JP2023052460A - Detection device, control method, and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a detection device capable of suitably detecting an object around a moving body.

SOLUTION: A lidar 1 includes: a scan unit 55 for emitting emission light Lo in response to a pulse trigger signal PT; an APD 41 for receiving return light Lr of the emission light Lo; and a DSP 16. The DSP 16 obtains current position information IP or the like indicating the position of a vehicle from an on-vehicle device 2. Then, the DSP 16 controls the intensity and emission frequency of the emission light Lo emitted by the scan unit 55 on the basis of the current position information IP or the like.

SELECTED DRAWING: Figure 12

COPYRIGHT: (C)2023,JPO&INPIT

Description

TECHNICAL FIELD The present invention relates to a technology for emission control of light pulses for measurement.

Conventionally, techniques for measuring distances to objects existing in the vicinity have been known. For example, Patent Literature 1 discloses an in-vehicle system equipped with a lidar that scans in the horizontal direction while intermittently emitting laser light and receives the reflected light to detect point groups on the surface of an object. there is

JP 2014-89691 A

When capturing a landmark in the surrounding environment using a lidar, if the landmark included in the scanning plane is relatively small compared to the scanning angular resolution, such as when the landmark is far away, The number of measurement points corresponding to the landmark becomes excessively small, and the shape of the landmark may not be recognized correctly. As described above, since the conventional lidar emits light with a constant light intensity and a constant scanning angular resolution, it may not be possible to accurately detect surrounding objects.

SUMMARY OF THE INVENTION The present invention has been made to solve the problems described above, and a main object of the present invention is to provide a detection device capable of suitably detecting objects around a moving object.

According to a claim of the invention, there is provided a detection device that can be arranged on a moving object, comprising an emission part that emits light and a light receiving part that receives the light reflected by an object, wherein the emission part is , the light emitted to the side is emitted with an intensity higher than the intensity of the light emitted to the opposite side, or the light emitted to the side is emitted to the opposite side It emits at a frequency higher than the frequency of light.

According to a claim of the invention, there is provided a detection device that can be arranged on a moving body, comprising: an emission section for emitting light; a light receiving section for receiving the light reflected by an object; and light emitted from the emission section. and a control unit that controls at least one of the intensity and frequency of emission of the control unit, wherein the intensity of the light emitted to the side is different from the intensity of the light emitted to the opposite side or control such that the frequency of the light emitted to the side is higher than the frequency of the light emitted to the opposite side.

The invention according to the claims includes an emitting section that emits light, a light receiving section that receives the light reflected by an object, and a first acquiring section that acquires position information indicating the position of the moving object. A control method executed by a detection device that can be arranged on a moving object, comprising a control step of controlling at least one of the intensity and emission frequency of light emitted by the emission unit, the control step comprising: Based on the position information, the intensity of the light emitted to the side is controlled so as to be higher than the intensity of the light emitted to the opposite side, or the intensity of the light emitted to the side is controlled. The frequency is controlled to be higher with respect to the frequency of the light emitted sideways on the opposite side.

The invention according to the claims includes an emitting section that emits light, a light receiving section that receives the light reflected by an object, and a first acquiring section that acquires position information indicating the position of the moving object. and a program executed by a computer of a detection device that can be arranged on a moving body, wherein the emission unit controls at least one of the intensity and emission frequency of emitted light, and the emission unit receives the position information Based on, the intensity of the light emitted sideways is controlled to be higher than the intensity of the light emitted sideways on the opposite side, or the frequency of the light emitted sideways is controlled to The frequency of the light emitted to the side of the opposite side is controlled to be higher.

1 shows a schematic configuration of an object detection system according to an embodiment; 1 shows the overall configuration of a lidar according to an embodiment; 1 shows the configuration of a transmitter and a receiver; 4 shows the configuration of a scanning optical unit; 4 shows an example of setting a register for a control signal generated by a synchronization control unit; 4 shows the temporal relationship of control signals generated by the synchronization control section; 4 is a graph showing the relationship between ADC output signals and gates; Fig. 4 shows the temporal relationship of the pulse train of the rotary encoder; Fig. 4 shows the temporal relationship between encoder pulses and segment slots in steady state; It is a block diagram of signal processing by DSP. FIG. 4 is a plan view of the surroundings of a vehicle schematically showing the emission power of emitted light and the scanning angular resolution in 360-degree scanning in the first control mode with broken-line arrows; FIG. 10 is a plan view of the surroundings of a vehicle schematically showing the emission power of emitted light and the scanning angular resolution in 360-degree scanning in the second control mode with dashed arrows; FIG. 10 is a plan view of the surroundings of a vehicle schematically showing the emission power of emitted light and the scanning angular resolution in 360-degree scanning in the third control mode with dashed arrows; FIG. 11 is a plan view of the surroundings of a vehicle schematically showing the emission power of emitted light and the scanning angular resolution in 360-degree scanning in the fourth control mode with dashed arrows;

In one preferred embodiment of the present invention, there is provided a detection device that can be placed on a moving object, comprising: an emitting unit that emits light; a light receiving unit that receives the light reflected by an object; A first acquisition unit that acquires position information indicating a position; and a control unit that controls at least one of the intensity of light emitted by the emission unit and the emission frequency based on the position information.

The detection device includes an emission section that emits light, a light reception section that receives light reflected by an object, a first acquisition section, and a control section. The first acquisition unit acquires position information indicating the position of the mobile object. The control unit controls at least one of the intensity of the light emitted by the emission unit and the frequency of emission based on the position information acquired by the first acquisition unit. According to this aspect, the detection device can suitably detect an object that should be preferentially detected according to the position of the moving body.

In one aspect of the detection device, the detection device further includes a second acquisition unit that acquires route information related to the movement route of the moving body, and the control unit controls the ejection position based on the position information and the route information. Controls at least one of the intensity and frequency of light emitted by the unit. In general, the direction in which an object to be detected preferentially exists differs for each route of movement (for example, whether it is a right-turning route or a left-turning route). Therefore, according to this aspect, the detection device can preferably detect an object existing in a direction with a high priority to be detected, taking into account the moving route of the moving object.

In another aspect of the detection device, the control section controls the emission section such that the intensity and emission frequency of the light are different between the front side and the side side of the moving body. According to this aspect, it is possible to suitably detect an object existing in a direction with a high priority to be detected.

In another aspect of the detection device, the control unit performs control such that the intensity of the light in front of the moving body is higher and the frequency of emission of the light is lower than that in the sides of the moving body. As a result, the detection device can quickly detect an obstacle or the like in front of the moving body while satisfying the eye-safe standard.

