Move to webcam based range finding & Banana PI

A project log for Autonomous Pi bot

Autonomous Pi Bot

rlsutton1rlsutton1 01/07/2015 at 22:310 Comments

See the picture of the bot with the 2 stripped down web cams on the front.

I've moved to using a pair of Logitech c-270 web cams for range finding. I printed a custom mount to hold both webcams and a laser line. I stripped the webcams out of their cases as the cases made them difficult to mount. One cam faces 25 degrees left and the other 25 degrees right, giving a field of view of 100 degrees and both are tilted up so that the bottom of the image is just below horizontal.

I've written my own code in java (see GitHub) to process the images and locate the laser line to calculate the ranges. I make n (30) vertical scans down the image looking for the laser line. Knowing that I am looking specifically for a laser line allows simplification of the problem for example; The line is never vertical, every point located on the line must have a neighboring point.

I've also moved from the Raspberry PI to the Banana PI, allowing the image processing to take place on the robot at 5 frames a second for each web cam and still leave some spare clock cycles for other things. I've created a pull request for the Pi4j project for a small change to work with the I2C bus number that the Banana PI has, otherwise the Banana PI was a drop in replacement for the Raspberry PI.

Work has started on SLAM from scratch, and a graphical mapping UI which runs on a laptop.