LiDAR device and its control method

Abstract

The present invention relates to a lidar device and a control method thereof. The present invention provides a lidar device, which includes: a light source for emitting pulsed light; a light detection unit for detecting the reflected light of the pulsed light reflected by an object; a mirror provided with a plurality of reflecting surfaces, reflecting the pulsed light to transmit it to the object, and reflecting the reflected light to transmit it to the light detection unit; a motor for rotating the mirror; an encoder for outputting a detection signal by detecting the rotation position of the mirror; and a control unit for controlling the emission timing of the light source and the detection time of the light detection unit by using the detection signal.

Description

Technical Field

[0001] The present invention relates to a lidar device and a control method thereof. Background Art

[0002] In recent years, in the fields of autonomous vehicles and intelligent vehicles, there is a need for an active response function for vehicles to cope with emergencies. That is, it is necessary to confirm in advance the following situations that threaten the safety of drivers and pedestrians, to identify suddenly appearing pedestrians, or to detect obstacles beyond the nighttime lighting range in advance, or to detect obstacles caused by weakened headlamps in rainy weather, or to detect road damage in advance, etc.

[0003] According to such requirements, a vehicle-mounted lidar (Light Detection And Ranging; LiDAR) device has been developed. The lidar device is provided on the windshield of the vehicle or in front of the vehicle, and obtains an image in front of the vehicle based on the self-emitted light. When the vehicle is moving, the lidar device warns the driver in advance by confirming the objects in front. The lidar device can transmit an image that serves as the basis for the vehicle to stop itself or avoid obstacles to the electronic control unit (Electronic Control Unit; ECU) of the vehicle. The electronic control unit can perform various controls using the image received from the lidar device.

[0004] The lidar device detects an object by calculating the time difference between the pulsed light emitted by the light source and the reflected light reflected back by the object to calculate the distance from the lidar device to the object.

[0005] The lidar device is classified into a mechanical (rotary) lidar device having a mirror and a flash type lidar device without a mirror according to whether it has a mirror. Among them, the mechanical lidar device requires a motor to rotate the mirror, and in order to keep the horizontal resolution of the lidar device at a specified level, the motor needs to rotate at a constant speed.

[0006] Generally, in the mechanical lidar device, the control unit receives the feedback of the rotation speed of the motor and adjusts the motor control signal according to the rotation speed of the motor to ensure the constant speed rotation of the motor.

[0007] However, the above-described method has a problem that it cannot meet the specifications of a lidar device that requires a jitter performance of less than 0.5%. Summary of the Invention

[0008] Technical Problem

[0009] An object of the present invention is to provide a lidar device and a control method thereof, which can not only improve the horizontal resolution of the lidar device, but also use a motor with a lower specification in the lidar device, thereby reducing the manufacturing cost of the lidar device.

[0010] In addition, an object of the present invention is to provide a lidar device and a control method thereof, which can block the detection of unnecessary noise signals when detecting an object and reduce the data capacity for processing detection signals.

[0011] The technical problems to be achieved by the present invention are not limited to the above-mentioned technical problems, and those of ordinary skill in the technical field to which the present invention pertains can clearly understand other technical problems not mentioned from the following description.

[0012] Solution to the problem

[0013] To achieve the foregoing object, the present invention provides a lidar device, which includes: a light source for emitting pulsed light; a light detection unit for detecting reflected light that is reflected back by an object from the pulsed light; a reflecting mirror provided with a plurality of reflecting surfaces, which reflects the pulsed light to transmit it to the object and reflects the reflected light to transmit it to the light detection unit; a motor for rotating the reflecting mirror; an encoder for outputting a detection signal by detecting the rotation position of the reflecting mirror; and a control unit for controlling the emission timing of the light source and the detection time of the light detection unit by using the detection signal.

[0014] Among them, the control unit controls in such a way that pulsed light is emitted from the light source when a detection signal is input from the encoder.

