On the Inverse Kinematics of Space Manipulators for Avoiding Dynamic Singularities

1997 ◽  
Vol 119 (2) ◽  
pp. 340-346 ◽  
Author(s):  
F. Xi ◽  
R. G. Fenton
Keyword(s):  
Conventional Method ◽  
Inverse Kinematics ◽  
Convergence Rates ◽  
Generalized Jacobian ◽  
Space Manipulators

A spacecraft-manipulator system is considered in this paper. Dynamic singularities are the singularities occurring when inverting the system generalized Jacobian required by the conventional method for solving the inverse kinematics of space manipulators. To avoid dynamic singularities, three methods are developed here based on the manipulator Jacobian, instead of the system generalized Jacobian. These methods are compared with the conventional method on the basis of their convergence rates, accuracies and sensitivities. Results of this comparison are presented in this paper.

Inverse kinematics of free-floating space robots with minimum dynamic disturbance

Robotica ◽  
1996 ◽  
Vol 14 (6) ◽  
pp. 667-675 ◽  
Author(s):  
Fengfeng Xi
Keyword(s):  
Inverse Kinematics ◽  
New Method ◽  
Space Robots ◽  
Simple Fact ◽  
Generalized Jacobian ◽  
Space Manipulator ◽  
End Effector ◽  
Dynamic Disturbance ◽  
Space Manipulators

In this paper a new method is presented for solving the inverse kinematics of free-floating space manipulators. The idea behind the method is to move the space manipulator along a path with minimum dynamic disturbance. The method is proposed to use the manipulator Jacobian instead of the generalized Jacobian of the spacecraft-manipulator system. This is based on the simple fact that, if the space manipulator moves along the so-called Zero Disturbance Path (ZDP), the spacecraft is immovable. As a result, the space manipulator can in this case be treated as a terrestrial fixed-based manipulator. Hence, the motion mapping between the joints and the end-effector can be described directly by the manipulator Jacobian. In the case that the ZDP does not exist, it can be shown that the solutions obtained by the proposed method provide a path with minimum dynamic disturbance.

Nonholonomic motion planning for minimizing base disturbances of space manipulators based on multi-swarm PSO

Robotica ◽  
2015 ◽  
Vol 35 (4) ◽  
pp. 861-875 ◽  
Author(s):  
Qiang Zhang ◽  
Lu Ji ◽  
Dongsheng Zhou ◽  
Xiaopeng Wei
Keyword(s):  
Motion Planning ◽  
Pso Algorithm ◽  
Planning Problem ◽  
Generalized Jacobian ◽  
Floating Base ◽  
Space Manipulators ◽  
Conservation Of Momentum ◽  
Generalized Jacobian Matrix ◽  
Quaternion Representation ◽  
Nonholonomic Motion Planning

SUMMARYBecause space manipulators must satisfy the law of conservation of momentum, any motion of a manipulator within a space-manipulator system disturbs the position and attitude of its free-floating base. In this study, the authors have designed a multi-swarm particle swarm optimization (PSO) algorithm to address the motion planning problem and so minimize base disturbances for 6-DOF space manipulators. First, the equation of kinematics for space manipulators in the form of a generalized Jacobian matrix (GJM) is introduced. Second, sinusoidal and polynomial functions are used to parameterize joint motion, and a quaternion representation is used to represent the attitude of the base. Moreover, by transforming the planning problem into an optimization problem, the objective function is analyzed and the proposed algorithm explained in detail. Finally, numerical simulation results are used to verify the validity of the proposed algorithm.

scholarly journals A Novel Analytical Inverse Kinematics Method for SSRMS-Type Space Manipulators Based on the POE Formula and the Paden-Kahan Subproblem

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Yecong Wang ◽  
Xilun Ding ◽  
Zixin Tang ◽  
Chengwei Hu ◽  
Qingqing Wei ◽  
...  
Keyword(s):  
Numerical Solution ◽  
Inverse Kinematics ◽  
Space Station ◽  
Algebraic Methods ◽  
Singular Problem ◽  
Symmetrical Structure ◽  
Type Space ◽  
Revolute Joints ◽  
Space Manipulators ◽  
Simulation Results

Space manipulators which have a similar symmetrical structure with seven revolute joints, such as the space station remote manipulator system (SSRMS), can be called SSRMS-type space manipulators. The analytical inverse kinematics of an SSRMS-type manipulator can be solved by locking a single joint; the locked joint (joint 1, 2, 6, or 7) can be determined by configuration analysis. Although widely used in establishing the kinematics of SSRMS-type manipulators, the Denavit-Hartenberg (DH) method has a singular problem when two adjacent joint axes are nearly parallel. To avoid this problem, this paper proposes a novel analytical inverse kinematics method for SSRMS-type manipulators based on the product of exponentials (POE) formula and the Paden-Kahan subproblem. Because of the symmetrical structure, an SSRMS-type manipulator degrades to two kinds of 6-degree-of-freedom (DOF) manipulators when locking a single joint (joint 1, 2, 6, or 7). The analytical inverse kinematics of these two kinds of 6-DOF manipulators is solved by combining the Paden-Kahan subproblems and geometric and algebraic methods, respectively. The proposed approach is not only singularity free compared with the traditional DH-based methods but also more accurate than the POE-based numerical solution. The simulation results verify the efficiency of the proposed approach.

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