[427v8]

Is it just me or do all the air ride controllers kinda suck.
Yea they control height pretty well but they seem very primitive and only slightly better than a bank of switches.

I have been looking at them for my 1929 Dodge project. It's bagged front and rear, it has a solid front axle and will have full fenders. It will be modern, but look period reminiscent. No digital gauges, tasteful chrome and be a car you can drive.

My problem with the controllers I see, unless I missed some is;
They have a zillion buttons,
They have a gaudy Vacuum fluorescent display.
They don't control height on the fly, only if you push the button ( or on startup).
They are very expensive.

So I'm thinking of making my own. ( I'm sure it will be even more expensive!)
*It will have one knob to set ride height.
*No display.
*Will use 4 corner height sensors, the normal rotary style
*Will adjust on the fly, quickly if a door is open or the car is in park, slowly if the car is moving.
*Compressor control
*Will have a USB connection to upload software updates, and to modify the tuning parameters used to set up the car.

Only ONE knob??
There is only one important ride height and that is the design height. The height where the suspension is designed to be. Any other height and you are sacrificing ride and stability. Therefore the height knob will have movable indicators showing different heights and one fixed indicator that is the design height.
There is no practical reason to be able to adjust each corner of the car individually and separately every time you want to change the height. One knob is all that is needed. Up, down. If you want to slam it and get all the air out, just turn it all the way down.

No display???
A Vacuum fluorescent display is great on, ...well nothing I can think of and certainly not on a 1929 Dodge. if you want to see pressures, add a pressure gauge. If you are shooting for a specific height, get a ruler and adjust the height sensors to be correct. The numbers on the displays don't mean anything anyway. Heights other than the design height will just be like "really low man" but still driveable, or "man that's one huge speed bump, crank up the bags!"

There will probably be a light that comes on to show the car is at the set height, or still trying.


Adjust on the fly???
It will continuously adjust the ride height whenever the ignition is on. There will be an input to the controller, usually connected to the door switch, that will tell the controller to update quickly. This will be nice when your 350lb buddy gets in and out of the car, it will automatically adjust. Once the doors are closed the load won't typically change except for gasoline usage so it will update very slowly. Except for what you toss that body in the ditch along the highway...


Compressor control???
It will control the compressor. this will eliminate the cost of a separate compressor switch and will allow the compressor to come on early if the controller sees it needs a lot of air, rather than waiting until the tank is low before turning on. So if you have it layed out and then hop in and start the car. The controller will see it's going to need a lot of air and start the compressor right away rather than waiting for the pressure to drop.

So, does everyone think I'm crazy?
Or does it sound interesting and you want to hear more?

Keith
The above statement is considered a public disclosure of the features described herein and are released into the public domain on the date of this post. No features described in this post may be patented, copyrighted subjected to DRM or otherwise access controlled in any manner by any party. All features and ideas in this disclosure and all related discussions are subject to the FreeBSD Documentation License.

 

[matt167]

you'll need a PLC to do what you want.. but it's possible

 

[427v8]

I write embedded software for a living. So I've got that covered.

I have a prototype started, The USB part works and I am reading the height sensors.

 

[snod83]

I think you could do all that you wanted with a very simple micro controller called the Arduino. It is based on the atmega328 micro controller which has about 32kb of space for code. I have been using this low end (about 30 dollars) micro controller to do very similar things with hydraulics at work.

 

[427v8]

snod,
I'm sure the Arduino would be fine, except I'm a PIC kinda guy and actually like writing in C. I'm using the PIC-18f4550 which has plenty of IO memory and horsepower to do the, fairly easy, job.

I'm hoping for more feedback on the controller design ideas, hopefully from someone with experience with them

 

[Brimstone]

What about failure modes? What will the controller try to do if one (or more) of the height sensors have failed or been damaged? What if one of the sensors develops a problem and still provides readings, but the readings are way out-of-whack with the rest of them? Will it try to "correct" that corner of the car by inflating/deflating the bag, or will it average out the valid readings as a safety measure?

I don't know a whole lot about air ride suspensions and the controls, but I would think that adding a couple LED's to your proposed system would be a good thing - their sole purpose being a tell-tale on the sensor's condition. So if you have 4 height sensors, you'd put in 4 LED's - and these could be as simple as dual-color green/red individual LED's - green (or off) for good, red for bad (or steady red for issues, and blinking red for real problems).

