白车身视觉检测系统中多类型传感器全局校准技术

摘要

A novel global calibration method for the multi-sensor vision measurement system in industrial field is proposed to solve the problem of multiple sensors of different types,large distribution space and complicated position relations in the car body-in-white vision measurement system. Based on the indirect coordinates transformation,two precise 3D targets are designed as the intermediary in coordinates transformation,and field calibration data is acquired by a laser tracker. On the basis of the unit quaternion global calibration model,the optimized transformation parameters can be established in order to unify the stationary sensor coordinates and flexible sensors coordinates to the global coordinate system. The method has been applied in the inline measurement station of a company successfully. Only the calibration of transformation relation between the sensor coordinates and the global coordinates is needed in the application filed. Therefore,the complex environmental restriction is reduced in multi-sensor global calibration. Meanwhile,the environment adaptability is improved and the calibration process is simplified. The maximum deviation of the vision measurement system is ± 0. 2 mm,which meets the accuracy requirements of the manufacture dimension changes control of car body-in-white.%针对白车身视觉检测系统中传感器数量多、种类各异、分布空间大、位置关系复杂等问题，提出了一种适用于工业现场的多视觉传感器全局校准技术。基于坐标系间接统一法，设计多个精密立体靶标作为坐标系转换中介，利用激光跟踪仪获取现场校准数据，在单位四元数数学模型的基础上，求解两坐标系间最优转换矩阵，将固定式传感器和柔性传感器的测量坐标系统一到全局坐标系。该方法已在某企业在线测量项目中成功应用，现场只需完成传感器坐标系与全局坐标系转换关系标定，降低了复杂现场环境对多传感器全局校准的限制，简化了校准过程，提高了环境适应性，校准后检测系统各向测量精度均优于±0.2 mm，满足白车身在线测量精度要求。