Sensor device

Abstract

A part of the electromagnetic wave emitted from the emission section (110) and reflected by the movable reflection section (120) is reflected or scattered by an object such as an object existing outside the sensor device (10). Another part of the electromagnetic wave emitted from the emission section (110) and reflected by the movable reflection section (120) is reflected or scattered by the structure (200) located in the vicinity of the movable reflection section (120) as compared with the above object. The control section (150) controls the amplitude of the vibration of the movable reflection section (120) on the basis of the reception result of the electromagnetic wave reflected or scattered by the structure (200) by the reception section (130). In addition, the control section (150) controls the interval of the emission timing of the electromagnetic wave from the emission section (110) on the basis of the reception result of the electromagnetic wave reflected or scattered by the structure (200) by the reception section (130).

Description

Technical Field

[0001] This invention relates to sensor devices. Background Technology

[0002] In recent years, various sensor devices, such as LiDAR (Light Detection and Ranging), have been developed. These sensor devices possess movable reflective parts, such as MEMS (Micro Electro Mechanical Systems) mirrors. By utilizing these movable reflective parts to reflect electromagnetic waves, such as infrared light, within a defined scanning range, the sensor device scans objects and other objects located outside the sensor device.

[0003] Patent Document 1 describes the following: In order to determine the direction in which the laser reflected by the movable reflector is output, a reflective member is disposed at one end of the scanning range of the movable reflector. The laser reflected by the reflective member is received by a light-receiving part. Based on the light-receiving result of the light-receiving part, the distance from the movable reflector to the reflective member is calculated. Based on the distance from the movable reflector to the reflective member, the direction in which the laser reflected by the movable reflector is output is calculated.

[0004] Patent document 2 describes the following: A reflective member is provided on the housing that houses the movable reflective part and other components constituting the sensor device, and the offset of the scanning position of the movable reflective part is detected by using the laser reflected by the reflective member.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: Japanese Patent Application Publication No. 2016-6403

[0008] Patent Document 2: Japanese Patent Application Publication No. 2020-16481 Summary of the Invention

[0009] The problem that the invention aims to solve

[0010] In sensor devices, a point group is generated by the illumination of electromagnetic waves reflected by a movable reflector. However, due to various factors, such as the gain of the transfer function of the movable reflector shifting from the design gain, the position of the point group sometimes deviates from the design position.

[0011] As an example of the problem to be solved by the present invention, one example is correcting the offset of the position of a point group from its designed position.

[0012] Methods for solving problems

[0013] The invention described in technical solution 1 is a sensor device, comprising:

[0014] A movable reflector that reflects electromagnetic waves within a specified scanning range;

[0015] A receiving unit that receives electromagnetic waves reflected or scattered by a structure located within the scanning range; and

[0016] The control unit controls the amplitude of the vibration of the movable reflector based on the reception result of the receiving unit on the electromagnetic waves reflected or scattered by the structure. Attached Figure Description

[0017] Figure 1 This is a diagram illustrating a sensor device according to an embodiment.

[0018] Figure 2 This is a diagram illustrating an example of the relationship between the scanning lines of the structure and the movable reflective part.

[0019] Figure 3 This is a diagram illustrating the first example of control in the control unit.

[0020] Figure 4 This is a diagram illustrating the first example of control in the control unit.

[0021] Figure 5 This is a diagram illustrating the second example of control in the control unit.

[0022] Figure 6 This is a diagram illustrating the second example of control in the control unit.

[0023] Figure 7 This is a diagram illustrating the first example of the relationship between the first and second light spots when the structure and the movable reflector are operating in their designed state.

[0024] Figure 8 It shows the use of Figure 7 A diagram showing an example of the signals generated by the first and second light spots in the receiving unit.

[0025] Figure 9 This shows the gain of the movable reflector in the first direction of the transfer function of the movable reflector, from the structure. Figure 7 The diagram shows an example of the relationship between the first and second light spots when the design is in a gain-off state.

[0026] Figure 10 It shows the use of Figure 9 A diagram showing an example of the signals generated by the first and second light spots in the receiving unit.

[0027] Figure 11This shows the phase of the transfer function of the movable reflector from the structure and the movable reflector. Figure 7 The diagram shows an example of the relationship between the first and second light spots when the phase shift is in the design state.

[0028] Figure 12 It shows the use of Figure 11 A diagram showing an example of the signals generated by the first and second light spots in the receiving unit.

[0029] Figure 13 This is a second example of the relationship between the first and second light spots when the structure and the movable reflector are operating in the designed state.

[0030] Figure 14 It shows the use of Figure 13 A diagram showing an example of the signals generated by the first and second light spots in the receiving unit.

[0031] Figure 15 This shows the gain of the movable reflector in the second direction of the transfer function of the movable reflector, from the structure. Figure 13 The diagram shows an example of the relationship between the first and second light spots when the design is in a gain-off state.

[0032] Figure 16 It shows the use of Figure 15 A diagram showing an example of the signals generated by the first and second light spots in the receiving unit. Detailed Implementation

[0033] Hereinafter, embodiments of the present invention will be described using the accompanying drawings. Furthermore, throughout the drawings, the same reference numerals are used to assign the same constituent elements, and descriptions are omitted where appropriate.

