Contributing Editor Toby Gooley is a writer and editor specializing in supply chain, logistics, and material handling, and a lecturer at MIT's Center for Transportation & Logistics. She previously was Senior Editor at DC VELOCITY and Editor of DCV's sister publication, CSCMP's Supply Chain Quarterly. Prior to joining AGiLE Business Media in 2007, she spent 20 years at Logistics Management magazine as Managing Editor and Senior Editor covering international trade and transportation. Prior to that she was an export traffic manager for 10 years. She holds a B.A. in Asian Studies from Cornell University.
In the early days of automated guided vehicles (AGVs), there typically was just one way the computer-controlled autonomous load carriers could find their way around the manufacturing plants where they initially were used: by following wires embedded in the floor. While revolutionary back then—load carriers could for the first time trundle around a facility without a human operator—that method was simply the first stage of a technological evolution that is not only changing the equipment itself but is also stretching the boundaries of where AGVs can go and how they're used.
In recent years, the number of navigation methods used by AGVs as they pick up, carry, and drop off their loads in factories, warehouses, and distribution centers has multiplied. But AGV manufacturers aren't done yet; they continue to tinker with existing guidance technologies and develop new ones. What follows is a brief overview of some of the navigation technologies in use today, along with a preview of what AGV users can expect in the future.
THE TRADITIONALISTS
Wires (also known as inductive guidance) and another early guidance method, magnetic tape, remain popular options, particularly for small and medium-sized operations, in part because they are relatively inexpensive and can offer a quick payback. With wire guidance, a continuous wire path is embedded in the floor. Antennas on the vehicle detect a radio signal from the wire, and encoders on the wheels calculate the distance traveled.
Magnetic tape, which also requires a continuous path, is attached to the floor with an adhesive and may require a protective coating. A sensor on the underside of the vehicle detects the magnetic field, leading the vehicle to follow the tape.
A variation on this theme is a magnetic grid, which uses magnets affixed to or embedded in the floor in a grid pattern. An onboard sensor detects the magnets, and the reference points are stored in the AGV's memory as X and Y coordinates. A gyroscope on the vehicle measures and maintains direction, and a wheel encoder calculates the distance traveled. In a magnetic grid, the guide paths can easily be changed.
Still another option is inertial navigation, where transponders are embedded in the floor. An onboard gyroscope detects slight directional changes and corrects the vehicle's travel path to keep it on course. Providers such as Daifuku's Jervis B. Webb division note that inertial guidance vehicles can operate in almost any environment, including tight aisles and extreme temperatures.
NEWER KIDS ON THE BLOCK
Who makes automated guided vehicles?
Just a few years ago, only a handful of companies were designing, making, and selling automated guided vehicles (AGVs). Today, there are quite a number of vendors and types of automated vehicles, including load carriers, load lifters, driverless forklifts, tuggers, low-profile carriers, and automated carts.
Interested in checking them out? This is by no means a comprehensive list, but the following are some of the AGV providers we've run across:
More recently developed guidance technologies rely on various ways of measuring distances, mapping, storing data, and decision making for navigation. All provide a degree of flexibility that earlier technologies couldn't offer—probably the biggest reason for the inroads AGVs are now making in warehouses and DCs. They all make it easy and fast to reprogram routes, require no (or, in the case of laser guidance, minimal) additional infrastructure, and can navigate on their own around obstacles.
Laser-guided vehicles map and store the facility layout in the vehicle's computer. A laser transmitter/receiver mounted on the vehicle detects reflective strips located at fixed reference points and measures both its distance and angle relative to the reflectors. By triangulating two reference points, the AGV can determine and update its location. AGV maker JBT Corp., for example, says its patented laser-guidance technology uses an eye-safe laser scanner that "strobes" the operating area and updates its position several times per second, resulting in highly accurate positioning. Transbotics, another AGV developer, touts laser guidance for its accuracy, reliability, security, dynamic traffic management, and short installation times.
