Object detection device, method, storage medium, and computer program product

Abstract

The present application relates to an object detection device, method, storage medium, and computer program product. High-precision collision determination is performed. The object detection device has: a plurality of transceiving sections that transceive ultrasonic waves; a triangulation operation section that, each time one or a plurality of reflected waves with respect to a transmission wave transmitted from any one of the plurality of transceiving sections is received, takes a distance based on the one or the plurality of reflected waves as sensing data, if the reflected wave has a prescribed reliability, takes sensing data of the reflected wave having the reliability as reference sensing data, performs triangulation on each of a plurality of sensing data included in a prescribed range of the reference sensing data, and thereby calculates a plurality of coordinates based on sensing data to the object; and a collision determination section that, based on the plurality of coordinates obtained each time the transmission wave is transmitted, finds a moving direction of the object, and based on the moving direction, determines whether the moving body collides with the object.

Description

Technical Field

[0001] This invention relates to object detection devices, object detection methods, storage media, and computer program products. Background Technology

[0002] In an object detection device that uses ultrasonic waves to detect obstacles and other objects present around a vehicle, the following technique is employed: multiple transceivers that transmit and receive ultrasonic waves are installed on the vehicle body, and the distance from the vehicle to the object is calculated based on the timing of the transmission and reception of ultrasonic waves by each transceiver.

[0003] For example, Patent Document 1 discloses the following: In an automatic braking control device, travel direction information representing the vehicle's travel direction, speed information about the vehicle, and position information of an object based on a detection wave sent and received to detect an object in the travel direction are acquired. Based on the travel direction information and speed information, and using a vehicle width line extending along the travel direction corresponding to the vehicle width as a reference, an automatic braking execution area, i.e., a collision determination area, is set in at least one area of ​​the inner region and the outer region of the vehicle width line. When an object is detected, it is determined whether to perform automatic braking based on the position information relative to the automatic braking execution area.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: International Publication No. 2023 / 276919 Summary of the Invention

[0007] The problem that the invention aims to solve

[0008] However, this existing technology has the following problems: the area to be determined by the vehicle's speed information is limited, therefore, the objects that can avoid collision and the actions of those objects are also limited, making it difficult to make high-precision collision determinations.

[0009] The present invention was made in view of the above-mentioned problems, and one object of it is to provide an object detection device and program capable of performing high-precision collision determination.

[0010] Technical solutions to the problem

[0011] The object detection device of the present invention is mounted on a moving body and detects objects existing around the moving body. The object detection device includes: a plurality of transceiver units for transmitting and receiving ultrasonic waves; and a calculation unit for calculating the distance from the moving body to the object, i.e., the object distance, based on the timing of the transmission and reception of the ultrasonic waves by the plurality of transceiver units. The calculation unit includes: a triangulation calculation unit that, each time it receives one or more reflected waves for a transmitted wave transmitted from any of the plurality of transceiver units, uses the distance of the one or more reflected waves as sensing data, and, if the reflected waves have a predetermined reliability, uses the sensing data of the reflected waves with the predetermined reliability as reference sensing data, performs triangulation on each of the plurality of sensing data within a predetermined range of the reference sensing data, thereby calculating a plurality of coordinates based on the sensing data to the object; and a collision determination unit that, based on the plurality of coordinates obtained each time the transmitted wave is transmitted, determines the direction of movement of the object, and determines whether the moving body collides with the object based on the direction of movement.

[0012] Invention Effects

[0013] The object detection device according to the present invention is capable of performing high-precision collision determination. Attached Figure Description

[0014] Figure 1 This is a diagram illustrating an example of the structure of the vehicle according to the first embodiment.

[0015] Figure 2 This is a diagram illustrating an example of the structure of the vehicle control system according to the first embodiment.

[0016] Figure 3 This is a diagram illustrating an example of a distance calculation method based on the TOF method in the first embodiment.

[0017] Figure 4 This is a diagram illustrating an example of the functional structure of the object detection device according to the first embodiment.

[0018] Figure 5 This is a diagram illustrating an example of the first direct wave distance and the second direct wave distance involved in the first embodiment.

[0019] Figure 6 This is a diagram illustrating an example of the first indirect wave distance and the second indirect wave distance involved in the first embodiment.

[0020] Figure 7 This is a diagram showing an example of the waveforms of a plurality of reflected waves of a transmitted wave according to the first embodiment.

[0021] Figure 8 This is a diagram showing an example of the waveform of the reflected wave according to the first embodiment.

[0022] Figure 9 This is a diagram showing an example of a defined range of waveforms of the reflected wave in the first embodiment based on reference sensing data.

[0023] Figure 10 This is a diagram showing an example of the center of gravity of the first embodiment.

[0024] Figure 11 This is a diagram illustrating an example of the triangulation points, centroid, and regression line in the first embodiment.

[0025] Figure 12 This is a diagram illustrating the method for calculating the distance to the obstacle in the case of a collision between vehicle 1 and the obstacle in the first embodiment.

[0026] Figure 13 This is a diagram illustrating the method for calculating the obstacle distance in the first embodiment when the vehicle 1 does not collide with the obstacle.

[0027] Figure 14 This is a flowchart illustrating an example of the object detection processing involved in the first embodiment.

[0028] Figure 15 This is a block diagram illustrating an example of the functional structure of the object detection device according to the second embodiment.

[0029] Figure 16 This is a diagram illustrating an example of sensing data involved in the second embodiment.

[0030] Figure 17 This is a diagram illustrating an example of the waveform of the moving vehicle 1 and the reflected wave in the second embodiment.

[0031] Figure 18 This is a flowchart illustrating an example of the object detection processing involved in the second embodiment.

[0032] Figure 19 This is a flowchart illustrating an example of the object detection processing (continued) involved in the second embodiment. Detailed Implementation

[0033] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. The configuration of the embodiments described below, as well as the effects and functions resulting from such configuration, are examples, and the present invention is not limited to the contents described below.

[0034] [First Implementation]

[0035] (Structure of vehicle 1)

[0036] Figure 1 This diagram illustrates an example of the structure of the vehicle 1 according to the first embodiment. The vehicle 1 is an example of a moving body equipped with the object detection device according to this embodiment. The object detection device according to this embodiment is a device that detects obstacles (an example of an object) existing around the vehicle 1 based on information such as TOF (Time of Flight) and Doppler shift acquired by transmitting and receiving ultrasonic waves.

