Distance detection system and distance detection method

Abstract

The present disclosure provides a distance detection system and a distance detection method. The method includes: capturing multiple image frames at multiple time points based on a field of view, wherein the field of view includes an object, and each image frame includes pixels corresponding to the object; obtaining the first and second modulation modes presented by the pixels at the multiple time points; finding the first specific light-emitting unit and the second specific light-emitting unit based on the first and second modulation modes respectively; and estimating the specific distance between the distance detection system and the object based on the first specific light-emitting unit and the second specific light-emitting unit. In this way, even in a strong light / weak light environment, the method of the present disclosure can still accurately determine the specific distance between the polarization vision system and the specific object.

Description

Technical Field

[0001] The present disclosure relates to a distance determination technology, and more particularly to a distance detection system and a distance detection method. Background Art

[0002] In the prior art, although there are vehicle vision systems that can be used for assisted driving, in some cases, the vehicle vision system may not be able to achieve good recognition effects. For example, in an environment with strong sunlight, shadows may be created under shelters such as overpasses and trees. At this time, if the contrast between the shadows on the road surface and the strong light on the road surface is too high, the image recognition function of the traditional vehicle vision system may not be able to determine the distance between the vehicle and objects such as road markings or obstacles, which may cause collisions, car accidents, etc.

[0003] In addition, in dim light conditions, it is less likely for traditional vehicle vision systems to identify road markings, vehicle or object outlines, and thus the above situation may also occur due to an inability to correctly judge the distance. Summary of the invention

[0004] In view of this, the present disclosure provides a distance detection system and a distance detection method, which can be used to solve the above technical problems.

[0005] The present disclosure provides a distance detection system, including a first light source, a second light source, an imaging circuit and a processor. The first light source has a first polarization direction and includes a plurality of first light emitting units, wherein each first light emitting unit emits a first light based on the first polarization direction and a respective first modulation method to illuminate a specific object. The second light source has a second polarization direction and includes a plurality of second light emitting units, wherein each second light emitting unit emits a second light based on the second polarization direction and a respective second modulation method to illuminate the specific object. The imaging circuit is used to capture a plurality of image frames at a plurality of time points in a specific field of view of the imaging circuit, wherein the specific field of view includes a specific object, and each image frame includes a specific pixel corresponding to the specific object. The processor is coupled to the first light source, the second light source and the imaging circuit, and is configured to: obtain a first specific modulation mode and a second specific modulation mode presented by a specific pixel at the multiple time points based on the multiple image frames, wherein the first specific modulation mode corresponds to a first polarization direction, and the second specific modulation mode corresponds to a second polarization direction; find a first specific light-emitting unit among the multiple first light-emitting units based on the first specific modulation mode, and find a second specific light-emitting unit among the multiple second light-emitting units based on the second specific modulation mode; and calculate a specific distance between the polarization vision system and the specific object based on the first specific light-emitting unit and the second specific light-emitting unit.

[0006] According to one embodiment of the present disclosure, an imaging circuit includes a first lens and a second lens corresponding to a first polarization direction and a second polarization direction, respectively, and the image frame includes a plurality of first image frames captured by the first lens and a plurality of second image frames captured by the second lens. The steps of the processor obtaining a first specific modulation mode and a second specific modulation mode include: obtaining a first specific modulation mode presented by a specific pixel at the time point based on the first image frame; and obtaining a second specific modulation mode presented by a specific pixel at the time point based on the second image frame.

[0007] According to one embodiment of the present disclosure, the steps for a processor to obtain a first specific modulation mode and a second specific modulation mode include: obtaining a plurality of first sub-pixels and a plurality of second sub-pixels corresponding to a first polarization direction and a second polarization direction, respectively, in a plurality of pixels of each image frame; combining the first sub-pixels into a plurality of first image frames, and combining the second sub-pixels into a plurality of second image frames; obtaining a first specific modulation mode presented by a specific pixel at the time point based on the first image frame; and obtaining a second specific modulation mode presented by the specific pixel at the time point based on the second image frame.

[0008] According to one embodiment of the present disclosure, the step of a processor calculating the distance between a distance detection system and a specific object includes: obtaining a preset distance between a first specific light-emitting unit and a second specific light-emitting unit; and performing a triangulation method based on a first emission direction of the first specific light-emitting unit, a second emission direction of the second specific light-emitting unit, and the preset distance to calculate the specific distance between the distance detection system and the specific object.

