Detection system

Abstract

To detect reduction of an air pressure of a tire in a situation where a movable body is in a non-traveling state.SOLUTION: A detection system includes a radar and a control device mounted on a movable body. The radar receives reflection waves formed by electric waves being radiated by the radar and reflected on a ground surface. The control device detects, based on the reflection waves, reduction of an air pressure of a tire included in the movable body.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present invention relates to a detection system. [Background technology]

[0002] In recent years, technologies for detecting the condition of tires mounted on moving objects have been developed. For example, Patent Document 1 discloses a method for detecting abnormal tire conditions according to tire condition types selected according to the vehicle's traveling speed. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-73313 Summary of the Invention [Problem to be solved by the invention]

[0004] However, Patent Document 1 does not take into consideration the detection of abnormal tire conditions when the mobile object is not moving.

[0005] The present invention has been made in view of the above problems, and an object of the present invention is to detect a drop in tire air pressure when a mobile object is not moving. [Means for solving the problem]

[0006] In order to solve the above problem, according to one aspect of the present invention, there is provided a detection system comprising a radar and a control device mounted on a mobile body, wherein the radar receives reflected waves formed when radio waves emitted by the radar are reflected by the ground, and the control device detects a drop in air pressure in tires mounted on the mobile body based on the reflected waves. [Effects of the Invention]

[0007] As described above, according to the present invention, it is possible to detect a drop in tire air pressure when the mobile object is not moving. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a block diagram showing an example of the functional configuration of a detection system 1 according to an embodiment of the present invention. [Figure 2] 10 is a diagram illustrating an example of the arrangement of the radar 120 according to the embodiment in a case where the radar 120 receives a reflected wave that is a radio wave that is emitted by the radar itself and reflected by the ground. [Figure 3] 3 is a diagram for explaining flat tire detection in the example arrangement shown in FIG. 2. FIG. [Figure 4] 3 is a diagram for explaining flat tire detection in the example arrangement shown in FIG. 2. FIG. [Figure 5] 10 is a diagram for explaining detection of puncture of a tire 110 based on a distance L2 for a plurality of tires 110 according to the embodiment. FIG. [Figure 6] 10 is a diagram for explaining a detection method in a case where the radar 120 according to the embodiment receives a reflected wave that is a radio wave radiated by another radar 120 and reflected by the ground. [Figure 7] 10 is a diagram for explaining a detection method in a case where the radar 120 according to the embodiment receives a reflected wave that is a radio wave radiated by another radar 120 and reflected by the ground. [Figure 8] 10A and 10B are diagrams for explaining detection of submergence according to the embodiment; DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In this specification and drawings, components having substantially the same functional configurations are designated by the same reference numerals, and redundant explanations will be omitted.

[0010] In addition, in this specification and drawings, when multiple identical components are to be described separately, letters or the like may be added to the end of the reference numerals. On the other hand, when it is not necessary to distinguish between multiple identical components, the letters or the like may be omitted and a description common to all of the multiple identical components may be given.

[0011] <1. Embodiment> <<1.1. System configuration example>> First, an example of the functional configuration of a detection system 1 according to an embodiment of the present invention will be described.

[0012] FIG. 1 is a block diagram showing an example of the functional configuration of a detection system 1 according to an embodiment of the present invention.

[0013] As shown in FIG. 1, a detection system 1 according to this embodiment includes a moving object 10.

[0014] (Mobile 10) The moving body 10 according to this embodiment is a vehicle such as a four-wheeled motor vehicle, a two-wheeled motor vehicle, or a two-wheeled vehicle.

[0015] In the following, a case where the moving body 10 according to this embodiment is a four-wheeled motor vehicle will be mainly described as an example.

[0016] As shown in FIG. 1, the moving object 10 includes tires 110, a radar 120, a control device 130, a notification device 140, a controlled device 150, and a communication device 160.

[0017] (Tire 110) The moving body 10 has at least one tire 110. For example, if the moving body 10 is a four-wheeled motor vehicle, the moving body 10 has a tire 110FL corresponding to the left front wheel, a tire 110RL corresponding to the left rear wheel, a tire 110FR corresponding to the right front wheel, and a tire 110RR corresponding to the right rear wheel.

