Boe-Bot tank kit drawbacks
langezwieper
Posts: 5
I currently ordered a Boe-Bot and the additional tank conversion kit. I havent build a bot before but do have some Arduino experience. I'm asking myself if the following issues can be overcome with the tank conversion kit or are not that serious at all:
- are there any (accurate) solutions for keeping track of travelled distance (compass, accelero,..) just like the rotary encounter kit for the normal Boe-Bot? Navigating rotation is possible with the compass but distance will remain a problem.
- will it drain the batteries noticeable faster when turning in place? Since it has a large contact surface
Like I said, I don't have any experience with robots but I already have a good understanding of what it should do when finished building (for example it should be able to navigate into a imaginary square box).
- are there any (accurate) solutions for keeping track of travelled distance (compass, accelero,..) just like the rotary encounter kit for the normal Boe-Bot? Navigating rotation is possible with the compass but distance will remain a problem.
- will it drain the batteries noticeable faster when turning in place? Since it has a large contact surface
Like I said, I don't have any experience with robots but I already have a good understanding of what it should do when finished building (for example it should be able to navigate into a imaginary square box).
Comments
The tracks add friction and that will take additional energy to drive over what the wheels take. Whether you'll notice any faster battery drain is another question entirely.
The tracks allow your BoeBot to move on surfaces where the wheels won't work. That's the compensation for the additional energy needed to drive them.
LINK: http://www.parallax.com/StoreSearchResults/tabid/768/txtSearch/battery/List/0/SortField/4/ProductID/782/Default.aspx
With slippage you mean slippage from the tank tracks onto the plastic 'gears/wheels' that hold them? Being able to navigate with great accuracy really is a wish. So propably I'll be better of with the tires (since the terrain is not very special and they are not suffering from slippage?).
If the battery life becomes a problem I will look into the power pack charger or I go for a lipo solution since I already have a balancer and charger for my rc heli.
Sorry for my English and the questions
Encoders are useful for wheeled or for tracked bases if the motors aren't turning at the same speed. So use them either way. But don't count on encoders to help you if you want to turn a tracked base. It's not possible with wheel/motor encoders alone to know with any degree of accuracy how much the treads are slipping in order to determine the amount of turn. That's how tracked bases turn -- by slipping the treads over the surface.
You need to navigate using other means. If you're using the robot in a line follow or maze course, you can use the line or perimeter to keep track of space. Otherwise, you'd need to employ things like compasses and other sensors to monitor the robot's placement. As Mike suggests, you use treads when their physical properties provide an advantage over wheels. Otherwise, wheels are cheaper and provide for more consistent results.
-- Gordon
Same with me. I have a good understanding that my robot should be able to conquer the world when I'm finished building, but I may need some help with the code.
Start with simple wheels to learn the basics. Treads on small robots are more of a novelty. In many cases, treads cause more problems than they solve. They will def drain your batteries twice as fast and make any kind of consistent turn attempts much harder and very surface dependant. And treads break, jam and fall off.
Ready when you are! http://www.youtube.com/watch?v=fuXMh1_-6Ag
Thanks in advance,
Mark
I used the same caster on another robot, you can see pics at: http://find.botmag.com/091206
Any small caster should work. This one looks nice, but TTYTT it is very picky. It has 2 seperate outer free-spinning wheels. If its mounting spindle isn't perfectly vertical, the caster will favor one direction and may mis-steer your robot. I would actually prefer a single center wheel caster for better control.
Mr. Erco: (silence)
20 minutes later
Mrs. Erco: Oh, there it is on the cart! Wonder how I could have missed it. Never mind!!
Mrs. Erco: Oh, look, the cart is moving all by itself. Somehow it's moving in a triangular route. Practically riding an invisible light beam between the three piles of BASIC Stamps, relays, and plywood scraps.
Mr. Erco: (silence)
I'm never one to leave well enough alone.
Appropriate all four and you eliminate several problems: No rocking, no listing and it won't roll around during a quake! Of course there may be some "internal" issues I've overlooked. ;-)
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