A landing light and a ranging method thereof

Abstract

This invention relates to the field of aircraft landing light technology, and discloses a landing light and its distance measurement method. The distance measurement method includes: S1, the control system controls each of the constantly lit LED beads to continuously illuminate at a first power, and the control system controls each of the scanning LED beads to illuminate sequentially at a second power according to a preset order, wherein the second power is greater than the first power; S2, the control system controls the camera module to start synchronously with each scanning LED bead; S3, the processing unit receives the obstacle images transmitted by the camera module; thereby enabling the landing light to generate identifiable illumination differences by utilizing the sequential high-power illumination of the scanning LED beads while maintaining continuous and stable basic illumination, and by controlling the camera module to start synchronously with each scanning LED bead, the processing unit calculates the distance between the obstacle and the landing light based on the obstacle images, allowing the pilot to obtain real-time distance information of obstacles ahead.

Description

Technical Field

[0001] This invention relates to the field of aircraft landing light technology, and in particular to a landing light and its ranging method. Background Technology

[0002] During the landing phase, aircraft need to determine whether there are obstacles on the runway ahead. To accurately measure the distance to obstacles, existing technologies typically install laser ranging radar or structured light visual ranging devices on the aircraft. However, laser ranging radar is expensive, with a single module costing thousands of yuan, and requires additional installation space. It is necessary to modify the original structure of the aircraft to install it, which makes airworthiness certification extremely difficult and maintenance costs high. Structured light visual ranging solutions also require the addition of a dedicated structured light projector, which involves significant hardware modifications and high costs. Therefore, to save costs, some solutions only provide illumination through landing lights. For example, patent document CN119617358A discloses a landing light that achieves mechanical adjustment of the pitch and roll angles of the light body through a mounting bracket, a rotating ring, a first drive mechanism, and a second drive mechanism. It can automatically adjust the illumination angle according to the flight attitude of the aircraft. Existing landing lights can only be used for illumination and rough distance judgment, and do not have the ability to actively detect the distance to obstacles or issue warnings.

[0003] Therefore, there is a need for a landing light that requires little installation space, is low in cost, and can achieve accurate obstacle distance measurement, as well as a distance measurement method thereof. Summary of the Invention

[0004] The purpose of this invention is to provide a landing light and its ranging method that are small in installation space, low in cost, and capable of accurate obstacle ranging.

[0005] To achieve the above objectives, the present invention provides a landing light for installation on an aircraft body, the aircraft body being equipped with a control system, a processing unit, and a camera module, comprising: Mounting base; A transparent lampshade connects to the mounting base and forms a mounting cavity; The light-emitting panel is fixed on the mounting base and has multiple LED beads. The lens is located in the mounting cavity at the top of the light-emitting plate; The control system is used to control the start and stop of each LED, and to control the camera module to capture images of obstacles when some LEDs are started. The processing unit is used to receive images of each obstacle transmitted by the camera module and calculate the distance between the obstacle and the landing light based on each obstacle image.

[0006] The present invention also provides a ranging method based on the above-mentioned landing light, wherein the landing light includes a processing unit, a control system, a camera module, and multiple LEDs, comprising: S1. Some LEDs are set as constantly lit LEDs and some LEDs are scanning LEDs; the control system controls each constantly lit LED to continuously illuminate at the first power, and the control system controls each scanning LED to light up sequentially at the second power in a preset order, where the second power is greater than the first power. S2. The control system controls the camera module to start synchronously with each scanning LED, and the camera module captures images of obstacles when each scanning LED starts. S3. The processing unit receives the images of each obstacle transmitted by the camera module, calculates the distance between the obstacle and the landing light based on the images of each obstacle, and outputs the distance signal between the obstacle and the landing light and / or the warning signal.

[0007] Preferably, each constantly lit LED is located in the center of the light-emitting panel, and each scanning LED is arranged in a ring around the center of the light-emitting panel outside the constantly lit LED; the lens is located on the light-emitting side of the landing light, and the lens is used to make the light-emitting directions of each constantly lit LED and each scanning LED parallel to each other.