[0034] Figure 1 This is a diagram illustrating the sensor device 10 according to an embodiment.

[0035] exist Figure 1 In the middle, the first direction X and the second direction Y intersect each other, specifically orthogonal. Figure 1 In this diagram, the first direction X is horizontal. The arrow pointing to the first direction X, i.e., the positive direction of the first direction X, indicates the left side when observing from the movable reflector 120 towards its scanning range (described later). The opposite direction, i.e., the negative direction of the first direction X, indicates the right side when observing from the side where the movable reflector 120 is located towards its scanning range. The second direction Y is vertical. The arrow pointing to the second direction Y, i.e., the positive direction of the second direction Y, indicates upward. The opposite direction, i.e., the negative direction of the second direction Y, indicates downward.

[0036] As can be seen from the description in this specification, the first direction X can be a direction different from the horizontal direction, and the second direction Y can be a direction different from the vertical direction.

[0037] The sensor device 10 includes an emission section 110, a movable reflector 120, a receiver 130, a beam splitter 140, and a control section 150. Figure 1 The dashed lines extending to the emission section 110, movable reflector 120, receiver 130, beam splitter 140, and scan line L represent the electromagnetic waves propagating within the range of the emission section 110, movable reflector 120, receiver 130, beam splitter 140, and scan line L. Figure 1 In the process, electromagnetic waves reflected from the movable reflector 120 toward the scan line L are irradiated toward approximately the center of the region forming the scan line L.

[0038] The emission section 110 emits pulsed electromagnetic waves such as infrared rays at regular intervals. The emission section 110 is, for example, a laser diode (LD) or other device capable of converting electrical current into electromagnetic waves such as light. The electromagnetic waves emitted from the emission section 110 pass through the beam splitter 140 and are incident on the movable reflector 120.

[0039] The movable reflector 120 reflects electromagnetic waves emitted from the emission section 110 within a predetermined scanning range. The scanning range of the movable reflector 120 is the range within which the electromagnetic waves reflected by the movable reflector 120 can be used for illumination. The movable reflector 120 is, for example, a biaxial MEMS mirror. The movable reflector 120 is resonantly driven in the first direction X and linearly driven in the second direction Y. For example, a sine wave or a cosine wave is used in the resonant drive of the movable reflector 120. For example, a sawtooth wave or a triangular wave is used in the linear drive of the movable reflector 120.

[0040] A portion of the electromagnetic waves emitted from the emission section 110 and reflected by the movable reflector 120 are reflected or scattered by objects or other objects present outside the sensor device 10. These electromagnetic waves return to the movable reflector 120 and, sequentially, are reflected by the movable reflector 120 and then by the beam splitter 140, before being incident on and received by the receiving section 130. The receiving section 130 is, for example, an avalanche photodiode (APD) or other element capable of converting electromagnetic waves such as light into electrical current.

[0041] Another portion of the electromagnetic waves emitted from the emission section 110 and reflected by the movable reflector 120 are reflected or scattered by the structure 200, which is located near the movable reflector 120 compared to the object. This electromagnetic wave returns to the movable reflector 120, and sequentially passes through the reflection of the movable reflector 120 and the transmission of the beam splitter 140 before entering and being received by the receiving section 130. The structure 200 can be, for example, a metal with a surface treatment that provides high stability over time, such as electroplating.

[0042] The distance from the movable reflector 120 to the structure 200 is shorter than the distance from the movable reflector 120 to the object. Therefore, the time from the emission of electromagnetic waves from the emission section 110 to the reception section 130 via reflection from the structure 200 is shorter than the time from the emission of electromagnetic waves from the emission section 110 to the reception section 130 via reflection from the object. Therefore, the sensor device 10 can distinguish whether the signal generated in the reception section 130 is caused by the structure 200 or by the object based on the time difference of the signal generated in the reception section 130.

[0043] The sensor device 10 may include a structure 200. Alternatively, the structure 200 may be disposed outside the sensor device 10. When the sensor device 10 includes a structure 200, the structure 200 may be disposed, for example, in a window portion of the housing that houses the components constituting the sensor device 10, such as the emission portion 110, the movable reflector 120, the receiver 130, and the beam splitter 140, i.e., the portion through which electromagnetic waves pass between the inside and outside of the housing. However, the location of the structure 200 is not limited to the window portion.

[0044] In this embodiment, the control unit 150 is shown as a module based on function rather than a hardware unit. The control unit 150 is implemented using any combination of hardware and software, centered around any computer's CPU, memory, program loaded into memory, storage medium such as a hard disk containing the program, and network connection interface. Furthermore, various variations of its implementation method and apparatus are possible.