In another aspect of the detection device, when a sidewalk exists on the side of the moving object, the control unit controls the intensity of the light on the side where the sidewalk exists to increase the intensity of the light on the side on the opposite side. control so that it is higher than With this aspect, the detection device can suitably detect an object (for example, a pedestrian, etc.) existing on the sidewalk side that requires special attention when driving.

In another aspect of the detection device, when a sidewalk exists on the side of the moving object, the control unit adjusts the frequency of emission of the light on the side of the side where the sidewalk exists to the opposite side. Control so that it is higher with respect to the side of the With this aspect, it is possible to suitably detect an object (for example, a pedestrian, etc.) present on the sidewalk side that requires special attention during driving. In addition, according to this aspect, the detection device can suitably detect thin features such as kilometer posts and signboards.

In another aspect of the detection device, when the moving body makes a right turn, the control unit controls that the front right side of the moving body has a higher intensity of the light than the other side, and the light is emitted from the other side. control to reduce the frequency of According to this aspect, when the mobile body turns right, the detection device can detect, for example, an oncoming vehicle traveling at high speed toward the right turn point at an early stage.

In another aspect of the detection device, when the moving body makes a left turn, the control unit controls the intensity of the light on the left side of the moving body to be lower than the other side, and the frequency at which the light is emitted. controlled to increase With this aspect, the detection device can accurately detect a pedestrian, a two-wheeled vehicle, or the like, which may be involved in a left turn of a mobile object.

In another preferred embodiment of the present invention, there is provided a detection device that can be placed on a moving object, comprising: an emitting portion that emits light; a light receiving portion that receives the light reflected by an object; The intensity of light emitted by the emitting portion in the front is higher than the intensity of light emitted by the emitting portion on the side of the moving body, and the emission frequency of the emitting portion in the front is higher than the intensity of light emitted by the emitting portion on the side of the moving body. and a control unit that controls the injection unit so that the injection frequency is lower than the injection frequency. According to this aspect, the detection device can quickly detect an obstacle or the like in front of the moving object while satisfying the eye-safe standard.

In another preferred embodiment of the present invention, a control executed by a detection device that has an emission unit that emits light and a light reception unit that receives the light reflected by an object and can be arranged on a moving body A method, comprising: a first acquisition step of acquiring position information indicating the position of the moving object; and control of controlling at least one of intensity and frequency of emission of light emitted by the emission unit based on the position information. and By executing this control method, the detection device can preferably detect an object that should be preferentially detected according to the position of the moving body.

In another preferred embodiment of the present invention, a computer of a detection device that can be arranged on a moving object, and that has an emission unit that emits light and a light reception unit that receives the light reflected by an object executes A program for controlling at least one of the intensity and frequency of light emitted by the emitting unit based on a first acquiring unit for acquiring position information indicating the position of the moving object, and the emitting unit based on the position information The computer functions as a control unit. By executing this program on a computer, the above detection device can be realized. This program can be handled by being stored in a storage medium.

Preferred embodiments of the present invention will be described below with reference to the drawings.

[Overview of object detection system]
FIG. 1 is a schematic configuration of an object detection system according to this embodiment. The object detection system has a lidar (Light Detection and Ranging, or Laser Illuminated Detection And Ranging) 1 that moves with the vehicle, and an in-vehicle device 2 that can communicate with the lidar 1 .

The lidar 1 discretely measures the distance to an object existing in the external world by emitting a pulsed laser over a predetermined angle range in the horizontal and vertical directions, and generates a three-dimensional point indicating the position of the object. Group information is generated and supplied to the in-vehicle device 2 . In this embodiment, the rider 1 receives the current position information, the map information, and the route information from the vehicle-mounted device 2, so that the pulse laser emission power and emission interval (i.e., emission frequency or scanning angular resolution) are adjusted for each direction. change. The lidar 1 is an example of a "detection device" in the present invention.

Based on the point cloud information output by the rider 1, the in-vehicle device 2 detects objects around the vehicle, controls the vehicle for driving support (including automatic driving), and performs predetermined display and audio output. go and do In this embodiment, the in-vehicle device 2 supplies the rider 1 with current position information "IP", map information "IM", and route information "IR". Here, the in-vehicle device 2 may transmit the position information output by the GPS receiver or the like to the rider 1 as the current position information IP. may be transmitted to the rider 1 as the current position information IP. In addition, the in-vehicle device 2 transmits, for example, the map information around the current position extracted from the map database to the rider 1 as the map information IM. In addition, the vehicle-mounted device 2 transmits information regarding the route to the set destination to the rider 1 as route information IR.

Note that the configuration in FIG. 1 is an example, and the configuration to which the present invention can be applied is not limited to this. For example, instead of receiving the map information IM from the vehicle-mounted device 1, the rider 1 may receive the map information IM from a server device (not shown) that stores a map database via a network. In another example, instead of receiving the current position information IP from the vehicle-mounted device 1, the rider 1 may generate the current position information IP by itself by providing a GPS receiver or the like. The current position information IP may be generated by estimating the self-position based on point cloud information or the like.

Also, the route information IR here is typically information relating to the route to the destination set by the vehicle-mounted device 2, but is not limited to this. For example, other than information set by the user of the vehicle-mounted device 2, it may be information indicating a route (running locus) that the vehicle is expected to travel in the future.

[Basic configuration of rider]
First, the basic configuration of the lidar according to the embodiment will be described.

(1) Overall structure
FIG. 2 shows the overall configuration of the lidar according to the embodiment. The lidar 1 scans the surrounding space by appropriately controlling the emission direction of light pulses repeatedly emitted (hereinafter referred to as "scanning direction"), and observes the returned light to detect objects in the surroundings. information (such as distance, its probability of existence, reflectance, etc.). Specifically, the rider 1 emits a light pulse (hereinafter referred to as "emission light Lo"), which is reflected by an external object (target) (hereinafter referred to as "return light Lr"). generates information about the object.

As shown in FIG. 2, the lidar 1 roughly includes a system CPU 5, an ASIC 10, a transmitter 30, a receiver 40, and a scanning optical section 50. As shown in FIG. The transmitter 30 repeatedly outputs laser light pulses with a width of about 5 nsec in response to the pulse trigger signal PT supplied from the ASIC 10 . A light pulse output from transmitter 30 is guided to scanning optical section 50 .

