Object detection device

Abstract

To provide an object detection device capable of detecting a low object with high accuracy.SOLUTION: An object detection device comprises: a transmission / reception unit that transmits transmission waves and receives reflection waves generated by the transmission waves being reflected from an object; a coordinate calculation unit that calculates coordinates indicating positions of objects present around a moving body on the basis of echo information indicating time-series changes in intensity of the reflection waves; and a determination unit that, when coordinates of an object present in a region on the traveling-direction side of the moving body are within a predetermined region defined in advance as a region where horizontal attenuation of the transmission waves is sufficiently small, and the same object has been continuously detected for a predetermined period of time, and the intensity of the reflection waves attenuates along with movement of the moving body in the traveling direction, determines that there exists a low detection target object being a detection target object having a height lower than a threshold value.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] FIELD An embodiment of the present invention relates to an object detection device. [Background technology]

[0002] Object detection devices are used to detect objects present around a vehicle based on information acquired by transmitting and receiving waves such as ultrasonic waves. A technology has been disclosed for such object detection devices that determines whether a detected object is a low object such as a curb that will not collide with the vehicle based on the difference between the theoretical reflection intensity and the actual reflection intensity (Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-80639 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in a configuration that uses theoretical reflection intensity as in the prior art, the theoretical reflection intensity differs depending on the detection target, etc., so it may be difficult to detect low-reflection objects with high accuracy.

[0005] One of the problems to be solved by the embodiments of the present invention is to provide an object detection device that can detect low objects with high accuracy. [Means for solving the problem]

[0006] An object detection device according to one embodiment of the present invention is an object detection device that detects objects present in the vicinity of a moving body, and includes a transmitter / receiver unit that transmits a transmission wave and receives a reflected wave generated when the transmission wave is reflected by an object; a coordinate calculation unit that calculates coordinates indicating the position of an object present in the vicinity of the moving body based on echo information that indicates time-series changes in the intensity of the reflected wave; and a determination unit that determines that a low-detection object, which is an object to be detected and whose height is lower than a threshold, is present if the coordinates of an object present in an area in the direction of travel of the moving body are within a predetermined area that has been determined in advance as an area in which the horizontal attenuation of the transmission wave is sufficiently small, and if the same object has been detected continuously for a predetermined period of time, and if the intensity of the reflected wave is attenuating as the moving body moves in the direction of travel.

[0007] According to the above configuration, if the coordinates of an object present in the area in the direction of travel of the moving body are within a predetermined area where the horizontal attenuation of the transmitted wave is sufficiently small, the same object has been detected continuously for a predetermined period of time, and the strength of the reflected wave is attenuated as the moving body moves, it is determined that a low-detection object that is the target of detection and whose height is lower than the threshold value is present. This makes it possible to detect low-detection objects such as curbs with weak reflected wave strength with high accuracy.

[0008] In the above configuration, the determination unit may determine whether or not the same object is detected based on differences between a plurality of coordinates calculated at predetermined time intervals.

[0009] According to the above configuration, it is possible to determine with high accuracy whether the same object is detected.

[0010] Another embodiment of the present invention provides an object detection device that detects objects present in the vicinity of a moving body, and includes: a transceiver unit that transmits a transmission wave and receives a reflected wave generated when the transmission wave is reflected by the object; a coordinate calculation unit that calculates coordinates indicating the position of an object present in the vicinity of the moving body based on echo information that indicates a time-series change in the intensity of the reflected wave; a distance calculation unit that calculates the distance from the moving body to the object based on the echo information; a height calculation unit that calculates the height of the object based on multiple distances calculated by the distance calculation unit; and a determination unit that determines that a low-detection object that is the target of detection and has a height lower than a threshold is present if the coordinates of the object present in the area in the direction of travel of the moving body are within a predetermined area that is determined in advance as an area in which the horizontal attenuation of the transmission wave is sufficiently small, the same object has been detected continuously for a predetermined time, the intensity of the reflected wave is attenuating as the moving body moves in the direction of travel, and the amount of change in height calculated by the height calculation unit is smaller than a threshold value for a predetermined time.

