Sensor device

Abstract

To correct deviation of the position of a point group from a position in a design state.SOLUTION: Part of an electromagnetic wave emitted from an emission unit (110) and reflected by a movable reflection unit (120) is reflected or scattered by a physical object such as an object present outside a sensor device (10). Another part of the electromagnetic wave emitted from the emission unit (110) and reflected by the movable reflection unit (120) is reflected or scattered by a structure (200) located nearer to the movable reflection unit (120) than the physical object. A control unit (150) controls the amplitude of vibration of the movable reflection unit (120) based on a result from a receiving unit (130) that receives the electromagnetic wave reflected or scattered by the structure (200). The control unit 150 controls the interval between timings to emit the electromagnetic wave from the emission unit (110) based on the result from the receiving unit (130) that receives the electromagnetic wave reflected or scattered by the structure (200).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 movable reflector such as a MEMS (Micro Electro Mechanical Systems) mirror. The sensor devices scan targets such as objects outside the sensor device by reflecting electromagnetic waves such as infrared rays toward a predetermined scanning range using the movable reflector.

[0003] Patent Document 1 describes that a reflecting member is disposed on one end side of the scanning range of a movable reflecting member in order to determine the direction in which laser light reflected by the movable reflecting member is output. The laser light reflected by the reflecting member is received by a light receiving unit. Based on the light receiving result from the light receiving unit, the distance from the movable reflecting member to the reflecting member is calculated. Based on the distance from the movable reflecting member to the reflecting member, the direction in which laser light reflected by the movable reflecting member is output is calculated.

[0004] Patent document 2 describes a method in which a reflective member is provided in a housing that houses components that constitute a sensor device, such as a movable reflecting member, and the deviation of the scanning position of the movable reflecting member is detected by laser light reflected by the reflective member. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-6403 [Patent Document 2] Japanese Patent Publication No. 2020-16481 Summary of the Invention [Problem to be solved by the invention]

[0006] In the sensor device, a point cloud is generated by irradiating electromagnetic waves reflected by a movable reflector. However, various factors, such as a deviation of the gain of the transfer function of the movable reflector from the gain in the designed state, can cause the position of the point cloud to deviate from the position in the designed state.

[0007] One example of a problem to be solved by the present invention is to correct deviations of the positions of point clouds from the positions in a design state. [Means for solving the problem]

[0008] The invention described in claim 1 is a movable reflecting unit that reflects electromagnetic waves toward a predetermined scanning range; a receiving unit that receives the electromagnetic waves reflected or scattered by structures located within the scanning range; a control unit that controls the amplitude of vibration of the movable reflecting unit based on the reception result of the electromagnetic wave reflected or scattered by the structure by the receiving unit; The sensor device is provided with: [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a diagram illustrating a sensor device according to an embodiment. [Figure 2] 10A and 10B are diagrams illustrating an example of the relationship between the structure and the scanning line of the movable reflecting portion. [Figure 3] FIG. 4 is a diagram for explaining a first example of control by a control unit. [Figure 4] FIG. 4 is a diagram for explaining a first example of control by a control unit. [Figure 5] FIG. 10 is a diagram for explaining a second example of control by the control unit. [Figure 6] FIG. 10 is a diagram for explaining a second example of control by the control unit. [Figure 7] 10 is a diagram showing a first example of the relationship between the structure and the first and second spots when the movable reflecting section operates in a designed state. FIG. [Figure 8] 8 is a graph showing an example of signals generated in a receiving section by the first spot and the second spot shown in FIG. 7. [Figure 9] 8 is a diagram showing an example of the relationship between the structure and the first spot and the second spot when the movable reflector operates in a state in which the gain in the first direction of the transfer function of the movable reflector deviates from the gain in the design state shown in FIG. [Figure 10] 10 is a graph showing an example of signals generated in a receiving section by the first spot and the second spot shown in FIG. 9. [Figure 11] 8 is a diagram showing an example of the relationship between the structure and the first spot and the second spot when the movable reflector operates in a state in which the phase of the transfer function of the movable reflector is shifted from the phase in the design state shown in FIG. [Figure 12] 12 is a graph showing an example of signals generated in a receiving section by the first spot and the second spot shown in FIG. 11. [Figure 13] FIG. 10 is a diagram showing a second example of the relationship between the structure and the first and second spots when the movable reflecting section operates in a designed state. [Figure 14] 14 is a graph showing an example of signals generated in a receiving section by the first spot and the second spot shown in FIG. 13. [Figure 15] 14 is a diagram showing an example of the relationship between the structure and the first spot and the second spot when the movable reflector operates in a state in which the gain in the second direction of the transfer function of the movable reflector deviates from the gain in the design state shown in FIG. [Figure 16] 16 is a graph showing an example of signals generated in a receiving section by the first spot and the second spot shown in FIG. 15. DETAILED DESCRIPTION OF THE INVENTION

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

[0011] FIG. 1 is a diagram showing a sensor device 10 according to an embodiment.