[0037] The object detection device according to this embodiment includes a plurality of transceiver units 21A to 21L. Hereinafter, unless it is necessary to distinguish between the plurality of transceiver units 21A to 21L, it will sometimes be referred to as transceiver unit 21. Each transceiver unit 21 is provided on the vehicle body 2, which is the outer casing of the vehicle 1, and transmits ultrasonic waves to the outside of the vehicle body 2, and receives ultrasonic waves generated by the reflection of the ultrasonic waves by objects located on the outside of the vehicle body 2. Hereinafter, the ultrasonic waves transmitted from the transceiver unit 21 will sometimes be referred to as transmitted waves, and the ultrasonic waves generated by the reflection of the transmitted waves by objects will sometimes be referred to as reflected waves.

[0038] exist Figure 1 In the example shown, four transceivers 21A-21D are arranged at the front end of the vehicle body 2, four transceivers 21E-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. Furthermore, the number and location of the transceivers 21 are not limited to this example.

[0039] (Structure of vehicle control system 50)

[0040] Figure 2 This diagram illustrates an example of the structure of the vehicle control system 50 according to the embodiment. The vehicle control system 50 performs processing for controlling the vehicle 1 based on information output from the object detection device 200. The vehicle control system 50 according to this embodiment includes an ECU 100 and an object detection device 200.

[0041] The object detection device 200 includes a plurality of transceiver units 21 and a control unit 220. Each transceiver unit 21 includes an oscillator 211 constructed using a piezoelectric element or the like, an amplifier, etc., and transmits and receives ultrasonic waves through the vibration of the oscillator 211. Specifically, each transceiver unit 21 transmits ultrasonic waves generated by the vibration of the oscillator 211 as a transmitted wave, and detects the vibration of the oscillator 211 caused by the reflected waves obtained from the transmitted wave being reflected by objects such as obstacles O and road surfaces. The vibration of the oscillator 211 can be converted into an electrical signal, and based on the electrical signal, information such as the Time of Flight (TOF) corresponding to the distance from the transceiver unit 21 to the obstacle O and the Doppler shift information corresponding to the relative velocity between the vehicle 1 and the obstacle O can be obtained.

[0042] In addition, Figure 2 The example shown illustrates a structure that utilizes a single transceiver 211 for both transmitting the transmitted wave and receiving the reflected wave. However, the structure of the transceiver 21 is not limited to this. For example, it may be a structure in which the transmitting and receiving sides are separated, such as by providing separate transceivers for transmitting the transmitted wave and for receiving the reflected wave.

[0043] 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 that enables the control unit 220 to transmit and receive information with external devices (transceiver unit 21, ECU 100, etc.). The storage device 222 includes main storage devices such as ROM (Read Only Memory) and RAM (Random Access Memory), and auxiliary storage devices such as HDD (Hard Disk Drive) and SSD (Solid State Drive). The processor 223 is an integrated circuit that performs various processes to implement the functions of the control unit 220. For example, it can be constructed using a CPU (Central Processing Unit), ASIC (Application Specific Integrated Circuit), or FPGA (Field Programmable Gate Array), which operates according to a program. The processor 223 reads and executes the program stored in the storage device 222 to perform various arithmetic and control processes.

[0044] ECU 100 is a unit that executes various processes for controlling vehicle 1 based on information acquired from object detection device 200, etc. ECU 100 includes an input / output device 110, a storage device 120, and a processor 130. The input / output device 110 is an interface device capable of transmitting and receiving information between ECU 100 and external mechanisms (object detection device 200, drive mechanism, braking mechanism, steering mechanism, transmission mechanism, in-vehicle display, speaker, various sensors, etc.). Storage device 120 includes main storage devices such as ROM and RAM, and auxiliary storage devices such as HDD and SSD. Processor 130 is an integrated circuit that executes various processes to implement the functions of ECU 100; for example, it can be constructed using CPU, ASIC, FPGA, etc. Processor 130 reads and executes programs stored in storage device 120 to perform various arithmetic and control processes.

[0045] (Distance calculation method based on TOF method)

[0046] Figure 3 This is a diagram illustrating an example of a distance calculation method based on the Time-of-Flight (TOF) method. Figure 3 The example shows the envelope L11 (echo information) representing the time-varying change in the intensity (signal level) of the ultrasonic waves transmitted and received by the transceiver unit 21. Figure 3 In the curve shown, the horizontal axis corresponds to time of day (TOF), and the vertical axis corresponds to the intensity of the ultrasonic waves transmitted and received by the transceiver unit 21 (the magnitude of the vibration of the transducer 211).

[0047] The envelope L11 shows the time-varying intensity of the vibration representing the magnitude of the oscillation of oscillator 211. From Figure 3 The following is read from the illustrated envelope L11: Oscillator 211 is driven to oscillate for time Ta starting from time t0. Thus, after the transmission of the wave is completed at time t1, the oscillation of oscillator 211 continues while decaying due to inertia during the time Tb up to time t2. Therefore, in Figure 3 In the curve described, time Tb corresponds to the so-called reverberation time.

[0048] Envelope L11, after a time interval Tp and a time interval t4 elapsed from the timing t0 when the transmitted wave began, reaches a peak value in the vibration of oscillator 211 that exceeds the detection threshold Ith. This detection threshold Ith is a set value used to distinguish whether the vibration of oscillator 211 is caused by reflected waves from an obstacle O (other vehicles, structures, pedestrians, etc.) or by reflected waves from objects other than the obstacle O (e.g., the road surface). Furthermore, while the detection threshold Ith is presented as a fixed value here, it can also be a variable value depending on the situation. Vibrations with a peak value exceeding the detection threshold Ith can be considered as being caused by reflected waves from the obstacle O.

[0049] In the envelope L11 of this example, the vibration attenuation of oscillator 211 after timing t4 is shown. Therefore, timing t4 corresponds to the timing at which the reception of the reflected wave from obstacle O is completed; in other words, it corresponds to the timing at which the transmitted wave last transmitted at timing t1 returns as a reflected wave.

[0050] Furthermore, in envelope L11, timing t3, which is the starting point of the peak value of timing t4, corresponds to the timing at which the reception of the reflected wave from obstacle O begins; in other words, it corresponds to the timing at which the transmitted wave initially sent 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.

