Research On The Navigation Mode Of The Forklift AGV Robot

- Aug 24, 2017 -

Referring to the navigation of the forklift's AGV robot, it can take a long time to introduce his historical evolution and the current mainstream application.The forklift AGV robot is also a member of AGV, but it is more complex in terms of mechanical structure and can achieve more diversified functions.In theory, of AGV navigation way, is also suitable for forklift truck on the AGV robot, so the electromagnetic navigation, magnetic stripe navigation, visual navigation, laser navigation and inertial navigation, qr code navigation, in theory can be used in forklift truck AGV.

However, this is not the case, given the specificity of the forklift AGV robot, some of the navigation methods are not directly applicable.Electromagnetic navigation is the earliest form of navigation, and some systems still use this kind of navigation.The advantage of electromagnetic navigation is that the guide sign is hidden underground, not easy to be polluted or damaged.The guiding principle is simple and reliable, easy to control communication, no interference to the sound light, and relatively low cost of investment is the biggest characteristic that it can retain to this day.However, the application of electromagnetic navigation is increasingly restricted, first of all to the destruction of the ground, and secondly, the extreme inflexibility leads to the effect of its application.Therefore, the method of electromagnetic guidance is difficult to apply to forklift AGV at present.

Magnetic stripe navigation technology is similar to that of electromagnetic navigation. The difference is that a magnetic tape can be used to attach metal wires to the surface of the road and guide the signal through magnetic tape.Magnetic tape navigation advantage: AGV positioning accuracy, magnetic tape navigation flexibility is relatively good, change or expansion path is easier, tape laying is relatively simple.At the same time, the cost of investment is relatively low, which is the main attraction of attracting customers and the main reason for the durability of magnetic stripe navigation.But the way the magnetic stripe is navigated is not suited to the forklift.First of all, the weight of the forklift body is less than one ton, more than a few tons, and it needs to rotate continuously, so that the destructive force of the magnetic stripe is too great to be used.Second, with the promotion of technology, high flexibility, intelligent navigation way cost is falling, it also brought a lot of to AGV navigation way change, have a better choice, customers are happy to.

Visual navigation, to be honest, I haven't seen much of it.Principle of vision navigation is besmear to brush in the motion of the AGV path and ground color contrast big paint or paste the color contrast of the ribbon, have taken photo sensor installed on the AGV will continuously compared with stored images, the images taken by the offset signal output to the drive control system, control system calculated to correct the walking direction of AGV, realization of AGV navigation.This way anyway not seen application on forklift, concluded that the reason may have the following several aspects: first, the reliability of the visual navigation and not a lot of evidence, this is the most important question of all navigation mode;Second, relative visual navigation is still a sign of navigation, less than magnetic navigation, and the application prospects are not ideal.

Laser navigation is now the mainstream application of forklift AGV.According to historical development, the laser navigation mode of the anti-photoreplate has been introduced from Europe and the United States, and has been used in the forklift AGV.Continuous navigation signs, such as electromagnetic lines, magnetic strips, and anti-light bands, are replaced by the anti-photoplate, becoming a discrete navigation mark.This is an improvement in application.At the very least, the reflector is made of a little bit of wire, and it hangs high, and the barriers to the ground become smaller.However, the laser forklift AGV with a reflector is still less flexible and intelligent, so it has led to the emergence of a non-reflector laser navigation forklift AGV.Navigation way without reflector liberated the limitation of navigation marks, logos of AGV navigation, the benefits of such needless to say, from the cost, technology, application and future can expand sex had brought a better experience.

Inertial navigation and two-dimensional code navigation, which are the same principles, are basically the same class.This type of navigation is less used on the forklift AGV, and is more popular on warehousing or KIVA robots.This has its history, thanks to KIVA's pioneering use and role model, which has been used by newcomers.The advantages of this kind of navigation are that you can also understand the form of a qr code or a magnetic spike, which will lead to smaller, lighter directions.However, the disadvantage is that when the line accuracy is not ideal, it is applicable to the application of a single scene in the storage shelf. It is difficult to cope with other moving areas requiring high precision and high complexity.

In conclusion, both AGV and forklift AGV navigation mode, the characteristics of the development is toward the logos navigation change, no matter how small signs, more humble, but as long as you also need to navigation marks, so this way of navigation is not essentially span.At present, the concept of unmarked navigation is realized by means of no anti-photoplate laser navigation.It is believed that future unmarked navigation will become more and more popular and lead industry changes.