[0015] In addition, the control unit controls in such a way that pulsed light is emitted from the light source at each predetermined rotation position of the reflecting mirror.

[0016] In addition, the control unit controls in such a way that the light detection unit detects the reflected light in at least a part of the output interval of the detection signal.

[0017] In addition, the reflecting mirror is composed of a polyhedron disposed on the side surfaces of a plurality of reflecting surfaces.

[0018] In addition, the reflecting mirror and the above-mentioned encoder are coupled to the motor shaft of the motor and rotate together with the motor shaft.

[0019] In addition, the encoder is a magnet encoder including a multi-pole magnet and a hole sensor, or an optical encoder including a slit member formed with a plurality of slits and a photodiode.

[0020] Moreover, the present invention provides a control method for a lidar device, which includes the following steps: a light source emits pulsed light; a mirror reflects the pulsed light to transmit it to an object; the pulsed light is reflected by the object; the mirror reflects the reflected light reflected by the object to transmit it to a light detection unit; the light detection unit detects the reflected light; a motor rotates the mirror; an encoder outputs a detection signal by detecting the rotation position of the mirror; and a control unit controls the emission timing of the light source and the detection time of the light detection unit by using the detection signal.

[0021] Effects of the Invention

[0022] According to the present invention, even if the motor does not rotate at a constant speed, the encoder detects a specific rotation position of the mirror, and the control unit controls the light source to emit pulsed light from the detected specific rotation position, so that not only the horizontal resolution of the lidar device can be improved, but also a motor with a lower specification can be used in the lidar device, thereby reducing the manufacturing cost of the lidar device.

[0023] Moreover, according to the present invention, the light detection unit detects the reflected light only within a specific detection time when the possibility of receiving the reflected light is high, so that noise signals unnecessary for detecting the object can be blocked from being detected, thereby reducing the data volume for processing the detection signal.

[0024] The effects of the present invention are not limited to the above-mentioned effects, and those of ordinary skill in the art can clearly understand other effects not mentioned through the following description. Description of the Drawings

[0025] Figure 1 It is a schematic block diagram of a lidar device according to an embodiment of the present invention.

[0026] Figure 2 It is an exploded perspective view of a mirror, a motor, and an encoder of a lidar device according to an embodiment of the present invention.

[0027] Figure 3 It is a cross-sectional view of a motor of a lidar device according to a first embodiment of the present invention.

[0028] Figure 4 It is a cross-sectional view of a motor of a lidar device according to a second embodiment of the present invention.

[0029] Figure 5 It is a cross-sectional view of a motor of a lidar device according to a third embodiment of the present invention.

[0030] Figure 6 It is a cross-sectional view of a motor of a lidar device according to a fourth embodiment of the present invention.

[0031] Figure 7Graphs showing, respectively, the detection signal (a) output by the encoder according to a specific rotational position of the mirror, the emission signal (b) of the light source output by the control unit according to the detection signal, and the detection signal (c) of the light detection unit detecting reflected light within a specific interval in the output interval of the detection signal, in the lidar device according to an embodiment of the present invention.

[0032] Figure 8 Flowchart of the control method of the lidar device according to an embodiment of the present invention.

[0033] Description of reference numerals

[0034] 110: Light source

[0035] 120: Light detection unit

[0036] 130: Mirror

[0037] 140: Motor

[0038] 150: Encoder

[0039] 160: Control unit Detailed description of the specific embodiment

[0040] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings, so that those of ordinary skill in the technical field to which the present invention pertains can easily implement the embodiments of the present invention. The present invention can be implemented in various different embodiments and is not limited to the embodiments described herein. In the drawings, parts irrelevant to the description are omitted for clarity of the present invention, and the same or similar reference numerals are given to the same or similar structural elements throughout the specification.