And individual LED's are extremely easy to hide .
- Mike

 

[427v8]

That would be a good idea, I could have a 3 color LED for each bag, Red for failure, yellow for adjusting and green for in position. put a transparent label over them so you know what they mean.

They could be hidden behind a piece of dark glass so they don't look too techie

Probably have one for the air compressor too

 

[hemi43]

I hear what you're saying about the controllers. I have the Dakota Digital unit using height positioning, and it is kinda primitive.( I for one don't mind the digital display) I end up driving my car when the unit is in manual mode, because it always decides to try and level the car when I'm either accelerating or stopping or even in a curve.
It's kinda Mickey mouse at the way solenoid valves are used also. They are either full on, or full off !
It would be nice to find some way to inflate the bag proportionally.
Did you ever think about using 4 valve per bag ? 2 large valves to lift and lower the car quickly, and 2 very small valves to control the height.

BTW, this is on my 28 Dodge!! PM me if you you have any questions.
I have some build pics at www.**************com
Dan

 

[427v8]

Hey Dan, thanks for the input, I guess I should look at the Dakota digital unit, forgot about that one.
Would you rather it didn't adjust at all during driving, or just maybe slower?
My concern is a slow air leak would cause the car to sag unless it auto leveled.

But it shouldn't have to autolevel more often than every minute or so...

As far as controlling big valves, I'll look into variable flow rate valves, that WOULD be cool

Yea I saw your 28 a while ago. I actually found it on the dodge owners club forum. You know, the resto guys. they absolutely hated you

I think it's cool, but I'm keeping all 4 doors

 

[hemi43]

I guess the "resto" guys still haven't figured it out that if you sink $25000 into the restoration of that type of car, you'll end up with a $20000 original that is absolutely useless as a vehicle !!

I would love to be able to drive my car in "auto" for the ride height, but it's a real pain the (I).

Here's a few more issues I found .
When you first drive the car after it's been sitting for a while, it takes about 15 minutes for the car to be at it's "happy" height. One reason I think is that when the air in the bags is cold, it heats up in those 15 minutes and increases the ride height. The computer then has to re adjust it. If you're drive down a highway it's OK, but you can bet that it will adust the bags when you're half way into a long curve. When you finally hit straight roads again, the car will not be level and you have to manually level it again.
Not a big deal but it is a nuisance !!
Good Luck !! Dan.

 

[Brimstone]

Ya know, something that might help in preventing the "auto adjustments in the middle of a curve" problem would be to include an accelerometer sensor in the circuit. This way you could limit auto adjusts to when the sensor is showing very little movement (as in cruising), and not when one or more forces are significantly higher than the rest (accelerating, stopping and/or cornering).

Obviously you'd have to fine-tune the adjustment threshold - or possibly have it be adjustable via another knob or setting that would handle the sensitivity, if you will.

 

[427v8]

Well I guess I can see the interest in restoration, but I'm just not into it.
My '29 is a shell, frame, body and fenders. I can do whatever I want to it.
A blank canvas if you may.

Back to the controller;
I am thinking about an accelerometer too, Or maybe just reading the speed sensor so I know the car is moving, I could slow down the update rate drastically. to like once every 5 minutes or something.

Then again, a 2 axis accelerometer could tell me speed too. But it would also lie to me about cornering if the road had a crown to it...Hmmmm

 

[AccuAirSuspension]

Is it just me or do all the air ride controllers kinda suck.
Yea they control height pretty well but they seem very primitive and only slightly better than a bank of switches.

I have been looking at them for my 1929 Dodge project. It's bagged front and rear, it has a solid front axle and will have full fenders. It will be modern, but look period reminiscent. No digital gauges, tasteful chrome and be a car you can drive.

My problem with the controllers I see, unless I missed some is;
They have a zillion buttons,
They have a gaudy Vacuum fluorescent display.
They don't control height on the fly, only if you push the button ( or on startup).
They are very expensive.