[0009] According to one embodiment of the present disclosure, the first modulation modes corresponding to the first light-emitting units are all different, and the second modulation modes corresponding to the second light-emitting units are all different.

[0010] According to one embodiment of the present disclosure, the first polarization direction and the second polarization direction are orthogonal to each other.

[0011] The present disclosure provides a distance detection method suitable for a distance detection system, comprising: a plurality of first light emitting units of a first light source respectively emit a first light based on a first polarization direction and a respective first modulation mode to illuminate a specific object; a plurality of second light emitting units of a second light source respectively emit a second light based on a second polarization direction and a respective second modulation mode to illuminate the specific object; an imaging circuit captures a plurality of image frames at a plurality of time points in a specific field of view, wherein the specific field of view includes a specific object, and each image frame includes a specific pixel corresponding to the specific object; a processor obtains a first specific modulation mode and a second specific modulation mode presented by a specific pixel at the plurality of time points based on the plurality of image frames; the processor finds a first specific light emitting unit among the plurality of first light emitting units based on the first specific modulation mode, and finds a second specific light emitting unit among the plurality of second light emitting units based on the second specific modulation mode; and the processor calculates a specific distance between the polarization vision system and the specific object based on the first specific light emitting unit and the second specific light emitting unit.

[0012] According to one embodiment of the present disclosure, the step of capturing the image frame by the imaging circuit includes: capturing a plurality of first image frames with a first polarization direction at the specific field of view at the time point by a first lens of the imaging circuit; and capturing a plurality of second image frames with a second polarization direction at the specific field of view at the time point by a second lens of the imaging circuit; wherein the step of the processor obtaining the first specific modulation mode and the second specific modulation mode includes: obtaining the first specific modulation mode presented by a specific pixel at the time point based on the first image frame; and obtaining the second specific modulation mode presented by the specific pixel at the time point based on the second image frame.

[0013] According to one embodiment of the present disclosure, the steps of obtaining a first specific modulation mode and a second specific modulation mode by a processor include: obtaining a plurality of first sub-pixels and a plurality of second sub-pixels corresponding to a first polarization direction and a second polarization direction, respectively, in a plurality of pixels of each image frame; combining the first sub-pixels into a plurality of first image frames, and combining the second sub-pixels of each pixel in the image frame into a plurality of second image frames; obtaining a first specific modulation mode presented by a specific pixel at the time point based on the first image frame; and obtaining a second specific modulation mode presented by a specific pixel at the time point based on the second image frame.

[0014] According to one embodiment of the present disclosure, the step of calculating by a processor a specific distance between a distance detection system and a specific object includes: obtaining a preset distance between a first specific light-emitting unit and a second specific light-emitting unit; and performing a triangulation method based on a first emission direction of the first specific light-emitting unit, a second emission direction of the second specific light-emitting unit and the preset distance to calculate the specific distance between the method and the specific object.

[0015] According to one embodiment of the present disclosure, the first polarization direction and the second polarization direction are orthogonal to each other.

[0016] Thereby, even in a strong light / weak light environment, the method disclosed in the present invention can still accurately determine the specific distance between the polarization vision system and a specific object, thereby reducing the probability of collision, car accidents, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a schematic diagram of a distance detection system according to an embodiment of the present disclosure.

[0018] Figure 2 is a flow chart of a distance detection method according to an embodiment of the present disclosure.

[0019] Figure 3 It is an application scenario diagram drawn according to an embodiment of the present disclosure.

[0020] Figure 4 FIG. 4 is a schematic diagram of a light source using a digital micro-mirror device technology according to an embodiment of the present disclosure.

