Rapid Position Control using Feedforward Control based on Inverse Dynamics : The Case of the Mechanical System of Linear DC Motor and Beam

A position control system consisting of a linear DC motor and a beam, based on inverse dynamics, is proposed. The rapid and exact control performance is confirmed experimentally and theoretically. In the experiment, the linear DC motor is made of an aluminum coil frame or an acrylic resin coil frame. It is confirmed that, by the present control method, the moving part of the linear DC motor can be controlled accurately to the position control command for an arbitrary settling time without undesirable mechanical vibrations. When the settling time is comparatively long, the wave shape of the control current of the motor is affected mainly by the bending force of the beam. Then, with a decreasing settling time, the inertial force has significant effects on the wave shape of the tontrol current. Furthermore, the numerical simulation results obtained with the finite element method agree well with the experimental results.