ISO/TS 22239-1:2018

TECHNICAL ISO/TS
SPECIFICATION 22239-1
Second edition
2018-05
Road vehicles — Child seat presence
and orientation detection system
(CPOD) —
Part 1:
Specifications and test methods
Véhicules routiers — Système de détection de la présence d'un siège
enfant et de son orientation (CPOD) —
Partie 1: Spécifications et méthodes d'essai
Reference number
ISO/TS 22239-1:2018(E)
©
ISO 2018

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ISO/TS 22239-1:2018(E)

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ISO/TS 22239-1:2018(E)

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Abbreviated terms . 3
5 Principle . 3
5.1 General . 3
5.2 Compatibility . 4
6 System functionality . 6
7 Design recommendations . 8
7.1 General . 8
7.2 Installation of CPOD resonators into the CRS . 8
7.3 Installation of CPOD sensors into passenger seats .11
8 Design requirements .12
8.1 Requirements for CPOD child seats .12
8.2 Requirements for CPOD passenger seats .13
8.2.1 Passenger seat design . .13
8.2.2 CPOD sensor .13
8.2.3 Operating range for CPOD passenger seats .13
9 Compatibility measurements .13
9.1 General specification .13
9.2 Compatibility test parameters range .14
9.3 Adjustment of backrest inclination .14
9.3.1 Adjustment of CTB backrest angle, α .14
9.3.2 Adjustment of passenger seat backrest angle, φ .15
9.4 Compatibility measurements for the CRS .16
9.4.1 General compatibility test description .16
9.4.2 Compatibility test (Part 1) .17
9.4.3 Compatibility test (Part 2) .19
9.4.4 CRS functional test .21
9.5 Compatibility measurements for passenger seats .22
9.5.1 General test description .22
9.5.2 Determination of passenger-seat-specific detection/failsafe area .26
9.5.3 Compatibility test procedure for passenger seats .29
9.5.4 Test result interpretation .30
10 Labelling .30
Annex A (normative) Determination of the passenger seat reference point (CRP) .32
Annex B (normative) Geometrical descriptions .34
Annex C (normative) Detailed specification of the CPOD system functionality .38
Annex D (normative) CPOD child seat compatibility test bench .49
Annex E (normative) CPOD passenger seat compatibility test device.61
Annex F (normative) Additional definitions .65
Annex G (normative) Magnetic coupling factor measurement procedure .70
Bibliography .76
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ISO/TS 22239-1:2018(E)

Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation on the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to the
World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see the following
URL: www .iso .org/iso/foreword .html.
This document was prepared by Technical Committee ISO/TC 22, Road vehicles, Subcommittee SC 36,
Safety and impact testing.
This second edition cancels and replaces the first edition (ISO/TS 22239-1:2009), which has been
technically revised to take into account the development in technology since the first edition was
published.
A list of all parts in the ISO/TS 22239 series can be found on the ISO website.
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ISO/TS 22239-1:2018(E)

