JP2023075170A - sensor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to reduce erroneous detection due to ambient light.

SOLUTION: A LiDAR comprises: a light source for intermittently irradiating a laser beam to scan a predetermined region; a light receiving element for receiving an external laser beam including reflected light of the laser beam to output a light receiving signal; and a control unit that restricts use of the light reception signal during a period of receiving reflected light based on a light receiving signal level during a period in which no reflected light is received in the light receiving element.

SELECTED DRAWING: Figure 4

COPYRIGHT: (C)2023,JPO&INPIT

Description

The present invention relates to a sensor device such as a lidar (LiDAR: Light Detection And Ranging).

In recent years, in ADAS (Advanced Driver Assistance Systems), automatic driving, etc., lidars are used as sensors for detecting obstacles and road surfaces around moving bodies such as vehicles. A lidar is, for example, a sensor that detects an obstacle or the like in front of a moving body by irradiating a laser beam in front of the moving body and receiving reflected light from an object in front of the moving body. See Reference 1).

A lidar detects an object such as an obstacle by receiving reflected light of an irradiated laser beam. However, various types of disturbance light other than the reflected light of the irradiated laser light enter the lidar, and the disturbance light may cause erroneous detection.

In order to prevent erroneous detection due to such disturbance light, in Patent Document 2, an adder circuit 23 is provided from a plurality of light receiving elements arranged within a predicted range of an imaging position corresponding to the irradiation direction of the laser light LT. A plurality of output analog detection signals are selected, and the selected analog detection signals are added together to output an analog reception signal. It is described that by doing so, erroneous detection of extraneous light components can be prevented even in an environment where ambient light components are received.

JP-A-11-94945 JP 2018-4471 A

In the case of the method described in Patent Document 2, an array photodetector having N photodetectors is required. Therefore, it cannot be applied to a configuration in which, for example, pulsed light is irradiated so as to scan a predetermined range and the reflected light of each pulsed light is sequentially received by one light receiving element.

One example of the problem to be solved by the present invention is that erroneous detection due to ambient light can be reduced.

In order to solve the above problems, the invention according to claim 1 provides an irradiation unit that intermittently irradiates light at predetermined time intervals to scan a predetermined area, and an external light including reflected light of the light. a light receiving unit that receives light and outputs a light reception signal; The reflected light set immediately before the first period in the non-irradiation period is received based on the level of the light reception signal corresponding to the light received by the light receiving unit during the first period, which is a period in which the reflected light is not received. a generating unit that generates restriction information for restricting the use of the received light signal by the light received by the light receiving unit during a second period that is a period in which the light receiving unit receives the light during the first period one of a first level, which is the level of a signal, and a second level, which is the level of the received light signal in the first period immediately before the first period in which the first level is acquired The restriction information is generated when the threshold is equal to or more than the threshold.

The invention according to claim 2 comprises an irradiation unit that intermittently irradiates light at predetermined time intervals to scan a predetermined area, and an irradiation unit that receives external light including reflected light of the light and outputs a light reception signal. A sensor control method executed in a sensor device having a light receiving unit that emits light, and is set within a non-irradiation period that is a period from when the irradiating unit irradiates the light to when it next irradiates the light. The reflected light set immediately before the first period in the non-irradiation period based on the level of the light reception signal due to the light received by the light receiving unit during the first period, which is a period in which the reflected light is not received. a generation step of generating restriction information for restricting the use of the light reception signal by the light received by the light receiving unit during a second period, which is a period for receiving the light received in the first period one of a first level, which is the level of a signal, and a second level, which is the level of the received light signal in the first period immediately before the first period in which the first level is acquired The restriction information is generated when the threshold is equal to or more than the threshold.

The invention according to claim 3 is characterized in that the sensor control method according to claim 2 is executed by a computer.

1 is an explanatory diagram showing a configuration example of a lidar according to a first embodiment of the present invention; FIG. FIG. 2 is a timing chart when the use of a light receiving signal received by a light receiving element of the lidar shown in FIG. 1 is not restricted; FIG. FIG. 2 is a timing chart for restricting the use of a light receiving signal received by a light receiving element of the lidar shown in FIG. 1; FIG. 2 is a flow chart of the operation of the lidar shown in FIG. 1; FIG. 9 is a timing chart for outputting a light receiving signal received by the light receiving element of the lidar according to the second embodiment of the present invention and limiting information; FIG. Figure 6 is a flow chart of the operation of the lidar shown in Figure 5; FIG. 11 is an explanatory diagram showing a configuration example of a lidar according to a third embodiment of the present invention; 8 is a timing chart when irradiation of laser light from the light source of the lidar shown in FIG. 7 is not restricted; FIG. 8 is a timing chart when limiting irradiation of laser light from the light source of the lidar shown in FIG. 7; FIG. Figure 8 is a flow chart of the operation of the lidar shown in Figure 7; FIG. 11 is an explanatory diagram showing a configuration example of a lidar according to a fourth embodiment of the present invention; FIG. 12 is a timing chart when the use of the light receiving signal received by the light receiving element of the lidar shown in FIG. 11 is not limited; FIG. 12 is a timing chart for restricting the use of light receiving signals received by the light receiving elements of the lidar shown in FIG. 11; FIG. FIG. 12 is a timing chart of another case of restricting the use of the light receiving signal received by the light receiving element of the lidar shown in FIG. 11; Figure 14 is a flow chart of the operation of the lidar shown in Figure 13; Figure 15 is a flow chart of the operation of the lidar shown in Figure 14; FIG. 12 is a timing chart for outputting a light receiving signal received by the light receiving element of the lidar according to the fifth embodiment of the present invention and limiting information; FIG. FIG. 18 is a timing chart according to a modification of FIG. 17; FIG. FIG. 18 is a timing chart according to a modification of FIG. 17; FIG. Figure 18 is a flow chart of the operation of the lidar shown in Figure 17; Figure 20 is a flow chart of the operation of the lidar shown in Figures 18 and 19; FIG. 20 is an explanatory diagram showing a configuration example of a lidar according to the sixth embodiment of the present invention; 23 is a timing chart when irradiation of laser light from the light source of the lidar shown in FIG. 22 is not restricted; FIG. 23 is a timing chart when limiting irradiation of laser light from the light source of the lidar shown in FIG. 22; FIG. Figure 23 is a flow chart of the operation of the lidar shown in Figure 22;

