Although its autonomous mobile robots (AMRs) were highly effective and productive, a client of a leading AMR producer encountered a significant safety issue: its facility had large caged areas—in which they deployed multiple robots—leading to risks if employees entered them.

To solve this safety challenge, the client wanted to implement a system to stop the robots instantly whenever people entered the caged area for maintenance or other operations. Each AMR was equipped with an e-stop button; however, it was time-consuming to track down each vehicle for a manual stop. And, as employees attempt to push the e-stop button, they could risk injuries if they’re too close to moving robots.

So, the AMR producer’s robotics team decided to offer a wireless e-stopping solution for their client that would stop all of the robots at once, adhere to industry safety requirements, be easy to use and have a highly dependable wireless signal that limits potential interference.

To install this solution, the AMR producer partnered with a smart machines safety and security solutions provider and used the provider’s vehicle safety controller (VSC), a module that sends and receives emergency commands, using patented wireless safety technology.

As a result of the partnership, a VSC was installed on each of the mobile robots, while a “master” VSC was installed on the door to the caged area. The master controller maintains constant two-way communication with each of the robot VSCs. Whenever the door is opened, it automatically sends a safety-rated e-stop signal to every robot—stopping them instantly.

To ensure high reliability, the solution uses patented wireless communication technology. It adheres to ISO 13849, Cat3 and PLd safety standards, while each endpoint has redundant, built-in safety technology to ensure all units stay in contact with the master controller. The VSC radios also use rapid frequency hopping to minimize any risk of wireless interference. Due to this highly reliable safety architecture, the open-door “stop” command will always be sent and received successfully.

Through its easy-to-use solution offering, the AMR producer was able to help its client increase employee safety around AMRs. The system has been successful in small test runs, and there are plans to scale it for larger areas with additional robots. It can also be easily replicated for many other applications where people and mobile robots work in proximity.