Ping )))

NsanecomX

I have my ping mounted on a servo on the front of my car to help it choose a clear path and it works fine when it is looking at a wall straight on but when it rotates the ping chirp doesnt return so it thinks that there isnt anything in the way.

i know in the manual it shows that this would happen but im curious if there is a way around it.

does anyone have any suggestions to fix this or a way around it?

any help would be great. thanks

Mike Green

There's no way around this. The PING has to get an echo from the object and, if the object is a flat surface at an oblique angle, it may not get an echo.

You may get better results by adding other types of object sensors like IR. Typically one type of sensor works better for some kinds of objects and the other type of sensor may work better for other kinds of object.

www.seattlerobotics.org/guide/infrared.html

Robert T

I tested the Parallax PING))) sensor for use in the Quadracopter project.

I mounted the Ping))) sensor on a platform over concrete and varied the height of the platform over the concrete as well as the angle of the platform. I found that the results were accurate from 0(sensor platform parallel to concrete) to 30 degrees with heights from 10" to 80".

Mike Green

Robert,
Concrete is a relatively rough surface that may provide a better echo at an incident angle far from 90 degrees while NsanecomX's surface may have less reflectivity at angles other than 90 degrees.

Robert T

Mike

Very true. I built the platform so that different materials(carpet, grass, dirt, stones, etc) could be placed under the sensors for testing. We were looking into using the PING))) for hovering. Concrete is the only surface I have tested so far.

Check out the Quadracopter Topic in the propeller chip thread. I posted some pictures of my setup.

NsanecomX

cool thanks guys. ya i found that if i have the ping sensor scanning back and forth while the car is driving, it will find just about any surface no matter the angle.