Object detection device and object detection method

Abstract

The present application relates to an object detection device and an object detection method. The object detection device includes: an acquisition unit that acquires a distance to an object, i.e., an object distance, based on a result of transmission of a transmission wave by a transceiver mounted on a vehicle and reception of a reflection wave from the object by the transceiver, a plurality of times at different predetermined times, and acquires a movement distance of the vehicle that has moved during the plurality of object distances; and a determination unit that determines a height of the object based on the plurality of object distances and the movement distance acquired by the acquisition unit.

Description

Technical Field

[0001] This invention relates to an object detection device and an object detection method. Background Technology

[0002] Previously, techniques for determining the height of objects existing around a vehicle have been studied. One known technique involves placing multiple ultrasonic sensors at different heights and front / rear positions of the vehicle, and using these sensors to transmit and receive ultrasonic waves to determine the height of objects.

[0003] Patent Document 1: Japanese Patent Application Publication No. 2015-105915

[0004] Patent Document 2: Japanese Patent Application Publication No. 2014-215283

[0005] Patent Document 3: Japanese Patent Application Publication No. 2018-204964

[0006] However, the aforementioned existing technologies require the placement of multiple ultrasonic sensors at different heights and front and rear positions of the vehicle, thus limiting the design freedom of the vehicle. Summary of the Invention

[0007] Therefore, one of the objectives of this invention is to obtain an object detection device and an object detection method that can determine the height of an object without sacrificing the design freedom of a vehicle.

[0008] An object detection apparatus, as an example of the present invention, comprises: an acquisition unit that acquires multiple times at different predetermined times the distance from the transceiver unit to the object, i.e., the object distance, detected based on the transmission of a transmitted wave by a transceiver unit mounted on a vehicle and the reception of a reflected wave from an object by the transceiver unit; and acquires the distance the vehicle has moved during the period in which the object distance is acquired multiple times; and a determination unit that determines the height of the object based on the multiple object distances acquired by the acquisition unit and the moving distance.

[0009] With this structure, regardless of the position of the transceiver unit, the height of the object can be determined based on the distance to the object and the distance traveled. Therefore, the height of the object can be determined without sacrificing the design freedom of the vehicle.

[0010] In the object detection device described above, for example, if the absolute value of the difference between the object distance at the specified number of times and the object distance at the number of times after the specified number of times, and the absolute value of the difference between the movement distance from the specified number of times to the number of times after the specified number of times, are below a threshold, the determination unit determines that the height of the object is above the installation height of the transceiver unit.

[0011] Based on such a structure, it is possible to detect objects whose height is above the installation height of the transceiver unit.

[0012] In the object detection device described above, for example, if the absolute value of the difference between the length of the adjacent side of the first right triangle (where the length of the hypotenuse is set to the object distance of the specified number of times and the length of the opposite side is set to the installation height of the transceiver unit), and the absolute value of the difference between the length of the adjacent side of the second right triangle (where the length of the hypotenuse is set to the object distance of the specified number of times and the length of the opposite side is set to the installation height of the transceiver unit), and the absolute value of the difference between the distance traveled from the specified number of times to the subsequent number of times, is below a threshold, then the device determines that the height of the object is less than the installation height of the transceiver unit.

[0013] Based on such a structure, it is possible to detect, for example, objects whose height is less than the installation height of the transceiver unit.

[0014] In the object detection device described above, for example, if the absolute value of the difference between the length of the adjacent side of the first right triangle and the length of the adjacent side of the second right triangle and the absolute value of the difference between the moving distance are above a threshold, the determination unit does not determine the height of the object.

[0015] The object detection device described above may include, for example, multiple transceivers, which are positioned differently in the width direction of the vehicle.

[0016] Based on this structure, for example, the height of an object can be determined by each of the multiple transceivers arranged along the width of the vehicle. Therefore, the height of objects located within a relatively large area around the vehicle can be determined.