The scanning optical unit 50 emits the light pulse output by the transmitter 30 in an appropriate direction, and collects the return light Lr that has returned by being reflected or scattered when the emitted light encounters an object in space. and lead it to the receiver 40 . The scanning optical section 50 is an example of the "ejection section" in the present invention. The receiver 40 outputs to the ASIC 10 a signal proportional to the intensity of the return light Lr. The receiver 40 is an example of the "light receiving section" in the present invention.

The ASIC 10 analyzes the output signal of the receiver 40 to estimate and output parameters related to the object in the scanning space, such as its distance. The ASIC 10 also controls the scanning optics 50 to ensure proper scanning. In addition, ASIC 10 provides transmitter 30 and receiver 40 with the high voltages required by each.
The system CPU 5 performs at least initial setting, monitoring and control of the ASIC 10 through the communication interface. Other functions vary depending on the application. In the case of the simplest lidar, the system CPU 5 merely converts the target information TI output by the ASIC 10 into an appropriate format and outputs it. The system CPU 5, for example, converts the target information TI into a highly versatile point group format, and then outputs it through the USB interface.

(2) Transmitter
The transmitter 30 outputs an optical pulse with a width of about 5 nsec in response to the pulse trigger signal PT supplied from the ASIC 10. FIG. The configuration of the transmitter 30 is shown in FIG. 3(A). Transmitter 30 comprises charging resistor 31 , driver circuit 32 , capacitor 33 , charging diode 34 , laser diode (LD) 35 and CMOS switch 36 .

A pulse trigger signal PT input from the ASIC 10 drives a switch 36 such as a CMOS through a driver circuit 32 . A driver circuit 32 is inserted to drive the switch 36 at high speed. During non-asserted periods of pulse trigger signal PT, switch 36 is open and capacitor 33 within transmitter 30 is charged with a high voltage “V _TX ” supplied by ASIC 10 . On the other hand, during the assertion period of the pulse trigger signal PT, the switch 36 is closed, and the electric charges stored in the capacitor 33 are discharged through the LD35. As a result, an optical pulse is output from the LD35.

(3) Receiver
The receiver 40 outputs a voltage signal proportional to the intensity of the return light Lr from the object. Generally, photodetection elements such as PDs and APDs output current, so the receiver 40 converts this current into voltage (I/V conversion) and outputs it. The configuration of the receiver 40 is shown in FIG. 3(B). The receiver 40 includes an APD (Avalanche Photodiode) 41 , an I/V converter 42 , a resistor 45 , a capacitor 46 and a low pass filter (LPF) 47 . The I/V converter 42 includes a feedback resistor 43 and an operational amplifier 44 .

In this embodiment, an APD 41 is used as the photodetector. A high voltage "V _RX " supplied from the ASIC 10 is applied to the APD 41 as a reverse bias, and a detection current proportional to the return light Lr from the object flows. By applying a reverse bias close to the breakdown voltage of the APD 41, it is possible to obtain a high avalanche gain and detect weak return light. The final stage LPF 47 is provided for the purpose of limiting the bandwidth of the signal prior to sampling by the ADC 20 within the ASIC 10 . In this embodiment, the sampling frequency of the ADC 20 is 512 MHz, and the cutoff frequency of the LPF 47 is approximately 250 MHz.

(4) Scanning optical unit
The scanning optical unit 50 emits a light pulse input from the transmitter 30 in an appropriate direction as emitted light Lo, and the emitted light Lo encounters an object in space and is reflected or scattered to return as a return light. It guides the light Lr to the receiver 40 . A configuration example of the scanning optical unit 50 is shown in FIG. The scanning optical section 50 includes a rotating mirror 61 , a collimator lens 62 , a condenser lens 64 , an optical filter 65 , a coaxial mirror 66 and a rotary encoder 67 .

A light pulse output from the LD 35 of the transmitter 30 enters the collimator lens 62 . A collimator lens 62 collimates the laser light to an appropriate divergence angle (generally on the order of 0-1°). The light emitted from the collimator lens 62 is reflected vertically downward by a small coaxial mirror 66 and enters the rotating shaft (center) of the rotating mirror 61 . The rotating mirror 61 horizontally reflects the laser light incident from vertically above and emits it into the scanning space. The rotating mirror 61 is attached to the rotating portion of the motor 54 , and the laser light reflected by the rotating mirror 61 scans the horizontal plane as the emitted light Lo as the motor 54 rotates.

The return light Lr returned to the lidar 1 by being reflected or scattered by an object existing in the scanning space is reflected vertically upward by the rotating mirror 61 and enters the optical filter 65 . In addition to the return light Lr, the background light caused by the object being illuminated by the sun or the like also enters the optical filter 65 . An optical filter 65 is provided to selectively eliminate such background light. Specifically, the optical filter 65 selectively allows only components around ±10 nm around the wavelength of the emitted light Lo (905 nm in this embodiment) to pass. If the passband of the optical filter 65 is wide, a large amount of background light will enter the subsequent receiver 40 . As a result, a large DC current component appears in the output of the APD 41 in the receiver 40, and shot noise (background light shot noise) caused by this DC component degrades SN, which is not preferable. However, if the passband is too narrow, the emitted light itself is also suppressed, which is not preferable. The condenser lens 64 collects the light that has passed through the optical filter 65 and guides it to the APD 41 of the receiver 40 .

A rotary encoder 67 is attached to the motor 54 to detect the scanning direction. The rotary encoder 67 has a turntable 68 attached to the motor rotating portion and a code detector 69 attached to the motor base. A slit representing the rotation angle of the motor 54 is engraved on the outer circumference of the rotating disk 68, and the code detector 69 reads and outputs the slit. Specific specifications of the rotary encoder 67 and motor control based on its output will be described later.

In the above configuration, the collimator lens 62 constitutes the transmission optical system 51 shown in FIG. 2, the rotating mirror 61 and the motor 54 constitute the scanning unit 55 shown in FIG. 2, and the rotary encoder 67 constitutes the scanning direction detector 53 in FIG.

(5) ASICs
The ASIC 10 performs timing control of emitted light pulses, AD conversion of APD output signals, and the like. The ASIC 10 also performs appropriate signal processing on the AD conversion output to estimate parameters (distance, return light intensity, etc.) related to the object, and outputs the estimation results to the outside. As shown in FIG. 2, the ASIC 10 includes a register section 11, a clock generation section 12, a synchronization control section 13, a gate extraction section 14, a reception segment memory 15, a DSP 16, and a transmitter high voltage generation section (TXHV ) 17 , a receiver high voltage generator (RXHV) 18 , a preamplifier 19 , an AD converter (ADC) 20 , and a scanning controller 21 .

