Big Blue's Transformation

[Gary Lewis]

It's good to see some things haven't changed over the years! Waiting for your Raspberry PI 4 - vacuum control module integration...

Jon! Good to see you on here!

But I think I'll use an Arduino rather than a Pi. My limited understanding is that while the Pi is much more of a computer the Arduino is better for controlling things. And that's what I need.

I've done a quick check and the Vent valve pulls 125 ma while the Vacuum valve pulls 210 ma. That's too much for the Arduino's output, but that just means I'll have to have an expansion board for that.

As for the input, I think tomorrow I'll put the cut-off speedo cable that came in the VSS in the lathe and see what the pulses look like and how many there are per revolution.

And my prelim thinking is that the Arduino will monitor the horn pad input wire to determine On, Off, Set, Coast, or Resume. When it detects On it'll start watching for Set, and when that comes it'll take a snapshot of the pulse rate coming in and dial some throttle in to keep the pulse rate the same. (There's a parameter there called something like Offset which would let me raise or lower the set-point speed slightly to tune it to get a smooth transition.)

Then, as it monitors the pulses it'll average them using another parameter that I can tweak to make things smooth. As the pulse rate speeds up or slows down it'll apply a parameter called Hysteresis to determine how far from the set point it can deviate w/o taking significant action. Or, maybe there's a curve that gets applied where deviations close to the set point get a little change and as you get farther and farther away from the set point more and more change is applied. And the parameter would be called Slope.

But I'm thinking I could change a few things about the Ford system that I'd like. For instance, right now if you are already on cruise then pressing Set/Accelerate causes it to speed up until you let up, which becomes the new set point. Instead, I think I'd like a quick press of the button to get you 1 MPH, but at a reasonably-relaxed rate. Ditto Coast.

And on Resume, instead of flooring it I want it to come up at a reasonable rate.

This could get me a speed control I really like!

[85lebaront2]

Jon! Good to see you on here!

But I think I'll use an Arduino rather than a Pi. My limited understanding is that while the Pi is much more of a computer the Arduino is better for controlling things. And that's what I need.

I've done a quick check and the Vent valve pulls 125 ma while the Vacuum valve pulls 210 ma. That's too much for the Arduino's output, but that just means I'll have to have an expansion board for that.

As for the input, I think tomorrow I'll put the cut-off speedo cable that came in the VSS in the lathe and see what the pulses look like and how many there are per revolution.

And my prelim thinking is that the Arduino will monitor the horn pad input wire to determine On, Off, Set, Coast, or Resume. When it detects On it'll start watching for Set, and when that comes it'll take a snapshot of the pulse rate coming in and dial some throttle in to keep the pulse rate the same. (There's a parameter there called something like Offset which would let me raise or lower the set-point speed slightly to tune it to get a smooth transition.)

Then, as it monitors the pulses it'll average them using another parameter that I can tweak to make things smooth. As the pulse rate speeds up or slows down it'll apply a parameter called Hysteresis to determine how far from the set point it can deviate w/o taking significant action. Or, maybe there's a curve that gets applied where deviations close to the set point get a little change and as you get farther and farther away from the set point more and more change is applied. And the parameter would be called Slope.

But I'm thinking I could change a few things about the Ford system that I'd like. For instance, right now if you are already on cruise then pressing Set/Accelerate causes it to speed up until you let up, which becomes the new set point. Instead, I think I'd like a quick press of the button to get you 1 MPH, but at a reasonably-relaxed rate. Ditto Coast.

And on Resume, instead of flooring it I want it to come up at a reasonable rate.

This could get me a speed control I really like!

The newer one on Darth is pretty smooth, resume from a lower speed isn't bad and a tap on the set button is about a 1 mph increase. The reason the cancel hydraulic switch is directly to the battery is because it is wired in parallel with the brake switch on the pedal so if the brake switch doesn't have power, the speed control clutch won't engage.

I would imagine it is a safety item.

