ISO/TS 15066:2016
(Main)Robots and robotic devices — Collaborative robots
Robots and robotic devices — Collaborative robots
ISO/TS 15066:2016 specifies safety requirements for collaborative industrial robot systems and the work environment, and supplements the requirements and guidance on collaborative industrial robot operation given in ISO 10218‑1 and ISO 10218‑2. ISO/TS 15066:2016 applies to industrial robot systems as described in ISO 10218‑1 and ISO 10218‑2. It does not apply to non-industrial robots, although the safety principles presented can be useful to other areas of robotics. NOTE This Technical Specification does not apply to collaborative applications designed prior to its publication.
Robots et dispositifs robotiques — Robots coopératifs
General Information
Standards Content (Sample)
TECHNICAL ISO/TS
SPECIFICATION 15066
First edition
2016-02-15
Robots and robotic devices —
Collaborative robots
Robots et dispositifs robotiques — Robots coopératifs
Reference number
©
ISO 2016
© ISO 2016, Published in Switzerland
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form
or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior
written permission. Permission can be requested from either ISO at the address below or ISO’s member body in the country of
the requester.
ISO copyright office
Ch. de Blandonnet 8 • CP 401
CH-1214 Vernier, Geneva, Switzerland
Tel. +41 22 749 01 11
Fax +41 22 749 09 47
copyright@iso.org
www.iso.org
ii © ISO 2016 – All rights reserved
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Collaborative industrial robot system design . 2
4.1 General . 2
4.2 Collaborative application design . 3
4.3 Hazard identification and risk assessment . 4
4.3.1 General. 4
4.3.2 Hazard identification. 4
4.3.3 Task identification . 5
4.3.4 Hazard elimination and risk reduction . 5
5 Requirements for collaborative robot system applications . 6
5.1 General . 6
5.2 Safety-related control system performance . 6
5.3 Design of the collaborative workspace . 6
5.4 Design of the collaborative robot operation . 6
5.4.1 General. 6
5.4.2 Protective measures . . 6
5.4.3 Stopping functions . 6
5.4.4 Transitions between non-collaborative operation and collaborative operation . 7
5.4.5 Enabling device requirements . 7
5.5 Collaborative operations . 7
5.5.1 General. 7
5.5.2 Safety-rated monitored stop . 8
5.5.3 Hand guiding . 9
5.5.4 Speed and separation monitoring .10
5.5.5 Power and force limiting .15
6 Verification and validation .19
7 Information for use .19
7.1 General .19
7.2 Information specific to collaborative robot operations .19
7.3 Description of the collaborative robot system.19
7.4 Description of the workplace application.19
7.5 Description of the work task .20
7.6 Information specific to power and force limiting applications .20
Annex A (informative) Limits for quasi-static and transient contact .21
Bibliography .33
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 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.
The committee responsible for this document is Technical Committee ISO/TC 299, Robots and
robotic devices.
This Technical Specification is relevant only in conjunction with the safety requirements for
collaborative industrial robot operation described in ISO 10218-1 and ISO 10218-2.
iv © ISO 2016 – All rights reserved
Introduction
The objective of collaborative robots is to combine the repetitive performance of robots with the
individual skills and ability of people. People have an excellent capability for solving imprecise exercises;
robots exhibit precision, power and endurance.
To achieve safety, robotic applications traditionally exclude operator access to the operations area
while the robot is active. Therefore, a variety of operations requiring human intervention often cannot
be automated using robot systems.
This Technical Specification provides guidance for collaborative robot operation where a robot system and
people share the same workspace. In such operations, the integrity of the safety-related control system is
of major importance, particularly when process parameters such as speed and force are being controlled.
A comprehensive risk assessment is required to assess not only the robot system itself, but also the
environment in which it is placed, i.e. the workplace. When implementing applications in which people and
robot systems collaborate, ergonomic advantages can also result, e.g. improvements of worker posture.
This Technical Specification supplements and supports the industrial robot safety standards
ISO 10218-1 and ISO 10218-2, and provides additional guidance on the identified operational functions
for collaborative robots.
The collaborative operations described in this Technical Specification are dependent upon the use
of robots meeting the requirements of ISO 10218-1 and their integration meeting the requirements
of ISO 10218-2.
