在自动驾驶车辆测试中计算加速度的变步长差分算法  

Differential algorithm with variable step-sizes to calculate accelerations in autonomous vehicle tests

作　　者：魏文明 刘伟平 范志鹏 白创 WEI Wenming;LIU Weiping;FAN Zhipeng;BAI Chuang(National Innovation Center of Intelligent and Connected Vehicles,Beijing 100176,China;Ningbo GEELY Automotive Research and Development Institute,Ningbo 315000,China)

机构地区：[1]国汽(北京)检测技术有限公司,北京100176 [2]宁波吉利汽车研究开发有限公司,宁波315000

出　　处：《汽车安全与节能学报》2023年第4期457-462,共6页Journal of Automotive Safety and Energy

摘　　要：为降低自动驾驶测试的成本并保证精度,不用惯性测量单元,而用了对速度进行差分的方法来计算加速度。对差分计算误差分析。对比了等步长差分、均值等步长差分及变步长差分等3种算法。与实车测量的结果对比。结果表明:合适的时间步长可提高计算精度。当步长取0.2 s或0.3 s时,等步长差分计算结果较符合实际;当步长相同时,均值等步长差分结果的波动小于等步长差分。等步长差分、均值等步长差分、变步长差分的最大绝对误差分别为0.77、0.64、0.46 m/s^(2),绝对误差平均值分别为93、82、65 mm/s^(2)。因此,变步长差分算法的精度是3种方法其中最高的。A differential algorithm was developed without using any inertial measurement unit,to calculate the acceleration of autonomous vehicles,and to reduce the test cost with a rational calculation accuracy.The calculation error was analyzed to contrast three algorithms,which had the fixed step-size,or the mean fixed step-size,or the variable step-size.The calculation results were compared with the measured accelerations in real car.The result shows that a suitable step-size improves the calculation accuracy;The calculation accuracies of the algorithms with 0.2-s or 0.3-s step-size are better than that of the algorithms with other step-sizes when using fixed step-size;The fluctuation of the calculation results by using the mean fixed step-size is smaller than that with the fixed step-size when the step-size is the same;The maximum absolute errors is 0.77 m/s^(2) for the fixed step-size algorithm,with being 0.64 m/s^(2) for the mean fixed step-size algorithm,and with being 0.46 m/s^(2) for the variable step-size algorithm;The average absolute errors are 93,82,and 65 mm/s^(2) respectively for the fixed step-size algorithm,the mean fixed step-size algorithm and the variable step-size algorithm.Therefore,the calculation accuracy by using the variable step-size algorithm is the best among the three algorithms.

关 键 词：自动驾驶测试 加速度 变步长 差分算法 计算精度 

分 类 号：U467.1[机械工程—车辆工程]