[0021] The reference numerals are described as follows:

[0022] 100: Distance detection system

[0023] 101, 501: First light source

[0024] 101a, 401a: first light emitting unit

[0025] 102,502: Second light source

[0026] 102a, 402a: second light emitting unit

[0027] 103: Image acquisition circuit

[0028] 104: Processor

[0029] 411: First irradiation range

[0030] 411a: First sub-irradiation range

[0031] 412: Second irradiation range

[0032] 412a: Second sub-irradiation range

[0033] 499, 599: Specific objects

[0034] 501a, 502a: micro mirror

[0035] 511, 512: Sub-light source

[0036] 512, 522: Micro mirror array

[0037] AN1, AN2: Angle

[0038] D1: First emission direction

[0039] D2: Second emission direction

[0040] DD: Preset distance

[0041] IM: Image Frame

[0042] IM1: First image area

[0043] IM2: Second Image Area

[0044] LL: Specific distance

[0045] MM: Modulation method

[0046] OR: Overlapping area

[0047] P1, P2: Polarizer

[0048] S210~S260: Steps DETAILED DESCRIPTION

[0049] Please refer to Figure 1 , which is a schematic diagram of a distance detection system according to an embodiment of the present disclosure. In different embodiments, the distance detection system 100 can be used to measure the distance between the distance detection system 100 and an object within its field of view (FOV) in various devices / scenes. To facilitate the description of the concept of the present disclosure, it will be assumed below that the distance detection system 100 is disposed in a vehicle and is used to measure the distance between the vehicle and an object located in front of the vehicle, but the present disclosure is not limited thereto.

[0050] like Figure 1As shown, the distance detection system 100 may include a first light source 101, a second light source 102, an imaging circuit 103 and a processor 104. In an embodiment of the present disclosure, the first light source 101 and the second light source 102 may be the left headlight and the right headlight of the above-mentioned vehicle, respectively, which can be used to illuminate the front of the vehicle. In different embodiments, the first light source 101 and the second light source 102 may be implemented as a pixel light device using digital light processing (DLP) / digital micro-mirror device (DMD) technology, a matrix light device using light emitting diodes (LEDs) and / or a scan light device, but it is not limited thereto.

[0051] In the embodiment of the present disclosure, the first light source 101 may have a first polarization direction and include a plurality of first light emitting units, wherein each first light emitting unit may emit a first light based on the first polarization direction and a respective first modulation mode to illuminate a specific object. Similarly, the second light source 102 may have a second polarization direction and include a plurality of second light emitting units, wherein each second light emitting unit may emit a second light based on a second polarization direction and a respective second modulation mode to illuminate the specific object.

[0052] In one embodiment, the first light source 101 includes a polarization device / element (e.g., a polarizer) corresponding to a first polarization direction, so that each first light emitting unit can emit a first light in the first polarization direction. Similarly, the second light source 102 includes another polarization device / element corresponding to a second polarization direction, so that each second light emitting unit can emit a second light in the second polarization direction.

[0053] In the embodiment of the present disclosure, a first combination of a first modulation mode and a first polarization direction of each first light emitting unit is unique in the distance detection system 100, and a second combination of a second modulation mode and a second polarization direction of each second light emitting unit is unique in the distance detection system 100.

[0054] For ease of explanation, it will be assumed below that the first polarization directions corresponding to the first light-emitting units are the same (for example, all are horizontal polarization directions), and the first modulation modes corresponding to the first light-emitting units are different. In addition, it is assumed that the second polarization directions corresponding to the second light-emitting units are the same (for example, all are vertical polarization directions), and the second modulation modes corresponding to the second light-emitting units are different. In addition, in some embodiments, the first polarization direction may be orthogonal to the second polarization direction, but is not limited thereto.

[0055] In one embodiment, the first light source 101 includes N1 first light emitting units, and a single horizontal polarizer may be disposed in front of the N1 first light emitting units, so that the first polarization direction of the first light emitted by each first light emitting unit is a horizontal polarization direction. In addition, the first modulation methods of each of the N1 first light emitting units may be pulse amplitude modulation (PAM) corresponding to different amplitudes. In this case, the first light emitted by each of the N1 first light emitting units will have the same first polarization direction (e.g., horizontal polarization direction) but different pulse amplitude modulation methods.

[0056] In addition, the second light source 102 includes N2 second light-emitting units, and a single vertical polarizer may be disposed in front of the N2 second light-emitting units, so that the second polarization direction of the second light emitted by each second light-emitting unit is a vertical polarization direction. In addition, the second modulation methods corresponding to the N2 second light-emitting units may be pulse amplitude modulation corresponding to different amplitudes. In this case, the second light emitted by the N2 second light-emitting units will have the same second polarization direction (e.g., vertical polarization direction) but different pulse amplitude modulation methods.

