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View Full Version : Is there a way to use LabVIEW to slow down the robot speed?


nickhilgupta
25-01-2013, 20:54
We have to reduce the speed because it is way to fast. So is there a way to slow it down using labview? I tried to multiply the joystick input by .5 but cant try it because we are missing a wire and wont get it for a few days. so can someone tell me if what i did in the picture (we have tank drive) with teleop.vi will work.
http://postimage.org/image/4lghy7lth/
and if it does not work, then can someone tell me what to do to slow it down?
thanks in advance.

tcjinaz
25-01-2013, 21:01
We just discovered SquaredInputs on the motor control VI. Interesting results.
Try it.

Ether
25-01-2013, 21:14
We have to reduce the speed because it is way to fast.

If your robot drivetrain is geared so fast that your drivers cannot control full throttle, then you should seriously consider changing the gear ratio of the drivetrain.

DonRotolo
26-01-2013, 18:04
I agree with ether. The reason he is saying that is because slowing your speed down 50% using software means that your motors are only spinning at half their normal speed, which implies a lot less power than you could be getting. Low power is not really what you're looking for an drivetrain.

bvisness
26-01-2013, 18:36
I agree with all the above posts...but that said, all you would have to do is multiply whatever values you're sending to the motor by 0.5 in order to limit your maximum speed from the code.

Greg McKaskle
26-01-2013, 18:43
To delve a little deeper. If too fast means it accelerates too fast but isn't too fast when the joystick is pegged, then the squared inputs is a good suggestion. If too fast means that the robot's velocity is to large and the robot is uncontrollable, then you really should look at the gearing and the wheel size rather than trying to work around it in SW.

Greg McKaskle

sasha831
27-01-2013, 05:52
What you are doing will work. We have a setup where we map the throttle (axis 3) to a value between 0 and 1, and then we multiply the joystick output by that value. This way, we can set the maximum speed mid game, and adjust it lower for more control, or higher if we need to push a robot out of our way