Object detection device

Abstract

This object detection device comprises: a plurality of transmission / reception units that each transmit a transmission wave and receive a reflected wave; a road surface reflection intensity calculation unit whereby, on the basis of reflected waves received by each of a pair of transmission / reception units installed at the same height and having a symmetrical positional relationship in the shape of a mobile body among the plurality of transmission / reception units, a first road surface reflection intensity that is the intensity of the road surface reflection wave received by one of the pair of transmission / reception units and a second road surface reflection intensity that is the intensity of the road surface reflection wave received by the other transmission / reception unit of the pair of transmission / reception units are calculated; and an abnormality detection unit that detects abnormality in at least one of the pair of transmission / reception units on the basis of the difference between the first road surface reflection intensity and the second road surface reflection intensity.

Description

Object detection device

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

[0002] Object detection devices are used in moving bodies such as vehicles to detect obstacles present around the moving body based on information such as time of flight (TOF) and Doppler shift obtained by transmitting and receiving ultrasonic waves, etc. In such object detection devices, a technology for detecting an abnormality in a transmitter / receiver unit that transmits and receives ultrasonic waves has been disclosed (Patent Document 1), in which ultrasonic waves of different frequencies are transmitted from the transmitter / receiver unit and the presence or absence of an abnormality in the transmitter / receiver unit is determined based on the frequency components of the reflected waves received by the transmitter / receiver unit.

[0003] JP 2018-54580 A

[0004] However, in the conventional technology, a means for generating different frequency components is necessary, which can lead to problems such as a complicated configuration and increased costs. Also, even if there is an abnormality in the transmitter / receiver, the effect may not be apparent in the frequency components.

[0005] The present invention has been made in view of the above, and provides an object detection device that can detect an abnormality in a transmitter / receiver with high accuracy using a simple configuration.

[0006] An object detection device according to one aspect of the present invention is an object detection device that detects obstacles present in the vicinity of a mobile body based on the intensity of reflected waves generated when a transmission wave transmitted from the mobile body is reflected by an object, and is equipped with: a plurality of transceivers that each transmit a transmission wave and receive reflected waves; a road surface reflection intensity calculation unit that calculates a first road surface reflection intensity, which is the intensity of the reflected wave from the road surface received by one of the pair of transceivers, and a second road surface reflection intensity, which is the intensity of the reflected wave from the road surface received by the other of the pair of transceivers, based on the reflected waves received by each of a pair of transceivers that are positioned symmetrically on the left and right of the shape of the mobile body and installed at the same height; and an abnormality detection unit that detects an abnormality in at least one of the pair of transceivers, based on the difference between the first road surface reflection intensity and the second road surface reflection intensity.

[0007] According to the present invention, it is possible to provide an object detection device that can detect abnormalities in a transmitter / receiver with high accuracy using a simple configuration.

[0008] FIG. 1 is a diagram showing an example of the configuration of a vehicle according to the first embodiment. FIG. 2 is a diagram showing an example of the configuration of a vehicle control system according to the first embodiment. FIG. 3 is a diagram showing an example of a distance calculation method using a TOF method according to the first embodiment. FIG. 4 is a diagram showing an example of the functional configuration of an object detection device according to the first embodiment. FIG. 5 is a diagram showing an example of road surface reflection intensity according to the first embodiment. FIG. 6 is a flowchart showing an example of processing in the object detection device according to the first embodiment. FIG. 7 is a diagram showing an example of a diffuse reflection region according to the second embodiment. FIG. 8 is a flowchart showing an example of processing in the object detection device according to the second embodiment.

[0009] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The configuration of the embodiment described below and the actions and effects brought about by the configuration are merely examples, and the present invention is not limited to the following description.

[0010] (First embodiment) Fig. 1 is a diagram showing an example of the configuration of a vehicle 1 according to a first embodiment. The vehicle 1 is an example of a moving body on which an object detection device according to this embodiment is mounted. The object detection device according to this embodiment is a device that detects obstacles present around the vehicle 1 based on information such as time of flight (TOF) and Doppler shift acquired by transmitting and receiving ultrasonic waves.

