Automotive electronics

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  • 1. Automotive Electronics

2. Introduction Silicon content in automobiles hasdoubled in the last 10 years and willdouble again over the next five years !!!! Why Electronics in Automobiles ? Where in the Automobile ? 3. Electronics in present and futureautomobiles.SAFETY &CONVENIENCEBODY CONTROL POWER TRAIN DRIVERINFORMATIONRear Window Defogger Cruise Control Ignition Digital GaugesClimate Control Intermittent Wiper Spark Timing Digital ClockKeyless Entry Antitheft Devices Voltage Regulator Audio AnnunciatorAutomatic Door Lock ElectronicSuspensionAlternator Engine DiagnosticResultsLight Dimmer Electronic Steering Idle Speed control Service RemindersTraction Control Multiplex Wiring Turbo Control Miles to EmptyAntiskid Braking Hard/Soft RideControlEmission System Shift IndicatorWindow Control Communications TransmissionControlHead-up DisplayAirbag Restraints Load SensitiveBrakingDiagnostics CRT Display 4. Cruise Control Keeps vehicles speed constant. Prevents driver fatigue. Not suitable for all road conditions. Ambiguously classified as Non-Safety-Critical. 5. Features of Cruise Control Below the set speed, interlocking switches and controllogic prevent the cruise control from being switched ON. Above the set speed, the choice to engage cruise controlrests with the driver. Kicks out of action immediately a very modest touch ofbraking is applied. Not considered safe in heavy traffic, on bends, on wet oricy roads etc. 6. Working of Cruise ControlSpeedEngine +TransmissionVehicle speedsensorSet SpeedSpeed error-+Proportional toerror signalThrottleActuatorRoad Speed 7. Working continuedMethods of Throttle actuation1. Electro pneumatic servo valve actuation (enginevacuum used to provide the force via bellows).2. Electronically controlled DC motor.3. Stepper motor with electronic control. 8. Working continuedTypes of Electronic Control1. Analogue + hard wired logic.2. Digital, using a discrete cruise controller.3. Digital cruise control function incorporated in theengine control module. 9. Challenges implementing CruiseControl A measure of protection against malfunction is takenby : reducing the supply voltage to the actuator or Mechanically decoupling the actuator, by means of anelectromagnetic clutch. The above may not protect against an internal fault,rogue signal, leading to malfunction. High resistance in signal lines may lead to incorrectdecoding of the states of Cruise Control switches. A wrongly decoded command signal or an internal faultmay cause sudden acceleration. 10. TCS & ABS TCS: Traction Control System ABS: Anti-Braking System TCS and ABS are strongly complimentarysystems. Both systems depend on accurate measurementof wheel speed, and share a single set of wheelspeed sensors and many other control sensors. 11. GPS in Automobiles Orbiting 11,000 miles above the Earth, the 24 satellitesare the heart of the system. They constantly broadcast signals that allow any groundreceiver to calculate its distance from each satellite,based on the delay calculations of signal. Each satellite carries four atomic clocks--so accuratethey lose only one second every 160,000 years. By capturing signals from at least three satellites, a GPSreceiver can determine which point on the Earth is theexact distance from the satellites. 12. Applications of GPS in Automobiles Determine the shortest path to a particular destination. Getting to a known location in case someone gets lost. Avoiding the maximum number of tollbooths and determine thecheapest route. Prevent accidents by warning us against approaching vehicles,especially on deserted roads during the night-time. Provide entertainment by means of wireless radio and video links. Enable us to stay connected via a satellite phone, especially inareas where cellular networks do not exist. 13. Integration Technologies inAutomobiles Bipolar technology was initially used in vehicles in thefirst analog systems. BiCMOS and/or CMOS are chosen to meet the highestperformance and the highest levels of integration. Smart power ICs combine bipolar, CMOS and DMOS toprovide higher power levels and integration of protectionand performance features. Microprocessors cannot sense mechanical parameters,can only switch low current and are low voltage devices. 14. Semiconductor Technologies 15. Integration vs. Cost 16. Additional Integration at Risk Adding electronics to vehicles has created anon-board energy crisis. A transition from 14V to 42V system is expected. 17. Future Trends 18. Hands Free ParkingSteps involved in ParkingManeuver: Estimating Parking space. Pre-positioning of car. Executing the maneuver. 19. Hands Free Parking cont One legal question is whether some countrieswould regard a car as not being under control ifthe drivers hands were off the steering wheel. 20. Intelligent Headlamps Headlamps follow the steering wheel. Headlamps use GPS and follow the road. Pixel technology, based on DigitalMicrometer Device (DMD). 21. Faster Processing Discrete Microprocessors add to cost andcomplexity. 32-bit processors can be included to do alltasks. 22. Conclusion