1.7 Risk Assessment
Some safety-related features are purposely designed for collaborative robot applications. These
features are configurable through the safety configuration settings and are particularly relevant
when addressing specific risks in the risk assessment conducted by the integrator:
• Force and power limiting: Used to reduce clamping forces and pressures exerted by the
robot in the direction of movement in case of collisions between the robot and the operator.
• Momentum limiting: Used to reduce high transient energy and impact forces in case of
collisions between robot and operator by reducing the speed of the robot.
• TCP and tool/end effector position limiting: Particularly used to reduce risks associated
with certain body parts. E.g. to avoid movement towards head and neck.
• TCP and tool/end effector orientation limiting: Particularly used to reduce risks associ-
ated with certain areas and features of the tool/end effector and work-piece. E.g. to avoid
sharp edges to be pointed towards the operator.
• Speed limitation: Particularly used to ensure a low speed of the robot arm.
The integrator must prevent unauthorized access to the safety configuration by using password
protection.
A collaborative robot application risk assessment for contacts that are intentional and/or due
to reasonably foreseeable misuse is required and must address:
• Severity of individual potential collisions
• Likeliness of occurrence of individual potential collisions
• Possibility to avoid individual potential collisions
If the robot is installed in a non-collaborative robot application where hazards cannot be rea-
sonably eliminated or risks cannot be sufficiently reduced by use of the built-in safety-related
functions (e.g. when using a hazardous tool/end effector), then the risk assessment conducted
by the integrator must conclude the need for additional protective measures (e.g. an enabling
device to protect the operator during set-up and programming).
Universal Robots identifies the potential significant hazards listed below as hazards that must
be considered by the integrator.
Note: Other significant hazards can be present in a specific robot installation.
1. Entrapment of fingers between robot arm cable connector and base (Joint 0).
2. Entrapment of fingers between robot foot and base (Joint 0).
3. Entrapment of fingers between robot wrist 1 and robot wrist 2 (Joint 3 and Joint 4).
4. Penetration of skin by sharp edges and sharp points on tool/end effector or tool/end ef-
fector connector.
5. Penetration of skin by sharp edges and sharp points on obstacles near the robot track.
6. Bruising due to contact with the robot.
7. Sprain or bone fracture due to strokes between a heavy payload and a hard surface.
8. Consequences due to loose bolts that hold the robot arm or tool/end effector.
9. Items falling out of tool/end effector, e.g. due to a poor grip or power interruption.
10. Mistakes due to different emergency stop buttons for different machines.
11. Mistakes due to unauthorized changes to the safety configuration parameters.
Information on stopping times and stopping distances are found in chapter 2 and appendix A.
Version 3.11
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I-9 UR5/e-Series
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