[0017] As an example of the present invention, the object detection method is an object detection method performed by an object detection device, which includes the following steps: acquiring, at different predetermined times, the distance from the transceiver unit to the object, i.e., the object distance, detected based on the transmission of a transmitted wave by a transceiver unit mounted on a vehicle and the reception of a reflected wave from an object by the transceiver unit; and acquiring the distance the vehicle has moved during the period of acquiring the multiple object distances; and determining the height of the object based on the multiple object distances acquired and the moving distance.

[0018] With this structure, regardless of the position of the transceiver unit, the height of the object can be determined based on the distance to the object and the distance traveled. Therefore, the height of the object can be determined without sacrificing the design freedom of the vehicle. Attached Figure Description

[0019] Figure 1 This is a top view illustrating an example of the structure of a vehicle according to an embodiment.

[0020] Figure 2 This is a block diagram illustrating an example of the structure of a vehicle control device according to an embodiment.

[0021] Figure 3 This is a block diagram illustrating an example of the functional structure of an object detection device according to an implementation method.

[0022] Figure 4 This is a diagram illustrating an example of echo information when detecting an object in an implementation method.

[0023] Figure 5 This diagram illustrates the method for determining the height of an object performed by the object detection device according to the embodiment, and is a diagram showing the case where the height of the object is above the installation height of the transceiver unit.

[0024] Figure 6 This diagram illustrates the method for determining the height of an object performed by the object detection device according to the embodiment, and is a diagram showing the case where the height of the object is less than the installation height of the transceiver unit.

[0025] Figure 7 This is a flowchart illustrating an example of the processing (object detection method) performed by the object detection device according to the embodiment. Detailed Implementation

[0026] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. The structure of the embodiments described below, as well as the functions and effects brought about by the structure, are merely examples, and the present invention is not limited to the following description.

[0027] Figure 1 This is a top view showing an example of the structure of vehicle 1 according to the embodiment. Vehicle 1 is an example of a vehicle equipped with the object detection device of this embodiment. The object detection device of this embodiment is a device that detects objects existing around vehicle 1 by transmitting ultrasonic waves from vehicle 1 and receiving reflected waves from objects, such as TOF (Time of Flight) and Doppler shift information.

[0028] The object detection device of this embodiment has multiple transceiver units 21A to 21H (hereinafter, unless it is necessary to distinguish between the multiple transceiver units 21A to 21H, they are simply referred to as transceiver unit 21). Each transceiver unit 21 is provided on the vehicle body 2, which is the exterior of the vehicle 1, and transmits ultrasonic waves (transmitting waves) toward the outside of the vehicle body 2, and receives reflected waves from objects located on the outside of the vehicle body 2. Figure 1In the example shown, multiple (four in this example) transceivers 21A to 21D are arranged at the front end of the vehicle body 2, and multiple (four in this example) transceivers 21E to 21H are arranged at the rear end. The multiple transceivers 21A to 21D are positioned differently in the width direction of the vehicle 1. In addition, the multiple transceivers 21E to 21H are positioned differently in the width direction of the vehicle. Furthermore, the number and arrangement of the transceivers 21 are not limited to the example described above.

[0029] Figure 2 This is a block diagram illustrating an example of the structure of a vehicle control device 10 according to an embodiment. The vehicle control device 10 includes an object detection device 11 and an ECU 12. The vehicle control device 10 performs processing for controlling the vehicle 1 based on information output from the object detection device 11.

[0030] The object detection device 11 includes multiple transceiver units 21 and a control unit 22. Each transceiver unit 21 includes an oscillator 31 constructed using piezoelectric elements, an amplifier, etc., and is a component that transmits and receives ultrasonic waves by means of the vibration of the oscillator 31. Specifically, each transceiver unit 21 transmits ultrasonic waves generated by the vibration of the oscillator 31 as a transmitting wave, and detects the vibration of the oscillator 31 caused by the reflected wave from the object О. The object О includes an object О that the vehicle 1 should avoid contact with, and the road surface G on which the vehicle 1 travels. The vibration of the oscillator 31 is converted into an electrical signal, and based on this electrical signal, echo information representing the time-varying intensity (amplitude) of the reflected wave from the object О can be obtained. Based on this echo information, Time-of-Flight (TOF) and other parameters corresponding to the distance from the transceiver unit 21 (vehicle body 2) to the object О can be obtained.

