Object detection device

Abstract

To provide a technology with which it is possible to prevent a process that must be executed in a shaft displaced state from being erroneously executed when not in the shaft displaced state.SOLUTION: A radar device is mounted on a vehicle and detects an object by receiving a reflected wave of a transmitted wave that is transmitted toward the outside of the vehicle. With the radar device, determination is made as to whether being in a shaft displaced state that a reference direction of the radar device is displaced from a reference direction of the vehicle that is defined in design. When determined as being in the shaft displaced state, a shaft displacement notification process is executed. Furthermore, when dirt is stuck to a transmission member provided so as to cover the transmission direction of the transmitted wave and / or the arrival direction of a reflected wave in the radar device, the transmission member transmitting the transmitted wave and reflected wave, determination is made of being an accuracy reduced state, or more specifically a dirt stuck state, where the accuracy of determining the shaft displaced state tends to decrease. When determination of being the dirt stuck state is made, the shaft displacement notification process is not executed.SELECTED DRAWING: Figure 5

Description

[Technical Field]

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

[0002] There are object detection devices that are mounted on a moving body and detect objects by receiving reflected waves of transmitted waves sent outward from the moving body. This type of object detection device may experience an axis misalignment, where the reference direction of the object detection device is misaligned from the reference direction of the moving body as determined by the design, due to aging, external impact, or other factors. This axis misalignment can result in a decrease in object detection accuracy.

[0003] Therefore, for example, Patent Document 1 describes an object detection device that can determine whether an axis is misaligned by utilizing the azimuth dependency of the ratio between the relative velocity of a detected stationary object and the velocity of a moving object. The object detection device described in Patent Document 1 executes a process to determine that an axis is misaligned when the reference direction of the object detection device deviates from the reference direction of the moving object by more than a certain amount, and to notify the occupant of the moving object of this fact. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-228749 Summary of the Invention [Problem to be solved by the invention]

[0005] However, as a result of detailed investigation by the inventors, the following problem was found: If dirt such as water, mud, snow, or ice adheres to a transparent member that transmits transmitted waves and reflected waves, the dirt can cause scattering or refraction of the transmitted waves or reflected waves, which can reduce the accuracy of determining whether an axis misalignment has occurred. If an axis misalignment is erroneously determined to be present, processing such as notification that should be performed when an axis misalignment has occurred will be erroneously performed when no axis misalignment has occurred.

[0006] One aspect of the present disclosure provides a technique capable of preventing a process that should be executed when an axis misalignment occurs from being erroneously executed when an axis misalignment does not occur. [Means for solving the problem]

[0007] One aspect of the present disclosure is an object detection device (1) mounted on a moving body and detecting an object by receiving a reflected wave of a transmitted wave transmitted toward the outside of the moving body. The object detection device includes an axis misalignment determination unit (S101), an axis misalignment response unit (S103), and an accuracy determination unit (S102). The axis misalignment determination unit determines whether an axis misalignment state exists, in which a reference direction of the object detection device is deviated from a reference direction of the moving body determined by design. The axis misalignment response unit executes a predetermined axis misalignment response process when the axis misalignment determination unit determines that an axis misalignment state exists. The accuracy determination unit determines that an accuracy degraded state exists, in which the accuracy of the axis misalignment determination unit's determination of whether an axis misalignment state exists, is likely to decrease, when dirt is attached to a transparent member provided to cover at least one of the transmission direction of the transmitted wave and the arrival direction of the reflected wave and that transmits the transmitted wave and the reflected wave. When the accuracy determination unit determines that an accuracy degraded state exists, the axis misalignment response unit does not execute the axis misalignment response process.

