ECE497 Project Beaglebone Blue Robotics

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thumb‎ Embedded Linux Class by Mark A. Yoder


Team members: Alvin Koontz, Samuel Lawrence

Grading Template

I'm using the following template to grade. Each slot is 10 points. 0 = Missing, 5=OK, 10=Wow!

00 Executive Summary
00 Installation Instructions 
00 User Instructions
00 Highlights
00 Theory of Operation
00 Work Breakdown
00 Future Work
00 Conclusions
00 Demo
00 Late
Comments: I'm looking forward to seeing this.

Score:  10/100

(Inline Comment)

Executive Summary

We will be interfacing the newly developed Beagle-bone Blue with an existing Robotics Platform from spark fun. Build an interface for existing libraries for motor control, servo control, and sensors will be developed. Stretch goals include some amount of image processing.

We have the blue working and mounted to the robot frame. We are able to connect to the school WiFi and host a web-server to interface with. We have rewired the robot to be connected to the beagebone blue board. We can read all the sensors on board and interface with the pixy camera.

What we haven't been able to get working is motor control because the motors for the spark fun robot were rated for much lower than what the blue provides so we had to replace those with continuous rotation servos. We have had power issues with the board itself, these are related to the 12 volt jack and the 6 volt regulator, sometimes the jack disconnects or something causing the whole board to shut down, and sometimes the 6 volt regulator fails to work. We have yet to find a solid reason to why these things happen.

In conclusion we had a number of difficulties getting the blue to work, and part of it would definitely be due to how experimental its current state is. After getting everything set up though we found it to be very easy to use.

Packaging

Installation Instructions

Give step by step instructions on how to install your project. TODO: write the install scripts

User Instructions

Once everything is installed, run python server located in the git project, and then connect to the website and the robot should be controllable from the website with web buttons and keyboard keys. TODO: Fill this in and write the instructions

Highlights

The blue is able to read position data of objects from a pixy camera and display the coordinates of the object on a grid in a socket.io based web interface. The coordinate position data also controls the speed and direction of the robot to track a brightly colored object. Integrated a variety of devices and sensors into a web based application on the bone. TODO: test and verify remote operation with a battery and wifi only. make sure connection is still open TODO: youtube video

Theory of Operation

The theory for the project was rather simple, start a web server and have it make function calls based on input from the user of the website. Most of the work for the project was debugging libraries and hardware. The python server program makes calls to the socket.io library for communicating with the client computer and the robotics cape library for controlling hardware
Routine for image tracking:
1. The object to be tracked is programmed into the pixy camera using the built in detection button on the camera(TODO: add reference to instructions for this)
2. There is a python script that interfaces with the libpixyusb library to communicate with the pixy camera over a USB interface.
3. The python script uses the object position to proportionally control 2 continuous rotation servos(via the robotics cape library).
4. The object position is written to a JSON file every 50 frames (roughly one second)
5. The webpage has a 127x127 gird. The webpage polls the JSON file every second through the socket.io interface and colors the appropriate grid representing the position.

Work Breakdown

List the major tasks in your project and who did what.

Also list here what doesn't work yet and when you think it will be finished and who is finishing it.

  • Alvin's Tasks
  1. Build web interface
  2. Update Wiki page
  3. Interfaced connectors
  4. integrate IR sensors, bump sensors, and gpio with the bone.
  5. integrate servos
  6. TODO: integrate IR sensors with the web interface.
  7. TODO: create instructions and install files for the web server
  8. TODO: make the server webpage look prettier
  • Sam's Tasks
  1. Find and order connectors
  2. Install pixycam libraries on the blue and use position data to control servos.
  3. send and visualize object position data on the web interface
  4. Mount the blue to the robot
  5. retrofit continuous rotation servos onto the wheels we were given with help from Gary and Jack
  6. integrate servos
  7. TODO: create instructions and scripts for setting up the pixy cam
  8. TODO: setup a socket.io function call from the webpage to start the pixycamera script automatically.
  9. TODO: make the server webpage look prettier (it's ugly and jumbled at the moment)
  • incomplete tasks
  1. The motor drivers were not used because our motors operate on 5v rather than the supplied 12v. We decided that retrofitting continuous rotation servos was a better idea.

Future Work

  1. PID control for the object follow script (currently only proportional control is implemented) would make the robots movement less erratic.
  2. Add a screenshot button and object recognition button to the web interface so that new objects could be programmed in remotely without being forced to use the hardware button on the pixy.
  3. implement a web programming interface like blockly to make the Blue accessible to younger students.

Conclusions

The beaglebone blue has some very good hardware built into it, one of the flaws with this project was that we just used what was really available to us for interfacing with it. It would have been a lot more fun to pick out parts and build a platform for it to fully utilize all its functions. The board still being in an experimental state resulted in some interesting hardware issues but was nothing that couldn't be worked around.



thumb‎ Embedded Linux Class by Mark A. Yoder