General Dynamic Climbing Notes

Interesting Points

• Is the gecko changing anything while it is climbing/stumbling dynamically?
  • TBD
• The roach definetely seems to change its gait while climbing dynamically and stumbling
  • Evidence in Dan Goldman's 04/08/05 telecon slides (% = same video group as below)
• The "deadpoint" rock climbing technique seems applicable to dynamic robot climbing
• Try to have posterior feet re-use good footholds from anterior holds
  • The roach does not seem to do this (6 legs) (%)
  • The gecko does seem to do this (4 legs) (%)
• Look for way to use SLR (Support Leg Rotation) ideas with 6 legs
  • Simultaneously ensure good pre-load and detachment
  • Link to Hirose '94 paper here - "Walking and Running of the Quadruped Wall-Climbing Robot"
• For localization (knowing where you are): On inclined and vertical surfaces, dont forget to account for path deviation due to gravity and system backlash & compliance
  • Link to Akinfiev '02 paper here - "The Influence of Gravity on Trajectory Planning for Climbing Robots with Non-Rigid Legs"

RAW NOTES - To be formatted and reorganized later

Dynamic climbing notes - 04/06/05
===================================

Videos
--------------
Gecko on graphite - dynamic climbing & non-dynamic failure, uses same footholds
-hemifastrun20xdivx.avi (A)
-hemifailure20xdivx.avi (A)
Roach stumbling while climbing
-slipsidedivx.avi (B)
Roach climbing -longitudinal leg placement (viewed from side)
-similar for front-mid legs, rear is different
-zz3new20xdivx.avi (B)
Roach climbing -lateral leg placement (viewed from back)
-different for all 3 ipsilateral legs
-blab10divx.avi (B)

(A) = \\chewie\RiSE\Presentations\Aug04\Full\

(B) = \\chewie\RiSE\Telecon\Telecon05-04-08\


Terminology
-----------
Campus: Dynamic climbing move executed using the arms only, orignated by Wolfang Gullich.
Deadpoint: A dynamic climbing technique in which a hold is grabbed at the very apex of upward motion, thereby placing the smallest possible load on the hold.
Dyno: Short for "dynamic," a gymnastic upward leap for a distant hold.
-http://climb.mountainzone.com/glossary_a_l.html

Dynamic Climbing - Jumping or lunging movements
-http://www.geocities.com/Yosemite/Trails/1187/defin.html


Archive of Rock Climbing: Moves and Tips
-http://climbing.tropic.org.uk/climb.html
-Using arms as pivots for dynos
--http://climbing.tropic.org.uk/page17.html

Ideas
--------
Need to have some knowledge of hold/terrain/something ahead
-sensory feedback
Want to try to reuse good holds
-Roach does not seem to do this
--ips front&mid are close to same vertical pos (From 04/08/05 D. Goldman ppt slide#9)
--but all 3 ips legs touch diff lateral pos (From 04/08/05 D. Goldman ppt slide#8)
Try to time gait with climb speed to reuse holds
Can push off rear legs to dynamically propel body and front legs to new foothold
May be able to use stance manuevers to turn dynamically
-create manuevering momentum during stance
-use effects of manuever momentum in flight
-touch down at desired time for certain manuever results
How do animal climbers use sensory info (gecko, roach, etc?)
-related to Seans research on roach
What are prototypical metrics for manuevers

RiSE Dynamic Climbing
-----------------------
Limitations on leg cycling time
-what are these (b/c of differential system, wing and beta limitations are not decoupled)
-Assume no stride freq limitations (may see strange behaviour due to differential & tracking though)
--see email response from Al Rizzi (04/08/05)
Limitations on range of motion
-lower leg and foot design can limit the amount of foothold overlap
--both because of interference with other legs and reach
-need to determine the usable leg motion
--relating to how much of the motion is usable to vertical progression
Both of these limitations can determine the what the minimal dynamic climbing speed is defined as
-body speed(motion) over one stride should match the cycle time for a leg
-BS >= LCS (BS=body speed, LCS=leg cycle speed)
-BS >= ULCS (ULCS=usable leg cycle speed, or part for vertical progress)
-We are currently at BS << ULCS
-Need to get to BS >= ULCS to even begin discussing 'dynamic climbing'
How do we use sensors to help here?
-body speed measurement
-foot placement knowledge/record
-likely foothold mapping

Manuevering Metrics
---------------------
Try to look at certain forces again to determine what makes a 'good' dynamic climbing gait
Try to establish metric for forward progress
-percentage to ULCS that is translated to vertical motion
-simalar to what may be in the Akinfiev02 paper (zig-zag motions)
Try to establish metric for manuevering
-percentage of manuevering effort for effectve manuevering
--ie. Is reversing leg directions causing unneccessary internal forces/moments?
--ie. Is reversing leg directions, wasteful for good manuevering, ie. similar to backtracking?
-may be simalar to what may be in the Akinfiev03 paper (zig-zag motions)
How do we use sensors to help here?
-current measurement
-internal stress measurements
-accel data
-IMU/inclinometer data
-GPS/localization info?