embedded system in automobiles seminar report

Seminar Report ’03 Embedded System in Automobiles

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.

Dept. of IT MESCE Kuttippuram1


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 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.

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.



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 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 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!



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

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

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

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

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.

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 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.



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.



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



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.



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


embedded system in automobiles seminar report

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