[0045] The control unit 150 controls the amplitude of the vibration of the movable reflector 120 based on the reception results of the receiving unit 130 of the electromagnetic waves reflected or scattered by the structure 200. Furthermore, the control unit 150 controls the interval of the emission timing of the electromagnetic waves from the emitter 110 based on the reception results of the receiving unit 130 of the electromagnetic waves reflected or scattered by the structure 200. Also, the control unit 150 changes the emission timing of the electromagnetic waves from the emitter 110 based on the reception results of the receiving unit 130 of the electromagnetic waves reflected or scattered by the structure 200. The control unit 150 implements at least one of these controls on the emitter 110 and the movable reflector 120 based on the reception results of the receiving unit 130 of the electromagnetic waves reflected or scattered by the structure 200. Through the control of the control unit 150, it is possible to correct for any deviation of the position of the point group generated by the movable reflector 120 from its designed position.

[0046] Figure 2 This is a diagram showing an example of the relationship between the structure 200 and the scan line L of the movable reflective part 120.

[0047] The scan line L folds back in the first direction X, i.e., the direction of resonant drive of the movable reflector 120, and extends in the second direction Y, i.e., the positive direction of linear drive of the movable reflector 120, towards the negative direction. Figure 2 The image shows a portion of the first period T1, the second period T2, and the third period T3 of the scan line L.

[0048] The first period T1 of the scan line L is the following interval: the upper end of the scan line L is set to a position offset from the starting point of the first period T1 by about 1 / 4 period, the first segment from the top on the right side of the scan line L is turned back, and the first segment from the top on the left side of the scan line L is taken as the end point.

[0049] The second period T2 of scan line L is the following interval: taking the end of the first period T1 of scan line L as the starting point, the second segment from the top on the right side of scan line L is reversed, and the second segment from the top on the left side of scan line L is reversed as the ending point.

[0050] The third period T3 of scan line L is the following interval: taking the end of the second period T2 of scan line L as the starting point, the third segment from the top on the right side of scan line L is reversed, and the third segment from the top on the left side of scan line L is reversed as the ending point.

[0051] At least a portion of the reflection of the scan line L of the movable reflector 120 intersects with that of the structure 200. Figure 2 In the example shown, the structure 200 intersects at least a portion of the rightward reflection of the first period T1 of the scan line L, at least a portion of the rightward reflection of the second period T2 of the scan line L, and at least a portion of the rightward reflection of the third period T3 of the scan line L. If the structure 200 is positioned approximately at or around the center of the region generating the scan line L in the first direction X, the sensor device 10 may be unable to detect or have difficulty detecting objects in the region where the structure 200 is positioned. In contrast, in this embodiment, the region where the sensor device 10 cannot detect or has difficulty detecting objects can be limited to the end of the scanning range of the movable reflective portion 120.

[0052] The area where the configuration construct 200 is located is not limited to Figure 2 The example shown. For example, the structure 200 may also be disposed approximately at the center or around the periphery of the region where the scan line L is generated in the first direction X. For example, the structure 200 may be a line or other member extending linearly along the second direction Y. In this case, even if the width of the structure 200 in the first direction X is relatively narrow, for example, narrower than the width of the light spot generated by the movable reflector 120 in the first direction X, it is still possible to suppress electromagnetic waves attenuated by the structure 200.

[0053] During the first period T1 of the scan line L, the movable reflector 120 operates in its designed state. At the right-side reversal point in the first period T1 of the scan line L, three light spots generated by electromagnetic waves emitted from the emission section 110 and reflected by the movable reflector 120 are represented as black dots.

[0054] In the second period T2 of scan line L, the movable reflector 120 operates with its transfer function gain shifted from the designed gain. At the right-hand foldback in the second period T2 of scan line L, three light spots generated by the electromagnetic waves emitted from the emission unit 110 and reflected by the movable reflector 120 are represented as black dots. Due to the gain shift, the amplitude in the first direction X of scan line L in the second period T2 becomes smaller than the designed amplitude. Therefore, the three light spots in the second period T2 of scan line L shift to the left relative to the three light spots in the first period T1 of scan line L.

[0055] In the third period T3 of scan line L, the movable reflector 120 operates with the phase of its transfer function shifted from the designed phase. Three light spots, represented as black dots, are generated by electromagnetic waves emitted from the emission unit 110 and reflected by the movable reflector 120, in the right-hand reflection and vicinity of the third period T3 of scan line L. Due to the phase shift, the phase of these three light spots in the third period T3 of scan line L lags behind the designed phase. Therefore, the three light spots in the third period T3 of scan line L are shifted relative to the three light spots in the first period T1 of scan line L.

[0056] Figure 3 and Figure 4 This is a diagram illustrating the first example of control of the control unit 150.

[0057] exist Figure 3 and Figure 4 In the diagram, the field of view (FOV) of the movable reflector 120 is shown by dashed lines. Figure 1 and Figure 2 The structure 200 shown is, for example, positioned outside the field of view F. Alternatively, the structure 200 may be positioned inside the field of view F.

[0058] exist Figure 3 and Figure 4 In the process, the point group, i.e. the light spot, generated by the electromagnetic wave emitted by the emission part 110 and reflected by the movable reflection part 120 is represented as multiple black circles overlapping the scan line L.

[0059] exist Figure 3In the first period T1, the movable reflector 120 operates in its designed state. In contrast, the gain of the transfer function of the movable reflector 120 in the second period T2 shifts from the gain in the designed state. Therefore, the amplitude of the second period T2 of the scan line L in the first direction X becomes larger than the amplitude in the designed state. Consequently, within the field of view F, the point groups of the first period T1 and the second period T2 are offset from each other in the first direction X. Specifically, within the field of view F, the spacing of the point groups of the second period T2 in the first direction X becomes wider than the spacing of the point groups of the first period T1 in the first direction X.

