AUTOMOTIVE ELECTRONICS
(21ECE112)
Dr. Bommegowda K. B.
Assistant Professor
Department of Electronics and Communication Engineering
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Course Learning Objectives:
After studying this Course, the student should be able to:
• Understand the overall Electrical and Electronic architecture of a
vehicle
• Understand the working of sensors and actuators used in
Automotive applications
• Understand the use of different communication protocols used in
Automotive systems
• Know about the AUTOSAR in the open-source platform for
Automotive development
• Know about the Automotive Control Systems
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UNIT – I
Electrical and Electronic Systems in the Vehicle:
Overview, Motronic-engine management system,
Electronic diesel control, Lighting technology,
electronic stability program, adaptive cruise control,
Infotainment System.
Automotive Sensors & Measuring Principle:
Air Flow Rate Sensor, Engine Crankshaft Angular
Position Sensor, Magnetic Reluctance Position Sensor,
Hall-Effect Position Sensor, Optical Crankshaft Position
Sensor, Throttle Angle Sensor, Temperature Sensors,
Exhaust Gas Oxygen Sensor, Knock Sensors,
Automotive Engine Control Actuators
15 Hours
UNIT - II
• In Vehicle Networking:
Need for In-vehicle Networking, Vehicle buses. Overview
of CAN, LIN, Flex Ray, MOST protocols. Vehicular ad
hoc networks (VANETs).
• AUTOSAR Concepts:
Architecture, Methodology and Application Interfaces.
ECU SW Architecture, Virtual Function Bus, Abstraction
Layer, BSW, RTE, ECU Communication.
15 Hours
UNIT - III
Architecture of Electronic Systems & Control Units:
Basics and Overview, vehicle system architecture. Control
units, Operating conditions, Design and data processing.
Digital modules in the control unit. Automotive
Applications.
09 Hours
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Course Outcomes
CO1 Describe the overall Electrical and Electronic architecture of a vehicle
CO2 Explain the operation of Basic Automotive sensors and actuators.
Explain the need and requirements of various Communication protocols
CO3
used in Automotive Applications.
CO4 Explain the architecture & Methodology of AUTOSAR.
CO5 Describe the various aspects of Automotive Control Systems.
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Text Books:
• Robert Bosch GmbH, “Bosch Automotive Electrics and Automotive
Electronics”, 5th Edition. John Wiley & Sons Ltd, 2007.
• William B. Ribbens “Understanding Automotive Electronics”, 6th Edition,
Elsevier, 2003.
• KPIT Technologies Ltd. “KPIT-AUTOSAR Handbook”,
https://www.kpit.com/resources/downloads/kpit-autosar-handbook.pdf
Reference Book:
• Tom Denton, “Automobile Electrical and Electronic Systems”, 3rd Edition,
Elsevier Butterworth-Heinemann Publication, 2004.
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Assessment Weightage in Marks
Mid Semester Exam 1 (MSE1) 20
Mid Semester Exam 2 (MSE2) 20
Mini-project 10
Total 50
Teaching No. of Full Questions in* Course
Unit Name
Hours MSE1 MSE2 SEE Outcome
Electrical and Electronic
Systems in the Vehicle,
I 15 4 - 03 CO1, CO2
Automotive Sensors &
Measuring Principle
In Vehicle Networking &
II AUTOSAR Concepts 15 - 4 03 CO3, CO4
Architecture of Electronic
III 9 - - 02 CO5
Systems & Control Units
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SL.
Activity End Date
No.
Group Formation and Topic
1. 13-Feb-2024
Finalization
Proposal/Abstract Submission
2. (with block diagram & 23-Feb-2024
requirements)
3. Mid-Term Progress Report 13-March-2024
Final Submission &
4. Before MSE-II
demonstration
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Compound annual growth rate for electronics systems (2015-2020).
Electronic systems as % of total car cost
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• Automotive electronics are any electrically-
generated systems used in road vehicles.
• Automotive electronics originated from the
need to control engines.
• The first electronic pieces were used to control
engine functions and were referred to
as Engine Control Units (ECU).
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• As electronic controls began to be used for more
automotive applications, the acronym ECU took on the
more general meaning of "Electronic Control Unit",
and then specific ECU's were developed.
• Two types include,
Engine Control Modules (ECM)
Transmission Control Modules (TCM)
• A modern car may have up to 100 ECU's and a
commercial vehicle up to 40.
