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.
Several algorithms in addition to the ones discussed above have been proposed for solving the obstacle avoidance problem @cite_36 @cite_31 @cite_1 @cite_11 @cite_6 . Other techniques use the idea of considering the free space as tunnels in the obstacle filled workspace and use differential kinematics as done by Chirikjian and Burdick @cite_2 @cite_14 ; while other techniques, as presented by Ma and Konno @cite_38 , separate the desired path into close points and for each step the manipulator tries to avoid the obstacles. Recent studies by da Gra @math @cite_26 combine the closed-loop differential pseudo-inverse way of the methods presented above, with genetic algorithms that provide repeatability for closed path operations.
@cite_38 @cite_14 @cite_26 @cite_36 @cite_1 @cite_6 @cite_2 @cite_31 @cite_11
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A hyper redundant manipulator has a very large or infinite degree of kinematic redundancy, thus it is possessed of unconventional features such as the ability to enter a narrow space while avoiding obstacles. We propose a novel obstacle avoidance technique for the hyper redundant manipulator to perform a payload location task from point to point while avoiding existing static obstacles in the environment. The scheme is based on analysis in the defined posture space, where three parameters were used to determine the hyper redundant manipulator configurations. The scheme is verified by computer simulation in case of using the model of the developed Hyper-R Arm. It shows that our method works perfect and the obstacles are well avoided globally. Novel kinematic algorithms for implementing planar hyperredundant manipulator obstacle avoidance is presented. Unlike artificial potential field methods, the method outlined is strictly geometric. Tunnels are defined in a workspace in which obstacles are presented. Methods of differential geometry are then used to formulate equations which guarantee that sections of the manipulator are confined to the tunnels and therefore avoid the obstacles. A general formulation is given with examples to illustrate this approach. > The trajectory planning of redundant robots is an important area of research and efficient optimization algorithms are needed. The pseudoinverse control is not repeatable, causing drift in joint space which is undesirable for physical control. This paper presents a new technique that combines the closed-loop pseudoinverse method with genetic algorithms, leading to an optimization criterion for repeatable control of redundant manipulators, and avoiding the joint angle drift problem. Computer simulations performed based on redundant and hyper-redundant planar manipulators show that, when the end-effector traces a closed path in the workspace, the robot returns to its initial configuration. The solution is repeatable for a workspace with and without obstacles in the sense that, after executing several cycles, the initial and final states of the manipulator are very close. "Hyper-redundant" robots have a very large or infinite degree of kinematic redundancy. This paper develops new methods for determining "optimal" hyper-redundant manipulator configurations based on a continuum formulation of kinematics. This formulation uses a backbone curve model to capture the robot's essential macroscopic geometric features. The calculus of variations is used to develop differential equations, whose solution is the optimal backbone curve shape. We show that this approach is computationally efficient on a single processor, and generates solutions in O(1) time for an N degree-of-freedom manipulator when implemented in parallel on O(N) processors. For this reason, it is better suited to hyper-redundant robots than other redundancy resolution methods. Furthermore, this approach is useful for many hyper-redundant mechanical morphologies which are not handled by known methods. 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. A new approach to solve the inverse kinematics problem of redundant robot manipulators in environments cluttered with obstacles is presented in this paper. The physical problem is formulated as an optimization problem under constraints, and solved via a modified genetic algorithm (mGA). The mGA searches for successive robot configurations in the entire free space so that the robot moves its end-effector from an initial placement to a final desired. The objective of this optimization is to simultaneously minimize the end-effector's positional error and the robot's joint displacements. The efficiency of the proposed approach is demonstrated through multiple experiments carried out on several redundant robot manipulators. Comparison with two other approaches, the well known Pseudoinverse method and a previous method based on a simple GA, shows that the accuracy of the present solution is substantially better. This paper presents a spline-based solution method for the inverse kinematics of hyper-redundant manipulators. The reference or backbone curve, that describes the macroscopic geometric shape of the manipulator is modelled by cubic and quintic piecewise parametric spline segments. A procedure for the coordinate frame distribution is proposed that allows any desirable rotation to be deployed about the backbone curve. Moreover, control points are used to determine the optimum shape and to change the length of the manipulator. The proposed solution method is general and applicable to non-extensible as well as extensible planar or spatial hyper-redundant manipulators with different morphologies. Motion planning capability is an essential part of an industrial robot system. Therefore research in robot motion planning remains as one of the important fields of study in the task of building industrial robot systems. A new method for the motion planning is presented in this paper. The basic idea is to find a smooth path consisting of points close enough to each other. Then the computation of the inverse kinematics for these points is accomplished with the help of a new proposed geometrical method to solve the problem of multi-solution caused by redundancy. The advantage of this method is that the angles between the adjacent links are the same, it makes controlling these links easier and the movement of the manipulator itself more stable. This method can be used for the equal length links planar manipulators. To demonstrate the effectiveness of this proposed method, experiments were conducted on a 10-links hyper redundant manipulator in this paper.