[0008] Preferably, step S1, "the control system controls each scanning LED to light up sequentially according to a preset order," specifically includes: S101. The total number of scanning LEDs is N. The control system controls each scanning LED to light up sequentially at the second power at a preset time interval Δt. When the next scanning LED lights up, the previously lit scanning LED switches to the third power. The third power is less than the second power. The scanning interval is established when the number of scanning LEDs lit at the same time reaches a preset number M. The preset number M is less than the total number N. S102, The control system continues to control the scanning lamp beads of NM to light up sequentially at the second power at a preset time interval Δt; When the N-M+1th scanning LED is added to the scanning interval at the second power, the first lit scanning LED in the scanning interval is turned off; the remaining scanning LEDs in the scanning interval are maintained at the third power to ensure that there are always M scanning LEDs lit at the same time in the scanning interval.

[0009] Preferably, step S101, "the control system controls each scanning LED to light up sequentially at a preset time interval Δt with the second power, and when the next scanning LED lights up, the previously lit scanning LED switches to the third power, which is less than the second power, until the number of simultaneously lit scanning LEDs reaches a preset number M, at which point the scanning interval is established," specifically includes: Define the initial time as t0, and the preset quantity M as four; At time t0: The first scanning LED is lit at the second power. At time t0+Δt: the second scanning LED is lit at the second power, and the first scanning LED switches to the third power. At time t0+2Δt: the third scanning LED is lit at the second power, while the first and second scanning LEDs switch to the third power. At time t0+3Δt: the fourth scanning LED is lit at the second power, while the first, second, and third scanning LEDs are maintained at the third power, thus completing the establishment of the scanning interval.

[0010] Preferably, in step S102, "the control system continues to control the scanning lamp beads of NM to light up sequentially at the second power at a preset time interval Δt; When the (N-M+1)th scanning LED is added to the scanning interval at the second power, the first lit scanning LED in the scanning interval turns off; the remaining scanning LEDs in the scanning interval switch to the third power to maintain M scanning LEDs lit simultaneously in the scanning interval at all times. Specifically, this includes: At time t0+4Δt, the fifth scanning LED is lit at the second power, the second, third and fourth scanning LEDs switch to the third power, and the first scanning LED is turned off; Starting from time t0+5Δt, after each Δt, a new scanning LED is lit at the second power and added to the scanning interval, while the first lit scanning LED in the scanning interval is turned off.

[0011] Preferably, step S3, "calculating the distance between the obstacle and the landing light based on the images of each obstacle," specifically includes: The center coordinates of the bright areas formed by the corresponding scanning LEDs on the obstacles are extracted from multiple images of each obstacle. The pixel displacement between the center coordinates of the bright areas formed by two adjacent scanning LEDs on the obstacles is obtained, and the distance between the obstacle and the landing light is calculated.

[0012] Preferably, the radius of the ring enclosed by each scanning LED is defined as R, the number of scanning LEDs is N, and the physical distance between adjacent scanning LEDs is b. Then: The physical distance b between adjacent scanning LEDs is calculated. Let the distance to the obstacle be D, the focal length of the camera module be f, and the pixel displacement between the centers of the bright areas formed by two adjacent scanning LEDs illuminating the obstacle be Δu. Then: The distance D to the obstacle is calculated.

[0013] Preferably, the method further includes step S4: defining each scanning lamp bead as completing one illumination in a preset order as a scanning cycle, and the processing unit calculates the relative moving speed between the obstacle and the landing light based on the obstacle distance calculated from multiple consecutive scanning cycles.

[0014] Preferably, the relative speed between the obstacle and the landing light is defined as V, and the distance to the obstacle measured in the current scanning cycle is defined as D. n The obstacle distance measured in the previous scan cycle is D. n ₋1, where the scan period is T, then: The relative speed V between the obstacle and the landing light was calculated.

