IEC TR 62998-2:2020

IEC TR 62998-2 ®
Edition 1.0 2020-04
TECHNICAL
REPORT
colour
inside
Safety of machinery –
Part 2: Examples of application
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IEC TR 62998-2 ®
Edition 1.0 2020-04
TECHNICAL
REPORT
colour
inside
Safety of machinery –
Part 2: Examples of application

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 13.110; 21.020 ISBN 978-2-8322-7975-5

– 2 – IEC TR 62998-2:2020 © IEC 2020
CONTENTS
FOREWORD . 4
INTRODUCTION . 6
1 Scope . 7
2 Normative references . 7
3 Terms, definitions and abbreviated terms . 7
3.1 Terms and definitions . 7
3.2 Abbreviated terms . 8
4 Applications for mobile robots . 8
4.1 General . 8
4.2 SRSS on mail transport mobile robot . 9
4.2.1 Intended use . 9
4.2.2 SRSS performance class determination . 10
4.2.3 SRS limits of use and SRSS function . 10
4.2.4 Safety-related requirements . 11
4.2.5 Object classes and physical properties . 12
4.2.6 Sensing zones . 13
4.2.7 Dependability under environmental influences . 15
4.2.8 Safety-related information . 16
4.2.9 Verification and validation . 17
4.2.10 Information for use of the SRSS . 18
4.3 SRSS on cleaning mobile robot . 19
4.3.1 Intended use . 19
4.3.2 SRSS performance class determination . 20
4.3.3 SRS limits of use and SRSS function . 20
4.3.4 Safety-related requirements . 21
4.3.5 Object classes and physical properties . 22
4.3.6 Sensing zones . 23
4.3.7 Dependability under environmental influences . 24
4.3.8 Safety-related information . 24
4.3.9 Verification and validation . 25
4.3.10 Information for use of the SRSS . 26
5 Application for container handling equipment for harbour logistics . 27
5.1 General . 27
5.2 SRSS for CHE . 28
5.2.1 Intended use . 28
5.2.2 SRS limits of use and SRSS function . 29
5.2.3 SRSS performance class determination . 30
5.2.4 Safety-related requirements . 31
5.2.5 Object classes and physical properties . 31
5.2.6 Sensing zones . 32
5.2.7 Dependability under environmental influences . 34
5.2.8 Safety-related information . 34
5.2.9 SRSS performance class after fusion . 34
5.2.10 Verification and validation . 34
5.2.11 Information for use of the SRSS . 35
Bibliography . 37

Figure 1 – Outdoor scene . 8
Figure 2 – Mobile robot with 2 distinctive safety-related zones . 10
Figure 3 – Combination of three SRSs into an SRSS and SRSS functions . 11
Figure 4 – Mounting positions and sensing zones of the SRS and safety-related zones
of SRSS . 14
Figure 5 – Mounting positions and sensing zones of the SRS and safety-related zones

of SRSS . 14
Figure 6 – Examples of measurement data for evaluation of coverage interval . 17
Figure 7 – Test setup . 18
Figure 8 – CHE application . 28
Figure 9 – Operation areas of CHE . 29
Figure 10 – SRSS structure and safety-related functions . 30
Figure 11 – Safety-related zones of SRSS . 32
Figure 12 – Mounting positions and sensing zones of the SRS, and safety-related
zones of the SRSS . 33

Table 1 – Safety-related requirements . 12
Table 2 – Example of confidence information for SRS . 17
Table 3 – Information for use of the SRSS . 19
Table 4 – Safety-related requirements . 22
Table 5 – Information for use of the SRSS . 27
Table 6 – Safety-related requirements . 31
Table 7 – Environmental limits of SRSS . 34
Table 8 – Information for use of the SRSS . 36

– 4 – IEC TR 62998-2:2020 © IEC 2020
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
SAFETY OF MACHINERY –
Part 2: Examples of application

FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
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8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
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9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of patent
rights. IEC shall not be held responsible for identifying any or all such patent rights.
The main task of IEC technical committees is to prepare International Standards. However, a
technical committee may propose the publication of a technical report when it has collected
data of a different kind from that which is normally published as an International Standard, for
example "state of the art".
IEC TR 62998-2, which is a Technical Report, has been prepared by IEC technical committee
TC 44: Safety of machinery – Electrotechnical aspects.
The text of this Technical Report is based on the following documents:
Enquiry draft Report on voting
44/849/DTR 44/865A/RVDTR
Full information on the voting for the approval of this technical report can be found in the report
on voting indicated in the above table.
This document has been drafted in accordance with the ISO/IEC Directives, Part 2.