[0008] With this configuration, it is possible to prevent a process that should be executed when an axis misalignment occurs from being erroneously executed when an axis misalignment does not occur. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a block diagram showing a configuration of a radar device. [Figure 2] FIG. 2 is a schematic diagram for explaining the direction of a detected object. [Figure 3] FIG. 2 is a schematic diagram for explaining the direction of a detected object. [Figure 4] 4 is a flowchart showing the flow of processing executed by a control unit. [Figure 5]FIG. 10 is a diagram for explaining patterns of notification processing. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, exemplary embodiments of the present disclosure will be described with reference to the drawings. [1. Configuration] The radar device 1 shown in FIG. 1 is mounted on a vehicle. Hereinafter, the vehicle on which the radar device 1 is mounted is referred to as the host vehicle. The radar device 1 is a so-called millimeter wave radar that transmits radar waves in the millimeter wave band as transmission waves to the outside of the host vehicle and receives reflected waves of the transmission waves to detect objects that have reflected the transmission waves. The radar device 1 of this embodiment is installed on the front side of the host vehicle and transmits transmission waves toward the front of the host vehicle. The radar device 1 includes a measurement unit 11 and a control unit 12.

[0011] The measurement unit 11 includes a transmitter 111 and a receiver 112. The transmitter 111 transmits a transmission wave toward the outside of the vehicle (i.e., toward the front of the vehicle in this embodiment) in accordance with a transmission signal output from the control unit 12. The transmitter 111 of this embodiment transmits a radar wave as the transmission wave by gradually increasing or decreasing it at a predetermined modulation period. The receiver 112 receives a reflected wave of the transmission wave transmitted by the transmitter 111 and outputs a reception signal of the reflected wave to the control unit 12.

[0012] The control unit 12 is mainly configured with a well-known microcomputer including a CPU 121 and a memory 122 such as a ROM and a RAM. The various functions of the control unit 12 are realized by the CPU 121 executing a program stored in a non-transitory tangible recording medium. In this example, the memory 122 corresponds to the non-transitory tangible recording medium. Furthermore, the execution of the program results in the execution of a method corresponding to the program. The number of microcomputers constituting the control unit 12 may be one or more. Furthermore, the method for realizing the various functions of the CPU 121 is not limited to software, and some or all of the functions may be realized by one or more pieces of hardware. For example, when the above functions are realized by electronic circuits that are hardware, the electronic circuits may be realized by digital circuits, analog circuits, or a combination of these.

[0013] The control unit 12 detects information about the object that reflected the transmitted wave based on the received signal of the reflected wave. Hereinafter, the object that reflected the transmitted wave will be referred to as the detected object, and information about the detected object will be referred to as detected object information. The detected object information includes the direction of the detected object relative to the radar device 1, the distance from the radar device 1 to the detected object, and the relative speed of the detected object relative to the radar device 1. The radar device 1 of this embodiment employs a well-known FCM method, and the control unit 12 detects the detected object information based on the frequency of a beat signal generated by the transmitted signal of the transmitted wave and the received signal of the reflected wave. FCM stands for Fast Chirp Modulation. Note that the method of the radar device 1 is not limited to the FCM method, and for example, a well-known FMCW method may be employed. FMCW stands for Frequency Modulated Continuous Wave.

[0014] The direction of the detected object M relative to the radar device 1 is determined based on the reference direction of the radar device 1. The reference direction of the radar device 1 is the direction of the radar device 1 that is determined as a reference in design. In this embodiment, the direction of the detected object M relative to the radar device 1 is determined on the assumption that the reference direction A of the radar device 1 coincides with the reference direction B of the host vehicle V, as shown in FIG. 2. The reference direction B of the host vehicle V is the direction of the host vehicle V that is determined as a reference, and in this embodiment, is the traveling direction of the host vehicle V. Therefore, in an axis misalignment state in which the reference direction A of the radar device 1 and the reference direction B of the host vehicle V are misaligned as shown in FIG. 3, the direction of the detected object M relative to the traveling direction of the host vehicle V cannot be obtained correctly.

[0015] Returning to FIG. 1 , at least the measurement unit 11 in the radar device 1 is disposed inside a housing (not shown). A radome (not shown) that transmits the transmitted and reflected waves is provided in this housing so as to cover both the transmitting direction of the transmitted wave and the arriving direction of the reflected wave. The radome corresponds to a transparent member. The transparent member is provided so as to cover at least one of the transmitting direction of the transmitted wave and the arriving direction of the reflected wave when the radar device 1 is mounted on the vehicle, and is a member that transmits the transmitted and reflected waves. If the radar device 1 is mounted, for example, behind an emblem on the vehicle, the emblem and emblem cover, in addition to the radome, also correspond to a transparent member. The control unit 12 determines the degree of contamination on the transparent member based on the arriving direction of the reflected wave, for example, as described in Japanese Patent No. 5978754, or based on changes in the intensity or phase of the reflected wave, or based on the detected object information described above.

