Object detection device and control method thereof

Abstract

The present invention relates to an object detection device and a control method for the object detection device. The object detection device (10) includes: a light emitting unit (30); a light receiving unit (20); a period determination unit (100) that determines an ambient light acquisition period for acquiring ambient light according to the intensity of the ambient light; a light reception control unit (21) that controls the light reception operation of incident light in the light receiving unit (20); and a light emission control unit (31) that controls the light emission operation of the light emitting unit (30). The light reception control unit (21) causes the light receiving unit (20) to perform a light reception operation for acquiring ambient light during the determined ambient light acquisition period.

Description

[0001] Cross - reference to related applications

[0002] This application claims the priority of a Japanese patent application with application number 2019 - 224974 filed on December 13, 2019, the entire disclosure of which is incorporated herein by reference. Technical field

[0003] The present disclosure relates to a technique for detecting an object used in a vehicle. Background art

[0004] In a distance measuring device or an object detection device that uses a laser to measure the distance to an object, that is, a lidar (Light Detection and Ranging), a technique for improving the distance measurement accuracy by considering interference light, that is, ambient light, is known (for example, Japanese Unexamined Patent Application Publication No. 2019 - 144186).

[0005] However, in the prior art, the dynamic range of the ambient light image or the background light image obtained by the lidar under ambient light is not considered.

[0006] Therefore, there is a demand for improving the dynamic range of the ambient light image obtained by a lidar - type object detection device. Summary of the invention

[0007] The present disclosure can be implemented in the following manner.

[0008] A first aspect provides an object detection device. The object detection device according to the first aspect includes: a light emitting unit that irradiates a laser; a light receiving unit; a period determination unit that determines an ambient light acquisition period for acquiring ambient light according to the intensity of the ambient light; a light reception control unit that controls the light reception operation of incident light in the light receiving unit and causes the light receiving unit to perform a light reception operation for acquiring ambient light during the determined ambient light acquisition period; and a light emission control unit that controls the light emission operation of the light emitting unit.

[0009] According to the object detection device according to the first aspect, the dynamic range of the ambient light image can be improved.

[0010] A second mode provides an object detection device. The object detection device according to the second mode includes: a light emitting unit that irradiates laser light; a light receiving unit; a period determination unit that determines a light emission period for object detection of the light emitting unit based on characteristics of detected reflected light, where the detected reflected light is incident light that is incident on the light receiving unit according to the light emission for object detection of the light emitting unit; a light reception control unit that controls the light reception operation of the incident light in the light receiving unit and causes the light receiving unit to perform a light reception operation for acquiring ambient light during an ambient light acquisition period, where the ambient light acquisition period is determined by the determined light emission period and an object detection period; and a light emission control unit that controls the light emission operation of the light emitting unit and causes the light emitting unit to perform a light emission operation for object detection during the determined light emission period. When the signal-to-noise ratio (SN ratio), which is a characteristic of the detected reflected light, is lower than a predetermined reference value, the period determination unit increases the light emission period and decreases the ambient light acquisition period.

[0011] According to the object detection device according to the second mode, the dynamic range of the ambient light image can be increased.

[0012] A third mode provides a control method for an object detection device. For the control method of the object detection device according to the third mode, an ambient light acquisition period for acquiring ambient light is determined based on the intensity of the ambient light. During the determined ambient light acquisition period, the light receiving unit performs a light reception operation for acquiring ambient light. After the ambient light acquisition period has elapsed, a light emission operation for object detection based on the light emitting unit is performed, where the light emitting unit irradiates laser light.

[0013] According to the control method of the object detection device according to the third mode, the dynamic range of the ambient light image can be increased.

[0014] A fourth mode provides a control method for an object detection device. For the control method of the object detection device according to the fourth mode, a light emission period for object detection of the light emitting unit is determined based on characteristics of detected reflected light, where the detected reflected light is incident light that is incident on the light receiving unit according to the light emission for object detection of the light emitting unit that irradiates laser light. During an ambient light acquisition period, the light receiving unit performs a light reception operation for acquiring ambient light, where the ambient light acquisition period is determined by the determined light emission period and an object detection period. During the determined light emission period, the light emitting unit performs a light emission operation for object detection. When the signal-to-noise ratio (SN ratio), which is a characteristic of the detected reflected light, is higher than a predetermined reference value, the light emission period is decreased and the ambient light acquisition period is increased.

[0015] According to the control method of the object detection device according to the fourth mode, the dynamic range of the ambient light image can be improved. In addition, the present disclosure can also be implemented as a control program for the object detection device or a computer-readable recording medium recording the program. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The above object and other objects, features, and advantages of the present disclosure will become more apparent with reference to the accompanying drawings and the following detailed description. In the drawings:

[0017] Figure 1 is an explanatory diagram showing an example of a vehicle equipped with the object detection device according to the first embodiment,

[0018] Figure 2 is an explanatory diagram showing a schematic structure of a lidar used in the first embodiment,

[0019] Figure 3 is an explanatory diagram schematically showing a light receiving element array used in the first embodiment,

[0020] Figure 4 is a block diagram showing a functional configuration of the object detection device according to the first embodiment,

[0021] Figure 5 is a flowchart showing a processing flow of an object detection process executed by the object detection device according to the first embodiment,

[0022] Figure 6 is a timing chart showing an environment acquisition period and an object detection period occupied in one time slot when the luminous intensity of the ambient light is higher than a reference value,

[0023] Figure 7 is a timing chart showing an environment acquisition period and an object detection period occupied in one time slot when the luminous intensity of the ambient light is lower than a reference value,

[0024] Figure 8 is a flowchart showing a processing flow of an object detection process executed by the object detection device according to the second embodiment. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0025] Hereinafter, the object detection device and the control method of the object detection device according to the present disclosure will be described based on several embodiments.

[0026] First Embodiment:

[0027] As Figure 1As shown in the figure, the object detection device 10 in the vehicle related to the first embodiment is mounted on the vehicle 50 for use. The object detection device 10 includes a lidar (Light Detection and Ranging) 200 and a control device 100 that controls the operation of the lidar 200. In addition, the object detection device 10 is also referred to as a ranging device. By using the lidar 200, in addition to being able to detect the distance to the object, it can also detect the position and characteristics of the object. In addition, the vehicle 50 may also include an illuminance sensor 48 for detecting ambient light, a wheel speed sensor, a yaw rate sensor, and a driving assistance control device for performing driving assistance.

[0028] As Figure 2 shown, the object detection device 10 includes: a lidar 200 as a light measurement unit that emits detection light by emitting light and receives the incident detection reflected light or ambient light; and a control device 100 that controls the light emission operation and light reception operation of the lidar 200. The lidar 200 and the control device 100 may be physically housed in an integrated housing, or may be housed in different housings. The lidar 200 includes: a light receiving unit 20, a light emitting unit 30, a motor 40, a rotation angle sensor 41, and a scanning mirror 42. In the present embodiment, the incident light that enters the light receiving unit 20 due to the light emission for object detection by the light emitting unit 30 is referred to as detection reflected light. The lidar 200 has a predetermined scanning angle range SR in the horizontal direction HD, and realizes ranging by performing irradiation of the detection light based on the light emitting unit 30 and reception of the detection reflected light based on the light receiving unit 20 in units of a unit scanning angle SC obtained by dividing the scanning angle range SR into a plurality of angles, and acquiring detection reflection points throughout the scanning angle range SR. The unit scanning angle SC defines the resolution of the lidar 200 in the horizontal direction HD or the resolution of the ranging result obtained by the lidar 200. As the unit scanning angle becomes smaller, that is, as the number of detection reflection points increases, the resolution and the resolution improve. When scanning the scanning angle range SR in one forward direction, or when reciprocally scanning the scanning angle range SR in two directions, the acquisition of detection points in units of the unit scanning angle SC in the lidar 200, that is, the light emission and light reception processes, are performed. The scanning angle range SR can be divided into a plurality of columns in the vertical direction VD according to the structure of the light receiving elements in the light receiving unit 20 and the light reception process sequence. In Figure 2 the example, it is divided into five columns L1 to L5.

