The kingpin angle of automobile wheels has great influence on the performance of the car. The accuracy of the four-wheel aligner for measuring these angles will affect the stability of the car when it travels in a straight line, this paper proposes a new kingpin angle measurement model, which is based on the laser four-wheel aligner system. By studying the measurement principle and image analysis technology of the laser four-wheel aligner, a new measurement method and function formulas are established, which can ensure higher measurement accuracy and have high application value in actual measurement.
When optical images are used to measure the three-dimensional position of a target, it is necessary to project a laser source onto the object, and the center position of the pupil spot should be calculated. The laser light source has high application value, because the brightness of the spot is much higher than the brightness of the environment. When the camera is in a low exposure time, the spot will be in stark contrast to the surrounding environment, which can achieve the conditions of the image measurement. The laser can be divided into point laser, line laser and cross laser according to the simple emission shape. In this paper, the center positions of these lasers are solved separately. After calculating and testing, the stability and accuracy of the cross laser can be verified. The results can provide an important source of light source selection and new ideas for image measurement.