Development of a Real-Time Hybrid Experimental System with Actuator Delay Compensation : 4th Report, Improvement of Control-Signal Generation for Actuator

Abstract

We developed an on-line experimental system for conducting hybrid experiments in real time that combine a computer conducting vibration simulation and generation of control-signal, and an actuator conducting a vibration experiment driven by the control signal. This system compensates for actuator delay, which enables experiments to be carried out in real time. For the real-time hybrid experiments, however, a large time step for simulation is required when the number of degrees of freedom of numerical model is large. On the other hand, a smaller time step for generating the control signal is desirable to improve the accuracy of the experiments. To solve this problem, we propose a new method for generating the control signal. The method is divided into two parts, a simulation part for simulating vibration response, and a control part for generating a control signal. The time step of the control part is set to be smaller than that of the simulation part. The control part calculates the control signal smooth enough for the compensation so that the actuator is driven as calculated at the time when the calculated value is provided. In addition, the validity of this method is verified by experiments.