Real-time Inverse Kinematics of (2n + 1) DOF hyper-redundant manipulator arm via a combined numerical and analytical approach

A novel closed-form solution for the inverse kinematics of redundant manipulators through workspace analysis

With many degrees of freedom (DOFs), a hyper-redundant manipulator has superior dexterity and flexible manipulation ability. However, its inverse kinematics and configuration planning are very challenging. With the increase in the number of DOFs, the corresponding computation load or training set will be much larger for traditional methods (such as the generalized inverse method and the artificial neural network method). In this paper, a segmented geometry method is proposed for a spatial hyper-redundant manipulator to solve the above problems. Similar to the human arm, the hyper-redundant manipulator is segmented into three sections from geometry, i.e., shoulder, elbow, and wrist. Then, its kinematics can be solved separately according to the segmentation, which reduces the complexity of the solution and simplifies the computation of the inverse kinematics. Furthermore, the configuration is parameterized by several parameters, i.e., the arm-angle, space arc parameters, and desired direction vector. The shoulder has proximal four DOFs, which is redundant for positioning the elbow and avoiding the joint limit. The arm-angle parameter is defined to solve the redundancy. The wrist consists of the distal two DOFs, and its joints are determined to match the desired direction vector of the end-effector. All the other joints (except for the joints belonging to shoulder and wrist) compose the elbow. These joint angles are solved by using space arc-based method. The configuration planning for avoiding joint limit, obstacles, and inspecting narrow pipeline are detailed for practical applications. Finally, circular trajectory tracking and pipeline inspection are, respectively, simulated and experimented on a 20-DOFs hyper-redundant manipulator. The results show that the proposed method can give solutions of the three-dimensional-pose-determining problem and the configuration-planning problem. The computation of the inverse kinematics is simplified for real-time control. It can also be applied to other spatial hyper-redundant manipulators with similar serial configurations.

A Segmented Geometry Method for Kinematics and Configuration Planning of Spatial Hyper-Redundant Manipulators

End-effector pose and arm-shape synchronous planning methods of a hyper-redundant manipulator for spacecraft repairing

The dynamics modeling and trajectory optimization of a segmented linkage cable-driven hyper-redundant robot (SL-CDHRR) become more challenging, since there are multiple couplings between the active cables, passive cables, joints and end-effector. To deal with these problems, this paper proposes a dynamic modeling and trajectory tracking control methods for such type of CDHRR, i.e., SL-CDHRR. First, the multi-coupling kinematics equation (i.e., cable-joint-end) of the hyper-redundant robot is derived. Then, according to the transmission characteristics of the hybrid active/passive segmented linkage, the dynamic equation of series–parallel coupling is derived. It consists of parallel-active dynamics and series-passive dynamics. Furthermore, using the tension of active cables and the pose of the end-effector as optimization indicators, a trajectory tracking framework was constructed by the combination of dynamic feedforward control and PD control. The multi-objective particle swarm optimization method is used to achieve the simultaneous optimization of the energy indicator and control accuracy indicator during the trajectory tracking process. Finally, a MATLAB/SimMechanics co-simulation system is built, and the proposed methods are verified by the built co-simulation system.

Dynamic modeling and trajectory tracking control method of segmented linkage cable-driven hyper-redundant robot

Inverse Kinematics (IK) of redundant manipulators has been an active research problem in the field of robotics for a long time. Many solutions exist, though the focus here is to solve the problem of inverse kinematics (both position and orientation) in real-time for a 7 DOF redundant manipulator with spherical wrist. In other words, a computationally efficient way. The approach taken here attempts to decouple the redundant manipulator at the wrist, thus solving for the first four angles satisfying the wrist position and the last three angles satisfying the End Effector (EE) position and orientation. A hybrid approach of using analytical and numerical methods is undertaken to improve the computational efficiency, and the performance is compared with pure numerical methods. Various paths are generated using this method and tested for performance in terms of accuracy and speed. Finally, simulations on a Motoman IA20 redundant manipulator are shown to display satisfactory performance.

Real-time Inverse Kinematics of redundant manipulator using a hybrid (analytical and numerical) method

A fast converging optimal technique applied to path planning of hyper-redundant manipulators

In this paper, an application robotic platform has been constructed based on the kinematic model of a 9-DOF hyper-redundant manipulator. The efficacy of our kinematic algorithm affects the accuracy and stability of both motion control and path tracking. The result of tracking different paths and error analysis shows that the 9-DOF manipulator works functionally and satisfies all the requirement of experimental design.

/pdf/design-and-construction-of-9-dof-hyper-redundant-robotic-arm-33rpyyiuyq.pdf

Hariharan Ananthanarayanan

Papers

Real-time Inverse Kinematics of (2n + 1) DOF hyper-redundant manipulator arm via a combined numerical and analytical approach

Real-time Inverse Kinematics of redundant manipulator using a hybrid (analytical and numerical) method

A fast converging optimal technique applied to path planning of hyper-redundant manipulators

Design and construction of 9-DOF hyper-redundant robotic arm