Warning device

Abstract

To reduce the possibility of a driver feeling uncomfortable due to a warning.SOLUTION: A warning device comprises: speed detection means (12) for detecting a speed of a vehicle (1); and determination means (25) which determines that a warning is to be issued if the speed is greater than a first threshold value, and determines that a warning is not to be issued if the speed is smaller than a second threshold value smaller than the first threshold value.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to the technical field of warning devices that issue warnings related to vehicle speed.

Background Art

[0002] As a device of this type, for example, a device has been proposed that warns a driver after a preset warning grace period has elapsed after the vehicle speed exceeds the limit speed (see Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the technique described in Cited Document 1, the value for determining whether to issue a warning is set to the limit speed. By the way, the speed of a vehicle often varies finely over time. For this reason, if a driver tries to maintain the vehicle speed near the limit speed, the ON / OFF transition of the warning may occur relatively frequently. Then, the driver may feel discomfort due to the warning.

[0005] The present invention has been made in view of the above problems, and an object thereof is to provide a warning device that can suppress a driver from feeling discomfort due to a warning.

Means for Solving the Problems

[0006] A warning device according to an aspect of the present invention includes speed detection means for detecting the speed of a vehicle, and determination means for determining that a warning is to be issued when the speed is greater than a first threshold value, and determining that no warning is to be issued when the speed is less than a second threshold value that is less than the first threshold value. The difference between the first threshold and the second threshold is 0.9 kilometers per hour.That is the case. [Brief explanation of the drawing]

[0007] [Figure 1] Block diagram showing the configuration of a vehicle according to the embodiment. [Figure 2] This is a flowchart showing the operation of the ECU according to the embodiment. [Figure 3] This is a conceptual diagram illustrating the concept of thresholds that determine whether the speed limit warning is turned ON or OFF. [Figure 4] This figure shows an example of the time-dependent changes in speed and the time-dependent changes in the ON / OFF state of the speed limit warning. [Figure 5] This figure shows another example of the time-dependent changes in speed and the time-dependent changes in the ON / OFF state of the speed limit warning. [Figure 6] This figure shows another example of the time-dependent changes in speed and the time-dependent changes in the ON / OFF state of the speed limit warning. [Modes for carrying out the invention]

[0008] Embodiments relating to the warning device will be described with reference to Figures 1 to 6.

[0009] In Figure 1, the vehicle 1 includes an external sensor 11, a speed sensor 12, an ACC (Adaptive Cruise Control) unit 13, an ACC (Variable Speed ​​Limiter) unit 14, an HMI (Human Machine Interface) 15, and an ECU (Electronic Control Unit) 20. The ECU 20 may be configured to perform automatic driving, which automatically controls at least one of the acceleration / deceleration and steering of the vehicle 1. In other words, the ECU 20 may have an automatic driving function.

[0010] The external sensor 11 includes a camera. The camera is for imaging the area in front of the vehicle 1. Such a camera may be located on the interior side of the windshield of the vehicle 1. The external sensor 11 may include multiple cameras. The external sensor 11 may also include at least one of a radar sensor and a LiDAR (Laser Imaging Detection and Ranging) sensor.

[0011] The speed sensor 12 detects the speed of the vehicle 1. In addition to the speed sensor 12, the vehicle 1 may also be equipped with at least one of an acceleration sensor and a yaw rate sensor as sensors capable of detecting the vehicle's behavior.

[0012] The HMI 14 is an interface for inputting and outputting information between the user of vehicle 1 (e.g., the driver) and the system of vehicle 1 (e.g., the ECU 20). The HMI 14 may have a display and speakers, etc. The display of the HMI 14 may be a HUD (Head Up Display) or a multi-information display provided on the instrument panel.

[0013] The ECU 20 includes a speed limit sign detection unit 21, an auxiliary sign detection unit 22, a vehicle category detection unit 23, a display determination unit 24, and a warning determination unit 25, either as logically constructed functional blocks or as physically implemented processing circuits. At least one of the speed limit sign detection unit 21, the auxiliary sign detection unit 22, the vehicle category detection unit 23, the display determination unit 24, and the warning determination unit 25 may be implemented in a form that combines logical functional blocks and physical processing circuits (i.e., hardware). If at least a part of the speed limit sign detection unit 21, the auxiliary sign detection unit 22, the vehicle category detection unit 23, the display determination unit 24, and the warning determination unit 25 is a functional block, then at least a part of it may be implemented by the ECU 20 executing a predetermined computer program.

