Measuring apparatus, measuring method, and program

Abstract

The present disclosure relates to a measurement device, a measurement method, and a program capable of performing measurement in a short time. According to the present invention, in order to output laser light having two or more times of pulse emission in one ranging range time, a signal indicating the emission timing of a pulse of emitted laser light is generated by setting the width of the round-trip time of flight of light to and from a ranging range to the ranging range time, the ranging range indicating a fixed distance width including a distance to be measured. Furthermore, a count code indicating the timing of a pulse in reflected light of laser light reflected by and returned from an object to be ranged is output according to the number of emissions in one ranging range time, and the distance to the object to be ranged is subsequently calculated from a specific count code among a plurality of count codes. The present technology can be applied to a measurement device that measures a distance.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a measurement apparatus, a measurement method, and a program, and more particularly, to a measurement apparatus, a measurement method, and a program capable of performing measurement in a shorter time. BACKGROUND

[0002] Conventionally, time-of-flight (TOF) is a technique that measures distance using the time of flight of light, which measures the time from outputting a pulsed laser light to a distance measuring target to receiving a reflected light pulse that is laser light reflected by the distance measuring target and returned. Then, a processing cycle of outputting the pulsed laser light is repeated, a histogram of measurement values measured in a plurality of processing cycles is generated, and a distance to the distance measuring target is calculated based on a measurement value indicating a peak of the histogram.

[0003] For example, Patent Literature 1 discloses a laser measurement method that sets a scanning speed of pulsed light and an emission period so that the measurement point is irradiated multiple times within the time for the pulsed light to pass through the measurement point, accumulates light reception signals obtained by the multiple irradiations, and performs distance measurement.

[0004] Further, Patent Literature 2 discloses a laser radar apparatus in which, in a distance measurement period corresponding to a predetermined distance measurement period, the projection timing of pulsed light is set to be random.

[0005] Prior Art Documents

[0006] Patent Literature

[0007] Patent Literature 1: Japanese Patent Application Publication No. 2019-60644

[0008] Patent Literature 2: Japanese Patent Application Publication No. 2017-125682 SUMMARY

[0009] Problem to be Solved by the Invention

[0010] For example, in conventional TOF, irradiation of pulsed light is performed only once within a time corresponding to one distance measurement range. That is, in the above-described Patent Literature 1, pulsed light is projected once every short period T1 corresponding to one distance measurement range, and in the above-described Patent Literature 2, pulsed light is projected once every projection period Tm corresponding to one distance measurement range.

[0011] Incidentally, there is a demand to perform measurement in a shorter time compared to conventional TOF.

[0012] The present disclosure is made in consideration of this situation, and aims to enable measurement in a shorter time.

[0013] Solution to Problem

[0014] A measurement device according to one aspect of the present disclosure includes: a transmission timing signal generation unit configured to generate a signal for giving an instruction of a transmission timing of a pulse of laser light by setting a width of a time of flight of light to and from between the measurement device and a ranging range indicating a fixed distance width including a distance to be measured as a ranging range time, so as to output laser light having a transmission number of a pulse of two or more times within one ranging range time; a count code output unit configured to output a count code indicating a timing of receiving a pulse of reflected light, which is laser light reflected by a ranging target and returned, according to the transmission number within one ranging range time; and a distance calculation unit configured to calculate a distance to the ranging target according to a specific count code among a plurality of count codes.

[0015] A measurement method or program according to one aspect of the present disclosure includes: generating, by a measurement device, a signal for giving an instruction of a transmission timing of a pulse of laser light by setting a width of a time of flight of light to and from between the measurement device and a ranging range indicating a fixed distance width including a distance to be measured as a ranging range time, so as to output laser light having a transmission number of a pulse of two or more times within one ranging range time; outputting a count code indicating a timing of receiving a pulse of reflected light, which is laser light reflected by a ranging target and returned, according to the transmission number within one ranging range time; and calculating a distance to the ranging target according to a specific count code among a plurality of count codes.

[0016] According to one aspect of the present disclosure, a signal for giving an instruction of a transmission timing of a pulse of laser light is generated by setting a width of a time of flight of light to and from between a measurement device and a ranging range indicating a fixed distance width as a ranging range time, so as to output laser light having a transmission number of a pulse of two or more times within one ranging range time; a count code indicating a timing of receiving a pulse of reflected light, which is laser light reflected by a ranging target and returned, is output according to the transmission number within one ranging range time; and a distance to the ranging target is calculated according to a specific count code among a plurality of count codes. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 is a block diagram showing a configuration example of a measurement device to which the present technology is applied.

[0018] Figure 2 is a diagram for describing a processing example of transmitting a pulse of laser light with a transmission number of two or more times within one ranging range time.

[0019] Figure 3 is a diagram for describing a filtering processing using transmission timing information.

[0020] Figure 4 is a flowchart for describing a first processing example of the distance measuring processing.

[0021] Figure 5 is a flowchart for describing a second processing example of the distance measuring processing.

[0022] Figure 6 is a graph for describing the filtering processing when the pulsed laser is emitted in different emission interval patterns.

[0023] Figure 7 is a graph for describing an example in which pulses are emitted in different emission interval patterns.

[0024] Figure 8 is a block diagram showing a configuration example of a second embodiment of the measurement apparatus to which the present technology is applied.

[0025] Figure 9 is a graph for describing a calculation result.

[0026] Figure 10 is a graph for describing a histogram of a calculation result.

[0027] Figure 11 is a block diagram showing a configuration example of a third embodiment of the measurement apparatus to which the present technology is applied.

[0028] Figure 12 is a graph for describing a count code output from a plurality of TDCs.

[0029] Figure 13 is a graph for describing a histogram of a count code output from a plurality of TDCs.

[0030] Figure 14 is a graph for describing a modification example in which a plurality of light receiving elements are provided.

[0031] Figure 15 is a graph for describing a shield signal.

[0032] Figure 16 is a graph for describing an example of correcting distortion.

[0033] Figure 17 is a graph for describing an example of correcting distortion.

[0034] Figure 18 is a block diagram showing a configuration example of an embodiment of a computer to which the present technology is applied.

[0035] Figure 19 is a block diagram showing an example of a schematic configuration of a vehicle control system.

[0036] Figure 20is an explanatory diagram showing an example of mounting positions of a vehicle exterior information detection unit and an imaging unit. DETAILED DESCRIPTION

[0037] Hereinafter, a specific embodiment to which the present technology is applied will be described in detail with reference to the drawings.

[0038] <First configuration example of measurement device>

[0039] Figure 1 is a block diagram showing a configuration example of a first embodiment of a measurement device to which the present technology is applied.

[0040] For example, Figure 1 The measurement device 11 shown measures a distance to a ranging target by measuring a time from outputting a pulsed laser to a ranging target to receiving a reflected light pulse that is laser reflected by the ranging target and returned. Note that, Figure 1 It is shown that even if four laser pulses are output to a ranging target, in a case where a distance to the ranging target is long, three pulses indicated by dotted lines do not return, and one pulse returns as reflected light.

[0041] As Figure 1 shown, the measurement device 11 includes a transmission timing signal generation unit 12, a laser driver 13, a light receiving element 14, a TDC 15, a histogram generation unit 16, a filter processing unit 17, and a distance calculation unit 18. Further, the TDC 15 includes a counter 21 and a latch 22.