[0015] The preferred embodiment of the distance measurement method of the present invention has the following advantages compared with the prior art: This invention divides the LEDs into constantly lit LEDs and scanning LEDs. The constantly lit LEDs are controlled to continuously illuminate at a first power, while the scanning LEDs are controlled to illuminate sequentially at a second power greater than the first power, according to a preset order. This allows the landing light to maintain continuous and stable basic illumination while generating identifiable illumination differences through the sequential high-power illumination of the scanning LEDs. Furthermore, by controlling a camera module to synchronously activate with each scanning LED, images of obstacles are captured at the moment each LED is activated. Each frame corresponds to the currently lit scanning LED, thus obtaining clear and reliable obstacle image data. The processing unit calculates the distance between the obstacle and the landing light based on each obstacle image and outputs a distance signal and / or a warning signal, enabling the pilot to obtain real-time distance information of obstacles ahead and take evasive action when necessary. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the overall structure of the landing light provided in a preferred embodiment of the present invention.

[0017] In the diagram, 1 is the mounting base; 2 is the light-emitting panel; 21 is the constantly lit LED bead; 22 is the scanning LED bead; 3 is the lens; and 4 is the transparent lampshade. Detailed Implementation

[0018] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings and preferred embodiments. The following preferred embodiments are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0019] In the description of this invention, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0020] It should be understood that the terms "first," "second," etc., are used in this invention to describe various types of information, but these terms are not limited to them; they are only used to distinguish information of the same type from one another. For example, without departing from the scope of this invention, "first" information may also be referred to as "second" information, and similarly, "second" information may also be referred to as "first" information.

[0021] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0022] like Figure 1 As shown, the landing light includes a mounting base 1, a light-emitting plate 2, a lens 3, and a transparent lamp cover 4. The mounting base 1 is used to connect to the aircraft body and also serves as a support base for other components. The light-emitting plate 2 is fixedly mounted on the mounting base 1 and serves as the core support and circuit board of the entire light. The central area of ​​the light-emitting plate 2 is provided with multiple LED beads, and the outer area of ​​the light-emitting plate 2 is also provided with multiple LED beads. The LED beads in the outer area are arranged in a ring with the center of the light-emitting plate 2 as a reference, outside the LED beads in the central area. The lens 3 is located on the light-emitting side of the landing light and adopts a parabolic optical design. The lens 3 is used to converge the light-emitting direction of each LED. No matter which LED is lit individually, its light-emitting direction is consistent with the main illumination direction of the landing light after being converged by the lens 3, and there will be no problem of light-emitting direction deviation. This ensures that a directional illumination beam that meets aviation standards is formed throughout the scanning process.

[0023] The transparent lamp cover 4 is made of polycarbonate material with high light transmittance. The transparent lamp cover 4 is connected to the mounting base 1 and covers the outside of the lens 3 and the light-emitting plate 2 to protect the internal optical components and circuits, while ensuring high light transmittance to reduce light energy loss. The overall shape and installation size of the landing light are consistent with those of traditional landing lights, which makes it easy to replace or upgrade directly.

[0024] The aircraft body is equipped with a processing unit, a control system and a camera module; in the ranging method provided in this application, multiple LED beads arranged in the middle area of ​​the light-emitting plate 2 are used as constantly lit LED beads 21, and multiple LED beads arranged in a ring at intervals in the outer area are used as scanning LED beads 22.

[0025] In this embodiment, there are 3 constantly lit LED beads 21 and 9 scanning LED beads 22. The annular diameter of the scanning LED beads 22 is 50 mm. Based on the above landing light, a preferred embodiment of the present invention provides a ranging method, including: S1. Some of the LEDs are set to be constantly lit LEDs 21, and some are set to be scanning LEDs 22; the control system controls each of the constantly lit LEDs 21 to continuously illuminate at a first power, and the control system controls each of the scanning LEDs 22 to be lit sequentially at a second power according to a preset order, wherein the second power is greater than the first power; in this embodiment, the sequential lighting of the scanning LEDs 22 adopts a sliding window mechanism, specifically including a scanning interval establishment stage and a steady-state sliding scanning stage; The scanning interval is S101. The control system controls each scanning lamp 22 to light up sequentially at the second power at a preset time interval Δt. When the next scanning lamp 22 lights up, the previously lit scanning lamp 22 switches to the third power. The third power is less than the second power. The scanning interval is established when the number of scanning lamps 22 lit up at the same time reaches the preset number M. In the steady-state sliding scan phase S102, the control system continues to control the subsequent scanning lamps 22 to light up sequentially at the second power at a preset time interval Δt. A new scanning lamp 22 is added to the scan interval at the second power. The first scanning lamp 22 lit in the scan interval is turned off. The remaining scanning lamps 22 in the scan interval are maintained at the third power, so that there are always M scanning lamps 22 lit up at the same time in the scan interval.