[0018] In this specification and drawings, when there is no need to distinguish between the tires 110FL, 110RL, 110FR, and 110RR, they will be simply referred to as tires 110.

[0019] (Radar 120) At least one radar 120 is mounted on the moving body 10 according to this embodiment.

[0020] The number of radars 120 mounted on the moving body 10 may be determined according to the number of tires 110 provided on the moving body 10.

[0021] For example, if the moving object 10 is equipped with four tires 110, the moving object 10 may be equipped with four radars 120 associated with the tires, respectively.

[0022] If the moving body 10 is a four-wheeled motor vehicle, the moving body 10 may be equipped with a radar 120FL associated with the tire 110FL, a radar 120RL associated with the tire 110RL, a radar 120FR associated with the tire 110FR, and a radar 120RR associated with the tire 110RR.

[0023] In this specification and drawings, when there is no need to distinguish between the radar 120FL, the radar 120RL, the radar 120FR, and the radar 120RR, they will be simply referred to as radar 120.

[0024] The radar 120 according to this embodiment may emit radio waves that comply with a prescribed communication standard, such as ultra-wide band (UWB) wireless communication.

[0025] In recent years, the Car Connectivity Consortium (CCC) and other organizations have been considering using ultra-wideband wireless communication for key (digital key) authentication.

[0026] More specifically, it is being considered to perform ultra-wideband wireless communication between a UWB communication device mounted on a mobile body 10 and a mobile device carried by a user of the mobile body 10, estimate the distance between the two (ranging) based on the ultra-wideband wireless communication, and control the operation of a controlled device 150 provided on the mobile body 10 based on the estimated distance (ranging value).

[0027] When performing the above-described authentication, multiple UWB communication devices are mounted on the mobile object 10. In this case, the UWB communication devices originally mounted on the mobile object 10 for authentication can be diverted as radar 120, thereby reducing costs.

[0028] As described above, the specified communication standard is preferably, but not limited to, ultra-wideband wireless communication. The radar 120 may radiate radio waves in other frequency bands, such as millimeter waves.

[0029] Furthermore, one of the features of the radar 120 according to this embodiment is that the radar 120 receives a reflected wave that is a radio wave radiated by the radar 120 and reflected by the ground.

[0030] (Control device 130) The control device 130 according to this embodiment may be an ECU (Electronic Control Unit) that controls the components mounted on the moving body 10.

[0031] For example, the control device 130 detects a drop in air pressure in the tire 110 based on the reflected wave received by the radar 120.

[0032] In the following, a case where the control device 130 detects a drop in air pressure of the tire 110, particularly a puncture, will be mainly described as an example.

[0033] The control device 130 also controls the notification device 140 to notify information about the detected flat tire or the like.

[0034] In addition, the control device 130 may perform authentication based on the distance to the mobile device carried by the user of the moving body 10, estimated by the radar 120, and control the operation of the controlled device 150 based on the result of the authentication.

[0035] The control device 130 may also control information communication between the communication device 160 and other devices.

[0036] (Notification device 140) The notification device 140 according to this embodiment notifies the user of information relating to a detected flat tire or the like, under the control of the control device 130.

[0037] The notification device 140 according to this embodiment may be, for example, a car navigation device, or may simply be a display, a speaker, or the like.

[0038] Furthermore, the notification device 140 according to this embodiment does not necessarily have to be mounted on the moving object 10.

[0039] The notification device 140 according to this embodiment may be, for example, a mobile device such as a smartphone carried by a user.

[0040] In this case, the control device 130 controls the mobile device via the communication device 160 .

[0041] (Controlled device 150) Controlled device 150 according to this embodiment is a device that performs a specified operation based on the result of the above authentication.

[0042] For example, the controlled device 150 according to this embodiment may be a locking / unlocking device that locks and unlocks a door provided in the moving body 10.

[0043] If the authentication is successful, the control device 130 may cause the controlled device 150, which is a locking / unlocking device, to lock or unlock the door.

[0044] Furthermore, for example, controlled device 150 according to the present embodiment may be an engine provided in moving body 10.

