Object detection device

Abstract

This object detection device comprises: an acquisition unit that acquires, by communicating with a transmitter / receiver mounted on a vehicle, distance information indicating a distance from the transmitter / receiver to an object on the basis of a time until a sound wave transmitted from the transmitter / receiver returns after being reflected by the object; a communication interruption setting unit that sets an interruption timing at which communication processing between the transmitter / receiver and the acquisition unit is temporarily interrupted on the basis of at least one of a relationship between a detection set distance in a detection scene of the object and communication noise generated by communication, or a relationship between road surface noise determined by a mounting height of the transmitter / receiver from the road surface and communication noise; and a communication restart setting unit capable of restarting the communication processing after a lapse of a predetermined interruption period after the interruption of the communication processing or after a lapse of an interruption period determined on the basis of the distance information to the object acquired in the past.

Description

Object detection device

[0001] The present disclosure relates to an object detection device.

[0002] Conventionally, object detection devices have been known that detect information about an object, such as the distance to the object, by transmitting sound waves such as ultrasonic waves as transmission waves and receiving reception waves as transmission waves that are reflected by the object and returned. It has been proposed that such object detection devices shorten the object detection cycle by performing communication to acquire measurement data from a transmitter / receiver (sensor) during ultrasonic measurement.

[0003] JP 2015-90268 A

[0004] However, when detecting an object (detecting the distance to an object) using sound waves such as ultrasound, the farther away the object is, the weaker the intensity level of the reflected waves (received waves) from the object becomes. This means that the reflected waves are buried in constantly present communication noise, making it difficult to identify the reflected waves and potentially reducing the accuracy of object detection.

[0005] Therefore, one of the problems that the embodiments of the present invention aim to solve is to provide an object detection device that can reduce the influence of communication noise and improve object detection accuracy.

[0006] An object detection device as an example of the present disclosure includes: an acquisition unit that acquires distance information indicating the distance from a transducer mounted on a vehicle to an object by communicating with the transducer based on the time it takes for sound waves transmitted from the transducer to be reflected by the object and return; a communication interruption setting unit that sets an interruption timing to temporarily interrupt communication processing between the transducer and the acquisition unit based on at least one of the relationship between a detection setting distance in a detection scene of the object and communication noise caused by the communication, or the relationship between road surface noise determined by the mounting height of the transducer from the road surface and the communication noise; and a communication resumption setting unit that enables the communication processing to be resumed after a predetermined interruption period has elapsed since the communication processing was interrupted or after an interruption period determined based on the distance information to the object acquired in the past has elapsed.

[0007] According to the above configuration, for example, by temporarily suspending communication processing after the start of communication processing, communication noise can be suppressed in areas where the strength of reflected waves is weak, such as distant areas. Then, after communication is resumed, distance information can be obtained for a period not affected by communication noise, making it possible to detect objects with an improved S / N ratio.

[0008] FIG. 1 is an exemplary and schematic diagram of a vehicle that can be equipped with an object detection device according to an embodiment, as seen from above. FIG. 2 is an exemplary and schematic block diagram showing a general hardware configuration of a vehicle control device including an object detection device according to an embodiment. FIG. 3 is an exemplary and schematic block diagram showing a functional configuration of an object detection device according to an embodiment. FIG. 4 is an exemplary and schematic diagram showing installation positions of transducers used in the object detection device according to an embodiment. FIG. 5 is an exemplary and schematic diagram showing timings for interrupting and resuming communication processing in the object detection device according to an embodiment. FIG. 6 is an exemplary and schematic diagram showing the relationship between noise (road surface noise, communication noise) and the reflection level of a reflected wave in the object detection device according to an embodiment. FIG. 7 is an exemplary flowchart showing the flow of communication interruption processing in the object detection device according to an embodiment. FIG. 8 is an exemplary and schematic diagram showing another manner of determining the communication resumption timing in the object detection device according to an embodiment.