[0016] The method for determining the degree of dirt adhesion to the transparent member is not particularly limited, and for example, if the vehicle is separately equipped with a dirt sensor, the control unit 12 may use this dirt sensor to detect the adhesion of dirt to the transparent member. Examples of such dirt sensors include a sensor that irradiates light onto the transparent member and detects the reflectance of the light on the transparent member, and a camera that captures an image of the transparent member.

[0017] The control unit 12 acquires information from a vehicle speed sensor 2 and an environmental information sensor 3 mounted on the vehicle. Specifically, the vehicle speed sensor 2 detects the speed of the vehicle and outputs speed information indicating the speed to the control unit 12.

[0018] The environmental information sensor 3 detects environmental information that indicates the environment around the host vehicle, and outputs this environmental information to the control unit 12. The environmental information includes at least information that indicates the weather conditions around the host vehicle, such as information that indicates rainfall, snowfall, etc. In this embodiment, the environmental information sensor 3 is a camera that captures an image of the host vehicle's windshield. The environmental information sensor 3 outputs the captured image of the host vehicle's windshield to the control unit 12 as environmental information. The control unit 12 uses this captured image to detect the adhesion of droplets such as rainwater to the host vehicle's windshield, thereby determining the rainfall and snowfall conditions around the host vehicle.

[0019] The environmental information sensor 3 is not limited to a camera that captures an image of the windshield as described above, but may be, for example, a sensor that receives weather information for the location where the vehicle is traveling from an external information and communication system such as VICS. VICS is a registered trademark. Furthermore, for example, the environmental information sensor 3 may be a sensor that detects the operating status of the windshield wipers of the vehicle.

[0020] As will be described in detail later, the control unit 12 uses the notification unit 4 mounted on the host vehicle to notify the occupants of the host vehicle that an axis misalignment state exists or that a dirty state exists, in which dirt is adhering to the transparent member. The notification unit 4 in this embodiment is a multi-information display that displays various information related to the host vehicle. The various information here includes the speed of the host vehicle, the engine RPM, the shift range of the transmission, etc. The multi-information display is installed in a position visible to the driver in the cabin of the host vehicle. That is, the mode of notification to the occupants of the host vehicle in this embodiment is the display of letters, marks, etc. on the multi-information display.

[0021] The notification unit 4 is not limited to the multi-information display as described above, and may be, for example, a buzzer or the like that is mounted on the vehicle and emits a sound in accordance with an instruction from the control unit 12. That is, the notification to the occupants of the vehicle may be made by sounding a buzzer or the like. Furthermore, the control unit 12 provides the object detection result (for example, the above-mentioned detected object information) to the driving control unit 5. The driving control unit 5 is an in-vehicle system that controls driving of the vehicle using the object detection result by the radar device 1. The driving control unit 5 is, for example, a PCS or ACC. PCS stands for Pre-Crush Safety. ACC stands for Adaptive Cruise Control. As will be described later, the control unit 12 notifies the driving control unit 5 that an axis misalignment state exists. Based on the notification from the control unit 12 that an axis misalignment state exists, the driving control unit 5 may, for example, change thresholds for various determinations or stop various processes.

[0022] [2. Processing] Next, the processing executed by the CPU 121 in the control unit 12 will be described with reference to Figures 4 and 5. The processing shown in Figure 4 is executed at regular intervals while the ignition switch of the vehicle is on.