[0011] According to the above configuration, if the coordinates of an object present in the area in the direction of travel of the moving body are within a predetermined area where the horizontal attenuation of the transmitted wave is sufficiently small, the same object has been detected continuously for a predetermined time, the intensity of the reflected wave has attenuated as the moving body moves, and the amount of change in the height of the object has remained smaller than the threshold value for a predetermined time, it is determined that a low-detection object that is the target of detection and whose height is lower than the threshold value is present. This makes it possible to more accurately detect low-detection objects such as curbs that have weak reflected wave intensity. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a diagram showing an example of the configuration of a vehicle according to the first embodiment. [Figure 2] FIG. 2 is a diagram showing an example of the configuration of the vehicle control system according to the first embodiment. [Figure 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 the functional configuration of the object detection device according to the first embodiment. [Figure 5] FIG. 5 is a diagram illustrating an example of the relationship between a change in the position of a low detection object and a change in the intensity of a reflected wave 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 the functional configuration of the object detection device 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 INVENTION

[0013] 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.

[0014] (First embodiment) FIG. 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 objects present around the vehicle 1 based on information such as TOF (Time Of Flight) and Doppler shift acquired by transmitting and receiving ultrasonic waves.

[0015] 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 transceivers 21. Each transceiver 21 is installed on the vehicle body 2, which is 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 transmitted waves, and ultrasonic waves generated when the transmitted waves are reflected by an object may be referred to as reflected waves.

[0016] 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. Note that the number and installation positions of the transceivers 21 are not limited to this example.

[0017] 2 is a diagram showing an example of the configuration of a 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.

[0018] The object detection device 11 includes a plurality of transmitter / receivers 21 and a control unit 22. Each transmitter / receiver 21 includes a vibrator 31 configured using a piezoelectric element or the like, an amplifier, etc., and transmits and receives ultrasonic waves by the vibration of the vibrator 31. Specifically, each transmitter / receiver 21 transmits ultrasonic waves generated in response to the vibration of the vibrator 31 as a transmission wave, and detects the vibration of the vibrator 31 caused by the reflected wave of the transmission wave reflected by an object such as a detection object O or a road surface G. The vibration of the vibrator 31 is converted into an electrical signal, and based on the electrical signal, it is possible to obtain a TOF corresponding to the distance from the transmitter / receiver 21 to the detection object O, a Doppler shift corresponding to the relative speed between the vehicle 1 and the detection object O, etc.

[0019] The detection object O is an object that should be detected among objects present around the vehicle 1. The detection object O includes high detection objects, which are objects having a height equal to or greater than a threshold, and low detection objects, which are objects having a height lower than the threshold. The threshold may be, for example, the height from the road surface G to the lowest part of the vehicle body 2 (such as the lower end of the bumper). High detection objects may be, for example, other vehicles, road accessories, walls, people, etc. Low detection objects may be, for example, curbs, bollards, small steps, etc.

[0020] 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.

[0021] 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), a field programmable gate array (FPGA), or the like 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.

[0022] 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.

[0023] 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 L11 (an example of echo information) that indicates a change over time 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).

[0024] The envelope L11 shows the change over time in the intensity, which indicates the magnitude of the vibration of the vibrator 31. From the envelope L11 shown in Fig. 3, it can be seen that the vibrator 31 is driven to vibrate for a period of 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 period of time Tb until time t2. Therefore, in the graph shown in Fig. 3, the period of time Tb corresponds to the so-called reverberation time.

[0025] The envelope L11 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 becomes equal to or greater than the detection threshold Ith. This detection threshold Ith is a value set to distinguish whether the vibration of the vibrator 31 is caused by reception of a wave reflected from the detection object O or reception of a wave reflected from an object other than the detection object O (e.g., road surface G). Note that although the detection threshold Ith is shown as a constant value here, the detection threshold Ith may also be a variable value that changes depending on the situation. Vibrations having a peak equal to or greater than the detection threshold Ith can be considered to be caused by reception of a wave reflected from the detection object O.

