In optical systems, reflectors are commonly used for directing light beams to desired directions. In this paper, a dielectric elastomer (DE) based optical manipulator is developed for two degrees-of-freedom (2-DOF) manipulation. The DE manipulator consists of a diaphragm with four segments that are controlled in two pairs, thus generating 2-DOF tilting motions. Due to its soft and gear-less moving structure, the DE manipulator is lightweight and naturally resistant to mechanical vibrations. Moreover, its nonelectromagnetic-driven mechanism allows it to work under the environments that are exposed to strong magnetic fields. To design a robust control strategy for the actuator, a physics-based and control-oriented nonlinear model is then developed and linearized around the equilibrium point. A feedback control system, which consists of two H-infinity controls, is developed to track two tilting angles along two axes. Experimental results have shown that this manipulator is able to track 0.3° 2-DOF tilting angle with 0.03° accuracy.
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Physics-lumped parameter based control oriented model of dielectric tubular actuator
Dielectric elastomers (DEs) deform and change shape when an electric field is applied across them. They are flexible, resilient, lightweight, and durable and as such are suitable for use as soft actuators. In this paper a physics-based and control-oriented model is developed for a DE tubular actuator using a physics-lumped parameter modeling approach. The model derives from the nonlinear partial differential equations (PDE) which govern the nonlinear elasticity of the DE actuator and the ordinary differential equation (ODE) that governs the electrical dynamics of the DE actuator. With the boundary conditions for the tubular actuator, the nonlinear PDEs are numerically solved and a quasi-static nonlinear model is obtained and validated by experiments. The full nonlinear model is then linearized around an operating point with an analytically derived Hessian matrix. The analytically linearized model is validated by experiments. Proportional–Integral–Derivative (PID) and H∞ control are developed and implemented to perform position reference tracking of the DEA and the controllers’ performances are evaluated according to control energy and tracking error.
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- Award ID(s):
- 1747855
- NSF-PAR ID:
- 10320990
- Date Published:
- Journal Name:
- International journal of intelligent robotics and applications
- ISSN:
- 2366-598X
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1007/s41315-021-00211-1