[0051] Based on the above, in order to use Time-of-Flight (TOF) to determine the distance from the ultrasonic transceiver 21 to the obstacle O, 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 obtained by subtracting a time ΔT, which is equal to the transmission time Ta of the transmitted wave, from the time Tp, which is the difference between timing t0 and the timing t4 when the intensity of the reflected wave exceeds the detection threshold Ith and reaches its peak.

[0052] The timing t0 at which the transmitted wave begins to be transmitted can be easily determined as the timing at which the object detection device 200 begins to operate, and the transmission time Ta of the transmitted wave is predetermined by setting, etc. Therefore, by determining the timing t4 at which the intensity of the received reflected wave reaches a peak value above the detection threshold Ith, the distance from the vehicle 1 (the transceiver unit 21, the source and receiver of the ultrasonic wave) to the obstacle O can be calculated.

[0053] Furthermore, the above calculation method is merely an example; the distance from vehicle 1 to obstacle O can be calculated using either known or new methods as appropriate.

[0054] (Functional structure of object detection device 200)

[0055] Figure 4 This diagram illustrates an example of the functional structure of the object detection device 200 according to the embodiment. The object detection device 200 according to this embodiment is as follows: Figure 4 As shown, it includes an arithmetic unit 301, the aforementioned storage device 222, and a plurality of transceiver units 21 (21A~21L).

[0056] The calculation unit 301 calculates the distance from vehicle 1 to obstacle O, i.e., obstacle distance (an example of object distance), based on the timing of the ultrasonic wave transmission and reception of each transceiver 21. The reflected waves received by each transceiver 21 in this embodiment include direct waves and indirect waves. A direct wave is a reflected wave corresponding to a transmitted wave sent from a certain transceiver 21 (e.g., transceiver 21A), which is received by the same transceiver 21 that sent the transmitted wave (e.g., transceiver 21A). An indirect wave is a reflected wave corresponding to a transmitted wave sent from a certain transceiver 21 (e.g., transceiver 21A), which is received by a different transceiver 21 (e.g., transceiver 21B). The calculation unit 301 in this embodiment uses both the timing of receiving direct waves and the timing of receiving indirect waves to calculate the obstacle distance.

[0057] Regarding the arithmetic unit 301 involved in this embodiment, as follows: Figure 4As shown, the arithmetic unit 301 includes a direct wave distance calculation unit 311, an indirect wave distance calculation unit 312, a storage unit 313, a triangulation calculation unit 314, a collision determination unit 316, and a distance calculation unit 317. These functional units can be, for example, through... Figure 2 The object detection device 200 shown is implemented through the cooperation of hardware and software (programs, etc.). In addition, at least some of these functional parts can also be implemented by dedicated hardware (circuit).

[0058] When the reflected wave of a transmitted wave transmitted from one of the plurality of transceivers 21, namely the first transceiver (e.g., 21A), is received by the first transceiver, the direct wave distance calculation unit 311 calculates a first direct wave distance based on the timing of the transmission of the transmitted wave from the first transceiver and the timing of the reception of the reflected wave (direct wave) by the first transceiver. Furthermore, when the reflected wave of a transmitted wave transmitted from a second transceiver (e.g., 21B), which is different from the first transceiver, is received by the second transceiver, the direct wave distance calculation unit 311 calculates a second direct wave distance based on the timing of the transmission of the transmitted wave from the second transceiver and the timing of the reception of the reflected wave (direct wave) by the second transceiver. In other words, the first direct wave distance is calculated based on the direct wave received by the first transceiver, and the second direct wave distance is calculated based on the direct wave received by the second transceiver.

[0059] When the reflected wave of a transmitted wave transmitted from one of the plurality of transceivers 21, namely the third transceiver (e.g., 21A), is received by a fourth transceiver (e.g., 21B), which is different from the third transceiver, the indirect wave distance calculation unit 312 calculates a first indirect wave distance based on the timing of the transmission of the transmitted wave from the third transceiver and the timing of the reception of the reflected wave (indirect wave) by the fourth transceiver. Furthermore, when the reflected wave of a transmitted wave transmitted from the fourth transceiver is received by the third transceiver, the indirect wave distance calculation unit 312 calculates a second indirect wave distance based on the timing of the transmission of the transmitted wave from the fourth transceiver and the timing of the reception of the reflected wave (indirect wave) by the third transceiver. That is, the first indirect wave distance is calculated based on the indirect wave transmitted from the third transceiver and received by the fourth transceiver, and the second indirect wave distance is calculated based on the indirect wave transmitted from the fourth transceiver and received by the third transceiver.

[0060] Figure 5 This is a diagram illustrating an example of the first direct wave distance Dd1 and the second direct wave distance Dd2 involved in the implementation method. Figure 5 The example illustrates a scenario where two transceivers 21G and 21H, located at the rear of vehicle 1, are designated as the first and second transceivers, respectively, and an obstacle O exists behind vehicle 1. Furthermore, in... Figure 5Examples include a first transmitted wave Wt1 transmitted from the first transceiver unit 21G and a first direct wave Wd1 received by the first transceiver unit 21G after the first transmitted wave Wt1 is reflected by an obstacle O. Additionally, examples include a second transmitted wave Wt2 transmitted from the second transceiver unit 21H and a second direct wave Wd2 received by the second transceiver unit 21H after the second transmitted wave Wt2 is reflected by an obstacle O.

[0061] The first direct wave distance Dd1 is calculated based on the timing of the first transmitted wave Wt1 being transmitted from the first transceiver unit 21G and the timing of the first direct wave Wd1 being received by the first transceiver unit 21G. The second direct wave distance Dd2 is calculated based on the timing of the second transmitted wave Wt2 being transmitted from the second transceiver unit 21H and the timing of the second direct wave Wd2 being received by the second transceiver unit 21H.

[0062] Figure 6 This is a diagram illustrating an example of the first indirect wave distance Di1 and the second indirect wave distance Di2 involved in the implementation method. Figure 6 The example illustrates a situation where two transceivers 21G and 21H located at the rear of vehicle 1 are designated as the third and fourth transceivers, respectively, and an obstacle O exists behind vehicle 1. Furthermore, this example illustrates a scenario where the first and third transceivers are the same transceiver 21G, and the second and fourth transceivers are the same transceiver 21H, but the example is not limited to this.