[0026] Taking M=4 and Δt=1.78ms as an example, and defining the initial time as t0, the scan interval establishment stage is as follows: t=0ms (time t0): The first scanning LED 22 is lit at the second power. At this time, the first scanning LED 22 is used as a timing coding LED. t=1.78ms (t0+Δt time): The second scanning LED 22 is lit at the second power, and the first scanning LED 22 is switched to the third power. At this time, the second scanning LED 22 acts as a timing code LED.

[0027] At t=3.56m (t0+2Δt time): the third scanning LED 22 is lit at the second power, and the first and second scanning LEDs 22 are maintained at the third power. At this time, the third scanning LED 22 acts as a timing code LED. At t=5.34m (t0+3Δt time): the fourth scanning LED 22 is lit at the second power, and the first, second and third scanning LEDs 22 switch to the third power. At this time, the fourth scanning LED 22 acts as a timing coding LED, and the scanning interval is established.

[0028] The steady-state sliding scan phase is as follows: At time t=7.12m(t0+4Δt): the fifth scanning lamp 22 is lit at the second power, and the second, third and fourth scanning lamps 22 switch to the third power. At this time, the fifth scanning lamp 22 acts as a timing code lamp, and the first scanning lamp 22 is turned off.

[0029] Starting from t=8.90m(t0+5Δt), after each Δt, a new scanning lamp 22 is lit up at the second power and added to the window, while the first lit scanning lamp 22 in the window is turned off, and the rest are maintained at the third power.

[0030] The scanning interval establishment phase is the initial stage when the landing lights are turned on. The total luminous flux starts from the basic illumination of only the constantly lit LED 21 and gradually increases with each additional scanning LED 22. This avoids the sudden brightness change caused by lighting up multiple high-power LEDs at once. Since the brightness change is gradual, the human eye cannot perceive obvious flickering or shock, thus ensuring the pilot's visual comfort when the landing lights are turned on and preventing distraction due to brief light jumps. At the same time, this gradual increase in driving method also avoids the step-like impact of the power supply current of the light-emitting board, making the load change of the power supply of the light-emitting board more gradual and helping to improve the working life of the power supply. In addition, in the steady-state sliding scanning phase, in this embodiment, M=4, that is, one scanning LED 22 is always lit at the second power as the timing code light at the current moment, while the other three scanning LEDs 22 are maintained at the third power. In this embodiment, there are nine scanning LEDs 22. Each scanning LED 22 completes one lighting cycle according to the preset order, so the scanning cycle is 16.02ms and the corresponding scanning frequency is 62.5Hz. This frequency is higher than the critical flicker frequency of the human eye (generally ranging from 30 to 55 times per second). Therefore, the human eye cannot distinguish the on / off switching of each scanning LED 22 and can only perceive the average brightness. At any given time, the lighting effect seen by the pilot is the stable illumination of each constantly lit LED 21 combined with the auxiliary illumination of four scanning LEDs 22. Moreover, one of the four scanning LEDs 22 has a higher power and is significantly brighter than the other three, while the total luminous flux remains constant. Therefore, the landing light illumination effect observed by the pilot during the steady-state sliding scan phase is continuous and stable, which not only ensures the sufficient illumination required for flight safety but also avoids visual fatigue caused by light flicker.

[0031] S2. The control system controls the camera module to start synchronously with each scanning LED 22. The camera module captures the obstacle image when each scanning LED 22 starts. Specifically, at the moment when each scanning LED 22 is lit at the second power (i.e., t0, t0+Δt, t0+2Δt, ...), the camera module is triggered to perform an exposure and capture the obstacle image at the current moment. In this way, each frame of obstacle image corresponds to a specific scanning LED 22 (which is in the second power lit state), while other scanning LEDs 22 (maintained at the third power) or constantly lit LEDs 21 provide background illumination.

