Research on the Method of Improving iGPS Dynamic Tracking Accuracy Based on Theoretical Trajectory Backward Compensation

Abstract

As a result of the ongoing upgrading of the manufacturing industries, higher and higher requirements are being proposed for assembly precision. In particular, in the industries that involve assembly of large-sized products, it is hoped that assembly accuracy can still be guaranteed as the product size increases. The emergence of the indoor Global Positioning System (iGPS) will enable this demand to be met. In this work, we have conducted in-depth research on the measurement principles and the dynamic measurement performance of the iGPS measurement system. In addition, based on the motion equation for the tracked target, an analytical method to calculate the compensation amount required for dynamic measurements is proposed. This method is suitable for accurate measurement of the actual trajectory of a target in real time when the theoretical trajectory of this tracked target is known. We set up a simulation environment in MATLAB and tested the proposed method. The simulation testing proved that the method can compensate effectively for errors in iGPS dynamic measurement.

Research on high-precision tracking and localization of industrial robots based on iGPS

“…By observing the simulation results we can find that, without using the correction algorithm, the measurement accuracy of iGPS decreases rapidly with the increase in speed and is strongly related to the instantaneous speed of the measured target. When the correction algorithm is used, the results of the simulation experiments are shown in figures [13][14][15] In the figure, the meanings of the axes and colors are consistent with the description above. Through the test results we can find that when the correction algorithm is used, the measurement error, although it still increases with the increase in the speed of the measured target, the increment is extremely small and the measurement accuracy is significantly improved.…”

“…Based on the measurement principle of iGPS we can establish the following system of equation ( 12) and approximation relations (13),…”

“…The system of equation ( 12) describes the perpendicular relationship that should exist between the individual vectors according to the measurement principle of iGPS. The approximation relation (13) describes that the coordinates of the points we virtualize as equivalent substitutes should converge infinitely to the results of this measurement so that the points, we virtualize can satisfy the role of equivalent substitutes. Through the above calculation, the coordinate (x 0 , y 0 , z 0 ) of the measured target at the beginning of the measurement cycle could be calculated by equation (14),…”

“…Similarly, comparative experiments using laser trackers and iGPS were conducted by Wang et al They took advantage of the programmability of industrial robots to increase the diversity of the trajectories of the tracked targets, and the results of the experiments were also compared and analyzed [12]. Han et al proposed an algorithm to compensate for the dynamic measurement results of iGPS based on the measurement principle of iGPS and verified the effectiveness of the algorithm through simulation but without the support of real experiments [13]. Zhao et al proposed a mathematical model for the new iGPS single-station and dual-station measurement systems, in which the speed of the tracked target is considered, and the modification of the mathematical model is verified by simulation and physical experiments, but the study only considered the case of the tracked target moving at a uniform speed in a straight line, so it lacks general applicability [14].…”