[0014] The ECU 20 may obtain (in other words, read) the predetermined computer program from a storage device (not shown) provided by the vehicle 1. The ECU 20 may also read the predetermined computer program stored on a computer-readable and non-temporary recording medium using a recording medium reader. The ECU 20 may obtain (in other words, download or read) the predetermined computer program from a device (not shown) outside the vehicle 1 via a communication device. At least one of the following may be used as the recording medium for recording the predetermined computer program: an optical disc, a magnetic medium, a magneto-optical disc, a semiconductor memory, and any other medium capable of storing a program.

[0015] The speed limit sign detection unit 21 detects speed limit signs from images captured by the camera included in the external sensor 11. The speed limit sign detection unit 21 may detect speed limit signs by applying image processing to the image. Image processing may include, for example, at least one of edge extraction processing, noise reduction processing, and pattern matching processing. When an image is input, the speed limit sign detection unit 21 may detect speed limit signs using a computational model for detecting speed limit signs. An example of such a computational model is a computational model using a neural network (for example, a Convolutional Neural Network: CNN).

[0016] The auxiliary sign detection unit 22 detects auxiliary speed signs from the image captured by the camera included in the external sensor 11. The auxiliary sign detection unit 22 may detect auxiliary signs by applying image processing to the image. Image processing may include, for example, at least one of edge extraction processing, noise reduction processing, and pattern matching processing. When the auxiliary sign detection unit 22 receives an image as input, it may detect auxiliary signs using a computational model for detecting auxiliary signs. An example of such a computational model is a computational model using a neural network (e.g., CNN).

[0017] Further, the auxiliary sign detection unit 22 may detect only auxiliary signs indicating content that supplements the speed regulation indicated by the speed limit sign. In this case, the auxiliary sign detection unit 22 may start processing for detecting an auxiliary sign on the condition that the speed limit sign has been detected by the speed limit sign detection unit 21. Further, the auxiliary sign detection unit 22 may detect an auxiliary sign indicating at least one of, for example, "day / hour", "section / area", and "type of vehicle".

[0018] The vehicle category detection unit 23 detects the vehicle category related to the vehicle 1. For example, when the ECU 20 stores in advance information indicating the vehicle category related to the vehicle 1, the vehicle category detection unit 23 may detect the vehicle category related to the vehicle 1 based on the information. For example, when the ECU 20 stores in advance information indicating at least one of the vehicle name and vehicle type of the vehicle 1, the vehicle category detection unit 23 may detect the vehicle category related to the vehicle 1 by specifying the vehicle category to which the vehicle 1 belongs from the information. Further, the vehicle category may include at least one of a large passenger car, a regular passenger car, a light automobile, a large motorcycle, a regular motorcycle, a large truck, a large special vehicle, a trailer, a regular motorcycle (125 cc or less), a motorized bicycle, and an emergency vehicle.

[0019] The display determination unit 24 may determine (or specify) the speed limit related to the vehicle 1 based on the detection result by the speed limit sign detection unit 21, the detection result by the auxiliary sign detection unit 22, and the detection result by the vehicle category detection unit 23. Further, when the speed limit sign has not been detected by the speed limit sign detection unit 21, the display determination unit 24 may specify the road on which the vehicle 1 is traveling based on the position information indicating the position of the vehicle 1 and the map information. Then, the display determination unit 24 may determine (or specify) the speed limit related to the vehicle 1 based on the specified road and the vehicle category related to the vehicle 1 detected by the vehicle category detection unit 23. Further, the position information indicating the position of the vehicle 1 may be obtained, for example, by using GNSS (Global Navigation Satellite System).

