Toward joint optimization of camera and marker configurations for robotic motion capture systems: simulation-based evaluation of camera placement

The achievable accuracy of industrial robots, both absolute and repeatability, is a critical quality parameter that determines the suitability of a system for specific applications. High precision is particularly essential in tasks such as robot-based measurement, milling, and grinding. One common method to enhance robotic accuracy is the use of external measurement systems, such as marker-based motion capture, which utilizes multiple camera systems and optical reference markers to determine spatial positions with a precision of up to micrometers via triangulation. However, the efficient integration of such systems remains a significant challenge. The placement of cameras and markers often relies on trial-and-error methods and expert intuition, often requiring physical mock-ups or real production environments. This results in a time-consuming, manual, and iterative process that delays system commissioning and hinders seamless integration into existing production workflows. This paper presents a holistic strategy for optimizing the planning of marker-based motion capture systems in industrial robotics. Beyond camera placement, the presented strategy considers the optimized positioning and alignment of individual markers, as well as the design of a volumetric body acting as a carrier for the reference markers. In detail, the addressed planning challenge is formulated as a mathematical optimization problem, followed by the solution strategy. While the solution strategy focuses on the joint camera and marker optimization, the experimental evaluation in this contribution considers a fixed marker set to assess the impact of camera optimization initially.