Sensor device

Abstract

To appropriately measure deviation of a scanning range position of a scanning section from a reference position.SOLUTION: Four reflection sections (200) are positioned at four corners, namely a first corner (CR1), a second corner (CR2), a third corner (CR3), and a fourth corner (CR4) of a scanning range (SA). The respective reflection sections (200) reflect at least one portion of a spot (S). A measurement section (310) measures deviation of a position of a scanning section (100) from a reference position by using a relationship of a reflection amount A1 of the spot (S) reflected by a reflection section (200) provided in the first corner (CR1), a reflection amount A2 of the spot (S) reflected by the reflection section (200) provided in the second corner (CR2), a reflection amount A3 of the spot (S) reflected by the reflection section (200) provided in the third corner (CR3), and a reflection amount A4 of the spot (S) reflected by the reflection section (200) provided in the fourth corner (CR4).SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a sensor device. [Background technology]

[0002] In recent years, various sensor devices such as LiDAR (Light Detection And Ranging) have been developed. The sensor devices include a scanning unit such as a MEMS (Micro Electro Mechanical Systems) mirror or a polygon mirror.

[0003] Patent Document 1 describes an example of a sensor device. In this sensor device, reflectors are provided at the scanning start position and scanning end position of the scanning unit. The positional deviation of the scanning range is measured based on a comparison result between the amount of reflection of the beam reflected by the reflector provided at the scanning start position and the amount of reflection of the beam reflected by the reflector provided at the scanning end position. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2020-16481 A Summary of the Invention [Problem to be solved by the invention]

[0005] For example, as described in Patent Document 1, the deviation of the scanning range may be measured using the amount of reflection of the beam reflected by a reflecting section provided at the start position of the scanning range of the scanning section and the amount of reflection of the beam reflected by a reflecting section provided at the end position of the scanning range of the scanning section. However, the rotation deviation of the scanning range may not be measured by using only two reflecting sections. In addition, when the scanning range is shifted by a relatively large distance, the beam may not be irradiated to the reflecting section provided at the start position of the scanning or the reflecting section provided at the end position of the scanning.

[0006] One example of a problem to be solved by the present invention is how to appropriately measure the deviation of the position of the scanning range of a scanning unit from a reference position. [Means for solving the problem]

[0007] The invention described in claim 1 is A scanning unit; A plurality of reflecting units that reflect at least a part of the beam irradiated onto a scanning range of the scanning unit; Equipped with The sensor device is such that the plurality of reflecting portions are positioned at at least four corners of the scanning range.

[0008] One aspect of the present invention is A scanning unit; A plurality of reflecting units that reflect at least a part of the beam irradiated onto a scanning range of the scanning unit; Equipped with The plurality of reflecting portions are located at least on both sides of the scanning range, This is a sensor device in which the multiple reflecting portions reflect at least a portion of the beam that is different from the beam irradiated at a start position of scanning of the scanning range of the scanning portion and the beam irradiated at an end position of scanning of the scanning range of the scanning portion. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a perspective view of a sensor device according to an embodiment. [Diagram 2] 5 is a diagram illustrating an example of a relationship between a scanning range of a scanning unit and a plurality of reflecting units. FIG. [Diagram 3] 11A and 11B are diagrams for explaining a first example of deviation of the position of the scanning unit from a reference position. [Figure 4] 13 is a diagram for explaining a second example of the deviation of the position of the scanning unit from the reference position. FIG. [Diagram 5] 13 is a diagram for explaining a third example of the deviation of the position of the scanning unit from the reference position. FIG. [Figure 6] FIG. 3 is a diagram showing a first modified example of FIG. 2. [Figure 7] FIG. 3 is a diagram showing a second modified example of FIG. 2. [Figure 8] FIG. 3 is a diagram showing a third modified example of FIG. 2. [Figure 9] FIG. 4 is a diagram showing a fourth modified example of FIG. 2. [Figure 10] FIG. 2 is a diagram illustrating an example of a hardware configuration of a measurement unit and a correction unit. [Figure 11] 1A and 1B are diagrams for explaining a first example of a measurement system that measures a deviation of the position of a scanning unit from a reference position. [Figure 12] 13 is a diagram for explaining a second example of a measurement system that measures the deviation of the position of the scanning unit from a reference position. FIG. [Figure 13] 13 is a diagram for explaining a third example of a measurement system that measures a deviation of the position of a scanning unit from a reference position. FIG. [Figure 14] 13 is a diagram for explaining a fourth example of a measurement system that measures a deviation of the position of a scanning unit from a reference position. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In all the drawings, the same components are denoted by the same reference numerals, and the description thereof will be omitted as appropriate.

[0011] In this specification, ordinal numbers such as "first," "second," "third," etc., unless otherwise specified, are used merely to distinguish between similarly named configurations and do not imply any particular characteristics (e.g., order or importance) of the configurations.

[0012] Fig. 1 is a perspective view of a sensor device 10 according to an embodiment of the present invention. Fig. 2 is a diagram showing an example of the relationship between a scanning range SA of a scanning section 100 and a plurality of reflecting sections 200.

[0013] 1 and 2, an arrow indicating the first direction X, the second direction Y, or the third direction Z indicates that the direction from the base end of the arrow to the tip is the positive direction of the direction indicated by the arrow, and the direction from the tip of the arrow to the base end is the negative direction of the direction indicated by the arrow. A white circle with a black dot indicating the third direction Z indicates that the direction from the back of the paper to the front of the paper is the positive direction of the direction indicated by the white circle with a black dot, and the direction from the front of the paper to the back of the paper is the negative direction of the direction indicated by the white circle with a black dot.