[0012] In FIG. 1, the first direction X and the second direction Y intersect with each other, specifically, are perpendicular to each other. In FIG. 1, the first direction X is the horizontal direction. The positive direction of the first direction X, which is the direction of the arrow indicating the first direction X, is the leftward direction when viewed from the movable reflector 120, which will be described later, toward the scanning range of the movable reflector 120, which will be described later. The negative direction of the first direction X, which is the opposite direction to the direction of the arrow indicating the first direction X, is the rightward direction when viewed from the side where the movable reflector 120 is located toward the scanning range of the movable reflector 120. The second direction Y is the vertical direction. The positive direction of the second direction Y, which is the direction of the arrow indicating the second direction Y, is the upward direction. The negative direction of the second direction Y, which is the opposite direction to the direction of the arrow indicating the second direction Y, is the downward direction.

[0013] As is clear from the description herein, the first direction X may be a direction different from the horizontal direction, and the second direction Y may be a direction different from the vertical direction.

[0014] The sensor device 10 includes a light emitting unit 110, a movable reflecting unit 120, a receiving unit 130, a beam splitter 140, and a control unit 150. In Fig. 1, the dotted lines extending from the light emitting unit 110, the movable reflecting unit 120, the receiving unit 130, the beam splitter 140, and the scanning line L indicate electromagnetic waves propagating from the light emitting unit 110, the movable reflecting unit 120, the receiving unit 130, the beam splitter 140, and the scanning line L. In Fig. 1, the electromagnetic waves reflected from the movable reflecting unit 120 toward the scanning line L are irradiated toward approximately the center of the area where the scanning line L is formed.

[0015] The emission unit 110 emits pulsed electromagnetic waves such as infrared rays at regular intervals. The emission unit 110 is an element, such as a laser diode (LD), that can convert electricity such as current into electromagnetic waves such as light. The electromagnetic waves emitted from the emission unit 110 pass through the beam splitter 140 and enter the movable reflector 120.

[0016] The movable reflector 120 reflects the electromagnetic waves emitted from the emission unit 110 toward a predetermined scanning range. The scanning range of the movable reflector 120 is a range that can be irradiated by the electromagnetic waves reflected by the movable reflector 120. The movable reflector 120 is, for example, a two-axis MEMS mirror. The movable reflector 120 is resonantly driven in a first direction X and linearly driven in a second direction Y. For example, a sine wave or a cosine wave is used for resonantly driving the movable reflector 120. For example, a sawtooth wave or a triangular wave is used for linearly driving the movable reflector 120.

[0017] A portion of the electromagnetic waves emitted from the emission unit 110 and reflected by the movable reflection unit 120 is reflected or scattered by an object such as a physical body present outside the sensor device 10. This electromagnetic wave returns to the movable reflection unit 120, is reflected by the movable reflection unit 120 and then by the beam splitter 140, and is incident on and received by the reception unit 130. The reception unit 130 is an element, such as an avalanche photodiode (APD), that can convert electromagnetic waves such as light into electricity such as current.

[0018] Another part of the electromagnetic waves emitted from the emission unit 110 and reflected by the movable reflector 120 is reflected or scattered by the structure 200, which is located closer to the movable reflector 120 than the target object. This electromagnetic wave returns toward the movable reflector 120, is reflected by the movable reflector 120, and passes through the beam splitter 140, before entering the receiving unit 130 and being received by the receiving unit 130. The structure 200 may be made of, for example, a metal that has been subjected to a surface treatment such as plating that provides high stability over time.

[0019] The distance from the movable reflecting unit 120 to the structure 200 is shorter than the distance from the movable reflecting unit 120 to the object. Therefore, the time from the emission of the electromagnetic wave from the emitting unit 110, through its reflection by the structure 200, to its reception by the receiving unit 130 is shorter than the time from the emission of the electromagnetic wave from the emitting unit 110, through its reflection by the object, to its reception by the receiving unit 130. Therefore, based on the time difference between the signals generated in the receiving unit 130, the sensor device 10 can distinguish whether the signal generated in the receiving unit 130 is a signal caused by the structure 200 or a signal caused by the object.

[0020] The sensor device 10 may include a structure 200. Alternatively, the structure 200 may be provided outside the sensor device 10. When the sensor device 10 includes the structure 200, the structure 200 can be provided, for example, in a window portion of a housing that houses components of the sensor device 10, such as the emission unit 110, the movable reflecting unit 120, the receiving unit 130, and the beam splitter 140, i.e., in a portion through which electromagnetic waves pass between the inside and outside of the housing. However, the location where the structure 200 is provided is not limited to the window portion.

[0021] In this embodiment, the control unit 150 represents a functional block rather than a hardware-based configuration. The control unit 150 is realized by any combination of hardware and software, centered around the CPU of any computer, memory, a program loaded into the memory, a storage medium such as a hard disk for storing the program, and a network connection interface. There are various variations in the realization method and device.

