Optical system for generating three-line laser light and three-line light source time division detection method

Abstract

The application relates to an optical system for generating three-line laser and a three-line light source time division detection method, the optical system comprising a three-line light source, a collimating mirror and a line expanding device, the three-line light source comprising a first line light source, a second line light source and a third line light source, the second line light source passing through a reference optical axis, and the first line light source and the third line light source being symmetrically arranged on the two sides of the third line light source; the optical axis of the collimating mirror is the reference optical axis, and the collimating mirror is used for collimating the first line laser, the second line laser and the third line laser respectively; and the line expanding device comprises three line expanding mirrors which are sequentially connected and are respectively arranged on the output light paths of the three lines of laser after passing through the collimating mirror, so as to respectively expand the three lines of laser in different directions. The application has the effect that three sets of mirror groups and three probes in the conventional technology can achieve, can effectively save elements, has the advantages of low cost and small size, and can effectively reduce the operation amount and the debugging difficulty in the later stage.

Description

Technical Field

[0001] This application relates to the field of optical technology, and in particular to an optical system for generating a three-line laser and a time-division detection method for a three-line light source. Background Technology

[0002] Line structured light 3D vision measurement is a non-contact measurement method based on the optical triangulation principle. It boasts advantages such as high measurement speed, high accuracy, simple structure, economy, and ease of implementation, leading to its increasingly widespread application in industrial measurement and inspection, medicine, engineering design, and reverse engineering. For example, in industrial measurement and inspection, it can be applied to equipment such as robotic vacuum cleaners, service robots, warehouse robots, and logistics robots. Its measurement principle involves first spreading a laser beam emitted from a laser into a continuous laser plane through a cylindrical mirror, which is then used to illuminate the object being measured. The laser beam intersects with the object's surface to form a deformed structured light fringe. Then, the geometric information of the deformed structured light fringe image captured by a CMOS or CCD probe, combined with the system's motion parameters during measurement, is used to extract the 3D topographic geometric information of the object's surface. The processing and calculation of the deformed structured light fringe image is one of the key aspects of 3D measurement.

[0003] Due to the need for detection in different directions, multiple line structured light sensors are installed on robotic vacuum cleaners, with each sensor facing a different direction. Each line structured light sensor requires a line light source and a camera module, which necessitates the use of multiple line light sources and multiple camera modules on the robotic vacuum cleaner, thus increasing costs. Summary of the Invention

[0004] In order to achieve efficient utilization of the camera module and lens assembly, thereby reducing costs, this application provides an optical system for generating three-line lasers and a time-division detection method for three-line light sources.

[0005] In a first aspect, this application provides an optical system for generating a three-line laser, employing the following technical solution: An optical system for generating a three-line laser, comprising:

[0006] The three-line light source includes a first line light source, a second line light source, and a third line light source. The second line light source passes through a reference optical axis, and the first line light source and the third line light source are located on both sides of the third line light source and are symmetrically arranged.

[0007] A collimating lens, wherein the optical axis of the collimating lens is coaxial with the reference optical axis, and the collimating lens is used to collimate the first line laser, the second line laser and the third line laser in the length direction of their respective line light sources, wherein the first line laser, the second line laser and the third line laser are emitted by the first line light source, the second line light source and the third line light source, respectively;

[0008] The line expansion device includes a first line expander, a second line expander, and a third line expander connected in sequence. They are located on the output optical paths of the first line laser, the second line laser, and the third line laser after passing through the collimating lens, and are used to expand the first line laser, the second line laser, and the third line laser.

[0009] Optionally, the first line light source and the second line light source are located on both sides of the optical axis of the collimating lens and are arranged parallel to each other, and the length direction of the third line light source is perpendicular to the length direction of the first line light source and the second line light source.

[0010] Optionally, the first, second, and third line light sources are composed of several laser light sources arranged in lines, wherein the laser light sources are edge-emitting lasers or area-emitting lasers.

[0011] Optionally, the laser source is an EEL edge-emitting laser, a VCSEL laser, or an HCSEL laser.

