Object detection device

Abstract

The present invention relates to an object detection device capable of effectively utilizing highly reliable distance information. The object detection device comprises: a transceiver that transmits a transmission wave and receives a reflected wave from an object; an acquisition unit that detects a reflected wave having a signal level exceeding a threshold value, thereby acquiring distance information indicating the distance from the transceiver to the object; a sorting unit that, when multiple pieces of distance information are acquired within a predetermined period, prioritizes the distance information so that the greater the difference between the signal level of the piece of distance information and the threshold value, the higher the priority; and an output control unit that outputs the multiple pieces of distance information in descending order of priority.

Description

Technical Field

[0001] The present invention relates to an object detection device. Background Art

[0002] Some devices for detecting objects use TOF (Time of Flight), which is the time it takes for a transmitted wave such as an ultrasonic wave or a millimeter wave to be reflected by an object and return, as distance information indicating the distance to the object.

[0003] For example, a technology is disclosed that detects the position of an object by performing triangulation calculation based on a plurality of distance information obtained by a plurality of sensors that transmit transmission waves and receive reflected waves from the object (Patent Document 1).

[0004] Patent Document 1: Japanese Patent Application Laid-Open No. 2016-80648

[0005] While multiple distance information (such as TOF) is often detected within a specified period, this distance information may include not only objects corresponding to the detection target (e.g., other vehicles, people, etc.) but also objects outside the detection target (e.g., the road surface). To improve detection accuracy, it is necessary to effectively utilize highly reliable distance information as the object corresponding to the detection target. Summary of the Invention

[0006] Therefore, one of the objects of the present invention is to effectively utilize highly reliable distance information.

[0007] An object detection device, as an example of the present invention, includes: a transceiver that transmits a transmission wave and receives a reflected wave from an object; an acquisition unit that detects a reflected wave having a signal level exceeding a threshold value, thereby acquiring distance information indicating the distance from the transceiver to the object; a sorting processing unit that, when multiple pieces of distance information are acquired within a predetermined period, sets a priority order for the distance information such that the greater the difference between the signal level corresponding to the distance information and the threshold value, the higher the priority order of the distance information; and an output control unit that outputs the multiple pieces of distance information in descending order of priority.

[0008] According to the above configuration, distance information with a larger difference between the signal level and the threshold is prioritized. This is because the larger the difference, the more reliable the distance information. This prioritizes the use of highly reliable distance information, improving object detection accuracy.

[0009] In the above-mentioned object detection device, the predetermined period may be one detection cycle from the transmission of one transmission wave to the transmission of the next transmission wave.

[0010] According to the above configuration, it is possible to preferentially output highly reliable distance information in units of one detection cycle.

[0011] Furthermore, in the above-mentioned object detection device, the threshold value may be a processed value using a moving average value.

[0012] According to the above configuration, noise components such as road clutter can be effectively eliminated.

[0013] In addition, the above-mentioned object detection device may also include: a triangulation calculation unit, which performs triangulation calculation for detecting the position of the object based on first distance information calculated based on a direct wave in which a transmission wave transmitted from the first transceiver is reflected by the object and received by the first transceiver, and second distance information calculated based on an indirect wave in which a transmission wave transmitted from a second transceiver arranged at a position different from the first transceiver is reflected by the object and received by the first transceiver; and a prohibition processing unit, which prohibits triangulation calculation when the difference between first speed information indicating the speed of the object calculated based on the first reflected wave and second speed information indicating the speed of the object calculated based on the second reflected wave exceeds a prescribed range.

[0014] With this configuration, triangulation can be performed using the first and second distance information, which have higher priority. Furthermore, the prohibition processing unit prohibits triangulation based on the first and second distance information if the difference between the first and second velocity information is large. This narrows the first and second distance information used for triangulation to those with higher reliability. This further improves object detection accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a plan view showing an example of the appearance of a vehicle equipped with the vehicle control system according to the first embodiment.

[0016] Figure 2 This is a block diagram showing an example of the hardware configuration of the vehicle control system according to the first embodiment.

[0017] Figure 3 This is a block diagram showing an example of the functional configuration of the object detection device according to the first embodiment.

[0018] Figure 4 It is a diagram for explaining the outline of the TOF method according to the first embodiment.

[0019] Figure 5 This is a diagram showing an example of processing by the sort processing unit according to the first embodiment.

