低频动态载荷理论分析及称重精度提高算法研究

Theoretical Analysis of Low Frequency Dynamic Load and Research on the Algorithm of Weighing Accuracy Improvement

超限超载运输不仅会对公路造成严重破坏,还会带来难以挽回的交通事故。动态称重技术可以治理车辆超限超载,并为高速公路货车计重收费提供可靠依据。现有主要动态称重设备包括弯板(称量部分轮载)、单台面秤(称量轴重)、双台面秤(称量轴重)、轴组秤(称量轴组重)与整车秤(称量整车重),它们在成本、安装维护、通行效率、动态称重准确等方面具有各种优缺点,其中动态称重准确度在科技治超、计重收费、交通量调查等实际应用中是需要主要考虑的关键指标之一。动态称重设备的秤体承载器长度随着动态称重准确度提高逐渐增加,导致施工成本和时间等也相应增加。为了保证动态称重准确度,考虑秤体承载器长度的经济性,基于汽车和秤体振动特性,建立了动态称重信号的滑动平均滤波和B样条最小二乘法的数学模型,有效消除了低频动态载荷振动干扰。试验结果表明:车辆分别以0~5 km/h和0~12 km/h范围内的速度通过长度为0.8 m和1.6 m的秤体,重量误差在0.5%以内,满足国家1级秤标准;试验车辆分别以理论速度限值20.7 km/h和24.3 km/h通过2.6 m和3 m长度秤体后,统计得出重量误差在0.5%以内。研究不仅对秤体承载器的设计长度提供理论依据,也对现有已安装的单台面秤、双台面秤的动态称重精度提高具有重要的参考意义。

Overload and oversize transport not only causes serious damage to highway,but also brings about irreparable traffic accidents. WIM technology can control the overload and oversize of vehicles and provide a reliable basis for the heavy truck toll collection. The main existing WIM equipment includes bending-plate（weighing part wheel load）,single-scale-platform（weighing load of single-axle）,double-scale-platform（weighing load of single-axle）, axis-group-scale（weighing weight of axis-group）, and vehicle-scale（weighing total weight of vehicle）. They have many advantages and disadvantages in cost,installation,maintenance,traffic efficiency and accuracy of WIM. The WIM accuracy is one of the key indicators considered in application of technology governance,toll by weight,and traffic investigation. The carrier length of WIM system increases gradually with the increase of WIM accuracy,which leads to the construction cost and time increase also. In order to ensure the WIM accuracy,considering the economy of the carrier length,based on the vibration characteristics of the vehicle and the scale,the mathematical model of theWIM signal is established by means of moving average filtering and B spline least square method,and the vibration disturbance of low frequency dynamic load is effectively eliminated. The test result shows that（1）the weight error is less than 0. 5 % if test vehicles pass through the 0. 8 m and 1. 6 m long scales in the speed range of 0-5 km/h and 0-12 km/h,which meets the national standard about Class 1 scale;（2） if test vehicles pass through the 2. 6 m and 3 m long scales with the theoretical limit speed of 20. 7 km/h and 24. 3 km/h,the statistical weight error is less than 0. 5 %. The research not only provided a theoretical basis for design the length of the scale,but also has important reference value for improvement of the WIM accuracy of the existing installed single scale and double scales.