[0011] The object detection device according to this embodiment includes a plurality of transceivers 21A to 21L. Hereinafter, when there is no need to distinguish between the plurality of transceivers 21A to 21L, they may be referred to as a transceiver 21. Each transceiver 21 is installed on a vehicle body 2 that serves as the exterior of the vehicle 1, transmits ultrasonic waves toward the outside of the vehicle body 2, and receives ultrasonic waves generated when the ultrasonic waves are reflected by an object present outside the vehicle body 2. Hereinafter, ultrasonic waves transmitted from the transceiver 21 may be referred to as a transmitted wave, and ultrasonic waves generated when the transmitted wave is reflected by an object may be referred to as a reflected wave.

[0012] In the example shown in Figure 1, four transceivers 21A to 21D are arranged at the front end of the vehicle body 2, four transceivers 21E to 21H are arranged at the rear end, two transceivers 21I and 21J are arranged on the right side, and two transceivers 21K and 21L are arranged on the left side.

[0013] In the example shown here, the transceivers 21A, 21B, 21E, 21F, 21I, and 21J on the right half of the vehicle body 2 and the transceivers 21C, 21D, 21G, 21H, 21K, and 21L on the left half of the vehicle body 2 are installed in symmetrical positions. The transceivers 21 in a pair, which are symmetrically positioned, are installed at the same height. This same height includes a height within an allowable error range that does not substantially affect the process for detecting an abnormality in the transceiver 21, which will be described later.

[0014] Specifically, the pair of transceivers 21A, 21D are installed at positions symmetrical with respect to a center line C that passes through the center of the left-right (width) direction of the vehicle body 2 and extends in the front-rear direction, and the heights from the road surface at each installation position are the same. The pair of transceivers 21B, 21C are installed at positions symmetrical with respect to the center line C, and the heights from the road surface at each installation position are the same. The pair of transceivers 21I, 21K are installed at positions symmetrical with respect to the center line C, and the heights from the road surface at each installation position are the same. The pair of transceivers 21E, 21H are installed at positions symmetrical with respect to the center line C, and the heights from the road surface at each installation position are the same. The pair of transceivers 21F, 21G are installed at positions symmetrical with respect to the center line C, and the heights from the road surface at each installation position are the same. The pair of transceivers 21J, 21L are installed at positions symmetrical with respect to the center line C, and the heights from the road surface at each installation position are the same. The number and installation locations of the transceivers 21 are not limited to those in this example.

[0015] 2 is a diagram showing an example of the configuration of the vehicle control system 10 according to the first embodiment. The vehicle control system 10 performs processing for controlling the vehicle 1 based on information output from the object detection device 11. The vehicle control system 10 according to this embodiment includes the object detection device 11 and an ECU 12.

[0016] The object detection device 11 includes multiple transceivers 21 and a control unit 22. Each transceiver 21 includes a transducer 31 configured using a piezoelectric element or the like, an amplifier, and the like, and transmits and receives ultrasonic waves through the vibration of the transducer 31. Specifically, each transceiver 21 transmits ultrasonic waves generated in response to the vibration of the transducer 31 as a transmission wave and detects the vibration of the transducer 31 caused by a reflected wave generated when the transmission wave is reflected by an object such as an obstacle O or a road surface G. The obstacle O is an object that is present around the vehicle 1 and is to be detected, and may be, for example, another vehicle, a roadside object, a wall, a person, a curb, a bollard, etc. The vibration of the transducer 31 is converted into an electrical signal, and based on the electrical signal, the time of flight corresponding to the distance from the transceiver 21 to the obstacle O, a Doppler shift corresponding to the relative velocity between the vehicle 1 and the obstacle O, and the like can be obtained.

[0017] 2 illustrates a configuration in which both transmission of the transmission wave and reception of the reflected wave are performed using a single oscillator 31, but the configuration of the transmitter / receiver 21 is not limited to this. For example, the transmitter and receiver may be separated, such as a configuration in which an oscillator for transmitting the transmission wave and an oscillator for receiving the reflected wave are separately provided.

