Collaborative Robot Safety & ISO/TS 15066 Integration
Just because you bought a "collaborative" robot doesn't mean your application is safe. Learn how to perform a proper risk assessment and achieve compliance.
Industrial Automation Hub
The Golden Rule of Cobot Safety
There is no such thing as a collaborative robot; there are only collaborative applications. If you attach a razor-sharp blade to a cobot arm and move it at eye level, the system is no longer collaborative, regardless of the robot's built-in sensors.
Understanding ISO/TS 15066
ISO/TS 15066 is the technical specification that builds upon ISO 10218 (safety requirements for industrial robots) to specifically address collaborative robots. It provides data-driven guidelines on pain thresholds and biomechanical limits for human-robot contact.
The 4 Types of Collaborative Operations
ISO/TS 15066 outlines four distinct methods for achieving a safe collaborative operation:
- Safety-Monitored Stop (SMS): The robot stops entirely before the operator enters the collaborative workspace. Once the operator leaves, the robot resumes. This is highly reliable but negates true collaboration.
- Hand-Guiding (HG): The operator uses a specialized device to directly guide the robot's motion. The robot only moves when the operator is actively holding the enable switch.
- Speed and Separation Monitoring (SSM): The system uses safety laser scanners (like SICK or Keyence) or vision systems to monitor the distance between the operator and the robot. As the operator gets closer, the robot slows down. If the operator breaches the minimum protective distance, the robot stops completely.
- Power and Force Limiting (PFL): This is what most people think of when they hear "cobot." The robot has built-in sensors that detect impact. If it hits an operator, the force is limited to levels below human pain thresholds (as defined by the extensive charts in ISO/TS 15066), and the robot stops or reverses.
Conducting the Risk Assessment
Before deploying any cobot, a comprehensive Risk Assessment (per ISO 12100) is mandatory. This cannot be skipped.
1. Analyze the Tooling
Is the End of Arm Tooling (EoAT) sharp? Does it involve extreme heat (welding)? Does it generate pinch points? You may need to round edges or add padding to the tooling itself.
2. Analyze the Workpiece
A cobot moving a soft cardboard box is low risk. A cobot swinging a 10lb piece of sheet metal with sharp burrs at 1000mm/sec is a lethal hazard. The workpiece dictates the risk.
3. Analyze the Environment
Can an operator be pinned between the cobot and a fixed object (like a wall or CNC machine)? ISO/TS 15066 treats "transient" (bumping into) and "quasi-static" (crushing) contact very differently.
4. Calculate the ROI Impact
If your risk assessment requires the cobot to run at 250mm/sec to be safe, will it still meet your production cycle times? Safety directly impacts ROI.
Safety Scanners vs. Cages
If your risk assessment reveals unacceptable risks (e.g., you are moving sharp objects fast), you must mitigate. While traditional robots use physical chain-link cages, cobot integrators usually deploy Area Safety Scanners.
These scanners cast an invisible laser grid across the floor. They are programmed with zones:
- Warning Zone (Yellow): Operator approaches. Cobot speed reduces by 50%. A warning light flashes.
- Protective Zone (Red): Operator is within striking distance. Cobot executes a Category 0 or Category 1 safety stop.
How Does Integration Cost Affect ROI?
Adding safety scanners and engineering integration time significantly alters your payback period. Use our calculator to model these exact CapEx costs against your labor savings.
Calculate Cobot ROI