[0060] exist Figure 4 In this process, the control unit 150 controls at least one of the amplitude of the movable reflector 120 and the interval of the timing of the emission of electromagnetic waves from the emitter 110, based on the reception result of the receiver 130 of the electromagnetic waves 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 group of the first period T1 and the point group of the second period T2 in the first direction X within the field of view F.

[0061] It should be noted that, in Figure 3 and Figure 4 The example shown illustrates how to align the point group of the first period T1 and the point group of the second period T2 within the field of view F in the first direction X. That is, in Figure 3 and Figure 4 In the example shown, the point groups of each period within the field of view F are as follows: Figure 4 The alignment shown in the first direction X serves as a reference state for the configuration of point groups within the field of view F. However, the reference state for the configuration of point groups within the field of view F is not limited to the alignment of point groups in each period within the field of view F in the first direction X. For example, the reference state for the configuration of point groups within the field of view F could also be that point groups in each period within the field of view F are offset by a predetermined distance along the first direction X. In this example, even if the configuration of point groups within the field of view F is offset from the configuration of the reference state, it is still consistent with the use of... Figure 3 and Figure 4 Similarly, the illustrated example enables the configuration of the point group within the field of view F to revert to the configuration of the baseline state. (The following will be discussed further.) Figure 5 and Figure 6 The same applies.

[0062] One example of controlling the amplitude of the movable reflector 120 using the control unit 150 is described below.

[0063] For example, such as Figure 3When the spacing of the point group of the second period T2 in the field of view F is wider than the spacing of the point group of the first period T1 in the first direction X, the control unit 150 can narrow the spacing of the point group of the second period T2 in the field of view F by reducing the amplitude of the vibration of the movable reflector 120 in the first direction X of the second period T2. This allows the positions of the point group of the first period T1 in the field of view F to be aligned with the positions of the point group of the second period T2 in the first direction X. Conversely, when the spacing of the point group of the second period T2 in the field of view F is narrower than the spacing of the point group of the first period T1 in the first direction X, the control unit 150 can increase the amplitude of the vibration of the movable reflector 120 in the first direction X of the second period T2. This allows the positions of the point group of the first period T1 in the field of view F to be aligned with the positions of the point group of the second period T2 in the first direction X.

[0064] One example of controlling the timing interval of the electromagnetic wave emission from the emission unit 110 using the control unit 150 is described below.

[0065] For example, such as Figure 3 When the spacing of the point group of the second period T2 in the field of view F is wider than the spacing of the point group of the first period T1 in the first direction X, the control unit 150 can narrow the spacing of the point group of the second period T2 in the field of view F by shortening the timing interval of the electromagnetic waves emitted from the emission unit 110 in the field of view F. Conversely, when the spacing of the point group of the second period T2 in the field of view F is narrower than the spacing of the point group of the first period T1 in the first direction X, the control unit 150 can increase the spacing of the point group of the second period T2 in the field of view F by extending the timing interval of the electromagnetic waves emitted from the emission unit 110 in the field of view F.

[0066] Figure 5 and Figure 6 This is a second example of a diagram used to illustrate the control of the control unit 150. Figure 5 and Figure 6 The examples shown, except for the following points, are similar to Figure 3 and Figure 4 The example shown is the same.

[0067] exist Figure 5In the first period T1, the movable reflector 120 operates in its designed state. On the other hand, the phase of the transfer function of the movable reflector 120 in the second period T2 shifts from its designed phase. Therefore, the phases of each point group in the second period T2 are ahead of their designed phases. Thus, within the field of view F, the point groups of the first period T1 and the second period T2 are arranged offset from each other in the first direction X.

[0068] exist Figure 6 In this process, the control unit 150 adjusts the emission timing of the electromagnetic waves from the emission unit 110 based on the reception results of the receiving unit 130 of the electromagnetic waves reflected or scattered by the structure 200. Specifically, the control unit 150 substantially aligns the point group of the first period T1 and the point group of the second period T2 in the first direction X within the field of view F.

[0069] An example of the change in the emission timing of electromagnetic waves from the emission unit 110 using the control unit 150 is described below.

[0070] For example, such as Figure 5 When the phases of the point group in the second period T2 are ahead of the phases in the design state, the control unit 150 advances the emission timing of the electromagnetic waves from the emission unit 110 within the field of view F in the second period T2, thereby aligning the positions of the point group in the first period T1 in the field of view F with the positions of the point group in the second period T2 in the first direction X. Conversely, when the phases of the point group in the second period T2 are lagging behind the phases in the design state, the control unit 150 delays the emission timing of the electromagnetic waves from the emission unit 110 within the field of view F in the second period T2, thereby aligning the positions of the point group in the first period T1 in the field of view F with the positions of the point group in the second period T2 in the first direction X.

