A Proposal of Method of Path Control on 3-Dimensional Space

Abstract

We propose a method of a path control on 3-dimensional space in this paper. In the proposed methods, a desired point that is a minimum distance from the present position is searched and the straight line which connects its front and after points is provided as a base line. Multi-axial type mechanical systems are considered and the equations of motion in an orthogonal coordinate system are transformed to rotational and movement coordinate system. The transformed system can be decoupled and decomposed into a component of the direction of movement and a component of a plain which estimates a path error. Therefore, the control systems for the components can be separately constructed. Moreover, the effect of disturbance is absorbed by the control system for the component of the direction of movement and the disturbance of the path error becomes little. However, large delay of a time response occurs as a result. In this paper, the preview feedforward compensation is added for the control system of the component of the direction of movement to compensate for the delay. The proposed path control method has been applied to a multi-axis linear motor table and the effectiveness of the method is confirmed experimentally.