[0042] The transmission timing signal generation unit 12 generates a Tx pulse signal for giving an instruction on a transmission timing of emitting a pulse by laser output from the measurement device 11, and provides the Tx pulse signal to the laser driver 13. For example, as will be described below with reference to Figure 2 the transmission timing signal generation unit 12 generates a Tx pulse signal for giving an instruction on outputting laser having a pulse transmission number of two or more times within one ranging range time, which is a width of a flight time of light to and fro between the measurement device 11 and a ranging range representing a fixed distance width including a distance to be measured. Then, the transmission timing signal generation unit 12 repeatedly executes output of pulsed laser within one ranging range time according to a predetermined output number.

[0043] Further, the transmission timing signal generation unit 12 provides a count start signal to the counter 21 of the TDC 15 for giving an instruction on starting counting up within one ranging range time. Further, the transmission timing signal generation unit 12 provides transmission timing information indicating a transmission timing of emitting a pulse within one ranging range time to the filter processing unit 17.

[0044] The laser driver 13 drives a laser light emitting element (not shown) according to the Tx pulse signal supplied from the emission timing signal generating unit 12 , and outputs pulse laser light based on emission timing.

[0045] The light receiving element 14 is, for example, a single photon avalanche diode (SPAD), receives reflected light of pulsed laser light reflected by a ranging target and returned, and supplies an Rx pulse signal representing a waveform of the reflected light to the latch 22 of the TDC 15 .

[0046] The time-to-digital converter (TDC) 15 converts the time until the laser light output from the measuring device 11 is reflected by the distance measurement target and returns to a digital value. That is, the counter 21 starts counting up the count code according to the count start signal provided by the transmission timing signal generating unit 12, and the latch 22 outputs the count code at the timing of the pulse indicated by the Rx pulse signal provided by the light receiving element 14.

[0047] The histogram generating unit 16 acquires the count code output from the latch 22 of the TDC 15, generates a histogram, and supplies the histogram to the filter processing unit 17. For example, in the measuring device 11, the output of the pulsed laser is repeatedly performed within one ranging range time according to a predetermined number of output times, and the histogram generating unit 16 generates a histogram of the count code acquired each time the pulsed laser is repeatedly output.

[0048] As will be referenced later Figure 3 As described above, the filter processing unit 17 applies a filter process to the histogram supplied from the histogram generating unit 16 based on a transfer function obtained from the transmit timing information supplied from the transmit timing signal generating unit 12. For example, a count code at the transmit timing of a transmit pulse according to the Tx pulse signal is used as the transmit timing information. Here, for example, the transfer function used for the filter processing by the filter processing unit 17 can be determined by machine learning.

[0049] The distance calculation unit 18 calculates the distance to the distance measurement target based on the speed of light using count codes indicating peaks in the histogram to which the filter processing has been applied by the filter processing unit 17 .

[0050] Will refer to Figure 2 and Figure 3 The processing performed in the measuring device 11 is further described.

[0051] Figure 2 Shown are a count code counted by the counter 21 , a waveform obtained by visualizing the count code, a Tx pulse signal indicating the timing of a pulse in the pulse laser light, and an Rx pulse signal indicating the timing of a pulse in the reflected light.

[0052] In addition, Figure 2In the example shown, the time for one count by the counter 21 is set to 100 psec, and the measurable ranging range in the measurement device 11 is set to 1.5 m. Thus, in the case where the ranging range is 1.5 m, one ranging range time, that is, the time required for one measurement of the distance to the ranging target, is 10 nsec, which is the time required for light to travel to and fro a distance of 1.5 m. Further, the resolution of the distance measured by the measurement device 11 is 1.5 cm, which is the distance traveled to and fro by light in 100 psec, which is the time corresponding to one count by the counter 21.

[0053] Then, the measurement device 11 outputs laser light for which the number of times of pulse emission is two or more within one ranging range time. That is, the interval of each pulse of the laser light is set to be shorter than one ranging range time. Thus, the measurement device 11 emits the next pulse at a timing earlier than the time at which the pulse emitted immediately before in the multiple pulses emitted within one ranging range time is reflected by the ranging target, returned, and received by the light receiving element 14.

[0054] For example, Figure 2 The Tx pulse signal shown indicates that laser light for which the number of times of pulse emission is three is output within one ranging range time, and pulses are emitted at the timings of count code 0, count code 2, and count code 5. Further, Figure 2 The Rx pulse signal shown indicates that reflected light having a waveform of pulses indicating the timings of count code 50, count code 52, and count code 55 is received by the light receiving element 14. For example, the next pulse is emitted at count code 2, at a time earlier than the time at which the pulse emitted at count code 0 is received at count code 50. Similarly, the next pulse is emitted at count code 5, at a time earlier than the time at which the pulse emitted at count code 2 is received at count code 52.

[0055] Here, one ranging range time is the operation cycle of the measurement device 11, and is set in accordance with the maximum time or distance measured by the measurement device 11. For example, one ranging range time is a time corresponding to the width of the ranging distance supported by a certain operation mode of the measurement device 11. Specifically, in the case of a "15 m wide ranging mode", one ranging range time becomes 100 nsec (15 / 3 x 10 to the 8th power x 2). Further, the ranging support distance in the "15 m ranging mode" can be, for example, 10 to 25 m or 15 to 30 m in addition to 0 to 15 m. Further, the minimum value of the distance of the measurable distance is not necessarily 0 m.

[0056] Then, in the measurement device 11, the output of the pulsed laser light within one ranging range time is repeatedly executed in accordance with the predetermined number of outputs, and the count codes 50, 52, and 55 indicated by the Rx pulse signal are repeatedly acquired. Thus, the histogram generated by the histogram generation unit 16 has peaks in the count codes 50, 52, and 55, as shown in FIG. 6.Figure 3 shown on the left.

[0057] Furthermore, the filtering processing unit 17 uses the transmission timing information supplied from the transmission timing signal generating unit 12, namely Figure 2 In the example shown, the transfer function (Y[n]=X[n]+X[n+2]+X[n+5]) is obtained by counting code 0, counting code 2, and counting code 5 indicated by the Tx pulse signal. Then, the filtering processing unit 17 applies filtering processing according to the transfer function to the histogram supplied from the histogram generating unit 16, thereby obtaining a histogram after filtering processing, which has a value corresponding to the value in the counting code 50. Figure 3 The highest peak in true distance is shown on the right.

[0058] Even when the laser pulses are emitted two or more times within a single distance measurement range, the measuring device 11, configured as described above, can specify the count code corresponding to the true distance by applying filtering processing using information about the pulse emission timing. Consequently, the measuring device 11 can double the height of the count code corresponding to the true distance based on the number of pulse emissions, and can generate a histogram with a peak count code in a shorter time. Consequently, the measuring device 11 can measure the distance to the target in a shorter time than before.

[0059] <Processing Example of Measurement Processing>

[0060] Will refer to Figure 4 A first processing example of the distance measurement processing executed in the measuring device 11 is described with reference to the flowchart shown.

[0061] For example, when control is executed to start the ranging process, the first ranging range time begins, and in step S11, the emission timing signal generation unit 12 provides a count start signal to the counter 21, which instructs the counter 21 to start counting up within the ranging range time. The emission timing signal generation unit 12 then provides a Tx pulse signal to the laser driver 13, which instructs the laser driver 13 to output a laser beam having two or more pulses within the ranging range time. As a result, the laser driver 13 drives the laser light emitting element (not shown) to output a laser beam that emits multiple pulses within the ranging range time based on the emission timing indicated by the Tx pulse signal.

