Details
| Original language | English |
|---|---|
| Title of host publication | Proceedings of the 18th International Conference on Informatics in Control, Automation and Robotics |
| Editors | Oleg Gusikhin, Henk Nijmeijer, Kurosh Madani |
| Pages | 338-349 |
| Number of pages | 12 |
| Volume | 1 |
| ISBN (electronic) | 9789897585227 |
| Publication status | Published - 2021 |
Abstract
Robot manipulators are often deployed in tool-symmetric tasks, which only requires defining end effector position and pointing direction. In this case six-axis serial industrial robots and full-mobility (spatial) parallel robots have one degree of task redundancy. Using Cardan angles as orientation coordinates, a unified formulation of the position-level and second-order inverse kinematics problem is set up for both robot types. An efficient scheme for difference-quotient approximation of gradients of performance criteria for projection into the task redundancy's nullspace is presented. The simulation example of a hexapod robot shows that avoiding and exiting parallel robot singularities of type II is possible with the nullspace of all joints. The nullspace controller scheme can be used in offline trajectory optimization and in online motion generation.
Keywords
- Cardan angles, Euler angles, Nullspace motion, Parallel robots, Singularity avoidance, Task redundancy
ASJC Scopus subject areas
- Engineering(all)
- Control and Systems Engineering
- Computer Science(all)
- Computer Vision and Pattern Recognition
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Proceedings of the 18th International Conference on Informatics in Control, Automation and Robotics. ed. / Oleg Gusikhin; Henk Nijmeijer; Kurosh Madani. Vol. 1 2021. p. 338-349.
Research output: Chapter in book/report/conference proceeding › Conference contribution › Research › peer review
}
TY - GEN
T1 - Singularity Avoidance of Task-redundant Robots in Pointing Tasks
T2 - On Nullspace Projection and Cardan Angles as Orientation Coordinates
AU - Schappler, Moritz
AU - Ortmaier, Tobias
N1 - Funding Information: The authors acknowledge the support by the Deutsche Forschungsgemeinschaft (DFG) under grant number 341489206. MATLAB Code to reproduce the results is available at GitHub under free license at https:// github.com/SchapplM/robotics-paper_icinco2021.
PY - 2021
Y1 - 2021
N2 - Robot manipulators are often deployed in tool-symmetric tasks, which only requires defining end effector position and pointing direction. In this case six-axis serial industrial robots and full-mobility (spatial) parallel robots have one degree of task redundancy. Using Cardan angles as orientation coordinates, a unified formulation of the position-level and second-order inverse kinematics problem is set up for both robot types. An efficient scheme for difference-quotient approximation of gradients of performance criteria for projection into the task redundancy's nullspace is presented. The simulation example of a hexapod robot shows that avoiding and exiting parallel robot singularities of type II is possible with the nullspace of all joints. The nullspace controller scheme can be used in offline trajectory optimization and in online motion generation.
AB - Robot manipulators are often deployed in tool-symmetric tasks, which only requires defining end effector position and pointing direction. In this case six-axis serial industrial robots and full-mobility (spatial) parallel robots have one degree of task redundancy. Using Cardan angles as orientation coordinates, a unified formulation of the position-level and second-order inverse kinematics problem is set up for both robot types. An efficient scheme for difference-quotient approximation of gradients of performance criteria for projection into the task redundancy's nullspace is presented. The simulation example of a hexapod robot shows that avoiding and exiting parallel robot singularities of type II is possible with the nullspace of all joints. The nullspace controller scheme can be used in offline trajectory optimization and in online motion generation.
KW - Cardan angles
KW - Euler angles
KW - Nullspace motion
KW - Parallel robots
KW - Singularity avoidance
KW - Task redundancy
UR - http://www.scopus.com/inward/record.url?scp=85111743073&partnerID=8YFLogxK
U2 - 10.5220/0010621103380349
DO - 10.5220/0010621103380349
M3 - Conference contribution
SN - 9789897585227
VL - 1
SP - 338
EP - 349
BT - Proceedings of the 18th International Conference on Informatics in Control, Automation and Robotics
A2 - Gusikhin, Oleg
A2 - Nijmeijer, Henk
A2 - Madani, Kurosh
ER -