[0009] Hereinafter, embodiments and modifications of the present disclosure will be described with reference to the drawings. The configurations of the embodiments and modifications described below, as well as the actions and effects brought about by the configurations, are merely examples and are not limited to the following description.

[0010] FIG. 1 is an exemplary schematic diagram showing a vehicle 1 on which an object detection device according to an embodiment can be mounted, as viewed from above.

[0011] The object detection device of this embodiment is a device that detects objects present in the vicinity of vehicle 1 based on, for example, TOF (Time Of Flight), Doppler shift information, etc., obtained by transmitting ultrasonic waves from the transducer 21 of vehicle 1 and receiving reflected waves from the object.

[0012] The object detection device according to this embodiment has a plurality of transducers 21A to 21H (hereinafter, referred to simply as transducers 21 when it is not necessary to distinguish between the plurality of transducers 21A to 21H). Each transducer 21 is installed on a vehicle body 2, which serves as the exterior of the vehicle 1, and transmits ultrasonic waves (transmitted waves) toward the outside of the vehicle body 2 and receives reflected waves from objects present around the vehicle body 2. In the example shown in FIG. 1 , a plurality of transducers 21A to 21D (four, for example) are arranged at the front end of the vehicle body 2, and a plurality of transducers 21E to 21H (four, for example) are arranged at the rear end. The plurality of transducers 21A to 21D are positioned at different widthwise positions in the vehicle 1. The plurality of transducers 21E to 21H are also positioned at different widthwise positions in the vehicle 1. The number and installation positions of the transducers 21 are not limited to the above example.

[0013] 2 is an exemplary schematic block diagram showing a general hardware configuration of a vehicle control device 10 including an object detection device 11 according to an embodiment. The vehicle control device 10 includes the object detection device 11 and an ECU (Electronic Control Unit) 12. The vehicle control device 10 performs processing for controlling the vehicle 1 based on information output from the object detection device 11.

[0014] The object detection device 11 includes multiple transducers 21 (only one representative transducer is shown in FIG. 2 ) and a control unit 22. Each transducer 21 includes a transducer 31 configured using a piezoelectric element or the like, an amplifier, and the like, and transmits and receives ultrasonic waves by the vibration of the transducer 31. Specifically, each transducer 21 transmits ultrasonic waves generated in response to the vibration of the transducer 31 as a transmission wave and detects the vibration of the transducer 31 caused by the reflected wave reflected by an object O. The object O includes an object O that the vehicle 1 should avoid contacting and a road surface G on which the vehicle 1 is traveling. The vibration of the transducer 31 is converted into an electrical signal, and echo information indicating a change in the intensity (amplitude) of the reflected wave from the object O over time can be obtained based on the electrical signal. Based on the echo information, a time of flight (TOF) corresponding to the distance from the transducer 21 (vehicle body 2) to the object O can be obtained.

[0015] The echo information may be generated based on data acquired by one transducer 21, or may be generated based on multiple pieces of data acquired by each of multiple transducers 21. For example, echo information about an object O present in front of the vehicle body 2 may be generated based on two or more pieces of data (e.g., average values) acquired by two or more of the four transducers 21A to 21D (see FIG. 1) arranged in front of the vehicle body 2. Similarly, echo information about an object O present behind the vehicle body 2 may be generated based on two or more pieces of data acquired by two or more of the four transducers 21E to 21H (see FIG. 1) arranged in the rear of the vehicle body 2.

[0016] 2 illustrates a configuration in which both transmission of the transmission wave and reception of the reflected wave are performed using a single transducer 31, but the configuration of the transducer 21 is not limited to this. For example, the transmitter and receiver may be configured separately, such as by providing a transducer for transmitting the transmission wave and a transducer for receiving the reflected wave.