[0020] The display determination unit 24 transmits speed limit information indicating the speed limit related to the vehicle 1 to the HMI 15. The speed limit display unit 151 of the HMI 15 displays the speed limit based on the speed limit information. At this time, the speed limit display unit 15 may display a character string indicating the speed limit. The speed limit display unit 15 may display an image indicating the speed limit. The speed limit display unit 15 may display an icon imitating a speed limit sign indicating the speed limit.

[0021] When the sign-linked ACC unit 13 is operating (in other words, when the sign-linked ACC is functioning), the display determination unit 24 transmits the speed limit information to the sign-linked ACC unit 13. Here, the sign-linked ACC unit 13 may detect the distance between the preceding vehicle, which is the vehicle traveling immediately in front of the vehicle 1, and the vehicle 1 based on the output of the external sensor 11 (for example, an image captured by a camera, the output of a radar sensor, the output of a LiDAR). The sign-linked ACC unit 13 may automatically control the acceleration and deceleration of the vehicle 1 so that the distance between the preceding vehicle and the vehicle 1 approaches (typically, matches) a predetermined distance. Also, when the distance between the preceding vehicle and the vehicle 1 is longer than a predetermined distance, or when there is no preceding vehicle within a predetermined range in front of the vehicle 1, the sign-linked ACC unit 13 may automatically control the acceleration and deceleration of the vehicle 1 so that the speed of the vehicle 1 approaches (typically, matches) a predetermined speed. The above-mentioned predetermined speed may be set by the user (for example, the driver) of the vehicle 1. When the predetermined speed set by the user is greater than the speed limit indicated by the speed limit information, the sign-linked ACC unit 13 automatically sets the predetermined speed to the speed limit.

[0022] The display determination unit 24 may transmit speed limit information to the traffic sign-linked variable speed limiter unit 14. The traffic sign-linked variable speed limiter unit 14 may correct the control signal transmitted to the drive actuator of the vehicle 1 so that the speed of the vehicle 1 does not exceed a predetermined speed limit. Alternatively, the traffic sign-linked variable speed limiter unit 14 may control the drive actuator so that the speed of the vehicle 1 does not exceed a predetermined speed limit. The traffic sign-linked variable speed limiter unit 14 may change the predetermined speed limit based on the speed limit level information. Note that if the traffic sign-linked ACC unit 13 is operating (in other words, if the traffic sign-linked ACC is functioning), the traffic sign-linked variable speed limiter unit 14 does not need to operate. In this case, the display determination unit 24 does not need to transmit speed limit information to the traffic sign-linked variable speed limiter unit 14.

[0023] Furthermore, if Vehicle 1 is a vehicle equipped with an engine, the drive actuator may be an actuator that controls the amount of air supplied to the engine (e.g., throttle opening). If Vehicle 1 is a hybrid vehicle, the drive actuator may be a concept that includes a motor as a power source. In other words, if Vehicle 1 is a hybrid vehicle, the drive actuator may include an actuator that controls the amount of air supplied to the engine and a motor as a power source. If Vehicle 1 is an electric vehicle, the drive actuator may be a motor as a power source.

[0024] The display determination unit 24 transmits the speed limit information to the warning determination unit 25. The warning determination unit 25 determines whether or not to issue a speeding warning based on the speed limit indicated by the speed limit information and the speed of the vehicle 1 detected by the speed sensor 12. Note that the warning device according to this embodiment may be configured to include a speed sensor 12 and a warning determination unit 25.

[0025] The operation of the warning determination unit 25 will be explained with reference to the flowchart in Figure 2. In Figure 2, the warning determination unit 25 acquires the speed of vehicle 1 detected by the speed sensor 12 (step S101). The warning determination unit 25 determines whether the speed of vehicle 1 is equal to or greater than a first threshold (step S102). In the process of step S102, if it is determined that the speed of vehicle 1 is less than the first threshold (step S102: No), the warning determination unit 25 determines not to issue a speeding warning. As a result, the operation shown in Figure 2 is terminated. After that, the process of step S101 may be performed after a predetermined time has elapsed. In other words, the operation shown in Figure 2 may be repeated at a cycle corresponding to a predetermined time.

