Knock Detection with variable sensitivity over RPM

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Re: Knock Detection with variable sensitivity over RPM

Postby dougie2 » Mon Jan 05, 2009 11:34 pm

Thanks for the offer vinister, for sure we can use any help available!

So what is the current problem? There are two different routes we could go (and we should maybe try both).
The standard KnockSensor I'm using and which is used in very man modern Cars is an Piezo Type sensor which need special attention when amplifying the Signal. At the same time wee need to keep in mind, that the signal we would like to detect will be around 4-6kHz.

First option: If we would like to make it most reliable and versatile, we would need a specialized KnockSensor IC commercially available. I ended up at the HIP9011 to be the best option. It includes programmable Amplifier, programmable Fliter, an Integrator and some other useful stuff. Downside: I will need to program a small Microprocessor, who takes control over the HIP9011, but this doesn't pose a problem.

Second option: We could try building an analog circuit. What I'm missing currently is a clear signal of a knocking Engine. Current weather conditions around here don't allow me to do a test drive with modified spark table (car is running on Yokohama Semi-Slicks).

As I already got some of the mentioned ICs, I would concentrate to realize the First option.
If you would go for the second option, we would need a FET or CMOS charge amplifier at the first stage, who's able amplifying signals up to 6kHz.

These are my preliminary thoughts ... comments?

BR
Ralf
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Re: Knock Detection with variable sensitivity over RPM

Postby jsmcortina » Tue Jan 06, 2009 8:59 am

Had to ban dougie2 as he is selling Megasquirt ripoffs.

James
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Re: Knock Detection with variable sensitivity over RPM

Postby dougie3 » Tue Jan 06, 2009 10:19 am

Well, this is the second time I've been banned without proper reasoning .... without having been contacted beforehand and without having had the chance to elaborate.

1. First of all: I'm NOT selling Megasquirt Ripoffs!
2. We developed an own and totally new PCB which only fits to old classic Rover Minis.
3. Our PCB runs the MS-1 Processor with MS-1 Extra Code PLUS AN ADDITIONAL Coprocessor, enabling it to run on a Rover Mini
4. There's no Megasquirt which could take direct use of the original Rover Sensors nor the unique trigger wheel, nor the unipolar Idle Stepper.
5. My two fellows and myself contacted Phil Ringwood, B&G already months ago seeking for approval (several times). Phil Ringwood doesn't mid if we use his code, and from B&G: no response until now.

What else can we do?

When posting on this forum, we only want to support user community by providing additional hardware development ... if this isn't desired, then kick me a third time. I don't mind, but maybe your users who would benefit. I'm electrical engineer whos simple interest is to improve his Mini's performance and to enable others to take use of this as well. There's no Megasquirt who could do that without major changes to the engine. I hope the difference is clear?

If you find this to be against YOUR rules.... well, this is your forum and you can do whatever you want with it.

So now it's up to you ...

BR
Ralf
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Re: Knock Detection with variable sensitivity over RPM

Postby racingmini_mtl » Tue Jan 06, 2009 10:32 am

MS2/extra supports the SPi wheel pattern and the unipolar stepper can be driven by the MS2 bipolar stepper driver (and if not then a small board to convert the PWM idle to unipolar driver is easy to do and is basically what you do anyway). There would be a need to have an adapter to connect to the OEM connector but that is not a big deal.

Jean
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Re: Knock Detection with variable sensitivity over RPM

Postby dougie3 » Tue Jan 06, 2009 10:38 am

Thanks for that Jean, but even than it wouldn't fit Plug-N-Play to the Mini Loom, nor would drive the Temperature Gauge in the dashboard.

All in all: what we did is specifically meant for a single type of car and is no "Ripoff" aiming at downgrading the work of B&G or others. Personally I find this treatment arbitrarily and not useful for other users. I'm still trying to figure out for what reason someone like me gets kicked here... :|
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Re: Knock Detection with variable sensitivity over RPM

Postby jsmcortina » Tue Jan 06, 2009 10:54 am

dougie3 wrote:Well, this is the second time I've been banned without proper reasoning

3. Our PCB runs the MS-1 Processor with MS-1 Extra Code


That's why.