[0071] Figure 7 This is a diagram illustrating a first example of the relationship between the first light spot S1 and the second light spot S2 when the structure 200 and the movable reflector 120 are operating in the designed state. Figure 8 It shows the use of Figure 7 A diagram showing an example of the signals generated by the first light spot S1 and the second light spot S2 in the receiving unit 130.

[0072] exist Figure 7 The image shows a portion of a cycle of a scan line L generated by the movable reflector 120, specifically the right-side fold and its periphery within the scan line L. The scan line L extends from the upper left to the right within the image, folds back on the right side within the image, and extends from the right side to the lower left within the image.

[0073] exist Figure 8In the graph, the horizontal axis represents time t, and the vertical axis represents the strength of the signal generated by the receiving unit 130. Figure 8 In the process, at time t1, a signal with intensity r0 is generated by the first light spot S1, and at time t2, a signal with intensity r0 is generated by the second light spot S2.

[0074] exist Figure 7 and Figure 8 In this configuration, the structure 200 is arranged such that the intensity r0 of the signal generated by the first light spot S1 at time t1 in the receiving unit 130 when the movable reflector 120 is operating in its designed state is substantially equal to the intensity r0 of the signal generated by the second light spot S2 in the receiving unit 130 at time t2 when the movable reflector 120 is operating in its designed state. Specifically, the edge of the structure 200 that intersects the right side of the scan line L is parallel to the second direction Y. Furthermore, the reflectivity of the structure 200 is the same in any region within the structure 200. However, the intensity of the signal generated by the first light spot S1 at time t1 in the receiving unit 130 when the movable reflector 120 is operating in its designed state and the intensity of the signal generated by the second light spot S2 in the receiving unit 130 at time t2 when the movable reflector 120 is operating in its designed state may not be substantially equal, or they may be different from each other.

[0075] Figure 9 This illustrates the gain of the movable reflector 120 in the first direction X of the transfer function of the movable reflector 120, from the structure 200. Figure 7 The diagram shows an example of the relationship between the first spot S1 and the second spot S2 when the design is in a gain-off state. Figure 10 It shows the use of Figure 9 A diagram showing an example of the signals generated by the first light spot S1 and the second light spot S2 in the receiving unit 130.

[0076] exist Figure 9 In this process, the gain in the first direction X of the transfer function of the movable reflector 120, i.e., the direction of resonance drive, shifts from the gain in the design state. As a result, the amplitude of the vibration of the movable reflector 120 in the first direction X becomes larger than the amplitude in the design state.

[0077] Figure 9 The illumination area of ​​the first light spot S1 on the structure 200 becomes larger than Figure 7 The area of ​​the first light spot S1 that illuminates the structure 200. Therefore, in Figure 10 At time t1, the amount of electromagnetic wave received by receiver 130 becomes greater than at time t1. Figure 8 The amount of electromagnetic wave received by the receiving unit 130 at time t1. Therefore, at Figure 10The intensity r1 of the signal generated at time t1 becomes higher than that at time t2. Figure 8 The intensity r0 of the signal generated at time t1.

[0078] Figure 9 The illumination area of ​​the second light spot S2 on the structure 200 becomes larger than Figure 7 The illumination area of ​​the second light spot S2 on the structure 200. Therefore, in Figure 10 At time t2, the amount of electromagnetic wave received by receiver 130 becomes greater than at time t3. Figure 8 The amount of electromagnetic wave received by the receiving unit 130 at time t2. Therefore, at Figure 10 The intensity r1 of the signal generated at time t2 becomes higher than that at time t2. Figure 8 The intensity r0 of the signal generated at time t2.

[0079] Figure 1 The control unit 150 shown can determine the shift of the gain in the first direction X of the transfer function of the movable reflector 120 from the gain in the design state based on the comparison results between the relationship between the first received value received by the receiving unit 130 from the electromagnetic waves reflected or scattered by the first part of the structure 200 and the second received value received by the receiving unit 130 from the electromagnetic waves reflected or scattered by the second part of the structure 200 when the movable reflector 120 is operating in a reference state, such as the design state, and the second reference received value received by the receiving unit 130 from the electromagnetic waves reflected or scattered by the second part of the structure 200 when the movable reflector 120 is operating in the reference state. Based on this determination result, the control unit 150 can perform various controls, such as controlling the amplitude of the vibration in the first direction X of the movable reflector 120 or controlling the interval of the emission timing of the electromagnetic waves from the emission unit 110. The first part of the structure 200 is, for example, the part of the structure 200 that generates the first light spot S1 or its vicinity. The second part of the structure 200 is, for example, the part of the structure 200 that generates the second light spot S2 or its vicinity. In addition, the first part and the second part of the structure 200, for example, sandwich the reflection of the scan line L of the movable reflector 120, are located on opposite sides of each other.

[0080] For example, the control unit 150 can determine the shift of the gain in the first direction X of the transfer function of the movable reflector 120 relative to the gain in the design state based on whether both the first received value and the second received value are greater than or less than the first reference received value or the second reference received value. For example, in Figure 10 The intensity r1 of the signal generated at time t1 and the intensity r1 of the signal generated at time t2 are both greater than those at time t1. Figure 8If the signal strength r0 generated at time t1 or the signal strength r0 generated at time t2 is greater than the signal strength r0, 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, in Figure 10 The intensity r1 of the signal generated at time t1 and the intensity r1 of the signal generated at time t2 are both less than the intensity r1 of the signal generated at time t2. Figure 8 If the strength r0 of the signal generated at time t1 or the strength r0 of the signal generated at time t2 is less than the gain in the design state, the control unit 150 can determine that the gain in the first direction X of the transfer function of the movable reflector 120 is less than the gain in the design state.

