Boundary detection method and device for target area

Abstract

This application discloses a method and device for detecting the boundary of a target area, belonging to the field of network technology. The boundary detection device can determine the distance between the boundary of the target area and a detection sensor in a first direction, and the distance between the boundary of the target area and the detection sensor in a second direction, based on the position parameters of multiple reflection points, thereby determining the location of the boundary of the target area. Because the boundary detection device can automatically determine the boundary of the target area without requiring the user to manually input the boundary of the target area, the efficiency and reliability of the target area boundary determination are improved.

Description

Technical Field

[0001] The present application relates to the field of network technology, and in particular to a method and device for detecting the boundary of a target area. Background Art

[0002] In an indoor space, a millimeter-wave radar sensor can usually be used to identify the number of people in the indoor space. Before identifying the number of people in the indoor space, the boundary of the indoor space needs to be determined first.

[0003] In related technologies, after installing a millimeter-wave radar sensor in an indoor space, a user can set the boundary location of the indoor space using location setting software installed in a terminal. After receiving the boundary location of the indoor space entered by the user in the location setting software, the terminal can send the boundary location to the millimeter-wave radar sensor, causing the millimeter-wave radar sensor to store the boundary location of the indoor space.

[0004] However, since the user is required to manually set the boundary position of the indoor space, the efficiency of determining the boundary of the indoor space is low. Summary of the Invention

[0005] The present invention provides a method and device for detecting the boundary of a target area, which can solve the problem of low efficiency in determining the boundary of an indoor space in related technologies. The technical solution is as follows:

[0006] In one aspect, a method for detecting a boundary of a target area is provided, which is applied to a boundary detection device, wherein the boundary detection device includes a detection sensor located in the target area; the method includes:

[0007] transmitting a detection signal through the detection sensor and receiving the detection signal reflected by a plurality of reflection points;

[0008] For each of the reflection points, determining position parameters of the reflection point based on the detection signal reflected by the reflection point, the position parameters including at least a first reference distance between the reflection point and the detection sensor in a first direction, a second reference distance between the reflection point and the detection sensor in a second direction, and an azimuth angle of the reflection point relative to the detection sensor, where the first direction is perpendicular to the second direction;

[0009] Determining a first target distance and a second target distance based on the position parameters of the multiple reflection points, respectively, wherein differences between the first target distance and a first reference distance of the multiple first target reflection points are all less than a first threshold, differences between the second target distance and a second reference distance of the multiple second target reflection points are all less than a second threshold, the azimuth angle of the first target reflection point is within a first azimuth angle range, the azimuth angle of the second target reflection point is within a second azimuth angle range, and an upper limit of the first azimuth angle range is less than a lower limit of the second azimuth angle range;

[0010] The first target distance is determined as the distance between the boundary of the target area and the detection sensor in the first direction, and the second target distance is determined as the distance between the boundary of the target area and the detection sensor in the second direction.

[0011] Optionally, determining the first target distance and the second target distance respectively based on the position parameters of the multiple reflection points includes:

[0012] determining a first target distance based on first reference distances of a plurality of first target reflection points;

[0013] determining a second target distance based on a second reference distance of a plurality of second target reflection points;

[0014] The lower limit of the first azimuth angle range is greater than or equal to the minimum detection angle of the detection sensor, and the upper limit of the second azimuth angle range is less than or equal to the maximum detection angle of the detection sensor.

[0015] Optionally, determining the first target distance based on the first reference distances of the plurality of first target reflection points includes:

[0016] For each candidate distance in a set of candidate distances, determining a sum of squares of differences between a plurality of first reference distances of the first target reflection points and the candidate distance, wherein the plurality of candidate distances included in the set of candidate distances are different from each other;

[0017] The candidate distance with the smallest sum of squares among the multiple candidate distances is determined as the first target distance.

[0018] Optionally, determining the second target distance based on the second reference distances of the plurality of second target reflection points includes:

[0019] For each candidate distance in the candidate distance set, determining a sum of squares of differences between a plurality of second reference distances of the second target reflection points and the candidate distance, wherein the plurality of candidate distances included in the candidate distance set are different from each other;

[0020] The candidate distance with the smallest sum of squares among the multiple candidate distances is determined as the second target distance.

[0021] Optionally, the position parameter further includes a third reference distance between the reflection point and the detection sensor in a third direction, where the third direction is parallel to the second direction and opposite to the second direction; and the method further includes:

[0022] determining a third target distance based on the position parameters of the multiple reflection points, wherein a difference between the third target distance and a third reference distance of the multiple third target reflection points is less than a third threshold, the azimuth angle of the third reflection point is within a third azimuth angle range, and an upper limit of the third azimuth angle range is less than a lower limit of the first azimuth angle range;

[0023] The third target distance is determined as the distance between the boundary of the target area and the detection sensor in the third direction.

[0024] Optionally, determining the third target distance based on the position parameters of the multiple reflection points includes:

[0025] determining the third target distance based on a third reference distance of the plurality of third target reflection points;

[0026] Wherein, the lower limit of the third azimuth angle range is greater than or equal to the minimum detection angle of the detection sensor.

[0027] Optionally, determining the third target distance based on the third reference distances of the plurality of third target reflection points includes:

[0028] For each candidate distance in the candidate distance set, determining a sum of squares of differences between a plurality of third reference distances of the third target reflection points and the candidate distance, wherein the plurality of candidate distances included in the candidate distance set are different from each other;

[0029] The candidate distance with the smallest sum of squares among the multiple candidate distances is determined as the third target distance.

[0030] Optionally, the method further includes:

[0031] determining a candidate reflection point from the plurality of reflection points based on position parameters of the plurality of reflection points, wherein a first reference distance of the candidate reflection point is less than the first target distance, and a second reference distance of the candidate reflection point is less than the second target distance;

[0032] The number of target objects in the target area is determined based on the position parameters of the candidate reflection points.