[0063] Figure 6 The example illustrates a situation where the fourth transceiver unit 21H receives a first indirect wave Wi1, and the third transceiver unit 21G receives a second indirect wave Wi2. The first indirect wave Wi1 is a reflected wave generated from the first transmitted wave Wt1 transmitted from the third transceiver unit 21G, which is reflected by an obstacle O. The second indirect wave Wi2 is a reflected wave generated from the second transmitted wave Wt2 transmitted from the fourth transceiver unit 21H, which is reflected by an obstacle O.

[0064] The first indirect wave distance Di1 is calculated based on the timing of the transmission of the third transmitted wave Wt1 from the first transceiver unit 21G and the timing of the reception of the first indirect wave Wi1 by the fourth transceiver unit 21H. The second indirect wave distance Di2 is calculated based on the timing of the transmission of the second transmitted wave Wt2 from the fourth transceiver unit 21H and the timing of the reception of the second indirect wave Wi2 by the third transceiver unit 21G.

[0065] return Figure 4 Each time one or more reflected waves are received for a transmitted wave sent from any one of the plurality of transceiver units 21, the storage unit 313 stores the distance of one or more reflected waves as sensing data in the storage device 222.

[0066] Specifically, when the reflected wave is a direct wave, the storage unit 313 stores the distance calculated by the direct wave distance calculation unit 311 as sensing data in the storage device 222 for each of one or more direct waves. Furthermore, when the reflected wave is an indirect wave, the storage unit 313 stores the distance calculated by the indirect wave distance calculation unit 312 as sensing data in the storage device 222 for each of one or more indirect waves. The details of the sensing data will be explained later.

[0067] Each time one or more reflected waves are received for a transmitted wave sent from any one of the plurality of transceiver units 21, the triangulation calculation unit 314 uses the distance of one or more reflected waves as sensing data, and uses the sensing data of the reliable reflected waves as reference sensing data if the reflected waves have a specified reliability.

[0068] Here, the triangulation calculation unit 314 determines that the reflected wave has a specified reliability (i.e., high reliability) when the intensity of the reflected wave exceeds a predetermined threshold. The predetermined threshold is an automatic threshold that varies based on the intensity. The triangulation calculation unit 314 determines that the reflected wave has a specified reliability when the intensity of the reflected wave exceeds the automatic threshold by a predetermined amount.

[0069] Furthermore, the value obtained by exceeding the automatic threshold by a predetermined amount is called the reliability threshold. Therefore, when the intensity of the reflected wave exceeds the reliability threshold, the triangulation calculation unit 314 determines that the reflected wave has the predetermined reliability.

[0070] Figure 7 This is a diagram illustrating an example of the waveforms of a plurality of reflected waves of a transmitted wave according to the first embodiment. Figure 7 In the diagram, the vertical axis represents the intensity of the reflected wave, and the horizontal axis represents the distance. Figure 7 In the diagram, solid lines represent the waveform of the reflected wave, and dashed lines represent the automatic threshold. Figure 7 In the waveform example, the two reflected waves that exceed the automatic threshold are referred to as wave one and wave two from left to right.

[0071] Figure 8 This is a diagram showing an example of the waveform of the reflected wave according to the first embodiment. Figure 8 In the diagram, the vertical axis represents the intensity of the reflected wave, and the horizontal axis represents the distance. Figure 8 In the diagram, solid lines represent the waveform of the reflected wave, dashed lines represent the automatic threshold, and double-dotted lines represent the reliability threshold.

[0072] exist Figure 8In the example shown, the triangulation unit 314 determines that the reflected wave indicated by the arrow exceeding the reliability threshold has a specified reliability, that is, high reliability. This reflected wave is referred to as reference sensing data.

[0073] Then, the triangulation calculation unit 314 performs triangulation on each of the plurality of sensing data contained within a specified range of the reference sensing data, calculating a plurality of coordinates based on the sensing data to the obstacle. Here, triangulation is sometimes referred to as trilateration. Additionally, each coordinate based on the plurality of coordinates of the sensing data is sometimes referred to as a triangulation point.

[0074] Figure 9 This is an example of a defined range in the reference sensing data representing the waveform of the reflected wave in the first embodiment. Figure 9 In the example, the range centered on the distance of the reference sensing data and extending forward and backward by a predetermined distance is set as the predetermined range 901. The triangulation calculation unit 314 performs triangulation on each of the plurality of sensing data contained within the predetermined range 901 of the reference sensing data, thereby calculating a plurality of coordinates based on the sensing data to the obstacle.

[0075] Here, Figure 9 The waveforms of the reflected waves shown are obtained for both direct and indirect waves. The triangulation calculation unit 314 performs triangulation on each of the plurality of sensing data of the reflected waves that are included within a specified range of the reference sensing data and are above the automatic threshold in the respective waveforms of the direct and indirect waves, thereby calculating a plurality of coordinates based on the sensing data to the obstacle.

[0076] More specifically, when the number of direct waves (n) and indirect waves (m) of the sensing data that exceed the automatic threshold within a specified range, the triangulation calculation unit 314 performs triangulation using a combination of n and m sensing data. For example, such as Figure 9 As shown in the example, when there are two sets of sensing data for both direct and indirect waves that exceed the automatic threshold, triangulation can be performed using the following four combinations to calculate coordinates based on the sensing data.

[0077] Direct wave 1 × Direct wave 2

[0078] Direct wave 1 × Indirect wave 1

[0079] Direct wave 2 × Indirect wave 1

[0080] Direct wave 2 × Indirect wave 2

[0081] return Figure 4 Specifically, the triangulation calculation unit 314 calculates the distance from the direct wave distance calculation unit 311. Figure 5 In the case of the first direct wave distance and the second direct wave distance shown, the coordinates based on the sensing data are calculated by triangulation based on the first direct wave distance and the second direct wave distance.

[0082] In addition, the triangulation calculation unit 314 calculates the distance through the indirect wave distance calculation unit 312. Figure 6 In the case of the first indirect wave distance and the second indirect wave distance shown, the coordinates based on the sensing data are calculated by triangulation based on the first indirect wave distance and the second indirect wave distance.

[0083] Furthermore, the triangulation calculation unit 314 calculates the distance via the direct wave distance calculation unit 311. Figure 5 The first direct wave distance shown is calculated by the indirect wave distance calculation unit 312. Figure 6 In the case of the second indirect wave distance shown, the coordinates based on the sensing data are calculated by triangulation based on the first direct wave distance and the second indirect wave distance.

[0084] The triangulation calculation unit 314 outputs the calculated coordinates to the collision determination unit 316.

