Hello from Germany

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TobyOctane
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Hello from Germany

Post by TobyOctane »

Hiho rusefi community,

I am a member of High-Octane Motorsports from Erlangen, Germany (http://www.octanes.de). We are a team of students that build a racecar each year for the international design competition Formula Student Combustion. Our car is nearly completely self-designed and uses a Aprilia SXV550 V2 motorcycle engine.

Over the last years we have developped a rather sophisticated distributed electronic system for our cars using the CAN bus with distinct nodes for each task, so for example water pump, fan an fuel pump are each actuated by their own nodes. The problem with this system is the integration of the ECU, as we did not yet find one that fits our specs. The DTAfast S80 we are currently using is designed as a standalone unit that sits centrally in the car and does all tasks necessary to run the car, collect logging data ect. So its CAN connector is for diagnostics only and we need an extra node to re-analogize all the already digitalized data to be able to feed it into the ECU. And all the features we don't use anymore add up on weight (600g for the ECU alone!) that is really critical in our 171kg racecar.

To get rid of that we think about developping a really basic ECU based on the RUSefi project. All we need is an ECU that drives Injection and Ignition for a 2 cylinder engine based on crank and camshaft, all the other values should be measured by other nodes and transmitted via CAN. So I am going to order a board (I think Frankenstein fits our purpose better) and we will try to get it running and test it side by side with a bought ECU (probably not the DTAfast as it has some other problems, too). The long term goal is to design a new, far more compact ECU board not using the brainboard that should compete at least as good as a bought solution with less weight and full acceess to soft- and hardware for further tweaking and error localisation.

We will try to post updates every now and then about our progress and share the experience we made and the tweaks we added to our system.

Cheers,
Toby
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AndreyB
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Re: Hello from Germany

Post by AndreyB »

Welcome and sorry for not shipping your kit yet, this week I am not at home most of the time.

After proof of concept with Frankenstein you should probably take Frankenso source files and cut away the things you do not need - that would give you a small native stm32 board. There is a thread on the hardware subforum where a guy is clingy exactly that.
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TobyOctane
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Re: Hello from Germany

Post by TobyOctane »

No problem, I will be on the racetrack next week ;)

Sorry for not digging enough through the threads before posting. ;) But which thread are you speaking of? I only found the minEFI one, and that seems to be a tinier expansion board.

And did anyone experience problems with high revving engines yet? I suspect the crank signal could be a problem as we are revving up to 12k RPM.
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kb1gtt
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Re: Hello from Germany

Post by kb1gtt »

Yes please keep us posted, sounds really interesting.

I'd like to help with the design and layout if possible. I have an older motorcycle which I dream of fuel injecting, as well I have wanted to spin a 2 cyl small board specifically for bikes or small engine applications. I've also wanted to modular-ize things remote sensors either via CAN or optical bus.

Have you seen this board? http://rusefi.com/forum/viewtopic.php?f=4&t=769

It's kind of a minimal board with CAN, which could some day be used as a platform for making remote sensors.

See some notes about my dream of using an optical bus found here http://rusefi.com/forum/viewtopic.php?f=4&t=412

I also dream of FSI. Once upon a time rus084 posted about these injectors http://www.fai.com.cn/English/Technology/2010-04-30/105.html which have some really interesting possibilities.

I see critical first steps being finding a suitable enclosure, and finding ways to keep the electrical loads minimal. Bikes and small engines often have minimal electrical generation abilities, which means every watt you can save in electrical loading helps decrease the weight and cost of the engine.

Do you know your crank wheel pattern? We might have a wheel decoder already, but if not one can be created.

On a down side, I'm really tight on time. I have the day job, kids, and normal life stuff. So many of my dreams are stuck as dreams instead of reality.
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AndreyB
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Re: Hello from Germany

Post by AndreyB »

TobyOctane wrote:And did anyone experience problems with high revving engines yet? I suspect the crank signal could be a problem as we are revving up to 12k RPM.
One of the engines was running above 10k RPM, to some extent depends on trigger pattern. 360 tooth is x10 times complexity of 36 tooth.

Frankenso board can host either brain board or stm32 chip could be soldered right to the board, it has the footprint and all the needed components.
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Re: Hello from Germany

Post by kb1gtt »

Russian has done a bunch of bench testing to get the high reving with out glitching which was then verified in the real world by this fellow who posted about his project here http://rusefi.com/forum/viewtopic.php?f=3&t=396
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TobyOctane
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Re: Hello from Germany

Post by TobyOctane »

Thanks for the feedback!

