Research On The Forcecalculation Method Ofinstrumented Roller-rig

Wheel-rail force is the basis of studying wheel rail relationship and the basic parameter to evaluate the safety performance of train.The continuous measurement of wheel-rail force can be realized by the strain signal and the data processing at the finite points of the roller-rig plate.However,in the measurement process,there is a coupling problem of wheel-rail force,and the effect of wheel-rail force measurement is not satisfactory until it is disturbed by high order harmonics and noise.In this context,the wheel-rail force calculation methods of instrumented roller-rig were studied in this paper.First of all,the paper analyzed the measuring principle,and studied the bridge scheme which can eliminate the influence of high order harmonics.Then,the roller-rig was modeled and simulated,and the radius of the bridge was determined by the simulation results.The coupling between the wheel-rail force can be reduced to the maximum on the selected radius.Then,after analyzing the wheel-rail force measurement model,a convex optimization algorithm was introduced.Simulation results showed that the algorithm was not real-time and could not be measured online.Then,the unscented kalman filter algorithm was studied from the point of view of state estimation.Due to the approximation error of the probability density of the unscented kalman filter,the error of the wheel-rail force calculation is increased.This paper improved the error of the wheel-rail force calculation.The nonlinear state variable was estimated by the unscented kalman filter alone.The linear state variables were estimated by the kalman filter,and the combination of the unscented kalman filter and the kalman filter was formed.Then,the improved algorithm was verified by simulation,which proved its feasibility and effectiveness in wheel-rail force calculation.Finally,the measurement model and wheel-rail force calculation method were verified by the test data.The results showed that the instrumented roller-rig could basically measure the lateral force,the vertical force and the position of the action point,and the correctness and feasibility of the model and wheel-rail force calculationmethod proposed in this paper were verified.