[0012] Optionally, the aperture of the laser source is 3 to 20 μm.

[0013] Optionally, the aperture of the laser source is 8 μm.

[0014] Optionally, the off-axis height of the first and third line light sources relative to the reference optical axis is 1.5 to 4.0 mm, and the line length of the first, second, and third line light sources is less than 2.5 mm.

[0015] Optionally, the collimating lens is a rotationally symmetric biconvex lens with a center thickness of 1–10 mm, an aperture of 5–18 mm, a focal length of 2–10 mm, and a refractive index of 1.3–2.

[0016] The expression for the front surface curve of the collimating mirror is:

[0017]

[0018] Where α0=0, 3≤r<4, n≥0,

[0019] When n = 0, the range values ​​of each parameter in equation ① are: c = (-2 ~ 1);

[0020] The expression for the back surface curve of the collimating mirror is:

[0021]

[0022] Where α0=0, -20≤r<-2, n≥6,

[0023] When n = 6, the range values ​​of each parameter in equation ② are as follows:

[0024] c = (-2 to 10);

[0025] α1 = (-10 ~ 10);

[0026] α2=(-9×10 4 ~10);

[0027] α3=(-50~9×10 4 );

[0028] α4=(-9×10 6 ~1×10 2 );

[0029] α5=(-3×10 2 ~6×10 7 );

[0030] α6=(-9×10 9 ~2×10 2 ).

[0031] Optionally, the first, second, and third expander lenses are used to expand the first, second, and third line lasers into illuminance distribution functions that tend towards E. w The emitted light has an illuminance distribution function of: 1≤n≤4, E0 is the illuminance at a point on the axis.

[0032] Optionally, the collimating lens is made of optical plastic, glass, quartz, or crystal.

[0033] Optionally, the refractive index of the collimating lens is typically 1.529.

[0034] Optionally, the first, second, and third magnifying lenses are all lenses with a wave structure. The wave structure includes multiple convex teeth arranged in parallel. The arrangement direction of the convex teeth on the first, second, and third magnifying lenses is the line arrangement direction of the laser light source on the first, second, and third line light sources, respectively, and the tooth tips face the collimating lens, while the tooth backs are located on the same plane.

[0035] Optionally, the maximum divergence angle of the first line laser after passing through the first magnifying glass is 30 to 150°.

[0036] Optionally, the maximum divergence angle of the first line laser after passing through the first magnifying glass is 65°.

[0037] Optionally, the maximum divergence angle of the second line laser after passing through the second magnifying glass is 30 to 150°.

[0038] Optionally, the maximum divergence angle of the second line laser after passing through the second magnifying glass is 120°.

[0039] Optionally, the maximum divergence angle of the third line laser after passing through the third magnifying glass is 30 to 150°.

[0040] Optionally, the maximum divergence angle of the third line laser after passing through the third magnifying glass is 65°.

[0041] Optionally, the extension direction of the first magnifying glass is perpendicular to the emission direction of the first line laser after passing through the collimating glass, wherein the emission direction is the propagation direction of the line laser when the divergence angle is 0.

[0042] Optionally, the extension direction of the second magnifying glass is perpendicular to the emission direction of the second line laser after passing through the collimating glass, wherein the emission direction is the propagation direction of the line laser when the divergence angle is 0.

[0043] Optionally, the extension direction of the third expanding mirror is perpendicular to the emission direction of the third line laser after passing through the collimating mirror, wherein the emission direction is the propagation direction of the line laser when the divergence angle is 0.

[0044] Optionally, the first magnifying lens and the second magnifying lens form an angle of (30°±20°).

[0045] Optionally, the first magnifying lens and the second magnifying lens form an angle of 30°.

[0046] Optionally, the second magnifying lens and the third magnifying lens form an angle of (30°±20°).

[0047] Optionally, the second magnifying lens and the third magnifying lens form an angle of 30°.

[0048] Optionally, the first magnifying lens, the second magnifying lens, and the third magnifying lens are integrated into one unit.

[0049] Optionally, the first magnifying lens and the second magnifying lens are detachably connected.

