Vehicular Technologies
Embedded Systems Seminar
Fall 2005
Elliot Jaffe
Sensors, Networks and Processors
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Applicable Vehicles
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Potential Uses
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Aside: Automotive equipment lifecycle
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Networking
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Processing
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Sensors
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Conclusions
Applicable Vehicles
Potential Uses
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Lifecycle Management
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Awareness of the Environment
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Weather Conditions, Air Pressure, Road Surface
Awareness of the Operators
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Equipment Monitoring, Maintenance, Performance
Physical State, Mental State, Comfort
Global vs. Local Interactions
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Convoys, Traffic Planning, Collision Detection
Automotive Component Lifecycle
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Long lead times between conception and wide
spread deployment
Case in point: Anti-Lock Brakes (ABS)
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Bosch 1930’s
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First Electronic system in production: 1978
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Trucks and Mercedes-Benz
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Standard Equipment – 1985 (Ford Grenada Mk3)
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GM stops offering ABS as Standard Equipment on
most of its 58 vehicles in 2003
Automotive Component
Requirements
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Low Cost
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Mass Production (availability, liability)
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Dependability (reliability, safety)
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System Modularity
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Easy Field Maintenance
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Simple MMI (drivers are not experts)
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Security (against prohibited actions)
Automotive Component Lifecycle
Source: Integrated Vehicle Control System Technology — Steering, Braking, Suspension, and Powertrain
Systems, Aloysius J. (Alois) Seewald, TRW Automotive Chassis
Networking
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Many bus definitions
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http://www.interfacebus.com/Design_Connector_Automotive.h
tml
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Class A: UART < 10kbps
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Class B: non-critical 10kbps to 125kbps
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Class C: real-time high-data: 125kbps – 1Mbps
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Emissions/Diagnostics
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Mobile Media
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X-By-Wire: replace mechanical systems
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-40  +125C
Examples
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LIN- local interconnect network
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http://lin-subbus.org
20Kbps
Master/slave architecture
CAN – controller area network (ISO 11898)
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http://www.ni.com/automotive/can.htm
High speed: 1Mbps
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Engine and powertrain
Low speed: 128kbps
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Body and comfort devices
Networking
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X-By-Wire Architecture
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Proposed by Consortium in 1996-1998
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Time Triggered Protocol (1993)
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Considered failure modes and requirements
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Composability
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Timeliness
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Fault Tolerance
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http://www.vmars.tuwien.ac.at/projects/xbywire/projects/new-home.html
X-By-Wire
Processing
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First Microprocessor, 1978 Cadillac Seville
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Trip Computer, 6802
Freescale (Motorola) MPC563 32bit microprocessor
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63-105 MIPS
-40C – 125C
2.6V Core Operating Voltage
5V I/O Operating Voltage
0.8, 1.12W Power dissipation (typical, max)
512K Flash RAM, 32K RAM
32 Channel A/D (10 bits)
Source: www.freescale.com
Sensors
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Engine and Drivetrain Sensors
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Emissions Control System Sensors
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Safety and Security Sensors
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Other Internal Sensors
Engine and Drivetrain Sensors
• Throttle Position
– Monitors the position of the accelerator pedal and the throttle
linkage, so the ECM can make accurate air/fuel mixture
adjustments
• Barometric Air Pressure (BAP
– Reads changes in barometric (air) pressure. The ECM uses this
information to adjust timing advance and air/fuel ratio
• Mass Air flow/ MAF
– Measures the amount of air drawn through the engine's air
intake, so the computer can compensate for altitude and
temperature
Engine and Drivetrain Sensors
• Permanent magnet vehicle speed sensor
– A permanent magnet generator
– Produces a pulsing (ac) voltage when it spins
– Voltage level and number of pulses increase with
vehicle speed
• Knock / Detonation
– Listens for engine "ping" so the ECM can retard the
spark timing, and thereby reduce emissions and
overheating, if the engine is knocking
Engine and Drivetrain Sensors
• Magnetic Fluid Level
– Used for brake fluid, coolant, washer fluid and oil
level sensing
• Temperature
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Air Temperature
Coolant Temperature
HVAC Temperature
Transmission Temperature
Emission Control Sensors
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Required due to emission control legislation
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EGR Valve
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Recalculates a measured amount of exhaust gas into
the engine's air intake, to lower combustion
temperatures and reduce emissions, especially NOx
Ported Vacuum Switch
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Senses engine temperature, and opens or closes
vacuum lines to various emissions-related
components
Safety and Security Sensors
• Inertial Sensors
– active stabilization and
navigation applications
• Wheel Speed
• Occupant Position
– Weight
– Driver Seat Position
• Tire Inflation
Other Interior Sensors
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Climate Control Systems
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Ambient Air Temperature
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Seat Temperature
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Air Flow
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Audio Volume (for Active Feedback)
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Ambient Light (for auto-tint)
External Sensors
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DARPA Grand Challenge
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http://www.darpa.mil/grandchallenge/TechPapers/AutonomousVehicleSystems.pdf
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Range Finding
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Obstacle Detection
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Terrain Detection
Team CIMAR
U. Indiana: Rubicon
Stanford
Range Finding
• RADAR
– Radio Detection and
Ranging
• LADAR
– Laser Detection and
Ranging
• SONAR
– Sound Navigation and
Ranging
Detection in Operation
Conclusion
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Applicable Vehicles
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Potential Uses
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Aside: Automotive equipment lifecycle
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Networking
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Processing
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Sensors