[0031] The echo information can be generated based on data acquired by one transceiver unit 21, or it can be generated based on multiple data acquired by multiple transceiver units 21. For example, the echo information about an object О located in front of the vehicle body 2 can also be generated based on data acquired by four transceiver units 21A to 21D (see reference 21A to 21D) located in front of the vehicle body 2. Figure 1 It is generated from two or more data points (e.g., average values) obtained from two or more sources. Similarly, echo information about an object О located behind the vehicle body 2 can also be generated based on four transceiver units 21E to 21H (see reference 21E to 21H) located behind the vehicle body 2. Figure 1 It is generated by obtaining two or more data from two or more sources.

[0032] In addition, Figure 2 The example shown illustrates a structure that utilizes a single oscillator 31 for both transmitting and receiving waves, but the structure of the transceiver unit 21 is not limited to this. For example, it is also possible to separate the transmitting and receiving sides, as in a structure where the oscillator for transmitting the wave and the oscillator for receiving the reflected wave are set up independently.

[0033] 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 used to transmit and receive information between the control unit 22 and external devices (such as the transceiver unit 21 and ECU 12). The storage device 42 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 43 is an integrated circuit that performs various processes to implement the functions of the control unit 22, including, for example, a CPU (Central Processing Unit) that operates according to a program, and an ASIC (Application Specific Integrated Circuit) designed for a specific purpose. The processor 43 performs various arithmetic and control processes by reading and executing programs stored in the storage device 42.

[0034] ECU 12 is a unit that executes various processes for controlling vehicle 1 based on information obtained from object detection device 11, etc. 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 for transmitting and receiving information between ECU 12 and external mechanisms (object detection device 11, vehicle speed sensor 54, drive mechanism, braking mechanism, steering mechanism, transmission mechanism, in-vehicle display, speakers, etc.). The storage device 52 includes main storage devices such as ROM and RAM, and auxiliary storage devices such as HDD and SSD. The processor 53 is an integrated circuit that executes various processes to implement the functions of ECU 12, including, for example, a CPU or ASIC. The processor 53 reads the program stored in the storage device 52 and performs various arithmetic and control processes.

[0035] The vehicle speed sensor 54, for example, has a Hall element located near the wheel of the vehicle 1, and is a sensor that detects the amount of wheel rotation or the rotational speed per unit time. The vehicle speed sensor 54 outputs the number of wheel speed pulses, representing the detected amount of rotation or rotational speed, as a sensor value used to calculate the vehicle speed. The ECU 12 can calculate the vehicle speed, the amount of movement, etc., of the vehicle 1 based on the sensor value obtained from the vehicle speed sensor 54.

[0036] Figure 3This is a block diagram illustrating an example of the functional structure of the object detection device 11 according to an embodiment. The object detection device 11 of this embodiment includes an acquisition unit 101 and a determination unit 102. The aforementioned functional structural members 101 and 102 are constructed via... Figure 2 The object detection device 11, as exemplified, is achieved through the cooperation of its hardware structural components and software structural components such as firmware and programs.

[0037] The acquisition unit 101 acquires various types of information. For example, the acquisition unit 101 processes the data acquired by the transceiver unit 21 and generates various types of information. For instance, the acquisition unit 101 performs amplification, filtering, and envelope processing on the electrical signal corresponding to the vibration of the oscillator 31, generating echo information representing the time-varying intensity (amplitude) of the reflected wave transmitted by the transceiver unit 21 and reflected by the object O. Based on this echo information, the Time-of-Flight (TOF) corresponding to the object O present around the vehicle 1 is detected, and the distance from the transceiver unit 21 (vehicle body 2) to the object O (hereinafter also referred to as the object distance) is calculated. The acquisition unit 101 acquires the object distance in units of transmitting the transmitted wave and receiving the reflected wave, i.e., transceiver operation. That is, the acquisition unit 101 acquires the object distance multiple times at different predetermined times.

