skyeg3
Posts: 24
Joined: Tue Jul 16, 2019 3:42 am

Advice on Quad-Steer Robot Development

Fri Mar 20, 2020 4:18 am

Hi all. I've had this idea for a while. I want to mount 4 hub motor skateboard wheels to a platform. Each will be mounted so they can spin 360 degrees. I then want to use a joystick's XY movements to control the movement of the platform in the XY plane. Also the twisting or rudder joystick movement should rotate the platform in the vertical (Z) axis. Eventually I'd like to mount a chair to the platform. Seemless transition from direction and twisting motions should be seemless. Also smarts will need to be built into the software so the steering wont do anything crazy when moving at speed. I'd like to simulate the movements in some kind of development environment. Does anyone know of a good environment to use for this? All advice appreciated. Thanks in advance.

Here is a video I made showing steering:
https://www.youtube.com/watch?v=8IEpuVRnK8o

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Gavinmc42
Posts: 4508
Joined: Wed Aug 28, 2013 3:31 am

Re: Advice on Quad-Steer Robot Development

Fri Mar 20, 2020 7:46 am

Use three rotocaster wheels.
Mecanum wheels is another option too.

Four wheels, unless you have suspension and flat surface, can slip.
Simulation can only do so much, the real world is messy.
Once you start playing with the real stuff it is easier to understand it.

You can start with a smaller version to test code.
I'm dancing on Rainbows.
Raspberries are not Apples or Oranges

skyeg3
Posts: 24
Joined: Tue Jul 16, 2019 3:42 am

Re: Advice on Quad-Steer Robot Development

Fri Mar 20, 2020 9:46 pm

Interesting. So if I was interested in pursuing the version I have above. (Using the hub motors) What software would I use to write the code that receives the joystick information and runs the controllers? What language would be used to code this?

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Gavinmc42
Posts: 4508
Joined: Wed Aug 28, 2013 3:31 am

Re: Advice on Quad-Steer Robot Development

Sat Mar 21, 2020 1:13 am

What language would be used to code this?
Python is a good place to start.
Any computer language should work, human input is slow.
You are only working in a 2D vector space.
Simple trig maths would be fine?
To make things smooth then acceleration control becomes important.

Using a game library gives you joystick inputs.
https://www.pygame.org/wiki/Joystick_analyzer
https://pyglet.readthedocs.io/en/latest ... input.html

You could use these to make your own simulation on a display.
I'm dancing on Rainbows.
Raspberries are not Apples or Oranges

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