Jordan James fuel assignment

Inputs

Input sensors:
O2 sensor.(DC)
Air temperature sensor.(DC)
Coolant temperature.(DC)
MAP sensor.(DC)
Crank/cam sensor.(Hz)
Throttle position sensor.(DC)


Ecu actuators:
Fuel injectors.(Hz, duty cycles)
VVTi.
Ignition Timing.(DC)


The Ecu is the 'hub'  of all the sensors and actuators.
This is the unit that controls both the fuel distribution and the timing of the spark plugs.


The O2 sensors measures the amount of oxygen molecules in the exhaust system and tells the Ecu if the engine is running rich or lean.

The air temperature tells the Ecu what the temperature of the air is, this is important because the temperature of the air changes its density. So the colder it is the more oxygen will be drawn into inlet manifold. If the this sensors is working incorrectly it give the ecu wrong readings, so the engine may run rich or lean.

The coolant  temperature tells the ecu what temperature the engine is, this is important so the ecu knows when the engine is at operating temperature and this will help the ecu decide when the engine should stop running rich to help warm it up. The coolant temperature will also turn on the coolant fan once it has reached a certain temperature.It will also help the ecu when to decide to lower the rpm to normal idle speed.

Crank and cam sensors help the ecu know where the crank and cam are. This helps the ecu to know what the correct timing is and when the ignition and fuel injectors should be operated.

The throttle position sensor tells the ecu if the person driving the car wants to accelerate, and will also help the ecu know how much are is being pushed through the throttle butterfly.

The map sensor tells the ecu how much air is available to the engine in the inlet manifold.


So an example of all these working.

Idling at the lights (engine warmed up).
Map sensor will tell the ecu there is little air in the inlet manifold .
The O2 sensor will likely say that the engine is running a little lean. ( because the engine does not need much fuel).

The coolant temperature will tell the ecu that engine is warm and may be beginning to rise above operating temperature, because the car is parked at the lights and will not be getting air flow over the engine to cool it down.

The air temperature sensor will tell the ecu the temp of the air.

The throttle position sensor will likely say that the throttle is closed and does not require more petrol for acceleration.

The crank and cam sensor are going to tell the ecu that the car is idling and requires a lean mixture to operate.

So the ecu will be getting all these signals and deciding what to do with the injectors and the ignition system. In this case it will likely say that the engine is idling and does not require much fuel and the timing of the engine does not need to be advanced any.


Accelerating from the lights.
The O2 sensor will say that the engine is running rich.
The crank and cam sensor will say that the car is accerating.
The tps sensor will say the person driving wishes to accelerate and the throttle butterfly is more open and that there is more air entering the inlet manifold.
The map sensor will tell the ecu that there is more air availible to the engine.
The coolant temp sensor will say the engine is at operating temp.

The ecu will interpret all these inputs as the person driving wishes to accelerate and will open the injectors longer allowing more fuel to enter the cylinders and creating more power. And may advance the timing of the  engine.

Closed loop is when the engine is cruising  and is able to enter this "closed loop" state. This is when the ecu will make adjustments on the fuel injectors by paying close attention to the O2 sensor, if the engine is rich it will spray less fuel, if it is lean it will spray more fuel. It does this constantly, by switching to lean and rich continuously the ecu will get as close to possible to lamda 1 as possible.
  This is perfect for cruising because the engine requires power to maintain a constant speed and it helps reduce the amount of emissions produced by the vehicle greatly. The ecu will not enter this state unless all the sensors are working and it is under the right conditions. 


Hey Steve sorry if this is not what the assignment was about, Ive been trying to get the adobe reader thing to work for along time and i cannot access the moodle file that is the assessment on input and outputs with close loop. I can only remember you telling us about it and from what other people have told it says. If there is anything else i need to put in here please let me know.

Thanks.
Jordan