An autonomous mobile robot (AMR) is a wheeled or legged robot that moves through its environment and plans its own path using onboard sensors, maps and computing, without physical guides such as floor wires, magnetic tape or reflectors. In robotics fundamentals, the AMR is the main example of a mobile robot that combines perception, localization, planning and control in one machine.
AMRs are most common in warehouses, factories, hospitals and retail stores, where they carry goods, tow carts or inspect facilities. Their defining capability is dynamic rerouting: when a person or pallet blocks the aisle, an AMR calculates a new path instead of stopping and waiting.
How an autonomous mobile robot navigates
An AMR runs a continuous sense-plan-act loop. Sensors measure the surroundings, a localization module estimates the robot’s pose on a map, a planner chooses a route to the goal and a controller converts that route into wheel speeds. The loop typically repeats 10 to 50 times per second.
Most AMRs build their map with SLAM (simultaneous localization and mapping) during commissioning, by driving the robot through the site once. In daily operation they localize against that map by matching 2D LiDAR scans or camera features, often fused with wheel encoders and an IMU. Planning is split into a global planner, which finds a route across the map, and a local planner, which avoids moving obstacles within a few meters.
| Subsystem | Typical components | Function |
|---|---|---|
| Perception | 2D or 3D LiDAR, depth cameras, ultrasonic sensors | Detect obstacles and features |
| Localization | Scan matching, encoders, IMU | Estimate position and heading |
| Planning | Global and local planners | Choose and adjust the route |
| Control and drive | Motor drivers, differential or omnidirectional base | Execute motion smoothly |
| Safety | Safety-rated scanners, bumpers, emergency stops | Slow or stop near people |
| Fleet interface | Wi-Fi, fleet manager software | Receive tasks and share traffic |
AMR compared with AGV and other mobile robots
The AMR is often confused with the automated guided vehicle (AGV). An AGV follows predefined paths marked by tape, wires, magnets or reflectors and stops when an obstacle blocks the way. An AMR navigates freely within a mapped area and replans around obstacles. The distinction is about navigation autonomy, not about size or payload.
| Robot type | Navigation | Response to obstacles | Typical use |
|---|---|---|---|
| AMR | Map-based, free paths | Replans around them | Flexible intralogistics |
| AGV | Fixed guides or routes | Stops and waits | Repetitive heavy transport |
| Service robot | Often AMR-based | Replans, interacts with people | Cleaning, delivery, reception |
| Quadruped robot | Legged, map and terrain based | Steps over or around | Inspection on rough terrain |
| Drone | Three-dimensional flight | Avoids in the air | Inspection and inventory scans |
Many vendors now sell hybrid machines: forklifts and tuggers that use natural-feature navigation like an AMR but restrict themselves to defined lanes like an AGV, because fixed lanes simplify traffic rules and safety assessments.
Key parameters when specifying an AMR
Specifications vary greatly by application. Small delivery units carry tens of kilograms, while heavy-duty platforms carry one tonne or more. Speed in shared spaces is deliberately modest, commonly 1 to 2 meters per second, and is reduced automatically near people.
| Parameter | Typical range | What it affects |
|---|---|---|
| Payload | About 50 kg to over 1,000 kg | Which loads and carts it can move |
| Maximum speed | About 1 to 2 m/s | Throughput and safety zone size |
| Positioning accuracy | About ±10 mm to ±50 mm | Docking at stations and racks |
| Runtime per charge | Often 8 to 16 hours | Fleet size and charging plan |
| Minimum aisle width | Robot width plus safety margin | Where the robot can operate |
| Floor tolerance | Small steps and gaps only | Suitability of the building |
Safety, standards and fleet operation
Because AMRs share space with people, functional safety is central. Safety-rated laser scanners define protective and warning fields that grow with speed, and the robot slows or stops when a field is violated. Industrial AMRs are designed against standards such as ISO 3691-4 for driverless industrial trucks and the North American ANSI/RIA R15.08 series for industrial mobile robots.
Real deployments use fleets, coordinated by a fleet manager that assigns tasks, manages traffic at intersections, schedules charging and integrates with warehouse or manufacturing systems. Fleet performance usually depends more on traffic management and task allocation than on the speed of individual robots.
Mixed fleets from several vendors raise an interoperability problem, because each vendor traditionally ships its own fleet manager. Interface standards such as VDA 5050 and the MassRobotics interoperability standard define common messages for orders, states and traffic, so one master control system can coordinate robots from different manufacturers. Support for such interfaces is worth checking early in procurement, since retrofitting integration later is costly.
Limitations and deployment pitfalls
- Changing environments: frequently moved pallets or racks can degrade localization unless the map is updated.
- Reflective and transparent surfaces: glass walls, mirrors and shiny wrap confuse LiDAR and cameras.
- Wireless coverage gaps: robots lose tasks or traffic coordination in areas with poor Wi-Fi.
- Underestimated congestion: too many robots in narrow aisles block each other and reduce throughput.
- Floor conditions: ramps, thresholds and wet floors limit traction and positioning accuracy.
A site survey and simulation before purchase, together with a pilot zone, reveal most of these issues while changes are still cheap.
A plain-language summary
An autonomous mobile robot is like a delivery cart that knows the building. It carries a map in its memory, uses sensors to see what is around it and finds its own way from one place to another.
Older factory vehicles followed a line painted or taped on the floor, like a train on rails. An AMR is more like a careful driver: if a person or a box is in the way, it slows down, steers around and continues. That flexibility is why companies can add AMRs without rebuilding their floors.
An example from practice
A hospital moves medication, lab samples and linen between departments on several floors. Porters spent much of their shifts walking the same routes, and urgent samples sometimes waited for a free person. Managers wanted transport that runs around the clock without adding staff on night shifts.
The hospital deploys a small fleet of AMRs with lockable compartments. The robots are mapped during a quiet weekend, use elevators through an integration with the building system and drive at reduced speed in patient corridors. A fleet manager prioritizes laboratory runs over linen deliveries. Porters now handle tasks that need people, and sample delivery times become predictable, with every trip logged for traceability.