[0085] The collision determination unit 316 calculates the direction of movement of the obstacle based on the multiple coordinates obtained from each transmission wave, and determines whether the vehicle 1 will collide with the obstacle based on the direction of movement.

[0086] Specifically, the collision determination unit 316 calculates the coordinates of the centroids of a plurality of coordinates. The collision determination unit 316 stores the calculated coordinates of the centroids in the storage device 222.

[0087] Figure 10 This is a diagram showing an example of the center of gravity in the first embodiment. Figure 10 In the diagram, ○ represents a complex set of coordinates (triangulation points) calculated through triangulation. × represents the centroid. The centroid is calculated using known methods.

[0088] Furthermore, the collision determination unit 316 calculates the regression line based on the positions of a plurality of center points obtained from each transmission wave. The regression line is a straight line representing the direction of movement of the obstacle.

[0089] Figure 11 This is a diagram illustrating an example of the triangulation points, centroid, and regression line of the first embodiment. Figure 11 In this equation, the regression line derived from the centroid is the line labeled 1001. The calculation of the regression line based on the centroid is performed using known methods.

[0090] return Figure 4If the return line intersects with the position of vehicle 1, the collision determination unit 316 determines that vehicle 1 will collide with the obstacle. If the return line does not intersect with the position of vehicle 1, the collision determination unit 316 determines that vehicle 1 will not collide with the obstacle. Figure 11 In the example, since the regression line 1001 intersects with vehicle 1, it is determined that vehicle 1 will collide with the obstacle.

[0091] Based on the judgment result of the collision judgment unit 316, the distance calculation unit 317 calculates the obstacle distance using calculation methods with varying degrees of precision, based on the coordinates (triangulation points) of the sensing data. Specifically, if it is determined that the vehicle 1 will not collide with the obstacle, the distance calculation unit 317 calculates the obstacle distance using a first method; if it is determined that the vehicle 1 will collide with the obstacle, the distance calculation unit 317 calculates the obstacle distance using a second method. Here, the second method is a distance calculation method with higher precision than the first method.

[0092] In this embodiment, as a first method, the distance calculation unit 317 calculates the distance from the corner of the end (e.g., the rear end) of the vehicle 1 on which the transceiver unit 21 is provided to the location of the reference sensing data as the obstacle distance.

[0093] In addition, as a second method, the distance calculation unit 317 calculates the distance from the intersection point of a line extending from the end (e.g., the rear end) of the vehicle 1 on which the transceiver unit 21 is installed, and a straight line orthogonal to the extended line that extends parallel to the direction of travel of the vehicle 1 and intersects the position of the reference sensing data, to the position of the reference sensing data, and uses this distance as the obstacle distance.

[0094] Figure 12 This is a diagram illustrating the method for calculating the distance to the obstacle in the case where vehicle 1 collides with the obstacle in the first embodiment.

[0095] Figure 13 This diagram illustrates the method for calculating the obstacle distance in the first embodiment, assuming the vehicle 1 will not collide with the obstacle.

[0096] Figure 13 In the example, the regression line 1001 does not intersect with vehicle 1, therefore, it is determined that vehicle 1 will not collide with the obstacle.

[0097] Figure 13 In the case of an example, as a first method, the distance calculation unit 317 calculates the distance 1201 from the corner 1202 of the rear end of the vehicle 1 on which the transceiver unit 21 is installed to the position of the reference sensing data, as the obstacle distance.

[0098] on the other hand, Figure 12In the example, the regression line 1001 intersects with vehicle 1, therefore, it is determined that vehicle 1 will collide with the obstacle.

[0099] exist Figure 12 In the example case, as a second method, the distance calculation unit 317 calculates the distance 1102 from the intersection point of the line 1203 extending from the rear end of the vehicle 1 where the transceiver unit 21 is installed, and a straight line orthogonal to the extended line 1203 that extends parallel to the direction of travel of the vehicle 1 and intersects the position of the reference sensing data, to the position of the reference sensing data, as the obstacle distance. Figure 12 In such cases, if Figure 13 As shown, the obstacle distance is calculated using the first method and becomes distance 1101. However, since vehicle 1 will collide with the obstacle, the distance calculation unit 317 calculates distance 1102 as the obstacle distance using the second method as a more accurate distance.

[0100] (Object detection and processing)

[0101] The object detection processing of the object detection apparatus 200 according to this embodiment, configured as described above, will now be explained.

[0102] Figure 14 This is a flowchart illustrating an example of the object detection processing involved in the first embodiment.

[0103] First, the transceiver unit 21 sends a transmission wave, thereby initiating distance measurement (S11).

[0104] Then, the storage unit 313 determines whether the transceiver unit 21 has received a direct wave or an indirect wave that is a reflected wave of the transmitted wave (S12). If no direct wave or indirect wave is received (S12: No), the process ends.

[0105] On the other hand, if a direct wave or an indirect wave is received (S12: Yes), the following processing is performed on the direct wave and the indirect wave respectively.

[0106] That is, when a direct wave is received, the direct wave distance calculation unit 311 calculates the distance to the object, and when an indirect wave is received, the indirect wave distance calculation unit 312 calculates the distance to the obstacle. Then, the storage unit 313 stores the calculated distance as sensing data for each reflected wave in the storage device 222 (S13).

[0107] Then, the triangulation calculation unit 314 determines whether the reliability of the reflected wave is high, that is, whether the reflected wave has the specified reliability (S14). If the reflected wave does not have the specified reliability and the reliability is low (S14: No), the process ends.

[0108] On the other hand, if the reflected wave has a specified reliability and the reliability is high (S14: Yes), the triangulation calculation unit 314 sets the current reflected wave sensing data as the reference sensing data (S15). Then, the triangulation calculation unit 314 performs triangulation on all sensing data that are near the distance of the reference sensing data, i.e., above the automatic threshold of the specified range mentioned above (S16). As a result, a plurality of coordinates (triangulation points) corresponding to a plurality of sensing data are obtained.

[0109] Then, the triangulation calculation unit 314 calculates the centroid of the complex coordinates obtained from the triangulation in S16 (S17). Then, the triangulation calculation unit 314 stores the coordinates of the centroid calculated in S17 in the storage device 222 (S18).

[0110] Then, the triangulation unit 314 determines whether the coordinates of the centroid have been calculated more than N times (S19). Here, N is a predetermined number that can be arbitrarily set. If the coordinates of the centroid have been calculated less than N times (S19: No), the process returns to S11, and the process from S11 to S18 is repeated.