[0041] In this specification, terms such as "comprising" or "having" are used to specify the presence of features, numbers, steps, actions, structural elements, components, or combinations thereof described in the specification, and do not preclude the presence or additional possibility of one or more other features, numbers, steps, actions, structural elements, components, or combinations thereof in advance.

[0042] Figure 1 Brief block diagram of the lidar device according to an embodiment of the present invention Figure 2 Exploded perspective view of the mirror, motor, and encoder of the lidar device according to an embodiment of the present invention.

[0043] As Figure 1 shown, the lidar device according to an embodiment of the present invention may include a light source 110, a light detection unit 120, a mirror 130, a motor 140, an encoder 150, and a control unit 160.

[0044] The light source 110 emits pulsed light toward the reflector 130 to detect the object, and the light detection unit 120 detects the reflected light of the pulsed light reflected by the object.

[0045] The lidar device according to an embodiment of the present invention detects an object by calculating the distance from the lidar device to the object by detecting the time difference between the pulsed light and the reflected light.

[0046] The light source 110 may be a single-channel light source that emits pulsed light of a single channel or a multi-channel light source that emits a plurality of pulsed lights of different channels.

[0047] The reflector 130 is provided with a plurality of reflecting surfaces, reflects the pulsed light emitted from the light source 110 and transmits it to the object, and reflects the reflected light reflected by the object and transmits it to the light detection unit 120. Among them, the reflector 130 may be composed of a polyhedron in which a plurality of reflecting surfaces are arranged on the side surface. For example, as Figure 2 shown, the reflector is composed of a hexahedron to provide reflecting surfaces on four side surfaces respectively.

[0048] The reflector 130 can also be rotated 360 degrees by the rotational force of the motor 140.

[0049] The light source 110 is configured to face the reflecting surface provided on the reflector 130 and emit pulsed light to the reflecting surface. Among them, the light source 110 can be arranged on a printed circuit board.

[0050] Although not shown, in order to improve the directivity of the pulsed light emitted from the light source 110, the lidar device according to an embodiment of the present invention may further include a collimating lens located between the light source 110 and the reflector 130.

[0051] Among them, the collimating lens prevents the pulsed light emitted from the light source 110 from being scattered or dispersed during the process of reaching the reflecting surface of the reflector 130.

[0052] The light source 110 can be arranged at a predetermined interval from the reflector 130 so as not to be affected by the vibration generated by the rotation of the reflector 130.

[0053] The light detection unit 120 is configured to face the reflecting surface of the reflector 130 to receive the reflected light reflected on the reflecting surface.

[0054] The motor 140 rotates the reflector 130 360 degrees, and the encoder 150 detects the rotation position of the reflector 130, that is, the rotation angle, and thus outputs a detection signal.

[0055] Among them, the encoder 150 may be formed in the shape of a circular plate having a rotation center. And, as Figure 1As shown, the encoder 150 may be a magnetic encoder including a multi-pole magnet 151 and a hole sensor 152, or an optical encoder including a slit member with a plurality of slits arranged radially and a photodiode, but is not limited thereto. Any encoder capable of detecting the rotational position of the mirror 130 is acceptable.

[0056] The magnetic encoder can detect the rotation angle of the mirror 130 by detecting the direction of the multi-pole magnet 151 that rotates the hole sensor 152. Among them, the multi-pole magnet 151 is composed of 4 poles or more and can be arranged radially. Also, the optical encoder can detect the rotation angle of the mirror 130 by detecting the light passing through the slit by the photodiode.

[0057] The mirror 130 and the encoder 150 are coupled to the motor shaft of the motor 140 and rotate together with the motor shaft 141.

[0058] Refer to Figure 2 , the encoder 150 is coupled to the base plate 143, and the motor 140 is coupled to the encoder 150. Also, the mirror 130 is formed with a receiving space capable of receiving the motor 140 and the encoder 150, and the lower part is opened in such a way that the motor 140 and the encoder 150 can be inserted into the receiving space.

[0059] Among them, when the motor 140 and the encoder 150 are received in the receiving space of the mirror 130, the mirror 130 and the motor 140 are combined through the flange 142 on the upper part of the motor.

[0060] The control unit 160 receives a detection signal from the encoder 150 and uses the received detection signal to control the emission timing of the light source 110 and the detection time of the light detection unit 120.

[0061] Specifically, the control unit 160 controls to emit pulsed light from the light source 110 when a detection signal is input from the encoder 150. Also, the control unit 160 controls to emit pulsed light from the light source 110 at a specified rotational position of each mirror 130.

[0062] The control unit 160 controls such that the light detection unit 120 detects the reflected light in at least a part of the output interval of the detection signal.

[0063] Figure 3 is a cross-sectional view of the motor of the lidar device according to the first embodiment of the present invention, Figure 4 is a cross-sectional view of the motor of the lidar device according to the second embodiment of the present invention.

[0064] The motors of the lidar devices according to the first and second embodiments of the present invention can be implemented by an inner rotor motor.

[0065] Refer to Figure 3and Figure 4 The mirror 130 can be manufactured by a mechanism other than welding or by mirror processing of glass (e.g., a Diamond Turning Machine (DTM)).

[0066] The motor housing 144 is provided with a magnet 146, a coil 147, and a motor shaft 141 inside. The motor shaft 141 is exposed outside by passing through the upper part of the motor housing 144.

[0067] Among them, the magnet 146 is coupled to the motor shaft 141, and the coil 147 can be coupled to the inner side surface of the motor housing 144. And a bearing 145 can be provided between the upper part of the motor housing 144 and the motor shaft 141 in such a way as to rotate the motor shaft 141.

[0068] The motor shaft 141 is coupled to the mirror 130 through a flange 142. When the motor shaft 141 rotates, the mirror 130 can also rotate together. At this time, if an electric current is supplied to the coil 147, the motor shaft 141 coupled to the magnet 146 can be rotated.

[0069] The bottom plate 143 can be coupled to the lower surface of the motor housing 144.

[0070] As Figure 3 shown, the multi-pole magnet 151 is coupled to the lower part of the mirror 130, or, as Figure 4 shown, it can be inserted into the inner side of the lower part of the mirror 130.

[0071] In particular, as Figure 4 shown, an insertion groove is formed in the inner side of the lower part of the mirror 130, and the height of the lidar device can be reduced by inserting the multi-pole magnet 151 into the insertion groove. At this time, in order to form the insertion groove, the thickness of the mirror 130 can be made thicker than that of the mirror 130 of Figure 3 .

[0072] The hole sensor 152 can be disposed below the multi-pole magnet 151 to detect the rotation angle of the mirror 130.

[0073] Figure 5 is a cross-sectional view of the motor of the lidar device according to the third embodiment of the present invention, Figure 6 is a cross-sectional view of the motor of the lidar device according to the fourth embodiment of the present invention.

[0074] The motors of the lidar devices according to the third and fourth embodiments of the present invention can be implemented by an outer rotor motor.

[0075] Referring to Figure 5 and Figure 6 , the mirror 130 can be manufactured by a mechanism other than welding or by glass mirror processing (e.g., a diamond turning machine).

[0076] The mirror 130 can function as a motor housing. That is, the mirror 130 has a magnet 146, a coil 147, and a motor shaft 141 disposed therein, and the motor shaft 141 can be exposed outside through the upper part of the mirror 130.

[0077] The coil 147 is coupled to the motor shaft 141, and the magnet 146 can be coupled to the inner side surface of the mirror 130. In addition, a bearing 145 can be provided between the upper part of the mirror 130 and the motor shaft 141 to rotate the mirror 130.

[0078] At this time, when current is supplied to the coil 147, the mirror 130 coupled to the magnet 146 can be rotated.

[0079] The bottom plate 143 can be coupled to the lower surface of the mirror 130.

[0080] As Figure 5 shown, the multi-pole magnet 151 can be coupled to the lower part of the mirror 130, or, as Figure 6 shown, can be inserted into the inner side of the lower part of the mirror 130.

[0081] In particular, as Figure 6 shown, an insertion groove is formed in the inner side of the lower part of the mirror 130, and the multi-pole magnet 151 is inserted into the insertion groove, thereby reducing the height of the lidar device. At this time, in order to form the insertion groove, the thickness of the mirror 130 can be made thicker than that of the Figure 3 mirror 130.

[0082] The hole sensor 152 can detect the rotation angle of the mirror 130 by being disposed below the multi-pole magnet 151.

[0083] Figure 7 Graphs are shown respectively for the detection signal (a) output by the encoder according to a specific rotation position of the mirror, the emission signal (b) of the light source output by the control unit according to the detection signal, and the detection signal (c) of the reflected light detected by the light detection unit within a specific interval in the output interval of the detection signal in the lidar device according to an embodiment of the present invention.

[0084] In Figure 7 , the horizontal axis represents time, and the vertical axis represents the magnitude of the signal (voltage).

[0085] First, referring to Figure 7 of (a), when the mirror 130 rotates, the encoder 150 detects a specific rotation position of the mirror 130 at regular intervals or irregular intervals. At this time, when the mirror 130 is rotated by using a motor 140 with a lower specification, the mirror 130 does not rotate at a constant speed, and thus the intervals of the specific rotation positions may be irregular.

[0086] Further, whenever the mirror 130 detects a specific rotational position, the encoder 150 outputs a detection signal at a high level. At this time, each detection signal at a high level can last for a specified time.

[0087] After that, referring to Figure 7 (a) and (b) of, the control unit 160 receives the detection signal from the encoder 150 and controls the light source 110 to emit pulsed light whenever a detection signal at a high level is input or at a specified input interval of each detection signal at a high level. For example, as shown in the figure, the control unit 160 controls the light source to emit pulsed light whenever a detection signal at a high level with an odd number (indicated by an arrow) is input.

[0088] Also, when a detection signal at a high level is input from the encoder 150, the control unit 160 outputs a transmission signal at a high level to the light source 110. Thereby, the light source 110 emits pulsed light according to the transmission signal received from the control unit 160. In the aforementioned example, when a detection signal at a high level with an odd number is input, the control unit 160 can output a transmission signal at a high level to the light source 110. At this time, due to the delay in the signal path, the rising time of the detection signal may be different from the rising time of the transmission signal. That is, the rising time of the transmission signal may be more delayed compared to the detection signal. This signal delay value corresponds to a very short time in the unit of several μs, and the signal delay problem can be solved by reflecting it in advance in the output timing of the transmission signal.

[0089] As described above, in the lidar device according to the embodiment of the present invention, even if the motor 140 does not rotate at a constant speed, the encoder 150 can detect a specific rotational position of the mirror 130, and the control unit 160 controls the light source 110 to emit pulsed light from the detected specific rotational position. Thereby, not only can the horizontal resolution of the lidar device be improved, but also a motor with a lower specification can be used in the lidar device, thus reducing the manufacturing cost of the lidar device.

[0090] After that, referring to Figure 7 (a) and (c) of, the control unit 160 controls the light detection unit 120 to detect the reflected light reflected by the object at a specific detection time, that is, at least a part of the output interval of the detection signal at a high level output by the encoder 150. At this time, the output interval of the detection signal at a high level is an interval in which the light detection unit 120 has a higher possibility of receiving the reflected light reflected by the object, and the detection possibility of the first half of the output interval is higher than that of the second half.

[0091] Also, the light detection unit 120 receives the reflected light simultaneously or sequentially within a specific detection time to output a detection signal of high level. Among them, the light detection unit 120 only detects the reflected light within the specific detection time and does not work at other times. For example, as shown in the figure, the light detection unit 120 can be controlled in such a way that it detects the reflected light in the interval (shaded area) from the rising time to the 1 / 2 position of the output interval in the detection signal of high level output by the encoder 150. At this time, the light detection unit 120 can detect one or more reflected lights with different detection times according to the distance from the object body.

[0092] As described above, in the lidar device according to the embodiment of the present invention, the reflected light is detected only within a specific detection time when the possibility of the light detection unit 120 receiving the reflected light is high. Thus, the noise signals that are not required when detecting the object can be blocked from being detected, and the data capacity for processing the detection signal can be reduced.

[0093] Figure 8 It is a flowchart of the control method of the lidar device according to the embodiment of the present invention.

[0094] Hereinafter, refer to Figures 1 to 8 The control method of the lidar device according to the embodiment of the present invention will be described.

[0095] First, in order to detect the object, the light source 110 emits pulsed light toward the reflecting mirror 130 (step S10). At this time, the light source 110 is configured to emit the pulsed light toward the reflecting surface provided on the reflecting mirror 130 and emit the pulsed light to the reflecting surface.

[0096] After that, the reflecting mirror 130 reflects the pulsed light to transmit it to the object (step S20). Thus, the pulsed light is reflected by the object (step S30).

[0097] Next, the reflecting mirror 130 reflects the reflected light reflected by the object to transmit it to the light detection unit 120 (step S40). Thus, the light detection unit 120 detects the reflected light (S50).

[0098] The lidar device according to the embodiment of the present invention calculates the distance from the lidar device to the object by detecting the time difference between the pulsed light and the reflected light, thereby detecting the object.

[0099] After that, the motor 140 rotates the reflecting mirror 130 by 360 degrees (step S60). Thus, the encoder 150 outputs a detection signal by detecting the rotation position of the reflecting mirror 130 (step S70).

[0100] Next, the control unit 160 receives the detection signal from the encoder 150 and uses this detection signal to control the emission timing of the light source 110 and the detection time of the light detection unit 120 (step S80).

[0101] At this time, the control unit 160 controls in such a manner that pulsed light is emitted from the light source 110 when a detection signal is input from the encoder 150. Further, the control unit 160 controls in such a manner that pulsed light is emitted from the light source 110 at each specified rotational position of the mirror 130.

[0102] The control unit 160 controls in such a manner that the light detection unit 120 detects reflected light in at least a part of the output interval of the detection signal.

[0103] As described above, in the control method of the lidar device according to an embodiment of the present invention, even if the motor 140 does not rotate at a constant speed, the encoder 150 detects a specific rotational position of the mirror 130, and the control unit 160 controls the light source 110 to emit pulsed light at the detected specific rotational position. Thereby, not only can the horizontal resolution of the lidar device be improved, but also a lower-specification motor can be used in the lidar device, so that the manufacturing cost of the lidar device can be reduced.

[0104] Further, in the control method of the lidar device according to an embodiment of the present invention, the reflected light is detected only during a specific detection time when the possibility of the light detection unit 120 receiving the reflected light is high. Thereby, noise signals unnecessary when detecting an object to be detected can be blocked from being detected, and the data volume for processing the detection signal can be reduced.

[0105] As described above, one embodiment of the present invention has been described. However, the idea of the present invention is not limited to the embodiments disclosed in this specification. Those of ordinary skill in the art who understand the idea of the present invention can easily propose other embodiments by adding, changing, deleting, adding, etc. of structural elements within the same scope of the idea, and this also falls within the scope of the idea of the present invention.

Claims

1. A lidar device, characterized in that, Comprising: A light source for emitting pulsed light; A light detection unit for detecting the reflected light of the pulsed light reflected back by the object; A reflecting mirror provided with a plurality of reflecting surfaces, reflecting the pulsed light to transmit it to the object, and reflecting the reflected light to transmit it to the light detection unit; A motor disposed within the reflecting mirror, including a motor housing, a motor shaft received within the motor housing and coupled to the reflecting mirror, a magnet coupled to the motor shaft, and a coil coupled to the inner side surface of the motor housing; An encoder that outputs a detection signal by detecting the rotational position of the reflecting mirror; And A control unit that controls the emission timing of the light source and the detection time of the light detection unit by using the detection signal, Even when the reflecting mirror does not rotate at a constant speed, the control unit controls in such a manner that the pulsed light is emitted from the light source at a prescribed input interval of the detection signal every time the detection signal is input from the encoder.

2. The lidar device according to claim 1, wherein, The control unit controls in such a manner that the pulsed light is emitted from the light source at each prescribed rotational position of the reflecting mirror.

3. The lidar device according to claim 1, wherein The control unit controls in such a manner that the light detection unit detects the reflected light within at least a part of the output interval of the detection signal.

4. The lidar device according to claim 1, wherein, The reflecting mirror is constituted by a polyhedron disposed on the side surfaces of the plurality of reflecting surfaces.

5. The lidar device according to claim 1, wherein The encoder includes: A multi-pole magnet coupled to the lower portion of the reflecting mirror to rotate together with the reflecting mirror; and A hole sensor that detects the rotational angle of the reflecting mirror by detecting the direction of the multi-pole magnet.

6. The lidar device according to claim 5, wherein, The motor is inserted into the inner side surface of the lower portion of the reflecting mirror.

7. The lidar device according to claim 1, characterized in that, The reflecting mirror rotates by the rotation of the motor shaft.

8. The lidar device according to claim 1, characterized in that, It further includes a flange that couples the motor shaft to the inner upper surface of the reflecting mirror.

9. A lidar device, characterized in that, Comprising: A light source for emitting pulsed light; A light detection unit for detecting the reflected light of the pulsed light reflected back by the object; A reflecting mirror provided with a plurality of reflecting surfaces, reflecting the pulsed light to transmit it to the object, and reflecting the reflected light to transmit it to the light detection unit; A motor disposed within the reflecting mirror, including a motor shaft coupled to the reflecting mirror, a coil coupled to the motor shaft, and a magnet coupled to the inner side surface of the reflecting mirror; An encoder that outputs a detection signal by detecting the rotational position of the reflecting mirror; And A control unit that controls the emission timing of the light source and the detection time of the light detection unit by using the detection signal, Even when the reflecting mirror does not rotate at a constant speed, the control unit controls in such a manner that the pulsed light is emitted from the light source at a prescribed input interval of the detection signal every time the detection signal is input from the encoder.

10. The lidar device according to claim 9, wherein, The control unit controls in such a manner that the pulsed light is emitted from the light source at each prescribed rotational position of the reflecting mirror.

11. The lidar device according to claim 9, wherein, The control unit controls in such a manner that the light detection unit detects the reflected light within at least a part of the output interval of the detection signal.

12. The lidar device according to claim 9, characterized in that, The reflecting mirror is constituted by a polyhedron disposed on the side surfaces of the plurality of reflecting surfaces.

13. The lidar device according to claim 9, characterized in that, The encoder includes: A multi-pole magnet, which is combined with the lower part of the above-mentioned mirror to rotate together with the above-mentioned mirror; and A hole sensor, which detects the rotation angle of the above-mentioned mirror by detecting the direction of the above-mentioned multi-pole magnet.

14. The lidar device according to claim 13, wherein The above-mentioned multi-pole magnet is inserted into the inner side surface of the lower part of the above-mentioned mirror.

15. The lidar device according to claim 9, wherein The above-mentioned mirror rotates by the rotation of the above-mentioned magnet.

16. The lidar device according to claim 9, wherein, The above-mentioned motor shaft is inserted through the upper inner surface of the above-mentioned mirror.

17. The lidar device according to claim 16, wherein It further includes a bearing, which is arranged between the above-mentioned motor shaft and the above-mentioned mirror.

Images