elizabethfeden / mechanic-arm

Physical simulation of a mechanic arm and reinforcement learning algorithms for controlling it.

Reinforcement Learning for Controlling a Mechanic Arm

We set the task as follows: given an arm holding a box, manipulate the arm's circle motors to put the box on a table.

The repository contains the implementation of all the subtasks of the problem:

• Physical simulation of the objects
• Physical (more or less) design of the mechanic arm
• Graphical presentation of the learning process, as well as the interactive mode
• Reinforcement learning algorithms (currently only cross-entropy)
• Results that one can achieve with these algorithms

Running on your desktop

Pre-requisites

Python3 and pip3 install -r requirements.txt.

Running simulation

python3 main.py [-i | -r]

Flags enable different modes:

• no flags - default mode: run with a cross-entropy agent
• -r: run with a random agent (uniformly chooses a random action each step)
• -i: interactive mode (controlled by the user).

Interactive mode controls:

• Left / Right arrow keys: rotate big motor
• Space: fix big motor
• A / D: rotate small motor
• F: fix small motor

Utility code

python3 plots.py [filename1] [filename2]

Plots the results saved by the default mode (raw results are in results.txt file by default).

Optional arguments:

• filename1: path to raw results (without .txt suffix). Default: "results".
• filename2: path to save plot to (without .png suffix). Default: "$filename1".

Results overview

We can see that we manage to learn the strategy pretty well. See also the comparison with the random agent:

Further reading

1. The actual process of creating the arm design and the learning algorithms is quite fun. Check out gifs folder to see the recordings of some early attempts. Teaser:

2. [ Russian language :( ] study report and presentation.
3. History of development and news on my other projects are on my Telegram channel: t.me/cowsay.