基于蒙特卡洛法的横向力系数不确定度评定

Evaluation on Side-way Force Coefficient Uncertainty Based on Monte Carlo Method

为了解决横向力系数检测结果的质量评价问题,采用蒙特卡洛法评定横向力系数的不确定度。通过对单轮式横向力系数测定仪的工作原理进行分析,建立测量模型,并对横向力系数测量结果的不确定度进行评定。基于横向力系数测量的影响因素,分析自适应蒙特卡洛法的各输入量,评估各输入量的概率分布,利用MATLAB建立了横向力系数检测结果测量不确定度的自适应蒙特卡洛法计算程序,得出横向力系数输出量和标准不确定度的最佳估算值。结果表明:自适应蒙特卡洛评定测量不确定度方法能够克服GUM测量不确定度评定方法需要计算偏导数和自由度的局限性,适用于非线性和非对称的数学模型,且不需要对输出量分布类型进行假设和近似,在横向力系数不确定度评定中有很好的应用。同时验证了运用MATLAB建立计算程序能够很好地解决自适应蒙特卡洛法多次循环和单次循环大容量模拟数值计算的需求,在公路工程试验检测领域实用性良好。

To solve the quality evaluation problem of side-way force coefficient detection result,the Monte Carlo method was used to evaluate the uncertainty of side-way force coefficient.By analyzing the working principle of side-way force coefficient measuring instrument,the measurement model was established.The uncertainty of side-way force coefficient measurement result was evaluated.Based on the influencing factors of side-way force coefficient measurement,the various input quantities of adaptive Monte Carlo method were analyzed.The probability distribution of each input quantity was evaluated,and the adaptive Monte Carlo method calculation program was established for the measurement uncertainty of side-way force coefficient detection results by using MATLAB.The optimal estimation value of output quantity and standard uncertainty of side-way force coefficient was obtained.The result indicates that the adaptive Monte Carlo method for evaluating measurement uncertainty can overcome the limitations of GUM method in calculating partial derivatives and degrees of freedom.It is suitable for nonlinear and asymmetric mathematical models.It does not require assumptions and approximations of output distribution types,and has good application in the evaluation of side-way force coefficient uncertainty.Simultaneously,it is verified that establishing the calculation program with MATLAB can effectively solve the needs of multi-cycle and single-cycle high-capacity simulation numerical calculations in the adaptive Monte Carlo method.It has good practicality in the field of highway engineering testing and detection.