[0018] 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 that enables transmission and reception of information between the control unit 22 and external devices (such as the transceiver unit 21 and the ECU 12). The storage device 42 includes a main storage device such as a read-only memory (ROM) or a random access memory (RAM), and an auxiliary storage device such as a hard disk drive (HDD) or a solid state drive (SSD). The processor 43 is an integrated circuit that executes various processes to realize the functions of the control unit 22, and may be configured using, for example, a central processing unit (CPU), an application specific integrated circuit (ASIC), or a field programmable gate array (FPGA) that operates according to a program. The processor 43 executes various arithmetic and control processes by reading and executing programs stored in the storage device 42.

[0019] The ECU 12 is a unit that executes various processes for controlling the vehicle 1 based on information acquired from the object detection device 11 and the like. The ECU 12 includes an input / output device 51, a storage device 52, and a processor 53. The input / output device 51 is an interface device that enables transmission and reception of information between the ECU 12 and external mechanisms (such as the object detection device 11, drive mechanism, braking mechanism, steering mechanism, transmission mechanism, in-vehicle display, speakers, and various sensors). The storage device 52 includes a main storage device such as a ROM or RAM, and an auxiliary storage device such as an HDD or SSD. The processor 53 is an integrated circuit that executes various processes for realizing the functions of the ECU 12, and may be configured using, for example, a CPU, an ASIC, an FPGA, or the like. The processor 53 reads programs stored in the storage device 52 and executes various arithmetic and control processes.

[0020] Fig. 3 is a diagram showing an example of a distance calculation method using the TOF method according to the first embodiment. Fig. 3 illustrates an envelope curve L that indicates time-series changes in the intensity (signal level) of ultrasonic waves transmitted and received by the transmitter / receiver 21. In the graph shown in Fig. 3, the horizontal axis corresponds to time (TOF), and the vertical axis corresponds to the intensity of ultrasonic waves transmitted and received by the transmitter / receiver 21 (the magnitude of vibration of the transducer 31).

[0021] The envelope L shows the time series change in intensity, which indicates the magnitude of vibration of the vibrator 31. From the envelope L shown in Fig. 3, it can be seen that the vibrator 31 is driven to vibrate for a time Ta from time t0, completing the transmission of the transmission wave at time t1, and then the vibration of the vibrator 31 due to inertia continues while attenuating for a time Tb until time t2. Therefore, in the graph shown in Fig. 3, the time Tb corresponds to the so-called reverberation time.

[0022] The envelope L reaches a peak at time t4, a time Tp after the start of transmission of the transmission wave at time t0, when the magnitude of the vibration of the vibrator 31 reaches or exceeds a threshold value Th. This threshold value Th is a value set to distinguish whether the vibration of the vibrator 31 is caused by reception of a wave reflected from the obstacle O or reception of a wave reflected from an object other than the obstacle O (e.g., the road surface G). Note that although the threshold value Th is shown as a constant value here, the threshold value Th may also be a variable value that changes depending on the situation. Vibrations having a peak equal to or greater than the threshold value Th can be considered to be caused by reception of a wave reflected from the obstacle O.

[0023] In this example, the envelope curve L indicates that the vibration of the vibrator 31 is attenuated after the timing t4. Therefore, the timing t4 corresponds to the timing at which the reception of the reflected wave from the obstacle O is completed, in other words, the timing at which the transmitted wave last transmitted at the timing t1 returns as a reflected wave.

[0024] Furthermore, in envelope L, timing t3, which is the start point of the peak at timing t4, corresponds to the timing when reception of the reflected wave from obstacle O begins, in other words, the timing when the transmitted wave first transmitted at timing t0 returns as a reflected wave. Therefore, the time ΔT between timing t3 and timing t4 is equal to the time Ta, which is the transmission time of the transmitted wave.

[0025] From the above, in order to use TOF to find the distance from the transmitter / receiver 21, which is the source of the ultrasonic waves, to the obstacle O, it is necessary to find the time Tf between the time t0 when the transmission of the transmitted wave begins and the time t3 when the reflected wave begins to be received. This time Tf can be found by subtracting the time ΔT, which is equal to the time Ta as the transmission time of the transmitted wave, from the time Tp, which is the difference between the time t0 and the time t4 when the intensity of the reflected wave exceeds the threshold Th and reaches its peak.