[0017] 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 for transmitting and receiving information between the control unit 22 and external devices (such as the transducer 21 and the ECU 12). The storage device 42 includes a main storage device such as a read-only memory (ROM) or a random access memory (RAM), and an auxiliary storage device such as a hard disk drive (HDD) or a solid state drive (SSD). The processor 43 is an integrated circuit that executes various processes to realize the functions of the control unit 22, and includes, for example, a central processing unit (CPU) that operates according to a program and an application-specific integrated circuit (ASIC) designed for a specific application. The processor 43 executes various arithmetic and control processes by reading and executing programs stored in the storage device 42. Details of the functions realized by the processor 43 will be described later.

[0018] The ECU 12 is a unit that executes various processes for controlling the vehicle 1 based on various information acquired from the object detection device 11, etc. The ECU 12 includes an input / output device 51, a storage device 52, and a processor 53. The input / output device 51 is an interface device for realizing the transmission and reception of information between the ECU 12 and external mechanisms (such as the object detection device 11, drive mechanism, braking mechanism, steering mechanism, transmission mechanism, in-vehicle display, speaker, etc.). The storage device 52 includes a main storage device such as a ROM or RAM, and an auxiliary storage device such as an HDD or SSD. The processor 53 is an integrated circuit that executes various processes for realizing the functions of the ECU 12, and includes, for example, a CPU, an ASIC, etc. The processor 53 reads programs stored in the storage device 52 and executes various arithmetic and control processes.

[0019] 3 is a block diagram showing an example of the functional configuration of the object detection device 11 according to the embodiment. The object detection device 11 according to the present embodiment includes an acquisition unit 101, a communication interruption setting unit 102, and a communication resumption setting unit 103. As described above, the acquisition unit 101, the communication interruption setting unit 102, and the communication resumption setting unit 103 may be realized by the processor 43 reading and executing a program stored in the storage device 42, or may be configured by dedicated hardware.

[0020] As described above, the acquisition unit 101 acquires distance information (measurement data) indicating the distance from the transducer 21 (vehicle 1) to the object O based on the time it takes for sound waves transmitted from the transducer 21 mounted on the vehicle 1 to be reflected by the object O and return, by communicating with the transducer 21. The transducer 21 constantly transmits and receives ultrasonic waves to acquire distance information in situations where detection of the object O is necessary, such as when the vehicle 1 is traveling or when it is stopped and can travel. The transducer 21 temporarily stores the received reflected waves (distance information, echo information) in a storage unit (not shown) one by one, and also transmits them sequentially to the control unit 22.

[0021] The communication interruption setting unit 102 sets an interruption timing for temporarily interrupting the communication process between the transducer and the acquisition unit based on at least one of the relationship between a detection setting distance M (e.g., 3 m ahead of the vehicle 1) in a detection scene of an object O (e.g., a collision prevention scene during parking assistance) and communication noise due to communication, or the relationship between road surface noise determined by the mounting height h of the transducer 21 from the road surface G and communication noise. The interruption timing can be set in advance by testing, etc.

[0022] Then, the communication resumption setting unit 103 enables the communication process to be resumed after a predetermined interruption period has elapsed since the communication process was interrupted by the communication interruption setting unit 102. The communication resumption timing can be set in advance by testing or the like.

[0023] In the transducer 21, the intensity (reception level) of the reflected wave from the object O increases as the distance from the transducer 21 to the object O decreases. In other words, the intensity of the reflected wave decreases as the distance from the object O increases. The transducer 21 generates a certain amount of noise due to thermal noise (noise caused by irregular thermal oscillations (Brownian motion) of free electrons in resistors) generated when the resistive elements constituting the transducer 21 operate. In addition, when transmitting distance information from the transducer 21 to the control unit 22, the transducer 21 generates a certain amount of communication noise. As a result, for example, when the object O is far away, the attenuated reflected wave obtained may be buried in the communication noise, making it difficult to distinguish the distance information. Therefore, the communication interruption setting unit 102 temporarily interrupts communication processing when the transducer 21 receives a reflected wave from the object O at a predetermined distance away. This eliminates the generation of communication noise, preventing the reflected wave received by the transducer 21 from being buried in the communication noise and becoming difficult to distinguish.

