| Abstract |
The paper presents experimental results of position controller for an electrohydrostatic actuator with fixed displacement pump based on the sliding-mode operation. The main task for sliding-mode controller design is to determine an adequate commutation' law, that makes . the system insensive to parameters and load variations. In two recent papers Barroso and Dente [2], [3], a principle of synthesizing a commutation law was presented. The
measure of certain state variables, like angular motor and linear piston accelerations and its derivates, put some implementation problems.To overcome these difficulties a simplified
commutation law with observers was used, that assures smaller position tracking error. Besides, experimental results show that the system have an nonlinearity produced by the fixed
displacement pump. This nonlinearity is due a dead zone in its fluid flow-rotor speed characteristic. However, simulation and experimental results show that the proposed control
with simplified commutation law, in spite of this nonlinearity, gives a good performance for regulation and tracking applications. |