[0014] The first direction X is a direction parallel to the horizontal direction perpendicular to the vertical direction. When viewed from the positive direction of the third direction Z, the positive direction of the first direction X is a direction from left to right in the horizontal direction, and the negative direction of the first direction X is a direction from right to left in the horizontal direction. The second direction Y is a direction parallel to the vertical direction. The positive direction of the second direction Y is a direction from bottom to top in the vertical direction, and the negative direction of the second direction Y is a direction from top to bottom in the vertical direction. The third direction Z is a direction parallel to the horizontal direction and perpendicular to the first direction X. When viewed from the negative direction of the first direction X, the positive direction of the third direction Z is a direction from left to right in the horizontal direction, and the negative direction of the third direction Z is a direction from right to left in the horizontal direction.

[0015] The relationships among the first direction X, the second direction Y, the third direction Z, the horizontal direction, and the vertical direction are not limited to those in this embodiment. The relationships among the first direction X, the second direction Y, the third direction Z, the horizontal direction, and the vertical direction vary depending on the arrangement of the sensor device 10. For example, the third direction Z may be parallel to the vertical direction.

[0016] The sensor device 10 includes a housing 12 , a scanning unit 100 , a plurality of reflecting units 200 , a measuring unit 310 , and a correcting unit 320 .

[0017] The scanning unit 100 is accommodated inside the housing 12. In this embodiment, the scanning unit 100 is a two-axis MEMS mirror. The scanning unit 100 may be a scanning unit other than the two-axis MEMS mirror, for example, a galvanometer mirror.

[0018] The scanning unit 100 scans a beam in a first direction X and a second direction Y on a virtual plane perpendicular to a third direction Z. Specifically, the scanning unit 100 has a reflecting surface 102 that reflects a beam emitted from a light source such as a laser (not shown). In FIG. 1, a dashed arrow extending toward the reflecting surface 102 indicates the optical axis of a beam emitted from a light source (not shown) and incident on the reflecting surface 102. In FIG. 1, each of two dashed arrows extending from the reflecting surface 102 indicates the optical axis of a beam reflected by the reflecting surface 102. The two beams indicated by the two dashed arrows are reflected by the reflecting surface 102 at different times.

[0019] The reflecting surface 102 rotates around a yaw axis 102y and a pitch axis 102p that are orthogonal to each other. The yaw axis 102y and the pitch axis 102p are orthogonal to a roll axis 102r that passes through a normal at the center of the reflecting surface 102. When the position of the scanning unit 100 is at a reference position, the yaw axis 102y is inclined obliquely toward the negative direction of the third direction Z with respect to the positive direction of the second direction Y. Also, when the position of the scanning unit 100 is at a predetermined reference position, the pitch axis 102p is parallel to the first direction X. The scanning unit 100 rotates the reflecting surface 102 around the yaw axis 102y, thereby scanning the beam incident on the reflecting surface 102 in the first direction X on a virtual plane perpendicular to the third direction Z. Also, the scanning unit 100 rotates the reflecting surface 102 around the pitch axis 102p, thereby scanning the beam incident on the reflecting surface 102 in the second direction Y on a virtual plane perpendicular to the third direction Z.

[0020] In this embodiment, the reference position of the scanning unit 100 refers to the position where the scanning unit 100 is provided when the scanning unit 100 is arranged as designed. For example, when the scanning unit 100 is assembled to the sensor device 10, the scanning unit 100 is provided at the reference position by a fixing means such as an adhesive. However, in order to provide the scanning unit 100 at the reference position, a relatively high-precision adjustment is required, which may require a relatively high cost. Furthermore, even if the scanning unit 100 is provided at the reference position by the fixing means, the position of the scanning unit 100 may deviate from the reference position due to a change in the fixing means over time.

[0021] The scanning unit 100 uses a beam to scan a predetermined scanning range SA projected on a virtual plane perpendicular to the third direction Z. Specifically, the sensor device 10 generates point cloud data by detecting the beam, which is irradiated by the scanning unit 100 toward the scanning range SA and reflected or scattered by an object (not shown) present outside the housing 12, with a light detection element such as an APD (avalanche photodiode) (not shown).

[0022] 1 and 2 show a scanning range SA projected on a virtual plane perpendicular to the third direction Z at a predetermined location of the housing 12, such as a window that transmits the beam irradiated by the scanning unit 100. The scanning range SA is irradiated with a beam by the scanning unit 100. Hereinafter, as necessary, a portion of the beam irradiated by the scanning unit 100 that is projected on the same virtual plane as the virtual plane on which the scanning range SA is projected is referred to as a spot. The scanning range SA shown in FIG. 1 and FIG. 2 shows a schematic area occupied by a locus through which the center of a spot generated by the beam scanned by the scanning unit 100 passes and a portion of the locus adjacent to the second direction Y. FIG. 1 and FIG. 2 show four spots S located at four corners of the scanning range SA, namely a first corner CR1, a second corner CR2, a third corner CR3, and a fourth corner CR4, which will be described later.

[0023] 1 and 2, for the sake of explanation, a first virtual line LX and a second virtual line LY are shown in the scanning range SA. The first virtual line LX is a virtual line that passes through the center of the scanning range SA parallel to the first direction X when the scanning unit 100 is in the reference position. The second virtual line LY is a virtual line that passes through the center of the scanning range SA parallel to the second direction Y when the scanning unit 100 is in the reference position.

