Mobile Robot Safety and Security Checklist
August 12, 2019      

Today’s mobile robots are loaded with sensors, vision systems and many other safety protocols. But it’s not just a situation of putting them in a warehouse, manufacturing or other facility and turning them on. Plant staff, robotics manufacturers and integrators need to work together to ensure the robots are deployed and used safely.

The impact of mobile robots within warehouses and factories is set to accelerate over the next five years. According to research and advisory firm LogisticsIQ, the warehouse automation market will more than double from $13 billion in 2018 to $27 billion by 2025. With more robots expected in the workplace, issues around safety and security will become more important for those tasked with their deployment.

Robotics Business Review recently talked with robotics industry experts to get their top priorities for safe deployment of robots.

Item #1: Map the plant

Karen Leavitt Locus Robotics CMOLocus Robotics and other robotics providers said one of the first things they do when they start negotiating with a new customer is to map the facility.

“We send out a scout robot to map the facility,” said Locus chief marketing office Karen Leavitt. “We want to make sure the floor is level and smooth and where any obstructions might be. If the floor is pitted or uneven, we fill in those things.”

Item #2: Consider all safety aspects

Safety isn’t restricted to sensors, speed, stopping ability and other features typically at top of mind when considering a robotic system, cautioned James Conrad, IEEE senior member and UNC Charlotte professor of electrical and computer engineering.

“Examine all of the safety aspects of the robot you are trying to buy – does it have a good charging solution,” Conrad said. “If it’s not charging correctly, it could be overcharging.”

The potential safety issue of fire from a robot’s batteries were brought to light in dramatic fashion in February, when a robot at an Ocado fulfillment warehouse in Britain sparked a massive fire that destroyed the warehouse. The warehouse was destroyed, and the British grocer has just revealed the price tag of the damage: $137 million. The company blamed the fire on a faulty battery charging unit.

Cybersecurity is another important consideration, Conrad said. “Imagine a large piece of equipment that runs autonomously having malicious behavior.”

Plant managers need to ensure robots are secure from hacking and unauthorized reprogramming, Conrad said, adding that robot manufacturers should provide the cybersecurity protections.

Item #3: Test, test, test

Fergal Glynn mobile robot checklist story

Fergal Glynn, 6 River Systems

There are simulations, and there is the reality of robots working with humans in a facility, said Fergal Glynn, vice president of marketing for 6 River Systems. “You need to rigorously test everything. You need to make sure that reality meets expectations when the robots are working alongside humans.”

“Make sure that customers are doing their own safety and risk assessments,” added Joe Lau, director of product marketing at Fetch Robotics. “There are a lot of solutions out there where they just throw a sensor on the front of an automated vehicle and call it a day. That is a poor way to do it. If a vehicle has only a single sensor, it can only detect something that interrupts a single plane.” So various sensors need to provide 360-degree detection, he added.

In addition, facilities managers should have full documentation from providers so they understand the robot’s mass capacity, center of gravity and other critical physical aspects of safe unit operation.

Item #4: Minimize loads when possible

While the autonomous mobile robots themselves may weigh 100 pounds or less, once loaded, they can weigh several thousand pounds. Though most the mobile robots will have sensors designed to slow them down as they near obstructions, using multiple robots with smaller loads is the better option, said Locus’ Leavitt. “It reduces the size and the mass of what they are carrying.”

Locus' mobile robot as a service in apparel order fulfillment.

LocusBot is helping with apparel order fulfillment.

Some facilities will use some mobile robots to move as many as 40 customer orders at a time, Glynn added. “You’re creating a monstrosity; that can weigh thousands of pounds.”

Not only are smaller loads better from a human safety perspective, it also puts less stress on the robot. Leavitt added that sometimes smaller loads are better from an efficiency perspective. For example, rather than sending out a single robot to pick up bolts in an automotive plant, Locus recommends using multiple robots for the task. Collectively, the loads aren’t heavy, but by collecting smaller amounts, the robots can deliver the parts much more quickly.

Item #5: Keep sensors, LiDAR, etc. clean

Some of the facilities, particularly the areas the robots frequent, can easily accumulate dust, dirt and other particles that can impede sensors, LiDAR, safety cameras and safety lights, as well as get into some of the moving parts, said Dale Walsh, Ricoh Service Advantage director of innovation.

mobile robot safety checklist article

Additionally, there are times a sensor or light is damaged, with a quick fix such as duct tape that keeps the robot in operation for the short term. Any of these issues may have only minor impact on the robot’s operation, but can compromise the safety of the unit.

In all these instances, facilities need to have regular, ongoing maintenance programs to clean various sensors, properly repair temporary fixes and check for any other issues (for example, a rope that becomes tangled in an axle). Walsh recommends quarterly or semi-annual maintenance, depending on the complexity and actual usage (for example 24×7, two shifts a day/six days a week, etc.). The maintenance should include full inspection of all safety and other components, lubrication and fixing any mechanical issues.

Walsh added that the periodic maintenance program should include cleaning of bar codes or other location sensors on the plant floor.

Glynn added that managers should endeavor to keep their facilities clean and orderly, with a regular maintenance schedule for the warehouses/plants to minimize the chances of a problem occurring.

Item #6: Teach safe robotic usage

Many robot users may be janitors or others who had never thought about using robots as part of their daily routine, Walsh said.

Beyond being taught safe practices, the employees need to feel safe around robots, Glynn added. So while it might be safe to have a robot moving quickly in close proximity to a human, an employee will likely feel safer if given wide clearance by a robot, which should operate at slower speeds when anywhere near humans.