An end-effector wrist module for the kinematically redundant manipulation of arm-type robots
Journal
Mechanism and Machine Theory
Journal Volume
155
Start Page
104064
ISSN
0094114X
Date Issued
2021
Author(s)
Abstract
Industrial arm-type robots have multiple degrees-of-freedom (DoFs), but the use of the roll-pitch-roll wrist configuration yields singularities inside the reachable workspace. Excessive joint velocities will occur and result in a poor path tracking response when encountering the wrist singularities. Arm-type robots currently do not have enough dexterity to move the end-effector path away from the wrist singularities. Robots with redundant DoFs can be used to provide additional dexterity required to avoid the singularities and reduce the excessive joint velocities. An end-effector wrist module is proposed to provide two redundant DoFs when interfaced with an existing 6-DoF robot. The new 8-DoF robot has a compact roll-pitch-yaw wrist that has no singularities inside the reachable workspace. Hence excessive joint velocities can be avoided. The highly redundant robot can also be used to avoid collisions in various directions. Three path tracking examples with experiments are provided to show the advantages of the proposed design when compared with existing redundant or non-redundant robots. We expect that this module can serve as a cost-effective solution in applications where singularity-free motion or collision-free motion is required
Subjects
Inverse Kinematics
Kinematically Redundant Robot
Roll-pitch-yaw
Wrist Module
Wrist Singularity
Cost Effectiveness
Degrees Of Freedom (mechanics)
Machine Design
Redundant Manipulators
Collision-free
Cost-effective Solutions
Joint Velocity
Multiple Degrees Of Freedom
Pitch-roll Wrists
Reachable Workspace
Redundant Robot
Singularity-free
End Effectors
Publisher
Elsevier Ltd
Type
journal article