The shape control of tentacle arms

Abstract

The paper discusses the shape control problem related to a class of hyper-redundant robot arms with continuum elements, i.e. tentacle arms. A spatial weighted technique for sensor measurements is used in order to facilitate the parameter estimation. The paper focuses on the shape control by using the curvature gradient a constant parameter along the segment arm. The conditions that ensure a constant curvature gradient for a class of tentacle arms characterized by elastic backbone are determined. A sensor network distributed along the robot arm is used for the shape control. The main parameters of the arm shape, curvature and curvature gradient or "shape" Jacobian for the control problem are estimated. Two measuring systems are used: a) a distributed angle sensor network and b) a curvature sensor placed at the end of the arm segment. The stability analysis and the resulting controllers are obtained using the concept of boundary geometric control and the weighted state control methods. The shape control algorithms for dynamic models with uncertain components are proposed. Numerical simulations and experimental results illustrate the effectiveness of the above mentioned algorithms.

Decentralized Control of Distributed Actuation in a Segmented Soft Robot Arm

“…Figures 3a, 4a, and 5a plot the evolution of the closed-loop H 1 norm bound, , over the execution of each algorithm when the optimization is performed alternately over the variables K and P during each iteration. Figures 3b, 4b, and 5b display the resulting closed-loop beam response for each controller given the initial condition (14). These figures show that all controllers successfully dampen the beam vibrations that are induced by the initial beam displacement within the first 5 seconds.…”

“…While dynamic models have been formulated, e.g. a Partial Differential Equation (PDE) model of bending in a hyper-redundant continuum robotic arm [14], their complexity often prevents their practical implementation in controller design and motion planning [32], [33].…”

A Hybrid Position/Force Control Method for a Continuum Robot With Robotic and Environmental Compliance

“…Mahl et al [21] provided kinematic real-time control to improve model accuracy and suitability of multi-section continuum robot. Ivanescu et al [22] proposed shape control algorithms for dynamic models with uncertain components. Cobos-Guzman et al [2] provided a kinematic approach for controlling the end-effector of continuum robot in hazardous environments.…”