Rolling linear guide pair is a high-precision linear motion mechanism widely used in machine tools, industrial robots, measuring instruments and other applications. With the increasing application, the requirements for the motion accuracy of rolling linear guide pairs are also becoming higher and higher. Motion accuracy refers to the degree to which a point in space approaches its actual position and theoretical position during motion.

The motion accuracy of a rolling linear guide pair is an important indicator for evaluating its performance, and it has a direct impact on the lifespan of the rolling linear guide pair. Currently, the main method for measuring the motion accuracy of a rolling linear guide pair is using a micrometer.

As a linear motion mechanism, the motion trajectory of any point on the slider should theoretically be a straight line. However, in reality, the rolling linear guide pair is affected by factors such as manufacturing accuracy, friction force, and installation accuracy. The slider often undergoes changes in three directions during actual operation, which means that there is a linear motion error in the slider of the rolling linear guide pair during operation.

Linear motion error is based on straightness, and can be defined as the straightness error along the direction of motion; Straightness error is the variation of the measured actual contour line from the ideal straight line.