[0045] If the authentication is successful, the control device 130 may permit the controlled device 150, which is an engine, to start.

[0046] (Communication device 160) The communication device 160 according to this embodiment communicates information with other devices via, for example, the Internet.

[0047] Examples of the other devices include a mobile device carried by the user of the mobile object 10, a server operated by a connected center (described later), and the like.

[0048] The above describes an example of the functional configuration of the detection system 1 according to this embodiment. Note that the functional configuration described above with reference to Fig. 1 is merely an example, and the functional configuration of the detection system 1 according to this embodiment is not limited to this example.

[0049] The functional configuration of the detection system 1 according to this embodiment can be flexibly modified according to specifications, operation, and the like.

[0050] <<1.2.Function Details>> As described above, Patent Document 1 does not take into consideration detecting a drop in air pressure in the tire 110 when the moving object 10 is not moving.

[0051] Furthermore, a method of detecting a drop in air pressure in the tire 110 can be, for example, a method using a TPMS (Tire Pressure Monitoring System). Even when an indirect TPMS is used, a drop in air pressure in the tire 110 cannot be detected when the mobile object 10 is not moving. On the other hand, when a direct TPMS is used, a drop in air pressure in the tire 110 can be detected when the mobile object 10 is moving, but a dedicated valve with a built-in radio is required, which increases costs.

[0052] The technical concept of one embodiment of the present invention was conceived with the above points in mind, and makes it possible to detect a drop in air pressure in a tire 110 at low cost when the moving body 10 is not moving.

[0053] According to this, for example, by notifying the user that the tire 110 is punctured before the moving body 10 starts moving, it is possible to prevent damage to the tire 110.

[0054] The detection method performed by the detection system 1 according to this embodiment will be described in detail below.

[0055] First, a detection method will be described in which the radar 120 according to this embodiment receives a reflected wave that is the radio wave that it radiates and is reflected by the ground.

[0056] FIG. 2 is a diagram showing an example of the arrangement of the radar 120 according to this embodiment in the case where the radar 120 receives a reflected wave that is the radio wave that it radiates and is reflected by the ground.

[0057] FIG. 2 shows an example of the arrangement of radars 120RL associated with tires 110RL.

[0058] Although not shown, the moving object 10 may further be equipped with radars 120FL, 120FR, and 120RR associated with the tires 110FL, 110FR, and 110RR, respectively.

[0059] The radar 120 is disposed on the exterior of the moving body 10 directly above (at 12 o'clock) the tire 110 to which it is associated.

[0060] Furthermore, the radar 120 is placed on a non-metallic member such as a resin bumper, thereby reducing the influence of metallic members on radio waves.

[0061] 3 and 4 are diagrams for explaining puncture detection in the example arrangement shown in FIG.

[0062] The left side of Fig. 3 shows the positional relationship between the tire 110 and the radar 120 associated with the tire 110 when the tire 110 is not punctured. The right side of Fig. 3 shows the positional relationship between the tire 110 and the radar 120 associated with the tire 110 when the tire 110 is punctured.

[0063] In this example, the radar 120 is placed directly above the tire 110 to which it is associated, as shown in FIG. 4, in a position where the radio waves it emits strike both the tire 110 and the ground.

[0064] In this case, the radar 120 estimates the distance L1 to the tire 110 based on the propagation time of the radio waves emitted by the radar 120 and reflected by the tire 110, and estimates the distance L2 to the ground based on the propagation time of the radio waves reflected by the ground.

[0065] Furthermore, the control device 130 according to this example detects a drop in the air pressure of the tire based on the distance L1 and the distance L2.

[0066] Specifically, the control device 130 may calculate the diameter of the tire 110 by subtracting the distance L1 from the distance L2, and may determine that the tire 110 is punctured if the displacement Δd between the diameter of the tire 110 calculated this time and the diameter of the tire 110 calculated last time exceeds a threshold value.

[0067] That is, the control device 130 detects a puncture of the tire 110 based on the displacement Δd, which is the difference between the distance L1 and the distance L2.