[0032] S3. The processing unit receives obstacle images transmitted by the camera module, calculates the distance between the obstacle and the landing light based on each obstacle image, extracts the center coordinates of the bright areas formed by the corresponding scanning LEDs 22 illuminating the obstacle from multiple obstacle images, obtains the pixel displacement between the center coordinates of the bright areas formed by two adjacent scanning LEDs 22 illuminating the obstacle, and calculates the distance between the obstacle and the landing light. The processing unit outputs the calculated obstacle distance signal and / or warning signal to the aircraft cockpit. The processing unit sends graded warning signals to the cockpit through the ARINC429 bus. When the obstacle distance is less than 50 meters, a first-level warning is immediately sent to the cockpit; when the distance is less than 20 meters, a second-level emergency warning is triggered, reminding the pilot to take evasive action through audible and visual signals to effectively avoid collision accidents.

[0033] Specifically, "the processing unit extracts the center coordinates of the bright areas formed by the scanning lamp beads 22 illuminating the obstacles from multiple obstacle images" includes: Define the current frame: The processing unit acquires a mixed illumination image of each constantly lit LED 21, the existing scanning LEDs 22 maintained at the third power within the scanning interval, and the newly added scanning LEDs 22 lit at the second power (i.e., the current timing code LEDs); Reference frame: The processing unit acquires the illumination image of the previous moment of the current frame, which includes the mixed illumination image of the previous timing coded lamp lit at the second power, the same constant-on lamp 21, and the existing scanning lamp 22 maintained at the third power in the scanning interval. Frame difference image: Current frame - reference frame ≈ Temporal bright area contributed by the current timing coded lamp; By using adaptive threshold segmentation, the center coordinates (uᵢ, vᵢ) of the high temporal bright area are extracted from the frame difference image. Through nine consecutive exposures, the bright area positions of the nine scanning LEDs 22 as one time-series coding lamp are completely acquired, forming a sequence of temporal bright areas {(u1, v1), (u2, v2), ..., (u9, v9)}. The pixel displacement Δu between the center coordinates of the temporal bright areas of two different time-series coding lamps is calculated by subtracting the center coordinates of the bright areas formed by the two adjacent scanning LEDs 22 illuminating the obstacle.

[0034] Specifically, let R be the radius of the ring enclosed by each scanning LED 22, N be the number of scanning LEDs 22, and b be the physical distance between adjacent scanning LEDs 22. Then: The physical spacing b between adjacent scanning LED beads 22 is calculated; Let the distance to the obstacle be D, the focal length of the camera module be f, and the pixel displacement between the centers of the bright areas formed by two adjacent scanning LEDs 22 illuminating the obstacle be Δu. Then: The distance D to the obstacle is calculated.

[0035] Specifically, it also includes step S4: defining each scanning lamp bead 22 as a scanning cycle after completing one illumination in a preset order, and the processing unit calculates the relative moving speed between the obstacle and the landing light based on the obstacle distance calculated from multiple consecutive scanning cycles.

[0036] Specifically, the relative speed between the obstacle and the landing light is defined as V, and the distance to the obstacle measured in the current scan cycle is defined as D. n The obstacle distance measured in the previous scan cycle is D. n ₋1, where the scan period is T, then: The relative speed V between the obstacle and the landing light is calculated. The direction of the relative speed V is determined by its sign: a positive speed indicates that the obstacle is moving away from the aircraft, and a negative speed indicates that the obstacle is moving towards the aircraft, providing the pilot with dynamic motion information of the obstacle.

