Another green laner build

After more software tweaks the suspension ECU is getting a lot closer. As the pneumatic system flows a lot more air than a standard Discovery and therefore moves quicker, it is tricky to get accurate height control. The suspension tended to over shoot then drop a bit of air to recover, overshoot down and so on. I now pulse the solenoids when I get close to slow down the movement. It works well but it's a bit noisy with the solenoids clacking away. I also had to add high-centre detection to stop it fully deflating the air bags if the car is high centred or on a lift. It is a very bad idea to deflate the bags when they are fully extended - they tend to fold up when you re-pressurise them.
The controller still gets a bit upset if the car is fully cross axled. I need to add a timeout so it doen't keep trying.

Next to be added to the code is speed sensing so it drops the ride height at speed. Air bags effectively get harder when you drop the ride height so as well as lowering the centre of gravity it should improve body roll control. I'd also like to add road condition detection. By monitoring how much the wheels are moving up and down it should be possible to work out how rough the surface is. From that and the road speed it should be able to work out an appropriate ride height to suit the conditions. In 4wd it always lifts to full off-road ride height.

Obviously there's not much to show with software tweaking but I have a few pics of articulation testing. Maximum articulation is about 500mm (20").

 

Here is the roll option in action. It's trying to keep the car level. It is quite common for lanes to have severe adverse camber so you end up dragging the side of the car in the hedge. With this option I can actively push the car upright to keep it away from the hedge/rocks.

 

This is the brains of the outfit. It's ridiculously over powered for the job with two computers, one for suspension control and one for the web interface. I'm probably only using around 5% of the suspension control computer's processing power. Microcontrollers are cheap so there is little difference in cost to go for cheaper parts.

 

The controller creates it's own wifi access point which allows me to control the suspension using a tablet. I normally have a tablet in the car for mapping so it seemed like an easy way to add controls without installing physical switches and knobs. This is the main page:

 

Some of the configuration options. By the time I'm finished there will probably be a bunch more:

 
 

That's cool. You lost me at computer controlled but it's still cool!

Well, designing control systems is a part of my job so it made sense to throw electronics at the problem.

My other 4x4 (not road legal) has purely manual control with a push button valve per wheel. It's a lot simpler to implement but can be a pain to use. It's surprisingly difficult to judge you ride height when sat in the vehicle.

Awesome!

I've an MCU coupled to an arduino to attempt something similar.....steep learning curve but much fun!

Other projects and life are getting in the way.

 

It was too warm to work on the Jimny over the summer but I'm finally back on it. When I left it I was just starting to dismantle it for final cleaning, painting and reassembly when I spotted this. I think all of the twisting I did while testing the suspension was the last straw for the body mount under the right hand footwell. Dammit, just as I think I have finished I find more rust!

 

The only way to access it is to cut out the floor and go in from the top. After removing the floor the bolt that goes though the rubber mount just lifted out.

 

Let's get rid of the rusty bits.

 

New mount goes in. I hammered a wooden wedge in between the body and chassis to lift the body back up to where it should be before welding in the mount.

 
 

And cover up the evidence.

 

Now maybe I can get back to the teardown and painting...

Getting there now. The last welding I know about is to add a couple of bumps in the floor to clear the rear shocks. I raised the rear shock mounts to prevent them from bottoming out at full compression.

 
 

With that done I could finally drop it off the ramp and try driving it. The MOT ran out several months ago so I could only drive it around in the field. With the shocks set fully soft it just floats over the bumps. The only problem is that the shocks over extend if I drive over a big pothole. With the adjusters set to 3 clicks it's a bit hard, though still much smoother than it was before the modifications. These AVO shocks are a bit hard for the Jimny. The adjusters have about 20 positions so 3 clicks is right at the far end of the adjustment range. They are rebuildable so I may be able to change the oil. I'll have a chat with AVO and see what they have to say.

An obligatory articulation shot, showing the suspension compensating for the steep end of my field.

 

And I can finally do what I should have done before I started on the suspension modifications - pressure wash it. Having the suspension at full lift makes access underneath pretty easy. I really must get some new trim clips so I can replace the sill protector. It looks a bit silly without the sill protector. Does anyone know of a good source for these clips?

 

This weekend I'll get the ECUs mounted back in the footwell and reinstall the interior.  All I have left after that is cleaning up the remaining Waxoyl splashes from the exploding waxoyl sprayer incident. If I get time I'll also have a go at fixing a big gouge I put in the roof last time I took it out - a branch that looked thin and weedy turned out to be neither.

The MOT is booked for Friday the 18th. My local MOT guy is pretty used to me bringing in modified vehicles. Hopefully it will pass so I can have a proper play next weekend. I've still got quite a bit of tuning and tweaking to do to the suspension ECU but I can't do that until I have driven it for a bit.

My old astravan is getting pretty tired and I'll soon be replacing it. Just out of idle curiosity I did a quick bit of measuring and it's 1.7CDTI diesel lump is all alloy and not that much bigger than a Jimny engine. Hmm...