[0024] As described above, the timing of interrupting the communication process can be set in advance based on the relationship between the detection setting distance M and the communication noise. The detection of object O varies depending on the control content of the vehicle 1. As an example of the use of distance information to object O, for example, in a collision prevention scene during parking assistance, the detection setting distance M can be set to, for example, 3 m ahead of the vehicle 1. In this case, for example, a range (e.g., 2 m) where the strength of the reflected wave is stronger than the strength of the communication noise is defined as a short distance. During this range, the reflected wave can be sufficiently identified even if the reception process of the reflected wave and the communication process of transmitting the measurement data of the reflected wave (distance information) to the control unit 22 are simultaneously performed. On the other hand, for example, a range (e.g., 2 m or more) where the strength of the reflected wave is weaker than the strength of the communication noise is defined as a long distance. During this range, the communication process is interrupted, and only the reception process of the reflected wave is performed. The measurement data of the reflected wave (distance information) with the communication noise removed is temporarily stored in the storage unit. The temporarily stored measurement data of the reflected wave is acquired by the communication resumption setting unit 103 as measurement data of the reflected wave in a state where communication noise has been removed, for example, when the communication process is resumed after a predetermined interruption period has elapsed since the interruption of the communication process. As a result, measurement data of the reflected wave that does not contain communication noise (is not buried) can be supplied to the control unit 22. In other words, the communication process is interrupted at the end of a range of the detection setting distance M that can be considered a short distance, and is resumed when the farthest position (area) of the detection setting distance M where detection of the object O is required is reached.

[0025] FIG. 5 is an exemplary schematic diagram showing the timings for suspending and resuming communication processing in the object detection device 11. As shown in FIG. 5, measurement by transmitting and receiving waves using the ultrasonic transmitter / receiver 21 begins in section T1, and measurement data (reflected wave information) is acquired in section T2. ​​This section T2 corresponds to a short distance from the ultrasonic transmitter / receiver 21, and the reflection intensity level when an object O is present is relatively strong, making it easy to identify reflected waves even if communication noise is generated. On the other hand, section T3 corresponds to a long distance from the ultrasonic transmitter / receiver 21 within the detection setting distance M, and the reflection intensity level when an object O is present is relatively weak (attenuated), and if communication noise is generated, the reflection intensity may be drowned out by the communication noise. Therefore, communication is suspended in section T3 to eliminate the generation of communication noise. Then, in section T4, communication processing is resumed, and measurement data received by the transducer 21 in section T3 and measurement data (measurement data with a relatively weak reflection intensity level) sufficient to detect the presence or absence of an object O at a distance farther than the detection setting distance M are acquired. The length of section T4 after communication is resumed can be determined by the measurement section P, which can be set in advance, and after the measurement in the measurement section P is completed, a new wave transmission and reception cycle (next detection cycle) is started by the transducer 21, and similar communication processing, interruption processing, and communication resumption processing are repeatedly executed, allowing continuous detection processing of the object O.

[0026] In another embodiment, the timing of interrupting the communication process of the object detection device 11 may be determined based on the relationship between the mounting height h of the transducer 21 from the road surface G (see FIG. 4 ) and communication noise. FIG. 6 is an exemplary schematic diagram showing the relationship between noise (road surface noise N1 (solid line), communication noise N2 (interruption indicated by dashed line, no interruption indicated by two-dot chain line)) and the reflection level of the reflected wave S (dash-dotted line) in the object detection device 11. The road surface noise N1 varies depending on the condition of the road surface G (type of road surface, smoothness, etc.), and as shown in FIG. 6 , the road surface noise N1 tends to attenuate as the distance from the transducer 21 increases. The road surface noise N1 also varies depending on the mounting height h of the transducer 21 from the road surface G. In other words, the higher the mounting height h, the smaller the influence of the road surface noise N1. Furthermore, as mentioned above, the communication noise N2 is a constant value, so by interrupting the communication process at the intersection C in the attenuation region of the communication noise N2 and the road noise N1 and eliminating the communication noise N2, it is possible to prevent the reflected wave S, which tends to attenuate, from being buried in the communication noise N2 and becoming difficult to identify.