Introduction
This document specifies a detection system for the automatic recognition of child seat presence and
orientation detection system (CPOD) child seats placed on CPOD passenger seats.
The purpose of this detection system is to improve the overall safety performance of passenger
restraint systems, particularly by reducing the risk of an airbag being deployed against a child seat
placed on a passenger seat.
The CPOD system is not intended to encourage the placing of children on the front passenger seats
of cars. However, in view of the fact that the following scenarios do occur in real life, children can be
placed on front passenger seats in these cases:
— in 2-seater vehicles, which have no rear seats;
— when there are more than 2 or 3 children in one vehicle;
— when back seats are folded down for the transport of cargo;
— when the installation of a rearward-facing child restraint system (CRS) and the placing of the child
in the CRS on the rear seats is very difficult or impossible, e.g. in 2-door vehicles;
— when the driver wants to see the baby and have easy access to it.
There might be benefit to be gained by encouraging the use of airbags on rear seats.
For the cases cited above, CPOD technology offers a reliable automatic solution for the protection of
children against any possible risk caused by non-deactivated airbags.
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TECHNICAL SPECIFICATION ISO/TS 22239-1:2018(E)
Road vehicles — Child seat presence and orientation
detection system (CPOD) —
Part 1:
Specifications and test methods
1 Scope
This document specifies a child seat presence detection system that enables child seats placed on any
passenger seats to be automatically detected where a child is at risk from an active airbag. The system
provides the option of using additional information about the orientation of the child seat.
This document specifies the minimum functional requirements in order to ensure compatibility between
child seat presence and orientation detection system (CPOD) child seats and CPOD passenger seats.
Compatibility measurements and labelling requirements complement the obligatory specifications of
this document.
This document also provides design recommendations which are not compulsory when claiming
compliance with ISO/TS 22239. However, these recommendations, based on experience of proven
designs, provide useful guidance to designers to avoid erroneous designs and thus, enable designers to
reduce time and cost of CPOD development.
The tell-tale “child seat detected” required for a CPOD vehicle, the specific labelling required for a
CPOD vehicle and CPOD child seat and the detailed information about the CPOD system functionality
required for owner's manuals of CPOD vehicles and CPOD child seats will mitigate considerably the
misuse probability. The document does not provide a failsafe physical mechanism that prevents the
installation of non-CPOD child seats in a CPOD vehicle or vice versa.
ISO/TS 22239 applies only to child restraint systems in which the child is orientated in the forward or
rearward driving direction.
NOTE 1 Throughout this document, the term “child seat” is used as an abbreviation of “CPOD child seat”.
NOTE 2 Throughout this document, the term “passenger seat” is used as an abbreviation of “CPOD-equipped
passenger seat”.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 6549:1999, Road vehicles — Procedure for H- and R-point determination
ISO/TS 22239-2:2018, Road vehicles — Child seat presence and orientation detection system (CPOD) —
Part 2: Resonator specification
ISO/TS 22239-3:2017, Road vehicles — Child seat presence and orientation detection system (CPOD) —
Part 3: Labelling
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
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ISO/TS 22239-1:2018(E)

ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— IEC Electropedia: available at http: //www .electropedia .org/
— ISO Online browsing platform: available at https: //www .iso .org/obp
3.1
child seat presence and orientation detection system
CPOD
radio frequency identification (RFID) system delivering information on the presence, orientation and
type of a child seat
3.2
passenger seat reference point
CRP
point located on the centre line of the passenger seat, determined by the procedure in Annex A
3.3
child seat reference point
CRC
point identical to the intersection of the centre plane of the child restraint system and the CR axis
Note 1 to entry: The CR axis is shown in Figure D.7.
3.4
resonator reference point
RRP
point located in the geometrical centre of the base surface of the resonator
3.5
resonator pair reference point
RPRP
point located in the centre between two resonator reference points (3.4)
3.6
reference coordinate system
Cartesian coordinate system associated with the passenger seat and the compatibility test bench,
having its origin in the passenger seat reference point (3.2), as shown in Figure B.4
3.7
CPOD detection area
three-dimensional area above the passenger seat cushion, where all relevant child seat information
needed to adapt the airbag deployment are transmitted to the restraint control module, provided that
the resonator pair reference point (3.5) is located within this area
3.8
CPOD failsafe area
three-dimensional area above the passenger seat cushion, where either all relevant child seat
information needed to adapt the airbag deployment or information indicating an incorrect positioning
of the child seat is transmitted to the restraint control module, provided that the resonator pair reference
point (3.5) is located within this area
3.9
ISOFIX
system for the connection of child restraint systems to vehicles which has two rigid anchorages in a
vehicle seating position located near the seat bight, corresponding rigid attachments on the child
restraint system, and a means to limit the pitch rotation of the CRS
[SOURCE: ISO 13216-1:1999, 3.6]
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ISO/TS 22239-1:2018(E)

4 Abbreviated terms
CPOD child seat presence and orientation detection system
CRC child seat reference point
CRP passenger seat reference point
CRS child restraint system
CTB compatibility test bench
ECU electronic control unit
FFCS forward facing child sea
PSCTD passenger seat compatibility test device
RCM restraint control module (electronic unit controlling deployment of supplemental restraints)
RFCS rearward facing child seat
RFID radio frequency identification
RMI restraint system malfunction indicator (vehicle-manufacturer-specific)
RPRP resonator pair reference point
RRP resonator reference point
5 Principle
5.1 General
CPOD is an RFID sensing system which is capable of determining the presence and orientation of a CRS
placed on a passenger seat. Depending on the positioning of the CRS, different types of information are
transmitted to the RCM.
If the CRS is correctly placed on the passenger seat such that its RPRP is located within the CPOD
detection area (see 3.7), the CRS is detected by the system.
If the CRS is placed outside of the CPOD detection area but within the CPOD failsafe area (see 3.8), the
system either detects the CRS or recognizes an incorrect CRS positioning.
The gathered information is sent to the central RCM, which enables the adaptation of the airbag
deployment specific to the occupancy situation.
NOTE The specifications of this document are in compliance with Reference [7].
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ISO/TS 22239-1:2018(E)

