The AGV in Logistics
Yes, we can define the AGV as a portable robot that takes and brings goods in a warehouse
Automatic Guided Vehicle or, in Portuguese, Automatically Guided Vehicles. This is the meaning of the acronym AGV. But why are they important for the Logistics sector? This question will be answered in the next lines. When we talk about vehicles driving around without a driver, we immediately think of robots and science fiction movies. And such a futuristic perception is perfectly understandable. But, between us, it’s been some time since fiction invaded reality. According to researchers, Chang Wan Kim and JMA Tanchoco “the AGV consists of an electric vehicle programmed and guided by rails, optical sensors, radio frequency or laser. It offers safety and speed in uninterrupted operations, being able to transport boxes or pallets. In addition, it favors the environmental and acoustic conditions of the factory (no noise) ”. That definition is 1999. By the way, AGVs have been around since the 1950s, when the American company Barrett Electronics created a tug that followed a wire on the ground instead of a rail.
Today we can indeed define the AGV as a portable robot that takes and brings goods in a warehouse using different technologies to guide itself in the internal space. And it is precisely the technology category that determines the classification of these autonomous vehicles, as we can see in the article “AGV to reduce manufacturing defects in the furniture industry ”, written by Vinícius Barcos Galli and published in 2019:
- “ Philosophical guided system : fixed path navigation method widely used in industries. It consists of tracing a route and making a cut in the floor, where embedded electrical conductors are installed. The mechanism of operation is by the cable that creates a magnetic field due to the electric current that crosses it, being detected by an antenna placed in the AGV. It is a non-flexible system as it does not allow for easy route changes, however, it is widely used due to its simplicity and robustness (SANTOS, 2013).
- Strip system : fixed path navigation method, consisting of placing magnetic tapes on the floor, glued or painted. The operating mechanism is similar to the philoguided system, however, instead of electrical cables, it uses magnetic strips and appropriate sensors. The main advantage is flexibility in modifying routes, however, on the other hand, the tape can be damaged or worn out when people and objects move over it. The system is recommended for AGVs of low cost and small dimensions (SANTOS, 2013).
- Optical system : fixed path navigation method, consisting of the placement of tracks marked by paint or adhesives. The operating mechanism is by optical sensors that detect the lanes and calculate path deviations. It is a flexible system as it allows easy modification of routes. Some systems use ultraviolet (UV) light underneath the vehicle to illuminate lanes that may not be visible in natural light. Video images can be transmitted in real time to a monitor, or barcodes fixed on the floor can be read to identify workstations or trajectory changes. The application of the system in industrial environments can be hampered by the need for cleaning and reapplication of the strips (CRANE TECH SOLUTIONS, 2019).
- Laser triangulation system : dynamic trajectory navigation method, consists of positioning poles or reflector lights on columns, walls or high places with easy access to the laser used by the AGVs, which performs a rotating sweep in search of reflectors, reference points for the location of autonomous vehicles. The detection of 3 reference points provides the location of the AGVs by triangulation, based on control algorithms. Therefore, good planning of the arrangement of reflectors is necessary. The system does not require any modifications to the factory floor. It is a flexible, reliable, safe and accurate method (SANTOS, 2013).
- Marker system : dynamic trajectory navigation method, consists of marking the factory floor with small spaced magnetic disks. The operating mechanism is based on storing the disk coordinates in an AGV database and, when detected by sensors, the vehicle’s position is determined. If there is any deviation from the idealized trajectory due to the accumulation of errors, the AGV will not find the next marker and will be lost, which is why this system is normally used with a gyroscope. It is a very flexible model and allows routes to be changed easily (SANTOS, 2013).
- Natural system: dynamic trajectory navigation method, uses the existing environment for locomotion, without the need to modify the production environment, facilitating the integration to existing processes and presenting a short implementation time. The main technology used is the LiDAR (Light Detection And Ranging) sensor (LYDON, 2018). For the implementation, the operation site is first mapped by laser scanners, where the robot receives the data and transcribes it to a 2D map, using reference elements as a base. The reference map is integrated in the robot’s memory with the routes. The operation is carried out through the real-time emission of laser beams by the digitizer in 360º of the environment in which it is inserted, correlating with the reference map and calculating its position, moving autonomously (BYLON, 2016).”
In the Logistics sector, AGVs are generally used in four ways:
- in the towing function (Tow Vehicle), when the AGV pulls one or more freight trains;
- in the single load function (Unit Load), when the vehicle carries individual loads on top of its base;
- in the function of loads on pallets (Pallet Trucks), when the AGV is very similar to a forklift, having the mechanism of vertical reach in shelves;
- and in the function of customized loads, when the autonomous vehicle is adapted for a specific load.
This equipment can be easily adapted to the warehouse’s WMS (Warehouse Management System) and despite the high implementation cost, the investment usually pays off in a short time, due to the large number of advantages that the Automatic Guided Vehicle presents. See some of them now:
- Speed and accuracy of operations: Mechanics and computer science together reduce errors. Human error and inaccuracies are avoided.
- Cost control: these robotic equipment have a very long useful life, with predictable maintenance and subject to few changes from a financial point of view. In addition, there is a reduction in personnel costs.
- Increased productivity: the AGV can operate 24 hours a day, streamlining storage and logistics processes, always ensuring punctual shipments.
- Flexibility: the path of an AGV can be changed according to production and handling needs.
- Fewer Constraints: Autonomous vehicles require less space than conventional forklifts, allowing for narrower aisles.
- Safety: warehouse workers can avoid potentially dangerous maneuvers and operations by interacting with machines via computers.
For all this, the guided vehicle has automatically been very successful in Logistics, accelerating processes with safety and accuracy. Everything the world has demanded with the advancement of information technology and the growth of online sales, so common during this pandemic. It is a resource that improves the performance of all organizations that deal with cargo handling, whether in Intralogistics or on the roads.
Yes, on the roads. There are already companies with trucks that can be self-driving or remotely guided, especially in Europe, where there is a shortage of truck drivers. Mercedes -Benz, for example, started testing the Actros model in 2015 on German highways. Tesla, GM, Ford and Honda are about to reveal their projects in this area. Of course, this will only be possible if the roads are also prepared for autonomous vehicles. The European Parliament wants the roads in the countries of the bloc to be ready for the highest level of automation (without human presence driving vehicles) by 2030. The cost of travel could fall by up to 33% and the number of accidents by 70 %, according to bloglogistica.com.br.
We, at Águia Sistemas, can collaborate in a fundamental part of this process. We are in a position to help your company with the very latest in Intralogistics. Keep in touch with us .
( The text above was written with information from the websites revistamundologistica.com.br, bloglogistica.com.br, linkedin.com, sinova.com.br, delage.com.br , ecommercebrasil.com.br, prodaditivos.com.br, amsbrasil.com.br and maxtonlogistica.com.br).