Introduction to the Hardware
17
Robot Testing and Safety Circuits
While some robots have 6 or even 7 axes and can move in many directions, generally testing can be
done in the horizontal plane and in the vertical direction. Since gravity adds to the force in the
downwards vertical direction, and since in the horizontal plane forces are symmetric in opposite
directions, testing in +X, +Y, and –Z (downwards) is generally sufficient to characterize robot forces.
Precise uses a test stand, to which a certified force gage can be attached in either the vertical or
horizontal direction, for testing forces. A “compliance plate” assembly is attached to the robot to simulate
the compliance of the human hand of 75N/mm.
Clamping/squeezing force is measured by moving the robot slowly into the force gage until the robot
reaches its maximum force and generates an error.
Based on Table A2 from ISO/TS 15066 (Appendix
C), Precise has selected the maximum clamping force (quasi-static) to be 140N for a collaborative
robot.
Transient impact force in free space is measured by moving the robot at its maximum permitted speed
and payload with the compliance plate impacting the force sensor when the force sensor is held by a
person in free space.
Based on Table A2 from ISO/TS 15066, Precise has selected the maximum
impact force (transient force) in free space to be 280N for the hand and forearm and 130N for the
skull for a collaborative robot.
Impact force against a rigid surface (trapping) is measured by moving the robot at speeds up to its
maximum permitted speed and payload with the compliance plate impacting the force sensor when the
force sensor is fixed to a rigid surface.
Pinch points. If a robot has pinch points, a full speed impact in these pinch points should not exceed the
quasi-static force above.
Pressure, or force per unit area, may be derived from the above tests and is not tested directly,
since it will depend on the application, including the end effector design.
It is desirable to eliminate
sharp edges or points on the robot or end effector that can result in high pressures. In some case foam
padding or spring-loaded end effectors may be used to limit pressure during a collision. Rounded covers
and compliant covers (plastic) are helpful in limiting pressure during clamping or impact collisions.
Precise has tested, and TUV has verified the forces for the PF400 robot (See Appendix B of this
section). This data is intended to aid the integrator in performing a Performance Level
Assessment for determining whether collision forces in a particular workcell may cause operator
injury.
An example PLr workcell application assessment based on ISO 13849-1:2006 is given for a PF400
workcell in Appendix A of this section.
Summary of Contents for PF3400
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Page 32: ...PreciseFlex_Robot 24 Appendix B TUV Verification of PF400 Collision Forces...
Page 33: ...Introduction to the Hardware 25...
Page 34: ...PreciseFlex_Robot 26...
Page 35: ...Introduction to the Hardware 27...
Page 37: ...Introduction to the Hardware 29 Appendix C Table A2 from ISO TS 15066 2016...
Page 38: ...PreciseFlex_Robot 30 Table A2 Continued...
Page 41: ...Introduction to the Hardware 33 PF400 500gm Safety Circuits PF3400 3kg Safety Circuits...
Page 45: ...Installation Information 37...
Page 46: ...PreciseFlex_Robot 38...
Page 47: ...Installation Information 39...
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Page 54: ...PreciseFlex_Robot 46 Schematic System Overview...
Page 55: ...Hardware Reference 47 Schematic FFC Boards Revision B PF400...
Page 56: ...PreciseFlex_Robot 48...
Page 57: ...Hardware Reference 49 Schematic FFC Boards Revision C PF400...
Page 58: ...PreciseFlex_Robot 50 Schematic FFC Boards 3kg PF400...
Page 59: ...Hardware Reference 51...
Page 60: ...PreciseFlex_Robot 52 Schematic Safety System Overview PF400 CAT3...
Page 61: ...Hardware Reference 53...
Page 62: ...PreciseFlex_Robot 54 Controller Power Amplifier Connectors Control Board Connectors...
Page 63: ...Hardware Reference 55 Gripper and Linear Axis Controller Connectors...
Page 64: ...PreciseFlex_Robot 56...
Page 65: ...Hardware Reference 57...
Page 66: ...PreciseFlex_Robot 58 Schematic Slip Ring for 60N Gripper...
Page 67: ...Hardware Reference 59...
Page 68: ...PreciseFlex_Robot 60...
Page 69: ...Hardware Reference 61...
Page 70: ...PreciseFlex_Robot 62...
Page 71: ...Hardware Reference 63...
Page 72: ...PreciseFlex_Robot 64...
Page 73: ...Hardware Reference 65 Motor 60N Gripper...
Page 74: ...PreciseFlex_Robot 66...
Page 106: ...PreciseFlex_Robot 98 b The CALPP application takes about 1 minute to run...
Page 124: ...PreciseFlex_Robot 116 Wiring for 60N Gripper with Battery Pigtail Wiring for Pneumatic Gripper...
Page 125: ...117 Wiring for Vacuum Gripper Wiring for Vacuum Pallet Gripper...
