Upload
natalie-gardner
View
213
Download
0
Embed Size (px)
Citation preview
Minibot Deployment Analysis
20 Jan 2011, Siri
How Do We Get There?Alignment Routes
Direct
Hit Wall
Swing Around
Routes also apply to same-side tower
Overshoot
Route ComparisonRoute Length Ease In Lane? Orientation
Hit Wall(also skim inside)
2 4? Yes Close Fit Long
Overshoot 3 3? Possible Either
Direct 4 3? No Either
Swing Around 1 1 Yes Either
Point: We’re not going to get this right on the fly.Auto-alignmentDriver feedback
Skills
• Speed• Crab• Snake• Running into things
Difficulties
• Little Time• Poor Visual• Possible Overshooting• Unknown Start Position/Config
Features
• Doesn’t require LoS• Let’s us run into things
• Fast orientation to correct side (e.g. locks on correct side in spin)
• Robust• Easy to Implement
CasesDirect Approach
+ Ease of implementation+ Robust- Requires some pre-alignment- Hard to lock on in a spin
Indirect Approach
+ Very little driver alignment+ Fast+ Locks on in a spin- Harder to implement-Less Robust?Going to happen.
Need to Redirect force
vector
Indirect CaseNeeds/Desires/Wishes
Inside• Shall have opening =30” [N], >35” [D], >45” [W]• Shall slope (linear or non-) inward [D]• Shall shape to base as much as necessary for deployment accuracy [N]• Shall not interfere with deploying or racing Minibot [N]
Outside• Shall direct funnel opening around tower [D]• Shall NOT misdirect robot along outside within last 5” [N], 10” [D], entire length [W]• Shall not interfere with deploying or racing Minibot [N]• Shall not exceed robot frame width when stowed (27”) [N]
Concept – Curved U(Hybot 7-work1)
Self-guides around base
(Robot won’t be able to strafe in this position back up) Aligns without hitting guides
Concept – Curved U Stored(Hypot 7-work)
Tower
Concept – Inverted Funnel
Best Case for auto alignment
Current Issue: SpaceApprox 50” wideFolded form stretches min 21”
Minibot Deployment
Features• FAST!!• Never Misses• Fast!• Low weight & volume• Fast!
Thoughts• Fast pneumatics• Consistent guides
Less-Known Rules• Minibot can never exceed 12” cube• Hostbot can enter base plane at any time
Deployment ActuationState Zero (Stored)Aligned: NoOn Post: NoReleased: No
State Final (Deployed)Aligned: YesOn Post: Yes
Released: Yes
Interim States
Aligning StateAligned: Progress
On Post: NoReleased: No
Our Specs require Aligning before Deploying.Aligning requires moving Release must be false.
Deploying StateAligned: Yes
On Post: ProgressReleased: ??
Hostbot doesn’t move in Deployment Release can be simultaneous
Conclusion: 3 properties (2 conditions each), at least 2 must occur separately 2 or 3 actuations
Deploying vs ReleasingThese can happen simultaneously, but doing it with a single driven
actuator requires some thought…
Example:
Minibot
Box Latch is in front of Minibot in z-axis
Minibot
Pneumatic cylinder opens latch, kicks down wall/guiderails, and pushes out Minibot
Next Steps
• Test funnel shapes/bending• Finalize U hinge & supports• Prototype Minibots– Define deployment specs– If rails: how to “lock” on Post – If not: come up with something