[0022] The control unit 150 controls the amplitude of vibration of the movable reflecting unit 120 based on the reception result by the receiving unit 130 of the electromagnetic waves reflected or scattered by the structure 200. The control unit 150 also controls the interval of the emission timing of the electromagnetic waves from the emitting unit 110 based on the reception result by the receiving unit 130 of the electromagnetic waves reflected or scattered by the structure 200. The control unit 150 also shifts the emission timing of the electromagnetic waves from the emitting unit 110 based on the reception result by the receiving unit 130 of the electromagnetic waves reflected or scattered by the structure 200. The control unit 150 performs at least one of these controls on the emitting unit 110 and the movable reflecting unit 120 according to the reception result by the receiving unit 130 of the electromagnetic waves reflected or scattered by the structure 200. By the control of the control unit 150, it is possible to correct the deviation of the position of the point cloud generated by the movable reflecting unit 120 from the position of the design state.

[0023] FIG. 2 is a diagram showing an example of the relationship between the structure 200 and the scanning line L of the movable reflecting portion 120. As shown in FIG.

[0024] The scanning line L extends in a second direction Y, i.e., from the positive direction to the negative direction of the linear drive of the movable reflector 120, while turning back in a first direction X, i.e., the direction of resonant drive of the movable reflector 120. In Fig. 2, a part of a first period T1 of the scanning line L, a second period T2, and a third period T3 are shown.

[0025] The first period T1 of the scanning line L is a section in which the upper end of the scanning line L is positioned approximately 1 / 4 period away from the starting point of the first period T1, passes through the first turn from the top on the right side of the scanning line L, and ends at the first turn from the top on the left side of the scanning line L.

[0026] The second period T2 of the scanning line L is a section that starts at the end point of the first period T1 of the scanning line L, passes through the second turn from the top on the right side of the scanning line L, and ends at the second turn from the top on the left side of the scanning line L.

[0027] The third period T3 of the scanning line L is a section that starts at the end point of the second period T2 of the scanning line L, passes through the third turn from the top on the right side of the scanning line L, and ends at the third turn from the top on the left side of the scanning line L.

[0028] The structure 200 intersects with at least a portion of the turn of the scanning line L of the movable reflective unit 120. In the example shown in FIG. 2 , the structure 200 intersects with at least a portion of the right turn of the first period T1 of the scanning line L, at least a portion of the right turn of the second period T2 of the scanning line L, and at least a portion of the right turn of the third period T3 of the scanning line L. If the structure 200 is disposed approximately in the center of the area in the first direction X where the scanning line L is generated or in its vicinity, the sensor device 10 may be unable to detect an object in the area where the structure 200 is disposed, or may have difficulty in detecting the object. In contrast, in the present embodiment, the area where the sensor device 10 is unable to detect an object, or may have difficulty in detecting the object, can be limited to the end of the scanning range of the movable reflective unit 120.

[0029] The region in which the structure 200 is disposed is not limited to the example shown in Fig. 2. For example, the structure 200 may be disposed approximately at the center in the first direction X of the region in which the scanning line L is generated or in its periphery. For example, the structure 200 may be a member such as a wire that extends linearly along the second direction Y. Even in this case, if the width of the structure 200 in the first direction X is relatively narrow, for example, narrower than the width in the first direction X of the spot generated by the movable reflector 120, it is possible to suppress electromagnetic waves attenuated by the structure 200.

[0030] The movable reflector 120 operates in a designed state during the first period T1 of the scanning line L. On the right side of the first period T1 of the scanning line L, three spots generated by the electromagnetic waves emitted from the emission portion 110 and reflected by the movable reflector 120 are shown as black circles.

[0031] In the second period T2 of the scanning line L, the movable reflector 120 operates in a state in which the gain of the transfer function of the movable reflector 120 is deviated from the gain in the designed state. Three spots generated by electromagnetic waves emitted from the emission unit 110 and reflected by the movable reflector 120 are shown as black circles at the right-hand turn in the second period T2 of the scanning line L. Due to the deviation in gain, the amplitude of the scanning line L in the first direction X in the second period T2 is smaller than the amplitude in the designed state. As a result, the three spots in the second period T2 of the scanning line L are deviated to the left with respect to the three spots in the first period T1 of the scanning line L.

[0032] In the third period T3 of the scanning line L, the movable reflector 120 operates in a state in which the phase of the transfer function of the movable reflector 120 is shifted from the phase in the designed state. Three spots generated by electromagnetic waves emitted from the emission unit 110 and reflected by the movable reflector 120 are shown as black circles at and near the right-hand turn in the third period T3 of the scanning line L. Due to the phase shift, the phases of the three spots in the third period T3 of the scanning line L are delayed from the phase in the designed state. As a result, the three spots in the third period T3 of the scanning line L are shifted from the three spots in the first period T1 of the scanning line L.

[0033] 3 and 4 are diagrams for explaining a first example of control by the control unit 150. FIG.