[0027] In another embodiment, the communication interruption setting unit 102 may determine the timing of interrupting the communication process of the object detection device 11 based on the number of times an object O is detected in the short distance. For example, the communication interruption setting unit 102 may interrupt the communication process when an object O is detected in the short distance. However, in this case, as shown in FIG. 4 , a small object O1 that is considered not to affect the traveling of the vehicle 1 may be located closer to the vehicle 1, and a large object O2 that is considered to affect the traveling of the vehicle 1 may be located behind it. In such a case, if the communication process is interrupted upon detection of the object O1, measurement data corresponding to the object O2 may be acquired after communication is resumed, which may result in a delay in the recognition timing of the object O2. Therefore, the communication interruption setting unit 102 may interrupt the communication process when the number of times the object O is detected in the short distance before the interruption of the communication process reaches multiple times (e.g., at least two times or more). In this case, the object O that may be located at a long distance within the detection setting distance M may be detected without being affected by communication noise. As a result, it is possible to prevent the attenuating reflected wave from becoming buried in communication noise and becoming difficult to identify.

[0028] If distance information deemed to indicate an object O is acquired prior to the interruption timing, the communication interruption setting unit 102 may interrupt the communication processing of the current processing cycle of the acquisition unit 101 regardless of the preset interruption timing and start the communication processing of the next processing cycle by the acquisition unit 101. In other words, if the vehicle 1 (transmitter / receiver 21) detects an object O at a short distance, dealing with that object O (such as preventing contact) takes top priority, and information about another object O located further away is less important. Therefore, if an object O is detected at a short distance within the detection setting distance M, the communication processing is interrupted and the acquisition unit 101 starts the communication processing of the next processing cycle. In other words, the processing for the current wave transmission by the transducer 21 is terminated and processing for the next wave transmission by the transducer 21 is started. This allows unnecessary measurement processing at long distances to be omitted. As a result, the detection cycle for the object O can be compressed (shortened), contributing to improved detection reliability of the object O. In this case, if one or both of the object O and the vehicle 1 are moving in the approaching direction, the timing of communication termination (transition to the next detection cycle) becomes earlier each time the above-mentioned detection termination is performed, so the detection cycle is further compressed.

[0029] Furthermore, if distance information (measurement data) deemed to indicate an object O is not acquired within a predetermined confirmation period after the communication process is resumed, the communication resumption setting unit 103 may interrupt the resumed communication process and cause the acquisition unit 101 to start the communication process for the next processing cycle. When the communication resumption setting unit 103 resumes the communication process, the measurement data for the section T3 during which the communication process was suspended is first transmitted to the control unit 22. That is, it is possible to determine whether or not an object O is present in an area within the detection setting distance M that corresponds to a long distance from the ultrasonic transmitter / receiver 21 and that requires detection. In other words, if an object O is not present in an area within the detection setting distance M that corresponds to a long distance from the ultrasonic transmitter / receiver 21, the importance of detecting an object O in an area farther away becomes lower. Therefore, if distance information (measurement data) deemed to indicate an object O is not acquired within the first predetermined confirmation period after the communication process is resumed, the communication resumption setting unit 103 interrupts the resumed communication process and causes the acquisition unit 101 to start the communication process for the next processing cycle. In this case as well, processing can be omitted in areas of low importance, which can contribute to compressing (shortening) the detection period.

[0030] The flow of communication interruption processing in the object detection device 11 configured as described above will be described with reference to the exemplary flowchart of FIG.

[0031] First, when a detection request for an object O (a request to start a detection cycle) is made in the vehicle control device 10, the transducer 21 starts transmitting and measuring ultrasonic waves, and the acquisition unit 101 starts acquiring measurement data (distance information). That is, the communication process with the transducer 21 is started, and acquisition of measurement data is started (S100).