[0037] Compared with existing technologies, the ranging method provided by the preferred embodiment of this invention does not require modification of the landing light's mechanical structure, new mold making, or changes to the aircraft's mounting interface. It is fully compatible with all existing LED array landing light products. The ranging warning function can be achieved solely through software upgrades to the lighting control logic and image processing algorithm. Airworthiness certification is extremely easy, and it can be quickly adapted to existing aircraft models without adding any additional hardware costs. Compared with traditional laser ranging solutions, it can save more than 90% of the cost. At the same time, by using continuous illumination from constant-on LEDs and time-sequential power level control from scanning LEDs, it achieves strobe coding that is imperceptible to the human eye without changing the perceived total brightness. The pilot still sees the same constant-on illumination effect as traditional landing lights, with no visible flicker and no impact on normal takeoff and landing operations. In addition, this invention can achieve obstacle ranging within a range of 0 to 50 meters, meeting the short-range obstacle warning requirements during aircraft takeoff and landing. It can also simultaneously output distance and relative speed information, supporting multi-level warnings (50-meter level 1 warning, 20-meter level 2 emergency warning), providing pilots with more comprehensive dynamic information.

[0038] In summary, the preferred embodiment of the present invention provides a landing light and its ranging method. The present invention divides the LED beads into constantly lit LED beads and scanning LED beads, and controls the constantly lit LED beads to continuously illuminate at a first power, while controlling the scanning LED beads to illuminate sequentially at a second power greater than the first power in a preset order. This allows the landing light to maintain continuous and stable basic illumination while generating identifiable illumination differences by utilizing the sequential high-power illumination of the scanning LED beads. Based on this, the camera module is controlled to start synchronously with each scanning LED bead to capture obstacle images when each scanning LED bead is activated, so that each frame of image corresponds to the currently lit scanning LED bead, thereby obtaining clear and reliable obstacle image data. The processing unit calculates the distance between the obstacle and the landing light based on each obstacle image and outputs a distance signal and / or a warning signal, enabling the pilot to obtain real-time distance information of obstacles ahead and take evasive measures when necessary.

[0039] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and substitutions can be made without departing from the technical principles of the present invention, and these improvements and substitutions should also be considered within the scope of protection of the present invention.

Claims

1. A landing light for mounting on an aircraft body, the aircraft body being provided with a control system, a processing unit, and a camera module, characterized in that, include: Mounting base (1); A transparent lampshade (4) is connected to the mounting base (1) to form a mounting cavity; A light-emitting plate (2) is fixed on the mounting base (1), and the light-emitting plate (2) is provided with multiple LED beads; The lens (3) is located in the mounting cavity above the light-emitting plate (2); The control system is used to control the starting and stopping of each of the LED beads, and to control the camera module to capture images of obstacles when some of the LED beads are started. The processing unit is used to receive the obstacle images transmitted by the camera module and calculate the distance between the obstacle and the landing light based on the obstacle images.

2. A ranging method based on the landing light according to claim 1, characterized in that, include: S1. Some of the LED beads are set to be constantly lit LED beads (21), and some of the LED beads are set to be scanning LED beads (22); the control system controls each of the constantly lit LED beads (21) to continuously illuminate with a first power, and the control system controls each of the scanning LED beads (22) to be lit sequentially with a second power in a preset order, wherein the second power is greater than the first power; S2. The control system controls the camera module to start synchronously with each scanning lamp (22), and the camera module captures the obstacle image when each scanning lamp (22) starts; S3. The processing unit receives the obstacle images transmitted by the camera module, calculates the distance between the obstacle and the landing light based on the obstacle images, and outputs the distance signal between the obstacle and the landing light and / or a warning signal.

3. The ranging method according to claim 2, characterized in that, Each of the constantly lit LED beads (21) is located in the middle of the light-emitting plate (2), and each of the scanning LED beads (22) is arranged in a ring around the center of the light-emitting plate (2) outside each of the constantly lit LED beads (21); the lens (3) is located on the light-emitting side of the landing light, and the lens (3) is used to make the light-emitting directions of each of the constantly lit LED beads (21) and each of the scanning LED beads (22) parallel to each other.

