Research In Real-Time Hybrid Simulation Based On Robust H-Infinity Control Theory

With development of energy dissipation,vibration reduction and isolation technology,new energy dissipation devices are widely used,and the performance of these new devices is related to the loading speed.Real-time hybrid simulation(RTHS)is a new structural testing method,which uses simple linear parts as numerical substructures and complex nonlinear parts as experimental substructures.RTHS enables real-time dynamic loading.The most critical step in RTHS is the synchronization of the numerical substructures and the experimental substructures.In order to improve the synchronization performance,the outer-loop actuator control technology has become one of the research hotspots.The robust H-infinity control is applied to the RTHS,the Self-centering viscous-hysteretic device(SC-VHDs)is used as the test substructure,and the control of single-actuator and double-actuator is considered.The specific research work and conclusions are as follows:(1)According to the problem that the current weighting function or design loop of the H-infinity controller in the design mainly relies on engineering experience and requires repeated manual debugging.The optimal design of the H-infinity controller based on particle swarm optimization is proposed.The amplitude error and time delay are used as the optimization target and the corresponding fitness function is proposed.The H-infinity controller is designed for a series of simulations.The results show that the H-infinity controller designed by this method has extremely robustess,tracking performance,anti-noise and antidisturbance.(2)The actuator parameter perturbation model is introduced in the virtual real-time hybrid simulation(VRTHS)to characterize the uncertainty,the stability conditions of the VRTHS are deduced,and three numerical substructure models with different mass and damping ratios are designed.The phase lead PI controller and the robust H-infinity controller are designed for the nominal model of the plant,and the VRTHS under the phase lead PI control and the robust H-infinity control is analyzed by comparing the measured displacement of the VRTHS system with the reference model.Errors of the VRTHS and tracking performance under parameter perturbations and frequency changes are evaluated.The results show that the robust H-infinity control VRTHS system almost identical to the reference model even the worst case,showing extremely robustess.When the parameters of the plant are perturbed and the frequency of the numerical substructure increases,the robust H-infinity control system has good robustess and tracking performance.(3)The SC-VHDs with strong nonlinearity is used as the experimental substructure to evaluate tracking performance.According to the working principle and test results of the SC-VHDs.The corresponding numerical model is established and evaluated for single-actuator and dual-actuator VRTHS.The results show that the proposed robust H-infinity controller has good tracking performance.(4)RTHS was carried out according to the robust H-infinity controller designed in the VRTHS,the tracking difficulty was improved by increasing the frequency of the numerical substructure.The displacement tracking performance was compared with the commonly used compensation methods.A dual-actuator RTHS platform was built,two SC-VHDs were used as the experimental substructure,and the two-layer steel frame was used as the numerical substructure.The corresponding H-infinity controller was designed to complete the dual-actuator RTHS.The results show that the robust H-infinity control RTHS has great improvements in both time delay and amplitude error,and has more advantages in actuator tracking than other commonly used compensation methods.