quantity corrections.pdf

1Quantity Correction Functions

Confidential | DS/ENA | 19/08/2010 | Bosch Limited 2010. All rights reserved, also regarding any disposal, exploitation, reproduction, editing,

distribution, as well as in the event of applications for industrial property rights.

Quantity Correction Functions




ZFLZFL

ZeroFuel Calibrn @ Low Idle




ZFLZFL



Confidential | DS\ NE | 19/08/2010 | Bosch Limited 2010. All rights reserved, also regarding any disposal, exploitation, reproduction, editing,


Injector Quantity Adjustment (IQA)

Concept

Effect of IMA

Advantages




Injector Quantity Adjustment (IQA/IMA)




Injector Quantity Adjustment (IQA)





Operating Principle

The deviation of the individual injector quantity to the nominal qty at the test point is used

ECU adjustment values represent the difference to the specified values of the respective test point Encoded on Injector

EOL programming to the ECU

IQA helps

To have better control on emission values

Equal Injection quantity for each cylinder

Increase of the injector first pass yield (FPY)

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Programming of the Control Unit (ECU)

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Processes for EOL-Programming

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ZFLZFL


13




FBC Fuel Balance Control

FBC Overview

Benefit for Emission

Application Boundary condition

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FBC Fuel Balance ControlFeatures

Correction of Cylinder to cylinder quantity deviations over lifetime

Reconstruction of fuel quantity deviations using engine speed signal

Smooth running control fulfils this task at low engine speeds

Fuel quantity control fulfils this task at all the speed ranges, using

Precise engine speed evaluation

Filtering of crankshaft oscillations

Pulse generator wheel correction in overrun

Benefits

Smooth running of engine

Lower exhaust emissions

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FBC Overview FBC uses information from the speed sensor to calculate correction

quantities in order to :

- Maintain a smooth engine speed for higher comfort and

- Less deviations from mean fuel quantity value for better emission results

FBC equals injection quantities between cylinders

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0000 5555 10101010 15151515 20202020 25252525 30303030 353535350000

0.50.50.50.5

1111

1.51.51.51.5

2222

2.52.52.52.5

3333

3.53.53.53.5

4444

4.54.54.54.5

5555

Frequency [Hz]Frequency [Hz]Frequency [Hz]Frequency [Hz]

Epm _nEng_w/o FBCEpm _nEng_w/o FBCEpm _nEng_w/o FBCEpm _nEng_w/o FBC

Epm _nEng_wi th FBCEpm _nEng_wi th FBCEpm _nEng_wi th FBCEpm _nEng_wi th FBC


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FBC Evaluation

FBC benefit

FFT Analysis Engine Speed

FFT Analysis shows benefit of FBC at CaS, 2CaS and 3CaS

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Evaluation of FBC

350

300

250

200

150

100

703...

702...

701...

700...

699...

698...

697...

700

650

600

550

500

450

400

350

300

2

1

0

-1

-2

FBC Off

FBC On

FBC Off

FBC Quantity

Engine Speed

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FBC Calibration is dependent on engine and drive train behaviour

Change in engine/drive train mechanics requires new calibration or a

validation of the calibration

Typical changes are Flywheel, drive train, engine mounting

Change in drive train concept like manual to automatic gearbox

Often same engine on different vehicle requires validation

FBC cannot be calibrated on engine test bench

FBC is calibrated at the beginning of the vehicle calibration phase

FBC has to be validated on series intended vehicle

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ZFLZFL


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ZFC - Zero Fuel Calibration

Overview of ZFC

Application Boundary condition

Service Concept

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ZFC Zero Fuel Calibration

Goal

Compensation of pilot injection quantity drift over lifetime to comply with emissions in the long run

Function

Calibration of pilot injection quantity by engine speed signal by variation of energising time in overrun ( learning time upto 3000Km)

Pilot injection corrections are based on the learning

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25





Application Boundary Conditions

ZFC should be Calibrated for

Each variant of engine / gearbox (PP batch vehicle with final hardware)

Application of each variant on roller test bench

Exact quantity should be measured, as basis for calibration

( eg.C-balance or Weighing method)

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Service Concept

ECU changed

- Read out of ZFC value from EEPROM of old ECU and copy to new ECU

All injectors changed

- Reset EEPROM ZFC value

One / more injector changed

- Reset EEPROM ZFC value of individual cylinder

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ZFLZFL


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Confidential | ENA32/Stk | 19/08/2010 | Bosch Limited 2010. All rights reserved, also regarding any disposal, exploitation, reproduction,

editing, distribution, as well as in the event of applications for industrial property rights.

ZFL what does it mean?

Z F L

Zero Fuel

Energizing Time

Inje

cte

d Q

ty

Calibration

during

Low Idle

29

ZFL Overview

Confidential | ENA32/Stk | 19/08/2010 | Bosch Limited 2010. All rights reserved, also regarding any disposal, exploitation, reproduction,


Function Overview

Cylinder individual calibration of pilot injection quantity drift over lifetime

Calibration by evaluation of low idle governorw/o cylinder balancing

Calibration for SV injectors w/o plateau

Customer Benefit

Applications

Off highway (no overrun mode required)

1- and 2-cylinder engines (no cylinder balancing)

Open market business (no drive train dependency)

Due to noise during calibration not for PC

I

Low Idle governor

qact,PI_on = qact,PI_off

shut off PI

Tolerances

EDCMetering

qPI ~ (nPIMI nMI)

qSetPIMI MI

Compliance with exhaust gas emission levels

No additional sensor necessary

Low calibration effort

Fast learning cycle

Features

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ZFL Overview



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ZFL Overview



Measurement Principle

Signal indicating PiI-quantity too low

nlow idle

1 2 3 4 1 2 3 4

Energizing

Current engine speed

Calibration Procedure:

Pilot Injection (PiI) is switched off every second camshaft revolution

Engine Speed Signal indicated PiI too low or PiI too high

Energising time of PiI is increased/decreased until correct PiI quantity

is reached

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correction map (EEPROM)

ZFL calibration

in low idle

ETZFL

ETZFL

ETBase

(ET-Map, IQA)cyl

pRail

The difference between ET found by ZFL and base ET is filtered and

stored in a correction map.

Filtering is done to minimize noise influences.

The stored learning values are used to correct the energizing times in the

low quantity range.

Filtering and storage of learning values

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ZFLZFL


35




PWC Pressure Wave Correction

Pressure in the line from the rail to the injector (HP line) is a function of the fuel quantity

It takes certain time for pressure to be stable.

Pline varies as a waveform during this period.

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PWC Pressure Wave Correction

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quantity corrections.pdf

Documents

industrial property

bosch limited

event of applications

individual injector

ecu adjustment values

injector eol programming

zflzflzerofuel calibrn

ecu iqa