FWIW, why don't you (a) quit trying to make a kluge work and finish up the EFI (b) see if maybe there is an issue with the throttle linkage at the AFB end, like make the lever length/angle match a Ford instead of a Chevy.

[Gary Lewis]

The newer one on Darth is pretty smooth, resume from a lower speed isn't bad and a tap on the set button is about a 1 mph increase. The reason the cancel hydraulic switch is directly to the battery is because it is wired in parallel with the brake switch on the pedal so if the brake switch doesn't have power, the speed control clutch won't engage.

I would imagine it is a safety item.

FWIW, why don't you (a) quit trying to make a kluge work and finish up the EFI (b) see if maybe there is an issue with the throttle linkage at the AFB end, like make the lever length/angle match a Ford instead of a Chevy.

I'm not going to do any/much actual work towards an Arduino to run the speed control right now. And I may go with the electronic speed control system later. But in the interim I'm going to think about how this might work.

And the reason I want to think through this is because it is an opportunity to get a speed control that works the way I want it to work. The electronic one works the way it works. There's no flexibility. But an Arduino would give me complete control.

On the carb issue, when we took Dad's truck to deliver your test 'scope, awa a load of furniture, I had an Edelbrock on that 351M and used a stock Ford speed control and this same ZF5 tranny. It worked well. But something is very different with this engine setup. So, how can it be a linkage issue if, in both cases, I can get full throttle? Surely the ball has to be in the same position on the lever or I couldn't. And I can't move this ball up or I won't get full throttle.

On the Arduino, I'm thinking it'll plug in exactly where the current module plugs in, which would let me go back if I wanted to. All of the needed inputs, outputs, as well as power and ground are in those 12 wires.

[Nothing Special]

I'm not going to do any/much actual work towards an Arduino to run the speed control right now. And I may go with the electronic speed control system later. But in the interim I'm going to think about how this might work.

And the reason I want to think through this is because it is an opportunity to get a speed control that works the way I want it to work. The electronic one works the way it works. There's no flexibility. But an Arduino would give me complete control.

On the carb issue, when we took Dad's truck to deliver your test 'scope, awa a load of furniture, I had an Edelbrock on that 351M and used a stock Ford speed control and this same ZF5 tranny. It worked well. But something is very different with this engine setup. So, how can it be a linkage issue if, in both cases, I can get full throttle? Surely the ball has to be in the same position on the lever or I couldn't. And I can't move this ball up or I won't get full throttle.

On the Arduino, I'm thinking it'll plug in exactly where the current module plugs in, which would let me go back if I wanted to. All of the needed inputs, outputs, as well as power and ground are in those 12 wires.

For what it's worth, I don't think Big Blue's speed control is any worse than the speed control in my 2015 E-450 motorhome. It'll drop about 5 mph below the set point before downshifting, which I kind of like. But when it down shifts it over-does it. I don't know if it drops 2 gears, or if it's just that unlocking the torque converter and downshifting is that substantial. But then it accelerates hard and noisily (throttle pretty much wide open). As it gets above the set point it starts to back off on the throttle, but it keeps it in the lower gear with the engine roaring until about 5 mph over the set point when I get sick of it and tap the brake pedal. It's not bad on flat ground, but it's pretty unusable in hills.

No real point to this other than to say that Ford didn't have electronic speed control nailed by 2015, so thinking through how you might do your own system might not just be a thought exercise.

It also makes me think (very briefly!) about swapping a Godzilla 7.3L and a manual trans into my motorhome!

[Gary Lewis]

For what it's worth, I don't think Big Blue's speed control is any worse than the speed control in my 2015 E-450 motorhome. It'll drop about 5 mph below the set point before downshifting, which I kind of like. But when it down shifts it over-does it. I don't know if it drops 2 gears, or if it's just that unlocking the torque converter and downshifting is that substantial. But then it accelerates hard and noisily (throttle pretty much wide open). As it gets above the set point it starts to back off on the throttle, but it keeps it in the lower gear with the engine roaring until about 5 mph over the set point when I get sick of it and tap the brake pedal. It's not bad on flat ground, but it's pretty unusable in hills.