[0038] Figure 4 This is a diagram illustrating an example of echo information detected when object O is detected in an implementation method. Figure 4 The image shows the envelope L11 of the echo information, which represents the time-varying intensity of the ultrasonic waves transmitted and received by the transceiver unit 21. Figure 4 In the chart shown, the horizontal axis corresponds to time (TOF), and the vertical axis corresponds to the intensity of the ultrasonic waves transmitted and received by the transceiver unit 21.

[0039] Envelope L11 shows the time-varying intensity of the vibration of oscillator 31, representing the magnitude of the vibration. From this envelope L11, we can deduce that oscillator 31 is driven to vibrate for time Ta from time t0, thus the transmission of the wave ends at time t1, and then, during the time Tb before reaching time t2, the vibration of oscillator 31 caused by inertia continues while decaying. Therefore, in Figure 4 In the chart shown, time Tb corresponds to the so-called reverberation time.

[0040] The envelope L11 reaches a peak value at time t4 after time Tp from the start of the transmitted wave transmission at time t0, where the magnitude of the vibration of oscillator 31 is a peak value exceeding the detection threshold Th1. This detection threshold Th1 is a value set to distinguish whether the vibration of oscillator 31 is caused by the reception of reflected waves from the object O (other vehicles, structures, pedestrians, etc.) being detected, or by the reception of reflected waves from objects other than the object O (e.g., road surface G). Vibrations with a peak value exceeding the detection threshold Th1 can be considered as being caused by the reception of reflected waves from the object O being detected.

[0041] In the envelope L11 of this example, the vibration decay of oscillator 31 after time t4 is shown. Therefore, time t4 corresponds to the time when the reception of the reflected wave from object O ends, in other words, the time when the transmitted wave last sent at time t1 returns as a reflected wave.

[0042] Furthermore, in envelope L11, the time t3, which is the starting point of the peak at time t4, corresponds to the time at which the reception of the reflected wave from object O begins; in other words, it corresponds to the time when the transmitted wave initially sent at time t0 returns as a reflected wave. Therefore, the time ΔT between time t3 and time t4 is equal to the time Ta, which is the transmission time of the transmitted wave.

[0043] Based on the above, in order to use Time-of-Flight (TOF) to determine the distance from the ultrasonic transceiver to object O, it is necessary to calculate the time Tf between the moment t0 when the transmitted wave begins to be transmitted and the moment t3 when the reflected wave begins to be received. This time Tf can be calculated by subtracting the time ΔT, which is equal to the transmission time Ta of the transmitted wave, from the time Tp, which is the difference between time t0 and the moment t4 when the intensity of the reflected wave exceeds the detection threshold Th1 and reaches its peak.

[0044] The moment t0 when the transmitted wave begins to be transmitted can be easily determined as the moment when the object detection device 11 starts operating, and the transmission time Ta of the transmitted wave is predetermined by setting, etc. Therefore, by determining the moment t4 when the intensity of the reflected wave reaches a peak value that is above the detection threshold Th1, the distance from the transceiver source to the object O (object distance) can be calculated. The acquisition unit 101 calculates the object distance, for example, by the method described above.

[0045] Additionally, the acquisition unit 101 receives the moving speed of the vehicle 1 from the ECU 12. Furthermore, the acquisition unit 101 can also receive the sensor value of the vehicle speed sensor 54 and calculate the moving speed of the vehicle 1 based on the sensor value.