[0062] In step S12, the light receiving element 14 receives the reflected light of the pulsed laser light output in step S11, and supplies an Rx pulse signal indicating the waveform of the reflected light to the latch 22. Thus, the latch 22 takes out a counter code from the counter 21 at the timing of the pulse indicated by the Rx pulse signal supplied from the light receiving element 14, and supplies the counter code to the histogram generating unit 16.

[0063] Then, when the counter 21 completes the count of one ranging range time from the start of the timing of one ranging range time in step Sll (count code 99 in the example) Figure 2 of the timing signal generation unit 12 determines that the number of times of repeating the output of the pulsed laser in one ranging range time has reached the predetermined output number of times.

[0064] In step S13, the transmission timing signal generation unit 12 determines whether the number of times of repeating the output of the pulsed laser in one ranging range time has reached the predetermined output number of times.

[0065] In step S13, in the case where the transmission timing signal generation unit 12 determines that the number of times of repeating the output of the pulsed laser in one ranging range time has not reached the predetermined output number of times, i.e., in the case where the number of times is smaller than the predetermined output number of times, the process returns to step Sll. Then, the second and subsequent ranging range times are repeatedly executed in a similar manner.

[0066] Meanwhile, in step S13, in the case where the transmission timing signal generation unit 12 determines that the number of times of repeating the output of the pulsed laser in one ranging range time has reached the predetermined output number of times, the process proceeds to step S14.

[0067] In step S14, the transmission timing signal generation unit 12 provides the filter processing unit 17 with transmission timing information indicating the transmission timing in accordance with the pulse indicated by the Tx pulse signal supplied to the laser driver 13 in step Sll.

[0068] In step S15, the histogram generation unit 16 generates a histogram of the count code supplied from the latch 22 in step S12 in which the predetermined output number of times has been repeated, and supplies the histogram to the filter processing unit 17.

[0069] In step S16, the filter processing unit 17 obtains a transfer function using the counter code of the transmission timing information supplied from the transmission timing signal generation unit 12 in step S14. Then, the filter processing unit 17 applies filter processing in accordance with the transfer function to the histogram supplied from the histogram generation unit 16 in step S15. Thereby, the filter processing unit 17 specifies the count code indicating the highest peak value in the histogram to which the filter processing has been applied, and notifies the count code to the distance calculation unit 18.

[0070] In step S17, the distance calculation unit 18 calculates the distance to the ranging target using the count code supplied from the filter processing unit 17 in step S16, and then ends the process.

[0071] By the measurement process as described above, the measurement device 11 can measure the distance to the ranging target in a shorter time.

[0072] The measurement processing will be described with reference to the flowchart shown in FIG. 8. Figure 5 A second processing example of the distance measurement processing performed in the measurement device 11 will be described with reference to the flowchart shown in FIG. 9.

[0073] In step S21, the transmission timing signal generation unit 12 sets an initial value (for example, 1) of the number of times of transmission of the pulse within one distance measurement range time.

[0074] In steps S22 to S27, processing similar to steps S11 to S16 in FIG. 8 is performed. Thereafter, in step S28, the filter processing unit 17 determines whether or not the count code indicating the highest peak value is specified in the histogram to which the filter processing is applied in step S27. Figure 4 In step S28, in a case where the filter processing unit 17 determines that the count code indicating the highest peak value is not specified, the processing proceeds to step S29. In step S29, the transmission timing signal generation unit 12 increments the number of times of transmission by 1 for the current timing, to increase the number of times of transmission, and then the processing returns to step S22, and thereafter similar processing is repeatedly performed.

[0075] Meanwhile, in step S28, in a case where the filter processing unit 17 determines that the count code indicating the highest peak value has been specified, the processing proceeds to step S30. In step S30, processing similar to step S17 in FIG. 8 is performed, and after the distance calculation unit 18 calculates the distance to the distance measurement target, the processing ends.

[0076] Figure 4 In step S28, in a case where the filter processing unit 17 determines that the count code indicating the highest peak value is not specified, the processing proceeds to step S29. In step S29, the transmission timing signal generation unit 12 increments the number of times of transmission by 1 for the current timing, to increase the number of times of transmission, and then the processing returns to step S22, and thereafter similar processing is repeatedly performed.

[0077] Through the above-described measurement processing, the measurement device 11 dynamically changes the number of times of transmission of the pulse within one distance measurement range time, and increases the number of times of transmission in a case where the number of times of transmission is small and a peak value cannot be obtained. In this way, the measurement device 11 can appropriately measure the distance according to the distance measurement target by, for example, increasing the number of times of transmission of the pulse according to the peak value of the histogram.

[0078] Note that, for example, the measurement device 11 can output laser light having a different transmission interval pattern for each distance measurement range time, in addition to repeatedly outputting laser light having the same pulse transmission interval pattern (hereinafter referred to as a transmission interval pattern) for each distance measurement range time.

[0079] For example, Figure 6 The Tx pulse signal shown in FIG. 10 indicates that the pulse is transmitted in the transmission interval pattern of the count code 0, the count code 2, and the count code 5 in the distance measurement range time #1. Further, in the distance measurement range time #2, the pulse is transmitted in the transmission interval pattern of the count code 1, the count code 4, and the count code 6. Further, in the distance measurement range time #3, the pulse is transmitted in the transmission interval pattern of the count code 1, the count code 3, and the count code 6.

[0080] ​As described above, even when the laser having a different emission interval pattern is output for each ranging range time, the measurement device 11 can specify the count number for the true distance by applying the filter processing using the emission timing information of the pulse. Note that, for example, as shown in Figure 6 In addition to changing the emission interval pattern for each ranging range time, for each different emission interval pattern, the same emission interval pattern can be repeated multiple times (1000 times for every three patterns as shown) to generate a histogram for each emission interval pattern.

[0081] Further, even if the interval for each ranging range time, that is, the time from the end of the ranging range time to the start of the next ranging range time, changes, the measurement device 11 can measure the distance to the ranging target. Further, even if the maximum value of the count number counted by the counter 21 changes for each ranging range time, the measurement device 11 can measure the distance to the ranging target.

[0082] Further, as shown in Figure 7 In the measurement device 11, in the case where the pulse is emitted in a different emission interval pattern, the filter processing is applied using the transfer function using each emission timing. As shown in Figure 7 By dynamically changing the transfer function using the emission timing in the emission interval pattern, it is possible to make the unnecessary peak component small.

[0083] For example, Figure 7 An example is shown in which by switching the first emission interval pattern and the second emission interval pattern with equal probability, the filter processing is applied using the transfer function using the respective emission timings, and then the histograms are merged, it is possible to reduce the false peak component to 1 / 6 of the true peak component. By this method, the false peak component is effectively suppressed, and in the calculation based on probability statistics, the false peak component is set to 1 / 10 or less of the true peak component, so that the false peak component can be ignored.

[0084] Note that the histograms that are not merged share one ripple counter, and the merged histograms are saved in a memory (for example, static random access memory (SRAM)), and the change frequency of the transfer function is set to a range that does not affect the frame rate. Then, by a method of performing the merging processing and the SRAM update at the same timing as the change of the transfer function, it is possible to suppress the increase in the circuit area of the histogram generation unit 16.

[0085] Here, the interval between the pulses emitted at two or more emission times within one ranging range time can be equal or unequal. Further, the emission timing signal generation unit 12 can change the interval between the pulses for each ranging range time. For example, the interval between the pulses is changed based on a predetermined random number, specifically, a true random number generator or a pseudo random number generator including cryptographic security is used.

