Abstract
Fast-moving industrial robots exert large varying reaction forces and moments on their base frame, inducing vibrations, wear and accuracy degeneration. These shaking forces and moments can be eliminated by a specific design of the mass distribution of the robot links, resulting in a dynamically balanced mechanism. Obtaining the conditions for dynamic balance proves to be a hurdle even for simple planar parallel mechanisms due to the required inclusion and inspection of the kinematic relations. In this paper, a screw theory based methodology is presented, which gives and solves the necessary instantaneous dynamic balance conditions for planar and spatial mechanisms in an uniform and geometrical manner. Instantaneous dynamic balance yields a pose in which robot accelerations induce no shaking forces and moments. This is interpreted as an intersection point of multiple reactionless paths. This method is applied to a 2-DOF planar mechanism, named the Fuga I, for which it resulted in two perpendicularly intersecting reactionless paths, intersecting in the middle of the workspace. Experiments on this demonstrator validated the instantaneous dynamic balance by showing a reduction of approximately 95% of the peak-to-peak shaking forces and moments over the intersecting reactionless paths.
| Original language | English |
|---|---|
| Pages (from-to) | 267-282 |
| Number of pages | 16 |
| Journal | Mechanism and machine theory |
| Volume | 141 |
| Early online date | 14 Aug 2019 |
| DOIs | |
| Publication status | Published - 1 Nov 2019 |
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Keywords
- Dynamic balance
- Experimental validation
- Five-bar mechanism
- Parallel manipulator
- Reactionless path
- Screw theory
- Spatial mechanisms
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A screw based methodology for instantaneous dynamic balance. / de Jong, J.J.; van Dijk, J.; Herder, J.L.
In: Mechanism and machine theory, Vol. 141, 01.11.2019, p. 267-282.Research output: Contribution to journal › Article › Academic › peer-review
TY - JOUR
T1 - A screw based methodology for instantaneous dynamic balance
AU - de Jong, J.J.
AU - van Dijk, J.
AU - Herder, J.L.
PY - 2019/11/1
Y1 - 2019/11/1
N2 - Fast-moving industrial robots exert large varying reaction forces and moments on their base frame, inducing vibrations, wear and accuracy degeneration. These shaking forces and moments can be eliminated by a specific design of the mass distribution of the robot links, resulting in a dynamically balanced mechanism. Obtaining the conditions for dynamic balance proves to be a hurdle even for simple planar parallel mechanisms due to the required inclusion and inspection of the kinematic relations. In this paper, a screw theory based methodology is presented, which gives and solves the necessary instantaneous dynamic balance conditions for planar and spatial mechanisms in an uniform and geometrical manner. Instantaneous dynamic balance yields a pose in which robot accelerations induce no shaking forces and moments. This is interpreted as an intersection point of multiple reactionless paths. This method is applied to a 2-DOF planar mechanism, named the Fuga I, for which it resulted in two perpendicularly intersecting reactionless paths, intersecting in the middle of the workspace. Experiments on this demonstrator validated the instantaneous dynamic balance by showing a reduction of approximately 95% of the peak-to-peak shaking forces and moments over the intersecting reactionless paths.
AB - Fast-moving industrial robots exert large varying reaction forces and moments on their base frame, inducing vibrations, wear and accuracy degeneration. These shaking forces and moments can be eliminated by a specific design of the mass distribution of the robot links, resulting in a dynamically balanced mechanism. Obtaining the conditions for dynamic balance proves to be a hurdle even for simple planar parallel mechanisms due to the required inclusion and inspection of the kinematic relations. In this paper, a screw theory based methodology is presented, which gives and solves the necessary instantaneous dynamic balance conditions for planar and spatial mechanisms in an uniform and geometrical manner. Instantaneous dynamic balance yields a pose in which robot accelerations induce no shaking forces and moments. This is interpreted as an intersection point of multiple reactionless paths. This method is applied to a 2-DOF planar mechanism, named the Fuga I, for which it resulted in two perpendicularly intersecting reactionless paths, intersecting in the middle of the workspace. Experiments on this demonstrator validated the instantaneous dynamic balance by showing a reduction of approximately 95% of the peak-to-peak shaking forces and moments over the intersecting reactionless paths.
KW - Dynamic balance
KW - Experimental validation
KW - Five-bar mechanism
KW - Parallel manipulator
KW - Reactionless path
KW - Screw theory
KW - Spatial mechanisms
UR - http://www.scopus.com/inward/record.url?scp=85070538110&partnerID=8YFLogxK
U2 - 10.1016/j.mechmachtheory.2019.07.014
DO - 10.1016/j.mechmachtheory.2019.07.014
M3 - Article
AN - SCOPUS:85070538110
VL - 141
SP - 267
EP - 282
JO - Mechanism and machine theory
JF - Mechanism and machine theory
SN - 0094-114X
ER -