IEC TS 61496-4-3:2022
(Main)Safety of machinery - Electro-sensitive protective equipment - Part 4-3: Particular requirements for equipment using vision based protective devices (VBPD) - Additional requirements when using stereo vision techniques (VBPDST)
Safety of machinery - Electro-sensitive protective equipment - Part 4-3: Particular requirements for equipment using vision based protective devices (VBPD) - Additional requirements when using stereo vision techniques (VBPDST)
IEC TS 61496-4-3:2022 specifies requirements for the design, construction and testing of non-contact electro-sensitive protective equipment (ESPE) designed specifically to detect persons or parts of persons as part of a safety-related system, employing vision-based protective devices (VBPDs) using stereo vision techniques (VBPDST) for the sensing function. Special attention is directed to features which ensure that an appropriate safety-related performance is achieved. An ESPE can include optional safety-related functions, the requirements for which are given in Annex A of IEC 61496-1:2020 and this document. Where this document does not contain all necessary provisions, IEC TS 62998-1 applies. It is also possible, for those aspects not considered in this document, to use provisions from IEC TS 62998-1 additionally. This document does not specify the dimensions or configurations of the detection zone and its disposition in relation to hazardous parts for any particular application, nor what constitutes a hazardous state of any machine. It is restricted to the functioning of the ESPE and how it interfaces with the machine. The detection principle is based on the evaluation of images from different viewing points (stereoscopic view) for the determination of distance information. This distance information is used to determine the position of an object(s).
– This document is limited to vision based ESPEs with fixed distances (stereo base) and fixed directions of the optical axes using a fixed focal length.
– It is limited to vision based ESPEs that do not require human intervention for detection.
– It is limited to vision based ESPEs that detect objects entering into or being present in a detection zone(s).
– It is limited to VBPDSTs employing radiation at wavelengths within the range 400 nm to 1 500 nm.
– This document does not address those aspects required for complex classification or differentiation of the object detected.
– This document does not consider the aspects of a moving ESPE installation.
Additional requirements and tests can apply in the following cases:
– Use of multi-spectral (colour) techniques;
– Setups other than as shown in Figure 2 and Figure 3 (e.g. changing backgrounds, horizontal orientation of the optical axis with respect to the floor);
– Intended for outdoor applications.
This document is relevant for VBPDSTs having a stated detection capability up to 200 mm. This document can be relevant to applications other than those for the protection of persons or parts of persons like arm or fingers (in the range 14 mm to 200 mm), for example the protection of machinery or products from mechanical damage. In those applications, additional requirements can be necessary, for example when the materials that are to be recognized by the sensing function have different properties from those of persons. This document does not deal with EMC emission requirements.
IEC TS 61496-4-3:2022 cancels and replaces the first edition published in 2015-05. This edition constitutes a technical revision. This edition includes the following technical changes with respect to the previous edition:
a) Some requirement clauses and test procedures have been adapted or removed because they have been consolidated in IEC 61496-1:2020 (e.g. 5.4.6.2 Light sources or Clause A.9).
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IEC TS 61496-4-3 ®
Edition 2.0 2022-09
TECHNICAL
SPECIFICATION
colour
inside
Safety of machinery – Electro-sensitive protective equipment –
Part 4-3: Particular requirements for equipment using vision based protective
devices (VBPD) – Additional requirements when using stereo vision techniques
(VBPDST)
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form
or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from
either IEC or IEC's member National Committee in the country of the requester. If you have any questions about IEC
copyright or have an enquiry about obtaining additional rights to this publication, please contact the address below or
your local IEC member National Committee for further information.
IEC Secretariat Tel.: +41 22 919 02 11
3, rue de Varembé info@iec.ch
CH-1211 Geneva 20 www.iec.ch
Switzerland
About the IEC
The International Electrotechnical Commission (IEC) is the leading global organization that prepares and publishes
International Standards for all electrical, electronic and related technologies.
About IEC publications
The technical content of IEC publications is kept under constant review by the IEC. Please make sure that you have the
latest edition, a corrigendum or an amendment might have been published.
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and French, with equivalent terms in 19 additional languages.
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(IEV) online.
