CN109940612A - Intelligent obstacle avoidance robot based on one-line laser and its obstacle avoidance method - Google Patents

Abstract

The invention discloses an intelligent obstacle avoidance robot based on a line laser and an obstacle avoidance method. On the basis of the existing camera of the mobile robot, the obstacle avoidance can be completed only by adding a line laser, and the obstacle avoidance information Compared with ultrasonic and infrared ranging, obstacle avoidance methods have more comprehensive information and lower cost than lidar, effectively balancing accuracy and cost.

Description

Intelligent obstacle avoidance robot based on one-line laser and its obstacle avoidance method

technical field

The invention relates to the field of robotics technology, and more particularly to an intelligent obstacle avoidance robot based on a one-line laser and an obstacle avoidance method thereof.

Background technique

With the continuous improvement of the level of modern science and technology, more and more robots have entered people's lives, greatly improving people's production and living efficiency. Among them, the obstacle avoidance function is an important part of the mobile intelligent robot.

At present, the existing obstacle avoidance methods cannot effectively balance the accuracy and cost. Although the obstacle avoidance method based on ultrasonic and infrared ranging is low in cost, the measurement range is limited, and most of them are single-point measurement. The obstacle avoidance method based on lidar contains comprehensive information, but it will greatly increase the cost.

Therefore, how to provide a robot obstacle avoidance method that can effectively balance accuracy and cost is an urgent problem to be solved by those skilled in the art.

SUMMARY OF THE INVENTION

In view of this, the present invention provides an intelligent obstacle avoidance robot based on a line laser and an obstacle avoidance method thereof, which can effectively balance accuracy and cost.

In order to achieve the above object, the present invention adopts the following technical solutions:

An intelligent obstacle avoidance robot based on a line laser, the robot is provided with a camera and a line laser, the line laser is arranged above the robot, and has a downward inclination angle, or the line The wordline laser is arranged in the lower part of the robot and has an upward inclination angle.

Preferably, the laser light emitted by the word line laser has a stable wavelength and a fixed color component.

Preferably, the plane divergence angle of the in-line laser is 110°.

An obstacle avoidance method for an intelligent obstacle avoidance robot based on a one-line laser is applicable to the above-mentioned intelligent obstacle avoidance robot based on a one-line laser, and the obstacle avoidance method includes:

The one-line laser robot projects a line laser in the forward direction;

The camera collects the image of each object after projecting the line laser, and extracts the height L of the object’s line laser projection line from the ground according to the collected image, where L=OAtan θ, θ is the line laser plane emitted by the one-line robot. The clip between the plane and the ground Angle, O is the intersection of the reverse extension line of the line laser and the ground, A is the intersection of the object and the ground;

Judging the distance of the object according to the height L of the projection line, and avoiding obstacles.

It can be seen from the above technical solutions that, compared with the prior art, the present invention discloses an intelligent obstacle avoidance robot based on a one-line laser and an obstacle avoidance method thereof. On the basis of the existing camera of the mobile robot, only Obstacle avoidance can be completed by adding a word-line laser, and the obstacle avoidance information is more comprehensive than the obstacle avoidance method information of ultrasonic and infrared ranging, and the cost is lower than that of lidar.

Therefore, the intelligent obstacle avoidance robot and the obstacle avoidance method based on the one-line laser provided by the present invention effectively balance the accuracy and the cost.

Description of drawings

In order to explain the embodiments of the present invention or the technical solutions in the prior art more clearly, the following briefly introduces the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only It is an embodiment of the present invention. For those of ordinary skill in the art, other drawings can also be obtained according to the provided drawings without creative work.

1 is a schematic diagram of an obstacle avoidance method of an intelligent obstacle avoidance robot based on a word line laser provided by the present invention;

FIG. 2 is a schematic diagram of an obstacle avoidance method for an intelligent obstacle avoidance robot based on a word line laser provided by the present invention.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

Referring to Fig. 1 and Fig. 2, an embodiment of the present invention discloses an intelligent obstacle avoidance robot based on a line laser. The robot is provided with a camera and a line laser, and the line laser is arranged above the robot and has A downward inclination, or inline laser, is arranged on the lower part of the robot and has an upward inclination. More specifically, the camera is a monocular camera.

