preliminary test track experiments
DESCRIPTION
Preliminary Test Track Experiments. April 16, 2004 Motohide Hatanaka, Emily Ma Stanford University. Preliminary Test Track Experiments. Goal: Validate simulations and to generate insights to improve on first generation foot design. Focus on three phases of leg trajectory. - PowerPoint PPT PresentationTRANSCRIPT
![Page 1: Preliminary Test Track Experiments](https://reader035.vdocuments.net/reader035/viewer/2022062218/56815ca2550346895dcaaa0e/html5/thumbnails/1.jpg)
1
Preliminary Test Track Experiments
April 16, 2004Motohide Hatanaka, Emily Ma
Stanford University
![Page 2: Preliminary Test Track Experiments](https://reader035.vdocuments.net/reader035/viewer/2022062218/56815ca2550346895dcaaa0e/html5/thumbnails/2.jpg)
2
Preliminary Test Track Experiments
Goal: Validate simulations and to generate insights to improve on first generation foot design. Focus on three phases of leg trajectory.Attachment Generate strong contact between claws and surface.
• Timing of attachment• Impact velocity• Orientation angle (compensate for motion in thru-
stroke?)
Through-stroke Ankle compliance – how much and for which axes?Detachment Detachment with least resistance and without breaking
claws.
• Orientation angle• Timing of detachment
Preliminary tests focused on timing of attachment and detachment.
![Page 3: Preliminary Test Track Experiments](https://reader035.vdocuments.net/reader035/viewer/2022062218/56815ca2550346895dcaaa0e/html5/thumbnails/3.jpg)
3
Test Track Coordinates
force plate
foot
![Page 4: Preliminary Test Track Experiments](https://reader035.vdocuments.net/reader035/viewer/2022062218/56815ca2550346895dcaaa0e/html5/thumbnails/4.jpg)
4
Timing of attach/detachment
![Page 5: Preliminary Test Track Experiments](https://reader035.vdocuments.net/reader035/viewer/2022062218/56815ca2550346895dcaaa0e/html5/thumbnails/5.jpg)
5
Observations[all cases]The robot is always pushing itself away from the wall. (-Z)
[early attachment]high lateral pull in (+X)robot pushes itself down at initial contact (-Y)robot pushes itself away from surface at initial contact (-Z)[late attachment]small lateral pull in (+X)[late detachment]lateral push out at detachment (-X)significant pull down or drag (-Y)large kick off away from surface (-Z)[early attachment, late detachment]largest pull down (drag) at detachment (-Y)
![Page 6: Preliminary Test Track Experiments](https://reader035.vdocuments.net/reader035/viewer/2022062218/56815ca2550346895dcaaa0e/html5/thumbnails/6.jpg)
6
DetachmentEarly Nominal Late
Attach
men
tVe
ry E
arly
Early
Nom
inal
Late
Lateral Force: X-direction (+X = pull in)
High pull-in force (+X) after early attachment
Low pull-in force (+X) after late attachment
Lateral push out (-X) at late detachment
6
optimal
![Page 7: Preliminary Test Track Experiments](https://reader035.vdocuments.net/reader035/viewer/2022062218/56815ca2550346895dcaaa0e/html5/thumbnails/7.jpg)
7
DetachmentEarly Nominal Late
Attach
men
tVe
ry E
arly
Early
Nom
inal
Late
Vertical Force: Y-direction (+Y = pull body up)
Robot pushes itself down (-Y) at early attachment
Significant pull down = drag (-Y) at late detachment
7
optimal
![Page 8: Preliminary Test Track Experiments](https://reader035.vdocuments.net/reader035/viewer/2022062218/56815ca2550346895dcaaa0e/html5/thumbnails/8.jpg)
8
DetachmentEarly Nominal Late
Attach
men
tVe
ry E
arly
Early
Nom
inal
Late
Normal Force: Z-direction (+Z = pull body into wall)
Large kick off away from wall (-Z) at late detachment
Robot pushes itself away from wall (-Z) especially at early attachment
8
optimal
![Page 9: Preliminary Test Track Experiments](https://reader035.vdocuments.net/reader035/viewer/2022062218/56815ca2550346895dcaaa0e/html5/thumbnails/9.jpg)
9
Summary of findingsAssuming we want lateral pull in, vertical self push/pull up, and pull into wall, (i.e. +X,+Y,+Z):
• Early attachment is to be avoided for -Y and -Z but useful for +X.
• Late detachment is to be avoided for all parameters.
![Page 10: Preliminary Test Track Experiments](https://reader035.vdocuments.net/reader035/viewer/2022062218/56815ca2550346895dcaaa0e/html5/thumbnails/10.jpg)
10
Next Steps (1)Further analyses with current
setup• Measure or calculate forces and torques at contact point (current contact point is offset from center of the force plate)
• Study the torques• Find out the reasons for the results
obtained (e.g. by closer observation at slower operation rate)
• Look at work generated in a cycle and quantify performance of each setup
![Page 11: Preliminary Test Track Experiments](https://reader035.vdocuments.net/reader035/viewer/2022062218/56815ca2550346895dcaaa0e/html5/thumbnails/11.jpg)
11
Next Steps (2)Experiment modification
• Modify the trajectory to have +Z values to measure claw attachment strength on wall
• Include amplitude as an additional parameter for optimization
• Use pull-up motor to emulate the five legs that are not there
• Identify control parameters to match ideal force & torque profiles derived from biology.