[0029] The light-receiving unit 20 includes a light-receiving control unit 21, a light-receiving element array 22, and a light-receiving lens (not shown), and performs a light-receiving process of outputting a detection signal indicating a detection point based on the reception of detection reflected light corresponding to the detection light irradiated from the light-emitting unit 30. In addition, it performs a light-receiving process of outputting ambient light image data or background light image data based on the reception of ambient light that does not enter corresponding to the reflection from the light-emitting unit 30. The ambient light includes surrounding light of the surrounding atmosphere brought by sunlight and illumination light that is not the detection light from the light-emitting unit 30, reflected light and scattered light from surrounding objects irradiated by sunlight and illumination light. The intensity of the ambient light is the basic light intensity when acquiring the detection reflected light, that is, the background light intensity, and the intensity of the ambient light affects the SN characteristics of the detection reflected light. As Figure 3 shown, the light-receiving element array 22 is a flat light sensor in which a plurality of light-receiving elements 220 are arranged in the vertical and horizontal directions. For example, SPAD (Single Photon Avalanche Diode) and other photodiodes constitute each light-receiving element. In addition, as the minimum unit of the light-receiving process, that is, the light-receiving unit corresponding to the detection point, the term light-receiving pixel is sometimes used. The light-receiving unit means either a light-receiving pixel 220 composed of a single light-receiving element or any one of the light-receiving pixels 221 composed of a plurality of light-receiving elements. In the light-receiving element array 22, as the number of light-receiving elements constituting the light-receiving pixel, that is, the light-receiving unit, decreases, the number of light-receiving units, that is, the number of detection points, increases. In the present embodiment, for example, a light-receiving pixel 222 composed of eight light-receiving elements 220 is used as the light-receiving unit to perform the light-receiving process. In the present embodiment, the light-receiving element array 22 includes, starting from the upper stage in the vertical direction, a first light-receiving pixel 221, a second light-receiving pixel 222, a third light-receiving pixel 223, a fourth light-receiving pixel 224, and a fifth light-receiving pixel 225 corresponding to five rows L1 to L5 of the scanning angle range SR.

[0030] The light receiving control unit 21 performs light receiving processing for outputting an incident light intensity signal corresponding to the incident light quantity or incident light intensity based on the detection light from the light emitting unit 30 in units of the unit scanning angle SC, that is, in column units corresponding to the unit scanning angle SC, using the light receiving pixels 221 to 225. Specifically, the light receiving control unit 21 uses all the light receiving pixels 221 to 225 for each unit scanning angle SC to extract the current generated by the light receiving elements constituting the light receiving pixels 221 to 225 according to the incident light quantity or the voltage converted from the current, and outputs it to the control device 100 as an incident light intensity signal. Alternatively, when light emission corresponding to each row in the scanning angle range SR is performed in the light emitting unit 30, the light receiving pixels 221 to 225 corresponding to the light emitting row are selected and output to the control device 100 as an incident light intensity signal. The incident light intensity signal can be output to the control device 100 for each unit scanning angle SC, or an incident light intensity signal corresponding to the scanning angle range SR can be output to the control device 100 when the scanning over the scanning angle range SR is completed. In addition, an incident light intensity signal corresponding to the total number of photons received by the light receiving elements constituting each of the light receiving pixels 221 to 225 can also be output to the control device 100. Generally, in a SPAD, the incident light quantity obtained by one light receiving element 220 is small, so the incident intensity signals from eight light receiving elements 220 such as the light receiving pixel 221 are added by an adder (not shown) to improve the S / N. The ranging function unit that performs ranging of detection points based on TOF (Time Of Flight) or the like can be integrally provided as a circuit of the light receiving control unit 21, or can be provided as a program executed in the control device 100 as described later.

[0031] In this embodiment, the light receiving control unit 21 switches between the ambient light acquisition mode and the reflected light detection acquisition mode according to the light receiving mode command signal output from the control device 100. More specifically, when the light receiving mode command signal is "0", the light receiving control unit 21 switches to the ambient light acquisition mode, starts the ambient light acquisition period T1, receives the ambient light acquisition command output from the control device 100, and acquires the ambient light. The light receiving control unit 21 continuously receives incident light during the ambient light acquisition period T1. If the light receiving mode command signal switches from "0" to "1", that is, if it switches from the ambient light acquisition mode to the reflected light detection acquisition mode and the ambient light acquisition period T1 ends, the light receiving control unit 21 outputs an incident light intensity signal representing the ambient light intensity Ei. During the light emission period T2, the light receiving control unit 21 repeatedly detects the reception of the reflected light and outputs the incident light intensity signal representing the detected reflected light intensity based on the light emission of the multiple detection lights by the light emitting unit 30, and accumulates the outputs of the incident light intensity signals multiple times. If the light receiving mode command signal switches from the reflected light detection acquisition mode to the ambient light acquisition mode, that is, if the light emission period T2 ends, the ranging operation for the unit scan angle SC, that is, related to the target column, is performed, and the operation result is output to the control device 100.

[0032] The light emitting unit 30 includes a light emission control unit 31, a light emitting element 32, and a collimating lens, and irradiates the detection light multiple times discretely in units of the unit scan angle SC. The light emitting element 32 is, for example, one or more infrared laser diodes, and emits infrared laser as the detection light. The light emitting unit 30 may have a single light emitting element in the vertical direction or may have multiple light emitting elements. In the case of having multiple light emitting elements, the light emission control unit 31 can switch the light emitting element for light emission according to the scanning timing. The light emission control unit 31 drives the light emitting element by a drive signal with a pulse drive waveform to perform the light emission of the infrared laser according to the light emission control signal indicating the light emission of the light emitting element input from the control device 100 for each unit scan angle. In this embodiment, as Figure 6 shown in FIGS. 6 and 7, a light emission command indicating the light emission of the detection light is sent from the control device 100 to the light emission control unit 31. The infrared laser irradiated from the light emitting unit 30 is reflected by the scanning mirror 42 and emitted toward the outside of the lidar 200, that is, the range where the object detection is desired.

