A short intro on functional safety when it comes to signal processing and transmission in ADAS systems

1. SIGNAL PROCESSING
IN ADAS SYSTEMS
Ahmed Mahrous

2. AGENDA
Introduction
Safety Targets & Hazards
Safety Measures
Wrap up
Questions
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3. IF YOU THINK SAFETY IS EXPENSIVE,
TRY AN ACCIDENT.​
Trevor Kletz – Safety Expert
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4. INTRODUCTION
• Safety is the heart of ADAS Systems and the key difference
to the “normal” software development.
• It is the reason why many high-tech companies are held
back on automotive development.
• All ADAS Systems are mainly doing lots of signal exchange,
where many safety hazards can take place.
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5. SAFETY TARGETS
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AVALABILITY
The source of the
information is alive
and able to
provide data.

6. SAFETY TARGETS
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AVALABILITY
The source of the
information is alive
and able to
provide data.
TIMING
The signal is
received in time

7. SAFETY TARGETS
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AVALABILITY
The source of the
information is alive
and able to
provide data.
TIMING
The signal is
received in time
INTEGRITY
The signal sent is
correctly received
without unintended
manipulation

8. SAFETY TARGETS
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AVALABILITY
The source of the
information is alive
and able to
provide data.
TIMING
The signal is
received in time
INTEGRITY
The signal sent is
correctly received
without unintended
manipulation
CORRECTNESS
The signal includes
sane data

9. SAFETY TARGETS
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AVALABILITY
The source of the
information is alive
and able to
provide data.
TIMING
The signal is
received in time
INTEGRITY
The signal sent is
correctly received
without unintended
manipulation
SECURITY
The signal sent is
correctly received
without intended
manipulation
CORRECTNESS
The signal includes
sane data

10. SAFETY HAZARDS
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AVALABILITY
- Hardware
failures
- Environmental
factors
TIMING
- Network
congestion
- Processing
performance
- Out of Sync
Data
INTEGRITY
- Unintended
Interference (noise)
- Weak signal
transmission
- Faulty Hardware
(memory)
SECURITY
- Manipulation of
data
- Spoofing
- Jamming
CORRECTNESS
- Faulty
Calculations
- Technical
insufficiencies
(sensor / actuator
limitation)

11. SAFETY MEASURES
HOMOGENOUS REDUNDANCY
Run the same software on two
different ECUs
HARDWARE MAINTAINCE
Grounding, shielding, and isolation
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DIVERSE REDUNDANCY
Send the ego velocity from two different
ECUs
DIAGNOSTICS
Detect mud/snow/blockage
Detect short/open circuit/timeout
AVALABILITY

12. SAFETY MEASURES
SYNCHRONIZATION
All senders sync to a global clock
PTP/NTP Protocols are implemented
REAL-TIME MONITORING
Watch-dog mechanisms to abort
processing after specific time
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REDUNDANCY
If one communication channel is
jammed, another one can be used
PRIORITIZATION
Important signals shall be processed
first and sent with priority.
TIMING

13. SAFETY MEASURES
VALIDITY CHECKS
Infinity or NAN values are usually
unintended
E2E CHECKS
Checksum / Parity bit / CRC / Sequence
Counter / Acknowledgment Message.
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HOMOGENOUS REDUNDANCY
Execution on two identical hardware
pieces and comparing their output
SIGNAL CONDITIONING
Filtering/ Amplifying /Transforming
signal to ensure no loss of data.
INTEGRITY

14. SAFETY MEASURES
DIVERSE REDUNDANCY
Confirm or correct data based on
similar calculations on different sources
DATA FUSION
Reduce risk by having complementary
information from different modalities
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PLAUSIBILITY CHECKS
A pedesrian of a speed 200 kilometers
per hour is definetly unintended.
VALIDATION
Over a large dataset and covering all
cases. (unknown unsafe → known)
CORRECTNESS

15. SAFETY MEASURES
ENCRYPTION
Agreed approach to understand
(convert) the sent message
AUTHENTICATION
Request rights to read the data using a
predefined identification code.
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REDUNDANCY
If a channel gets jammed, the data
can be delivered on another.
MONITORING
Watch-dog for flow control between
different components.
SECURITY

16. SAFETY MEASURES
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AVALABILITY
- Back up systems
- Maintenance
- Diagnostics
TIMING
- Synchronization
- Prioritization
- Monitoring
INTEGRITY
- E2E checks
- Redundancy
- Validity Checks
SECURITY
- Encryption
- Authentication
- Access Control
CORRECTNESS
- Sanity Checks
- Input diversity
- Validation

17. SUMMARY
- Signal processing in Advanced Driver Assistance Systems
(ADAS) is crucial to ensure the safety of passengers and
pedestrians.
- Generally, the goal is to have available, punctual, reliable,
secure and integral data
- Hazards have to be identified as a first step to implement
counter measures. Once identified, faults shall be either
prevented or tolerated.
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18. The signal sent is
correctly received
without intended
manipulation
The signal includes
sane data
The signal sent is
correctly received
without unintended
manipulation
The signal is
received in time
The source of the
information is alive
and able to
provide data.
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AVALABILITY TIMING INTEGRITY SECURITY
CORRECTNESS
- Back up systems
- Maintenance
- Diagnostics
- Synchronization
- Prioritization
- Monitoring
- E2E checks
- Redundancy
- Validity Checks
- Encryption
- Authentication
- Access Control
- Sanity Checks
- Input diversity
- Validation
- Hardware
failures
- Environmental
factors.
- Network
congestion
- Processing
performance
- Out of Sync data
- Unintended
Interference (noise)
- Faulty Hardware
- Manipulation of
data
- Spoofing
- Jamming
- Faulty / Buggy
Calculations
- Technical
insufficiencies

19. THANK YOU
Ahmed Mahrous
ahmedsabek@live.com
linkedin.com/in/ahmedsabek
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