Two-stage Adaptive Delay Compensation Method For Real-time Hybrid Simulation

The real-time hybrid simulation is based on the traditional pseudo-dynamic testing,combined with the sub-structure testing technology,to give full play to the advantages of calculation and testing,improve the reliability of the testing results,and is widely studied and applied by scholars from various countries.Ensuring the boundary conditions of the substructure is critical to the accuracy of the real-time hybrid simulation results.However,in the process of calculating the desired displacement of the numerical substructure and transmitting it to the servo system for loading,errors will inevitably be introduced.Among them,the system delay caused by the dynamic performance of the actuator has the largest effect.The existence of system delay not only affects the testing results,but also causes irreversible damage to the test specimen and equipment.Among the many delay compensation methods,the principle of the method based on the assumption of constant time delay is simple and easy to implement,but it is not ideal for the compensation effect of real-time hybrid simulation with variable time delay.The proposed adaptive delay compensation method improves the accuracy of delay compensation.To further improve the effect of delay compensation in real-time hybrid simulation,this paper makes improvements based on adaptive delay compensation.The main work and conclusions are as follows:Firstly,research on the delay compensation of the Benchmark control problem of RTHS,and propose an adaptive filter to reduce the noise of the measured response.Combining adaptive compensation and traditional polynomial extrapolation methods,this paper proposed a two-stage adaptive delay compensation method.The compensation method divided into two stages to perform coarse and fine compensation respectively.While compensating most of the time delay,the adaptive technology can effectively deal with the time delay of the changing part and the residual time delay,and has a double guarantee for the effect of delay compensation.Carry out a comparative analysis of the virtual real-time hybrid simulation with the traditional delay compensation method,is demonstrated that the two-stage adaptive delay compensation method has higher compensation accuracy and robustnessSecondly,in a real-time hybrid simulation with a high-frequency loading target,the effect of the traditional delay compensation method is not ideal,and even the phenomenon of signal amplification may occur.This paper improves the two-stage adaptive delay compensation method.The inverse model of the loading system identification model used as the first stage compensation controller,and the second stage adopts the adaptive delay compensation method,demonstrated through a virtual real-time hybrid simulation based on the Benchmark control problem of three incentive conditions.Research showed that the improved two-stage adaptive method has better compensation effect in high frequency loading testing.Thirdly,using the proposed two-stage adaptive delay compensation method and its improved method,demonstrated the feasibility and compensation effect of the two-stage adaptive delay compensation method,through the real-time hybrid simulation of the damper.A 20 Hz swept frequency signal loading testing was carried out to verify the improvement of the compensation performance of the two-stage adaptive compensation method in the high frequency loading target testing.