A sensor device according to an embodiment of the present invention will be described below. A sensor device according to an embodiment of the present invention includes an irradiation unit that intermittently emits light to scan a predetermined area, and a light receiving unit that receives light from the outside including reflected light of the light and outputs a light reception signal. and a controller for restricting the use of the light receiving signal during the period when the reflected light is received based on the light receiving signal level during the period when the reflected light is not received in the light receiving section. By doing so, it is possible to determine that disturbance light is being received from the received light signal level during the period in which reflected light is not received, and in this case, restrictions such as prohibiting the use of the received light signal output by the light receiving unit are made. can do Therefore, erroneous detection due to ambient light can be reduced.

Further, the control unit may determine the effectiveness of the use of the light receiving signal during the reflected light receiving period when the light receiving signal level during the reflected light receiving period is equal to or higher than a predetermined threshold. By doing so, it is determined that disturbance light is being received when the level of the received light signal during a period in which reflected light is not received is equal to or higher than the threshold value, and the effectiveness of the use of the received light signal output by the light receiving unit is determined. can.

A sensor device according to another embodiment of the present invention includes an irradiation unit that intermittently emits light to scan a predetermined area, and an irradiation unit that receives external light including reflected light of the light and generates a light reception signal. a sensor that outputs a light receiving portion; and a control portion that limits irradiation of light from the irradiation portion based on a light receiving signal level during a period in which the light receiving portion does not receive reflected light. By doing so, it is possible to determine that disturbance light is being received from the received light signal level during the period in which reflected light is not received. be able to. In other words, by stopping the irradiation of light when detecting ambient light and receiving a waveform different from the received light signal due to the reflected light of the irradiated light, it becomes possible to filter the waveform by judging it as noise, etc. False positives can be reduced.

Further, the control unit may limit the irradiation of light from the irradiation unit when the received light signal level during the period in which the reflected light is not received is equal to or higher than a predetermined threshold value. By doing so, when the received light signal level during the period in which the reflected light is not received becomes equal to or higher than the threshold value, it is determined that the disturbance light is received, and the irradiation of the light from the irradiation unit is restricted, for example. be able to.

A sensor device according to another embodiment of the present invention includes an irradiation unit that intermittently emits light to scan a predetermined area, and an irradiation unit that receives external light including reflected light of the light and generates a light reception signal. a light receiving unit for outputting; and a sensor having a light receiving unit that generates restriction information for limiting use of the light receiving signal during the period when the reflected light is received, based on the level of the light receiving signal during the period when the reflected light is not received. a generator; By doing so, it is possible to determine that disturbance light is being received from the received light signal level during the period in which reflected light is not received. , the use of the received light signal can be restricted by referring to the flag in the subsequent processing.

Further, the control unit may output the restriction information when the received light signal level during the period in which the reflected light is not received is equal to or higher than a predetermined threshold. By doing so, when light having an intensity equal to or higher than the threshold is received during a period in which reflected light is not received, it is possible to recognize that disturbance light has been received and generate restriction information.

A sensor control method according to an embodiment of the present invention includes an irradiation unit that intermittently irradiates light to scan a predetermined area; A sensor control method executed in a sensor device having a light receiving unit that outputs, wherein the light receiving unit utilizes a light receiving signal during a period in which reflected light is received based on a light receiving signal level in a period in which reflected light is not received in the light receiving unit. Includes limiting control steps. By doing so, it is possible to determine that disturbance light is being received from the received light signal level during the period in which reflected light is not received, and in this case, restrictions such as prohibiting the use of the received light signal output by the light receiving unit are made. can do Therefore, erroneous detection due to ambient light can be reduced.

Also, the sensor control method described above may be executed by a computer. By doing so, it is possible to determine that disturbance light is being received from the received light signal level during the period in which reflected light is not received. It is possible to set restrictions such as not to allow Therefore, erroneous detection due to ambient light can be reduced.

Further, a sensor control method according to another embodiment of the present invention includes an irradiation unit that intermittently irradiates light to scan a predetermined area, and an irradiation unit that receives light from the outside including reflected light of the light and receives a light reception signal. A sensor control method executed in a sensor device having a light receiving unit that outputs a light receiving unit that limits the irradiation of light from the irradiating unit based on the light receiving signal level during a period in which the light receiving unit does not receive reflected light. Includes process. By doing so, it is possible to determine that disturbance light is being received from the received light signal level during the period in which reflected light is not received. be able to. In other words, by stopping the irradiation of light when detecting ambient light and receiving a waveform different from the received light signal due to the reflected light of the irradiated light, it becomes possible to filter the waveform by judging it as noise, etc. False positives can be reduced.

Also, the sensor control method described above may be executed by a computer. By doing so, it is possible to determine that disturbance light is being received from the received light signal level during the period in which reflected light is not received. etc. can be restricted.