[0034] 3 and 4, a field of view F, such as an FOV (Field of View) of the movable reflecting unit 120, is indicated by a dashed line. The structure 200 shown in FIGS. 1 and 2 is, for example, disposed outside the field of view F. Alternatively, the structure 200 may be disposed inside the field of view F.

[0035] 3 and 4, a group of points, that is, spots, generated by the electromagnetic waves emitted by the emission section 110 and reflected by the movable reflection section 120 are shown as a plurality of black circles overlapping the scanning line L.

[0036] In FIG. 3, the movable reflector 120 in the first period T1 operates in a designed state. In contrast, the gain of the transfer function of the movable reflector 120 in the second period T2 deviates from the gain in the designed state. Therefore, the amplitude of the scanning line L in the first direction X in the second period T2 is larger than the amplitude in the designed state. Therefore, in the field of view F, the point clouds of the first period T1 and the point clouds of the second period T2 are arranged with a deviation from each other in the first direction X. Specifically, in the field of view F, the intervals in the first direction X of the point clouds of the second period T2 are wider than the intervals in the first direction X of the point clouds of the first period T1.

[0037] 4, the control unit 150 controls at least one of the amplitude of the movable reflector 120 and the interval of the emission timing of the electromagnetic wave from the emission unit 110 based on the reception result by the reception unit 130 of the electromagnetic wave reflected or scattered by the structure 200. The amplitude of the movable reflector 120 can be controlled, for example, by the amplitude of the drive signal input to the movable reflector 120. Specifically, the control unit 150 substantially aligns the point cloud of the first period T1 and the point cloud of the second period T2 in the first direction X within the field of view F.

[0038] 3 and 4 illustrate the alignment of the point clouds of the first period T1 and the second period T2 in the field of view F in the first direction X. In other words, in the example illustrated in FIGS. 3 and 4, the state in which the point clouds of each period in the field of view F are aligned in the first direction X as shown in FIG. 4 is the reference state, such as the design state, for the arrangement of the point clouds in the field of view F. However, the reference state for the arrangement of the point clouds in the field of view F is not limited to the state in which the point clouds of each period in the field of view F are aligned in the first direction X. For example, the reference state for the arrangement of the point clouds in the field of view F may be such that the point clouds of each period in the field of view F are shifted by a predetermined distance along the first direction X. In this example, even if the arrangement of the point clouds in the field of view F deviates from the arrangement of the reference state, the arrangement of the point clouds in the field of view F can be restored to the arrangement of the reference state in the same manner as in the example described using FIGS. 3 and 4. The same applies to FIGS. 5 and 6, which will be described later.

[0039] An example of the control of the amplitude of the movable reflecting section 120 by the control section 150 is as follows.

[0040] For example, as shown in FIG. 3, if the spacing in the first direction X of the point group of the second period T2 in the field of view F is wider than the spacing in the first direction X of the point group of the first period T1, the control unit 150 can narrow the spacing in the first direction X of the point group of the second period T2 in the field of view F by reducing the amplitude of the vibration in the first direction X of the second period T2 of the movable reflector 120, thereby aligning the positions in the first direction X of the point group of the first period T1 and the positions in the first direction X of the point group of the second period T2 in the field of view F. Furthermore, if the spacing in the first direction X of the point group of the second period T2 within the field of view F is narrower than the spacing in the first direction X of the point group of the first period T1, the control unit 150 can increase the amplitude of the vibration in the first direction X of the second period T2 of the movable reflector 120, thereby widening the spacing in the first direction X of the point group of the second period T2 within the field of view F, and thereby aligning the positions in the first direction X of the point group of the first period T1 and the positions in the first direction X of the point group of the second period T2 within the field of view F.

[0041] An example of control of the interval of the emission timing of the electromagnetic wave from the emission unit 110 by the control unit 150 is as follows.

[0042] 3 , when the intervals in the first direction X of the point group of the second period T2 within the field of view F are wider than the intervals in the first direction X of the point group of the first period T1, the control unit 150 can narrow the intervals in the first direction X of the point group of the second period T2 within the field of view F by shortening the intervals between the timings at which the electromagnetic waves are emitted from the emitter 110 within the field of view F. Furthermore, when the intervals in the first direction X of the point group of the second period T2 within the field of view F are narrower than the intervals in the first direction X of the point group of the first period T1 within the field of view F, the control unit 150 can widen the intervals in the first direction X of the point group of the second period T2 within the field of view F by lengthening the intervals between the timings at which the electromagnetic waves are emitted from the emitter 110 within the field of view F.

[0043] Figures 5 and 6 are diagrams for explaining a second example of control by the control unit 150. The example shown in Figures 5 and 6 is similar to the example shown in Figures 3 and 4 except for the following points.

[0044] 5, the movable reflector 120 in the first period T1 operates in a designed state. Meanwhile, the phase of the transfer function of the movable reflector 120 in the second period T2 is shifted from the phase in the designed state. Therefore, each phase of the point cloud in the second period T2 leads from the phase in the designed state. Therefore, within the field of view F, the point cloud in the first period T1 and the point cloud in the second period T2 are arranged to be shifted from each other in the first direction X.

