1. WHAT ARE EMBEDDED SYSTEMS?
We read in newspapers that a doctor had successfully transplanted a cardiac
pacemaker in his patient’s chest by sitting around 200kilometres away. Also we know about
driverless cars that could take us to the destiny by using its inbuilt navigation systems.
Embedded microprocessors or micro controllers are the brain behind these.
An embedded system is any device controlled by instructions stored on a chip. These
devices are usually controlled by a micro processor that executes the instructions stored on a
read only memory(ROM) chip.
The software for the embedded system is called firmware. The firmware will be
written in assembly language for time or resource critical operations or using higher level
languages like C or embedded C. The software will be simulated using micro code simulators
for the target processor. Since they are supposed to perform only specific tasks, these
programs are stored in read only memories(ROMs).Moreover they may need no or minimal
inputs from the user, hence the user interface like monitor, mouse and large keyboard etc,may
be absent.
Embedded systems are computer systems that monitor, respond to, or control an
external environment. This environment is connected to the computer system through sensors,
actuators, and other input-output interfaces. It may consist of physical or biological objects of
any form and structure. Often humans are part of the connected external world, but a wide
range of other natural and artificial objects, as well as animals are also possible.
Embedded systems are also known as real time systems since they respond to an input
or event and produce the result within a guaranteed time period. This time period can be few
microseconds to days or months. The computer system must meet various timing and other

2. constraints that are imposed on it by the real-time behavior of the external world to which it is
interfaced. Hence comes the name real time. Another Name for many of these systems is
reactive systems, because their primary purpose is to respond to or react to signals from their
environment. A real time computer system may be a component of a larger system in which it
is embedded; reasonably such a computer component is called an embedded system.
Embedded systems control engine management systems in automobiles, monitor home
heating systems and regulate the quiet operation and the even distribution of laundry in
washing machines. They are the heart of toys like Furby and Tamagotchi, of golf balls that
cannot get lost and of gas pumps at gasoline stations that advertise nearby restaurants on
video. Above all, state-of-the art communications equipment like WAP mobile telephones,
MP3 players, set-top boxes and Net devices would not be possible without these powerful
miniature brains.
Applications and examples of real time systems are ubiquitous and proliferating,
appearing as part of our commercial, government, military, medical, educational, and cultural
infrastructures. Included are:
• Vehicle systems for automobiles, subways, aircraft, railways and ships.
• Traffic control for highways, airspace, railway tracks and shipping lanes.
• Process control for power plants, chemical plants and consumer products such as soft
drinks and beer.
• Medical systems for radiation therapy, patient monitoring and defibrillation
• Military uses such as firing weapons, tracking and command and control.

3. • Manufacturing systems with robots.
• Telephone, radio and satellite communications.
• Computer games.
• Multi media systems that provide text, graphic, audio and video interfaces.
• House holds systems for monitoring and controlling appliances.
• Building managers that controls such entities as heat, light, Doors and elevators.

4. IN THE DRIVING SEAT
There are several tasks in which real time OSs beat their desktop counterparts hands-
down. A common application of embedded systems in the real world is in automobiles
because these systems are cheap, efficient and problem free. Almost every car that rolls off the
production line these days makes use of embedded technology in one form or the
other.RTOSs are performed in this area due to their fast response times and minimal system
requirements.
Most of the embedded systems in automobiles are rugged in nature, as most of these
systems are made up of a single chip. Other factors aiding their use are the low costs involved,
ease of development, and the fact that embedded devices can be networked to act as sub
modules in a large system. No driver clashes or ‘system busy’ condition happen in these
systems. Their compact profiles enable them to fit easily under the cramped hood of a car.
Embedded systems can be used to implement features ranging from adjustment of the
suspension to suit road conditions and the octane content in the fuel to anti lock braking

5. systems (ABS) and security systems. Speaking of the things nearer home the ‘computer chip’
that control fuel injections in a Hyundai Santro or the one that controls the activation of air
bag in a Fiat in a weekend in nothing but an embedded system. Right from brakes to
automatic traction control to air bags and fuel/air mixture controls, there may be upto 30-50
embedded systems within a present-day car. And this is just a beginning.
THE DOCTOR WILL SEE YOU NOW
Imagine a time when body transplants like cardiac pacemakers will be able to monitor
and manage themselves remotely. These systems will be so compact that the patient wouldn’t

6. even be aware that they are embedded in his body. Another point in favor of RTOSs is their
stability, instantaneous
response and efficiency. No OS crashes or delay in responding, as in the case with most
desktop OSes. After all, which patient can rest easy with the thought of his life literally
hanging by a thread due to the time taken by the OS to load!

