Popee
Newbie level 3
Hey everyone Im new here! I was wondering if you could help me solve a problem. I am developing a Traction Control System for a Formula Student RaceCar www.formulastudent.com
As an Electronic Engineer I head a 2 man team that must design a digital dash and traction control system utilizing a CAN network on the car.
The CAN network and digital dash are almost complete, I am however having one problem with regards to Traction Control.
For the traction controller I am using a PIC18F1320 to read wheel speeds from the CAN network, calculate slip and adjust the firing sequence of the injectors accordingly.
My problem lies with actually cutting the injector pulses so the injectors do not deliver any fuel.
When I was developing the system I designed it with the assumption that the injector is permanently grounded and the Engine ECU supplies the injector with 12v when an injector is required to deliver fuel. The injector cut would be achieved by this simple system.
**broken link removed**
However, after reading further literature on websites and texts books; it is evident that in most cases the injector is permanently connected to 12v and the Engine ECU grounds the injector when it wishes to deliver fuel. This is where I am stuck; I am unable to come up with any satisfactory way to interrupt the signal. This is one idea I have:
**broken link removed**
The TCS has an input pin that measures the voltage across the engine ECU, when the Engine ECU wishes to fire the injector the voltage will drop as it is now connected to ground. Once I have detected that I could switch off a power transistor in the Traction Control unit keeping the injector turned off; however how would I know when to return the injector back to its normal state? Do I just wait two revolutions of the engine or do you have a sensor that detects when the Engine ECU intents to turn off the injector by returning to a high impedance state?
Im not sure if this will work or if I am over complicating things.
I don’t really wish to try any of the above methods on our engine as it is a brand new engine costing $6000 and if I get it wrong and manage to mess up the fuelling I could destroy the engine and the team has no money for a replacement engine, which means our 25+ strong team would not get to race at Silverstone this year after a year of dedication.
I apologise for the Rant and I hope someone understands what I am trying to acheive as im finding hard to explain it.
Any help would be much apprechiated.
regards,
Lee
As an Electronic Engineer I head a 2 man team that must design a digital dash and traction control system utilizing a CAN network on the car.
The CAN network and digital dash are almost complete, I am however having one problem with regards to Traction Control.
For the traction controller I am using a PIC18F1320 to read wheel speeds from the CAN network, calculate slip and adjust the firing sequence of the injectors accordingly.
My problem lies with actually cutting the injector pulses so the injectors do not deliver any fuel.
When I was developing the system I designed it with the assumption that the injector is permanently grounded and the Engine ECU supplies the injector with 12v when an injector is required to deliver fuel. The injector cut would be achieved by this simple system.
**broken link removed**
However, after reading further literature on websites and texts books; it is evident that in most cases the injector is permanently connected to 12v and the Engine ECU grounds the injector when it wishes to deliver fuel. This is where I am stuck; I am unable to come up with any satisfactory way to interrupt the signal. This is one idea I have:
**broken link removed**
The TCS has an input pin that measures the voltage across the engine ECU, when the Engine ECU wishes to fire the injector the voltage will drop as it is now connected to ground. Once I have detected that I could switch off a power transistor in the Traction Control unit keeping the injector turned off; however how would I know when to return the injector back to its normal state? Do I just wait two revolutions of the engine or do you have a sensor that detects when the Engine ECU intents to turn off the injector by returning to a high impedance state?
Im not sure if this will work or if I am over complicating things.
I don’t really wish to try any of the above methods on our engine as it is a brand new engine costing $6000 and if I get it wrong and manage to mess up the fuelling I could destroy the engine and the team has no money for a replacement engine, which means our 25+ strong team would not get to race at Silverstone this year after a year of dedication.
I apologise for the Rant and I hope someone understands what I am trying to acheive as im finding hard to explain it.
Any help would be much apprechiated.
regards,
Lee