Control device

Abstract

A control device is provided with: an acquisition means for acquiring a detection result of a sensor provided in an underground passage, the detection result being generated by a receiver of the sensor receiving a portion of the terahertz wave reflected by the road surface while the propagation direction of the terahertz wave emitted from a transmitter of the sensor changes; and a calculation means for calculating the ponding range of the underground passage on the basis of the detection result.

Description

Technical Field

[0001] This invention relates to the technical field of a control device. Background Technology

[0002] As such a device, for example, a device has been proposed that determines the degree of water accumulation on the road by identifying whether there is water splashing onto surrounding vehicles traveling around it, and the visibility of the surrounding vehicles' bodies. The visibility of the surrounding vehicles' bodies is identified, for example, based on images taken by an onboard camera. (Ref. Japanese Patent Application Publication No. 2021-114102.) Summary of the Invention

[0003] The technology described in Japanese Patent Application Publication No. 2021-114102 has room for improvement.

[0004] The present invention was made in view of the above circumstances, and its object is to provide a control device capable of detecting water accumulation in underground passages with high precision.

[0005] The control device according to one aspect of the present invention includes:

[0006] An acquisition unit acquires the sensor's detection result by acquiring a portion of the terahertz wave reflected from the road surface at a receiver simultaneously with a change in the propagation direction of the terahertz wave emitted from the transmitter of a sensor installed in the underground passage; and...

[0007] The calculation unit calculates the water accumulation range of the underground passage based on the detection results. Attached Figure Description

[0008] Hereinafter, with reference to the accompanying drawings, the features, advantages, and technical and industrial significance of exemplary embodiments of the present invention will be described, in which the same reference numerals denote the same elements, and wherein:

[0009] Figure 1 This is a block diagram illustrating the configuration of the control device involved in the implementation method.

[0010] Figure 2 This is a conceptual diagram illustrating an example of how the sensors are arranged in an implementation method.

[0011] Figure 3 This is a flowchart illustrating an example of the operation of the control device involved in the implementation method.

[0012] Figure 4 This is a diagram illustrating an example of the swing angle of the sensor involved in the implementation method. Detailed Implementation

[0013] refer to Figures 1 to 4The control device involved in the implementation method will be described. Figure 1 In this device, the control unit 10 includes a sensor 11, an angle-variable device 12, a control and collection device 13, and a computing device 14. The sensor 11 has a terahertz wave transmitter 111 and a terahertz wave receiver 112.

[0014] like Figure 2 As shown, sensor 11 can be installed in the ceiling of the underground passage. Sensor 11 may have a swing mechanism (not shown). An angle-variable device 12 can change the propagation direction of the terahertz wave emitted from transmitter 111 by controlling the swing mechanism of sensor 11. For example, angle-variable device 12 can control the swing mechanism of sensor 11 to make the terahertz wave emitted from transmitter 111 scan the underground passage in the direction of its extension.

[0015] The control and collection device 13 controls the transmitter 111 to irradiate terahertz waves onto the surface of the underground passage. The receiver 112 receives at least a portion of the terahertz waves reflected by the surface. The control and collection device 13 collects detection information (i.e., data) related to the detection results of the receiver 112. In other words, the control and collection device 13 acquires the detection results of the sensor 11. Furthermore, the aforementioned detection information (in other words, the detection results of the sensor 11) may include angular information representing the swing angle of the sensor 11.

[0016] The control and collection device 13 controls the transmitter 111 to irradiate the road surface with a first terahertz wave having a first frequency and a second terahertz wave having a second frequency different from the first frequency. Here, the reflectivity of the first terahertz wave in water is the same as the reflectivity of the first terahertz wave on a dry road surface. The reflectivity of the second terahertz wave in water is less than the reflectivity of the second terahertz wave on a dry road surface. Furthermore, the first frequency can be less than the second frequency.

[0017] The computing device 14 may include, for example, at least one of a central processing unit (CPU) and a graphics processing unit (GPU). The computing device 14 acquires the aforementioned detection information from the control and collection device 13. The computing device 14 can calculate the extent of water accumulation in the underground passage (in other words, the range of water accumulation) based on the acquired detection information. Additionally, the computing device 14 can control the angle-variable device 12 to change the propagation direction of the terahertz waves emitted from the transmitter 111.