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IEC TS 61496-4-3 ®
Edition 1.0 2022-09
TECHNICAL
SPECIFICATION
colour
inside
Safety of machinery – Electro-sensitive protective equipment –
Part 4-3: Particular requirements for equipment using vision based protective
devices (VBPD) – Additional requirements when using stereo vision techniques
(VBPDST)
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 13.110; 29.260.99 ISBN 978-2-8322-5739-5
– 2 – IEC TS 61496-4-3:2022 © IEC 2022
CONTENTS
FOREWORD . 4
INTRODUCTION . 6
1 Scope . 7
2 Normative references . 8
3 Terms and definitions . 8
4 Functional, design and environmental requirements . 12
5 Testing . 21
6 Marking for identification and for safe use . 34
7 Accompanying documents . 34
Annex A (normative) Optional functions of the ESPE . 36
Annex B (normative) Catalogue of single faults affecting the electrical equipment of
the ESPE, to be applied as specified in 5.3 . 38
Annex AA (informative) The positioning of VBPDST employing a volume as a
detection zone in respect of parts of the human body . 39
Annex BB (informative) Relationship between position accuracy and tolerance zones
for VBPDST . 48
Annex CC (informative) Basic principles of physics for contrast of convex
homogeneous bodies . 54
Bibliography . 61
Figure 1 – Image planes in imaging device of a VBPDST . 9
Figure 2 – 3D view of a vision based protective device using stereo vision techniques
(VBPDST) . 12
Figure 3 – 2D view of a vision based protective device using stereo vision techniques
(VBPDST) . 13
Figure 4 – Examples for periodic surface structures on the background . 25
Figure 5 – Test setup for indirect light interference on the background. 30
Figure 6 – Test setup for VBPDST of identical design with PAPT . 31
Figure 7 – Test setup for direct light interference on the sensing device . 32
Figure AA.1 – Minimum distance S – Example 1 . 42
Figure AA.2 – Overall minimum distance S without tolerance zone – Example 1 . 42
o
Figure AA.3 – Overall minimum distance S including tolerance zone – Example 1 . 43
o
Figure AA.4 – Minimum distance S – Example 2 . 44
Figure AA.5 – Overall minimum distance S without tolerance zone – Example 2 . 45
o
Figure AA.6 – Overall minimum distance S including tolerance zone – Example 2 . 45
o
Figure AA.7 – Application example for body detection of a VBPDST employing a
volume as a detection zone . 47
Figure BB.1 – Relationship between test piece position and the probability of detection . 49
Figure BB.2 – Example for measurement of the probability of detection . 50
Figure BB.3 – Relationship between detection zone and tolerance zone . 52
Figure BB.4 – Overall minimum distance S including tolerance zone . 53
o
Figure CC.1 – Illumination model – Sphere illuminated by a point source . 55
Figure CC.2 – Illumination model – Sphere illuminated by a half-Ulbricht sphere . 55
Figure CC.3 – Brightness of a surface element of a sphere in spherical coordinates . 56
Figure CC.4 – Brightness distribution in an image of a sphere . 56
Figure CC.5 – Grey value profile over a sphere with low contrast for a typical imaging
contrast (Modulation Transfer Function) . 57
Figure CC.6 – Grey value profile over a sphere with the same colour as the
background . 57
Figure CC.7 – Grey value profile over a sphere in front of a background that is half as
bright . 58
Figure CC.8 – Grey value profile over a sphere in front of a background that is twice as
bright . 58
Figure CC.9 – Grey value profile over a sphere by low contrast . 59
Figure CC.10 – Grey value profile over the sphere from Figure CC.9 but with the
direction to the imaging device changed by 10° . 59
Figure CC.11 – Grey value profile over a small sphere that results in an image that is 5
pixels in diameter . 60
Table 431 – Verification of detection capability requirements (see also 4.2.12) . 23
Table 432 – Overview of light interference tests . 28
– 4 – IEC TS 61496-4-3:2022 © IEC 2022
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
SAFETY OF MACHINERY –
ELECTRO-SENSITIVE PROTECTIVE EQUIPMENT –
Part 4-3: Particular requirements for equipment using
vision based protective devices (VBPD) –
Additional requirements when using stereo
vision techniques (VBPDST)
FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote international
co-operation on all questions concerning standardization in the electrical and electronic fields. To this end and
in addition to other activities, IEC publishes International Standards, Technical Specifications, Technical Reports,
Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC Publication(s)”). Their
preparation is entrusted to technical committees; any IEC National Committee interested in the subject dealt with
may participate in this preparatory work. International, governmental and non-governmental organizations liaising
with the IEC also participate in this preparation. IEC collaborates closely with the International Organization for
Standardization (ISO) in accordance with conditions determined by agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence between
any IEC Publication and the corresponding national or regional publication shall be clearly indicated in the latter.