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According to different domains in the
automotive field, they can be classified into:
• Engine electronics
• Transmission electronics
• Chassis electronics
• Passive safety
• Driver assistance
• Passenger comfort
• Entertainment systems
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Engine Electronics
• Most demanding electronic parts of an automobile is the engine
control unit.
In a diesel engine:
• Fuel injection rate
• Emission control
• Regeneration of oxidation catalytic converter
• Turbocharger control
• Cooling system control
• Throttle control
In a gasoline engine:
• Lambda control
• OBD (On-Board Diagnostics)
• Cooling system control
• Ignition system control
• Lubrication system control (only a few have electronic control)
• Fuel injection rate control
• Throttle control
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Transmission Electronics
• Mainly the shifting of the gears for better shift comfort
and to lower torque interrupt while shifting.
• Automatic transmissions use controls for their
operation, and also many semi-automatic transmissions
having a fully automatic clutch or a semi-auto clutch.
• The engine control unit and the transmission control
exchange messages, sensor signals and control signals
for their operation.
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• AGS (Auto Gear Shift) is also called Auto or Self-Shifting
Transmission, is a type of gearbox which automatically
changes gear ratios, it allows an internal combustion engine
to provide speed and torque o/p necessary for the car
movement.
• AGS does not depend on a clutch to change gears in the car,
instead, it shifts gears by hydraulically locking and unlocking
the system of gears.
• AMT (Automated manual transmission) is also known as
Clutch-less Manual Transmission or Semi-Automatic
Transmission, basically it is an automatic gearbox which does
not change gears automatically but facilitates manual gear
changes without the need to depress the clutch pedal
manually.
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Chassis electronics
The chassis system has lot of sub-systems which
monitor various parameters and are actively
controlled.
• ABS - Anti-lock Braking System
• TCS – Traction Control System
• EBD – Electronic Brake Distribution
• ESP – Electronic Stability Program
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Passive safety
These systems are always ready to act when
there is a collision in progress or to prevent it
when it senses a dangerous situation:
• Air bags
• Hill descent control
• Emergency brake assist system
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Driver assistance
• Lane assist system
• Speed assist system
• Blind spot detection
• Park assist system
• Adaptive cruise control system
• Pre-collision Assist
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Passenger Comfort
• Automatic climate control
• Electronic seat adjustment
• Automatic wipers
• Automatic headlamps - adjusts beam automatically
• Automatic cooling - temperature adjustment
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Entertainment systems
(Infotainment systems)
• Navigation system
• Vehicle audio
• Information access
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UNIT – I
ELECTRICAL AND ELECTRONIC SYSTEMS IN
THE VEHICLE , AUTOMOTIVE SENSORS &
MEASURING PRINCIPLE
• Task of an electronic system:
Open-loop and closed-loop control
The nerve center of an electronic system is the control
unit.
All the open and closed-loop algorithms of the electronic
system run inside the control unit.
The heart of the control unit is a microcontroller with the
program memory (flash EPROM) 32
Function modules of an electronic system
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• The input variables for the sequence control are derived
from the signals from sensors and set-point generators.
• They influence the calculations in the algorithms, and thus
the triggering signals for the actuators.
• These convert into mechanical variables, the electrical
signals that are output by the microcontroller and amplified
in the output stage modules.
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Communication
Many systems have a mutual influence on each other.
Ex: it may sometimes be necessary to not only have the ESP carry
out a braking intervention in the event wheel spin but also to
request that the engine-management system reduce torque and
thus counteract wheel spin.
The systems are networked with each other, i.e. they are
able to communicate with each other on data buses
(e.g. CAN, LIN).
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1.2 Motronic Engine-Management System
“Motronic” is the name of an engine-management system that
facilitates open & closed-loop control of gasoline engines within a
single control unit.
Functions
• To adjust the torque desired & input by the driver depressing the
accelerator pedal.
• To operate the engine in such a way as to comply with the
requirements of the ever more stringent emission-control
legislation.
• To ensure the lowest possible fuel consumption.
• To guarantee high levels of driving comfort & driving a pleasure.
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• Motronic comprises all the components which
control & regulate the gasoline engine.
1. The electrically actuated throttle valve
(air system) This regulates the air-mass flow to
the cylinders & thus the cylinder
charge.
2. The fuel injectors (fuel system)
This monitors the correct amount of
fuel for the cylinder charge
3. The ignition coils & spark plugs (ignition
system)
Correctly timed ignition of the air-
fuel mixture present in the cylinder
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Inductive Ignition System:
➢ Ignition driver stage (4), which is integrated into the Motronic ECU or in the
ignition coil
➢ Ignition coils (3)
➢ AAS diode (2) [Activation Arc Suppression]
➢ Spark plugs (5) & Connecting devices and interference suppressors 38
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1.3 Electronic Diesel Control (EDC)
• Function of the EDC is to control the injected fuel quantity & the
injection timing.
