Robot Safety: Tools, Guarding, and Strategies 

Robot Safety: Tools, Guarding, and Strategies

It is impossible to ignore the safety gains an automated robot, engineering solution, or industrial machine can bring to your business. Over the past thirty years, robots have allowed businesses to produce far beyond human workers’ capacity while reducing worker health risks to environmental hazards. The market is waking up to automated solutions to high turnover tasks, and seeing defined increases in worker satisfaction and positive employee mental health outcomes when those tasks are offloaded to a machine. 

At the same time, when you have a machine working in proximity with human workers, you need to respect the power of the machine, and the capacity for injury irresponsible use of a robot can inflict. An automated machine operates at inhuman speeds and autonomously wields heavy grippers, blades, stampers, and other tools that require safeguards, training, and specialized equipment. People can damage or contaminate products if mishandled. End effectors can handle sharp, hot, or toxic materials. Here is an overview of the basics of what you can expect when accounting for robot safety.  


Safety Devices 


Safeguarding equipment can range from complex sensors to barriers and have built in redundancies. Here are some of the common safety devices you encounter when supervising your robot: 

Barrier Guards- These are physical obstructions designed to keep employees from accidentally or intentionally entering unsafe zones around your automated machines.  

  • Fixed guards- These are physical cages that either completely fit the shape of your machine (sometimes called an enclosing guard) or a permanent fence (sometimes called a perimeter guard). Even if they have openings for things like raw material feeding, they are considered permanent, should only be removable with tools, and should enclose all points of hazardous contact. 
  • Interlocked guards- These are physical barriers, usually in the form of gate or door, that stop all machine activity when the interlock is broken. These interlocked guards will not allow the machine to restart until the interlock is reset (i.e. the door is closed) and a control system outside of the hazardous zone is manually activated to reset the machine. They allow access to your machine for things like maintenance work without having to remove permanent barriers. 
  • Awareness Barriers- These are physical indicators that can visually define a safety perimeter but can be climbed over, stepped around, or crawled under (i.e. a low railing or chain). This should only be used in concert with interlocked and fixed barriers already in place or when safety concerns are minimal. 

Prescence Detection Devices- These are devices that rely on area-based detection to additionally safeguard machines. Often used in concert with physical barriers, but sometimes used as a substitute, these devices utilize the same interlock style machine shut down but trade solid barriers for easier access to machines for maintenance. These are placed outside of the reach of your machine. 

  • Light Curtains- These opto-electronic devices use a series of transmitters and receivers to create a screen of light. Any breaks in the beams (i.e. a worker entering the curtain) will trigger a shutdown of the machine. 
  • Pressure Sensitive Safety Mats- These heavy-duty floor mats contain pressure sensitive plates that shut down a machine if it detects the weight of a person or object. They can be customized for size and can come in assorted styles. 

Emergency Brakes- These are emergency stop buttons or pull cords within reach of everyone who works with or near the machine. Dynamic braking systems will arrest movement in a way that counteracts the motion of the of the robot and prevent hazards such as suddenly dropping the robot arm. Even in the event of loss of power, a braked robot will not automatically restart. 

Control Devices- Also known as Human Machine Interfaces (HMI), these are the panels, screens, or pendants that the operator uses to control the robot. The control device will not only have clear instructions and labeling, but it will also have emergency stops that lock your robot in the ‘off’ position, status indicators on the quality of the robot, and control safeguards that prevent accidental button press, switch flipping, or activations. The main panel or control device is always located outside of the hazard area and in sight of the robot. The control device should be the only location a robot can be reactivated from. 

Audible and Visual Warning Systems- These are the more common worksite indicators of safety. Lights and emergency tape should all frame the hazard area and signs should communicate the proper safety conduct around the robot. Gauges, displays, and monitors should all accurately reflect the condition of the robot. Separate emergency lights and audible alerts should communicate emergency situations.  


Placement Safety 


Safeguarding your equipment is as much about understanding how you position your machine. 

Securing- Your machine should be locked to its location and secured so that even at maximum exertion there are no dangers from tipping, vibration, or movement. 

Environment- Your machine should be compatible with the temperature and environmental conditions where it is placed. 


Safety Ownership 


Effective accident prevention cannot rely on technology alone. Partnering with your automation integrator comes with an expectation that you will receive training, education, and instruction on how to integrate your automated industrial machine responsibly. DEVELOP LLC trains beyond our competitors to help our customers achieve self-reliance. These are ways you will need to take safety ownership during long-term operation of your industrial machine. 

Operation Training- Supervisors, managers, and machine operators must fully train in the use, programming, and basic maintenance of your automated machine. 

Safety Policy- All employees must agree to a written safety policy, and hazard prevention training. This includes agreements on who is and who is not allowed to operate the robot. Only a fully trained operator or trainee supervised by one should operate the robot. 

Safety Checklists- Make sure there is a periodic condition checklist to evaluate the robot’s working condition. Include a pre-operation safety checklist before activation, this includes a visual inspection and evaluation of gauges and screens. 

Regular Maintenance- Respect that when you integrate an automated machine into your business, you need to do regular comprehensive checks and maintenance. An automated machine that is not properly maintained can malfunction. This can jeopardize the speed, consistency, and quality of your production, but it more importantly can jeopardize your workforce. Evaluate the condition of your machine, schedule maintenance, make repairs as necessary, and look forward to longevity. 

DEVELOP LLC’s engineers, manufacturing experts, and project managers are experts at every aspect of automation integration. We know how to seamlessly and painlessly fold the necessities of machine safety into your integration so your team can maintain ownership, expertise, and longevity. Tell us more about your project, schedule a virtual meeting, or call (262)-622-6104 to learn more about how we can help you automate your production today.  

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