Automated Guided Vehicle is abbreviated as an automatic guided vehicle, usually also called automatic guided vehicle. It refers to a transport vehicle equipped with electromagnetic or optical automatic guidance devices that can travel along a prescribed guidance path, with safety protection and various transfer functions. In industrial applications, A truck does not require a driver and uses a rechargeable battery as its power source.
Generally, a computer can be used to control its travel route and behavior, or an electromagnetic track can be used to establish its travel route. The electromagnetic track is pasted on the floor, and the unmanned vehicle relies on the information brought by the electromagnetic track to move and move.
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Types of Automated Guided Vehicle
- Latent type: Dive into the bottom of the material truck, automatically hook up and separate to realize material delivery and recycling operations.
- Traction type: the material truck traction is realized through the tail automatic hook and trip mechanism.
- Self-unloading type: knapsack platform, using rollers, belts, or other methods to achieve material docking.
- Lifting type: the carrying platform can automatically lift materials, and can run operations synchronously with the assembly line. 5. Forklift: use an open forklift for material handling.
Advantages
① High degree of automation.
It is controlled by a computer, electronic control equipment, magnetic induction sensor, laser reflector, etc. When auxiliary materials are needed in a certain part of the workshop, the staff enters relevant information into the computer terminal, and the computer terminal sends the information to the central control room. Professional technicians issue instructions to the computer. With the cooperation of electronic control equipment, this instruction was finally accepted and executed by the automatic guided vehicle-sending the auxiliary materials to the corresponding place.
② Automatic charging.
When the power of the automatic guided vehicle is about to run out, it will send a request instruction to the system to request charging (general technicians will set a value in advance), and automatically go to the charging place after the system allows it to “queue” for charging. In addition, the battery life of the automatic guided vehicle trolley is very long (more than 2 years), and it can work for about 4 hours every 15 minutes of charging.
③ It is beautiful and enhances the viewing degree, thereby enhancing the corporate image.
④ Convenient and reduce floor space; the AGV trolley in the production workshop can shuttle back and forth in each workshop.
Guidance Method
①Electromagnetic guidance
Electromagnetic guidance is one of the more traditional guidance methods, which is still used by many systems. It embeds metal wires on the driving path of the automatic guided vehicle, loads the guiding frequency on the metal wires, and realizes the automatic guided vehicle by identifying the guiding frequency of The guide. Its main advantage is that the lead is concealed, not easy to be polluted and damaged, the guiding principle is simple and reliable, easy to control and communicate, no interference to sound and light, and has low manufacturing cost. The disadvantage is that the laying of metal wires is troublesome, and it is difficult to change and expand the path. Electromagnetic induction is easily affected by ferromagnetic materials such as metal, which has great limitations on complex paths.
②Tape guide
Similar to electromagnetic guidance, it uses tape on the road instead of burying metal wires under the ground. The guidance is achieved through magnetic induction signals. It has better flexibility, and it is easier to change or expand the path. Tape laying is simple and easy, but this guidance The method is susceptible to interference from metal materials around the loop, and the tape is susceptible to mechanical damage, so the reliability of the guidance is greatly affected by the outside world. Once the automatic guided vehicle executes the task, it can only move along the fixed tape and cannot change the task.
③Magnetic nail guidance
Magnetic nail navigation uses positioning blocks to divide the AGV’s driving area into several small coordinate areas and realizes guidance by counting small areas. Generally, there are photoelectric (a division of small coordinate areas in two colors and counting by photoelectric devices) and electromagnetic Formula (dividing the small coordinate area into metal blocks or magnetic blocks and counting by electromagnetic induction devices) two forms.
④Two-dimensional code guide / QR code guide
⑤ Ribbon guide
Paint or stick ribbons (sticky ribbon or paint) on the driving path of the automatic guided vehicle, and realize guidance by simply processing the ribbon image signals taken by the camera. Optical guidance is similar to tape guidance. The main advantage is that the road is easier to lay, its flexibility is better, the ground route is easy to set up, and the cost is low. The disadvantage is that the ribbon is more susceptible to pollution and damage, has high requirements for the environment, poor guiding reliability, and low precision.
Laser guidance is to install a precise laser reflector around the automatic guided vehicle’s driving path. The automatic guided vehicle emits a laser beam through a laser scanner and collects the laser beam reflected by the reflector to determine its current position and heading. The triangular geometric operation to realize the guidance of the automatic guided vehicles.
This method uses the camera of the automatic guided vehicle trolley to capture the ground texture for automatic map creation and then compares the ground texture information obtained during the operation with the texture image in the self-built map to estimate the current position of the automatic guided vehicle trolley Attitude, realize the positioning of automatic guided vehicle trolley. The hardware needs a down-view camera, fill light, and hood to support the realization of this kind of navigation method. Rich ground texture information can be used, and the displacement and rotation between the two images can be calculated based on the phase correlation method, and then obtained by integrating the current location.
