Arthur Barrett invented automated guided vehicles (AGVs) back in 1954. Since then, AGVs have advanced tremendously, in the process revolutionizing material handling and transport. We review what AGVs are, how they function, the types of navigations systems, and present five questions you should ask when choosing an AGV or AMR.
Types of AGVs
Automated Guided Carts (AGCs) or under rides
AGCs are mobile platform robots for safe and efficient transportation that engage carts, trollies, or shelves underneath using a lifting device or a pin hook. Because the load remains above or on the AGC, they are often referred to as under rides. AGCs are the most affordable type of AGVs, ranging from around $15,000 (for a 1-ton payload) to $25,000 (with natural navigation).
Forklift AGVs
An automated pallet jack is an example of a forklift AGV, and it is designed to transport palletized loads in manufacturing facilities. Forklift AGVs can be employed in floor-to-floor operations and can typically fulfill lifting requirements up to 2 meters high. Some automated forklift trucks are more versatile in nature, and they can be configured to handle heavy payloads (up to 4 tons) or high stocking operations (around 8 meters high).
Other types of forklift AGVs include reaching trucks and Very Narrow Aisle (VNA) trucks, both of which are designed to operate in narrow aisles while performing high lifting loading operations. The only difference between the two is that the former is smaller and faster than the latter.
Unit load vehicles
Unit load AGVs are self-driving vehicles furnished with roll conveyors that can navigate swiftly and safely in warehouses and production facilities. They are built to carry one or several unit loads at a time, to and from conveyors, stands, end-of-line equipment (such as robots and palletizers) as well as automated storage and retrieval systems (ASRS).
Towing AGVs
A motorized AGV tugger vehicle is designed to tow one or more non-motorized carts, either autonomously or both manually and autonomously. Compared to AGCs, towing AGVs have greater throughput as they can transport several carts at once (similar to a train). Towing AGVs are equipped with trays that can be lifted and lowered, and with motorized rollers and belts that enable automatic load transfer.
Heavy burden carriers
Heavy burden carriers are, as the name suggests, for the heaviest loads. These AGVs are used in applications such as large assembly situations, casting, and coil and plate transport. Some heavy burden carriers have self-loading capabilities and may have standard, pivot or omnidirectional steering.
Types of AGV navigation systems
Laser guiding
AGVs are equipped with a rotating laser transmitter and receiver that allows them to detect reflectors mounted in their environment and establish their location with extreme precision. With a level of accuracy to carry out product handling to the nearest quarter of a centimetre, they are particularly suited to medical applications.
Wire guidance
Rails need to be installed to implement wire guidance, which means this navigation system is only recommended for applications that do not require flexibility. An AGV is steered along a ground track embedded into a facility floor that can be composed of wires, tracks, magnetic lines, or cables. The wire transmits a signal that AGVs detect via an antenna or sensor.
Visual guidance
Vision-guided AGVs follows paths painted on the ground while its camera records features along the route, which are then used to navigate. Compared to wire guidance, the cost for visual guiding is lower as it does not require any special installation work.
Geo-guidance
Geo-guided AGVs recognize and map objects in their environment to establish their location in real-time and navigate independently around the facility, without having to adapt infrastructure. This provides high levels of flexibility for warehouses and production sites. Similar to vision-guided AGVs, no infrastructure modifications are required for AGVS that use geo-guidance.
LiDAR (Light Detection and Ranging)
LiDAR, also known as natural navigation, is an advanced navigation technology utilizing sensors that transmit laser pulses to measure the distance between the robot and objects in its environment. This data is compiled to create a 360-degree map of the environment, allowing AGVs to navigate the facility and avoid obstacles without the need for additional infrastructure.
Type of Loads
A central question is whether an AGV will be required to move light or heavy loads because different AGVs have unique payloads. For heavy loads, a bespoke AGV may be a better solution.
Type of Navigation
The type of navigation system implemented will depend on everything from weather and temperature to the degree of human interaction and the type of loads being moved.
Level of Accuracy
AGVs need to be equipped with an appropriate level of accuracy to safeguard loads and circumvent potential damage.
Compatibility with company’s logistics system
Because an AGV is part of an automated logistics system, it is paramount that it is compatible with the business’ existing logistics system, such as a warehouse management system (WMS).
Safety Devices
Businesses can equip their AGVs with detection sensors that will halt its movement when it encounters an obstacle. Sound and visual elements can also be built on.
Frequently Asked Question: AGV vs AMR
The choice of an AGV system depends heavily on the task the vehicle is required to execute, as well as the complexity of existing or future infrastructure. But how do AGVs differ from Automated Mobile Robots (AMRs)?
This is a common question asked by prospective adopters of automated solutions. While both technologies optimize material handling and increase the productivity of warehousing facilities, there are differences.
*This blog article is based on content kindly provided to us by Geek+.
