Object detecting device

Abstract

To provide an object detecting device capable of accurately detecting an abnormality of a transmission and reception unit with a simple configuration.SOLUTION: An object detection device comprises: a plurality of transceivers for transmitting a transmission wave and receiving a reflected wave; a road surface reflection intensity calculation unit for calculating a first road surface reflection intensity, which is the intensity of a road surface reflection wave received by one of a pair of transceivers, and a second road surface reflection intensity, which is the intensity of a road surface reflection wave received by the other transceiver of the pair on the basis of the reflected waves received by each of the pair of transceivers installed symmetrically with respect to the shape of a mobile body and installed at the same height among the plurality of transceivers; and an abnormality detection unit for detecting an abnormality in at least one of the pair of transceivers on the basis of the difference between the first road surface reflection intensity and the second road surface reflection intensity.SELECTED DRAWING: Figure 4

Description

[Technical field]

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

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

[0003] [Patent Document 1] JP 2018-54580 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the conventional technology, a means for generating different frequency components is necessary, which may lead to problems such as a complicated configuration and increased costs, etc. Furthermore, even if there is an abnormality in the transmitting / receiving unit, the effect of the abnormality may not appear in the frequency components.

[0005] The present invention has been made in view of the above, and provides an object detection device that is capable of detecting an abnormality in a transmitter / receiver with high accuracy using a simple configuration. [Means for solving the problem]

[0006] One embodiment of the present invention is an object detection device that detects obstacles present in the vicinity of 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, and is equipped with a plurality of transceivers that each transmit a transmission wave and receive a reflected wave, 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 moving 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. Effect of the Invention

[0007] According to the present invention, it is possible to provide an object detection device that is capable of detecting an abnormality in a transmitting / receiving unit with high accuracy using a simple configuration. [Brief description of the drawings]

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

[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) 1 is a diagram showing an example of the configuration of a vehicle 1 according to the first embodiment. The vehicle 1 is an example of a moving body on which an object detection device according to the present embodiment is mounted. The object detection device according to the present embodiment is a device that detects obstacles present around the vehicle 1 based on information such as TOF (Time Of Flight) 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-21L. Hereinafter, when there is no need to distinguish between the plurality of transceivers 21A-21L, they may be referred to as transceivers 21. Each transceiver 21 is installed on a vehicle body 2 serving as the exterior of a 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 transmission wave, and ultrasonic waves generated when the transmission 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, 21J are arranged on the right side, and two transceivers 21K, 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 at symmetrical positions. The pair of transceivers 21 that are symmetrically positioned on the left and right are installed at the same height. The 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 symmetrical positions 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 symmetrical positions 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 symmetrical positions 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 symmetrical positions 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 symmetrical positions 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 symmetrical positions 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 positions 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 an 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 a plurality of transmitting / receiving units 21 and a control unit 22. Each transmitting / receiving unit 21 includes a transducer 31 configured using a piezoelectric element or the like, an amplifier, and the like, and realizes transmission and reception of ultrasonic waves by the vibration of the transducer 31. Specifically, each transmitting / receiving unit 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 to be detected among objects present around the vehicle 1, and may be, for example, another vehicle, a road accessory, a wall, a person, a curb, a car stop, and the like. The vibration of the transducer 31 is converted into an electric signal, and based on the electric signal, a TOF corresponding to the distance from the transmitting / receiving unit 21 to the obstacle O, a Doppler shift corresponding to the relative speed between the vehicle 1 and the obstacle O, and the like can be obtained.

[0017] 2, a configuration is illustrated in which both transmission of the transmission wave and reception of the reflected wave are performed using a single transducer 31, but the configuration of the transceiver unit 21 is not limited to this. For example, the transmission side and the reception side may be separated, such as a configuration in which a transducer for transmitting the transmission wave and a transducer 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 (the transmission / reception unit 21, the ECU 12, etc.). The storage device 42 includes a main storage device such as a read only memory (ROM) and a random access memory (RAM), and an auxiliary storage device such as a hard disk drive (HDD) and a solid state drive (SSD). The processor 43 is an integrated circuit that executes various processes for realizing 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), a field programmable gate array (FPGA), etc. that operate according to a program. The processor 43 executes various arithmetic processes and control processes by reading and executing the 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 has 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, the drive mechanism, the braking mechanism, the steering mechanism, the transmission mechanism, the in-vehicle display, the speaker, 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 out a program stored in the storage device 52 and executes various arithmetic processes and control processes.

[0020] Fig. 3 is a diagram showing an example of a method for calculating distance using the TOF method according to the first embodiment. Fig. 3 illustrates an envelope curve L indicating a time series change in the intensity (signal level) of ultrasonic waves transmitted and received by the transmitting and receiving unit 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 transmitting and receiving unit 21 (the magnitude of vibration of the transducer 31).

