Object detection device and mobile object control device

Abstract

To provide an object detection device and a movable body control unit that can detect abnormality by using a non-directional component of an ultrasonic wave.SOLUTION: An object detection device comprises: a transmission-reception unit that transmits a transmission wave including an ultrasonic wave having directivity in a direction parallel or substantially parallel to the direction of travel of a movable body and receives reflected wave from an object; a determination unit that determines the presence or absence of abnormality based on a lower distance that is calculated based on, of the transmission wave, reflected wave of an ultrasonic wave traveling downward in the vertical direction from the transmission-reception unit, the lower distance between the transmission-reception unit and an object present below the transmission-reception unit in the vertical direction, and a reference distance determined in advance; and an output unit that outputs information on the abnormality.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to an object detection device and a mobile object control device. [Background technology]

[0002] In systems for controlling moving bodies such as vehicles, object detection devices are used that detect objects present around the moving body based on the time it takes for transmitted ultrasonic waves to be reflected by the object and return (TOF: Time Of Flight). Such object detection devices use technology that gives directionality to ultrasonic waves (for example, Patent Documents 1 and 2). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Utility Model Application Publication No. 61-1180 [Patent Document 2] Japanese Patent Application Publication No. 6-331742 Summary of the Invention [Problem to be solved by the invention]

[0004] Directivity ultrasonic waves contain components (non-directional components) that travel in directions other than the direction corresponding to the direction of the directionality. Conventional technologies have not effectively utilized such non-directional components, so there is room for improvement.

[0005] One of the problems to be solved by the present disclosure is to provide an object detection device and a mobile object control device that are capable of detecting abnormalities by utilizing non-directional components of ultrasonic waves. [Means for solving the problem]

[0006] An object detection device as an example of the present disclosure transmits ultrasonic waves as transmission waves including a main lobe having directivity in a direction parallel or approximately parallel to the traveling direction of a moving object and side lobes traveling vertically downward relative to the main lobe, and includes a transceiver that receives a reflected wave from an object relating to the main lobe and a reflected wave from an object relating to the side lobe, a downward distance between the transceiver and an object present vertically below the transceiver, the downward distance being calculated based on the reflected wave of the side lobe among the transmitted waves, and The average downward distance is the average downward distance based on the ultrasonic waves transmitted and received by the transmitter and receiver multiple times when the moving object is stopped. Based on the specified reference distance, the presence or absence of abnormalities in the vertical direction below is detected. Before the vehicle departs The device comprises a determination unit that determines whether an object is present in the direction of travel of the moving body, an object detection unit that detects an object present in the direction of travel of the moving body based on the reflected wave of the main lobe of the transmitted wave, and an output unit that outputs information regarding the abnormality and information regarding the detection of an object present in the direction of travel of the moving body.

[0007] According to the above configuration, it is possible to effectively use the side lobes (an example of non-directional components) of ultrasonic waves that travel vertically downward from the transmitting and receiving unit to detect abnormalities. Furthermore, the presence or absence of any abnormalities below the moving body (for example, an object entering under the vehicle, a malfunction in the transmitter / receiver unit, etc.) that may occur when the moving body is stopped can be determined before the moving body starts by comparing the condition below the transmitter / receiver unit when the moving body is stopped and when the moving body starts.

[0010] The reference distance may also be a distance corresponding to the height of the transmitter / receiver from the road surface.

[0011] This makes it possible to detect the intrusion of an object between the transmitter / receiver and the road surface.

[0014] The determination unit may also determine that an abnormality exists when the downward distance is shorter than a reference distance.

[0015] This makes it possible to detect the intrusion of an object between the moving body and the road surface, etc.

[0016] The determination unit may determine that an abnormality exists when the intensity of the reflected wave corresponding to a distance equal to or shorter than the reference distance does not reach a predetermined reference intensity.

[0017] This makes it possible to detect malfunctions in the transmitter / receiver section (for example, a state in which ultrasonic waves cannot be transmitted or received properly due to dirt or other factors).