Further, a sensor control method according to another embodiment of the present invention includes an irradiation unit that intermittently irradiates light to scan a predetermined area, and an irradiation unit that receives light from the outside including the reflected light of the light and receives a light reception signal. and a light receiving unit for outputting a period of time during which the reflected light is received based on a light receiving signal level during a period during which the reflected light is not received in the light receiving unit. and a generating step of generating restriction information for restricting use of the received light signal. By doing so, it is possible to determine that disturbance light is being received from the received light signal level during the period in which reflected light is not received. , the use of the received light signal can be restricted by referring to the flag in the subsequent processing.

Also, the sensor control method described above may be executed by a computer. By doing so, it can be determined that disturbance light is being received from the received light signal level during the period in which reflected light is not received. In this case, a computer is used to generate restriction information such as a flag. , it is possible to limit the use of the received light signal by referring to the flag in the subsequent processing.

A sensor device according to a first embodiment of the present invention will be described with reference to FIGS. 1 to 4. FIG. A lidar 1 as a sensor device is mounted, for example, on a vehicle as a mobile object.

The rider 1 irradiates a predetermined area with light and receives the reflected light to detect the road surface and obstacles on the road. The configuration of the rider 1 is shown in FIG.

As shown in FIG. 1, the lidar 1 includes a light source 11, a collimating lens 12, a beam splitter 13, a MEMS mirror 14, a projecting/receiving lens 15, a condenser lens 16, a light receiving element 17, and a control unit. 18 and a photodetector 19 .

The light source 11 as an irradiating section is composed of, for example, a laser diode. The light source 11 intermittently emits (irradiates) pulsed laser light of a predetermined wavelength.

The collimating lens 12 collimates the laser light emitted from the light source 11 into a parallel light beam. The beam splitter 13 outputs the laser light collimated by the collimator lens 12 to the MEMS mirror 14 and reflects the incident light reflected by the MEMS mirror 14 toward the condenser lens 16 .

The MEMS mirror 14 horizontally and vertically scans the laser light emitted from the beam splitter 13 toward the area where the object 100 exists. Here, the object 100 indicates, for example, a road surface, an obstacle, or the like. Also, the MEMS mirror 14 reflects incident light, which is incident on the light projecting/receiving lens 15 after being reflected by the object 100 , to the beam splitter 13 . The MEMS mirror 14 is a mirror configured by MEMS (Micro Electro Mechanical Systems) and driven by an actuator (not shown) integrally formed with the mirror. Also, the MEMS mirror 14 may be other beam deflection means such as a galvanomirror or a polygon mirror.

The light projecting/receiving lens 15 irradiates (projects) the laser light reflected by the MEMS mirror 14 onto a region where the object 100 exists. Reflected light, which is laser light reflected by the object 100 , or the like is incident (received) on the light projecting/receiving lens 15 as incident light.

The condenser lens 16 is provided between the beam splitter 13 and the light receiving element 17 and collects the light reflected by the beam splitter 13 onto the light receiving element 17 .

A light-receiving element 17 as a light-receiving part receives the reflected light condensed by the condensing lens 16 . The light receiving element 17 is composed of, for example, one (single pixel) avalanche photodiode (APD). The light receiving element 17 outputs a signal (light receiving signal) whose level corresponds to the intensity of the received light.

The control unit 18 restricts the use of the light reception signal received by the light receiving element 17 based on the light received by the photodetector 19 . Further, when the use is not restricted, the control unit 18 outputs the light receiving signal received by the light receiving element 17 to, for example, an ADAS or an automatic driving control device. The control unit 18 is composed of a microcomputer having a CPU (Central Processing Unit), for example. Alternatively, a logic device such as an FPGA (Field-Programmable Gate Array) may be used.

The photodetector 19 receives light in the direction of the object 100 in the same manner as the light projecting/receiving lens 15 . In other words, it suffices to receive light in an area including a predetermined area to be scanned with laser light. The photodetector 19 outputs the intensity of the received light to the controller 18 as a luminance value. In this embodiment, the photodetector 19 is used as the second sensor, but the photodetector 19 may be replaced by a camera or the like. (Capturing) I wish I could.

Moreover, the photodetector 19 is not limited to being newly installed, and may be a sensor such as an on-vehicle camera or a light receiving element that is already installed. In this embodiment, the purpose of the photodetector 19 is to detect ambient light that the light receiving element 17 erroneously detects as reflected light. may have.

As is well known, the lidar 1 can acquire the state of the object 100 in the scanning area as a point group by intermittently scanning a predetermined area with a laser beam.

As is clear from the above description, the light source 11, the collimating lens 12, the beam splitter 13, the MEMS mirror 14, the projecting/receiving lens 15, the condensing lens 16, and the light receiving element 17 serve as the first sensor. Function. The photodetector 19 then functions as a second sensor.

Next, the operation principle of the lidar 1 in this embodiment will be described with reference to FIGS. 2 and 3. FIG. FIG. 2 is a timing chart when the use of the light receiving signal received by the light receiving element 17 is not restricted. In FIG. 2, the light source 11 intermittently emits pulsed light at predetermined intervals. The light receiving element 17 receives the reflected light of the pulsed light. The photodetector in FIG. 2 indicates the luminance value of the light received by the photodetector 19 . In FIG. 2, since the luminance value is less than the predetermined threshold value, the controller 18 outputs the received light signal of the light receiving element 17 as it is.