In the actual use process, the angle of the line laser and the camera can be adjusted according to the actual situation and specific needs. Preferably, the elevation angle or depression angle of the in-line laser is smaller than the viewing angle of the camera.

Taking the camera's 80-degree viewing angle as an example, when the angle between the laser extension line and the ground is 30 degrees, the intersection of the laser reverse extension line and the ground and the center of the camera are located at the same point on the top view. In this case, it can be judged that the distance is greater than 14.1cm. For small robot systems, the general obstacle safety distance is at least 20cm, which meets the requirements. To judge that the distance is smaller, tilt the camera slightly downward. If you want to calculate the distance of the obstacle in the middle more accurately, you can increase the upward tilt angle. The angle of the line laser and the camera can be adjusted according to the actual situation.

When the in-line laser emits line laser upward, the optical surface angle of the in-line laser is slightly smaller than the viewing angle of the camera, so that the distance of the far obstacle can be distinguished, as long as the angle is suitable and does not enter the human eye. For the downward angle, place the line laser on the upper end of the robot and look down. In order to be precise in this case, the angle is generally made very large, so that it will soon hit the ground, and the obstacle avoidance range is limited. In the case of the laser from bottom to top, the lower the intersection of the laser line and the object is in the field of view, the closer the obstacle is. In the case of the laser going from top to bottom, the higher the intersection, the closer it is.

In order to further optimize the above technical solution, the laser light emitted by the word line laser has a stable wavelength and a fixed color component.

After reading a frame of image, the position of the projection line can be easily extracted through the difference of colors in the image, and then its height can be calculated to identify the distance of the obstacle.

In order to further optimize the above technical solution, the plane divergence angle of the word line laser is 110°. Set the plane divergence angle of the inline laser to be slightly larger than the viewing angle of the camera.

In addition, an embodiment of the present invention also discloses an obstacle avoidance method for an intelligent obstacle avoidance robot based on a one-line laser, which is applicable to the above-mentioned intelligent obstacle avoidance robot based on a one-line laser. The obstacle avoidance method includes:

The one-line laser robot projects a line laser in the forward direction;

The camera collects the image after projecting the line laser, and extracts the height L of the laser projection line on the object from the ground according to the collected image, where L=OAtanθ, θ is the angle between the line laser plane emitted by the one-line robot and the ground, O is the intersection of the reverse extension line of the line laser and the ground, and A is the intersection of the object and the ground;

Judging the distance of the object according to the height L of the projection line, and avoiding obstacles.

The technical solution of the present invention will be further elaborated below with reference to Figure 1 and Figure 2 .

A wordline laser can project a transverse laser line. Since the wavelength of the laser is fixed, the color is also fixed. When encountering an obstacle, the projected laser will show a light trace of a fixed color on the obstacle. The laser plane angle of the laser is 110°, and the one-line laser is inclined upward at a certain angle, and the projection lines of different heights will be obtained according to the distance of the obstacle. As shown in Figure 1, the ground object 1 is closer to the one-line laser, the ground object 2 is farther from the one-line laser, the projection line obtained by the object 1 closer to the laser is L1, and the projection line obtained by the object 2 is L2 , according to the principle of inclined plane, the height of L2 is obviously larger than that of L1. After adding a line laser with a certain angle, the height of the intersection of the laser line and the object directly reflects the distance between the object and the light source. Since the laser is a light beam with a stable wavelength and its color component is fixed, the three-dimensional information is converted into the height of the two-dimensional laser line after being read by the camera. In a frame of image, the position of the light can be extracted by the color threshold.