Registers for communication with the system CPU 5 as an external processor are arranged in the register unit 11 . The registers provided in the register unit 11 are roughly classified into R registers that can be referenced only from the outside and W registers that can be set from the outside. The R register mainly holds status values inside the ASIC, and the system CPU 5 can monitor the internal status of the ASIC 10 by reading these values through the communication interface. On the other hand, the W register holds various parameter values referred to inside the ASIC 10 . These various parameter values can be set from the system CPU 5 through the communication interface. Note that the communication register may be implemented by a flip-flop or may be implemented as a RAM.

The clock generator 12 generates a system clock “SCK” and supplies it to each block within the ASIC 10 . Many blocks of the ASIC 10 operate in synchronization with the system clock SCK. In this embodiment, the system clock SCK has a frequency of 512 MHz. The system clock SCK is generated by the PLL so as to synchronize with the externally input reference clock "RCK". A crystal oscillator is normally used as the source of the reference clock RCK.

TXHV 17 generates the high voltage V _TX required by transmitter 30 . This high voltage is generated by boosting a low voltage with a DCDC converter circuit. As will be described later, the TXHV 17 changes the high voltage _VTX generated based on the control signal “Ct” supplied from the DSP 16 to adjust the voltage applied to the LD 35 within the transmitter 30 .

RXHV 18 generates the DC high voltage (on the order of 100V) required by receiver 40 . This high voltage is generated by boosting a low voltage (about 5V to 15V) by a DCDC converter circuit.

The synchronization control unit 13 generates and outputs various control signals. The synchronization control section 13 in this embodiment outputs two control signals, ie, a pulse trigger signal PT and an AD gate signal GT. A setting example of these control signals is shown in FIG. 5, and their temporal relationship is shown in FIG. As shown in FIG. 6, these control signals are generated in synchronization with time intervals (segment slots) divided at predetermined intervals. The time interval width (segment period) of the segment slot can be set by "nSeg". Here, the longer the segment period nSeg, the smaller the number of segment slots in the 360-degree scanning of the emitted light Lo, and the coarser the emission interval of the emitted light Lo. On the other hand, the shorter the segment period nSeg, the greater the number of segment slots in the 360-degree scanning of the emitted light Lo, and the closer the emission intervals of the emitted light Lo.

A pulse trigger signal PT is supplied to a transmitter 30 provided outside the ASIC 10 . The transmitter 30 outputs optical pulses in response to the pulse trigger signal PT. For the pulse trigger signal PT, it is possible to set a delay "dTrg" and a pulse width "wTrg" with respect to the segment slot start point. If the pulse width wTrg is too narrow, the transmitter 30 will not respond, so it is determined in consideration of the trigger response specifications of the transmitter 30 .

The AD gate signal GT is supplied to the gate extractor 14 . As will be described later, the gate extraction unit 14 extracts only the asserted period of the AD gate signal GT from the ADC output signal input from the ADC 20 and stores it in the reception segment memory 15 . For the AD gate signal GT, it is possible to set a delay time "dGate" and a gate width "wGate" with respect to the segment slot start point. Here, the longer the gate width wGate, the longer the maximum ranging distance (range-finding limit distance) of the rider 1 .

Also, in this embodiment, the synchronization control unit 13 changes the segment cycle nSeg based on the control signal “Cs” supplied from the DSP 16 . Specifically, based on the control signal Cs, the synchronization control unit 13 sets the segment period nSeg shorter than the normal period (for example, nSeg=8192) in the scanning direction in which the emitted light Lo is emitted densely, and the emitted light In the scanning direction in which Lo is emitted roughly, the segment cycle nSeg is set longer than the normal cycle. In addition to this, the synchronization control unit 13 sets the gate width wGate longer than the normal width (for example, wGate=1024) in the scanning direction in which the emission power of the emitted light Lo is increased. In the scanning direction in which the distance is lengthened and the emission power of the emission light Lo is weakened, the gate width wGate may be set shorter than the normal width, thereby shortening the maximum ranging distance of the rider 1 .

The preamplifier 19 amplifies the voltage of the analog voltage signal input from the receiver 40 installed outside the ASIC 10 and supplies it to the subsequent ADC 20 . Note that the voltage gain of the preamplifier 19 can be set by the W register.

The ADC 20 AD-converts the output signal of the preamplifier 19 and converts it into a digital series. In this embodiment, the system clock SCK is used as the sampling clock for the ADC 20, and the input signal of the ADC 20 is sampled at 512 MHz.

The gate extraction unit 14 extracts only the asserted period of the AD gate signal GT from the ADC output signal input from the ADC 20 and stores it in the reception segment memory 15 . The segment signal extracted by the gate extractor 14 is hereinafter referred to as "received segment signal RS". That is, the received segment signal RS is a real vector whose vector length is equal to the gate width wGate.

Here, the relationship between the ADC output signal and the received segment and the setting of the gate position will be described. FIG. 7A shows segment slots. As shown in FIG. 7B, the pulse trigger signal PT is asserted with a delay of dTrg from the segment slot start point. Since "dTrg=0" in the example of FIG. 7, the pulse trigger signal PT is asserted at the start point of the segment slot. FIG. 7C shows the ADC output signal (received segment signal RS) when an object is placed at the scanning origin of the lidar. That is, FIG. 7C illustrates the received segment signal RS when the target distance (radius radius R) is 0 m. As shown, even when R=0 m, the rising edge of the received pulse is observed after the rising edge of the pulse trigger signal by the system delay _{D_SYS} . The system delay _DSYS is caused by electrical delay in the LD driver circuit in the transmitter 30, optical delay in the transmission optical system 51, optical delay in the reception optical system 52, and electrical delay in the receiver 40. Delays, conversion delays in the ADC 20, etc. are conceivable.

FIG. 7(D) illustrates the received segment signal RS when an object is placed at radius R. FIG. In this case, the delay increases by the round trip time of the light from the scanning origin to the object as compared with FIG. 7(C). This increased delay is the so-called "TOF (Time Of Flight) delay". If this TOF delay is D samples, the radius R can be calculated by the following equation.

