High-precision and fast response control for complex mechanical systems

The complex mechanical system with dedicated servo have servo bursts continuously stored in between data recording layer and the SUL of conventional PMR (perpendicular magnetic recording) media. It thus provides high sampling rate for servo control loop implementation. Its servo performance is investigated by imposing an external vibration in 0–500Hz, and its advantageous over conventional servo systems is verified. Dual-stage actuation mechanism is applied to enhance servo performance, making use of the high servo sampling rate. Extremely high servo bandwidth is then achieved with sufficient PES samples provided by the dedicated servo. In addition to 0–500Hz vibration, the high bandwidth servo loop is able to significantly attenuate the audio vibration which is dominant in 1k-5kHz. Testing and simulation results are provided in this paper to demonstrate the performance of the dedicated servo recording systems.