The growing need now the robot has a voice is to complete its ability to communicate better with humans. To assist in this it was decided that a basic face, was to be constructed and animated via some simple servo motors. The proportions of this basic mask are close to an adult human. The eyes can scan left/right, the head can lift and drop from its rest position and the mouth can open/close. As these are gestures which are needed to supplement, the voice communication. The position data is extracted from the output module, such that for example if an enquiry is required to be expressed, not only does the voice raise in pitch at the end of the sentence, but the platform (head) is raised slightly to reinforce the enquiry.
Further basic communication is possible as the robot can now reinforce a nod, or even shake its head as well as say yes and no. Can reinforce the left and right direction messages, using its eyes, there are no limbs as yet, so it cannot point. It has also been found that instead of trying to concentrate on what the robot was saying the added animation keeps peoples attention focused on the machine, and its messages are getting over better.
The layout of the servos's in the mask assembly, the camera assy and the motion sensors are close to human eye sized modules, these are placed on top of the servo motor mounts. The two chip home brew servo driver receives 1200 baud position data from the output module and moves the combination of elements to that which approximates an expression. These include opening and closing of the emulated mouth area and eye and head positioning data. some extra noise is now generated by these servo movements, so the slew factor of the motors is processed by the driver and minimized, otherwise the amplitude of the voice would have to be raised to overcome the extra noise. Whilst the servos are slewing the speech module receives data at 38000 baud and to date little or no lip sync problems can be detected.
One spin off of this new ability is that some people now try to answer the robot by speaking back, sorry to say there is no input via speech yet. But the fact that they are trying to talk to it, is to me, a sign that it is communicating at a level that Humans find acceptable.