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.
Leaving aside the technical limitations there are also problems deriving from the complexity of the kinematic and dynamic models of those arms. The complexity issues have been extensively discussed by Chirikjian @cite_13 where some macroscopic curve fitting solutions have been imposed. The complexity of dealing with hyper redundant arms, according to previous studies, is a problem that is treated as four subproblems: The dynamics that aim to control the robotic arm more efficiently with respect to the forces the robotic arm accepts and exerts. Improvements in the kinematics which aim to compute more efficiently the kinematic chain and control the actuators. Obstacle avoidance methods which aim to move the hyper redundant manipulator in environments with obstacles in an optimal manner. Fourth fault tolerance mechanisms which aim to control a hyper redundant robotic arm even when it is damaged.
@cite_13
1675003565
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.