[0026] In the process of step S102, if it is determined that the speed of vehicle 1 is equal to or greater than the first threshold (step S102: Yes), the warning determination unit 25 determines to issue a speeding warning. In this case, the warning determination unit 25 transmits a warning signal to the HMI 15 indicating a warning ON state corresponding to the execution of a speeding warning. As a result, the speeding warning unit 152 of the HMI 15 issues a speeding warning based on the warning ON state indicated by the warning signal (step S103). The speeding warning unit 152 may issue a speeding warning by lighting or flashing a predetermined lamp. The speeding warning unit 152 may issue a speeding warning by emitting a warning sound. The speeding warning unit 152 may issue a speeding warning by displaying an image indicating that the vehicle is speeding.

[0027] After the processing in step S103, the warning determination unit 25 obtains the speed of vehicle 1 detected by the speed sensor 12 (step S104). The warning determination unit 25 determines whether the speed of vehicle 1 is less than the second threshold (step S105). Here, the second threshold is a smaller value than the first threshold (see, for example, Figure 3). If, in the processing of step S105, it is determined that the speed of vehicle 1 is equal to or greater than the second threshold (step S105: No), the warning determination unit 25 determines to issue a speeding warning. In this case, the warning determination unit 25 transmits a warning signal indicating the warning ON state to the HMI 15. After that, the processing in step S103 is performed. In other words, the execution of the speeding warning continues.

[0028] In step S105, if it is determined that the speed of vehicle 1 is less than the second threshold (step S105: Yes), the warning determination unit 25 determines not to issue a speeding warning (in other words, to stop the speeding warning). In this case, the warning determination unit 25 transmits a warning signal to the HMI 15 indicating a warning OFF state, which corresponds to stopping the speeding warning. As a result, the speeding warning unit 152 of the HMI 15 stops the speeding warning based on the warning OFF state indicated by the warning signal (step S106). After a predetermined time has elapsed, the process in step S101 may be performed.

[0029] The speeding warning will be explained with reference to Figure 3. In Figure 3, the solid line shows an example of the change in the speed of vehicle 1 over time. At time T1 in Figure 3, the speed of vehicle 1 is equal to or greater than the first threshold, so the warning determination unit 25 determines to issue a speeding warning. As a result, the speeding warning unit 152 issues a speeding warning. Subsequently, at time T2 in Figure 3, the speed of vehicle 1 falls below the second threshold, so the warning determination unit 25 determines not to issue a speeding warning. As a result, the speeding warning unit 152 stops the speeding warning. Therefore, in the example shown in Figure 3, a speeding warning is issued from time T1 to time T2.

[0030] As is clear from Figures 2 and 3, the first threshold is a value used to determine whether or not to initiate a speeding warning, and the second threshold is a value used to determine whether or not to stop the speeding warning. Therefore, if the speeding warning unit 152 is issuing a speeding warning, and the speed of vehicle 1 is less than the first threshold and greater than the second threshold, the warning determination unit 25 determines to issue a speeding warning. If the speeding warning unit 152 is issuing a speeding warning, and the speed of vehicle 1 is less than the second threshold, the warning determination unit 25 determines not to issue a speeding warning.

[0031] Next, the relationship between the first threshold, the second threshold, and the speed limit will be explained with reference to Figures 4 to 6. For example, the speed of vehicle 1 displayed by HMI 15 is often shown as a value with the decimal part truncated. On the other hand, the speed of vehicle 1 detected by speed sensor 12 includes the decimal part. Specifically, if the speed of vehicle 1 detected by speed sensor 12 is 40.1 kilometers per hour, the number indicating the speed of vehicle 1 displayed by HMI 15 is often "40".

[0032] For example, if the speed limit is 40 kilometers per hour, and the threshold for determining whether or not to initiate a speeding warning (corresponding to the first threshold mentioned above) is set to 40.1 kilometers per hour, the following problem arises. That is, if the speed of vehicle 1 detected by the speed sensor 12 is 40.2 kilometers per hour, a speeding warning will be issued even though the number indicating the speed of vehicle 1 displayed by the HMI 15 is "40". As a result, the user of vehicle 1 (for example, the driver) may feel uneasy because a speeding warning was issued even though the speed of vehicle 1 displayed by the HMI 15 does not exceed the speed limit.