[0086] <Measurement device second configuration example>

[0087] Figure 8 is a block diagram showing a configuration example of a second embodiment of a measurement device to which the present technology is applied. Note that, in the measurement device 11A shown in Figure 8 the measurement device 11A shown in FIG. 10, the configuration common to the measurement device 11 in FIG. 1 is given the same reference numeral, and detailed description of the configuration is omitted. Figure 1

[0088] That is, the measurement device 11A has the configuration common to the measurement device 11 in FIG. 1, including the transmission timing signal generation unit 12, the laser driver 13, the light receiving element 14, the TDC 15, the histogram generation unit 16, and the distance calculation unit 18. Figure 1

[0089] Then, the measurement device 11A differs from the measurement device 11 in FIG. 1 in that the calculation unit 19 is included between the TDC 15 and the histogram generation unit 16, and the transmission timing information is provided from the transmission timing signal generation unit 12 to the calculation unit 19. Figure 1

[0090] The calculation unit 19 acquires the count codes output from the latch 22 of the TDC 15, and provides the calculation results obtained by performing calculation using the transmission timing information provided from the transmission timing signal generation unit 12 to the histogram generation unit 16. For example, the calculation unit 19 performs calculation to obtain, for each count code at which a reflected light pulse is detected, a calculation result obtained by subtracting the transmission timings of all the pulses transmitted within one ranging range time from the count code.

[0091] For example, in the example shown in Figure 9 the calculation results (50, 48, 45) obtained by subtracting the transmission timings (0, 2, 5) of all the pulses from the count codes 50 at which the pulses of reflected light are detected are obtained. Similarly, the calculation results (52, 50, 47) obtained by subtracting the transmission timings (0, 2, 5) of all the pulses from the count codes 52 at which the pulses of reflected light are detected are obtained. Further, the calculation results (55, 53, 50) obtained by subtracting the transmission timings (0, 2, 5) of all the pulses from the count codes 55 at which the pulses of reflected light are detected are obtained.

[0092] Then, the histogram generation unit 16 generates a histogram of the calculation results provided from the calculation unit 19. For example, as shown in Figure 10 in the case where the calculation results as shown in Figure 9 are obtained, a histogram indicating the peak in the calculation result 50 is generated. That is, in Figure 10 ​​​In the histogram shown, since the number of pulse emissions in one ranging range time is three times, the calculation result 50 indicating the peak is three times higher than the other calculation results. Note that, as described with reference to Figure 7 As described, by outputting laser light having different emission interval patterns for each ranging range time and merging the histograms, the calculation results other than the calculation result indicating the peak can be further reduced.

[0093] Similarly to the measurement device 11 in Figure 1 The measurement device 11A configured as described above can generate a histogram in which the count code shows the peak in a shorter time, and can measure the distance to the ranging target in a shorter time.

[0094] <Measurement Device Third Configuration Example>

[0095] Figure 11 is a block diagram showing a configuration example of a third embodiment of a measurement device to which the present technology is applied. Note that, in Figure 11 In the measurement device 11B shown, the same reference numerals are given to configurations common to the measurement device 11 in Figure 1

[0096] That is, the measurement device 11B has configurations common to the measurement device 11 in Figure 1 including the emission timing signal generation unit 12, the laser driver 13, the light receiving element 14, the histogram generation unit 16, and the distance calculation unit 18. Note that, although not shown, each of the TDCs 15-1 to 15-3 includes the counter 21 and the latch 22.

[0097] Then, the measurement device 11B differs from the measurement device 11 in Figure 1 in that it includes three TDCs 15-1 to 15-3. Note that, for example, in a configuration in which a plurality of TDCs 15 are provided, as in the measurement device 11B, the number of TDCs 15, that is, the number corresponding to the number of pulse emissions in one ranging range time, is provided.

[0098] Then, each TDC 15 starts counting the count code in accordance with the emission timing of the corresponding pulse. For example, in the example shown in Figure 12 the emission timing information indicates emission timing 0, emission timing 2, and emission timing 5. Therefore, the TDC 15-1 starts counting the count code in accordance with emission timing 0, the TDC 15-2 starts counting the count code in accordance with emission timing 2, and the TDC 15-2 starts counting the count code in accordance with emission timing 5.

[0099] ​Therefore, at the timing when the light receiving element 14 receives the reflected light of the pulse emitted at emission timing 0 and reflected by the ranging target, the TDC 15-1 outputs a count code 50, the TDC 15-2 outputs a count code 47, and the TDC 15-3 outputs a count code 45. Similarly, at the timing when the light receiving element 14 receives the reflected light of the pulse emitted at emission timing 2 and reflected by the ranging target, the TDC 15-1 outputs a count code 52, the TDC 15-2 outputs a count code 50, and the TDC 15-3 outputs a count code 47. Furthermore, at the timing when the light receiving element 14 receives the reflected light of the pulse emitted at emission timing 5 and reflected by the ranging target, the TDC 15-1 outputs a count code 55, the TDC 15-2 outputs a count code 53, and the TDC 15-3 outputs a count code 50.

[0100] Then, in the measuring device 11B, the histogram generating unit 16 acquires all the count codes outputted from the TDCs 15-1 to 15-3 and generates a histogram. Figure 12 In the case of the counting code shown, Figure 13 As shown in FIG. 5 , a histogram indicating the peak value in the calculation result 50 is generated. Figure 13 In the histogram shown, the calculation result 50 indicating the peak value is three times higher than the other calculation results because the number of pulse transmissions is three times greater within one ranging range time. Figure 7 As described, by outputting laser light having different emission interval patterns for each ranging range time and combining histograms, calculation results other than the calculation results indicating the peak value can be further reduced.

[0101] Similar to Figure 1 In the measuring device 11 , the measuring device 11B configured as described above can generate a histogram in which count codes show a peak in a shorter time, and can measure the distance to the ranging target in a shorter time.

[0102] <Modifications of the Measuring Device>

[0103] Will refer to Figure 14 and Figure 15 Modifications of the measuring device 11 will be described.

[0104] For example, the measuring device 11 may be provided with a number of light receiving elements 14 corresponding to the number of pulse transmissions within one ranging range time. These light receiving elements 14 can receive a single pulse.

[0105] Figure 14 A modified example of the measuring device 11 is shown in which four light receiving elements 14-1 to 14-4 are provided. Figure 1a diagram of modules other than the light-receiving element 14 provided in the measurement device 11.

[0106] For example, laser light output from the laser 31 driven in accordance with the Tx pulse signal provided from the laser driver 13 is diffracted by the diffraction grating 32 toward the four optical switches 33-1 to 33-4. The optical switches 33-1 to 33-4 shield passage of pulses other than the corresponding pulse in accordance with the shield signals 1 to 4, respectively.

[0107] For example, as shown in Figure 15 the optical switch 33-1 passes only the first pulse in accordance with the shield signal 1, and the optical switch 33-2 passes only the second pulse in accordance with the shield signal 2. Similarly, the optical switch 33-3 passes only the third pulse in accordance with the shield signal 3, and the optical switch 33-4 passes only the fourth pulse in accordance with the shield signal 4.

[0108] Then, the light-receiving element 14-1 receives reflected light of the first pulse that has passed through the optical switch 33-1 and been reflected by the distance measurement target, and outputs an Rx pulse signal 1 indicating the timing of receiving the pulse. Further, the light-receiving element 14-2 receives reflected light of the second pulse that has passed through the optical switch 33-2 and been reflected by the distance measurement target, and outputs an Rx pulse signal 2 indicating the timing of receiving the pulse. Hereinafter, similarly, the light-receiving element 14-3 outputs an Rx pulse signal 3, and the light-receiving element 14-4 outputs an Rx pulse signal 4.

