Laser Ranger Finder - Jumpy Reading?

[robheathcock]

Hello

 

I am using 3 x Laser Range Finders in a garage turntable application.  This is to estimate the distance of a vehicle from 3 x walls, if the vehicle is between certain distances the turn table is allowed to moved.

 

The problem I am seeing is that when the table is empty the readings are steady, although they can bounce up to 50cm in a matter of seconds (wall are white textured cement).  However when a vehicle is put on the turn table the readings are all over the show.  They will rapidly change from 1cm to 300cm (distance is approx 300cm from the sensor).  The problem is it changes so quickly it is not reliable (don't want to put a Roller into the wall). 

 

Is this sensor not suitable for painted metallic surfaces? 

 

Does anyone have any experience with this sensor?

 

Thanks in advance

 

Rob