Ranging module, optical ranging device and mobile robot

Abstract

The utility model relates to the technical field of laser ranging, and discloses a ranging module, an optical ranging device and a mobile robot, the ranging module comprises a transmitting unit and a receiving unit, the transmitting unit comprises a laser transmitting light source, an optical lens, and a spectroscope used for dividing a single laser point into two or more light spots to perform multi-point distance measurement; a single-point laser of a laser emission light source is divided into two laser points through a spectroscope, one laser point is used for navigation and is emitted in the horizontal direction, and the other laser point is used for obstacle avoidance and is emitted at an obliquely downward angle of 15-20 degrees; the receiving unit adopts an area array sensor to carry out triangulation distance measurement, and the area array sensor is provided with a horizontal navigation distance measurement window, an obliquely downward obstacle avoidance distance measurement window and a plurality of distance measurement windows; the area array sensor is used for triangulation ranging, higher precision is achieved, the performance can be kept, meanwhile, cost is reduced, and the navigation and obstacle avoidance capacity of the robot is improved.

Description

Technical Field

[0001] This utility model belongs to the field of laser ranging technology, specifically relating to a ranging module, an optical ranging device, and a mobile robot. Background Technology

[0002] LiDAR is a sensor used for detection and navigation in robotic vacuum cleaners, service robots, and other similar applications. It rotates 360 degrees to measure distances with lasers, and then the main controller completes path planning. Currently, most LiDAR systems are single-line, while multi-line LiDAR is generally used in automotive or industrial applications and is more expensive.

[0003] Various obstacles inevitably appear along the robot's path. The height of a self-propelled robot affects its maneuverability during operation, making it more susceptible to being blocked and potentially limiting its working area. Current robotic vacuum cleaners use single-line LiDAR, which can perform path planning and navigation, but it struggles to avoid obstacles in the robot's blind spots (such as...). Figure 7 As shown), it is necessary to add a line laser or use a 3D area array TOF sensor for obstacle avoidance, or a dual-module self-walking robot for ranging and obstacle avoidance, such as a self-walking robot with the publication (announcement) number "CN 221696918 U";

[0004] The current method has a major drawback: it requires the addition of auxiliary obstacle avoidance sensors, such as front-facing linear lasers or dual ranging modules, to complete obstacle avoidance, but these are all expensive.

[0005] In view of this, a low-cost ranging module, optical ranging device, and mobile robot that can perform robot navigation and obstacle avoidance functions are proposed to solve the above problems. Utility Model Content

[0006] The present invention addresses the problem that existing robotic vacuum cleaner LiDAR systems are all single-line structures. While they can meet navigation requirements, they struggle to effectively avoid obstacles in the blind spot. To solve this problem, auxiliary obstacle avoidance sensors, such as front-facing linear LiDAR or dual ranging modules, are needed, but this increases costs.

[0007] To achieve the above objectives, this utility model provides the following technical solution:

[0008] A ranging module includes a transmitting unit and a receiving unit. The transmitting unit generates and transmits a laser signal for ranging into the environment, and the receiving unit captures the echo of the laser signal emitted by the transmitting unit after it is reflected by the environment, and calculates the distance between the receiving unit and the reflection point.

[0009] The emitting unit includes a laser emitting source for generating laser pulses or continuous laser beams, an optical lens for focusing and adjusting the shape of the laser beam to ensure that the laser point is accurately projected into the environment, and a beam splitter for splitting a single laser point into two or more spots for multi-point distance measurement.

[0010] The emitting unit splits the single-point laser light from the laser emission source into two laser points using a beam splitter on it;

[0011] The receiving unit uses an array sensor for triangulation ranging. The array sensor is equipped with a horizontal navigation ranging window for receiving laser signals emitted in the horizontal direction, an oblique obstacle avoidance ranging window for receiving laser signals emitted in the oblique downward direction, and multiple ranging windows for capturing optical signals and converting them into electrical signals.

[0012] By measuring the angle between the laser emission point and the receiving point, as well as the position of the laser point on the array sensor, the distance between the laser point and the obstacle is calculated using the geometric relationships of triangles. This method is generally more accurate than TOF (Time-of-Flight) ranging.