[0111] In S19, if the coordinates of the centroid are calculated more than N times (S19: Yes), the triangulation calculation unit 314 calculates the regression line for the coordinates of the centroid N times (S20).

[0112] Then, the collision determination unit 316 determines whether there is a collision between the vehicle (vehicle 1) and the obstacle based on the regression line (S21). Then, the distance calculation unit 317 calculates the obstacle distance from vehicle 1 to the obstacle using the method described above, corresponding to whether there is a collision (S22). Then, the process ends.

[0113] (Summary)

[0114] As described above, each time the object detection device 200 of this embodiment receives one or more reflected waves of a transmitted wave sent from any one of the plurality of transceiver units 21, it uses the distance of one or more reflected waves as sensing data. If the reflected waves have a specified reliability, it uses the sensing data of the reliable reflected waves as reference sensing data. It performs triangulation on each of the plurality of sensing data within a specified range of the reference sensing data to calculate a plurality of coordinates based on the sensing data to the obstacle. Based on the plurality of coordinates obtained according to each transmission of the transmitted wave, it determines the movement direction of the obstacle. Based on the movement direction, it determines whether the vehicle 1 has collided with the obstacle.

[0115] Therefore, in this embodiment, the direction of movement of the obstacle is predicted and the probability of collision is determined. Thus, it is not limited by the object of the obstacle or the action of the object, and can perform high-precision collision determination.

[0116] In addition, the object detection device 200 of this embodiment calculates the centroids of a plurality of coordinates, and calculates the regression line representing the direction of movement based on the position of the plurality of centroids obtained by each transmission of the transmission wave. If the regression line intersects the position of the vehicle 1, it is determined that the vehicle 1 will collide with the obstacle.

[0117] Therefore, in this embodiment, multiple coordinates and their centroids based on the sensing data are calculated, reducing the calculation error of the obstacle's position. Thus, according to this embodiment, collision determination can be performed with high accuracy, regardless of the obstacle or the object's movement.

[0118] Furthermore, the object detection device 200 of this embodiment calculates the obstacle distance using a first method when it determines that the vehicle 1 will not collide with the obstacle, and calculates the obstacle distance using a second method with higher accuracy than the first method when it determines that the vehicle 1 will collide with the obstacle.

[0119] Therefore, according to this embodiment, when it is determined that vehicle 1 will collide with an obstacle, the distance to the obstacle is calculated using a highly accurate second method. Thus, it is not limited by the object of the obstacle or the action of the object, and can perform collision determination with higher accuracy.

[0120] [Second Implementation]

[0121] In the first embodiment, collision determination with an obstacle is performed using sensing data of reflected waves whose reflection intensity is above an automatic threshold in the reflected waves of the transmitted wave. However, in this second embodiment, even if the sensing data of reflected waves with a reflection intensity less than the automatic threshold can be sensed as the same object, the sensing data is used to determine collision with an obstacle.

[0122] The structure of the vehicle 1 and the vehicle control system 50 involved in this embodiment are the same as those in the first embodiment. Therefore, the description of the structure of the vehicle 1 and the vehicle control system 50 is omitted.

[0123] (Structure of object detection device 1200)

[0124] Figure 15 This is a block diagram illustrating an example of the functional structure of the object detection device 1200 according to the second embodiment. The object detection device 200 according to this embodiment is as follows: Figure 15As shown, it includes an arithmetic unit 1301, a storage device 222, and a plurality of transceiver units 21 (21A-21L). The storage device 222 and the plurality of transceiver units 21 (21A-21L) are the same as in the first embodiment. Therefore, the same reference numerals as in the first embodiment are used for these structures and descriptions are omitted.

[0125] Similar to the first embodiment, the arithmetic unit 1301 calculates the distance from the vehicle 1 to the obstacle O, i.e., the obstacle distance (an example of object distance), based on the timing of the ultrasonic wave transmission and reception of each transceiver unit 21. Regarding the arithmetic unit 1301 involved in this embodiment, as follows... Figure 15 As shown, the arithmetic unit 1301 includes a direct wave distance calculation unit 311, an indirect wave distance calculation unit 312, a storage unit 313, a determination unit 1315, a triangulation calculation unit 1314, a collision determination unit 316, and a distance calculation unit 317. These functional units are also the same as in the first embodiment, and can be... Figure 2 The object detection device 1200 shown is implemented through a combination of hardware and software (programs, etc.). Furthermore, at least some of these functional units can also be implemented using dedicated hardware (circuit).

[0126] Here, the direct wave distance calculation unit 311, the indirect wave distance calculation unit 312, the storage unit 313, the collision determination unit 316, and the distance calculation unit 317 are the same as in the first embodiment.

[0127] If the reflected wave has a specified reliability, the determination unit 1315 uses the sensing data of the reflected wave as reference sensing data and calculates a traceability amount based on the vehicle 1's movement information (e.g., vehicle 1's speed and movement time) since the receiving time of the previous reflected wave. Then, the determination unit 1315 determines the sensing data of the same object from the plurality of sensing data stored in the storage device 222 based on the reference sensing data and the traceability amount.

[0128] More specifically, the determining unit 1315 determines the sensing data related to the reflected wave received at the timed timing from the time of receiving the reflected wave using the calculated tracing amount, and based on the reference sensing data and the tracing amount, the sensing data is identified as the same object.

[0129] Here, if the intensity of the reflected wave exceeds a predetermined threshold, the determination unit 1315 determines that the reflected wave has a predetermined reliability (i.e., high reliability). More specifically, the predetermined threshold is, like in the first embodiment, an automatic threshold that varies based on intensity. Then, if the intensity of the reflected wave exceeds the automatic threshold by a predetermined amount, the determination unit 1315 determines that the reflected wave has a predetermined reliability. The reliability threshold is also the same as in the first embodiment.

[0130] Figure 16 This is a diagram illustrating an example of sensing data involved in the second embodiment. Figure 16 In the example, the transmitted wave, the number of the reflected wave received for a single transmitted wave (i.e., wave one, wave two, wave three, etc.), and the distance calculated based on the reflected wave are recorded as sensing data.

[0131] Figure 16 The corresponding sensing data Figure 7 The reflected wave. Figure 7 The first and second waves of the reflected wave correspond to respectively Figure 16 The arrows in the sensing data indicate the distance of the first wave ("1.5m") and the distance of the second wave ("1.7m") to the reflected waves of the transmitted wave.