[0033] On the other hand, a target area boundary detection device is provided, characterized in that the boundary detection device includes a detection sensor and a processor located in the target area;

[0034] The detection sensor is used to transmit a detection signal and receive the detection signal reflected by multiple reflection points;

[0035] The processor is configured to:

[0036] For each of the reflection points, determining position parameters of the reflection point based on the detection signal reflected by the reflection point, the position parameters including at least a first reference distance between the reflection point and the detection sensor in a first direction, a second reference distance between the reflection point and the detection sensor in a second direction, and an azimuth angle of the reflection point relative to the detection sensor, where the first direction is perpendicular to the second direction;

[0037] Determining a first target distance and a second target distance based on the position parameters of the multiple reflection points, respectively, wherein differences between the first target distance and a first reference distance of the multiple first target reflection points are all less than a first threshold, differences between the second target distance and a second reference distance of the multiple second target reflection points are all less than a second threshold, the azimuth angle of the first target reflection point is within a first azimuth angle range, the azimuth angle of the second target reflection point is within a second azimuth angle range, and an upper limit of the first azimuth angle range is less than a lower limit of the second azimuth angle range;

[0038] The first target distance is determined as the distance between the boundary of the target area and the detection sensor in the first direction, and the second target distance is determined as the distance between the boundary of the target area and the detection sensor in the second direction.

[0039] Optionally, the processor is configured to:

[0040] determining a first target distance based on first reference distances of a plurality of first target reflection points;

[0041] determining a second target distance based on a second reference distance of a plurality of second target reflection points;

[0042] The lower limit of the first azimuth angle range is greater than or equal to the minimum detection angle of the detection sensor, and the upper limit of the second azimuth angle range is less than or equal to the maximum detection angle of the detection sensor.

[0043] On the other hand, a boundary detection device is provided, comprising: a memory, a processor, and a computer program stored in the memory, wherein the processor implements the boundary detection method of the target area described in the above aspect when executing the computer program.

[0044] In another aspect, a computer-readable storage medium is provided, wherein instructions are stored in the computer-readable storage medium. When the instructions are loaded and executed by a processor, the method for detecting the boundary of a target area described in the above aspect is implemented.

[0045] In yet another aspect, a computer program product comprising instructions is provided. When the computer program product is run on a computer, the computer is enabled to execute the target area boundary detection method described in the above aspects.

[0046] The beneficial effects of the technical solutions provided in the embodiments of the present application include at least:

[0047] Embodiments of the present application provide a method and device for detecting the boundary of a target area. The boundary detection device can determine, based on the position parameters of multiple reflection points, the distance between the boundary of the target area and a detection sensor in a first direction, as well as the distance between the boundary of the target area and the detection sensor in a second direction, thereby determining the location of the boundary of the target area. Because the boundary detection device can automatically determine the boundary of the target area without requiring manual input of the boundary by the user, the efficiency and reliability of determining the boundary of the target area are improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0049] Figure 1 Schematic diagram of an implementation environment involved in a target area boundary detection method provided in an embodiment of the present application;

[0050] Figure 2 This is a target area boundary detection method provided by an embodiment of the present application;

[0051] Figure 3 This is another target area boundary detection method provided by an embodiment of the present application;

[0052] Figure 4 is a schematic diagram of a target coordinate system provided in an embodiment of the present application;

[0053] Figure 5 is a schematic diagram of a first reference distance and a second reference distance provided in an embodiment of the present application;

[0054] Figure 6 is a schematic diagram of determining the boundary of a target area provided in an embodiment of the present application;

[0055] Figure 7 This is a schematic diagram of displaying the boundary of a target area in a mobile terminal provided by an embodiment of the present application;

[0056] Figure 8 This is a schematic diagram of a second prompt information provided in an embodiment of the present application;

[0057] Figure 9 Schematic diagram of the structure of a boundary detection device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0058] In order to make the objectives, technical solutions and advantages of this application clearer, the implementation methods of this application will be further described in detail below with reference to the accompanying drawings.

[0059] Figure 1 Schematic diagram of the implementation environment involved in a target area boundary detection method provided in an embodiment of the present application. Figure 1 As shown, the implementation environment may include a boundary detection device 10, the boundary detection device 10 includes a detection sensor 11 located in a target area 20, and the target area 20 may include one or more boundaries. For example, the target area 20 may be an indoor space including an arc boundary. Alternatively, referring to Figure 1 The target area 20 may be an indoor space having four boundaries, namely, a first boundary 21, a second boundary 22, a third boundary 23, and a fourth boundary 24. The boundary detection device 10 may be a device installed at any boundary within the indoor space and capable of being equipped with a detection sensor 11. For example, the boundary detection device 10 may be installed at the fourth boundary 24 of the indoor space 20, and the boundary detection device 10 may be a television.

[0060] In the examples of this application, refer to Figure 1 The detection sensor 11 can be arranged on a side of the housing of the boundary detection device 10 away from the fourth boundary 24. Alternatively, the detection sensor 11 can be arranged on a side of the housing of the boundary detection device 10, the extension direction of which is perpendicular to the plane where the fourth boundary 24 is located.

[0061] The detection sensor 11 is used to transmit a detection signal and receive the detection signal reflected by a plurality of reflection points, wherein the reference Figure 1 The multiple reflection points may include reflection points on a target object and / or reflection points on a boundary of the target area 20. For example, the target object may be a person, and the boundary of the target area 20 may be an object such as a wall or a fence that can separate the target area 20 from other areas. In the embodiment of the present application, the detection sensor 11 may be a millimeter wave radar sensor, and the detection signal may be a millimeter wave signal.

[0062] Figure 2 This is a target area boundary detection method provided by the embodiment of the present application, which can be applied to Figure 1 The boundary detection device 10 shown. Figure 2 As shown, the method includes:

[0063] Step 201: A detection sensor transmits a detection signal and receives the detection signal reflected by a plurality of reflection points.

[0064] In the embodiment of the present application, the detection sensor can transmit a detection signal and can receive the detection signal reflected by multiple reflection points. The detection sensor can transmit the detection signal periodically or in real time.

[0065] Step 202: For each reflection point, determine the position parameters of the reflection point based on the detection signal reflected by the reflection point.

[0066] After the detection sensor receives detection signals reflected from multiple reflection points, the boundary detection device can determine the position parameters of each reflection point based on the detection signal reflected by the reflection point. These position parameters include at least a first reference distance between the reflection point and the detection sensor in a first direction, a second reference distance between the reflection point and the detection sensor in a second direction, and the azimuth angle of the reflection point relative to the detection sensor. The first direction is perpendicular to the second direction. The azimuth angle of the reflection point refers to the angle between a line connecting the reflection point and a reference point on the detection sensor and a first direction passing through the reference point.