[0023] First, in S101, the CPU 121 executes an axis misalignment determination process. The axis misalignment determination process is a process for determining whether the axis misalignment state described above exists. The method for determining whether the axis misalignment state exists is not particularly limited, and various known methods can be applied. In this embodiment, a method for determining whether the axis misalignment state exists is used, such as that disclosed in Japanese Patent Application Laid-Open No. 2021-143906, which uses egomotion that predicts the behavior of the vehicle and a relative movement vector of a stationary object. In this type of determination method, if dirt such as water, mud, snow, or ice adheres to the transparent member, the dirt may scatter or refract the transmitted wave or reflected wave, reducing the detection accuracy of the relative speed and orientation of the detected object, and the accuracy of determining whether the axis misalignment state exists may be reduced.

[0024] In this embodiment, a storage area for storing a flag (hereinafter referred to as axis misalignment flag) indicating the determination result of whether or not an axis misalignment state exists is provided in the memory 122. The axis misalignment flag takes on a value of "0" or "1." An axis misalignment flag of "0" indicates that it has been determined that the axis misalignment state does not exist. An axis misalignment flag of "1" indicates that it has been determined that the axis misalignment state exists. The CPU 121 resets the axis misalignment flag to "0" when the ignition switch of the host vehicle is turned on. If it is determined in S101 that the axis misalignment state exists, the CPU 121 updates the axis misalignment flag to "1."

[0025] Next, in S102, the CPU 121 executes a dirt adhesion determination process. The dirt adhesion determination process is a process for determining the state of dirt adhesion on the transparent member. In this embodiment, the CPU 121 executes the dirt adhesion determination process as follows (1) and (2).

[0026] (1) As described above, the CPU 121 determines whether dirt is attached to the transparent member based on the detection result of the reflected wave, the detected object information, etc. In other words, the CPU 121 determines whether the above-mentioned dirty state exists. For example, when the intensity of the reflected wave is attenuated to a predetermined reference intensity or less, the CPU 121 determines that the dirty state exists. The dirty state is included in the accuracy-decreasing state, which is a state in which the accuracy of determining whether or not there is an axis misalignment state is likely to decrease.

[0027] In this embodiment, a storage area for storing a flag (hereinafter referred to as a dirt flag) indicating the determination result of whether or not the vehicle is in a dirty state is prepared in advance in the memory 122. The dirt flag takes a value of "0" or "1." The dirt flag "0" indicates that the vehicle is not determined to be in a dirty state. The dirt flag "1" indicates that the vehicle is determined to be in a dirty state. The CPU 121 resets the dirt flag to "0" when the ignition switch of the vehicle is turned on. If the CPU 121 determines that the vehicle is in a dirty state, it updates the dirt flag to "1." When the dirt flag is updated to "1" in this manner, the CPU 121 does not update the dirt flag to "0" until it determines that a predetermined cancellation condition is met. In other words, the CPU 121 maintains the determination that the vehicle is in a dirty state until it determines that the cancellation condition is met. The cancellation condition in this embodiment is a condition for enabling the determination that the vehicle is in a dirty state to be cancelled. More specifically, the cancellation condition in this embodiment is that the ignition switch of the vehicle is turned off. As described above, in S101 of this embodiment, a method using the egomotion of the host vehicle and the movement vector of a stationary object is used to determine whether an axis misalignment state exists. However, this determination method may require a certain amount of time to acquire information required to produce a determination result. Therefore, even if the vehicle is not dirty at the time the axis misalignment state determination result is issued, if the vehicle is dirty during the information acquisition process to produce the determination result, it is possible that the axis misalignment state determination was not performed correctly. For this reason, this embodiment employs a configuration in which the determination of the reduced accuracy state is maintained from the time the vehicle is determined to be dirty until the time the cancellation condition is determined to be satisfied. Note that the cancellation condition is not limited to the ignition switch of the host vehicle being turned off, as in this embodiment. For example, the cancellation condition may be the passage of a predetermined time since the dirt state was determined to be present. Alternatively, the cancellation condition may be, for example, the passage of a predetermined cancellation operation by an occupant of the host vehicle.