NOTE Collaborative operation is a developing field. The values for power and force limiting stated in this
Technical Specification are expected to evolve in future editions.
TECHNICAL SPECIFICATION ISO/TS 15066:2016(E)
Robots and robotic devices — Collaborative robots
1 Scope
This Technical Specification specifies safety requirements for collaborative industrial robot systems
and the work environment, and supplements the requirements and guidance on collaborative industrial
robot operation given in ISO 10218-1 and ISO 10218-2.
This Technical Specification applies to industrial robot systems as described in ISO 10218-1 and
ISO 10218-2. It does not apply to non-industrial robots, although the safety principles presented can be
useful to other areas of robotics.
NOTE This Technical Specification does not apply to collaborative applications designed prior to its publication.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.
ISO 10218-1:2011, Robots and robotic devices — Safety requirements for industrial robots — Part 1: Robots
ISO 10218-2:2011, Robots and robotic devices — Safety requirements for industrial robots — Part 2: Robot
systems and integration
ISO 12100, Safety of machinery — General principles for design — Risk assessment and risk reduction
ISO 13850, Safety of machinery — Emergency stop function — Principles for design
ISO 13855, Safety of machinery — Positioning of safeguards with respect to the approach speeds of parts
of the human body
IEC 60204-1, Safety of machinery — Electrical equipment of machines — Part 1: General requirements
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 10218-1, ISO 10218-2 and
ISO 12100 and the following apply.
3.1
collaborative operation
state in which a purposely designed robot system and an operator work within a collaborative workspace
[SOURCE: ISO 10218-1:2011, 3.4, modified]
3.2
power
mechanical power
mechanical rate of doing work, or the amount of energy consumed per unit time
Note 1 to entry: Power does not pertain to the electrical power rating on an electronic device, such as a motor.
3.3
collaborative workspace
space within the operating space where the robot system (including the workpiece) and a human can
perform tasks concurrently during production operation
Note 1 to entry: See Figure 1.
[SOURCE: ISO 10218-1:2011, 3.5, modified]
3.4
quasi-static contact
contact between an operator and part of a robot system, where the operator body part can be clamped
between a moving part of a robot system and another fixed or moving part of the robot cell
3.5
transient contact
contact between an operator and part of a robot system, where the operator body part is not clamped
and can recoil or retract from the moving part of the robot system
3.6
protective separation distance
shortest permissible distance between any moving hazardous part of the robot system and any human
in the collaborative workspace
Note 1 to entry: This value can be fixed or variable.
3.7
body model
representation of the human body consisting of individual body segments characterized by
biomechanical properties
4 Collaborative industrial robot system design
4.1 General
ISO 10218-2:2011 describes safety requirements for the integration of industrial robots and robot
systems, including collaborative robot systems. The operational characteristics of collaborative robot
systems are significantly different from those of traditional robot system installations and other
machines and equipment. In collaborative robot operations, operators can work in close proximity to
the robot system while power to the robot’s actuators is available, and physical contact between an
operator and the robot system can occur within a collaborative workspace. See Figure 1.
2 © ISO 2016 – All rights reserved
Key
1 operating space
2 collaborative workspace
Figure 1 — Example of a collaborative workspace
Any collaborative robot system design requires protective measures to ensure the operator’s safety at
all times during collaborative robot operation. A risk assessment is necessary to identify the hazards
and estimate the risks associated with a collaborative robot system application so that proper risk
reduction measures can be selected.
4.2 Collaborative application design
A key process in the design of the collaborative robot system and the associated cell layout is the
elimination of hazards and reduction of risks, and can include or influence the design of the working
environment. The following factors shall be taken into consideration:
a) the established limits (three dimensional) of the collaborative workspace;
b) collaborative workspace, access and clearance:
1) delineation of the restricted space and collaborative workspaces;
2) influences on the collaborative workspace (e.g. material storage, work flow requirements,
obstacles);
3) the need for clearances around obstacles such as fixtures, equipment and building supports;
4) accessibility for operators;
5) the intended and reasonably foreseeable contact(s) between portions of the robot system
and an operator;
6) access routes (e.g. paths taken by operators, material movement to the collaborative workspace);
7) hazards associated with slips, trips and falls (e.g. cable trays, cables, uneven surfaces, carts);
c) ergonomics and human interface with equipment:
1) clarity of controls;
2) possible stress, fatigue, or lack of concentration arising from the collaborative operation;
3) error or misuse (intentional or unintentional) by operator;
4) possible reflex behaviour of operator to operation of the robot system and related equipment;
5) required training level and skills of the operator;
6) acceptable biomechanical limits under intended operation and reasonably foreseeable misuse;
7) potential consequences of single or repetitive contacts;
d) use limits:
1) description of the tasks including the required training and skills of an operator;
2) identification of persons (groups) with access to the collaborative robot system;
3) potential intended and unintended contact situations;
4) restriction of access to authorized operators only;
e) transitions (time limits):
1) starting and ending of collaborative operation;
2) transitions from collaborative operations to other types of operation.