[0068] It is also possible to detect a puncture of a tire 110 based on the amount of displacement of only the distance L2 related to a single tire 110. However, the distance L2 may vary due to deterioration of the suspension provided on the moving body 10, the weight of the luggage carried on the moving body 10, and the like.

[0069] In contrast, a detection method based on the displacement Δd of distance L2 - distance L1 eliminates the effects of deterioration of the suspension provided on the moving body 10, the weight of the luggage loaded on the moving body 10, etc., and makes it possible to detect a puncture in the tire 110 with high accuracy.

[0070] On the other hand, the control device 130 may detect a puncture of a tire 110 based on the distance L2 related to a plurality of tires 110.

[0071] FIG. 5 is a diagram for explaining detection of a puncture of a tire 110 based on the distance L2 relating to a plurality of tires 110. In FIG.

[0072] 5, the radar 120FL associated with the tire 110FL estimates the distance L2fl to the ground. Similarly, the radar 120RL associated with the tire 110RL estimates the distance L2rl to the ground.

[0073] Although not shown, the radar 120FR associated with the tire 110FR estimates the distance L2fr to the ground, and the radar 120RR associated with the tire 110RR estimates the distance L2rr to the ground.

[0074] It should be noted that when the detection method described with reference to FIG. 5 is employed, the radar 120 does not need to be placed directly above the corresponding tire 110.

[0075] Here, if the difference between the distance L2fl and the distance L2fr exceeds a threshold value, the control device 130 determines that the tire 110 corresponding to the shorter distance out of the distance L2fl and the distance L2fr is punctured.

[0076] Similarly, if the difference between the distance L2rl and the distance L2rr exceeds a threshold value, the control device 130 determines that the tire 110 corresponding to the shorter distance out of the distance L2rl and the distance L2rr is punctured.

[0077] That is, the control device 130 can detect a puncture in the tires 110 provided on the left and right front sides of the moving body 10 based on the difference between the distances L2 estimated by each of the two radars 120 arranged on the left and right front sides of the moving body 10.

[0078] Similarly, the control device 130 can detect a puncture in the tires 110 provided on the left and right rear sides of the mobile body 10 based on the difference in the distance L2 estimated by each of the two radars 120 arranged on the left and right rear sides of the mobile body 10.

[0079] Generally, it is rare for both the left and right tires 110 at the front or rear to be punctured at the same time. Therefore, the detection method described with reference to FIG. 5 can eliminate the influence of suspension deterioration, the weight of luggage, etc., and enable highly accurate detection of punctures in the tires 110.

[0080] It should be noted that flat tire detection based on comparison of the distance L2 on the left and right can be combined with the detection method described with reference to FIGS.

[0081] The detection method in which the radar 120 according to this embodiment receives a reflected wave that is the radio wave that it radiates and is reflected by the ground has been described above.

[0082] Next, with reference to FIGS. 6 and 7, a detection method in which the radar 120 according to this embodiment receives a reflected wave that is a radio wave emitted by another radar 120 and reflected by the ground will be described.

[0083] In this detection method, the radar 120 is classified into a first radar that emits radio waves and a second radar that receives the waves that are reflected by the ground from the radio waves emitted by the first radar.

[0084] In FIGS. 6 and 7, the radar 120FL is an example of the first radar, and the radar 120RL is an example of the second radar.

[0085] In this detection method, the radar 120 does not need to be placed directly above the corresponding tire 110.

[0086] FIG. 6 illustrates the distance L3a when the tires 110RL and 110FL are not punctured.

[0087] FIG. 7 also illustrates the distance L3b when the tire 110RL is punctured.

[0088] As shown in FIGS. 6 and 7, the distance L3b when the tire 110RL is punctured is shorter than the distance L3a when the tires 110RL and 110FL are not punctured.

[0089] Similarly, the distance L3c (not shown) when the tire 110FL is punctured is shorter than the distance L3a when the tires 110RL and 110FL are not punctured.

[0090] Therefore, the control device 130 may detect a puncture of the tire 110 based on a change in the distance L3.

[0091] Although it is difficult to determine which tire 110 is punctured from the distance L3 alone, it is immediately obvious to the user which tire 110 is punctured by visual inspection.