[0067] Step 203: Determine the first target distance and the second target distance based on the position parameters of the multiple reflection points.

[0068] The difference between the first target distance and the first reference distances of the multiple first target reflection points is less than a first threshold. The difference between the second target distance and the second reference distances of the multiple second target reflection points is less than a second threshold. The first target reflection point and the second target reflection point both belong to the multiple reflection points, and the azimuth angle of the first target reflection point is within a first azimuth angle range, the azimuth angle of the second target reflection point is within a second azimuth angle range, and the upper limit of the first azimuth angle range is less than the lower limit of the second azimuth angle range. That is, the azimuth angle of the first target reflection point is smaller, and the azimuth angle of the second target reflection point is larger.

[0069] The first threshold value may be a fixed value pre-stored in the boundary detection device, or may be the second-to-last smallest difference between the first target distance and the first reference distances of the plurality of first target reflection points. The second threshold value may be a fixed value pre-stored in the boundary detection device, or may be the second-to-last smallest difference between the second target distance and the second reference distances of the plurality of second target reflection points.

[0070] Step 204 : Determine the first target distance as the distance between the boundary of the target area and the detection sensor in the first direction, and determine the second target distance as the distance between the boundary of the target area and the detection sensor in the second direction.

[0071] After determining the first target distance and the second target distance, the boundary detection device can determine the first target distance as the distance between the boundary of the target area and the detection sensor in the first direction, and the second target distance as the distance between the boundary of the target area and the detection sensor in the second direction. In this way, the location of the boundary of the target area can be determined.

[0072] It should be understood that the first target distance can be greater than or equal to any first reference distance. Furthermore, because the difference between the first target distance and the first reference distances of multiple first target reflection points is relatively small, it can be ensured that the first target distance is equal to or approximately equal to the distance between the boundary of the target area and the detection sensor in the first direction. Similarly, the second target distance can be greater than or equal to any second reference distance. Furthermore, because the difference between the second target distance and the second reference distances of multiple second target reflection points is relatively small, it can be ensured that the second target distance is equal to or approximately equal to the distance between the boundary of the target area and the detection sensor in the second direction. Based on the above analysis, it can be seen that the location of the boundary of the target area determined based on the first target distance and the second target distance is relatively accurate.

[0073] In summary, embodiments of the present application provide a method for detecting the boundary of a target area. A boundary detection device can determine, based on the position parameters of multiple reflection points, the distance between the boundary of the target area and a detection sensor in a first direction, as well as the distance between the boundary of the target area and the detection sensor in a second direction, thereby determining the location of the boundary of the target area. Because the boundary detection device can automatically determine the boundary of the target area without requiring the user to manually input the boundary of the target area, the efficiency and reliability of determining the boundary of the target area are improved.

[0074] Figure 3 This is another target area boundary detection method provided by the embodiment of the present application, which can be applied to Figure 1 The boundary detection device 10 shown. Figure 3 As shown, the method may include:

[0075] Step 301: A detection sensor transmits a detection signal and receives the detection signal reflected by a plurality of reflection points.

[0076] The detection sensor is capable of emitting a detection signal and receiving the detection signal reflected by a plurality of reflection points. The plurality of reflection points may include reflection points on a target object and / or reflection points on a boundary of a target area. The detection sensor may emit the detection signal periodically or in real time. The detection sensor may be a millimeter wave radar sensor, and accordingly, the detection signal may be a millimeter wave signal, which may be a frequency modulated continuous wave (FMCW) signal.

[0077] In an embodiment of the present application, the millimeter-wave radar sensor may be provided with multiple transmitting antennas and multiple receiving antennas. The multiple transmitting antennas can transmit millimeter-wave signals, and the multiple receiving antennas can receive millimeter-wave signals.

[0078] Step 302: For each reflection point, determine the position parameters of the reflection point based on the detection signal reflected by the reflection point.

[0079] After receiving the detection signals reflected by the multiple reflection points, the boundary detection device may determine, for each reflection point, a position parameter of the reflection point based on the detection signal reflected by the reflection point.

[0080] The position parameter may include at least a first reference distance between the reflection point and the detection sensor in a first direction, and a second reference distance between the reflection point and the detection sensor in a second direction.

[0081] Alternatively, the position parameter may include at least a first reference distance between the reflection point and the detection sensor in a first direction, and a third reference distance between the reflection point and the detection sensor in a third direction.

[0082] refer to Figure 4 The first direction s1 is perpendicular to the second direction s2 and the third direction s3. The third direction s3 is parallel to the second direction s2 and opposite to the second direction s2. The first direction s1 is parallel to the positive direction of the first coordinate axis Y in the target coordinate system XY. The second direction s2 is aligned with the positive semi-axis of the second coordinate axis X in the target coordinate system XY. The third direction s3 is aligned with the negative semi-axis of the second coordinate axis X in the target coordinate system XY. The origin O of the target coordinate system XY may be a reference point on the detection sensor 11. For example, the reference point may be the center point of the detection sensor 11.

[0083] refer to Figure 4The detection angle range of the detection sensor 11 may be [θ1, θ2]. The detection angle of the detection sensor 11 is the angle between the transmission direction of the detection signal emitted by the detection sensor 11 and the first coordinate axis Y of the target coordinate system XY. θ1 is the minimum detection angle of the detection sensor 11, and θ2 is the maximum detection angle of the detection sensor 11. For example, θ1 may be -60 degrees, and θ2 may be 60 degrees.

[0084] It is understood that if the transmission direction of the detection signal is located between the first coordinate axis Y and the negative semi-axis of the second coordinate axis X of the target coordinate system XY, then the angle between the transmission direction of the detection signal and the first coordinate axis Y of the target coordinate system XY is negative. If the transmission direction of the detection signal is located between the first coordinate axis Y and the positive semi-axis of the second coordinate axis X, then the angle between the transmission direction of the detection signal and the first coordinate axis Y of the target coordinate system XY is positive, and the positive direction of the second coordinate axis X can be predetermined.

