As automobiles evolve, design engineers are continuously calling for components that offer increased performance and flexibility. Further still are the requirements that these devices be versatile and adaptable to a wide range of applications. While traditional position sensing technologies have their strengths, the development of inductive sensing technology offers solutions to the technical challenges and needs of today's demanding automotive electronics. The design flexibility of this type of sensing technology makes it a robust and cost effective solution for many automotive applications. This is particularly true for sensors and other feedback electronics that are required to make cars safer, more fuel-efficient, and emissions friendly. This talk will discuss position sensor challenges such as the issue of stray fields, harsh environments, installation space, mechanical tolerances, as well as levels of accuracy performance for safety critical applications such as electronic power steering (EPS) and electrical motor control to meet new safety and efficiency regulations.

1. Copyright 2017, IDT Inc.
Technical Education Webinar Series, January 25, 2017
Presented by Jan Leuckfeld and Heinz Oyrer
Addressing the Challenges of Position
Sensor Solutions in Safety Critical
Automotive Applications
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2. Copyright 2017, IDT Inc.
Abstract
This talk will discuss position sensor challenges
such as the issue of stray fields, harsh
environments, installation space, mechanical
tolerances, as well as levels of accuracy
performance for safety critical applications such
as electronic power steering (EPS) and electrical
motor control to meet new safety and efficiency
regulations.
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3. Copyright 2017, IDT Inc.
Introduction to
Automotive
Electronics
• Sensing is a major function of the
electronics system
 with position sensors as on of the biggest market
segment in regards to automotive sensor demand.
• Position sensors in vehicles are
increasingly installed for applications
such as
 throttle valve position, suspension control, power
assisted steering, electronic gas pedals, electronic
brake pedals and fluid level systems.
• Systems are increasingly being
electrically-powered
 In addition to previously mechanically-driven
applications such as power steering.
• Increasing for brushless DC motors
 stimulating the demand for motor position and
control sensors in the automotive sector.
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4. Copyright 2017, IDT Inc.
What does Safety-critical mean?
• Safety-critical or Life-critical system
is a system whose failure or malfunction may
result in one (or more) of the following
outcomes:
– Death or serious injury to people
– Severe damage to equipment/property and
environmental harm
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5. Copyright 2017, IDT Inc.
ISO 26262 - titled
"Road vehicles – Functional safety”
• The standard ISO 26262 is an
adaptation of the Functional
Safety standard IEC 61508 for
Automotive Electric/Electronic
Systems.
• Functional safety features form an
integral part of each automotive
product development phase
• ISO 26262 defines functional
safety for automotive equipment
applicable throughout the lifecycle
of all automotive electronic and
electrical safety-related systems.
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6. Copyright 2017, IDT Inc.
Model-based Functional Safety in E/E
system development
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• ISO 26262 - increased awareness
of this topic in the industry.
• Challenge of fulfilling the
requirements of the standard and
addressing the rising complexity of
safety-related functions.
• It takes much greater work effort
to develop safety-critical
compared to conventional
systems
• Development, analysis and test
methods need to be integrated in
a uniform process.
Source: Vector Consulting Services (Model-based Functional Safety in E/E system development)

7. Copyright 2017, IDT Inc.
Safety-critical applications in
Automotive
• Modern cars are stuffed full of microprocessors and microcontrollers that perform a variety of
functions, which vary in their importance from convenience to safety critical.
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Source: www.nexteer.com product images
• Systems in cars may be broadly divided into 3 categories,
depending on their safety requirements:
1. Convenience systems, which add to the comfort and
pleasure of using the vehicle, but are only an
inconvenience if they malfunction; an example is
climate control.
2. Non-critical safety systems, which add to the safety of
the vehicle, but do not render the vehicle unsafe if
switched off, but may introduce problems if they
malfunction; an example is an electronic stability
program (ESP).
3. Critical systems, the correct functioning of which is
essential to the safe operation of the vehicle; the
braking and the steering system is a good
example.
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8. Copyright 2017, IDT Inc.
Improved fuel efficiency & emissions in
vehicles
• Europe CAFE standards
require OEM’s to raise
average fuel efficiency to
 60.6 mpg ≈ 26 km/l
for new vehicles by 2025.
– Translates in CO2
emission reductions to 70
g/km by 2025.
• U.S. CAFE standards
require OEMs to raise
average fuel efficiency to
 56.2 mpg ≈ 24 km/l for
new vehicles by 2025
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Source: Center for Climate and Energy Solutions
CAFE = Corporate Average Fuel Economy

