Transmissions: General Info

Hi:
An idea was being passed around amongst the software members of our team about using a pneumatic transmission to improve precise maneuvers. What are your experiences with transmissions? Is it worth looking into?

Any advice is greatly appreciated!

I’ve never worked with pneumatic shifters before, but we always code in a “precision” mode for driving. Basically, as long as the driver is holding a particular button on the joystick, the motors run at 10% of normal speed. This allows for smaller, more precise movements of the robot, for carefully lining up shots or mechanisms.

This is certainly a less-expensive (and lighter) solution than a pneumatic shifter transmission if all you want is more precise driving.

That’s another idea we had, but we usually come pretty close to running out of buttons on the gamepad we use…Thanks for your input!

That seems excessive. Maybe this is because I prefer to take control out of the drivers hands whenever possible. Could you go over what buttons you used this year?

I agree, that’s pretty excessive, but the software team uses the buttons to test specific parts of the code.

I don’t have access to the code right now, so I don’t know the specific button numbers/letters…
We’ve got

  • Shooter Motor ON button

  • Shooter Motor OFF button

  • Hopper Loader button

  • Loading extension Toggle button(commonly known as the “Tongue”)

  • Stutter Left (This allows the angle of the robot to be changed precisely) [Trigger]

  • Stutter right (Same as above) [Trigger]

  • Driving on the sticks

  • A diagnostic Winch motor winding mechanism (For the climber)

  • Everyone prefers not to use the buttons under the actual sticks themselves because they’re hard to press without moving the robot

  • We (Software Team) prefers not to use the digital D-Pad because it can also be used to dive the robot, if the controller is in the wrong mode…

  • In addition to the gamepad, we have a custom control box that controls the majority of our climbing operations.

Ah. Typically what we do is use those buttons during build season, then take them out for competition. The only buttons on the gamepad are buttons we use during competition. We do have some ‘test’ buttons we need to keep on, but we put those as the hard to reach ones under the joysticks.

Interesting…We keep ours in, so if something goes wrong at a competition, we can easily test it with the code in the robot without re-downloading.

every time we decide to have a two speed transmission we have used pneumatics. for example last year it was a great help as we could drive around very quick collecting and shooting but when balancing came we could shift to low speed and make very small adjustments without rolling of the bridge either. our lead engineer has developed a very good transmission that we used. the pneumatic shifter works very well as just a click of a button will change gears. it has worked wonders for us.
here is a post to the white pages on the gearbox:

http://www.chiefdelphi.com/media/papers/1715

Couldn’t those be consolidated into one button that toggles?

Also, do you only have one person who controls the whole robot?

Toggling buttons are often a very poor way to control something. If you don’t have an immediately obvious indication of which state it’s in, you might turn it off when you want to turn it on, or vice versa.

For several years, the TechnoKats “gear shift” control was a foot pedal that toggled between high and low gears. The drivers eventually decided that it would be better to use separate “go high” and “go low” buttons on a joystick.

That’s a good point. Though couldn’t you build an indicator light into the driver’s station or control software?

I just build things, closest I ever got to the electronics and programming was building an electrical board :stuck_out_tongue: So I admit, I’m a little out of my element here.

The drivers’ attention isn’t on the operator console, but an indicator light on the robot itself could work.

There’s a light strip in the TechnoKats’ shooter that indicates when the wheels are spinning and when they’re up to speed. Our team programmers also put in some fancy software this year to flash the underglow LEDs for status feedback. So far, however, the LEDs haven’t been installed.

We don’t intend to make any drive changes to this year’s robot, but we saw a lot of 2 speed transmissions at the Chesapeake Regional and got curious.

To respond to CENTURION’s question, we have two people controlling the robot. One person uses the gamepad controller, and the other person uses the custom control box to control climbing operations.

Thanks for sharing the transmission, who716!