[0020] The object detection device may further include a directivity change unit that changes the directivity.

[0021] This makes it possible to improve the accuracy of detecting objects and abnormalities depending on the situation.

[0022] Furthermore, a mobile body control device as an example of the present disclosure includes the above-mentioned object detection device and a control device that performs processing to control the mobile body based on information regarding an abnormality output from the object detection device.

[0023] This makes it possible to control the moving object based on the abnormality detected by the object detection device described above. [Brief explanation of the drawings]

[0024] [Figure 1] FIG. 1 is a top view showing an example of the configuration of a vehicle according to the first embodiment. [Figure 2] FIG. 2 is a block diagram showing an example of the configuration of the vehicle control device according to the first embodiment. [Figure 3] FIG. 3 is a block diagram illustrating an example of the functional configuration of the object detection device according to the first embodiment. [Figure 4] FIG. 4 is a diagram showing envelopes for explaining an outline of an object detection method using TOF in the first embodiment. [Figure 5] FIG. 5 is a diagram showing an example of the characteristics of ultrasonic waves transmitted and received by the transmitting and receiving unit according to this embodiment. [Figure 6] FIG. 6 is a graph showing an example of an envelope detected in a normal state in the first embodiment. [Figure 7] FIG. 7 is a graph showing an example of an envelope curve detected when an object has entered between the transmitting / receiving unit and the road surface in the first embodiment. [Figure 8] FIG. 8 is a graph showing an example of an envelope detected when there is a problem in the transmitting and receiving unit in the first embodiment. [Figure 9]FIG. 9 is a flowchart showing an example of processing in the object detection device according to the first embodiment. [Figure 10] FIG. 10 is a flowchart showing an example of a method for setting the reference distance according to the first embodiment. [Figure 11] FIG. 11 is a block diagram illustrating an example of the functional configuration of the object detection device according to the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0025] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. The configurations of the embodiments described below and the actions and effects brought about by the configurations are merely examples, and the present invention is not limited to the following description.

[0026] (First embodiment) 1 is a top view 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 objects (other vehicles, structures, pedestrians, etc.) present around the vehicle 1 based on TOF, Doppler shift information, etc. acquired by transmitting ultrasonic waves from the vehicle 1 and receiving reflected waves from the objects.

[0027] The object detection device according to this embodiment has a plurality of transceivers 21A to 21H (hereinafter, abbreviated to transceiver 21 when there is no need to distinguish between the plurality of transceivers 21A to 21H). Each transceiver 21 is installed on a vehicle body 2 that serves as the exterior of a vehicle 1, and transmits ultrasonic waves (transmission waves) toward the outside of the vehicle body 2 and receives reflected waves from objects present outside the vehicle body 2. In the example shown in FIG. 1, four transceivers 21A to 21D are arranged at the front end of the vehicle body 2, and four transceivers 21E to 21H are arranged at the rear end. Note that the number and installation positions of the transceivers 21 are not limited to those in the above example.

[0028] 2 is a block diagram showing an example of the configuration of a vehicle control device 50 according to the first embodiment. The vehicle control device 50 (an example of a mobile body control device) performs processing for controlling the vehicle 1 based on information output from the object detection device 200. The vehicle control device 50 according to this embodiment includes an ECU 100 and the object detection device 200.

[0029] The object detection device 200 includes a plurality of transmitter / receivers 21 and a control unit 22. Each transmitter / receiver 21 includes a vibrator 211 configured using a piezoelectric element or the like, an amplifier, etc., and realizes transmission and reception of ultrasonic waves by the vibration of the vibrator 211. Specifically, each transmitter / receiver 21 transmits ultrasonic waves generated in response to the vibration of the vibrator 211 as a transmission wave, and detects the vibration of the vibrator 211 caused by a wave reflected by the object O from the transmission wave. The vibration of the vibrator 211 is converted into an electrical signal, and based on the electrical signal, it is possible to obtain TOF corresponding to the distance from the transmitter / receiver 21 to the object O, Doppler shift information corresponding to the relative velocity of the object O, etc.

