Impact of a Robot Manipulation on the Dimensional Measurements in an SPC-Based Robot Cell

Applied Sciences

Aleš Zore¹  Marko Munih¹  Robert Čerin² 

[1] Faculty of Electrical Engineering, University of Ljubljana, Tržaška Cesta 25, 1000 Ljubljana, Slovenia;Kolektor Orodjarna d.o.o., Vojkova Ulica 10, 5280 Idrija, Slovenia;

关键词: CMM;    robot;    manipulation;    SPC;    dimensional measurement;    comparative measurements;   

DOI  :  10.3390/app11146397

来源: DOAJ

【 摘 要 】

In our study a robot was used to deliver objects for measurement into the Equator gauging system. To investigate the robot’s manipulation influence on dimensional measurements, the robot’s tasks were divided into basic functions. Based on these basic functions, nine different robot-manipulation scenarios were defined, i.e., from zero to full robot manipulation, for two measuring objects (named Magnet and PKR) and six measurement characteristics (rectangular and spherical). The robot’s manipulation influence was determined on the basis of the statistical parameters $C_p$, R, and the $6\sigma$ obtained from a measurement system analysis (MSA) type-1 study. The results show that the degree of implemented manipulation of the robot affects the scattering of the measurement data. However, the effect is much more pronounced in the case of length measurements than with spherical geometries. Different measuring methods (touch-triggering or scanning measurement mode, number of sampling points) were used, which showed similar measurement data. This directly indicated the influence of the robot’s manipulation on $C_p$, R and $6\sigma$. Increasing the degree of the robot’s manipulation decreases the $C_p$ value and increases the R and $6\sigma$ values for the length measurements. There is no such pronounced course in the spherical geometries, where the values of $C_p$, R and $6\sigma$ remain approximately the same. The main influential factor for decreasing the $C_p$ value with increasing robot manipulation was the angular misalignment of the object’s orientation in the fixture.

【 授权许可】

Unknown