[0050] Optionally, the first magnifying lens and the second magnifying lens are connected by a clamp.

[0051] Optionally, the first magnifying lens and the second magnifying lens are fixedly connected.

[0052] Optionally, the first magnifying lens and the second magnifying lens are bonded together.

[0053] Optionally, the second and third magnifying lenses are detachably connected.

[0054] Optionally, the second and third magnifying lenses are connected by a clamp.

[0055] Optionally, the second and third magnifying lenses are fixedly connected.

[0056] Optionally, the second magnifying lens and the third magnifying lens are bonded together.

[0057] Secondly, the three-line light source time-division detection method provided in this application adopts the following technical solution:

[0058] A three-line light source time-division detection method includes the following steps:

[0059] Set a reference optical axis and install the optical system described above for generating a three-line laser based on the reference optical axis;

[0060] Based on a preset timing control, the first, second, and third linear light sources are turned on and off sequentially.

[0061] Light reflection signals are collected sequentially based on a preset time sequence, and information is extracted and identified from the light reflection signals according to a preset strategy.

[0062] Different line light sources have different preset strategies.

[0063] Thirdly, the device provided in this application adopts the following technical solution:

[0064] An apparatus includes a body and a line structured light detection device, the line structured light detection device including a camera module, a controller, and an optical system as described above for generating a three-line laser.

[0065] Optionally, the line structured light detection device employs the three-line light source time-division detection method described above for line structured light detection.

[0066] Optionally, the device may be a sweeping robot, a service robot, a warehouse robot, or a logistics robot.

[0067] In summary, this application includes at least one of the following beneficial technical effects:

[0068] 1. The optical system provided in this application consists of a three-line light source, a collimating lens, and a beam expander, and is used in conjunction with a camera module. One optical system can emit three lines of structured light, which are then detected by a camera module using time-division multiplexing, achieving the effect that requires three optical systems and three camera modules in the prior art. This effectively saves on component requirements and has the advantages of low cost and small size.

[0069] 2. The optical system provided in this application contains fewer lenses, which effectively reduces the amount of post-assembly operations and debugging difficulty compared to complex lens groups, and also facilitates the later maintenance work.

[0070] 3. The time-division multiplexing method provided in this application allows a single optical system to process and receive different line lasers using only the same set of mirrors and the same camera module. Related technologies typically employ frequency-division multiplexing, using multiple sets of different mirrors to process line lasers of different frequencies, or using one or more camera modules to process and receive multiple line lasers, avoiding mutual interference between different line lasers. However, these technologies suffer from several drawbacks. First, different mirrors and camera modules have tolerances, making it difficult to systematically adjust them using software to reduce errors based on mirror characteristics. Second, these technologies require more components, resulting in lower overall system reliability. This application, on the other hand, can process and receive multiple line lasers using the same set of mirrors and camera modules. Subsequent software design allows for convenient processing of the received light information based on shared tolerances, leading to better overall system reliability. Attached Figure Description

[0071] Figure 1 This is a schematic diagram of the structure of an optical system for generating a three-line laser according to an embodiment of this application. Figure 1 .

[0072] Figure 2 This describes the optical effect of an optical system for generating a three-line laser in an embodiment of this application. Figure 2 .

[0073] Figure 3 This describes the optical effect of an optical system for generating a three-line laser in an embodiment of this application. Figure 1 .

[0074] Figure 4 This describes the optical effect of an optical system for generating a three-line laser in an embodiment of this application. Figure 2 .

[0075] Figure 5 This is a light intensity distribution diagram of the optical field after the linear laser in the embodiment of this application is expanded along the length direction by the expansion device.

[0076] Explanation of reference numerals in the attached figures:

[0077] 1. Three-line light source; 2. Collimating lens; 3. Line expansion device. Detailed Implementation

[0078] The present application will be further described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are merely illustrative of the present application and are not intended to limit the scope of the application.