[0046] The determination unit 102 determines the height of object О (hereinafter also referred to as object height H2) based on the distances of multiple objects acquired by the acquisition unit 101 and the moving speed of vehicle 1. For example, the determination unit 102 determines the height of object О based on the distances of multiple objects acquired by the acquisition unit 101 and the moving distance of vehicle 1 based on the moving speed of vehicle 1. The determination unit 102 can, for example, determine whether the height of object О is above the installation height of transceiver unit 21 (hereinafter also referred to as transceiver height H1). Here, the height of object О and the installation height of transceiver unit 21 are, for example, the height above the road surface G. That is, the road surface G is the reference for the height of object О and the height of transceiver unit 21. The transceiver height H1 is the height from the road surface G to a predetermined position of transceiver unit 21 (e.g., the center of oscillator 31, etc.), which is a known value.

[0047] Figure 5 This diagram illustrates the method for determining the height of object O performed by the object detection device 11 according to the embodiment, specifically a case where the height of object O is above the mounting height of the transceiver unit 21. The determination unit 102 can use the following method to determine that the height of object O is above the mounting height of the transceiver unit 21. Here, Figure 5 This example illustrates the scenario where vehicle 1 moves from position P1 to position P2 via transceiver 21, and the transceiver 21 performs transceiver operations at both positions P1 and P2. Specifically, position P1 is the position where the transceiver 21 performs a predetermined number of transceiver operations, and position P2 is the position where the transceiver 21 performs one more transceiver operation (for example, the next one). The distance Y that vehicle 1 travels is the distance between positions P2 and P1, calculated by multiplying the vehicle 1's travel speed by the time from the predetermined number of operations to the subsequent number of operations. Here, the distance between the transceiver 21 at position P1 (the predetermined number of operations) and object O is defined as distance F1, and the distance between the transceiver 21 at position P2 (the subsequent number of operations) and object O is defined as distance F2. If the absolute value of the difference between distance F1 and distance F2, and the absolute value of the difference between the distance Y and the distance F1 traveled, are below a threshold K, the determination unit 102 determines that the object height H2 is above the transceiver height H1. That is, when the following formula (1) is true, the determination unit 102 determines that the height H2 of the object is greater than or equal to the height H1 of the receiving unit.

[0048] ||(F1-F2)|-Y|≤K···(1)

[0049] Here, the threshold K is "0" as an example. That is, if the absolute value of the difference between distance F1 and distance F2 is the same as the moving distance Y of vehicle 1, the determination unit 102 determines that the object height H2 is greater than or equal to the transceiver height H1. However, the threshold K can also be a value greater than "0". For example, the threshold K can also be the maximum value of the difference between the deviation of distance F1 and the deviation of distance F2 corresponding to the TOF deviation, for example, it can be 2 to 3 [cm]. In other words, the determination unit 102 can also determine that the object height H2 is greater than or equal to the transceiver height H1 if the absolute value of the difference between distance F1 and distance F2 and the absolute value of the difference between the moving distance Y of vehicle 1 is within a predetermined range. Furthermore, the threshold is not limited to the above cases and can be set considering factors such as the deviation of the installation position of the transceiver 21. Additionally, the time from the specified number of times to the next time is also called the detection cycle. Furthermore, the specified number of times is also called an arbitrary number of times, a reference number of times, a certain number of times, etc.

[0050] Figure 6 This diagram illustrates the method for determining the height of object O performed by the object detection device 11 according to the embodiment, specifically showing a case where the height of object O is less than the mounting height of the transceiver unit 21. The determination unit 102 can use the following method to determine the case where the height of object O is less than the mounting height of the transceiver unit 21. Here, Figure 6 and Figure 5 The same applies to the case where vehicle 1 moves from position P1 to position P2 via transceiver 21, and transceiver 21 is used for both positions P1 and P2.

[0051] The determination unit 102 constructs right triangles R1 and R2 at positions P1 and P2, and determines the height of object О based on these right triangles R1 and R2. Right triangles R1 and R2 each have hypotenuses R1a and R2a, opposite sides R1b and R2b, and adjacent sides R1c and R2c. Right triangle R1 is an example of a first right triangle, and right triangle R2 is an example of a second right triangle.

