Research On Calibration Method Of Collimated Laser Beam

In the system of tridimensional attitude measurement, the laser beams laser beams, and then shoot to the screen and the attitude of object can be calculated by the light-spot on the screen. The linearity of laser beams is the guaranty of the whole system, to calibrate the linearity of laser beams is the primary problem in the paper.There are many methods about straightness measurement in and abroad. After the traditional methods of straightness measurement are analyzed and compared, the measurement based on the precise guide rail is adopted. The methods of straightness measurement are mostly about a line, but the straightness of couple lasers is the mainly problem in the system. First the couple laser beams should be calibrated separately. Then, the couple laser beams should be aligned, and it is the most important problem in the design.The principle of the reference line design is based on the precise guide rail. The laser beams of the couple lasers should be aligned. First, we can use a camera to take over the laser beam at one end, record the position of the light-spot, and calculate the centroid of the light-spot, then, move the laser on the guide rail. We should rectify the screw until the position of light-spot is unchangeable. Then, the camera should be moved to the other end of the guide rail. We should move the laser on the guide rail, and rectify the screw until the position of the light-spot is unchangeable and the same position with the first time, and then, the straightness calibration of the laser is accomplished.The design of the laser and its bracket, neutral density filters, lens, and digital camera are complete in the hardware design; the image collection and centroid calculation are complete in the software design; and the experiment of straightness calibration is accomplished. The possible errors are analyzed about the whole system, and some methods to decrease the errors are put forward.