Brooks Automation
P/N: PFD0-DI-00010, Rev 5.0.0, April 9, 2022
Collaborative Robot Safety
Copyright © 2022, Brooks Automation, Inc.
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Appendix A: Example Performance Level Evaluation for
PFDDR, Update for PFDD example
Example Workcell description:
A PFDD4 moves 100-gram plastic trays from storage racks to an
instrument and back to the storage racks. Gripper is an electric parallel jaw gripper with maximum 23N of
gripping force for plastic trays and is spring loaded so it will not drop trays if power fails. Robot motion is
programmed with approach point 50mm above the instrument tray and final motion into instrument is
made at 50mm/sec. Lowest storage rack position is 50mm above table surface.
Figure 9: Example PF400 Workcell: Courtesy of Biosero
Normal Operator Interaction with robot:
Teaching locations in workcell by hand guiding or teach pendant. Maximum robot forces under manual
control from PFDDR Table 1 are 105N.
Pausing robot and removing racks from workcell with safety interlocks in workspace. Robot is stopped.
Possible Low Frequency (rare) Interaction with Robot:
Untrained operator reaches into workcell while robot is moving and robot collides with
operator. Maximum free space collision force from PFDDR Table 1 is 182N, which is below free space
collision for 500ms maximum of 280N.
Untrained operator reaches into workcell while robot is moving into instrument tray and hand is trapped
between robot and instrument tray. From PFDDR Table 1 max trapping force in downwards Z direction at
60mm/sec (10% of max speed of 600mm/sec) is 77N.
Performance Level: From the above, based on ISO 13849-1:2006:
S is S1, as possible operator collision forces will not injure operators.
F is F1 as normal operation does not involve collisions with robot.
P is P1 as the robot does not make unexpected motions