This document is to be used in conjunction with IEC TS 62998-1:2019.
A list of all parts in the IEC 62998 series, published under the general title Safety of machinery,
can be found on the IEC website.
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under "http://webstore.iec.ch" in the data related to
the specific document. At this date, the document will be
reconfirmed,
withdrawn,
replaced by a revised edition, or
amended.
IMPORTANT – The 'colour inside' logo on the cover page of this publication indicates
that it contains colours which are considered to be useful for the correct understanding
of its contents. Users should therefore print this document using a colour printer.

– 6 – IEC TR 62998-2:2020 © IEC 2020
INTRODUCTION
Safety-related sensors are applied to machinery presenting a risk of personal injury. They
provide protection by causing the machine to revert to a safe condition before a person can be
placed in a hazardous situation.
IEC TS 62998-1:2019 is intended for use by safety-related sensor manufacturers and
integrators of safety-related sensors for the design of safety-related sensor systems used for
the protection of persons.
This document gives guidance for manufacturers and integrators on the application of IEC TS
62998-1:2019.
SAFETY OF MACHINERY –
Part 2: Examples of application

1 Scope
This document establishes guidance for the application of IEC TS 62998-1:2019.
It provides examples of:
– application for which SRS/SRSS are relevant,
– use of SRS/SRSS information from an application point of view,
– fusion of SRS into SRSS for given applications, and
– appropriate information for use for given applications.
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.
IEC TS 62998-1:2019, Safety of machinery – Safety-related sensors used for protection of
persons
3 Terms, definitions and abbreviated terms
For the purposes of this document, the following terms and definitions apply.
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 http://www.iso.org/obp
3.1 Terms and definitions
3.1.1
mobile robot
robot able to travel under its own control
[SOURCE: ISO 8373:2012, 2.13, modified – The note has been omitted.]
3.1.2
robot
actuated mechanism programmable in two or more axes with a degree of autonomy, moving
within its environment, to perform intended tasks
[SOURCE: ISO 8373:2012, 2.6, modified – Notes 1 and 2 have been omitted.]

– 8 – IEC TR 62998-2:2020 © IEC 2020
3.2 Abbreviated terms
CHE container-handling equipment
ALARP as low as reasonably practical
LiDAR light detection and ranging
MOR meteorological optical range
TOF time of flight
SLAM Simultaneous Localization and Mapping
SRS safety-related sensor
SRSS safety-related sensor system
SCS safety-related control system
4 Applications for mobile robots
4.1 General
This example covers the integration and installation phase using fusion of three SRSs into an
SRSS in accordance with Clause 6 of IEC TS 62998-1:2019 to improve sensing zones and
safety-related zones in accordance with requirements for the intended use. The intended uses
are 2 different mobile robot types, in accordance with ISO 13482:2014, that operate
autonomously in a public area with limited access. The reader should be aware that the
following descriptions are not based on comprehensive analysis and are only examples for
mobile robotics.
NOTE ISO 13482:2014 covers mobile robots operating in an autonomous manner. For simplification, the term
"mobile robot" will be used from now on.
Two different mobile robots operate on a certain university campus with buildings to achieve:
transport of in-house mail items among office buildings of the university, and
cleaning of pavements of the university.
Figure 1 shows the typical outdoor pavement of a university campus. Person(s) being present
or approaching the safety related zone(s) of an SRSS should be detected and the safety-related
control system should initiate appropriate reaction of the mobile robot.

