1. Electromagnetic guidance
Electromagnetic guidance is the earliest and most widely used method. It embeds the wire into the underground trench, and the AC frequency generator inputs low-voltage and low-frequency current to generate a magnetic field around the wire. AGV is equipped with two induction coils, which can detect the strength of magnetic field and express it in the form of voltage. ?
2. Tape guidance
The principle of magnetic tape guidance is very similar to that of electromagnetic guidance. Magnetic tape guidance replaces the buried metal wire of electromagnetic guidance. Compared with electromagnetic guidance, AGV has better flexibility, and it is easier to change or expand the guidance path, but it is more susceptible to the interference of surrounding metal objects than electromagnetic guidance, so AGV with this guidance mode requires higher application environment.
3. Laser guidance
This guidance method is to install a laser reflector with accurate position around the driving path of AGV. The current position and direction of AGV are determined by colleagues emitting a laser beam and collecting the laser beam reflected by the reflector, and the guidance of AGV is realized by continuous trigonometric geometry operation. It has the advantages of accurate positioning, no need for other positioning facilities on the ground, flexible guiding path and adaptability to various field environments. It is an advanced guidance mode limited by many foreign AGV manufacturers at present.
4. Visual guidance
There are two methods of visual guidance. One is to use the camera to collect the image information of the environment around the driving path in real time, and compare it with the information in the established image database of the environment around the driving path to realize the control of AGV. The other is the image recognition method based on the guide line, which uses the camera to collect the image of the guide line in real time and calculate the deviation between the guide line and the car, so as to control the AGV to drive along the predetermined planned guide line.