On the other hand, FIG. 3 is a timing chart for restricting the use of the light receiving signal received by the light receiving element 17. In FIG. In FIG. 3, the waveforms of the light source 11 and the light receiving element 17 are the same as those in FIG. does not output the light receiving signal of the light receiving element 17 during this time t1 to time t2. This is because the luminance value of the light received by the photodetector 19 is equal to or higher than the threshold between time t1 and time t2, and transient disturbance light other than reflected light (for example, thunder, camera flash, fireworks, etc.) ) has entered the light receiving element 17 between time t1 and time t2. (Mask). In other words, the light receiving signal of the light receiving element 17 between time t1 and time t2 is restricted so as not to be used in subsequent processing.

Next, the operation (sensor control method) of the rider 1 described above will be described with reference to the flowchart of FIG. The flow chart of FIG. 4 is executed by the control unit 18 . Further, by configuring the flowchart shown in FIG. 4 as a program to be executed by the CPU of the control unit 18, a sensor control program can be obtained.

First, in step S<b>11 , a received light signal is obtained from the photodetector 19 . Next, in step S12, the brightness value of the received light signal acquired in step S11 is calculated. That is, in step S12, the intensity of light received by the photodetector 19 is calculated.

Next, in step S13, it is determined whether or not the luminance value calculated in step S12 is equal to or greater than the above-described predetermined threshold value. The received light signal of element 17 is gated. In step S13, the light receiving signal is gated when it can be determined from the luminance value that strong disturbance light that affects the operation of the rider 1 has been detected. That is, the control unit 18 restricts the use of the light receiving signal output by the light receiving element 17 when the intensity of the light received by the photodetector 19 exceeds a predetermined threshold value. Therefore, steps S11 to S14 function as control steps.

On the other hand, in step S13, if the luminance value calculated in step S12 is less than the threshold value (NO), the light receiving signal of the light receiving element 17 is not gated in step S15.

In the description of FIGS. 3 and 4, since the photodetector 19 is used as the second sensor, the luminance value is simply the luminance value. However, in the case of an imaging means such as a camera, the average luminance value for a predetermined period of time, such as one frame period, may be used for determination.

According to this embodiment, the lidar 1 has a light source 11 that emits laser light and scans a predetermined range, and a light receiving element 17 that receives the reflected light of the laser light and outputs a light reception signal, Furthermore, the control unit 18 acquires the light reception signal of the photodetector 19 that receives the light in the area including the range scanned by the light from the light source 11, and restricts the use of the light reception signal output by the light receiving unit based on the light reception signal. and have. By doing so, when the photodetector 19 picks up an image of disturbance light such as thunder or a flash of a camera, the received light signal output from the light receiving element 17 is gated based on the result of reception of the disturbance light by the photodetector 19. can be restricted. Therefore, erroneous detection due to ambient light can be reduced.

Further, the control unit 18 gates the light receiving signal output from the light receiving element 17 when the luminance value of the light received by the photodetector 19 exceeds a predetermined threshold value. By doing so, when the photodetector 19 receives a luminance value equal to or higher than the threshold value, it is possible to recognize that disturbance light has been received and gate the received light signal output from the light receiving element 17 .

Next, a lidar 1 according to a second embodiment of the invention will be described with reference to FIGS. 5 and 6. FIG. The same reference numerals are given to the same parts as those of the first embodiment described above, and the description thereof will be omitted.

In the first embodiment, the use of the light receiving signal of the light receiving element 17 was restricted based on the light received by the photodetector 19, but in the present embodiment, the use of the light receiving signal is restricted based on the light received by the photodetector 19. A flag signal is output as restriction information for restriction.

The configuration of this embodiment is the same as that of FIG. FIG. 5 shows a timing chart for outputting the light receiving signal received by the light receiving element of the lidar according to the present embodiment and the limit information.

In this embodiment, as shown in FIG. 5, the light reception signal of the receiving element 17 is output as it is, and a flag signal corresponding to the period from time t1 to time t2 when the transient disturbance light other than the reflected light is incident is output. output. In FIG. 5, light-receiving periods #1 to #4 are light-receiving periods of reflected light corresponding to pulsed light emitted from the light source. The signal processing period indicates the period of signal processing at the output destination of the control section 18 . Since the distance at which the rider 1B can detect an obstacle or the like can be set in advance depending on the intensity of the light emitted from the light source 11 or the like, the light receiving period can be predicted. Further, the signal processing period is a period between the end of the corresponding light receiving period and the start of the next light receiving period, but the signal processing period may be started during the light receiving period or at the start of the light receiving period.

In FIG. 5, the flag signal is set to ON when disturbance light is received. Here, since the flag signal is in the ON state during the signal processing periods (distance calculation, etc.) of #1, #2, and #3, which were periods during which the ambient light was received, the flag signal is controlled not to be used in subsequent processing. can be done.

Next, the operation (sensor control method) of the rider 1 in this embodiment will be described with reference to the flowchart of FIG. The flowchart of FIG. 6 is executed by the control unit 18 . Further, by configuring the flowchart shown in FIG. 6 as a program to be executed by the CPU of the control unit 18, a sensor control program can be obtained.

First, in step S21, it is determined whether or not the light receiving element 17 is in a period during which it receives reflected light. goes to step S28.

Next, in step S22, it is determined whether or not the flag signal is OFF, and if it is ON (NO), the process returns to step S21. On the other hand, in the case of OFF (in the case of YES), the process proceeds to step S23, and a received light signal is acquired from the photodetector 19 in the same manner as in step S11 of FIG. Then, in step S24, the luminance value of the received light signal obtained in step S23 is calculated in the same manner as in step S12 of FIG.

