Determination of the positioning accuracy of industrial manipulators using a digital photo/video camera

Purpose of research. The aim of the study is to develop a system for the analysis and evaluation of positioning errors manipulators precision industrial robots used in the production of microelectronic equipment. The positioning accuracy of the manipulator varies depending on the operating modes of the robot and is difficult to predict and difficult to analyze. The accuracy of positioning is influenced by the design features of the robot manipulator, the speed of movement and rotation of the manipulator, intermediate stops and accelerations, vibrations, both own and caused by the location of the robot in production. The positioning accuracy may differ for different points of the robot working area. We need a system of analysis and error estimation that allows us to effectively carry out a series of hundreds and thousands of measurements. One of the promising areas is the use of digital technology with subsequent processing of data on the computer.

Materials and methods of research. The construction of effective robotic systems depends on the correct implementation of the certification of industrial robots in order to provide control systems of industrial robots with accurate data for trouble-free and correct operation in conditions specific to a particular production. The solution of the complex problem of certification of precision industrial robots faces difficulties in the selection of measuring equipment. Studies have been conducted aimed at the formation of point light sources of small diameter. A non-contact measurement method based on obtaining an image of point light sources using a digital photo/video camera is proposed. Application of point light sources for calibration of measuring system is described. Possibilities of specification of positions of point sources by means of computer processing of the images received from the digital camera were investigated. The algorithm of image processing of the camera carrying out in several stages definition of accuracy of positioning of the manipulator of the robot is offered.

Results. A remote, non-contact method for measuring the positioning errors of industrial robot manipulators has been developed. A method of assessing the positioning accuracy of industrial robot manipulators based on specially formed point light sources installed in the grips of the manipulators and in the working area of the robot. Implemented the use of digital photo/video cameras for monitoring and fixing the space of the resulting spread of the manipulator positions. The software processing the digital image and allowing to make calculations of an error of positioning is developed. The method makes it possible to effectively carry out large series of measurements and meets the following parameters: the absence of physical points of contact between the measuring system and the robot manipulator, satisfying the accuracy of measurements, ease of operation with measuring equipment, low cost of measuring equipment. The work was presented at the XLV International youth scientific conference Gagarin readings, MATI, Moscow, Russia, 2019. and was awarded a diploma.

Conclusion. The article presents the results of research on the development of non-contact system of analysis and evaluation of positioning errors of precision industrial robots. The obtained results can be used for certification of industrial robots. It is possible to control the positioning accuracy of manipulators without removing the robot from the production process. 

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