[0109] Thereafter, in the measurement device 11, a count code in accordance with the timing of the pulses indicated by the Rx pulse signals 1 to 4 is output from the latch 22, and processing similar to the above-described processing is performed.

[0110] As described above, the measurement device 11 can be configured so that the number of light-receiving elements 14 (corresponding to the number of the number of pulse emissions within one distance measurement range time) detects individual pulses. Note that it is enough for the measurement device 11 to be configured to have such a correspondence, and can have a configuration in which, for example, the number of lasers 31, that is, the number corresponding to the number of pulse emissions within one distance measurement range time, is provided, and each laser 31 emits an individual pulse.

[0111] <Correction of Distortion>

[0112] An example of correcting distortion in a measurement device 11 including a plurality of lasers and a plurality of light-receiving elements will be described with reference to Figure 16 and Figure 17

[0113] For example, in order to prevent the light-receiving element 14 from reacting at the timing of laser emission due to stray light generated in a module containing a plurality of lasers 31 and a plurality of light-receiving elements 14, it can be as Figure 16 ​The operation of disabling the light receiving element 14 at the timing of laser emission is shown. However, in this case, it is predicted that the components of the acquired histogram due to the background light do not become flat with respect to all count values, and distortion occurs (for example, the components due to the background light decrease at the time of disabling). Therefore, it is necessary to correct the distortion using the emission timing.

[0114] First, it is assumed that Figure 16 The frequencies of the patterns A and B are each 50% as shown. Then, the timing at which the two light receiving elements 14 are shielded, that is, the timing at which the light receiving elements are disabled by the shield signal, can be identified from the Tx pulse signals of the patterns A and B. Therefore, the count code of the histogram in which the sensitivity is reduced can be predicted from the timing. Further, since the rate of reduction in sensitivity at this time can also be obtained by calculation, the reciprocal of the rate of reduction in sensitivity is obtained as a correction coefficient, and the count code in which the sensitivity is reduced is multiplied by the correction coefficient, so that the floor noise average value can be equalized.

[0115] That is, in Figure 16 In the example shown, the sensitivity is reduced in the count code 0, the count code 2, the count code 5, and the count code 9, and a histogram as shown on the left in Figure 17 is acquired. Then, since the frequencies of the patterns A and B are each 50%, 2 is obtained as a correction coefficient, and the histogram in which the sensitivity is reduced is multiplied by 2 to equalize the floor noise average value as shown in the center of Figure 17 Thereafter, by applying the filter processing using the emission timing information by the filter processing unit 17, a histogram showing a peak value can be obtained as shown on the right in Figure 17

[0116] <Configuration example of computer>

[0117] Next, the above series of processes (measurement method) can be executed by hardware or software. In the case where the series of processes is executed by software, a program configuring the software is installed in a general-purpose computer or the like.

[0118] Figure 18 is a block diagram showing a configuration example of an embodiment of a computer in which a program for executing the above series of processes is installed.

[0119] The program can be recorded in advance in the hard disk 105 or the ROM 103 as a recording medium built into the computer.

[0120] ​Alternatively, the program can be stored (recorded) in a removable recording medium 111 that is driven by the drive 109. Such a removable recording medium 111 can be provided as a so-called packaged software. Here, examples of the removable recording medium 111 include a floppy disk, a compact disc read only memory (CD-ROM), a magneto optical (MO) disk, a digital versatile disc (DVD), a magnetic disk, a semiconductor memory, and the like.

[0121] Note that, in addition to the program installed from the removable recording medium 111 to the computer as described above, the program can be downloaded via a communication network or a broadcast network to the computer and installed in the built-in hard disk 105. In other words, the program can be transmitted in a wireless manner from a download site to the computer via an artificial satellite for digital satellite broadcasting, or in a wired manner to the computer via a network such as a local area network (LAN) or the Internet, for example.

[0122] The computer includes a central processing unit (CPU) 102, and the input / output interface 110 is connected to the CPU 102 via the bus 101.

[0123] When a user who operates the input unit 107 or the like inputs a command through the input / output interface 110, the CPU 102 executes the program stored in the read only memory (ROM) 103 according to the command. Alternatively, the CPU 102 loads the program stored in the hard disk 105 into the random access memory (RAM) 104 and executes the program.

[0124] As a result, the CPU 102 executes the above-described processing according to the above-described processing of the flowchart or block diagram. Then, the CPU 102 causes the output unit 106 to output the processing result, causes the communication unit 108 to transmit the processing result, and causes the hard disk 105 to record the processing result, via the input / output interface 110, for example, as necessary.

[0125] Note that the input unit 107 is configured by a keyboard, a mouse, a microphone, or the like. Furthermore, the output unit 106 is configured by a liquid crystal display (LCD), a speaker, or the like.

[0126] Here, in the present specification, the processing executed by the computer according to the program does not necessarily have to be executed chronologically in the order described in the flowchart or block diagram. In other words, the processing executed by the computer according to the program can also include processing executed in parallel or individually (for example, parallel processing or processing by an object).

[0127] Furthermore, the program can be processed by one computer (processor), or can be processed in a distributed manner by a plurality of computers. Furthermore, the program can be transmitted to a remote computer and executed.

[0128] Further, in the present specification, the term "system" refers to a group of a plurality of configuration elements (apparatuses, modules (parts), and the like), and is irrelevant to whether all the configuration elements are in the same housing or not. Therefore, a plurality of apparatuses housed in different housings and connected via a network, and one apparatus housing a plurality of modules in one housing are all systems.

[0129] Further, for example, a configuration described as one apparatus (or processing unit) can be divided and configured as a plurality of apparatuses (or processing units). Conversely, configurations described as a plurality of apparatuses (or processing units) can be collectively configured as one apparatus (or processing unit). Further, configurations other than the above-described configurations can be added to the configuration of each apparatus (or each processing unit). Further, a part of the configuration of a certain apparatus (or processing unit) can be included in the configuration of another apparatus (or another processing unit) as long as the configuration and operation of the entire system are substantially the same.

[0130] Further, for example, in the present technology, a cloud computing configuration in which one function is shared and cooperatively processed by a plurality of apparatuses via a network can be employed.

[0131] Further, for example, the above-described program can be executed by any apparatus. In this case, only the apparatus is required to have the necessary functions (functional blocks and the like) and obtain the necessary information.

[0132] Further, for example, the steps described in the above-described flowcharts can be executed by one apparatus, or can be executed in a shared manner by a plurality of apparatuses. Further, in the case where a plurality of processes are included in one step, the plurality of processes included in one step can be executed by one apparatus, or can be shared and executed by a plurality of apparatuses. In other words, the plurality of processes included in one step can be executed as processes of a plurality of steps. Conversely, processes described as a plurality of steps can be collectively executed as one step.

[0133] Note that, in a program executed by a computer, the processes of the steps described in the program can be executed in time series according to the order described in the present specification, or can be executed individually in parallel, or at necessary timing, for example, when a call is made. That is, the processes of each step can be executed in an order different from the above-described order as long as no contradiction occurs. Further, the processes of the steps of the program can be executed in parallel with the processes of another program, or can be executed in combination with the processes of another program.

[0134] Note that, as long as there are no inconsistencies, multiple prior arts described in this specification can be implemented independently of each other as a single unit. Of course, any number of the present technologies can be implemented together. For example, part or all of the present technology described in any embodiment can be implemented in combination with part or all of the present technology described in another embodiment. In addition, part or all of any of the above-mentioned present technologies can be implemented in combination with another technology not described above.