[0081] Figure 11 This shows the phase of the transfer function of the movable reflector 120 in the structure 200. Figure 7 The diagram shows an example of the relationship between the first spot S1 and the second spot S2 when the phase shift is in the design state. Figure 12 It shows the use of Figure 11 A diagram showing an example of the signals generated by the first light spot S1 and the second light spot S2 in the receiving unit 130.

[0082] exist Figure 11 In this process, the phase of the transfer function of the movable reflector 120 is ahead of the phase in the design state.

[0083] Figure 11 The illumination area of ​​the first light spot S1 on the structure 200 becomes larger than Figure 7 The area of ​​the first light spot S1 that illuminates the structure 200. Therefore, in Figure 12 At time t1, the amount of electromagnetic wave received by receiver 130 becomes greater than at time t1. Figure 8 The amount of electromagnetic wave received by the receiving unit 130 at time t1. Therefore, at Figure 12 The intensity r2 of the signal generated at time t1 becomes higher than that at time t2. Figure 8 The intensity r0 of the signal generated at time t1.

[0084] Figure 11 The illumination area of ​​the second light spot S2 on the structure 200 becomes smaller than Figure 7 The illumination area of ​​the second light spot S2 on the structure 200. Therefore, in Figure 12 At time t2, the amount of electromagnetic wave received by receiver 130 becomes less than at time t2. Figure 8 The amount of electromagnetic wave received by the receiving unit 130 at time t2. Therefore, at Figure 12 The intensity r3 of the signal generated at time t2 becomes lower than that at time t3. Figure 8 The intensity r0 of the signal generated at time t2.

[0085] Figure 1 The control unit 150 shown can determine the phase shift of the transfer function of the movable reflector 120 relative to the phase shift in the design state based on the comparison between the relationship between the first received value received by the receiving unit 130 from the electromagnetic waves reflected or scattered by the first part of the structure 200 and the second received value received by the receiving unit 130 from the electromagnetic waves reflected or scattered by the second part of the structure 200 when the movable reflector 120 is operating in a reference state, such as the design state, and the second reference received value received by the receiving unit 130 from the electromagnetic waves reflected or scattered by the second part of the structure 200 when the movable reflector 120 is operating in a reference state. The control unit 150 can perform various controls based on this determination result, such as changing the emission timing of the electromagnetic waves from the emission unit 110. The first part of the structure 200 is, for example, the part of the structure 200 that generates the first light spot S1 or its vicinity. The second part of the structure 200 is, for example, the part of the structure 200 that generates the second light spot S2 or its vicinity. In addition, the first part and the second part of the structure 200 are located on opposite sides of each other, for example, sandwiched by the reflection of the scan line L of the movable reflector 120.

[0086] For example, the control unit 150 can determine the phase shift of the transfer function of the movable reflector 120 relative to the phase in the design state based on the fact that one of the first received value and the second received value is greater than the first reference received value or the second reference received value, and the other of the first received value and the second received value is less than the first reference received value or the second reference received value. For example, in Figure 12 The signal strength r2 generated at time t1 is greater than that generated at time t2. Figure 8 The intensity r0 of the signal generated at time t1 and in Figure 12 The signal strength r3 generated at time t2 is less than that generated at time t3. Figure 8 Given that the signal strength r0 generated at time t1 is such that the phase of the transfer function of the movable reflector 120 is ahead of the phase in the design state, the control unit 150 can determine that... Furthermore, in... Figure 12 The signal strength r2 generated at time t1 is less than that generated at time t2. Figure 8 The intensity r0 of the signal generated at time t1 and in Figure 12 The signal strength r3 generated at time t2 is greater than that generated at time t3. Figure 8 When the intensity r0 of the signal generated at time t1 is , the control unit 150 can determine that the phase of the transfer function of the movable reflector 120 is lagging behind the phase in the design state.

[0087] Figure 13This is a second example of the relationship between the first light spot S1 and the second light spot S2 when the structure 200A and the movable reflector 120 are operating in the designed state. Figure 14 It shows the use of Figure 13 A diagram showing an example of the signals generated by the first light spot S1 and the second light spot S2 in the receiving unit 130.

[0088] exist Figure 13 and Figure 14 In this configuration, the structure 200A is arranged such that the intensity r0 of the signal generated by the first light spot S1 at time t1 in the receiving unit 130 when the movable reflector 120 is operating in its designed state is different from the intensity r0' of the signal generated by the second light spot S2 at time t2 in the receiving unit 130 when the movable reflector 120 is operating in its designed state. Specifically, the edge of the structure 200A that intersects the right side of the scan line L is inclined relative to the second direction Y. More specifically, this edge of the structure 200A is inclined obliquely from the left side to the right side as it moves from the top to the bottom of the structure 200A. Furthermore, the reflectivity of the structure 200A is the same in any region within the structure 200A.

