Uncertainty analysis of an augmented industrial robot

Khanesar, Mojtaba Ahmadieh; Piano, Samanta; Branson, David

Abstract

Industrial robots are often used in additive manufacturing (AM) environments to automate the process of creating complex parts and structures. One example of an industrial robot used in AM is for wire and arc additive manufacturing. This process involves using an industrial robot to deposit metal wire onto a workpiece while simultaneously melting it with an electric arc. This allows for the creation of large-scale metal parts with high precision and efficiency. Moreover, industrial robots can be used to move a printing nozzle along a predefined path to create a three-dimensional (3D) object. This method is commonly used to produce plastic parts and is often faster and more cost-effective than traditional manufacturing methods. However, industrial robots can sometimes struggle with achieving the required positional accuracy for AM tasks. To overcome this challenge, a 3D move stage is added to the robot's end effector, and it is then possible to fine tune its pose in closed loop using optical metrological devices, such as laser trackers and laser interferometers. These devices benefit from high levels of accuracy, which make it possible to use them in a feedback loop to increase the overall accuracy of the industrial robots and the moving stage. However, adding the move stage to the industrial robot changes the system's geometry. In this paper, an overall uncertainty analysis for the augmented robot is performed. The forward kinematics of the overall industrial robot and the move stage are obtained. The probability distribution of position depends on industrial robot joint angle values and move stage displacement values. As a part of uncertainty analysis, the probability density function associated with a sample industrial robot joint angle values and a move stage displacement value is calculated.

Citation

Khanesar, M. A., Piano, S., & Branson, D. (in press). Uncertainty analysis of an augmented industrial robot.

• Start Date: Sep 19, 2023
• End Date: Sep 21, 2023
• Acceptance Date: Aug 3, 2023
• Deposit Date: Sep 15, 2023
• Publicly Available Date: Sep 15, 2023
• Keywords: Uncertainty analysis; industrial robots; linear stages; surface; laser tracker
• Public URL: https://nottingham-repository.worktribe.com/output/25353870
• Additional Information: Joint Special Interest Group meeting between euspen and ASPE Advancing Precision in Additive Manufacturing KU Leuven, Belgium, September 2023