Project : DBW throttle with Jean's TinyIOX & Polulu JRK12v12

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Matt Cramer
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Re: Project : DBW throttle with Jean's TinyIOX & Polulu JRK1

Post by Matt Cramer »

anzelmi wrote:Now also Maxxecu and Ecumaster include DBW feature. When does Ms3pro get this feature?
When we can absolutely, positively guaranty we won't repeat Toyota's "Moving Forward - whether you're on the gas or the brakes!" disaster. One of our engineers had a racing teammate whose car got pushed into the wall when a DBW system from a big name motorsports ECU manufacturer got locked fully open.

Any DBW device we build at DIYAutoTune is going to take a similar approach to Haltech's "redundant watchdog" type approach. The MS3 architecture doesn't have this feature, but it could be implemented in an external CAN device, or in a next generation device running a different processor.
Matt Cramer -1966 Dodge Dart slant six running on MS3X
ol boy
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Re: Project : DBW throttle with Jean's TinyIOX & Polulu JRK1

Post by ol boy »

I was playing with a GM DBW this past weekend using a teensy3.2 receiving CAN messages from an MS2 for throttle position. Driving the DC motor was simple with a low side driver but it took some fooling around to get the valve to hold position correctly. The return spring is stout enough that the valve snaps shut quickly so I don't see much need for a H-bridge. Since the motor also winds up the internal return spring a bit of hold current is required to hold the valve in the desired position. As the spring is wound up the hold current also needs to increase to get better response from a changing input.

Has anyone sorted a control loop for a DBW yet?

Matt. I though Toyota's problem was the floor mats getting stuffed under the pedal assembly, not the manufactures software/hardware problem.
306 SBFord, Torquer II EFI intake, 60 lbs injectors, 8 LS2 coils, VS Racing 7668 turbo, 4R70W, MS3x fw1.4 w/built in trans controller.
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Re: Project : DBW throttle with Jean's TinyIOX & Polulu JRK1

Post by jsmcortina »

ol boy wrote:Matt. I though Toyota's problem was the floor mats getting stuffed under the pedal assembly, not the manufactures software/hardware problem.
That was their initial excuse.

The court found that their software was hopeless.

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ol boy
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Re: Project : DBW throttle with Jean's TinyIOX & Polulu JRK1

Post by ol boy »

I have a 2000 Ford diesel pick up, it's DBW as all non injector pump diesels are. I poked my head under the dash and found a single pot style pedal sensor. I guess a diesel being only fuel based(no throttle valve) system has it's own level of fail safes while a gas motor in theory only needs air volume for the injection system to produce power output.

Shouldn't both the desired commanded throttle position(foot pedal) be checked against the current condition/state of the motor? If foot pedal is at zero and engine is at 5K rpm making 10# then something is wrong.

Are all DBW throttle bodies the same? are they all a geared DC motors? The GM truck unit I was playing with doesn't shut all the way and would require a H-bride to get the last 10%, but would the engine even run with the valve completely shut or is that the default cranking position? so many questions..
306 SBFord, Torquer II EFI intake, 60 lbs injectors, 8 LS2 coils, VS Racing 7668 turbo, 4R70W, MS3x fw1.4 w/built in trans controller.
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Re: Project : DBW throttle with Jean's TinyIOX & Polulu JRK1

Post by jsmcortina »

You need to be able to close it beyond the spring position.
All DBW safe pedals have multiple pots.

James
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jsiedlicki
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Re: Project : DBW throttle with Jean's TinyIOX & Polulu JRK1

Post by jsiedlicki »

ol boy wrote:Are all DBW throttle bodies the same? are they all a geared DC motors? The GM truck unit I was playing with doesn't shut all the way and would require a H-bride to get the last 10%, but would the engine even run with the valve completely shut or is that the default cranking position? so many questions..
Most DBW throttle bodies use geared DC brush motors. Their neutral position is slightly open to allow the motor to run at a fast idle in case there is a malfunction and power to the throttle is cut.
MS3-Pro 1st Gen | Honda K24 Supercharged
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jamies
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Re: Project : DBW throttle with Jean's TinyIOX & Polulu JRK1

Post by jamies »

you could look at adapting GM TAC?
if you figure out the data stream, then it will also support cruise control etc too
ol boy
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Re: Project : DBW throttle with Jean's TinyIOX & Polulu JRK1

Post by ol boy »

Im thinking of an extender board.. Teensy3.2 or 3.5. Ive slowly moved my picaxe based transcontroller over to a 3.2 along with CAN data and uSD logging. I modded the end stops on a GM DBW unit and just low side switch the motor with feed back from one of the pots. The unit seemed to need around 25% duty at 8khz to just hold position and that hold duty seems to change with position and voltage applied to the motor.

I played with adding duty cycle based on the delta from the commanded position to the feedback position plus the hold value. Seemed pretty responcsive in both open and closeing. This was all bread boarded setting on the glove box with the DBW sitting on the dash.