[0085] In the embodiment of the present application, for each reflection point, the boundary detection device can determine the distance between the reflection point and the detection sensor, and the azimuth of the reflection point relative to the detection sensor based on the detection signal reflected by the reflection point, and then the boundary detection device can determine the position parameters of the reflection point based on the distance and azimuth. Figure 5 The azimuth angle ɑ is the angle between the line connecting the reflection point 001 and the reference point O on the detection sensor and the first coordinate axis Y. If the line connecting the reflection point 001 and the reference point O on the detection sensor is between the first coordinate axis Y and the negative semi-axis of the second coordinate axis X of the target coordinate system XY, the azimuth angle ɑ is negative. If the line connecting the reflection point 001 and the reference point O on the detection sensor is between the first coordinate axis Y and the positive semi-axis of the second coordinate axis X of the target coordinate system XY, the azimuth angle ɑ is positive. The distance d is the length of the line connecting the reflection point 001 and the reference point O on the detection sensor.

[0086] In the process of determining the position parameters of each reflection point, if the azimuth angle of the reflection point is greater than 0, the boundary detection device can determine that the position parameters of the reflection point may at least include a first reference distance between the reflection point and the detection sensor in the first direction s1, and a second reference distance between the reflection point and the detection sensor in the second direction s2.

[0087] Among them, the first reference distance D1 of the reflection point satisfies: D1 = d × cos (α), and the second reference distance D2 satisfies: D2 = d × sin (α), wherein d is the distance between the reflection point and the detection sensor, α is the azimuth angle of the reflection point relative to the detection sensor, and the azimuth angle α is greater than 0.

[0088] Example, reference Figure 5 , the azimuth angle α of the reflection point 001 relative to the detection sensor is greater than 0. The boundary detection device can determine, based on the distance d between the reflection point 001 and the detection sensor, and the azimuth angle α of the reflection point 001 relative to the detection sensor, that the position parameters of the reflection point 001 may at least include a first reference distance between the reflection point 001 and the detection sensor in a first direction s1, and a second reference distance between the reflection point 001 and the detection sensor in a second direction s2.

[0089] If the azimuth angle of the reflection point is less than or equal to 0, the boundary detection device can determine that the position parameters of the reflection point may at least include a first reference distance between the reflection point and the detection sensor in the first direction s1, and a third reference distance between the reflection point and the detection sensor in the third direction s3.

[0090] The third reference distance D3 of the reflection point satisfies: D3 = |d×sin(α)|, where α is less than or equal to 0.

[0091] In the examples of this application, refer to Figure 6 After receiving the detection signals reflected by multiple reflection points, the boundary detection device can convert the detection signal reflected by each reflection point into a digital signal, and determine the distance (i.e., the distance between the reflection point and the detection sensor) and the azimuth (i.e., the azimuth of the reflection point relative to the detection sensor) based on the digital signal.

[0092] Optionally, for each reflection point, the boundary detection device may perform a fast Fourier transform (FFT) on the digital signal of the reflection point and, based on the peak frequency of the FFT-processed digital signal, determine the distance corresponding to the peak frequency from a pre-stored frequency-distance correspondence, thereby obtaining the distance between the reflection point and the detection sensor. Furthermore, the boundary detection device may use a digital beamforming (DOA) estimation algorithm to process the FFT-processed digital signal to obtain the azimuth of the reflection point.

[0093] refer to Figure 6After determining the distance between each reflection point and the detection sensor, and the azimuth angle of the reflection point relative to the detection sensor, the boundary detection device can also screen the multiple reflection points, and then determine the boundary of the target area based on the position parameters of the screened reflection points. Optionally, for each reflection point, the boundary detection device can detect whether the distance between the reflection point and the detection sensor is less than a distance threshold, and whether the azimuth angle of the reflection point relative to the detection sensor is less than an angle threshold. If the distance is greater than the distance threshold, and the azimuth angle is greater than the angle threshold, the boundary detection device can determine that the reflection point is a reflection point on the target object or a reflection point on the boundary of the target area, that is, the detection signal reflected by the reflection point is not a noise signal. Therefore, the boundary detection device can retain the reflection point and determine the boundary of the target area based on the detection signal reflected by the reflection point, thereby ensuring the reliability of the determination of the boundary of the target area.

[0094] If the distance is less than or equal to the distance threshold, and / or the azimuth angle is less than or equal to the angle threshold, the boundary detection device can determine that the reflection point is not a reflection point on the target object or a reflection point on the boundary of the target area, that is, the detection signal reflected by the reflection point is a noise signal, so the boundary detection device can delete the reflection point, that is, not determine the boundary of the target area based on the detection signal reflected by the reflection point.

[0095] The distance threshold may be a fixed value pre-stored in the boundary detection device, or may be obtained by the boundary detection device using a constant false alarm rate (CFAR) algorithm to evaluate the distances of multiple reflection points. The angle threshold may be a fixed value pre-stored in the boundary detection device, or may be obtained by the boundary detection device using a CFAR algorithm to evaluate the azimuths of multiple reflection points.

[0096] Step 303: Determine the reflection point with an azimuth angle within the first azimuth angle range as the first target reflection point, determine the reflection point with an azimuth angle within the second azimuth angle range as the second target reflection point, and determine the reflection point with an azimuth angle within the third azimuth angle range as the third target reflection point.

[0097] In an embodiment of the present application, the position parameter of each reflection point may further include the azimuth angle of the reflection point relative to the detection sensor. After determining the azimuth angle of each reflection point, the boundary detection device may determine a reflection point with an azimuth angle within a first azimuth angle range as a first target reflection point, a reflection point with an azimuth angle within a second azimuth angle range as a second target reflection point, and a reflection point with an azimuth angle within a third azimuth angle range as a third target reflection point.

[0098] Among them, reference Figure 4The first azimuth angle range may be [β1, β2]. The second azimuth angle range may be [β3, β4], and the third azimuth angle range may be [β5, β6]. The lower limit β5 of the third azimuth angle range is greater than or equal to the minimum detection angle θ1 of the detection sensor, and the upper limit β6 of the third azimuth angle range is less than the lower limit β1 of the first azimuth angle range. The upper limit β2 of the first azimuth angle range is less than the lower limit β3 of the second azimuth angle range, and the upper limit β4 of the second azimuth angle range is less than or equal to the maximum detection angle θ2 of the detection sensor.

[0099] For example, θ1 is -60 degrees, θ2 is 60 degrees, β1 may be -30 degrees, β2 may be 30 degrees, β3 may be 31 degrees, β4 may be 60 degrees, β5 may be -60 degrees, and β6 may be 29 degrees.

[0100] Step 304: Determine a first target distance based on first reference distances of a plurality of first target reflection points.