5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
services carried out by independent certification bodies.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
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.
IEC TS 61496-4-3 has been prepared by IEC technical committee TC 44: Safety of machinery
– Electrotechnical aspects. It is a Technical Specification.
This second edition cancels and replaces the first edition published in 2015-05. This edition
constitutes a technical revision.
This edition includes the following technical changes with respect to the previous edition:
a) Some requirement clauses and test procedures have been adapted or removed because
they have been consolidated in IEC 61496-1:2020 (e.g. 5.4.6.2 Light sources or
Clause A.9).
The text of this document is based on the following documents:
Draft Report on voting
44/934/DTS 44/957A/RVDTS
Full information on the voting for its approval can be found in the report on voting indicated in
the above table.
The language used for the development of this document is English.
This document was drafted in accordance with ISO/IEC Direc
...
IEC TS 61496-4-3 ®
Edition 2.0 2022-09
REDLINE VERSION
TECHNICAL
SPECIFICATION
colour
inside
Safety of machinery – Electro-sensitive protective equipment –
Part 4-3: Particular requirements for equipment using vision based protective
devices (VBPD) – Additional requirements when using stereo vision techniques
(VBPDST)
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form
or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from
either IEC or IEC's member National Committee in the country of the requester. If you have any questions about IEC
copyright or have an enquiry about obtaining additional rights to this publication, please contact the address below or
your local IEC member National Committee for further information.
IEC Secretariat Tel.: +41 22 919 02 11
3, rue de Varembé info@iec.ch
CH-1211 Geneva 20 www.iec.ch
Switzerland
About the IEC
The International Electrotechnical Commission (IEC) is the leading global organization that prepares and publishes
International Standards for all electrical, electronic and related technologies.
About IEC publications
The technical content of IEC publications is kept under constant review by the IEC. Please make sure that you have the
latest edition, a corrigendum or an amendment might have been published.
IEC publications search - webstore.iec.ch/advsearchform IEC Products & Services Portal - products.iec.ch
The advanced search enables to find IEC publications by a Discover our powerful search engine and read freely all the
variety of criteria (reference number, text, technical publications previews. With a subscription you will always
committee, …). It also gives information on projects, replaced have access to up to date content tailored to your needs.
and withdrawn publications.
Electropedia - www.electropedia.org
IEC Just Published - webstore.iec.ch/justpublished
The world's leading online dictionary on electrotechnology,
Stay up to date on all new IEC publications. Just Published
containing more than 22 300 terminological entries in English
details all new publications released. Available online and
and French, with equivalent terms in 19 additional languages.
once a month by email.
Also known as the International Electrotechnical Vocabulary
(IEV) online.
IEC Customer Service Centre - webstore.iec.ch/csc
If you wish to give us your feedback on this publication or
need further assistance, please contact the Customer Service
Centre: sales@iec.ch.
IEC TS 61496-4-3 ®
Edition 2.0 2022-09
REDLINE VERSION
TECHNICAL
SPECIFICATION
colour
inside
Safety of machinery – Electro-sensitive protective equipment –
Part 4-3: Particular requirements for equipment using vision based protective
devices (VBPD) – Additional requirements when using stereo vision techniques
(VBPDST)
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 13.110; 29.260.99 ISBN 978-2-8322-5815-6
– 2 – IEC TS 61496-4-3:2022 RLV © IEC 2022
CONTENTS
FOREWORD . 4
INTRODUCTION . 2
1 Scope . 8
2 Normative references . 9
3 Terms and definitions . 9
4 Functional, design and environmental requirements . 13
5 Testing . 23
6 Marking for identification and for safe use . 39
7 Accompanying documents . 39
Annex A (normative) Optional functions of the ESPE . 41
Annex B (normative) Catalogue of single faults affecting the electrical equipment of
the ESPE, to be applied as specified in 5.3 . 43
Annex AA (informative) The positioning of VBPDST employing a volume as a
detection zone in respect of parts of the human body . 44
Annex BB (informative) Relationship between position accuracy and tolerance zones
for VBPDST . 53
Annex CC (informative) Basic principles of physics for contrast of convex
homogeneous bodies . 59
Bibliography . 66
Figure 1 – Image planes in imaging device of a VBPDST . 10
Figure 2 – 3D view of a vision based protective device using stereo vision techniques
(VBPDST) . 13
