Post on 18-Nov-2014
SENSORS IN AUTOMOBILES
By
Branch AEIE
Purushottam Institute Of Engg. And Tech.
WHAT IS A SENSOR ?
A sensor is a device that measures a physical quantity and converts it into a signal which can be read by an observer or by an instrument. For example, a mercury thermometer converts the measured temperature into expansion and contraction of a liquid which can be read on a calibrated glass tube. A thermocouple converts temperature to an output voltage which can be read by a voltmeter.
AUTOMOBILES CONTAIN HUNDREDS OF SENSORS!
anti-lock brakes seatbelts automatic locks
gas gauge airbags oxygen sensors
air conditioner heater temperature sensor
car alarm speedometer oil pressure
VEHICLE NAVIGATION SYSTEM
Cooperation of wireless sensors (e.g. GPS + Accelerometer + Camera
SMART CAR : SPECIAL FEATURES
1. There are so many people killed in the car accidents that car accident reports can be found in newspaper nearly every day.
2. A smart car can alert the driver if he becomes drowsy.
3. The computer in the car will totally eliminate the cases of getting lost and getting stuck in traffic.
4. The computer in the car sends out a radio signal that can be detected by a satellite.
5. By establishing the relation between the rotation in the steering wheel and the car’s position on a map, the computer can tell us where the car is.
At the heart of each automobile is the engine
Modern engines use software loaded in the engine’s Engine Control Module (ECM) to optimize performance and efficiency
OVERVIEW OF THE MITSUBISHI 4G93 ENGINE
The sensors connected to the ECM are:
… air flow sensor
… air intake temperature sensor
… intake-manifold vacuum or manifold absolute pressure (MAP) sensor
… engine coolant temperature sensor
… throttle position sensor
… oxygen sensor
… Hall effect crankshaft sensor
… Hall effect camshaft sensor
MITSUBISHI ENGINE SENSORS
Throttle Position Sensor
… rotary type sensor – wiper blade and resistance coil form a simple voltage divider
… controls the idle speed of the engine
The Oxygen Sensor
… measures amount of oxygen that is left after combustion
… air-fuel ratio is correct when the oxygen sensor reads 0.45V
The Hall Effect Crank Sensor
… calculate the speed of the engine
… calculate the position of each cylinder
The Hall Effect Camshaft Sensor
… calculate the position of each cylinder
… firing must occur a few degrees before Top Dead Center (TDC)
WSNS - APPLICATIONS: AUTOMOBILE
º Intra-vehicle:
: Objective: remove excessive wires
: Monitoring difficult access areas
: Easy access to useful information
Inter-vehicle:
: Objective: improve driving safety
Automobiles are the nodes themselves
Messages may be:
. Dangerous conditions
Traffic jams
“Smart” road signs
USE OF SENSORS IN RACING SCENARIO
º Provide to the driver:
: Tire pressure
: Lights failure
: Fuel consumption
: Acceleration
º Send to the pit:
: Heart rate and blood pressure
:Help requests
ACTIVE ELECTRICAL POWER STEERING, AUTOMATED PARKING,
ACTIVE STEERING Active electrical power steering
… The steering gear box is controlled by the electronics to achieve smoother, more accurate steering
Automated Parking
… BMW Park-Assist uses sensors to detect an empty parking and parallel-park the car
… Commonly-used sensor: Lidar (light detection and ranging technology) – laser-based range detection
Active Steering
… Superposition steering (BMW)
INTERSECTION ASSISTANT WITH CAR TO CAR COMMUNICATION
(USING WLAN)
Collisions at street intersections can be avoided with Intersection Assistant
Cornering and Intersection Assistant
… Radar and laser sensors enable the monitoring of surroundings of cars
… Obstacles are identified. Cars can be braked automatically
… Intersection Assistant can be realized with currently commercially available WLAN. Up to now, it is only used in driver assist mode.
STEERING SYSTEMS
Automated parking and disturbance control (e.g., from side wind) will be the next development steps
To realize the accident-free vehicle, more near-field information will be necessary
After so-called “collision avoidance,” automated driving can be realized
The next development steps will need to concentrate on “camera vision”
Content/ Information Providers
Traffic / Weather / TravelRoute Guidance /
Internet Access /E-MAIL / Car Diagnosis / Navigation
Extra Functions
Exclusive Line
Integrated ECU
GPS
Traffic Events / Weather / Travel
POI / Stocks / News
NAVI. ControlAccident Report
E-mailContents/Information
AV/NAVI
Hands Free
Wireless MODEM
TelecomCompany
AVICSCenter
DAB/Cellular
Data CollectingData Processing
Exclusive Line
AVICS Center or Internet Sites Connection
AVICS (Advanced Vehicle Information & Communication System)
VIBRATION REDUCTION ON AUTOMOTIVE SHAFTS USING
PIEZOCERAMICS The use of intelligent
materials e.g. piezoelectric ceramics seems to be the most promisingly ones for the use in automobile structures.
Piezoelectric devices and active vibration reduction are advantageous in this application field due to their low mass to performance ratio.
Applied piezoceramics on a test automotive shaft
THANK YOU
Questions ?