How did you control your robot?
What did you see that you liked?
670 used a negative feed back loop for its rear wheel diff system this year. This was controlled by a wheel and stick method. The stick to regulate power to the front wheel drive system, and the wheel to have semi-real time steering feedback.
Next year we are going to use the same control unit but the robot will be 6 wheel tank and the steering will be all software controlled. In the past we have used the “tank” method of driving but we found that it always drifted after a while. Team 254 solved that problem, they used the stick and wheel method only now when the wheel turns software sends exact opposite values to each side of the robot, this removes the problem of “human error” in driving.
Tell me how you did your steering or control unit.
We just use two sticks and drive it like a tank because it is built like a tank. I am strongly opposed to a one stick drive for anything that is built like a tank. It would be more suited to an omnidirectional robot.
As far as a steering wheel goes, when I first saw 22 and 254 using a wheel to drive their tank-like machines, I thought they had gone out of their minds. But then I watched how effective 254 was in game play easily maneuvering around obstacles even while driving in reverse.
Then at the JPL open house this past weekend, we got to do a few very high speed runs (in reverse too) with ours and we found that it is not all that easy easy to keep it straight and maneuver around obstacles while going at that kind of speed (14fps) by controlling it with two joysticks.
So now I’m beginning to think a wheel might be worthwhile to try. It seems like it would allow for very smooth arced driving lines if desired.
The key to it’s success though is getting feedback from the shaft encoders on the robot.
We currently use the wheel stick method. I like it a lot and with a gyro to keep it driving straight it works fine. It gives you a lot of control. In the past we have used both one and two stick configurations. Out of those two, I would have to go with the two sticks for a tank drive.
in a perfect world i would have asked for 2 sticks.
However we used one and it seems to be fine.
Also we were thinking of steered wheels but me and the other guy building them kinda didn’t get anywhere near finishing them. Anyone else manage?
lol same as everyone that posted before me we have i guess always used 2 joysticks , 2003 we had the robot set up with a steering wheel but that driver liked the 2 joysticks better soo we put the wheel in storage. our operator now that will most likely be driving in 2007 loves the steering wheel sooo i cant wait to get her behind that wheel.
I built a splitter box with a few switches. We had 2 joysticks hooked to the box. The driver could configure it for 2 joystick drive, or 1 joystick drive and even select which stick they wanted to use. I did that in case we had joysticks that weren’t ambidextrous (but we ended up with the 2003 flight sticks, so it didn’t matter.)
That way the driver couldn’t complain they didn’t like the control setup, because they could switch it on the fly during a match.
For the arm operator, (me…) I had a project box with a db-15 cable coming out of it. It had a double momentary ( (on)-off-(on) ) switch for up and down of the arm, and a pot to control the speed. Most of the time I left the speed all the way up, but it was easy enough to turn down for when I needed to be gentle. (not that often just putting the arm away)
I also had other switches on the box for our unfolding hook (that didn’t work and got replaced with a fixed hook) and our latch to keep the arm for back driving, (which really wasn’t needed so it was taken off) and selection of our autonomous mode, (I never got the selection working, so that was never needed either. I just left it on our “good” mode)
The driver drove, and had nothing else to fiddle with, and the arm operator did all the arm stuff, and I would have to say with a good team, we worked fairly well.
Team 647 uses one joystick drive to allow the operator to have complete control of the robot using only two joysticks. The reason for this is because we have never found a team of drivers that can work as well and make decisions on the fly as well as one driver can alone.
We go pretty simple. 2 joysticks to drive with, 1 joystick for the up and down motion of the arm. The operator also has a switch box in order to control the pneumatics for the arm. I am gonna push for the steering wheel next year though, sounds fun !!!
just putting the arm away)