Next, in step S25, if the luminance value calculated in step S24 is equal to or greater than the above-described predetermined threshold value (if YES), in step S26, the flag signal is turned ON as described above. That is, the control unit 18 generates restriction information for restricting the use of the received light signal output by the light receiving unit when the intensity of the light received by the photodetector 19 exceeds a predetermined threshold. Therefore, steps S23 to S26 function as generation steps.

On the other hand, if the luminance value calculated in step S24 is less than the threshold value in step S25 (NO), the flag signal is turned OFF in step S27.

Also, in step S28, since it is determined in step S21 that it is a period during which no reflected light is received, a flag signal is output to the subsequent signal processing section or the like. Next, in step S29, it is determined whether or not a signal or the like indicating completion of signal processing has been received from the subsequent signal processing section or the like. If received, the flag signal is turned off in step S2A.

According to this embodiment, the lidar 1 has a light source 11 that emits laser light and scans a predetermined range, and a light receiving element 17 that receives the reflected light of the laser light and outputs a light reception signal, Further, a light reception signal of the photodetector 19 that receives light in an area including the range scanned by the light from the light source 11 is acquired, and the use of the light reception signal output by the light receiving element 17 is restricted based on the light reception signal. and a control unit 18 that generates a flag signal. By doing so, when the photodetector 19 receives disturbance light such as thunder or a flash of a camera, a flag signal is generated and output so that the flag can be referred to in subsequent processing. The use of received light signals can be restricted.

Also, the control unit 18 outputs a flag signal when the luminance value of the light received by the photodetector 19 is greater than or equal to a predetermined threshold value. By doing so, when the photodetector 19 receives light having an intensity equal to or higher than the threshold, it is possible to recognize that disturbance light has been received and generate a flag signal.

In addition to restricting the use of the light receiving signal of the light receiving element 17 as the flag signal, the flag signal may be used as the reliability of object recognition. For example, when the flag signal is ON, there is ambient light exceeding a predetermined threshold, and the reliability of object recognition decreases. can be made to rise.

Next, a rider 1A according to a third embodiment of the invention will be described with reference to FIGS. 7 to 10. FIG. The same parts as those in the first and second embodiments described above are denoted by the same reference numerals, and descriptions thereof are omitted.

In the first embodiment, the use of the light reception signal of the light receiving element 17 was restricted based on the light received by the photodetector 19, but in the present embodiment, the laser light emitted from the light source 11 is based on the light received by the photodetector 19. limit the irradiation of That is, the control unit 18 acquires a light reception signal received by the photodetector 19 that captures an image of an area including the scanning range, and limits irradiation from the light source 11 based on the light reception signal.

FIG. 7 is a configuration diagram of the rider 1A according to this embodiment. The configuration shown in FIG. 7 differs from FIG. 1 in that the light receiving element 17 is connected to the control unit 18 instead of the light source 11 .

The principle of operation of the rider 1A in this embodiment will be described with reference to FIGS. 8 and 9. FIG. FIG. 8 is a timing chart when irradiation of laser light from the light source 11 is not restricted, and is the same as FIG. 2 except that there is no output from the control section of FIG.

On the other hand, FIG. 9 is a timing chart for limiting the irradiation of laser light from the light source 11. In FIG. In FIG. 9, since the luminance value of the light received by the photodetector 19 is equal to or greater than the predetermined threshold between time t1 and time t2, the controller 18 controls the laser light from the light source 11 between time t1 and time t2. Do not irradiate This is because the luminance value of the light received by the photodetector 19 is equal to or higher than the threshold between time t1 and time t2, and transient disturbance light other than reflected light (for example, thunder, camera flash, fireworks, etc.) ) is incident thereon, it is determined that there is a high possibility of erroneously detecting light other than the reflected light between time t1 and time t2, and the irradiation itself from the light source 11 is stopped.

Next, the operation (sensor control method) of the rider 1A described above will be described with reference to the flowchart of FIG. The flowchart of FIG. 10 is executed by the control unit 18 . Further, by configuring the flowchart shown in FIG. 10 as a program to be executed by the CPU of the control unit 18, a sensor control program can be obtained.

Steps S11 to S13 are the same as those in the flowchart of FIG. In step S13, if the brightness value calculated in step S12 is equal to or greater than the above-described predetermined threshold value (if YES), in step S14B, irradiation of laser light from the light source 11 is stopped as described above. That is, the control unit 18 limits irradiation from the light source 11 when the intensity of the light received by the photodetector 19 is equal to or higher than a predetermined threshold. Therefore, steps S11 to S14B function as control steps.

On the other hand, if the luminance value calculated in step S12 is less than the threshold value in step S13 (NO), the irradiation of the laser light from the light source 11 is not stopped in step S15B.

According to this embodiment, the lidar 1 has a light source 11 that emits laser light and scans a predetermined range, and a light receiving element 17 that receives the reflected light of the laser light and outputs a light reception signal, Furthermore, a control unit that acquires a light reception signal received by the photodetector 19 that captures an image of an area including the range scanned by the light from the light source 11 and limits the irradiation of the laser light from the light source 11 based on the light reception signal. 18 and . By doing so, when the photodetector 19 picks up an image of ambient light such as thunder or a flash of a camera, irradiation of the laser beam from the light source 11 is prevented based on the result of the image of the ambient light by the photodetector 19. etc. can be restricted. In other words, by stopping the irradiation of the laser light when detecting the disturbance light and receiving a waveform different from the received light signal due to the reflected light of the irradiation light, it becomes possible to filter the waveform by judging it as noise, etc., and to filter the disturbance light. It is possible to reduce erroneous detection due to

Further, the control unit 18 limits irradiation from the light source 11 when the luminance value of the light received by the photodetector 19 is equal to or higher than a predetermined threshold. By doing so, when the photodetector 19 receives a luminance value equal to or higher than the threshold, it is possible to recognize that the ambient light has been received and limit the irradiation from the light source 11 .

