Modeling and compensation of flexible modes in 3-DOF H-gantry with decoupling design: a primitive study

Si-Lu Chen; Fraj Gharib; Chek Sing Teo; Wei Lin

doi:10.1117/12.2084924

4 March 2015 Modeling and compensation of flexible modes in 3-DOF H-gantry with decoupling design: a primitive study

Si-Lu Chen, Fraj Gharib, Chek Sing Teo, Wei Lin

Proceedings Volume 9302, International Conference on Experimental Mechanics 2014; 930239 (2015) https://doi.org/10.1117/12.2084924
Event: International Conference on Experimental Mechanics 2014, 2014, Singapore, Singapore

Abstract

The special designed 3-DOF direct-drive air bearing decoupling stage has the advantages of high repeatability and free coupling error between different axes. And it is suitable for wafer scanning application. However, due to the flexible joints between the orthogonal axes, the relatively low frequency resonant modes limit the bandwidth of closed loop tracking control. This presentation shows how we obtain the frequency response model of the decouple stage accurately and safely with closed-loop identification approach, using dSPACE modular control systems, and how we use the model to achieve high-speed tracking control using model-based feedforward / feedback composite control. For safety purposes, the electrical portion of decoupled stage is carefully designed with appropriate limit sensors and emergency safety switch. The decoupled stage is controlled by DS1005 modular control system, which gives ultra-high control loop updating rate at 100us. With such high profile controller, we model the frequency response of 3-DOF system using sequential closed-loop relay feedback. From here, the model of rigid body mode and flexible modes are identified. The identified model provides a guideline for trajectory design and closed-loop PID plus feedforward controller design for synchronization of dual-drive X-axis motion. Although the trial on design of decoupling controller has been proposed, internal stability of such decoupling control schemes remains a research issue for our future work.

Citation Download Citation

Si-Lu Chen, Fraj Gharib, Chek Sing Teo, and Wei Lin "Modeling and compensation of flexible modes in 3-DOF H-gantry with decoupling design: a primitive study", Proc. SPIE 9302, International Conference on Experimental Mechanics 2014, 930239 (4 March 2015); https://doi.org/10.1117/12.2084924

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available