[0045] 6, the control unit 150 shifts the emission timing of the electromagnetic waves from the emission unit 110 based on the reception result by the reception unit 130 of the electromagnetic waves reflected or scattered by the structure 200. Specifically, the control unit 150 substantially aligns the point cloud of the first period T1 and the point cloud of the second period T2 in the first direction X within the field of view F.

[0046] An example of the transition of the emission timing of the electromagnetic wave from the emission unit 110 by the control unit 150 is as follows.

[0047] 5, when the phases of the points in the second period T2 are ahead of the phases in the design state, the control unit 150 can align the positions of the points in the first direction X of the points in the first period T1 and the positions of the points in the second period T2 in the first direction X within the field of view F by advancing the timing of emission of the electromagnetic wave from the emitter 110 in the second period T2 within the field of view F. Furthermore, when the phases of the points in the second period T2 are behind the phases in the design state, the control unit 150 can align the positions of the points in the first direction X of the points in the first period T1 and the positions of the points in the second period T2 in the first direction X within the field of view F by delaying the timing of emission of the electromagnetic wave from the emitter 110 in the second period T2 within the field of view F.

[0048] Fig. 7 is a diagram showing a first example of the relationship between the structure 200 and the first spot S1 and second spot S2 when the movable reflecting unit 120 operates in a designed state. Fig. 8 is a graph showing an example of a signal generated in the receiving unit 130 by the first spot S1 and second spot S2 shown in Fig. 7.

[0049] 7 shows a portion of one cycle of the scanning line L generated by the movable reflecting portion 120, specifically the right-hand turn-back portion and its surroundings of the scanning line L. The scanning line L extends from the upper left to the right in the drawing, turns back at the right side in the drawing, and extends from the right to the lower left in the drawing.

[0050] In Fig. 8, the horizontal axis of the graph represents time t, and the vertical axis of the graph represents the intensity of the signal generated by the receiving unit 130. In Fig. 8, at time t1, a signal with intensity r0 is generated by the first spot S1, and at time t2, a signal with intensity r0 is generated by the second spot S2.

[0051] 7 and 8, the structure 200 is provided so that the intensity r0 of the signal generated in the receiving unit 130 by the first spot S1 at time t1 when the movable reflector 120 operates in the design state and the intensity r0 of the signal generated in the receiving unit 130 by the second spot S2 at time t2 when the movable reflector 120 operates in the design state are substantially equal. Specifically, the edge of the structure 200 that intersects with the right-hand turn of the scanning line L is parallel to the second direction Y. Furthermore, the reflectivity of the structure 200 is uniform throughout all regions within the structure 200. However, the intensity of the signal generated in the receiving unit 130 by the first spot S1 at time t1 when the movable reflector 120 operates in the design state and the intensity of the signal generated in the receiving unit 130 by the second spot S2 at time t2 when the movable reflector 120 operates in the design state do not have to be substantially equal, and may be different from each other.

[0052] Fig. 9 is a diagram showing an example of the relationship between the structure 200 and the first spot S1 and the second spot S2 when the movable reflector 120 operates in a state in which the gain in the first direction X of the transfer function of the movable reflector 120 deviates from the gain in the designed state shown in Fig. 7. Fig. 10 is a graph showing an example of signals generated in the receiving unit 130 by the first spot S1 and the second spot S2 shown in Fig. 9.

[0053] 9, the gain of the transfer function of the movable reflector 120 in the first direction X, i.e., the direction of resonant driving, deviates from the gain in the designed state, which causes the amplitude of vibration of the movable reflector 120 in the first direction X to be larger than the amplitude in the designed state.

[0054] The area of ​​the first spot S1 irradiated onto the structure 200 in Fig. 9 is larger than the area of ​​the first spot S1 irradiated onto the structure 200 in Fig. 7. Therefore, the amount of electromagnetic waves received by the receiving unit 130 at time t1 in Fig. 10 is larger than the amount of electromagnetic waves received by the receiving unit 130 at time t1 in Fig. 8. For this reason, the intensity r1 of the signal generated at time t1 in Fig. 10 is higher than the intensity r0 of the signal generated at time t1 in Fig. 8.

[0055] The area of ​​the second spot S2 irradiated onto the structure 200 in Fig. 9 is larger than the area of ​​the second spot S2 irradiated onto the structure 200 in Fig. 7. Therefore, the amount of electromagnetic waves received by the receiving unit 130 at time t2 in Fig. 10 is larger than the amount of electromagnetic waves received by the receiving unit 130 at time t2 in Fig. 8. For this reason, the intensity r1 of the signal generated at time t2 in Fig. 10 is higher than the intensity r0 of the signal generated at time t2 in Fig. 8.

