Robotic Safety Guarding Fundamentals
Robotic automation for industrial applications is rapidly growing due to the reliability of programmed robots, as well as the low overhead costs compared to traditional manufacturing processes. Some of the common robots used in the manufacturing processes are Cartesian, cylindrical, and spherical robots. Robots are reliable and consistent, but failures can occur such as loss of air pressure, power failures, or glitches in the controls. A controlled environment should be developed to minimize the “human-factor” decision making due to the inherent trust between robot and human.
A controlled environment for robot automation safety is a development of robotic safety guarding, which is a hard-sided barrier or fencing integrated with electronic safety devices to create a controlled system taking a standard barrier to a true safety guard. This guarding is designed to define a clear unobstructed area for the robot to function properly protecting workers from hazards due to robot activity, material handling, and production debris. Hazards that can occur if robotic safety guarding is not in place are pinch, crush, wrap, cut, and nip points as well as colliding with the robot or the robot losing control of a part. Designs are created using a combination of OSHA, ANSI, ISO, and RIA safety standards. These safety standards are written with some inherent flexibility or “gray area” due to the wide range of manufacturing processes. A level of “common sense” and manufacturing experience needs to be factored in when closing the gap between the “gray area” and the guarding being designed.
When designing robotic safety guarding, several things need to be considered such as footprint, robot reachability, human interaction, and type of material being processed. A layout must be developed using the safety standards as it relates to the operational interaction as well as potential interaction the robot could have with a human. This layout will determine the shape of the robot cell which includes length, width, and height of the guarding required. A determination is also made for the material type of the structure and panels needed.
The hard guarding is most designed with either T-Slotted Aluminum Extrusion or prefabricated steel. The T-Slotted material is a lightweight, yet rigid material, high aesthetic look, and completely modular for custom designs. Prefabricated steel provides higher strength, fixed sections, and a hi-vis safety yellow finish. Both guards require the use of solid plastic, metal, or wire mesh panels which is determined by the distance between the hazard and the personnel per the appropriate safety standards, as well as type of material being processed. These guards are designed with access doors for personnel and material handling entry, as well as a wide variety of accessories needed to create a complete barrier.
Once the physical barrier is designed, the specifications for the electronic safety devices can then be determined. These devices include safety interlock switches for door and removable access panels, safety light curtains and safety laser scanners for frequently accessed areas along with all the required safety controllers, relays, cables, and hardware to design the proper safety circuit. A wide range of sizes, protection coverage, durability, and safety levels are offered to properly fit the needs of each particular application.
The fundamentals of robotic safety guarding are straight forward on the surface but requires a lot of technical detail. Creating the proper design, choosing the right products, and implementing everything together as a “system” is critical to the protection of personnel and the robotic automation equipment when developing a safe and controlled environment. It is highly recommended to partner with a company that specializes in providing a turnkey solution due to the challenge’s companies face such as lack of time, skill level, and knowledge of the ever-changing safety standards. Companies that offer design thru nationwide installation services of machine safety and automation applications can provide a level of consistency throughout the entire process, as well as a single point of contact minimizing communication issues.
Check out our video on this article…
You can check out the article on our website:
To help with your machine safety guarding needs in effort to “Improving Workplace Safety Attitudes”, email PowerSafe Automation at psa365@powersafeautomation.com or call us at 844–520-SAFE.
Written and Published by Shawn Mantel and Professional Safety Journal (PSJ), January 2019
