Hardware - Overhead Controller

This page contains information about the overhead controller (OHC) for the Kilobot collective robotics platform.

The overhead controller (OHC) is used to send coded infrared messages to the Kilobots.

There are two types of OHC boards:

1. the board provided by K-Team (the commercial distributors of the Kilobots).

2. custom Sheffield Robotics OHC boards (which allow for a wider range coverage)

Both of these boards are controlled by the KiloGUI (its usage is described in this tutorial: Getting_Started:_How_to_work_with_kilobots).

K-Team's OHC

Main characteristics:

• Coverage area: (approx) circle 1 meter diameter
• Cost: about $600

Controlling multiple K-Team OHC boards from a unique PC might be complicated.

More information is available at: https://www.k-team.com/kilobot-extensions

Sheffield Robotics OHC

Motivated by the K-Team's OHC limitations, Sheffield Robotics designed a custom OHC board which is open-source, low-cost, and can cover an area up to 6 square meters (approx).

This OHC consists of two parts: The Control Board and the Infrared (IR) LED Boards (up to 6).

Sheffield Robotics Control Board

Sheffield Robotics Infrared (IR) LED Boards.

Control Board

The control board is responsible for sending the IR messages to the LED boards. This is achieved by switching the MOSFETs on and off to provide the LED boards with 12V (from the external power supply) and to create the square wave that holds the message.

IR LED boards

With the ARK controller, we can control up to 6 IR LED boards. This allows us to cover large areas (approximately 3m²). To solve the problem with the interferences we added in our structure 4 more IR LED boards that send constant infrared light. These boards cover a big part of the receiver's threshold (on the Kilobot) and now weak signals can also be detected. We can even send commands to the Kilobots in the absence of any visible light source.

All the details about Sheffield Robotics OHC boards, design files, and specifications are available in this technical report:

Characterisation and upgrade of the communication between overhead controllers and Kilobots (Figshare, 2017) by E. Nikolaidis, C. Sabo, J. A. R. Marshal and A. Reina.