Voice-command wheelchair developed at Coimbra University

A wheelchair robot developed by scientists at Coimbra University already has a prototype “capable of navigating without colliding with obstacles by commanded human voice”, as professor Urbano Nunes states, the person with joint responsibility, with professor Gabriel Pires, for the team of professors and students of the Electro-technical Engineering Department responsible for the project.

For the last five years this project has been developed and integrated in degree classes and post-graduate courses of this department of the oldest Portuguese university, the “gradual objective” research project was created to facilitate the lives of the dependent elderly and those with major motor skills deficiencies.

Various practical demonstrations have already been done with the wheelchair for interested parties and the media, but at present the project is undergoing some modifications.

Although only a prototype at the development stage and with improvements in the very near future, the Robchair can actually already be sold – of great use for people who have difficulty with their movement: simple voice commands, like “forward”, “backwards”, “to the right” and “to the left” can give great autonomy to the elderly, the infra-red sensors allow mobility without accidents, with no collisions with obstacles, narrow passages or doors.

But the prototype, which uses a common wheelchair moved by electricity, is not only going to be limited by voice commands: the idea is to expand its autonomy giving it the power of decision based on its environment through a controller that uses fuzzy-logic. Communicating with “intelligent” buildings like hospitals, therapy units or centres for the elderly, the chair can get around according to pre-established programme of routes

“We are redoing the control architecture (electronic and communications), to be able to test more developed capabilities: better symbiosis with human beings, greater capacity of autonomous navigation from A to B in indoor environments (from one room to another, for example). We also intend to incorporate autonomous/semi-autonomous navigation capacity in outdoor environments”, Urbano Nunes outlines.

In a scientific article recently published in an international robotic magazine by Gabriel Pires and Urbano Nunes, the last results obtained by the research scientists are described with regard to the “Reactive Shared-Control” system. It is this that makes the semi-autonomous navigation of the wheelchair possible in unknown and dynamic environments.

The objective of the above-mentioned reactive system is to give assistance to wheelchair users, making navigation easier and safer. Little used in traditional information systems, fuzzy logic is however widely used in information networks where speed of decision is fundamental. One of the best-known examples is the system that runs the Tokyo underground. In the case of Robchair, the fuzzy logic helps the taking of decisions based on behaviour and environment.

According to the article, three types of behaviour were implemented: avoiding obstacles intelligently, detection of collision and the capacity of going round or around obstacles.

In this way, the user of the chair and the actual vehicle share movement commands, facilitating the progression of taking some of the weight of responsibility for making decisions each time.