Key
1 CPOD sensor consisting of:
one transmitting antenna
two receiving antennas
2 CPOD resonators
3 CPOD child seat
4 passenger seat
5 CPOD electronics
6 in-vehicle information
Figure 1 — CPOD system topology
5.2 Compatibility
The compatibility of the system is given if the CPOD component compatibility checks have been passed.
These compatibility checks consist of the following parts:
a) CRS compatibility check to verify the performance of the CRS design;
b) resonator compatibility check to verify the electrical performance of the resonators;
c) passenger seat compatibility check to verify the performance of passenger seat and CPOD
sensor design.
The flow chart in Figure 2 shows how these compatibility checks fit together to assure the CPOD
compatibility of the entire system.
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Figure 2 — Main steps for obtaining the CPOD compatibility of the entire system
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ISO/TS 22239-1:2018(E)

6 System functionality
In order to achieve its performance and, in addition, to provide failsafe behaviour in case of an error,
the following features are implemented in the CPOD system:
— generation of a sinusoidal signal in the 130 kHz band for contact-less energy and information
transmission;
— adaptation of the transmitting signal to different environmental conditions by variation of frequency
and amplitude;
— demodulation of the signal phase modulated by the CRS resonators;
— monitoring of the power and demodulation circuits of the system via integrated self-diagnosis;
— interface to RCM for transmission of CPOD data;
— monitoring of transmitting and receiving antennas for disconnections and short circuits;
— detection of the presence of CRS which is compliant with this document;
— detection of the orientation of CRS which is compliant with this document in vehicles where the
orientation of the CRS impacts the airbag deployment.
Examples of CRS orientations are given in Figures 3 to 5.
Compliance with the detailed system functionality specifications of Annex C shall be provided.
Figure 3 — CRS in forward facing position
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ISO/TS 22239-1:2018(E)

Figure 4 — CRS in rearward facing position
Figure 5 — Example of CRS wrongly positioned
Depending on the positioning of the CRS, the CPOD system delivers the information to the RCM as
shown in Figure 6, provided that the RPRP is located within the CPOD detection area.
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ISO/TS 22239-1:2018(E)

Figure 6 — Information to be submitted to the RCM
7 Design recommendations
7.1 General
In order to maximize the chance of passing the compatibility measurements successfully, the following
recommendations should be respected during the design of CRSs and passenger seats fitted with CPOD.
7.2 Installation of CPOD resonators into the CRS
7.2.1 Electroconductive materials might have an influence on the resonator detection in the CRS.
Therefore, the distance between large electroconductive materials and the resonators in the CRS should
be maximized during the design of the CRS.
The detection capability of the system is very sensitive to electroconductive materials above the
resonator pair or directly between the resonator pair and the CPOD passenger seat. Possible problems
can be avoided by replacing these materials by non-electroconductive materials, as shown in Figure 8.
7.2.2 Closed electroconductive loops as indicated by Figure 7 might have an influence on the resonator
detection in the CRS. Therefore, the distance between closed electroconductive loops and the resonators
in the CRS should be maximized during the design of the CRS.
Closed electroconductive loops, which surround the volume above or below the resonator pair, should
be avoided. This can be achieved by cutting closed loops using non-electroconductive materials, as
shown in Figure 8.
7.2.3 The distance between the bottom of the resonators inside the CRS and the surface of the CRS
compatibility test bench should not exceed 30 mm when the CRS is placed correctly on the CTB in
accordance with Annex D (see Figure 9). In addition, in that position, the bottom of the resonator should
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be parallel with the corresponding seat surface below it. An inclination of ±3° should not be exceeded
(see Figure 9).
Key
1 electro-conductive loop
2 electro-conductive surface
Figure 7 — Closed electro-conductive loop or surface close to the resonators
Key
1 non-electro-conductive
Figure 8 — Closed conducting loop opened using a non-electro-conductive connection
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Dimensions in millimetres
a
d, 10 mm < d < 30 mm.
Figure 9 — Distance between the resonator reference point and CTB surface
7.2.4 The distance between the CRC and RPRP (see Figure 10) should be chosen in such a way that the
resonator pair reference point remains within the CRS detection area when varying the CRS compatibility
test bench adjustments in accordance with 9.4.2 and 9.4.3. A value as close as possible to 200 mm is
recommended for this distance.
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Dimensions in millimetres
a) Forward facing CRS b) Rearward facing CRS
Key
1 left resonator
2 right resonator
Figure 10 — Assembly of resonators in a CRS
7.3 Installation of CPOD sensors into passenger seats
With respect to the installation of CPOD sensors into passenger seats:
— it is recommended to position the CPOD sensors directly under the seat cover instead of foaming them;
— the maximum distance between the CPOD sensor and surface of the seat cover should not exceed
20 mm;
— the seat area should be designed to be as flat as possible (see A.2, Note);
— for non-adjustable seat cushions, the distance between the CPOD sensor and the passenger’s seat
metal shell should be maximized;
— the distance between the seat’s CRP and the centre of the CPOD sensor should be as close as possible
to 200 mm, as indicated by Figure 11;
— during CPOD sensor design, account should be taken of any possible seat adjustment and/or feature
that could affect the performance of the system; in order to improve the detection performance of a
CRS, the two receiving antennas should overlap (see Figure 11).
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ISO/TS 22239-1:2018(E)

