|Minimization of Modeling Error of the Linear Motion System with Voice Coil Actuator
Jin-Dong Hwang, Yong-Kil Kwak, Hong-Jung Jung, Sun-Ho Kim, and Jung-Hwan Ahn
International Journal of Control, Automation, and Systems, vol. 6, no. 1, pp.54-61, 2008
Abstract : This paper presents a method for reducing modelling error in the linear motion system with voicecoil actuator (VCA). A model of linear motion system composed of a mechanism and control was prepared to verify the proposed method. In modeling of the system, the damping coefficient obtained experimentally is applied to the model in order to consider the effect of the viscous friction for the moving part in VCA. The response velocity of VCA for duty ratio of PWM signal was analyzed in the time domain. Consequently, the relation between velocity and duty ratio was obtained. The result from the experiment showed an error of 9% when compared with that of simulation. In order to reduce the modeling error, impedance variation according to input frequency was analyzed, and equivalent impedance with multi-frequency was applied to the control part. As a result, the modeling error decreased to 5%.
Keyword : Friction, modeling error, PWM response, voice coil actuator (VCA).