[0028] (2) The CPU 121 determines whether the environment around the vehicle is an environment in which dirt is likely to adhere to transparent members, based on the environmental information acquired from the environmental information sensor 3. For example, as described above in the description of the environmental information sensor 3, if the number or area of ​​droplets of rainwater or the like adhering to the windshield of the vehicle, detected using an image of the windshield, is equal to or greater than a predetermined threshold, the CPU 121 determines that the weather conditions around the vehicle are rainfall or snowfall. The weather conditions around the vehicle being rainfall or snowfall are included in the environment in which dirt is likely to adhere to transparent members. If the CPU 121 determines that the environment around the vehicle is an environment in which dirt is likely to adhere to transparent members, it determines that there is a possibility that dirt is adhering to the transparent member. Hereinafter, a state in which there is a possibility that dirt is adhering to the transparent member is referred to as a dirt possibility state. The dirt possibility state is also included in the accuracy reduction state.

[0029] In this embodiment, a storage area for storing a flag indicating the determination result of whether or not the vehicle is in a state where there is a possibility of contamination (hereinafter referred to as a contamination possibility flag) is provided in advance in the memory 122. The contamination possibility flag takes on a value of "0" or "1." A contamination possibility flag of "0" indicates that it has been determined that the vehicle is not in a state where there is a possibility of contamination. A contamination flag of "1" indicates that it has been determined that the vehicle is in a state where there is a possibility of contamination. When the ignition switch of the vehicle is turned on, the CPU 121 resets the contamination possibility flag to "0." If the CPU 121 determines that the vehicle is in a state where there is a possibility of contamination, it updates the contamination possibility flag to "1."

[0030] Next, in S103, the CPU 121 executes notification processing in accordance with the determination results in S101 and S102. The notification processing is processing for issuing a notification to an occupant of the host vehicle using the notification unit 4. The notification processing in this embodiment includes axis misalignment notification processing, dirt notification processing, and non-notification processing. In the axis misalignment notification processing, an occupant of the host vehicle is notified that an axis misalignment state exists. The axis misalignment notification processing corresponds to the axis misalignment response processing. In the dirt notification processing, an occupant of the host vehicle is notified that a dirt adhesion state exists. In the non-notification processing, no notification is issued to the occupant of the host vehicle. As shown in FIG. 5, the CPU 121 executes any one of the axis misalignment notification processing, dirt notification processing, and non-notification processing in accordance with the determination results in S101 and S102.

[0031] In FIG. 5, the result of the dirt adhesion determination in S102 is divided into three categories: a dirty state, a possible dirt state, and neither a possible dirt state nor a possible dirt state (i.e., a non-dirt adhesion state). If it is determined in S102 that the state is both a dirty state and a possible dirt state, the determination result that the state is dirty takes precedence, and the state is treated as corresponding to (a) or (b) in FIG. 5. In this embodiment, the cases (a) and (b) in FIG. 5 correspond to cases where at least the dirt flag of the dirt flag and the dirt possibility flag is "1." If it is determined in S102 that the state is not dirty and that the state is a possible dirt state (i.e., in this embodiment, when the dirt flag is "0" and the dirt possibility flag is "1"), the case corresponds to cases (c) or (d) in FIG. 5.

[0032] Specifically, in S103, the CPU 121 executes axis misalignment notification processing if it determines in S101 that the axis is misaligned. However, even if it determines in S101 that the axis is misaligned, if it determines in S102 that the axis is at least one of a soiled state and a soiling possibility state (i.e., a reduced accuracy state), the CPU 121 does not execute axis misalignment notification processing in S103. In other words, the CPU 121 executes axis misalignment notification processing in S103 if it determines in S101 that the axis is misaligned and if it determines in S102 that the axis is neither a soiled state nor a soiling possibility state (i.e., not a reduced accuracy state), that is, in the case of (e) in Fig. 5. In this embodiment, the case of (e) in Fig. 5 corresponds to the case where the axis misalignment flag is "1" and the soiling flag and the soiling possibility flag are both "0."

[0033] If it is determined in S102 that there is a dirt adhesion state, that is, in the cases (a) and (b) in Fig. 5, the CPU 121 executes a dirt notification process. In this embodiment, the cases (a) and (b) in Fig. 5 correspond to the cases where the dirt flag is "1".