[0020] Figure 6It is a diagram showing another example of the processing of the sort processing unit according to the first embodiment.

[0021] Figure 7 This is a flowchart showing an example of processing by the distance information acquisition unit and the output control unit according to the first embodiment.

[0022] Figure 8 This is a diagram showing an example of a Doppler shift generated between a transmission wave transmitted from the transmission / reception unit of the first embodiment and a reflected wave from an object.

[0023] Figure 9 This is a flowchart showing an example of processing by the calculation unit according to this embodiment.

[0024] Figure 10 This is a block diagram showing an example of the functional configuration of the object detection device according to the second embodiment.

[0025] Description of Reference Signs

[0026] 1...Vehicle, 2...Vehicle body, 10...Vehicle control system, 11...Object detection device, 12...ECU, 21, 21A-21L...Transmitter-receiver, 22...Control unit, 25A, 25B...Transmitted wave, 26A...Direct wave, 26B...Indirect wave, 31...Oscillator, 41...Input / output device, 42...Storage device, 43...Processor, 51...Input / output device, 52...Storage device, 53...Processor, 101...Distance information acquisition unit, 102...Output control unit, 103...Calculation unit, 111...Sorting processing unit, 121...Triangulation calculation unit, 122...Speed ​​information acquisition unit, 123...Prohibition processing unit, L, L'...Envelope, Lth, Lth'...Threshold, P1-P4...Peak value, ΔA...Difference DETAILED DESCRIPTION

[0027] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. The structures of the embodiments described below, and the functions and effects thereof, are merely examples, and the present invention is not limited to the following description.

[0028] (First embodiment)

[0029] Figure 1 This is a top view showing an example of the appearance of a vehicle 1 equipped with a vehicle control system according to the first embodiment. The vehicle control system is a system including, for example, an object detection device that detects objects around the vehicle 1 and an ECU (Electronic Control Unit) that controls the vehicle 1 based on the detection results of the object detection device.

[0030] The object detection device of this embodiment is a device that detects information related to objects (other vehicles, obstacles, people, etc.) around vehicle 1 (whether there are objects, the location of the objects, etc.) based on TOF (Time Of Flight) information, Doppler shift information, etc. obtained by sending waves such as ultrasonic waves from vehicle 1 and receiving reflected waves from objects.

[0031] The object detection device of this embodiment includes a plurality of transceivers 21A to 21L (hereinafter, these are sometimes collectively referred to as transceivers 21). Each transceiver 21 is provided on a vehicle body 2 as an exterior of a vehicle 1, transmits a transmission wave toward the outside of the vehicle body 2, and receives a reflected wave from an object existing outside the vehicle body 2. Figure 1 In the example shown, four transceivers 21A to 21D are disposed at the front end of the vehicle body 2, four transceivers 21E to 21H are disposed at the rear end, two transceivers 21I and 21J are disposed on the right side of the vehicle body, and two transceivers 21K and 21L are disposed on the left side of the vehicle body. The number and placement of the transceivers 21 are not limited to the example shown above.

[0032] Figure 2 1 is a block diagram showing an example of the hardware configuration of the vehicle control system 10 according to the first embodiment. The vehicle control system 10 according to the present embodiment includes an object detection device 11 and an ECU 12 .

[0033] The object detection device 11 includes a plurality of transceivers 21 and a control unit 22 .

[0034] Figure 2 Each of the illustrated transceivers 21 includes a transducer 31 constructed using a piezoelectric element or the like, and transmits and receives ultrasonic waves through the vibration of the transducer 31. Specifically, each transceiver 21 transmits an ultrasonic wave generated in response to the vibration of the transducer 31 as a transmission wave, and detects the vibration of the transducer 31 caused by the reflected wave of the transmission wave reflected by the object X.

[0035] Each transceiver 21 can receive not only the reflected wave corresponding to the transmission wave sent by itself, but also the reflected wave corresponding to the transmission wave sent by other transceivers 21. Figure 2 As shown, the first transceiver 21A receives a direct wave 26A, which is a reflected wave resulting from a transmission wave 25A transmitted from the first transceiver 21A and reflected by an object X, and an indirect wave 26B, which is a reflected wave resulting from a transmission wave 25B transmitted from the second transceiver 21B and reflected by an object X. To distinguish between the direct wave 26A and the indirect wave 26B, appropriate identification processing (e.g., frequency modulation, phase modulation, etc.) is performed on each transmission wave. Time of flight (TOF) information indicating the distance to the object X and Doppler shift information indicating the velocity (relative velocity) of the object X can be obtained from each of the direct wave 26A and the indirect wave 26B.