[0057] In addition, in other embodiments, other modulation methods (such as pulse width modulation (PWM)) may also be used to implement the first modulation method corresponding to each first light-emitting unit and / or the second modulation method corresponding to each second light-emitting unit, but it is not limited to this.

[0058] In the embodiments of the present disclosure, the image capturing circuit 103 is, for example, a variety of polarization image capturing devices. For example, in the first embodiment, the image capturing circuit 103 may include a first lens and a second lens corresponding to a first polarization direction and a second polarization direction, respectively, wherein the first lens includes a first polarizer corresponding to the first polarization direction, and the second lens includes a second polarizer corresponding to the second polarization direction. In this case, the first lens can capture a plurality of first image frames having a first polarization direction through the first polarizer at the plurality of time points in a specific field of view, and the second lens can capture a plurality of second image frames having a second polarization direction through the second polarizer at the plurality of time points in the specific field of view.

[0059] In the second embodiment, the image capturing circuit 103 may be provided with a polarization element array, wherein the polarization element array may include a plurality of polarization element groups, and each polarization element group may correspond to one of the image capturing pixels of the image capturing circuit 103. In addition, each polarization element group may include a first polarization element and a second polarization element corresponding to the first polarization direction and the second polarization direction, respectively. In this case, each image frame captured by the image capturing circuit 103 will include a plurality of pixels, and each pixel may include a first sub-pixel and a second sub-pixel corresponding to the first polarization direction and the second polarization direction, respectively, but it is not limited thereto.

[0060] In one embodiment, the imaging circuit 103 may be designed to shoot / capture image frames toward the front of the vehicle. That is, the field of view (hereinafter referred to as a specific field of view) of the imaging circuit 103 for capturing image frames extends toward the front of the vehicle, but the present disclosure is not limited thereto.

[0061] In different embodiments, the processor 104 can be coupled to the first light source 101, the second light source 102, and the imaging circuit 103, and can be a general-purpose processor, a special-purpose processor, a traditional processor, a digital signal processor, a plurality of microprocessors, one or more microprocessors combined with a digital signal processor core, a controller, a microcontroller, an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), any other type of integrated circuit, a state machine, an advanced RISC machine (ARM)-based processor, and the like.

[0062] In the embodiment of the present disclosure, the processor 104 can access the required modules and program codes to implement the method for determining distance based on polarization vision proposed in the present disclosure, the details of which are described as follows.

[0063] Please refer to Figure 2 , which is a flow chart of a distance detection method according to an embodiment of the present disclosure. The method of this embodiment can be Figure 1 The distance detection system 100 is executed as follows: Figure 1 Description of components shown Figure 2 In order to make the present disclosure easier to understand, the following will be supplemented with Figure 3 To further explain, Figure 3 It is an application scenario diagram drawn according to an embodiment of the present disclosure.

[0064] First, in step S210, the first light emitting units 101a of the first light source 101 may emit first light rays based on first polarization directions and respective first modulation modes to illuminate the specific object 499. Figure 3 As shown, the plurality of first light emitting units 101a may be arranged in a matrix, and a polarizer P1 (such as a horizontal polarizer) may be disposed in front of the matrix. Furthermore, the first modulation mode corresponding to each first light emitting unit 101a may be one of the plurality of pulse width modulation modes MM shown, and the first modulation modes corresponding to each first light emitting unit 101a are different from each other, but are not limited thereto.

[0065] In this case, the first light emitted by each first light emitting unit 101a (whose respective first polarization direction is, for example, a horizontal polarization direction) can be integrated to form a first irradiation range 411, wherein the first irradiation range 411 may include a first sub-irradiation range 411a corresponding to each first light emitting unit 101a.

[0066] In addition, in step S220, the plurality of second light emitting units 102a of the second light source 102 may respectively emit second light based on the second polarization direction and the respective second modulation modes to illuminate the specific object 499. Figure 3 As shown, the plurality of second light emitting units 102a may be arranged in a matrix, and a polarizer P2 (such as a vertical polarizer) may be disposed in front of the matrix. Furthermore, the second modulation mode corresponding to each second light emitting unit 102a may be one of the plurality of pulse width modulation modes MM shown, and the second modulation modes corresponding to each second light emitting unit 102a are different from each other, but are not limited thereto.