[0026] The time t0 when the transmission of the transmission wave begins can be easily identified as the time when the object detection device 200 starts operating, and the time Ta as the transmission time of the transmission wave is determined in advance by settings, etc. Therefore, by identifying the time t4 when the intensity of the reflected wave reaches a peak equal to or greater than the threshold value Th, the distance from the vehicle 1 (the transmitter / receiver 21, which is the source of the transmission and reception of the ultrasonic waves) to the obstacle O can be calculated. Note that the above calculation method is an example, and the distance from the vehicle 1 to the obstacle O may be calculated using any known or new method as appropriate.

[0027] 4 is a diagram showing an example of the functional configuration of the object detection device 11 according to the first embodiment. The object detection device 11 (control unit 22) according to this embodiment includes an echo information generation unit 101, a road surface reflection intensity calculation unit 102, an abnormality detection unit 103, and an output unit 104. These functional units can be realized, for example, by cooperation between the hardware and software (programs, etc.) of the object detection device 11 as shown in FIG. 2. Furthermore, at least some of these functional units may be realized by dedicated hardware (circuits).

[0028] The echo information generating unit 101 generates echo information indicating time-series changes in the intensity of the reflected wave for each transmitter / receiver 21 based on information acquired from each transmitter / receiver 21. The echo information may include data on an envelope L as exemplified in Fig. 3, for example.

[0029] The road surface reflection intensity calculation unit 102 calculates a first road surface reflection intensity and a second road surface reflection intensity based on reflected waves (echo information indicating time-series changes in the reflected waves) received by each of a pair of transceivers 21 (e.g., transceivers 21A and 21D or transceivers 21B and 21C, etc.) among the multiple transceivers 21, which are positioned symmetrically in the shape of the vehicle 1 (car body 2) and installed at the same height. The first road surface reflection intensity is the intensity of the road surface reflected wave (the reflected wave generated when the transmission wave transmitted from one transceiver is reflected by the road surface) received by one transceiver (e.g., transceiver 21A) of the pair of transceivers 21. The second intensity is the intensity of the road surface reflected wave (the reflected wave generated when the transmission wave transmitted from the other transceiver is reflected by the road surface) received by the other transceiver (e.g., transceiver 21B) of the pair of transceivers 21.

[0030] The abnormality detection unit 103 detects an abnormality in at least one of the pair of transmitter-receivers 21 based on the difference between the first road surface reflection intensity and the second road surface reflection intensity. For example, the abnormality detection unit 103 determines that there is an abnormality in at least one of the pair of transmitter-receivers 21 when the difference between the first road surface reflection intensity and the second road surface reflection intensity is greater than a predetermined threshold value.

[0031] In this case, even if the pair of transmitter-receivers 21 is in a normal state, there may be an error between the first road surface reflection intensity and the second road surface reflection intensity due to the structural conditions of each transmitter-receiver 21. Such structural conditions may be, for example, a slight misalignment in the installation position that occurred during assembly or the characteristics of the transducer 31. Therefore, the abnormality detection unit 103 may correct the difference used when detecting an abnormality based on at least one of the first road surface reflection intensity and the second road surface reflection intensity in a normal state, so as to reduce the influence of the error between the first road surface reflection intensity and the second road surface reflection intensity that occurs between the pair of transmitter-receivers 21 that are normal. Note that the correction of the difference may be achieved by correcting at least one of the first road surface reflection intensity and the second road surface reflection intensity used when detecting an abnormality.

[0032] The output unit 104 outputs the detection result by the abnormality detection unit 103 in a predetermined manner. The method of outputting the detection result may be determined appropriately depending on the specifications of the vehicle 1, and may, for example, output an alarm to an output device such as an in-vehicle display or speaker, or output a signal indicating the occurrence of an abnormality to the ECU 12, when it is determined that an abnormality has occurred.