[0013] A beam splitter is an optical element that can split incident light into two or more beams. In this scheme, the beam splitter divides the single-point laser beam from a laser emission source into two laser points for simultaneous navigation and obstacle avoidance. By using a beam splitter, the cost of additional line laser ranging modules or dual ranging modules is saved, and only a rotating base is needed. Using an area array sensor for triangulation can achieve higher ranging accuracy, especially in short-range and high-precision wall-following capabilities, outperforming single-line lidar. This scheme improves the robot's navigation and obstacle avoidance capabilities while reducing costs.

[0014] Preferably, the beam splitter, optical lens, and laser emission source are arranged in sequence from front to back.

[0015] Preferably, the horizontal navigation ranging window, the downward obstacle avoidance ranging window, and multiple ranging windows are arranged sequentially from top to bottom.

[0016] Preferably, the beam splitter, optical lens, and laser emission source are mounted on a cylindrical housing, which is fixed to a rotating base and rotates around the central axis of the rotating base. The light outlet of the cylindrical housing emits two laser beams. One laser beam is used for navigation and is emitted horizontally, while the other is used for obstacle avoidance and is emitted at a downward angle of 15-20 degrees.

[0017] Preferably, the outer shell of the area array sensor is also cylindrical, with the area array sensor located on one side of the cylindrical shell. The area array sensor is a CCD area array image sensor, a CMOS area array image sensor, or a sensor array composed of PD, APD, or SPAD.

[0018] An optical ranging device includes a laser ranging bracket, a base, and the aforementioned ranging module. A cylindrical housing A and an area array sensor are mounted on the laser ranging bracket and respectively extend through the front side of the bracket. A rotating base is installed inside the laser ranging bracket, and a motor is installed inside the laser ranging bracket to drive and control the rotation speed and angle of the rotating base. The laser ranging bracket is fixed to the top edge of the base. This is because if placed in the middle, the downward-sloping light would be blocked from reaching the ground.

[0019] A mobile robot includes a robot body and an optical ranging device, wherein the base of the optical ranging device is fixed to the robot body's platform.

[0020] Compared with the prior art, the technical effects and advantages of this utility model are:

[0021] This ranging module, optical ranging device, and mobile robot split a single laser point into two using a beam splitter on the transmitting unit, one for navigation and the other for obstacle avoidance. This design reduces the robot's hardware requirements, saves costs, and further reduces system complexity by sharing a single rotating base. Furthermore, this solution utilizes an area array sensor for triangulation, which offers higher accuracy at close range compared to traditional Time-of-Flight (TOF) ranging methods—crucial for functions such as wall cleaning. In this way, the robot can achieve enhanced navigation and obstacle avoidance capabilities without increasing costs, thus improving overall performance.

[0022] This ranging module, optical ranging device, and mobile robot split a single laser point into two laser points using a beam splitter on the transmitting unit: one for navigation and the other for obstacle avoidance. These two laser points are emitted at horizontal and downward angles, respectively, to cover different detection areas. An area array sensor receives the signals reflected from these laser points and calculates the distance to obstacles using triangulation principles. This method offers higher accuracy than traditional Time-of-Flight (TOF) ranging methods, especially at close range. Therefore, this solution maintains performance while reducing costs and improving the robot's navigation and obstacle avoidance capabilities.

[0023] This ranging module, optical ranging device, and mobile robot reduce the robot's hardware costs. By reducing hardware requirements and optimizing measurement methods, it achieves enhanced navigation and obstacle avoidance capabilities. Furthermore, the use of an area array sensor for triangulation improves ranging accuracy, especially at close range. This allows the robot to more precisely control the distance to obstacles during task execution, improving overall performance.

[0024] In summary, this invention reduces costs while maintaining performance, improves the robot's navigation and obstacle avoidance capabilities, and provides new possibilities for the development of robotics technology. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the structure of this utility model;

[0026] Figure 2 This is a schematic diagram of the optical ranging device of this utility model;

[0027] Figure 3 This is a schematic diagram of the structure of the transmitting unit of this utility model;

[0028] Figure 4 This is a schematic diagram of the receiving unit of this utility model;

[0029] Figure 5 This is a state diagram of two laser points emitted by the laser ranging module when the mobile robot of this utility model is walking;

[0030] Figure 6 This is a route diagram for the emission of the light source from the emission unit of this utility model;

[0031] Figure 7 This is a state diagram of the laser point emitted by a traditional laser ranging module.

