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.
For the dynamics problem a first continuum approximation approach with the backbone curve and the ability to parallelize the problem was introduced by Chirikjian @cite_21 . Other ways to solve the dynamics problem for a hyper redundant arm have been presented by @cite_28 . In particular, a dynamic control scheme is introduced in a constrained operational space. In addition with a dynamic formulation for the hyper redundant robotic arm, the solution is provided efficiently and the execution is accurate. Moreover, other approaches as presented in the work of @cite_7 aimed to design manipulators by focusing on the desired force at the end-effector to achieve a desired acceleration. Other studies use biomimetic approaches to solve efficiently the problem ( @cite_24 , and @cite_35 ) that consider also the hydrodynamic forces in underwater applications, and also studies based on the screw theory can be seen in the work of @cite_0 .
@cite_35 @cite_7 @cite_28 @cite_21 @cite_24 @cite_0
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A new and efficient kinematic position and velocity solution scheme for spatial hyper-redundant manipulators is presented. The manipulator's arm has discrete links and universal joints. Backbone curve concepts and a modal approach are used to resolve the manipulator's redundancy. The effects of the mode shapes and the slope of the backbone curve at the starting point on the workspace are studied. It is shown that the usage of conventional mode shapes limits the workspace of the hyper-redundant arm. By introducing new mode shapes, an improved workspace is obtained. A simple and efficient recursive fitting method is introduced to avoid complications involved with solving systems of nonlinear algebraic equations. This method also guarantees the existence of solutions for the inverse kinematic problem at the velocity level. Velocity properties of the backbone curve are investigated and the inverse velocity propagation is solved for the spatial hyper-redundant arm. The velocity propagation scheme is recursive and is efficiently applicable to any number of links. 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 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. In this paper we consider the motion planning problem of humanoid with articulated-spine for object manipulation in double support phase. Complexity of motion planning increases due to higher degrees-of-freedom (DOF), redundancy arising due to articulated spine, inherent underactuation and stability constraint. Additionally, loop-closure constraints arise during double-support phase, and self-collision constraints exist independent of the task to be performed. These problems make motion planning of humanoids a challenging task. In this work, we address the above issues by proposing a sampling based approach for planning the motion of the humanoid. Our approach to the problem is based on RRT* which can generate asymptotically optimal paths. The proposed approach deals with the stability constraints by rejective sampling approach which divides random configurations generated into valid and invalid configurations. Additionally, the loop-closure constraints are tackled by separating the humanoid into two open-kinematic sub-chains, and then generating random configurations in one sub-chain whereas the remaining sub-chain uses inverse kinematics for closure. Efficacy of the proposed approach is demonstrated for whole-body motion planning of a 25-DOF humanoid in generating asymptotically optimal end-effector paths.