Wheel+Problems

For question #1: See here: [] and here: []

For question #2: Consider what the causes could be for your robot not going straight. 1) mismatched power level settings for B& C motors 2) encoder problems - match the motors by putting an axle through two motors and set the power at 50% for 10 rot and see that they end up in the same place (or not) 3) Check that the wheels are on correctly and are true 4) Do you have some problem with the front caster?

With kids, don't tell them the answer to the problem. Always ask them "Why do you think you are having this problem? What could be the cause?" Then they end up thinking you know all, even when you don't.

-Nathan

On Wed, Jul 28, 2010 at 2:20 PM, Smart Kids  wrote: > HI, > I'm teaching robotics for the first time. I'm using the TaskBot and explaining the move bloc and the relation between wheels and distance. Our exercise is a maze the robot move from the start point without any sensors and have to go to the finish point through some obstacles the problem: > 1/ it doesn't turn the 90 degrees needed > 2/ it doesn't go straight (on the same line) > my students ask why ? > > Any answers ?

I've been struggling lately with trying to explain to kids (4th and

5th graders) and to their parents about the sometimes "random"

behaviors of mobile robots (this is for an FLL program). For example,

if we seemingly start the robot and program in what appears to be the

exact same position two different times, the robot's ending location

always ends up at least an inch or two off. The kids want to know

"what changed" and I'm struggling to explain it to them in terms

they'd understand. I know that a ton of things can cause the

discrepancy, and I've often tried to explain to them that the robot

doesn't start from the exact same mark everytime, the "free" wheel

isn't in the same orientation, etc..., but I'm not convinced that is

the best answer.

Not being as familiar with robotics as I like, I'm sure there is a

term for this behavior and I'd really like to know it. Does anyone

have a successful method or exercise that they've used to reinforce

this "randomness" concept?

Thanks!

Have you seen this video?

 @http://www.youtube.com/watch?v=OlAO9Ho-N58