Next, a lidar 1B according to a fourth embodiment of the invention will be described with reference to FIGS. 11 to 15. FIG. The same parts as those of the first to third embodiments described above are denoted by the same reference numerals, and descriptions thereof are omitted.

In the first embodiment, the light receiving signal of the light receiving element 17 is gated based on the light received by the photodetector 19. However, in the present embodiment, the photodetector 19 is not used and the light reflected by the light receiving element 17 is not received. Based on the received light signal level of the period, the received light signal of the subsequent period for receiving the reflected light is gated. That is, the control unit 18 restricts the use of the light receiving signal during the period during which the reflected light is received based on the light receiving signal level during the period during which the reflected light is not received by the light receiving element 17 .

FIG. 11 is a configuration diagram of the rider 1B according to this embodiment. The configuration shown in FIG. 11 differs from the configuration shown in FIG. 1 in that the photodetector 19 is omitted.

The principle of operation of the rider 1B in this embodiment will be described with reference to FIGS. 12 to 14. FIG. FIG. 12 is a timing chart when the use of the light receiving signal received by the light receiving element 17 is not restricted. In FIG. 12, the light source 11 emits pulsed light at predetermined intervals. The light receiving element 17 receives the reflected light of the pulsed light. Light-receiving periods #1 to #4 are light-receiving periods for reflected light corresponding to pulsed light emitted from the light source. Then, the control unit 18 outputs the received light signal of the light receiving element 17 as it is.

On the other hand, FIG. 13 is a timing chart for restricting the use of the light receiving signal received by the light receiving element 17. In FIG. In FIG. 13, the waveform of the light source 11 is similar to that in FIG. At this time, the light receiving signal level of the light receiving element 17 rises above the threshold. Therefore, it is judged that there is a high possibility that the light reception signal received at the timing of receiving the reflected light immediately after the time t3 to time t4 erroneously detects light other than the reflected light, and the light reception signal of the light receiving element 17 is gated (masked). )are doing. In other words, the light receiving signal of the light receiving element 17 between time t3 and time t4 is not used in subsequent processing.

Similarly, FIG. 14 is a timing chart for restricting the use of the light receiving signal received by the light receiving element 17. In FIG. In FIG. 14, the waveform of the light source 11 is the same as in FIG. 12, but transient disturbance light other than the reflected light is incident. It is assumed that the amount of disturbance light in FIG. 14 is smaller than that in FIG. 13 and the received light level is lower. In this case, the light receiving signal level of the light receiving element 17 rises above the threshold during the time t3' to time t4', which is the timing at which the reflected light is not received. Therefore, it is determined that there is a high possibility that the light-receiving signal received at the timing of receiving the reflected light (light-receiving period #3) immediately after the time t3′ to time t4′ will erroneously detect light other than the reflected light, and the light-receiving element 17 is gated (masked). In other words, the light receiving signal of the light receiving element 17 during the light receiving period #3 is not used in the subsequent processing. In the case of FIG. 14, the threshold can be reduced because the determination is made based on the level of the received light signal from time t3' to time t4', which is the timing at which the reflected light is not received.

Next, the operation (sensor control method) of the rider 1B described above will be described with reference to the flow charts of FIGS. 15 and 16. FIG. The flowcharts of FIGS. 15 and 16 are executed by the control unit 18. FIG. Further, the flowchart shown in FIGS. 15 and 16 can be configured as a program to be executed by the CPU of the control unit 18 to form a sensor control program. FIG. 15 is a flow chart corresponding to the timing chart shown in FIG.

First, in step S31, the light receiving signal level of the light receiving element 17 is obtained. In step S32, it is determined whether or not the light receiving signal level obtained in step S31 is equal to or higher than a predetermined threshold. If YES), in step S33, the light receiving signal of the light receiving element 17 is limited (gated) as described above. In step S33, if it can be determined from the received light signal level that strong disturbance light that affects the operation of the rider 1B has been detected, the effectiveness of the use of the received light signal during the period in which the reflected light is received immediately after is determined. , to gate the received light signal.

On the other hand, if the received light signal level obtained in step S31 is less than the threshold value in step S32 (NO), the light receiving signal of the light receiving element 17 is not limited (gated) in step S34.

Next, a flowchart corresponding to the timing chart shown in FIG. 14 will be described with reference to FIG. First, in step S41, it is determined whether or not the light receiving element 17 is in a period during which it does not receive reflected light. ) acquires the light receiving signal level of the light receiving element 17 in step S42.

Next, in step S43, it is determined whether or not the received light signal level acquired in step S42 is equal to or higher than a predetermined threshold. It limits (gates) the light receiving signal of the element 17 . In step S43, if it can be determined that strong disturbance light that affects the operation of the rider 1B has been detected from the received light signal level during the period in which the reflected light is not received, the received light signal in the period during which the reflected light is received immediately after is used. is judged to be effective, and the received light signal is gated. That is, when the level of the received light signal during the period in which reflected light is not received exceeds a predetermined threshold value, the control unit 18 determines the effectiveness of the use of the received light signal in the period in which reflected light is received. Therefore, steps S41 to S44 function as control steps.

On the other hand, in step S43, if the received light signal level acquired in step S42 is less than the threshold value (in the case of NO), the light receiving signal of the light receiving element 17 is not gated in step S45.

