Friday, December 28, 2007

HummBot: basic object avoidance

Here is a new video of the HummBot. As you can see in the video, I unmounted the IR sensors from the servos and moved them to the front and back bumpers of the HummBot. This way they can be used as short distance (25 cm) object detectors.
I have ordered ultrasonic sensors (at Sparkfun.com) for longer range object detection. These will be mounted on the servos to scan a wide area (1-2 meters) in front of the HummBot.

Another thing that needs attention is speed control. First I want to buy/build an encoder to measure the travelled distance. This is highly needed since the ESC is very inaccurate, resulting in unpredictable distances.I am still thinking about the correct mounting place for an encoder. Suggestions are welcome!
Next to that I am considering to replace the motor with a high torque motor which will make it easier to drive at slow speeds. Currently this is very difficult since there is a subtle balance between driving slow and stalling the motor.

3 comments:

EF Mechanic said...

looks pretty good

though your algorithm needs some work...

Mega said...

Thanks. And yes, my algorithm is still very basic, it only lets the hummbot drive back and steers left/right.
Once I mount the US sensors I create/get a fancier algorithm.

Matthias said...

Since you have the IR sensors mounted on servos are you doing any left to right scanning to see if you can get a better idea of how the object obscures the path? It seems like just that kind of adjustment would vastly improve the avoidance algorithm with the need for a sensor upgrade.