[0089] Figure 15 This illustrates the gain of the movable reflector 120 in the second direction Y of the transfer function of the movable reflector 120, as shown by the structure 200A. Figure 13 The diagram shows an example of the relationship between the first spot S1 and the second spot S2 when the design is in a gain-off state. Figure 16 It shows the use of Figure 15 A diagram showing an example of the signals generated by the first light spot S1 and the second light spot S2 in the receiving unit 130.

[0090] exist Figure 15 In this process, the gain in the second direction Y of the transfer function of the movable reflector 120, i.e., the direction of linear drive, shifts from the gain in the design state. As a result, the interval in the second direction Y between the first light spot S1 and the second light spot S2 becomes larger than the interval in the design state.

[0091] Figure 15 The ratio of the irradiated area of ​​the second light spot S2 on the structure 200A to the irradiated area of ​​the first light spot S1 on the structure 200A becomes more... Figure 13 The ratio of the illumination area of ​​the second light spot S2 on the structure 200A to the illumination area of ​​the first light spot S1 on the structure 200A is smaller. Therefore, in Figure 16 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 becomes more than that at time t2. Figure 14The intensity r0' of the signal generated at time t2 is smaller than the intensity r0 of the signal generated at time t1 by α (α = r0' / r0, β = r1' / r1).

[0092] For example, the control unit 150 can determine, 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 and the second reference received value, whether the gain in the second direction Y of the transfer function of the movable reflector 120 deviates from the gain in the design state. For example, if the ratio β is less than the ratio α, the control unit 150 can determine that the gain in the second direction Y of the transfer function of the movable reflector 120 is greater than the gain in the design state. Furthermore, if the ratio β is greater than the ratio α, the control unit 150 can determine that the gain in the second direction Y of the transfer function of the movable reflector 120 is less than the gain in the design state. Based on this determination result, the control unit 150 can perform various controls, such as controlling the amplitude of the vibration in the second direction Y of the movable reflector 120.

[0093] It should be noted that, Figure 7 and Figure 9 The shown structure 200 and Figure 13 and Figure 15 The illustrated structures 200A can be arranged opposite each other in the first direction X in the region forming the scan line L. In this case, the control unit 150 can utilize... Figure 7 and Figure 9 The structure 200 shown determines the shift in gain in the first direction X of the transfer function of the movable reflector 120 from the gain in the design state, and can utilize... Figure 13 and Figure 15 The structure 200A shown determines the shift of the gain in the second direction Y of the transfer function of the movable reflector 120 from the gain in the design state.

[0094] The embodiments have been described above with reference to the accompanying drawings, but these are merely examples of the present invention, and various other structures may also be employed.

[0095] For example, in one embodiment, the sensor device 10 is a coaxial LiDAR. However, the sensor device 10 can also be a biaxial LiDAR.

[0096] According to this instruction manual, the following solutions are provided.

[0097] (Solution 1-1) A sensor device, comprising:

[0098] A movable reflector that reflects electromagnetic waves within a specified scanning range;

[0099] A receiving unit that receives electromagnetic waves reflected or scattered by a structure located within the scanning range; and

[0100] The control unit controls the amplitude of the vibration of the movable reflector based on the reception result of the receiving unit on the electromagnetic waves reflected or scattered by the structure.

[0101] (Option 1-2)

[0102] According to the sensor device described in Scheme 1-1

[0103] The movable reflective part reflects the electromagnetic waves emitted from the emission part within the scanning range.

[0104] The control unit further controls the timing interval of the electromagnetic waves emitted from the emission unit.

[0105] (Options 1-3)

[0106] The sensor device according to scheme 1-1 or 1-2

[0107] The control unit controls the amplitude of the vibration of the movable reflector based on a comparison of the relationship between a first received value received by the receiving unit from the electromagnetic waves reflected or scattered by the first part of the structure and a second received value received by the receiving unit from the electromagnetic waves reflected or scattered by the second part of the structure, and the relationship between the first reference received value and the second reference received value. The first reference received value is the reference received value received by the receiving unit from the electromagnetic waves reflected or scattered by the first part of the structure when the movable reflector is operating in a reference state, and the second reference received value is the reference received value received by the receiving unit from the electromagnetic waves reflected or scattered by the second part of the structure when the movable reflector is operating in the reference state.

[0108] (Options 1-4)

[0109] The sensor device according to schemes 1-3

[0110] The control unit controls the amplitude of the vibration of the movable reflector based on whether the first received value and the second received value are greater than or less than the first reference received value or the second reference received value.

[0111] (Options 1-5)

[0112] The sensor device according to schemes 1-3

[0113] The construct is configured in a manner that makes the first reference received value different from the second reference received value.

[0114] The control unit controls the amplitude of the vibration of the movable reflector 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 and the second reference received value.

[0115] (Options 1-6)

[0116] The sensor device according to any one of schemes 1-3 to 1-5

[0117] The first and second parts of the structure are located on opposite sides of each other, sandwiching the folded scan lines of the movable reflective part.