図７（Ｆ）は、「ｄＧａｔｅ＝０」の場合のＡＤゲート信号ＧＴを例示するものである。前述したとおり、ゲート抽出部１４は、ＡＤＣ出力信号から、ＡＤゲート信号ＧＴのアサート区間のみを抽出する。後述するＤＳＰ１６は、この抽出区間のみに基づいて、物体に関するパラメータ推定を行う。したがって、ＴＯＦ遅延時間が大きい場合には、物体からの戻りパルス成分がゲートからはみ出してしまい正当なパラメータ推定が行えない。正当なパラメータ推定が行われるためにはＴＯＦ遅延時間Ｄが次式を満たしていることが必要となる。

FIG. 7F exemplifies the AD gate signal GT when "dGate=0". As described above, the gate extraction unit 14 extracts only the asserted period of the AD gate signal GT from the ADC output signal. The DSP 16, which will be described later, performs parameter estimation regarding the object based only on this extracted section. Therefore, when the TOF delay time is long, the return pulse component from the object protrudes from the gate, making proper parameter estimation impossible. In order to perform valid parameter estimation, the TOF delay time D must satisfy the following equation.

ここでＬ_ＩＲはシステムの総合インパルス応答の長さであり、Ｄ_ＭＡＸは正当なパラメータ推定が可能な最大ＴＯＦ遅延時間として定義される。図７（Ｅ）は、ＴＯＦ遅延時間がこの最大ＴＯＦ遅延時間に等しい場合の受信セグメント信号ＲＳを例示している。

where _LIR is the length of the total impulse response of the system and _DMAX is defined as the maximum TOF delay time for which valid parameter estimation is possible. FIG. 7(E) illustrates the received segment signal RS when the TOF delay time is equal to this maximum TOF delay time.

Note that instead of the example of FIG. 7, the gate delay dGate may be set equal to the system delay time. By setting in this way, correct parameter estimation is possible even for objects at a longer distance.

The scanning control unit 21 monitors the output of a rotary encoder 67 installed outside the ASIC 10 and controls the rotation of the motor 54 based on this. Specifically, the scanning control unit 21 transmits the torque control signal “TC” to the motor 54 based on the scanning direction information “SDI” output from the rotary encoder 67 (scanning direction detection unit 53) of the scanning optical unit 50. supply. The rotary encoder 67 in this embodiment outputs two pulse trains of A phase and Z phase (hereinafter referred to as "encoder pulses"). The temporal relationship between both pulse trains is shown in FIG. 8(A). As shown, for the A phase, one pulse is generated and output for every 1° rotation of the motor 54 . Therefore, 360 A-phase encoder pulses are generated and output for each rotation of the motor 54 . On the other hand, for the Z phase, one pulse is generated and output for one rotation of the motor 54 corresponding to a predetermined rotation angle.

The scanning control unit 21 measures the rise time of the encoder pulse as the counter value of the system clock SCK, and controls the torque of the motor 54 so that this counter value becomes a desired value. That is, the scanning control unit 21 performs PLL control of the motor 54 so that the encoder pulse and the segment slot have a desired time relationship.

The time relationship between encoder pulses and segment slots can be set by the W register shown in FIG. 8(B). The number of A-phase encoder pulses per motor rotation is set in "nPpr". This value is determined by the specifications of the rotary encoder 67, and is set to 360 as described above in this embodiment. "nRpf" gives the number of rotations per frame, and "nSpf" gives the number of segments per frame. "dSmpA" and "dSmpZ" are prepared to adjust the time relationship between the rise of the encoder pulse and the segment slot in units of sample clocks, and can define the delay of the encoder pulse with respect to the start point of the segment slot. . On the other hand, "dSegZ" is prepared to adjust the temporal relationship between the rise of the Z-phase pulse and the frame in units of segments.

FIG. 9 shows the time relationship between encoder pulses and segment slots in a steady state. As shown, in the default settings, one frame consists of 1800 segments, and the motor 54 makes one revolution in one frame.

(6) DSPs
First, the processing executed by the DSP 16 by reading out the received segment "y _frm,seg " from the received segment memory 15 will be described. Here, "frm" is a frame index and "seg" is a segment index. In the following, the notation of these indices is omitted to the extent that there is no fear of misunderstanding.

FIG. 10A shows a block diagram of signal processing performed by the DSP 16. FIG. As illustrated, the DSP 16 includes a reception filter 71, a peak detector 72, a decision section 73, and a formatter 74. FIG. The DSP 16 sequentially reads out the received segments y from the received segment memory 15 and processes them. The receiving segment y is a real vector of vector length wGate and is expressed by the following equation.

受信フィルタ７１は、受信セグメントｙに対して、所定のインパルス応答を畳み込んで、フィルタードセグメントｚを算出する。ピーク検出部７２は、フィルタードセグメントｚ内で振幅が最大となる点、即ちピーク点を検出し、当該ピーク点の遅延Ｄと振幅Ａを出力する。判定部７３は、振幅Ａが所定の閾値ｔＤｅｔより大きい点のみを選択的にフォーマッタ７４に送る。フォーマッタ７４は、遅延Ｄと振幅Ａ、及び当該セグメントのフレームインデックスｆｒｍ、セグメントインデックスｓｅｇを、適切なフォーマットに変換して外部に出力する。以下、各ブロックについて詳しく説明する。

The reception filter 71 convolves a predetermined impulse response with the reception segment y to calculate a filtered segment z. The peak detector 72 detects the point where the amplitude is maximum in the filtered segment z, that is, the peak point, and outputs the delay D and the amplitude A of the peak point. The determination unit 73 selectively sends to the formatter 74 only the points where the amplitude A is greater than a predetermined threshold value tDet. The formatter 74 converts the delay D, the amplitude A, the frame index frm and the segment index seg of the segment into an appropriate format and outputs them to the outside. Each block will be described in detail below.

The reception filter unit 71 convolves the reception segment y with a predetermined impulse response h (cyclic convolution) to calculate the filtered segment z. The impulse response of the reception filter section 71 can be set by the W register, and is set in advance by the system CPU 5 so that the SNR at the filter output is increased.

For example, the filter impulse response h is set to satisfy the following equation. This setting achieves optimal performance (high SNR) when the noise is white and when the overall system impulse response is significantly shorter than wGate.

上式において、リファレンスパルスｇは走査原点（Ｒ＝０ｍ）に物体を置いた場合に観測される受信セグメント波形であり、トランスミッタ３０とレシーバ４０を含むシステム全体の総合インパルス応答を代表している。実際に走査原点に物体を置くことが困難な場合には、例えば「Ｒ＝１ｍ」での受信セグメント波形を観測し、これを数学的に時間シフトすることで、等価的にリファレンスパルスを測定すれば良い。

In the above equation, the reference pulse g is a received segment waveform observed when an object is placed at the scanning origin (R=0 m), and represents the overall impulse response of the entire system including transmitter 30 and receiver 40. If it is difficult to actually place the object at the scanning origin, for example, observe the received segment waveform at "R = 1 m" and shift it mathematically in time to equivalently measure the reference pulse. Good luck.

