Design, modeling, and seek control of a voice-coil motor actuator with nonlinear magnetic bias

The research investigates the feasibility and trajectory tracking performance of an adaptive controller applied to a voice-coil motor actuator (VCMA) influenced by nonlinear magnetic bias. A magnetic bias feature on the actuator arm is designed to compensate for nonoperational shock. Because the resulting bias is nonlinear and uncertain, a model-based adaptive controller was developed to meet the seek performance requirements and simultaneously handle effects of the nonlinear bias. A VCMA with the bias feature was manufactured according to the design requirements. Extensive experiments were conducted to characterize the VCMA physical parameters and verify the controller performance. The effects of sample rate and bias modeling accuracy are also discussed. A representative sample of the results is presented.