Concentric-tube continuum robots have formed an active field of research in robotics because of their manipulative exquisiteness essential to facilitate delicate surgical procedures. A set of concentric tubes with designed initial curvatures comprises a robot whose workspace can be controlled by relative translations and rotations of the tubes. Kinematic models have been widely used to predict the movement of the robot, but they are incapable of describing its time-dependent hysteretic behaviors accurately particularly when snapping occurs. To overcome this limitation, here we present a finite element modeling approach to investigating the dynamics of concentric-tube continuum robots. In our model, each tube is discretized using MITC shell elements and its transient responses are computed implicitly using the Bathe time integration method. Inter-tube contacts, the key actuation mechanism of this robot, are modeled using the constraint function method with contact damping to capture the hysteresis in robot trajectories. Performance of the proposed method is demonstrated by analyzing three specifications of two-tube robots including the one exhibiting snapping phenomena while the method can be applied to multiple-tube robots as well.
Bibliographical noteFunding Information:
This work was supported by the Center for Advanced Meta-Materials (CAMM) funded by the Ministry of Science, ICT and Future Planning as Global Frontier project (CAMM-2014M3A6B3063711). This work was also supported by the National Research Foundation of Korea (NRF) Grant funded by the Ministry of Science, ICT and Future Planning for convergent research in sport scientification (NRF-2014M3C1B1033983). Changyeob Baek was supported by SNU Undergraduate Research Program.
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All Science Journal Classification (ASJC) codes
- Civil and Structural Engineering
- Building and Construction
- Mechanics of Materials
- Mechanical Engineering