4.3 Hazard identification and risk assessment
4.3.1 General
The integrator shall conduct a risk assessment for the collaborative operation as described in
ISO 10218-2:2011, 4.3. Special consideration concerning potential intended or reasonably foreseeable
unintended contact situations between an operator and the robot system, as well as the expected
accessibility of an operator to interact in the collaborative workspace, shall be taken into account.
The user should participate in the risk assessment and design of the workspace. The integrator
is responsible for coordinating this participation and for selecting the appropriate robot system
components based on the requirements of the application.
4.3.2 Hazard identification
The list of significant hazards for robot and robot systems contained in ISO 10218-2:2011, Annex A,
is the result of hazard identification carried out as described in ISO 12100. Additional hazards (e.g.
fumes, gases, chemicals and hot materials) can be created by the specific collaborative applications
(e.g. welding, assembly, grinding, or milling). These hazards shall be addressed on an individual basis
through a risk assessment for the specific collaborative application.
The hazard identification process shall consider the following as a minimum:
a) robot related hazards, including:
1) robot characteristics (e.g. load, speed, force, momentum, torque, power, geometry, surface
shape and material);
2) quasi-static contact conditions in the robot;
3) operator location with respect to proximity of the robot (e.g. working under the robot) ;
b) hazards related to the robot system, including:
1) end-effector and workpiece hazards, including lack of ergonomic design, sharp edges, loss of
workpiece, protrusions, working with tool changer;
2) operator motion and location with respect to positioning of parts, orientation of structures
(e.g. fixtures, building supports, walls) and location of hazards on fixtures;
3) fixture design, clamp placement and operation, other related hazards;
4 © ISO 2016 – All rights reserved
4) a determination as to whether contact would be transient or quasi-static, and the parts of the
operator’s body that could be affected;
5) the design and location of any manually controlled robot guiding device (e.g. accessibility,
ergonomic, potential misuse, possible confusion from control and status indicators, etc.);
6) the influence and effects of the surroundings (e.g. where a protective cover has been removed
from an adjacent machine, proximity of a laser cutter);
c) application related hazards, including:
1) process-specific hazards (e.g. temperature, ejected parts, welding splatters);
2) limitations caused by the required use of personal protective equipment;
3) deficiency in ergonomic design (e.g. resulting in loss of attention, improper operation).
4.3.3 Task identification
In consultation with the user, the integrator shall identify and document the tasks associated with the
robot cell. All reasonably foreseeable task and hazard combinations shall be identified. The collaborative
tasks can be characterized by:
a) the frequency and duration of operator presence in the collaborative workspace with a moving
robot system (e.g. collaborative assembly with external fixtures);
b) the frequency and duration of contact between an operator and robot system with the drive
power or application-related sources of energy active (e.g. hand guiding, physical interaction with
tool or workpiece);
c) transitioning between non-collaborative operation and collaborative operation;
d) automatic or manual restart of robot system motion after the collaborative operation has been
completed;
e) tasks involving more than one operator;
f) any additional tasks within the collaborative workspace.
4.3.4 Hazard elimination and risk reduction
After hazards are identified, the risks associated with the collaborative robot system shall be assessed
before applying risk reduction measures. These measures are based upon these fundamental principles
listed in their order of priority (see ISO 10218-2:2011, 4.1.2):
a) the elimination of hazards by inherently safe design or their reduction by substitution;
b) protective measures that prevent personnel from accessing a hazard or control the hazards by
bringing them to a safe state (e.g. stopping, limiting forces, limiting speed) before an operator can
access or be exposed to the hazards;
c) the provision of supplementary protective measures such as information for use, training, signs,
personal protective equipment, etc.