So I'm thinking of making my own. ( I'm sure it will be even more expensive!)
*It will have one knob to set ride height.
*No display.
*Will use 4 corner height sensors, the normal rotary style
*Will adjust on the fly, quickly if a door is open or the car is in park, slowly if the car is moving.
*Compressor control
*Will have a USB connection to upload software updates, and to modify the tuning parameters used to set up the car.

Only ONE knob??
There is only one important ride height and that is the design height. The height where the suspension is designed to be. Any other height and you are sacrificing ride and stability. Therefore the height knob will have movable indicators showing different heights and one fixed indicator that is the design height.
There is no practical reason to be able to adjust each corner of the car individually and separately every time you want to change the height. One knob is all that is needed. Up, down. If you want to slam it and get all the air out, just turn it all the way down.

No display???
A Vacuum fluorescent display is great on, ...well nothing I can think of and certainly not on a 1929 Dodge. if you want to see pressures, add a pressure gauge. If you are shooting for a specific height, get a ruler and adjust the height sensors to be correct. The numbers on the displays don't mean anything anyway. Heights other than the design height will just be like "really low man" but still driveable, or "man that's one huge speed bump, crank up the bags!"

There will probably be a light that comes on to show the car is at the set height, or still trying.


Adjust on the fly???
It will continuously adjust the ride height whenever the ignition is on. There will be an input to the controller, usually connected to the door switch, that will tell the controller to update quickly. This will be nice when your 350lb buddy gets in and out of the car, it will automatically adjust. Once the doors are closed the load won't typically change except for gasoline usage so it will update very slowly. Except for what you toss that body in the ditch along the highway...


Compressor control???
It will control the compressor. this will eliminate the cost of a separate compressor switch and will allow the compressor to come on early if the controller sees it needs a lot of air, rather than waiting until the tank is low before turning on. So if you have it layed out and then hop in and start the car. The controller will see it's going to need a lot of air and start the compressor right away rather than waiting for the pressure to drop.

So, does everyone think I'm crazy?
Or does it sound interesting and you want to hear more?

Keith
The above statement is considered a public disclosure of the features described herein and are released into the public domain on the date of this post. No features described in this post may be patented, copyrighted subjected to DRM or otherwise access controlled in any manner by any party. All features and ideas in this disclosure and all related discussions are subject to the FreeBSD Documentation License.

I just came across your post and I think that you hit it right on the head

My brother and I had about the same exact thought process in 2001 when we started our company AccuAir. We are in the process of becoming much more well known in the industry, but we clearly haven't hit our mark yet since you have clearly never seen or heard of our products

We just spent the last three years re-developing our GEN1 system to do everything that you have described and more... it is called e-Level. Yes, three years with three full time engineers (I happen to have an Mechanical Engineering degree as well). The current firmware that we ship today is well over 30,000 lines... yes our team was powered by Redbull =) It was not an easy undertaking. I will now address some of your specific topics below:

Only ONE knob??
The one knob or switch idea would be kind of similar to our Rocker Switch Interface system. A lot of hotrod guys like this because it is so small and simple, but it does exactly what you are describing (we also use this system for our ambulance and utility vehicle applications). Turn the IGN on and you are at ride height. Press down to go to your lower saved height. Press up to go to your raised saved height. You can also use the hidden program button which allows for manual adjustment of individual corners or pairs with the rocker switch. This is also how you save new preferred heights.

Our TouchPad style interface is for the guy who wants more functions right at his finger tips. Manual adjustments are right there along with your three preset heights and the all-down function for parking.

No display???
I wish that everyone understood that pressures are completely irrelevant when it comes to setting the height of a vehicle. Air spring pressures change severely with load and temperature, which every vehicle is guaranteed to be faced with. We chose to not confuse our customers with this non-sense.

Side Note: Have you ever seen a factory vehicle with air suspension come with pressure gauges??? Nope, ride height sensors are the only way to go.

Adjust on the fly???
This is the most important part of an air suspension controller and it managed to consume about 2 of our 3 years worth of development. I saw the comment that someone just turned that feature off on one of the other manufacturer's systems because it operated so poorly.