[0030] The transceiver 21 according to this embodiment transmits a transmission wave including ultrasonic waves having directivity in a direction parallel or approximately parallel to the traveling direction of the vehicle 1. The transmission wave includes ultrasonic waves (non-directional components) that travel vertically downward from the transceiver 21. The transmission wave will be described later.

[0031] 2 illustrates a configuration in which both transmission of the transmission wave and reception of the reflected wave are performed using a single oscillator 211, 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.

[0032] The control unit 220 includes an input / output device 221, a storage device 222, and a processor 223. The input / output device 221 is an interface device for transmitting and receiving information between the control unit 220 and the outside (the transmission / reception unit 21, the ECU 100, etc.). The storage device 222 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 223 is an integrated circuit that executes various processes to realize the functions of the control unit 220, and includes, for example, a central processing unit (CPU) that operates according to a program, an application-specific integrated circuit (ASIC) designed for a specific application, etc. The processor 223 executes various arithmetic and control processes by reading and executing programs stored in the storage device 222.

[0033] The ECU 100 is a unit that executes various processes for controlling the vehicle 1 based on various information acquired from the object detection device 200 and the like. The ECU 100 has an input / output device 110, a storage device 120, and a processor 130. The input / output device 110 is an interface device that realizes transmission and reception of information between the ECU 100 and external mechanisms (such as the object detection device 200, drive mechanism, braking mechanism, steering mechanism, transmission mechanism, in-vehicle display, speaker, etc.). The storage device 120 includes a main storage device such as a ROM or RAM, and an auxiliary storage device such as an HDD or SSD. The processor 130 is an integrated circuit that executes various processes for realizing the functions of the ECU 100, and includes, for example, a CPU, an ASIC, etc. The processor 130 reads programs stored in the storage device 120 and executes various arithmetic and control processes.

[0034] 3 is a block diagram showing an example of the functional configuration of object detection device 200 according to the first embodiment. Object detection device 200 according to this embodiment includes a signal processing unit 302, an object detection unit 303, an abnormality determination unit 304 (determination unit), a reference information storage unit 305, and an output unit 306. These functional components 302 to 306 are realized by cooperation between hardware components of object detection device 200 as shown in FIG. 2 and software components such as firmware and programs.

[0035] The signal processing unit 302 processes the signal acquired by the transmitting / receiving unit 21 and generates various data. For example, the signal processing unit 302 performs amplification processing, filtering processing, envelope processing, etc. on the electrical signal corresponding to the vibration of the transducer 211, and generates envelope data, etc., that indicate changes over time in the intensity (amplitude) of the ultrasonic waves transmitted and received by the transmitting / receiving unit 21. Based on the envelope data, the TOF corresponding to an object present in the vicinity of the vehicle 1 can be detected, and the distance from the vehicle 1 (transmitting / receiving unit 21) to the object can be calculated.

[0036] The object detection unit 303 detects objects (e.g., other vehicles, structures, pedestrians, etc.) present around the vehicle 1 based on the data generated by the signal processing unit 302, and generates object information related to the objects. The object information may include, for example, the distance from the vehicle 1 (transmitter / receiver 21) to the object, the relative speed of the object, the type of object, etc.

[0037] The abnormality determination unit 304 determines whether or not an abnormality exists based on the downward distance between the transceiver unit 21 and an object present vertically below the transceiver unit 21, which is calculated based on the reflected waves of the ultrasonic waves that travel vertically downward from the transceiver unit 21 among the transmitted waves, and based on a predetermined reference distance. The ultrasonic waves that travel vertically downward from the transceiver unit 21 correspond to non-directional components that travel in a direction other than the direction corresponding to the directivity (a direction parallel or approximately parallel to the traveling direction of the vehicle 1) among the components of the transmitted waves transmitted from the transceiver unit 21. In this case, the abnormality may be the intrusion of an object (for example, a child, an animal, etc.) between the transceiver unit 21 and the road surface, etc.

