Fast Stop and Jerky need help

[Michael Fadaie]

This is our groups rookie year and currently I am the only programmer. I have programmed all of the tele code including the compressor and kicker. So, far all I have in auto is that it moves forward one second back one second and then it will kick and retract. Along, with the compressor working.

Currently, I have two problems and there is no way that my current labView skills will be able to solve them. Well, at least not in the time we have left.

If you press the joystick foward and then let up on it suddenly. The robot will stop very fast. So, is there a VI that will control acceleration. This would make the motors come to a slow stop.

Next, if you push the joystick a little it seems like the robot just takes off. Is there a way to make it so when you move the joystick just a little it only moves a tiny bit? There is no middle or beginning. There is only fast, faster, and fastest.

If you have any questions, feel free to ask. Any help would be great. Thanks.

[Greg McKaskle]

For the first issue, this may best be solved by looking at the motor controllers and seeing if the jumper is set for Coast or Brake. I believe the Jaguars in particular ship set for Brake, and you likely want to move it to Coast for your drive motors.

For the second issue, since the numbers go between -1 and 1, try adding some math in between the joystick code and the drive code. If you never need to top speed, you can simply divide by a number. If you want to affect small numbers more, you can square and reapply the sign, or you can even cube the number or put it to any power you like.

You may also find it useful to build a small program to plot joystick versus motor to check the various math options and help visualize what they do.

Greg McKaskle

[GLaDOS]

We had this same exact problem. This was because we had it round up the nearest whole number. Allowing the program to use decimals solved the problem for us.

[Michael Fadaie]

Thanks for the reply Greg McKaskle. I just got in and changed the jaguar to coast. I haven't gotten a chance to try it out yet though.

Also, GLaDOS what do you mean that you had to rounding to whole numbers and how did you change that?

[Michael Fadaie]

Nvm I got the robot to work. Thanks for the help.

[Alan Anderson]

For the benefit of others reading this thread who might have similar problems, it would be helpful if you described what was wrong and what you did to make it work the way you wanted it to.