[0024] In this embodiment, the scanning range SA has four corners, a first corner CR1, a second corner CR2, a third corner CR3, and a fourth corner CR4, and has a shape that is approximately a sector. The shape of the scanning range SA is not limited to a shape that is approximately a sector, and may be a shape other than a sector, for example, a quadrangle or a shape that is approximately a quadrangle, such as a rectangle or a square. When viewed from the positive side of the third direction Z, the first angle CR1 is located on the negative side of the first direction X with respect to the second virtual line LY and on the positive side of the second direction Y with respect to the first virtual line LX. When viewed from the third direction Z, the second angle CR2 is located on the positive side of the first direction X with respect to the second virtual line LY and on the positive side of the second direction Y with respect to the first virtual line LX. When viewed from the third direction Z, the third angle CR3 is located on the negative side of the first direction X with respect to the second virtual line LY and on the negative side of the second direction Y with respect to the first virtual line LX. When viewed from the third direction Z, the fourth corner CR4 is located on the positive side of the first direction X with respect to the second virtual line LY and on the negative side of the second direction Y with respect to the first virtual line LX.

[0025] The scanning unit 100 starts scanning each frame of the scanning range SA from the first angle CR1 or the second angle CR2. For example, when scanning starts from the first angle CR1, the reflecting surface 102 is rotated in the positive direction of the first direction X around the yaw axis 102y to scan the step between the first angle CR1 and the second angle CR2 in the scanning range SA. After the scanning of the step between the first angle CR1 and the second angle CR2 in the scanning range SA is completed, the reflecting surface 102 is rotated in the negative direction of the second direction Y around the pitch axis 102p, and then the reflecting surface 102 is rotated around the yaw axis 102y to scan the step located on the negative side of the second direction Y with respect to the step scanned previously. In this way, the scanning unit 100 repeats scanning of a plurality of steps arranged in the second direction Y in the scanning range SA. The rotation direction of the yaw axis 102y when scanning a certain stage of the scanning range SA may be the same as or opposite to the rotation direction of the yaw axis 102y when scanning another stage adjacent to the certain stage of the scanning range SA in the second direction Y. In the final stage of each frame of the scanning range SA, the scanning unit 100 scans the stage between the third corner CR3 and the fourth corner CR4 of the scanning range SA. As a result, the scanning unit 100 ends the scanning of each frame of the scanning range SA at the third corner CR3 or the fourth corner CR4.

[0026] FIG. 3 is a diagram for explaining a first example of the deviation of the position of the scanning unit 100 from the reference position.

[0027] In Fig. 3, the scanning range SA indicated by a solid line indicates the scanning range projected onto a virtual plane perpendicular to the third direction Z when the position of the scanning unit 100 is at the reference position. The scanning range SA indicated by a dashed line indicates the scanning range projected onto a virtual plane perpendicular to the third direction Z when the scanning unit 100 rotates around the yaw axis 102y in the negative direction of the first direction X compared to when the position of the scanning unit 100 is at the reference position. As shown in Fig. 3, the scanning range SA when the scanning unit 100 rotates around the yaw axis 102y in the negative direction of the first direction X compared to when the position of the scanning unit 100 is at the reference position not only moves from the scanning range SA when the position of the scanning unit 100 is at the reference position, but also deforms.

[0028] FIG. 4 is a diagram for explaining a second example of the deviation of the position of the scanning unit 100 from the reference position.

[0029] In FIG. 4, the scanning range SA shown by a solid line indicates the scanning range projected onto a virtual plane perpendicular to the third direction Z when the position of the scanning unit 100 is at the reference position. The scanning range SA shown by a dashed line indicates the scanning range projected onto a virtual plane perpendicular to the third direction Z when the scanning unit 100 rotates around the pitch axis 102p in the positive direction of the second direction Y compared to when the position of the scanning unit 100 is at the reference position. As shown in FIG. 4, the scanning range SA when the scanning unit 100 rotates around the pitch axis 102p in the positive direction of the second direction Y compared to when the position of the scanning unit 100 is at the reference position not only moves from the scanning range SA when the position of the scanning unit 100 is at the reference position, but also deforms.

[0030] FIG. 5 is a diagram for explaining a third example of the deviation of the position of the scanning unit 100 from the reference position.

[0031] In FIG. 5, the scanning range SA shown by a solid line indicates the scanning range projected onto a virtual plane perpendicular to the third direction Z when the position of the scanning unit 100 is at the reference position. The scanning range SA shown by a dashed line indicates the scanning range projected onto a virtual plane perpendicular to the third direction Z when the scanning unit 100 rotates clockwise around the roll axis 102r as viewed from the positive direction of the third direction Z compared to when the position of the scanning unit 100 is at the reference position. As shown in FIG. 5, the scanning range SA when the scanning unit 100 rotates clockwise around the roll axis 102r as viewed from the positive direction of the third direction Z compared to when the position of the scanning unit 100 is at the reference position not only moves from the scanning range SA when the position of the scanning unit 100 is at the reference position, but also deforms.

[0032] Returning to Figures 1 and 2.

[0033] In this embodiment, four reflecting portions 200 are located at four corners, namely, a first corner CR1, a second corner CR2, a third corner CR3, and a fourth corner CR4, of the scanning range SA. Each reflecting portion 200 reflects at least a part of the spot S. The sensor device 10 may further include another reflecting portion 200 in addition to the four reflecting portions 200 shown in FIG. 1 and FIG. 2.

[0034] The measurement unit 310 measures the deviation of the position of the scanning unit 100 from the reference position using the relationship between the reflection amount A1 of the spot S reflected by the reflecting unit 200 provided at the first corner CR1, the reflection amount A2 of the spot S reflected by the reflecting unit 200 provided at the second corner CR2, the reflection amount A3 of the spot S reflected by the reflecting unit 200 provided at the third corner CR3, and the reflection amount A4 of the spot S reflected by the reflecting unit 200 provided at the fourth corner CR4.