[0038] Furthermore, the abnormality determination unit 304 determines that an abnormality exists when the intensity of the reflected wave corresponding to a distance equal to or shorter than the reference distance does not reach a predetermined reference intensity. The abnormality in this case may be a malfunction of the transmitter / receiver 21 (for example, a state in which ultrasonic waves are not properly transmitted and received due to adhesion of dirt, etc.). Furthermore, the abnormality determination unit 304 determines whether or not an abnormality exists before the stopped (parked) vehicle 1 starts moving.

[0039] The reference information storage unit 305 stores a reference distance and a reference intensity used for abnormality determination by the abnormality determination unit 304. The reference information storage unit 305 stores a distance corresponding to the height of the transmitter / receiver 21 from the road surface as the reference distance. The reference information setting unit 305 may also use the downward distance calculated when the vehicle 1 is stopped (parked) as the reference distance. The reference information setting unit 305 also stores the intensity of the reflected wave corresponding to the reference distance as the reference intensity. The reference distance and the reference intensity are stored in a storage device and are read out when the abnormality determination unit 304 determines an abnormality (for example, when the vehicle 1 transitions from a stopped state to a starting state).

[0040] The output unit 306 outputs object information relating to an object detected by the object detection unit 303, abnormality information relating to an abnormality determined by the abnormality determination unit 304, etc. The abnormality information, etc. is output to, for example, the ECU 100, etc., and is used to control the vehicle 1 (for example, to warn the occupants, to perform travel restriction processing, etc.).

[0041] Fig. 4 is a diagram showing envelopes for explaining an overview of the object detection method using TOF in the first embodiment. Fig. 4 illustrates an envelope showing a change over time in the intensity of ultrasonic waves transmitted and received by the transmitting and receiving unit 21. In the graph shown in Fig. 4, 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.

[0042] Solid line L11 represents an example of an envelope curve showing the change over time in the intensity, which indicates the magnitude of vibration of oscillator 211. From this solid line L11, it can be seen that oscillator 211 is driven to vibrate for time Ta from time t0, completing the transmission of the transmission wave at time t1, and then the vibration of oscillator 211 due to inertia continues while attenuating for time Tb until time t2. Therefore, in the graph shown in Fig. 4, time Tb corresponds to the so-called reverberation time.

[0043] The solid line L11 indicates that the magnitude of vibration of the vibrator 211 reaches a peak at time t4, which is a time Tp after time t0 when the transmission of the transmission wave begins, and exceeds (or is equal to or greater than) a predetermined threshold value represented by the dashed-dotted line L21. This threshold value is a value that is set in advance to distinguish whether the vibration of the vibrator 211 is caused by reception of a reflected wave from an object to be detected or by reception of a reflected wave from an object that is not to be detected. Here, the threshold value represented by the dashed-dotted line L21 is shown as a constant value, but the threshold value may be a variable value that changes over time, depending on the situation, etc.

[0044] Vibrations having peaks above (or equal to or greater than) the threshold indicated by the dashed-dotted line L21 can be considered to be caused by reception of reflected waves from the object to be detected. On the other hand, vibrations having peaks below (or less than) the threshold can be considered to be caused by reception of reflected waves from an object that is not the object to be detected. Therefore, it can be seen from the solid line L11 that the vibration of the vibrator 211 at time t4 was caused by reception of reflected waves from the object to be detected.

[0045] In the solid line L11, the vibration of the vibrator 211 attenuates after timing t4. Therefore, timing t4 corresponds to the timing at which reception of the reflected wave from the object to be detected is completed, in other words, the timing at which the transmission wave last transmitted at timing t1 returns as a reflected wave.

[0046] Furthermore, in solid line L11, timing t3, which is the start point of the peak at timing t4, corresponds to the timing when reception of the reflected wave from the object to be detected begins, in other words, the timing when the transmitted wave, which was 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.