[0033] The motor 40 is provided with a motor driver (not shown). A rotation angle sensor 41 for detecting the rotation angle of the motor 40 is disposed in the motor 40. The motor driver receives the input of the rotation angle signal from the rotation angle sensor 41 and the rotation angle indication signal output by the control device 100, and changes the voltage applied to the motor 40 to control the rotation angle of the motor 40. The motor 40 is, for example, an ultrasonic motor, a brushless motor, or a brushed motor, and includes a known mechanism for reciprocating driving within the scanning angle range SR. A scanning mirror 42 is mounted at the front end of the output shaft of the motor 40. The scanning mirror 42 is a reflector, i.e., a mirror body, that scans the detection light emitted from the light-emitting element 32 in the horizontal direction HD. Scanning within the scanning angle range SR in the horizontal direction HD is achieved by reciprocating driving of the motor 40. In addition, one reciprocation of the scanning mirror 42 is referred to as one frame, which is the detection unit of the lidar 200. Further, the light emission of the detection light from the light-emitting unit 30 is performed only corresponding to the forward displacement of the scanning mirror 42, and no light emission is performed when the scanning mirror 42 is displaced in the reverse direction. That is, object detection of the lidar 200 is performed only in one direction of the scanning angle range SR, specifically, only in the forward direction. The scanning mirror 42, for example, achieves the scanning of the detection light and the reception of the reflected light within a scanning angle range such as 120 degrees or 180 degrees. In addition to the horizontal direction HD, scanning in the vertical direction VD may also be achieved, that is, a change in the scanning position in the vertical direction VD may be achieved. To achieve scanning in the horizontal direction HD and the vertical direction VD, the scanning mirror 42 may be a multi-faceted mirror body, such as a multi-faceted mirror, or may include a single-sided mirror body having a mechanism capable of swinging in the vertical direction VD or another single-sided mirror body capable of swinging in the vertical direction VD. Further, the scanning mirror 42 may also perform rotational scanning by being rotationally driven by the motor 40. In this case, the light emission and light reception processes based on the light-emitting unit 30 and the light-receiving unit 20 may be performed corresponding to the scanning angle range SR. And, for example, when a scanning angle range SR of about 60 degrees is achieved, the scanning mirror 42 may not be provided, and a light-receiving element array having a lateral width corresponding to the scanning angle range SR may be provided, and object detection, i.e., ranging processing, may be performed by sequentially selecting rows and columns.

[0034] The detection light irradiated from the light emitting unit 30 is reflected by the scanning mirror 42 and scanned over the scanning angle range SR in the horizontal direction in units of the unit scanning angle SC. The detection reflected light reflected by the target is reflected by the scanning mirror 42 toward the light receiving unit 20 and enters the light receiving unit 20 for each unit scanning angle SC. The light receiving unit 20 performs light receiving processing for each column unit according to the light emission timing of the light emitting unit 30. By sequentially increasing the unit scanning angle SC for which the light receiving processing is performed, as a result, scanning for light receiving processing over the desired scanning angle range SR can be performed. The light emitting unit 30 and the light receiving unit 20 may be rotated together with the scanning mirror 42 by the motor 40, or may be independent of the scanning mirror 42 and not rotated by the motor 40. Further, a structure may be provided in which the scanning mirror 42 is not provided, but a plurality of light receiving pixels or a light receiving element array 22 arranged in a matrix corresponding to the scanning angle range SR is provided, and the laser is directly irradiated to the outside in sequence, and the light receiving pixels are sequentially switched to directly receive the reflected light.

[0035] As Figure 4 shown, the control device 100 includes a central processing unit (CPU) 101 as an arithmetic unit, a memory 102 as a storage unit, an input / output interface 103 as an input / output unit, and a clock generator (not shown). The CPU 101, the memory 102, the input / output interface 103, and the clock generator are connected via an internal bus 104 so as to be able to communicate bidirectionally. The memory 102 includes a memory such as a ROM that stores non-volatile and read-only the object detection processing program Pr1 for executing the object detection processing, and a memory such as a RAM that can be read and written by the CPU 101. The object detection processing program Pr1 includes a period determination process for determining an ambient light acquisition period T1 for detecting the ambient light intensity or a light emission period T2 for detecting an object. The non-volatile and read-only area of the memory 102 includes an ambient light reference storage area 102a that stores the reference ambient light intensity Eir that becomes a reference when determining the ambient light acquisition period, and a reference SN storage area 102b that stores the SN, that is, the reference SNr, that becomes a reference when determining the light emission period. However, the non-volatile and read-only area may be rewritten when the program is updated or the reference value is updated. The CPU 101, that is, the control device 100, functions as an object detection unit and a period determination unit by expanding the object detection processing program Pr1 stored in the memory 102 to a readable and writable memory and executing it. Further, the CPU 101 may be a single CPU, or may be a plurality of CPUs that execute each program, or may be a multi-task type or multi-thread type CPU that can execute a plurality of programs simultaneously. Further, in addition to being executed in the light reception control unit 21, the distance measurement processing to the object using the light emission timing and the light reception timing may also be executed by the control device 100 as one process of the object detection processing.

[0036] The light-receiving control unit 21 that constitutes the light-receiving unit 20, the light-emitting control unit 31 that constitutes the light-emitting unit 30, the motor 40, the rotation angle sensor 41, and the illuminance sensor 48 are respectively connected to the input / output interface 103 via control signal lines. A light-emitting control signal is sent to the light-emitting control unit 31, and a light-receiving control signal for instructing a light-receiving process for ambient light acquisition or a light-receiving process for object detection is sent to the light-receiving control unit 21. An incident light intensity signal indicating the ambient light intensity or the detected reflected light intensity is received from the light-receiving control unit 21. A rotation angle instruction signal is sent to the motor 40, and a rotation angle signal is received from the rotation angle sensor 41. An illuminance signal indicating the illuminance of the ambient light around the object detection device 10 is received from the illuminance sensor 48.

[0037] The object detection process including the acquisition of the ambient light intensity performed by the object detection device 10 according to the first embodiment will be described. For example, from the start to the stop of the vehicle control system, or from when the start switch is turned on to when the start switch is turned off, the process routine shown is repeatedly executed at regular time intervals, for example, every several 100 ms. Figure 5 The CPU 101 executes the processing flow shown by executing the object detection processing program Pr1. Figure 5 Hereinafter, the object detection period (unit) that performs the process of acquiring the ambient light intensity of the unit scan angle SC or column and the acquisition of the detected reflected light will be referred to as one time slot, and the period (unit) of reciprocating once from the start range to the end range of the scan angle range SR will be referred to as one frame.

[0038] The CPU 101 acquires the ambient light intensity Ei obtained at the previous timing before the current time or the ambient light intensity Ei obtained in the previous time slot via the input / output interface 103, or the ambient light intensity Ei currently obtained from the illuminance sensor 48 (step S100). As shown in and, one time slot in the object detection device 10, that is, the object detection period t2, is composed of the ambient light acquisition period T1 and the light-emitting period T2. In this embodiment, T1 + T2 = t2 μs (constant), T1 = t1 μs, and T2 = t2 - t1 μs. t1 is also referred to as the exposure time, for example, 10 to 13 μs, and t2 is, for example, 250 to 270 μs. Therefore, the time required for the process of one time slot is, for example, 250 to 270 μs. The cumulative ambient light quantity [lux·sec] or [mJ / cm is obtained by multiplying the ambient light intensity Ei by t1. Figure 6 And Figure 7 As shown, the cumulative ambient light quantity [lux·sec] or [mJ / cm is obtained by multiplying the ambient light intensity Ei by t1. 2, that is, the exposure amount. In addition, these values are only examples and are not limited to these values. For example, the ambient light acquisition period T1 for acquiring ambient light, that is, the light emission instruction interval t1 in t1 and the light emission period T2, can also be different values. Additionally, although in one time slot, the light emission period T2 starts after the ambient light is acquired, it can also be set to start the ambient light acquisition period T1 after the light emission period T2. The ambient light intensity Ei in the previous frame or the previous time slot can be, for example, the ambient light intensity Ei obtained during the ambient light acquisition period T1 in the immediately preceding frame or the immediately preceding time slot, or the maximum value or average value of the ambient light intensity Ei obtained during the ambient light acquisition period T1 in the immediately preceding several frames or the immediately preceding several time slots. The ambient light intensity Ei obtained from the illuminance sensor 48 is an illuminance value representing the brightness of the surrounding environment of the object detection device 10 at the current moment. In addition, when using the illuminance sensor 48 to acquire the ambient light intensity Ei, the ambient light acquisition period T1 can be simply set without using the past ambient light intensity data, that is, the ambient light intensity Ei in the previous frame and the previous time slot.

