Feasible Arm Configurations and its Application for Human-Like Motion Control of S-R-S-Redundant Manipulators with Multiple Constraints

Robotica ◽  
2021 ◽  
pp. 1-17
Author(s):  
Jing Xia ◽  
Zai-nan Jiang ◽  
Ting Zhang
Keyword(s):  
Motion Control ◽  
Inverse Kinematics ◽  
Humanoid Robot ◽  
Redundant Manipulators ◽  
Multiple Constraints ◽  
Redundant Manipulator ◽  
Human Movements ◽  
Feasibility Evaluation ◽  
Joint Limit ◽  
New Framework

SUMMARY This paper presents a general framework for human-like motion control of 7-DOF S-R-S-redundant manipulators. The new framework simultaneously accomplishes five objectives: Cartesian trajectory tracking, obstacle avoidance, joint limit avoidance, human-like movement, and a feasibility evaluation of the Cartesian trajectory.We exhaustively compute all feasible arm configurations. This allows for quick evaluations of the feasibility of the Cartesian trajectories. They are applied to inverse kinematics of the redundant manipulator to improve the capability to handle multiple constraints, and enable the manipulator to imitate human movements. The efficiency of the proposed framework is demonstrated by kinematic experiments with a humanoid robot.

Dual arm-angle parameterisation and its applications for analytical inverse kinematics of redundant manipulators

Robotica ◽  
2015 ◽  
Vol 34 (12) ◽  
pp. 2669-2688 ◽  
Author(s):  
Wenfu Xu ◽  
Lei Yan ◽  
Zonggao Mu ◽  
Zhiying Wang
Keyword(s):  
Inverse Kinematics ◽  
Reference Plane ◽  
Redundant Manipulators ◽  
Redundant Manipulator ◽  
Singularity Problem ◽  
Human Arm ◽  
Angle Method ◽  
Self Motion ◽  
Dual Arm ◽  
Configuration Control

SUMMARYAn S-R-S (Spherical-Revolute-Spherical) redundant manipulator is similar to a human arm and is often used to perform dexterous tasks. To solve the inverse kinematics analytically, the arm-angle was usually used to parameterise the self-motion. However, the previous studies have had shortcomings; some methods cannot avoid algorithm singularity and some are unsuitable for configuration control because they use a temporary reference plane. In this paper, we propose a method of analytical inverse kinematics resolution based on dual arm-angle parameterisation. By making use of two orthogonal vectors to define two absolute reference planes, we obtain two arm angles that satisfy a specific condition. The algorithm singularity problem is avoided because there is always at least one arm angle to represent the redundancy. The dual arm angle method overcomes the shortcomings of traditional methods and retains the advantages of the arm angle. Another contribution of this paper is the derivation of the absolute reference attitude matrix, which is the key to the resolution of analytical inverse kinematics but has not been previously addressed. The simulation results for typical cases that include the algorithm singularity condition verified our method.

Inverse Kinematics of Serial Redundant Manipulators With Locked Articulations

1995 ◽  
Author(s):  
Louis Perreault ◽  
Clément M. Gosselin
Keyword(s):  
Inverse Kinematics ◽  
General Procedure ◽  
Inverse Kinematic ◽  
Redundant Manipulators ◽  
Redundant Manipulator ◽  
Inverse Kinematic Problem

Abstract This paper presents an algorithm for the solution of the inverse kinematics of a serial redundant manipulator with one (or more) locked joint(s). To this end, a general procedure is developed for the determination of the equivalent Denavit-Hartenberg parameters of a serial manipulator with locked joints. This procedure can be applied to any serial architecture. The solution of the inverse kinematic problem for the three cases which can arise is then addressed. An example of the application of the method to a SARCOS 7-DOF manipulator is also given.

scholarly journals A Solution of the Inverse Kinematics Problem for a 7-Degrees-of-Freedom Serial Redundant Manipulator Using Gröbner Bases Theory