[0047] Based on the above, to calculate the distance to an object using TOF, it is necessary to calculate the time Tf between the timing t0 when the transmitted wave begins to be transmitted and the timing t3 when the reflected wave begins to be received. This time Tf can be calculated by subtracting the time ΔT, which is equal to the time Ta for transmitting 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 exceeds the threshold and reaches its peak.

[0048] The time t0 when the transmission wave starts to be transmitted can be easily identified as the time when 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 exceeds the threshold and reaches its peak, the distance to the object to be detected can be obtained.

[0049] 5 is a diagram showing an example of the characteristics of ultrasonic waves transmitted and received by the transceiver 21 according to this embodiment. The transmission waves transmitted from the transceiver 21 according to this embodiment include a transmission wave Wt1 having directivity in a direction parallel or approximately parallel to the traveling direction of the vehicle 1, and a transmission wave Wt2 traveling vertically downward from the transceiver 21. The transmission wave Wt2 corresponds to the non-directional component.

[0050] The direction parallel or substantially parallel to the traveling direction of the vehicle 1 includes the forward direction, backward direction, and vehicle width direction. The transmission wave transmitted from the transceiver unit 21 may be, for example, an ultrasonic wave including a transmission wave Wt1 as a main lobe and a transmission wave Wt2 as a side lobe. The transceiver unit 21 receives a reflected wave Wr1 of the transmission wave Wt1 reflected by an object (e.g., another vehicle, a structure, a pedestrian, etc.) present in a direction parallel or substantially parallel to the traveling direction of the vehicle 1. The transceiver unit 21 also receives a reflected wave Wr2 of the transmission wave Wt2 reflected by an object (e.g., road surface G, an object that has entered between the transceiver unit 21 and the road surface G, etc.) present vertically below the transceiver unit 21. If no object is present between the transceiver unit 21 and the road surface G, a TOF corresponding to the distance D between the transceiver unit 21 and the road surface G is detected. This distance D is an example of the reference distance described above.

[0051] FIG. 6 is a graph showing an example of an envelope detected under normal conditions in the first embodiment. In FIG. 6, the horizontal axis corresponds to the elapsed time since the transmission waves Wt1 and Wt2 were transmitted, and the vertical axis corresponds to the intensity of the ultrasonic waves transmitted and received by the transmission / reception unit 21. FIG. 6 also shows thresholds A1 and A2. The threshold A1 is a threshold set to remove noise due to the structure of the transmission / reception unit 21, etc. The threshold A2 is a threshold used to detect a peak corresponding to a reference distance (distance D in this example) from the reflected wave Wr2 of the transmission wave Wt2 traveling vertically downward from the transmission / reception unit 21. The threshold A2 is preferably lower than a threshold used to detect objects that are normally the target of detection (other vehicles, structures, pedestrians, etc.) (for example, a threshold such as that shown by the dashed dotted line L21 in FIG. 4).

[0052] 6, under normal circumstances (when there are no abnormalities such as an object entering under the vehicle 1 or a malfunction of the transceiver unit 21), a peak is detected at timing ts (TOF: ts-t0) corresponding to distance D. The timing ts (TOF: ts-t0) may be stored in advance in a storage device as a known value, or may be measured at a predetermined timing (for example, when parking of the vehicle 1 is completed, before starting, etc.). In other words, if a peak having an intensity exceeding threshold A2 is detected at timing ts corresponding to distance D as a reference distance, it can be determined that the vehicle is in a normal state.

[0053] 7 is a graph showing an example of an envelope curve detected when an object has entered between the transmitter / receiver 21 and the road surface G in the first embodiment. As shown in FIG. 7, when an object is present between the transmitter / receiver 21 and the road surface G, a peak is detected at a timing tu earlier than the timing ts corresponding to the distance D. In this case, the time difference Δt = ts - tu corresponds to the height of the object from the road surface G. In this way, if a peak having an intensity exceeding the threshold A2 is detected at a timing tu earlier than the timing ts corresponding to the distance D as the reference distance, it can be determined that there is an abnormality (such as an object entering under the vehicle 1).

