POSITION PRECISION MEASURING DEVICE AND METHOD FOR MECHANICAL ARM

摘要

The present invention relates to the field of dynamic trajectory precision calibration of mechanical arms, and provides a position precision measuring device and method for a mechanical arm. The dynamic trajectory error of the mechanical arm is measured by means of two orthogonal turntables and one radial telescopic mechanism passing through two rotating centers. A precise standard steel ball fixed at an end point of the radial telescopic mechanism is attracted to a magnetic ball seat fixed at an end point of the mechanical arm, the spatial position coordinates (X, Y, Z) of the end point of the arm are obtained by coordinate transformation of the steel ball coordinates (R, θ, ϕ) on a three-dimensional spherical coordinate mechanism, and the position error of the end point of the mechanical arm can be obtained by subtracting the coordinate position from the motion command position of the mechanical arm. A three-dimensional spherical coordinate system is formed by integrating an azimuth angle, a pitch angle and a radial length, and the precision of the spherical coordinate mechanism is higher than that of the mechanical arm. The device is easy to carry, has a low cost and good practicability, is easy to develop, and can complete real-time measurement of the error of the mechanical arm.