[0079] In the following description, numerous specific details are set forth for illustrative purposes in order to provide a thorough understanding of the inventive concept. For clarity, not all features of the actual embodiment need to be described. Furthermore, the language used in this disclosure has been primarily chosen for readability and instructional purposes and may not have been chosen to define or limit the subject matter of the invention, thus requiring the necessary claims to determine such inventive subject matter. References to “an embodiment” or “an embodiment” in this disclosure mean that a particular feature, structure, or characteristic described in connection with that embodiment is included in at least one embodiment, and multiple references to “an embodiment” or “an embodiment” should not be construed as necessarily referring to the same embodiment.

[0080] Unless explicitly defined, the terms “a,” “an,” and “the” are not intended to refer to a singular entity, but rather to include a general category whose specific examples can be used for illustration. Therefore, the use of the terms “a” or “an” can mean any number of at least one, including “a,” “one or more,” “at least one,” and “one or more.” The term “or” means any of the options and any combination of the options, including all options unless explicitly indicated that the options are mutually exclusive. The phrase “at least one of” when combined with a list of items refers to a single item in the list or any combination of items in the list. The phrase does not require all items listed unless explicitly defined as such.

[0081] This application discloses an optical system for generating a three-line laser. (Refer to...) Figure 1 and Figure 2 The optical system includes a three-line light source 1, a collimating lens 2, and a line expander 3. The three-line light source 1 is used to emit multiple staggered line lasers, the collimating lens 2 is used to collimate the multiple staggered line lasers, and the line expander 3 is used to expand the line lasers in the linear direction so that the light field distribution of the line lasers is adjusted to meet the requirements.

[0082] The three-line light source 1 is usually placed on a substrate, which can be a PCB circuit board, a ceramic substrate, or a copper substrate, or other board material with wires. This does not impose specific limitations on the installation of the three-line light source 1, but any structure that can fix the three-line light source 1 and provide power is acceptable.

[0083] The three-line light source 1 includes a first line light source, a second line light source, and a third line light source. For ease of description of the positions of each component of this optical system, a straight line set in a uniform space is used as a reference, and this straight line serves as the reference optical axis. Therefore, the second line light source passes through the reference optical axis, and the first and third line light sources are symmetrically positioned on either side of the second line light source. In different embodiments, the first, second, and third line light sources can form different relative orientations. For example, the first and third line light sources may be located on the same plane and form an angle with each other, or the first and second line light sources may form an angle with each other. For different relative positions, the parameters of the alignment lens 2 and the line-expanding device 3 need to be adjusted accordingly so that the light field distribution of the final emitted line structured light meets the requirements, and the linewidth and relative position of the line structured light meet the requirements.

[0084] To facilitate parameter adjustment, this scheme employs a configuration where the first, second, and third line light sources are arranged in an "I" shape on the same plane, perpendicular to the reference optical axis. Specifically, the center of the second line light source is traversed by the reference optical axis, and the first and third line light sources are positioned perpendicular to the second line light source. Furthermore, the center point of the first line light source is opposite to the endpoint of the second line light source, and the center point of the third line light source is opposite to the endpoint of the second line light source. More specifically, but not limitedly, a configuration of the three line light sources 1 is proposed, where the off-axis height of the first and third line light sources relative to the reference optical axis is 1.5–4.0 mm, and the line lengths of the first, second, and third line light sources are less than or equal to 2.5 mm.

[0085] In different embodiments, the first, second, and third line light sources are composed of several laser light sources arranged in a line. The laser light sources are EEL edge-emitting lasers, VCSEL lasers, or HCSEL lasers, as long as the light field of the laser light source has a conical divergence, a small maximum divergence angle, and sufficient luminous power. As an example, in this application, a VCSEL laser is used as the laser light source.

[0086] VCSEL, or Vertical-Cavity Surface-Emitting Laser, typically employs molecular beam epitaxy (MBE) or metal-organic chemical vapor deposition (MOCVD) methods. Dozens of N-type gallium aluminum arsenide epitaxial layers (each with a different refractive index) are grown on a gallium arsenide wafer. Next, another gallium arsenide epitaxial layer is grown as the emitting region, followed by dozens of P-type gallium aluminum arsenide epitaxial layers (each with a different refractive index). Finally, a metal electrode layer is grown on both the top and bottom surfaces of the wafer, and a circular hole is created in the top metal electrode using chemical etching, allowing the laser to emit from above. It boasts advantages such as extremely low divergence, high brightness (power), good monochromaticity, and good coherence.