[0056] 1 can determine a deviation of the gain of the transfer function of the movable reflector 120 in the first direction X from the gain in the design state, based on a comparison result between a first reception value by the receiving unit 130 of the electromagnetic wave reflected or scattered by the first portion of the structure 200 and a second reception value by the receiving unit 130 of the electromagnetic wave reflected or scattered by the second portion of the structure 200, and a first reference reception value by the receiving unit 130 of the electromagnetic wave reflected or scattered by the first portion of the structure 200 when the movable reflector 120 operates in a reference state, for example, a design state, and a second reference reception value by the receiving unit 130 of the electromagnetic wave reflected or scattered by the second portion of the structure 200 when the movable reflector 120 operates in the reference state. Based on this determination result, the control unit 150 can perform various controls, for example, control of the amplitude of vibration of the movable reflector 120 in the first direction X or control of the interval of the emission timing of the electromagnetic wave from the emitting unit 110. The first portion of the structure 200 is, for example, a portion of the structure 200 where the first spot S1 is generated or its vicinity. The second portion of the structure 200 is, for example, a portion of the structure 200 where the second spot S2 is generated or its vicinity. Furthermore, the first and second portions of the structure 200 are located on opposite sides of the return of the scanning line L of the movable reflecting unit 120, for example.

[0057] For example, the control unit 150 can determine a deviation of the gain of the transfer function of the movable reflector 120 in the first direction X from the gain in the design state, based on whether both the first received value and the second received value are greater than or smaller than the first reference received value or the second reference received value. For example, if the intensity r1 of the signal generated at time t1 in FIG. 10 and the intensity r1 of the signal generated at time t2 are both greater than the intensity r0 of the signal generated at time t1 in FIG. 8 or the intensity r0 of the signal generated at time t2 in FIG. 8, the control unit 150 can determine that the gain of the transfer function of the movable reflector 120 in the first direction X is greater than the gain in the design state. Furthermore, if the intensity r1 of the signal generated at time t1 in FIG. 10 and the intensity r1 of the signal generated at time t2 are both less than the intensity r0 of the signal generated at time t1 in FIG. 8 or the intensity r0 of the signal generated at time t2 in FIG. 8, the control unit 150 can determine that the gain of the transfer function of the movable reflector 120 in the first direction X is smaller than the gain in the design state.

[0058] Fig. 11 is a diagram showing an example of the relationship between the structure 200 and the first spot S1 and the second spot S2 when the movable reflector 120 operates in a state where the phase of the transfer function of the movable reflector 120 is shifted from the phase in the designed state shown in Fig. 7. Fig. 12 is a graph showing an example of signals generated in the receiving unit 130 by the first spot S1 and the second spot S2 shown in Fig. 11.

[0059] In FIG. 11, the phase of the transfer function of the movable reflecting portion 120 leads from the phase in the designed state.

[0060] The area of ​​the first spot S1 irradiated onto the structure 200 in Fig. 11 is larger than the area of ​​the first spot S1 irradiated onto the structure 200 in Fig. 7. Therefore, the amount of electromagnetic waves received by the receiving unit 130 at time t1 in Fig. 12 is larger than the amount of electromagnetic waves received by the receiving unit 130 at time t1 in Fig. 8. For this reason, the intensity r2 of the signal generated at time t1 in Fig. 12 is higher than the intensity r0 of the signal generated at time t1 in Fig. 8.

[0061] The area of ​​the second spot S2 irradiated onto the structure 200 in Fig. 11 is smaller than the area of ​​the second spot S2 irradiated onto the structure 200 in Fig. 7. Therefore, the amount of electromagnetic waves received by the receiving unit 130 at time t2 in Fig. 12 is smaller than the amount of electromagnetic waves received by the receiving unit 130 at time t2 in Fig. 8. For this reason, the intensity r3 of the signal generated at time t2 in Fig. 12 is lower than the intensity r0 of the signal generated at time t2 in Fig. 8.

[0062] 1 can determine a deviation of the phase of the transfer function of the movable reflector 120 from the phase in the design state based on a comparison result between a first reception value by the receiving unit 130 of the electromagnetic wave reflected or scattered by the first portion of the structure 200 and a second reception value by the receiving unit 130 of the electromagnetic wave reflected or scattered by the second portion of the structure 200, and a first reference reception value by the receiving unit 130 of the electromagnetic wave reflected or scattered by the first portion of the structure 200 when the movable reflector 120 operates in a reference state, e.g., a design state, and a second reference reception value by the receiving unit 130 of the electromagnetic wave reflected or scattered by the second portion of the structure 200 when the movable reflector 120 operates in the reference state. Based on this determination result, the control unit 150 can perform various controls, for example, transition of the emission timing of the electromagnetic wave from the emitting unit 110. The first portion of the structure 200 is, for example, a portion of the structure 200 where the first spot S1 is generated or its vicinity. The second portion of the structure 200 is, for example, a portion of the structure 200 where the second spot S2 is generated or its vicinity. The first and second portions of the structure 200 are located on opposite sides of the return of the scanning line L of the movable reflecting unit 120, for example.

