| The displacement error was analyzed and on improvement measures studied in the detection of gear parameter by laser triangulation in this paper. The measurement accuracy is affected by the tilt and roughness of the measured gear surface when the gear parameter was detected by non-contact method using laser triangulation sensor. Therefore, it is important to reduce the error generated tilt and roughness of the measured surface effectively, which can improve stability and accuracy of the laser triangulation sensor.The influence generated by the inclination and roughness of the surface was analyzed mainly, the formula of error relationship was derived in the paper. It is concluded that the change of spot distribution on the line array CCD is the basic reason for the error caused by inclination and roughness of the surface. The error can be reduced effectively by using high precision sub-pixel center positioning algorithm. A new algorithm which combines the nonlinear weighted and linear interpolation for spot location is presented in this paper. The new algorithm can improve the measurement accuracy effectively. The experiments show that the new algorithm has better noise immunity and robustness, and could reduce the error caused by the title of measured surface effectively. The method of reducing error caused by the roughness of measured surface was proposed in the paper through analysis of scattering intensity on the measured surface. |