Natural-feature guidance is a relative newcomer to the AGV scene. AGVs equipped with this type of technology record and store reference images as a map of the operating area. They then navigate by calculating their position relative to existing features—walls, racks, I-beams, doorways, stacks of pallets, and so forth—following the most efficient path, just as a human being would when walking through the facility. A major advantage of this technology is that it requires no markers, transponders, or reflectors. In addition, guide paths can easily be changed by retraining the AGV or by drawing a new route on the map. Sweden's Kollmorgen was one of the first to develop this capability, and others have followed. AutoGuide, for example, is about to introduce a low-profile AGV that measures the locations of natural features to use as reference points as it moves along its route, says Sarah Carlson, vice president of marketing and business development.
In somewhat similar fashion, the Otto Motors division of Clearpath Robotics uses simultaneous localization and mapping (SLAM) technology for its self-driving material handling vehicles—the same underlying technology used in self-driving highway vehicles, says Simon Drexler, director of industrial solutions. Otto uses laser-based "lidar" (from "light" and "radar") scanning to gather data and construct a highly detailed map of the facility floor. Once it has the reference map, it can navigate any route without a defined path or line. The vehicle is intelligent enough to plan and follow its own route, Drexler says. Once the reference map is in place, users can drag and drop location pins on the map to instruct the vehicle where to stop for pickups and dropoffs.
Vehicles that use vision-based navigation come closest to processing visual information the way a human being does. AGVs built by Seegrid, which pioneered this technology, use five pairs of stereo cameras to record the surrounding environment as an operator "trains" them by walking them through their route. The cameras take two images simultaneously, achieving binocular vision with depth perception that's similar to a human being's. This information is used to create a three-dimensional map of the surroundings every few centimeters; the images are then tied together to create a route, explains Jeff Christensen, Seegrid's vice president of products. The AGVs replay the route from their memory and follow it precisely. Changing the route is a simple matter of taking them on another "walk" with an operator.
While each navigation method has its advantages, each has some drawbacks, too. For wire guidance, the principal drawback is that paths are fixed and cannot be easily changed, since they require cutting into the floor. Magnetic tape paths are also fixed but can be changed with comparatively little time and expense. And magnetic grids can be expanded without making major alterations to the facility, though extensive layouts can get complicated.
The more technologically complex navigation systems also have some constraints. Vision-guided AGVs, for instance, need a certain level of ambient light, and their cameras and lenses aren't suited for cold environments. As with human vision, the farther away an object is, the harder it is to judge that distance. Laser and lidar users praise their accuracy, but if lasers from two vehicles point at each other, they can in effect blind each other's sensors, a phenomenon known as dazzling interference, Christensen says. Similarly, bright sunlight has been known to interrupt the images and compromise data gathering in natural-feature and vision guidance systems, Carlson says. Plus, natural-feature technology would be ineffective in environments where there are frequent changes or few permanent features or structures to navigate off of, she adds.
BLAZING NEW TRAILS
Can AGVs get any more sophisticated than they already are? The vendors we spoke with for this story believe that more advances in navigation technology are just over the horizon. For example, innovations in image-sensing technology for consumer applications will benefit AGV design, says Seegrid's Christensen. The availability of more-sensitive image sensors that provide exceptionally high-quality images in less-than-ideal conditions continues to grow. His company's vehicles, for instance, will soon be able to take high-resolution pictures in lower light because of such advances.
New developments in navigation are one reason AGVs are moving more deeply into warehousing, distribution, and supply chain applications, AutoGuide's Carlson says. She also predicts that navigation systems that allow users to control a small fleet of AGVs through an app on a tablet, mobile phone, or laptop without a large-scale traffic management software installation will make these vehicles affordable and feasible for smaller companies.
The new navigation technologies will help customers participate in and take advantage of Industry 4.0, the "fourth industrial revolution," characterized by the acquisition, analysis, and consumption of real-time operational data, says Drexler of Clearpath Robotics. "That's where I see the industry going—moving more away from the focus on hard goods and more toward the utilization of real-time data."