Figure 1 – Outdoor scene
4.2 SRSS on mail transport mobile robot
4.2.1 Intended use
The intended use should be determined (see 6.2.1 of IEC TS 62998-1:2019) by the integrator.
It is defined by the following selected example items:
1) The mobile robot is a Type 1.1 robot specified in ISO 13482:2014 with a weight of 30 kg
and size of length: 500mm × width: 500mm × height: 600mm.
2) The mobile robot automatically navigates the pavement connecting the university office
buildings. The path of the robot is predetermined according to the map created by SLAM
technology [1] and physical constraints. The map includes position information for objects
that are fixed along the pavement, such as guardrails, building walls, trees, etc. By referring
to the map, the robot determines its own restricted space (ISO 13482:2014, 3.18.2) while
moving.
3) The mobile robot moves during daytime on non-carriageways where:
a) light vehicles such as bicycles are not allowed to enter;
b) wheelchairs can enter;
c) pavements are smooth paved with slopes of up to 5 degrees in some areas, as shown
in Figure 1;
d) standing or walking people on the pavements are adults and/or children. Children under
and including 3 years are assumed to be controlled and children from 4 years up to
including 10 years are assumed to be accompanied by adults. An adult might not
accompany children over 10 years up to 14. For the purpose of this example, the speed
of a person towards the mobile robot is assumed to be between 0 mm/s and 800 mm/s
if the person enters into the safeguarded zone.
NOTE The speed in this example deviates from ISO 13855:2010 under the assumption of different human
behaviour in this application. For other applications, faster or slower speeds might be more appropriate. On
the campus, people are informed by organizational measures and warning signals that running is not
allowed in the areas where mobile robots are present. Other examples of properties are given in 4.2.4.
4) The mobile robot:
a) is intended to make a protective stop when a standing or walking person comes into the
protective stop zone (see Figure 2);
b) is intended to reduce the speed when a standing or walking person moves into the
safeguarded zone (see Figure 2);
c) is driven with a speed up to 700 mm/s reduced by the safety related speed control
function down to 300 mm/s;
d) can reduce speed within 0,5 s from 700 mm/s to 300 mm/s, and another 0,2 s to reduce
to zero speed;
e) is intended to be used in the daytime.
5) The outdoor environmental conditions during operation:
a) can be up to 10 mm/h precipitation;
b) can have light interference representing daytime.
___________
Numbers in square brackets refer to the Bibliography.

– 10 – IEC TR 62998-2:2020 © IEC 2020

The mobile robot has two distinctive zones, in accordance with ISO 13482:2014. The protective stop zone, where
the mobile robot performs a protective stop, and the safeguarded zone, where a safety-related speed control function
is performed when a safety-related object is detected. In accordance with IEC TS 62998-1:2019, the protective stop
zone and safeguarded zone would be safety-related zone(s).
Figure 2 – Mobile robot with 2 distinctive safety-related zones
4.2.2 SRSS performance class determination
In the chosen approach, using ISO 13482:2014 the required performance level of the safety
functions of a Type 1.1 mobile robot is PL b, in accordance with ISO 13849-1:2015. The safety
functions include the protective stop function, the safety-related speed control function, the
hazardous collision avoidance function, and the travel surface detection function in accordance
with ISO 13482:2014, which will be initiated by the SRSS.
The required performance class of the SRSS corresponding to PL b is the sensor performance
class B specified in IEC TS 62998-1:2019.
4.2.3 SRS limits of use and SRSS function
The SRSS consists of three SRSs defined by the manufacturer as follows (see Figure 3).
1. SRS1: a 2D LiDAR suitable to be used up to PL b, in accordance with ISO 13849-1:2015,
which allows the detection of persons and other safety-related objects and the measurement
of their positions and velocities with high accuracy. The systematic capabilities are
assessed in accordance with IEC TS 62998-1:2019. The sensing zone is up to a radius of
7 000 mm, and a viewing angle of 270°. The detection capability is given for safety-related
objects with the properties: minimum size 40 mm × 40mm; minimum object reflectivity 5 %;
maximum object speed 1 600 mm/s. The response time is 0,05 s. Use in indoor and outdoor
environmental conditions is possible within defined limits.
2. SRS2: a TOF camera suitable to be used up to PL b, in accordance with ISO 13849-1:2015,
which allows detecting parts of 3D volumes of persons, road surface, and other safety-
related objects using 3D imaging technology. The systematic capabilities are assessed in
accordance with IEC TS 62998-1:2019. SRS2 is capable of measuring the position and
velocity of objects within the 3D sensor coordinate system. The sensing zone is up to
4 000 mm and vertical and horizontal field of views angle of 60° and 70°, respectively. The
detection capability is given for safety-related objects with properties: minimum size
40 mm × 40 mm × 40 mm; minimum object reflectivity 5 %; maximum object speed
1 600 mm/s. The response time is 0,05 s. It is possible to distinguish a paved road surface
and other objects three-dimensionally. Use in indoor and outdoor environmental conditions
is possible within defined limits.
3. SRS3: the same specification as SRS1.