[0035] First, the measurement unit 310 measures the deviation of the position of the scanning unit 100 from the reference position due to the rotation of the reflecting surface 102 around the yaw axis 102y by using the comparison result between the sum of A1 and A3 and the sum of A2 and A4. For example, when the position of the scanning unit 100 is at the reference position, the ratio {(A1+A3)-(A2+A4)} / {(A1+A3)+(A2+A4)} is a known reference value. In this case, when the ratio is larger than the reference value, the measurement unit 310 can measure that the scanning range SA is deviated in the negative direction of the first direction X compared to when the position of the scanning unit 100 is at the reference position. On the other hand, when the ratio is smaller than the reference value, the measurement unit 310 can measure that the scanning range SA is deviated in the positive direction of the first direction X compared to when the position of the scanning unit 100 is at the reference position. In particular, when a plurality of reflecting portions 200 are provided so that the reference value is zero, it is easier to determine whether the ratio is greater than or smaller than the reference value based only on the positive or negative of the ratio, compared to when the reference value is a value other than zero. From this viewpoint, it is preferable that the reference value is zero. Note that the reference value may be a value other than zero.

[0036] Secondly, the measurement unit 310 measures the deviation of the position of the scanning unit 100 from the reference position due to the rotation of the reflecting surface 102 around the pitch axis 102p using the comparison result between the sum of A1 and A2 and the sum of A3 and A4. For example, when the position of the scanning unit 100 is at the reference position, the ratio {(A1+A2)-(A3+A4)} / {(A1+A2)+(A3+A4)} is a known reference value. In this case, when the ratio is greater than the reference value, the measurement unit 310 can measure that the scanning range SA is deviated in the positive direction of the second direction Y compared to when the position of the scanning unit 100 is at the reference position. On the other hand, when the ratio is smaller than the reference value, the measurement unit 310 can measure that the scanning range SA is deviated in the negative direction of the second direction Y compared to when the position of the scanning unit 100 is at the reference position. In particular, when a plurality of reflecting portions 200 are provided so that the reference value is zero, it is easier to determine whether the ratio is greater than or smaller than the reference value based only on the positive or negative of the ratio, compared to when the reference value is a value other than zero. From this viewpoint, it is preferable that the reference value is zero. Note that the reference value may be a value other than zero.

[0037] Thirdly, the measurement unit 310 measures the deviation of the position of the scanning unit 100 from the reference position due to the rotation of the reflecting surface 102 around the roll axis 102r by using the result of comparing the relative value of A1 with respect to A3 and the relative value of A4 with respect to A2. For example, when the position of the scanning unit 100 is at the reference position, the ratio (A1-A3) / (A1+A3)+(A4-A2) / (A4+A2) is a known reference value. In this case, when the ratio is greater than the reference value, the measurement unit 310 can measure that the scanning range SA rotates counterclockwise when viewed from the positive direction of the third direction Z compared to when the position of the scanning unit 100 is at the reference position. On the other hand, when the ratio is smaller than the reference value, the measurement unit 310 can measure that the scanning range SA rotates clockwise when viewed from the positive direction of the third direction Z compared to when the position of the scanning unit 100 is at the reference position. In particular, when a plurality of reflecting portions 200 are provided so that the reference value is zero, it is easier to determine whether the ratio is greater than or smaller than the reference value based only on the positive or negative of the ratio, compared to when the reference value is a value other than zero. From this viewpoint, it is preferable that the reference value is zero. Note that the reference value may be a value other than zero.

[0038] 2, the start position of the scan of the scanning range SA of the scanning unit 100 is the first corner CR1 or the second corner CR2, and the end position of the scan of the scanning range SA of the scanning unit 100 is the third corner CR3 or the fourth corner CR4. Therefore, two of the four reflecting units 200 located at the first corner CR1, the second corner CR2, the third corner CR3, and the fourth corner CR4 reflect at least a part of a spot S that is different between the spot S irradiated at the start position of the scan of the scanning range SA of the scanning unit 100 and the spot S irradiated at the end position of the scan of the scanning range SA of the scanning unit 100. For example, if the start position and end position of scanning of the scanning range SA of the scanning unit 100 are the first corner CR1 and the third corner CR3, respectively, and the reflecting units 200 are located only at the first corner CR1 and the third corner CR3, when the scanning range SA is shifted a relatively large distance in the positive direction of the first direction X compared to when the scanning unit 100 is located at the reference position, the spot S may not be irradiated onto the two reflecting units 200 located at the first corner CR1 and the third corner CR3. In contrast, in the example shown in FIG. 2, even if the scanning range SA is shifted a relatively large distance compared to when the scanning unit 100 is located at the reference position, at least a part of the spot S can be irradiated onto at least one of the four reflecting units 200.

[0039] Fig. 6 is a diagram showing a first modified example of Fig. 2. The modified example shown in Fig. 6 is similar to the embodiment shown in Fig. 2 except for the following points.

[0040] In the modification shown in Fig. 6, two reflecting portions 200 are located on both sides of the scanning range SA in the second direction Y. The two reflecting portions 200 are also located on a second virtual line LY. The sensor device 10 may further include another reflecting portion 200 in addition to the two reflecting portions 200 shown in Fig. 6.

