Comparison of mainstream navigation methods for intelligent handling robots

As an important tool for automated transportation and handling, intelligent handling robots are very mature in technology and have been widely used in smart factories. Intelligent handling robots can transport materials to the target site accurately, safely and intelligently. Since the development of intelligent handling robots, a variety of navigation methods have been derived.

At present, the mainstream intelligent handling robot navigation methods are as follows:

Magnetic strip navigation

Magnetic strip navigation is considered to be a very mature navigation technology. The magnetic strip is laid on the running route of the intelligent handling robot. The intelligent handling robot obtains the position deviation between the vehicle itself and the target tracking path by measuring the magnetic field signal on the path. To achieve vehicle control and navigation.

The advantages of magnetic strip navigation are low cost, mature and reliable technology, good positioning stability and convenient use.

The disadvantage of magnetic stripe navigation is that it requires construction on the ground, the construction workload is large, the surface card is easy to be lost, and the magnetic strip needs to be re-laid when the route is changed. The flexibility is poor, the maintenance cost is high, and it can only walk along the magnetic strip, which cannot be realized. Intelligent avoidance, or change tasks in real time through the control system.

Magnetic nail navigation

The magnetic nail navigation method uses the magnetic navigation sensor to detect the magnetic signal of the magnetic nail to find the traveling path, but the continuous induction of the magnetic strip by the original magnetic stripe navigation becomes intermittent induction, so the distance between the magnetic nails cannot be exceeded. The large, intelligent robot between the two magnetic nails is in a state of distance measurement, in which the encoder is required to measure the distance traveled. Secondly, the control module used for magnetic nail navigation is the same as the magnetic strip navigation control module.

The advantage of magnetic nail navigation is that the cost is low, the technology is mature and reliable, the magnetic nail is buried in the ground, and the privacy is good and the appearance is strong. The magnetic nail has strong anti-interference, strong anti-wear, anti-acid and alkali, oil pollution, etc. It can be used outdoors and indoors.

The disadvantage of magnetic nail navigation is that there can be no other magnetic substances in the navigation route of the intelligent handling robot. The intelligent handling robot magnetic nail navigation line is laid once, and the subsequent modification of the line must perform secondary operations. The intelligent handling robot magnetic nail navigation construction will perform certain damage functions on the ground, that is, opening holes in the ground and then backfilling, and the construction technology is strict, in order to restore the original ground aesthetic requirements.

Slam laser navigation

Slam laser navigation is also called natural navigation. Natural navigation is the advanced navigation technology of the current intelligent handling robot. This technology uses a two-dimensional laser scanner to measure, learn and draw the navigation environment. The intelligent handling robot does not have the surrounding environment information. Under the premise, the mobile robot makes its own positioning according to the sensors carried by itself and the perception of the surrounding environment during the movement, and incrementally constructs the surrounding environment map.

The advantage of Slam laser navigation is that it can locate the marker and can be information such as the wall surface in the working environment. It does not need to be applied to the road surface and does not have to rely on the reflector. Slam laser navigation can eliminate the need to pre-lay any track, which is convenient for upgrading the factory production line and changing the navigation route. Slam laser navigation can avoid obstacles in real time and has strong environmental adaptability. Compared to traditional laser navigation, natural navigation is simple to construct and has a low cycle.

The disadvantage of Slam laser navigation is that the positioning stability is poor, and it is easy to lose positioning in some complicated factory environments, which is greatly affected by the environment, and the cost of laser navigation intelligent handling robot is high.

Laser navigation (installation reflector)

The intelligent handling robot trolley mounts a precise reflector on the driving path. The laser scanner is mounted on the roof of the intelligent handling robot. The intelligent handling robot emits a laser beam. The laser scanner emits a laser beam with the laser of the intelligent handling robot. The bundle is directly reflected back by a plurality of sets of reflectors laid along the path of the intelligent handling robot, and the laser beam reflected by the reflector is collected, and the guidance of the intelligent handling robot is realized by continuous triangular geometric operation to determine its current position. And direction.

The advantage of laser navigation is that the intelligent handling robot is accurately positioned, and the ground does not need other positioning facilities, and the driving path can be flexibly changed.

The disadvantages of laser navigation are the complicated laser navigation control and the expensive investment cost of laser technology. The reflection film and the intelligent handling robot laser sensor can not directly have obstacles, and are not suitable for occasions where there is logistics influence in the air.

Visual navigation (two-dimensional code)

A vision camera mounted, on the chassis of intelligent intelligent transfer robot transfer robot running on a paved road at a distance from the two-dimensional code, the intelligent transfer robot during running, the current position information acquired by analyzing the two-dimensional code information. Two-dimensional code navigation is often combined with inertial navigation for precise positioning.

The advantages of two-dimensional code navigation are good positioning stability, mature technology, high navigation flexibility, less environmental interference, and lower cost.

The disadvantage of two-dimensional code navigation lies in the need to lay a large number of two-dimensional codes on the running route of the intelligent handling robot. The construction engineering quantity is large, and the two-dimensional code needs to be regularly maintained and replaced. The maintenance workload is large, and the two-dimensional code navigation range is relatively small. Used in unattended environments such as warehouses.

Fusion navigation

1. Traditional laser navigation, when encountering complex terrain (such as the corridor, the glass on both sides of the road, the factory environment changes greatly), it is easy to lose the positioning.

2. In some scenarios (high docking accuracy requirements), the positioning accuracy does not meet the automatic loading and unloading accuracy requirements.

In order to solve the above problems, it is possible to use a combination of two or more navigation methods for navigation. We call this method a fusion navigation. Currently, there are the following common navigation methods.

1, laser navigation and magnetic strip navigation combination

2, laser navigation and QR code navigation combination

3, QR code navigation and inertial navigation combination

4, laser navigation and 3D visual navigation combination

Laying magnetic strips and two-dimensional codes on the ground requires construction on the ground. It takes a long time to wear, and needs to be re-laid when the production line changes. The maintenance cost is high.

Blue Core Technology's self-developed laser navigation and 3D vision sensor fusion navigation method does not require any changes to the environment. Intelligent handling robots make full use of environmental information to create 2D planar maps through laser sensors, establish 3D maps through visual sensors, and use slam laser navigation and The two modes of visual navigation combine navigation to adapt to the complex terrain of the factory.

Slam laser navigation and visual navigation technology cover three parts, namely mapping, positioning and path planning (motion control).

Positioning

Bluecore's visual positioning solution is based on 3D mapping and relies on stable image features to obtain position. At the same time, the map can be dynamically updated to prevent possible small changes in the scene. The 3D map has a high adaptability to scene changes and machine aging, tilting, and the like.

navigation

Blue Core Technology has a unique navigation scheme that can be fixed or fixed.

Blue Core Technology has a rich path planning solution for actual scenarios, providing fixed point, fixed path and other solutions that meet the needs of the scene. At the same time, a variety of sensors are integrated to complete the obstacle avoidance, and the security is ensured in the warehouse and other scenarios.

Blue Core Technology Laser Navigation and 3D Vision Fusion Navigation Intelligent Handling Robot

Comparison of several navigation methods

As an advanced automated handling solution, intelligent handling robots have been used by more and more industries and enterprises. The market share of integrated navigation is gradually expanding, and its flexibility is irreplaceable. Under the environment of German Industry 4.0 and China Manufacturing 2025, Bluecore Technology has been committed to providing intelligent logistics solutions for its factories. Converged navigation intelligent handling robots hope to help more and more companies.