Absolute positioning error correction method of in-series joint type robot and calibration system

Abstract

The invention provides an absolute positioning error correction method of an in-series joint type robot and a calibration system. The absolute positioning error correction method comprises the following steps: establishing an axis model of a detected joint and an adjacent joint for obtaining and correcting parameters of an arm rod in an upper computer by an optical positioning instrument, outputting a neural network model of a target corner and carrying out zero error correction. The absolute positioning error correction method provided by the invention has the advantages that since the calculation result can reflect actual structure parameters of the robot really and further D-H parameters are corrected, a low-cost optical tracking and positioning test instrument (namely an NDI optical positioning instrument) is adopted for carrying out analysis and error compensation on the absolute positioning accuracy of a robot system from three aspects of a kinematic model, a joint-transmission return difference and zero positioning, so that not only is the accuracy improved, but also the cost is reduced.

Description

technical field [0001] The invention relates to a robot calibration method and equipment, in particular to a calibrating method and a calibration system for an absolute positioning error of a tandem articulated robot. Background technique [0002] The mechanical arm of the series articulated robot generally realizes various motion functions through the combination of multiple rotary joints in series, and is widely used in industrial sites such as automatic handling, assembly, welding, and spraying. Since serial articulated robots often work in applications that require high precision and safety, this requires the robot to have high absolute positioning accuracy. However, it is a well-known fact in robot applications that the repeatability is high and the absolute positioning accuracy is low. In general, the absolute positioning accuracy is only 2 to 3mm, which cannot meet the needs of the actual application of robots. Therefore, the research on the analysis of the absolute p...

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Problems solved by technology

[0006] However, these high-precision testing equipment are expensive, and ordinary research and development units are unable and unwilling to purchase them. Therefore, it is impossible to carry out related specific calibration work

In addition, the data analysis of the above-mentioned test equipment is not comprehensive enough. Only the parameters of the rods of the robot are corrected, and the angle between the axes of the joint shafts is not analyzed and corrected. The error (installation error of the zero position sensor) is analyzed and compensated; in the test, three more points are taken as the correction value for calculating the length of the rod, and the calculation method of the data is not rigorous enough

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