[0032] In the diagram: 1. Transmitting unit; 101. Laser emission source; 102. Optical lens; 103. Beam splitter; 104. Cylindrical outer shell; 105. Rotating base; 106. Motor; 107. Light outlet; 2. Receiving unit; 201. Area array sensor; 202. Horizontal navigation ranging window; 203. Downward obstacle avoidance ranging window; 204. Multiple ranging windows; 3. Laser ranging bracket; 4. Base; 5. Robot body; 6. Vehicle platform.

[0033] a. Obstacles. Detailed Implementation

[0034] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0035] The following is in conjunction with the appendix Figure 1-6 This application will be described in further detail.

[0036] This application discloses a ranging module, including a transmitting unit 1 and a receiving unit 2. The transmitting unit 1 is used to generate and transmit a laser signal for ranging into the environment, and the receiving unit 2 is used to capture the echo of the laser signal emitted by the transmitting unit 1 after being reflected by the environment, and to calculate the distance between the receiving unit 1 and the reflection point.

[0037] The emitting unit 1 includes a laser emitting source 101 for generating laser pulses or continuous laser beams, an optical lens 102 for focusing and adjusting the shape of the laser beam to ensure that the laser point is accurately projected into the environment, and a beam splitter 103 for splitting a single laser point into two or more light spots for multi-point distance measurement. The beam splitter 103, the optical lens 102, and the laser emitting source 101 are arranged sequentially from front to back. The beam splitter 103, the optical lens 102, and the laser emitting source 101 are mounted on a cylindrical housing 104, which is fixed on a rotating base 105 and rotates around the central axis of the rotating base 105. Two laser beams are emitted from the light outlet 107 of the cylindrical housing 104.

[0038] The laser emission of the emitting unit 1 uses a beam splitter 103, with a minimum of two light spots and a maximum of three to an infinite number of N light spots. The line connecting two or more light spots is perpendicular to the robot, which facilitates the calibration and confirmation of angles.

[0039] The transmitting unit 1 splits the single-point laser of the laser emitting source 101 into two laser points through the beam splitter 103 on it. One laser point is used for navigation and is emitted in a horizontal direction, while the other is used for obstacle avoidance and is emitted at a downward angle of 15-20 degrees.

[0040] The receiving unit 2 uses an area array sensor 201 for triangulation ranging. The area array sensor 201 is equipped with a horizontal navigation ranging window 202 for receiving laser signals emitted in the horizontal direction, an oblique obstacle avoidance ranging window 203 for receiving laser signals emitted in the oblique downward direction, and multiple ranging windows 204 for capturing light signals and converting them into electrical signals. The receiving unit uses the area array sensor 201 to open multiple optical windows to receive signals, thus completing the two functions of robot path navigation and obstacle avoidance.

[0041] The area array sensor 201 is a CCD area array image sensor, a CMOS area array image sensor, or a sensor array composed of PD, APD, and SPAD.

[0042] By measuring the angle between the laser emission point and the receiving point, as well as the position of the laser point on the array sensor 201, the distance between the laser point and the obstacle a is calculated using the geometric relationships of triangles. This method is generally more accurate than TOF (Time-of-Flight) ranging.

[0043] The horizontal navigation ranging window 202, the downward obstacle avoidance ranging window 203, and multiple ranging windows 204 are arranged sequentially from top to bottom. The outer shell of the area array sensor 201 is also a cylindrical structure, and the area array sensor 201 is located on one side of the cylindrical shell 104.

[0044] The primary function of the horizontal navigation ranging window 202 is to receive laser signals emitted in the horizontal direction. It allows sensors to detect reflected light from a horizontal laser point, used to measure the distance between the robot and its surroundings, and to create a map for navigation. By measuring the time or intensity of the light reflected back from the horizontal laser point, the horizontal distance between the robot and obstacle 'a' can be calculated, which is crucial for the robot to plan its path and avoid collisions.

[0045] The purpose of the downward-sloping obstacle avoidance ranging window 203 is to receive laser signals emitted in a downward-sloping direction. It is used to detect low obstacles a in front of the robot, ensuring that the robot can avoid these obstacles in time during its movement. The light reflected back from the downward-sloping laser point is received by the downward-sloping obstacle avoidance ranging window 203 and then used to calculate the distance between the laser and the ground obstacle a, assisting the robot in performing obstacle avoidance operations.

