HighPrecisionStepperJuggler

HighPrecisionStepperJuggler

a.k.a Octo-Bouncer. Highly precise stepper motor driving with a Teensy 4.0 and custom pulse generating algorithm and PC based image processing with the goal of getting a machine to juggle a ping pong ball.

Here's a blog post with more infos about this project. And here's a YouTube video of the machine in action.

The Arduino folder contains the code for the Teensy 4.0. The Teensy 4.0's job is simple:

• Listen for movement comments on the serial bus
• Generate pulses for the stepper motors

The Unity folder contains the code for the Unity Application. This Application is responsible for:

• Set up the camera (120 FPS 640×480 data stream, gain, exposure, contrast, ISO, saturation) via OpenCV
• Set up Camera Device and getting image stream via OpenCV
• Run Image Processing and get 2D pixel position of ping pong ball
• Get 3D position of ping pong ball using the results of above-mentioned image processing
• Calculate ball velocity
• Use ball position and velocity in PID/Analytical control code to calculate correction-tilt of plate
• Execute Inverse Kinematic code to figure out how much each motor needs to rotate in order to get the plate to a certain height with a specific tilt.
• Send result of IK calculation to the microcontroller via serial interface
• Render machine position and movements
• Render image processing data
• Render graph showing several data streams

The UVCCameraPlugin folder contains the C++ code for the camera plugin. This is a Unity plugin. All the OpenCV code is being executed in here.

Important

You need to download openCV 4.2 and get the opencv_world420.dll from the build folder and put it inside Plugins/UVC Camera Plugin next to UVCCameraPlugin.dll. If you don't do that you'll get below error message on play:

Plugins: Failed to load 'Assets/Plugins/UVC Camera Plugin/UVCCameraPlugin.dll' because one or more of its dependencies could not be loaded.

Also, you need to use Unity Editor version 2019.2.6f1. It won't run with newer versions.