[0036] In addition, the relationship between direct waves and indirect waves is not limited to the above example. The first transceiver 21A can also receive indirect waves from other transceivers 21 (such as the third transceiver 21C, the ninth transceiver 21I, etc.) that are physically located in a position relationship that can receive indirect waves. In addition, the situation in which indirect waves can be received is not limited to the first transceiver 21A, and the other transceivers 21B to 21L can also receive indirect waves. In addition, Figure 2 In the illustrated example, a configuration is shown in which both transmission of transmission waves and reception of reflected waves (direct waves and indirect waves) are performed using a single transducer 31. However, the configuration of the transceiver 21 is not limited to this. For example, a configuration in which the transmission side and the reception side are separated may be employed, such as providing a first transducer for transmitting transmission waves and a second transducer for receiving reflected waves separately.

[0037] The control unit 22 includes an input / output device 41, a storage device 42, and a processor 43. The input / output device 41 is an interface device for transmitting and receiving information between the control unit 22 and the outside (transceiver unit 21, ECU 12, etc.). The storage device 42 includes main storage devices such as ROM (Read Only Memory) and RAM (Random Access Memory), and auxiliary storage devices such as HDD (Hard Disk Drive) and SSD (Solid State Drive). The processor 43 is an integrated circuit that performs various processes for realizing the functions of the control unit 22, and includes, for example, a CPU (Central Processing Unit) that operates according to a program, an ASIC (Application Specific Integrated Circuit) designed for a specific purpose, etc. The processor 43 reads and executes the program stored in the storage device 42 to perform various calculations and control processes.

[0038] ECU12 is a unit that performs various processes for controlling the vehicle 1 based on various information obtained from the object detection device 11 and the like. ECU12 has an input / output device 51, a storage device 52, and a processor 53. The input / output device 51 is an interface device for transmitting and receiving information between the ECU12 and the outside (object detection device 11, drive mechanism, brake mechanism, steering mechanism, etc.). The storage device 52 includes a main storage device such as ROM and RAM, and an auxiliary storage device such as HDD and SSD. The processor 53 is an integrated circuit that performs various processes for realizing the functions of the ECU12, and includes, for example, a CPU and an ASIC. The processor 53 reads the program stored in the storage device 52 to perform various calculation processes and control processes.

[0039] Figure 3 1 is a block diagram showing an example of the functional configuration of the object detection device 11 according to the first embodiment. The object detection device 11 includes a distance information acquisition unit 101, an output control unit 102, and a calculation unit 103. These functional units 101 to 103 are connected to each other through Figure 2 The object detection device 11 shown is realized by cooperation of hardware components and software components such as programs.

[0040] The distance information acquisition unit 101 acquires distance information indicating the distance from the transceiver unit 21 to the object X based on the temporal change in the signal level (reception intensity) of the reflected waves (direct waves and indirect waves) received by each transceiver unit 21. Examples of distance information include time of flight (TOF) and distance calculated based on TOF. For example, the distance information acquisition unit 101 acquires direct TOF, which is TOF calculated based on direct waves received by each transceiver unit 21, and indirect TOF, which is TOF calculated based on indirect waves received by each transceiver unit 21.

[0041] The output control unit 102 controls the output of the distance information acquired by the distance information acquisition unit 101. The output control unit 102 of this embodiment performs processing for outputting a plurality of distance information in descending order of priority (reliability).

[0042] When the sorting processing unit 111 acquires multiple pieces of distance information within a predetermined period, it prioritizes the distance information so that the greater the difference between the signal level of the reflected wave (direct wave or indirect wave) corresponding to the distance information and a predetermined threshold, the higher the priority of the distance information. The output control unit 102 outputs the multiple pieces of distance information to the calculation unit 103 in descending order of priority. The predetermined period may be, for example, a detection cycle (the waiting time for reflected waves) from the transmission of one transmission wave to the transmission of the next transmission wave. The predetermined threshold may be, for example, a threshold set to distinguish between detection target objects (e.g., other vehicles, people, etc.) and non-detection targets (e.g., the road surface, etc.).

