Automatic Leveling for the Oliver Trailer — DIY style!

[Snackchaser]

As far as I can tell, I’ve made the first automatic leveling system for the Oliver’s Barker stabilizing jacks!  Maybe even the first 3-jack leveling system on a travel trailer!  It’s simple to operate, safe, and works great!

I built the leveling system as a novelty for my own entertainment, so I’m only posting it as a interest item not a recommended project.  In reality, manually leveling with the electric jacks is already easy, particularly with a LevelMate, so automatic leveling isn’t really needed.  There are even warnings that the jacks are stabilizers, not to be used for leveling.  However, I believe the warnings are more about liability than capability, as long as the jacks are used within reasonable limits.

I'd been thinking about an auto-leveling project for a long time, but was deterred by the thought of modifying the jacks with fiddly proximity sensors or revolution counters as used in conventional leveling systems. I didn't want to alter the jacks for a DIY project that might not even work.

But then it dawned on me.  The only time I really needed to know the position of the jacks, is when retracting them to their parked position.  I wasn’t interested in returning the tongue jack to the truck hitch hight like some systems offer.  So this led to a revelation that automatic leveling could be done with nothing more than current sensors mounted in a control box rather than on the jacks themselves. This was only possible because of the Barker jack’s mechanical clutch.  When the jack reaches the end of its travel, the clutch activates with a distinct clack-clack sound. It was likely that clutch engagement would produce a unique current signature that could be used to detect when the jack is fully retracted.

A plan was developing, but I needed actual amperage values for proof of concept. Fortunately I had a data logging ammeter, and the chart below illustrates the results for one of rear jacks starting from its fully retracted parked position. The jack was extended through free air until it touched ground and began picking up load, maxing out when the wheel lifted off the ground. Then it was retracted to the parked position until the clutch actuated:

I didn’t include the tongue jack chart because it's far less dynamic — it's always under load, and the clutch doesn't normally actuate during leveling.  The clutch only comes into play after trailer is hooked up to the TV and the tongue is manually retracted.

The amperage results confirmed that current sensors could work, and beyond detecting the parked position, they could also be used to distinguish the different leveling phases: rear jack extension until firm ground contact for stabilizing, and then transition to "roll" leveling if needed.  Completion of the rear jack phase could then trigger the tongue jack phase to handle "pitch" leveling.

The amperage chart became the basis for the circuit and software design. No proximity sensors. No revolution counting. No permanent modifications — just two wires to each jack, a component box, and a control board.  Sounds easy, but this was only just the start of a long process to perfect the system.

I hope someone finds this interesting!   Cheers!  Geoff