No real point to this other than to say that Ford didn't have electronic speed control nailed by 2015, so thinking through how you might do your own system might not just be a thought exercise.

It also makes me think (very briefly!) about swapping a Godzilla 7.3L and a manual trans into my motorhome!

Well, Blue's speed control isn't the best either, so I agree that they weren't "there" as of 2015. It lights the turbos on a gentle hill as it tries to keep the speed spot-on. I can easily beat the MPG of the speed control by at least two, if not three, MPG. And I can keep it from downshifting on all but the steepest hills. But that's tiring.

On Big Blue the system wants to keep the speed at the set point. (That's a full-stop.) No deviation whatsoever! So it is constantly sawing the throttle back and forth.

This is an opportunity to put some smarts into the system. I want hysteresis so that on a hill the speed can fall/increase a few MPG. And, when some action is needed it is gentle.

Today I hit Resume at about 35 MPH with the set point at 65. The vacuum gauge went to 2" and stayed there until we hit 65 and then backed off - too much. Then it had to come back in, and we went back and forth a few times until it settled out. WRONG! I'd like the thing to accelerate gently to the set point.

And, as said, I'd like to be able to hit Coast or Accel and drop/increase one MPH as I'm frequently catching someone and having to back off. Blue can do that. So in an Arduino I could tell it to change the speed by one MPH each time either button is pushed, or drop/accelerate gently when it is held. But the current system chops the throttle completely or opens it fully when you hit either button.

And the beauty of the Arduino is that I can change parameters on the fly. Some allow Bluetooth and some do USB, either of which I can handle.

[85lebaront2]

For what it's worth, I don't think Big Blue's speed control is any worse than the speed control in my 2015 E-450 motorhome. It'll drop about 5 mph below the set point before downshifting, which I kind of like. But when it down shifts it over-does it. I don't know if it drops 2 gears, or if it's just that unlocking the torque converter and downshifting is that substantial. But then it accelerates hard and noisily (throttle pretty much wide open). As it gets above the set point it starts to back off on the throttle, but it keeps it in the lower gear with the engine roaring until about 5 mph over the set point when I get sick of it and tap the brake pedal. It's not bad on flat ground, but it's pretty unusable in hills.

No real point to this other than to say that Ford didn't have electronic speed control nailed by 2015, so thinking through how you might do your own system might not just be a thought exercise.

It also makes me think (very briefly!) about swapping a Godzilla 7.3L and a manual trans into my motorhome!

Part of the problem with the motorhome is the V10, they are designed to rev and the other issue is harder to fix. The TC clutch unlock/lock points are in the computer programming, I have mine in Darth set to take 80% throttle to unlock. Loaded, towing a heavy trailer also loaded, when I hit the upslopes in the CBBT tunnels it would slow down, downshift to 3rd, rev to about 2700 (which is where the C6 ran under those conditions) then lock in and run at 2200 rpm and maintain 54 mph uphill. What it will do with the new engine and more compression should be interesting.

I thought of something else last night, on our two Flexes, a 2009 and 2011, there is no separate speed control system as both these vehicles are "drive by wire" with no mechanical throttle system. I suspect your 2015 E450 may well be the same way. On these systems the throttle has a big stepper motor, three (at least) feedback potentiometers and the accelerator pedal has a set of usually three potentiometers at it's pivot. The reason for the multiple is the same logic NASA uses, redundant sensors for safety and accuracy. A lot of auto manufacturers have gone this route as it simplifies design, easily allows for adjustable pedal assemblies and eliminates the old frayed throttle cable issue where it would stick in either direction.

What I have noticed on the Flexes, if you are a little below the desired speed when you resume, it pretty well eases the throttle with no downshift, if I am well below, say after slowing way down maybe 20 mph and resume, it will downshift maybe 2 gears (6F50 transaxle) and open the throttle pretty far.

