2. Contents
What are embedded systems ?
Why.. ..for automobiles ?
Embedded Development
Applications
Anti-lock Braking System
Adaptive Cruise Control
Tire Pressure Monitoring System
Satellite Radio- XM
Conclusion
3. What are embedded systems ?
• A combination of hardware and software ,
which creates a dedicated computer system, to
perform specific pre-defined tasks.
• They are usually controlled by a micro
processor that executes the instructions stored
on a ROM chip.
• Specifically designed codes using embedded C
, bring about “Artificial Intelligence” in the
device.
4. Sophisticated functionality (operate on multiple
algorithms simultaneously )
Multi-rate systems (operations handled at
widely –varying rates )
Real-time operation (perform the operation
within the deadline)
Low manufacturing cost
Low power
5. Embedded Development
• Embedded software
development flow
C-Code
Compiler/ linker
Simulator
Object Code
Download to board and FPGA
Debugger
Outer
• FPGA hardware development
flow
VHDL/ Verilog
Synthesizer
Simulator
Place and Route
Download to FPGA
6. Wheels in your full control now..
It consists of 1 Electronic Control Unit
(ECU),4 wheel speed sensors and Hydraulic
Control Valves.
ECU actuates the valves to reduce or
increase hydraulic pressure to the brake at
the affected wheel.
ABS usually apply and release braking
pressure up to 20 times a second.
7.
8. It is a technology which allows drivers to set a basic
speed of the car and the distance between his car and
others that the car will maintain on its own.
Each car with ACC has a microwave radar unit fixed in
front of it to determine the distance and relative speed of
any vehicle in the path.
When ACC is ON, the radar unit will be transmitting
radio waves while the ACC computer will constantly control
the throttle and the brakes of the car.
9.
10. Doppler Effect :
It refers to the change in frequency of the waves
when there is a relative motion between the
transmitting and receiving units.
For example… when the separation in between,
decreases below the specified value, the reflected
waves received by the radar unit ,will have higher
frequency than the waves transmitted by it.
The embedded systems connected to the radar unit
give output to the braking units ,which apply the
brakes moderately and a constant distance is
maintained.
11. Main objectives are :
Reducing CO2 emission
Avoiding traffic accidents due to under-inflated tires
Reducing tire abrasion
The main components of a typical TPMS sensor are:
Pressure sensor
Temperature sensor
Signal processer (C to V Convertor)
Analog to Digital Convertor (ADC)
Microcontroller
RF Transmitter
Reference Quartz Oscillator
12. • The pressure –sensing cell is capacitive and
requires a ‘ C to V’ conversion stage.
• In read mode, the A to D convertor converts the
analog voltage on capacitor in it’s digital form and the
microcontroller reads the data serially.
• The RF transmitter connected to it ,uses this serial
data to modulate a reference oscillator of 13 .56 MHz
(using both ASK and FSK) and generates 315, 433
and 868 MHz waves of ISM BAND for RF
communication.
13.
14. • The RF waves are recepted by the RF receiver
connected to the microcontroller ,mounted
inside car’s dashboard.
• Upon demodulation ,the data is finally
displayed on the screen .
An extension to it….
Send this RF data to the engine working
module via RF communication and the car will
not start until and unless the tire pressure is
made correct. :)
15. XM radio service adopts communication satellite
broadcasting technology and is
an emerging satellite digital audio radio service
suitable for automotive environment.
XM service, on account of its better signal
coverage , surpasses existing radio services like
FM and AM both in terms of sound quality and
geographic coverage.
17. • The XM tuner receives radio program signal from
the satellites, and a serial bus named IEBUS
connects it to the main microcontroller in the
head unit of the digital car audio system.
• The main uC forwards audio signal output to
DSP chips for sound output and also monitors
data exchange with external devices via
different kinds of serial data buses.
18. • The video-audio micro controller is meant for
effective human- machine interface via touch panel
display.
• The main microcontroller used here is
V850ES/SJ3 , manufactured by NEC company ,
which has a high working frequency of 32 MHz and
is compatible with serial buses like CAN bus, I2C,
UART, IEBUS and CSI for communication.
19. • The embedded systems work upon carefully
designed software and their proper
implementation .Still , the main concerns are :
Meeting the real time constraints more
effectively
Validation of real time software (testing of large
data may be critical to safety)
With fast expanding autonomous market and
luxury getting over the human mind, embedded
systems have got a bright future ahead.