[0101] After determining the plurality of first target reflection points, the boundary detection device may determine the first target distance based on the first reference distances of the plurality of first target reflection points. The difference between the first target distance and the first reference distances of the plurality of first target reflection points is less than a first threshold. The first threshold may be a fixed value pre-stored in the boundary detection device, or the second-to-last smallest difference between the first target distance and the first reference distances of the plurality of first target reflection points.

[0102] In an embodiment of the present application, a boundary detection device may pre-store a set of alternative distances, wherein the set includes multiple different alternative distances. After determining multiple first target reflection points, the boundary detection device may determine, for each alternative distance in the set of alternative distances, the sum of the squares of the differences between the first reference distances of the multiple first target reflection points and the alternative distances, and determine the alternative distance with the smallest square sum among the multiple alternative distances as the first target distance. This ensures that the difference between the first target distance and the first reference distances of the multiple first target reflection points is less than a first threshold, ensuring that the first target distance is equal to or approximately equal to the distance between the boundary of the target area and the detection sensor in the first direction, thereby improving the reliability of the determined first target distance.

[0103] The sum of squares of the differences between the first reference distances of the multiple first target reflection points and the jth candidate distance is F j satisfy: The boundary detection device can be min (F1, F2, ..., F N ) is determined as the first target distance.

[0104] The L jis the jth candidate distance among multiple candidate distances, D1 i is the first reference distance of the i-th first target reflection point among the multiple first target reflection points, n1 is the total number of the multiple first target reflection points, and n1 is a positive integer. N is the total number of the multiple alternative distances, and N is a positive integer. j is the sum of the squares of the differences between the first reference distances of the multiple first target reflection points and the jth candidate distance. i is a positive integer less than or equal to n1, and j is a positive integer less than or equal to N. min(F1, F2, ..., F N ) means taking F1 to F N The minimum value in .

[0105] In the embodiment of the present application, the boundary detection device may also determine the largest first reference distance among multiple first target reflection points as the first target distance.

[0106] In an embodiment of the present application, when setting multiple alternative distances in the alternative distance set, a worker may start from an initial distance and increase the initial distance to a target distance using a fixed distance as a step size, thereby determining multiple alternative distances in the alternative distance set. For example, if the initial distance is 0, the fixed distance is 1, and the target distance is 5, the alternative distance set may include 6 alternative distances: 0, 1, 2, 3, 4, and 5.

[0107] Step 305: Determine a second target distance based on second reference distances of a plurality of second target reflection points.

[0108] After determining the plurality of second target reflection points, the boundary detection device may determine the second target distance based on the second reference distances of the plurality of second target reflection points.

[0109] The first reference distance of the first target reflection point is greater than the first reference distance of the second target reflection point. The difference between the second target distance and the second reference distances of the plurality of second target reflection points is less than a second threshold. The difference between the second target distance and the second reference distances of the plurality of second target reflection points is less than the second threshold. The second threshold may be a fixed value pre-stored in the boundary detection device, or may be the second-to-last smallest difference between the second target distance and the second reference distances of the plurality of second target reflection points.

[0110] In an embodiment of the present application, after determining multiple second target reflection points, the boundary detection device determines, for each candidate distance in the candidate distance set, the sum of the squares of the differences between the second reference distances of the multiple second target reflection points and the candidate distances, and may determine the candidate distance with the smallest square sum among the multiple candidate distances as the second target distance. This ensures that the differences between the second target distance and the second reference distances of the multiple second target reflection points are all less than a second threshold, ensuring that the second target distance is equal to or approximately equal to the distance in the second direction between the boundary of the target area and the detection sensor, thereby improving the reliability of the determined second target distance.

[0111] The sum of squares of the differences between the second reference distances of the plurality of second target reflection points and the jth candidate distance is Q j satisfy: The boundary detection device can be min (Q1, Q2, ..., Q N ) is determined as the second target distance.

[0112] The D2 k is the second reference distance of the kth second target reflection point among the plurality of second target reflection points, and n2 is the total number of the plurality of second target reflection points. j is the sum of the squares of the differences between the second reference distances of the plurality of second target reflection points and the jth candidate distance. k is a positive integer less than or equal to n2. min(Q1, Q2, ..., Q N ) means taking Q1 to Q N The minimum value in .

[0113] In the embodiment of the present application, the boundary detection device may also determine the largest second reference distance among multiple second target reflection points as the second target distance.

[0114] Step 306: Determine a third target distance based on third reference distances of a plurality of third target reflection points.

[0115] After determining the plurality of third target reflection points, the boundary detection device may determine the third target distance based on position parameters of the plurality of reflection points.

[0116] Among them, the first reference distance of the first target reflection point is greater than the first reference distance of the third target reflection point, and the difference between the third target distance and the third reference distances of multiple third target reflection points is less than a third threshold. The third threshold can be a fixed value pre-stored in the boundary detection device, or it can be the second-to-last smallest difference between the third target distance and the third reference distances of multiple third target reflection points.

[0117] In an embodiment of the present application, after determining multiple third target reflection points, the boundary detection device may determine, for each candidate distance in the candidate distance set, the sum of the squares of the differences between the third reference distances of the multiple third target reflection points and the candidate distances, and may determine the candidate distance with the smallest square sum among the multiple candidate distances as the third target distance. This ensures that the differences between the third target distance and the third reference distances of the multiple third target reflection points are all less than a third threshold, ensuring that the third target distance is equal to or approximately equal to the distance between the boundary of the target area and the detection sensor in the third direction, thereby improving the reliability of the determined third target distance.

[0118] The sum of squares of the differences between the third reference distances of the plurality of third target reflection points and the jth candidate distance is P j satisfy: The boundary detection device can be min(P1, P2, ..., P N ) is determined as the third target distance.

[0119] The D3 v is the third reference distance of the vth third target reflection point among the plurality of third target reflection points, and n3 is the total number of the plurality of third target reflection points. j is the sum of the squares of the differences between the third reference distances of the plurality of third target reflection points and the jth candidate distance. v is a positive integer less than or equal to n3. min(P1, P2, ..., P N ) represents P1 to P N The minimum value in .

[0120] In the embodiment of the present application, the boundary detection device may also determine the largest third reference distance among multiple third target reflection points as the third target distance.

