城市轨道交通基于连续测量法的车辆曲辐板测力轮对组桥方案

Electrical Bridge Scheme of Urban Rail Transit Vehicle Curved Radial Plate Force-measuring Wheelset Based on Continuous Measurement Method

目的:轮轨力是评价城市轨道交通车辆动力学性能的重要指标。为了提高轮轨力的测量精度,提出采用连续测量法对车辆曲辐板测力轮对组桥方案进行研究。方法:设计了测力轮对1/4电桥应变响应静载试验,分析了测力轮对的最优组桥半径。根据梯度下降算法原理和1/4电桥应变响应旋转试验中获得的应变周期曲线,采用对称组桥和正交双桥组合的方式对连续测量法测力轮对的应变片布置角度进行优化,并对曲辐板测力轮对进行组桥试验。结果及结论:静载试验表明:横向力、垂向力电桥最佳应变片粘贴半径分别为170 mm和300 mm,且两者耦合作用最小。组桥试验表明:当组桥的应变片组数为7组时,横向力电桥与垂向力电桥输出SRSS(平方和开平方根)波形的方差均为最小;横向力、垂向力电桥组桥输出波形的最小平均误差分别为0.918%和0.822%;输出的SRSS波形较为平稳,故横向力电桥与垂向力电桥均采用7组应变片的组桥方式。通过标定试验台分别对测力轮对施加横向力和垂向力时,其获取的轮轨力与实测轮轨力吻合良好,且两者的平均误差分别为1.27%和3.81%。优化组桥方案下测力轮对具有较高的精度,验证了该方案的可行性与准确性。

Objective:Wheel-rail forces are crucial indicators for evaluating the dynamics performance of urban rail transit vehicles.To enhance the measurement accuracy of wheel-rail force,a scheme for vehicle curved radial plate force-measuring wheelset electrical bridge using continuous measurement method is proposed.Method:A static load test is designed for a force-measuring wheelset 1/4 bridge strain response and an optimal electrical bridge radius for force-measuring wheelset is analyzed.According to the principles of gradient descent algorithm and strain cycle curves obtained from the 1/4 bridge strain response rotation test,an optimized arrangement angle for force-measuring wheelset strain gauge by continuous measurement method is proposed using symmetric electrical bridge and orthogonal double bridge combination.Subsequently,an electrical bridge test is performed on the curved radial plate force-measuring wheelset.Result&Conclusion:The static load test reveals that the optimal strain adhesive radii of transverse and perpendicular force bridges are 170 mm and 300 mm respectively,with minimal coupling action between them.The electrical bridge test demonstrates that when there are 7 groups of strain gauge pairs,the variance of the SRSS(square root of the sum of squares)waveform for transverse and perpendicular force bridges is minimized.The minimum average errors for the output waveforms of transverse and perpendicular force bridges are 0.918%and 0.822%respectively.The SRSS waveform output is steady,leading to the adoption of a 7-group strain gauge arrangement for both transverse and perpendicular force bridges.When transverse and perpendicular forces are applied separately to force-measuring wheelset on a calibration test bench,the obtained wheel-rail forces match well with the field measured ones,with average errors of 1.27%and 3.81%respectively.The optimized electrical bridge scheme ensures high precision for force-measuring wheelset,confirming the feasibility and accuracy of this scheme.