[0052] Hypotenuses R1a and R2a are the sides of the receiving and sending parts 21 at each position P1 and P2 and the object О. The lengths of hypotenuses R1a and R2a are the distances F1 and F2 at each position P1 and P2.

[0053] The opposite sides R1b and R2b are the sides that extend across the road surface G and the receiving / transmitting unit 21, and the length of the opposite sides R1b and R2b is the height H1 of the receiving / transmitting unit.

[0054] Adjacent edges R1c and R2c are edges along the direction of movement of vehicle 1, along the road surface G. The lengths D1 and D2 of adjacent edges R1c and R2c are represented by the following equations (2) and (3).

[0055]

[0056]

[0057] If the absolute value of the difference between the length D1 of adjacent side R1c and the length D2 of adjacent side R2c, and the absolute value of the difference between the distance traveled by vehicle 1 from a predetermined number of times calculated based on the moving speed of vehicle 1 to subsequent numbers of times, are below a threshold, then the determination unit 102 determines that the object height H2 is less than the receiver / dispatch height H1. That is, the determination unit 102 determines that the object height H2 is less than the receiver / dispatch height H1 if the following equation (4) is true.

[0058] ||(D1-D2)|-Y|≤K···(4)

[0059] Furthermore, an object О whose height H2 is less than the height H1 of the transceiver unit is also called a low object or a low step. Additionally, object 0 is also called an obstacle. Furthermore, if the object О of the detection target (determination target, stationary object) is a wall, there may be a situation where the reflected wave becomes multipath and is also reflected from the boundary between object О and the road surface G to the transceiver unit 21. In this case, the reflected wave can be assumed to originate from the wall, and the above processing can be performed.

[0060] Figure 7 This is a flowchart illustrating an example of the processing (object detection method) performed by the object detection device 11 in the embodiment. Figure 7 The processing is performed on each of the multiple transceiver units 21.

[0061] The acquisition unit 101 acquires the object distance and the travel distance of the vehicle 1 (S101). The object distance is the distance of the object obtained by the transceiver unit 21 through N (for example, twice) ultrasonic wave transmissions. Here, in the case where the above-mentioned N times are twice, the number of times is defined as the number of times in the first transmission, and the number of times after that is the number of times in the second transmission.

[0062] Next, the determination unit 102 determines whether ||(F1-F2)|-Y|≤K (S102). If the determination unit 102 determines that ||(F1-F2)|-Y|≤K (S102: Yes), it determines that the height of the object is above the height of the transmitter / receiver unit (S103). If the determination unit 102 determines that ||(F1-F2)|-Y|≤K is not (S102: No), it proceeds to S104.

[0063] In S104, the determination unit 102 determines whether ||(D1-D2)|-Y|≤K. If the determination unit 102 determines that ||(D1-D2)|-Y|≤K (S104: Yes), it determines that the object height is less than the height of the receiving / transmitting unit (S105). If the determination unit 102 determines that ||(D1-D2)|-Y|≤K is not true (S104: No), it does not determine the object height (S106) and returns to S101.

[0064] As described above, the object detection apparatus 11 of this embodiment includes an acquisition unit 101 and a determination unit 102. The acquisition unit 101 acquires multiple times at different predetermined times the distance from the transceiver unit 21 to the object 0, i.e., the object distance, detected based on the transmission of a transmitted wave by the transceiver unit 21 mounted on the vehicle 1 and the reception of a reflected wave from the object 0 by the transceiver unit 21, and acquires the distance the vehicle 1 has moved during the period when the object distance is acquired multiple times. The determination unit 102 determines the height of the object 0 based on the multiple object distances acquired by the acquisition unit 101 and the moving distance.

[0065] Based on this structure, regardless of the position of the transceiver unit 21, the height of object О can be determined based on the distance to the object and the distance traveled. Therefore, the height of object О can be determined without sacrificing the design freedom of vehicle 1.

