Analyses of Key Variables to Industrialize a Multi-Camera System to Guide Robotic Arms

Abstract

Robotic arms are widely used in sectors such as automotive or assembly logistics due to their flexibility and cost. Other manufacturing sectors would like to take advantage of this technology, however, higher accuracy is required for their purposes. This paper integrated a multi-camera system to achieve the requirements for milling and drilling tasks in aeronautic parts. A closed-loop framework allows the position of the robot’s end-effector to be corrected with respect to a static reference. This is due to the multi-camera system tracking the position of both elements due to the passive targets on their surface. The challenge is to find an auxiliary system to measure these targets with an uncertainty that allows the desired accuracy to be achieved in high volumes (>3 m3). Firstly, in a reduced scenario, a coordinate measuring machine (CMM), a laser tracker (LT), and portable photogrammetry (PP) have been compared following the guidelines from VDI/VDE 2634-part 1. The conclusions allowed us to jump into an industrial scenario and run a similar test with a higher payload than in the laboratory. The article ends with an application example demonstrating the suitability of the solution.

The generation mechanism and identification of spatially non-continuous error in integral multi-station measurement systems

“…dF dX and dF dθ are the Jacobian matrices of F and X, respectively. The Eigen-decomposition of u ∆θ k is shown in equation (10):…”

“…The integral multi-station measurement system represented by indoor GPS (iGPS), workshop Measuring and Positioning System (wMPS) or a multi-camera system, is becoming increasingly popular in in the past decade [8][9][10][11]. They can measure the position or pose of multiple targets based on the principle of multi-observation intersection, as shown in the blue zone in figure 1.…”