A hyper-redundant robotic arm is a manipulator with many degrees of freedom, capable of executing tasks in cluttered environments where robotic arms with fewer degrees of freedom are unable to operate. This paper introduces a new method for modeling those manipulators in a completely dynamic way. The proposed method enables online changes of the kinematic structure with the use of a special function; termed “meta-controlling function”. This function can be used to develop policies to reduce drastically the computational cost for a single task, and to robustly control the robotic arm, even in the event of partial damage. The direct and inverse kinematics are solved for a generic three-dimensional articulated hyperredundant arm, that can be used as a proof of concept for more specific structures. To demonstrate the robustness of our method, experimental simulation results, for a basic “meta-controlling” function, are presented.
In contrast to regular robotic arms, a hyper redundant manipulator can be functional even if it has many damaged joints, so it is essential to be able for a controller to control the manipulator properly with or without damage. An approach that explicitly deals with failures is that of @cite_27 , who presents decentralized autonomous architecture for space hyper redundant manipulators.
@cite_27
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Adaptation to partial failure is one of the most important requirements for space robotics, since space robots cannot be repaired after they have been launched. We propose a decentralized autonomous control algorithm for hyper-redundant manipulators that uses parallel processing with low-performance processors to achieve this adaptation. In this paper, a number of manipulator joints are locked at a certain angle in a computer simulation and the adaptability of the control algorithm to these failures is assessed. The control algorithm successfully continues its positioning task at a rate of more than 90 , even after half of its joints have failed. The control algorithm is also compared with behavior-based control architecture. The term "hyper-redundant" refers to robotic manipulators and mobile robots with a very large, possibly infinite, number of actuatable degrees of freedom. These robots are analogous in morphology and operation to snakes, worms, elephant trunks, and tentacles. This thesis presents a novel kinematic framework for hyper-redundant manipulator motion planning and task implementation. The basis of this formulation is the use of a "backbone reference set" which captures the essential macroscopic geometric features of hyper-redundant robots. In the analytical part of this work, the backbone representation is developed and used to solve problems in obstacle avoidance, locomotion, grasping, and "optimal" end effector placement. The latter part of this thesis deals with the design and implementation of a thirty-degree-of-freedom planar hyper-redundant manipulator which is used to demonstrate these novel kinematic and motion planning techniques. Design issues such as robustness with respect to mechanical failure, and design for easy assembly and repair are also addressed. The analytical and design concepts are combined to illustrate tasks for which hyper-redundant robotic mechanisms are well suited. Hyper-redundant manipulators have large number of kinematic degrees of freedom, thus possessing some unconventional features such as the ability to enter a narrow space while avoiding obstacles. To control these hyper-redundant manipulators accurately, the manipulator dynamics must be included into consideration. This is however time-expensive and makes implementation of the real-time control difficult. In this paper, we propose a dynamic control scheme for hyper-redundant manipulators, which is based on analysis in the defined posture space where three parameters were used to determine the manipulator posture. The manipulator dynamics is modeled in the parameterized form with the parameter of the posture space path and the posture space path-tracking feedforward controller is formulated on the basis of the parameterized dynamic equation. Computer simulation was executed to show the validity of the proposed technique, where a hyper-redundant manipulator traces the posture space path well by the proposed feedforward controller. As a result, it is proven that the hyper-redundant manipulator can track the workspace path accurately. Hyper-redundant manipulators have been widely used in many fields, however many existing hyper redundant manipulators actuated directly by motors have the disadvantages of complicate structure and high cost. This paper proposes a novel remote cable-driven hyper redundant manipulator. This manipulator is based on elephant trunk bionics, and composed of several serial links combined by Hook joints. Each link is pulled by two antagonized pairs of cables. Two antagonized pairs belonged to the same link are tied and driven by only one motor, which can reduced largely the number of step motors needed. This paper fully discusses the structure and analyzes the cable stretching and retracting displacement. Analysis and motion simulation results show that the proposed scheme is practical and effective.