For traditional robot systems, risk reduction is typically achieved through safeguards that separate the
operator from the robot system. For collaborative operation, the risk reduction is primarily addressed
by the design and application of the robot system and of the collaborative workspace. Specific measures
for risk reduction for collaborative operation are identified in Clause 5.
5 Requirements for collaborative robot system applications
5.1 General
Robot systems with collaborative applications shall meet the requirements of ISO 10218-1:2011 and
ISO 10218-2:2011. The information contained in this clause supplements that given in ISO 10218-1:2011,
5.10 and ISO 10218-2:2011, 5.11.
5.2 Safety-related control system performance
The safety-related control system functions shall comply with ISO 10218-1:2011, 5.4, or
ISO 10218-2:2011, 5.2.
5.3 Design of the collaborative workspace
The design of the collaborative workspace shall be such that the operator can perform all intended
tasks. Any risks introduced by machinery or equipment shall be sufficiently mitigated by the measures
identified in the risk assessment. The location of equipment and machinery should not introduce
additional hazards. Safety-rated soft axis and space limiting, as described in ISO 10218-1:2011, 5.12.3,
should be used whenever practicable, to reduce the size of the restricted space.
Risks associated with whole body trapping or crushing between the robot system and, for example,
parts of buildings, structures, utilities, other machines, and equipment, shall be eliminated or safely
controlled. Clearance in accordance with ISO 10218-2:2011, 5.11.3 should be provided.
NOTE The clearance can be different for systems designed to comply with 5.5.4 and 5.5.5.
If other machines in the collaborative workspace present a hazard, then protective measures shall be
applied in accordance with ISO 10218-2:2011, 5.11.2. Any relevant safety-related functions shall comply
with the requirements of 5.2.
5.4 Design of the collaborative robot operation
5.4.1 General
The requirements for the design of the collaborative robot operation are provided in ISO 10218-2:2011,
5.11. The operating methods in 5.5 may be used singularly or in combination when designing a
collaborative application.
Any detected failure in the safety-related parts of the control system shall result in a protective stop
(ISO 10218-2:2011, 5.3.8.3). Operation shall not resume until reset by a deliberate restart action with
the operator outside of the collaborative workspace.
5.4.2 Protective measures
All persons within the collaborative workspace shall be protected by protective measures. Safeguards
used in a collaborative workspace shall meet the requirements of ISO 10218-2:2011, 5.10.
Information on active settings and configuration of collaborative safety parameters shall be capable
of being viewed and documented with a unique identifier (e.g. checksum) so that changes to the
configuration can be easily identified (see ISO 10218-1:2011, 5.12.3). Setting and adjusting collaborative
safety parameters shall be protected against unauthorized and unintentional changes by password
protection or similar security measures.
5.4.3 Stopping functions
During collaborative operation, the operator shall have the means to either stop robot motion at any
time by a single action or have an unobstructed means of exiting the collaborative workspace.
6 © ISO 2016 – All rights reserved
Examples of means to stop robot motion can include, but are not limited to:
a) an enabling device;
b) an emergency stop device;
c) stopping the robot by hand, in the case of robots that include this feature.
The number and location of emergency stop devices shall be determined by risk assessment and shall
meet the requirements of ISO 13850.
5.4.4 Transitions between non-collaborative operation and collaborative operation
Transitions between methods of collaborative operation or between non-collaborative operation and
collaborative operation are particularly critical parts of a collaborative application. These shall be designed
such that the robot system shall not pose unacceptable risks to the operator during the transition.
NOTE A visual indicator to identify transitions between collaborative and non-collaborative operations can
be used.
5.4.5 Enabling device requirements
ISO 10218-1:2011, 5.8, includes provisions for a pendant control having an enabling device
(ISO 10218-1:2011, 5.8.3) and an emergency stop function (ISO 10218-1:2011, 5.8.4). If a risk assessment
determines that risk reduction traditionally achieved by the use of an enabling device would be
alternatively achieved by inherently safe design measures or safety-rated limiting functions, then the
pendant control for a collaborative robot system may be provided without an enabling device.