You aren't permitted to take the B&G code or B&G derived code and put it onto your own PCB and sell it. (For one off DIY personal use, I think you may get away with it.)

However, if you wish to license the Megasquirt concept (like Spectre did for their EMS-Pro) then I'm sure B&G will be prepared to discuss this with you. If this is agreed then you and your product will be allowed here. Otherwise you are considered an illegal ripoff - simple as that.

See here for licensing info: http://www.msefi.com/viewtopic.php?f=92&t=23352

Until you have something agreed and I have confirmation from Bruce of this you will not be permitted to discuss your product or anything related to hardware design or non-standard Megasquirt features on this forum.

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

My Success story: viewtopic.php?f=104&t=34277
MSEXTRA documentation at: http://www.msextra.com/doc/index.html
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Re: Knock Detection with variable sensitivity over RPM

Postby richyvrlimited » Wed Jan 07, 2009 2:20 am

Seems a tad unfair considering he's contacted B&G and they've just not responded to his query/request...
2003 MX5. Coldside MP62
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MS3, RTC, & Knock board, Release 1.2. LC-1 Wideband.
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Re: Knock Detection with variable sensitivity over RPM

Postby vinister » Wed Jan 07, 2009 8:46 am

agreed, what a joke.

Let's start banning all the smart people, that will be a great help :?
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Re: Knock Detection with variable sensitivity over RPM

Postby racingmini_mtl » Wed Jan 07, 2009 10:58 am

Smart people play by the rules of the game or start their own game if they don't like the rules. If you search the different forums you'll see the reasons why the rules are what they are. You may agree with them or not but if you can't live with them just start your own thing without taking what isn't yours to take or join another project (that also hopefully respects others).

Having said that, it seems that this particular issue is on it's way to being resolved or at least there is now communication between the 2 parties.

Jean
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Re: Knock Detection with variable sensitivity over RPM

Postby wes kiser » Sat Jan 10, 2009 8:09 am

This needs to get back on topic, and a relatively easy solution has been dropped in my lap.

Attached is the datasheet for a specialized automotive knock detection IC. This is the chip used by most high end engine management systems for proper knock control. There are many parameters to set up, but a solution using this chip will likely be less complex to set up, while providing much more useful operation for proper detonation control. The chips are less than $4 US.

http://www.intersil.com/cda/deviceinfo/ ... 11,00.html

In the tuning software, we need the ability to "window" how we respond to knock in the strategy (basically not retard timing unless we hear knock within a limited amount of crank rotation following an ignition event).
86 Rx-7, swapped to 2.3 ford turbo (BW EFR 6758), ms3/ms3x sequential fuel /waste spark, ls2 coils
88 Tbird 2.3t, Microsquirt Module (PIMP), TFI ignition
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Re: Knock Detection with variable sensitivity over RPM

Postby dougie3 » Sat Jan 10, 2009 8:47 am

....well, right!

Image

Image

This is exactly what I did today.... the bigger Chip is the HIP9011, the smaller one is an ATMega8 hosting the control program.
Currently I'm searching for a bug which doesn't make the HIP react reliably on my SPI Bus commands. For the rest the Chip is working fine.
Will continue tomorrow
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Re: Knock Detection with variable sensitivity over RPM

Postby Trev16v » Sun Jan 11, 2009 3:19 am

dougie2 wrote:...well, this is exactly what I expected to happen... nothing! :roll:


BR
Ralf


Ralf. Let me assure you that when you have a wife in hospital with a large stomach tumour, things like electronic projects, knock sensors and .wav files tend to take a bit of a back seat. I am only just getting life in order and getting back into things. So do us all a favour, and wind your neck in a bit.

For some reason Ralf you seem to have showed a disdainful attitude towards me ever since I started posting in this thread, and I really cannot understand why. This has virtually killed my enthusiasm to take part in this thread anymore.

My 80mb .WAV file was uploaded to a fellow member's FTP area just a few days ago, but I need to ask his permission to post the URL here. I'll post it when I have that permission, hopefully in a day or two. I trust people will find it very useful.

