[Diy-efi] Traction Control System - In progress (Update 1)

[Brian Sidebotham]

hmmm interesting, glad you've decided to start a system. I'm still 
trying to locate some CV's with ABS rotors for my car ATM.

The ABS sensors work by an inductive pickup with a rotor 
somewhere on each wheel. This is an AC signal. Where abouts is 
the DC signal you've found? Does it come from the ABS ECU?

To use this voltage, you're going to need a analogue to digital 
converter, and a processor to convert this information to serial form, 
generally RS-232.

If you've absoloutley no hardware experience, it may prove to be a 
little problem. Try the Atmel site http://www.atmel.com and check 
out their AVR processors. If your more familier with PIC's then 
maybe try them. Simply get one with an ADC, and a UART built in. 
you can then code to convert the ADC inputs to a serial form that 
the PC will recognise. 

Personnaly, I will not be including the main ECU in the Traction 
Control system. I am unsure wich signals you'd modify to 'fool' the 
ECU into reducing engine power. I will simply defeat injectors 
directly. I may use the output of the crank sensor or something to 
define the timing required to defeat each injector.

The Atmel + PIC sites both have excellent info on using the Atmel 
with the ADC, and programming the UART, you'd just need an RS-
232 transeiver. 

Good Luck, let us know how it goes.

Cheers, Brian.

> Hello guys,
>   We've been following the diy traction control system for some time now and
> we've finally decided to get the ball rolling on our own. Our test vehicle
> is a 1999 Acura Integra equipped with ABS that is naturally aspirated (
> www.c-speedracing.com/integra.html )
> 
> Our current approach is as follows (in a nut shell):
> 
> 	- read input from existing ABS sensors
> 	- collect data from sensors to incar laptop via serial connection
> 	- process the data via some algorithm X
> 	- cut spark and/or fuel to reduce power due to wheelspin
> 
> We examined the ABS wiring diagram for the test vehicle and were able to
> read a signal for each wheel. This is the results from the readings:
> 
> 	Front wheels: 50mv and up (increases with vehicle speed)
> 	Rear wheels: 50mv and up (increases with vehicle speed)
> 
> 	At around 30mph the reading was around 140mv
> 
> 	The vehicle manual states that when the wheels are turned at 1 revolution
> per second, a digital 	meter should read 70mv or above in AC. From our
> testing, it looks like the faster the vehicle is 	traveling, the higher the
> voltage is.
> 
> Our next hurdle at this point is figuring out how to interface the ABS
> signal to our laptop through a serial connection. We have pretty extensive
> programming experience, however none that deals with hardware interface.
> We're wondering what we can do as far as implementing a serial connection
> and what is required as far as libraries (C++) and where to get them.
> 
> The reason we would like to use a serial connection is so that we can send
> modified signals to the ECU to reduce engine power. We're not sure how to do
> this yet as we haven't gotten that far to tackle that hurdle. On a side
> note, we talked about taking the analog input from the ABS sensors and
> feeding them to the microphone input jack on the laptop since there is an
> abundance of softare and libraries that will work with that. But I don't
> that is the best approach.
> 
> So, at this stage in the game, if anyone knows of how we can take that
> signal from the ABS and read it on a laptop, please let me know... we'd like
> further this developement as quickly as we can.
> 
> Thanks.
> 
> 
> Crescent Kao
> Director of Marketing and Sales
> www.c-speedracing.com
> 
> 
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> Diy-efi at diy-efi.org
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> 



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