[0032] When measurement begins, the communication interruption setting unit 102 acquires the communication interruption timing, and the communication restart setting unit 103 acquires the communication restart timing. The acquisition unit 101 calculates the amount of measurement data that can be acquired before the communication interruption timing (S102). The communication interruption setting unit 102 then monitors whether the communication interruption timing has occurred (S104). If the communication interruption timing has not occurred (No in S104), the process returns to S102, where the communication interruption timing, communication restart timing, and amount of acquired data are confirmed, while continuing to monitor whether the communication interruption timing has occurred. If the communication interruption timing has occurred (Yes in S104), the communication between the acquisition unit 101 and the ultrasonic transmitter / receiver 21 is temporarily interrupted (S106). In other words, the measurement data received by the ultrasonic transmitter / receiver 21 during the interruption of communication processing is data that does not contain communication noise. The communication interruption setting unit 102 may also set the start and end periods of the communication interruption processing (communication restart). In other words, the communication interruption setting unit 102 may also acquire the communication interruption timing and the communication restart timing.

[0033] When the interruption of the communication process is initiated, the communication resumption setting unit 103 monitors whether the communication interruption has ended, i.e., whether the timing for restarting communication has arrived (No in S108). When the communication resumption setting unit 103 determines that the communication interruption has ended (Yes in S108), it resumes communication between the acquisition unit 101 and the ultrasonic transmitter / receiver 21, acquires the remaining data (including the measurement data received by the ultrasonic transmitter / receiver 21 during the interruption) (S110), and temporarily ends the processing for the current detection cycle. Then, when the next detection cycle begins, the processing from S100 is executed to acquire the measurement data, including the interruption of the communication process. Thereafter, the flow of FIG. 7 is repeatedly executed to continuously perform the detection processing for the object O.

[0034] In the above-described embodiment, an example has been shown in which the communication resumption timing is set in advance through testing or the like. In other embodiments, the timing to resume communication may be determined using past detection results of the ultrasonic transmitter / receiver 21. For example, if the approach of an object O is predicted from multiple past detection results (detection distances) and it is estimated that the predicted object O is present in section T3, the communication interruption is terminated at a timing sufficient to detect the predicted object O. In other words, the communication interruption time (section T3) may be shortened to advance the communication resumption timing.

[0035] For example, as shown in FIG. 8, in the previous detection period, an object O ｍ－１ is detected in section T4, and object O ｍ If the object O is detected in the section T3, it can be considered that the object O is approaching the transducer 21. Therefore, the object O at the next detection timing ｍ＋１ It can be predicted that in the section T3, an object O having a high detection importance is approaching. ｍ＋１ Distance information of (O) is acquired in a state where communication noise is suppressed due to communication interruption. On the other hand, if the closest approaching object can be detected, objects that may exist further away can be considered to be less important in a collision prevention scene during parking assistance, etc. In other words, if the presence or absence of an object can be detected, accurate distance information can be considered to be unimportant. Therefore, the communication interruption section (section T3) in which communication noise is suppressed in the next detection cycle is set based on the past detection results (object O ｍ In other words, the communication resumption setting unit 103 enables the communication process to be resumed after the lapse of an interruption period determined based on previously acquired information on the distance to the object O. In this case, the communication resumption timing is set to, for example, ｍ The detection distance may be determined by the object O ｍ The detection distance of the next object O ｍ＋１The timing for restarting communication may be determined based on the detection distance taking into account the prediction error of the object Om. FIG. 8 shows an example in which the timing for restarting communication is determined based on the detection distance of an object Om that has already been detected. As a result, it is possible to hasten the end of the communication interruption in the entire next detection cycle, which can contribute to compressing (shortening) the detection cycle. By repeating this process of shortening the communication interruption period, the entire detection cycle can be shortened, and object detection accuracy can be improved.

[0036] In another embodiment, the timing to start communication may be determined based on, for example, the reflection level of an object. For example, if, based on the reflection intensity levels of the object O measured multiple times in the past, an object O is found to have a reflection level large enough to not be buried in communication noise, the timing to resume communication may be set immediately after the end of interval T2. In other words, the communication interruption period may be minimized (close to zero), and measurement may be continued while essentially communicating as normal. This also contributes to shortening the overall detection cycle and improving object detection accuracy.