[0039] The CPU 101 determines whether the acquired ambient light intensity Ei is lower than the reference ambient light intensity Eir (step S102). The reference ambient light intensity Eir is the incident light intensity on the light receiving unit 20 when the dynamic range of the ambient light image or the background light image obtained by the light receiving element array 22 during the reference ambient light acquisition period T1, that is, the exposure time, becomes a value equal to or greater than the desired value. For example, it can be set to the incident light intensity that obtains a dynamic range of 50% of the theoretically maximum dynamic range (exposure time × number of light receiving pixels). The ambient light image is a pixel image formed corresponding to the pixels corresponding to the respective light receiving pixels 221 to 225 of the light receiving element array 22, and is a monochromatic image represented by the pixel values, that is, the brightness values, obtained by the respective light receiving pixels 221 to 225 of the light receiving element array 22 through the incidence of ambient light. As the desired dynamic range value, in addition to the above, for example, it can also be the dynamic range at which each subject and background included in the ambient light image can be clearly recognized, and is a dynamic range equal to or greater than the dynamic range in a captured image that cannot be called underexposed.

[0040] If the CPU 101 determines that the ambient light intensity Ei is lower than the reference ambient light intensity Eir, that is, Ei < Eir (step S102: Yes), it increases the ambient light acquisition period T1 (step S104). For example, as Figure 7As shown, the time when T1 increases from t1 to 10×t1 μs, that is, ten times the time, during the ambient light acquisition period is set as the ambient light acquisition period T1. As a result, the light emission period T2 decreases by 9×t1 μs. As a result, even in a darker environment, an ambient light image with a wider dynamic range can be acquired, and the discrimination accuracy of the objects included in the ambient light image can be improved. If the CPU 101 determines that the ambient light intensity Ei is above the reference ambient light intensity Eir, that is, Ei≥Eir (step S102: No), it reduces the ambient light acquisition period T1 (step S106). For example, when the ambient light acquisition period T1 is Figure 7 10×t1 μs as shown, the time after being reduced to 1 / 10 times, that is, t1 μs, is set as the ambient light acquisition period T1. At this time, an ambient light image with a sufficient dynamic range can be acquired even in a shorter period, and the objects included in the ambient light image can be discriminated with the desired discrimination accuracy. In addition, since the light emission period T2 increases by 9×t1 μs, the object detection performance can be improved. In addition, the increase and decrease of the ambient light acquisition period T1 are relative time increases and decreases with respect to the ambient light acquisition period T1 set before the determination in step S102, and the time does not necessarily have to be increased or decreased absolutely. In addition, the reduction of the ambient light acquisition period T1 may also mean setting a predetermined initial value. In this case, the setting of T1 = t1 can be executed regardless of the value of the ambient light acquisition period T1 set before the determination in step S102. In addition, in addition to the reference ambient light intensity Eir, a second reference ambient light intensity Eir2 whose value is larger than the reference ambient light intensity Eir can also be used. When the ambient light intensity Ei is stronger than the second reference ambient light intensity Eir2, the ambient light acquisition period T1 is set to a period shorter than t1.

[0041] If the ambient light acquisition period T1 is set, the CPU 101 executes object detection processing (step S108). As Figure 6 and Figure 7As shown, the object detection process includes an ambient light intensity acquisition process performed for a unit scan angle SC during ambient light acquisition period T1 and a detected reflected light acquisition process performed for a unit scan angle SC during light emission period T2. The CPU 101 outputs a light reception mode instruction signal "0" to the light reception control unit 21 and the light emission control unit 31 to switch the light reception mode to the ambient light acquisition mode. The CPU 101 outputs an ambient light acquisition instruction to the light reception control unit 21. The light reception control unit 21 receives the input of the light reception mode instruction signal "0" and the ambient light acquisition instruction, and starts acquiring ambient light. For example, during ambient light acquisition period T1, the intensity of the ambient light received by each light reception pixel 221 to 225 of the light reception element array 22, that is, the incident light intensity, is acquired to perform the acquisition of the ambient light intensity based on the light reception control unit 21. As a result, for a unit scan angle SC, a pixel image represented by each light reception pixel 221 to 225 is obtained. When acquiring or determining the ambient light intensity, the maximum value or average value of the incident light intensity received by each light reception pixel 221 to 225 of the light reception element array 22 can be used. For example, relative to Figure 6 Before increasing the ambient light acquisition period T1 as shown, Figure 7 After increasing the ambient light acquisition period T1 as shown, it takes ten times as long to perform the acquisition of the ambient light intensity. Since the exposure time increases, the cumulative ambient light amount (T1 × Ei) increases, and an ambient light image with a wider dynamic range can be obtained. As a result, the discrimination accuracy of the objects included in the ambient light image can be improved.

[0042] If the ambient light acquisition period T1 has elapsed, the CPU 101 outputs a light reception mode instruction signal "1" to the light reception control unit 21 and the light emission control unit 31 to switch the light reception mode to the detected reflected light acquisition mode. The light emission control unit 31 causes the light emitting element 32 to emit light repeatedly at intervals of t1 μs. The light reception control unit 21 receives the incidence of the first detected reflected light corresponding to the light emission and the input of the light reception mode instruction signal "1", and starts acquiring the detected reflected light. For example, during light emission period T2, the acquisition of the detected reflected light based on the light reception control unit 21 is performed by receiving the detected reflected light incident at a timing according to the irradiation of the detection light at intervals of t1 μs performed by the light emitting unit 30. For example, before increasing the ambient light acquisition period T1 as shown in Figure 6 nineteen irradiations of the detection light are performed, and in Figure 7After the increase in ambient light acquisition shown, the irradiation of the detection light is reduced to nine executions after T1. The light receiving control unit 21 also functions as a distance calculation unit, and executes distance calculation processing for calculating the distance of an object that exists in the unit scan angle SC and reflects the detection light to bring about the detection reflected light, using the light emission timing of the detection light based on the light emitting unit 30 and the light reception timing of the detection reflected light based on the light receiving element array 22. Alternatively, the same distance calculation processing may be executed by the CPU 101, and the CPU 101 also functions as a distance calculation unit.

[0043] When the CPU 101 finishes the object detection processing, it determines whether scanning for object detection has been completed for all columns constituting the scan angle range SR (step S110). If the CPU 101 determines that scanning for object detection has not been completed for all columns (step S110: No), it moves to step S100 and executes steps S100 to S108 using the ambient light intensity Ei acquired this time. If the CPU 101 determines that scanning for object detection has been completed for all columns (step S110: Yes), it ends this processing routine. By acquiring the ambient light intensity Ei for all columns constituting the scan angle range SR and executing the distance calculation processing for the object, an ambient light image corresponding to the scan angle range SR is formed, and a reflection point image indicating the distance of the object existing in the scan angle range SR is also formed. Since the distance to the object is calculated, the discrimination accuracy of the object can be improved.

