Disha NEET Physics Guide for classes 11 and 12.pdf
Embedded Systems in Automobile
1. A Technical Seminar on
Embedded System in
Automobile
By
ABHISHEK SUTRAVE
(1RN05EC004)
RNS INSTITUTE OF TECHNOLOGY
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. Industry Development Process
Requirement System
Specification Delivery
System System
Specification Test
System System
Design Integration
Module Module
Design Test
Implementation
4. Embedded Development
Tool Flow Overview
Standard Embedded SW Standard FPGA HW
Development Flow Development Flow
C Code VHDL/Verilog
Compiler/Linker Synthesizer
(Simulator) Simulator
Object Code Place & Route
? ?
CPU code in CPU code in
off-chip on-chip
memory memory Download to FPGA
Download to Board & FPGA
Debugger
5. Embedded system components
Software
FPGA/ Memory
ASIC
A/D D/A
Sensors CPU Actuators
conversion conversion
User Aux system
interface Diagnostic (power
port cooling, etc
Electromechanical
Backup and safety
External
environment
7. 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.
Hard real time: missing deadline causes failure.
Soft real time: missing deadline results in degraded performance.
Many systems are multi-rate: must handle operations at
widely varying rates.
• Low manufacturing cost.
• Low power.
• Designed to tight deadlines by small teams.
9. Automotive Systems:
Technology in today’s vehicle
• Air Bags • Traction Control
• The Black Box • Automatic Parking
• Anti-lock Brake • In-vehicle
System(ABS) entertainment
• Adaptive Cruise • Heads-up display
Control
• Night Vision
• Drive by wire
• Satellite Radio Eg:XM • Back-up collision
sensor
• Telematics Eg:OnStar
• Rain-sensing Wipers • Navigation Systems
• Emission Control • Tire Pressure Monitor
• Climate Control
10. Automotive Systems:
Technology in today’s vehicle
Temperature control
Air bags
EGR control Active
suspension
Electronic fuel injection
Electronic ignition
Electric power
steering (PAS) Electronic transmission
Cruise control
Anti-lock brakes
12. 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
14. Airbag System: Possible Sensors
(Including Crash Severity and Occupant
Detection)
SAT SAT
passenger
detection
SAT
passen.
WS
BS
BS
BS
SAT ECU ROS
BS
ACC BS
driver
detection
WS
driver
SAT
SAT SAT
SAT = satellite with serial communication interface
ECU = central airbag control unit (including accelerometers)
ROS = roll over sensing unit
WS = weight sensor
BS = buckle switch
15. Airbag System: Possible Actuators
(Including Crash Severity and Occupant
Detection)
Headbag TB Headbag TB
Kneebag
Airbag
2stage
PBP
PBP PBP
Emergency
Equipment ECU Interactionbag
PBP
Kneebag
Airbag
2stage PBP
Headbag TB Headbag TB
TB = Thorax bag
PBP = pyrotechnical buckle pretensioner with load
limiter
ECU = central airbag control unit
16. Automotive Seat Occupancy Detection
DSP-based
Emb system
(Processes
Seat w/ Fiber
Information)
Sensing Technology -Airbag Deployment Decisions
(fire airbag? which airbags?
how much to inflate?, etc.)
18. Event Data Recorder-EDR
• 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 bag's components;
• (3) it permanently records information.
19. Event data Recorder-EDR
Simplified Block Diagram
Engine Speed Vehicle Speed Brake ON/OFF Throttle Pos
Sensor Sensor Sensor Sensor Pre-impact data
Serial data bus
SDM Accelerometer Warning Indicator
Low-pass Filter Airbags
Power
Ignition Switch Microcomputer Including EDR
RAM
32k ROM
640 EEPROM
Driver Seat Belt Manual Pass.
Sensor Airbag Cutoff Sw.
And Indicator
22. Conclusion
• The EDR is not a replacement for the
accident reconstructionist.
• The EDR can be a source of additional data
to confirm the conclusions of the accident
reconstructionist.
• The EDR may serve as an effective tool to
impeach conclusions reached by accident
reconstructionists who fail to consider the
data generated by the EDR.
• A lot of trial lawyers are going to be very busy
litigating all of the issues the “black box” will
generate during the coming years.
24. Why 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
25. On preventing wheel lock-up
Reduce the total braking distance as far as possible
Increase vehicle stability
Maintain steerability even in case of all-out braking
26. Its 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
28. A BASIC ANTI-LOCK BRAKE SYSTEM
sensor sensor
brake brake
hydraulic
ABS
pump
brake brake
sensor sensor
29. 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
30. The Difference
With ABS
Without ABS
The vehicle
The vehicle is remains
no longer steerable even
steerable during panic
when the braking
driver hits
the brake
34. Introduction
• 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
35. Its Principle
• 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
36. The Principle of Functioning of TCS
with brakes
Without TCS:
The powered wheel spins –
the wheel does not accelerate.
Snow or ice/
Asphalt
With TCS: Intervention in the brake
Improved traction, the vehicle
accelerates
37. The Principle of functioning of TCS
with Drive Train Control
External Slip Angle
Sensors Radius
X/Y/Z
Acceleration
Driver Physics
Model +
- Engine Wheels
Pedal
(Saturator)
RPM μs/μk
Throttle Pos.
Wheel Slip
ECU Detector
41. 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.
x2 x1
r
Vehicle 2 Vehicle 1
42. Why this is hard…
Around curve Rapid deceleration
Elevation changes
Dense traffic
Cut-ins
43. 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
