Pneumatics not working properly. Help rookies, please!

[ashweeeeeeeeeen]

We just got our pneumatics for our claw working yesterday, and they seem to work fine, except that the cylinders randomly open and close very quickly. We are using Vex Pro single acting solenoids on a 3 output base mount.

One of our members thinks that this happens because the solenoids lose power briefly.

Do you have any ideas?

Help us pls. :ahh:

[Foster]

For us to help you, you need to help us:

How are the pneumatics wired?

What make you think they are powering off/on

What is the robot code written in?

Can we see the code?

Can we see pictures of the wiring and the claw?

How is the claw activated? (Button, joystick, etc.)

Are there sensors that control the claw open / close states.

Do you have an onboard compressor?

Is it keeping the pressure up to 60 PSI?

....

Anything you can tell us past you are a rookie team and in a panic helps. :)

[ashweeeeeeeeeen]

We think that its powering off then on because in the unpowered state the pneumatics keep the claw opened, and the claws open then close without us giving it the command.

The robot code is written in Java and we are using eclipse.

I do not have access to the code.

The claw is activated with Attack 3 joystick buttons.

We do not have sensors or an onboard compressor, and the pressure is maintained at 60 PSI.

Photos are attached.

[Foster]

The Java code would really be helpful.

Can you do a flow of what happens (like this

Robot powered off, tanks full, claw is opened

Robot powered on, claw open

Robot gets enabled, claw closes

Using the joystick, claw will open and close

If claw is closed when we disable the robot the claw does not move

(This is all made up, but we are looking for details we can't see, so you need to report back as much detail as you can)

What is your team number and where are you, there may be a team close that can help.

[rich2202]

Check to make sure the voltage of the solenoids matches the PCM. If you have 24 volt solenoids, and the PCM is set for 12 volts, you could get random, or no, action.

[Foster]

I'm done for the night, see what answers you can get. you have about 28 hours to go.

[ashweeeeeeeeeen]

We have a video of the failure happening: http://youtu.be/LFC2dyT4D04

We also have a video of the solenoid status lights turning off when the failure occurs. We will be posting this shortly.

[ashweeeeeeeeeen]

Here is the other video: http://youtu.be/2kFg81dtRwg

[snoman]

did the compressor kick on before or after the arms opened?

[Gregor]

Are you using a battery in need of a charge? When the battery gets low the Roborio shuts everything off (which returns single solenoids to their default state) to protect a radio reboot.

[GeeTwo]

I can't see enough detail in the videos to see your wiring or even the lights that are going out.
[LIST]
Are the solenoid status lights you referring to the ones on the PCB, or something on the solenoid itself?
Are these single solenoid valves (with a spring return) or doubles (which will only switch based on positive electrical signal)?
If they are singles, the most likely case is a loss of voltage causing a PCB brown out. This happens when your motor is running, so this makes sense. Have you been tracking the voltage? I see that in 12V mode, the PCB just passes battery voltage to the solenoids; in 24V it is regulated. I didn't find the brownout voltage for the PCB itself.
If it's not some sort of brownout, it may be a loose connection anywhere from the PDP to the solenoid actuator somewhere. It may also be a software issue, though this seems unlikely. If you can't find any electrical issue, I would suggest creating a smart dashboard widget to monitor the programmed state of each solenoid valve.

[Foster]

It looks like a battery charge problem. Is the battery fully charged? What does the dashboard voltage show.

It looks like the elevator part is moving up and down when it happens. Does the power th hit happen only when you are moving the elevator?

[Foster]

I'll get burned, but "BUMP* to get this in the top. You guys have the day to work, what are you finding out?

OB "Why do you care?" Its scary to be in a high school physics classroom with no idea what to do. Or so I've heard :rolleyes:

The last 48 hours are the worst in most rookie teams lives. Second is when they roll this robot onto a field in 11 days....

[mshafer1]

Just looking at the video, I'm not sure if it's a battery or program issue, could you post your code?

[Foster]

One last bump since it is after school on the left coast....