Distance sensor question

Hey guys,

I’m currently working on a university project that we are gonna make a shooter that tries to shoot a golf ball to the target basket by trial and errors. The platform is flat except a simple linear obstacle and approximately 1m2. The shooter and the basket is fixed on the two opposite side of the platform for every shooting process. I’m searching a distance sensor that will be constructed on the line of the basket and measures the vertical distance of the passing golf balls’ trajectory to the left side of the platform. We will use this measurement to understand how far the ball has passed from the basket and according to this result, the shooter will try another rational shoot.

Ultrasonic sensors first came to the mind, but I’m worried about their low sample rate that the sensor can skip the ball. The velocity of the ball is considered to be about 2m/s.

Which sensor or sensor type can you suggest for this situation? Any comment will be appreciated.


What kind of range will you need out of the sensor? I think sonar sensors would be a poor choice for this application due to their low sampling rate, and I’m skeptical that Sharp IR rangefinders would fare much better for such a small object (though they’re fairly inexpensive, so you could always try one and see). Can you use a side-mounted camera to film the shot and image-processing software to determine the height of the ball at the location you care about? You might be able to make it really simple (e.g. have the launcher trigger the camera to take a single picture after a fixed delay from the time of the shot, and use the location of the ball in the picture to figure out what correction is required).

- Ben


Sounds like an interesting project.

The cross sectional area of the golf ball will be your challenge and trying to detect it whislt moving is tricky. Measuring
with light will be your best bet. Considered a laser diode measuring system? Golf balls reflect laser light pretty well!

Just an idea to consider- you can get laser diodes which produce dots,lines and cross hairs too now. You can get a few and line them up
in vertical or horizontal line of your platform. Then mount another laser on a RC servo. Depending on how high/far
the golf ball reaches,one of the fixed lasers will pick it up and give you an indication.
Obviously to make this work, you will need to pair up every laser with a receptive photo diode.

Your program can then instruct that servo to move up and down accordingly in order to refine the iterative adjustments required for your
shooting mechanisms. At lasers are visible (or not if IR).

To make this idea work, buy the materials and program the device would be far simpler than using a camera system. Really depends on
how much time you have more than anything. Good luck with it.