We’ve added the first bit of autonomy to our Cellbots by having the Truckbot stop before going off a ledge. We did this by building upon the Wheelchairbot’s ability to sense distance with an ultrasonic range finder. Then it just took a bit of tweaking to the Arduino code to use this reading whenever the servos are moving.
The latest version of the code supports two range sensors, where one is intended to move forward and another looking down at the ground. These are both optional but should help prevent your robot from collisions and dangerous tumbles. It is especially handy if your streaming video and controlling the robot with some high latency.
We’ve tested with this Maxbotix and Parallax ultrasonic sensors, and we’ve also ordered some infrared proximity sensors and very small reflectance sensors. Our goal is to have the robot not bump into things or fall off ledges and we’ll likely need somewhere between four and six total sensors to do that. We want to keep the price down so we’re trying different options on our Cellbots and will share the results with you here.