9. Copyright 2017, IDT Inc.
Selected Automotive Applications
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Powertrain
• Air intake manifold
• Throttle valve
• Turbocharger wastegate
• Turbocharger bypass valve
• Exhaust gas recirculation
• Transfer case gear position
• Transmission gear position
• Gear shift lever position
• Double clutch actuator
• Transmission actuator
• Engine cooling fan
• Hybrid E- Generator
• Fluid level sensors
• Crankshaft
• Camshaft
Chassis
• Steering motor
• Steering column position
• Suspension height
• Headlamp leveling
• Power seat position
• Electric park brake
• Fuel level sensor
• Convertible roof position
Safety
• Auto Brake actuator
• Steering Angle & Torque
Body
• HVAC pump motor
• Airflow actuators position
• Wiper position & motor
• Mirror Position
• Seat position
• Accelerator pedal
• Clutch pedal, e-clutch
• Brake pedal

10. Copyright 2017, IDT Inc.
What are Position Sensors?
• Contacting: through a mechanical connection (switch)
• Non-contacting: without physical contact
Sensors which measure linear or rotational motion
• More reliable
• Longer functional life due to the absence of mechanical parts and physical
contact
Non-contacting position sensors are
• From simple angle sensors towards robust and intelligent sensor systems
• Contact-less AND magnet-less position sensor solutions
Strong trend
• Non-contacting, magnet-less, intelligent position sensors!
IDT Position Sensors
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11. Copyright 2017, IDT Inc.
Focus on Inductive Technology
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Metallic target
(Al, Cu,..)
Simple coil
design
on 2-sided
PCB
• Ultra-thin solution - Small
form factor, no magnet
required
• Total stray field immunity -
ISO 11452-8 compliant
• No external sensor needed -
the sensor is a PCB coil
• Compliant to auto standards
- AECQ-100, ESD, EMC,
ISO26262
• Suitable for high
temperature
• On and off-axis capability
and alignment
Chip

12. Copyright 2017, IDT Inc.
Typical Inductive Position Applications
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linear motion
end of shaft
360°
on- axis
rotation
end of shaft
180°
on- axis
rotation
hollow shaft 360°
off-axis rotation
arc motion
2D (XY) motion
Torque
Side shaft, 1x 360°
off- axis rotation
res.: 0.088° / step
Side shaft, 2x 180°
off- axis rotation
res.: 0,044°/step
End of shaft 1x 360°
on- axis rotation
res.: 0.088° / step
Side shaft, 6x 60°
off- axis rotation
res.: 0,015°/step
arc coil shape for
limited space

13. Copyright 2017, IDT Inc.
Identifying and solving
the challenges (1)
• ISO11452-8
compliant!
Stray field
immunity
• No
temperature
limitations
Harsh
environments • Thinnest
position
sensor on
the market!
Installation
space
• No tight
assembly
tolerances
required!
Mechanical
tolerances • No magnet
required!
Sensing target
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14. Copyright 2017, IDT Inc.
Identifying and solving
the challenges (2)
• High
accuracy in
every
application!
Accuracy
• Same IC for
on-axis + off-
axis!
Off-axis
capability
• Fully
automotive
qualified!
EMC and
overvoltage
protection
• Suitable for
any number
of rotor
poles!
Motor position
and commutation
• Thinnest
torque
sensor
available!
Torque Sensing
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15. Copyright 2017, IDT Inc.
Identifying and solving
the challenges (3)
• Maximum
resolution at
every angle
range!
Narrow angle
• Full resolution
for long or
short linear
strokes!
Long strokes
• 2D motion
with only one
IC!
2D Sensing
• Flexible
motion paths!
Arc Motion and
Non-uniform
Sensing • ISO11452-8
compliant!
Stray field
immunity
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16. Copyright 2017, IDT Inc.
Sensors and strayfields
• Sensors
– Use of sensors has dramatically increased
– Number and strengths of electric fields have increased
– Exposure to environmental factors such as magnetic stray fields,
vibration and misalignment cause issues with system safety and
reliability
• What is a stray field?
– Magnetic fields are generated by magnets, motors, transformers or any
current-carrying conductors
– Stray Fields are parasitic magnetic fields as observed by a sensor
• Why stray fields in automotive
– Increased electrification of automobiles
– Electric cars - large high current carrying wires run between the front and
back of the vehicle
• Issues caused by stray fields
– High levels of electro-magnetic interference (EMI) are a strong concern
in industrial and automotive applications
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17. Copyright 2017, IDT Inc.
Examples of strayfields
• Electric motor
– Generates a magnetic field that effect e.g. the angle position
sensor accuracy
• Drive-train of vehicles becomes partially or wholly
electrified
– Battery cable connections can be negatively impacted e.g. the
position sensor in an acceleration pedal or an electronic
power steering system
– Stray magnetic field from a high-voltage power line in an EV
or HEV is easily large enough to affect safety-critical systems
such as the brake pedal
• Huge induction fields – such as in future charging
stations of electric vehicles
– Can result in an adverse impact on all on-board sensors in a
car
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18. Copyright 2017, IDT Inc.
Inductive –
solving the strayfield problem
• Adherence to Standards
– Naturally, these unique inductive position sensors meet
the latest standards for immunity to magnetic fields and
functional safety
• ISO11452-8 - immunity to magnetic fields
• ISO26262 - functional safety
– Inductive = Stray field immunity. This enables a small
form factor and it allows for a cost effective solution as
external components and expensive external shielding
are not needed - in short:
• Simple
• Inexpensive
• Small form factor
• Safer usage
• Unlimited protection from stray fields
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19. Copyright 2017, IDT Inc.
Position Sensors Ubiquitous
in EPS Systems (safety-critical)
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• Enable Auto OEMs to meet improved steering safety and fuel efficiency requirements
• Hand-wheel position for ESP and adaptive light control as well turns-counting
• Torque sensing to control the steering power support for the driver
• Rotor position for motor commutation, particularly in BLDC motors for power steering
assistance
Torque Sensor
Steering Angle Sensor
Steering Torque Sensor
Rotor position Sensor
Source: Nexteer