[0066] Furthermore, if the absolute value of the difference between the object distance of a predetermined number of times and the object distance of a number of times after the predetermined number of times, and the absolute value of the difference between the distance traveled by vehicle 1 from the predetermined number of times calculated based on the moving speed to the subsequent number of times, is below a threshold, the determination unit 102 determines that the height of object О is above the installation height of the transceiver unit 21.

[0067] Based on this structure, for example, it is possible to detect an object О whose height is above the installation height of the transceiver unit 21.

[0068] Furthermore, if the absolute value of the difference between the length of the adjacent side R1c of the right triangle R1 (first triangle) with the length of the hypotenuse R1a set to a predetermined number of times and the length of the opposite side R1b set to the installation height of the transceiver 21, and the absolute value of the difference between the length of the adjacent side R1c of the right triangle R2 (second triangle) with the length of the hypotenuse R2a set to a predetermined number of times and the length of the opposite side R1b set to the installation height of the transceiver 21, and the absolute value of the difference between the distance traveled by the vehicle 1 from the predetermined number of times calculated based on the moving speed to the subsequent number of times, the determination unit 102 determines that the height of the object О is less than the installation height of the transceiver 21.

[0069] Based on this structure, for example, it is possible to detect an object О whose height is less than the installation height of the transceiver unit 21.

[0070] Furthermore, if the absolute value of the difference between the length of the adjacent side R1c of right triangle R1 (first triangle) and the length of the adjacent side R1c of right triangle R2 (second triangle) and the absolute value of the difference between the distance traveled by the vehicle and the threshold value, the determination unit 102 does not determine the height of object О.

[0071] In addition, the object detection device 11 has a plurality of transceivers 21 arranged along the width direction of the vehicle 1.

[0072] Based on this structure, for example, the height of object O can be determined for each of the plurality of transceivers 21 arranged along the width direction of vehicle 1. Therefore, the height of object O within a relatively large area around vehicle 1 can be determined. In addition, since the height determination process of object O can be performed for each of the plurality of transceivers 21, for example, even if there are multiple steps as object O at close range, the height determination process of each step can be performed, thus easily suppressing the situation where multiple steps are mistakenly identified as a wall.

[0073] The program that enables a computer (e.g., processor 43 of control unit 22, processor 53 of ECU 12, etc.) to perform processing to implement the various functions of the above-described embodiments is a program that can be provided in an installable or executable form on a computer-readable recording medium such as a CD (Compact Disc)-ROM, floppy disk (FD), CD-R (Recordable), or DVD (Digital Versatile Disk). Alternatively, the program can also be provided or distributed via a network such as the Internet.

[0074] Furthermore, while the above example illustrates how, in S101, the acquisition unit 101 acquires the object distance and the vehicle 1's travel distance for each of the two ultrasonic wave transmissions performed by the transceiver unit 21, the example is not limited to this. For instance, in S101, the acquisition unit 101 may acquire the object distance and the vehicle 1's travel distance for each of the three or more ultrasonic wave transmissions performed by the transceiver unit 21. In this case, for example, distance F1, distance F2, and the vehicle 1's travel distance are acquired for each of the two consecutive ultrasonic wave transmissions performed by the transceiver unit 21. That is, the acquisition unit 101 acquires multiple distances F1, multiple distances F2, and multiple travel distances of the vehicle 1. Moreover, the determination unit 102 may use the average value of the multiple distances F1, the average value of the multiple distances F2, and the average value of the multiple travel distances to perform processing after S102.

[0075] Here, if the multiple transceivers 21 are not staggered along the vertical direction of the vehicle 1, there is a possibility that a reflected wave from the boundary between the object О and the road surface G might be mistaken for an object О located at a position higher than the height of the transceivers 21 (e.g., a barrier bar located above the road surface G and extending horizontally at the entrance / exit of a parking lot). In this case, by staggering the multiple transceivers 21 along the vertical direction of the vehicle 1 and performing the above-described processing on the transmission and reception of each transceiver 21, it is possible to determine whether the object О is located at a position higher than the height of the transceivers 21 based on the height position of the transceivers 21 and the transmission and reception results of the transceivers 21, thereby suppressing the possibility of misidentifying the object О as a step when it is a barrier bar or the like.