[0067] In this case, the second light emitted by each second light emitting unit 102a (whose respective second polarization direction is, for example, a vertical polarization direction) can be integrated to form a second irradiation range 412, wherein the second irradiation range 412 can include a second sub-irradiation range 412a corresponding to each second light emitting unit 102a.

[0068] Next, in step S230, the imaging circuit 103 may capture multiple image frames at multiple time points in a specific field of view, wherein the specific field of view contains a specific object 499 illuminated by the first light source 101 and the second light source 102. In this case, each image frame captured by the imaging circuit 103 includes an image region (which includes at least one specific image pixel) corresponding to the specific object 499. In other words, each image frame includes at least one specific image pixel corresponding to the specific object 499.

[0069] In the embodiment of the present disclosure, the processor 104 can know which first light ray of the first light emitting unit 101a and which second light ray of the second light emitting unit 102a contribute to the light corresponding to the specific image pixel (hereinafter referred to as the specific pixel) based on the change in the polarization degree of the specific image pixel corresponding to the specific object 499 in each image frame. For example, the specific pixel is a pixel located at the center of the specific object 499 in each image frame, but the present disclosure is not limited to this, and any pixel that can represent the specific object 499 is within the scope of protection of the present disclosure.

[0070] Next, in step S240 , the processor 104 may obtain the first specific modulation mode and the second specific modulation mode presented by the specific pixel at the multiple time points based on the multiple image frames.

[0071] For example, in one embodiment, the plurality of image frames may include the plurality of first image frames (corresponding to the first polarization direction) and the plurality of second image frames (corresponding to the first polarization direction) in the first embodiment. In this case, the processor 104 may obtain the first specific modulation mode presented by the specific pixel at the above time point based on the first image frame, and obtain the second specific modulation mode presented by the specific pixel at the above time point based on the second image frame.

[0072] In another embodiment, the image capturing circuit 103 obtains the plurality of image frames in the manner described in the second embodiment. In this case, the processor 104 obtains a plurality of first sub-pixels and a plurality of second sub-pixels corresponding to the first polarization direction and the second polarization direction, respectively, from a plurality of pixels of each image frame, and combines the plurality of first sub-pixels into a plurality of first image frames, and combines the plurality of second sub-pixels into a plurality of second image frames.

[0073] Specifically, for the i-th (i is a positive integer) image frame in the above-mentioned image frames, the processor 104 may combine the first sub-pixels of each pixel in the i-th image frame into a first image frame corresponding to the i-th image frame, and combine the second sub-pixels of each pixel in the i-th image frame into a second image frame corresponding to the i-th image frame. Furthermore, the processor 104 may analyze the first image frame corresponding to each image frame to obtain the first specific modulation mode presented by the specific pixel at the above-mentioned time point. Similarly, the processor 104 may obtain the second specific modulation mode presented by the specific pixel at the above-mentioned time point based on the second image frame corresponding to each image frame.

[0074] Furthermore, in step S250 , the processor 104 may find a first specific light-emitting unit in the first light-emitting unit 101 a based on the first specific modulation mode, and find a second specific light-emitting unit in the second light-emitting unit 102 a based on the second specific modulation mode.

[0075] For example, a first light emitting unit A1 in the first light source 101 is modulated to send a first light (which has a horizontal polarization direction, for example) using a first modulation method of "bright-dark-bright-dark". In this case, after analyzing the specific pixels in the first image frame, the processor 104 finds that the degree of polarization (DOP) of the specific pixels in each first image frame presents a first specific modulation method of "bright-dark-bright-dark", and the processor 104 can determine that the light of the specific pixel is at least contributed by the first light of the first light emitting unit A1. Based on this, the processor 104 can determine that the first light emitting unit A1 is the first specific light emitting unit. In addition, a second light emitting unit B1 in the second light source 102 is modulated to send a second light (which has a vertical polarization direction, for example) using a second modulation method of "dark-dark-bright-bright". In this case, after analyzing the specific pixels in the second image frame, the processor 104 also finds that the DOP of the specific pixels in each second image frame presents a second specific modulation method of "dark-dark-bright-bright", and the processor 104 can determine that the light of the specific pixel is also contributed by the second light of the second light emitting unit B1. Based on this, the processor 104 can determine that the second light-emitting unit B1 is the second specific light-emitting unit.