[0087] In this embodiment, multiple VCSEL light sources can be formed by chemically etching several circular holes into the metal electrodes on a single high-power VCSEL chip, or by arranging several VCSEL chips side by side. In different embodiments, multiple VCSEL chips can be independently fixed on the substrate, with the substrate supplying power to each VCSEL chip independently; alternatively, multiple VCSEL chips can be made into a light strip, fixed in series, and then placed on the substrate for unified power supply. This application does not impose specific limitations on this approach. As an example, but not a limitation, in one embodiment provided in this application, the VCSEL chip is fixedly packaged on the substrate using COB packaging technology, and the aperture of the laser light source is 3–20 μm. It should be noted that the aperture of the laser light source is positively correlated with the linewidth of the final structured light. Specifically, the aperture of the laser light source is 8 μm.

[0088] Furthermore, since the power of a single VCSEL light source is difficult to increase significantly, when high power is required, it is necessary to extend the length of the line source to increase the overall power. This would severely affect the setting of the collimating lens 2. Therefore, in this scheme, the laser power of the first, second, and third line sources is set to be greater than 50mW and less than 100mW. It should be noted that when improvements in the light source manufacturing process enable a single light source to produce higher power lasers, this is not considered to exceed the recommended laser power setting range in this scheme. The limitation on laser power is mainly due to the limitation of the line length of the line sources.

[0089] In various embodiments of this application, the laser light sources can be arranged strictly in a straight line, or they can be located on opposite sides of a straight line with a certain deviation from the line. This deviation can be overcome by adjusting the mirror parameters of the collimating lens 2 and the line-expanding device 3, so that the laser emitted by the VCSEL light source can be collimated as much as possible in the line width direction and form the smallest possible line width. In order to reduce the workload of adjusting the mirror parameters of the collimating lens 2 and the line-expanding device 3, in this application, the laser light sources are arranged strictly in the same straight line with equal spacing.

[0090] Collimating lens 2 is a rotationally symmetric biconvex lens with its optical axis coaxial with the reference optical axis, thus collimating the first, second, and third line lasers, which are emitted by the first, second, and third line light sources, respectively. In the laser linewidth direction, since the VCSEL light source is a single point and the maximum divergence angle of a single VCSEL light source in the laser linewidth direction is approximately thirty degrees, the collimation is excellent, with the divergence angle approaching zero degrees after collimation. However, in the laser length direction, because the VCSEL light sources are arranged in a straight line, a certain off-axis height is generated, resulting in a specific angle for the emitted laser. Therefore, collimating lens 2 is mainly used for collimating the laser in both the linewidth and length directions.

[0091] As an example, the collimating lens 2 has a center thickness of 1–10 mm, an aperture of 5–18 mm, a focal length of 2–10 mm, and a refractive index of 1.3–2. Furthermore, in different embodiments, the collimating lens 2 can be made of optical plastic, glass, quartz, crystal, or other typical optical materials, as long as the refractive index is between 1.3 and 2. Here, a typical value for the refractive index of the collimating lens 2 is 1.529.

[0092] It should be noted that the "collimation" mentioned in this application, in addition to collimation in the conventional sense, also refers to the use of collimating lens 2 to correct the passing off-axis laser light to achieve a "collimation" effect. For collimating lens 2 in the conventional sense, it is usually used to refract the accompanying axis light to refract the conical light field emitted by a continuous point source towards a parallel light field. However, when conventional collimating lens 2 refracts laser light emitted from off-axis sources, such as the first and third line sources with a distance of 1.5–4.0 mm from the optical axis as described in this application, the refracted laser light field often cannot maintain its original shape; for example, when it strikes a plane perpendicular to the optical axis, it will produce a curved linear light spot. In this scheme, referring to... Figure 3 and Figure 4 The collimation of collimating lens 2 refers not only to its ability to refract the laser to make the emitted light approach a parallel light field, but also to its ability to correct the overall emission direction of the laser from the paraxial point to the far axis, so that the emitted line laser is distributed in a straight line.

