Technical Bulletin

Euro NCAP Assisted Driving
Sensor Blocking Method
Version 1.0

June 2023
TB 041

TitleVersion
Document NumberAuthor
Date
Related Documents
StatusApplication Date

Assisted Driving Sensor Blocking Method
1.0
TB 041
Dominic Tough, Adriano Palao
June 2023
Assisted Driving - Highway Assist Systems v1.1, TB025
Information
1st January 2023

Copyright ©Euro NCAP 2023 - This work is the intellectual property of Euro NCAP. Permission is granted forthis material to be shared for non-commercial, educational purposes, provided that this copyright statement
appears on the reproduced materials and notice is given that the copying is by permission of Euro NCAP. To
disseminate otherwise or to republish requires written permission from Euro NCAP.

Preface
DISCLAIMER: Euro NCAP has taken all reasonable care to ensure that the information
published in this document is accurate and reflects the technical decisions taken by theorganisation. In the unlikely event that this protocol contains a typographical error or
any other inaccuracy, Euro NCAP reserves the right to make corrections and determine
the assessment and subsequent result of the affected requirement(s).

EUROPEAN NEW CAR ASSESSMENT PROGRAMME (Euro NCAP)
Table of Contents
1INTRODUCTION .................................................................................................................... 12

RADAR COVERAGE .............................................................................................................. 23

2.1

Material Specifications ................................................................................................................2

2.2

Application Method .....................................................................................................................3

CAMERA COVERAGE ........................................................................................................... 4
3.1

Material Specifications ................................................................................................................4

3.2

Application method .....................................................................................................................4

Annex 1:RCS Measurement of Blocked RADAR ........................................................................... 5Annex 2: Examples of Euro NCAP Test Lab Blocking Devices .................................................... 6

1INTRODUCTION
In real world driving it is anticipated that the sensors involved with the DriverAssistance System (Radar, LiDAR, or camera) may either deteriorate by age or damage
or become blocked in adverse weather conditions. Having a blocked or deteriorated
sensor may reduce the competency of the system. It is important that the system does
not operate with reduced competency and that the driver is aware of the reason that thesystem becomes unavailable. It is believed that all current systems will see some
reduction in competency when a sensor fails, but there may be redundancy built into
the system or multi-function sensors used to mitigate the effects to the performance ofthe system if a single sensor fails.
Due to the complexity of modern radar technology a suitable material specification isrequired for consistent and repeatable testing across multiple Euro NCAP testinglaboratories. This Technical Bulletin (TB 041) outlines the specification of the material
that shall be used to block the forward facing radar and forward facing camera, in
addition to outlining parameters in which the blocking material shall be applied to thesensors which will simulate a blocked sensor whilst the vehicle is in motion. The
material and application methods were verified as acceptable through a Euro NCAP
workshop hosting multiple Vehicle Manufactures and Tier 1 Suppliers.

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2

RADAR COVERAGE

2.1

Material Specifications
The material to be used for blocking the forward facing radar has the correct attributes
required to ensure the effect of a physically fully blocked radar therefore, reducing thesystem competency which shall initiate a warning to the driver of a blocked sensor. A
common blocking material is needed to ensure consistent and repeatable testing acrossmultiple Euro NCAP laboratories.
This radar blocking material is to be used only for the forward facing radar.

2.1.1

Material PropertiesThe blocking material to be used shall be a broadband Radar Absorbing Material(RAM), two way damping within 77-81Ghz automotive frequency range atapproximately 50dB. The required material to be used is the RAM found within therear and side skirts of the Global Vehicle Target as specified in TB025. Item number
10 in Figure 1Figure 1 Global Vehicle Target areas

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2.1.2

Material dimensions
The required blocking material used shall be the following dimensions:- The width shall be 200mm ± 10mm
-The length shall be 200mm ± 10mm-The height shall be 10mm ± 1mm*Figure 2 Example images of GVT foam material*If a stationary GVT is detected by the VUT with a blocked radar then it is permissible to use adouble layered material, 20mm ± 1mm.

2.2

Application Method
The application method of the blocking material shall result in full physically
blockage of the front radar. The method shall ensure that the sensor is fully blocked ina consistent way throughout the time in which is require as per the Assisted Driving Highway Assist Systems v1.1 protocol such that the systems blockage detectionalgorithm does not reset.
The blocking material shall be applied with the following criteria:• It shall be close conforming to external vehicle surface in front of sensor,
acknowledging challenge of corner sensors and non-planar coverage. (e.g., if
the sensor is placed behind the front bumper the material shall be placed close
conforming to the section of the bumper directly in front of the radar
placement.)• There shall be minimal vibration of the blocking material whilst it is applied tothe vehicle surface.
• For tests within the Assisted Driving protocol which requiring the sensor to gofrom an unlocked to a blocked state, sections 4.1.2.2 and 4.1.2.3. The material
shall be applied to block the sensor so that it goes from a fully unblocked to a
fully blocked physical condition within two seconds.

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CAMERA COVERAGE

3.1

Material Specifications

3.1.1

For blocking a camera sensor mounted behind the front windscreen, a solid single pieceof opaque material is to be applied to the outside of windscreen.

3.2

Application method
The application method of the blocking material shall result in full physically blockageof the front camera. The camera shall be blocked using a solid material piece e.g.,plastic, which fully covers the camera view.
The method shall ensure that the sensor is fully blocked in a consistent way
throughout the time in which is require as per the Assisted Driving - Highway Assist
Systems v1.1 protocol such that the systems blockage detection algorithm does notreset. The blocking material shall fully block the camera view when fixed to thewindscreen in front of the camera, and shall be applied with the following criteria:•••It shall be close conforming to external vehicle surface in front of sensor
There shall be minimal vibration of the blocking material whilst it is applied tothe vehicle surface.
For tests within the Assisted Driving protocol which requiring the sensor to gofrom an unlocked to a blocked state, sections 4.1.2.2 and 4.1.2.3. The material
shall be applied to block the sensor so that it goes from a fully unblocked to a
fully blocked physical condition within two seconds.

Whilst it is common for the lateral support of the Assisted Driving system to be control
by a camera mounted within the windscreen, if an alternative method is use by the OEM
this shall informed to Euro NCAP.

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Annex 1:RCS Measurement of Blocked RADAR
The RCS value was measured using a Continental ARS5408 radar. Two measurements weretaken: one with a clear view, and a second with the RAM material in front of the sensor.

Figure 3 RCS Measurement Test Setup

Figure 4 shows the RCS measurements of both test setups, showing a 50dBm2 decrease with thesensor blocked by the RAM material.

Figure 4 RCS Results of Clear View and Blocked

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Annex 2: Examples of Euro NCAP Test Lab Blocking Devices

Figure 5 Thatcham Research Manual Blocking Method

Figure 6 UTAC Electronic Servo Blocking Method

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Figure 7 IDIADA Electronic Servo Blocking Method

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