AGV (Automated Guided Vehicles), also known as unmanned transport vehicle, automatic navigation vehicle, laser navigation vehicle. Its notable feature is unmanned driving, and the AGV is equipped with an automatic guidance system, which can ensure that the system can automatically travel along the predetermined route without the need for manual navigation, and automatically transport goods or materials from the starting point to the destination. Another characteristic of AGV is its good flexibility, high degree of automation, and high level of intelligence. The driving path of AGV can be flexibly changed according to storage space requirements, production processes, and other changes. The cost of changing the operating path is very low compared to traditional conveyor belts and rigid conveyor lines. AGVs are generally equipped with loading and unloading mechanisms that can automatically interface with other logistics equipment, achieving full process automation of cargo and material loading and unloading and handling. In addition, AGVs also have the characteristics of clean production. AGVs rely on their own batteries to provide power, and operate without noise or pollution. They can be applied in many places that require a clean working environment.
AGV has a history of 50 years since its invention, and with the expansion of its application fields, its types and forms have become diverse. AGVs are often classified into the following types based on their navigation methods during automatic driving:
Types of AGV cars:
1. Electromagnetic induction guided AGV
Electromagnetic induction guidance generally involves burying wires along a predetermined driving path on the ground. When high-frequency current flows through the wires, electromagnetic fields are generated around the wires. There are two electromagnetic sensors symmetrically installed on the AGV, and the difference in the strength of the electromagnetic signals they receive can reflect the degree of AGV deviation from the path. The automatic control system of AGV controls the vehicle's steering based on this deviation, and continuous dynamic closed-loop control can ensure the stable automatic tracking of AGV on the set path. This electromagnetic induction guided navigation method is currently used in the vast majority of commercial AGVS, especially for large and medium-sized AGVs.
2. Laser guided AGV
This type of AGV is equipped with a rotatable laser scanner, and laser positioning signs with high reflective reflective plates are installed on walls or pillars along the running path. The AGV relies on the laser scanner to emit a laser beam, and then receives the laser beam reflected back by the surrounding positioning signs. The onboard computer calculates the current position and direction of movement of the vehicle, and corrects its orientation by comparing it with the built-in digital map, thereby achieving automatic handling.
At present, the application of this type of AGV is becoming increasingly common. And based on the same guiding principle, if the laser scanner is replaced with an infrared emitter or an ultrasonic emitter, the laser guided AGV can become an infrared guided AGV and an ultrasonic guided AGV.
3. Visual guided AGV
Visual guided AGV is a rapidly developing and mature AGV, which is equipped with CCD cameras and sensors, and a database of environmental images of the AGV's intended driving path is set up in the onboard computer. During the AGV driving process, the camera dynamically obtains image information of the vehicle's surrounding environment and compares it with the image database to determine the current position and make decisions for the next step of driving.
This type of AGV has the best guidance flexibility in theory because it does not require any artificial physical path setting. With the rapid development of computer image acquisition, storage, and processing technology, the practicality of this AGV is becoming stronger and stronger.
In addition, there are various forms of AGVs such as ferromagnetic gyroscopic inertial guided AGVs and optical guided AGVs.