IEC TS 61496-4-3:2015

IEC TS 61496-4-3 ®
Edition 1.0 2015-05
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)
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IEC TS 61496-4-3 ®
Edition 1.0 2015-05
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 978-2-8322-2611-7

– 2 – IEC TS 61496-4-3:2015 © IEC 2015
CONTENTS
FOREWORD . 5
INTRODUCTION . 7
1 Scope . 8
2 Normative references . 9
3 Terms and definitions . 9
Abbreviated terms . 12
4 Functional, design and environmental requirements . 12
4.1 Functional requirements . 12
4.1.2 Sensing function . 12
4.1.3 Types of ESPE . 15
4.1.6 Zone with limited detection capability . 15
4.2 Design requirements . 16
4.2.2 Fault detection requirements . 16
4.2.12 Integrity of the VBPDST detection capability . 17
4.2.13 Test pieces for type testing . 19
4.2.14 Wavelength . 21
4.2.15 Radiation intensity . 21
4.2.16 Mechanical construction . 21
4.3 Environmental requirements . 21
4.3.1 Ambient air temperature range and humidity . 21
4.3.5 Ambient light intensity. 21
4.3.6 Light interference . 21
4.3.7 Pollution interference . 22
4.3.8 Manual interference . 22
4.3.9 Optical occlusion (eclipsed by small object) . 23
4.3.10 Drift or ageing of components . 23
5 Testing . 23
5.1 General . 23
5.1.2 Test conditions . 23
5.1.4 Test conditions and test plan . 24
5.2 Functional tests . 24
5.2.1 Sensing function . 24
5.2.9 Verification of optical performance . 28
5.2.10 Wavelength . 28
5.2.11 Radiation intensity . 28
5.3 Performance testing under fault conditions . 28
5.3.2 Type 1 ESPE . 28
5.3.3 Type 2 ESPE . 28
5.3.4 Type 3 ESPE . 29
5.3.5 Type 4 ESPE . 29
5.4 Environmental tests . 29
5.4.2 Ambient temperature variation and humidity . 29
5.4.4 Mechanical influences . 29
5.4.6 Light interference . 30
5.4.7 Pollution interference . 36
5.4.8 Manual interference . 37

5.4.9 Optical occlusion . 37
6 Marking for identification and for safe use . 38
6.1 General . 38
7 Accompanying documents . 38
Annex A (normative) Optional functions of the ESPE . 40
A.9 Setting the detection zone and/or other safety-related parameters . 40
A.9.1 Functional requirements . 40
A.9.2 Verification . 40
A.10 Selection of multiple detection zones . 41
A.10.1 Functional requirements . 41
A.10.2 Verification . 41
Annex B (normative) Catalogue of single faults affecting the electrical equipment of
the ESPE, to be applied as specified in 5.3 . 42
B.7 Imaging sensor . 42
Annex AA (informative) The positioning of VBPDST employing a volume as a
detection zone in respect of parts of the human body . 43
AA.1 Calculation of distances for electro-sensitive protective equipment employing
vision based protective devices (VBPDST) . 43
AA.1.1 General . 43
AA.1.2 Calculation of the overall minimum distance S . 43
o
AA.1.3 Vision based protective devices with a detection capability > 40 mm and
≤ 55 mm . 44
AA.1.4 Vision based protective devices with a detection capability > 55 mm and
≤ 200 mm . 45
AA.1.5 Examples of detection zone and tolerance zone . 45
AA.2 Application examples for body detection of a VBPDST employing a volume
as a detection zone . 49
Annex BB (informative) Relationship between position accuracy and tolerance zones
for VBPDST . 51
BB.1 Probability of detection . 51
BB.2 Tolerance zone related to probability . 52
BB.3 Determination of tolerance zone for systems not providing object distance
information . 52
BB.4 Determination of tolerance zone for systems providing distance information . 53
BB.5 Tolerance zone related to systematic interferences . 54
BB.6 Adding the tolerance zone on the outer border of the detection zone . 54
Annex CC (informative) Basic principles of physics for contrast of convex
homogeneous bodies . 56
CC.1 Illumination on a surface element . 56
CC.2 Brightness of a surface element . 58
Bibliography . 63

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. 34

– 4 – IEC TS 61496-4
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