[0037] In this embodiment, the timing for interrupting communication or the timing for restarting communication may be determined during the period T1 or during the period T2.

[0038] In the present embodiment, the acquisition unit 101 may acquire various additional data in addition to the measurement data (distance information) of the reflected waves as information to be communicated with the transducer 21. The acquisition unit 101 may acquire, as the additional information, for example, sensor failure information or abnormality information of the transducer 21 (sensor), information on data reliability, etc. In this case where various additional data is acquired in addition to the measurement data, if the communication process is interrupted to suppress communication noise (to improve the detection accuracy of the object O) as described above, the communication of the additional data will also be interrupted, albeit for a short time.

[0039] Here, consider a case where the object detection device 11 of this embodiment can detect an object O at a short distance, for example, a case where measurement data is acquired in section T2 in FIG. 5 and the presence of object O is detected in this section T2 (i.e., at a short distance). In this case, as described above, objects that may exist farther away than the object O detected at a short distance can be considered to be less important in scenes such as parking assistance. In other words, it can be considered that the need for communication noise suppression processing is low in areas farther away than the detected object O.

[0040] Therefore, if distance information (measurement data) deemed to indicate an object is acquired prior to the timing of the interruption of the communication process, the communication interruption setting unit 102 may continue the communication process between the transducer 21 and the acquisition unit 101 regardless of the timing of the interruption. For example, in FIG. 5 , if the measurement data is acquired during section T2 and the presence of object O is detected during this section T2 (i.e., a short distance), the communication interruption setting unit 102 does not interrupt the communication process and continues the communication process. If the presence of object O is detected at such an early stage, the communication interruption setting unit 102 continues the communication process without interrupting the communication process, thereby allowing the communication process of the various auxiliary data described above to continue. As a result, the object detection device 11 can successfully detect object O while continuously acquiring auxiliary data, allowing the operation and management of the object detection device 11 itself (the object detection device 11) to be performed as usual.

[0041] As described above, according to the present embodiment, the object detection device 11 includes: an acquisition unit 101 that acquires distance information indicating the distance from the transducer 21 to the object O by communicating with the transducer 21 based on the time it takes for sound waves transmitted from the transducer 21 mounted on the vehicle 1 to be reflected by the object O and return; a communication interruption setting unit 102 that sets an interruption timing for temporarily interrupting communication processing between the transducer 21 and the acquisition unit 101 based on at least one of the relationship between a detection setting distance M in a detection scene of the object O and a communication noise N2 due to communication, or the relationship between a road surface noise N1 determined by the mounting height h of the transducer 21 from the road surface G and the communication noise N2; and a communication resumption setting unit 103 that enables the communication processing to be resumed after a predetermined interruption period has elapsed since the interruption of the communication processing or after an interruption period determined based on previously acquired distance information to the object O has elapsed. With this configuration, for example, by temporarily interrupting the communication processing after it has started, the communication noise N2 can be suppressed in an area where the strength of the reflected wave is weak, for example, in a distant area. After communication is resumed, distance information can be obtained for a period not affected by communication noise N2, making it possible to detect an object with an improved S / N ratio.

[0042] Furthermore, in the above embodiment, if distance information deemed to indicate object O is acquired prior to the interruption timing, the communication interruption setting unit 102 may continue the communication process between the transducer 21 and the acquisition unit 101 regardless of the interruption timing. According to this configuration, for example, if object O is detected at a short distance within the detection setting distance M, that is, if the presence of object O is detected at an early stage, the communication process continues without interruption. By continuing the communication process, the object detection device 11 can continuously acquire auxiliary data while successfully detecting object O. Based on the acquired auxiliary data, the operation and management of the object detection device 11 can be performed as before. This contributes to improving the reliability of the object detection device 11's detection of object O.