[0054] Fig. 8 is a graph showing an example of an envelope curve detected when there is a malfunction in the transceiver unit 21 in the first embodiment. As shown in Fig. 8, when there is a malfunction (such as dirt adhesion) in the transceiver unit 21, a peak of intensity reaching the threshold A2 (an example of the reference intensity) is not detected during the time (t0 to ts) before the timing ts corresponding to the distance D. In other words, if a peak having an intensity reaching the threshold A2 is not detected during the time t0 to ts corresponding to the distance D or less as the reference distance, it can be determined that there is an abnormality (such as a malfunction in the transceiver unit 21).

[0055] 9 is a flowchart showing an example of processing in the object detection device 200 according to the first embodiment. When the ignition power of the vehicle 1 is turned on (S101), the transmitter / receiver 21 transmits and receives ultrasonic waves (transmitted waves Wt1, Wt2 and reflected waves Wr1, Wr2) one or more times (S102), and the signal processor 302 measures the downward distance and the intensity of the reflected wave Wr2 from envelope data based on the results of the transmission and reception of the ultrasonic waves (S103).

[0056] The determination unit 304 determines whether or not a peak exceeding the threshold A2 was detected before time ts based on the measurement results (S104). If a peak exceeding the threshold A2 was detected before time ts (S104: Yes), the determination unit 304 determines that there is an abnormality, such as an object entering under the vehicle 1, and the output unit 306 outputs abnormality information indicating the abnormality to the ECU 100, etc. (S105). Thereafter, the determination unit 304 determines whether or not a peak having an intensity exceeding the threshold A2 was detected between times t0 and ts based on the measurement results (S106). If no peak exceeding the threshold A2 was detected before time ts (S104: No), step S106 is executed without executing step S105. If no peak having an intensity exceeding the threshold A2 is detected between times t0 and ts (S106: No), the determination unit 204 determines that there is an abnormality (such as dirt adhesion) such as a malfunction of the transmitter / receiver 21, and the output unit 306 outputs abnormality information indicating the abnormality to the ECU 100, etc. (S107). If a peak having an intensity exceeding the threshold A2 is detected between times t0 and ts (S106: Yes), this routine ends without executing step S107.

[0057] In the above example, the reference distance is the distance D between the transmitter / receiver 21 and the road surface G, but the reference distance is not limited to this.

[0058] 10 is a flowchart showing an example of a method for setting a reference distance according to the first embodiment. Before parking of the vehicle 1 is completed, the transceiver 21 transmits and receives ultrasonic waves multiple times (S201). Based on the results of transmitting and receiving the ultrasonic waves, the signal processor 302 calculates an average downward distance, which is the average value of the multiple downward distances, and an average intensity, which is the average value of the intensities of the reflected waves Wr2 corresponding to each of the multiple downward distances, and the reference information storage unit 305 stores the average downward distance and the average intensity in the storage device (S202). When parking is completed, the ignition power is turned off (S203).

[0059] Subsequently, when the ignition power is turned on to start the vehicle 1, the reference information storage unit 305 reads the average downward distance and average intensity stored in the storage device (S204), sets the average downward distance as the reference distance (S205), and sets thresholds A1 and A2 based on the average intensity (S206). The threshold A1 is set to remove low-intensity noise due to the structure of the transceiver unit 21, etc. The threshold A2 is set to detect the reflected wave Wr2 from an object corresponding to the average downward distance (an object located vertically below the transceiver unit 21). The object corresponding to the average downward distance is often the road surface G, but may also be a curb, parking block, etc. By setting the reference distance and reference intensity as described above, an abnormality can be detected based on the state before parking. While the above example illustrates the use of average values obtained by transmitting and receiving ultrasonic waves multiple times, the reference downward distance and reference intensity may also be the downward distance and intensity obtained from a single ultrasonic transmission and reception.

