DBW whats required

[Gizmo]

Fancy having a fiddle with this for a few reasons. I notice there appears to be some External Electrickery involved. What exactly is required, i.e. how many Outputs from the Syvecs are required to impliment etc. ?


cheers ---john---

[Gizmo]

Ah, the penny drops after looking at SCal. There are only two Drive by Wire outputs so I assume the external circuitry is an H Bridge to drive the Throttle Motor, then just two more inputs for pedal position and throttle position.

---john---

[pat]

You kinda got it

You need....

• ppsA and ppsB, the two pedal position sensors
• tps1A and tps1B, the two throttle position sensors
• dbw1, the DBW control duty output
• an H-Bridge driver to make the DBW motor work

You must have two pedal position sensors for safety reasons, and they must agree with each other, if they do not, DBW shuts down. You must also have two throttle position sensors for safety reasons and they must agree with each other, if they do not, DBW shuts down. You need a control output to make the motor move; whilst it is possible to use a PWM or INJ output to directly drive the motor you will be relying on the spring to close it, so an H Bridge is better. The H Bridge takes a 3.8kHz PWM signal and turns it into a 32kHz bidirectional drive signal; 50% duty is no drive, down from 50% to 15% is progressively more drive in one direction and up from 50% to 85% is progressively more drive in the other direction. Normally the H Bridge module is driven from an IGN output on an S6.

The DBW system has PID control over the DBW motor and of course a demand map, which translates between PPS and desired TPS (sometimes you find that inertial supercharging is better at part throttle in the midrange so it may be sensible to limit throttle opening there; indeed some wild NA motors benefit from this almost across the board). The system does tolerate some error between desired and actual position, for a small amount of time (both are configurable) but any large or long term errors will again result in DBW shutdown.

Hope this helps,

Pat.

[Gizmo]

Thanks for that Pat, don't have a peddle in my hand yet, only the body. but that explains a couple of issues.

Sitting here with a DBW throttle in bits and couldn't understand why the Hall effect sensor had 4 wires. It's nice I guess from a reliability point of view to have no moving parts in the sensors but a pain in the ass to try to figure out how it's wired.

So I'll assume I'll find similar on the peddle mech. incidentally is that Hall or Resistor, do you know ?

If you had pinouts for peddle it would be handy, save me a bit of scratching about ?

Recieved new ECU from Andy today, thanks for that.

---john---

[Gizmo]

Received DBW Peddle and had it in bits too. Dual Hall Sensors in there too, nice reliable setup hopefully.

---john---