Sorting out the Barrels

We've done a ton more work on the machine vision, Dan-ED now able to distinguish between specific colours.

That got us thinking about the Eco-Disaster challenge.  We previously thought it would be too difficult to automate and were just going to drive Dan-ED around using the remote control.

Ben had already developed a clever 'pick up' contraption, made entirely out of lego, that could be used to gather up the barrels.  We previously practised driving Dan-ED around to collect the various 3D printed barrels around the arena.

Ben's original 'barrel' pickup.  It doesn't actually pickup the barrels, instead the two wheels guide the barrel between the jaws, which is then used to 'push' the barrel around the arena.

The video shows some of the difficulties we had developing reliable machine vision.  The biggest one is change in the ambient light.  If light levels drop, captured images can suffer from significant 'motion blur', making it difficult to pick out an object.  We solved the problem by setting a fixed 'fast' shutter speed.  Unfortunately doing so meant the overall captured image could be very dark.  We solved this problem by adding a 'selfie light' to provide additional illumination!

Here you can see Dan-ED using machine vision to pick out only the 'green' barrels.  It is able to move reliably between the green barrels whilst avoiding the red barrels.  You'll notice some 'stuttering' where Dan-ED seems to go slow when it crosses the white lines on the arena floor.  It turned out the 'line follower' code was still active and trying to react to the lines on the floor!