Watched a youtube vid of a guy using a small DBW unit for blow off valve. Might be other uses than just for throttle...
306 SBFord, Torquer II EFI intake, 60 lbs injectors, 8 LS2 coils, VS Racing 7668 turbo, 4R70W, MS3x fw1.4 w/built in trans controller.
Matt Cramer
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Re: Project : DBW throttle with Jean's TinyIOX & Polulu JRK1

Post by Matt Cramer »

jamies wrote:you could look at adapting GM TAC?
That is one possibility under investigation.
Matt Cramer -1966 Dodge Dart slant six running on MS3X
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Re: Project : DBW throttle with Jean's TinyIOX & Polulu JRK1

Post by jsmcortina »

ol boy wrote:Watched a youtube vid of a guy using a small DBW unit for blow off valve. Might be other uses than just for throttle...
Using a servo throttle for functions like this or controlling bike secondary throttles etc. is all fine and shouldn't have the safety-critical implications.

The primary throttle is a different matter altogether.

James
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dll67
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Re: Project : DBW throttle with Jean's TinyIOX & Polulu JRK1

Post by dll67 »

Any news .. TAC module adaptation .. Standalone controllers .. Anything?

Did everyone dump their MS and go with just about any other ECU on the market?
MS3PU/IOx/CAN-EGT/DBWx2 540ci BBC 325cc int runners (2)innovate LC2 wbo2's, Hilborn ITB injector cnvrtd to EFI, 55LB Inj, d585 coil near plg, 60-2 trg whl & cam ph snsr, Muncie 4spd w/10T VSS, Tilton 7.25" cerametalic cltch 8.5LB flywhl
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Re: Project : DBW throttle with Jean's TinyIOX & Polulu JRK1

Post by jsmcortina »

Is aftermarket DBW permitted in your class of motorsport?

It is not permitted in drag racing as far as I can tell. USA IHRA rules or UK rules.

James
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dll67
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Re: Project : DBW throttle with Jean's TinyIOX & Polulu JRK1

Post by dll67 »

Im not up on the rules so i do not know. But I can not imagine they would let anything on the track with non-oem DBW that did not have an ECU from either haltech, aem or holley.

I understand your safety concerns here.. Self assembled automotive computers, controlling the engines and transmissions of several thousand pound hunks of steel, traveling at high speeds, driven by who knows, In a sue happy society .. is a recipe for some real thinning-of-the-heard kinds of accident numbers. Even in an off-road only system.
I also understand that because of the diy nature of the megasquirt computer that there will never be a built-in DBW control or steer-by-wire control or even both .. A self driving system.
But surely Matt at diyautotune, who seems to be taking this to a new level of investment with his products, has to be giving real thought into an external, standalone DBW controller that has all the safety factors required to keep the lawyers happy.
. After all .. look at all the options that open up with DBW .. Cruise control, real traction control, idle control without a idle air control valve and that opens up outputs for other uses, non-linear pedal-to-throttle angles and more. Then when you start thinking about integration with transmission controls, were just a hop, skip and 2 jumps from endless possibilities.
MS3PU/IOx/CAN-EGT/DBWx2 540ci BBC 325cc int runners (2)innovate LC2 wbo2's, Hilborn ITB injector cnvrtd to EFI, 55LB Inj, d585 coil near plg, 60-2 trg whl & cam ph snsr, Muncie 4spd w/10T VSS, Tilton 7.25" cerametalic cltch 8.5LB flywhl
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Re: Project : DBW throttle with Jean's TinyIOX & Polulu JRK1

Post by jsmcortina »

I agree conceptually, but from the 2018 UK MSA drag racing rulebook which is based on IHRA, it says:

"Throttle control must be manually operated by driver's foot, electronics, pneumatics, hydraulics or any other device may in no way affect the throttle operation. ..... Electronic operation of the throttle is allowable where fitted as an OEM system applicable to the vehicle concerned."

So, if I'm reading it correctly, aftermarket DBW is not permitted at all. Engine swap DBW is not permitted. The only allowance is for a factory car with the factory install.

The 2018 version of the IHRA rules do not have the OEM clause.

James
I can repair or upgrade Megasquirts in UK. http://www.jamesmurrayengineering.co.uk

My Success story: http://www.msextra.com/forums/viewtopic ... 04&t=34277
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dll67
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Re: Project : DBW throttle with Jean's TinyIOX & Polulu JRK1

Post by dll67 »

It sure sounds like at this point there's no non-oem DBW allowed by the rule book .. Currently
I've tackled bigger problems than this .. Like myself i imagine most are coming from linkage/cable systems and converting to DBW. Wouldn't be tough to design a system to allow temporarily switching back to linkage/cable for those who have a need.
You just gotta want it ..

Having seen some of solutions and possibilities available right now there's no way I'm going to try and build something into the MS3. It's just to involved trying to pack that many features into an already stuffed case and the DBW needs to be built around the safety and other redundant systems needed to keep everyone safe.
By design or not, the MS's are a modular system where bulky features like DBW are going to need to be housed externally. Not only for safety but to keep the costs down for everyone.
With that in mind .. I want it .. Stay tuned for more
MS3PU/IOx/CAN-EGT/DBWx2 540ci BBC 325cc int runners (2)innovate LC2 wbo2's, Hilborn ITB injector cnvrtd to EFI, 55LB Inj, d585 coil near plg, 60-2 trg whl & cam ph snsr, Muncie 4spd w/10T VSS, Tilton 7.25" cerametalic cltch 8.5LB flywhl
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