Thanks for the research Randy. The thought on rotating the steerable wheels to provide higher stopping power had occured to us as well. As the post says, we will be sacrificing directional control if we do this. Still might be useful in a "Panic Stop" sort of condition.

Some things to think about for strategy: With the higher transverse coefficient of friction it is not likely we will be able to push a robot up to the wall and unload balls into it. The carpet around the outside will also make it unlikely to pin a robot against the way in any sort of defensive or offensive way. Will be nice to get an automated, auto-aimed, ball-shooting system in place...

Kevin and I mocked up a simple ball handling system last night. This is what some of us discussed over a week ago. Give it a look and think about it. See the link from my past post to see this type of ball-handler in action. What we have added is a means of storing more balls in a space-efficient manner and for grouping balls. If asked, Kevin can probably describe the way to convert the system to eject balls, too.

Casandra, meant to comment on the addition of the detailed countdown timer to the home page. Nice work!

Students, are you reading the blog? I hope so, because this is the first of 5 clues you'll have to pick up in order to qualify for some goodies on Saturday. Here it is: The square root of 64 is 8. That's it! Just something simple that you can take note of.

Sorry I won't be there tonight. Have fun!

Dean

Ok here is a lot of info I found tonight. I also have a working two color tracking (boxes, but not mapped to servos) on the laptop. Programmers we will want to get it onto the robot and working and try to map that to servos, or at least walk through the process of how we would do that. Lot's to do Monday night. Come ready to try things and work hard on programming.

If you have time, please take a look at some of these threads to get and idea of the process I used while researching the camera issue.

I have a couple of other research items in here I ran across.

Camera Links

multiple cameras
http://www.chiefdelphi.com/forums/showt ... light=axis


tracking
http://www.chiefdelphi.com/forums/showt ... adid=71181

other vision links
http://www.frc.ri.cmu.edu/~axs/doc/auvsi03.pdf
http://www.investigacion.frc.utn.edu.ar ... reo2en.pdf

http://www.chiefdelphi.com/forums/showt ... adid=71890 this one we could post to to give them help, has tip on labview (need to write up the the things that have slowed me down)

traction control
http://www.chiefdelphi.com/forums/showt ... light=axis

camera on pc
http://www.chiefdelphi.com/forums/showt ... hp?t=70741

labview
http://www.lvmastery.com/tipjar2008-12-12 tutorial videos
http://sine.ni.com/manuals/main/p/sn/n23:13 manuals

huricane drive
http://www.chiefdelphi.com/forums/showt ... light=axis

extract from the post above ....

Re: Crab Steering on Regolith

--------------------------------------------------------------------------------

Note that the published values for the wheel's transverse coefficient of friction are almost twice that for the inline coefficients.

In other words, yeah... turning the wheel 90 degrees to your direction of travel will bring you to a stop more quickly than just stopping the wheel.

The downside is that you will be in a skid at that point and will have sacrificed directional control.

Jason


camera pan tilt
http://www.chiefdelphi.com/forums/showt ... light=axis

Hey, check out the ball handling in this video! Simple belts, up and out it goes!

http://www.youtube.com/watch?v=Lcjl8nWDzmo&NR=1

Also, picked up red and blue trailer bumper fabric today. What color do we want, and what color goes to Nampa?

Dean and Kevin

Greetings team(s)!

One of you had asked about round drive belts. I did a little web research and found these:

https://sdp-si.com/eStore/Direct.asp?Exp1=69778&GroupID=168

They are neoprene, and it looks like these are only in black.

The belts seen on some other team robots appear to be urethane belts. Here is a link to urethane belt companies:

http://www.pyramidbelts.com/rbelts.php

And:

http://www.durabelt.com/

Here is a source for all sorts of drive products, including belts and gears:

http://www.wmberg.com/

Cody, you should have a look at the WM Berg site for gears. It looks like they have a number of possible pinion gear options in anodized aluminum that might satisfy our requirements. They have a nice selection tool. For example, see their M48N-1A. We’ll have to see what can be done for price…

I’ll be out for a couple of days. In the meantime, listen to Sherbot! KISS. And check out those sites!