[0044] According to the object detection device 10 according to the first embodiment described above, when the obtained ambient light intensity is low, the ambient light acquisition period T1 for acquiring the ambient light intensity is increased, so that the cumulative ambient light amount can be increased, and an ambient light image with a wider dynamic range can be obtained. In addition, compared with the prior art, even when the ambient light intensity Ei is low, that is, even in a darker environment, an ambient light image with a wider dynamic range can be acquired. Therefore, the discrimination accuracy of the object in the ambient light image can be improved. For example, the matching accuracy of the coordinate position of the light receiving point in the ambient light image and the coordinate position of the object in the captured image can be improved in the fusion processing with the captured image obtained by the camera. As a result, the correspondence accuracy between the detected reflection point of the object obtained in the object detection processing and the coordinate position of the object in the captured image is improved, and the detection accuracy of the position and distance of the object can be improved. In addition, when the ambient light intensity Ei is higher than the reference ambient light intensity Eir, the ambient light acquisition period T1 is reduced, so that the light emission period T2 is increased, and the object detection performance can be improved. In addition, since the object detection period t2 is constant, object detection can be completed at a constant time interval all the time, and a high spatial resolution ability can be achieved all the time.

[0045] In the above description, the total period of T1 during ambient light acquisition and T2 during light emission, that is, the object detection period t2, is constant. However, when the increase time of T1 during ambient light acquisition is about three times, the light emission period T2 may not decrease according to the increase of the ambient light acquisition period T1. In this case, although the processing time for object detection in the scanning angle range SR increases, the accuracy of object detection can be maintained at a predetermined accuracy.

[0046] In the above description, when the ambient light intensity Ei is above the reference ambient light intensity Eir, the ambient light acquisition period T1 is reduced. However, the current ambient light acquisition period T1 can also be maintained until the ambient light intensity Ei reaches the ambient light intensity corresponding to the maximum dynamic range. When the ambient light intensity Ei is equal to the ambient light intensity corresponding to the maximum dynamic range, the ambient light acquisition period T1 is reduced. In this case, an ambient light image can be obtained with a larger cumulative ambient light quantity, that is, a larger exposure amount. Also, in the above description, the ambient light acquisition period T1 is either t1 μs or 10×t1 μs, but it can be further refined. For example, 25%, 50%, and 75% of the maximum dynamic range can be set as the determination value of the strength or weakness of the ambient light intensity Ei, that is, the reference ambient light intensity Eir, and the corresponding ambient light acquisition periods T1 can be set as 10×t1 μs, 5×t1 μs, and 2×t1 μs. In this case, the rationalization of the increase amount of the ambient light acquisition period T1 can be achieved. In addition, the reference ambient light intensity Eir can take other multiple values. In addition to this, a table or arithmetic expression corresponding the reference ambient light intensity Eir to the ambient light intensity Ei can be prepared, and the ambient light acquisition period T1 can be dynamically set according to the ambient light intensity Ei. In this case, the ambient light acquisition period T1 more suitable for the ambient light intensity Ei can be set, and the increase of the dynamic range and the improvement of object detection performance can be further achieved simultaneously.

[0047] Second Embodiment:

[0048] In the first embodiment, the ambient light acquisition period T1 is determined according to the ambient light intensity Ei. However, in the second embodiment, the light emission period T2 is determined according to the characteristics of detecting reflected light during the light emission period T2, and the ambient light acquisition period T1 is changed. In addition, the structure of the object detection device in the second embodiment is the same as that of the object detection device 10 according to the first embodiment, so the description is omitted by adding the same reference numerals.

[0049] The object detection process including the acquisition of the ambient light intensity performed by the object detection device 10 according to the second embodiment will be described. For example, from the start to the stop of the vehicle control system, or from when the start switch is turned on to when the start switch is turned off, it is repeatedly executed at a predetermined time interval, for example, every several 100 ms.Figure 8 The processing routine shown. The CPU 101 executes by executing the object detection processing program Pr1 Figure 8 The processing flow shown. In addition, for Figure 8 In each processing step in Figure 5 The processing steps that are the same as those in

[0050] The CPU 101 acquires the detection reflected light SNi acquired at a timing before the current time via the input / output interface 103, that is, the SN ratio [dB] or the SN difference [dB] in the detection reflected light signal (step S200). In the present embodiment, the SN ratio is used as the characteristic of the detection reflected light. In addition to this, the maximum value, average value, or mode of the signal intensity of the detection reflected signal can also be used as the characteristic of the detection reflected light. As Figure 6 And Figure 7 Shown, one time slot in the object detection device 10 is composed of an ambient light acquisition period T1 and a light emission period T2. The detection reflected light SNi in the previous time slot is, for example, the average value or maximum value of the detection reflected light signal obtained during the light emission period T2 in the immediately previous time slot or the average value or maximum value of the detection reflected light signal obtained during the light emission period T2 in several immediately previous time slots.

[0051] The CPU 101 determines whether the acquired detection reflected light SNi is lower than the reference SNr (step S202). The reference SNr is the signal-to-noise ratio at which the reflected light from the object can be sufficiently distinguished from the ambient light or background light in the detection reflected light signal, and is, for example, 20 dB. Alternatively, instead of comparing the SN ratios, the standard deviation σ of the detection reflected light SNi with respect to the peak in the histogram can be used for determination. For example, 10σ can also be used as the reference. When the ambient light intensity is high, even if the detection reflected light intensity is the same, the detection reflected light SNi decreases, and when the ambient light intensity is low, even if the detection reflected light intensity is the same, the detection reflected light SNi increases. When the ambient light intensity is high, an ambient light image with a sufficient dynamic range can be obtained during the short ambient light acquisition period T1. In the present embodiment, the sum of the ambient light acquisition period T1 and the light emission period T2, that is, the object detection period, is constant, but the ambient light acquisition period T1 and the light emission period T2 are in a complementary relationship. Even if the object detection period, that is, the ambient light acquisition period T1 + the light emission period T2 = constant, it is possible to simultaneously obtain an ambient light image with a sufficient dynamic range and a detection reflected light signal with a good SN ratio.

[0052] If the CPU 101 determines that the detected reflected light SNi is lower than the reference SNr, i.e., SNi < SNr (step S202: Yes), it increases the light emission period T2 (step S204). As a result, the number of light emissions of the light emitting unit 30, that is, the light emission opportunity and the light emission timing increase, the number of incidents of the detected reflected light in the light receiving element array 22 increases, and the signal intensity of the detected reflected light increases. Therefore, even under bright conditions with high ambient light intensity, object detection of objects existing at a long distance can be performed. A lower SNi of the detected reflected light means a higher ambient light intensity. By increasing the light emission period T2, an ambient light image with a sufficient dynamic range can be obtained even if the ambient light acquisition period T1 is reduced. If the CPU 101 determines that the detected reflected light SNi is above the reference SNr, i.e., SNi ≥ SNr (step S202: No), it decreases the light emission period T2 (step S206). In this case, even under dark conditions with low ambient light intensity, object detection of objects existing at a long distance can be performed in a short period. In addition, the detected reflected light obtained during the currently set light emission period T2 can be sufficiently distinguished from the ambient light, suggesting the possibility of low ambient light intensity. Therefore, by decreasing the light emission period T2 to increase the ambient light acquisition period T1, an ambient light image with an expanded dynamic range can be obtained. In addition, the increase and decrease of the light emission period T2 are relative time increases and decreases with respect to the light emission period T2 set before the determination in step S202, and the time does not necessarily have to be increased or decreased absolutely. In addition, the decrease of the light emission period T2 may also mean setting a predetermined initial value. In this case, the setting of T2 = t2 - t1 can be performed regardless of the value of the light emission period T2 set before the determination in step S202. And there is an upper limit to the increase of the light emission period T2. For example, it is increased in such a way that the ambient light acquisition period T1 = t1 is at least maintained.