[0092] Therefore, the control device 130 may cause the notification device 140 to notify the user that one of the tires 110 is punctured and to prompt the user to visually check the tire.

[0093] The control device 130 may also detect a puncture in the tire 110 based on a comparison of the distance L3 between the left and right sides of the moving body 10.

[0094] The distance L3 on the punctured side corresponds to the distance L3b shown in FIG. 7, and the distance L3 on the non-punctured side corresponds to the distance L3a shown in FIG.

[0095] Therefore, the control device 130 may determine that one of the tires 110 is punctured, for example, if the difference between the distance L3 estimated by the radar 120RL (first radar: radar 120FL) and the distance L3 estimated by the radar 120RR (first radar: radar 120FR) exceeds a threshold value.

[0096] Furthermore, the control device 130 may perform flat tire detection based on a comparison of the distance L2 between the left and right sides described with reference to FIG. 5 in addition to the distance L3.

[0097] Furthermore, the distance L3 may be estimated based on the propagation time of the second earliest radio wave among the radio waves received by the second radar. The first earliest radio wave among the radio waves received by the second radar is assumed to be a direct wave received directly from the first radar without being reflected by an object, and the second earliest radio wave among the radio waves received by the second radar is assumed to be a reflected wave reflected by the ground.

[0098] The puncture detection method according to this embodiment has been described above.

[0099] The distances L1, L2, and L3 or the threshold values ​​in the above-described detection method may be corrected based on the vehicle height detected when the headlight auto-leveling function is executed, for example.

[0100] In addition, the control device 130 may control the radar 120, for example, when locking and unlocking the doors of the mobile body 10, or when stopping and starting (allowing) the engine of the mobile body 10, to obtain the distance L1, the distance L2, the distance L2 - the distance L1 (the diameter of the tire 110), the distance L3, etc.

[0101] According to this, the control device 130 can attempt to detect a puncture in the tire 110 when the door of the mobile body 10 is locked or unlocked, or when the engine of the mobile body 10 is stopped or started (allowed), i.e., when the mobile body 10 is not moving, and if a puncture in the tire 110 is detected, the control device 130 can notify the notification device 140 of this.

[0102] Furthermore, by using the timing described above, the influence of the weight of the passengers, luggage, etc. can be reduced, and puncture detection can be performed with higher accuracy.

[0103] In particular, when comparing the distance when the door is locked and the distance when it is unlocked for the first time after being locked, or when comparing the distance when the engine is stopped and the distance when it is started for the first time after being stopped, the effect of weight is eliminated, making it possible to reliably detect a puncture even in cases where a puncture occurs slowly over time while the vehicle is stopped.

[0104] Furthermore, when adopting a detection method in which the radar 120 receives reflected waves that are the result of radio waves emitted by another radar 120 being reflected by the ground, it is desirable to attempt detection when the doors of the mobile body 10 are closed.

[0105] This is because when the door is open, the radio waves are diffracted by the open door, thereby extending the distance L3.

[0106] Furthermore, since it is anticipated that a flat tire may occur while the moving object 10 is traveling, the control device 130 may, for example, attempt to detect a flat tire when the speed of the moving object 10 is zero while the moving object 10 is traveling. Furthermore, the control device 130 may, for example, attempt to detect a flat tire at predetermined time intervals.

[0107] <<1.3. Variations>> Next, a modified example in which the above-described puncture detection technology is applied to flood detection will be described.

[0108] FIG. 8 is a diagram for explaining detection of submergence.

[0109] In FIG. 8, radar 120FL is an example of the first radar, and radar 120RL is an example of the second radar.

[0110] When the moving object 10 is submerged, the second-fastest radio wave received by the radar 120RL is a wave reflected by the water surface. This allows the control device 130 to detect submergence and estimate the depth of the submergence based on the distance L5 of the radio wave propagation path of the wave reflected by the water surface.

[0111] Since there is usually little risk of flooding on sunny days, the control device 130 may cause the radar 120 to estimate the distance L5 only when it is raining, for example, by using the operation of the wipers as a sensing trigger. Also, the control device 130 may activate the flood detection function only when the speed of the mobile object 10 falls below a predetermined value.

