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10/11/07
Teleconference with Vytas
Needs:
-
Order of importance from the slides looks good
- Weight of the robot is important, but not at the top of the list
-
Shoot for 200lbs of force and see if we can generate 250-300lbs in order to meet
that goal
If we are designing to break with a 200lb force, the robot will lift off of the ground
- Look into using percussive motion so that the robot won’t lift off of the
ground when breaking soil
-
Vytas wants us to dig 5-10inches deep.
Keep shovel head small in order to increase force applied
Specs:
Depth:
Max weight of rover vs. force to ground:
- Stiff actuation – push ground with high force… robot will come off of ground
- Percussive force will allow a larger force to be applied
Springs:
-
Okay to use, but his office does not design specifically for moon conditions, so he
was not sure how springs would be affected.
Don’t need to build specifically for the moon though, so we can use common springs
Springs near the joints might make it hard to control
If springs are used in a joint system, then maybe have a way to lock the spring
motion out.
Optimal angle to break certain soils:
- Some soils break better with different types of force
- Work with the soil around Moscow so tests can be done locally. Don’t need to
design to work with every kind of soil
- Research terrestrial soil tests
- Make a table for what types of digging works in different types of soil
- Something that works well in Idaho, might not work well in California
Determining force from power draw:
- Using power draw to find force required does not work very well with designs
involving gears and gear ratios
- If gear ratios are low this could work, but if high power consumption won’t
work well
- Having multiple force-torque type sensing systems will help determine accuracy of
readings
Core Focus:
- Develop mechanism that breaks soil
- Don’t focus on doing a lot of soil tests and researching types, but some
research is important
- Vytas likes the idea of getting rid of the linear actuator and using a percussive motion
system
- Maybe incorporate a swinging arm and percussive device
- Focus more on the percussive end effecter, and if time permits look into
swinging arm
- Have a way to lock percussive end… maybe a brake on the end
Tools/End effecters:
- Focus on making only two different end effecters, but do them well
- Don’t use a super pointed tip as it will break easily
- Make a tip with a lower angle and it might dull, but it won’t break
- Chisel is a good idea to have for multiple uses. Can use corner as a point force and
long edge for digging
- Maybe a point tip with a chisel around it