[0053] If the light emission period T2 is set, the CPU 101 performs object detection processing (step S208). As Figure 6 and Figure 7As shown, the object detection process includes an ambient light intensity acquisition process performed for each unit scan angle SC during ambient light acquisition at T1 and a detected reflected light acquisition process performed for each unit scan angle SC during light emission at T2. When the CPU 101 finishes the object detection process, it determines whether scanning for object detection has been completed for all columns constituting the scan angle range SR (step S210). If the CPU 101 determines that scanning for object detection has not been completed for all columns (step S210: No), it moves to step S200 and executes steps S200 to S208 using the ambient light intensity Ei acquired this time. If the CPU 101 determines that scanning for object detection has been completed for all columns (step S210: Yes), it ends this processing routine. By acquiring the ambient light intensity Ei for all columns constituting the scan angle range SR and performing distance calculation processing for the object, an ambient light image corresponding to the scan angle range SR is formed, and in addition, a reflected point image indicating the distance of the object existing in the scan angle range SR is formed.

[0054] According to the object detection device 10 according to the second embodiment described above, when the SN ratio of the obtained detected reflected light, that is, the detected reflected light signal, is low, the light emission period T2 for acquiring the detected reflected light is increased, so that a detected reflected light with a higher SN ratio can be obtained, and an object at a farther distance can be detected. As a result, the discrimination accuracy of the object in the object detection device 10 can be improved. In addition, even if the object detection period is constant, the SN ratio of the detected reflected light and the level of the ambient light intensity Ei are in a complementary relationship. Therefore, even if the light emission period T2 is increased to reduce the ambient light acquisition period T1, an ambient light image with a desired dynamic range can be acquired. Moreover, within the constant time required for object detection processing for one column in the scan angle range SR, an improvement in the SN ratio of the detected reflected light and an improvement in the cumulative ambient light amount can be achieved, the object detection processing can be completed within a predetermined object detection period, and a high spatial resolution can always be achieved. In addition, the object detection period is not limited to one predetermined period. For example, it can also be selected from two or more previously prepared object detection period candidates according to the conditions for obtaining an ambient light image with a desired dynamic range and the characteristics of the detected reflected light. In this case, the spatial resolution will not change significantly, and a desired spatial resolution can be achieved.

[0055] Other embodiments:

[0056] (1) In the above-described embodiments, the acquisition of the ambient light intensity Ei and the acquisition of the detected reflected light are continuously performed during the determined ambient light acquisition period T1 and the light emission period T2. In contrast, when an appropriate cumulative ambient light amount is obtained, for example, when the average of the cumulative ambient light amount or the maximum value of the output value (pixel value) of the light-receiving pixels exceeds a predetermined reference value, the ambient light acquisition period T1 may be ended and the transition to the light emission period T2 may be performed. Alternatively, when an appropriate detected reflected light SNi is obtained, for example, when the peak light amount represented by the detected reflected light signal exceeds a predetermined reference value, the light emission period T2 may be ended and the transition to the ambient light acquisition period T1 may be performed. In these cases, more appropriate settings for the ambient light acquisition period T1 and the light emission period T2 can be made.

[0057] (2) In the above-described embodiments, the acquisition of the ambient light intensity and the acquisition of the detected reflected light are performed in column units corresponding to the unit scan angle SC. However, the acquisition of the ambient light intensity and the acquisition of the detected reflected light, that is, the output to the control device 100, may be performed after the scanning of all columns corresponding to the scan angle range SR is completed. Alternatively, the ambient light acquisition period T1 or the light emission period T2 may be changed in units of the unit scan angle SC. In this case, the followability to changes in the ambient light intensity can be improved, and the dynamic range of the ambient light image in units of the unit scan angle SC can be increased. Or it may be performed in units of the scan angle range SR. In this case, the influence of temporary changes in the ambient light intensity of noise can be suppressed, and an ambient light image with an increased dynamic range and less variation in the dynamic range in the scan angle range SR can be obtained. In addition, the same applies to the S / N ratio of the detected reflected light.

[0058] (3) In the first embodiment, the ambient light acquisition period T1 is set according to the intensity of the ambient light. In contrast, the ambient light acquisition period T1 may be set according to at least any one of the current time, weather, map information, vehicle information, and user instructions.

[0059] · When the control device 100 sets the ambient light acquisition period T1 according to the current time, for example, when the current time is in the period from 1 hour before sunset to 1 hour after sunrise, that is, at night, it may be determined that the ambient light is small and the ambient light acquisition period T1 may be set longer. In the remaining period, that is, during the day, it may be determined that the ambient light is large and the ambient light acquisition period T1 may be set shorter. The times of sunrise and sunset can be obtained through vehicle-to-vehicle communication and mobile data communication. In this case, since a parameter such as time information that does not depend on the vehicle's surrounding environment is used, the ambient light acquisition period T1 can be set more appropriately.

[0060] · When the control device 100 sets the ambient light acquisition period T1 according to the weather, for example, it can also be determined that the ambient light is small and the ambient light acquisition period T1 is set longer when the rain drop sensor detects rain drops or snow on a rainy or snowy day, and it is determined that the ambient light is large and the ambient light acquisition period T1 is set shorter on a sunny or cloudy day when the rain drop sensor does not detect rain drops or snow. In this case, since the vehicle surrounding environment such as weather information can be reflected, the ambient light acquisition period T1 can be set more appropriately.

[0061] · When the control device 100 sets the ambient light acquisition period T1 according to the map information, for example, it can also be determined that the ambient light is small and the ambient light acquisition period T1 is set longer when the vehicle 50 is located in a tunnel or on a road with an obstacle blocking external light, and in other cases, it is determined that the ambient light is large and the ambient light acquisition period T1 is set shorter. The map information can be stored in the vehicle control device 40 of the vehicle 50 or can be obtained from an external server in real time through communication. The position of the vehicle 50 can be determined by GNSS (Global Navigation Satellite System), vehicle-to-vehicle communication, or mobile data communication. In this case, the ambient light acquisition period T1 can be set by reflecting the magnitude of the ambient light caused by the position of the vehicle 50.

[0062] · When the control device 100 sets the ambient light acquisition period T1 according to the vehicle information or the user instruction, for example, it can also be determined that the ambient light is small and the ambient light acquisition period T1 is set longer when the headlamp is turned on, and it is determined that the ambient light is large and the ambient light acquisition period T1 is set shorter when the headlamp is turned off. The vehicle information can include the on / off information of the headlamp that does not accompany the user operation, the on / off of the windshield wiper, that is, the information related to the automatic headlamp and the automatic windshield wiper. The user instruction can include the on / off information of the headlamp, the on / off of the windshield wiper, etc. based on the user operation. In this case, by using the detection results of other sensors equipped in the vehicle 50, the ambient light acquisition period T1 can be set more appropriately. In addition, when the user instruction is used, the vehicle surrounding environment felt by the user, that is, the driver, can be reflected, and the ambient light acquisition period T1 can be set more appropriately.

