A calibration method for tool frame in the three-dimensional measurement system based on R-test

Calibration of the tool frame is essential to ensure the accuracy of the measurement system. To enhance the detection range of R-test and make it more suitable for robot calibration, we designed a low-cost and high-precision three-dimensional measurement system with R-test. Then, a two-stage method is proposed to reduce the uncertainty caused by the orthogonalization procedure in the identification of the R-test frame, which consists of an orthogonalization solution that gives an initial value and an intelligent algorithm that improves the identification accuracy. The measurement structure of the R-test and the proposed identification method are easily applicable to articulated arm measuring machines (AMMs). Additionally, we provide an extension method for AMMs. In the experiment, a prototype of the three-dimensional measurement system based on R-test is developed. And, the comparative experiment proves the effectiveness of the proposed method.