[0018] When rainwater flows into the underground passage, the ramp that is part of the underground passage will also be soaked. According to the inventors' research, the following is known: The reflectivity of the second terahertz wave in the water-filled portion of the road surface is significantly lower than that in the wet portion (i.e., the portion of the road surface without water). This is because the receiver 112 receives more of the terahertz wave component reflected by the road surface than the component reflected by the water. Therefore, the processing device 14 is able to calculate the extent of the water accumulation based on the aforementioned detection information.

[0019] If water accumulation is detected in the underpass based on the calculation results of the computing device 14, the computing device 14 can send water accumulation information to vehicles traveling around the underpass. Vehicles receiving the water accumulation information can display the information on their in-vehicle monitors 20. As a result, the vehicle's occupants are informed of the water accumulation in the underpass.

[0020] Additionally, the angle-variable device 12 can control the swing mechanism of the sensor 11 to scan the underground passage in the width direction of the underground passage with the terahertz wave emitted from the transmitter 111. In this case, the terahertz wave emitted from the transmitter 111 can illuminate the surface of the underground passage and also the side walls of the underground passage.

[0021] For example, the swing angle of sensor 11 is set to 0 degrees when the propagation direction of the terahertz wave emitted from transmitter 111 is perpendicular to the road surface of the underground passage. Also, for example, the swing angle of sensor 11 is set to 90 degrees when the propagation direction of the terahertz wave emitted from transmitter 111 is perpendicular to one side wall of the underground passage. If the underground passage is flooded, a portion of the side wall will be submerged. In this case, within a relatively small range of the swing angle of sensor 11, the reflectivity of the second terahertz wave becomes the reflectivity of the second terahertz wave in water. Furthermore, within a relatively large range of the swing angle of sensor 11, the reflectivity of the second terahertz wave becomes the reflectivity of the second terahertz wave on a dry road surface.

[0022] Therefore, the water accumulation in the underground passage can be detected within the range of the swing angle of sensor 11, which measures the reflectivity of the second terahertz wave as the reflectivity of the second terahertz wave in water. Furthermore, if the relationship between the swing angle of sensor 11 and the height of the sidewall of the underground passage is known, the water depth in the water-filled underground passage can be determined based on the swing angle of sensor 11. Less water seeps into the underground passage along its sidewall. Therefore, when the terahertz wave emitted from transmitter 111 scans the underground passage in the width direction, the water accumulation in the underground passage can be detected with higher precision.

[0023] In addition, the angle-variable device 12 can control the swing mechanism of the sensor 11 so that the terahertz wave emitted from the transmitter 111 scans the underground passage in the extension direction of the underground passage and in the width direction of the underground passage.

[0024] Action of the control device

[0025] Next, refer to Figure 3 The flowchart illustrates an example of the operation of the control device 10. Figure 3 In this process, the control device 10 uses the sensor 11 to measure the water level in the underground passage (S101). Specifically, the control and collection device 13 controls the transmitter 111 to irradiate terahertz waves onto the surface of the underground passage and collects detection information related to the detection results of the receiver 112. At this time, because the angle-variable device 12 controls the swing mechanism of the sensor 11, the propagation direction of the terahertz waves emitted from the transmitter 111 changes, and the receiver 112 receives a portion of the terahertz waves reflected from the surface.

[0026] The processing unit 14, based on the detection information, adjusts the swing angle of the sensor 11 by θ1 (reference). Figure 4 In the case of [the situation described in the original text], it is determined whether the reflectivity of the first terahertz wave is a first predetermined value and whether the reflectivity of the second terahertz wave is less than a second predetermined value (S102). Here, the second predetermined value is a value smaller than the first predetermined value. The second predetermined value can be a value between the reflectivity of the second terahertz wave in water and the reflectivity of the second terahertz wave on a dry road surface. In addition, the reflectivity of the terahertz wave can be calculated based on the intensity of the terahertz wave emitted from the transmitter 111 and the intensity of the terahertz wave received by the receiver 112.

[0027] In the S102 process, if the reflectivity of the first terahertz wave is determined to be less than the first specified value when the swing angle is θ1, the process ends. Figure 3 The action shown. Alternatively, in the processing of S102, if it is determined that the reflectivity of the second terahertz wave is not below the second specified value when the swing angle is θ1 (S102: "No"), then the process ends. Figure 3 The actions shown.