[0063] (4)In each of the above-described embodiments, the object detection apparatus 10 that determines and executes object detection during execution is realized by the CPU 101 executing the object detection processing program Pr1, but it may also be realized in hardware by a pre-programmed integrated circuit or discrete circuit. That is, the control unit and its method in each of the above-described embodiments may also be realized by a dedicated computer provided by configuring a processor and a memory programmed to execute one or more functions embodied by a computer program. Alternatively, the control unit and its method described in the present disclosure may also be realized by a dedicated computer provided by configuring a processor from one or more dedicated hardware logic circuits. Alternatively, the control unit and its method described in the present disclosure may also be realized by one or more dedicated computers provided by a combination of a processor programmed to execute one or more functions and a memory and a processor configured from one or more hardware logic circuits. In addition, the computer program may also be stored as instructions executable by a computer in a non-transitory tangible recording medium readable by the computer.

[0064] As described above, the present disclosure has been described based on the embodiments and modification examples, but the above-described embodiments of the invention are for easily understanding the present disclosure and do not limit the present disclosure. The present disclosure can be changed and improved without departing from its gist and claims, and equivalents thereof are included in the present disclosure. For example, regarding the technical features in the embodiments and modification examples corresponding to the technical features in each mode described in the section of the invention content, in order to solve part or all of the above-described problems or to achieve part or all of the above-described effects, they can be appropriately replaced or combined. In addition, if the technical feature is not described as an essential feature in this specification, it can be appropriately deleted.

Claims

1. An object detection device, comprising: A light emitting unit that irradiates laser light; A light receiving unit; A period determination unit that determines an ambient light acquisition period for acquiring ambient light according to the intensity of the ambient light; A light receiving control unit that controls the light receiving operation of the incident light in the above-mentioned light receiving unit, and causes the above-mentioned light receiving unit to perform a light receiving operation for acquiring ambient light during the determined ambient light acquisition period; A light emitting control unit that controls the light emitting operation of the above-mentioned light emitting unit; and A processing unit that detects the above-mentioned object based on the incident light including the reflected light of the above-mentioned laser reflected by the object, and acquires an ambient light image based on the ambient light incident independently of the above-mentioned laser, The sum of the above-mentioned ambient light acquisition period and the light emitting period for object detection of the above-mentioned light emitting unit, that is, the object detection period, is constant, The change of the above-mentioned ambient light acquisition period or the above-mentioned light emitting period is performed in units of unit scan angle.

2. The object detection device according to claim 1, wherein, When the intensity of the ambient light obtained by the above-mentioned light-receiving unit is lower than a predetermined reference value, the above-mentioned period determination unit increases the above-mentioned ambient light acquisition period.

3. The object detection device according to claim 1 or 2, wherein, When the intensity of the ambient light obtained by the above-mentioned light-receiving unit is higher than a predetermined reference value, the above-mentioned period determination unit decreases the above-mentioned ambient light acquisition period.

4. The object detection device according to claim 1, wherein, When the intensity of the ambient light obtained by an illuminance sensor different from the above-mentioned light-receiving unit is lower than a predetermined reference value, the above-mentioned period determination unit increases the above-mentioned ambient light acquisition period.

5. The object detection device according to claim 1 or 4, wherein, When the intensity of the ambient light obtained by an illuminance sensor different from the above-mentioned light-receiving unit is higher than a predetermined reference value, the above-mentioned period determination unit decreases the above-mentioned ambient light acquisition period.

6. An object detection device, comprising: A light emitting unit that irradiates laser light; A light receiving unit; A period determination unit that determines an ambient light acquisition period for acquiring ambient light according to time; A light receiving control unit that controls the light receiving operation of the incident light in the above-mentioned light receiving unit, and causes the above-mentioned light receiving unit to perform a light receiving operation for acquiring ambient light during the determined ambient light acquisition period; A light emitting control unit that controls the light emitting operation of the above-mentioned light emitting unit; and A processing unit that detects the above-mentioned object based on the incident light including the reflected light of the above-mentioned laser reflected by the object, and acquires an ambient light image based on the ambient light incident independently of the above-mentioned laser, The sum of the above-mentioned ambient light acquisition period and the light emitting period for object detection of the above-mentioned light emitting unit, that is, the object detection period, is constant, Perform the change during the above-mentioned ambient light acquisition period or the above-mentioned light emission period in units of the unit scan angle.

7. An object detection device, comprising: A light emitting unit that irradiates a laser; A light receiving unit; A period determination unit that determines an ambient light acquisition period for acquiring ambient light according to the weather; A light receiving control unit that controls the light receiving operation of incident light in the above-mentioned light receiving unit, and causes the above-mentioned light receiving unit to perform a light receiving operation for acquiring ambient light during the determined ambient light acquisition period; A light emitting control unit that controls the light emitting operation of the above-mentioned light emitting unit; and A processing unit that detects the above-mentioned object based on incident light including reflected light of the above-mentioned laser reflected by the object, and acquires an ambient light image based on the ambient light incident independently of the above-mentioned laser, The sum of the above-mentioned ambient light acquisition period and the light emission period for object detection of the above-mentioned light emitting unit, that is, the object detection period, is constant, Perform the change of the above-mentioned ambient light acquisition period or the above-mentioned light emission period in units of the unit scan angle.

8. An object detection device, comprising: A light emitting unit that irradiates a laser; A light receiving unit; A period determination unit that determines an ambient light acquisition period for acquiring ambient light according to map information; A light receiving control unit that controls the light receiving operation of incident light in the above-mentioned light receiving unit, and causes the above-mentioned light receiving unit to perform a light receiving operation for acquiring ambient light during the determined ambient light acquisition period; A light emitting control unit that controls the light emitting operation of the above-mentioned light emitting unit; and A processing unit that detects the above-mentioned object based on incident light including reflected light of the above-mentioned laser reflected by the object, and acquires an ambient light image based on the ambient light incident independently of the above-mentioned laser, The sum of the above-mentioned ambient light acquisition period and the light emission period for object detection of the above-mentioned light emitting unit, that is, the object detection period, is constant, Perform the change of the above-mentioned ambient light acquisition period or the above-mentioned light emission period in units of the unit scan angle.

9. An object detection device, comprising: A light emitting unit that irradiates a laser; A light receiving unit; A period determination unit that determines an ambient light acquisition period for acquiring ambient light according to vehicle information; A light receiving control unit controls the light receiving operation of the incident light in the above light receiving unit, and causes the light receiving unit to perform a light receiving operation for acquiring ambient light during the determined ambient light acquisition period; A light emitting control unit controls the light emitting operation of the above light emitting unit; and A processing unit detects the object based on the incident light including the reflected light of the above laser reflected by the object, and acquires an ambient light image based on the ambient light incident independently of the above laser, The sum of the above ambient light acquisition period and the light emitting period for object detection of the above light emitting unit, that is, the object detection period, is constant, The change of the above ambient light acquisition period or the above light emitting period is performed in units of unit scan angle.