If a collaborative robot system relying upon safety-rated limiting functions is used without an enabling
device, then these functions shall always remain active. The limits (e.g. speed, force, or range) shall
be set to a level that provides sufficient risk reduction for programming, setting, troubleshooting,
maintenance and other tasks traditionally performed with the use of an enabling device.
Whenever safety-rated limiting functions are not active in the task-specific configuration, the
collaborative robot system shall include an alternative protection method, such as an enabling device
that meets the requirements of ISO 10218-1:2011, 5.8.3.
When an enabling device is not included with the robot system, the information for use shall include
the following:
a) a notification that the enabling device is not included with the robot. If an enabling device is an
option, the manufacturer shall provide instructions for how to install the enabling device;
b) a disclaimer stating a robot without an enabling device shall only be used in applications with
inherently safe design measures or active safety-rated limiting functions.
5.5 Collaborative operations
5.5.1 General
Collaborative operations may include one or more of the following methods:
a) safety-rated monitored stop;
b) hand guiding;
c) speed and separation monitoring;
d) power and force limiting.
5.5.2 Safety-rated monitored stop
5.5.2.1 Description
In this method, the safety-rated monitored stop robot feature is used to cease robot motion in the
collaborative workspace before an operator enters the collaborative workspace to interact with the
robot system and complete a task (e.g. loading a part onto the end-effector). If there is no operator in the
collaborative workspace, the robot may operate non-collaboratively. When the robot system is in the
collaborative workspace, the safety-rated monitored function is active and robot motion is stopped, the
operator is permitted to enter the collaborative workspace. Robot system motion can resume without
any additional intervention only after the operator has exited the collaborative workspace.
5.5.2.2 Robot requirements
For collaborative operation with safety-rated monitored stop, the following robot system
requirements apply:
a) when robot motion is limited, the limits shall comply with ISO 10218-1:2011, 5.12;
b) the robot shall be equipped with the function to achieve a protective stop in accordance with
ISO 10218-1:2011, 5.5.3.
5.5.2.3 Robot system requirements
The operations of the safety-rated monitored stop feature are outlined in Figure 2. The robot system is
permitted to enter the collaborative workspace only when an operator is not present in the collaborative
workspace. If an operator is not present in the collaborative workspace, the robot system may operate
non-collaboratively in the collaborative workspace.
Figure 2 — Truth table for safety-rated monitored stop operations
The collaborative workspace shall be established with distances that meet the requirements of
ISO 13855. The robot system shall be equipped with safety-rated devices which detect the presence of
an operator within the collaborative workspace. Access to the restricted space outside the collaborative
workspace shall be prevented in accordance with a risk assessment.
When the safety-rated monitored stop feature is used, an operator shall be permitted to enter the
collaborative workspace only under the following conditions:
a) when the robot system or other hazards are not present in the collaborative workspace;
8 © ISO 2016 – All rights reserved
b) when the robot system is in the collaborative workspace and is in a safety-rated monitored stop
(stop category 2) in accordance with ISO 10218-1:2011, 5.4 the safety-rated monitored stop shall
remain active at all times when an operator is in the collaborative workspace;
c) when the robot system is in the collaborative workspace in a protective stop in accordance with
ISO 10218-1:2011, 5.4 and 5.5.3.
In the intended use of this function, the robot may decelerate, resulting in a safety-rated monitored
stop (stop category 2) in accordance with IEC 60204-1.
When the operator leaves the collaborative workspace, the safety-rated monitored stop function may
be deactivated and robot system motion may resume automatically.
Any condition that violates these operational requirements shall result in a protective stop (stop
category 0) in accordance with IEC 60204-1.
5.5.3 Hand guiding
5.5.3.1 Description
In this method of operation, an operator uses a hand-operated device to transmit motion commands to
the robot system. Before the operator is permitted to enter the collaborative workspace and conduct
the hand-guiding task, the robot achieves a safety-rated monitored stop (see 5.5.2). The task is carried
out by manually actuating guiding devices located at or near the robot end-effector.
Robot systems used for hand guiding can be equipped with additional features, such as force
amplification, virtual safety zones or tracking technologies.
If the requirements of 5.5.5 are fulfilled in a hand guiding task, then the requirements of 5.5.3 do not apply.