[0076] While the embodiments of the present invention have been described above, these embodiments and their modifications are merely examples and are not intended to limit the scope of the invention. The new embodiments and modifications described above can be implemented in various forms, and various omissions, substitutions, and changes can be made without departing from the spirit of the invention. The above embodiments and modifications are included within the scope and spirit of the invention, and are also included within the scope of the invention described in the technical solution and its equivalents.

[0077] Explanation of reference numerals in the attached figures

[0078] 1…vehicle, 11…object detection device, 21, 21A~21H…receiving and receiving unit, 101…acquisition unit, 102…judgment unit, O…object, R1…right triangle (first right triangle), R2…right triangle (second right triangle), R1a, R2a…hypotenuse, R1b, R2b…opposite side, R1c, R2c…adjacent side.

Claims

1. An object detection device, comprising: The acquisition unit acquires, at different predetermined times, the distance from the transceiver unit to the object, i.e., the object distance, detected based on the transmission of a transmitted wave by the transceiver unit mounted on the vehicle and the reception of a reflected wave from the object by the transceiver unit; and acquires the distance the vehicle has moved during the period in which the object distance is acquired; and The determination unit determines the height of the object based on the distances to the multiple objects obtained by the acquisition unit and the distance traveled. If the absolute value of the difference between the object distance at the specified number of times and the object distance at the specified number of times, and the absolute value of the difference between the distance traveled from the specified number of times to the subsequent number of times, are both below a threshold, then the determination unit determines that the height of the object is above the installation height of the transceiver unit. If the absolute value of the difference between the length of the adjacent side of the first right triangle (where the length of the hypotenuse is set to the distance to the object for a predetermined number of times and the length of the opposite side is set to the installation height of the transceiver unit), and the absolute value of the difference between the length of the adjacent side of the second right triangle (where the length of the hypotenuse is set to the distance to the object for a predetermined number of times and the length of the opposite side is set to the installation height of the transceiver unit), and the absolute value of the difference between the distance traveled from the predetermined number of times to the subsequent number of times, is below a threshold, then the determination unit determines that the height of the object is less than the installation height of the transceiver unit.

2. The object detection device according to claim 1, wherein, If the absolute value of the difference between the length of the adjacent side of the first right triangle and the length of the adjacent side of the second right triangle and the absolute value of the difference between the moving distance are above a threshold, the determination unit will not determine the height of the object.

3. The object detection device according to claim 1 or 2, wherein, The vehicle is equipped with multiple transceivers located at different positions in the width direction of the vehicle.

4. An object detection method, executed by an object detection device, comprising the following steps: The steps include: acquiring, at different predetermined times, the distance from the transceiver unit to the object (i.e., the object distance), detected based on the transmission of transmitted waves by the transceiver unit mounted on the vehicle and the reception of reflected waves from the object by the transceiver unit; and acquiring, at different predetermined times, the distance the vehicle has moved during the period in which the object distance is acquired; and... The step of determining the height of the object based on the obtained distances to the aforementioned objects and the aforementioned distances traveled. If the absolute value of the difference between the object distance at the specified number of times mentioned above and the object distance at the specified number of times mentioned above, and the absolute value of the difference between the distance traveled from the specified number of times to the specified number of times mentioned above, are both below a threshold, then the step of determining that the height of the object is above the installation height of the transceiver unit is taken. The step of determining that the height of the object is less than the installation height of the transceiver is when the absolute value of the difference between the length of the adjacent side of the first right triangle (where the length of the hypotenuse is set to the distance to the object for a predetermined number of times and the length of the opposite side is set to the installation height of the transceiver), the distance to the object for a predetermined number of times and the distance to the object for a predetermined number of times, and the distance to the object for a predetermined number of times, and the absolute value of the difference between the distance traveled from the predetermined number of times to the subsequent number of times, is less than a threshold value.

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