Dean

I was just checking out Chief Delphi again and got this link.

http://www.youtube.com/watch?v=UMXqbfWOj5o

Hmmmm, wide chassis, doesn't look like 4 wheel steering, maneuverable, and moves better and faster than I thought it would.

Maybe we should keep it simple students. Get this bot built and let the programmers do there tricks while we tweak and fine to.

And then again look at this one with steering.

http://uk.youtube.com/watch?v=Dbi4zbcp3wE

Sherwood

Howdy all,

Well all who went with Dean. Did a great job on the trailer.

Programing it's great to see the camera running and that we are able to give a somewhat functioning chassis running.

Progress on the KOP chassis seemed to be going well until we realized a little to excessive man handling bent the rails.

The pictures of the chassis on Chief Delphi looked cool. That is a concept I not sure we discussed. Front steering and differential rear steer. That would definitely give us 4 wheel steering with some simplification.

Ball manipulation and the team has some decisions to make. Will the auger be to slow? Why foam inside the auger? Can we accomplish more with belts?

I hop those who did the "destructive testing" of the balls, found the Chief Delphi link for making and repairing balls. Remember all resources are in need. Let's be careful out there.

There will be an optional Wednesday build night this week. I would really like to see mechanical get a more firm chassis and the ball manipulation be on it's way to some final decisions and actual construction.

Sherbot

Our team was a little split today as part of the programming staff helped in construction of the trailier.

But we accomplished three main things.

First a draft version of instructions for the camera base mount were created while assembling the base. Pictures were taken as well during the assembly proces.

We used the advanced robot template in Labview and added joystick control in USB3 of the camera base (servo control). This required some changes to typedefs and learning how the structure of these VI's worked.

The other thing accomplished is the camera is running with the cRIO, and we can probe the VI and see the images. The vision detection routine is returning an error (generated from the vision assistant). The vision assistant is working on the color detection, but not in the running VI on the robot. Further tests need to be done.

Also the control system was mounted on a running chassis. Some addjustments need to be made to the mechanical side, but the joystick tank drive worked well with what is built so far.

Goals for Monday, get the vision detection working on the colors. Write up the camera mount instructions for use by other teams. Continue sensor testing. Work with electrical to set up one of the sensors fro mteh kit of parts and test it with the cRIO. Perhaps also test ultrasonics from last year.

Lots to do and we are already into week 2.

Something interesting, take a look at these links of another teams bot chassis they have completed already. Notice the location of the electric and computing components.

http://www.chiefdelphi.com/media/photos/32317?
http://www.chiefdelphi.com/media/photos/32318?

I will post some vision links later that look like they could be very useful.

As we know, the computers were down today which really put a damper on some stuff. But the some of the mechanical team and I came up with the equation that can be used to determine our driving radius inner and radius outer using the preset radius of that which we want to turn. For example, to calculate the angle of our inner wheels we use trigonometry. C/R=sinx. C being a constant distance from the center of the robot, R being the radius of the inner or outer wheels, and x being in degrees because I couldn't find theta lol. This equation will be helpful for the programming part of steering. Thanks Dean

The practice trailer has been assembled! A afternoon of hard work paid off. Thanks to Dean for letting us use his shop and helping out a lot. It is the correct specs and all. It shall work wonderfully. Only problem is that we do not have the correct wheels, but that will soon be fixed.

I was not a part of the ball manipulator team today, but from what I have learned they are favoring the idea of a auger. It seems as though it will work.

Lastly, we are quite on schedule with project milestone. The concepts have been "prototyped" for our ball manipulator and the drive train is designed. The trailer has been built and the kit of part chassis has been assembled. We are doing good.

The newest update to the rules effects how wide the opening can be for bringing in the moon rocks. The measurement that the team came up with last night will not work. Please stay on top of the rules.

The team is off to a great start keep it going!

You will need to enjoy math for this one but it is very interesting if you ever wondered why the robot wouldn't turn (first year). Team 308 has a paper titled "Drive Train Basics (How to be sure your robot will turn)"
Team 1189 used this information and put it in a spreadsheet so you can play with the numbers. Download spreadsheet
Have fun and ask for mentor help understanding this