Satellites are used to track and guide control objects in non-fixed road systems. This technology is still being developed and improved. It is usually used for outdoor long-distance tracking and guidance. Its accuracy depends on the fixed accuracy and number of satellites in the air and Control factors such as the surrounding environment of the object.
Inertial navigation is to install a gyroscope on the automatic guided vehicle. The gyroscope can be used to obtain the three-axis angular velocity and acceleration of the mobile robot, and the position and attitude information can be obtained through the integral operation. The two dead reckonings can be fused.
The positioning block is installed on the ground in the driving area, and the automatic guided vehicle can determine its own position and head by calculating the gyroscope deviation signal (angular rate) and collecting the ground positioning block signal to achieve guidance.
Compound navigation refers to the method of using two or more guidance (or navigation) methods to realize the operation of automatic guided vehicles. For example, the combination of two-dimensional code navigation and inertial navigation takes advantage of the short-distance positioning accuracy of inertial navigation and uses inertial navigation for the navigation blind zone between two two-dimensional codes. The combined application of laser navigation and magnetic nail navigation uses magnetic nail navigation in the station position with high positioning accuracy requirements to increase the stability of automatic guided vehicle positioning. Composite navigation is to adapt the automatic guided vehicles to common navigation methods in various usage scenarios, and it will be more and more widely used in various automatic guided vehicles.
Basic Application of Automated Guided Vehicle
① Warehousing industry
The warehousing industry is the earliest application place for automatic guided vehicles. In 1954, the world’s first automatic guided vehicle was put into operation in the warehouse of Mercury Motor Freight Company in South Carolina, USA, to realize the automatic transportation of goods in and out of the warehouse.
At present, there are about 20,000 automatic guided vehicles of various kinds operating in 2,100 large and small warehouses in the world. In the three-dimensional warehouse of Haier Group’s development zone that was put into operation in 2000, 9 automatic guided vehicles formed a flexible automatic handling system in the warehouse, which successfully completed 23,400 daily inbound and outbound goods and parts handling tasks.
② Manufacturing
automatic guided vehicle shows its talents in the production line of the manufacturing industry, completing material handling tasks efficiently, accurately, and flexibly. And a flexible logistics handling system can be composed of multiple automatic guided vehicles, and the handling route can be adjusted in time with the adjustment of the production process so that a production line can produce more than a dozen products, which greatly improves the flexibility of production and the competitiveness of the enterprise.
In 1974, in order to improve the flexibility of the transportation system, the Volvo Kalmar car assembly plant in Sweden adopted an automatic car assembly line based on the automatic guided vehicles as a carrier. The assembly line is composed of multiple automatic guided vehicles that can load car bodies. After adopting this assembly line, assembly time is reduced. By 20%, assembly failures were reduced by 39%, investment recovery time was reduced by 57%, and labor was reduced by 5%. At present, the automatic guided vehicle has been widely used in the manufacturing and assembly lines of major automobile factories in the world, such as GM, Toyota, Chrysler, and Volkswagen.
In recent years, as the basic handling tool of CIMS, the application of automatic guided vehicles has penetrated into many industries such as mechanical processing, home appliance production, microelectronics manufacturing, cigarettes, and the production and processing field has become the most widely used field of automatic guided vehicle.
③ Post office, library, port terminal and airport
In post offices, libraries, docks, airports, and other occasions, the transportation of items has the characteristics of large changes in workload, strong dynamics, frequent adjustments of operating procedures, and single handling procedures. automatic guided vehicle’s parallel operations, automation, intelligence, and flexibility The characteristics of chemistry can well meet the handling requirements of the above-mentioned occasions.
Sweden started to use automatic guided vehicles at the Stockholm Post Office in Greater Stockholm in 1983, Japan at the Tama Post Office in Tokyo in 1988, and China in 1990 at the Shanghai Post Hub to complete the handling of postal products. At the port of Rotterdam, the Netherlands, 50 automatic guided vehicles called “yard tractors” complete the repetitive work of transporting containers from the side of the ship to a warehouse hundreds of yards away.
④ Tobacco, medicine, food, chemical industry
For the tobacco, medicine, food, chemical, and other industries that have special requirements for handling operations such as cleanness, safety, and emission-free pollution, the application of automatic guided vehicles has also received attention. Many domestic cigarette companies, such as Qingdao Yizhong Group, Yuxi Hongta Group, Honghe Cigarette Factory, Huaiyin Cigarette Factory, use a laser-guided automatic guided vehicle to complete the handling of pallet cargo.
⑤ Dangerous places and special industries
In the military, it integrates other detection and disassembly equipment based on the automatic driving of the automatic guided vehicles, which can be used for battlefield demining and position reconnaissance. The MINDER Recce that the British military is developing is a reconnaissance vehicle with mine detection, destruction, and route verification capabilities Automatic reconnaissance vehicle.
