Measure dimension of rotating large hot steel shell using pulse laser on PRRR robot

During the industrial forging or rolling of hot steel shells, the raw material utilization ratio is very low because of the absence of precise on-line measurement instrument for the forging dimensions. In order to reduce the waste and increase the productivity, the pulse laser measuring instrument with dual PRRR mechanism has been developed in this study. The adjusting algorithm of rotary table based on the dual PRRR mechanism has been presented, which ensures that the scanning plane is perpendicular to the axis of cylinder shell. So the circle fitting can be adopted and the robust and accurate dimensions can be obtained rapidly by the present data-processing method. The measurement error of cold cylinder shell’s diameter is less than 3 mm. The measuring results of hot steel shells are also very accurate. The present system has been used in the rolling production of large hot steel shells, which enhances the raw material utilization ratio during the rolling.