Dimensions in millimetres
Key
1 centre of CPOD sensor
2 CPOD sensor consisting of:
one transmitting antenna
two receiving antennas
Figure 11 — Assembly of CPOD antennas into a passenger seat
8 Design requirements
8.1 Requirements for CPOD child seats
8.1.1 Only resonators that are CPOD-compatible in accordance with ISO/TS 22239-2:2018 shall be used.
8.1.2 The CRS shall be equipped with two CPOD resonators.
8.1.3 Easy removal of the resonators without special tools shall be avoided by the CRS design.
8.1.4 The distance between both resonator reference points shall be 140 mm ± 2 mm, as indicated in
Figure B.1.
8.1.5 The resonator pair shall be positioned symmetrically in the CRS in accordance with Figure 10,
such that the right resonator is assembled into the CRS right side and the left resonator in the CRS left
side (CRS left and right side referenced on the child’s line of sight).
— Exception for CRS type 4 (see ISO/TS 22239-2:2018, Table 2): The resonators shall be assembled
symmetrically in the CRS such that, if the CRS is mounted on the passenger seat, the left resonator is
positioned above the left side and the right resonator is placed above the right side of the passenger
seat (passenger seat’s left and right side referenced on the driving direction).
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— For all CRS types: The resonator pair reference point shall be part of the x-z plane of the passenger
seat if the CRS is mounted correctly on the passenger seat.
8.2 Requirements for CPOD passenger seats
8.2.1 Passenger seat design
Passenger seats shall be designed to allow the installation of the fixture (Gabarit) in accordance with
Annex A.
8.2.2 CPOD sensor
CPOD passenger seats shall be equipped with a CPOD sensor consisting of one transmitting and two
receiving antennas. The CPOD sensor shall meet the requirements defined in Annex C. In addition, it
shall meet the manufacturer's seat and electronic requirements.
It shall be assured that the CPOD sensor maintains its function during the entire life cycle, e.g. position of
the antennas in the seat cushion, environmental stability, as specified by the seat/vehicle manufacturer.
8.2.3 Operating range for CPOD passenger seats
The CPOD system shall meet its functionality in accordance with Clause 6 within the limits specified in
Table 1.
Table 1 — CPOD operating range
Parameter Min. Max.
Operating temperature
T −35 85
OP
°C
Operating voltage (12 V power net)
V 10 16
OP,12
V
Operating voltage (24 V power net)
V 20 32
OP, 24
V
9 Compatibility measurements
9.1 General specification
In order to ensure the performance of the CPOD system, the CRS manufacturers and the vehicle
manufacturers shall perform compatibility measurements for introducing new CRS respectively new
CPOD passenger seats. By means of these compatibility measurement procedures, it is ensured that all
released CRS and all released CPOD passenger seats feature CPOD performance, which is characterized
as described below.
a) If the CRS is placed on th
...