• Electronic control of a diesel engine enables precise &
differentiated modulation of fuel-injection parameters.
• The injected fuel quantity is determined by a number of
influencing variables.
• Driver command (accelerator-pedal position)
• Operating status
• Engine temperature
• Interventions by other systems
• Effects on exhaust emissions
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EDC SYSTEM BLOCKS
The EDC is divided into three system blocks:
sensors/set-point generators,
ECU, and
actuators, 41
Used to detect operating conditions and set-point values.
Convert physical variables to electrical signals.
Process the information from the sensors and set-point generators in
mathematical computing processes.
Controls the actuators by electrical o/p signals.
It acts as an interface to other systems.
Convert the electrical o/p signals from the ECU into
mechanical variables.
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1.4 Lighting Technology
• Most important light sources for the lighting systems
on the vehicle are front and rear are halogen lamps,
gas-discharge lamps, & LEDs.
Incandescent (vacuum) bulb:
1 Glass bulb
2 Filament
3 Lamp socket base
4 Electrical connection
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Halogen lamp:
• Bulb is made of quartz glass.
• The halogen lamps H1, H3, H7, HB3 and HB4 only have
one filament.
• They are used as light sources for the low & high-beam
and fog lights.
• The filament to heat up to temperatures approaching
tungsten’s melting point (around 3,400°C), thereby
achieving high levels of luminous power.
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1 Glass bulb
2 Low-beam filament with cap
3 High-beam filament
4 Lamp base
5 Electrical connection
H4 halogen lamp
1 Tungsten filament
2 Halogen charge (iodine or bromine)
3 Evaporated tungsten
4 Halogenated tungsten
5 Tungsten deposits
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Main Headlamps
• Provide maximum visual range
• It is vital to provide the lateral illumination needed to
safely negotiate bends.
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High beam:
The maximum luminous intensity which is available
during high-beam operation is largely a function of the
reflector’s mirrored surface area.
1. Low-beam filament
2. Cap
3. High-beam filament
at focal point
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Low beam (dipped beam):
• The low beams serve as the primary source of light
under normal conditions
1. Low-beam filament
2. Cap
3. High-beam filament
point
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Headlamp Systems
a. Dual-headlamp system
b. Quad headlamp
system
c. Six-headlamp system
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1.5 Electronic Stability Program (ESP)
• It is a closed-loop system designed to improve
drivability through programmed intervention in the
brake system.
• The integrated functionality of ABS prevents the
wheels from locking when the brakes are applied,
while TCS inhibits wheel spin during acceleration.
• overall role is to prevent the vehicle’s tendency to
become unstable.
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ESP control loop in vehicle
1. Yaw-rate sensor 2. Steering-wheel angle sensor 3. Brake-pressure sensor
4. Wheel-speed sensors 5. ESP control unit 6. Hydraulic modulator 7.
Wheel brakes 8. Engine-management system 9. Fuel injection
Only for gasoline engines:
10. Ignition-timing intervention
11. Throttle-valve intervention (ETC)
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Sensors that determine
the controller input ESP-CU with its structured controller,
parameters higher level vehicle dynamics controller,
Subordinate slip controllers
Used for control of braking,
drive, and side forces
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• It is a gyroscopic device that measures a vehicle's angular
Yaw-rate
velocity around its vertical axis.
Steering-
wheel angle
• It measures the steering wheel position angle and rate of turn.
Brake- • It is used to detect the pressure distribution across many braking
pressure surfaces.
Wheel- • It is used for reading the speed of a vehicle's wheel rotation.
speed
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Antilock Brake System (ABS)
• It detects incipient lock on one or more wheels and
makes sure that the brake pressure remains constant
or is reduced.
• It prevents the wheels from locking-up and the vehicle
remains steerable.
➢ Wheel-speed sensors
➢ Electronic Control Unit (ECU)
➢ Hydraulic modulator
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Speed sensors are located on each wheel or, in some
cases, in the differential. To generate a signal, these
sensors use a magnet, a Hall effect sensor, or a
toothed wheel and a coil of electromagnetic energy.
Pump is used to restore pressure to the
hydraulic brake after the valves have
been released. A signal from the ECU will
release the valve upon detection of wheel
slip.