[0118] (Options 1-7)

[0119] The sensor device according to any one of schemes 1-1 to 1-6

[0120] The structure intersects at least a portion of the folded-back scan line of the movable reflective part.

[0121] (Solution 2-1) A sensor device, comprising:

[0122] An ejector section that emits electromagnetic waves;

[0123] A movable reflector that reflects the electromagnetic waves within a specified scanning range;

[0124] A receiving unit that receives electromagnetic waves reflected or scattered by a structure located within the scanning range; and

[0125] The control unit, based on the reception result of the electromagnetic wave reflected by the structure by the receiving unit, changes the emission timing of the electromagnetic wave from the emitting unit.

[0126] (Option 2-2)

[0127] According to the sensor device described in Scheme 2-1

[0128] The control unit adjusts the emission timing of the electromagnetic waves from the emission unit based on a comparison between a first received value received by the receiving unit from the electromagnetic waves reflected or scattered by the first part of the structure and a second received value received by the receiving unit from the electromagnetic waves reflected or scattered by the second part of the structure, and a comparison between a first reference received value and a second reference received value. The first reference received value is the reference received value received by the receiving unit from the electromagnetic waves reflected or scattered by the first part of the structure when the movable reflector is operating in the reference state, and the second reference received value is the reference received value received by the receiving unit from the electromagnetic waves reflected or scattered by the second part of the structure when the movable reflector is operating in the reference state.

[0129] (Option 2-3)

[0130] According to the sensor device described in Scheme 2-2

[0131] The control unit causes a timing change in the emission of the electromagnetic wave from the emission unit based on the fact that one of the first received value and the second received value is greater than the first reference received value or the second reference received value, and the other of the first received value and the second received value is less than the first reference received value or the second reference received value.

[0132] (Options 2-4)

[0133] The sensor device according to scheme 2-2 or 2-3

[0134] The first and second parts of the structure are located on opposite sides of each other, sandwiching the folded scan lines of the movable reflective part.

[0135] (Options 2-5)

[0136] The sensor device according to any one of schemes 2-1 to 2-4

[0137] The structure intersects at least a portion of the folded-back scan line of the movable reflective part.

[0138] This application claims priority based on Japanese Patent Application No. 2020-058896, filed on March 27, 2020, the entire contents of which are hereby incorporated.

[0139] Explanation of reference numerals in the attached figures

[0140] 10 Sensor Devices

[0141] 110 Ejection section

[0142] 120 Movable Reflector

[0143] 130 Receiving Department

[0144] 140 beam splitter

[0145] 150 Control Department

[0146] 200 Constructs

[0147] 200A Construct

[0148] F field of view

[0149] L scan line

[0150] S1 First Light Spot

[0151] S2 Second Light Spot

[0152] T1 First Period

[0153] T2 Second Cycle

[0154] T3 Third Cycle

[0155] X First Direction

[0156] Y Second Direction

Claims

1. A sensor device, wherein, Possessing: a movable reflection section that reflects pulsed electromagnetic waves into a prescribed scanning range; a reception section that receives the electromagnetic waves reflected or scattered by a structure located at an end portion of at least one of the first direction within the scanning range; and a control section that controls the amplitude of the vibration of the movable reflection section based on the reception results of the electromagnetic waves reflected or scattered by the structure by the reception section, the movable reflection section reflects the electromagnetic waves toward the structure before and after the turnaround of the scanning line of the electromagnetic waves within the scanning range.

2. The sensor device according to claim 1, wherein the movable reflection section reflects the electromagnetic waves emitted from an emission section into the scanning range, the control section further controls the interval of the emission timing of the electromagnetic waves from the emission section.

3. The sensor device according to claim 1, wherein the control section controls the amplitude of the vibration of the movable reflection section based on the comparison result between the relationship between a first reception value received by the reception section of the electromagnetic waves reflected or scattered by a first portion of the structure and a second reception value received by the reception section of the electromagnetic waves reflected or scattered by a second portion of the structure and the relationship between a first reference reception value and a second reference reception value, the first reference reception value being a reference reception value received by the reception section of the electromagnetic waves reflected or scattered by the first portion of the structure in the case where the movable reflection section is operated in a reference state, the second reference reception value being a reference reception value received by the reception section of the electromagnetic waves reflected or scattered by the second portion of the structure in the case where the movable reflection section is operated in the reference state.

4. The sensor device according to claim 3, wherein the control section controls the amplitude of the vibration of the movable reflection section based on whether both the first reception value and the second reception value are greater than or less than the first reference reception value or the second reference reception value.

5. The sensor device according to claim 3, wherein the structure is provided in such a manner that the first reference reception value and the second reference reception value are different, the control section controls the amplitude of the vibration of the movable reflection section based on the comparison result between at least one of the ratio and the difference of the first reception value and the second reception value and at least one of the ratio and the difference of the first reference reception value and the second reference reception value.

6. The sensor device according to claim 3, wherein the first portion and the second portion of the structure are located on opposite sides of the turnaround of the scanning line of the movable reflection section.

7. The sensor device according to any one of claims 1 to 6, wherein the structure intersects at least a portion of the turnaround of the scanning line of the movable reflection section.

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