The peak detection unit 72 detects the point where the amplitude is maximum in the filtered segment, that is, the peak point with sub-sample precision, and outputs the delay D and the amplitude A of the peak point. Based on the peak point information D, A (delay D, amplitude A) output from the peak detection unit 72, the determination unit 73 determines whether an object exists at the detection point. This determination is made by comparing the amplitude A of the peak point and the determination threshold tDec. Specifically, when A>tDec, the determination unit 73 determines that “an object exists” and outputs the peak point information. On the other hand, when A≦tDec, the determination unit 73 determines that “the object does not exist” and does not output the peak point information. The formatter 74 converts the peak point information D and A output from the determination unit 73 and the scanning information (frame index frm, segment index seg) corresponding to the peak points into a format that is easy for the user (upper system) to use.

Note that the cyclic convolution operation of the receive filter 71 may be implemented in the frequency domain using DFT. By doing so, the amount of calculation can be greatly reduced. In this case, instead of allowing the impulse response h to be set by the W register, the frequency response H may be set by previously obtaining the frequency response H by performing a DFT operation on the impulse response h. FIG. 10B shows a block diagram of signal processing performed by the DSP 16 when the circular convolution operation of the reception filter 71 is implemented in the frequency domain using DFT.

In addition, the DSP 16 performs control (simply referred to as “emission control”) for adjusting the emission power and the emission interval (that is, scanning angular resolution) of the emission light Lo according to the scanning direction of the emission light Lo. In this case, the DSP 16 performs injection control using control signals Ct and Cs.

Specifically, first, the DSP 16 detects the scanning direction based on the scanning direction information SDI received from the scanning direction detection section 53 . Then, the DSP 16 adjusts the emission power of the LD 35 by supplying the TXHV 17 with a control signal Ct for adjusting the high voltage _VTX generated by the TXHV 17 according to the detected scanning direction. Further, the DSP 16 adjusts the ejection interval by supplying the synchronization control section 13 with a control signal Cs for adjusting the segment period nSeg according to the detected scanning direction. In this case, for example, the DSP 16 stores in advance a table or the like indicating combinations of the high voltage V _TX and the segment period nSeg to be set for each scanning direction in the W register or the like, and refers to the table to detect Control signals Ct and Cs are generated according to the scanning direction. The specific setting of the emission power and the emission interval of the emission light Lo for each scanning direction will be described in the next section. The DSP 16 is an example of the "first acquisition unit", the "second acquisition unit", and the "control unit" in the present invention and a computer that executes the program in the present invention.

[Setting of injection power and injection interval according to scanning direction]
Next, an example of setting the ejection power and the ejection interval according to the scanning direction will be described. During normal running of the vehicle, the DS 16 executes a control mode (also referred to as "normal mode") in which light is emitted uniformly (with the same intensity and frequency) in all directions. In this embodiment, the DSP 16 may implement the following first to fourth control modes instead of the normal mode.
Examples of setting the injection power and the injection interval will be described below.

(1) Settings in the first control mode
FIG. 11 is a plan view of the surroundings of the vehicle schematically showing the emission power and the emission interval of the emission light Lo in the 360-degree scanning in the first control mode with dashed arrows. In FIG. 11, the length of the dashed arrow indicates the emission power, and the interval between the dashed arrows indicates the emission interval (emission frequency) of the emitted light Lo. Note that the length of the dashed arrow shown in FIG. 11 does not indicate the range that the emitted light Lo actually reaches, and the number of dashed arrows indicates the number of the emitted light Lo that is actually emitted in 360-degree scanning. number does not match.

As shown in FIG. 11, in the first control mode, the DSP 16 increases the emission power of the emitted light Lo in the forward direction of the vehicle (in FIG. 11, the direction in the range of about 30 degrees left and right with respect to the traveling direction). It is strong and the interval of the emitted light Lo is made coarse (that is, the scanning angular resolution is made low). In this way, the DSP 16 makes the emission power of the emission light Lo emitted in the forward direction of the vehicle stronger than usual from the viewpoint of detecting a farther obstacle. Further, in this case, the DSP 16 roughly emits the emission light Lo emitted in the forward direction of the vehicle from the viewpoint of eye safety and the like. As a result, the DSP 16 can preferentially detect a relatively large object located in front within a distance range equal to or longer than the braking distance, and can preferably satisfy the eye-safe standard. In other words, it is possible to detect an object in front of the vehicle that is farther away than those to the side and rear of the vehicle while satisfactorily satisfying the eye-safe standard.

Further, as shown in FIG. 11, in the first control mode, the DSP 16 makes the emission power of the emission light Lo weaker than normal in the rearward direction of the vehicle (the direction of about 30 degrees left and right with respect to the backward direction in FIG. 11). , and emits the emitted light Lo roughly. In this way, the DSP 16 avoids unnecessarily detecting distant objects behind the vehicle in the rear direction, where the need for obstacle detection is relatively low.

Further, as shown in FIG. 11, in the first control mode, the DSP 16 makes the emission power of the emission light Lo weaker than normal in the lateral direction of the vehicle (right side direction, left side direction) and increases the power of the emission light Lo. Close the spacing (that is, increase the scanning angular resolution). In general, objects that are far away in the lateral direction are farther from the road and need less detection. On the other hand, if there is a need to detect a kilometer post, other signs, signboards, etc., that are relatively close in the lateral direction, as a landmark in self-position estimation, and they have a relatively thin shape. There is In addition, it is highly necessary to detect moving objects existing in the lateral direction (for example, vehicles in other lanes, pedestrians on sidewalks, etc.) from the viewpoint of obstacle detection. Also, if the frequency of ejection is simply increased, there is a possibility that the eye-safe standard cannot be met. In consideration of the above, the DSP 16 makes the emission power of the emission light Lo weaker than usual and emits the emission light Lo densely in the lateral direction of the vehicle, thereby satisfactorily satisfying the eye-safe standard, and relatively close to the vehicle. Detect objects in the side direction of existing vehicles with high accuracy.

(2) Settings in 2nd to 4th control modes
Next, an example of setting the ejection power and the ejection interval for each scanning direction when predetermined conditions are satisfied will be described. Three modes (second to fourth control modes) will be described in order below as specific examples.