Advances in autonomous cars and trucks are likely to influence material handling AGVs in the future, all agree. "AGVs have been around a lot longer, but autonomous cars are a really big story in a much bigger sphere than warehousing, so there will continue to be a lot more discoveries and development in that area," Christensen says. "[Automakers] can learn something from autonomous industrial vehicles, and we can learn some things from what they're doing."
Drexler, for one, believes AGVs will have an edge over autonomous highway vehicles. "We believe the adoption rate for self-driving vehicles will accelerate faster indoors than outdoors," he says. Otto Motors, he adds, is currently on track to surpass Google's self-driving car in the number of autonomous miles driven by the end of next year.
Related story: Starting over. Read about how Calsonic Kansei North America eliminated local drayage, built a brand-new DC, and installed custom-designed automatic guided carts. The award-winning project achieved ROI well ahead of schedule.
Online merchants should consider seven key factors about American consumers in order to optimize their sales and operations this holiday season, according to a report from DHL eCommerce.
First, many of the most powerful sales platforms are marketplaces. With nearly universal appeal, 99% of U.S. shoppers buy from marketplaces, ranked in popularity from Amazon (92%) to Walmart (68%), eBay (47%), Temu (32%), Etsy (28%), and Shein (21%).
Second, they use them often, with 61% of American shoppers buying online at least once a week. Among the most popular items are online clothing and footwear (63%), followed by consumer electronics (33%) and health supplements (30%).
Third, delivery is a crucial aspect of making the sale. Fully 94% of U.S. shoppers say delivery options influence where they shop online, and 45% of consumers abandon their baskets if their preferred delivery option is not offered.
That finding meshes with another report released this week, as a white paper from FedEx Corp. and Morning Consult said that 75% of consumers prioritize free shipping over fast shipping. Over half of those surveyed (57%) prioritize free shipping when making an online purchase, even more than finding the best prices (54%). In fact, 81% of shoppers are willing to increase their spending to meet a retailer’s free shipping threshold, FedEx said.
In additional findings from DHL, the Weston, Florida-based company found:
43% of Americans have an online shopping subscription, with pet food subscriptions being particularly popular (44% compared to 25% globally). Social Media Influence:
61% of shoppers use social media for shopping inspiration, and 26% have made a purchase directly on a social platform.
37% of Americans buy from online retailers in other countries, with 70% doing so at least once a month. Of the 49% of Americans who buy from abroad, most shop from China (64%), followed by the U.K. (29%), France (23%), Canada (15%), and Germany (13%).
While 58% of shoppers say sustainability is important, they are not necessarily willing to pay more for sustainable delivery options.
Schneider says its FreightPower platform now offers owner-operators significantly more access to Schneider’s range of freight options. That can help drivers to generate revenue and strengthen their business through: increased access to freight, high drop and hook rates of over 95% of loads, and a trip planning feature that calculates road miles.
“Collaborating with owner-operators is an important component in the success of our business and the reliable service we can provide customers, which is why the network has grown tremendously in the last 25 years,” Schneider Senior Vice President and General Manager of Truckload and Mexico John Bozec said in a release. "We want to invest in tools that support owner-operators in running and growing their businesses. With Schneider FreightPower, they gain access to better load management, increasing their productivity and revenue potential.”
Economic activity in the logistics industry continued its expansion streak in October, growing for the 11th straight month and reaching its highest level in two years, according to the most recent Logistics Managers’ Index report (LMI), released this week.
The LMI registered 58.9, up from 58.6 in September, and continued a run of moderate growth that began late in 2023. The LMI is a monthly measure of business activity across warehousing and transportation markets. A reading above 50 indicates expansion, and a reading below 50 indicates contraction.
October’s reading showed the fastest rate of expansion in the overall index since September of 2022, when the index hit 61.4. The results show that the industry is continuing its steady recovery from the volatility and sluggish freight market conditions that plagued the sector just after the Covid-19 pandemic, according to the LMI researchers.
“The big takeaway is that we’re continuing the slow, steady recovery,” said LMI researcher Zac Rogers, associate professor of supply chain management at Colorado State University. “I think, ultimately, it’s better to have the slow and steady recovery because it is more sustainable.”