[0043] The greater the difference between the reflected wave signal level and the threshold, the more reliable the detected distance information can be. Therefore, by setting the priority (output order) of the plurality of distance information based on the difference, the distance information with higher reliability can be outputted preferentially.

[0044] The calculation unit 103 performs calculations for generating information about objects existing around the vehicle 1 using the distance information output from the output control unit 102. The calculation unit 103 of this embodiment includes a triangulation calculation unit 121, a speed information acquisition unit 122, and a prohibition processing unit 123.

[0045] The triangulation operation unit 121 performs triangulation operation to detect the position of the object based on the first distance information calculated based on the direct wave and the second distance information calculated based on the indirect wave. The first distance information is the direct TOF, etc. The second distance information is the indirect TOF, etc.

[0046] The velocity information acquisition unit 122 acquires first velocity information based on the direct wave and second velocity information based on the indirect wave. The first velocity information may include, for example, the Doppler shift amount calculated based on the direct wave and the relative velocity calculated based on the Doppler shift amount. The second velocity information may include, for example, the Doppler shift amount calculated based on the indirect wave and the relative velocity calculated based on the Doppler shift amount.

[0047] The prohibition processing unit 123 prohibits the triangulation operation unit 121 from executing the triangulation operation based on the first distance information and the second distance information when the difference between the first speed information and the second speed information exceeds a predetermined range.

[0048] If the error between the first velocity information based on the direct wave and the second velocity information based on the indirect wave is large, there's a high probability that the object captured by the direct wave and the object captured by the indirect wave are different. In this case, the accuracy of the triangulation calculation performed using the first distance information based on the direct wave and the second distance information based on the indirect wave decreases. Therefore, by performing the processing of the prohibition processing unit 123 as described above, it is possible to suppress the execution of low-accuracy triangulation calculations.

[0049] The object detection device 11 of this embodiment detects objects using the TOF method using ultrasonic waves. The TOF method calculates the distance to an object based on the difference between the time when a transmitted wave is transmitted (more specifically, when transmission starts) and the time when a reflected wave is received (more specifically, when reception starts).

[0050] Figure 4 : is a diagram for explaining the outline of the TOF method of the first embodiment. Figure 4 The envelope curve of the temporal change of the signal level of the ultrasonic wave transmitted and received by the transmitting and receiving unit 21 is shown in FIG. Figure 4 In the graph shown, the horizontal axis corresponds to time, and the vertical axis corresponds to the signal level.

[0051] The solid line L11 shows an example of an envelope curve representing the temporal change in the signal level of the signal transmitted and received by the transceiver 21, that is, the degree of vibration of the vibrator 31. As can be seen from the solid line L11, the vibrator 31 is driven and vibrates for a time Ta from time t0, and the transmission of the transmission wave ends at time t1. Then, during the time Tb before reaching time t2, the vibration of the vibrator 31 due to inertia decays and continues. Figure 4 In the diagram shown, the time Tb corresponds to the so-called reverberation time.

[0052] At time t4, a time Tp has passed since the start of the transmission wave transmission, as shown by the solid line L11, the vibration level of the vibrator 31 reaches a peak value that exceeds (or exceeds) a predetermined threshold value Th1, indicated by the dashed line L21. This threshold value Th1 is a predetermined value that is used to distinguish whether the vibration of the vibrator 31 is caused by the reception of a reflected wave from an object under examination or by the reception of a reflected wave from an object outside the examination object. While the threshold value indicated by the dashed line L21 is shown here as a constant value that does not change with the passage of time, it can also be set to a value that changes with the passage of time.

[0053] Vibrations with a peak value exceeding (or exceeding) the threshold value indicated by the dashed-dotted line L21 can be considered to be caused by the reception of reflected waves from the object being detected. On the other hand, vibrations with a peak value below (or below) the threshold value can be considered to be caused by the reception of reflected waves from an object outside the detection target. Therefore, as can be seen from the solid line L11, the vibration of vibrator 31 at time t4 is caused by the reception of reflected waves from the object being detected.

[0054] In the solid line L11, the vibration of the transducer 31 attenuates after time t4. Therefore, time t4 corresponds to the time when the reception of the reflected wave from the detection target object ends, in other words, the time when the transmission wave last transmitted at time t1 returns as a reception wave.