[0060] A program that causes a computer (for example, processor 223 of control unit 220, processor 130 of ECU 100, etc.) to execute processes for realizing the various functions in the above-described embodiments can be provided by being recorded 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), or a DVD (Digital Versatile Disk). The program may also be provided or distributed via a network such as the Internet.

[0061] According to the above embodiment, non-directional components (transmitted wave Wt2 and reflected wave Wr2) contained in directional ultrasonic waves transmitted to detect objects present around the vehicle 1 can be used to detect abnormalities such as an object entering underneath the vehicle 1 or a malfunction of the transmitter / receiver 21. This makes it possible to detect abnormalities without adding a separate sensor.

[0062] Other embodiments will be described below with reference to the drawings, but parts that have the same or similar effects as those in the first embodiment will be given the same reference numerals and descriptions thereof may be omitted.

[0063] (Second embodiment) 11 is a block diagram showing an example of the functional configuration of an object detection device 500 according to the second embodiment. The object detection device 500 according to this embodiment differs from the object detection device 200 according to the first embodiment in that it includes a directivity changing unit 511.

[0064] The directivity changing unit 511 according to this embodiment changes the directivity of the transmission wave (either or both of the transmission wave Wt1 and the transmission wave Wt2 shown in FIG. 5) transmitted from the transmitting / receiving unit 21. The method for changing the directivity of the transmission wave is not particularly limited, but for example, a method of adjusting the electrical application characteristics to the piezoelectric element constituting the vibrator 211 in accordance with the desired directivity can be employed.

[0065] According to the above configuration, it is possible to improve the accuracy of detecting an object or an abnormality depending on the situation.

[0066] Although the embodiments of the present disclosure 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 inventions and their equivalents as defined in the claims. [Explanation of symbols]

[0067] 1...vehicle, 2...vehicle body, 21, 21A to 21H...transmitter / receiver unit, 50...vehicle control device (mobile body control device), 100...ECU (control device), 110...input / output device, 120...storage device, 130...processor, 200, 500...object detection device, 211...transducer, 220...control unit, 221...input / output device, 222...storage device, 223...processor, 302...signal processing unit, 303...object detection unit, 304...abnormality determination unit, 305...reference information storage unit, 306...output unit, 511...directivity change unit, D...distance (reference distance), G...road surface, O...object, Wr1, Wr2...reflected wave, Wt1, Wt2...transmitted wave

Claims

1. a transceiver that transmits, as a transmission wave, an ultrasonic wave including a main lobe having directivity in a direction parallel or approximately parallel to the traveling direction of the moving object and side lobes traveling vertically downward relative to the main lobe, and receives a wave reflected from an object relating to the main lobe and a wave reflected from an object relating to the side lobe; a determination unit that determines whether or not there is an abnormality in the vertical downward direction before the moving body starts moving, based on a downward distance between the transmitting / receiving unit and an object present in the vertical downward direction of the transmitting / receiving unit, the downward distance being calculated based on the reflected waves of the side lobes of the transmitted waves, and a reference distance that is determined by an average downward distance that is an average value of downward distances based on ultrasonic waves transmitted and received multiple times by the transmitting / receiving unit when the moving body is stopped; an object detection unit that detects an object present in the traveling direction of the moving object based on a reflected wave of the main lobe of the transmitted wave; an output unit that outputs information about the abnormality and information about the detection of the object present in the traveling direction of the moving body; An object detection device comprising:

2. The reference distance is a distance corresponding to the height of the transmitter / receiver from the road surface. The object detection device according to claim 1 .

3. The determination unit determines that an abnormality exists when the downward distance is shorter than the reference distance. The object detection device according to claim 1 or 2.

4. The determination unit determines that an abnormality exists when the intensity of the reflected wave corresponding to the reference distance or less does not reach a predetermined reference intensity. The object detection device according to any one of claims 1 to 3.

5. a directivity change unit that changes the directivity; The object detection device according to any one of claims 1 to 4, further comprising:

6. An object detection device according to any one of claims 1 to 5; a control device that performs processing to control the moving object based on information about the abnormality output from the object detection device; A mobile object control device comprising:

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