Micron level robot positioning accuracy requirements: how to validate?

When robots must be positioned within tens of microns to ensure manufacturing process quality is maintained during automation, capability validation is key for successful implementation. This project investigated this issue, providing statistical robust conclusions that could be relied on for making roll-out decisions.

In practice, evaluation of robot positional accuracy and repeatability was done by taking measurements of its relative motion between programmed points using a laser tracker in multiple test cases. This was done using a procedure adapted from ISO 9283 - Manipulating Industrial Robots - Performance Criteria and Related Test Methods and datasets collected were analysed.

Work done quantified robot positional error characteristics from various perspectives, including how they vary according to position in the working envelope. Investigations also found that, when the robot encounters high levels of positional error, a portion of these could be offset, which lead to more projects developing techniques for in-process error compensation.

This investigation provided key understanding of robot operating performance and set the foundation for further R&D, which was key for successful ongoing process optimisation.

This work was published in The International Journal of Advanced Manufacturing Technology in 2016. For more information please contact us or see the full article:

Positional capability of a hexapod robot for machining applications