Ultrasonic rangers for obstacle avoidance

[pogenwurst]

For our team's hybrid mode, I've been thinking of using data from four ultrasonic rangers, one on each side of the robot, in conjuction with known distances accross the field, to detect obstacles.

I have to questions about this:

- First of all, is this a valid concept? I can explain in more detail, if necessary.
- Secondly, what beam width should we look for for optimal performance? Maxbotix's LV-EZx (which seem to have worked well for several teams) sensors come in configurations of 4 different beam widths -- from my research, it would seem that the LV-EZ4, with the longest beam width, would be most effective, but I would like to be sure before we buy any.