Study on Method of Dynamic Simulation Using Adaptive Control

Road simulation algorithm is the key point of developing a next-generation road simulation testing system. Traditional algorithms need to excite the test system to estimate the FRF matrixes and then iterate again and again until the real response approaches the expect response. The purpose of this paper is to develop a real-time control algorithm of vehicle road simulation test. Road simulation test system is in nature an automatic control and tracking system. Minimum variance self-tuning controller algorithm is presented. It can estimate the system parameters and calculate the output signals needed to control the test bench to track the expected response signals in a short period of one time-step. The algorithm is programmed on a personal computer to realize real-time control. A vibration control test on a T-shape beam structure is carried out. The system can exactly reproduce the expect response. It shows that the method can achieve high simulation accuracy to meet the requirement of road simulation test and this method is practical. NOMENCLATURE {xr(t)} expect response {Xr( )} {xr(t)} in frequency domain [H( )] FRF matrix {ui(t)} Initial drive {U0( )} {ui(t)} in frequency domain {xi(t)} i th iteration response { i(t)} i th iteration error { Xi { i(t)} in frequency domain { ui t i th iteration drive update { Ui { ui t in frequency domain A, B, C, F, G, H Polynomials na, nb, nc, nf, ng, nh order of each polynomial (t) white noise J variance E [ ] taking expectation ) ( ˆ t d t x prediction of x(t+d) at time t ) ( ~ t d t x prediction error of ) ( ˆ t d t x ) ( * t d t x optimal prediction of ) ( ˆ t d t x t time variable round frequency d delay between output and input q backward shift operator: