ISO 24647:2023

INTERNATIONAL ISO
STANDARD 24647
First edition
2023-02
Non-destructive testing — Robotic
ultrasonic test systems — General
requirements
Essais non destructifs — Systèmes robotisés de contrôle par ultrasons
— Exigences générales
Reference number
ISO 24647:2023(E)
© ISO 2023

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ISO 24647:2023(E)
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© ISO 2023
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Published in Switzerland
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ISO 24647:2023(E)
Contents Page
Foreword .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Requirements for test personnel .2
5 Test system .2
5.1 General . 2
5.2 Design principles . 3
5.3 Test equipment . 3
5.3.1 Instrument . 3
5.3.2 Probes . 3
5.3.3 Robots . 3
5.3.4 Couplant . 4
5.4 Typical test systems . . 4
5.4.1 Single-robot test system . 4
5.4.2 Twin-robot test system . 6
6 Characteristics and requirements for robotic ultrasonic test systems .9
6.1 General . 9
6.2 Test technique . 9
6.2.1 General . 9
6.2.2 Pulse-echo technique . 9
6.2.3 Trough-transmission technique . 9
6.3 Planning of scan pattern and programming of robot motion control . 9
6.3.1 General . 9
6.3.2 Path planning method . 9
6.3.3 Restrictions . 12
6.4 Synchronisation of the acquisition of ultrasonic and position data .12
6.4.1 Synchronisation of ultrasonic signal and robot position .12
6.4.2 Synchronisation — Minimum requirements .12
6.4.3 Synchronisation — Optional requirements .13
6.5 Conditions for the application . 13
7 Verification of the test system .13
7.1 General .13
7.2 Ultrasonic instrument and probes . . 14
7.2.1 General . 14
7.2.2 Single-probe systems . 14
7.2.3 Multi-probe systems . 14
7.2.4 Normalization of pulse-echo systems . 14
7.2.5 Normalization of through-transmission systems . 14
7.3 Robots . 14
7.4 Synchronization . 15
7.5 Complete system — Robots, instrument and probes combined . 15
7.5.1 General .15
7.5.2 Signal-to-noise ratio . 15
7.5.3 Image distortion coefficient . 16
7.5.4 Detection sensitivity . 16
8 Typical process of an automated test for a robotic ultrasonic test system .17
8.1 Preparation . 17
8.2 Probes . 17
8.3 Trajectory planning . 17
8.4 Setup of the scanning reference coordinate system . 17
8.5 Test procedure . 17
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ISO 24647:2023(E)
9 Documentation of the verification results .18
Annex A (informative) Trajectory planning .19
Annex B (informative) Example of a verification report .30
Bibliography .34
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ISO 24647:2023(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
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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).
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www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 135, Non-destructive testing,
Subcommittee SC 3, Ultrasonic testing.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.
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INTERNATIONAL STANDARD ISO 24647:2023(E)
Non-destructive testing — Robotic ultrasonic test systems
— General requirements
1 Scope
This document specifies the necessary system hardware components, the characteristics, the
component requirements and conditions for the application of robotic ultrasonic test systems.
This document specifies the general requirements and acceptance criteria for robotic ultrasonic test
systems.
This document is applicable to robotic ultrasonic test systems composed of one or more robot(s). Some
of the characteristics of a robot ultrasonic testing system can be application-specific.
This document is applicable to conventional straight-beam probes and immersion technique.
This document is also applicable for phased array equipment, but additional tests can be necessary.
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 230-1, Test code for machine tools — Part 1: Geometric accuracy of machines operating under no-load
or quasi-static conditions
ISO 230-2, Test code for machine tools — Part 2: Determination of accuracy and repeatability of positioning
of numerically controlled axes
ISO 5577, Non-destructive testing — Ultrasonic testing — Vocabulary
ISO 8373, Robotics — Vocabulary
ISO 9283, Manipulating industrial robots — Performance criteria and related test methods
ISO 9712, Non-destructive testing — Qualification and certification of NDT personnel
ISO 22232 (all parts), Non-destructive testing — Characterization and verification of ultrasonic test
equipment
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 5577, ISO 8373, ISO 9283,
ISO 22232 (all parts) and the following apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1
robotic ultrasonic test system
automatic scanning ultrasonic test system, controlled by computer program, with the scanning motion
implemented by one or multiple robots
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ISO 24647:2023(E)
3.2
joint robot
robot fitted with rotary joints
Note 1 to entry: Rotary joints allow a full range of motion, as they rotate through multiple planes, and they
increase the manipulating capabilities of the robot considerably. An articulated robot can have one or more
rotary joints, and other types of joints may be used as well, depending on the design of the robot and its intended
function.
3.3
scan path
motion trajectory of the probe relative to the test object when the robot is executing the ultrasonic
scanning with the probe or the test object held by the end effector (3.5) of the robot
3.4
Cartesian robot
robot whose arm has three prismatic joints, whose axes are coincident with a Cartesian coordinate
system
3.5
end effector
device specifically designed for attachment to the robot’s mechanical interface to enable the robot to
perform its task
3.6
tool coordinate system
coordinate system referenced to the tool (probe or test piece) or to the end effector (3.5) attached to the
mechanical interface
4 Requirements for test personnel
a) Personnel to perform verification tests using this document shall be qualified in accordance with
ISO 9712 or equivalent.
b) The personnel shall be familiar with the robotic ultrasonic scanning equipment and robot motion
control technique.
c) The personnel shall be authorized by the employer or his/her agent.
5 Test system
5.1 General
Robotic ultrasonic test systems are automated high-performance ultrasonic test systems.
They are equipped with robotic manipulating technology and ultrasonic testing technology.
A robotic ultrasonic test system is mainly composed of one or more robot(s), with one or more ultrasonic
probe(s), an ultrasonic instrument and a fluid, gas or contact coupling system.
Single-pulse excitation or tone burst excitation is used.
Ultrasonic reflection or through-transmission technique may be implemented.
Two-dimensional or three-dimensional images may be used to display the test results to show the
shape and the position of the detected imperfections.
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ISO 24647:2023(E)
5.2 Design principles
a) The design of the test system shall meet the requirements of the application for the objects to be
tested.
b) The ambient conditions and the requirements of the test method shall be taken into account.
c) The distance between the surface of the test objects and the probes shall be kept constant during
ultrasonic scanning.
d) Electrical or mechanical interferences shall be reduced to a minimum by design.
5.3 Test equipment
5.3.1 Instrument
a) The ultrasonic instrument shall meet the requirements of ISO 22232-1 where applicable.
b) The ultrasonic instrument shall be selected according to the application.
c) The ultrasonic instrument shall support ultrasonic pulse-echo and/or ultrasonic through-
transmission mode.
d) The ultrasonic instrument shall have signal conditioning circuits for the excitation and the
reception of ultrasonic pulses.
e) The technical properties such as transmitter pulse voltage, transmitter pulse width, repetition
frequency, gain range, filtering bandwidth, digitizing frequency, digitizing dynamic range (A/D
converter bits) and crosstalk shall be specified in accordance with ISO 22232-1 and shall satisfy the
requirements of the application.
f) The technical properties of the ultrasonic instrument shall be determined according to the
application (e.g. material characteristics and the sensitivity requirements).
5.3.2 Probes
a) The ultrasonic probes shall be selected according to the test procedure.
b) The ultrasonic probes shall meet the requirements of ISO 22232-2.
c) The technical parameters of the ultrasonic probes, such as frequency, beam diameter, focal distance
and relative bandwidth, shall be specified in accordance with ISO 22232-2 and shall satisfy the
requirements of the application.
d) The cable length between the probes and the instrument shall be reduced to a minimum to reduce
cable attenuation and electrical noise. The housing shall be electrically grounded.
5.3.3 Robots
a) The robots shall be selected according to the requirements of the test procedure.
b) The robots shall conform to the requirements for the scan pattern and the scan speed.
c) The robots may be joint robots or Cartesian robots.
d) The technical properties such as freedom of mechanical movement, range for manipulation,
maximum moving speed, motion accuracy and positioning repetition accuracy shall be specified
and shall satisfy the requirements of the application.
e) The end effector of the robots shall provide a flange for the attachment of an ultrasonic probe and/
or the test object as well as a coupling supply squirter if necessary.
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ISO 24647:2023(E)
f) The position and orientation of the probe’s coordinate system or the coordinate system of the
test object relative to the coordinate system of the robots end effector flange or the coordinate
system of the robot base shall be provided to express tested point position in different geometrical
coordinate systems.
5.3.4 Couplant
a) Dependent on the application, gas or liquid may be used as couplant with a robotic ultrasonic test
system.
b) For liquid coupling, a squirter or immersion device and a circulation system for the couplant shall
be provided.
5.4 Typical test systems
5.4.1 Single-robot test system
5.4.1.1 System components
Figure 1 shows the composition of a robotic ultrasonic test system based on one robot. The system
setup is mainly composed of an ultrasonic instrument, an ultrasonic probe, a robot and its control
system including software and a couplant circulation system. The system shall be arranged in a way
that either the probe or the test object is moved by the robot.
a) Computer and robot controller shall be connected for control command and trajectory data
transfer.
b) Computer and ultrasonic instrument shall be connected for control command and ultrasonic data
transfer.
Key
1 test object
2 probe
3 robot
4 ultrasonic instrument
5 robot controller
6 computer and software
sound path
electrical connection
mechanical connection
Figure 1 — Single-robot ultrasonic test system
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ISO 24647:2023(E)
5.4.1.2 Scan modes
5.4.1.2.1 Scan mode with movement of the probe
The robot moves the probe while the test object is fixed, as shown in Figure 2.
This mode shall be used when the test object is too large or too heavy to be held by a robot.
It is suitable when the size of the test object is large and/or the acoustic attenuation is low so that the
back-wall echo can be evaluated.
Usually, the ultrasonic probe is of little weight so that the robot can hold it without overload.
Key
1 robot controller
2 robot
3 circulatory system for couplant
4 couplant supply
5 test object
6 probe
7 ultrasonic instrument
8 couplant (e.g. water)
Figure 2 — Scan mode with movement of the probe (example for squirter technique)
5.4.1.2.2 Scan mode with movement of the test object
The robot moves the test object while the probe is fixed, as shown in Figure 3.