[0034] If it is determined in S101 that the axis misalignment state is not present, and if it is determined in S102 that the state is neither a soiled state nor a state where soiling is possible, that is, in the case of (f) in Fig. 5, the CPU 121 executes a non-alarm process. In this embodiment, the case of (f) in Fig. 5 corresponds to the case where the axis misalignment flag, the soiled flag, and the soiling possibility flag are all "0".

[0035] When it is determined in S102 that the state is not a soiled state and that the state is a state in which soiling is possible, the CPU 121 may uniformly execute a non-alert process. However, in this embodiment, the process executed by the CPU 121 differs depending on the result of the determination of whether or not the state is an axis misalignment state in S101. Specifically, when it is determined in S101 that the state is an axis misalignment state, when it is determined in S102 that the state is not a soiled state and that the state is a state in which soiling is possible, i.e., in the case of (c) in FIG. 5, the CPU 121 executes a soiling notification process. In this embodiment, the case of (c) in FIG. 5 corresponds to the case in which the axis misalignment flag is "1," the soiling flag is "0," and the soiling possibility flag is "1." On the other hand, when it is determined in S101 that the state is not an axis misalignment state, when it is determined in S102 that the state is not a soiled state and that the state is a state in which soiling is possible, i.e., in the case of (d) in FIG. 5, the CPU 121 executes a non-alert process. The case (d) in FIG. 5 corresponds to the case where both the axis deviation flag and the dirt flag are "0" and the dirt possibility flag is "1."

[0036] When the notification process in S103 ends, this process ends. As described above, the CPU 121 provides the object detection result to the driving control unit 5. If it is determined in S101 that the axis is misaligned, the CPU 121 executes an axis misalignment notification process to notify the driving control unit 5 that the axis is misaligned. However, even if it is determined in S101 that the axis is misaligned, if it is determined in S102 that the axis is at least one of a soiled state and a soiling possibility state, the CPU 121 does not execute the axis misalignment notification process. In other words, if the CPU 121 determines that the axis is misaligned in S101 and determines that the axis is not the soiled state or the soiling possibility state in S102, that is, if it executes the axis misalignment notification process in S103, the CPU 121 executes the axis misalignment notification process.

[0037] [3.Effects] According to the embodiment described above in detail, the following effects can be obtained.

[0038] (3a) The radar device 1 determines whether it is in an axis misalignment state. If it is determined that it is in an axis misalignment state, an axis misalignment notification process is executed. However, if it is determined that the accuracy is reduced because dirt is attached to the transparent member, specifically if it is determined that it is in a dirty state, the axis misalignment notification process is not executed.

[0039] With this configuration, the axis misalignment notification process is not executed when the device is dirty, which may reduce the accuracy of determining whether or not the device is in an axis misalignment state, thereby preventing the axis misalignment notification process from being executed by mistake when the device is not in an axis misalignment state.

[0040] (3b) In the radar device 1, when it is determined that the environment around the vehicle is one in which dirt is likely to adhere to the transparent member based on the environmental information acquired from the environmental information sensor 3, the radar device 1 determines that the accuracy is in a degraded state. Specifically, it determines that the radar device 1 is in a state in which dirt is likely to adhere to the transparent member.

[0041] In an environment where the transparent member is prone to becoming dirty, there is an increased possibility that the transparent member will become dirty and result in an erroneous determination that an axis misalignment state has occurred. With the above-described configuration, it is possible to prevent the transparent member from becoming dirty and result in an erroneous determination that an axis misalignment state has occurred, thereby further preventing the axis misalignment notification process from being erroneously executed when an axis misalignment state has not occurred.

[0042] (3c) In the radar device 1, the determination that the state is dirty is maintained from the time when the state is determined to be dirty until it is determined that the cancellation condition is satisfied. As described above, if a dirt adhering state is detected during information collection for producing a determination result of whether or not an axis misalignment state exists, the accuracy of the determination of whether or not an axis misalignment state exists may be reduced even if the dirt adhering state is not detected at the time the determination result is produced. With the above-described configuration, the determination of a dirt adhering state is maintained until it is determined that the cancellation condition is satisfied, thereby further preventing the axis misalignment notification process from being erroneously executed when the axis misalignment state does not exist.

