10_Different Sensor and Actuator Used in Vehicle

Sensors and Actuators

AUGUST 2006

© Siemens VDO reserves all rights even in the event of industrial property rights. Siemens VDO reserves all rights of disposal such as copying and passing on to third parties.

© Siemens VDO Automotive AG 2006 | Venkatasubramaniyan.K© Siemens AG 2006 I SV P GS BLR 2

Sensors and ActuatorsMechatronics

Mechatronics is the synergistic combination of mechanical engineering ("Mecha" for mechanisms), electronic engineering ("tron" for electronics), and Informatics ("ics").

The purpose of this interdisciplinary engineering field is the study of automata from an engineering perspective and serves the purposes of controlling advanced hybrid systems.



Sensors and ActuatorsApplication of Mechatronics in Automotive Engineering



An electronic device used to measure a physical quantity such as

temperature, pressure and convert into an electronic signal.

Sensors and ActuatorsDefinition

Purpose and Application

Function (open loop and closed loop

control circuits)

Safety and Back up

Monitoring and information

Types of Characteristic curve

Continuous linear

Continuous non linear



What is to be measured.

Magnitude, range, Dynamics of measure quantity.

Required resolution.

Cost.

Environment.

Interface requirement.

Output quantity

Sensitivity

Sensors and ActuatorsSelection Criteria



Sensors and ActuatorsOver View



Sensors and ActuatorsOverview



Sensors and ActuatorsCommonly used sensors

Engine Speed Sensor Temperature sensors

Coolant Temperature sensorOil Temperature sensorBoost Temperature sensor (Turbo Charge Engine)

Flow SensorsAir mass flow sensor

Position sensors.Throttle position sensor

Pressure sensorsOil pressure sensorBoost pressure sensor

Needle Movement Sensor



Dependent Functions:

Fuel quantity calculation

Begin of Injection

Activate pre-injection

Limiting fuel quantity

Cyl. Balancing

Sensors and ActuatorsSpeed Sensors



When a current is passed through a semiconductor wafer, a voltage is developed at right angles to the direction of current. The magnitude of this voltage is proportional tothe magnetic field through the semiconductor. This voltage is called Hall voltage.

Sensors and ActuatorsMagnetic sensors – Hall sensor

Dependent functionsDigital speed measurements.Non-contacting measurements. Therefore wear free.Output signal independent of rotational speed.Insensitive to dirt and contamination.



Magnetic sensors – induction sensor: Ferromagnetic ring gear turns past sensor and generates a voltage in the coil. Period of voltage signal is proportional to variation in magnetic flux proportional to the rotation speed.

Sensors and ActuatorsSpeed Sensors



Sensors and ActuatorsNeedle Movement Sensor

A ferromagnetic needle moves in a magnetic field, which is produced by a constant current flowing through a coil. The needle movement induces a voltage pulse in that coil, which can be sensed by a evaluation circuit.

Dependent functions - Sampling the injection point by means of nozzle needle lift.Closed loop control of injection timing (for sleeve controlled FIP)



The sensitivity of electrical resistance is used as sensor. By holding the resistance value constant, while the air-flow is changing, it is possible to calculate the flow.

Sensors and ActuatorsMass Air Flow Sensor



Potentio metric sensors are resistive and can be read by applying a current and

measuring the voltage drop across the resistor.

Throttle angle sensing

Sensors and ActuatorsPosition Sensors - Potentiometer



Sensors and ActuatorsMAP Sensors

Vo

ltag

e

Pressure



Abnormally rapid rise in cylinder pressure during combustion, followed by rapid oscillation in cylinder pressure. Frequency of these oscillations is specific to a given engine configuration and is typically in the range of few kHz.The sensor converts acoustical energy in the spectrum of the rapid cylinder pressure oscillation and Generates high frequency output voltage.

Sensors and ActuatorsKnock Sensors



Sensors and ActuatorsOxygen sensor

An Oxygen sensor is a small sensor inserted into the exhaust system of a petrol engine to measure the concentration of oxygen remaining in the exhaust gas to allow an electronic control unit (ECU) to control the efficiency of the combustion process in the engine.

The sensing element is usually made with a zirconium ceramic bulb coated on both sides with a thin layer of platinumand comes in both heated and unheated forms.



A thermocouple is created when two dissimilar metals touch and the contact point produces a small open-circuit voltage as a function of temperature. V = S * T, where S is the Seebeck coefficient.

S changes with temperature,

Output voltages is non linear over the operating range.

Amplification for High-Resolution A/D Converter

Thermocouples generate very low-voltage signals (mV).

Sensors and ActuatorsTemperature sensor

• Temperature sensor (Thermistor):

Temperature sensors are usually based on the

sensitivity of electrical resistance materials

with a positive or negative temperature

coefficient

NTC: Negative Temperature Coefficient

PTC: Positive Temperature Coefficient

)11

(.o

o TTeRR

R - resistance at TRo - resistance at To - PTC / NTC coefficient



Sensors and ActuatorsActuators - Overview



Examples: There is a huge range of actuators necessary for proper operation of an internal combustion engine. Examples are

Fuel pump supply

Electronic thermostat valve

Fuel injectors

Electric EGR-Valve

Electrical water pump

Electrical Oil pump

Sensors and ActuatorsActuators - Overview

DEFINITION: (Electrical Signal to Non-Electrical Signal)

A device used to convert Electronic signal into physical quantity.



Sensors and ActuatorsSolSensors and ActuatorsSolenoids



Fuel pressure acts against this face of the needle to work against spring force and open

nozzle

Spring force is adjustable to alter “pop” pressure

Fuel is allowed to internally “leak” to

lubricate the needle.

Sensors and ActuatorsInjection Nozzles



Air fuel mixture

Exhaust gas re circulation

EGR valve

Sensors and ActuatorsExhaust Gas Recirculation systems



Intake flow

MAF

MAT

TPS

Intake vacuum

Exhaust Pressure

Metering orificeUpstream pressure

Down stream pressure

Source vacuum

EVR

Duty cycle output

ECU

Delta pressure input

sensor EGR valveEGR vacuum

Sensors and ActuatorsExhaust Gas Recirculation systems



Thanks Suggestion

Documents

10_Different Sensor and Actuator Used in Vehicle