5.5.3.2 Requirements
5.5.3.2.1 General
The robot shall utilize a safety-rated monitored speed function (ISO 10218-1:2011, 5.6.4) and a safety-
rated monitored stop function (see 5.5.2). A risk assessment shall be used to determine the safety-rated
monitored speed limit. If operator safety is dependent on limiting the range of motion of the robot, the
robot shall utilize safety-rated soft axis and space limiting (ISO 10218-1:2011, 5.12.3).
The operating sequence for hand guiding is as follows:
a) the robot system is ready for hand guiding when it enters the collaborative workspace and issues a
safety-rated monitored stop (see 5.5.2) — the operator may then enter the collaborative workspace;
b) when the operator has taken control of the robot system with the hand guiding device, the safety-
rated monitored stop is cleared and the operator performs the hand guiding task;
c) when the operator releases the guiding device, a safety-rated monitored stop (see 5.5.2) shall be
issued;
d) when the operator has exited the collaborative workspace, the robot system may resume non-
collaborative operation.
If the operator enters the collaborative workspace before the robot system is ready for hand guiding, a
protective stop (ISO 10218-1:2011, 5.5.3) shall be issued.
Access to the restricted space outside the collaborative workspace shall be prevented in accordance
with a risk assessment.
5.5.3.2.2 Guiding device
The robot system shall be equipped with a guiding device that incorporates an emergency stop
(ISO 10218-1:2011, 5.5.2 and 5.8.4) and an enabling device (ISO 10218-1:2011, 5.8.3), unless the
enabling device exclusion requirements of 5.4.5 are met.
The guiding device shall be located considering the following:
a) proximity of operator to robot so as to be able to directly observe robot motion and any hazards
that might arise from this motion (e.g. controls mounted on end effector);
b) operator position and posture shall not lead to additional hazards (e.g. operator not under heavy
loads or under manipulator arm);
c) operator vantage point shall allow for unobstructed view of entire collaborative workspace (e.g.
additional persons entering collaborative workspace).
The mapping between the motion axes of the hand guiding device and the motion axes of the robot shall
be clearly presented and easily understood. The direction of motion of the robot and end effector shall
be intuitively understandable and controllable from the hand guiding device.
5.5.3.2.3 Transitions between hand guiding and other types of operation
Transitions between hand guiding operations and non-collaborative operation or other types of
collaborative operation shall not introduce additional risk. The operator shall control such transitions by
deliberate actions (e.g. activating enabling device) and behaviour (e.g. leaving collaborative workspace).
Specific aspects to consider in these cases are:
a) in transitions from hand guiding to the safety-rated monitored stop (see 5.1), the halting of robot
motion and the initiation of the safety-rated monitored stop shall not introduce additional hazards;
b) transitions from safety-rated monitored stop to hand guiding shall not lead to unexpected motion;
c) in transitions from hand guiding to non-collaborative operation, all operators shall have exited the
collaborative workspace before the robot system can continue with non-collaborative operation;
d) transitions from non-collaborative operation to hand guiding shall not introduce additional hazards.
5.5.3.2.4 Risk assessment
Risk reduction is achieved by the combination of direct control of motion by the operator and
appropriate safety-rated limitation of speed and position, as determined by risk assessment. The risk
assessment shall specifically take into account:
a) safety-rated monitored speed that allows the operator control of the robot and relevant hazards;
b) the time and distance that is required by the robot to come to a stop upon release of the enabling
device or initiation of the protective stop, e.g. for workspace layout with respect to location of
operator and obstacles;
c) hazards caused by the workpiece, end effector, peripherals, or application devices.
5.5.4 Speed and separation monitoring
5.5.4.1 Description
In this method of operation, the robot system and operator may move concurrently in the collaborative
workspace. Risk reduction is achieved by maintaining at least the protective separation distance
between operator and robot at all times. During robot motion, the robot system never gets closer to the
operator than the protective separation distance. When the separation distance decreases to a value
10 © ISO 2016 – All rights reserved
below the protective separation distance, the robot system stops. When the operator moves away from
the robot system, the robot system can resume motion automatically according to the requirements
of this clause while maintaining at least the protective separation distance. When the robot system
reduces its speed, the protective separation distance decreases correspondingly.