[0041] The measurement unit 310 measures the deviation of the position of the scanning unit 100 from the reference position due to the rotation around the pitch axis 102p of the reflection surface 102 by using the result of comparison between the reflection amount A5 of the spot S reflected by the reflecting unit 200 located on the positive side of the second direction Y with respect to the first virtual line LX and the reflection amount A6 of the spot S reflected by the reflecting unit 200 located on the negative side of the second direction Y with respect to the first virtual line LX. For example, when the position of the scanning unit 100 is at the reference position, the ratio (A5-A6) / (A5+A6) is a known reference value. In this case, when the ratio is larger than the reference value, the measurement unit 310 can measure that the scanning range SA is deviated in the positive direction of the second direction Y compared to when the position of the scanning unit 100 is at the reference position. On the other hand, when the ratio is smaller than the reference value, the measurement unit 310 can measure that the scanning range SA is deviated in the negative direction of the second direction Y compared to when the position of the scanning unit 100 is at the reference position. In particular, when a plurality of reflecting portions 200 are provided so that the reference value is zero, it is easier to determine whether the ratio is greater than or smaller than the reference value based only on the positive or negative of the ratio, compared to when the reference value is a value other than zero. From this viewpoint, it is preferable that the reference value is zero. Note that the reference value may be a value other than zero.

[0042] In the example shown in Fig. 6, the start position of the scan of the scanning range SA of the scanning unit 100 is the first angle CR1 or the second angle CR2, and the end position of the scan of the scanning range SA of the scanning unit 100 is the third angle CR3 or the fourth angle CR4. Therefore, the two reflecting units 200 reflect at least a part of the spot S that is different from the spot S that is irradiated at the start position of the scan of the scanning range SA of the scanning unit 100 and the spot S that is irradiated at the end position of the scan of the scanning range SA of the scanning unit 100. For example, assuming that the start position and the end position of the scan of the scanning range SA of the scanning unit 100 are the first angle CR1 and the third angle CR3, respectively, and two reflecting units 200 are located at the first angle CR1 and the third angle CR3, when the scanning range SA is shifted by a relatively large distance in the positive direction of the first direction X compared to when the position of the scanning unit 100 is at the reference position, the spot S may not be irradiated to the two reflecting units 200 located at the first angle CR1 and the third angle CR3. In contrast, in the example shown in FIG. 6, even if the scanning range SA shifts a relatively large distance in the first direction X compared to when the position of the scanning unit 100 is at the reference position, at least a portion of the spot S can be irradiated onto both of the two reflecting units 200.

[0043] Fig. 7 is a diagram showing a second modified example of Fig. 2. The modified example shown in Fig. 7 is similar to the modified example shown in Fig. 6 except for the following points.

[0044] In the modified example shown in FIG. 7, the two reflecting parts 200 are positioned so as to be shifted toward the negative side of the first direction X with respect to the second virtual line LY. The two reflecting parts 200 may be positioned so as to be shifted toward the positive side of the first direction X with respect to the second virtual line LY. In the modified example shown in FIG. 7, similarly to the modified example shown in FIG. 6, the measuring part 310 can measure the deviation of the position of the scanning part 100 from the reference position due to the rotation of the reflecting surface 102 about the pitch axis 102p. Also, similarly to the modified example shown in FIG. 6, even if the scanning range SA is shifted by a relatively large distance in the first direction X compared to when the position of the scanning part 100 is at the reference position, at least a part of the spot S can be irradiated to both of the two reflecting parts 200.

[0045] Fig. 8 is a diagram showing a third modified example of Fig. 2. The modified example shown in Fig. 8 is similar to the embodiment shown in Fig. 2 except for the following points.

[0046] In the modification shown in Fig. 8, two reflecting portions 200 are located on both sides of the scanning range SA in the first direction X. The two reflecting portions 200 are located on a first virtual line LX. The sensor device 10 may further include another reflecting portion 200 in addition to the two reflecting portions 200 shown in Fig. 8.

[0047] The measurement unit 310 measures the deviation of the position of the scanning unit 100 from the reference position due to the rotation of the reflecting surface 102 about the yaw axis 102y by using the result of comparison between the reflection amount A7 of the spot S reflected by the reflecting unit 200 located on the positive side of the first direction X with respect to the second virtual line LY and the reflection amount A8 of the spot S reflected by the reflecting unit 200 located on the negative side of the first direction X with respect to the second virtual line LY. For example, when the position of the scanning unit 100 is at the reference position, the ratio (A7-A8) / (A7+A8) is a known reference value. In this case, when the ratio is larger than the reference value, the measurement unit 310 can measure that the scanning range SA is deviated in the positive direction of the first direction X compared to when the position of the scanning unit 100 is at the reference position. On the other hand, when the ratio is smaller than the reference value, the measurement unit 310 can measure that the scanning range SA is deviated in the negative direction of the first direction X compared to when the position of the scanning unit 100 is at the reference position. In particular, when a plurality of reflecting portions 200 are provided so that the reference value is zero, it is easier to determine whether the ratio is greater than or smaller than the reference value based only on the positive or negative of the ratio, compared to when the reference value is a value other than zero. From this viewpoint, it is preferable that the reference value is zero. Note that the reference value may be a value other than zero.

[0048] 8, the start position of the scan of the scanning range SA of the scanning unit 100 is the first angle CR1 or the second angle CR2, and the end position of the scan of the scanning range SA of the scanning unit 100 is the third angle CR3 or the fourth angle CR4. Therefore, the two reflecting units 200 reflect at least a part of a spot S that is different from the spot S that is irradiated at the start position of the scan of the scanning range SA of the scanning unit 100 and the spot S that is irradiated at the end position of the scan of the scanning range SA of the scanning unit 100. If the two reflecting units 200 are located at the start position and the end position of the scan of the scanning range SA of the scanning unit 100, when the scanning range SA is shifted by a relatively large distance in the second direction Y compared to when the position of the scanning unit 100 is at the reference position, the spot S may not be irradiated to at least one of the two reflecting units 200. In contrast, in the example shown in Figure 6, even if the scanning range SA shifts a relatively large distance in the second direction Y compared to when the position of the scanning unit 100 is at the reference position, at least a portion of the spot S can be irradiated to both of the two reflecting units 200.

