By Ed Mullen, Contributor
Transporting materials across facilities can be difficult, time-consuming and dangerous, potentially resulting in overexertion for workers and contact with objects and equipment. In 2018, for example, forklifts alone caused 85 work-related deaths and 7,940 non-fatal injuries involving an average of 12 days away from work, according to the National Safety Council.
Not only does automation present opportunities for increased productivity and faster ROI, but it can also make work conditions safer. Implementing autonomous mobile robots (AMRs) in particular, which navigate using sensors, software algorithms and artificial intelligence capabilities, can help improve safety in part by eliminating accidents caused by blocked views from materials in front of the forklift.
When Visteon Electronics first implemented its fleet of four AMRs, employees wondered if the AMRs would be able to transport materials throughout the plant without running into workers or even other robots. It didn’t take long for the employees to see that as the robots maneuvered through the manufacturing facility in 24-hour operations, five days a week, they avoided obstacles and could actually recompute their path on the fly. In fact, extensive built-in safety mechanisms allow the robots to navigate collaboratively around human co-workers and other obstacles by slowing down, changing direction or stopping completely to avoid collision.
Employees quickly appreciated that the robots freed them from heavy, monotonous and low-value material-moving tasks, and as the days went on, they became increasingly confident in the AMRs’ safety features.
With safety a top priority, management had to be onboard as well. The AMRs’ safety features were carefully researched and scrutinized before any decisions were made, as was the manufacturer’s and integrator’s suggestions for how to work together to ensure a safe mobile robot installation that complies with evolving standards to ensure safe conditions for workers interacting with these robots.
Safety Standards Still in Flux but Expanding for Mobile Robots
Safety standard requirements vary by region or country. The three main AMR safety standards for functional safety of the robot are currently the ANSI/ITSDF B56.5-2019 from the American National Standards Institute / Industrial Truck Standards Development Foundation, which addresses automated guided industrial vehicles; the EN 1525:1997 (EU), and the ISO 3691-2020: “Driverless industrial trucks and their systems,” which was released in February 2020.
The EN 1525:1997 also applies to an automated guided industrial vehicle as well as its systems and to the commissioning and preparation of the environment in which the robot will be used. The ISO 3691-4:2020 addresses safety concerns for internal logistics and the hazards related to recompute paths on-the-fly, which are key aspects of AMRs. The new standard provides detailed requirements for deploying mobile robots, as well as environment and work-cell design.
Other standards in progress that will likely have an impact on manufacturers, users and integrators of mobile robots include the prUL 3100, and the ANSI/prRIA 15:08 (expected to be published at the end of 2020). As addressed in a Robotics Industries Association (RIA) webinar in July, this latest standard covers ground-based industrial mobile robots in a semi-structured environment with trained personnel and no public interactions (i.e. retail warehouse space with only employees vs. retail floor). These must be fully autonomous and capable of moving and planning its own path along a free space, which distinguishes the AMRs covered under this standard from traditional automated guided vehicles (AGVs).
Proven European Guidelines Set the Stage for Global Safety
In addition to the safety standards previously addressed, consider following the guidelines established by European MD, which has proven to be a solid framework that can be applied to all factories, with amendments to address local requirements. Discuss the following steps (more detail in chart) with your AMRs manufacturer and system integrator:
- The AMR manufacturer must provide a vehicle designed to be deployed in a safe AMR system, which includes the environment, charging station, top modules, and other peripherals, along with providing adequate information for integration and operation. This means the manufacturer is responsible for specifying intended use and limitations of the AMR, which is typically to transport materials in industrial environments without a human driver. In Europe, the manufacturer must CE-mark the AMR according to intended use through compliance to safety standards for AGVs, which is what most standards are based on today. They must also comply with complementary standards to address all risks and provide integrated safety functions to address expected hazards.
- When the robot is ready to deploy, the AMR system integrator becomes responsible for the safe workplace. If the end user is installing the AMR themselves, they are the responsible party. The integrator must provide an installation where all hazards are addressed or identified while providing adequate information for operation. Because AMRs can be programmed to move throughout a building, factory, or warehouse, the integrator must anticipate potential safety hazards and program the robot and top module to act appropriately in compliance with safety standards.
If the robot is deployed outside of those limitations, the integrator (or end user) must incorporate additional protections to ensure that safety standards are met for the full robot application. Consequently, the integrator must specify the intended use and limits of the AMR system and make a risk assessment of the AMR system in light of the AMR manufacturer’s specifications, intended use and limitations.
- Once the AMR system is deployed, the end user is then responsible for setting up and following procedures for operation and maintenance. The end user must ensure that the intended use and limitations are met and set up procedures for inspections and maintenance for the AMR system, including warning and markings.
Ensuring a safe workforce around autonomous mobile robots isn’t an easy process but it can be facilitated by following the chart shown, or by contacting the AMR vendor being considered to help effectively and safely navigate the process. With the increasing number of AMRs installed worldwide, new AMRs on the market, and new customers with limited experience with this technology, every relevant member of the implementation team must work together to ensure a safe workplace. It’s too important to try to do alone. WMHS
Ed Mullen is the VP of Sales, Americas at Mobile Industrial Robots.