7. Embedded technology advances are pointing towards the use of pace makers that can
be transplanted in or near the heart itself. The pacemaker will be able to monitor parameters
like blood pressure, blood flow, pulse rate, temperature, etc, using micro sensors planted in
various parts of the body. This capability will enable the pace maker to automatically vary its
operation to suit the changing body conditions. It will also transmit data using wireless
transmission, thus enabling a doctor to constantly monitor its operation. In most cases,
wireless transmitter implanted near the surface of the skin. In case any abnormality is detected
the doctor will be able to take remedial actions even from a remote location.
WIRED WEARABLES

8. A mobile phone in the form of a ring or an ear ring? What about cool sunglasses with
streaming video displays built into them? All these can soon be a reality. Embedded systems
have a small foot print and consume very little power which makes them ideal for wearable
computing applications.The minimal system requirements of these devices ensure that the
hardware is almost microscopic.
IBM is already working on the prototype of a mobile phone that can be worn as
jewellery.The components of the phone will be distributed among different pieces of jewellery
ear ring, necklace, ring and bracelet.
The phone is likely to have blue tooth capability built into it. The ear rings will have
embedded speakers and will act as the receiver. The necklace will have embedded micro
phones that will act as a mouth piece user can talk into. IBM called the ring part of the phone
the decoder ring. Light emitting diodes (LEDs) will flash to indicate an incoming call. The
ring will also have features that will enable it to be programmed to flash different colors for a
particular user or to indicate the importance of a call. A video graphics array (VGA) will be
built into the bracelet, which will display the name and phone number of the caller. The
bracelet will also integrate the keypad and the dialing functions in it. IBM plans to incorporate
voice recognition technology for dialing a number. The phone may also have features to
indicate new email.
DON’T KEEP YOUR EYES ON THE ROAD

9. Embedded systems can also make driverless vehicle control a reality. Major
automobile manufacturers are already engaged in work on these concepts. One such
technology is Adaptive Cruise Control (ACC).
ACC allows cars to keep safe distances from other vehicles on busy highways. The
driver can set the speed of his car and the distance between his car and others. When traffic
slows down, ACC alters vehicle speed using moderate braking. This ensures that a constant
distance is maintained between cars. As soon as traffic becomes less, ACC moves up to the
desired cruise speed that has been set by the driver. The driver can over ride the system any
time he wants to be breaking.
Each car with ACC has a micro wave radar unit or laser transceiver fixed in front of it
to determine the distance and relative speed of any vehicle in the path. The ACC computer
(What else but an embedded system or a grouped system of embedded system) constantly
controls the throttle and brakes of the car. This helps to make sure that the set cruise speed or
adapted speed of traffic at that time is not exceeded.
THE WORKING PRINCIPLE OF ADAPTIVE CRUISE CONTROL

10. As already mentioned each car with ACC have a micro wave radar unit fixed in front
of it to determine the distance and relative speed of any vehicle in it’s path. The principle
behind the working of this type of radar is- the Doppler Effect.
Doppler Effect:
Doppler Effect is the change in frequency of the waves when there is a relative motion
between the transmitting and receiving units. The two figures below clearly show the Doppler
Effect.
1. Higher Pitch Sound
In this case the vehicle is speeding towards the stationary listener. The distance
between the listener and the car is decreasing. Then the listener will hear a higher pitch sound
from the car, which means the frequency of sound, is increased.
2. Lower pitch sound

11. In this case the vehicle is moving away from the listener. The distance between and
the car is increasing. Then the listener will hear a lower pitch sound from the car, which
means the frequency of sound, is decreased. So that is the Doppler Effect in case of sound
waves.
Similarly the radar unit in ACC will be continuously transmitting radio waves. They
will be reflected and echo singles (reflected waves) will be having the same frequency or
different frequency depending on speed/position of the object due to which the echo singles
originate. If the echoes singles have the same frequency it is clear that there is no relative
motion between the transmitting and receiving ends. If the frequency is increased it is clear
that the distance between the two is decreasing and if the frequency is decreased it means that
the distance is increasing.
The figure below shows a car having ACC transmitting and receiving radio waves.