[0063] For example, the control unit 150 can determine the deviation of the phase of the transfer function of the movable reflector 120 from the phase in the design state based on whether one of the first and second reception values ​​is greater than the first or second reference reception value and whether the other of the first and second reception values ​​is smaller than the first or second reference reception value. For example, if the intensity r2 of the signal generated at time t1 in Fig. 12 is greater than the intensity r0 of the signal generated at time t1 in Fig. 8 and the intensity r3 of the signal generated at time t2 in Fig. 12 is less than the intensity r0 of the signal generated at time t1 in Fig. 8, the control unit 150 can determine that the phase of the transfer function of the movable reflector 120 leads the phase in the design state. Furthermore, if the intensity r2 of the signal generated at time t1 in Figure 12 is smaller than the intensity r0 of the signal generated at time t1 in Figure 8, and the intensity r3 of the signal generated at time t2 in Figure 12 is greater than the intensity r0 of the signal generated at time t1 in Figure 8, the control unit 150 can determine that the phase of the transfer function of the movable reflecting unit 120 lags behind the phase in the design state.

[0064] Fig. 13 is a diagram showing a second example of the relationship between the structure 200A and the first spot S1 and the second spot S2 when the movable reflector 120 operates in a designed state. Fig. 14 is a graph showing an example of a signal generated in the receiving unit 130 by the first spot S1 and the second spot S2 shown in Fig. 13.

[0065] 13 and 14, the structure 200A is arranged so that the intensity r0 of the signal generated in the receiving unit 130 by the first spot S1 at time t1 when the movable reflecting unit 120 operates in the designed state is different from the intensity r0' of the signal generated in the receiving unit 130 by the second spot S2 at time t2 when the movable reflecting unit 120 operates in the designed state. Specifically, the edge of the structure 200A that intersects with the right-hand turn of the scanning line L is oblique with respect to the second direction Y. More specifically, the edge of the structure 200A is obliquely inclined from the left side to the right side of the structure 200A as it moves from the top to the bottom of the structure 200A. Furthermore, the reflectance of the structure 200A is uniform in any region within the structure 200A.

[0066] Fig. 15 is a diagram showing an example of the relationship between the structure 200A and the first spot S1 and the second spot S2 when the movable reflector 120 operates in a state in which the gain in the second direction Y of the transfer function of the movable reflector 120 deviates from the gain in the designed state shown in Fig. 13. Fig. 16 is a graph showing an example of signals generated in the receiving unit 130 by the first spot S1 and the second spot S2 shown in Fig. 15.

[0067] 15, the gain of the transfer function of the movable reflector 120 in the second direction Y, i.e., the direction of linear drive, is deviated from the gain in the designed state, which causes the distance between the first spot S1 and the second spot S2 in the second direction Y to be wider than the distance in the designed state.

[0068] The ratio of the irradiation area of ​​the second spot S2 onto the structure 200A to the irradiation area of ​​the first spot S1 onto the structure 200A in Fig. 15 is smaller than the ratio of the irradiation area of ​​the second spot S2 onto the structure 200A to the irradiation area of ​​the first spot S1 onto the structure 200A in Fig. 13. Therefore, the ratio β of the intensity r1' of the signal generated at time t2 to the intensity r1 of the signal generated at time t1 in Fig. 16 is smaller than the ratio α of the intensity r0' of the signal generated at time t2 to the intensity r0 of the signal generated at time t1 in Fig. 14 (α=r0' / r0, β=r1' / r1).

[0069] For example, the control unit 150 can determine a deviation of the gain of the transfer function of the movable reflector 120 in the second direction Y from the gain in the designed state, based on a comparison result between at least one of the ratio and difference between the first received value and the second received value and at least one of the ratio and difference between the first reference received value or the second reference received value. For example, if the ratio β is smaller than the ratio α, the control unit 150 can determine that the gain of the transfer function of the movable reflector 120 in the second direction Y is larger than the gain in the designed state. Furthermore, if the ratio β is larger than the ratio α, the control unit 150 can determine that the gain of the transfer function of the movable reflector 120 in the second direction Y is smaller than the gain in the designed state. Based on this determination result, the control unit 150 can perform various controls, for example, control of the amplitude of vibration of the movable reflector 120 in the second direction Y.

[0070] 7 and 9 and the structure 200A shown in Figures 13 and 15 may be arranged on opposite sides to each other in the first direction X in the region where the scanning line L is formed. In this case, the control unit 150 can determine the deviation of the gain of the transfer function of the movable reflector 120 in the first direction X from the gain in the designed state by using the structure 200 shown in Figures 7 and 9, and can determine the deviation of the gain of the transfer function of the movable reflector 120 in the second direction Y from the gain in the designed state by using the structure 200A shown in Figures 13 and 15.

[0071] Although the embodiments have been described above with reference to the drawings, these are merely examples of the present invention, and various other configurations can also be adopted.

[0072] For example, in the embodiment, the sensor device 10 is a coaxial LiDAR. However, the sensor device 10 may be a biaxial LiDAR.

