Once a funny and futuristic idea seen in Jetson cartoons, today automatic guided vehicles (AGV’s) are a reality and even considered common equipment in plants and distribution centers around the globe.
These unmanned vehicles have built a reputation for safety and efficiency. Businesses looking for new ways to increase productivity in manufacturing and distribution facilities are looking to this emerging technology to increase profits. The technology used in AGV’s seeks to decrease the amount of human labor a company must use, while increasing the level of safety in environments where mobile equipment is mixed with pedestrian employees.
Automatic Guided Vehicle Safety
According to the Occupational Safety and Health Administration, someone gets killed every three days in a manned forklift accident. There are about 110,000 forklift accidents each year and over 80 percent of them involve a pedestrian. Those injuries cost employees money – worker’s compensation, medical costs, lost time on the job and lawsuits. Accidents involving forklifts are usually caused by someone walking or working near forklifts and not seen by the forklift operator.
Although AGVs are not immune to safety incidents, they are designed to be safer than manned mobile equipment. The technology built into AGVs is meant to offer safety features that are better able to curtail accidents than human judgement.
Roger Bostleman, project manager in the Intelligent Systems Division at National Institute of Standards and Technology says the AGVs have onboard technology that can mitigate the risk to pedestrian employees. Bostleman, an industry expert, said some of the safety capabilities AGVs offer include three-dimensional sensors and algorithms that provide industrial vehicles with information about potential collisions.
Bostelman said the NIST is working with industry engineers and researchers to provide technical foundations to strengthen and expand safety standards. “NIST conducts experiments that provide data to support the development of test methods that augment safety standards for industrial vehicles,” he said.
The safety standard Bostelman refers to is ANSI B56.5. These protocols were developed under the American National Standards Institute (ANSI) canvass method and approved by ANSI in 2012. The standard is a guide to safety requirements for system suppliers, manufacturers, purchasers and users in the design, construction, application, operation and maintenance of unmanned guided industrial vehicles and automated functions of manned industrial vehicles.
Pedestrian Floor Markings: Why They’re Important
The safety technology being developed for AGVs is exciting and innovative. But Bostleman points out that floor markings are used quite often with AGVs. “Painted or tape, they define where pedestrians are and are not allowed to be. Vehicles are pre-programmed to follow paths. As such, the vehicles don’t typically cross into pedestrian paths. However, pedestrians may not know where the paths are, and are typically the safest when they stay behind or within the indicated lines,” Bostleman says.
InSite Solutions Director Cliff Lowe believes these pedestrian lines should be marked with an adhesive tape, like his company’s Superior Mark™ floor tape, rather than painting. “One of the reasons companies bring in these AGVs is flexibility. You could design a turn-key system or piece of equipment and build it in your plant, or purchase AGVs to get the job done. The AGVs can be rerouted as your business expands or changes. By putting down your floor marking system in industrial grade adhesive, you can easily pull it up and put it back down where you need it,” Lowe says. “It’s a lot faster than removing paint from concrete, preparing the concrete for paint, applying paint and letting it cure for three days.”
Better communication about AGV accidents, especially fatal accidents, could benefit pedestrian employee safety in settings where AGVs are used. In August of 2012, a fatal accident at a Kraft Foods plant killed Kraft employee James P. Gentilello Jr. While there are many published reports detailing when the accident occurred and the subsequent investigation, there is no final report on what caused the accident and how it could be avoided in the future.
NIST (thanks to much of the work overseen by Bostleman) has made several important amendments and improvements to the B56.5 standard over the past ten years, through research and investigation.
However, the standard still includes an exception for obstacles suddenly appearing at less than the minimum AGV stopping distance. The exception states: “Although the vehicle braking system may perform correctly as intended, it cannot be expected to function properly if an object suddenly appears in its path inside of the designed safe stopping distance. Examples include, but are not limited to, an object falling from overhead or a pedestrian stepping into the path of a vehicle at the last instant.”
As more automatic guided vehicles are used in manufacturing, distribution and logistics operations, the need for keeping pedestrian employees safe is paramount. The on-board safety technology in AGVs continues to change and improve. With advanced safety technology and equipment, excellent training, and visual cues like signs and floor markings, employee injuries in mobile equipment related accidents could shrink dramatically in the near future.