Thesis
Development of a linear MR-brake for haptics
Washington State University
Master of Science (MS), Washington State University
2012
Handle:
https://hdl.handle.net/2376/102461
Abstract
In haptics applications, actuators with compact volume and high force output are desired for stable and stiff interfaces. Magnetorheological (MR) brakes are viable options since they have large force-to-volume ratios. However, linear MR-brakes available on the market have limited stroke due to the piston-cylinder design and show viscous damping behavior where the force output highly depends on the velocity of the actuator resulting in a high off-state friction force. Another problem is the inherent magnetic hysteresis, which requires complex control systems. In this research, we focused on the development and control of a linear MR-brake with infinite stroke and minimal off-state friction. The common piston-cylinder arrangement was removed from the design to address the limited stroke and high off-state-friction issues. The serpentine flux path methodology was followed to achieve compact geometry. Three control strategies namely, open-loop control, force feedback control, and current feedback with Preisach model, were implemented on the developed prototype. The results using Preisach model showed that the hysteresis could be reduced significantly without the need for an expensive force sensor. Our new device has a 3% ratio of the off-state friction force to the maximum force output in comparison to more than 10% for most MR-damper devices in the literature. At the same time, our prototype is about half the size of a commercially available product.
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Details
- Title
- Development of a linear MR-brake for haptics
- Creators
- Mustafa Sait Alkan
- Contributors
- Hakan Gurocak (Degree Supervisor)
- Awarding Institution
- Washington State University
- Academic Unit
- Mechanical and Materials Engineering, School of
- Theses and Dissertations
- Master of Science (MS), Washington State University
- Publisher
- Washington State University; Pullman, Wash. :
- Identifiers
- 99900525168801842
- Language
- English
- Resource Type
- Thesis