Wern Central

V.C.O.D. Wheelchair (Voice Controlled OmniDirectional Wheelchair)

Published on Sep 15, 2016

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Voice Controlled OmniDirectional Wheelchair, as the name suggests, it is possibly the first wheelchair to be able to move in an infinite amount of directions and controlled using voice commands. It is built with Rero and Lego, along with a mobile phone for transcribing your voice to beeps, which the robot’s brain (Rero Controller) can understand.

V.C.O.D. wheelchair operates on multiple sensors to detect its surroundings. Therefore, it automatically stops when an obstacle is detected. It also has brake lights which will turn on when the wheelchair stops.

Since the robotics set does not have voice recognition functionality, a mobile phone with a custom-made app by me is attached onto the wheelchair. The mobile phone transcribes what you said and plays a series of beeps to the Rero head module, which contains a microphone. The brain (Rero Controller) then analyses the beeps and transcribes it into movements.

This wheelchair’s design makes it have the potential to move in any direction, and any rotation around any point in space, using a 3-wheel omnidirectional drive system. The 3 wheels can rotate, making it possible to act in any driving system, including differential drive system, steering drive system and omnidirectional drive system. Since it is only powered by 6 motors, it is more efficient than using 8 motors for a 4 wheel drive system as it is lighter and consumes less energy.


It is able to move in multiple directions, such as:

  • Go Straight (Moves forward)
  • Reverse (Goes backward)
  • Turn Left (Turns to the left, not directly & not rotating)
  • Move Right (Moves directly right)
  • Rotate Clockwise (Rotates to the right)

You do not need to remember any commands, just tell the wheelchair what to do and it will understand. For example, to move forward, you can say:

  • Please move forward
  • Wheelchair, go straight
  • Go forward
  • Move in a straight line
  • Move in front
  • Go in front, wheelchair
  • Move to the front

To stop the wheelchair from moving, you can either clap, or just say “Stop, wheelchair!”.