All eight of the LMI’s indices grew during the month, with the Transportation Prices index showing the most growth, at nearly 6 points higher than September, reflecting increased activity across transportation markets. Transportation capacity expanded slightly during the month, remaining just above the 50-point threshold. Rogers said more capacity will enter the market if prices continue to rise, citing idle capacity across the market due to overbuilding during the pandemic years.
“Normally we don’t have this much slack in the market,” he said. “We overbuilt in 2021, so there’s more slack available to soak up this additional demand.”
The LMI is a monthly survey of logistics managers from across the country. It tracks industry growth overall and across eight areas: inventory levels and costs; warehousing capacity, utilization, and prices; and transportation capacity, utilization, and prices. The report is released monthly by researchers from Arizona State University, Colorado State University, Rochester Institute of Technology, Rutgers University, and the University of Nevada, Reno, in conjunction with the Council of Supply Chain Management Professionals (CSCMP).
The port worker strike that began yesterday on Canada’s west coast could cost that country $765 million a day in lost trade, according to the ALPS Marine analysis by Russell Group, a British data and analytics company.
Specifically, the labor strike at the ports of Vancouver, Prince Rupert, and Fraser-Surrey will hurt the commodities of furniture, metal products, meat products, aluminum, and clothing. But since the strike action is focused on stopping containers and general cargo, it will not slow operations in grain vessels or cruise ships, the firm said.
“The Canadian port strike is a microcosm of many of the issues that are impacting Western economies today; protection against automation, better work-life balance, and a cost-of-living crisis,” Russell Group Managing Director Suki Basi said in a release. “Taken together, these pressures are creating a cocktail of connected risk for countries, business, individuals and entire sectors such as marine insurance, which help to mitigate cargo exposures.”
The strike is also sending ripples through neighboring U.S. ports, which are hustling to absorb the diverted cargo, according to David Kamran, assistant vice president for Moody’s Ratings.
“The recurrence of strikes at Canadian seaports is positive for U.S. ports that may gain cargo throughput, depending on the strike duration,” Kamran said in a statement. “The current dispute at Vancouver is another example of the resistance of port unions to automation and the social risk involved with implementing these technologies. Persistent disruption in Canadian port access would strengthen the competitive position of US West Coast ports over the medium-term, as shippers seek to diversify cargo away from unreliable gateways.”
The strike is also affected rail movements, according to ocean cargo carrier Maersk. CN has stopped all international intermodal shipments bound for the west coast ports of Prince Rupert, Robbank, Centerm, Vanterm, and Fraser Surrey Docks. And CPKC has stopped acceptance of all export loads and pre-billed empties destined for Vancouver ports.
Connected with the turmoil, Maersk has suspended its import and export carrier demurrage and detention clock for most affected operations. The ultimate duration of the strike is unknown, but the situation is “rapidly evolving” as talks continue between the Longshore Workers Union (ILWU 514) and the British Columbia Maritime Employers Association (BCMEA), Maersk said.
Terms of the acquisition were not disclosed, but Mode Global said it will now assume Jillamy's comprehensive logistics and freight management solutions, while Jillamy's warehousing, packaging and fulfillment services remain unchanged. Under the agreement, Mode Global will gain more than 200 employees and add facilities in Pennsylvania, Arizona, Florida, Texas, Illinois, South Carolina, Maryland, and Ontario to its existing national footprint.
Chalfont, Pennsylvania-based Jillamy calls itself a 3PL provider with expertise in international freight, intermodal, less than truckload (LTL), consolidation, over the road truckload, partials, expedited, and air freight.
"We are excited to welcome the Jillamy freight team into the Mode Global family," Lance Malesh, Mode’s president and CEO, said in a release. "This acquisition represents a significant step forward in our growth strategy and aligns perfectly with Mode's strategic vision to expand our footprint, ensuring we remain at the forefront of the logistics industry. Joining forces with Jillamy enhances our service portfolio and provides our clients with more comprehensive and efficient logistics solutions."