What guides an AGV?
Various navigation systems can be selected depending on frequency of transportation, existing environment, accuracy requirements, cost of installation, future expansion and technology preferences. Some of the most common navigation methods are described here.
Types of AGV Navigation Systems
Laser navigation
Laser navigation is one of the most common navigation methods for AGVs. A rotating laser beam is mounted on the AGV to detect reflectors placed in the building. The AGV’s position is calculated in real-time using the angle and distance between the reflectors. Laser navigation systems often rely on predefined maps of the environment and use laser sensors to detect obstacles.
Laser navigation offers freedom to rather easily change the driving route, high precision and reliability.
AGV Navigation via Natural Feature Recognition
Natural features recognition or contour navigation uses sensors to recognize and navigate based on specific objects in the existing environment. This navigation method is accurate when objects in the driving path do not change frequently.
Magnetic spot navigation
Magnetic spot navigation uses magnetic discs embedded in the floor. This method is durable and a good complement to other navigation methods.
Magnetic tape or inductive wire navigation
Magnetic tape or inductive wire navigation means that the AGV follows embedded magnetic tape on or wires in the floor. This method is applicable when precise positioning is critical, and the layout is planned to remain unchanged.
Barcode navigation
Barcode navigation uses position markers on the floor to provide the AGVs with location information. A laser scanner or camera is typically used to read the barcode data as the AGV moves.
Multi- or hybrid navigation
Multi-navigation or hybrid navigation is a combination of navigation methods used when extended precision and reliability is required.
RFID navigation
RFID navigation (Radio-Frequency Identification) consists of RFID tags in the building and RFID readers in the AGV. While driving the AGV reads the RFID tags and defines its position and gets navigation instructions.
Inertial navigation
Inertial navigation means that the AGV uses accelerometers, gyroscopes, and other inertial sensors to track its movements and calculate its position. This method may require periodic recalibration.
Simultaneous localization and mapping
SLAM (Simultaneous Localization and Mapping) means that the AGV/AMR creates a map and routes while driving in the layout. Since SLAM is not an actual navigation method compared to the above mentioned, it often uses natural feature as navigation.