[0055] Furthermore, in solid line L11, time t3, which is the starting point of the peak at time t4, corresponds to the moment when the reception of the reflected wave from the object being detected begins. In other words, the time when the transmission wave initially transmitted at time t0 returns as the received wave. Therefore, in solid line L11, the time ΔT between time t3 and time t4 is equal to the time Ta, which is the transmission time of the transmission wave.

[0056] Based on the above, to determine the distance to the target object using the TOF method, it is necessary to determine the time Tf between time t0, when the transmission wave starts, and time t3, when the reflected wave starts receiving. This time Tf can be determined by subtracting a time ΔT, which is equal to the time Ta (the transmission time of the transmission wave), from the time Tp, which is the difference between time t0 and time t4, when the reflected wave's signal level reaches a peak exceeding a threshold.

[0057] Time t0, at which transmission of the transmission wave begins, can be easily determined as the time at which object detection device 11 begins operation. Time Ta, which is the transmission time of the transmission wave, is predetermined by settings, etc. Therefore, by determining time t4, at which the signal level of the reflected wave reaches a peak exceeding a threshold, the distance to the object to be detected can be determined.

[0058] The distance information acquisition unit 101 of this embodiment performs the aforementioned processing on the direct and indirect waves acquired by each transceiver 21, acquiring a direct time of flight (TOF) based on the direct wave and an indirect time of flight (TOF) based on the indirect wave. Furthermore, when the sorting processing unit 111 of this embodiment acquires multiple TOFs (either direct or indirect) within a predetermined period, it prioritizes each TOF so that the greater the difference between the signal level corresponding to the TOF and a threshold, the higher the priority. Furthermore, the output control unit 102 of this embodiment outputs the multiple TOFs to the calculation unit 103 in descending order of priority, in descending order of priority.

[0059] Figure 5 1 is a diagram showing an example of the processing of the sorting processing unit 111 according to the first embodiment. Figure 5 In FIG, there are shown an envelope line L showing the temporal variation of the signal level of the reflected wave (direct wave or indirect wave) in one detection cycle, and a threshold line Lth showing the threshold value for detecting TOF (direct TOF or indirect TOF). Figure 5 , an example is shown in which four peaks P1 to P4 corresponding to four TOF1 to TOF4 are detected in one detection cycle.

[0060] like Figure 5 As shown, the order of priority of TOF1-TOF4 before sorting is determined based on the order of the elapsed time from the time t0 when the transmission wave was transmitted to the detection of the corresponding peaks P1-P4, from shortest to longest, that is, the time when peaks P1-P4 were detected. In this case, the four TOF1-TOF4 are output to the calculation unit 103 in the order of TOF1 → TOF2 → TOF3 → TOF4.

[0061] In contrast, the order of priority for TOF1 to TOF4 after sorting is determined in descending order of the difference ΔA between the signal level of each peak P1 to P4 on the envelope L and the threshold value indicated by the threshold line Lth. In this case, the four TOF1 to TOF4 are output to the calculation unit 103 in the order of TOF3 → TOF1 → TOF4 → TOF2.

[0062] The larger the difference ΔA, the more likely it is that the detected peak corresponds to the object being detected (the less likely it is caused by noise such as road clutter). Therefore, as described above, by setting the priority (output order) of TOF1 to TOF4 based on the difference ΔA, TOFs with higher reliability can be output to the calculation unit 103 preferentially.

[0063] Figure 6 FIG. 1 is a diagram showing another example of the processing performed by the sorting processing unit 111 according to the first embodiment. Figure 6 , an envelope L′ showing temporal changes in the signal level of a reflected wave (direct wave or indirect wave) in one detection cycle, and a threshold line Lth′ showing a threshold for detecting TOF (direct TOF or indirect TOF) are shown. Figure 6 The threshold line Lth' in the example shown is a processed value using the moving average of the envelope line L'. This processed value can be any value that can detect the TOF corresponding to the object to be detected. For example, it can be a value obtained by adding or subtracting a threshold based on a predetermined reference (such as a threshold for removing road clutter) from the moving average. The priority setting method of each TOF1 to TOF4 (each peak P1 to P4) is the same as Figure 5 By setting the TOF threshold to a processed value using a moving average in this manner, the effect of removing noise such as road clutter can be enhanced.