[0033] 5 is a diagram showing an example of the road surface reflection intensity Ia according to the first embodiment, illustrating an envelope La obtained when the normal transceiver 21 transmits and receives ultrasonic waves while the vehicle 1 is stopped.

[0034] As shown in Figure 5, this envelope La has a peak P due to road surface reflection waves from the road surface directly below the installation position of the transceiver unit 21. The distance Da corresponding to this peak P approximately coincides with the height from the road surface of the installation position of the transceiver unit 21. If the transceiver unit 21 is in a normal state, the road surface reflection intensity Ia corresponding to this peak P will be a relatively stable value. Note that the distance Da may vary slightly from the position directly below the transceiver unit 21 due to the directionality of the ultrasonic waves transmitted from the transceiver unit 21.

[0035] The object detection device 11 of this embodiment uses the road surface reflection intensity Ia described above to detect an abnormality in a pair of transceiver units 21 that are positioned symmetrically and at the same height. That is, when both of the pair of transceiver units 21 are normal, the road surface reflection intensity Ia (first road surface reflection intensity) of one transceiver unit 21 (e.g., transceiver unit 21A) and the road surface reflection intensity Ia (second road surface reflection intensity) of the other transceiver unit 21 (e.g., transceiver unit 21D) are approximately the same. In contrast, when there is an abnormality in at least one of the pair of transceiver units 21, the difference between the road surface reflection intensity Ia (first road surface reflection intensity) of one transceiver unit 21 and the road surface reflection intensity Ia (second road surface reflection intensity) of the other transceiver unit 21 becomes large. That is, when the difference between the first road surface reflection intensity and the second road surface reflection intensity is greater than a threshold, it can be determined that there is an abnormality in at least one of the pair of transceiver units 21.

[0036] 6 is a flowchart showing an example of processing in the object detection device 11 according to the first embodiment. In step S101, the transmitter / receiver 21 starts transmitting and receiving ultrasonic waves. In step S102, the echo information generator 101 generates echo information from one transmitter / receiver (hereinafter referred to as transmitter / receiver 21A) and the other transmitter / receiver (hereinafter referred to as transmitter / receiver 21D) of the pair of transmitter / receivers (hereinafter referred to as transmitter / receiver 21A and 21D). The echo information may include, for example, an envelope La as shown in FIG. 5.

[0037] In step S103, the road surface reflection intensity calculation unit 102 calculates the difference ΔI between the first road surface reflection intensity Ia corresponding to one transceiver unit 21A and the second road surface reflection intensity Ia corresponding to the other transceiver unit 21D based on the generated echo information.

[0038] In step S104, the abnormality detection unit 103 determines whether the difference ΔI is greater than the threshold value K1. If the difference ΔI is not greater than the threshold value K1 in step S104 (S104: No), the abnormality detection unit 103 determines that the pair of transmitter / receivers 21A, 21D is normal, and this routine ends.

[0039] In step S104, if the difference ΔI is greater than the threshold value K1 (S104: Yes), in step S105, the abnormality detection unit 103 determines that there is an abnormality in at least one of the pair of transmission / reception units 21A, 21D, and in step S106, the output unit 104 outputs an abnormality signal indicating the occurrence of the abnormality.

[0040] As described above, according to this embodiment, an abnormality in a pair of transmitters and receivers that are installed at the same height and in a symmetrical positional relationship is detected based on the difference between the road surface reflection intensities (first road surface reflection intensity and second road surface reflection intensity) of the pair of transmitters and receivers. This makes it possible to detect an abnormality in the transmitters and receivers with high accuracy using a simple configuration.

[0041] In the above embodiment, the first road surface reflection intensity includes the intensity of road surface reflected waves from the road surface directly below one of the transmitter-receivers, and the second road surface reflection intensity includes the intensity of road surface reflected waves from the road surface directly below the other transmitter-receiver, and the abnormality detection unit 103 determines that an abnormality has occurred when the difference ΔI between the first road surface reflection intensity and the second road surface reflection intensity is greater than the threshold value K1. The intensity of the road surface reflected waves from the road surface directly below the transmitter-receiver 21 can be detected with relatively high accuracy due to the directionality of ultrasonic waves, so the above configuration makes it possible to detect abnormalities in the transmitter-receiver 21 with high accuracy.