Figure 3 – 2D view of a vision based protective device using stereo vision techniques
(VBPDST) . 14
Figure 4 – Examples for periodic surface structures on the background . 28
Figure 5 – Test setup for indirect light interference on the background. 35
Figure 6 – Test setup for VBPDST of identical design with PAPT . 36
Figure 7 – Test setup for direct light interference on the sensing device . 37
Figure AA.1 – Minimum distance S – Example 1 . 47
Figure AA.2 – Overall minimum distance S without tolerance zone – Example 1 . 47
o
Figure AA.3 – Overall minimum distance S including tolerance zone – Example 1 . 48
o
Figure AA.4 – Minimum distance S – Example 2 . 49
Figure AA.5 – Overall minimum distance S without tolerance zone – Example 2 . 50
o
Figure AA.6 – Overall minimum distance S including tolerance zone – Example 2 . 50
o
Figure AA.7 – Application example for body detection of a VBPDST employing a
volume as a detection zone . 52
Figure BB.1 – Relationship between test piece position and the probability of detection . 54
Figure BB.2 – Example for measurement of the probability of detection . 55
Figure BB.3 – Relationship between detection zone and tolerance zone . 57
Figure BB.4 – Overall minimum distance S including tolerance zone . 58
o
Figure CC.1 – Illumination model – Sphere illuminated by a point source . 60
Figure CC.2 – Illumination model – Sphere illuminated by a half-Ulbricht sphere . 60
Figure CC.3 – Brightness of a surface element of a sphere in spherical coordinates . 61
Figure CC.4 – Brightness distribution in an image of a sphere . 61
Figure CC.5 – Grey value profile over a sphere with low contrast for a typical imaging
contrast (Modulation Transfer Function) . 62
Figure CC.6 – Grey value profile over a sphere with the same colour as the
background . 62
Figure CC.7 – Grey value profile over a sphere in front of a background that is half as
bright . 63
Figure CC.8 – Grey value profile over a sphere in front of a background that is twice as
bright . 63
Figure CC.9 – Grey value profile over a sphere by low contrast . 64
Figure CC.10 – Grey value profile over the sphere from Figure CC.9 but with the
direction to the imaging device changed by 10° . 64
Figure CC.11 – Grey value profile over a small sphere that results in an image that is 5
pixels in diameter . 65
Table 1 431 – Verification of detection capability requirements (see also 4.2.12) . 26
Table 2 432 – Overview of light interference tests . 31
– 4 – IEC TS 61496-4-3:2022 RLV © IEC 2022
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
SAFETY OF MACHINERY –
ELECTRO-SENSITIVE PROTECTIVE EQUIPMENT –
Part 4-3: Particular requirements for equipment using
vision based protective devices (VBPD) –
Additional requirements when using stereo
vision techniques (VBPDST)
FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote international
co-operation on all questions concerning standardization in the electrical and electronic fields. To this end and
in addition to other activities, IEC publishes International Standards, Technical Specifications, Technical Reports,
Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC Publication(s)”). Their
preparation is entrusted to technical committees; any IEC National Committee interested in the subject dealt with
may participate in this preparatory work. International, governmental and non-governmental organizations liaising
with the IEC also participate in this preparation. IEC collaborates closely with the International Organization for
Standardization (ISO) in accordance with conditions determined by agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence between
any IEC Publication and the corresponding national or regional publication shall be clearly indicated in the latter.
5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
services carried out by independent certification bodies.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
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.
This redline version of the official IEC Standard allows the user to identify the changes made to
the previous edition IEC TS 61496-4-3:2015. A vertical bar appears in the margin wherever a
change has been made. Additions are in green text, deletions are in strikethrough red text.
IEC TS 61496-4-3 has been prepared by IEC technical committee TC 44: Safety of machinery
– Electrotechnical aspects. It is a Technical Specification.
This second edition cancels and replaces the first edition published in 2015-05. This edition
constitutes a technical revision.
This edition includes the following technical changes with respect to the previous edition:
a) Some requirement clauses and test procedures have been adapted or removed because
they have been consolidated in IEC 61496-1:2020 (e.g. 5.4.6.2 Light sources or
Clause A.9).
The text of this document is based on the following documents:
Draft Report on voting
44/934/DTS 44/957A/RVDTS
Full information on the voting for its approval c
...
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