[0064] Figure 7 This is a flowchart illustrating an example of the processing performed by the distance information acquisition unit 101 and the output control unit 102 of the first embodiment. The distance information acquisition unit 101 generates an envelope of the reflected waves (direct and / or indirect waves) received by the transceiver 21 (S101) and sets a threshold for detecting time of flight (TOF) (S102). In this case, the distance information acquisition unit 101 may also generate the envelope and set the threshold based on data processed using CFAR (Constant False Alarm Rate) processing. CFAR processing obtains a difference signal obtained by subtracting a moving average from the signal level of the reflected wave being processed. Using CFAR processing can reduce the influence of noise such as road clutter. The distance information acquisition unit 101 then detects TOF from reflected waves whose signal levels exceed the threshold (S103).

[0065] The sorting processing unit 111 of the output control unit 102 calculates the difference ΔA (the difference between the signal level of each peak P1 to P4 and the threshold value indicated by the threshold lines Lth and Lth′) for each detected TOF (S104), and sorts the plurality of TOFs in descending order of the difference ΔA (S105). The output control unit 102 outputs the plurality of TOFs in sorted order to the calculation unit 103 (S106).

[0066] Through the above-described processing, a TOF with high reliability can be preferably output to the calculation unit 103 .

[0067] The triangulation operation unit 121 of the operation unit 103 performs a triangulation operation to detect the position of an object based on the sorted distance information output from the output control unit 102 as described above, namely, the first distance information (direct time of flight) and the second distance information (indirect time of flight) with a higher priority (reliability). Furthermore, the velocity information acquisition unit 122 acquires first velocity information (Doppler shift amount or relative velocity) based on the first distance information, and second velocity information (Doppler shift amount or relative velocity) based on the second distance information. Furthermore, if the difference between the first velocity information and the second velocity information exceeds a predetermined range, the prohibition processing unit 123 prohibits the execution of the triangulation operation based on the first and second distance information.

[0068] Here, the Doppler shift will be described. Figure 8This diagram illustrates an example of the Doppler shift generated between the transmission wave sent by the transceiver 21 and the reflected wave from an object in the first embodiment. The diagram illustrates a case where the transmission wave is frequency modulated so that the frequency varies in a sawtooth pattern. The horizontal axis of the diagram corresponds to time, and the vertical axis corresponds to the frequency of the transmission wave and the reflected wave.

[0069] Waveform W1 shows the frequency characteristics of the transmission wave, and waveform W2 shows the frequency characteristics of the reflected wave. Transmission wave waveform W1 corresponds to a linear frequency modulation (chirp) signal whose instantaneous frequency varies within the range of fc-Δf to fc+Δf.

[0070] When the relative distance between an object and the transceiver 21 decreases (when the vehicle 1 and / or the object are moving closer to each other), the Doppler effect causes the frequency band of the received wave, represented by waveform W2, to shift toward higher frequencies compared to the frequency band of the transmitted wave, represented by waveform W1. At this time, while the frequency bands differ between waveforms W1 and W2, they share a common waveform characteristic, with the frequency changing in a jagged pattern over time. Therefore, after the transmission of the transmitted wave, by extracting a signal with the same waveform characteristics as waveform W1 from the acquired signal, waveform W2, the reflected wave corresponding to the transmitted wave, can be determined. Furthermore, when the relative distance increases (when the vehicle 1 and / or the object are moving farther away from each other), the frequency band represented by waveform W2 shifts toward lower frequencies compared to the frequency band represented by waveform W1.

[0071] As described above, by determining the correspondence between waveforms W1 and W2, it is possible to obtain the TOF corresponding to the distance to the object and the Doppler shift (frequency difference) fd generated between the transmitted wave and the reflected wave. Furthermore, the relative speed of vehicle 1 (transceiver 21) with respect to the object can be calculated based on the Doppler shift fd.

[0072] Figure 9 This is a flowchart illustrating an example of processing by the calculation unit 103 of this embodiment. First, the velocity information acquisition unit 122 determines whether direct TOF (first distance information) has been acquired from the output control unit 102 (S201). If direct TOF has not been acquired (S201: No), this routine ends. On the other hand, if direct TOF has been acquired (S201: Yes), the velocity information acquisition unit 122 acquires first velocity information (Doppler shift amount or relative velocity) based on the direct wave (S202).

[0073] The speed information acquisition unit 122 then determines whether the indirect TOF (second distance information) has been acquired from the output control unit 102 (S203). If the indirect TOF has not been acquired (S203: No), the calculation unit 103 outputs the position information generated using only the direct TOF to the ECU 12 (S209). On the other hand, if the indirect TOF has been acquired (S203: Yes), the speed information acquisition unit 122 acquires the second speed information (Doppler shift amount or relative speed) based on the indirect wave (S204).