[0121] Step 307: determine the first target distance as the distance between the boundary of the target area and the detection sensor in the first direction, determine the second target distance as the distance between the boundary of the target area and the detection sensor in the second direction, and determine the third target distance as the distance between the boundary of the target area and the detection sensor in the third direction.

[0122] After determining the first target distance, the boundary detection device may determine the first target distance as the distance between the boundary of the target area and the detection sensor in a first direction. After determining the second target distance, the boundary detection device may determine the second target distance as the distance between the boundary of the target area and the detection sensor in a second direction. After determining the third target distance, the boundary detection device may determine the third target distance as the distance between the boundary of the target area and the detection sensor in a third direction. The boundary detection device can thereby obtain the location of the boundary of the target area and store the location of the boundary of the target area.

[0123] In an embodiment of the present application, the boundary detection device may also establish a communication connection with the mobile terminal. After determining the location of the boundary of the target area, the boundary detection device may also send the location of the boundary of the target area (i.e., the first target distance, the second target distance, and the third target distance) to the mobile terminal. After receiving the location of the boundary of the target area, the mobile terminal may display the location of the boundary of the target area on its display interface.

[0124] For example, assume that the first target distance is L1, the second target distance is L2, the third target distance is L3, and the target area is a room. Figure 7 After receiving the location of the target area's boundary from the boundary detection device, the mobile terminal can display the detection sensor 11, a first target distance L1 between the second boundary 22 of the target area and the detection sensor 11 in the first direction, a second target distance L2 between the first boundary 21 of the target area and the detection sensor 11 in the second direction, and a third target distance L3 between the third boundary 23 of the target area and the detection sensor 11 in the third direction. The mobile terminal can also display a first prompt message 002, which can be "The following is the location of the room boundary."

[0125] Step 308: Determine a candidate reflection point from the multiple reflection points based on the position parameters of the multiple reflection points.

[0126] After determining the boundary of the target area, the boundary detection device can determine an alternative reflection point from the multiple reflection points based on the position parameters of the multiple reflection points. The alternative reflection point is a reflection point on the target object, that is, a reflection point among the multiple reflection points other than the reflection point on the boundary of the target area. The target object can be a person.

[0127] Wherein, if the location parameters of the alternative reflection point include a first reference distance and a second reference distance, the first reference distance of the alternative reflection point is less than the first target distance, and the second reference distance of the alternative reflection point is less than the second target distance. Alternatively, if the location parameters of the alternative reflection point include a first reference distance and a third reference distance, the first reference distance of the alternative reflection point is less than the first target distance, and the third reference distance of the alternative reflection point is less than the third target distance.

[0128] Taking the example of a reflection point whose location parameters include a first reference distance and a second reference distance, after determining the boundary of the target area, the boundary detection device can compare whether the first reference distance of the reflection point is less than the first target distance, and whether the second reference distance of the reflection point is less than the second target distance. If the first reference distance of the reflection point is less than the first target distance, and the second reference distance of the reflection point is less than the second target distance, the boundary detection device can determine that the reflection point is an alternative reflection point. If the first reference distance of the reflection point is equal to the first target distance, and / or the second reference distance of the reflection point is equal to the second target distance, the boundary detection device can determine that the reflection point is not an alternative reflection point, that is, the reflection point is a reflection point on the boundary of the target area.

[0129] Step 309: Determine the number of target objects in the target area based on the position parameters of the candidate reflection points.

[0130] After determining the candidate reflection point, the boundary detection device may determine the number of target objects in the target area based on the position parameters of the candidate reflection point.

[0131] For each candidate reflection point, the boundary detection device can also determine the velocity of the candidate reflection point based on the detection signal reflected by the candidate reflection point. The boundary detection device can then use a clustering algorithm to cluster the distances, azimuths, and velocities of the multiple candidate reflection points, thereby determining reflection points belonging to the same target object and, in turn, the number of targets. The boundary detection device can then adjust its operating state based on the determined number of targets.

[0132] For example, if the boundary detection device is a desk lamp, the boundary detection device can adjust the brightness of its emitted light beam based on the number of target objects, where the adjusted brightness is positively correlated with the number of target objects. If the boundary detection device determines that the number of target objects is zero, the boundary detection device can adjust its operating state to standby mode, in which case the brightness of the light beam emitted by the boundary detection device is zero. If the boundary detection device is a television, when the boundary detection device determines that the number of target objects is zero, it can adjust its operating state to standby mode, in which case the boundary detection device screen does not display an image.

[0133] It is understood that when the boundary detection device is in the standby state, the detection sensor and processor are still in the working state, and all other components in the boundary detection device are in the off state. The boundary detection device can detect the number of targets in the target area in real time based on the detection sensor and processor, and adjust its working state from the standby state to the on state when the number of detected targets is greater than 0.

[0134] In an embodiment of the present application, after determining the number of target objects, the boundary detection device can also send the number of target objects to the mobile terminal. After receiving the number of target objects, the mobile terminal can display a second prompt information, which is used to indicate the number of target objects in the target area.

[0135] For example, if the target area is a room, the number of targets is 3 and the targets are people, then refer to Figure 8 , the second prompt information 003 may be "There are 3 people in the room at present".

[0136] For each candidate reflection point, the boundary detection device may use a Doppler shift algorithm to process the digital signal after FFT to obtain the velocity of the candidate reflection point.

[0137] In an embodiment of the present application, a boundary determination identifier is pre-set in the boundary detection device as an initial value. The initial value is used to indicate that the boundary detection device has not determined the boundary of the target area. Accordingly, the boundary detection device does not store the boundary of the target area. After determining the boundary of the target area, the boundary detection device can update the boundary determination identifier from the initial value to the target value. The target value is used to indicate that the boundary detection device has determined the boundary of the target area. Accordingly, the boundary detection device also stores the boundary of the target area. Therefore, after the boundary detection device executes step 302, if the boundary detection device determines that the boundary determination identifier is the target value, steps 308 and 309 can be directly executed. If the boundary determination identifier is determined to be the initial value, steps 303 to 309 can be executed.

[0138] It should be noted that the order of the steps of the target area boundary detection method provided in the embodiment of the present application can be appropriately adjusted, and steps can also be deleted according to the situation. For example, the above steps 304 to 306 can be performed simultaneously or in sequence. Alternatively, the above steps 308 and 309 can also be deleted according to the situation. Any person skilled in the art who can easily think of a modified method within the technical scope disclosed in this disclosure should be included in the scope of protection of this disclosure, so they will not be repeated here.