My son has an Excursion, V10 3.73 gears and 4R100 trans (updated E4OD) he was delivering his 1986 F150 4X4 down this way (Chesapeake VA) and going over the Eastern Continental divide on US 17, he was down into 2nd, no where near what I was hauling with Darth.

[grumpin]

Well, Blue's speed control isn't the best either, so I agree that they weren't "there" as of 2015. It lights the turbos on a gentle hill as it tries to keep the speed spot-on. I can easily beat the MPG of the speed control by at least two, if not three, MPG. And I can keep it from downshifting on all but the steepest hills. But that's tiring.

On Big Blue the system wants to keep the speed at the set point. (That's a full-stop.) No deviation whatsoever! So it is constantly sawing the throttle back and forth.

This is an opportunity to put some smarts into the system. I want hysteresis so that on a hill the speed can fall/increase a few MPG. And, when some action is needed it is gentle.

Today I hit Resume at about 35 MPH with the set point at 65. The vacuum gauge went to 2" and stayed there until we hit 65 and then backed off - too much. Then it had to come back in, and we went back and forth a few times until it settled out. WRONG! I'd like the thing to accelerate gently to the set point.

And, as said, I'd like to be able to hit Coast or Accel and drop/increase one MPH as I'm frequently catching someone and having to back off. Blue can do that. So in an Arduino I could tell it to change the speed by one MPH each time either button is pushed, or drop/accelerate gently when it is held. But the current system chops the throttle completely or opens it fully when you hit either button.

And the beauty of the Arduino is that I can change parameters on the fly. Some allow Bluetooth and some do USB, either of which I can handle.

Hysteresis...

[grumpin]

Well, Blue's speed control isn't the best either, so I agree that they weren't "there" as of 2015. It lights the turbos on a gentle hill as it tries to keep the speed spot-on. I can easily beat the MPG of the speed control by at least two, if not three, MPG. And I can keep it from downshifting on all but the steepest hills. But that's tiring.

On Big Blue the system wants to keep the speed at the set point. (That's a full-stop.) No deviation whatsoever! So it is constantly sawing the throttle back and forth.

This is an opportunity to put some smarts into the system. I want hysteresis so that on a hill the speed can fall/increase a few MPG. And, when some action is needed it is gentle.

Today I hit Resume at about 35 MPH with the set point at 65. The vacuum gauge went to 2" and stayed there until we hit 65 and then backed off - too much. Then it had to come back in, and we went back and forth a few times until it settled out. WRONG! I'd like the thing to accelerate gently to the set point.

And, as said, I'd like to be able to hit Coast or Accel and drop/increase one MPH as I'm frequently catching someone and having to back off. Blue can do that. So in an Arduino I could tell it to change the speed by one MPH each time either button is pushed, or drop/accelerate gently when it is held. But the current system chops the throttle completely or opens it fully when you hit either button.

And the beauty of the Arduino is that I can change parameters on the fly. Some allow Bluetooth and some do USB, either of which I can handle.

Sorry, couldn’t help myself!

[Gary Lewis]

Sorry, couldn’t help myself!

It probably doesn't mean what I think it means.

To tell the truth, I'm not sure I understand "hysteresis" vs "deadband". Nor am I sure they are important in this discussion.

But, while reading up on those terms I found this, and I'm applying the coffee at present and we'll see if a solution or sarcasm comes out. (There is a 3rd output, but we won't touch it. )

[85lebaront2]

It probably doesn't mean what I think it means.

To tell the truth, I'm not sure I understand "hysteresis" vs "deadband". Nor am I sure they are important in this discussion.

But, while reading up on those terms I found this, and I'm applying the coffee at present and we'll see if a solution or sarcasm comes out. (There is a 3rd output, but we won't touch it. )

Gee, that's a lot simpler than most of the engineers I worked with would do, it would need at least 3 feedback loops to be complete.