[0042] In the above embodiment, the anomaly detection unit 103 corrects at least one of the difference and threshold used when detecting an anomaly, based on at least one of the first road surface reflection intensity and the second road surface reflection intensity during normal operation, so as to reduce the influence of an error between the first road surface reflection intensity and the second road surface reflection intensity that occurs between a pair of normal transceivers 21. This improves the accuracy of detecting an anomaly.

[0043] Other embodiments will be described below with reference to the drawings, but descriptions of parts that are the same as or similar to the first embodiment will be omitted as appropriate.

[0044] (Second embodiment) The object detection device 11 according to the second embodiment differs from the first embodiment in that it determines whether or not there is an abnormality based not only on road surface reflected waves from the road surface directly below the transmitter / receiver 21, but also on road surface reflected waves from the road surface within a predetermined diffuse reflection area.

[0045] 7 is a diagram showing an example of a diffuse reflection region ΔD according to the second embodiment. The diffuse reflection region ΔD is a predetermined region within a range farther than directly below the pair of transmitter-receivers 21. The diffuse reflection region ΔD is preferably a region where the intensity of the reflected wave (diffuse road surface reflected wave) that is the transmission wave transmitted from the pair of transmitter-receivers 21 and diffusely reflected by the road surface becomes relatively high. The region where the intensity of the diffuse road surface reflected wave becomes relatively high differs depending on the directivity of the ultrasonic waves, and therefore the diffuse reflection region ΔD should be set appropriately depending on the installation position of the transmitter-receiver 21 to be used and the characteristics of the ultrasonic waves (frequency components, etc.).

[0046] The diffuse reflection region ΔD illustrated here is a region from distance Db1 to distance Db2. The relationship Da<Db1<Db2 holds between the distances Db1 and Db2 that define the diffuse reflection region ΔD and the distance Da corresponding to the peak P (the road surface reflected wave from directly below the transmitter / receiver 21).

[0047] The abnormality detection unit 103 of this embodiment determines whether or not an abnormality exists based on the variation in the intensity of the waves reflected from the road surface within the diffuse reflection region ΔD (diffuse road surface reflected waves) between one transceiver unit (e.g., transceiver unit 21A) and the other transceiver unit (e.g., transceiver unit 21D). For example, if the road surface reflection intensity Ia of the road surface directly below is greater than a threshold and the variation in the intensity of the diffuse road surface reflected waves is also greater than a threshold, the abnormality detection unit 103 determines that at least one of the transceivers 21 has an abnormality.

[0048] 8 is a flowchart showing an example of processing in the object detection device 11 according to the second embodiment. In step S201, the transmitter / receiver 21 starts transmitting and receiving ultrasonic waves. In step S202, the echo information generator 101 generates echo information from one transmitter / receiver (hereinafter referred to as transmitter / receiver 21A) and the other transmitter / receiver (hereinafter referred to as transmitter / receiver 21D) of the pair of transmitter / receivers (hereinafter referred to as transmitter / receiver 21A and 21D).

[0049] In step S203, the road surface reflection intensity calculation unit 102 calculates the difference ΔI between the first road surface reflection intensity Ia corresponding to one transceiver unit 21A and the second road surface reflection intensity Ia corresponding to the other transceiver unit 21D based on the generated echo information.

[0050] In step S204, the road surface reflection intensity calculation unit 102 calculates the variation S in the intensity of the diffuse road surface reflected wave from the diffuse reflection area ΔD between one transceiver unit 21A and the other transceiver unit 21D based on the generated echo information.

[0051] In step S205, the abnormality detection unit 103 determines whether the difference ΔI is greater than the threshold value K1 and whether the variation S is greater than the threshold value K2. In step S205, if the difference ΔI is not greater than the threshold value K1 or the variation S is not greater than the threshold value K2 (S205: No), the abnormality detection unit 103 determines that the pair of transmitter-receivers 21A, 21D is normal, and this routine ends.