[0135] <Mobile Application Examples>

[0136] The technology according to the present disclosure (the present technology) can be applied to various products. For example, the technology according to the present disclosure can be implemented as a device installed on any type of mobile object, including automobiles, electric vehicles, hybrid electric vehicles, motorcycles, bicycles, personal mobile objects, aircraft, drones, ships, and robots.

[0137] Figure 19 : is a block diagram showing a schematic configuration example of a vehicle control system which is an example of a moving body control system to which the technology according to the present disclosure is applied.

[0138] The vehicle control system 12000 includes a plurality of electronic control units connected via a communication network 12001. Figure 19 In the illustrated example, a vehicle control system 12000 includes a drive system control unit 12010, a body system control unit 12020, a vehicle exterior information detection unit 12030, a vehicle interior information detection unit 12040, and an integrated control unit 12050. Furthermore, as a functional configuration of the integrated control unit 12050, a microcomputer 12051, a sound and image output unit 12052, and an in-vehicle network I / F (interface) 12053 are illustrated.

[0139] The drive system control unit 12010 controls the operation of devices related to the vehicle's drive system according to various programs. For example, the drive system control unit 12010 functions as a control device for a drive force generating device (e.g., an internal combustion engine or a drive motor) that generates the vehicle's drive force, a drive force transmission mechanism that transmits the drive force to the wheels, a steering mechanism that adjusts the vehicle's steering angle, and a brake device that generates the vehicle's braking force.

[0140] The body system control unit 12020 controls the operation of various devices mounted to the vehicle body in accordance with various programs. For example, the body system control unit 12020 functions as a control device of a keyless entry system, an intelligent key system, an automatic window device, and various lamps (for example, head lamps, rear lamps, brake lamps, turn signals, and fog lamps). In this case, radio waves transmitted from a mobile device of a substitute key or signals of various switches can be input to the body system control unit 12020. The body system control unit 12020 receives the input of the radio waves or the signals and controls a door lock device, an automatic window device, lamps, and the like of the vehicle.

[0141] The vehicle exterior information detection unit 12030 detects information outside the vehicle on which the vehicle control system 12000 is mounted. For example, an imaging unit 12031 is connected to the vehicle exterior information detection unit 12030. The vehicle exterior information detection unit 12030 causes the imaging unit 12031 to capture an image of the outside of the vehicle and receives the captured image. Based on the received image, the vehicle exterior information detection unit 12030 can perform object detection processing or distance detection processing with respect to a person, a vehicle, an obstacle, a sign, a character on a road surface, and the like.

[0142] The imaging unit 12031 is an optical sensor that receives light and outputs an electric signal in accordance with the amount of received light. The imaging unit 12031 can output an electric signal as an image, and can output an electric signal as information of a measured distance. In addition, the light received by the imaging unit 12031 can be visible light, or can be invisible light such as infrared light.

[0143] The vehicle interior information detection unit 12040 detects information inside the vehicle. For example, a driver state detection unit 12041 that detects a driver state is connected to the vehicle interior information detection unit 12040. For example, the driver state detection unit 12041 includes a camera that captures an image of the driver, and the vehicle interior information detection unit 12040 can calculate the degree of fatigue or concentration of the driver, or can determine whether the driver is asleep, on the basis of detection information input from the driver state detection unit 12041.

[0144] The microcomputer 12051 can calculate a control target value of a driving force generation device, a steering mechanism, or a braking device on the basis of information inside or outside the vehicle acquired by the vehicle exterior information detection unit 12030 or the vehicle interior information detection unit 12040, and can output a control command to the drive system control unit 12010. For example, the microcomputer 12051 can perform cooperative control to realize an advanced driver assistance system (ADAS) function including collision avoidance or impact mitigation of the vehicle, follow-up running based on an inter-vehicle distance, vehicle speed maintenance running, warning of a vehicle collision, warning of vehicle lane departure, and the like.

[0145] Further, the microcomputer 12051 controls a driving force generation device, a steering mechanism, a braking device, and the like on the basis of information around the vehicle acquired in the vehicle exterior information detection unit 12030 or the vehicle interior information detection unit 12040 to perform cooperative control for automatic driving for autonomous driving without depending on an operation of a driver or the like.

[0146] Further, the microcomputer 12051 can output a control command to the body system control unit 12020 on the basis of information outside the vehicle acquired by the vehicle exterior information detection unit 12030. For example, the microcomputer 12051 can perform cooperative control for achieving a purpose of non-dazzling by controlling a headlamp in accordance with a position of a preceding vehicle or an oncoming vehicle detected in the vehicle exterior information detection unit 12030 and switching a high beam to a low beam.

[0147] The sound image output unit 12052 transmits an output signal of at least one of a sound and an image to an output device that can visually or aurally notify information to an occupant on the vehicle or outside the vehicle. In Figure 19 Examples of the output device are exemplified by an audio speaker 12061, a display unit 12062, and an instrument panel 12063. The display unit 12062 can include at least one of, for example, an on-vehicle display or a head-up display.

[0148] Figure 20 is a diagram showing an example of a mounting position of the imaging unit 12031.

[0149] In Figure 20 , the vehicle 12100 includes imaging units 12101, 12102, 12103, 12104, and 12105 as the imaging unit 12031.

[0150] For example, the imaging units 12101, 12102, 12103, 12104, and 12105 are provided at positions of a front nose, a side mirror, a rear bumper or a back door, an upper portion of a windshield, or the like in the vehicle interior of the vehicle 12100. The imaging unit 12101 provided on the front nose and the imaging unit 12105 provided at the upper portion of the windshield in the vehicle interior mainly acquire images of the front of the vehicle 12100. The imaging units 12102 and 12103 provided on the side mirror mainly acquire images of the side of the vehicle 12100. The imaging unit 12104 provided on the rear bumper or the back door mainly acquires an image of the rear of the vehicle 12100. The front images acquired in the imaging units 12101 and 12105 are mainly used for detecting a preceding vehicle, a pedestrian, an obstacle, a traffic signal, a traffic sign, a lane, or the like.

[0151] Note that Figure 20Examples of the imaging ranges of the imaging units 12101 to 12104 are shown. The imaging range 12111 represents the imaging range of the imaging unit 12101 provided at the front nose, the imaging ranges 12112 and 12113 respectively represent the imaging ranges of the imaging units 12102 and 12103 provided at the side mirrors, and the imaging range 12114 represents the imaging range of the imaging unit 12104 provided at the rear bumper or the rear door. A bird's-eye image of the vehicle 12100 viewed from above is obtained, for example, by superimposing image data taken by the imaging units 12101 to 12104.

[0152] At least one of the imaging units 12101 to 12104 can have a function of acquiring distance information. For example, at least one of the imaging units 12101 to 12104 can be a stereo camera including a plurality of imaging elements, or can be an imaging element having pixels for phase difference detection.

[0153] For example, the microcomputer 12051 obtains distances to three-dimensional objects in the imaging ranges 12111 to 12114 and time changes of the distances (relative speeds with respect to the vehicle 12100) on the basis of distance information obtained from the imaging units 12101 to 12104, and thereby extracts, in particular, a three-dimensional object closest to the vehicle 12100 on a travel road, which travels at a predetermined speed (for example, 0 km / h or more) in substantially the same direction as the vehicle 12100, as a preceding vehicle. Further, the microcomputer 12051 can set a vehicle-to-vehicle distance to be ensured in advance for the preceding vehicle, and perform automatic brake control (including follow-up stop control) and automatic acceleration control (including follow-up start control), and the like. In this way, cooperative control of autonomous travel for the purpose of automatic driving can be performed without depending on the operation of the driver or the like.

