2 research outputs found
Influence Of Each Of The Geometric Errors On The Total Displacement Error Of The Machine
An algorithm for volumetric calibration is
developed and verified practically by measuring of all geometric
errors after numerical compensation. In this paper, analysis of
the contribution of each of 9 translational and 9 rotational
position dependent errors and each of 3 position independent
errors in total displacement error vector is presented. Changing
only one of the errors, and keeping all the others unchanged, the
final total error is examined using the simulation based on
forward calibration part of the calibration algorithm. The
measurement of all 21 volumetric errors is expensive and time
consuming. Instead of numerical compensation in the controller,
this analysis yields opportunity to enhance accuracy of the
machine, measuring and making correction of only few of the
geometric errors. Results from the simulation showed that
position independent errors have most significant influence on
total displacement error. Decreasing of the squareness error S XY
improves the mean of norms of total displacement vectors about
25%, and percentage of improvement for squareness error S ZX is
about 20%. If all squareness errors are reduced by factor 0.04,
then total improvement is more than 51%
Computer-based simulation and validation of robot accuracy improvement method and its verification in robot calibration procedure
Algorithm for improving accuracy of six-axes robot
is developed and validation method based on computer
simulation is implemented. Optimization is used to minimize the
distances between nominal and actual positions of the tool. That
way, the parameters of the robot are calibrated and using such
calibrated parameters, accuracy of the robot is significantly
enhanced.
Measurement is done using API Radian laser tracker and
experimental data is collected on KUKA 480 R3330. For the set
of 75 points used for calibration, simulation predicted reduction
of the mean of the total displacement error from 1.619 mm to
0.174 mm. After that, the same points were used for verification
procedure. Another measurement is performed, using the
calibrated parameters and numerically calculated compensation
of the machine coordinates of the robot. The mean of total
displacement error was 0.293 mm and that way the correctness of
described method is verified