Figure 3 – Combination of three SRSs into an SRSS and SRSS functions
The target applications require four SRSS functions (see Figure 3):
• Safety-related function 1: to detect persons and hazardous objects in the protective stop
zone for initiating the protective stop function specified in ISO 13482:2014, 6.2.2.3.
• Safety-related function 2: to detect persons and hazardous objects and to provide their
positions and velocities as safety-related information for the safety-related speed control
function and/or the hazardous collision avoidance function specified in ISO 13482:2014,
6.4 and 6.5.2.1.
• Safety-related function 3: to detect the geometry of the travel surface of the robot as
specified in ISO 13482:2014, 6.5.3. When a travelable surface is observed in the
travelling direction of the robot, the robot can move forwards. If the robot moves
backwards, the road surface that it has already travelled is definitely present, so this
function is not required.
• Automation related function: to provide 3D point cloud with timestamp in the robot
coordinate system for SLAM.
4.2.4 Safety-related requirements
The SRSS safety-related requirements should be specified by the integrator (see 6.2.1 of
IEC TS 62998-1:2019) based on the intended use. For example, see the requirements defined
in Table 1.
– 12 – IEC TR 62998-2:2020 © IEC 2020
Table 1 – Safety-related requirements
Term Requirement Details
SRSS performance class B See 4.2.2
Intended to be integrated from SRS
of the same performance class B
Demand rate of SRSS safety 10/h
related function(s)
SRSS response time 0,1 s
SRSS detection capability e.g. Person related properties: See 4.2.5
Sizes representing a 4-year-old
person in an upright position.
Minimum reflection value 5 %
Speed 800 mm/s
e.g. Hazardous object properties:
Sizes representing wheelchair
Minimum reflection value 5 %
Speed 800mm/s
SRSS sensing zones e.g. Safety related zones See 4.2.6
2-dimensional; 360° with S = 656
mm and S = 1 255 mm;
3-dimensional; vertical and
horizontal field of view 60°; with S
= 656 mm and S = 1 255 mm;
4.2.5 Object classes and physical properties
The SRSS detection capability should be specified by the integrator in accordance with 6.2.3
of IEC TS 62998-1:2019. The following specific examples are considered.
Object classes to be analysed are:
1) objects used to perform the person detection function;
a) supervised children up to and including 3 years;
b) accompanied children between 4 years and including 10 years;
c) unaccompanied children between 11 years and including 13 years;
d) adult persons from 14 years.
2) objects used to perform the hazardous object function;
a) wheelchairs.
3) objects used to perform the automation related function
a) landmarks used for navigation.
Furthermore, only the properties of an accompanied standing or walking child will be analysed
for the safety-related function 1 and safety related function 2.
For safety related function 2, the limit that SRS2 detects is the forearm of a 4-year-old child.
The simplified shape is estimated as cylinder with a diameter of 40 mm or more and a length of
200 mm.
NOTE 1 The 5th percentile value of the hand width and the hand length of a Japanese 4-year-old child is 49 mm
and 107 mm respectively. There is no arm length data for the child [2].

