[BK Seminar] July 15 (Wed) Prof. Robert G. Landers (University of Notre Dame) "Off-Line and On-Line Volumetric Error Compensation of Machine Tools and Industrial Robots"

We ask for the active interest and participation of all members of the Department of Mechanical Engineering.

▣ Topic: Off-Line and On-Line Volumetric Error Compensation of Machine Tools and Industrial Robots

▣ Speaker: Prof. Robert G. Landers

▣ Affiliation: University of Notre Dame

▣ Date and Time: Wednesday, July 15, 2026, at 10:30 a.m.

▣ Location: Room A205, Engineering Building 1

▣ Invited by: Professor Byung-Kwon Min

▣ Abstract

Due to inaccuracies in component fabrication and assembly, machine tools and industrial robots exhibit geometric errors (i.e., the difference between nominal and actual kinematic motions), which significantly contribute to errors in parts manufactured on these machines, as well as unduly long process certification times. To compensate for machine tool geometric errors, the standard practice is to measure each error individually and use these measurements to directly populate compensation tables within the machine tool controller. The drawback of this method is that it is extremely slow due to lengthy instrument setup times and fails to capture the complexity of large machine tools. To compensate for industrial robot geometric errors, circle-point analysis is used, in which the errors of each joint are measured independently. While this method is fast, it still does not capture the complexity of robot kinematic errors. In addition, machine tools and industrial robots suffer from thermal deformations and deflections between the tool and the part due to processing forces.

This talk will discuss recent work on volumetric error compensation for large machine tools and industrial robots used in manufacturing tasks. A laser tracker is used to measure the geometric errors of the machine tool and robot across the entire visible joint space. A 6-degree-of-freedom geometric error model is constructed for each joint. Based on this model, an optimization algorithm is used to generate compensation tables for machine tools, or the inverse Jacobian method is used to adjust the joint commands for robots. Several examples of machine tools and robots that have been modeled and compensated for industrial partners will be presented, along with recent work on online compensation for industrial robots.