关键词: 车辆工程, 计量学, 误差分析, 检定, 主销后倾, 主销内倾

Abstract: To improve the measuring precision of the automobile caster by a linear model on the fourwheel aligner, a precise measuring model was built. The model showed that the factors affecting the caster measuring precision are the kingpin inclination, the camber, and the turntable angle. the measuring error caused by the kingpin inclination was analyzed and it was concluded that it is impossible to measure the caster precisely with the linear model when the kingpin inclination is more than 10°. To calibrate the measuring results of the kingpin obliquity on the fourwheel aligner, a calibration apparatus was developed based on the principle of independent acquisition of the kingpin obliquities in the vertical and horizontal planes of the automobile. The experiment results show that the measuring errors are more than 10′ and these are zero point error and the nonlincar system error when the two obliquity angles of the kingpin are more than 15°, and the system errors increase as the kingpin obliquities increase. The automolile caster measuring results calibration problem has thus been solved.

Key words: vehicle engineering, metrology, error analysis, calibration, caster, kingpin inclination