[0033] Therefore, the threshold for determining whether or not to initiate a speeding warning (corresponding to the first threshold mentioned above) may be set to a value at least 1 kilometer per hour greater than the speed limit. In this case, considering that no speeding warning is issued until the speed of vehicle 1 exceeds the speed limit and reaches or exceeds the threshold for determining whether or not to initiate a speeding warning (corresponding to the first threshold mentioned above), it is preferable that the threshold for determining whether or not to initiate a speeding warning (corresponding to the first threshold mentioned above) be set to a value at least 1 kilometer per hour greater than the speed limit. This is because the period from when the speed of vehicle 1 exceeds the speed limit until a speeding warning is initiated can be made relatively short.

[0034] The upper part of Figure 4 shows an example of the time variation of the speed of vehicle 1. The lower part of Figure 4 shows an example of the time variation of the state indicated by the warning signal (i.e., warning ON state and warning OFF state). In Figure 4, threshold A is a value that is 1 kilometer per hour greater than the speed limit.

[0035] In the example shown in Figure 4, the threshold for determining whether or not to start a speeding warning (corresponding to the first threshold described above) and the threshold for determining whether or not to stop a speeding warning (corresponding to the second threshold described above) are both assumed to be threshold A. In the example shown in Figure 4, the warning determination unit 25 determines to issue a speeding warning if the speed of vehicle 1 is greater than or equal to threshold A. The warning determination unit 25 also determines to stop the speeding warning if the speed of vehicle 1 is less than threshold A.

[0036] As shown in the upper part of Figure 4, the speed of vehicle 1 fluctuates slightly over time. These speed fluctuations occur due to external disturbances (e.g., uneven and inclined road surface, wind) even when the driver of vehicle 1 keeps the accelerator pedal operation constant or when the traffic sign-linked ACC unit 13 automatically controls the acceleration and deceleration of vehicle 1.

[0037] Therefore, if the threshold for determining whether or not to start the speeding warning (corresponding to the first threshold mentioned above) and the threshold for determining whether or not to stop the speeding warning (corresponding to the second threshold mentioned above) are the same value (here, threshold A), the state indicated by the warning signal (i.e., warning ON state and warning OFF state) will change relatively frequently due to the influence of disturbances (see the lower part of Figure 4). In other words, transitions between the warning ON state and the warning OFF state will occur relatively frequently. As a result, the user of vehicle 1 (for example, the driver) may feel uncomfortable due to the speeding warning.

[0038] Next, the upper part of Figure 5 shows an example of the time change of vehicle 1's speed. The lower part of Figure 5 shows other examples of the time change of the state indicated by the warning signal (i.e., warning ON state and warning OFF state). In Figure 5, threshold A is a value that is 1 kilometer per hour greater than the speed limit. In Figure 5, threshold B is a value that is 0.5 kilometers per hour greater than the speed limit. Note that the example of the time change of vehicle 1 shown in the upper part of Figure 5 is the same as the example of the time change of vehicle 1 shown in the upper part of Figure 4.

[0039] In the example shown in Figure 5, the threshold for determining whether or not to start a speeding warning (corresponding to the first threshold mentioned above) is threshold A, and the threshold for determining whether or not to stop a speeding warning (corresponding to the second threshold mentioned above) is threshold B. In the example shown in Figure 5, the warning determination unit 25 determines to issue a speeding warning if the speed of vehicle 1 is greater than or equal to threshold A. The warning determination unit 25 also determines to stop the speeding warning if the speed of vehicle 1 is less than threshold B.

[0040] By comparing the state changes indicated by the warning signals shown in the lower part of Figure 5 with the state changes indicated by the warning signals shown in the lower part of Figure 4, the following can be concluded: That is, by setting the threshold for deciding whether or not to stop the speeding warning (here, threshold B) to a value smaller than the threshold for deciding whether or not to start the speeding warning (here, threshold A), the state changes indicated by the warning signals can be suppressed.