[0139] In summary, embodiments of the present application provide a method for detecting the boundary of a target area. A boundary detection device can determine, based on the position parameters of multiple reflection points, the distance between the boundary of the target area and a detection sensor in a first direction, as well as the distance between the boundary of the target area and the detection sensor in a second direction, thereby determining the location of the boundary of the target area. Because the boundary detection device can automatically determine the boundary of the target area without requiring the user to manually input the boundary of the target area, the efficiency and reliability of determining the boundary of the target area are improved.

[0140] The present invention provides a device for detecting the boundary of a target area. Figure 9 The boundary detection device 10 may include a detection sensor 11 located in the target area and a processor 12.

[0141] The detection sensor 11 is used to transmit a detection signal and receive the detection signal reflected by a plurality of reflection points.

[0142] The processor 12 is configured to:

[0143] For each reflection point, the position parameters of the reflection point are determined based on the detection signal reflected by the reflection point, and the position parameters include at least a first reference distance between the reflection point and the detection sensor in a first direction, a second reference distance between the reflection point and the detection sensor in a second direction, and an azimuth angle of the reflection point relative to the detection sensor, where the first direction is perpendicular to the second direction.

[0144] Based on the position parameters of multiple reflection points, a first target distance and a second target distance are respectively determined, wherein the difference between the first target distance and the first reference distances of the multiple first target reflection points is less than a first threshold, the difference between the second target distance and the second reference distances of the multiple second target reflection points is less than a second threshold, the azimuth angle of the first target reflection point is within a first azimuth angle range, the azimuth angle of the second target reflection point is within a second azimuth angle range, and the upper limit of the first azimuth angle range is less than the lower limit of the second azimuth angle range.

[0145] The first target distance is determined as the distance between the boundary of the target area and the detection sensor in the first direction, and the second target distance is determined as the distance between the boundary of the target area and the detection sensor in the second direction.

[0146] In summary, embodiments of the present application provide a target area boundary detection device. Based on the position parameters of multiple reflection points, the boundary detection device can determine the distance between the boundary of the target area and the detection sensor in a first direction, as well as the distance between the boundary of the target area and the detection sensor in a second direction, thereby determining the location of the boundary of the target area. Because the boundary detection device can automatically determine the boundary of the target area without requiring the user to manually input the boundary of the target area, the efficiency and reliability of determining the boundary of the target area are improved.

[0147] Optionally, the processor 12 is configured to:

[0148] A first target distance is determined based on first reference distances of a plurality of first target reflection points.

[0149] The second target distance is determined based on the second reference distances of the plurality of second target reflection points.

[0150] The lower limit of the first azimuth angle range is greater than or equal to the minimum detection angle of the detection sensor, and the upper limit of the second azimuth angle range is less than or equal to the maximum detection angle of the detection sensor.

[0151] Optionally, the processor 12 is configured to:

[0152] For each candidate distance in the candidate distance set, the sum of squares of differences between the first reference distances of the plurality of first target reflection points and the candidate distance is determined, and the plurality of candidate distances included in the candidate distance set are different from each other.

[0153] The candidate distance with the smallest sum of squares among the multiple candidate distances is determined as the first target distance.

[0154] Optionally, the processor 12 is configured to:

[0155] For each candidate distance in the candidate distance set, the sum of squares of differences between the second reference distances of the plurality of second target reflection points and the candidate distance is determined, and the plurality of candidate distances included in the candidate distance set are different from each other.

[0156] The candidate distance with the smallest sum of squares among the multiple candidate distances is determined as the second target distance.

[0157] Optionally, the position parameter also includes a third reference distance between the reflection point and the detection sensor in a third direction, where the third direction is parallel to the second direction and opposite to the second direction. The processor is further configured to:

[0158] A third target distance is determined based on position parameters of multiple reflection points, wherein a difference between the third target distance and a third reference distance of the multiple third target reflection points is less than a third threshold, the azimuth angle of the third reflection point is within a third azimuth angle range, and an upper limit of the third azimuth angle range is less than a lower limit of the first azimuth angle range.

[0159] The third target distance is determined as the distance between the boundary of the target area and the detection sensor in the third direction.

[0160] Optionally, the processor 12 is further configured to:

[0161] A third target distance is determined based on a third reference distance of a plurality of third target reflection points.

[0162] The lower limit of the third azimuth angle range is greater than or equal to the minimum detection angle of the detection sensor.

[0163] Optionally, the processor 12 is configured to:

[0164] For each candidate distance in the candidate distance set, the sum of squares of differences between the third reference distances of the plurality of third target reflection points and the candidate distance is determined, and the plurality of candidate distances included in the candidate distance set are different from each other.

[0165] The candidate distance with the smallest sum of squares among the multiple candidate distances is determined as the third target distance.

[0166] Optionally, the processor 12 is further configured to:

[0167] An alternative reflection point is determined from the multiple reflection points based on position parameters of the multiple reflection points, wherein a first reference distance of the alternative reflection point is less than the first target distance, and a second reference distance of the alternative reflection point is less than the second target distance.

[0168] The number of target objects in the target area is determined based on the position parameters of the candidate reflection points.

[0169] In summary, embodiments of the present application provide a target area boundary detection device. Based on the position parameters of multiple reflection points, the boundary detection device can determine the distance between the boundary of the target area and the detection sensor in a first direction, as well as the distance between the boundary of the target area and the detection sensor in a second direction, thereby determining the location of the boundary of the target area. Because the boundary detection device can automatically determine the boundary of the target area without requiring the user to manually input the boundary of the target area, the efficiency and reliability of determining the boundary of the target area are improved.

[0170] The embodiment of the present application provides a boundary detection device, including: a memory, a processor and a computer program stored in the memory, and the processor implements the above method embodiment when executing the computer program. (For example Figure 2 or Figure 3 embodiment shown).

[0171] The present application embodiment provides a computer-readable storage medium, which stores instructions, which are loaded and executed by a processor to implement the above method embodiment. (For example Figure 2 or Figure 3 embodiment shown).

[0172] The present application embodiment provides a computer program product containing instructions, which, when executed on a computer, causes the computer to execute the above method embodiment. (For example Figure 2 or Figure 3 embodiment shown).

