Overview

            
The project robot
            consists of a three platform octagonal shaped platform, driven
            by modified servo motors similar to those used in model airplanes.
            A omnidirectional caster ball on the back forms the third point
            of contact with the ground and allows the robot to rotate effortlessly
            in any direction. This type of arrangement is called a differential
            drive and is the most common type today in home robotics. I chose
            this style because my goal of providing the home robotics community
            with vision on a type they are most accustomed to using.
          
        
      


      
The three decks

      
Each deck performs
      a specific function. The lower most deck has the wheel drive
      motors on the bottom, and the battery pack on the top. The batteries
      are NiMH type rechargeables, and connects with a simple charging
      circuit to the front of the robot for vision guided docking experiments.
      The middle deck houses my custom made robot board, one of three
      produced in the previous SweepBot project. This contains a PIC16F876A
      processor, and two 12F629 sub processors to drive the servos.
      This board takes up the entire deck and is very capable in interfacing
      with the vision experimental apparatus. This level also contains
      a new addition that I have not used before, a speech synthesizer
      so that the robot can talk and describe what it is seeing as
      it navigates. The top deck is the blank platform which will contain
      the visual experiment in progress. Here I will mount home brew
      digital robot "eyes", and some small machine vision
      cameras which interface with the deck below. The top deck will
      also have a back illuminated LCD display for non verbal data
      and voltage readings.

      
Why speech?

      
A key component
      in this robot is a Devantech text to speech synthesizer. The
      robot will be performing most of the time in a large arena, attempting
      to do tasks or mazes using vision only. Rather than hover over
      the robot (creating shadows to boot) to read a tiny LCD display
      on its back, Ive decided it will be easiest - and of course very
      cool - to have the robot simply talk to us, and tell us whats
      going on internally. An example of this might be the recognition
      of a shape or target, or perhaps to relay a light intensity real
      time.

      
Additional sensors

      
Because this robot
      is to perform primarily using vision guidance, I am keeping the
      other usual sensors to a minimum. I also plan to add to the front
      of this robot a Sony IR distance sensor to alleviate the need
      for stereoscopic vision on target acquisition, and for bland
      object detection. Two music wire front whiskers complete the
      frontal sensing to keep the robot out of trouble during vision
      algorithm development. I haven't decided yet on what charging
      plate arrangement Ill be using at this time for docking experiments.


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