[0041] Next, the upper part of Figure 6 shows an example of the time change of vehicle 1's speed. The lower part of Figure 6 shows other examples of the time change of the state indicated by the warning signal (i.e., warning ON state and warning OFF state). In Figure 6, threshold A is a value that is 1 kilometer per hour greater than the speed limit. In Figure 6, threshold C is a value that is 0.1 kilometers per hour greater than the speed limit. Note that the example of the time change of vehicle 1 shown in the upper part of Figure 6 is the same as the example of the time change of vehicle 1 shown in the upper part of Figure 4.

[0042] In the example shown in Figure 6, the threshold for determining whether or not to start a speeding warning (corresponding to the first threshold mentioned above) is threshold A, and the threshold for determining whether or not to stop a speeding warning (corresponding to the second threshold mentioned above) is threshold C. In the example shown in Figure 6, the warning determination unit 25 determines to issue a speeding warning if the speed of vehicle 1 is greater than or equal to threshold A. The warning determination unit 25 also determines to stop the speeding warning if the speed of vehicle 1 is less than threshold C.

[0043] By comparing the state changes indicated by the warning signals shown in the lower part of Figure 6 with the state changes indicated by the warning signals shown in the lower part of Figure 5, the following can be said: That is, when the threshold for deciding whether or not to stop the speeding warning is 0.1 kilometers per hour greater than the speed limit, the state changes indicated by the warning signals can be reduced compared to when the threshold for deciding whether or not to stop the speeding warning is 0.5 kilometers per hour greater than the speed limit.

[0044] From the explanation with reference to Figures 4 to 6, the following can be said: By setting the threshold for deciding whether or not to stop the speeding warning (corresponding to the second threshold mentioned above) to a value smaller than the threshold for deciding whether or not to start the speeding warning (corresponding to the first threshold mentioned above), it is possible to suppress the change in state indicated by the warning signal (in other words, the transition between the warning ON state and the warning OFF state). If the threshold for deciding whether or not to start the speeding warning (corresponding to the first threshold mentioned above) is set to a value 1 kilometer per hour greater than the speed limit, and the threshold for deciding whether or not to stop the speeding warning (corresponding to the second threshold mentioned above) is set to a value 0.1 kilometers per hour greater than the speed limit, the change in state indicated by the warning signal can be reduced compared to the case where the threshold for deciding whether or not to stop the speeding warning is set to a value 0.5 kilometers per hour greater than the speed limit.

[0045] Based on these considerations, it is preferable that the first threshold is 1 kilometer per hour greater than the speed limit. It is preferable that the second threshold is 0.1 kilometers per hour greater than the speed limit. In this case, the difference between the first threshold and the second threshold is 0.9 kilometers per hour.

[0046] The first threshold is a value used to determine whether or not to initiate a speeding warning. When the warning determination unit 25 determines that the speed of vehicle 1 is equal to or greater than the first threshold, a speeding warning is issued to inform the vehicle that its speed has exceeded the speed limit. Therefore, the first threshold can be said to be a value used to determine whether or not the speed of vehicle 1 has exceeded the speed limit. The second threshold is a value used to determine whether or not to stop the speeding warning. When the warning determination unit 25 determines that the speed of vehicle 1 is less than the second threshold, the speeding warning that informs the vehicle that its speed has exceeded the speed limit is stopped. Therefore, the second threshold can be said to be a value used to determine whether or not the speed of vehicle 1 has fallen below the speed limit.

[0047] The first and second thresholds described above are merely examples and are not limiting. The difference between the first and second thresholds may be determined by considering, for example, at least one of the effects of disturbances and the effects of control errors in vehicle 1. Specifically, the range of fluctuation in the speed of vehicle 1 due to at least one of the effects of disturbances and the effects of control errors in vehicle 1 may be determined experimentally, empirically, or by simulation. The difference between the first and second thresholds may be the maximum value of the determined range of fluctuation. The first threshold may be a fixed value or a variable value depending on some physical quantity or parameter. The second threshold may be set as a value smaller than the first threshold by the difference between the first and second thresholds. If the first threshold is a variable value, it may be set according to the operating characteristics of the driver of vehicle 1. For example, the first threshold when the range of fluctuation in the amount the driver depresses the accelerator pedal is relatively large may be set to a larger value than the first threshold when the range of fluctuation in the amount the driver depresses the accelerator pedal is relatively small.

