Measurement Method of Automobile Body Inclination Angle Based on Headlamp Area Detection

In the standards about the contour dimension of automobile in most countries, the height difference of body symmetrical points or body inclination angle of automobile was specified. To improve the vehicle performance and operation safety, a measurement method of car body inclination angle was studied. According to the camera calibration and the distance between camera and automobile, the front license plate detection area was estimated, and the accurate license plate positioning was realized based on the constraint on length to width ratio. According to the statistics of distance between license plate and headlamps, the headlamp detection areas were estimated. The feature points of the headlamps were extracted based on the angle and distance constraints of lines, and then the height difference of the symmetrical headlamp feature points were analyzed and the automobile body inclination angle was gotten. The experiment results showed that this method effectively detected the automobile inclination angle, and the measurement could provide data support to improve car’s usage performance and lay foundation for the next automobile detecting applications. It was a non-contact measurement method that could realize automatic detection and easily combined with other testing projects.