We have harped about humanoid robots, CNC mills and even photography systems being built out of Lego bricks. However, this time we have a Lego conception that alludes to the more conscientious side of affairs. Modder Yaya Lu has a created a prototype of what can be considered as a full fledged voice controlled wheelchair. And, to give effect to this ambitious project, he utilized Lego Mindstorms NXT components along with other suitable elements like Rotacaster omniwheels and a Dexter Industries NXTBee module.
Quite obviously, the definitive feature of this whole Lego fueled scope is the 'intelligent' voice control mechanism. According to the designer, his mechanism differs from a slew of other comparable voice oriented systems in its ability to recognize (and respond) to particular phrases. These command phrases like 'dit' and 'dah' are indigenous to the wheelchair system, thus effectively making it independent from the constraints and confusions of spoken language. In fact, there are a total of only eight such commands, consisting of three short 'dit' and three long 'dah' sounds.
The working of the mechanism entails the sending and receiving of radio commands between the two NXTBee modules, with one acting as the transmitter and the other one being attached to the wheelchair robot. The NXT computer brick on the wheelchair in turn utilizes a RobotC program that translates these commands into motional patterns. The movements ultimately vary like going forward, moving backward, making turns and even spinning.
Now, before we sign off, it should be duly mentioned that this conception was not designed to bear the load of an actual person. However, given the relative simplicity of circuitry involved, we can surely hope for a 'real' wheelchair with advanced voice controlled attributes in the future.