Accuracy Design of Double Parallel-Joints Coordinate Measuring Machine

Double parallel-joints coordinate measuring machine(CMM)is a new type of coordinate measuring devices.It has many advantages simple structure,high in measuring accuracy and protable.In this paper,measuring principle of double parallel-joints CMM are introduced at first and then total error sources that influence the measuring accuracy are analyzed.The possible accuracy of error sources correction is analyzed and the total error of the instrument is calculated.The error distribution is presented on the basis of accuracy design of the instrument.The error distribution is simulated and the error distribution law of the instrument is summarized.The calibration and the structure design of the instrument are guided by the research in the paper,and the solid theoretical basis is provided by the error correction to achieve the accuracy indicators of double parallel-joint CMM.