[0073] According to the present specification, the following aspects are provided. (Aspect 1-1) a movable reflecting unit that reflects electromagnetic waves toward a predetermined scanning range; a receiving unit that receives the electromagnetic waves reflected or scattered by structures located within the scanning range; a control unit that controls the amplitude of vibration of the movable reflecting unit based on the reception result of the electromagnetic wave reflected or scattered by the structure by the receiving unit; A sensor device comprising: (Aspect 1-2) In the sensor device according to aspect 1-1, the movable reflecting portion reflects the electromagnetic wave emitted from the emitting portion toward the scanning range, The control unit further controls an interval of the emission timing of the electromagnetic wave from the emission unit. (Aspects 1-3) In the sensor device according to aspect 1-1 or 1-2, The control unit controls the amplitude of the vibration of the movable reflecting unit based on a comparison result between a relationship between a first reception value by the receiving unit of the electromagnetic wave reflected or scattered by a first part of the structure and a second reception value by the receiving unit of the electromagnetic wave reflected or scattered by a second part of the structure, and a relationship between a first reference reception value by the receiving unit of the electromagnetic wave reflected or scattered by the first part of the structure when the movable reflecting unit operates in a reference state and a second reference reception value by the receiving unit of the electromagnetic wave reflected or scattered by the second part of the structure when the movable reflecting unit operates in the reference state. (Aspects 1-4) In the sensor device according to any one of aspects 1 to 3, The control unit controls the amplitude of the vibration of the movable reflecting unit based on whether both the first reception value and the second reception value are greater than or smaller than the first reference reception value or the second reference reception value. (Aspects 1-5) In the sensor device according to any one of aspects 1 to 3, the structure is provided so that the first reference reception value and the second reference reception value are different from each other; The control unit controls the amplitude of the vibration of the movable reflecting unit based on a comparison result of at least one of the ratio and difference between the first received value and the second received value and at least one of the ratio and difference between the first reference received value and the second reference received value. (Aspects 1-6) In the sensor device according to any one of aspects 1-3 to 1-5, The sensor device, wherein the first portion and the second portion of the structure are located on opposite sides of a return of the scanning line of the movable reflecting portion. (Aspects 1-7) In the sensor device according to any one of aspects 1-1 to 1-6, The structure intersects at least a portion of a turn of a scan line of the movable reflective portion. (Aspect 2-1) an emission unit that emits electromagnetic waves; a movable reflecting unit that reflects the electromagnetic wave toward a predetermined scanning range; a receiving unit that receives the electromagnetic waves reflected or scattered by structures located within the scanning range; a control unit that shifts the emission timing of the electromagnetic wave from the emission unit based on a reception result of the electromagnetic wave reflected by the structure by the reception unit; A sensor device comprising: (Aspect 2-2) In the sensor device according to aspect 2-1, The control unit shifts the emission timing of the electromagnetic wave from the emission unit based on a comparison result between a relationship between a first reception value by the receiving unit of the electromagnetic wave reflected or scattered by a first part of the structure and a second reception value by the receiving unit of the electromagnetic wave reflected or scattered by a second part of the structure, and a relationship between a first reference reception value by the receiving unit of the electromagnetic wave reflected or scattered by the first part of the structure when the movable reflecting unit operates in a reference state and a second reference reception value by the receiving unit of the electromagnetic wave reflected or scattered by the second part of the structure when the movable reflecting unit operates in the reference state. (Aspect 2-3) In the sensor device according to aspect 2-2, The control unit shifts the emission timing of the electromagnetic wave from the emission unit based on whether one of the first reception value and the second reception value is greater than the first reference reception value or the second reference reception value, and whether the other of the first reception value and the second reception value is smaller than the first reference reception value or the second reference reception value. (Aspects 2-4) In the sensor device according to aspect 2-2 or 2-3, The sensor device, wherein the first portion and the second portion of the structure are located on opposite sides of a return of the scanning line of the movable reflecting portion. (Aspects 2-5) In the sensor device according to any one of aspects 2-1 to 2-4, The structure intersects at least a portion of a turn of a scan line of the movable reflective portion.

[0074] This application claims priority based on Japanese Patent Application No. 2020-058896, filed on March 27, 2020, the disclosure of which is incorporated herein in its entirety. [Explanation of symbols]

[0075] 10 Sensor device 110 Exit section 120 Movable reflector 130 Receiving unit 140 Beam Splitter 150 control section 200 structures 200A Structure F field of view L scan line S1 1st spot S2 2nd spot T1 1st period T2 2nd period T3 3rd period X 1st direction Y Second direction

Claims

[Claim 1] a movable reflecting unit that reflects electromagnetic waves toward a predetermined scanning range; a receiving unit that receives the electromagnetic waves reflected or scattered by structures located within the scanning range; a control unit that controls the amplitude of vibration of the movable reflecting unit based on the reception result of the electromagnetic wave reflected or scattered by the structure by the receiving unit; A sensor device comprising:

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