bobbyluig/dexter

Robotic arm project for 6.A01 Fall 2016.

Dexter

This is my project for MIT's 6.A01 Fall 2016.

Dexter is a 4-DOF robotic arm capable of performing a variety of drawing-related tasks. At the time of writing, Dexter can fetch the weather, draw images from the Internet, and chat with you! The entire system can be operated using voice control using any modern browser supporting the Web Speech API.

The back end is written in Python 3 and uses asyncio along with the WAMP protocol to communicate with the front end. Notable features include real-time inverse kinematics, asynchronous communcation, automated path optimization, and accurate servo synchronization.

Arm

This is Dexter. All parts can be made using laser-cut acrylic and a 3D printer. The CAD package is located in docs/cad.7z. It must be opened using Autodesk Inventor 2017 or higher.

Running

It's relatively easy to begin using Dexter. Follow the steps below to get started.

1. (optional) Generate new server certificates and change passwords for all devices.
2. Start Crossbar from inside of src/crossbar. This can be on any device that allows incoming SSL connection on port 443.
3. Navigate to the the IP of the device running Crossbar. Use HTTPS and skip any security notifications you may receive.
4. Edit the IP in src/config/main.py to match that of the machine running Crossbar.
5. Run automaton.py ensuring that src is in PYTHONPATH.

Commands

The robot responds to the following voice commands. Commands are listed in order of priority.

Command	Function
dexter	Wake up the robot. No other commands will work until the robot is woken.
(dexter) calibrate	Set the current z position as the z-depth parameter.
(dexter) get position	Get the current (x, y, z) position.
(dexter) home	Go to the home position.
(dexter) info	Provide info on configuration parameters.
(dexter) introduce (yourself)	Gives a brief introduction.
(dexter) ready	Asks the robot if all modules have initialized.
(dexter) sleep	Put the robot to sleep. No commands will work until the robot is woken again.
(dexter) stop	Stop the current drawing.
(dexter) draw the weather	Draw today's weather using data from Open Weather Map.
(dexter) draw the weather in :value :units	Draw the forecast using data from Open Weather Map. :value can be any float. :units can be one of minute(s), hour(s), day(s), or week(s).
(dexter) draw index :i *q	Similar to draw, but allows an offset index. :i can be any integer. *q can be any text.
(dexter) draw *q	Queries Pixabay for a desired SVG. *q can be any text.
(dexter) trace index :i *q	Similar to trace, but allows an offset index. :i can be any integer. *q can be any text.
(dexter) trace *q	Queries Pixabay for a desired image. Use Potrace to convert to SVG. *q can be any text.
(dexter) stocks :name :value :units	Queries Yahoo Finance for historical stock data. :name can be any text. :value can be any float. :units can be one of day(s) or week(s).
(dexter) move :direction :float	Move the arm a certain amount in a particular direction. :direction can be one of up, down, left, right, forward, or backward. :float can be any float.
(dexter) move (to) :x, :y, :z, :phi	Move to a constraint in space. :x, :y, :z, :phi can be any float.
(dexter) move (to) :x, :y, :z	Move to a coordinate in space. :x, :y, :z can be any float.
(dexter) load point :name	Load a previously saved position. :name can be any text.
(dexter) save point as :name	Save the arm's current position under an alias. :name can be any text.
(dexter) set :parameter :float	Set a configuration parameter. :parameter can be one of lift, speed, offset, or depth. :float can be any float.
(dexter) *input	All other inputs will query Cleverbot for a response. :input can be any text.

Requirements

The following software are required to run this project.

• Python 3.5 or higher
• Python packages: numpy, scipy, matplotlib, pillow (PIL), autobahn, requests, cleverbot, pyowm, yahoo-finance
• Crossbar.io (or equivalent router supporting WAMP 2)
• A browser that supports the Web Speech API (Chrome 33+ or Firefox 49+)

References

This project's SVG parser uses some modified implementations from the following packages.

• svg.path
• svgpathtools
• svg
• Flatten.js