[0154] For example, on the basis of distance information obtained from the imaging units 12101 to 12104, the microcomputer 12051 can classify three-dimensional object data related to three-dimensional objects into a two-wheeled vehicle, a normal car, a large vehicle, a pedestrian, a utility pole, and other three-dimensional objects to be extracted, and use the data to automatically avoid obstacles. For example, the microcomputer 12051 distinguishes obstacles around the vehicle 12100 into obstacles that can be visually recognized by the driver of the vehicle 12100 and obstacles that cannot be visually recognized. Then, the microcomputer 12051 determines a collision risk indicating a risk of collision with each obstacle, and when the collision risk is greater than or equal to a set value and there is a possibility of collision, can perform a driving assist for collision avoidance by outputting an alarm to the driver through the audio speaker 12061 or the display unit 12062, and performing forced deceleration or collision avoidance steering by driving the system control unit 12010.

[0155] At least one of the imaging units 12101 to 12104 can be an infrared camera that detects infrared rays. For example, the microcomputer 12051 determines whether a pedestrian is present in a captured image of the imaging units 12101 to 12104, thereby recognizing the pedestrian. For example, such recognition of the pedestrian is performed by a process of extracting feature points in an image captured by the imaging units 12101 to 12104 as infrared cameras, and by a process of performing pattern matching processing on a series of feature points indicating the outline of an object and determining whether the object is a pedestrian. When the microcomputer 12051 determines that a pedestrian is present in an image captured by the imaging units 12101 to 12104 and recognizes the pedestrian, the sound image output unit 12052 causes the display unit 12062 to superimpose and display a square outline to emphasize the recognized pedestrian. In addition, the sound image output unit 12052 can cause the display unit 12062 to display an icon or the like indicating the pedestrian at a desired position.

[0156] An example of a vehicle control system to which the technology according to the present disclosure is applied has been described. The technology according to the present disclosure is applicable to the imaging unit 12031 of the above-described configuration. By applying the technology according to the present disclosure to the measurement device 11, the distance to another vehicle can be measured in a shorter time than before, and a safer automated driving can be realized.

[0157] <Configuration Combination Example>

[0158] Note that the present technology can also have the following configurations. (1)

[0160] A measurement device includes:

[0161] A transmission timing signal generation unit configured to generate a signal for indicating a transmission timing of a pulse of a transmission laser light by setting a width of a time of flight of light to and from between the measurement device and a ranging range indicating a fixed distance width as a ranging range time so as to output a laser light having a transmission number of a pulse of two or more times within one ranging range time, the fixed distance width including a distance to be measured;

[0162] A count code output unit configured to output a count code indicating a timing of a pulse of a reception reflected light, the reflected light being the laser light reflected by a ranging target and returned, according to the transmission number within one ranging range time; and

[0163] A distance calculation unit configured to calculate a distance to the ranging target according to a specific count code among the plurality of count codes. (2)

[0165] The measurement device according to (1), wherein

[0166] The transmission timing signal generation unit makes the intervals between the pulses of the laser transmitted two or more times within one ranging time equal. (3)

[0168] The measurement device according to (1) or (2), wherein

[0169] The transmission timing signal generation unit makes the intervals between the pulses of the laser transmitted two or more times within one ranging time unequal. (4)

[0171] The measurement device according to any one of (1) to (3), wherein

[0172] The transmission timing signal generation unit changes the intervals between the pulses of the laser for each ranging time. (5)

[0174] The measurement device according to (4), wherein

[0175] The transmission timing signal generation unit changes the intervals between the pulses of the laser based on a predetermined random number. (6)

[0177] The measurement device according to any one of (1) to (5), wherein,

[0178] With respect to the pulses of the laser transmitted according to the number of transmissions within one ranging time, the next pulse is transmitted at a timing before a reflected wave of the immediately preceding transmitted pulse is received. (7)

[0180] The measurement device according to any one of (1) to (6), further comprising:

[0181] a histogram generation unit configured to generate a histogram of the plurality of count codes output from the count code output unit, the histogram generation unit being repeatedly executed according to a predetermined number of outputs; and

[0182] a filter processing unit configured to apply filter processing to the histogram generated by the histogram generation unit according to a transfer function obtained from the transmission timing, wherein

[0183] a distance calculation unit configured to calculate a distance to the ranging target using a count code indicating a peak in the histogram to which the filter processing has been applied by the filter processing unit. (8)

[0185] The measurement device according to (7), wherein,

[0186] in a case where the intervals between the pulses of the laser are changed for each ranging time,

[0187] The filter processing unit acquires a transfer function obtained from the emission timing of each ranging range time, and applies filter processing, and then merges the histogram. (9)

[0189] The measurement device according to (8), wherein

[0190] The transfer function used by the filter processing unit is determined by machine learning. (10)

[0192] The measurement device according to (7), wherein

[0193] In a case where a peak is not specified in the histogram to which the filter processing is applied, the filter processing unit increases the number of emissions of the pulse of the laser light, and causes the ranging range time to be repeated. (11)

[0195] The measurement device according to any one of (1) to (10), further comprising:

[0196] a calculation unit configured to perform a calculation on each of a plurality of count codes output from the count code output unit to obtain a calculation result obtained by subtracting, from the count code, each emission timing of all pulses emitted in one ranging range time; and

[0197] a histogram generation unit configured to generate a histogram of the plurality of calculation results obtained by the calculation unit, wherein

[0198] a distance calculation unit calculates a distance to the ranging target using a count code indicating a peak in the histogram generated by the histogram generation unit. (12)

[0200] The measurement device according to any one of (1) to (11), further comprising:

[0201] a plurality of count code output units, wherein

[0202] each count code output unit starts counting of a count code at a timing according to the emission timing, and

[0203] a distance calculation unit calculates a distance to the ranging target using a count code indicating a peak in a histogram generated using all count codes output from the plurality of count code output units. (13)

[0205] The measurement device according to any one of (1) to (12), further comprising:

[0206] a plurality of light-receiving elements configured to receive reflected light, the reflected light being laser light reflected by a distance-measuring target and returned. (14)

[0208] The measurement device according to (13), wherein

[0209] In the configuration in which the plurality of light-receiving elements are provided, light reception by the plurality of light-receiving elements is disabled at a timing at which the pulse of the laser light is emitted, and

[0210] Based on the emission timing, a histogram of count codes indicating timings when each of the light-receiving elements is disabled is corrected. (15)

[0212] A measurement method, comprising:

[0213] by the measurement device,

[0214] by setting a width of a time of flight of light to and from between the measurement device and a distance-measuring range representing a fixed distance width including a distance to be measured as a distance-measuring range time, generating a signal for indicating an emission timing of a pulse of laser light so as to output laser light having a number of times of emission of the pulse twice or more within one distance-measuring range time;

[0215] within one distance-measuring range time, outputting count codes indicating timings at which a pulse of reflected light is received, the reflected light being laser light reflected by a distance-measuring target and returned; and

[0216] calculating a distance to the distance-measuring target based on a specific count code among the plurality of count codes. (16)

[0218] A program for causing a computer of a measurement device to execute a measurement process, the measurement process comprising:

[0219] by setting a width of a time of flight of light to and from between the measurement device and a distance-measuring range representing a fixed distance width including a distance to be measured as a distance-measuring range time, generating a signal for indicating an emission timing of a pulse of laser light so as to output laser light having a number of times of emission of the pulse twice or more within one distance-measuring range time;

[0220] within one distance-measuring range time, outputting count codes indicating timings at which a pulse of reflected light is received, the reflected light being laser light reflected by a distance-measuring target and returned; and

[0221] calculating a distance to the distance-measuring target based on a specific count code among the plurality of count codes.

