1. Engine Management Systems and Calibration
Shaping the Future
Engine Management Systems and Calibration

2. Engine Management Systems
The basic role of an Engine Management System is to provide precise control of engine operation by managing fuel supply, ignition, and the quantity of air inducted into the engine
At the heart of every Engine Management System is an electronic control module (ECM), which is an on-board computer incorporating a digital microprocessor.
The ECM is linked to the engine by means of sensors installed on the engine (to read data about the operating conditions of the engine), and actuators such as ignition coils, stepper motors, relays, etc as the means for effecting control on engine operation.
The modern EMS also has to provide a comprehensive level of self-diagnosis in the case of faulty components or engine operation. This is referred to as On-Board Diagnostics (OBD).

3. Engine Management Systems
Engine Control Module (ECM)
Sensors
Actuators

4. Engine Management Systems
Early EMS
Fuel Tank
ECM
Fuel Pump
Distributor Based Spark Ignition
Throttle Position Sensor
Port Fuel Injector
Cold Start Injector
Gate – Air Mass Flow Meter
Idle Speed By-Pass

5. Engine Management Systems
Bosch L-Jetronic

6. Engine Management Systems

7. Engine Management Systems
Wide Band – Linear Lambda Sensor
Bosch Motronic MED EMS (Direct Petrol Injection)

8. Typical Functions of an EMS
Spark Advance Control (with or without Waste Spark)
Knock Control through Adaptive Spark Advance
Idle Speed Control
Independent Cylinder Fuel Injection (inc Multi Strike)
Exhaust Gas Recirculation Control
Adaptation for Alternative Fuels
Charcoal Canister Purge Control
Cam Phasing and Valve Lift
Variable Geometry Turbocharging and Intake Systems
Full Diagnostics (compliance with OBD legislation)
Cylinder Disablement for torque control
Engine Temperature Management

9. Main Components of an EMS
Electronic Control Module (ECM)
Crankshaft Speed Sensor
Camshaft Position Sensor
Fuel Pump
Fuel Injectors
Fuel Pressure Regulator
Air Mass Flow Meter
Manifold Absolute Pressure Sensor
Throttle Position Sensor
Throttle Actuator
Exhaust Gas Recirculation Valve
Idle Speed Air By-Pass Valve
Exhaust Gas Oxygen Sensor
Ignition Coil
Spark Plug
Sensors and Actuators

10. Sensors - Speed & Position
Variable Reluctance Crankshaft Speed Sensor
Hall Effect Camshaft Position Sensor
A voltage is generated transversely (between points E and F) to the direction of current flow (A to B) if a magnetic field is applied perpendicularly to the conductor. (usually a semiconductor)

11. Sensors – Mass Air Flow
Air Mass Flow Meter

12. Sensors – Oxygen Sensor
Oxygen or Lambda Sensor

13. Engine Control Module (ECM)
Delphi MT80 Control Module

14. EMS Control Overview
Fundamentally the Engine Management System (EMS) attempts to control the highly complex thermodynamic functions that define the continuously varying engine operating conditions, by providing the right quantities of air, fuel, timing of ignition, exhaust gas recirculation etc.
A theoretical approach to this problem would be to incorporate a complex set of mathematical models or algorithms that define every possible condition. The EMS would then only have to run these models in real time to correctly supply the desired fuel, air, egr and ignition advance.

15. EMS Control Overview
Algorithms used in the EMS are models that describe the operation of a particular function for given values of input data but also use some previously determined empirical data (maps)
An EMS will have a wide range of relatively simple models (also known as strategies) for specific control functions

16. Instructions to Actuators
EMS Control Overview
Data from Sensors
Instructions to Actuators
Structured 2-D and 3-D Maps or “Look Up Tables” (Maps) and algorithms (“Strategy”)

17. EMS Control Strategies
Spark Advance Control (with or without Waste Spark)
Knock Control through Adaptive Spark Advance
Idle Speed Control
Independent Cylinder Fuel Injection (inc Multi Strike)
Exhaust Gas Recirculation Control
Adaptation for Alternative Fuels
Charcoal Canister Purge Control
Cam Phasing and Valve Lift
Variable Geometry Turbocharging and Intake Systems
Full Diagnostics (compliance with OBD legislation)
Cylinder Disablement for torque control
Engine Temperature Management

18. EMS Strategy Example Idle Speed Control
Idle speed variation is caused by;
Changes in auxiliary power take off requirements, for example air compressors and alternators.
Combustion performance variability (eg COV of IMEP)
Driver input – “blipping the throttle”
The task of the idle speed control system is to primarily manage the step torque demands of the auxiliary systems through air flow control and ensure that the idle speed is kept as low as possible

19. EMS Strategy Example Idle Speed Control Inputs Outputs
Engine Speed
Engine Load
(Man Abs Press)
Dynamic Control Loops
Energy conversion
Intake manifold
Torque balance
Outputs
Air mass flow
modulator
Plant Model
(algorithms & maps)

20. EMS Strategy Example Idle Speed Control Air Manifold Pressure
Engine Speed
Intake air flow rate
Man Press
Engine Torque
Engine Friction Load

21. EMS Strategy Example Idle Speed Control
Manifold Air Mass Outflow Estimation (Map)
Engine Speed
Manifold Pressure
Integrator
Manifold Air Mass Inflow
dpm /dt = (1/)  dmin/dt – dm*out/dt 

22. EMS Strategy Example Idle Speed Control Engine Speed Engine Speed
Integrator
Man Press
Combustion Torque Pulse per Cylinder
(Map)
Torque Delay due to cylinder firing order (dead time & lag)
2J (dn/dt) = Tcomb - Tload

23. Air Mass Flow Modulator
EMS Strategy Example
Idle Speed Control
Air Mass Flow Modulator
Proportional & Integral Controllers

24. “The process of determining the calibre of a gun”
Engine Calibration
Term coined in late 1980s
The precise measurement and optimisation of the characteristics of an engine and drive train in all possible vehicle model variants
A Calibration Engineer instigates the measurement of the engine characteristics and subsequently decides which are the optimum
The Engineer includes the optimum values within the engine EMS
Calibration
“The process of determining the calibre of a gun”
Brian Hall

25. Typical Calibration Programme
Initial calibrations based on previous experience
Testing of prototype engines on an engine dynamometer
Calibration transferred to vehicle for refinement
Successive approximations
Homologation
Final Calibration Validation
Sold to production
+90 days support
2 to 3 Years
Brian Hall

26. “Tools of the Trade” Engine Test Cell Vehicle Chassis Dynamometer
Linear AFR sensor
Measurement & Calibration (Interface) System
Automated Calibration System
Cold and Hot chambers
(and/or equivalent ambients)
Emissions Lab
Test Track
Analysis tools Excel Matlab Simulink Model Based Calibration toolbox
Brian Hall

27. Measurement & Calibration System
e.g. AVL CAMEO
e.g. ATI Vision
Brian Hall

28. MCS Calibration Tool – ATI Vision
Brian Hall

29. MCS Calibration Tool – ATI Vision
Engine Speed
Lambda
Throttle Position
Brian Hall

30. MCS Calibration Tool – ATI Vision
Brian Hall

31. Automated Calibration – AVL Cameo
Optimises Engine Testing using Design of Experiments Models to gather data for EMS Maps
Brian Hall

32. Thank You for Listening