Measuring mechanism and method for space pose and posture of industrial robot based on cable rotation sensor

Abstract

The invention discloses an industrial robot space pose measurement mechanism and a measurement method based on a cable rotation sensor. The measurement mechanism is based on three cable encoders and a rotary encoder; the method is specifically: the measurement mechanism calibrates itself before measurement, When the measuring mechanism is measuring, the industrial robot changes the position of the point to be tested in the end space once. First, the rotary encoder does not rotate, and the measuring mechanism obtains the displacement length data of three pull wires. Then the rotary encoder rotates a certain angle for the first time, and the measuring mechanism obtains three Based on the above data and the Stewart mathematical model, a set of pose solutions of the point to be tested in the end space of the industrial robot in the base coordinate system of the testing mechanism is obtained. Through coordinate conversion, the base coordinate system of the end motion of the industrial robot is obtained. A set of pose solutions in . The invention has self-calibration function, simple structure, strong environmental adaptability, low cost and high 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 measurement method based on a pull-wire rotation sensor. Background technique [0002] With the continuous expansion of the application scope of industrial robots and the complexity of their tasks in industrial production, industrial robots with different positions 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 equipment based on precision machinery, but it occupies a large space and costs a lot. Similarly, the laser track...

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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