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Microlocated AGVs in the flexible factory

Dec. 17, 2018

The deficiencies of legacy navigation technologies are limiting their benefits. 

Any observer of smart manufacturing knows that we are still far from realizing the full promise of

Humatics' David Mindell

productivity gains and cost savings. Most manufacturers still rely on assembly lines with origins in 19th century railroad technology.

To move beyond the limitations of legacy systems, manufacturers are looking for innovative ways to leverage autonomous guided vehicles (AGVs), or mobile robots. In fact, recent research finds that the AGV market will grow to $2.5 billion by 2027. Manufacturers and other industrial verticals will be able to take advantage of next steps on their paths to Industry 4.0, if they know which paths to take.

The growing pains of AGV navigation

AGVs are essential to the Industry 4.0 ideal of smart, flexible factories and logistics centers, but the deficiencies of legacy navigation technologies are limiting their benefits. Magnetic tape and fiducial-based systems are inflexible and damage-prone, while LiDAR systems are expensive and restricted to indoor, structured environments.

Most AGVs today navigate by following magnetic tape, which is literally stuck to a factory floor, limiting flexibility for shifting a vehicle’s route. Tape-based AGVs are difficult to maintain because the tape itself is easily damaged in industrial settings. Other AGVs (including Amazon’s warehouse bots) rely on 1990s technology of barcode stickers pasted on the floor, but they’re also inflexible. If you want to change a robot’s path, you have to move all the fiducials and remap the environment. Plus, they don’t work outdoors or in dirty or dusty environments.

Some AGVs are using newer, laser-based technology called LiDAR, which may sound familiar as it is also being rolled out in almost all semi-autonomous cars. Industrial LiDAR is relatively expensive at $4K–$5K per robot, and though LiDAR promises more flexibility compared to magnetic-tape options, it still has a vision problem. Sunlight and ramps can be showstoppers, and when LiDARs get dust or dirt on a sensor or suffer a dent or scratch on the lens (common in industrial settings) their sight becomes impaired and the precision of their location technology gets compromised.

Outdoors, some automated tugs and carriers use GPS. But the classic problems that limit the usefulness of satellite navigation for autonomous driving also afflict AGVs. GPS is imprecise and degrades in areas with walls or lots of metal objects (a good description of almost any shipping terminal or holding area). It gets confused by signal reflections.

Today’s most future-forward industrial environments are extraordinarily dynamic. For instance, in an automated port terminal, heavy cranes engage in an intricate logistical ballet with AGVs, cargo ships, and intermodal containers. Existing positioning technologies are poorly equipped for the constant changes in these settings.

The promise of microlocation

As leading global enterprises look to add AGVs to their Industry 4.0 portfolios, they want robust, precise and cost-effective positioning technology. Microlocation is a radio-frequency-based technology that synthesizes time-of-flight measurements with inertial sensors to determine the 3D location of AGVs. A microlocation system is deployed like WiFi as a factory-wide service to provide centimeter-scale positioning and motion tracking. It functions much like a local GPS, except that it works both indoors and outdoors and is robust to the multipath reflections that confuse GPS and other RF-based systems. Microlocation systems are easy to install and retrofittable to existing AGV fleets.

Flexibility is microlocation’s hallmark. Automotive suppliers are investing heavily in upgrading their current assembly-line setups. If they were to rely on tape-based AGV navigation systems, the suppliers would have to reconfigure the assembly floor every time they wanted to add a new product or update their process. It’s expensive, time-consuming, and, frankly, not very flexible.

With microlocation, suppliers can reroute AGV paths in minutes.

The blueprint for flexible-factory superiority

Microlocation improves AGV performance in three specific areas for factories and logistics centers. First, it enables effortless route changes without remapping or infrastructure adjustments. Next, it works in both indoor and outdoor environments in all weather conditions. Finally, it allows for navigation in open and constantly-changing environments where vision systems degrade.

Ten years from now, the companies that have established flexible-factory superiority will be those that energetically adopted real-time positioning systems that are truly adaptable, precise and robust.

David Mindell is the co-founder and CEO of Humatics.