[0046] Multiple ranging windows 204 are the portion of the area array sensor 201 used to capture light signals and convert them into electrical signals. These electrical signals are then further processed to determine the position and distance information of the laser point. Each pixel on the photosensitive surface can independently detect changes in light intensity, which is crucial for achieving accurate distance measurement and image capture.

[0047] The advantage of this design lies in its ability to reduce the number of components and system complexity by integrating multiple functional windows onto a single CMOS sensor, thereby achieving navigation and obstacle avoidance functions at a lower cost. Furthermore, this design can improve response speed and measurement accuracy.

[0048] The emitting unit 1 splits the single-point laser light from the laser emitting source 101 into two laser points using a beam splitter 103. These two laser points typically have the following characteristics:

[0049] Navigation laser point: The first laser point is used for navigation. It is emitted horizontally to create a map of the surrounding environment as the robot rotates 360 degrees, aiding in path planning. This laser point is typically used to measure the distance between the robot and surrounding obstacles, thus creating an accurate map to help the robot navigate.

[0050] Obstacle Avoidance Laser Point: The second laser point is used for obstacle avoidance, and it is emitted at a downward angle of 15-20 degrees. This angle is set so that the laser point can detect obstacle 'a' at a low position in front of the robot, thus avoiding collisions during the movement of the robot vacuum or service robot. Since ground obstacles 'a' are usually located in front of and below the robot, this downward-angled laser point helps to detect and avoid these obstacles.

[0051] The two laser points are split by a beam splitter 103, allowing the robot to navigate and avoid obstacles simultaneously without additional sensors. The design of the beam splitter 103 ensures that the two laser points are perpendicular to the robot, which helps simplify the robot calibration process and ensures measurement accuracy.

[0052] Beam splitter 103 is an optical element that can split incident light into two or more beams. In this scheme, beam splitter 103 splits the single-point laser of laser emission source 101 into two laser points for simultaneous navigation and obstacle avoidance. By using beam splitter 103, the cost of additional line laser ranging modules or dual ranging modules is saved, and only a rotating base 105 is needed. Using area array sensor 201 for triangulation can achieve higher ranging accuracy, especially in short-range and high-precision wall-following capabilities, which is superior to single-line lidar. This scheme can improve the robot's navigation and obstacle avoidance capabilities while reducing costs.

[0053] An optical ranging device includes a laser ranging bracket 3, a base 4, and the aforementioned ranging module. A cylindrical housing 104A and an area array sensor 201 are mounted on the laser ranging bracket 3 and are respectively disposed through the front side of the laser ranging bracket 3. A rotating base 105 is installed inside the laser ranging bracket 3, and a motor 106 is installed inside the laser ranging bracket 3 to drive and control the rotation speed and angle of the rotating base 105. The laser ranging bracket 3 is fixed to the top edge of the base 4.

[0054] A mobile robot includes a robot body 5 and an optical ranging device, wherein a base 4 on the optical ranging device is fixed to the vehicle platform 6 of the robot body 5.

[0055] like Figure 5 As shown, when the mobile robot is walking, the laser ranging module emits two laser points. The two laser points are perpendicular to the robot in a straight line and rotate 360 ​​degrees. One laser point is horizontal to build a map for navigation, and the other is diagonally downward at 15-20 degrees to avoid obstacles.

[0056] The receiving sensor uses an area array sensor 201. For two laser points, the photosensitive surface of the area array sensor 201 needs to have two optical windows. The distance is calculated using the principle of triangulation (the reason why two TOF-APD or SPAD receivers are not used is that triangulation has higher accuracy, while TOF ranging has very high sensitivity and it is easy for two lasers to be fused into one receiver, making them difficult to distinguish).

[0057] This ranging module, optical ranging device, and mobile robot replace a single line laser ranging module. Traditionally, robotic vacuum cleaners or service robots may require a separate line laser ranging module for navigation and obstacle avoidance. Such modules are typically expensive. In this solution, a beam splitter 103 splits a single laser point into two laser points, enabling simultaneous navigation and obstacle avoidance, thus replacing the previously required separate line laser ranging module or dual ranging module. Because a single beam splitter 103 and area array sensor 201 are used to achieve both functions (navigation and obstacle avoidance), the need for additional hardware is reduced. This translates to savings in material and assembly costs.

