Abstract:Calibration is a crucial part of the car driving assistance system. In order to make the driving assistance system perceive the target more accurately and improve the active safety of car driving, a multi-sensor Factory calibration system for cameras and millimeter-wave radars is designed. The system establishes a mathematical model by using the structural characteristics of the camera and the millimeter-wave radar, calculates the external parameters of each sensor, and converts the target data perceived by different sensors into a unified world coordinate system, realizing the camera and the millimeter-wave radar joint calibration. The Unified Diagnostic Services(UDS) based on CAN bus is used as the communication medium, which realizes the diagnostic services such as session control, security access, standby handshake, routine program control, etc., and designs the factory calibration process that conforms to the standard of pre-installation and mass production. In order to facilitate the operation of the production line workers and simplify the operation steps in the front-loading mass production, the upper computer calibration software specially designed for the pre-installation production is designed. The reliability, real-time performance and accuracy of the factory calibration system have been verified by experimental tests. The average value of ranging error after calibration is around 0.25m, and the ratio of the millimeter-wave radar projection point to the coordinates of the image detection frame is 93.2%. The calibration system can meet the perception accuracy requirements of cameras and millimeter-wave radars in automotive assisted driving systems.