4. The ranging method according to claim 3, characterized in that, Step S1, "the control system controls each of the scanning LED beads (22) to light up sequentially in a preset order," specifically includes: S101. The total number of the scanning lamp beads (22) is N. The control system controls each of the scanning lamp beads (22) to be lit sequentially at the second power at a preset time interval Δt. When the next scanning lamp bead (22) is lit, the previous lit scanning lamp bead (22) is switched to the third power. The third power is less than the second power. The scanning interval is established when the number of scanning lamp beads (22) lit at the same time reaches a preset number M. The preset number M is less than the total number N. S102, the control system continues to control the scanning lamp beads (22) of NM to light up sequentially at the second power at a preset time interval Δt; When the N-M+1th scanning LED (22) is added to the scanning interval at the second power, the first scanning LED (22) lit in the scanning interval is turned off; the remaining scanning LEDs (22) in the scanning interval are maintained at the third power so that M scanning LEDs (22) are always lit at the same time in the scanning interval.

5. The ranging method according to claim 4, characterized in that, In step S101, "the control system controls each of the scanning lamp beads (22) to light up sequentially at the second power at a preset time interval Δt, and when the next scanning lamp bead (22) lights up, the previously lit scanning lamp bead (22) switches to the third power, which is less than the second power, until the number of simultaneously lit scanning lamp beads (22) reaches a preset number M, and the establishment of the scanning interval is completed." Specifically, this includes: The initial time is defined as t0, and the preset quantity M is four; At time t0: the first scanning LED (22) is lit at the second power; At time t0+Δt: the second scanning lamp (22) is lit at the second power, and the first scanning lamp (22) is switched to be maintained at the third power; At time t0+2Δt: the third scanning lamp (22) is lit at the second power, and the first and second scanning lamps (22) are switched to be maintained at the third power; At time t0+3Δt: the fourth scanning lamp (22) is lit at the second power, and the first, second and third scanning lamps (22) are switched to be maintained at the third power, thus completing the establishment of the scanning interval.

6. The ranging method according to claim 4, characterized in that, In step S102, "the control system continues to control the scanning lamp beads (22) of NM to light up sequentially at the second power at a preset time interval Δt; When the N-M+1th scanning LED (22) is added to the scanning interval at the second power, the first lit scanning LED (22) in the scanning interval is turned off; the remaining scanning LEDs (22) in the scanning interval are switched to the third power to maintain M scanning LEDs (22) lit simultaneously in the scanning interval. This specifically includes: At time t0+4Δt, the fifth scanning lamp (22) is lit at the second power, the second, third and fourth scanning lamps (22) switch to the third power, and the first scanning lamp (22) is turned off; Starting from time t0+5Δt, after each Δt, a new scanning lamp (22) is lit up with the second power and added to the scanning interval, and the first scanning lamp (22) lit up in the scanning interval is turned off.

7. The ranging method according to claim 6, characterized in that, Step S3, "calculating the distance between the obstacle and the landing light based on the images of each obstacle," specifically includes: Extract the center coordinates of the bright areas formed by the scanning lamp (22) on the obstacle from each of the multiple obstacle images, obtain the pixel displacement between the center coordinates of the bright areas formed by two adjacent scanning lamps (22) on the obstacle, and calculate the distance between the obstacle and the landing light.

8. The ranging method according to claim 7, characterized in that, Let R be the radius of the annulus enclosed by each of the scanning LEDs (22), N be the number of scanning LEDs (22), and b be the physical distance between adjacent scanning LEDs (22). Then: The physical distance b between adjacent scanning LED beads (22) is calculated; Let the distance to the obstacle be D, the focal length of the camera module be f, and the pixel displacement between the center coordinates of the bright areas formed by two adjacent scanning LEDs (22) illuminating the obstacle be Δu, then: The distance D to the obstacle is calculated.

9. The ranging method according to claim 2, characterized in that, It also includes step S4: defining each scanning lamp (22) as a scanning cycle when each completes one lighting in the preset order, and the processing unit calculates the relative moving speed between the obstacle and the landing light based on the obstacle distance calculated in multiple consecutive scanning cycles.

10. The ranging method according to claim 9, characterized in that, Let V be the relative speed between the obstacle and the landing light, and D be the distance to the obstacle measured in the current scan cycle. n The obstacle distance measured in the previous scan cycle is D. n ₋1, where the scan period is T, then: The relative speed V between the obstacle and the landing light is calculated.

Images