[0173] In the embodiments of the present application, the terms "first," "second," and "third" are used for descriptive purposes only and should not be understood to indicate or imply relative importance. In the embodiments of the present application, the term "and / or" is merely a description of the association relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In the embodiments of the present application, the term "plurality" means two or more.

[0174] The above description is merely an optional embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application shall be included in the scope of protection of the present application.

Claims

1. A method for detecting the boundary of a target area, characterized in that: Applied to a boundary detection device, the boundary detection device includes a detection sensor located in the target area; the method includes: transmitting a detection signal through the detection sensor and receiving the detection signal reflected by a plurality of reflection points; For each of the reflection points, determining position parameters of the reflection point based on the detection signal reflected by the reflection point, the position parameters including at least a first reference distance between the reflection point and the detection sensor in a first direction, a second reference distance between the reflection point and the detection sensor in a second direction, and an azimuth angle of the reflection point relative to the detection sensor, where the first direction is perpendicular to the second direction; Determining a first target distance and a second target distance based on the position parameters of the multiple reflection points, respectively, wherein differences between the first target distance and a first reference distance of the multiple first target reflection points are all less than a first threshold, differences between the second target distance and a second reference distance of the multiple second target reflection points are all less than a second threshold, the azimuth angle of the first target reflection point is within a first azimuth angle range, the azimuth angle of the second target reflection point is within a second azimuth angle range, and an upper limit of the first azimuth angle range is less than a lower limit of the second azimuth angle range; The first target distance is determined as the distance between the boundary of the target area and the detection sensor in the first direction, and the second target distance is determined as the distance between the boundary of the target area and the detection sensor in the second direction.

2. The method according to claim 1, characterized in that The determining the first target distance and the second target distance based on the position parameters of the plurality of reflection points respectively includes: determining a first target distance based on first reference distances of a plurality of first target reflection points; determining a second target distance based on a second reference distance of a plurality of second target reflection points; The lower limit of the first azimuth angle range is greater than or equal to the minimum detection angle of the detection sensor, and the upper limit of the second azimuth angle range is less than or equal to the maximum detection angle of the detection sensor.

3. The method according to claim 2, characterized in that The determining the first target distance based on the first reference distances of the plurality of first target reflection points comprises: For each candidate distance in a set of candidate distances, determining a sum of squares of differences between a plurality of first reference distances of the first target reflection points and the candidate distance, wherein the plurality of candidate distances included in the set of candidate distances are different from each other; The candidate distance with the smallest sum of squares among the multiple candidate distances is determined as the first target distance.

4. The method according to claim 2, characterized in that The determining the second target distance based on the second reference distances of the plurality of second target reflection points comprises: For each candidate distance in the candidate distance set, determining a sum of squares of differences between a plurality of second reference distances of the second target reflection points and the candidate distance, wherein the plurality of candidate distances included in the candidate distance set are different from each other; The candidate distance with the smallest sum of squares among the multiple candidate distances is determined as the second target distance.

5. The method according to any one of claims 1 to 4, characterized in that: The position parameter further includes a third reference distance between the reflection point and the detection sensor in a third direction, where the third direction is parallel to the second direction and opposite to the second direction; and the method further includes: determining a third target distance based on the position parameters of the multiple reflection points, wherein a difference between the third target distance and a third reference distance of the multiple third target reflection points is less than a third threshold, the azimuth angle of the third target reflection point is within a third azimuth angle range, and an upper limit of the third azimuth angle range is less than a lower limit of the first azimuth angle range; The third target distance is determined as the distance between the boundary of the target area and the detection sensor in the third direction.

6. The method according to claim 5, characterized in that The determining of the third target distance based on the position parameters of the plurality of reflection points includes: determining the third target distance based on a third reference distance of the plurality of third target reflection points; Wherein, the lower limit of the third azimuth angle range is greater than or equal to the minimum detection angle of the detection sensor.

7. The method according to claim 6, characterized in that The determining the third target distance based on the third reference distances of the plurality of third target reflection points comprises: For each candidate distance in the candidate distance set, determining a sum of squares of differences between a plurality of third reference distances of the third target reflection points and the candidate distance, wherein the plurality of candidate distances included in the candidate distance set are different from each other; The candidate distance with the smallest sum of squares among the multiple candidate distances is determined as the third target distance.

8. The method according to any one of claims 1 to 4, characterized in that: The method further comprises: determining a candidate reflection point from the plurality of reflection points based on position parameters of the plurality of reflection points, wherein a first reference distance of the candidate reflection point is less than the first target distance, and a second reference distance of the candidate reflection point is less than the second target distance; The number of target objects in the target area is determined based on the position parameters of the candidate reflection points.

9. A target area boundary detection device, characterized in that: The boundary detection device includes a detection sensor and a processor located in the target area; The detection sensor is used to transmit a detection signal and receive the detection signal reflected by multiple reflection points; The processor is configured to: For each of the reflection points, determining position parameters of the reflection point based on the detection signal reflected by the reflection point, the position parameters including at least a first reference distance between the reflection point and the detection sensor in a first direction, a second reference distance between the reflection point and the detection sensor in a second direction, and an azimuth angle of the reflection point relative to the detection sensor, where the first direction is perpendicular to the second direction; Determining a first target distance and a second target distance based on the position parameters of the multiple reflection points, respectively, wherein differences between the first target distance and a first reference distance of the multiple first target reflection points are all less than a first threshold, differences between the second target distance and a second reference distance of the multiple second target reflection points are all less than a second threshold, the azimuth angle of the first target reflection point is within a first azimuth angle range, the azimuth angle of the second target reflection point is within a second azimuth angle range, and an upper limit of the first azimuth angle range is less than a lower limit of the second azimuth angle range; The first target distance is determined as the distance between the boundary of the target area and the detection sensor in the first direction, and the second target distance is determined as the distance between the boundary of the target area and the detection sensor in the second direction.

10. The boundary detection device according to claim 9, characterized in that The processor is configured to: determining a first target distance based on first reference distances of a plurality of first target reflection points; determining a second target distance based on a second reference distance of a plurality of second target reflection points; The lower limit of the first azimuth angle range is greater than or equal to the minimum detection angle of the detection sensor, and the upper limit of the second azimuth angle range is less than or equal to the maximum detection angle of the detection sensor.

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