(2-1) When Driving on a Road Adjacent to a Sidewalk The DSP 16 selects a road adjacent to a sidewalk (in the case of a road with multiple lanes, the lane closest to the sidewalk) based on the current position information IP and map information IM. When it is detected that the vehicle is traveling, the emission power of the emission light Lo and the scanning angular resolution are controlled by the second control mode described below. In this case, for example, the DSP 16 recognizes the road on which the vehicle is currently traveling based on the current position information IP and the map information IM, and determines whether there is a sidewalk adjacent to the road by referring to the map information IM.

FIG. 12 is a plan view of the surroundings of the vehicle schematically showing the emission power and the emission interval of the emission light Lo in the 360-degree scanning in the second control mode with dashed arrows. In the example of FIG. 12, the DSP 16 recognizes, based on the current position information IP and the map information IM, that the vehicle is traveling in the lane 81 adjacent to the sidewalk 80 registered in the map information IM, and executes the second control mode. .

In the example of FIG. 12, the DSP 16 makes the emission power of the emitted light Lo slightly stronger in the left side direction, which is the side direction where the sidewalk 80 exists, than in the right side direction, and makes the emitted light Lo denser (that is, high scanning angular resolution). In other words, the DSP 16 intensifies the emission power of the emitted light Lo within a range that satisfies the eye-safe standard while emitting the emitted light Lo densely in the left side direction.

Thus, in the second control mode, the DSP 16 makes the emission power of the emission light Lo in the left side direction where the sidewalk 80 exists stronger than the emission power of the emission light Lo in the right side direction on the opposite side, In addition, the scanning angular resolution of the emitted light Lo in the left lateral direction is made higher than the scanning angular resolution of the emitted light Lo in the right lateral direction on the opposite side. By doing so, the DSP 16 can preferably increase the detection accuracy of objects on the sidewalk where pedestrians and the like that must be captured accurately for safety are present.

In addition, in the second control mode, the DSP 16 makes the emission power of the emission light Lo stronger than usual and makes the interval of the emission light Lo coarser (i.e., scan Angular resolution may be lowered). As a result, the DSP 16 preferentially detects relatively large obstacles positioned ahead within a distance range equal to or greater than the braking distance while satisfying the eye-safe criteria, as in the first control mode. Further, in the second control mode, the DSP 16 sets the emission power of the emitted light Lo to be weaker than usual in the rearward direction of the vehicle where the need for obstacle detection is relatively low, and the emitted light Lo The Lo intervals may be coarse.

(2-2) When turning right at an intersection When the DSP 16 detects that the vehicle is approaching the intersection where the right turn is to be made within a predetermined distance based on the current position information IP, the map information IM, and the route information IR, the following is explained. Injection control is performed in the third control mode. In this case, for example, the DSP 16 recognizes the road on which the vehicle is currently traveling based on the current position information IP and the map information IM, and determines whether there is a right turn point on the recognized road based on the route information IR. When the DSP 16 determines that there is a right turn point, it determines whether the distance from the current position to the right turn point is within a predetermined distance, and if the distance is within the predetermined distance, the third control mode is selected. Execute.

FIG. 13 is a plan view of the surroundings of the vehicle schematically showing the emission power and the emission interval of the emission light Lo in the 360-degree scanning in the third control mode with dashed arrows. In the example of FIG. 13, the DSP 16 recognizes that the intersection 82 corresponding to the next right turn point is approaching within a predetermined distance based on the current position information IP, the map information IM, and the route information IR, and switches to the third control mode. Execute.

In the example of FIG. 13, the DSP 16 increases the emission power of the emitted light Lo in the forward right direction (in FIG. 13, the direction within about 45 degrees to the right from the straight ahead direction), which is the direction in which an oncoming vehicle is estimated to exist. is also getting stronger. In addition, in consideration of satisfying the eye-safe standard, the emitted light Lo is emitted coarsely (that is, the scanning angular resolution is lowered). In this way, in the third control mode, when turning right when oncoming vehicles should be preferentially detected, the injection power is increased more than usual so that even oncoming vehicles that are some distance away can be detected in consideration of the fact that oncoming vehicles are moving at high speed. also strengthen This allows the DSP 16 to preferably detect oncoming vehicles while preferably complying with eye-safe standards.

In the example of FIG. 13, the DSP 16 sets the emission power and the scanning angular resolution of the emitted light Lo to normal settings or settings lower than normal in directions other than the forward right direction, which is the direction in which an oncoming vehicle is estimated to exist. I have to.

(2-3) When Turning Left at an Intersection When the DSP 16 detects that the vehicle is approaching an intersection to turn left within a predetermined distance based on the current position information IP, the map information IM, and the route information IR, the following is explained. The emission power of the emission light Lo and the scanning angular resolution are controlled by the fourth control mode. In this case, for example, the DSP 16 recognizes the road on which the vehicle is currently traveling based on the current position information IP and the map information IM, and determines whether there is a left turn point on the recognized road based on the route information IR. When the DSP 16 determines that a left turn point exists, it determines whether the distance from the current position to the left turn point is within a predetermined distance, and if the distance is within a predetermined distance, the fourth control mode is selected. Execute.

FIG. 14 is a plan view of the surroundings of the vehicle schematically showing the emission power of the emission light Lo and the scanning angular resolution in 360-degree scanning in the fourth control mode with dashed arrows. In the example of FIG. 14, the DSP 16 recognizes that the intersection 83 corresponding to the next left turn point is approaching within a predetermined distance based on the current position information IP, the map information IM, and the route information IR, and switches to the fourth control mode. Execute.

In the example of FIG. 14, the DSP 16 detects the left lateral direction (the left direction of the vehicle in FIG. (range of about 120 degrees) is weak, and the emitted light Lo is emitted densely.

In general, when turning left, it is necessary to preferentially detect a relatively nearby object existing on the left side of the vehicle in order to prevent a pedestrian or a two-wheeled vehicle from getting caught in the crossing. In consideration of the above, in the fourth control mode, in the left lateral direction, the scanning angle resolution is increased so as to reliably detect pedestrians and two-wheeled vehicles that are crossing, while making the injection power weaker than usual. As a result, the DSP 16 can accurately detect a pedestrian, a two-wheeled vehicle, or the like to which attention should be paid, while suitably satisfying the eye-safe standard when turning left.

In addition, in the example of FIG. 14, the DSP 16 sets the emission power and scanning angular resolution of the emission light Lo to normal settings or settings lower than normal in directions other than the left lateral direction.

