EXPERIMENTAL EVALUATION OF AN ADAPTIVE ACTUATOR CONTROL SCHEME FOR REAL-TIME TESTS OF LARGE-SCALE MAGNETO-RHEOLOGICAL DAMPER UNDER VARIABLE CURRENT INPUTS

摘要

A Magneto-Rheological (MR) fluid damper is a semi-active device for vibration control of engineering structures subjected to dynamic loading. The characteristics of MR dampers vary under different current inputs to achieve optimized vibration control of structural systems. Experimental evaluation of MR dampers under different control laws is necessary before the device can be accepted by the practical design community. Real-time hybrid simulation provides an economical and efficient dynamic testing technique by accounting for the damper rate-dependency and the damper-structure interaction. A successful real-time hybrid simulation requires accurate actuator control to achieve reliable experiment results. A servo-hydraulic actuator usually introduces a time delay due to servo-hydraulic dynamics. The variable current inputs induced by semi-active control laws would pose additional challenges for actuator control by introducing variable delay in a real-time hybrid simulation. In this paper an adaptive compensation technique is experimentally evaluated for real-time hybrid simulation involving an MR damper under variable current inputs. Predefined band-limited white noise is used as the displacement command for the servo-hydraulic actuator and current command for the MR damper. The adaptive compensation scheme is demonstrated to achieve accurate actuator control and therefore shows great potential for real-time hybrid simulation of structural systems with semi-active energy dissipation devices.