[0132] exist Figure 7 In this example, the second wave of the reflected wave of the transmitted wave has a specified reliability (i.e., high reliability). Therefore, the determination unit 1315 sets the sensing data of the second wave, i.e., the distance "1.7m", as the reference sensing data.

[0133] Figure 17 This is a diagram illustrating an example of the movement of vehicle 1 and the waveform of the reflected wave in the second embodiment. Vehicle 1 from Figure 17 (b) The position on the left is moved to Figure 17 (a) shows the position on the left. The waveform of the reflected wave at this time is respectively in... Figure 17 (a) and (b) are shown on the right.

[0134] The determining unit 1315 calculates the amount of movement of vehicle 1 based on its moving speed and moving time, and uses this value as the traceability quantity. Here, in Figure 16 In the example of the sensing data, the calculated trace distance is, for example, 0.4m. At this time, the determination unit 1315 determines that the sensing data with a distance of "2.1m" obtained by adding the trace distance of 0.4m to the sensing data of the second wave of the reflected wave of the third (current) transmitted wave (i.e., the sensing data of the third wave, indicated by the arrow in the second (previous) transmitted wave) is the same obstacle sensed in the second wave of the reflected wave of the third (current) transmitted wave. Then, the determination unit 1315 removes the reflected waves other than the third wave as reflected waves from the road surface or other sources outside the obstacle. Through this process, reflected waves from the same obstacle can be determined.

[0135] In other words, the previous reflected wave, even when its intensity was below the automatic threshold, was not used for calculating the center of gravity for collision detection. However, even when the intensity was below the automatic threshold, the presence of reflections from the same obstacle, which would be used as reference sensing data for the current collision detection, was considered in the previous reflected wave. In this case, compared to using sensing data above the automatic threshold, calculating the center of gravity using reflected waves from the same obstacle and using it for obstacle detection can further improve the accuracy of collision detection. Therefore, in this embodiment, the determination unit 1315 can determine the sensing data of reflected waves from the same obstacle.

[0136] The triangulation calculation unit 1314 calculates a first distance and a centroid point for the previous reflected wave using the method described in the first embodiment, based on sensing data that exceeds an automatic threshold within a specified range 901 of the reference sensing data. Then, for the previous reflected wave, the triangulation calculation unit 1314 further performs triangulation on the sensing data determined by the determination unit 1315, calculates a plurality of coordinates based on the previous sensing data, calculates the centroid point using these coordinates, and uses the centroid point to calculate a regression line for the previous reflected wave.

[0137] (Object sensing and processing)

[0138] The object detection process of the object detection apparatus 1200 configured in this embodiment as described above will now be explained.

[0139] Figure 18 , 19 This is a flowchart illustrating an example of the object detection processing involved in the second embodiment. The processing from the start of sending the wave and measurement to saving the sensing data (S11~S13) is the same as in the first embodiment.

[0140] Then, the determination unit 1315 determines whether the reliability of the reflected wave is high, that is, whether the reflected wave has the specified reliability (S14). If the reflected wave does not have the specified reliability and the reliability is low (S14: No), the process ends.

[0141] On the other hand, if the reflected wave has a specified reliability and the reliability is high (S14: Yes), the determination unit 315 sets the sensing data of the reflected wave as the reference sensing data (S15). Then, the determination unit 315 calculates the traceability amount based on the movement information of vehicle 1 (S31).

[0142] Then, the determining unit 315 determines, as described above, the sensing data of the obstacle located at the distance of the reference sensing data as the same obstacle based on the calculated tracing amount and the sensing data stored in the storage device 222 (S32).

[0143] Then, the triangulation calculation unit 1314 performs triangulation on the previous reflected wave, abandoning the calculated center of gravity point, and uses the determined sensing data of the same obstacle to calculate the coordinates (triangulation points) based on the sensing data, and further calculates the center of gravity point (S33).

[0144] Then, the triangulation calculation unit 1314 performs the same triangulation (S16), centroid calculation (S17), and centroid coordinate storage (S18) processing for the reflected wave as in the first embodiment.

[0145] Then, the triangulation unit 314 determines whether the coordinates of the centroid have been calculated more than N times (S19). If the coordinates of the centroid have been calculated less than N times (S19: No), the process returns to S11, and the process from S11 to S18 is repeated.

[0146] In S19, if the coordinates of the center of gravity are calculated more than N times (S19: Yes), the calculation of the regression line of the triangulation calculation unit 314 (S20), the collision judgment of the collision judgment unit 316 (S21), and the calculation of the obstacle distance of the distance calculation unit 317 (S22) are performed in the same way as in the first embodiment, and then the process ends.

[0147] (Summary)

[0148] In the object detection device 1200 of this embodiment as described above, if the current reflected wave has a specified reliability, the sensing data of the current reflected wave is used as reference sensing data. Based on the movement information of vehicle 1 from the receiving time of the previous reflected wave, a traceability is calculated. From the plurality of sensing data stored in the storage device 222, the sensing data of the same obstacle is determined based on the reference sensing data and the traceability. For the previous reflected wave, triangulation is performed on the determined sensing data, thereby calculating the coordinates based on the plurality of sensing data from the previous time.

[0149] Therefore, even when the intensity of the reflected wave corresponding to the previous obstacle is low, it is possible to determine that the obstacle in the current reference sensing data is the same obstacle. This determined sensing data is then used to calculate the center of gravity and determine the collision. Therefore, according to this embodiment, collision determination is not limited by the obstacle itself or its movement, enabling more accurate collision detection.

[0150] In the above embodiment, an obstacle was listed as an example of an object, and the collision judgment between vehicle 1 and the obstacle and the distance from vehicle 1 to the obstacle were explained. However, this embodiment can also be applied to objects other than obstacles.

[0151] In the above embodiment, vehicle 1 is cited as an example of a moving body, and the collision judgment between vehicle 1 and the obstacle and the distance from vehicle 1 to the obstacle are explained. However, this embodiment can also be applied to moving bodies other than vehicle 1.

[0152] The object detection program executed by the object detection devices 200 and 1200 according to the above embodiments can be pre-embedded in ROM or the like.

[0153] The object detection program executed by the object detection devices 200 and 1200 of the above embodiments can also be configured to be recorded in an installable or executable form on a computer-readable recording medium such as a CD-ROM, floppy disk (FD), CD-R, or DVD (Digital Versatile Disk).

