Question about ultrasonic sensors and velocity sensors...

[Rob L]

Hey guys, I am working on my senior design project and I need to incorporate
sensors that will detect dynamic objects like cars, walls, etc... within a
reasonable range from a device (so we were thinking about using sonar
sensor(s) for this)... we also need to somehow track the position of the
device (possibly using a compass module and a velocity sensor because we
kinda want to stay away from GPS)...

Any suggestions for particular modules would be much appreciated. Please
email me at [email protected].


I was looking at Devantech's Ultrasonic Ranger SRF08
(http://www.robot-electronics.co.uk/shop/Ultrasonic_Ranger_SRF082001.htm).
This module only has a maximum range of 3 meters though.

I was also looking at Polaroid's Environmental Grade Sonar Ranging Package
(http://www.acroname.com/robotics/parts/R135-SONAR4.html). Supposedly this
module is capable of doing up to 35 feet but I wasn't able to find a range
rating for the transducer itself. This transducer seems to have a somewhat
spread range too which looked nice (our project has to kinda be able to
detect objects over the frontal 180 degrees of the device).


I only started looking briefly but I wasn't able to find any velocity
sensors that track the velocity of the device. Anyone have any ideas?


Thanks in advance,


Rob L
[email protected]

 

[Cameron Dorrough]

Hey guys, I am working on my senior design project and I need to incorporate
sensors that will detect dynamic objects like cars, walls, etc... within a
reasonable range from a device (so we were thinking about using sonar
sensor(s) for this)... we also need to somehow track the position of the
device (possibly using a compass module and a velocity sensor because we
kinda want to stay away from GPS)...

Have a look at Sick's LMS (Laser Measurement System) range of laser distance
scanners at www.sick.de . From what I can tell, these devices will do
exactly what you want.

In their simplest form, they give a 4-20mA continuous output of the distance
to an object over the scanning range. You then use your software to
calculate the relative velocities of the incoming objects based on the
analog distance at each scan angle.

These devices are not cheap, but they are extremely robust and reliable in
all kinds of conditions.

Good luck with your project!

Cameron