[0222] Note that the present technology is not limited to the embodiments, and various modifications can be made without departing from the spirit of the present disclosure. Furthermore, the effects described in the present specification are merely examples and are not limiting, and other effects can be exhibited.

[0223] List of reference symbols

[0224] 11 measurement device

[0225] 12 transmission timing signal generation unit

[0226] 13 laser driver

[0227] 14 light receiving element

[0228] 15 TDC

[0229] 16 histogram generation unit

[0230] 17 filter processing unit

[0231] 18 distance calculation unit

[0232] 19 calculation unit

[0233] 21 counter

[0234] 22 latch

[0235] 31 laser

[0236] 32 diffraction grating

[0237] 33 optical switch

Claims

1. A measuring device comprising: an emission timing signal generating unit configured to generate an emission timing signal for instructing emission of a pulse of laser light by setting a width of a round-trip flight time of light between the measuring device and a ranging range representing a fixed distance width including a distance to be measured as a ranging range time, so as to output laser light having a number of emissions of the pulse of two or more times within one ranging range time; a count code output unit configured to output a count code indicating a timing of receiving a pulse of reflected light according to the number of transmissions within one ranging range time, the reflected light being laser light reflected and returned by a ranging target, wherein the count code is determined based on a predetermined time for one count by a counter and the ranging range time; and a distance calculation unit configured to calculate the distance to the ranging target based on a specific counting code among the plurality of counting codes, wherein the measuring device includes a plurality of counting code output units, the number of the counting code output units corresponding to the number of times the pulse is transmitted within one ranging range time; and a histogram generating unit in which the ranging range time is repeatedly executed according to a predetermined number of output times, the histogram generating unit being configured to generate a histogram of the plurality of count codes output from the count code output unit; and a filter processing unit configured to apply filter processing according to a transfer function obtained from the transmission timing to the histogram generated by the histogram generating unit, wherein the filter processing unit obtains the transfer function from a count code of the transmission timing information provided by the transmission timing signal generating unit, and wherein each of the count code output units starts counting the count codes at a timing according to the transmission timing of a corresponding pulse, and wherein the distance calculating unit is configured to calculate the distance to the ranging target using the count code indicating a peak in a histogram generated using all the count codes output from the plurality of count code output units.

2. The measuring device according to claim 1, wherein The emission timing signal generating unit equalizes intervals between pulses of the laser light emitted two or more times within one ranging range time.

3. The measuring device according to claim 1, wherein The emission timing signal generating unit makes intervals between pulses of the laser light emitted two or more times within one ranging range time unequal.

4. The measuring device according to claim 1, wherein The emission timing signal generating unit changes the interval between pulses of the laser light for each time of the ranging range.

5. The measuring device according to claim 4, wherein The emission timing signal generating unit changes the interval between pulses of the laser light based on a predetermined random number.

6. The measuring device according to claim 1, wherein Regarding the pulses of the laser light emitted according to the number of emission times within one ranging range time, the next pulse is emitted at a timing before a reflected wave of the pulse emitted immediately before is received.

7. The measuring device according to claim 1, in, The distance calculation unit calculates the distance to the distance measurement target using the count code indicating the peak in the histogram to which the filter processing is applied by the filter processing unit.

8. The measuring device according to claim 7, wherein In the case where the interval between the laser pulses is changed for each time of the ranging range, The filter processing unit acquires the transfer function obtained from the transmission timing every time of the ranging range, applies the filter processing, and then combines the histograms.

9. The measuring device according to claim 8, wherein The transfer function used by the filter processing unit is determined by machine learning.

10. The measuring device according to claim 7, wherein In a case where the peak is not specified in the histogram to which the filter processing is applied, the filter processing unit increases the number of emission times of the pulse of the laser light and repeats the distance measurement range time.

11. The measuring device according to claim 1 , further comprising: a calculation unit configured to perform calculation on each of the plurality of counting codes output from the counting code output unit to obtain a calculation result obtained by subtracting each of the transmission timings of all the pulses transmitted within one ranging range time from the counting code; as well as a histogram generating unit configured to generate a histogram of the plurality of calculation results obtained by the calculating unit, wherein: The distance calculation unit calculates the distance to the distance measurement target using the calculation result indicating the peak in the histogram generated by the histogram generation unit.

12. The measuring device according to claim 1, further comprising: A plurality of light receiving elements are configured to receive the reflected light, which is the laser light reflected and returned by the ranging target.

13. The measuring device according to claim 12, wherein In a configuration in which a plurality of the light receiving elements are provided, light reception by the plurality of light receiving elements is disabled at the timing of emitting a pulse of the laser light, and Based on the emission timing, a histogram of count codes indicating a timing at which each of the light receiving elements is disabled is corrected.

14. A measurement method comprising: By measuring equipment: generating a signal for instructing emission timing of a pulse of laser light by setting a width of a round-trip flight time of light between the measuring device and a ranging range representing a fixed distance width including the distance to be measured as a ranging range time, so as to output laser light having a number of emissions of the pulse of two or more times within one ranging range time; outputting a count code indicating a timing of receiving a pulse of reflected light according to the number of transmissions within one ranging range time, the reflected light being laser light reflected and returned by a ranging target, wherein the count code is determined based on a predetermined time for one count by a counter and the ranging range time; and calculating the distance to the ranging target according to a specific counting code among the plurality of counting codes, The measuring device includes a plurality of counting code output units, and the number of the counting code output units corresponds to the number of times the pulse is transmitted within the ranging range time. and wherein each of the count code output units starts counting the count codes at a timing according to the emission timing of the corresponding pulse, and the distance calculation unit of the measuring device is configured to calculate the distance to the ranging target using the count code indicating a peak in a histogram generated using all the count codes output from the plurality of count code output units; Repeating the ranging time according to a predetermined number of output times and generating a plurality of histograms of the counting codes; and A filtering process according to a transfer function obtained from a counting code of transmission timing information is applied to the generated histogram.

15. A computer-readable storage medium having a program stored thereon, wherein when the program is executed by a computer of a device under measurement, the computer is caused to perform a measurement process, the measurement process comprising: generating a signal for instructing emission timing of a pulse of laser light by setting a width of a round-trip flight time of light between the measuring device and a distance measuring range representing a fixed distance width including the distance to be measured as a distance measuring range time, so as to output laser light having a pulse emission number of two or more within one distance measuring range time; outputting a count code indicating a timing of receiving a pulse of reflected light, the reflected light being the laser light reflected and returned by a ranging target, according to the number of transmissions within one ranging range time, wherein the count code is determined based on a predetermined time for one count by a counter and the ranging range time; and calculating the distance to the ranging target according to a specific counting code among the plurality of counting codes, The measuring device includes a plurality of counting code output units, and the number of the counting code output units corresponds to the number of times the pulse is transmitted within the ranging range time. and wherein each of the count code output units starts counting the count code at a timing according to the emission timing of the corresponding pulse, and the distance calculation unit of the measuring device is configured to calculate the distance to the ranging target using the count code indicating a peak in a histogram generated using all the count codes output from the plurality of count code output units, Repeating the ranging time according to a predetermined number of output times, and generating a histogram of the outputted plurality of counting codes; and A filtering process according to an obtained transfer function is applied to the generated histogram, wherein the transfer function is obtained from a counting code of the provided transmission timing information.

Images