12. In the above case, the gun transmits the waves at a given frequency toward an
oncoming car. Reflecting waves return to the gun at a different frequency, depending on how
fast the car being tracked is moving. A device in the gun compares the transmission frequency
to the received frequency to determine the speed of the car. Here, the high frequency or the
reflected waves indicate the motorist in the left car is speeding.
The embedded system is connected to the radar unit and its output will be sent to
breaking and accelerating unit as early mentioned the embedded system is a device controlled
by instructions stored in a chip. So we can design the chip or ACC having an algorithm such
that it will give output only when the input signals are less than the corresponding safe
distance value. So only when the between the car and the object in front of it is less then the
same distance value the embedded system will give output to the breaking and the
accelerating units. Thus the safe distance will be kept always. That’s how the ACC works.
ABOUT THE BEAUTY OF ADAPTIVE CRUISE CONTROL
As the driver in the next lane swerves in front of you, you feel that gas back off and
the brakes grab in the car you’ re driving- a Mercedes Benz S-class luxury vehicle, the first

13. passenger car equipped with a technology called adaptive cruise control. The technology
makes these adjustments even though you haven’t touched the brake or gas pedal.
At a safe distance behind, your Mercedes settles to a speed matching that of the driver
in front of you. That’s too slow, so after a look in your rear view mirror you pull into the
empty outside lane and feel the acceleration as your car speeds up to the preset cruising speed.
You still haven’t press the accelerator pedal. That’s the beauty of this racing star of the auto
industry, a millimeter- wave radar technology that promises not only to make driving easier,
but to ignite a market for gallium arsenide and other compound semi conductor components.
Although grey hound buses and some heavy- goods vehicles have been fitted with
automotive radar systems, the Mercedes is reckoned to be the first passenger automobile to
sport this advanced use of electronics, and observers say it is likely to lead a proliferation of
the technology. The Mercedes Benz system uses a 77-GHz Doppler radar linked into the
electronic control and braking system to maintain a safe distance between a car with the
system and the vehicle in front of it. Daimler Benz Aero space has completed the design of a
hybrid 77-GHz radar, called Tempo mat, which is being considered for deployment.
Holger Meinel, senior researcher at Daimler Benz Aerospace AG (Ulm, Germany),
was quick to make a point stressed by all the companies working in this field. “This is not
anti- collision radar” he said. “It’s not a safety feature, it’s a comfort feature”.
The source of this distinction is concerned that if adaptive cruise control is marketed
as a safety feature, the first accident that occurs involving a vehicle equipped with millimeter-
wave radar will bring a damaging liability suit. That’s why companies are at great pains to
point out that the driver retains control and responsibility.

14. CONCLUSION
Most of the microprocessors in the world are not in pcs, they are embedded in devices
which control traffic for highways, airspace, railway tracks, and shipping lanes to
manufacturing systems with robots. An embedded system is any device controlled by
instructions stored on a chip. These devices are usually controlled by a microprocessor that
executes the instructions stored on a read only memory (ROM) chip. This the topic of my
seminar. Embedded systems can be used to implement features ranging from the way
pacemakers operate and mobile phone that can be worn as jewellery to adaptive cruise
control(ACC). In this seminar I will explain one such technology that uses the embedded
systems- The Adaptive Cruise Control.

15. ACKNOWLEDGEMENT
I express my sincere and heartfelt gratitude to
PROF: AGNISHARMAN NAMBOODIRI , Head of Department of Information
Technology and computer science , for giving me an opportunity to present this seminar. I
also express my sincere thanks to ASSISTANT PROF: SANGEETHA for providing the
expert guidance and help needed for successfully presenting the seminar and for the
completion of this report there after. I also thank profoundly, the services of Miss. Deepa
.S.S. , coordinator of seminar activities. I also thank Ms Anees Philip, Mr.Lino Varghese,
Mrs.Shajila Beegam, Department of Information Technology , for their guidance in the
presentation of this seminar.
Last but not least, I thank all of my friends who helped me for the successful
presentation of the seminar.
SHAHID MOHAMED

16. ABSTRACT
Most of the microprocessors in the world are not in pcs, they are embedded in devices
which control traffic for highways, airspace, railway tracks, and shipping lanes to
manufacturing systems with robots. An embedded system is any device controlled by
instructions stored on a chip. These devices are usually controlled by a microprocessor that
executes the instructions stored on a read only memory (ROM) chip. This the topic of my
seminar. Embedded systems can be used to implement features ranging from the way
pacemakers operate and mobile phone that can be worn as jewellery to adaptive cruise
control(ACC). In this seminar I will explain one such technology that uses the embedded
systems- The Adaptive Cruise Control.

17. CONTENTS
1. What are embedded systems? 1
2. In the driving seat 4
3. The doctor will see you now 6
4. Wired wearables 8
5. Don’t keep your eyes on the road 9
6. The working principle of Adaptive cruise control 10
7. About the beauty of Adaptive Cruise Control 13
8. Conclusion 15