[0076] Thereafter, in step S260 , the processor 104 may calculate a specific distance LL between the distance detection system 100 and the specific object 499 based on the first specific light emitting unit and the second specific light emitting unit.

[0077] In one embodiment, the processor 104 may obtain a preset distance between the first specific light emitting unit and the second specific light emitting unit. Then, the processor 104 may perform a triangulation method based on the first emission direction of the first specific light emitting unit, the second emission direction of the second specific light emitting unit, and the preset distance to calculate the specific distance LL between the distance detection system 100 and the specific object 499.

[0078] For example, in Figure 3 In the scenario, the first specific light-emitting unit and the second specific light-emitting unit found by the processor 104 after executing step S250 are the first light-emitting unit 401a and the second light-emitting unit 402a shown, respectively, and the processor 104 can estimate the specific distance LL accordingly. Specifically, in the embodiment of the present disclosure, the positions of each first light-emitting unit 101a in the first light source 101 and each second light-emitting unit 102a in the second light source 102 are known, and the distance between any first light-emitting unit 101a and any second light-emitting unit 102a can be considered known through pre-measurement. In other words, the distance between the first light-emitting unit 401a and the second light-emitting unit 402a (hereinafter referred to as the preset distance DD) is also known.

[0079] In addition, the first emission direction of the first light emitted by each first light emitting unit 101 a may be fixed, and the second emission direction of the second light emitted by each second light emitting unit 102 a in the second light source 102 may also be fixed.

[0080] Therefore, after determining that the first specific light-emitting unit and the second specific light-emitting unit are the first light-emitting unit 401a and the second light-emitting unit 402a shown, respectively, the processor 104 can obtain the preset distance DD (its value is, for example, d) between the first light-emitting unit 401a and the second light-emitting unit 402a. Afterwards, the processor 104 can perform triangulation based on the first emission direction D1 of the first light-emitting unit 401a, the second emission direction D2 of the second light-emitting unit 402a, and the preset distance DD to calculate the specific distance LL (its value is, for example, l) between the distance detection system 100 and the specific object 499.

[0081] exist Figure 3 In the embodiment, there is an angle AN1 (the value of which is, for example, α) between the line connecting the first light-emitting unit 401a and the second light-emitting unit 402a and the first emission direction D1, and there is an angle AN2 (the value of which is, for example, β) between the line connecting the first light-emitting unit 401a and the second light-emitting unit 402a and the second emission direction D2. In this case, the specific distance LL can be calculated by the processor 104 as follows: But it is not limited to this.

[0082] From the above, it can be seen that the method disclosed in the present invention can determine the specific distance LL between the distance detection system 100 and the specific object 499 in a manner different from the prior art, and even in a strong light / weak light environment, the method disclosed in the present invention can still accurately determine the specific distance LL between the distance detection system 100 and the specific object 499, thereby reducing the probability of collisions, car accidents, etc.

[0083] In other embodiments, when there are multiple specific objects in the specific field of view of the imaging circuit 103 , the method disclosed in the present invention can still be used to determine the specific distance between the distance detection system 100 and each specific object, but is not limited thereto.

[0084] In addition, the present disclosure further proposes the following mechanism to improve the efficiency of finding the first specific light-emitting unit and the second specific light-emitting unit. Figure 3 In the scenario, the first light source 101 can be considered to be located on the left side of the distance detection system 100, and the second light source 102 can be considered to be located on the right side of the distance detection system 100. In this case, the first illumination range 411 of the first light source 101 will correspond to the first image area located on the left side of each image frame, and the second illumination range 412 of the second light source 102 will correspond to the second image area located on the right side of each image frame.

[0085] For example, assuming that the image frame IM1 is one of the above-mentioned image frames, it may include a first image region IM1 and a second image region IM2 corresponding to the first illumination range 411 and the second illumination range 412, respectively. Figure 3 As shown, the first image region IM1 and the second image region IM2 have an overlapping region OR, and the specific pixel corresponding to the specific object 199 may be located in the overlapping region OR.

[0086] Depend on Figure 3 It can be seen that among the first light emitting units 101a of the first light source 101, only a portion of the first light emitting units 101a located on the right side is more likely to contribute the first light to the specific pixel. Similarly, among the second light emitting units 102a of the second light source 102, only a portion of the second light emitting units 102a located on the left side is more likely to contribute the second light to the specific pixel. Therefore, the processor 104 can only find the first specific light emitting unit among the first light emitting units 101a closer to the right, and find the second specific light emitting unit among the second light emitting units 102a closer to the left side.

