With the advancement of science and technology, mobile robots have been widely used in many industries. It is an intelligent device that realizes autonomous movement control and automatic work execution. It can not only accept the command of the user, but also run pre-programmed programs, and even operate without human intervention. According to the difference in robot navigation methods, the current robot navigation methods can be mainly divided into inertial navigation, road sign navigation, laser navigation, etc., and laser navigation has become the mainstream navigation method to realize the autonomous movement of robots by virtue of its flexibility and autonomy.
Inertial navigation is a comprehensive technology involving multiple disciplines and fields such as precision machinery, computer technology, microelectronics, optics, and automatic control. A method of determining the current position by describing the azimuth of the robot and the distance traveled from a reference point. This navigation method controls the direction and distance of the mobile robot by comparing it with the known map route so that the robot's autonomous navigation can be realized.
Its main working principle is based on Newton's laws of mechanics. By measuring the acceleration and angular acceleration of the carrier in the inertial reference frame, it is integrated with time once to obtain the speed and angular velocity of the moving carrier, and then the second integral is performed to obtain the motion. The position information of the carrier is then transformed into the navigation coordinate system to obtain the speed, yaw angle, and position information in the navigation coordinate system.
The advantage of this navigation method is that it does not be disturbed by climatic conditions and external information, but with the accumulation of time, even if it is a small constant, its error will increase infinitely. So the sensors used in inertial navigation are not suitable for long-term precise positioning.
Road sign navigation refers to the signs of special environments that can be recognized by inputting information into the internal sensors of the mobile robot. This road sign itself has a fixed position, which can be geometric shapes in mathematics, letters, two-dimensional codes, etc. . According to the different road signs used by robots, they can also be divided into two categories: artificial road sign navigation and natural road sign navigation.
Although this navigation method does not destroy the original environment and has good universality, it is computationally complex and not robust. The reason is mainly that the detection and extraction of natural road signs are relatively complicated, and it is often necessary to save all the image information in the robot's field of vision, and then perform feature extraction, storage, detection, matching, etc. Considering that there are often too many feature points in a typical indoor scene image or the process of indoor navigation, similar scenes are detected in the database, coupled with various factors such as the dimension of local feature points, which often leads to excessive computational complexity required by the application.
Laser navigation is mainly based on the principle of SLAM, which realizes the functions of autonomous positioning, mapping, and path planning of robots in unknown environments. Compared with the inertial navigation and road sign navigation described above, it is more flexible and autonomous. It mainly obtains information about the surrounding environment through lasers, measures the time from laser emission to reception, calculates its distance and the distance of obstacles in front, and obtains the environment model through algorithm processing, which is obtained by self-positioning and walking routes in continuous scanning and ranging.
It's believed that this is the ideal robot in most people's minds. It seems to be a simple operation to apply Laser SLAM navigation, but actually, it is a great challenge for the robot because it needs to cooperate with additional algorithms.
As one of the earliest companies to apply laser navigation to robots, Youibot has developed autonomous positioning and navigation technology that has been maturely applied to autonomous mobile robots. If you are interested in ordering an autonomous mobile robot, please feel free to contact us!