Accurate extrinsic calibration method of a line structured-light sensor based on a standard ball

In order to implement 3D measurement in different measurement systems with line structured-light sensor, the extrinsic matrix for transforming the position between the structured-light sensor and the measurement platform must be calibrated. An extrinsic calibration method, achieved by measuring the fixed point (the centre of a standard ball) of the measuring system with the sensor in different positions, was proposed. In order to calculate the coordinate of the ball centre in the laser plane frame more accurately, the images containing fewer pixels were filtered and the noise around the slice was removed. Experimental study was carried out on a four-axis coordinate measuring machine (CMM) with a ball supplied by CIMCORE and showed that the method is simple; it can also be used in a non-orthogonal measurement system.