[0058] In this solution, only one rotating base 105 is needed to support 360-degree scanning of the two laser points after beam splitting, while traditional solutions may require two rotating bases 105 to support the navigation and obstacle avoidance laser ranging modules respectively. The shared rotating base 105 further reduces costs.

[0059] The area array sensor 201, combined with the principle of triangulation, can achieve high-precision distance measurement. Triangulation uses geometric relationships to calculate distance and is generally more accurate than time-of-flight (TOF) based ranging methods, especially at shorter distances.

[0060] Because this solution uses two laser points (one for navigation and one for obstacle avoidance), it enables the robot to achieve higher ranging accuracy when approaching walls or other obstacles. This is especially important for the wall-following cleaning function of robots such as vacuum cleaners, as it allows for more precise control of the distance to the wall, avoiding collisions while maintaining cleaning effectiveness.

[0061] In summary, this solution reduces costs while maintaining or improving performance by minimizing hardware requirements and optimizing measurement methods, and performs particularly well in accurate distance measurement and wall-following functions.

[0062] Finally, it should be noted that the above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Although the present utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A ranging module, characterized in that, include: The transmitting unit (1) is used to generate and transmit laser signals for ranging to the environment. The transmitting unit (1) includes a laser emitting source (101) for generating laser pulses or continuous laser beams, an optical lens (102) for focusing and adjusting the shape of the laser beam to ensure that the laser point is accurately projected into the environment, and a beam splitter (103) for splitting a single laser point into two or more spots for multi-point distance measurement. The emitting unit (1) splits the single-point laser of the laser emitting source (101) into two laser points through the beam splitter (103) on it; The receiving unit (2) is used to capture the echo of the laser signal emitted by the transmitting unit (1) after being reflected by the environment and to calculate the distance between the receiving unit (2) and the reflection point. The receiving unit (2) uses an array sensor (201) for triangulation ranging. The array sensor (201) is provided with a horizontal navigation ranging window (202) for receiving laser signals emitted in the horizontal direction, an oblique obstacle avoidance ranging window (203) for receiving laser signals emitted in the oblique downward direction, and multiple ranging windows (204) for capturing optical signals and converting them into electrical signals.

2. The ranging module according to claim 1, characterized in that: The beam splitter (103), optical lens (102), and laser emission source (101) are arranged in sequence from front to back.

3. The ranging module according to claim 1, characterized in that: The horizontal navigation ranging window (202), the downward obstacle avoidance ranging window (203), and multiple ranging windows (204) are arranged sequentially from top to bottom.

4. A ranging module according to claim 1, characterized in that: The beam splitter (103), optical lens (102) and laser emission source (101) are mounted on the cylindrical shell (104). The cylindrical shell (104) is fixed on the rotating base (105) and rotates around the central axis of the rotating base (105). The light outlet (107) of the cylindrical shell (104) emits two laser beams.

5. A ranging module according to claim 4, characterized in that: Two laser beams are emitted from the light outlet (107), one of which is used for navigation and is emitted in a horizontal direction, and the other is used for obstacle avoidance and is emitted at a downward angle of 15-20 degrees.

6. A ranging module according to claim 4, characterized in that: The outer shell of the area array sensor (201) is also a cylindrical structure. The area array sensor (201) is located on one side of the cylindrical shell (104). The area array sensor (201) is a CCD area array image sensor, a CMOS area array image sensor, or a sensor array composed of PD, APD, and SPAD.

7. An optical ranging device, characterized in that, The system includes a laser rangefinder bracket (3), a base (4), and a rangefinder module as described in any one of claims 1-6. A cylindrical housing (104) and an area array sensor (201) are mounted on the laser rangefinder bracket (3) and are respectively disposed through the front side of the laser rangefinder bracket (3). A rotating base (105) is installed inside the laser rangefinder bracket (3), and a motor (106) is installed inside the laser rangefinder bracket (3) to drive and control the rotation speed and angle of the rotating base (105). The laser rangefinder bracket (3) is fixed at the top edge of the base (4).

8. A mobile robot, characterized in that, It includes a robot body (5) and an optical ranging device as described in claim 7, wherein the base (4) on the optical ranging device is fixed on the vehicle platform (6) of the robot body (5).

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