DESIGN OF A FORCE CONTROLLER FOR A HYDRAULIC ACTUATOR IN CONTACT WITH AN UNCERTAIN ENVIRONMENT VIA QUANTITATIVE FEEDBACK THEORY

摘要

This paper presents design, implementation and evaluation of a force controller, for a hydraulic actuator. First, a linear mathematical model for the hydraulic actuator in contact with the environment is derived. Plant variations such asenvironmental stiffness and operating points are explicitly considered in both the plant transfer function and the design process, as uncertainties. Quantitative Feedback Theory (QFT) is then applied to design a robust controller which satisfies a priorispecified tracking and disturbance rejection performances. The controller is implemented on an industrial hydraulic actuator. In spite of significant actuator dynamics and under varying conditions, successful control tests are performed repetitively.