Ever wonder how AGVs “know” where to go?
Some follow tape or wires on the floor. Others use lasers, QR codes, or onboard sensors to scan their surroundings and build a live map. These systems are what guide an AGV through your warehouse, helping it reach its destination, avoid collisions, and stay on schedule.
This is called AGV navigation, and it plays a big role in how flexible, scalable, and efficient your warehouse automation will be.
In this article, we’ll cover:
- What AGV navigation actually means (in plain English)
- 6 common navigation systems: how they work, pros and cons
- Which systems are easiest to reconfigure or expand
- How to choose the right fit for your facility and budget
Magnetic Tape AGVs
Magnetic tape automated guided vehicles (AGVs) follow a path marked by magnetic tape on the floor.
Operators install this tape in preplanned routes. The AGV then navigates this path without deviation. This makes for a very predictable route.
However, like all systems, it has its pros and cons.
Pros
- Economical. These models have a lower investment cost than many other AGV navigation systems and require little IT infrastructure.
- Simple reconfiguration. Tape marks the AGV's path. To alter or add routes, you simply add, subtract, or move tape. This allows you to reconfigure more quickly than other line-following AGVs.
- Repetition accuracy. These AGVs are great for high-volume, repetitive routes where precision is vital, such as narrow aisles.
Cons
- Low traffic. While magnetic tape is durable, it is susceptible to damage from forklift traffic or other machinery.
- Limited scaling. These navigation systems use a finite amount of tape, creating a finite space for AGVs to travel. Consequently, the space limits the number of AGVs that can fit. This can make scaling more difficult.
- No auto-avoidance. While these AGVs will auto-stop for obstacles, they cannot navigate around objects in their path, thus halting productivity.
Inductive Wire AGVs
Similar to magnetic tape AGVs, inductive wire AGVs follow a path marked by wire embedded in the facility floor.
Pros
- Durable. Because the route is embedded in the floor, it is not susceptible to damage from heavy traffic.
- Precision. Because their routes are explicitly defined, these AGVs are very precise. They follow their routes with minimal deviation. This accuracy makes them great for many manufacturing or material handling applications.
- No environmental interference. Since these models use radio signals to recognize the wire, they are less vulnerable to environmental interference such as smoke, steam, or dust.
Cons
- Limited reconfiguration. As the wire is in the floor, reconfiguration involves the time and expense of removing and reinstalling new wire.
- No auto-avoidance. Like magnetic tape AGVs, inductive wire AGVs will auto-stop. However, they cannot navigate around objects in their path. Consequently, their routes must be free of obstructions.
- Not suitable for all areas. All route areas must accommodate the induction wire, making slopes and uneven terrain challenging.
Spot Navigation AGVs
Spot navigation AGVs use an installed grid of location markers to determine their position within your facility.
This grid installs on or in the floor. The markers can be magnetic or QR codes. Whichever the style, the AGV treats these like trail markers, using each to orient itself and navigate to the next.
These varieties offer some of the benefits of line navigation mixed with some benefits of natural navigation.
Pros
- Fixed installation. Unlike magnetic tape or induction wire models, altering paths does not require moving the installed tags.
- Accurate positioning. Line-guided systems like magnetic tape are the most accurate for position. However, spot navigation is the most accurate of the free navigation systems. It can be accurate up to 0.1 inches.
- Reduced maintenance costs. Magnetic tags require almost no maintenance, while QR codes only need periodic replacement.
Cons
- Installation. Installation requires careful placement of markers, making it more complicated than some other methods.
- Programming-heavy. Adding new paths or destinations requires more IT support than line-guided systems.
Laser Navigation AGVs
Laser-guided vehicles use laser triangulation to chart their position in your facility.
They constantly scan the environment. The sensors note the distance and angle when the laser hits a specially mounted reflector. By hitting three of these markers, the vehicle can calculate its relative position in your warehouse.
These are one of the most popular AGV navigation methods.
Pros
- Reliable. Laser triangulation provides highly accurate and reliable navigation without guide wires or tape.
- Easy fleet management. A central server controls all the AGVs. Centralized control makes fleet management easy. Consequently, controlling multiple AGVs remains fast and efficient.
- Combinable. This AGV navigation type combines well with other navigation options. One model can use laser navigation alongside GPS and/or magnetic tape. This allows the unit to move between buildings while effortlessly navigating narrow aisles.
- Simple rerouting. So long as you don’t need to install new reflectors, creating or changing paths is as simple as updating the AGV navigation software.
Cons
- Infrastructure changes. Installing, or in some cases updating, routes includes adding or repositioning reflectors. This can be time-consuming and expensive. The reflector layout has to be carefully planned and validated before the AGVs can enter service.
- Environmental disruption. Environmental factors such as smoke, airborne debris, or reflections can interfere with navigational accuracy.
LIDAR AGVs
LIDAR-guided AGVs, sometimes called SLAM navigation AGVs, are a variety of natural or contour-guided navigation.
These models use onboard LIDAR to actively scan the environment. The lasers sense thousands of data points and use that information to create a facility map. The AGV’s computer then compares that to a theoretical map and calculates its position based on that comparison.
LIDAR AGVs are a relatively new technology that will likely improve in the future.
Pros
- Efficient fleet management. All paths are virtual, making large-scale modifications as simple as a few programming adjustments.
- No installation. LIDAR models require no tape, wire, or tags. They use the environment as their position reference. Consequently, they require only a few reflective stickers to install. Unlike the reflectors used in laser navigation AGVs, there is also no need to validate the position of these stickers.
- Obstacle avoidance. These models can navigate around obstacles. By creating an active map of your facility, LIDAR navigation allows the vehicle to adjust the route as needed. Intelligent systems like this keep production flowing even in high-traffic areas.
- Easy to scale. Since all paths are virtual, you can add new units by uploading existing programming.
Cons
- Environmental disturbances. LIDAR-guided vehicles can have difficulty navigating chaotic, ever-changing environments. Reduced access to fixed reference points results in reduced positioning accuracy.
- Heavy programming. Because there are no physical guide points, SLAM navigation AGVs must rely entirely on programming. This puts a heavy burden on the initial programming and requires consistent IT support. Consequently, they are one of the most programming-heavy AGVs.
- Lower accuracy. Without fixed tags, natural navigation AGVs can be less precise in their positioning than other systems.
Combined Navigation AGVs
Individual AGVs are not necessarily limited to a single navigation system.
Kollmorgen AGVs are an example of this principle. By combining multiple technologies, such as LIDAR and magnetic tape, they create an AGV that has the benefits of both. Most of the above navigation systems can be combined. Still, natural navigation is most often combined with a more precise navigation method for traversing narrow areas.
Combined navigation AGVs are an excellent way to get the best of all worlds out of your AGV fleet.
You Don’t Need to Navigate This Alone
AGVs can’t move without a navigation system. And when you’re leading a warehouse through change, you might feel the same way.
That’s where we come in.
Whether you need help mapping out your automation plan or just want to see what’s possible, we’ll guide you every step of the way—with real insight, not generic advice.
Choose the next step that fits you:
Let’s Find the Right Path Forward
Arkansas - Jonesboro
Alabama - Dothan, Irondale, Mobile, and Montgomery
Mississippi - Richland and Tupelo
Tennessee - Jackson and Memphis
Further Reading
AGVs 101: Your Guide To Autonomous Warehouse Vehicles
Product Review: Bastian Solutions ML2 AV
Answers to Your Most Frequently Asked Questions about AGV