Robotic Crash Protection

Overview

Robotic Crash Protection

Safeguard Your Tooling, Robot & Assembly System with an Overload Protection Device (OPD)

How It Works – The OPD’s mechanical wrist is held rigid pneumatically during normal operation. Varied stiffness to accommodate payload is achieved by adjusting the input air pressure. Once an overload is detected, a signal is generated to shut down, or correct your process, and the mechanical wrist transforms to a compliant state, protecting equipment and end-of-arm tooling. The OPD is easily reset by placing the mechanical wrist and interface module in their ready positions.

Two Modes of Protection – PFA’s OPD provides for independent adjustment of both pneumatic rigidity and electronic sensitivity, thus allowing you independent control of the amount of force and the amount of tooling plate travel required to initiate a protective function. As applications vary, this flexibility ensures the best possible performance under all conditions.

Modular Interface – The interface module provides all the necessary components for “plug and play” operation. Multiple signal outputs (source, sink, and NO/NC relay contacts), three point sensor adjustments, and integrated air valve, vent valve controls, ensure that all the work is done for you. Install, apply services, and you’re protected.

Robotic OPD Collision Protection nested with On Arm Electronic Control

Specifications

OPD-MS-1A Mechanical Unit

Load Capacity:	10 lbs. (dynamic load)
Operating Pressure:	5 – 50 psi.
Weight:	0.8 lbs.
Operating Temp:	-4˚ to +248˚ F
Sensitivity: (at interface center)	0.002 in. axial
Repeatability: (at interface center)	X, Y, Z, Axis +/-0.0005 in. Rotationally +/-20’.
Material:	Aluminum and Nickel Plated Aluminum

OPD-MS-2HD Mechanical Unit

Load Capacity:	65 lbs. (dynamic load)
Operating Pressure:	5 – 60 psi.
Weight:	2.0 lbs.
Operating Temp:	-4˚ to +248˚ F
Sensitivity: (at interface center)	0.002 in. axial
Repeatability: (at interface center)	X, Y, Z, Axis +/-0.0008 in. Rotationally +/-20’.
Material:	Aluminum and Nickel Plated Aluminum

OPD-MS-3 Mechanical Unit

Load Capacity:	350 lbs. (dynamic load)
Operating Pressure:	10 – 80 psi.
Pilot for Valve:	20 psi. minimum
Weight:	30.0 lbs.
Operating Temp:	-4˚ to +248˚ F
Sensitivity: (at interface center)	0.002 in. axial
Repeatability: (at interface center)	X, Y, Z, Axis +/-0.001 in. Rotationally +/-20’
Material:	Aluminum, Nickel Plated Aluminum, and Steel

OPD-EM-U Interface Module

Signal Outputs:	12 VDC Current Source, 50 mA max. 5 – 24 VDC Current Sink. 75 mA max. Pulsed Signal for 1 second or continuous 2 Relay NO or NC, 110 VAC, 1 A max.
Response Speed:	Signal – 5 microseconds max. Relay – 6 milliseconds max.
Supply Voltage:	+12 VDC or +24 VDC
Maximum Current:	250 mA.
Operating Temp:	+35˚ to +112˚ F
Weight:	20 oz.

Robotic OPD Collision Protection overload conditions and axis

Overload Protection Device (OPD)

With PFA’s Overload Protection Device (OPD), save time, save money, save your tooling!

Robotic OPD Collision Protection product drawings

Customer Interface Wiring Diagram

Identify Your Part Number

Robotic Collision Protection - Emergency Shutdown - Crash protection for Robotic EOAT

Application Data

To estimate the approximate input air pressure for your specific application perform the following steps.

Purely Lateral Overloads

Step 1: Determine the total weight in lbs. of your end of arm tooling. This will give you your mass at the end of the tooling.
Let this = M.
M = Weight of Tooling + Part (lbs) / 32

Step 2: Determine the maximum acceleration in ft/sec2 under full payload for your application at the end of the robot arm.
Let this = A

Step 3: Use the following formula to determine your known expected force in lbs.
Force (Fy) = M x A

Step 4: Use your Force (Fy) in the following equation to determine P in psi, your ideal input pressure.

application-data
Note: D = Distance from OPD plate to Cg (center of gravity) in inches.

Model
OPD-MS-1A	P = Fy [(D) x (.581) + .389]
OPD-MS-2HD	P = Fy [(D) x (.172) + .166]
OPD-MS-3	P = Fy [(D) x (0.019) + 0.05]

Purely Axial or Torsional Overloads

To approximate the operational input air pressure (P) for pure Z axis axial overloads, or purely torsional overloads about the Z axis, determine your maximum torque (Mz) in in-lbs or axial force (Fz) lbs. and apply it to the appropriate formula listed below.

Model	Pure Axial Overload	Pure Torsional Overload
OPD-MS-1A	P = Fz (.389)	P = Mz (.512)
OPD-MS-2HD	P = Fz (.166)	P = Mz (.247)
OPD-MS-3	P = Fz (.05)	P = Mz (.024)

Note: Input air pressure settings were determined under laboratory conditions. Your performance settings may vary. The input air pressure may be varied in process to achieve the most sensitive overload protection without sacrificing high payload capacities.

Electrical Interface. The OPD Electronic Interface Module can be used on 12 VDC or 24 VDC Systems. Module outputs are both current sinking, sourcing, and isolated relay contacts. The outputs are independently selectable to (1) a momentary off pulse typically interfaced to the systems emergency stop circuit or (2) a continuous off signal when faulted (until reset).