This scan mode shall be used when the test object has a small size and complex profile.
It is suitable for the case when the size of the test object is small and the acoustic attenuation is low so
that the back-wall echo can be received.
The weight of the test object is limited by the robot’s load ability.
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ISO 24647:2023(E)
Key
1 robot controller
2 robot
3 ultrasonic instrument
4 probe
5 test object
6 couplant (e.g. water)
Figure 3 — Scan mode with movement of the test object (example for immersion technique)
5.4.2 Twin-robot test system
5.4.2.1 System components
Figure 4 shows twin-robots ultrasonic test systems.
The system setup is mainly composed of one or two ultrasonic probes, one ultrasonic instrument, two
robots and their control systems, including software and a couplant circulation system.
The software shall be able to send robot control commands, to transfer scan pattern data, to send
commands to the ultrasonic instrument and to transfer ultrasonic signal data.
a) Setup with two robots and two probes
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ISO 24647:2023(E)
b) Setup with two robots and one single probe
Key
1 robot 1 7 ultrasonic instrument
2 probe 1 8 robot controller 2
3 test object 9 computer and software
4 probe 2 sound path
5 robot 2 electrical connection
6 robot controller 1 mechanical connections
Figure 4 — Twin-robots ultrasonic test systems
5.4.2.2 Scan modes
5.4.2.2.1 Each robot moves a probe
Each robot moves a probe simultaneously while the test object is fixed, as shown in Figure 5.
This scan mode is suitable for the case when the size of the test object is large and/or the acoustic
attenuation is high so that the back-wall echo cannot be received and evaluated by reflection method.
Usually, the ultrasonic probes are of little weight so that the robot can hold them without overload.
The ultrasonic transmission technique requires that both beam axes be aligned to each other and be
consistent with the normal vector to the surface of the test object at the test point.
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ISO 24647:2023(E)
Key
1 robot 1
2 probe 1
3 probe 2
4 test object
5 robot 2
Figure 5 — Each robot moves a probe (example gas couplant)
5.4.2.2.2 One robot moves the probe and another robot moves the test object
One robot moves the probe and another robot moves the test object, as shown in Figure 6.
This scan mode shall be used when the size of the test object is small and/or the acoustic attenuation is
low so that the back-wall echo can be evaluated. In this case, the weight of the test object is limited by
the robot’s load ability.
Key
1 robot 1
2 test object
3 couplant (e.g. water)
4 probe
5 robot 2
Figure 6 — One robot moves the probe and another robot moves the test object
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ISO 24647:2023(E)
6 Characteristics and requirements for robotic ultrasonic test systems
6.1 General
Robotic ultrasonic test systems are mainly used for automated scanning of test objects with complex
geometries.
In order to obtain reliable test results, proper planning of the scan pattern and synchronized acquisition
of ultrasonic and position data are important.
6.2 Test technique
6.2.1 General
A robotic ultrasonic test system shall be able to carry out the pulse-echo technique or the through-
transmission technique.
6.2.2 Pulse-echo technique
The pulse-echo technique is an ultrasonic reflection technique with the probe or the test object being
attached to the robot as shown in Figure 2, Figure 3 and Figure 6, where the single probe transmits and
receives ultrasonic pulses.
The test results may be presented as A-scan images, B-scan images or C-scan images.
Information on amplitude, time of flight and position is available for evaluation.
6.2.3 Trough-transmission technique
The through-transmission technique uses two probes, one for transmitting ultrasonic waves, the other
for receiving, as shown in Figure 5.
The test result may be presented as A-scan images, B-scan images or C-scan images.
Information on amplitude and position is available for evaluation.
6.3 Planning of scan pattern and programming of robot motion control
6.3.1 General
A suited scan path planning method and/or software tool shall be provided to create the robot motion
control program for a robotic ultrasonic test system.
6.3.2 Path planning method
6.3.2.1 General
This subclause describes the scan path calculation and the post-processing.
The result of the scan path calculation gives the position and the orientation normal to the surface
for each discrete test point on the scanning trajectory expressed in the coordinate system of the test
object.
The post-processing converts the position and the orientation normal to the surface of scan points
expressed in the coordinate system of the test object into the position and orientation of the robot end
effector expressed in the robot base coordinate system.
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ISO 24647:2023(E)
Another task of the post-processing is to form the motion control program (with the converted scan
point data) that the particular robot controller accepts.
The discrete scan path point is usually described by the position and the orientation normal to the
surface relative to the coordinate system of the test object. It is often mathematically expressed as a
vector P (p , p , p , I, J, K) in test object coordinate system. Where (p , p , p ) gives the position of the
x y z x y z
scan point and (I, J, K) gives the cosine of the orientation normal to the surface relative to the X, Y, Z axes
of the coordinate system of test object.
Normally, the movement of the robot end effector is described for robot controller by the position
and orientation of a coordinate system fixed on the end effector [often called tool centre point (TCP)]
relative to the base coordinate system of the robot.
The position and orientation of the tool coordinate system is often mathematically exp
...