Every wheel speed sensor
sends information to the
ECU. The controller receives
a signal when a wheel loses
traction.
Each brake controlled by ABS has a valve in its brake
line. Some systems have three positions for the valve
•Position one has the valve open; the master cylinder’s pressure is passed directly to the brake
•In position two, the valve blocks the line, separating that brake from the master cylinder. As a result, if
the driver pushes the brake pedal harder, the pressure won’t rise further.
•During position three, the valve releases some brake pressure. 58
ABS control loop:
1. Brake pedal
2. Brake booster
3. Master cylinder with
expansion tank
4. Wheel-brake cylinder
5. Wheel-speed sensor
6. Warning lamp
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It is based on the objective to keep
the wheels from getting locked up
and to maintain the traction
between the tire and road surface
controls the brake actuator based
on the output from the electronic
feeds the wheel spin velocity to the control unit.
electronic control unit, and give an
output signal to the brake actuator
control unit.
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Adaptive Cruise Control (ACC)
• It can be categorized as a driver-assistance system.
• Cruise control regulates driving speed to maintain the
desired speed selected by the driver using the
cruise-control unit.
• It measures the distance to the vehicle in front & its
relative speed.
• It also adapt the vehicle’s speed to match the speed of
the vehicle traveling in front and maintain a safe
distance from it.
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Basic structure and components of the ACC control system
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Components of the ACC System
• Distance Sensor
• Network Architecture
• Course Setting
• Setting Options
• Engine-Control Interventions
• Brake Intervention
• Control & Display
• System Limits
• Control Algorithms
• Object Detection & Lane Allocation
• Ranging RADAR
• Measuring Principles of ACC
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• Distance sensor
▪ ACC systems currently have a
radar sensor.
▪ Frequency range of b/w 76 and 77
GHz.
▪ Emits four radar lobes.
▪ ACC detects a range of up to ~200
m in front of the vehicle.
▪ Radar beams reflected by vehicles
in front are analyzed for timing,
Doppler shift and amplitude ratio.
▪ These factors are used to calculate
distance, relative speed and angle
position relative to vehicles in
front.
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• Network Architecture
▪ ACC function cannot be
represented in dependently as a
stand-alone system
▪ various subsystems must
be networked with each other.
▪ The evaluation and control
electronics (control unit) of the
ACC are integrated in the sensor
housing.
▪ They receive and send data on a
CAN data bus from and to other
electronic control units.
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• Control algorithms
Control module 1: cruise control
Control module 2: follow-up control
Control module 3: control when cornering
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If the RADAR sensor has not detected any
Control Module – 1
vehicles in front, the s/m maintains the
(Cruise Control)
desired speed set by the driver
If the RADAR sensor has detected vehicle
Control Module – 2 in front.
(Follow-up Control) Controller maintains the time gap to the
nearest vehicle at a constant settings
Control Module – 3 When negotiating tight bends, the RADAR
(Control when Cornering) sensor can “lose of sight” of the vehicle in
front because of limited of field of vision
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Ranging radar
• Radar transceiver unit transmits packets of EM waves using an
antenna. These reflect off an object made of electrically
conductive materials (e.g. vehicle body) and are then received.
• The received signals are “compared” with the transmitted
signals with respect to their propagation time and/or frequency.
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Measuring Principles of ACC
• Propagation time Measurement
(Direct Propagation)
• Frequency Modulation
(Indirect Propagation)
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RADAR sensor
Sensor alignment in vehicle
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Automotive Sensors & Measuring Principle
• Sensors and actuators play a critical role in determining
automotive control system performance.
• Sensors are used to transform (or transduce) physical
quantities into output signals (electrical) that serve as inputs for
control systems.
• Actuators are electrically operated devices that regulate
inputs to the plant that directly control its output.
• Actuators are the devices, that are operated by outputs from the
ECU.
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• The superset of variables sensed in engine control includes the
following:
1. Mass air flow (MAF) rate
2. Exhaust gas oxygen concentration
3. Throttle plate angular position
4. Crankshaft angular position/RPM
5. Coolant temperature
6. Intake air temperature
7. Manifold absolute pressure (MAP)
8. Differential exhaust gas pressure
9. Vehicle speed
10. Transmission gear selector position
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Air Flow Rate Sensor
• Requires a measurement of the mass flow rate of
air (Rm) into the engine.
• The Mass Air Flow rate (MAF) sensor is a
variation of a classic air flow sensor that was
known as a hot wire anemometer.