[0049] Fig. 9 is a diagram showing a fourth modified example of Fig. 2. The modified example shown in Fig. 9 is similar to the modified example shown in Fig. 8 except for the following points.

[0050] In the modified example shown in FIG. 9, the two reflecting parts 200 are positioned so as to be shifted toward the negative side of the second direction Y with respect to the first virtual line LX. The two reflecting parts 200 may be positioned so as to be shifted toward the positive side of the second direction Y with respect to the first virtual line LX. In the modified example shown in FIG. 9, similarly to the modified example shown in FIG. 8, the measuring part 310 can measure the deviation of the position of the scanning part 100 from the reference position due to the rotation of the reflecting surface 102 about the yaw axis 102y. Also, similarly to the modified example shown in FIG. 8, even if the scanning range SA is shifted by a relatively large distance in the second direction Y compared to when the position of the scanning part 100 is at the reference position, at least a part of the spot S can be irradiated to both of the two reflecting parts 200.

[0051] Returning to FIG. 1, the correction unit 320 will be described.

[0052] The correction unit 320 corrects the data indicating the measurement direction of the scanning unit 100 in accordance with the deviation of the position of the scanning unit 100 from the reference position.

[0053] Assume that the position of the scanning unit 100 is at the reference position. In this case, the unit normal vector of the reflecting surface 102 when the reflecting surface 102 is in a stationary state is n 0 Let n be the unit direction vector parallel to the yaw axis 102y. y Let n be the unit direction vector parallel to the pitch axis 102p. p When the reflecting surface 102 rotates around the yaw axis 102y from a stationary state, the angle θ y,1 Rotate around pitch axis 102p by angle θ p,1 When rotated, the normal vector n of the reflecting surface 102 1 is as shown in the following equation (1).

number

number

[0054] The normal vector is the normal vector n shown in equation (1). 1 When a beam with a direction vector r is incident on the reflecting surface 102 having the reflecting surface 102, the direction vector of the beam reflected by the reflecting surface 102, that is, the direction vector m of the measurement direction of the scanning unit 100, is 1 is as shown in the following equation (3).

number

[0055] The reflecting surface 102 rotates around the roll axis 102r at an angle Δθ compared to when the scanning unit 100 is at the reference position. r , angle Δθ about the yaw axis 102y y , angle Δθ around pitch axis 102p p , the roll axis 102r, the yaw axis 102y, and the pitch axis 102p in this order. In the following, as necessary, the reflecting surface 102 rotates around the roll axis 102r at an angle Δθ r , angle Δθ about the yaw axis 102y y , angle Δθ around pitch axis 102p p When the reflecting surface 102 rotates in the order of the roll axis 102r, the yaw axis 102y, and the pitch axis 102p, it is said that the reflecting surface 102 is in a rotationally shifted position.

[0056] The unit normal vector n of the reflecting surface 102 when the reflecting surface 102 is in a stationary position and rotated out of position. 0 ´, the unit direction vector parallel to the yaw axis is n y ´ and the unit direction vector n parallel to the pitch axis p ´ is the vector n 0 , vector n y and vector n p is rotated around the roll axis 102r by an angle Δθ r , angle Δθ about the yaw axis 102y y , angle Δθ around pitch axis 102p p , the roll axis 102r, the yaw axis 102y, and the pitch axis 102p are rotated in this order, to calculate the rotational speed.

[0057] In equations (1), (2) and (3), vector n 0 , vector n y and vector n p respectively, vector n 0 ´, vector n y ´ and vector n p By replacing m′ with , it is possible to calculate the direction vector m′ of the measurement direction of the scanning unit 100 when the reflecting surface 102 is in a rotationally shifted position.

[0058] If the data indicating the measurement direction of the scanning unit 100 is not replaced from the direction vector m to the direction vector m' even though the reflecting surface 102 is in a rotationally shifted position, the sensor device 10 will erroneously detect an object existing in the direction of the direction vector m' as an object existing in the direction of the direction vector m. In contrast, in the embodiment, the correction unit 320 corrects the data indicating the measurement direction of the scanning unit 100 from the direction vector m to the direction vector m'. This allows the sensor device 10 to accurately detect the direction in which the object exists. In addition, when the data indicating the measurement direction of the scanning unit 100 is corrected by the correction unit 320, high-precision adjustment to set the scanning unit 100 at a reference position is not required when assembling the scanning unit 100 to the sensor device 10. In this case, the cost of assembling the scanning unit 100 to the sensor device 10 can be reduced compared to when high-precision adjustment is required.

[0059] 10 is a diagram illustrating an example of a hardware configuration of the measurement unit 310 and the correction unit 320. The measurement unit 310 and the correction unit 320 are implemented using an integrated circuit 400. The integrated circuit 400 is, for example, a System-on-a-Chip (SoC).

[0060] The integrated circuit 400 includes a bus 402, a processor 404, a memory 406, a storage device 408, an input / output interface 410, and a network interface 412. The bus 402 is a data transmission path for the processor 404, the memory 406, the storage device 408, the input / output interface 410, and the network interface 412 to transmit and receive data to and from each other. However, the method of connecting the processor 404, the memory 406, the storage device 408, the input / output interface 410, and the network interface 412 to each other is not limited to a bus connection. The processor 404 is an arithmetic processing device realized by using a microprocessor or the like. The memory 406 is a memory realized by using a RAM (Random Access Memory) or the like. The storage device 408 is a storage device realized by using a ROM (Read Only Memory), a flash memory, or the like.

[0061] The input / output interface 410 is an interface for connecting the integrated circuit 400 to peripheral devices. The input / output interface 410 is connected to the scanning unit 100.