[0026] The envelope L11 in this example shows that the vibration of the vibrator 31 attenuates after timing t4. Therefore, timing t4 corresponds to the timing at which reception of the reflected wave from the detection object O is completed, in other words, the timing at which the transmission wave last transmitted at timing t1 returns as a reflected wave.

[0027] Furthermore, in envelope 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 detection object O 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.

[0028] From the above, in order to use TOF to find the distance from the transmitter / receiver unit 21, which is the source of transmission and reception of ultrasonic waves, to the detection target O, it is necessary to find the time Tf between the timing t0 when the transmission of the transmission 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 transmission 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 detection threshold Ith and reaches its peak.

[0029] The time t0 when the transmission wave begins to be transmitted 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 predetermined 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 detection threshold Ith, the distance from the vehicle 1 (the transceiver unit 21 that transmits and receives the ultrasonic waves) to the detection target O can be calculated. Note that the above calculation method is an example, and the distance from the vehicle 1 to the detection target O may be calculated using any known or new method as appropriate.

[0030] Here, the strength of the reflected wave from a low-detection object such as a curb tends to be weak due to the directivity of the transmitted wave, etc. Therefore, it may be difficult to detect a low-detection object with high accuracy using only the method described above. Therefore, the object detection device 11 according to this embodiment has a function that enables high-accuracy detection of a low-detection object.

[0031] 4 is a diagram showing an example of the functional configuration of the object detection device 11 according to the first embodiment. The control unit 22 of the object detection device 11 according to this embodiment includes an echo information generation unit 101, a coordinate calculation unit 102, a determination unit 103, and an output unit 104. These functional units can be realized, for example, by cooperation between 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).

[0032] The echo information generating unit 101 generates echo information indicating time-series changes in the intensity of the reflected wave based on information (signals) acquired from the transmitting / receiving unit 21.

[0033] The coordinate calculation unit 102 calculates coordinates indicating the position of an object present around the vehicle 1 based on the echo information generated by the echo information generation unit 101. The coordinates are information that can identify the relative positional relationship between the transmitting / receiving unit 21 and the object, and may be, for example, information indicating a position on a plane coordinate system in which the width direction of the vehicle 1 is the X axis and the front-rear direction of the vehicle 1 is the Y axis.

[0034] The determination unit 103 determines whether or not an object present in the vicinity of the vehicle 1 is a low detection target, based on information such as coordinates calculated by the coordinate calculation unit 102. Specifically, if the coordinates of an object present in an area in the traveling direction of the vehicle 1 are within a predetermined area that is determined in advance as an area in which horizontal attenuation of the transmitted wave is sufficiently small, if the same object has been detected continuously for a predetermined time, and if the intensity of the reflected wave is attenuated as the moving object moves in the traveling direction of the moving object, the determination unit 103 determines that a low detection target, which is an object to be detected and whose height is lower than a threshold, is present in the area in the traveling direction of the moving object.

[0035] The output unit 104 outputs the judgment result by the judgment unit 103, i.e., the object detection result including information indicating whether or not there is a low-detection object in the vicinity of the vehicle 1 (such as the area in the direction of travel), to a predetermined mechanism (e.g., ECU 12, etc.).

[0036] FIG. 5 shows a low detection target O according to the first embodiment. low 5 is a diagram showing an example of the relationship between the change in position of the vehicle 1 (transmitter / receiver 21) and the change in intensity of the reflected wave. low A top view showing the relative positional relationship between the low detection object O and the low detection object O is shown. low does not move, and the vehicle 1 moves in the direction of the arrow, i.e., the low detection object O low The example shows a situation where the object is moving in a direction approaching the target.