[0028] In the S102 processing, when the swing angle is θ1, if it is determined that the reflectivity of the first terahertz wave is below a first predetermined value and the reflectivity of the second terahertz wave is below a second predetermined value (S102: "Yes"), the arithmetic unit 14 performs the S103 processing. In the S103 processing, the arithmetic unit 14, based on the detection information, determines that the reflectivity of the first terahertz wave is below a first predetermined value and the reflectivity of the second terahertz wave is below a second predetermined value (S102: "Yes"), and the arithmetic unit 14 performs the S103 processing. Figure 4In the case of ), it is determined whether the reflectivity of the first terahertz wave is a first specified value and whether the reflectivity of the second terahertz wave is below a second specified value (S103).

[0029] In the S103 process, if the reflectivity of the first terahertz wave is determined to be less than the first specified value when the swing angle is θ2, the process ends. Figure 3 The action shown. Alternatively, in the processing of S103, if the reflectivity of the second terahertz wave is determined to be less than or equal to the second specified value when the swing angle is θ2 (S103: "No"), then the process ends. Figure 3 The actions shown.

[0030] In the processing of S103, if the swing angle is θ2, it may be determined that the reflectivity of the first terahertz wave is below a first predetermined value and the reflectivity of the second terahertz wave is below a second predetermined value (S103: "Yes"). In this case, the processing unit 14 determines that the water accumulation in the underground passage is to the extent that it poses a driving hazard to vehicles (step S104). The processing unit 14 can send water accumulation information indicating water accumulation in the underground passage to vehicles traveling around the underground passage (S105). Alternatively, the processing of S102 can be performed after the processing of S103.

[0031] Technical effect

[0032] The control device 10 uses terahertz waves to detect water accumulation on the surface of the underground passage. For example, compared to using images of the underground passage to determine whether it is flooded, the control device 10 can detect water accumulation with high precision.

[0033] like Figure 4 As shown, the height of position P1 irradiated with terahertz waves when the swing angle of sensor 11 is θ1 is different from the height of position P2 irradiated with terahertz waves when the swing angle of sensor 11 is θ2. Therefore, when water accumulation is detected at position P2 (for example, when it is determined to be "yes" in the process of S103 above), the water level in the underground passage is equal to the distance from the bottom of the underground passage to the height of position P2. Therefore, by appropriately setting the swing angle θ2, it is relatively easy to detect the degree of water accumulation in the underground passage that poses a danger to vehicle travel.

[0034] Variations

[0035] Following the processing in S104 described above, the control device 10 can send the water accumulation information to the management center that manages the underground passage. In this case, the management center can issue an instruction to block the entrances and exits of the underground passage based on the water accumulation information. Furthermore, the management center can distribute information indicating water accumulation in the underground passage to vehicles within a designated area centered on the underground passage.

[0036] The invention described below is an example of the embodiments and variations described above.

[0037] One aspect of the invention relates to a control device comprising: an acquisition unit that acquires a detection result of the sensor generated by acquiring a portion of the terahertz wave reflected on the road surface at a receiver of the sensor as the propagation direction of the terahertz wave emitted from a transmitter of a sensor installed in an underground passage changes; and a calculation unit that calculates the extent of water accumulation in the underground passage based on the detection result.

[0038] In the above embodiments, "control and collection device 13" is equivalent to an example of "acquisition unit", and "computation device 14" is equivalent to an example of "computation unit".

[0039] In one example of this control device, the transmitter can emit a first terahertz wave having a first frequency and a second terahertz wave having a second frequency different from the first frequency. Here, the reflectivity of the first terahertz wave in water can be equivalent to the reflectivity of the first terahertz wave on a dry road surface, and the reflectivity of the second terahertz wave in water can be less than the reflectivity of the second terahertz wave on a dry road surface.

[0040] This invention is not limited to the embodiments described above, and appropriate modifications can be made without departing from the spirit or concept of the invention as read in its entirety from the claims and description. Control devices that accompany such modifications are also included within the technical scope of this invention.

Claims

1. A control device, characterized in that, have: The acquisition unit acquires the sensor's detection result by acquiring the change in the propagation direction of the terahertz wave emitted from the transmitter of the sensor installed in the underground passage, while the receiver of the sensor receives a portion of the terahertz wave reflected on the road surface. and The calculation unit calculates the water accumulation range of the underground passage based on the detection results.

2. The control device according to claim 1, characterized in that, The transmitter emits a first terahertz wave with a first frequency and a second terahertz wave with a second frequency different from the first frequency.

3. The control device according to claim 2, characterized in that, The reflectivity of the first terahertz wave in water is the same as the reflectivity of the first terahertz wave on a dry road surface. The reflectivity of the second terahertz wave in water is less than that of the second terahertz wave on a dry road surface.

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