Industrial robot space pose measuring mechanism and measuring method based on stay wire rotation sensor

Abstract

The invention discloses an industrial robot space pose measuring mechanism and measuring method based on a stay wire rotation sensor. The measuring mechanism is based on three stay wire encoders and arotary encoder. The measuring method specifically comprises the steps that the measuring mechanism is self-calibrated before measurement, and during measurement of the measuring mechanism, an industrial robot changes the pose of a tail end space to-be-tested point once, the rotary encoder does not rotate firstly, and the measuring mechanism obtains displacement length data of three stay wires; then the rotary encoder rotates by a certain angle for the first time, and the measuring mechanism obtains displacement length data of the three stay wires; and finally, the measuring mechanism obtainsa group of pose solutions of the tail end space to-be-tested point of the industrial robot under a base coordinate system of the measuring mechanism based on the above data and by means of a Stewart mathematical model, and obtains a group of pose solutions in the base coordinate system of tail end motion of the industrial robot through coordinate conversion. The industrial robot space pose measuring mechanism based on the stay wire rotation sensor has a self-calibration function, and is simple in structure, high in environmental adaptability, low in cost and high in precision.

Description

technical field [0001] The invention relates to the technical field of industrial robots, in particular to an industrial robot space pose measurement mechanism and a measurement method based on a cable rotation sensor. Background technique [0002] With the continuous expansion of the scope of application of industrial robots and the complexity of their tasks in industrial production, industrial robots with different position and attitude accuracy are used in different occasions due to factors such as cost and technology. Therefore, it is inevitable to evaluate the performance of industrial robots. [0003] Commonly used industrial robot performance testing instruments include three-coordinate measuring instruments, laser trackers and four-wire space measuring instruments. The three-coordinate measuring instrument is a high-efficiency and high-precision measuring device based on precision machinery, but it takes up a lot of space and high cost; similarly, the laser tracker h...

AI Technical Summary

Problems solved by technology

The three-coordinate measuring instrument is a high-efficiency and high-precision measuring device based on precision machinery, but it takes up a lot of space and high cost; similarly, the laser tracker has high precision, a wide measurement range, and is relatively convenient to use, but the price is very expensive ; The four-line space measuring instrument can realize the three-dimensional dynamic measurement of the absolute accuracy of the robot's position and the repeatability of the positioning accuracy. The price of the laser tracker is much lower. The four-wire space measuring instrument cannot evaluate the performance of the robot's attitude, and it needs to be returned to the factory for maintenance after a certain period of use.

[0004] For the performance testing methods of industrial robots related to the pull wire displacement sensor, the existing technology almost guarantees the error of the performance testing mechanism through mechanical processing. The size of the above error affects the accuracy of the performance testing mechanism to calibrate itself before the test to a certain extent. ; In the prior art, the position and attitude of the robot (hereinafter referred to as the pose) can be measured, almost all through at least six wire displacement sensors, and based on the kinematics principle of the parallel mechanism, and then with the help of error minimization, the final result is obtained. pose solution, which leads to an increase in the number of sensors and an increase in error variables, which will inevitably affect the validity of the performance test results of industrial robots and increase the cost of testing institutions

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