2013-10-03 - EMC safety control in automotive - Istwaan

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Istwaan Knijff

[email protected]

EMC & Safety themadag - 03 oktober 2013

- Istwaan Knijff --- EMC & Safety --- 03 oktober 2013 - 2

• Sensata Technologies – Almelo

• What about EMC?

• Functional safety – ISO26262

• How is EMC controlled in automotive

• Pressure sensor technologies

• Automotive sensor interfaces

• Pressure sensor applications

Presentation Overview

2


Sensata Technologies

• Sensata Technologies

– Former Texas Instruments

– 3 Business Centers + 7 Make sites

– Worldwide 6,000 employees


Sensata Customers

3


• Number of sensor: 1 (?) > 100

Need for EMC in the automotive world?


YES !!!!

4


Automotive, EMC… & Safety??


Functional safety vs. Nominal performance

• ISO 26262 Functional safety of E/E systems, classified in ASIL

� Freedom from unacceptable risk caused by:

Specifications Implementation Operation failure Foreseeable error Misuse

• Detect and control: Process & Product

• Diagnostics

• Redundant hardware

• Program flow monitoring

• Etc…

• Verifications

• Tests

• Audits

• Etc..

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Failure Mode Effect (Diagnostic) Analysis

• FMEA: focus on systematic failures

Quality approach: find problems in design on all levels

• FMEDA focus on random failures

Quantitative approach: determine failure rate + fault control/detect mechanism


Risk classification - ASIL

• Risk is classified via Automotive Safety Integrity Levels (ASIL

ASIL level = X X

Severity Exposure Controllability

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Exhaust Back Pressure Sensor

Transmission Pressure Sensor

Cylinder PressureSensor

Oil PressureSensor

Mass AirflowSensor

Differential/ Relative Pressure

Sensor

Manifold Pressure Sensor

Fuel Level Sensor

CR / GDI / CNG & LPG Rail Pressure Sensor

NOx Sensor

Fuel PressureSensor

CNG & LPG

Pressure Sensor

Air Pressure Sensor

AccelerationSensor

Suspension PressureSensor

ESP Pressure Sensor

Tire Pressure Sensor

Occupant Weight Sensor

EMB Force SensorAC Pressure sensor

Blind Spot Detection Sensor

Solar and Twilight sensor

Air Classification

Module

Humidity sensor

Lane Departure Warning

Rain sensor

Steering Angle Sensor

Power Steering

Fuel Cut-off switch

Crash sensor modules

Night Vision Sensor

Belt Alert

Transmission Range SensorInternal Mode

Switch

Automotive Sensors


EMC Requirements – Radiated Immunity

Radiated immunity requirements

0

200

400

600

800

1000

1200

1 10 100 1000 10000Frequency (MHz)

Level

(V/m

)

Field (V/m) RDW

Field (V/m) Huis tuin

Field (V/m) Daimler

Field (V/m) BMW

Field (V/m) Brakes

Field (V/m) Brakes

Field (V/m) Brakes

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Radiated Immunity - Stripline test


Other EMC Requirements

• Frequency range: 150kHz – 4 GHz / Radar bands

• Modulation: CW / AM / GSM...

• BCI: 60 - 500mA

• ESD: 2-25kV

• DPI / GTEM / Stripline

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Simulations - Expert System for EMC Analysis

• Total length of cables: 1,7 – 2,8 km

• Number of sensor: 1 ... > 100

• Number of cables: 1100 - 1900

• Number of contacts: 1800 – 2500

• Cables per bundle: up to 200


Simulations & Data sets for model generation

cable harness models

device models

car bodymodels

RTH

M2

MbreakP

R7

10

R3

1k

CANH

DbreakD2

DbreakD1

V2

TD = 100n

TF = 10nPW = 10uPER = 20u

V1 = 0

TR = 10n

V2 = 1

RTL

M1

MbreakNC2.5n

0

R4

1k

C1.5n R8

10

R1

120

R6

10

CANL

R5

10

V3

TD = 100n

TF = 10nPW = 10uPER = 20u

V1 = 0

TR = 10n

V2 = 1

V1

5Vdc

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Reduction of vehicle tests


Exhaust gasAfter treatment &

soot filter

Air quality

Fuel injection & pump

Air mass

Airco(pressure & switch)

Cylinder Pressure

Transmission

Automotive Sensors

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soot filter

Pressure Technologies 1/3

Air quality


Air mass


Cylinder Pressure

Transmission

MEMSMicroElectroMechanical

System

High & Low

Pressure side

Low pressure (< 10 bar) applications



soot filter

Air quality


Air mass


Cylinder Pressure

Transmission

Ceramic Capacitive

Medium pressure ( < 200bar) applications


Capacitor PlatesMedia Pressure

∆ cap. range = 5pFAccuracy = 0.5% �� 25fF !!!

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Cylinder Pressure




soot filter

Air quality

Air mass


Transmission

R1R2

R2

R1

MSG MICROFUSED STRAIN GAGE

High pressure (35-3500bar) applications


How to determine sensor interface ??

Electrical sensor interface �� Analog V PWM LIN SENT PSI5 CAN

Resolution

Trade-off Trade-off

High High High High

Speed / bandwidth Low

(20Kbit/s)

Med

(50Kbit var)

High

(125kbit/s)

High

(1Mbit/s)

Cost (sensor level) Low Low Low…Med Low…Med High Highest

Power supply 3.3V or 5V 5V or Vbat Vbat 5V Variable 5V

Number of nodes 3(+) 3 3 3 2 4

Flexibility Low Low High Med High Highest

Immunity & EMC performance Low (or

costly)

Trade-off Good Good (tbp) Good Good

“Real-life” OEM acceptance Very good Good OK Increasing

(new)

OK Good

Suitable for safety applications High-end

sensors only

No No No Yes Yes (CAN-B)

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Glow rod

Engine seal

Cylinder Pressure Sensor – Glow Plug

Sensor part

• Bandwith: 10 kHz

• Interface: Analog V

• Supply: 3.3 – 5 volt

• Plug current: 30Hz PWM <30Amp Tr=150us


ESP Sensors

• Sensor interface: double analog / digital

• Sensor response: us

• Sensor supply: 5 volt

• Module interface: CAN

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DCT – Double Clutch Transmission

• Sensor interface: Analog

• Sensor response: 10 ms

• Sensor supply: 5 volt

• Module interface: CAN


Email: [email protected] - Istwaan Knijff

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Backup slide: ASIL

Outputs: QM or ASIL X level

Where from least severe to most severe:

QM = Quality Management

A = ASIL A (additional requirements)

B = ASIL B

C = ASIL C

D = ASIL D (highest in ranking ,

the most additional

requirements)

ASIL stands for

Automotive Safety Integrity Level

Important: An ASIL level is always assigned to a safety goal/technical safety requirement and not to a product! ASIL level is a result from a Hazard and Risk analysis

Automotive Safety Integrity LevelASIL = Severity x Exposure x Controllability

Documents

2013-10-03 - EMC safety control in automotive - Istwaan