Hardware-in-the-loop environment for servo system controller design, tuning and testing

The paper analyses the possibility to replace the hydraulic and mechanical parts of a hydraulic position servo with a real-time simulation model. The aim is to test the controller hardware against the simulation model that includes the dynamics of the servo system as well as the feedback sensors and amplifier card. The requirements caused by this hardware-in-the-loop (HIL) approach are analyzed. A special attention is paid to the correct modeling of incremental encoders that are widely used as a feedback sensor. Experimental results show that there is no remarkable difference between the responses of the real system and HIL model and so the HIL model can replace the real system. (C) 2000 Elsevier Science B.V. All rights reserved.