[0074] The prohibition processing unit 123 determines whether the difference between the first and second speed information is within a specified range (S205). If the difference is not within the specified range (S205: No), the triangulation operation unit 121 is prohibited from performing the triangulation operation (S208). In this case, the operation unit 103 outputs position information generated solely by direct TOF to the ECU 12 (S209). On the other hand, if the difference between the first and second speed information is within the specified range (S205: Yes), the triangulation operation unit 121 performs a triangulation operation based on both direct TOF and indirect TOF (S206), and the operation unit 102 outputs position information based on the triangulation operation result to the ECU 12 (S207).

[0075] According to the above processing, when the error between the first speed information and the second speed information is large, triangulation calculation based on the first distance information (direct TOF) and the second distance information (indirect TOF) is prohibited. This can prevent the execution of low-precision triangulation calculation.

[0076] The program that causes the processor 43 and the like to execute the processing for realizing the various functions in the above-described embodiment can be provided as an installable or executable file recorded on a computer-readable recording medium such as a CD (Compact Disc)-ROM, a floppy disk (FD), a CD-R (Recordable), or a DVD (Digital Versatile Disk). Alternatively, the program can be provided or distributed via a network such as the Internet.

[0077] According to the above-described embodiment, the accuracy of object detection can be improved.

[0078] Hereinafter, although other embodiments will be described with reference to the drawings, parts that achieve the same or substantially the same functions and effects as those of the first embodiment are often denoted by the same reference numerals and their description will be omitted.

[0079] (Second embodiment)

[0080] Figure 101 is a block diagram showing an example of the functional configuration of an object detection device 61 according to the second embodiment. Object detection device 61 according to this embodiment differs from object detection device 11 according to the first embodiment in that it does not include the output control unit 102 and sorting unit 111 described above.

[0081] In this embodiment, the plurality of first distance information (direct TOF) or the plurality of second distance information (indirect TOF) obtained by the distance information obtaining unit 101 are output to the calculation unit 103 without setting a priority order. For example, the first distance information or the second distance information of this embodiment may be output in the form of Figure 5 or Figure 6 The data are output in the order before sorting shown (the order based on the time at which the peak corresponding to TOF is detected).

[0082] Even with the above-described configuration, the prohibition processing unit 123 can improve the accuracy of the triangulation operation and detect an object with high accuracy.

[0083] While the embodiments of the present invention have been described above, the embodiments are merely examples and are not intended to limit the scope of the invention. The new embodiments described above can be implemented in various forms and can be omitted, replaced, or modified in various ways without departing from the spirit of the invention. The embodiments described above are included within the scope and spirit of the invention and are included within the scope of the invention described in the technical solution and its equivalents.

Claims

1. An object detection device, characterized in that: have: a transceiver unit that transmits a transmission wave and receives a reflected wave from an object; an acquisition unit configured to acquire distance information indicating a distance from the transmitting and receiving unit to the object by detecting the reflected wave having a signal level exceeding a threshold value; a sorting processing unit configured to, when a plurality of pieces of distance information are acquired within a predetermined period, set a priority order for the distance information such that the greater the difference between the signal level corresponding to the distance information and the threshold value, the higher the priority order; and The output control unit outputs all of the plurality of distance information in descending order of priority.

2. The object detection device according to claim 1, wherein The predetermined period is a detection cycle from the time when one transmission wave is transmitted to the time when the next transmission wave is transmitted.

3. The object detection device according to claim 1 or 2, characterized in that The above threshold values ​​are processed values ​​using a moving average.

4. The object detection device according to claim 1, wherein Also features: a triangulation operation unit for performing triangulation operation for detecting the position of an object based on first distance information calculated based on direct waves resulting from reflection of a transmission wave transmitted from a first transceiver unit by an object and received by the first transceiver unit, and second distance information calculated based on indirect waves resulting from reflection of a transmission wave transmitted from a second transceiver unit disposed at a different position from the first transceiver unit by an object and received by the first transceiver unit; as well as The prohibition processing unit prohibits the triangulation calculation when a difference between first speed information indicating the speed of the object calculated based on the direct wave and second speed information indicating the speed of the object calculated based on the indirect wave exceeds a predetermined range.

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