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.
The octopus arm is a unique tool that combines strength and flexibility. It can shorten, elongate and bend at any point along its length. To model this behavior, a hyper-redundant manipulator composed of multiple segments is proposed. Each segment is a parallel robotic mechanism with redundant actuation. The kinematics and dynamics of this manipulator are analyzed and simulated utilizing a modular computational modeling method. Simulation results for some primitive movements are presented, and the effect of hydrodynamic forces is included. In this paper, a motion control strategy based on a disturbance observer for a hyper-redundant manipulator is proposed. In the hyper-redundant manipulator, it is difficult to realize a force or an arbitrary motion control at the end-effector because it requires complicated calculations to construct an acceleration controller in the workspace. To improve this issue, we introduce a simplified motion control strategy based on both the backbone curve (BC) which is generally used in hyper-redundant manipulator control and a workspace observer. The proposed method makes it possible to design the motion controller flexibly and to simplify its calculation process. Furthermore, we are also considering a decentralized control method to extend our proposed controller to a more highly redundant manipulator. The validity of the proposed strategy is confirmed by several experimental results in this paper. 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, or 'snake-like', manipulators have a very large number of actuatable degrees of freedom. This paper develops an efficient formulation of approximate hyper-redundant manipulator dynamics. The most efficient methods for representing manipulator dynamics in the literature require serial computations proportional to the number of degrees of freedom. Furthermore, these methods are not fully parallelizable. For hyper-redundant manipulators, which may have tens, hundreds or thousands of actuators, these formulations preclude real time implementation. This paper therefore looks at the mechanics of hyper-redundant manipulators from the point of view of an approximation to an 'infinite degree-or-freedom' (or continuum) problem. The dynamics for this case is developed. The approximate dynamics of actual hyper-redundant manipulators is then reduced to a problem which is O(1) in time, i.e. the algorithm is O(n) is the total number of computations, but these computations can be completely distributed o... This paper presents an improved 3D dynamic model based on mode shape functions for biomimetic continuum robotic arms intended for underwater operation. It is an extension to the dynamic model proposed in the author's previous work to incorporate angular moments and hydrodynamic forces such as buoyancy, lift, and drag. The proposed model is based on an accurate kinematic model and gives an enhanced insight into practical mechanics. Also, it can be generalized for any variable length continuum arm to include external forces. A feedback control structure in the joint space is also implemented for increased performance of the continuum arm. Numerical results demonstrate underwater effects for spatial bending and pure elongations contractions. The model carefully accounts for mechanical constraints in the joint space to yield physically accurate results. In this contribution, a systematic methodology for solving the kinematic and dynamic analyses of a modular spatial hyper-redundant manipulator built with an optional number of serially connected three-legged in-parallel manipulators are presented.