10. An object detection device includes: A light emitting unit that irradiates a laser; A light receiving unit; A period determination unit determines an ambient light acquisition period for acquiring ambient light according to a user's instruction; A light receiving control unit controls the light receiving operation of the incident light in the above light receiving unit, and causes the light receiving unit to perform a light receiving operation for acquiring ambient light during the determined ambient light acquisition period; A light emitting control unit controls the light emitting operation of the above light emitting unit; and A processing unit detects the object based on the incident light including the reflected light of the above laser reflected by the object, and acquires an ambient light image based on the ambient light incident independently of the above laser, The sum of the above ambient light acquisition period and the light emitting period for object detection of the above light emitting unit, that is, the object detection period, is constant, The change of the above ambient light acquisition period or the above light emitting period is performed in units of unit scan angle.

11. An object detection device includes: A light emitting unit that irradiates a laser; A light receiving unit; A period determination unit determines the light emitting period for object detection of the above light emitting unit according to the characteristics of detecting the reflected light, where, The above-mentioned detected reflected light is incident light that is incident on the above-mentioned light-receiving unit according to the light emission of the above-mentioned light-emitting unit for object detection; A light-receiving control unit that controls the light-receiving operation of the incident light in the above-mentioned light-receiving unit, and during the ambient light acquisition period, causes the above-mentioned light-receiving unit to perform a light-receiving operation for acquiring ambient light, wherein the above-mentioned ambient light acquisition period is determined by the determined above-mentioned light emission period and object detection period; A light-emitting control unit that controls the light-emitting operation of the above-mentioned light-emitting unit, and during the determined above-mentioned light emission period, causes the above-mentioned light-emitting unit to perform a light-emitting operation for object detection; and A processing unit that detects the above-mentioned object based on incident light including reflected light of the above-mentioned laser reflected by the object, and acquires an ambient light image based on the above-mentioned ambient light incident independently of the above-mentioned laser, The sum of the above-mentioned ambient light acquisition period and the light emission period for performing the light emission of the above-mentioned light-emitting unit for object detection, that is, the object detection period, is constant, When the SN ratio, which is a characteristic of the above-mentioned detected reflected light, is lower than a predetermined reference value, the above-mentioned period determination unit increases the above-mentioned light emission period and decreases the above-mentioned ambient light acquisition period.

12. An object detection device includes: A light emitting unit that irradiates a laser; Light-receiving part; A period determination unit that determines the light emission period for object detection of the light-emitting part according to the characteristics of the detected reflected light, where The above-mentioned detected reflected light is incident light that is incident on the above-mentioned light-receiving unit according to the light emission of the above-mentioned light-emitting unit for object detection; A light-receiving control unit that controls the light-receiving operation of the incident light in the above-mentioned light-receiving unit, and during the ambient light acquisition period, causes the above-mentioned light-receiving unit to perform a light-receiving operation for acquiring ambient light, wherein the above-mentioned ambient light acquisition period is determined by the determined above-mentioned light emission period and object detection period; A light-emitting control unit that controls the light-emitting operation of the above-mentioned light-emitting unit, and during the determined above-mentioned light emission period, causes the above-mentioned light-emitting unit to perform a light-emitting operation for object detection; and A processing unit that detects the above-mentioned object based on incident light including reflected light of the above-mentioned laser reflected by the object, and acquires an ambient light image based on the above-mentioned ambient light incident independently of the above-mentioned laser, The sum of the above-mentioned ambient light acquisition period and the light emission period for performing the light emission of the above-mentioned light-emitting unit for object detection, that is, the object detection period, is constant, When the SN ratio, which is a characteristic of the above-mentioned detected reflected light, is higher than a predetermined reference value, the above-mentioned period determination unit decreases the above-mentioned light emission period and increases the above-mentioned ambient light acquisition period.

13. An object detection device, comprising: A light-emitting part that irradiates laser light; Light-receiving part; A period determination unit that determines the ambient light acquisition period for acquiring ambient light; A light-receiving control unit that controls the light-receiving operation of incident light in the light-receiving part, and causes the light-receiving part to perform the light-receiving operation of acquiring ambient light during the determined ambient light acquisition period; A light-emitting control unit that controls the light-emitting operation of the light-emitting part; A distance calculation unit that calculates the distance to an object using the light emission timing of the light-emitting part and the light-receiving timing of the detected reflected light, where The above-mentioned detected reflected light is incident light that is incident on the above-mentioned light-receiving unit according to the light emission of the above-mentioned light-emitting unit for object detection; And A processing unit that acquires an ambient light image based on the above-mentioned ambient light incident independently of the above-mentioned laser, The sum of the above-described ambient light acquisition period and the light emission period for object detection of the above-described light emitting unit, that is, the object detection period, is constant. The change of the above-described ambient light acquisition period or the above-described light emission period is performed in units of unit scan angles.

14. An object detection device, comprising: A light-emitting part that irradiates laser light; Light-receiving part; A period determination unit that determines the light emission period for object detection of the light-emitting part according to the characteristics of the detected reflected light, where The above-described detected reflected light is incident light that is incident on the above-described light receiving unit according to the light emission for object detection of the above-described light emitting unit. A light receiving control unit that controls the light receiving operation of incident light in the above-described light receiving unit and causes the above-described light receiving unit to perform a light receiving operation for acquiring ambient light during the ambient light acquisition period, where the ambient light acquisition period is determined by the determined above-described light emission period and the object detection period. A light emission control unit that controls the light emission operation of the above-described light emitting unit and causes the above-described light emitting unit to perform a light emission operation for object detection during the determined above-described light emission period. A distance calculation unit that calculates the distance to an object using the light emission timing of the above-described light emitting unit and the light receiving timing of the above-described detected reflected light; and A processing unit that acquires an ambient light image based on the ambient light that is incident independently of the above-described laser. The sum of the above-described ambient light acquisition period and the light emission period for object detection of the above-described light emitting unit, that is, the object detection period, is constant. The change of the above-described ambient light acquisition period or the above-described light emission period is performed in units of unit scan angles.

15. A control method for an object detection device, Determine the ambient light acquisition period for acquiring ambient light according to the intensity of the ambient light, During the determined ambient light acquisition period, the light-receiving part performs the light-receiving operation of acquiring ambient light, After the above ambient light acquisition period, perform a light emission operation for object detection by the light emitting unit, where, The above-described light emitting unit irradiates a laser. The above-described object is detected based on incident light including reflected light of the above-described laser reflected by an object, and an ambient light image is acquired based on the ambient light that is incident independently of the above-described laser. The sum of the above-described ambient light acquisition period and the light emission period for object detection of the above-described light emitting unit, that is, the object detection period, is constant. The change of the above-described ambient light acquisition period or the above-described light emission period is performed in units of unit scan angles.

16. A control method for an object detection device, Determine the light emission period for object detection by the light emitting unit according to the characteristics of the detected reflected light, where, The above-described detected reflected light is incident light that is incident on the light receiving unit according to the light emission for object detection of the light emitting unit that irradiates the laser. During the ambient light acquisition period, the above-described light receiving unit performs a light receiving operation for acquiring ambient light, where the ambient light acquisition period is determined by the determined above-described light emission period and the object detection period. During the determined above-described light emission period, the above-described light emitting unit performs a light emission operation for object detection. When the signal-to-noise ratio (SN ratio), which is a characteristic of the above-described detected reflected light, is lower than a predetermined reference value, the above-described light emission period is increased and the above-described ambient light acquisition period is decreased. The above-described object is detected based on incident light including reflected light of the above-described laser reflected by an object, and an ambient light image is acquired based on the ambient light that is incident independently of the above-described laser. The sum of the above-described ambient light acquisition period and the light emission period for object detection of the above-described light emitting unit, that is, the object detection period, is constant.

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