[0043] In this embodiment, the radar device 1 corresponds to an object detection device. The process of S101 corresponds to a process performed by an axis deviation determination unit. The process of S102 corresponds to a process performed by an accuracy determination unit. If it is determined in S101 that the axis is misaligned, and if it is determined in S102 that the axis is not dirty or possibly dirty, The process of S103 corresponds to the process performed by the axis deviation handling unit. The process of S103 when it is determined in S102 that the state is at least one of the soiled state and the soiling possibility state corresponds to the process performed by the soiling response unit.

[0044] 4. Other Embodiments Although the embodiments of the present disclosure have been described above, it goes without saying that the present disclosure is not limited to the above-described embodiments and can take on various forms.

[0045] (4a) In the above embodiment, the axis misalignment response process is exemplified by the axis misalignment notification process and the notification process. However, the axis misalignment response process is not limited to the axis misalignment notification process. The axis misalignment response process may be, for example, an axis correction process that corrects the reference direction of the radar device 1 so that it coincides with the reference direction of the host vehicle. This axis correction process may be a process that physically corrects the reference direction of the radar device 1, or a process that corrects the reference direction of the radar device 1 during calculation in the control unit 12. Furthermore, for example, the axis misalignment response process may be a storage process that stores information indicating that an axis misalignment state exists as a log. Furthermore, the axis misalignment response process may involve multiple processes as in the above embodiment, or may involve a single process.

[0046] (4b) In the above embodiment, the axis misalignment determination process is performed in S101, and then the dirt determination process is performed in S102. However, the order of the axis misalignment determination process and the dirt determination process is not particularly limited, and the axis misalignment determination process may be performed after the dirt determination process is performed, or these processes may be performed in parallel.

[0047] (4c) For example, if the dirt determination process determines that the sensor is dirty, the axis misalignment determination process may not be executed. Also, for example, if the determination that the sensor is dirty is maintained until it is determined that the cancellation condition is met, as in the above embodiment, both the axis misalignment determination process and the dirt determination process may not be executed until it is determined that the cancellation condition is met.

[0048] (4d) The cancellation conditions in the above embodiments are conditions for canceling the determination that the vehicle is in a dirty state. That is, in the above embodiments, conditions for canceling the determination that the vehicle is in a dirty state are defined. For example, such cancellation conditions may also be defined for the dirty state. That is, the cancellation conditions may be conditions for canceling the determination that the vehicle is in a reduced accuracy state. Also, for example, such cancellation conditions do not necessarily have to be defined.

[0049] (4e) As mentioned above, the method for determining whether an axis misalignment exists is not particularly limited. The method may be the method used in the above embodiment, which uses egomotion to predict the behavior of the vehicle and the movement vector of a stationary object. Alternatively, the method may be a method that utilizes the azimuth dependency of the ratio between the relative velocity of a stationary object and the velocity of the vehicle, as disclosed in, for example, Japanese Patent Application Laid-Open No. 2002-228749 (i.e., the above-mentioned Patent Document 1) or Japanese Patent Application Laid-Open No. 2018-54315. Furthermore, the method may be a method that compares the object detection results obtained by the radar device 1 with the object detection results obtained by a camera separately mounted on the vehicle, as disclosed in, for example, Japanese Patent Application Laid-Open No. 2010-249613 or Japanese Patent Application Laid-Open No. 2016-065759. Even with such a method, the accuracy of the determination may be reduced if the transparent member becomes dirty.

[0050] (4f) In the above embodiment, the radar device 1 is mounted on a vehicle. However, the radar device 1 may be mounted on a moving body other than a vehicle (for example, a ship, an aircraft such as a drone, etc.).

[0051] (4g) In the above embodiment, the weather conditions around the vehicle are exemplified as being an environment in which dirt is likely to adhere to the transparent member, such as rain or snow. In addition, the road on which the vehicle is traveling is wet or unpaved, which also falls under the category of an environment in which dirt is likely to adhere to the transparent member. In this case, dirt is likely to adhere to the transparent member due to water splashes from the road surface or dust. Low temperatures around the vehicle (e.g., below freezing) are also included in the category of an environment in which dirt is likely to adhere to the transparent member. In this case, frost or condensation is likely to form on the transparent member.