For safety-related function 1, the lower limbs of a 4 year-old-child are used to identify the
minimum size. The simplified shape is estimated as cylinder with a diameter of 50 mm in
mounting height of SRS1 and SRS3.
NOTE 2 The 5th percentile value of circumference is estimated based on Data for Japanese Children measured for
calf and ankle [3].
For the safety-related function 3, performed by SRS2 of the SRSS, the travelling surface to be
detected is a continuous flat surface or smooth curved surface with a slope of 5° or less in front
of the robot.
NOTE 3 SRS1 may detect the road surface as a hazardous object at the entrance to the slope. Other measures
might be put in place to prevent a permanent stop of the mobile robot.
The minimum diffuse reflectivity used as representation for a person, a hazardous object, and
a travel surface is assumed to be 5 % or more at the wavelength used by each SRS.
NOTE 4 The 5 % minimum reflectivity value is taken for a safety function of PL b following the ALARP principle.
Many standard LiDAR sensors state 10 % as minimum reflectivity value in security and automation applications, or
6% minimum reflection value is required for person detection with sensors used on automated guided vehicles in
accordance with B56.5:2012. In general, additional validation in the application can be required for mobile robots
within information for use as a possibility to test appropriateness of used object properties or stated performance
(e.g. speed of objects or minimum reflection value). The minimum reflectivity value is discussed specifically taking
care of the situation that many people using sensors for person protection in machinery are focused on it. The reader
of this document is asked to consider that detection capability of SRS is often based on a combination of different
properties and not a single one taken for deterministic analysis. For example, a combination of low reflection value
with small object size and maximum assumed speed can be estimated as of very low probability. The practical use
and the combination of properties, under consideration of their probability distribution, is an increasing challenge in
applications of SRSs and SRSS.
The speed of persons moving during daytime towards the mobile robot is assumed to be
800 mm/s.
NOTE 5 Persons moving over the university are informed that mobile robots are in progress and that they are
required to stay at a distance from them.
For the automation-related function of the SRSS, all objects within the SRSS sensing zone
representing reliable, fixed landmarks on the mobile-robot travelling path will be identified within
a procedure during the starting of operation.
4.2.6 Sensing zones
The integrator should specify the SRSS sensing zones in accordance with 6.2.4 of
IEC TS 62998-1:2019.
The mounting position and the sensing zone of each SRS, and the improved safety-related
zones of the SRSS after fusion, are shown in Figure 4 and Figure 5.
SRS1 and SRS3 are mounted horizontally on the left front and the right rear of the robot,
respectively, at a height of 200 mm from the ground level. By mounting SRS1 and SRS3 to the
opposite corners of the robot, it is possible to observe the entire circumference of the robot
without blind spots.
SRS2 is mounted at the centre of the front of the robot at a height of 400 mm to measure in the
direction of robot’s movement. It enables detection of safety-related objects above the detection
plane of SRS1 and carries out the travel surface detection function.
The mounting positions of the SRS are calibrated with a dedicated calibration tool before use.

– 14 – IEC TR 62998-2:2020 © IEC 2020

Exemplary top view.
Figure 4 – Mounting positions and sensing zones of the SRS
and safety-related zones of SRSS

Exemplary side view not corresponding to top view.
Figure 5 – Mounting positions and sensing zones of the SRS
and safety-related zones of SRSS
The safety-related zones of the SRSS correspond to the protective stop zone and safeguarded
zone of the robot. They are defined by distances S and S respectively from the robot's outer
0 1
surface, as shown in Figure 4.