[0112] Furthermore, the control device 130 may attempt to detect flooding based on a request from the connected center.

[0113] In recent years, the use of connected cars has progressed, and attempts are being made to collect various big data from cars traveling around town. Applying this invention can contribute to the creation of flood area maps in real time.

[0114] In addition, if the flooding is so severe that the radar 120 is submerged, it becomes impossible to estimate the distance L5. In this case, the height of the flooding may be estimated based on the height at which the radar 120 is positioned instead of the estimated result of the distance L5.

[0115] Furthermore, the control device 130 may detect flooding and estimate the flood height based on the distance L6fl estimated by the radar 120FL, the distance L6rl estimated by the radar 120RL, and the like.

[0116] <2. Supplementary Information> Although the preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings, the present invention is not limited to these examples. It is clear that a person skilled in the art to which the present invention pertains can conceive of various modifications and alterations within the scope of the technical ideas set forth in the claims, and it is understood that these also naturally fall within the technical scope of the present invention.

[0117] For example, in the above embodiment, the radar 120 is a radio wave radar, but the radar 120 may be an optical radar, a sonic radar, or the like.

[0118] Furthermore, the series of processes performed by each device described in this specification may be realized by a program stored in a non-transitory computer-readable storage medium. Each program is, for example, loaded into RAM when executed by a computer and executed by a processor such as a CPU. The storage medium may be, for example, a magnetic disk, an optical disk, a magneto-optical disk, or a flash memory. The program may also be distributed, for example, via a network, without using a storage medium. [Explanation of symbols]

[0119] 1: detection device, 10: moving object, 110: tire, 120: radar, 130: control device, 140: notification device, 150: controlled device, 160: communication device

Claims

1. A radar and a control device are mounted on a moving body, The radar receives a reflected wave that is a radio wave irradiated by the radar and reflected by the ground, the control device detects a decrease in air pressure in a tire provided on the moving object based on the reflected wave. Detection system.

2. A plurality of the radars is provided, At least one of the plurality of radars receives a reflected wave that is a radio wave emitted by another of the radars and reflected by the ground, The control device detects a decrease in air pressure of the tire based on a change in the length of the radio wave propagation path of the reflected wave. The detection system of claim 1 .

3. the plurality of radars include a first radar arranged in association with one of a front tire or a rear tire of the moving object, and a second radar arranged in association with the other of the front tire or the rear tire, the second radar receives a reflected wave that is a radio wave irradiated by the first radar and reflected by the ground; the control device detects a decrease in air pressure of the front tire or the rear tire based on a change in the length of the radio wave propagation path of the reflected wave. The detection system of claim 2 .

4. The radar receives a reflected wave of the radio wave that it emits and that is reflected by the ground. The detection system of claim 1 .

5. The radar estimates a distance to the tire based on a wave reflected by the tire from a radio wave emitted by the radar, and estimates a distance to the ground based on a wave reflected by the ground from a radio wave emitted by the radar, the control device detects a decrease in air pressure of the tire based on the estimated distance to the tire and the distance to the ground. The detection system of claim 4 .

6. the control device detects a decrease in air pressure of the tire based on an amount of change in the difference between the estimated distance to the tire and the distance to the ground. The detection system of claim 5 .

7. The radar is disposed directly above the tire at a position where the radiated radio waves strike both the tire and the ground. The detection system of claim 5 .

8. the control device attempts to detect a decrease in air pressure of the tire when a door of the mobile body is unlocked, when the door is locked, when an engine of the mobile body is stopped, or when the engine is started; The detection system of claim 1 .

9. The radar emits radio waves conforming to ultra-wideband wireless communication. A detection system according to any one of claims 1 to 8.

10. the radar further functions as a communication device for performing ultra-wideband wireless communication with a mobile device carried by a user of the moving object; The distance to the mobile device estimated by the radar is used to control the operation of a controlled device provided in the moving object. The detection system of claim 9.

11. The controlled device includes at least one of a door locking / unlocking device provided in the moving body and an engine. The detection system of claim 10.

12. The radar is disposed on a non-metallic member in the moving body. The detection system of claim 1 .

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