[0021] The envelope curve L shows a time series change in the intensity indicating the magnitude of the vibration of the oscillator 31. From the envelope curve L shown in Fig. 3, it can be seen that the oscillator 31 is driven to vibrate for a time Ta from timing t0, and the transmission of the transmission wave is completed at timing t1, and then the vibration of the oscillator 31 due to inertia continues while attenuating for a time Tb until timing 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 a time t4, which is a time Tp after the time t0 when the transmission of the transmission wave starts, at which the magnitude of the vibration of the vibrator 31 reaches or exceeds a threshold value Th. This threshold value Th is a value that is set to distinguish whether the vibration of the vibrator 31 is caused by the reception of a reflected wave from the obstacle O or the reception of a reflected wave from an object other than the obstacle O (e.g., the road surface G, etc.). Note that although the threshold value Th is shown here as a constant value, the threshold value Th may 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 the reception of a reflected wave from the obstacle O.

[0023] In this example, the envelope curve L indicates that the vibration of the transducer 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 transmission wave finally transmitted at the timing t1 returns as a reflected wave.

[0024] Furthermore, in the envelope L, timing t3 as the start point of the peak at timing t4 corresponds to the timing at which reception of the reflected wave from the obstacle O begins, in other words, the timing at which the transmission 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 as the transmission time of the transmission wave.

[0025] From the above, in order to use TOF to find the distance from the transmitting / receiving unit 21, which is the source of transmitting and receiving ultrasonic waves, to the obstacle O, it is necessary to find the time Tf between the timing t0 when the transmission of the transmitted wave begins and the timing 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 timing t0 and the timing t4 when the intensity of the reflected wave reaches a peak by exceeding the threshold value Th.

[0026] The timing t0 when the transmission wave starts to be transmitted can be easily identified as the timing when the object detection device 200 starts to operate, and the time Ta as the transmission time of the transmission wave is determined in advance by settings, etc. Therefore, by identifying the timing t4 when the intensity of the reflected wave reaches a peak and exceeds the threshold value Th, the distance from the vehicle 1 (the transceiver unit 21 which is the source of transmission and reception of the ultrasonic waves) to the obstacle O can be obtained. Note that the above calculation method is merely an example, and the distance from the vehicle 1 to the obstacle O may be calculated by appropriately using a known or new method.

[0027] Fig. 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 may 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 a time series change in the intensity of the reflected wave for each transmitting / receiving unit 21 based on the information acquired from each transmitting / receiving unit 21. The echo information may include data on an envelope L as exemplified in FIG.

[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 the reflected waves (echo information showing the time series changes of the reflected waves) received by each of a pair of transceivers 21 (e.g., transceivers 21A and 21D or transceivers 21B and 21C, etc.) that are symmetrically positioned on the left and right sides of the shape of the vehicle 1 (vehicle body 2) and installed at the same height among the multiple transceivers 21. 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 transceivers 21 based on the difference between the first road surface reflection intensity and the second road surface reflection intensity. The abnormality detection unit 103 determines that there is an abnormality in at least one of the pair of transceivers 21 when, for example, the difference between the first road surface reflection intensity and the second road surface reflection intensity is greater than a predetermined threshold value.

[0031] At this time, even if the pair of transceivers 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 transceiver 21. The structural conditions may be, for example, a slight deviation in the installation position that occurs during assembly, the characteristics of the transducer 31, etc. 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 transceivers 21 that are normal. The correction of the difference may be realized 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 appropriately determined according to 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 exists.

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

[0034] 5, a peak P appears in such an envelope La due to a road surface reflected wave from the road surface directly below the installation position of the transceiver unit 21. The distance Da corresponding to the peak P is approximately equal to the height from the road surface to 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 the 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 the present embodiment uses the road surface reflection intensity Ia as described above to detect an abnormality in a pair of transceiver units 21 that are symmetrically positioned and installed at the same height. That is, when both of the pair of transceiver units 21 are in a normal state, 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 equal. 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 value, 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 transceiver 21 starts transmitting and receiving ultrasonic waves, and in step S102, the echo information generator 101 generates echo information of one transceiver (here, the transceiver 21A) and the other transceiver (here, the transceiver 21D) of a pair of transceivers (here, the transceivers 21A and 21D). The echo information may be information including an envelope La as exemplified in FIG. 5, for example.

[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 transmission / reception units 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 an abnormality exists in at least one of the pair of transceivers 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 transceivers that are symmetrically positioned and installed at the same height 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 transceivers. This makes it possible to detect an abnormality in the transceivers with high accuracy using a simple configuration.