[0037] The position P0 is the low detection target O detected at time t0. low The position P1 is the position of the low detection object O detected at time t1, a predetermined time after time t0. low Position P2 is the position of the low detection object O detected at time t2, a predetermined time after time t1. low Position P3 is the position of the low detection object O detected at time t4, a predetermined time after time t2. low The predetermined time here may be, for example, the time for one detection cycle. One detection cycle is, for example, the time from when a transmission wave is transmitted once until the end of waiting for the reception of a reflected wave.

[0038] The moving distance Δd1 is the distance from the position P0 to the position P1, the moving distance Δd2 is the distance from the position P1 to the position P2, the moving distance Δd3 is the distance from the position P2 to the position P3, and the moving distance Δd4 is the distance from the position P2 to the position P3. Based on these moving distances Δd1 to Δd3, the same object (low detection target O low ) is continuously detected. That is, it is possible to determine whether the same object is being detected based on the differences between multiple coordinates calculated at predetermined time intervals. For example, if the same object is being detected continuously, the calculated movement distances Δd1 to Δd3 will be relatively small values, but if another object is detected along the way, there is a high possibility that the movement distances Δd1 to Δd3 will suddenly increase. Therefore, it is possible to determine that the same object is being detected continuously while the movement distances Δd1 to Δd3 remain smaller than the threshold value.

[0039] 5, a predetermined area A is illustrated as an area where the horizontal attenuation of the transmission wave transmitted from the transmitting / receiving unit 21 is sufficiently small. The area A can be determined based on the results of a verification experiment, a simulation, or the like that is conducted in advance. Here, the area A is determined based on the results of a low detection target O. low 10 shows an example in which the coordinates of the positions P0 to P3 are within the area A.

[0040] In the lower part of Figure 5, the low detection target O low The intensities I0 to I3 of the reflected waves corresponding to the respective positions P0 to P3 are shown. low The intensity of the reflected wave from the vehicle 1 is low. low As the sensor moves in the direction approaching the object O, that is, as the sensor moves in the direction approaching the object O, the sensor low This is due to the directivity of the transmission wave transmitted from the transmitter / receiver 21. Therefore, when such a change in the intensity of the reflected wave is detected, it is assumed that there is a low detection target O in the area in the traveling direction of the vehicle 1. low It can be assumed that there is a high possibility that

[0041] 6 is a flowchart showing an example of processing in the object detection device 11 according to the first embodiment. When the transmitter / receiver 21 starts transmitting and receiving ultrasonic waves (S101), the echo information generator 101 generates echo information indicating time-series changes in the reflected waves based on information acquired from the transmitter / receiver 21 (S102). The coordinate calculator 102 determines whether or not an object is present around the vehicle 1 based on the echo information (S103). If no object is present (S103: No), the routine ends, and if an object is present (S103: Yes), the coordinates of the object are calculated (S104).

[0042] Thereafter, the determination unit 103 determines whether the calculated coordinates of the object are within a predetermined area (area A) (S105), and if the coordinates are not within the predetermined area (S105: No), ends this routine. If the coordinates are within the predetermined area (S105: Yes), the determination unit 103 determines whether the same object has been detected continuously for a predetermined time (S106). Whether the same object has been detected continuously can be determined based on, for example, the difference between the coordinates of multiple objects calculated every predetermined time, as described above.

[0043] If the same object has not been detected for a predetermined period of time (S106: No), this routine is terminated. If the same object has been detected for a predetermined period of time (S106: Yes), the determination unit 103 determines whether the intensity of the reflected wave has attenuated by a predetermined amount or more as the vehicle 1 moves (S107). If the intensity of the reflected wave has not attenuated (S107: No), this routine is terminated. If the intensity of the reflected wave has attenuated (S107: Yes), the determination unit 103 determines whether a low detection object O is present in the area in the traveling direction of the vehicle 1. low It is determined that exists (S108).

[0044] As described above, according to this embodiment, if the coordinates of an object present in the area in the traveling direction of the vehicle 1 are within the predetermined area A as an area where the horizontal attenuation of the transmitted wave is sufficiently small, and the same object has been detected continuously for a predetermined time, and the intensity of the reflected wave is attenuated as the vehicle 1 moves, then the object is a low detection object O that is a target for detection and has a height lower than the threshold value.low This makes it possible to determine whether a low detection target O, such as a curbstone, exists. low It is possible to detect with high accuracy.