[0093] Since collimating lens 2 is a rotationally symmetric biconvex lens, any plane passing through the reference optical axis will produce the same cross-section on collimating lens 2. Taking any cross-section as an example, there will be two mirror curves on this cross-section, namely the front surface curve and the back surface curve.

[0094] The expression for the front surface curve of collimating mirror 2 is:

[0095]

[0096] Where α0=0, 3≤r<4, n≥0,

[0097] When n = 0, the range values ​​of each parameter in equation ① are: c = (-2 to 1).

[0098] As an example, if c is -1, then equation ① becomes:

[0099]

[0100] The expression for the back surface curve of collimating lens 2 is:

[0101]

[0102] Where α0=0, -20≤r<-2,n≥6;

[0103] When n = 6, the range values ​​of each parameter in equation ② are as follows:

[0104] c = (-2 to 10);

[0105] α1 = (-10 ~ 10);

[0106] α2=(-9×10 4 ~10);

[0107] α3=(-50~9×10 4 );

[0108] α4=(-9×10 6 ~1×10 2 );

[0109] α5=(3×10 2 ~6×10 7 );

[0110] α6=(-9×10 9 ~2×10 2 ).

[0111] As an example, c is -1, α1 is -5, and α2 is -3 × 10. 4α3 is -15, α4 is 20, and α5 is 2 × 10⁻⁶. 6 α6 is taken as -5×10 6 .

[0112] It is important to note that for the low-order examples of equations ① and ② given in this scheme, higher-order polynomial curve expressions can be easily obtained through a finite number of repeated experiments, and the curve shapes corresponding to these polynomial expressions within the same range of r values ​​can be essentially the same. However, the examples given in this scheme are used to illustrate that a collimating lens 2 can correct the overall emission direction of the laser beam passing through it from the paraxial point to the abaxial direction, thereby ensuring a straight distribution of the emitted linear laser beam. The specific expression for the collimating lens 2 is not limited. In other words, the shape that achieves this function is basically determined, but the corresponding expression can differ, and the corresponding parameters can have very significant differences.

[0113] Furthermore, this application prefers a 0th-order front surface curve and a 6th-order rear surface curve because lower-order surface curves are more difficult to tune and have lower corresponding processing costs. For higher-order surface curves, although similar curve shapes can be obtained within the same range of r values, the resulting processing costs will be higher.

[0114] The beam amplification device 3 includes a first beam amplification mirror, a second beam amplification mirror, and a third beam amplification mirror connected in sequence. These mirrors are located on the output optical paths of the first, second, and third line lasers after passing through the collimating mirror 2, and are used to amplify the first, second, and third line lasers. The first, second, and third beam amplification mirrors are used to amplify the first, second, and third line lasers so that the illuminance distribution function tends to E. w The emitted light has an illuminance distribution function of: 1 ≤ n ≤ 4, E0 is the illuminance at a point on the axis. For details, refer to... Figure 2 The first, second, and third expander lenses are all lenses with a wave structure. The wave structure includes multiple parallel-arranged convex teeth. The arrangement direction of the convex teeth on the first, second, and third expander lenses is the same as the line arrangement direction of the laser light sources on the first, second, and third line light sources, respectively, with the tooth tips facing the collimating lens 2 and the tooth backs located on the same plane. In different embodiments, the tooth shape of the convex teeth on the expander lenses can be different, as long as it ensures that the illuminance distribution function of the light emitted from the collimating lens 2 tends to E after passing through the expander lens. w That's all. (Refer to...) Figure 5 The illuminance distribution function is E w At the origin, the light intensity approaches zero. As the divergence angle along the laser beam increases to a certain distance, the light intensity gradually increases and then rapidly decreases until it approaches zero.

