Singularity avoidance of a six degree of freedom three dimensional redundant planar manipulator

Yahya, Samer; Moghavvemi, Mahmoud; Mohamed, Haider A. F.

doi:10.1016/j.camwa.2011.12.073

“…Because the inverse of the Jacobian is required for the inverse kinematics solution, it is desirable that the Jacobian be square so that it is directly invertible. Additionally, a square Jacobian matrix with full rank results in a unique inverse kinematics solution [ 13 ]. If the task vector only involves the

vector of Cartesian linear velocities of the hand, the AX-12 Smart Arm is a redundant manipulator because it has four DOFs (excluding Hand Open-Close), one more than required to achieve the desired hand behavior.…”

Section: Inverse Kinematics Solutionmentioning

confidence: 99%

Introduction and Testing of an Alternative Control Approach for a Robotic Prosthetic Arm

Griggs¹,

Fahimi²

2014

TOBEJ

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Commercially available robotic prosthetic arms currently use independent joint control. An alternative controller involving only control of the hand in a Cartesian frame rather than controlling each joint independently is proposed and tested. An experimental 4DOF robotic arm was used as the platform for testing the proposed control approach. As opposed to joint control, Cartesian control requires the solution to the inverse kinematics problem. The inverse kinematics solution was developed for the robotic arm using the extended Jacobian method. The two control methodologies, joint control and Cartesian control, were tested on five able-bodied human subjects. Improvement of one control methodology over the other was measured by the time it took for the subjects to complete a simple motor task. The timed trial results indicated that Cartesian control was both more intuitive and more effective than joint control. So, the results suggest that much improvement can be achieved by using the proposed Cartesian control methodology.

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“…Because the inverse of the Jacobian is required for the inverse kinematics solution, it is desirable that the Jacobian be square so that it is directly invertible. Additionally, a square Jacobian matrix with full rank results in a unique inverse kinematics solution [13]. If the task vector only involves the 1 3 vector of Cartesian linear velocities of the hand, the AX-12 Smart Arm is a redundant manipulator because it has four DOFs (excluding Hand Open-Close), one more than required to achieve the desired hand behavior.…”

Section: Fig (5)mentioning

confidence: 99%

Introduction and Testing of an Alternative Control Approach for a Robotic Prosthetic Arm

Griggs¹,

Fahimi²

2014

TOBEJ

0

View full text Add to dashboard Cite

Commercially available robotic prosthetic arms currently use independent joint control. An alternative controller involving only control of the hand in a Cartesian frame rather than controlling each joint independently is proposed and tested. An experimental 4DOF robotic arm was used as the platform for testing the proposed control approach. As opposed to joint control, Cartesian control requires the solution to the inverse kinematics problem. The inverse kinematics solution was developed for the robotic arm using the extended Jacobian method. The two control methodologies, joint control and Cartesian control, were tested on five able-bodied human subjects. Improvement of one control methodology over the other was measured by the time it took for the subjects to complete a simple motor task. The timed trial results indicated that Cartesian control was both more intuitive and more effective than joint control. So, the results suggest that much improvement can be achieved by using the proposed Cartesian control methodology.

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“…Redundant actuation is an effective method of eliminating the singularity of the PMs. [2][3][4][5] However, it is an expensive solution to the problem because of the additional actuators and the complicated control of the manipulator caused by actuation redundancy. 6 Another method of avoiding the singularities is to obtain the singularity-free workspace, in which the PM should work.…”

Section: Introductionmentioning

confidence: 99%

Singularity property and singularity-free path planning of the Gough–Stewart parallel mechanism

Li

¹

,

Wang

²

,

Han

³

et al. 2017

International Journal of Advanced Robotic Systems

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Singularity affects the performance of the parallel mechanisms seriously and so should be avoided as the mechanisms work. It is necessary to obtain the distribution of the singularity locus in the task space of a parallel mechanism and then further explore singularity avoidance. This article mainly deals with the singularity-free path planning of the widely used Gough-Stewart parallel mechanism. After obtaining the characteristics of the position-singularity locus for a constant orientation and the orientation-singularity locus for a given position, the position-singularity path planning and orientationsingularity path planning are explored, respectively. For the position-singularity path planning, after obtaining the positionsingularity locus equation and analyzing the geometric property of the position-singularity curve in a moving plane, a general method for identifying the probability of existence of a singularity-free path connecting two given points in the moving plane is illustrated, and then the technique of the singularity-free path planning is also represented in case if a singularity-free path exists. For the orientation-singularity path planning, the orientation kinematic equation and the time optimal orientation path of a rigid body are constructed using the quaternion algebra theory, respectively. After analyzing the orientation-singularity locus and using the results of time optimal orientation path of a rigid body, the method of time optimal orientation path planning of the mechanism is investigated. The validation of the aforementioned methods of two types of singularity-free path is tested and verified by applying numerical examples. The research has important theoretical significance and practical reference value for the exploration of the singularity avoidance of the parallel mechanism.

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Singularity avoidance of a six degree of freedom three dimensional redundant planar manipulator

Cited by 27 publications

References 12 publications

Introduction and Testing of an Alternative Control Approach for a Robotic Prosthetic Arm

Introduction and Testing of an Alternative Control Approach for a Robotic Prosthetic Arm

Introduction and Testing of an Alternative Control Approach for a Robotic Prosthetic Arm

Singularity property and singularity-free path planning of the Gough–Stewart parallel mechanism

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