[0048] (Technical effects) By setting a first threshold for determining whether or not to initiate a speeding warning to, for example, a value 1 kilometer per hour greater than the speed limit, a speeding warning can be initiated when the numerical value indicating the speed of vehicle 1 displayed by the HMI 15 exceeds the speed limit. This reduces the likelihood that the user of vehicle 1 (e.g., the driver) viewing the numerical value indicating the speed of vehicle 1 displayed by the HMI 15 may feel uncomfortable due to the speeding warning.

[0049] By making the second threshold for determining whether to stop the speeding warning smaller than the first threshold for determining whether to start the speeding warning (in other words, by introducing a hysteresis characteristic), the frequency of transitions between the warning ON state and the warning OFF state can be suppressed. This makes it possible to suppress the feeling of discomfort experienced by the user of vehicle 1 (e.g., the driver) due to the speeding warning.

[0050] The embodiments of the invention derived from the above-described embodiments are described below.

[0051] A warning device according to one aspect of the invention includes a speed detection means for detecting the speed of a vehicle, and a determination means for determining whether to issue a warning if the speed is greater than a first threshold, and whether to issue a warning if the speed is less than a second threshold which is less than the first threshold. In the above embodiment, the speed sensor 12 corresponds to an example of the speed detection means, and the warning determination unit 25 corresponds to an example of the determination means.

[0052] In the warning device, if the determination means determines that the warning should be issued because the speed is greater than the first threshold, and the warning has been issued, and the speed is less than the first threshold and greater than the second threshold, the determination means may determine that the warning should be issued.

[0053] In the warning device, if the determination means determines that the warning should be issued because the speed is greater than the first threshold, and the warning has been issued, and the speed is less than the second threshold, the determination means may determine not to issue the warning.

[0054] In the warning device, the first threshold may be a value for determining whether the speed has exceeded the speed limit, and the second threshold may be a value for determining whether the speed has fallen below the speed limit.

[0055] In this warning device, the difference between the first threshold and the second threshold may be 0.9 kilometers per hour.

[0056] In the warning device, the first threshold may be a value 1 kilometer per hour greater than the speed limit, and the second threshold may be a value 0.1 kilometers per hour greater than the speed limit.

[0057] In this warning device, the warning may be a warning related to speeding.

[0058] The present invention is not limited to the embodiments described above, and can be modified as appropriate without contradicting the gist or idea of ​​the invention as can be read from the claims and specification as a whole. Warning devices with such modifications are also included within the technical scope of the present invention. [Explanation of Symbols]

[0059] 1...Vehicle, 11...External sensor, 12...Speed ​​sensor, 15...HMI, 20...ECU, 21...Speed ​​limit sign detection unit, 22...Auxiliary sign detection unit, 23...Vehicle category detection unit, 24...Display determination unit, 25...Warning determination unit

Claims

1. A speed detection means for detecting the speed of a vehicle, A determination means that determines whether to issue a warning if the speed is greater than a first threshold, and whether to issue a warning if the speed is less than a second threshold which is less than the first threshold, Equipped with, The difference between the first threshold and the second threshold is 0.9 kilometers per hour. A warning device characterized by the following features.

2. If the determination means determines that the warning should be issued because the speed is greater than the first threshold, and if the warning has been issued, and the speed is less than the first threshold and greater than the second threshold, the determination means determines that the warning should be issued. The warning device according to feature 1.

3. If the determination means determines that the warning should be issued because the speed is greater than the first threshold, and the warning has been issued and the speed is less than the second threshold, the determination means determines that the warning should not be issued. The warning device according to feature 1.

4. The first threshold is a value used to determine whether the speed exceeds the speed limit, The second threshold value is a value used to determine whether the speed has fallen below the speed limit. The warning device according to feature 1.

5. The first threshold is a value that is 1 kilometer per hour greater than the speed limit. The second threshold is a value 0.1 kilometers per hour greater than the speed limit. The warning device according to feature 1.

6. The warning device according to claim 1, characterized in that the warning is a warning regarding speeding.

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