[0115] Furthermore, by employing the 3-tooth design of the beam expander, the maximum divergence angles of the first, second, and third line lasers after passing through the first, second, and third beam expanders can be controlled. Specifically, the maximum divergence angles of the first, second, and third line lasers after passing through the first, second, and third beam expanders are all within the range of 30–150°. For example, the maximum divergence angle of the first, second, and third line lasers after passing through the first, second, and third beam expanders is 65°.

[0116] Furthermore, to achieve better beam amplification, the extension direction of the first beam amplifier is perpendicular to the emission direction of the first line laser after passing through collimating lens 2, the extension direction of the second beam amplifier is perpendicular to the emission direction of the second line laser after passing through collimating lens 2, and the extension direction of the third beam amplifier is perpendicular to the emission direction of the third line laser after passing through collimating lens 2. The emission direction is the propagation direction of the line laser when the divergence angle is 0. Specifically, the first and second beam amplifiers form an angle of (30°±20°), and the second and third beam amplifiers form an angle of (30°±20°). For example, the first and second beam amplifiers form an angle of 30°, and the second and third beam amplifiers form an angle of 30°.

[0117] In different embodiments, the first, second, and third expanding lenses can be fixedly connected or detachably connected. The fixed connection can be integral, adhesive, or other methods, as long as it prevents relative displacement between the first, second, and third expanding lenses. The detachable connection can be achieved through connecting structures or connectors, such as snap-fit ​​structures or clamps, again ensuring that the first, second, and third expanding lenses do not experience relative displacement.

[0118] This application also discloses a three-line light source time-division detection method, including the following steps:

[0119] S1. Set a reference optical axis and install the optical system for generating tri-line laser as described above based on the reference optical axis;

[0120] S2. Based on a preset timing sequence, the first, second, and third linear light sources are controlled to turn on and off sequentially;

[0121] S3. Acquire light reflection signals sequentially based on a preset time sequence, and extract and identify information from the light reflection signals based on preset strategies. Different preset strategies correspond to different line light sources.

[0122] The three-line light source 1 can provide three laser outputs and achieve time-division control of the three lines. For example, each of the three line light sources is equipped with a switch to control the power supply to the line light source. The controller is connected to each of the three switches and outputs control signals according to a preset timing sequence, thereby causing the three line light sources to light up and turn off sequentially. In addition, the controller is connected to a camera module, which sequentially collects light reflection signals based on a preset timing sequence. Since the spot positions of different line structured light beams are different, different preset strategies are required to extract and identify information from the light reflection signals, thereby realizing the time-division detection method of the three-line light source 1.

[0123] This application also discloses a device, including a body and a line structured light detection apparatus. The line structured light detection apparatus includes a camera module, a controller, and an optical system for generating a three-line laser as described above. This line structured light detection apparatus utilizes the three-line light source time-division detection method described above for line structured light detection. In different embodiments, the device can be a sweeping robot, service robot, warehouse robot, or logistics robot; any device capable of optical detection using this line structured light detection apparatus is acceptable.

[0124] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. An optical system for generating a three-line laser, characterized in that, include: The three-line light source includes a first line light source, a second line light source, and a third line light source. The second line light source passes through a reference optical axis, and the first line light source and the third line light source are symmetrically arranged on both sides of the second line light source. A collimating lens, wherein the optical axis of the collimating lens is coaxial with the reference optical axis, and the collimating lens is used to collimate a first line laser, a second line laser, and a third line laser, wherein the first line laser, the second line laser, and the third line laser are emitted by a first line light source, a second line light source, and a third line light source, respectively; The beam expander includes a first beam expander, a second beam expander, and a third beam expander connected in sequence. They are located on the output optical paths of the first, second, and third line lasers after passing through the collimating lens, and are used to expand the beams of the first, second, and third line lasers. The extension direction of the first magnifying glass is perpendicular to the emission direction of the first line laser after passing through the collimating glass; The extension direction of the second magnifying glass is perpendicular to the emission direction of the second line laser after passing through the collimating glass; The extension direction of the third expanding mirror is perpendicular to the emission direction of the third line laser after passing through the collimating mirror; Wherein, the emission direction is the propagation direction when the divergence angle of the linear laser is 0; The first magnifying glass and the second magnifying glass form The included angle between the second magnifying lens and the third magnifying lens, The included angle.