[0041] In the above embodiment, the first road surface reflection intensity includes the intensity of the road surface reflected wave from the road surface directly below one of the transceivers, and the second road surface reflection intensity includes the intensity of the road surface reflected wave from the road surface directly below the other transceiver, 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. Since the intensity of the road surface reflected wave from the road surface directly below the transceiver 21 can be detected with relatively high accuracy due to the directionality of ultrasonic waves, the above configuration makes it possible to detect an abnormality in the transceiver 21 with high accuracy.

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

[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 the presence or absence of an abnormality based not only on the road surface reflection wave from the road surface directly below the transmission / reception unit 21 but also on the road surface reflection wave from the road surface within a predetermined diffuse reflection region.

[0045] FIG. 7 is a diagram showing an example of the diffuse reflection region ΔD according to the second embodiment. The diffuse reflection region ΔD is a region predetermined within a range farther from directly below the pair of transmission / reception units 21. The diffuse reflection region ΔD is preferably a region where the intensity of the reflected wave (diffuse road surface reflection wave) obtained by diffusely reflecting the transmission wave transmitted from the pair of transmission / reception units 21 by the road surface is relatively large. Since the region where the intensity of the diffuse road surface reflection wave becomes relatively large varies depending on the directivity of the ultrasonic wave and the like, the diffuse reflection region ΔD should be appropriately set according to the installation position of the transmission / reception unit 21 to be used and the characteristics (frequency components, etc.) of the ultrasonic wave.

[0046] The diffuse reflection region ΔD exemplified here is a region from distance Db1 to distance Db2. A relationship of Da < Db1 < Db2 holds between the distances Db1 and Db2 defining the diffuse reflection region ΔD and the distance Da corresponding to the above-described peak P (road surface reflection wave from directly below the transmission / reception unit 21).

[0047] The abnormality detection unit 103 of the present embodiment determines the presence or absence of an abnormality based on the variation in the intensity of the reflected wave (diffuse road surface reflection wave) from the road surface within the diffuse reflection region ΔD between one transmission / reception unit (for example, transmission / reception unit 21A) and the other transmission / reception unit (for example, transmission / reception unit 21D). The abnormality detection unit 103 determines that there is an abnormality in at least one of the one transmission / reception units 21, for example, when the road surface reflection intensity Ia of the road surface directly below described above is greater than the threshold value and the variation in the intensity of the diffuse road surface reflection wave is greater than the threshold value.

[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 transceiver 21 starts transmitting and receiving ultrasonic waves, and in step S202, the echo information generating unit 101 generates echo information of one transceiver (here, the transceiver 21A) and the other transceiver (here, the transceiver 21D) of the pair of transceivers (here, the transceivers 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 K1 and the variation S is greater than the threshold K2. In step S205, if the difference ΔI is not greater than the threshold K1 or the variation S is not greater than the threshold K2 (S205: No), the abnormality detection unit 103 determines that the pair of transmission / reception units 21A, 21D is normal, and this routine ends.

[0052] In step S205, if the difference ΔI is greater than the threshold K1 and the variation S is greater than the threshold K2 (S205: Yes), in step S206, the abnormality detection unit 103 determines that an abnormality exists in at least one of the pair of transceivers 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 wave from directly below the transmitting / receiving unit 21, but also the variation S in the intensity of the road surface reflected wave from the diffuse reflection area ΔD. This makes it possible to improve the accuracy of detecting an abnormality.

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

[0055] 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 an obstacle, but the configuration of the object detection device is not limited to this. For example, a millimeter wave radar or the like may be used.

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

[0057] Although the embodiment of the present invention has been described above, the above-mentioned embodiment and its modifications are merely examples and are not intended to limit the scope of the invention. The above-mentioned novel embodiment and modifications can be implemented in various forms, and various omissions, substitutions, and modifications can be made without departing from the gist of the invention. The above-mentioned embodiment and modifications are included in the scope and gist of the invention, and are included in the scope of the invention and its equivalents described in the claims. [Explanation of symbols]

[0058] 1...vehicle (moving body), 11...object detection device, 21, 21A to 21L...transmitter / receiver, 102...road surface reflection intensity calculation unit, 103...abnormality detection unit, Ia...road surface reflection intensity, ΔD...diffuse reflection area

Claims

1. 1. An object detection device that detects an obstacle present around a moving body based on the intensity of a reflected wave generated when a transmission wave transmitted from the moving body is reflected by an object, A plurality of transceivers, each of which transmits the transmission wave and receives the reflected wave; 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 symmetrically positioned in the left-right direction of the shape of the moving body and installed at the same height among the multiple transceivers; an abnormality detection unit that detects an abnormality in at least one of the pair of transmitting / receiving units based on a difference between the first road surface reflection intensity and the second road surface reflection intensity; An object detection device comprising:

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

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

4. 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 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 generated between the pair of normal transmitting / receiving units. The object detection device according to any one of claims 1 to 3, further comprising:

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