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					Vehicular Technologies



 Embedded Systems Seminar
        Fall 2005

        Elliot Jaffe
    Sensors, Networks and Processors
●   Applicable Vehicles
●   Potential Uses
●   Aside: Automotive equipment lifecycle
●   Networking
●   Processing
●   Sensors
●   Conclusions
Applicable Vehicles
                    Potential Uses
●   Lifecycle Management
    –   Equipment Monitoring, Maintenance, Performance
●   Awareness of the Environment
    –   Weather Conditions, Air Pressure, Road Surface
●   Awareness of the Operators
    –   Physical State, Mental State, Comfort
●   Global vs. Local Interactions
    –   Convoys, Traffic Planning, Collision Detection
    Automotive Component Lifecycle
●   Long lead times between conception and wide
    spread deployment
●   Case in point: Anti-Lock Brakes (ABS)
    –   Bosch 1930’s
    –   First Electronic system in production: 1978
         ●   Trucks and Mercedes-Benz
    –   Standard Equipment – 1985 (Ford Grenada Mk3)
    –   GM stops offering ABS as Standard Equipment on
        most of its 58 vehicles in 2003
           Automotive Component
               Requirements
●   Low Cost
●   Mass Production (availability, liability)
●   Dependability (reliability, safety)
●   System Modularity
●   Easy Field Maintenance
●   Simple MMI (drivers are not experts)
●   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
●   Many bus definitions
    –   http://www.interfacebus.com/Design_Connector_Automotive.
        html
    –   Class A: UART < 10kbps
    –   Class B: non-critical 10kbps to 125kbps
    –   Class C: real-time high-data: 125kbps – 1Mbps
    –   Emissions/Diagnostics
    –   Mobile Media
    –   X-By-Wire: replace mechanical systems
         ●   -40  +125C
                              Examples
●   LIN- local interconnect network
    –   http://lin-subbus.org
    –   20Kbps
    –   Master/slave architecture
●   CAN – controller area network (ISO 11898)
    –   http://www.ni.com/automotive/can.htm
    –   High speed: 1Mbps
         ●   Engine and powertrain
    –   Low speed: 128kbps
         ●   Body and comfort devices
                           Networking
●   X-By-Wire Architecture
    –   Proposed by Consortium in 1996-1998
    –   Time Triggered Protocol (1993)
    –   Considered failure modes and requirements
    –   Composability
    –   Timeliness
    –   Fault Tolerance
    –   http://www.vmars.tuwien.ac.at/projects/xbywire/projects/new-home.html
X-By-Wire
                          Processing
●   First Microprocessor, 1978 Cadillac Seville
     –   Trip Computer, 6802
●   Freescale (Motorola) MPC563 32bit microprocessor
     –   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
●   Engine and Drivetrain Sensors
●   Emissions Control System Sensors
●   Safety and Security Sensors
●   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
  –   Air Temperature
  –   Coolant Temperature
  –   HVAC Temperature
  –   Transmission Temperature
           Emission Control Sensors
●   Required due to emission control legislation
●   EGR Valve
    –   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
    –   Senses engine temperature, and opens or closes
        vacuum lines to various emissions-related
        components
       Safety and Security Sensors
• Inertial Sensors             • Wheel Speed
  – active stabilization and
    navigation applications
                               • Occupant Position
                                 – Weight
                                 – Driver Seat Position


                               • Tire Inflation
            Other Interior Sensors
●   Climate Control Systems
●   Ambient Air Temperature
●   Seat Temperature
●   Air Flow
●   Audio Volume (for Active Feedback)
●   Ambient Light (for auto-tint)
                       External Sensors
●   DARPA Grand Challenge
●   http://www.darpa.mil/grandchallenge/TechPapers/AutonomousVehicleSystems.pdf




●   Range Finding
●   Obstacle Detection
●   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
●   Applicable Vehicles
●   Potential Uses
●   Aside: Automotive equipment lifecycle
●   Networking
●   Processing
●   Sensors

				
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