According to this embodiment, the lidar 1B includes a light source 11 that intermittently emits laser light to scan a predetermined area, receives external laser light including reflected light of the laser light, and outputs a light reception signal. The light receiving element 17 has a light receiving element 17, and the light receiving element 17 is provided with a control unit 18 for restricting the use of the light receiving signal during the period during which the reflected light is received based on the light receiving signal level during the period during which the reflected light is not received. . By doing so, it is possible to determine that disturbance light is being received from the received light signal level during the period in which reflected light is not received. can be restricted. Therefore, erroneous detection due to ambient light can be reduced.

Further, when the level of the received light signal during the period in which the reflected light is not received exceeds a predetermined threshold value, the control unit 18 determines the effectiveness of the use of the received light signal in the period in which the reflected light is received. By doing so, it is determined that disturbance light is being received when the level of the received light signal during the period in which no reflected light is received is equal to or higher than the threshold value, and the use of the received light signal output by the light receiving section of the first sensor is determined. Effectiveness can be determined.

Next, a lidar 1B according to a fifth embodiment of the invention will be described with reference to FIGS. 17 to 21. FIG. The same reference numerals are given to the same parts as those of the first to fourth embodiments described above, and the description thereof will be omitted.

In the fourth embodiment, the use of the light receiving signal of the light receiving element 17 is restricted based on the light receiving signal level during the period in which the reflected light is not received. A flag signal is output as restriction information for restricting the use of the received light signal during the period in which the reflected light is received.

The configuration of this embodiment is similar to that of FIG. 17 to 19 are timing charts for outputting light receiving signals received by the light receiving element of the lidar according to the present embodiment and the limit information.

In this embodiment, as shown in FIG. 17, the light reception signal of the receiving element 17 is output as it is, and a flag signal corresponding to the period from time t1 to time t2 when the transient disturbance light other than the reflected light is incident is output. output.

In FIG. 17, the flag signal is set during the signal processing periods (distance calculation, etc.) of #1, #2, and #3, which were light receiving periods during the disturbance light period, and is controlled not to be used in subsequent processing. be able to.

FIG. 18 is a timing chart of a modification of this embodiment. In FIG. 18, due to the incident of transient disturbance light other than the reflected light, the received light signal of the receiving element 17 is changed between time t3 and time t4 and time t3' and time t4', which are timings at which reflected light is not received. Your level has risen above the threshold. Therefore, during the time t3 to the time t4 and the time t3' to the time t4', the flag signal is set, and in the signal processing period (distance calculation, etc.) during this period, control is performed so that the output of the control unit is not used in the process. be able to. Further, the signal processing period is a period between the end of the corresponding light receiving period and the start of the next light receiving period, but the signal processing period may be started during the light receiving period or at the start of the light receiving period.

In addition, in the case of FIG. 18, since the determination is made based on the received light signal level at times t3 to t4 and t3' to t4', which are timings at which reflected light is not received, the threshold can be reduced.

FIG. 19 is a timing chart of a modification of this embodiment. In FIG. 19, the output of the flag signal is controlled based on the result of comparison with the preceding and succeeding signal processing period thresholds. For example, in #1b of the signal processing period, the flag signal is set because #0b, which is one before, is less than the threshold, but the current (#1b) is greater than or equal to the threshold. In the next #2b, since the previous #1b is equal to or higher than the threshold and the current (#2b) is also equal to or higher than the threshold, the flag signal is set to ON. Further, in the next #3b, the current (#3b) is less than the threshold, but the previous #2b is greater than or equal to the threshold, so a flag signal is set. In the next #4b, the flag signal is reset because the previous #3b is less than the threshold and the current (#4b) is also less than the threshold. In the example of FIG. 19, the flag is set ON when either the previous period or the current period is equal to or greater than the threshold.

As shown in FIG. 19, by controlling the output of the flag signal based on the results of the preceding and succeeding thresholds, it is possible to perform control so that the received light signal due to the influence of disturbance light is not used in subsequent processing with higher precision than in FIG. .

Next, the operation (sensor control method) of the rider 1B described above will be described with reference to the flow charts of FIGS. 20 and 21. FIG. The flowcharts of FIGS. 20 and 21 are executed by the control unit 18. FIG. 20 and 21 as a program to be executed by the CPU of the control unit 18, a sensor control program can be obtained. FIG. 20 is a flow chart corresponding to the timing chart shown in FIG.

First, in step S51, it is determined whether or not the light receiving element 17 is in a period for receiving reflected light. goes to step S57.

Next, in step S52, it is determined whether or not the flag signal is OFF, and if it is ON (NO), the process returns to step S51. On the other hand, in the case of OFF (in the case of YES), the process proceeds to step S53, and the received light signal level of the light receiving element 17 is obtained in the same manner as in step S42 of FIG.

Next, in step S54, it is determined whether or not the received light signal level obtained in step S53 is equal to or higher than a predetermined threshold. do.

On the other hand, in step S54, if the received light signal level obtained in step S53 is less than the predetermined threshold value (in the case of NO), the flag signal is turned OFF in step S56.

Further, in step S57, since it is determined in step S51 that it is a period during which no reflected light is received, a flag signal is output to the subsequent signal processing section or the like. Next, in step S58, it is determined whether or not a signal or the like indicating completion of signal processing has been received from the subsequent signal processing section or the like. If received, the flag signal is turned off in step S59.

Next, a flowchart corresponding to the timing charts shown in FIGS. 18 and 19 will be described with reference to FIG. Steps S41 to S43 are the same as those in the flowchart of FIG. In step S43, if the received light signal level obtained in step S42 is equal to or higher than the predetermined threshold value, the flag signal is turned ON as described above in step S44A.