[0045] Other embodiments will be described below with reference to the drawings, but the same or similar parts as those in the first embodiment will be given the same reference numerals and descriptions thereof will be omitted as appropriate.

[0046] (Second embodiment) The object detection device 11 according to the second embodiment detects a low detection target O low This embodiment differs from the first embodiment in that the conditions for determining the presence or absence of an object include whether or not the fluctuation in the height of an object present around the vehicle 1 continues to be small for a predetermined time (predetermined section).

[0047] 7 is a diagram showing an example of the functional configuration of an object detection device 11 according to the second embodiment. The control unit 22 of the object detection device 11 of this embodiment includes an echo information generation unit 101, a coordinate calculation unit 102, a determination unit 103, an output unit 104, a distance calculation unit 111, and a height calculation unit 112.

[0048] The distance calculation unit 111 calculates the distance between the vehicle 1 (transmitter / receiver 21) and an object present around the vehicle 1, based on the echo information generated by the echo information generation unit 101 and the coordinates of the object calculated by the coordinate calculation unit 102. The calculation of the distance may be realized by appropriately using a known or new method, and may be calculated based on information such as TOF, for example.

[0049] The height calculation unit 112 calculates the height of an object present around the vehicle 1 based on the distance calculated by the distance calculation unit 111. The height may be calculated by appropriately using a known or new method, and may be calculated, for example, based on the difference between two distances calculated for objects present on the same or approximately the same coordinates.

[0050] The determination unit 103 according to this embodiment determines that a low detection object O is present in the area on the traveling direction side of the moving body when the coordinates of the object present in the area on the traveling direction side of the vehicle 1 are within a predetermined area (area A) that has been determined in advance as an area where the horizontal attenuation of the transmitted wave is sufficiently small, the same object has been detected continuously for a predetermined time, the intensity of the reflected wave has been attenuated as the vehicle 1 moves in the traveling direction, and the amount of change in height calculated by the height calculation unit 112 is smaller than a threshold value for a predetermined time. low is determined to exist.

[0051] 8 is a flowchart showing an example of processing in the object detection device 11 according to the second embodiment. When the transmitter / receiver 21 starts transmitting and receiving ultrasonic waves (S201), the echo information generator 101 generates echo information indicating time-series changes in the reflected waves based on information acquired from the transmitter / receiver 21 (S202). The coordinate calculator 102 determines whether or not an object is present around the vehicle 1 based on the echo information (S203). If no object is present (S203: No), the routine ends, and if an object is present (S203: Yes), the coordinate calculator 102 calculates the coordinates of the object (S204).

[0052] Thereafter, the distance calculation unit 111 calculates the distance from the vehicle 1 (transmitter / receiver 21) to the object based on the coordinates of the object calculated as described above and the echo information, and the height calculation unit 112 calculates the height of the object based on the distance to the object (S205). At this time, the distance calculation unit 111 calculates two distances for objects that exist on the same or approximately the same coordinates, and the height calculation unit 112 calculates the height of the object based on the two distances.

[0053] Thereafter, the determination unit 103 determines whether the calculated coordinates of the object are within a predetermined area (area A) (S206), and if the coordinates are not within the predetermined area (S206: No), ends this routine. If the coordinates are within the predetermined area (S206: Yes), the determination unit 103 determines whether the same object has been detected continuously for a predetermined time (S207).

[0054] If the same object has not been detected for a predetermined period of time (S207: No), this routine is terminated, and if the same object has been detected for a predetermined period of time (S207: Yes), the determination unit 103 determines whether the intensity of the reflected wave has attenuated by a predetermined amount or more as the vehicle 1 moves (S208). If the intensity of the reflected wave has not attenuated (S208: No), this routine is terminated, and if the intensity of the reflected wave has attenuated (S208: Yes), the determination unit 103 determines whether the amount of change in the height of the object has remained smaller than the threshold value for a predetermined period of time (S209).

