sensor for leveling trailer

HI I am new and looking for a sensor to level a trailer? do I use a attitude or gyro sensor for an input or is there a degree sensor that I could use, does any one have a suggestion.

thanks Mike

What output would you like to have? Serial or Analog?

I think they make some pretty nice sensors with SPI interface.

Looky here:
https://www.sparkfun.com/pages/accel_gyro_guide

I have made cheap, reliable devices that serve the purpose. If it doesn't have to be overly accurate and you can use discrete inputs, try this:

You need:

Four pieces of 1/2" x 6" schedule 80 PVC pipe
Two pieces of 1/2" x 1" schedule 80 PVC pipe
Two schedule 80 PVC Tees
Six Schedule 80 PVC caps
Six barrel-style prox switches that will detect the ball bearings -


1. Bore holes through the center of each cap to accept the prox switches
2. Mount four prox switches so they protrude into the inside of the PVC caps
3. Using a PVC Tee, join the two 6" pieces of pipe. make sure the pieces of pipe are cut square and inserted fully into the socket. Try to keep the bore as smooth as possible.
4. Close the ends of the pipes with the caps you prepared in step 2
5. Glue the 1" long pieces into the side run of the tee
6. Drop ball bearing into the tee and make sure it can roll from end to end
7. With the ball bearing in the tee, measure from the top of the ball bearing to the top of the short pipe
8. Set up the remaining two prox switches so there is a couple mm clearance between the end of the switch and the ball bearing
9. Glue the caps in place

Once completed, mount the two assemblies perpendicular to each other on your trailer when it's in the LEVEL position. The top prox switches should detect the ball bearing, which should be in the middle of the tee. I have dimpled the bottom of the tee with a suitable drill bit to keep the ball bearing in position. I have also filled the entire assembly with mineral oil to dampen the ball movement - just be sure to seal the prox switch openings appropriately.

For levelling, tie all six switches to a PLC. Four PLC outputs control electric jacks at each corner of the trailer. If the switch that detects the ball on the right side of the trailer is made, extend both jack on the right until the center prox switch detects the ball. If the switch that detects the front of the trailer being low is made, move extend both forward jacks until the center prox switch is made.

Sketch attached.

I love DIY solutions, but wouldn't a simple 3 axis sensor be much simpler and cheaper?

I recently did a machine where we have to level an underwater structure using a BEI T-series inclinometer.

http://www.beisensors.com/news/BEI-...t-Measurement_Harsh-Outdoor-Applications.html

Four hundred bucks and none of the satisfaction of a MacGyver sensor, but we needed the accuracy.

There are plenty of inclinometers on the market that take advantage of the low cost of MEMS type sensors. Thank Apple and the iPhone !

More options:

http://www.meas-spec.com/position-s...s/single-axis-tilt-sensors-inclinometers.aspx

Hello,
if you don't need an accurate level, try this:
http://pdb.turck.de/uk/DE/group/000000120003482300020023

Thank Apple and the iPhone !

Click to expand...

Thats funny, when I first read this thread, I thought "Heck I can do that with an app I have on my I phone" and it only cost $1....

Of course you would have to stand on the trailer and look at the display.

depending on the money and the needed machine, you can use from a joystick upside down, via a leveler (10 euro), a MEMS, a laser system
i have a system accurate 0.01 mm/m working with laser and PSD.
when hydraulic you will need more safeties and 4 leg control.
use always 2 cilinders same time.