Robust control of an active tilting actuator for high-density optical disk

We design a new actuator for optical disk pick-up device in order to control the tilting motion. The newly designed actuator makes it possible to control the tilting motion actively, while the conventional actuator prevent tilting with passive spring. We present the 3-DOF dynamic model of the wire spring type actuator and suggest a design method of voice coil motor. To consider the assembling error, such as the difference of mass center and force center, we designed a robust H _∞ controller. The simulation results show the designed actuator with MIMO H_∞ controller enhances the rejection of tilting motion compared with conventional actuator with SISO lead-lag compensator