[0154] Furthermore, the object detection program executed by the object detection devices 200 and 1200 of the above embodiments can be stored on a computer connected to a network such as the Internet, and thus provided via network download. Alternatively, the object detection program executed by the object detection devices 200 and 1200 of the above embodiments can be provided or distributed via a network such as the Internet.

[0155] The object detection program executed by the object detection devices 200 and 1200 according to the above embodiments is a modular structure including the above-mentioned functional units. As actual hardware, the CPU (processor) reads the control program from the above-mentioned ROM and executes it. As a result, the above-mentioned functional units are loaded onto the main storage device and generated on the main storage device.

[0156] While some embodiments of the invention have been described, these embodiments are given by way of example and are not intended to limit the scope of the invention. These new embodiments can be implemented in various other ways, with various omissions, substitutions, and modifications possible without departing from the spirit of the invention. These embodiments, and their variations, are included within the scope or spirit of the invention and within the scope of the claims and their equivalents.

[0157] Explanation of reference numerals in the attached figures

[0158] 1…Vehicle (moving body), 2…Vehicle body, 21, 21A~21L…Transceiver unit, 50…Vehicle control system, 100…ECU, 200, 1200…Object detection device, 211…Vibrator, 220…Control unit, 221…Input / output device, 222…Storage device, 223…Processor, 301…Arithmetic unit, 311…Direct wave distance calculation unit, 312…Indirect wave distance calculation unit, 313…Storage unit, 314, 1314…Triangulation calculation unit, 316…Collision judgment unit, 317…Distance calculation unit, 1315…Determination unit, O…Obstacle (object).

Claims

1. An object detection device, mounted on a moving body, for detecting objects present in the vicinity of the moving body, wherein, The object detection device includes: Multiple transceiver units, transmitting and receiving ultrasonic waves; and The arithmetic unit calculates the object distance, which is the distance from the moving body to the object, based on the transmission and reception times of the ultrasonic waves of each of the plurality of transceiver units. The arithmetic unit includes: The triangulation unit, each time it receives one or more reflected waves for a transmitted wave sent from any of the plurality of transceivers, uses the distance of the one or more reflected waves as sensing data. If the reflected wave has a specified reliability, it uses the sensing data of the reflected wave with the specified reliability as reference sensing data. It performs triangulation on each of the plurality of sensing data within a specified range of the reference sensing data to calculate a plurality of coordinates based on the sensing data to the object. as well as The collision determination unit calculates the direction of movement of the object based on the plurality of coordinates obtained each time the transmitted wave is sent, and determines whether the moving body collides with the object based on the direction of movement.

2. The object detection device according to claim 1, wherein, The collision determination unit calculates the centroids of the plurality of coordinates, and calculates the regression line representing the direction of movement based on the position of the plurality of centroids obtained each time the transmitted wave is sent. If the regression line intersects the position of the moving body, it is determined that the moving body has collided with the object.

3. The object detection device according to claim 1, wherein, It also includes a distance calculation unit. When it is determined that the moving body will not collide with the object, the distance calculation unit calculates the distance to the object using a first method. When it is determined that the moving body will collide with the object, the distance calculation unit calculates the distance to the object using a second method with higher precision than the first method.

4. The object detection device according to claim 1, wherein, It also has a storage unit. The arithmetic unit also includes: The storage unit, each time it receives one or more reflected waves for a transmitted wave sent from any of the plurality of transceivers, stores the distance based on the one or more reflected waves as sensing data in the storage unit. as well as The determination unit, if the reflected wave has a specified reliability, uses the sensing data of the reflected wave as reference sensing data, calculates a traceability amount based on the movement information of the moving body since the receiving time of the previous reflected wave, and determines the sensing data of the same object from the plurality of sensing data stored in the storage unit based on the reference sensing data and the traceability amount. The triangulation unit further performs the triangulation on the determined sensing data based on the previous reflected wave to calculate the previous complex coordinates.

5. An object detection method, performed by an object detection device mounted on a moving body and detecting objects present around the moving body, wherein, Includes the following steps: The transceiver steps involving multiple transceiver units transmitting and receiving ultrasonic waves; and The calculation step involves determining the object distance, which is the distance from the moving body to the object, based on the transmission and reception times of the ultrasonic waves at each of the plurality of transceivers. The calculation steps include: Each time one or more reflected waves are received for a transmitted wave transmitted from any of the plurality of transceivers, the distance of the one or more reflected waves is used as sensing data. If the reflected wave has a specified reliability, the sensing data of the reflected wave with the specified reliability is used as reference sensing data. Triangulation is performed on each of the plurality of sensing data within a specified range of the reference sensing data to calculate a plurality of coordinates based on the sensing data to the object. as well as The steps are as follows: based on the plurality of coordinates obtained from each transmission of the transmitted wave, the direction of movement of the object is calculated, and based on the direction of movement, it is determined whether the moving body collides with the object.

6. The object detection method according to claim 5, wherein, In the step of determining whether the moving body collides with the object, the centroids of the plurality of coordinates are calculated. Based on the positions of the plurality of centroids obtained each time the transmitted wave is sent, a regression line representing the direction of movement is obtained. If the regression line intersects the position of the moving body, it is determined that the moving body collides with the object.

7. The object detection method according to claim 5, wherein, It also includes the following steps: If it is determined that the moving body will not collide with the object, the distance to the object is calculated using a first method; if it is determined that the moving body collides with the object, the distance to the object is calculated using a second method with higher precision than the first method.

8. The object detection method according to claim 5, wherein, The object detection device also includes a storage unit. The calculation steps also include: Each time one or more reflected waves are received for a transmitted wave transmitted from any of the plurality of transceivers, the distance based on the one or more reflected waves is stored in the storage unit as sensing data. as well as If the reflected wave has the specified reliability, the sensing data of the reflected wave is used as the reference sensing data. Based on the movement information of the moving body since the receiving time of the previous reflected wave, a traceability value is calculated. From the plurality of sensing data stored in the storage unit, based on the reference sensing data and the traceability value, the sensing data of the same object is determined. In the step of performing triangulation, the triangulation is also performed on the determined sensing data for the previous reflected wave to calculate the previous plurality of coordinates.

9. A computer-readable storage medium storing a computer program that, when executed by a processor, implements the object detection function according to any one of claims 1 to 8.

10. A computer program product comprising a computer program that, when executed by a processor, implements the object detection function according to any one of claims 1 to 8.

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