NOTE This is not in accordance with informative Annex C of ISO 13482:2014, which references the centre point of
the robot and not the outer surface. To prevent confusion for the typical, assumed reader of this document, the
calculations are based on concepts of ISO 13855:2010 as referenced in normative Subclause 5.10.8.3 of
ISO 13482:2014. Concepts of ISO 13855:2010 are adapted in accordance with the results of an assumed, exhaustive,
application specific risk assessment. Existing calculations in accordance with ISO 13855:2010 seem to be developed
often under consideration of "high" performance classes like PL d respective SIL 2 and parameters considered out
of context (e.g. speed without consideration of direction of movement, stopped hazardous movement when hazardous
point is reached or bending over of a human body during movement).
S is a minimum distance between the mobile robot and a safety-related object. It is assumed
to be calculated based on concepts of ISO 13855:2010 and application of the specific risk
assessment in accordance with ISO 12100 as follows:
S= K×+T C+M= V +V × T +T+ 300 mm+M (1)
( )
( )
0 r−stop obj SRSS r
Where V is a maximum speed of the robot when initiating a protective stop, V is the
r-stop obj
approaching speed of the object, T and T are the response times of the SRSS and the
SRSS r
robot respectively, and M is the measurement uncertainty determined in accordance with 4.2.8,
which can be half value of the coverage intervals around the measurement distance (for values
see Table 2 of this document).
The distance C is an additional distance in millimetres, based on intrusion towards the danger
zone prior to actuation of the protective equipment in accordance with concepts of
ISO 13855:2010. The value of C is the result of an analysis of potential hazards for the lower
limbs. For upper limbs, there is no significant hazard due to the characteristic of the mobile
robot.
NOTE 2 If it is significant, an additional stopping distance can be considered when S is calculated.
S specifies the safeguarded zone where the robot is moving with maximum speed V
1 r-reduce
when initiating the safety-related speed control function for speed reduction down to V .
r-stop
The formula for the calculation is as follows:
(2)
S V +V×(T+T)++CM
( )
1 r-reduce obj SRSS r
The safety related zones of the SRSS sensing zone are determined as follows:
S = (300 mm/s + 800 mm/s) × (0,1 s + 0,2 s) + 300 mm + 26 mm = 656 mm
S = (700 mm/s + 800 mm/s) × (0,1 s + 0,5 s) + 300 mm + 55 mm = 1 255 mm
The automation related zone of the SRSS is the union of the sensing zones of the SRS.
4.2.7 Dependability under environmental influences
The SRSS integrator should specify the limits of all relevant environmental influences (see 6.2.5
of IEC TS 62998-1:2019).
In the following, the integrator verified that no failure to danger occurs and normal operation is
achieved within the specified limits for the environmental influences of precipitation and direct
sunlight in 4.2.1.
NOTE Further information is given in Annex F of IEC TS 62998-1:2019 for environmental influences and the use of
environmental classes in accordance with IEC 60721 series.
=
– 16 – IEC TR 62998-2:2020 © IEC 2020
4.2.8 Safety-related information
The SRSS integrator should specify logic functions performed in a processing unit of the SRSS
and should specify the safety-related information provided by the SRSS (see 6.2.6 of
IEC TS 62998-1:2019). Examples of safety-related information are given in the following
paragraphs.
The SRSS provides safety-related information as output signals. The safety-related information
(see Figure 3) of the SRSS consists of:
decision information relating to safety-related function 1, binary;
decision information related to safety-related function 3, binary;
measurement information related to safety-related function 2, n-ary;
confidence information for all safety-related function, n-ary.
The automation-related information of the SRSS output functions consists of:
point cloud for SLAM, n-ary;
The confidence information provided within the information for use as stated by the
manufacturer is as follows:
For each SRS the stated performance class is B. The required one for the SRSS is also B.
−6
The stated coverage probability or decision probability is 1 − 10 . The required one is
determined in accordance with Formula (1) in IEC TS 62998-1:2019 as follows:
coverage probability or decision probability > 1 – (upper limit PFH corresponding to
−5
SRS/SRSS performance class B)/(the application-specific demand rate) = 1 – 10 /
−6
10 = 1 – 10 .
The manufacturers provide results of confidence information of each SRS depending on the
detection distance. The value of the coverage interval is determined statistically from the
uncertainty of the SRS.
In addition to the information for use provided by the manufacturer, the integrator is performing
their own measurements in accordance with Figure 6. The tests are carried out using a test
piece with about 5 % reflection value. The experimental results obtained by measuring the
uncertainty of SRS1 and 3 and SRS 2 result in a standard deviation of 76,29 mm (SRS1 and 3)
at 7 m distance and 48,24 mm (SRS2) at 4 m distance.
−6
Because the coverage interval corresponding to the coverage probability 1 – 10 is calculated
as 2 × 4,89σ, assuming that SRS1 and SRS2 use this LiDAR and TOF camera as sensor units
respectively, the coverage interval of SRS1 at a distance of 7 m is 2 × 4,89 × 76,29 = 746,10 mm
(±373,05 mm) and the coverage interval of SRS2 at distance 4 m is 2 × 4,89 × 48,24 =
471,75 mm (±235,88 mm). These values are below the ones provided by the SRS manufacturer
within the information for use. For calculations in 5.2.6, the integrators decide to use the ones
stated in Table 2.
Table 2 – Example of confidence information for SRS
Distance Coverage probability Coverage intervals Coverage intervals
of SRS1/3 of SRS2
[m]
[mm] [mm]
−6
1 m 51,67 62,89
1 − 10
−6
2 m 53,43 110,60
1 − 10
−6
3 m 57,37 232,46
1 − 10
−6
4 m 72,08 471,75
1 − 10
−6
5 m 77,06 -
1 − 10
−6
6 m 106,17 -
1 − 10
−6
7 m 746,10 -
1 − 10
NOTE For calculation of M in Formulas (1) and (2), the half value in accordance with Table 2 is used under the
assumption that a normal distribution can be claimed.