[0052] (4h) In the above embodiment, a determination is made in S102(1) as to whether the transparent member is in a dirty state, and a determination is made in S102(2) as to whether the transparent member is in a dirty state. However, the determination as to whether the transparent member is in a dirty state as in S102(2) does not necessarily have to be made. In other words, the CPU 121 may determine that the transparent member is in a degraded accuracy state only when dirt is actually attached to the transparent member.

[0053] (4i) The function of one component in the above embodiments may be distributed among multiple components, or the functions of multiple components may be integrated into one component. Also, part of the configuration of the above embodiments may be omitted. Furthermore, at least part of the configuration of the above embodiments may be added to or substituted for the configuration of another of the above embodiments.

[0054] (4j) The present disclosure can be realized in various forms, such as the radar device 1 described above, a control unit 12 constituting the radar device 1, a program for causing a computer to function as the control unit 12, a medium on which this program is recorded, and an axis misalignment response method. [Explanation of symbols]

[0055] 1... radar device, 11... measurement unit, 12... control unit, 2... vehicle speed sensor, 3... environmental information sensor, 4... notification unit, 5... driving control unit.

Claims

1. An object detection device (1) mounted on a moving body and detecting an object by receiving a reflected wave of a transmission wave transmitted to the outside of the moving body, an axis deviation determination unit (S101) that determines whether the reference direction of the object detection device is in an axis deviation state, that is, a state in which the reference direction of the moving body is deviated from a reference direction determined in design; an axis deviation response unit (S103) that executes a predetermined axis deviation response process when the axis deviation determination unit determines that the axis deviation state exists; an accuracy determination unit (S102) that determines whether the axis deviation determination unit is in an accuracy-decreasing state, which is a state in which the accuracy of the axis deviation determination unit's determination of whether the axis deviation is in the state is likely to decrease; A dirt handling unit (S103), Equipped with The accuracy degraded state includes a dirty state in which dirt is attached to a transparent member that is provided so as to cover at least one of the transmission direction of the transmission wave and the arrival direction of the reflected wave and that transmits the transmission wave and the reflected wave, and a dirty possibility state in which there is a possibility that dirt is attached to the transparent member, The accuracy determination unit When it is determined that the dirt is attached to the transparent member based on the received signal of the reflected wave, it is determined that the dirt is attached to the transparent member, and determining that the mobile object is in the contamination possibility state when it is determined that the environment around the mobile object is an environment in which the contamination is likely to adhere to the transparent member based on environmental information that is information indicating the environment around the mobile object; The dirt handling portion is When the accuracy determination unit determines that the vehicle is in the dirty state, a dirt notification process is executed to notify an occupant of the vehicle that the vehicle is in the dirty state; When the accuracy determination unit determines that the dirt is not in the dirt-adhered state and that the dirt is likely to be in the state, if the axis misalignment determination unit determines that the axis is misaligned, the dirt notification process is executed; and when the axis misalignment determination unit determines that the axis is not misaligned, the dirt notification process is not executed. The object detection device, wherein the axis misalignment compensation unit does not execute the axis misalignment compensation process when the accuracy determination unit determines that the accuracy is in the reduced state.

2. The object detection device according to claim 1 , The accuracy determination unit maintains the determination that the accuracy is in the degraded state from the time when the accuracy determination unit determines that the accuracy is in the degraded state until the time when the accuracy determination unit determines that a predetermined cancellation condition is satisfied.

3. 3. The object detection device according to claim 1, The axis misalignment response processing includes at least one of an axis misalignment notification processing that notifies an occupant of the moving body that the axis misalignment state exists, an axis misalignment notification processing that notifies a system that controls the moving body that the axis misalignment state exists using the object detection result by the object detection device, an axis correction processing that corrects the reference direction of the object detection device to match the reference direction of the moving body, and a storage processing that stores the axis misalignment state as a log.

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