[0052] In step S205, if the difference ΔI is greater than the threshold value K1 and the variation S is greater than the threshold value K2 (S205: Yes), in step S206, the abnormality detection unit 103 determines that there is an abnormality in at least one of the pair of transmission / reception units 21A, 21D, and in step S207, the output unit 104 outputs an abnormality signal indicating the occurrence of the abnormality.

[0053] As described above, according to this embodiment, the presence or absence of an abnormality is determined taking into consideration not only the difference ΔI in the intensity of the road surface reflected waves from directly below the transmitter / receiver 21, but also the variation S in the intensity of the road surface reflected waves from the diffuse reflection area ΔD. This improves the accuracy of detecting an abnormality.

[0054] The presence or absence of an abnormality may be determined based only on the variation S in the intensity of the road surface reflected waves from the diffuse reflection area ΔD, without taking into consideration the difference ΔI in the intensity of the road surface reflected waves from directly below.

[0055] In addition, in the above-described embodiment, an example has been given of a configuration in which ultrasonic waves are used as the waves transmitted and received to detect obstacles, but the configuration of the object detection device is not limited to this. For example, a configuration in which millimeter wave radar or the like is used may also be used.

[0056] A program that causes a computer (such as the processor 43) to execute processing for realizing the functions of the object detection device described above can be provided by being recorded in an installable or executable file on a computer-readable recording medium such as a CD (Compact Disc)-ROM, a flexible disk (FD), a CD-R (Recordable), or a DVD (Digital Versatile Disk). The program may also be provided or distributed via a network such as the Internet.

[0057] Although the embodiments of the present invention have been described above, the above-described embodiments and their modifications are merely examples and are not intended to limit the scope of the invention. The novel embodiments and modifications described above can be implemented in various forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. The above-described embodiments and modifications are included within the scope and spirit of the invention, and are also included in the invention and its equivalents as defined in the claims.

[0058] [Summary of the Present Embodiment] The present embodiment has at least the following configuration.

[0059] The object detection device (11) of the embodiment is an object detection device (11) that detects an obstacle present around a moving body (1) based on the intensity of a reflected wave generated when a transmission wave transmitted from the moving body (1) is reflected by the object, and includes a plurality of transmitting / receiving units (21) that each transmit the transmission wave and receive the reflected wave, and a pair of transmitting / receiving units (21) that are symmetrically positioned in the shape of the moving body (1) and installed at the same height, among the plurality of transmitting / receiving units (21), based on the reflected wave received by each of the pair of transmitting / receiving units (21). The device is equipped with a road surface reflection intensity calculation unit (102) that calculates a first road surface reflection intensity (Ia), which is the intensity of the reflected wave from the road surface (G) received by one of the transmitter / receiver units (21) of the pair of transmitter / receiver units (21), and a second road surface reflection intensity (Ia), which is the intensity of the reflected wave from the road surface (G) received by the other transmitter / receiver unit (21) of the pair of transmitter / receiver units (21), and an abnormality detection unit (103) that detects an abnormality in at least one of the pair of transmitter / receiver units (21) based on the difference between the first road surface reflection intensity (Ia) and the second road surface reflection intensity (Ia).

[0060] According to this configuration, it is possible to detect abnormalities in the transmitting / receiving unit (21) with high accuracy using a simple configuration.

[0061] In the object detection device (11) of the embodiment, for example, the first road surface reflection intensity (Ia) includes the intensity of the reflected wave from the road surface (G) directly below one of the transmitter-receivers (21), and the second road surface reflection intensity (Ia) includes the intensity of the reflected wave from the road surface (G) directly below the other transmitter-receiver (21), and the abnormality detection unit (103) determines that an abnormality exists when the difference between the first road surface reflection intensity (Ia) and the second road surface reflection intensity (Ia) is greater than a threshold value.

[0062] This configuration makes it possible to detect abnormalities in the transmitting / receiving unit (21) with high accuracy.

[0063] In the object detection device (11) of the embodiment, for example, the abnormality detection unit (103) determines whether or not an abnormality exists based on the variation in the intensity of the reflected wave from the road surface (G) within a predetermined diffuse reflection area (ΔD) located farther away than directly below the pair of transmitter-receivers (21) between one transmitter-receiver (21) and the other transmitter-receiver (21).