[0062] The network interface 412 is an interface for connecting the integrated circuit 400 to a network. This network is, for example, a Controller Area Network (CAN) network. The method for connecting the network interface 412 to the network may be a wireless connection or a wired connection.

[0063] The storage device 408 stores a program module for realizing the functions of the measurement unit 310 and a program module for realizing the functions of the correction unit 320. The processor 404 reads these program modules into the memory 406 and executes them to realize the respective functions of the measurement unit 310 and the correction unit 320.

[0064] The hardware configuration of the integrated circuit 400 is not limited to the configuration shown in Fig. 10. For example, the program module may be stored in the memory 406. In this case, the integrated circuit 400 may not include the storage device 408.

[0065] FIG. 11 is a diagram for explaining a first example of a measurement system 50A that measures the deviation of the position of the scanning unit 100 from a reference position.

[0066] The measurement system 50A includes a screen 500A and an imaging unit 510A. The screen 500A is a plane perpendicular to the third direction Z. For the purpose of explanation, a first virtual line LXA and a second virtual line LYA are shown in the measurement system 50A. The first virtual line LXA is a virtual line that passes through the center of the screen 500A parallel to the first direction X. The second virtual line LYA is a virtual line that passes through the center of the screen 500A parallel to the second direction Y.

[0067] The imaging unit 510A captures an image of a beam spot generated by projecting the beam irradiated by the scanning unit 100 onto the screen 500A. The measurement system 50A measures the deviation of the position of the scanning unit 100 from a reference position using the imaging result of the imaging unit 510A.

[0068] Measurement of the deviation of the position of the scanning unit 100 from the reference position due to rotation around at least one of the pitch axis 102p and the yaw axis 102y of the scanning unit 100 will be described. Assume that the scanning unit 100 is in a stationary state. In this case, when the scanning unit 100 is in the reference position, a beam emitted from a light source such as a laser (not shown) is incident on the reflecting surface 102 as shown by a dashed arrow extending toward the reflecting surface 102 in FIG. 11. The beam incident on the reflecting surface 102 is projected by the scanning unit 100 onto the center of the screen 500A, that is, the intersection of the first virtual line LXA and the second virtual line LYA of the screen 500A, as shown by a first dashed arrow AR1 extending from the reflecting surface 102 toward the intersection of the first virtual line LXA and the second virtual line LYA of the screen 500A in FIG. 11. When the scanning unit 100 is in a stationary state and the position of the scanning unit 100 is displaced from the reference position due to rotation of at least one of the pitch axis 102p and the yaw axis 102y of the reflecting surface 102, the beam projected by the scanning unit 100 onto the screen 500A is displaced from the center of the screen 500A, for example, as shown by a second dashed arrow AR2 extending from the reflecting surface 102 toward a position displaced in the positive direction of the first direction X and the positive direction of the second direction Y with respect to the intersection of the first virtual line LXA and the second virtual line LYA in FIG. 11. The imaging unit 510A captures the beam spot projected at the position displaced from the center of the screen 500A. The measurement system 50A can measure the displacement of the position of the scanning unit 100 from the reference position due to rotation of the reflecting surface 102 around at least one of the pitch axis 102p and the yaw axis 102y using the imaging result of the imaging unit 510A.

[0069] Measurement of the deviation of the position of the scanning unit 100 from the reference position due to the rotation of the scanning unit 100 around the roll axis 102r will be described. Assume that the reflecting surface 102 is rotated around the pitch axis 102p without rotating around the yaw axis 102y. In this case, when the position of the scanning unit 100 is at the reference position, a beam incident on the reflecting surface 102 from a light source such as a laser (not shown) is projected onto the second virtual line LYA by the scanning unit 100. Similarly, assume that the reflecting surface 102 is rotated around the pitch axis 102p without rotating around the yaw axis 102y. In this case, when the position of the scanning unit 100 is deviated from the reference position due to the rotation of the scanning unit 100 around the roll axis 102r, the trajectory of the beam spot projected onto the screen 500A by the scanning unit 100 is inclined with respect to the second virtual line LYA. The imaging unit 510A captures the trajectory of the beam spot inclined from the second virtual line LYA. The measurement system 50A can measure the deviation of the position of the scanning unit 100 from the reference position due to the rotation of the reflecting surface 102 around the roll axis 102r, using the imaging result of the imaging unit 510A.

[0070] FIG. 12 is a diagram for explaining a second example of a measurement system 50B that measures the deviation of the position of the scanning unit 100 from the reference position.

[0071] 12, the scanning range SA indicated by a solid line indicates the scanning range projected onto the screen 500B by the scanning unit 100 when the position of the scanning unit 100 is at the reference position. Also, the scanning range SA indicated by a dashed line indicates the scanning range projected onto the screen 500B by the scanning unit 100 when the position of the scanning unit 100 is displaced from the reference position. The screen 500B is a plane perpendicular to the third direction Z.

[0072] The imaging unit 510B images the scanning range SA projected on the screen 500B by the scanning unit 100. The measurement system 50B measures the deviation of the position of the scanning unit 100 from the reference position by using the imaging result of the imaging unit 510B. Specifically, the measurement system 50B can measure the deviation of the position of the scanning unit 100 from the reference position by comparing the scanning range SA projected on the screen 500B by the scanning unit 100 when the position of the scanning unit 100 is at the reference position with the scanning range SA projected on the screen 500B by the scanning unit 100 when the position of the scanning unit 100 is deviated from the reference position, based on the imaging result of the imaging unit 510B. When the imaging unit 510B images the scanning range SA projected on the screen 500B, the sensor device 10 may irradiate the pulse beam over the entire range of the scanning range SA on the screen 500B, or may irradiate only a part of the scanning range SA on the screen 500B with the pulse beam.