We call this feature on the e-Level the RideMonitor Mode and it is incredible. When you are parked, it will correct for any change in load after being out of range for 5 seconds, (the scenario that you describe about your big buddy getting in the car). When you start driving, the system realizes that you are driving and requires a corner to be out of range for 45 seconds before it will make a correction. We filter out things like hard starts, stops, and turns that simply skew the data and we only adjust when necessary, (a change in load like fuel consumption, a significant change in road angle, or air temperature related air spring expansion or contraction). All of this guarantees that the vehicle is always within alignment specifications the entire time that you are driving it.

Our system achieves all of this because it conducts an automatic calibration when you first install it which allows us to learn all of the parameters for your specific vehicle (bag size, valve size, shock ratio, sway bars, vehicle weight, etc). This means that the user never has to go in and adjust speeds or parameters because the system does it automatically for you. Then over time, the system constantly learns any variations in your vehicle (often due to suspension wear etc.) I said it wasn't easy

Compressor control???
Also all great ideas. We use a 0-200 psi tank pressure to tell the e-Level ECU what pressure the tank is at. The ECU then turns your compressor(s) ON or OFF as necessary. This also gives the controller lot more understanding of the entire system. For instance, if we have the compressor ON and aren't building pressure over a minute, we know that the compressor is failing, so we turn it OFF and tell user how to solve the problem. We also monitor the battery supply voltage so that if the user is operating the compressor without the engine running, they can only run their battery down so far before they have to start the engine.

I hope that I didn't take any wind from your sails 427v8, but if I were in your shoes I would appreciate it if someone saved the next 3 years of my life by letting me know about a product that solved all of my desires for less than a grand.

P.S. I'm not going to put our URL up here, because it's against the rules. But search the web and you will find us to learn more.

 

[AccuAirSuspension]

What about failure modes? What will the controller try to do if one (or more) of the height sensors have failed or been damaged? What if one of the sensors develops a problem and still provides readings, but the readings are way out-of-whack with the rest of them? Will it try to "correct" that corner of the car by inflating/deflating the bag, or will it average out the valid readings as a safety measure?

I don't know a whole lot about air ride suspensions and the controls, but I would think that adding a couple LED's to your proposed system would be a good thing - their sole purpose being a tell-tale on the sensor's condition. So if you have 4 height sensors, you'd put in 4 LED's - and these could be as simple as dual-color green/red individual LED's - green (or off) for good, red for bad (or steady red for issues, and blinking red for real problems).

And individual LED's are extremely easy to hide .
- Mike

We had a similar idea to this as well. We display different potential error conditions for each corner of the vehicle on the TouchPad with multi-color LED backlighting:

The e-Level ECU constantly diagnosis the system and then displays any potential problems on the TouchPad like:

*Height sensor disconnection or failure for each corner
*Valve Failure for each corner in each direction
*Pressure Sensor Failure
*Compressor Failure
*Low system supply voltage

 

[427v8]

Accu Air,
your system does sound good. I like the controller, looks like a nice well designed unit. I can only imagine the work involved in developing a complete product like that. Well, I have an idea, as I do embedded software for a living and work along side electrical and mechanical engineers...

I will take a good look at your system, thanks for mentioning it!

 

[Old Fool]

We had a similar idea to this as well. We display different potential error conditions for each corner of the vehicle on the TouchPad with multi-color LED backlighting:

The e-Level ECU constantly diagnosis the system and then displays any potential problems on the TouchPad like:

*Height sensor disconnection or failure for each corner
*Valve Failure for each corner in each direction
*Pressure Sensor Failure
*Compressor Failure
*Low system supply voltage

Is the controller wireless, or does it always require the mini usb cable connection at all times?
Are the key fobs programmable to unlock doors as a second function?

 

[yobsmitty]

Accuair.. Really looking for a height based controller yet I can't come up with the bucks I need to buy yours right now. I have a pressure based system but am concerned that I will wear my tires irregularly with front and rear independent suspension. I am using a 1997 c5 corvette chassis with a custom chassis. I can't seem to find a used unit of yours and was wondering whether you had a reconditioned unit for sale I could buy... I would obviously prefer your pad version but I'll take what I can get. I'm a shop teacher in Pennsylvania. I would also consider teaching a unit on your products when I cover pneumatics if you could provide me with more information from your research of varying loads. I think my high schoolers would enjoy learning about it and have some "real-word" problems to solve

 

[Crosley]

7 year old thread.

AccuAir has not logged in since 2011