[0055] If the state in which the amount of change in the height of the object is smaller than the threshold value has not continued for a predetermined time (S209: No), this routine is terminated. If the state in which the amount of change in the height of the object is smaller than the threshold value has continued for a predetermined time (S209: Yes), the determination unit 103 determines that there is a low detection object O in the area in the traveling direction of the vehicle 1. low It is determined that exists (S210).

[0056] As described above, according to this embodiment, if the coordinates of an object present in the area in the traveling direction of the vehicle 1 are within the predetermined area A as an area where the horizontal attenuation of the transmitted wave is sufficiently small, and the same object has been detected continuously for a predetermined time, and the intensity of the reflected wave has been attenuated as the vehicle 1 moves, and the state in which the amount of change in the height of the object is smaller than the threshold value has continued for a predetermined time, then the object is detected as a low detection object O that is a target for detection and has a height lower than the threshold value. low In this way, by taking into consideration the change in the height of the object, it is possible to determine whether a low detection object O exists. low It is possible to detect with higher accuracy.

[0057] A program that causes a computer (such as the processor 43) to execute processing for realizing the functions of the object detection device 11 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.

[0058] In the above embodiment, the configuration has been described in which ultrasonic waves are used as waves for detecting objects, but the configuration of the object detection device is not limited to this. For example, a configuration using millimeter wave radar, LiDAR, etc. may also be used.

[0059] 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 inventions and their equivalents as defined in the claims. [Explanation of symbols]

[0060] 1...vehicle, 2...vehicle body, 10...vehicle control system, 11...object detection device, 12...ECU, 21, 21A to 21L...transmitter / receiver unit, 22...control unit, 31...transducer, 41...input / output device, 42...storage device, 43...processor, 101...echo information generation unit, 102...coordinate calculation unit, 103...determination unit, 104...output unit, 111...distance calculation unit, 112...height calculation unit, A...area (predetermined area), G...road surface, O...detection target, O low ...Low detection target

Claims

1. An object detection device that detects objects present around a moving body, a transceiver that transmits a transmission wave and receives a reflected wave generated when the transmission wave is reflected by an object; a coordinate calculation unit that calculates coordinates indicating the position of an object present around the moving object based on echo information indicating a time-series change in the intensity of the reflected wave; a determination unit that determines that a low detection target object, which is an object to be detected and has a height lower than a threshold value, is present when the coordinates of an object present in an area in the traveling direction of the moving body are within a predetermined area that is determined in advance as an area in which horizontal attenuation of the transmitted wave is sufficiently small, the same object has been detected continuously for a predetermined time, and the intensity of the reflected wave is attenuated as the moving body moves in the traveling direction; An object detection device comprising:

2. the determination unit determines whether or not the same object is detected based on differences between the plurality of coordinates calculated at predetermined time intervals. The object detection device according to claim 1 .

3. An object detection device that detects objects present around a moving body, a transceiver that transmits a transmission wave and receives a reflected wave generated when the transmission wave is reflected by an object; a coordinate calculation unit that calculates coordinates indicating the position of an object present around the moving object based on echo information indicating a time-series change in the intensity of the reflected wave; a distance calculation unit that calculates a distance from the moving body to an object based on the echo information; a height calculation unit that calculates a height of an object based on the plurality of distances calculated by the distance calculation unit; a determination unit that determines that a low detection target object, which is an object to be detected and whose height is lower than a threshold value, is present when the coordinates of an object present in an area in the traveling direction of the moving body are within a predetermined area that is determined in advance as an area where horizontal attenuation of the transmitted wave is sufficiently small, the same object has been detected continuously for a predetermined time, the intensity of the reflected wave has been attenuated as the moving body moves in the traveling direction, and a state in which the amount of change in height calculated by the height calculation unit is smaller than a threshold value has continued for a predetermined time; An object detection device comprising:

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