Real-time target alignment system for high-power high-repetition rate laser operations using a five degree-of-freedom hybrid mechanism

Leach, Richard; Branson, David; Karim, Shah; Tolley, Martin; Piano, Samanta; Santoso, Teguh

Abstract

This paper presents a real-time position control solution for the targets used in the high-repetition rate laser operations of high-power laser facilities. The control system is designed based on an Abbe-compliant, in-process position measurement system of targets, employing a plane mirror interferometer and a five degree-of-freedom hybrid mechanism. An error model is developed to characterise the position feedback information of target for a high-repetition rate process to determine the effects of the non-collocation of the sensor’s measurement point and target on the control system’s performance– a challenge for the real-time position control of targets. Behaviour of the control system is investigated with the error model and experimental data. It is found that a controller’s position compensation scheme can be ineffective due to the erroneous position feedback as a result of the non-linear position information associated with the non-collocated measurement point and the actual target. To solve the problem, an angular compensation technique is proposed.

Citation

Leach, R., Branson, D., Karim, S., Tolley, M., Piano, S., & Santoso, T. (2020). Real-time target alignment system for high-power high-repetition rate laser operations using a five degree-of-freedom hybrid mechanism. International Journal of Control, 95(4), 867-885. https://doi.org/10.1080/00207179.2020.1827297

• Journal Article Type: Article
• Acceptance Date: Sep 13, 2020
• Online Publication Date: Dec 4, 2020
• Publication Date: Apr 3, 2020
• Deposit Date: Mar 24, 2021
• Publicly Available Date: Apr 14, 2021
• Journal: International Journal of Control
• Print ISSN: 0020-7179
• Electronic ISSN: 1366-5820
• Publisher: Taylor and Francis
• Peer Reviewed: Peer Reviewed
• Volume: 95
• Issue: 4
• Pages: 867-885
• DOI: https://doi.org/10.1080/00207179.2020.1827297
• Keywords: real-time position and orientation control; in-process metrology; hybrid mechanism; Abbe error; error model; closed-loop control; target position feedback; position and angular compensation; complaint and non-complaint feedback information
• Public URL: https://nottingham-repository.worktribe.com/output/4959033
• Publisher URL: https://www.tandfonline.com/doi/full/10.1080/00207179.2020.1827297