1. Embedded System in Automobile
By : Amit Kumar Sah
Roll No: 09/ECE/73
NIT Durgapur
2. Embedded System- Definition?
“An embedded system is a
combination of hardware and
software which creates a
dedicated computer system
that performs specific, pre-
defined tasks and which is
encapsulated within the
device it controls (if it is part
of a larger device).”
3. • FPGA (Field-Programmable Gate Array) : A type of logic chip that can be programmed & supports
thousands of gates
•ASIC (Application-specific integrated circuit): An integrated circuit (IC) that has been customized for
a specific use
Embedded system components
4. Characteristics of embedded systems
Sophisticated functionality.
Often have to run sophisticated algorithms or multiple algorithms.
Often provide sophisticated user interfaces.
Real-time operation .
Must finish operations by deadlines
Many systems are multi-rate must handle operations at widely varying
rates
Low manufacturing cost.
Low power.
Designed to tight deadlines by small teams.
5. Automotive Systems: Technology in today's vehicle
Air Bags
The Black Box
Anti-lock Brake System(ABS)
Adaptive Cruise Control
Drive by wire
Satellite Radio Eg:XM
Telematics Eg:OnStar
Rain-sensing Wipers
Emission Control
Traction Control
Automatic Parking
In-vehicle entertainment
Heads-up display
Night Vision
Back-up collision sensor
Navigation Systems
Tire Pressure Monitor
Climate Control
6. Air Bags : Principle of function
It is from the Newton's 2nd law of
motion
It basically restrains the
continuous motion of the
passenger, by giving a soft surface
to land on.
AIR BAGS are among the most
important safety improvements
added to cars and light trucks in
recent years, providing extra
protection for front-seat occupants
in head-on crashes.
And of late, every passengers
protection
Fig : Air Bag- Working
7. Event Data Recorder-EDR or the The "Black Box"
The Event Data Recorder (EDR) in
an automobile is based upon the
sensors and microprocessor
computer system that are used to
activate the airbag in the vehicle
during a crash.
The SDM, which is controlled by a
microprocessor, has multiple
functions:
(1) It determines if a severe enough
impact has occurred to warrant
deployment of the air bag;
(2) It monitors the air bags components;
(3) It permanently records information.
Black Box – Exterior View
Black Box – Interior View
8. Anti-lock Braking System(ABS)
Up until the seventies, hitting the brakes too
hard could lead to an accident.
The reason: When the coefficient of slip
between tires and road surface is too low,
hitting the brakes can cause wheel lock-up.
The vehicle is no longer steerable and goes
into a skid.
In particular, this danger is present
On wet or slippery road surfaces with different
levels of grip between tires and road
On preventing wheel lock-up:
Reduces the total braking distance as far
as possible
Increase vehicle stability
Maintains steer ability even in case of all-out
braking
Without ABS
The vehicle in no longer
steerable when driver
hits the brake
With ABS
The vehicle remains
steerable even during
panic
9. Principle of functioning
Wheel-speed sensors detect whether a wheel is showing a tendency to
lock-up
In case of a lock-up tendency, the electronic control unit reduces the
braking pressure individually at the wheel concerned
High-speed correction of the braking pressure up to shortly before the
lock-up threshold
The brake-fluid return together with the closed-loop brake circuits makes
this a safe, reliable, and cost-effective system
Advantage
A gain for driving safety
The vehicle remains steerable, even in case of panic braking
Shorter stopping distances on practically all road surfaces
Many accidents are avoided
10. Dynamic Traction & Stability Control
The traction control system is required to prevent driver error from
overloading any of the four wheels and causing slip, through either
throttle or brake application
Drastically improve vehicle performance and safety by maintaining
optimal wheel traction in all road conditions
The basic principle is always the adaptation of the wheel torque to the
coefficient of friction between the wheel and the road surface.
To this end, the systems make use of different intervention methods
In the wheel brakes
In the drivetrain control
11. Dynamic Traction & Stability Control
Fig: The Principle of Functioning of TCS with brakes
12. Intelligent Cruise Control
Cooperative Adaptive Cruise Control with Collision Warning (CACC +
CW)
CACC: Cruise at given speed when the road is clear (cruise control)
otherwise follow the car in front, using radar (adaptive) and/or
communications (cooperative).
CW: Warn the driver when an object is being approached too fast, or
is too close
How it works :
Uses forward-looking radar, installed behind the grill of a vehicle, to
detect the speed and distance of the vehicle ahead of it.
Can automatically adjust speed in order to maintain a proper distance
between vehicles in the same lane
13. Drive by wire
Drive-by-Wire replaces mechanical connections – push rods,rack
& pinion, steering columns, overhead cams, cables – by
mechatronic connections – sensors, actuators, embedded
microprocessors, control software
Fig: Drive-by-Wire Throttle Control Fig: Future Car with drive by wire technology