RoboBobLet #6 The Scanning Laser Rangefinder

RE: RoboBobLet #6 The Scanning Laser Rangefinder

balearicdynamics — Wed, 11 Apr 2018 00:12:57 GMT

I am curious to see live acanning data somewhere... and the wheels shoukd be exoeexpe to see them moving?

Enrico

RE: RoboBobLet #6 The Scanning Laser Rangefinder

mcb1 — Wed, 11 Apr 2018 00:08:16 GMT

Interesting results.

I was also keen to see how narrow it was, which is why I found the spec sheet in your last blog.

In theory you might be able to restrict the FOV by shielding it in a tube. If it can't illuminae the traget then it can't see a return.

BUT it may also cause noise and false readings which it seems you can ignore in the API

[View:/resized-image/__size/668x126/__key/commentfiles/f7d226abd59f475c9d224a79e3f0ec07-aa92a016-5fa1-46d3-8b71-1200461a17fd/contentimage_5F00_187070.png:668:126]

There is a small spike at the beginning of the scan. I'm not entirely sure what this is but it is always there so it might be some part of the RoboBobLet chassis that is being detected.

You have indicated that you're using the USB to power the device, along with the servo and the Laser.

Have you considered it may be power supply related?

We continually see issues when motors are driven without adding a decent sized capacitor across the supply to the motor.

I ran into weird results with a Ping sensor and Neopixels doing this.

Ultrasonic Reversing Monitor Part2

I didn't have the capacitor across the supply to the neopixels ... and they aren't inductive.

My range finders have arrived, the weather is cold, wet and generally horrible so it might be a good day to spend inside trying them out.

Mark

RE: RoboBobLet #6 The Scanning Laser Rangefinder

DAB — Tue, 10 Apr 2018 19:11:10 GMT

Nice post.

You results with the laser sensor is about what I would expect.

You can do multiple samples at each angle to reduce the noise in each position. A four sample average cuts your noise by 75%.

Also remember, the structure of the target also has an effect as some of the laser energy gets scattered off the various features of the target.

DAB

RE: RoboBobLet #6 The Scanning Laser Rangefinder

genebren — Tue, 10 Apr 2018 18:58:32 GMT

Very nice update to your robotics project. Interesting data that you have acquired. Is it possible that the small glitch at the beginning/ending of your sensor sweep is you? From the camera angle in your video, it seems to occur near to where your position might be. Also, the servo seemed to be not exactly centered and maybe the front wheel of the robot comes in view of the sensor at the extreme end of the movement.

Keep up the good work!

Gene