sensors in automobiles
TRANSCRIPT
Oil sensor
Oxygen sensor
Fuel level
Accelerometer
Seat belt tension
Passenger Occupancy
Wheel speed
Tire pressure monitor
Anti thief sensors
Radar sensor
Rain sensor
Parking sensor
Indoor/outdoor temperature sensors
GPS
Water coolant temperature
TachometerSpeedometer
Odometer
Oxygen sensor Oil sensors Fuel gauge
Dip - stick
Miniature voltage generator Compare the exhaust O2 level and outside air
O2 level
On-board oil sensors and oil analyzers installed Oil pressure: Hydrostatic
force per unit area Age of the oil in the
engine: dielectric constant of the oil. Parallel plate capacitor separated by oil. An oil dielectric tester correlates to the acidity of the oil and indicates the level of oil degradation
Inaccurate due to its mechanism, shape of fuel tank
Gauge: resistance ↑, current ↓, bimetallic cools, straighten out, pull needle form full to empty.
Newer car: resistor output into a microprocessor – compensate shape of tank
Damping needle movment up hill , down hill , turnFloat
They are proximity sensors.
These system feature ultrasonic proximity detectors.
An Audi A4 B7 Avant 2.0 TDI Parksensor
Left figure shows a tachometer that can show up to 7000 RPM
Speed Wheel speed Engine ignition timing Tahometer Odometer
Transmission and driveshaft rotate → mandrel too → permanent magnet rotate → rotating magnetic field → force act on speed cup → electrical curretn flows (Eddy current) → drag torque → needle rotate same direction as magnetic field
• Transmission output rotate with a toothed metal disk at the end
• Stationary detector covers a magnetic coil
• Teeth move past the coil “interrupt” the magnetic field → series of pulses sent to computer
Distance indicator.
LCD Digital Odometer Blue Display from 2000 Jeep Grand Cherokee Laredo.
An another (specifically neon) Odometer.
For ABS one need to know the speed of each wheel
Modern accelerometers based on simplest MEMS design
Mass-damper-spring Air bag deployment
system – rapid negative acceleration
Electronic stability control
Si
tether
Two capacitator configuration
Measure difference between two capacitance
RF communication with on board computer
Simplest form, it is nothing but one or more sensors connected to some sort of siren
Most modern car alarm systems: An array of sensors that can include switches, pressure
sensors and motion detectors A siren, often able to create a variety of sounds so that you
can pick a distinct sound for your car A radio receiver to allow wireless control from a key fob An auxil iary battery so that the alarm can operate even if
the main battery gets disconnected A computer control unit that monitors everything and
sounds the alarm -- the "brain" of the system
In a closed-circuit system, the electric circuit is closed when the door is shut. This means that as long as the door is closed, electricity can flow from one end of the circuit to the other. But if somebody opens the door, the circuit is opened, and electricity can't flow. This triggers an alarm.
In an open-circuit system, opening the door closes the circuit, so electricity begins to flow. In this system, the alarm is triggered when the circuit is completed
Breaking glass has its own sound frequency
Air pressure brief change as door open, windows break, even if the inside outside pressure is the same
Detects radar/laser signals
Try to disturb the reflected waves
Emits jamming signals Warn the driver
Car radar detector (Japanese)
Vehicle wil l be f itted with sensors that can detect potential coll isions and take action
Firm claims 'nobody wil l be kil led or injured in a new Volvo by 2020'
The headline of dailymail.uk (as on 5 t h Dec,2012) read “Volvo develops the 'no death' car: Vehicles which drive themselves and are totally crashproof could be on Brit ish roads in eight years.”
Future Concepts
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