Research on the System Error Analysis and Compensation Method for the 3-D Profile Measurement with CCD Based on Linear Structure Lighting

摘要

For the 3-D profile measurement with CCD, the calibration of CCD measurement system is still the focus of the researchers' attention. Firstly taking no account of some factors, such as the CCD lens aberration, image process error, etc., the principle error of the CCD calibration method constructing the coordinates mapping relation from image coordinates to space coordinates based on the polynomial fitting solution is analyzed through the experimental data in the paper. Then the paper analyzes the device error and operation error that is mainly from CCD lens aberration and image process. By measuring the standard geometry element, the error value can be picked up on the different depth position of field. After filtering the noise, the system error can be got, and can be used to compensate and amend the measurement result. The experimental result shows that with the system error compensation method, the measurable depth of field can be increased efficiently and the precision of the measurement result can be control within ±50um with common table of which the simple axis machine precision is 15um and open-loop control driven by the stepper motor, which can meet the profile measuring requirements well.