ADAPTIVE VARIABLE STRUCTURE CONTROL OF PNEUMATICALLY ACTUATED ROBOT

摘要

To apply a pneumatic robot to not only conventional simple tasks but also more rigorous ones, a servo type control is required. Since it has some high nonlinear properties, some type of adaptive control strategy should be adopted to improve its conrol performance. In this kind of robot, the simplicity of control algorism is also important.In this study, an adaptive variable structure control scheme is developed on the basis of the well-known variable structure system theory. This control scheme confines a phase-plane trajectory on the switching line momentarily rotated adaptively to the phase-state of controlled system. It can suppress the chattering often encountered in the usual sliding mode control with a fixed switching line, to achieve a smooth response. Further, it can automatically generate the specified phase-plane trajectory heading toward the desired position asymptotically.As a result of the application to the PTP type position control of an articulated pneumatic robot, the expected control performance can be well attained. Some advantages of this control method are the simplicity of a control algorism and the flexibility in the decision of control parameter values. Its availability may be verified.