[0064] This configuration can improve the accuracy of detecting abnormalities in the transmitter / receiver (21).

[0065] In the object detection device (11) of the embodiment, for example, the abnormality detection unit (103) corrects at least one of the first road surface reflection intensity (Ia) and the second road surface reflection intensity (Ia) used when detecting an abnormality, based on at least one of the first road surface reflection intensity (Ia) and the second road surface reflection intensity (Ia) under normal conditions, so as to reduce the influence of an error between the first road surface reflection intensity (Ia) and the second road surface reflection intensity (Ia) that occurs between the pair of normal transmitter-receiver units (21).

[0066] This configuration can improve the accuracy of detecting abnormalities in the transmitter / receiver (21).

[0067] In the object detection device (11) of the embodiment, for example, the abnormality detection unit (103) determines the presence or absence of an abnormality based on the variation in the intensity of the reflected wave from the road surface (G) within a predetermined diffuse reflection area (ΔD) located farther away than directly below the pair of transmitter-receivers (21) between one transmitter-receiver (21) and the other transmitter-receiver (21), and the diffuse reflection area (ΔD) is set according to at least one of the installation positions of the multiple transmitter-receivers (21) and the characteristics of the transmission waves transmitted by the multiple transmitter-receivers (21).

[0068] This configuration can improve the accuracy of detecting abnormalities in the transmitter / receiver (21).

[0069] 1... vehicle (moving body), 11... object detection device, 21, 21A to 21L... transmitter / receiver unit, 102... road surface reflection intensity calculation unit, 103... abnormality detection unit, Ia... road surface reflection intensity, ΔD... diffuse reflection area

Claims

1. An object detection device that detects obstacles present around a moving body based on the intensity of reflected waves generated when a transmission wave transmitted from the moving body is reflected by an object, comprising: a plurality of transceiver units each transmitting the transmission wave and receiving the reflected waves; a road surface reflection intensity calculation unit that calculates a first road surface reflection intensity, which is the intensity of the reflected wave from the road surface received by one of the pair of transceiver units, and a second road surface reflection intensity, which is the intensity of the reflected wave from the road surface received by the other of the pair of transceiver units, based on the reflected waves received by each of a pair of transceiver units that are positioned symmetrically on the left and right of the shape of the moving body and installed at the same height among the plurality of transceivers; and an abnormality detection unit that detects an abnormality in at least one of the pair of transceivers, based on the difference between the first road surface reflection intensity and the second road surface reflection intensity.

2. The object detection device of claim 1, wherein the first road surface reflection intensity includes the intensity of the reflected wave from the road surface directly below the one of the transceivers, the second road surface reflection intensity includes the intensity of the reflected wave from the road surface directly below the other of the transceivers, and the abnormality detection unit determines that an abnormality exists when the difference between the first road surface reflection intensity and the second road surface reflection intensity is greater than a threshold value.

3. The object detection device according to claim 2, wherein the abnormality detection unit determines the presence or absence of an abnormality based on the variation in the intensity of the reflected wave from the road surface within a predetermined diffuse reflection area located away from directly below the pair of transmitter-receivers, between one transmitter-receiver and the other transmitter-receiver.

4. The object detection device of any one of claims 1 to 3, further comprising: the abnormality detection unit corrects at least one of the first road surface reflection intensity, the second road surface reflection intensity, and the difference used when detecting an abnormality, based on at least one of the first road surface reflection intensity and the second road surface reflection intensity under normal conditions, so as to reduce the influence of an error between the first road surface reflection intensity and the second road surface reflection intensity that occurs between the pair of normal transmitting / receiving units.

5. The object detection device described in claim 1, wherein the abnormality detection unit determines the presence or absence of an abnormality based on the variation in the intensity of the reflected waves from the road surface within a predetermined diffuse reflection area distant from directly below the pair of transceivers, between one transceiver and the other transceiver, and the diffuse reflection area is set according to at least one of the installation positions of the multiple transceivers and the characteristics of the transmission waves transmitted by the multiple transceivers.

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