20. Copyright 2017, IDT Inc.
Opportunities for efficiency -
Electrical motors
• Electric motors use majority of global electricity
– Electric motors are the single biggest consumer of electricity.
– They account for about 2/3 of industrial power consumption and, about 45% of
global power consumption, according to a new analysis by the International Energy
Agency
• Majority of electric motors are inefficient
– Rarely discussed is the fact that the majority of electric motors are inefficient,
oversized, or running when they don’t need to be running.
• Addressing the efficiency of electric motors is an important topic that
needs to be tackled.
– Reducing CO2-emissions by saving weight and reducing fuel consumption as a
key requirements in Automotive market
– Brushless Direct Current (BLDC) motors are rapidly gaining popularity. Major
advantages of brushless DC motors include higher efficiency at converting
electricity into mechanical power, reduced noise, longer lifetime and higher
reliability
– Government regulations worldwide: Require the industry to implement new
efficiency classes IE1, IE2, IE3, … (IE = International Efficiency to reduce CO2
(higher efficiency means better motor control)
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Source: CleanTechnica, abb.com/energyefficiency

21. Copyright 2017, IDT Inc.
Motor Position Sensor IC - enables
efficient EPS motor commutation
• Controls commutation of a brushless DC
motor employed in the system
• Eliminates need for discrete hall sensors in
stator
• More design freedom - the sensor does not
need to reside on specific positions inside
the motor
• Provides fast and accurate measurements
• Power efficient - no power dissipation
• Easy integration, high temperature
environment
• High start-up torque, low torque ripple
• Low audible noise, excellent reliability
• High safety levels, high accuracy
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Source: press picture Brose Fahrzeugteile
Brushless DC (BLDC)
Motor is preferred
choice in EPS as it
offers better starting
torque and efficiency

22. Copyright 2017, IDT Inc.
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How EPS Technology is Paving the
Way for ADAS
• EPS is the gateway
technology to autonomous
driving of the future.
• EPS technology is enabling
the future of “intuitive motion
control” with its advanced
mechatronic hardware/
electronics, software and
sensor building blocks.
• Safety-critical components
play a key role in “Advanced
Driver Assistance Systems” –
or ADAS
Source: Hitachi IR Day 2015
Position Sensor Controls
commutation of a
brushless DC motor
employed in the system

23. Copyright 2017, IDT Inc.
Wrap up
• Sensing is a major function of the electronics system
in automotive.
• Position sensors as one of the biggest market
segment in regards to automotive sensor demand.
• Position sensors provide system power and cost
savings while improving vehicle performance and
safety.
• Inductive Position Sensor technology will continue to
experience strong adoption in EPS/ADAS and other
automotive safety critical and fuel efficiency
applications.
• Inductive Position Sensor ICs offer many benefits
over other sensing technologies.
• Superior robustness through contactless, magnet-
less, intelligent “system-on-chip” solution.
• Stray field immune technology provide high
accuracy measurements even in the noisiest of
electromagnetic interference (EMI) environments,
commonly found in automotive applications.
• New emission regulations and safety standards are
key business drivers.
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24. Copyright 2017, IDT Inc.
ZMID520x Video
Inductive Contactless Position Sensors
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25. Copyright 2017, IDT Inc.
Playback
If you want to hear a playback please register for
this webinar at
Microwave Journal
by clicking at the Inductive Position Sensor icon
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26. Copyright 2017, IDT Inc.
Thank You Analog Mixed Signal Product
Leadership in Growth Markets
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