[0087] In other words, the processor 104 can search for the first specific light-emitting unit / the second specific light-emitting unit in a smaller range, thereby improving the efficiency of searching for the first specific light-emitting unit / the second specific light-emitting unit.

[0088] Please refer to Figure 4 , which is a schematic diagram of a light source using a digital micro-mirror device technology according to an embodiment of the present disclosure. Figure 4 In the embodiment, the first light source 501 of the distance detection system 100 may include a sub-light source 511 and a micro-mirror array 512, wherein the micro-mirror array 512 may include a plurality of micro-mirrors, each of which may emit a first light by reflecting the light of the sub-light source 511. In other words, the micro-mirrors in the micro-mirror array 512 may be understood as the first light-emitting unit in the present embodiment. In addition, the second light source 502 of the distance detection system 100 may include a sub-light source 521 and a micro-mirror array 522, wherein the micro-mirror array 522 may include a plurality of micro-mirrors, each of which may emit a second light by reflecting the light of the sub-light source 521. In other words, the micro-mirrors in the micro-mirror array 522 may be understood as the second light-emitting unit in the present embodiment.

[0089] In this embodiment, assuming that the first specific light-emitting unit and the second specific light-emitting unit found are micro-reflectors 501a and 502a respectively, the processor 104 can still calculate the specific distance between the distance detection system 100 and the specific object 599 based on the previous teachings, and the details are not repeated here.

[0090] In summary, since each first light-emitting unit in the first light source emits a first light based on a first polarization direction and a corresponding first modulation mode, and each second light-emitting unit in the second light source emits a second light based on a second polarization direction and a corresponding second modulation mode, the method disclosed herein can find the first specific light-emitting unit and the second specific light-emitting unit after determining the first specific modulation mode and the second specific modulation mode presented by a specific pixel in multiple image frames. Afterwards, the method disclosed herein can estimate the specific distance between the distance detection system and the specific object corresponding to the specific pixel based on the relative position between the first specific light-emitting unit and the second specific light-emitting unit. Thereby, even in a strong light / weak light environment, the method disclosed herein can still accurately determine the specific distance between the distance detection system and the specific object, thereby reducing the probability of collisions, car accidents, and the like.

[0091] Although the present disclosure has been disclosed as above by way of embodiments, it is not intended to limit the present disclosure. Any person having ordinary knowledge in the technical field may make slight changes and modifications without departing from the spirit and scope of the present disclosure. Therefore, the protection scope of the present disclosure shall be determined by the appended claims.

Claims

1. A distance detection system, characterized in that: include: A first light source has a first polarization direction and includes a plurality of first light emitting units, each of which emits a first light beam based on the first polarization direction and a respective first modulation mode to illuminate a specific object; A second light source has a second polarization direction and includes a plurality of second light emitting units, each of which emits a second light based on the second polarization direction and a respective second modulation mode to illuminate the specific object; An image capturing circuit, used for capturing a plurality of image frames at a plurality of time points in a specific field of view, wherein the specific field of view includes the specific object, and each of the image frames includes a specific pixel corresponding to the specific object; as well as A processor is coupled to the first light source, the second light source and the image capturing circuit and is configured to: Acquire a first specific modulation mode and a second specific modulation mode presented by the specific pixel at the time point based on the image frame, wherein the first specific modulation mode corresponds to the first polarization direction, and the second specific modulation mode corresponds to the second polarization direction; Finding a first specific light-emitting unit in the first light-emitting units based on the first specific modulation mode, and finding a second specific light-emitting unit in the second light-emitting units based on the second specific modulation mode; and A specific distance between the distance detection system and the specific object is calculated based on the first specific light emitting unit and the second specific light emitting unit.

2. The distance detection system as claimed in claim 1, characterized in that: The imaging circuit includes a first lens and a second lens corresponding to the first polarization direction and the second polarization direction respectively, the image frame includes a plurality of first image frames captured by the first lens and a plurality of second image frames captured by the second lens, and the processor obtains the first specific modulation mode and the second specific modulation mode in the following steps: Acquire the first specific modulation mode presented by the specific pixel at the time point based on the first image frame; and The second specific modulation mode presented by the specific pixel at the time point is obtained based on the second image frame.