[0043] Furthermore, in the above embodiment, if distance information deemed to indicate object O is acquired prior to the interruption timing, the communication interruption setting unit 102 may interrupt the communication processing of the current processing cycle of the acquisition unit 101 regardless of the interruption timing and start the communication processing of the next processing cycle by the acquisition unit 101. If object O is detected at a short distance within the detection setting distance M, the communication processing is interrupted and the communication processing of the next processing cycle by the acquisition unit 101 is started. In other words, the processing for the current wave transmission by the ultrasonic transmitter / receiver 21 is terminated and processing for the next wave transmission by the ultrasonic transmitter / receiver 21 is transitioned to. In other words, unnecessary measurement processing for long distances can be omitted. As a result, the detection cycle for object O can be compressed (shortened), contributing to improved detection reliability of object O. According to this configuration, for example, if object O is detected at a short distance within the detection setting distance M, the communication processing is interrupted and the communication processing of the next processing cycle by the acquisition unit 101 is started. In other words, the processing for the wave transmitted this time by the ultrasonic transmitter / receiver 21 is completed, and the processing shifts to the processing for the next wave transmitted by the ultrasonic transmitter / receiver 21. This makes it possible to omit unnecessary measurement processing for long distances. As a result, it becomes possible to compress (shorten) the detection cycle of the object O, which contributes to improving the detection reliability of the object O.

[0044] Furthermore, in the above embodiment, if distance information deemed to indicate an object O is not acquired within a predetermined confirmation period after the communication process is resumed, the communication resumption setting unit 103 may suspend the resumed communication process and cause the acquisition unit 101 to start the communication process for the next processing cycle. According to this configuration, for example, if object O is not present in an area corresponding to a long distance from the transducer 21 within the detection setting distance M, the importance of detecting object O in areas farther away becomes low. Therefore, if distance information deemed to indicate object O is not acquired within the first predetermined confirmation period after the communication process is resumed, the communication resumption setting unit 103 suspends the resumed communication process and causes the acquisition unit 101 to start the communication process for the next processing cycle. In this case, processing can be omitted in areas of low importance, which can contribute to compressing (shortening) the detection cycle.

[0045] Although the embodiments and modifications of the present disclosure have been described above, the above-described embodiments and modifications are merely examples and are not intended to limit the scope of the invention. The novel embodiments and modifications described above can be implemented in various forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. The above-described embodiments and modifications are included within the scope and spirit of the invention, and are also included in the inventions and their equivalents as defined in the claims.

[0046] 1...vehicle, 10...vehicle control device, 11...object detection device, 12...ECU, 21...transmitter / receiver, 22...control unit, 53...processor, 101...acquisition unit, 102...communication interruption setting unit, 103...communication resumption setting unit.

Claims

1. An object detection device comprising: an acquisition unit that acquires distance information indicating a distance from a transducer mounted on a vehicle to an object by communicating with the transducer based on a time it takes for a sound wave transmitted from the transducer to be reflected by the object and return; a communication interruption setting unit that sets an interruption timing to temporarily interrupt communication processing between the transducer and the acquisition unit based on at least one of a relationship between a detection set distance in a detection scene of the object and communication noise caused by the communication, or a relationship between road noise determined by a mounting height of the transducer from the road surface and the communication noise; and a communication resumption setting unit that enables the communication processing to be resumed after a predetermined interruption period has elapsed since the interruption of the communication processing or after an interruption period determined based on the distance information to the object acquired in the past has elapsed.

2. The object detection device of claim 1, wherein the communication interruption setting unit continues communication processing between the transmitter / receiver and the acquisition unit regardless of the interruption timing when distance information deemed to indicate the object is acquired at a timing prior to the interruption timing.

3. The object detection device of claim 1, wherein the communication interruption setting unit interrupts the communication processing of the current processing cycle of the acquisition unit regardless of the interruption timing when distance information deemed to indicate the object is acquired at a timing prior to the interruption timing, and causes the acquisition unit to start the communication processing of the next processing cycle.

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