title: Obstacle avoidance using 2 fixed cameras on a robot
body: <p>I will be start working on a robotics project which involves a mobile robot that has mounted 2 cameras (1.3 MP) fixed at a distance of 0.5m in between.I also have a few ultrasonic sensors, but they have only a 10 metter range and my enviroment is rather large (as an example, take a large warehouse with many pillars, boxes, walls .etc) .My main task is to identify obstacles and also find a roughly "best" route that the robot must take in order to navigate in a "rough" enviroment (the ground floor is not smooth at all). All the image processing is not made on the robot, but on a computer with NVIDIA GT425 2Gb Ram.   </p>
  
  <p>My questions are :</p>
  
  <ol>
  <li><p>Should I mount the cameras on a rotative suport, so that they take pictures on a wider angle?</p></li>
  <li><p>It is posible creating a reasonable 3D reconstruction based on only 2 views at such a small distance in between? If so, to what degree I can use this for obstacle avoidance and a best route construction?</p></li>
  <li><p>If a roughly accurate 3D representation of the enviroment can be made, how can it be used as creating a map of the enviroment? (Consider the following example: the robot must sweep an fairly large area and it would be energy efficient if it would not go through the same place (or course) twice;however when a 3D reconstruction is made from one direction, how can it tell if it has already been there if it comes from the opposite direction  )</p></li>
  </ol>
  
  <p>I have found this <a href="http://mkoval.org/downloads/projects/igvc/igvc_design.pdf" rel="nofollow">response</a> on a similar question , but  I am still concerned with the accuracy of 3D reconstruction (for example a couple of boxes situated at 100m considering the small resolution and distance between the cameras).</p>
  
  <p>I am just starting gathering information for this project, so if you haved worked on something similar please give me some guidelines (and some links:D) on how should I approach this specific task. </p>
  
  <p>Thanks in advance,
  Tamash</p>