5.5.4.2 Requirements
5.5.4.2.1 General
The robot shall be equipped with a safety-rated monitored speed function (ISO 10218-1:2011, 5.6.4)
and a safety-rated monitored stop function (see 5.5.2). If operator safety is dependent on limiting
the range of motion of the robot, the robot shall be equipped with safety-rated soft axis and space
limiting (ISO 10218-1:2011, 5.12.3). The speed and separation monitoring system shall meet the
requirements of 5.2.
Speed and separation monitoring shall apply to all persons within the collaborative workspace. If
the performance of the protective measure is limited by the number of persons in the collaborative
workspace, the maximum number of persons shall be stated in the information for use. If that maximum
value is exceeded, a protective stop shall occur.
If the separation distance between a hazardous part of the robot system and any operator falls below
the protective separation distance, then the robot system shall:
a) initiate a protective stop;
b) initiate safety-related functions connected to the robot system in accordance with ISO 10218-2:2011,
5.11.2 g), e.g. turn off any hazardous tools.
The possibilities by which the robot control system can avoid violating the protective separation
distance include, but are not limited to:
— speed reduction, possibly followed by a transition to safety-rated monitored stop (see 5.4.1);
— execution of an alternative path which does not violate the protective separation distance, continuing
with active speed and separation monitoring.
When the actual separation distance meets or exceeds the protective separation distance, robot motion
may be resumed.
5.5.4.2.2 Constant and variable speed and separation values
The maximum permissible speeds and the minimum protective separation distances in an application
can be either variable or constant. For variable values, the maximum permissible speeds and the
protective separation distances may be adjusted continuously based on the relative speeds and
distances of the robot system and the operator. For constant values, the maximum permissible speed
and the protective separation distance shall be determined through the risk assessment as worst cases
over the entire course of the application.
The means for determining the relative speeds and distances of the operator and robot system shall be
safety-rated in accordance with the requirements in ISO 10218-2:2011, 5.2.2.
5.5.4.2.3 Maintaining sufficient separation distance
During automatic operation, the hazardous parts of the robot system shall never get closer to the
operator than the protective separation distance. The protective separation distance can be calculated
based on the concepts used to create the minimum distance formula in ISO 13855, modified to take into
account the following hazards associated with speed and separation monitoring.
a) In constant speed setting situations, the worst-case value for the safety-rated monitored speed of
the robot is used. This value depends on the application and is validated by the risk assessment. The
constant limit value shall be set as a safety-rated monitored speed according to ISO 10218-1:2011,
5.6.4, to ensure the constant limit is not exceeded.
b) In variable speed setting situations, the speeds of the robot system and of the operator are used to
determine the applicable value for the protective separation distance at each instant. Alternatively,
the maximum allowed robot speed can be determined based on operator speed and actual
separation distance between the robot and operator. The control function to accomplish this shall
comply with ISO 10218-2:2011, 5.2.2.
c) The stopping distance of the robot is determined according to ISO 10218-1:2011, Annex B.
The protective separation distance, S , can be described by Formula (1):
p
St()=+SS ++SC++ZZ (1)
ph0 rs dr
where
S (t ) is the protective separation distance at time t ;
p 0 0
t is the present or current time;
S is the contribution to the protective separation distance attributable to the operator’s change in
h
location;
S is the contribution to the protective separation distance attributable to the robot system’s reac-
r
tion time;
S is the contribution to the protective separation distance due to the robot system’s stopping distance;
s
C is the intrusion distance, as defined in ISO 13855; this is the distance that a part of the body can
intrude into the sensing field before it is detected;
Z is the position uncertainty of the operator in the collaborative workspace, as measured by the
d
presence sensing device resulting from the sensing system measurement tolerance;
Z is the position uncertainty of the robot system, resulting from the accuracy of the robot position
r
measurement system.
NOTE S (t ) allows the protective separation distance to be calculated dynamically, allowing the robot speed
p 0
to vary during the application. S (t ) can also be used to calculate a fixed value for the protective separation
p 0
distance, based on worst case values.
Formula (1) applies to all combinations of personnel in the collaborative workspace and moving
parts of the robot system. The closest part of the robot and the person in the collaborative
workspace could be moving away from each other, while a different part of the robot and the person
are approaching each other.
The contributi
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.