[0073] FIG. 13 is a diagram for explaining a third example of a measurement system 50C that measures the deviation of the position of the scanning unit 100 from the reference position.

[0074] 13, the scanning range SA indicated by a solid line indicates the scanning range projected onto the screen 500C by the scanning unit 100 when the position of the scanning unit 100 is at the reference position. Also, the scanning range SA indicated by a dashed line indicates the scanning range projected onto the screen 500C by the scanning unit 100 when the position of the scanning unit 100 is displaced from the reference position. The screen 500C is a plane perpendicular to the third direction Z.

[0075] The screen 500C has a first region 502C and a second region 504C. In at least a part of the screen 500C, the first region 502C and the second region 504C are regularly arranged in the first direction X and the second direction Y. Specifically, the first region 502C and the second region 504C are arranged in a checkered pattern. The pattern of the first region 502C and the second region 504C is not limited to the example shown in FIG.

[0076] The first region 502C and the second region 504C have different reflectivities with respect to the beam scanned by the scanning unit 100. For example, the second region 504C has a higher reflectivity than the first region 502C with respect to the beam scanned by the scanning unit 100. The second region 504C may be a retroreflector.

[0077] The sensor device 10 obtains point cloud data by scanning the screen 500C. In the point cloud data obtained by scanning the screen 500C, a characteristic pattern appears due to the difference in reflectance between the first region 502C and the second region 504C. Therefore, the sensor device 10 can determine which region of the screen 500C the scanning range SA is projected onto, using the point cloud data obtained by scanning the screen 500C. The measurement system 50C can measure the deviation of the position of the scanning unit 100 from the reference position by comparing the scanning range SA projected onto the screen 500C by the scanning unit 100 when the position of the scanning unit 100 is at the reference position with the scanning range SA projected onto the screen 500C by the scanning unit 100 when the position of the scanning unit 100 is shifted from the reference position, based on the detection result of the sensor device 10.

[0078] FIG. 14 is a diagram for explaining a fourth example of a measurement system 50D that measures the deviation of the position of the scanning unit 100 from the reference position.

[0079] The measurement system 50D includes a first screen 500Da and a second screen 500Db. The first screen 500Da and the second screen 500Db are aligned in the third direction Z. The first screen 500Da is located closer to the sensor device 10 in the third direction Z than the second screen 500Db.

[0080] 14, the scanning range SA indicated by a solid line indicates the scanning range projected onto the first screen 500Da by the scanning unit 100 when the position of the scanning unit 100 is at the reference position. Also, the scanning range SA indicated by a dashed line indicates the scanning range projected onto the first screen 500Da by the scanning unit 100 when the position of the scanning unit 100 is displaced from the reference position. The first screen 500Da and the second screen 500Db are flat surfaces perpendicular to the third direction Z.

[0081] The first screen 500Da is provided with through-holes 502Da. In at least a part of the first screen 500Da, the through-holes 502Da are regularly arranged in the first direction X and the second direction Y. Specifically, the through-holes 502Da are arranged in a checkerboard pattern. The pattern of the through-holes 502Da is not limited to the example shown in FIG.

[0082] The sensor device 10 obtains point cloud data by scanning the first screen 500Da. The beam irradiated toward the through-hole 502Da passes through the through-hole 502Da and is irradiated to the second screen 500Db. Therefore, in the point cloud data obtained by scanning the first screen 500Da, the measurement data of the area of ​​the first screen 500Da where the through-hole 502Da is provided is more distant than the measurement data of the area of ​​the first screen 500Da where the through-hole 502Da is not provided. Therefore, the sensor device 10 can determine on which area of ​​the first screen 500Da the scanning range SA is projected, using the point cloud data obtained by scanning the first screen 500Da. The measurement system 50D can measure the deviation of the position of the scanning unit 100 from the reference position by comparing the scanning range SA projected onto the first screen 500Da by the scanning unit 100 when the position of the scanning unit 100 is in the reference position with the scanning range SA projected onto the first screen 500Da by the scanning unit 100 when the position of the scanning unit 100 is deviated from the reference position based on the detection results of the sensor device 10.

[0083] Although the embodiments of the present invention have been described above with reference to the drawings, these are merely examples of the present invention, and various configurations other than those described above can also be adopted.

[0084] This application claims priority based on Japanese Patent Application No. 2021-038050, filed on March 10, 2021, the disclosure of which is incorporated herein in its entirety. [Explanation of symbols]

[0085] 10 Sensor device 12. Cabinet 50A measurement system 50B measurement system 50C measurement system 50D measurement system 100 Scanning unit 102 Reflective surface 102p Pitch axis 102r roll axis 102y Yaw axis 200 Reflector 310 Measuring section 320 Correction Unit 400 Integrated Circuits 402 Bus 404 Processor 406 Memory 408 Storage Devices 410 Input / Output Interface 412 Network Interface 500A Screen 500B Screen 500C Screen 500Da 1st Screen 500Db 2nd screen 502C 1st area 502Da through hole 504C 2nd area 510A Imaging unit 510B Imaging unit AR1 First dashed arrow AR2 Second dashed arrow CR1 1st corner CR2 2nd corner CR3 3rd corner CR4 4th corner LX 1st Virtual Line LXA 1st Virtual Line LY 2nd virtual line LYA 2nd Virtual Line S Spot SA Scan Range X 1st direction Y Second direction Z 3rd direction

Claims

[Claim 1] A scanning unit; A plurality of reflecting units that reflect at least a part of the beam irradiated onto a scanning range of the scanning unit; Equipped with A sensor device, wherein the plurality of reflective portions are positioned at at least four corners of the scanning range.

Images