by Catie Hillard - Machinery Safety Client Success Manager
According to the World Robotics 20211 reports, published by the International Federation of Robotics (IFR), South Korea, Singapore, Japan, Germany, and Sweden are the most automated countries in the world. While the U.S. lags behind, it is rapidly picking up pace as technology advances and organizations search for solutions to labor shortages. We live in a time where automated manufacturing is gaining momentum and robot integration is becoming more popular in the sector, with new robot applications invented daily.
However, just as robotics exhibit a tremendous potential for applications, they also represent a tremendous potential for risk of injury. As part of the machinery safety lifecycle, a robotics system Risk Assessment (RA) identifies the proper risk-reduction safeguards to reduce the high level risks (e.g., crushing, shearing, trapping, striking) that are associated with certain robotic operational scenarios. The robot user – which is typically the employer – is responsible for the safety of the plant; therefore, it is of utmost importance that an application-specific and site-specific RA is carried out by the robot user.
One of the horrific examples of past robot accidents has been published in the OSHA Technical Manual Section IV: Chapter 4, where a worker accidentally tripped the power switch while another worker was servicing an assembly robot. As a result, the robot manipulator struck the maintenance worker’s hand, resulting in a severe injury. This would have been prevented if a RA had been conducted through identifying the need for proper lockout/tagout to prevent repowering the assembly robot, relocating the power switch since it was easy to inadvertently change its power state, or ensuring the application met electrical safety standards.
An effective RA starts with including knowledgeable employees with expertise in the operations, specific robotic application, RA methodology, and any specialized experience. The assessment team identifies all of the tasks to be performed as part of the robot operations and maintenance, with special attention given to any tasks that may be particularly hazardous or complicated. RAs are completed for hazardous situations associated with each stage of the robot development (i.e., assembly, integration, operation, and maintenance). The potential for harm and likelihood of occurrence of each hazardous situation is identified along with the most appropriate risk reduction technique. The documented RA is distributed to and accepted by the team and all affected employees, ensuring that all personnel involved with the robot operations and maintenance understand the associated hazards and safeguarding.
Furthermore, similar applications within the same plant should each have their own individual robotic system RAs, analyzed on an application-specific and site-specific level. Although the equipment may be of the same make and model, the robot applications may work on different parts or processes, be integrated into different upstream and downstream equipment, or perform unique automated functions that expose workers to particular hazards. Additionally, a robot’s end-effector, programming, or physical placement in the facility may be different from another robot with otherwise identical characteristics, which must be properly and individually analyzed for the potential for serious injury and risk mitigation.
Safeguards must be tailored specifically to protect against each hazardous situation, meeting the organization’s safety requirements and those dictated by industry consensus standards. Preferred safeguards may change based on the application and on the robot user’s risk tolerance. For example, the access frequency, orientation of the robot within a facility, and organizational disposition may dictate whether the preferred safeguard for access to the robotic cell is an interlocking gate or presence-sensing device, and whether or not the robot is designed and programmed to reset automatically. The RA defines the required safety functions and safety requirements specifications, both of which depend on the application. The RA team develops the safety system design requirements and selects the safeguards to perform each safety function. ANSI/RIA R15.06 Safety Requirements for Industrial Robots and Robot Systems provides detailed steps for conducting a task-based RA to conform with the industry consensus standards and includes examples that apply to many common robot applications.
The IFR estimates that there were more than 2 million robots in the worldwide workforce at the end of 2018, which continues to increase yearly as robotic systems appear in even more industries. As more workers become exposed to robots, assuring compliance with industry consensus safety standards is of paramount importance as a means of reducing the risk of injury associated with robot interaction. An application-specific, site-specific RA identifies the hazards, risks, controls, and safeguards that apply towards the proper safety system design. The robot user is responsible for plant safety, which is why it is imperative that the user ensures that the RA is properly performed. aeSolutions offers robotic risk assessments and can provide expert guidance and training to help you effectively perform an application-specific, site-specific RA for your robotic systems.
1. The International Federation of Robotics. Executive Summary World Robotics 2021 Industrial Robots. 2021, ifr.org/img/worldrobotics/Executive_Summary_WR_Industrial_Robots_2021.pdf