An AGV (automated guided vehicle) is a driverless, battery-powered industrial vehicle that transports materials along predefined routes using a guidance system such as magnetic tape, floor markers or laser reflectors. Within robotics fundamentals, the AGV is the classic form of the mobile robot for intralogistics: it follows paths defined by engineers rather than planning its own routes, which makes its behavior highly predictable, repeatable and easy to certify.
AGVs move pallets, carts, rolls, car bodies and other loads between production cells, storage areas and shipping docks. They have been used since the 1950s, and modern fleets are coordinated by a fleet management system that assigns tasks, controls traffic at intersections and schedules charging.
How an AGV navigates and moves loads
Every AGV combines four subsystems: guidance and localization, which tells the vehicle where it is relative to its path; drive and steering, which moves it; safety sensors, which stop it before a collision; and load handling, such as forks, rollers, lift tables or tow hitches. A vehicle controller links these parts and communicates with the fleet manager over Wi-Fi.
Routes are stored as a network of segments and stations. When the fleet manager assigns a transport order, the AGV drives segment by segment, reserving each section so that two vehicles never occupy the same zone. At the destination, a fine-positioning step aligns the vehicle precisely with the conveyor, rack or machine before the load is transferred.
| Navigation method | How position is determined | Typical accuracy | Flexibility |
|---|---|---|---|
| Wire guidance | Senses a signal from a wire in the floor | High | Very low, route changes need floor work |
| Magnetic tape | Follows tape or magnets on the floor | Roughly a centimeter | Low, tape must be relaid |
| Floor codes and inertial | Reads grid markers, dead-reckons between | Millimeters to a centimeter | Medium |
| Laser reflector | Triangulates from reflectors on walls | About a centimeter or better | High, routes are changed in software |
| Natural features | Matches scans to a map of the building | One to a few centimeters | High, no infrastructure needed |
Types of AGVs and typical parameters
AGVs are classified mainly by how they carry the load. The right type depends on the load carrier, the transfer points and the required throughput.
| Type | Typical load | Typical application |
|---|---|---|
| Tugger or tow AGV | Trains of carts | Line-side supply in assembly plants |
| Unit load AGV | Single pallet or container on top deck | Transfers between conveyors |
| Forklift AGV | Pallets at floor or rack height | Warehouse storage and dock loading |
| Underride or lift AGV | Racks or carts lifted from below | Goods-to-person and kitting |
| Assembly line AGV | Product being built, such as an engine | Flexible assembly lines |
| Heavy-load AGV | Many tons, such as coils or molds | Steel, paper and machine building |
Typical indoor AGVs travel at about 1 to 2 meters per second on open paths and much slower near people or stations. Payloads range from tens of kilograms for small carts to tens of tons for heavy-load platforms. Energy comes from lead-acid or, increasingly, lithium-ion batteries, often with opportunity charging at stations during short idle periods so that vehicles can operate around the clock.
AGV compared with an autonomous mobile robot
The most important distinction is between an AGV and an autonomous mobile robot (AMR). An AGV follows fixed, engineered paths and stops when something blocks the way; an AMR plans its own path on a map and drives around obstacles. The line has blurred because many AGVs now use natural-feature navigation, but the control philosophy still differs.
| Aspect | AGV | Autonomous mobile robot |
|---|---|---|
| Path | Predefined route network | Planned dynamically on a map |
| Obstacle response | Slows and stops, waits | Replans and drives around |
| Predictability | Very high | Lower, routes vary |
| Heavy loads | Common, up to many tons | Mostly light to medium loads |
| Commissioning | Route engineering required | Mapping and zone setup |
| Best environment | Structured, repetitive flows | Changing layouts, mixed traffic |
Predictability is not a weakness. In plants where forklifts, people and automated vehicles share aisles, knowing exactly where a vehicle will drive simplifies safety assessment and makes throughput easier to calculate.
Safety standards and system integration
AGVs operate near people, so safety is designed in from the start. Safety laser scanners monitor protective fields that grow with speed and switch with direction; if a person enters the field, the vehicle slows or performs a safety-rated stop. Bumpers, emergency stop buttons, warning lights and acoustic signals complete the system. In Europe, driverless industrial trucks are commonly assessed against ISO 3691-4, and in North America the ANSI/ITSDF B56.5 standard is widely referenced.
Integration matters as much as the vehicle. The fleet manager connects to the warehouse management or manufacturing execution system, to automatic doors, elevators and conveyors. In multi-vendor installations, the VDA 5050 interface defines a common communication protocol between vehicles and a master control, which reduces dependence on one supplier.
Common pitfalls in AGV projects
Most AGV problems come from the environment and the process rather than from the vehicles themselves.
- Poor floor condition: cracks, slopes and joints affect wheels, guidance and load stability.
- Blocked paths: pallets left in aisles stop AGVs repeatedly, because they wait instead of driving around.
- Underestimated traffic: intersections and narrow aisles become bottlenecks when the fleet grows.
- Wi-Fi gaps: dead zones delay orders and can stop vehicles at critical points.
- Inconsistent load carriers: damaged or nonstandard pallets cause failed pickups at stations.
A simulation of the material flow before purchase, with realistic order peaks and charging time, is the most reliable way to size the fleet and to find bottlenecks while the layout can still be changed cheaply.
In plain words
An AGV is a driverless cart or forklift that follows invisible rails through a factory or warehouse. The rails might be a strip of tape on the floor, small codes, or reflectors on the walls that the vehicle uses to find its position.
Because it always takes the same routes, everyone knows where it will go. If something is in the way, it simply stops and waits instead of improvising, which makes it safe and dependable for moving heavy goods all day.
A real-world example
An automotive supplier assembles seats on two production lines and needs a steady flow of parts from a central storage area 150 meters away. The company installs six tugger AGVs, each pulling a train of three carts, on a fixed loop with laser reflector navigation and opportunity charging at the loading station.
The fleet manager receives part requests from the manufacturing execution system and dispatches trains every few minutes. Safety scanners slow the vehicles in the two aisles shared with pedestrians. Manual forklift trips to the lines drop to a few exceptions per shift, line stops caused by missing parts become rare, and the predictable delivery rhythm lets the plant reduce the buffer stock kept at each workstation.