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Sérgio Ricardo Xavier da Silva ◽  
Leizer Schnitman ◽  
Vitalino Cesca Filho
Keyword(s):  
Inverse Kinematics ◽  
Degrees Of Freedom ◽  
Gröbner Bases ◽  
Grobner Bases ◽  
Operational Performance ◽  
Redundant Manipulators ◽  
Redundant Manipulator ◽  
All Solutions ◽  
Inverse Kinematics Problem ◽  
Algebraic Computing

This article presents a solution of the inverse kinematics problem of 7-degrees-of-freedom serial redundant manipulators. A 7-degrees-of-freedom (7-DoF) redundant manipulator can avoid obstacles and thus improve operational performance. However, its inverse kinematics is difficult to solve since it has one more DoF than that necessary for reaching the whole workspace, which causes infinite solutions. In this article, Gröbner bases theory is proposed to solve the inverse kinematics. First, the Denavit–Hartenberg model for the manipulator is established. Second, different joint configurations are obtained using Gröbner bases theory. All solutions are confirmed with the aid of algebraic computing software, confirming that this method is accurate and easy to be implemented.

scholarly journals Computing Robust Inverse Kinematics Under Uncertainty

2019 ◽  
Author(s):  
Anirban Sinha ◽  
Nilanjan Chakraborty
Keyword(s):  
Inverse Kinematics ◽  
Joint Space ◽  
Redundant Manipulators ◽  
Task Space ◽  
Success Rates ◽  
Redundant Manipulator ◽  
Space Error ◽  
Inverse Kinematics Problem ◽  
Robotic Tasks ◽  
Present Simulation

Abstract Robotic tasks, like reaching a pre-grasp configuration, are specified in the end effector space or task space, whereas, robot motion is controlled in joint space. Because of inherent actuation errors in joint space, robots cannot achieve desired configurations in task space exactly. Furthermore, different inverse kinematics (IK) solutions map joint space error set to task space differently. Thus for a given task with a prescribed error tolerance, all IK solutions will not be guaranteed to successfully execute the task. Any IK solution that is guaranteed to execute a task (possibly with high probability) irrespective of the realization of the joint space error is called a robust IK solution. In this paper we formulate and solve the robust inverse kinematics problem for redundant manipulators with actuation uncertainties (errors). We also present simulation and experimental results on a 7-DoF redundant manipulator for two applications, namely, a pre-grasp positioning and a pre-insertion positioning scenario. Our results show that the robust IK solutions result in higher success rates and also allows the robot to self-evaluate how successful it might be in any application scenario.

scholarly journals Finite-Horizon Kinetic Energy Optimization of a Redundant Space Manipulator

2021 ◽  
Vol 11 (5) ◽  
pp. 2346
Author(s):  
Alessandro Tringali ◽  
Silvio Cocuzza
Keyword(s):  
Kinetic Energy ◽  
Real Time ◽  
Inverse Kinematics ◽  
Degrees Of Freedom ◽  
Computational Time ◽  
Redundant Manipulators ◽  
Space Robotics ◽  
Optimal Method ◽  
End Effector ◽  
Global Optimal

The minimization of energy consumption is of the utmost importance in space robotics. For redundant manipulators tracking a desired end-effector trajectory, most of the proposed solutions are based on locally optimal inverse kinematics methods. On the one hand, these methods are suitable for real-time implementation; nevertheless, on the other hand, they often provide solutions quite far from the globally optimal one and, moreover, are prone to singularities. In this paper, a novel inverse kinematics method for redundant manipulators is presented, which overcomes the above mentioned issues and is suitable for real-time implementation. The proposed method is based on the optimization of the kinetic energy integral on a limited subset of future end-effector path points, making the manipulator joints to move in the direction of minimum kinetic energy. The proposed method is tested by simulation of a three degrees of freedom (DOF) planar manipulator in a number of test cases, and its performance is compared to the classical pseudoinverse solution and to a global optimal method. The proposed method outperforms the pseudoinverse-based one and proves to be able to avoid singularities. Furthermore, it provides a solution very close to the global optimal one with a much lower computational time, which is compatible for real-time implementation.

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