2. The optical system according to claim 1, characterized in that, The first and second line light sources are located on opposite sides of the collimating lens optical axis and are arranged parallel to each other. The length direction of the third line light source is perpendicular to the length direction of the first and second line light sources.

3. The optical system according to claim 1 or 2, characterized in that, The first, second, and third line light sources are composed of several laser light sources arranged in lines, and the laser light sources are edge-emitting lasers or area-emitting lasers.

4. The optical system according to claim 3, characterized in that, The laser source is an EEL edge-emitting laser, a VCSEL laser, or an HCSEL laser.

5. The optical system according to claim 3, characterized in that, The aperture of the laser source is 3~20um.

6. The optical system according to claim 5, characterized in that, The aperture of the laser source is 8 μm.

7. The optical system according to claim 5, characterized in that, The off-axis height of the first and third line light sources relative to the reference optical axis is 1.5~4.0mm, and the line length of the first, second, and third line light sources is less than 2.5mm.

8. The optical system according to claim 7, characterized in that, The collimating lens is a rotationally symmetrical biconvex lens.

9. The optical system according to claim 8, characterized in that, The center thickness is 1~10mm, the aperture is 5~18mm, the focal length is 2~10mm, and the refractive index is 1.3~2; The expression for the front surface curve of the collimating mirror is: ； in, ; When n=0, the range values ​​of each parameter in equation ① are as follows: ; The expression for the back surface curve of the collimating mirror is: ； in, ; When n=6, the range values ​​of each parameter in equation ② are as follows: 。 10. The optical system according to claim 1 or 9, characterized in that, The first, second, and third magnifying lenses are used to magnify the first, second, and third line lasers into a light intensity distribution function that tends towards a certain value. The emitted light has an illuminance distribution function of: , is the illuminance at a point on the axis.

11. The optical system according to claim 10, characterized in that, The first, second, and third magnifying lenses are all lenses with a wave structure. The wave structure includes multiple convex teeth arranged in parallel. The arrangement direction of the convex teeth on the first, second, and third magnifying lenses is the line arrangement direction of the laser light source on the first, second, and third line light sources, respectively, and the tooth tips face the collimating lens, while the tooth backs are located on the same plane.

12. The optical system according to claim 1 or 11, characterized in that, The maximum divergence angle of the first line laser after passing through the first magnifying lens is 30~150°; And / or, the maximum divergence angle of the second line laser after passing through the second magnifying lens is 30~150°; And / or, the maximum divergence angle of the third line laser after passing through the third magnifying glass is 30~150°.

13. The optical system according to claim 1, characterized in that, The first magnifying lens, the second magnifying lens, and the third magnifying lens are integrated into one unit.

14. The optical system according to claim 1, characterized in that, The first, second, and third magnifying lenses are either detachably or fixedly connected.

15. A three-line light source time-division detection method, characterized in that, Includes the following steps: A reference optical axis is set, and an optical system for generating a tri-line laser as described in any one of claims 1 to 14 is installed based on the reference optical axis; Based on a preset timing control, the first, second, and third linear light sources are turned on and off sequentially. Light reflection signals are collected sequentially based on a preset time sequence, and information is extracted and identified from the light reflection signals based on preset strategies. Different preset strategies are used for different line light sources.

16. A device, characterized in that, The device includes a body and a line structured light detection device, wherein the line structured light detection device includes a camera module, a controller, and an optical system for generating a three-line laser as described in any one of claims 1 to 14.

17. The device according to claim 16, characterized in that, The line structured light detection device uses the three-line light source time-division detection method as described in claim 15 to perform line structured light detection.

18. The device according to claim 16 or 17, characterized in that, The equipment is a sweeping robot, service robot, warehouse robot, or logistics robot.

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