LIDAR alternative idea
 

I just thought of this a few days ago, so bear with me.

I was thinking of having the students build a SONAR system of sorts for autonomous navigation. Using a servo spinning around, with two ultrasonic sensors, (one at a greater angle, for short range, and another at a more shallow angle for long range.), create a "map" of directions that are clear for the robot to drive. (If we have time) I was also thinking of linking this to vision, (w/ OpenCV), to identify the colour of the flat areas (i.e floor) to make better decisions about where to drive.

Do you guys this would be effective/useful?

Re: LIDAR alternative idea
 

If you do use ultrasonic sensors, be sure to use high quality sensors. We've always had trouble with reliability and accuracy.

Depending on what range you do want, you also need to keep in mind the sound is comparatively slow to radiation. The sensor platform itself will have a much smaller maximum rate of rotation. If your sensors are less sensitive to direction, then you also will have to worry about interference issues when using two ultrasonic sensors, even if they are angled differently.