Figure 6 – Examples of measurement data for evaluation of coverage interval
4.2.9 Verification and validation
The SRSS integrator should verify and/or validate the SRSS in accordance with 6.2.3, 6.2.4
and 6.2.7 of IEC TS 62998-1:2019.
A normal operation laboratory test of the safety-related function 1 and 2 as example for
verification of an SRSS is given in the following.
Test setup for normal operation test is as follows:
SRS1, SRS2, and SRS3 are mounted at predefined positions of the robot with the brackets, as
defined by the manufacturer;
the safety-related zones described in 4.2.6 are determined as S = 656 mm and S = 1 255 mm;
0 1
as described in 4.2.5, a black cylinder with diameter 40 mm, height 200 mm and surface
reflectivity 5 % is chosen as the test piece representing safety-related object properties for
children.
– 18 – IEC TR 62998-2:2020 © IEC 2020
Figure 7 illustrates the example of the test setup. The linear slider is placed at a location that
intersects the protective stop zone and/or the safeguarded zone of the SRSS.

Exemplary top view
Figure 7 – Test setup
Test procedures are as follows:
1) Power on the SRSS.
2) Construct the map to register test equipment such as the linear slider.
3) Place the test piece on the linear slider.
4) Start to move the slider and let the test piece enter the safety-related zones at the maximum
relative speed.
5) Record the safety-related information of the SRSS and the motion of the linear slider with
timestamps.
6) Power off the SRSS.
7) Change the relative locations of the linear slider and repeat from at least the test piece
approaches from the front, left, right, rear of the robot covering all field of views of the
different SRS and relevant speeds of the test piece.
8) Analyse the recorded safety related information and the slider motion.
During further verification by the integrator, it was determined that the SRSS can be used within
the limits of use as defined by the manufacturer of each SRS.
4.2.10 Information for use of the SRSS
This subclause describes the documentation of the limits of use in accordance with 6.2.2 of
IEC/TS 62998-1:2019. Table 3 shows examples for the limit of use of an SRSS documented in
the information for use of the SRSS.

Table 3 – Information for use of the SRSS
Clause(s) of IEC Overview of information for Information for use of the SRSS
TS 62998-1:2019 use to be provided
The SRSS performance class is B in accordance with IEC TS
4.3 The supplier should state the
62998-1 to achieve the level of safety performance PL b in
SRS/SRSS performance class
accordance with ISO 13849-1:2015.
and the level of safety
performance (PL, SIL or SIL CL)
and the referenced standard.
Safety-related function 1: to detect persons and hazardous
5.2 The SRSS function should be
objects in the protective stop zone for initiating the protective
defined by the manufacturer in
stop function specified in ISO 13482:2014, 6.2.2.3.
accordance with general
description of Table 2 of IEC TS
Safety-related function 2: to detect persons and hazardous
62998-1:2019.
objects and to provide their positions as safety related
information for the safety-related speed control function
and/or the hazardous collision avoidance function specified
in ISO 13482:2014, 6.4 and 6.5.2.1.
Safety-related function 3: to detect the geometry of the travel
surface of the robot, which is specified in ISO 13482:2014,
6.5.3. When a travelable surface is observed in the travelling
direction of the robot, the robot can move forwards. If the
robot moves backwards, the road surface that has already
travelled is definitely present, so this function is not required.
Automation-related function: to provide a 3D point cloud
...