3. The distance detection system as claimed in claim 1, characterized in that: The step of the processor obtaining the first specific modulation method and the second specific modulation method comprises: Acquire a plurality of first sub-pixels and a plurality of second sub-pixels corresponding to the first polarization direction and the second polarization direction respectively in a plurality of pixels of each of the image frames; Combining the first sub-pixels into a plurality of first image frames, and combining the second sub-pixels into a plurality of second image frames; Acquire the first specific modulation mode presented by the specific pixel at the time point based on the first image frame; and The second specific modulation mode presented by the specific pixel at the time point is obtained based on the second image frame.

4. The distance detection system as claimed in claim 1, characterized in that: The step of the processor calculating the specific distance between the distance detection system and the specific object comprises: Obtaining a preset distance between the first specific light emitting unit and the second specific light emitting unit; and A triangulation method is performed based on a first emission direction of the first specific light emitting unit, a second emission direction of the second specific light emitting unit, and the preset distance to calculate the specific distance between the distance detection system and the specific object.

5. The distance detection system as claimed in claim 1, characterized in that: The first modulation modes corresponding to the first light-emitting units are all different, and the second modulation modes corresponding to the second light-emitting units are all different.

6. The distance detection system as claimed in claim 1, characterized in that: The first polarization direction and the second polarization direction are orthogonal to each other.

7. A distance detection method, suitable for a distance detection system, characterized in that: include: A plurality of first light emitting units of a first light source emit a first light beam based on a first polarization direction and a first modulation mode to illuminate a specific object; A plurality of second light emitting units of a second light source respectively emit a second light beam based on a second polarization direction and a respective second modulation mode to illuminate the specific object; Capturing a plurality of image frames at a plurality of time points in a specific field of view by an image capturing circuit, wherein the specific field of view includes the specific object, and each of the image frames includes a specific pixel corresponding to the specific object; A processor obtains a first specific modulation mode and a second specific modulation mode presented by the specific pixel at the time point based on the image frame, wherein the first specific modulation mode corresponds to the first polarization direction, and the second specific modulation mode corresponds to the second polarization direction; The processor finds a first specific light-emitting unit in the first light-emitting units based on the first specific modulation mode, and finds a second specific light-emitting unit in the second light-emitting units based on the second specific modulation mode; as well as The processor calculates a specific distance between the distance detection system and the specific object based on the first specific light emitting unit and the second specific light emitting unit.

8. The method according to claim 7, characterized in that The step of capturing the image frame by the image capturing circuit includes: Capturing a plurality of first image frames having the first polarization direction at the specific field of view at the time point by a first lens of the image capturing circuit; and Capturing a plurality of second image frames having the second polarization direction at the specific field of view at the time point by a second lens of the image capturing circuit; The step of the processor obtaining the first specific modulation method and the second specific modulation method comprises: Acquire the first specific modulation mode presented by the specific pixel at the time point based on the first image frame; and The second specific modulation mode presented by the specific pixel at the time point is obtained based on the second image frame.

9. The method according to claim 7, characterized in that The step of obtaining the first specific modulation method and the second specific modulation method by the processor includes: Acquire a plurality of first sub-pixels and a plurality of second sub-pixels corresponding to the first polarization direction and the second polarization direction respectively in a plurality of pixels of each of the image frames; Combining the first sub-pixels into a plurality of first image frames, and combining the second sub-pixels of each pixel in the image frames into a plurality of second image frames; Acquire the first specific modulation mode presented by the specific pixel at the time point based on the first image frame; and The second specific modulation mode presented by the specific pixel at the time point is obtained based on the second image frame.

10. The method according to claim 7, characterized in that The step of calculating, by the processor, the specific distance between the distance detection system and the specific object comprises: Obtaining a preset distance between the first specific light emitting unit and the second specific light emitting unit; and A triangulation method is performed based on a first emission direction of the first specific light emitting unit, a second emission direction of the second specific light emitting unit, and the preset distance to calculate the specific distance between the distance detection system and the specific object.

11. The method according to claim 7, characterized in that The first polarization direction and the second polarization direction are orthogonal to each other.

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