On the other hand, in step S43, if the received light signal level acquired in step S42 is less than the threshold value (in the case of NO), the flag signal is turned OFF in step S45A.

According to this embodiment, the lidar 1B includes a light source 11 that intermittently emits laser light to scan a predetermined area, receives external laser light including reflected light of the laser light, and outputs a light reception signal. and a light-receiving element 17 for generating a flag signal for restricting the use of the light-receiving signal output from the light-receiving element 17 based on the light-receiving signal level during a period in which the light-receiving element 17 does not receive the reflected light. a portion 18; By doing so, it is possible to determine that disturbance light is being received from the received light signal level during the period in which reflected light is not received. The use of the light receiving signal can be restricted by referring to the flag at the time of .

Further, the control unit 18 outputs a flag signal when the received light signal level during the period in which the reflected light is not received exceeds a predetermined threshold value. By doing so, it is possible to determine that disturbance light is being received and generate a flag signal when the received light signal level in a period in which reflected light is not received is equal to or higher than the threshold value.

Also in this embodiment, as in the second embodiment, the flag signal may be used as the reliability of object recognition instead of restricting the use of the light receiving signal of the light receiving element 17 .

Next, a rider 1C according to a sixth embodiment of the invention will be described with reference to FIGS. 22-25. The same reference numerals are given to the same parts as those of the first to fifth embodiments described above, and the description thereof will be omitted.

In the fourth embodiment, the use of the light-receiving signal of the light-receiving element 17 is restricted based on the light-receiving signal level during the period in which no reflected light is received. The irradiation of laser light from the light source 11 is restricted based on. That is, the control unit 18 limits the irradiation of the light from the light source 11 based on the received light signal level during the period in which the light receiving element 17 does not receive the reflected light.

FIG. 22 is a configuration diagram of the rider 1C according to this embodiment. The configuration shown in FIG. 22 is different from that in FIG. 11 in that the light receiving element 17 is connected to the control unit 18 instead of the light source 11 .

The principle of operation of the rider 1C in this embodiment will be described with reference to FIGS. 23 and 24. FIG. FIG. 23 is a timing chart when irradiation of laser light from the light source 11 is not limited, and is the same as FIG. 12 except that there is no control section output.

On the other hand, FIG. 24 is a timing chart for limiting the irradiation of laser light from the light source 11. In FIG. In FIG. 24, due to the incidence of transient disturbance light other than reflected light (for example, thunder, camera flash, fireworks, etc.), the light receiving element 17 does not receive reflected light between time t5 and time t6. The received light signal level has risen above the threshold. Therefore, it is judged that there is a high possibility that the received light signal received at the timing of receiving the reflected light immediately after the time t5 to time t6 erroneously detects light other than the reflected light, and the irradiation itself from the light source 11 is stopped.

Next, the operation (sensor control method) of the rider 1A described above will be described with reference to the flowchart of FIG. The flowchart of FIG. 25 is executed by the control unit 18 . Further, by configuring the flowchart shown in FIG. 25 as a program to be executed by the CPU of the control unit 18, a sensor control program can be obtained.

Steps S41 to S43 are the same as those in the flowchart of FIG. In step S43, if the received light signal level obtained in step S42 is equal to or higher than the predetermined threshold value (if YES), in step S44B, irradiation of laser light from the light source 11 is stopped as described above. That is, the control unit 18 limits the irradiation of light from the irradiation unit when the received light signal level during the period in which the reflected light is not received is equal to or higher than a predetermined threshold value. Therefore, steps S41 to S44B function as control steps.

On the other hand, if the received light signal level obtained in step S42 is less than the threshold value in step S43 (NO), the laser light irradiation from the light source 11 is not stopped in step S45B.

According to this embodiment, the lidar 1C has a light source 11 that intermittently emits laser light to scan a predetermined area, receives external laser light including reflected light of the laser light, and outputs a light reception signal. and a control unit 18 for limiting the irradiation of laser light from the light source 11 based on the light receiving signal level during the period in which the light receiving element 17 does not receive the reflected light. By doing so, it is possible to determine that disturbance light is being received from the received light signal level during the period in which reflected light is not received. be able to. In other words, by stopping the irradiation of the laser light when detecting the disturbance light and receiving a waveform different from the received light signal due to the reflected light of the irradiation light, it becomes possible to filter the waveform by judging it as noise, etc., and to filter the disturbance light. It is possible to reduce erroneous detection due to

Further, the control unit 18 may limit the irradiation of the laser light from the light source 11 when the received light signal level during the period in which the reflected light is not received is equal to or higher than a predetermined threshold. By doing so, it is possible to determine that disturbance light is received when the received light signal level in the period in which reflected light is not received is equal to or higher than the threshold value. It is possible to restrict such as not to irradiate.

It should be noted that the present invention is not limited to the above examples. That is, those skilled in the art can carry out various modifications according to conventionally known knowledge without departing from the gist of the present invention. As long as the sensor device of the present invention is provided even in such a modification, it is, of course, included in the scope of the present invention.

1, 1A, 1B, 1C lidar (sensor device)
11 light source (irradiation part)
17 light receiving element (light receiving part)
18 control unit 19 photodetector (second sensor)

Claims (1)

a sensor having an irradiation unit that intermittently emits light to scan a predetermined area, and a light receiving unit that receives light from the outside including the reflected light of the light and outputs a light reception signal;
a control unit for limiting the use of the light receiving signal during the period during which the reflected light is received based on the level of the light receiving signal during the period during which the reflected light is not received in the light receiving unit;
A sensor device comprising:

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