As described above, the lidar 1 according to the embodiment includes the scanning unit 55 that emits the emitted light Lo according to the pulse trigger signal PT, the APD 41 that receives the return light Lr of the emitted light Lo, and the DSP 16 . The DSP 16 acquires current position information IP indicating the position of the vehicle from the vehicle-mounted device 2 . Then, the DSP 16 controls the intensity and emission frequency of the emission light Lo emitted by the scanning unit 55 based on the current position information IP and the like. As a result, the rider 1 can suitably improve the object detection performance necessary for automatic driving or the like.

[Modification]
Next, a modification suitable for the embodiment will be described. The following modifications may be combined and applied to the above embodiment.

(Modification 1)
The DSP 16 receives turn signal information from the vehicle using a predetermined communication protocol such as CAN instead of receiving route information IR and the like from the in-vehicle device 2, thereby determining whether or not execution of the third or fourth control mode is necessary. may

In this case, the DSP 16 determines that the third control mode should be executed when the winker information indicating to turn right is received, and the fourth control mode should be executed when the winker information indicating to turn left is received. I judge. This aspect also allows the rider 1 to suitably detect that the vehicle is approaching a right turn point or a left turn point, and execute injection control suitable for the situation. In this case, the winker information is an example of "route information" in the present invention.

(Modification 2)
The DSP 16 may control only either the emission power or the emission interval of the emission light Lo as the emission control.

For example, when the DSP 16 adjusts only the emission power of the emitted light Lo, the first control mode makes the emission power in the forward direction stronger than the emission power in other directions, and the third control mode adjusts the emission power in the right forward direction. Make the injection power stronger than the injection power in other directions. Further, when the DSP 16 adjusts only the emission interval of the emission light Lo, in the first control mode, the emission light Lo is emitted more densely in the side direction than in other directions, and in the second and fourth control modes, the left side The emission light Lo is emitted more densely in the surface direction than in other directions. In this manner, the DSP 16 can preferably improve the detection accuracy of the target to be detected with priority in this modified example as well.

1 rider 2 on-vehicle device 10 ASIC
16 DSPs
17 Transmitter high voltage generator (TXHV)
18 Receiver high voltage generator (RXHV)
30 transmitter 35 LD
40 receiver 50 scanning optical unit

Claims (14)

A detection device that can be arranged on a moving body,
an emission part that emits light;
a light receiving unit that receives the light reflected by the object,
The emitting section emits the light emitted to the side with an intensity higher than the intensity of the light emitted to the opposite side, or emits the light emitted to the side to the opposite side. A detection device that emits at a frequency higher than the frequency of said light emitted to the. A detection device that can be arranged on a moving body,
an emission part that emits light;
a light receiving unit that receives the light reflected by the object;
a control unit that controls at least one of the intensity of the light emitted by the emission unit and the frequency of emission,
The control unit controls the intensity of the light emitted sideways to be higher than the intensity of the light emitted sideways on the opposite side, or controls the frequency of the light emitted sideways. , a detection device controlled to be high relative to the frequency of said light emerging laterally on the opposite side. Further comprising a first acquisition unit that acquires position information indicating the position of the mobile body,
Based on the position information, the emission unit emits the light emitted sideways with an intensity higher than the intensity of the light emitted sideways on the opposite side, or the light emitted sideways. is emitted with a higher frequency than the frequency of said light emitted laterally on the opposite side. Based on the presence or absence of a specific point on the road, the emitting unit emits the light emitted to the side with an intensity higher than the intensity of the light emitted to the opposite side, or emits the light to the side 2. The detection device according to claim 1, wherein the emitted light is emitted with a frequency higher than the frequency of the emitted light to the opposite side. Further comprising a first acquisition unit that acquires position information indicating the position of the mobile body,
Based on the position information, the control unit controls the intensity of the light emitted to the side to be higher than the intensity of the light emitted to the opposite side, or 3. The detecting device according to claim 2, wherein the frequency of said emitted light is controlled to be higher than the frequency of said light emitted to the opposite side. The control unit controls the intensity of the light emitted to the side based on the presence or absence of a specific point on the road so that the intensity of the light emitted to the side is higher than the intensity of the light emitted to the opposite side, or 3. The detection device according to claim 2, wherein the frequency of said light emitted sideways is controlled to be higher than the frequency of said light emitted sideways on the opposite side. further comprising a second acquisition unit that acquires route information related to the movement route of the mobile body,
Based on the position information and the route information, the emitting unit emits the light emitted sideways with an intensity higher than the intensity of the light emitted sideways on the opposite side, or emits the light sideways. 4. The detection device according to claim 3, wherein the emitted light is emitted with a frequency higher than the frequency of the emitted light to the opposite side. 8. The detection device according to claim 3, wherein the light emitting unit emits the light so that the intensity and the frequency of emission of the light are different between the front side and the side side of the moving body. 9. The detection device according to claim 8, wherein the emitting unit emits the light toward the side of the moving body so that the intensity of the light in front of the moving body is high and the frequency of emission is low. When the moving body makes a right turn, the emitting part emits the light so that the front right side of the moving body has a higher intensity of the light and the light is emitted less frequently than the other side. 8. A detection device according to claim 7. When the moving body makes a left turn, the emitting part emits the light so that the left side of the moving body has a higher intensity of the light and the light is emitted less frequently than the other side of the moving body. Item 11. The detection device according to Item 7 or 10. It has an emitting part that emits light, a light receiving part that receives the light reflected by an object, and a first acquisition part that acquires position information indicating the position of the moving body, and can be arranged on the moving body. A control method executed by a detection device,
a control step of controlling at least one of the intensity and frequency of light emitted by the emission unit;
In the controlling step, based on the position information, the intensity of the light emitted to the side is controlled so as to be higher than the intensity of the light emitted to the opposite side, or A control method for controlling the frequency of the emitted light to be higher than the frequency of the light emitted to the opposite side. It has an emitting part that emits light, a light receiving part that receives the light reflected by an object, and a first acquisition part that acquires position information indicating the position of the moving body, and can be arranged on the moving body. A program executed by a computer of a detection device,
The injection unit controls at least one of the intensity of emitted light and the frequency of emission,
Based on the position information, the emitting unit controls the intensity of the light emitted to the side to be higher than the intensity of the light emitted to the opposite side, or A program for controlling the frequency of the emitted light to be higher than the frequency of the light emitted to the opposite side. A storage medium storing the program according to claim 13.

Images