The sensor nodes we use for Lambda, Thermocouples etc are based on stm32f103, the concept looks quite similar to russians board. We only use native boards to keep them as small as possible ;)

I have also thought quite a bit about optical bus systems, but so far we simply don't need them. The CAN structure has not yet reached its limits in our car an is dead easy, so we will stick to it in the nearer future. Flexray is also not necessary as we use only few event triggered messages, so the CAN works quite deterministic for lower identifiers.

The fuel injectors also look quite interesting, but we will stick to the standard ones at the moment to keep the system comparable to the bought solutions. But in the future it might help to tickle the last power reserves from the italian beast :D

The enclosure should not be a problem, we have a sponsor that will powder sinter one for us. And electrical power is not the greatest problem in our car, we use a 350W alternator as the cooling at low speeds (we rarely exceed 100km/h in the extremely narrow formula student circuits) is quite power hungry. And I doubt that the self designed, lean ECU will be able to guzzle as many electrons as the bought solution.

I forgot the crank wheel pattern, but it should be rather easy to acquire.

We are students with no kids but a lack in experience - so perhaps we might be able to realise that dream :D
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kb1gtt
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Re: Hello from Germany

Post by kb1gtt »

What type of enclosure is possible? Machined block, folded metal, other? We tend to look beyond one project and it would be good if we can make it low cost and easy to obtain. I tend to think 3D printer, flat aluminum plate and if water tight is needed then pot it after its assembled and tested.

Connectors are stupid expensive. Any thoughts on a low cost connector?
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TobyOctane
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Re: Hello from Germany

Post by TobyOctane »

We used 3D pinted enclosures in 2013, it took some iterations but worked rather well. Power FETs and voltage regulators were mounted to a aluminum plate that served as the lid and connected with flexible wires to ensure cooling, but that is probably not the best idea woth fast switching Ignition and Injection drivers.

Another idea could be using cast aluminium rails that can be cut to the desirable length and then sealed with endplates that that serve as the mounting surface for the connectors as in the picture below. If anyone is interested I can try to dig up some information as this system was abandonned by the team some years ago.

Image

Perhaps the cost of connectors could be lowered by dividing it up into several standard connectors instead of the usual single ones. I am thinking of 4pin connectors, a standard CAN + power supply connector on all nodes plus one for crank/cam and one for coils and injectors. Mounting on different sides of the housing could also help with EMI suppression.

Besides, we are using a 30-2 trigger pattern.

edit: the picture will appear as soon as I manage to insert it, have never been very active in a forum ;)
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kb1gtt
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Re: Hello from Germany

Post by kb1gtt »

The connector has been a key costly point of a design. Even standard connectors become very costly very quickly. Keep in mind to check the cost of both sides of the connector. I have found that some are low cost for the harness, while others are low cost for the PCB side. But as a whole system they were expensive. It's very common that the connector costs around $100 in low qty.

It would be great if the connector can be found with a pig tail pre-installed as most people don't have crimp tools or good quality control over the crimping process. Getting a good crimp is a critical step in getting a good connector.

I have posted some items related to suggested connector guide lines found here

http://rusefi.com/wiki/index.php?title=Manual:Hardware#Connectors

A common connector in industrial application is the MateNLok which has some splash resistance seals that can be installed if so chosen. See catalog pages below. I wonder if these can be found with a pigtail.

http://documents.tycoelectronics.com/commerce/DocumentDelivery/DDEController?Action=srchrtrv&DocNm=82181_SOFTSHELL_HIGH_DENSITY&DocType=CS&DocLang=EN
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TobyOctane
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Re: Hello from Germany

Post by TobyOctane »

Sorry for not having posted anything for eons. The rusEFI project in our team was cancelled as we (electronics guys) could not convince the engine guys that an open Source ECU could be trusted. So lots of money were spent an a Motec M130 that solves quite some of the problems of the old bought solution. It has full CAN support, weighs only 290g (aproximately what we calculated for a rusefi with a RP housing), but still uses the horrible 34pin AMP Superseal connectors. And it has lots of In- and Outputs we will never use and could be removed ;).
Thaks for all your answers and sorry for not being able to contribute to this project, it would have been fun to run this ECU.
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kb1gtt
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Re: Hello from Germany

Post by kb1gtt »

Thanks for the consideration. Perhaps something in the future will come up, there are always projects going on :) Good luck with your effort, and I hope Motec gives you enough low level details that you can ensure the application is properly installed.
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