Trev
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Re: Knock Detection with variable sensitivity over RPM

Postby dougie3 » Sun Jan 11, 2009 3:25 am

Trev16v wrote:Ralf. Let me assure you that when you have a wife in hospital with a large stomach tumour, things like electronic projects, knock sensors and .wav files tend to take a bit of a back seat. I am only just getting life in order and getting back into things. So do us all a favour, and wind your neck in a bit.


Sorry for that and my best wishes to you and your family. The health of family members is of course of utmost importance. For all the rest: I would propose having a restart and join forces!

BR
Ralf
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Re: Knock Detection with variable sensitivity over RPM

Postby Trev16v » Sun Jan 11, 2009 4:00 am

Okay cool, no worries. It's a shame to have a misunderstanding over a forum!

I'll ensure I get the .WAV available ASAP.

I may be a bit quiet after that though due to other projects and a possible house move on the way but will keep an interest in this. Your design using that commercially available knock IC looks useful, and would be a good thing for those people who need a reliable and proven circuit immediately.

Trev
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Re: Knock Detection with variable sensitivity over RPM

Postby wes kiser » Sun Jan 11, 2009 6:02 am

Did not see the reference to the HIP9011, sorry. As soon as I found out these were available for very little money, I felt the need to make it known. I do know this is the chip used in many high end ecus.
86 Rx-7, swapped to 2.3 ford turbo (BW EFR 6758), ms3/ms3x sequential fuel /waste spark, ls2 coils
88 Tbird 2.3t, Microsquirt Module (PIMP), TFI ignition
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Re: Knock Detection with variable sensitivity over RPM

Postby Poolside » Sun Jan 11, 2009 9:01 pm

Here's a useful Application Note on the Intersil part, (and its Texas Instruments TPIC8101 brother).
Intersil Engine Knock Interface App Note and Eval Board:
http://www.intersil.com/data/an/an9770.pdf

- Jim
Last edited by Poolside on Mon Apr 27, 2009 5:39 pm, edited 1 time in total.
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Re: Knock Detection with variable sensitivity over RPM

Postby dougie3 » Tue Jan 13, 2009 3:51 am

thanks for the hint Jim, for sure we had taken that into account already.

Today I can report the first success as our small PCB is working fine on my workbench. This means that the microcontroller is communicating reliably and accurate with the Knocksensor chip. So the next tasks will be getting a proper input signal and to adjust the settings of the Knocksensor to properly detect any knocking occurring. I guess the biggest challenge will be implementing a program in the microcontroller which automatically adapts all parameters when driving on the road.
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Re: Knock Detection with variable sensitivity over RPM

Postby Poolside » Tue Jan 13, 2009 6:24 pm

dougie3 wrote:thanks for the hint Jim, for sure we had taken that into account already.


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Re: Knock Detection with variable sensitivity over RPM

Postby Trev16v » Mon Jan 19, 2009 1:50 pm

Here is the 80mb WAV recording that I made. It exhibits knocking in many places. My thanks to Steve Hauer on here for kindly providing this FTP space.


ftp://www.77e21.info/polo1.wav

Username: knockfiles

Password: guest0


The text file contains many of the times when knock occurs in the recording. Note that this text file was typed into the laptop while I was riding with my friend who was driving; it is a bit messy and I've not attempted to tidy it up. The times are approximate.

The recording contains loud valvetrain noise because it was impossible to mount the sensor onto the block itself without stripping components away from the engine, and it was already late at night and pouring with rain when we did this. So we mounted the sensor very near to the head. However, the recording still captures very good knock sounds.

There are times when the engine knocked during high RPM, when going up a hill in a high gear. There are also one or two times when the engine very loudly knocks at a very, very low RPM; this was achieved by attempting to move the car from standstill in 5th.

Trev

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Re: Knock Detection with variable sensitivity over RPM

Postby dougie3 » Tue Jan 20, 2009 12:03 am

Hi Trevor,

this is cool stuff!! Thanks for sharing this!
At a first glance I was able to isolate one dominant frequency when knocking occurs, which is around 6300 to 6400 Hz.
Most likely this will be specific for each engine block.

For getting a feeling on the signal level, could you please provide some info how the recording was done?
I believe you used a kind of amplifier for the sensor. Which amplification and/or specification did it have?

BR
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