator called Nano Motion Actuator (NMA) by the authors consists of a piezoelectric element and a displacement amplifying mechanism. In this paper, a design method of a PID controller to realize a specified gain crossover frequency for the NMA is proposed. At first, we discussed about a model matching problem of an open loop transfer function and decided PID gains from physical parameters of the NMA. Next, based on a loop shaping method, the properties of the frequency response of the open loop transfer function were improved. The effectiveness of the proposed method is illustrated by the simulation results and experimental results.