Referring to Figure 2, point O is the intersection of the reverse extension line of the line laser and the ground, the angle between the one-line laser plane and the ground is θ, the intersection of ground object 1 and the ground is A, and the distance from point O is OA; ground object 2 The point of intersection with the ground is B, and the distance from point B is OB. A line of laser light is projected onto the ground object 1, and a ray of light parallel to the ground will be formed. It can be easily obtained from FIG. 2 that the distance between the intersection line and the ground is AA1=OAtanθ. Similarly, the height of the projection line of the ground object from the ground BB1=OBtanθ. Before the system is started, the line laser has been fixed, then the θ angle has been fixed and is a known parameter. The height of the intersection of the line laser plane and the ground object (that is, the height of the projection line) is opposite to the distance between the object and the light source line. The distance to the intersection of the extension line and the ground is proportional. After that, the image is read in by the camera. The intersection line is higher, and it is an obstacle with a long distance, which can be temporarily not processed. If the distance is short, the obstacle information needs to be processed immediately. The left and right information of the obstacle is also the left and right relationship in the image, which is relatively easy to obtain. If the obstacle is on the left, you need to turn right, and if the obstacle is on the right, you need to turn left.

In general, the obstacle avoidance method provided by the present invention is simple in equipment, and the existing robot already has a camera, and the obstacle avoidance can be completed only by adding a line laser transmitter. Moreover, when the present invention recognizes obstacles, it uses the line laser projection line projected on the object, that is, the projection light mark, and the distance between the object and the robot can be quickly determined by extracting the height L of the laser projection line on the object from the ground. Depending on the distance, the position information of the obstacle can be obtained in one frame of image, which greatly reduces the amount of calculation, and the image information captured by the camera can also be used in other algorithms in the robot work, making full use of the collected images, Don't waste.

The method provided by the present invention is a more flexible triangulation ranging method, which can clear the distribution of obstacles on an oblique plane with one projection. If it is used on an intelligent mobile device, due to its continuity, it can meet the requirements of obstacle avoidance in the forward direction. function.

If the one-line laser is changed to an infrared light source, and the camera is changed to an infrared camera with a visible wavelength, this method is also applicable.

In addition, it should be noted that the existing technologies mostly use ultrasonic and infrared ranging for measurement, but both ultrasonic and infrared ranging are typical single-point ranging, that is, they can only be measured at a specific angle where the sensor is arranged. If the above method is used, the accuracy is generally improved by increasing the number of sensors, which cannot cover all angles, and there is often a large blind spot, making it difficult to avoid small obstacles such as table legs.

The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments, and the same and similar parts between the various embodiments can be referred to each other. As for the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant part can be referred to the description of the method.

The above description of the disclosed embodiments enables any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims (4)

1. a kind of intelligent barrier avoiding robot based on a wordline laser, which is characterized in that be provided with camera in the robot With a wordline laser device, a wordline laser device is arranged in above the robot, and has downward inclination angle or described one Word line laser device is arranged in the lower part of the robot, and has upward inclination angle.

2. the intelligent barrier avoiding robot according to claim 1 based on a wordline laser, which is characterized in that a wordline The laser that laser issues has stable wavelength, and its colour component is fixed.

3. the intelligent barrier avoiding robot according to claim 1 based on a wordline laser, which is characterized in that a wordline The plane angle of divergence of laser is 110 °.

4. a kind of barrier-avoiding method of the intelligent barrier avoiding robot based on a wordline laser, which is characterized in that be suitable for claim 1 Intelligent barrier avoiding robot described in~3 any one based on a wordline laser, the barrier-avoiding method include:

A wordline laser robot march forward direction projection line laser；

The image of each object after camera acquisition projection line laser, extracts the online laser of object according to acquired image and throws The height L of raydist from the ground, wherein L=OAtan θ, θ are the line laser plane of wordline robot transmitting and the folder on ground Angle, O are the reverse extending line of line laser and the intersection point on ground, and A is the intersection point of object and ground；

According to the distance of the height L judgment object of the incident line, and carry out avoidance.