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Engine Crankshaft Angular Position
Sensor
• Crankshaft angular position is an important
variable in automotive control systems, particularly for
controlling ignition timing and fuel injection timing.
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• Crankshaft angular position can be sensed directly at the camshaft,
since the camshaft rotates at exactly one-half the speed of the
crankshaft.
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Magnetic Reluctance Position Sensor
• Engine sensor configuration that measures crankshaft position directly (using
magnetic phenomena).
• This sensor consists of a permanent magnet with a coil of wire wound around it.
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Hall-Effect Position Sensor
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Optical Crankshaft Position Sensor
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Throttle Angle Sensor/ Throttle Position Sensor (TPS)
A TPS is a sensor used to monitor the air intake of an engine.
Modern-day sensors are non-contact type.
These modern non-contact TPS include Hall effect sensors, inductive sensors, and
magneto resistive.
In the potentiometric type sensors, a multi-finger metal brush is in contact with a resistive
strip.
Inside of the throttle position sensor (potentiometer) from a Bosch
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Most throttle angle sensors are essentially
potentiometers. A potentiometer consists of a resistor
with a movable contact
v(a) = k*a
V(a) - Voltage at the contact point
K – Constant
a – Angle of the contact point from
the ground connection
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Temperature Sensors
• Temperature is an important parameter
throughout the automotive system.
• In operation of an electronic fuel control system
it is vital to know the temperature of the
➢coolant
➢inlet air
➢exhaust gas oxygen sensor
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Typical Coolant Sensor
• One kind of coolant sensor uses a temperature-sensitive
semiconductor called a thermistor.
• The sensor is typically connected as a varying
resistance across a fixed reference voltage.
• As the temperature increases, the output voltage
decreases.
• A thermistor is made of semiconductor material whose
resistance varies inversely with temperature.
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• Coolant temperature sensor resistance is denoted
RT. This resistance is connected to a reference voltage
through a fixed resistance R.
• The sensor output voltage, VT,
sensor output voltage varies inversely with temperature;
the output voltage decreases as the temperature increases.
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SENSORS FOR FEEDBACK
CONTROL
• The feedback control for fuel delivery is based on
maintaining the air/fuel ratio.
• The primary sensor for fuel control is the Exhaust
Gas Oxygen Sensor
• Knock Sensor
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Exhaust Gas Oxygen (EGO) Sensor
(lambda sensor)
• Primary sensor for fuel control.
• Amount of oxygen in the exhaust gas
is used as an indirect measurement of
the air/fuel ratio.
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• The two types of EGO sensors
that have been used are based
on the use of active oxides of
two types of materials.
Zirconium dioxide (ZrO2)
Titanium dioxide (TiO2)
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EGO Characteristics
1. Abrupt change in voltage at stoichiometry
2. Rapid switching of output voltage in response to
exhaust gas oxygen changes
3. Large difference in sensor output voltage between
rich and lean mixture conditions
4. Stable voltages with respect to exhaust temperature
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Switching Characteristics
Ideal EGO Switching Characteristics Typical EGO Sensor Characteristics
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Knock Sensors
• Another sensor having applications in closed-loop
engine control is -----knock sensor.
• It is employed in closed-loop ignition timing to prevent
undesirable knock.
• It is important to detect knock and avoid excessive
knock; otherwise, there may be damage to the engine.
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• A key to the control loop for this method is a knock
sensor.
• Knock sensor uses magnetostrictive technique.
• One way of controlling knocking is to sense when
knocking begins and then retard the ignition until
the knocking stops.
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Automotive Engine Control Actuators
• In addition to the set of sensors, electronic engine
control is critically dependent on a set of actuators to
control air/fuel ratio, ignition, and EGR.
• In general, an actuator is a device that receives an
electrical input & produces a mechanical or thermal
output.
• Ex:
➢ Electric motors
➢ Solenoids
➢ Piezoelectric force generators
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• In automotive electronics the solenoid is the most
commonly used device because it is relatively simple &
inexpensive.
• The solenoid is used in precise fuel control
applications.
• A solenoid is an essence of powerful electromagnet
configuration.
• Applications
➢ Fuel injectors
➢ EGR valves 101
Schematic diagram of a Solenoid
102
Solenoid consists of a fixed steel
frame with a movable steel
element.
Coil wound around the steel frame,
forming a powerful electromagnet.
When current passes through the
coil, magnetic field is created, that
tends to pull the movable element
towards the steel frame.
As the element moves, the size of
the gap is reduced, causing an
increase in the strength of the M.F.
