Dozing prevention device, dozing prevention method, and dozing prevention program

Abstract

To provide a dozing prevention device, a dozing prevention method, and a dozing prevention program capable of preventing a driver from dozing while minimizing the loss of comfort for the driver even if the driver's drowsiness is detected.SOLUTION: The dozing prevention device comprises a drowsiness state acquisition unit 111 acquiring a drowsiness state, which is a state regarding drowsiness of a driver of a self vehicle, and a first speed suppression unit 131 activating a first speed suppression function that suppresses a vehicle speed from exceeding a first upper limit speed, which is an upper limit speed set to be greater than 0, according to the drowsiness state acquired by the drowsiness state acquisition unit 111 being the drowsiness of the driver.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to a driver doze prevention device, a driver doze prevention method, and a driver doze prevention program. [Background technology]

[0002] Patent Document 1 discloses a technology that controls the vehicle to stop traveling when a driver abnormality is detected and the abnormality is not resolved even after a warning is issued to the driver. The technology disclosed in Patent Document 1 detects abnormalities in the driver such as myocardial infarction, physical abnormalities such as fever, excessive fatigue, drowsiness, etc. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-119385 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, according to the technology disclosed in Patent Document 1, excessive measures are taken in response to the driver's abnormality, which may impair the comfort of the driver. The details are as follows. If the driver's abnormality is one that is difficult to recover from in a short time, it is considered difficult to continue driving. Therefore, controlling the vehicle to stop is unlikely to be an excessive measure. On the other hand, in the case of an abnormality such as drowsiness that is likely to be recovered from in a short time, it is quite conceivable that the abnormality will improve while driving. In such a case, controlling the vehicle to stop may be perceived as an excessive measure by the driver, which may impair the comfort of the driver.

[0005] One objective of this disclosure is to provide a doze prevention device, a doze prevention method, and a doze prevention program that can prevent the driver from dozing off while making it difficult for the driver's comfort to be compromised even when drowsiness is detected in the driver. [Means for solving the problem]

[0006] The above object is achieved by the combination of features recited in the independent claims, and the subclaims define further advantageous embodiments of the disclosure. The reference characters in parentheses in the claims indicate a correspondence with specific means described in the following embodiment as one aspect, and do not limit the technical scope of the present disclosure.

[0007] In order to achieve the above object, the drowsiness prevention device disclosed herein is a drowsiness prevention device that can be used in a vehicle, and includes a drowsiness state acquisition unit (111) that acquires a drowsiness state that is a state related to the drowsiness of the driver of the vehicle, and a drowsiness speed suppression unit (131, 132a, 131b, 131c) that activates a drowsiness speed suppression function that inhibits the vehicle speed from exceeding a set upper limit speed, which is an upper limit speed that is set greater than 0, when the drowsiness state acquired by the drowsiness state acquisition unit is a state that indicates that the driver is drowsy.

[0008] In order to achieve the above-mentioned object, the dozing-off prevention method disclosed herein is a dozing-off prevention method that can be used in a vehicle, and includes a drowsiness state acquisition step executed by at least one processor for acquiring a drowsiness state that is a state related to the drowsiness of a driver of the vehicle, and a drowsiness speed suppression step for activating a drowsiness speed suppression function that suppresses the vehicle speed from exceeding a set upper limit speed, which is an upper limit speed that is set greater than 0, if the drowsiness state acquired in the drowsiness state acquisition step is a state that indicates that the driver is drowsy.

[0009] In order to achieve the above-mentioned object, the drowsiness prevention program disclosed herein is a drowsiness prevention program that can be used in a vehicle, and causes a computer to function as a drowsiness state acquisition unit (111) that acquires a drowsiness state that is a state related to the drowsiness of the driver of the vehicle, and a drowsiness speed suppression unit (131, 132a, 131b, 131c) that activates a drowsiness speed suppression function that suppresses the vehicle speed from exceeding a set upper limit speed, which is an upper limit speed that is set greater than 0, depending on whether the drowsiness state acquired by the drowsiness state acquisition unit is a state that indicates that the driver is drowsy.

[0010] According to the above configuration, in response to the driver's drowsiness, the acceleration of the vehicle to the speed intended by the driver is suppressed by the driver's operation. Therefore, the driver feels uncomfortable about this suppression, which makes it easier for the driver's drowsiness to be relieved. Since this suppression is a milder measure than stopping the vehicle, it is possible to prevent the driver from falling asleep while making it difficult for the driver's comfort to be impaired. In addition, this suppression also makes it possible to encourage the driver to stop the vehicle by driving operation and take a break from driving operation, thereby relieving the driver's drowsiness. Since this stop is due to the driver's driving operation and not due to stop control, it is difficult for the driver's comfort to be impaired. As a result, even if the driver's drowsiness is detected, it is possible to prevent the driver from falling asleep while making it difficult for the driver's comfort to be impaired. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a diagram illustrating an example of a schematic configuration of a vehicle system. [Diagram 2] FIG. 1 is a diagram illustrating an example of a schematic configuration of a driving assistance device. [Diagram 3] 11 is a diagram for explaining an example of the timing of activation of a first speed suppression function and various warnings. FIG. [Figure 4] FIG. 11 is a diagram for explaining an example of a warning display. [Diagram 5]11 is a diagram for explaining an example of the timing of activation of a first speed suppression function due to a deterioration in the depth level and various warnings. FIG. [Figure 6] FIG. 11 is a diagram for explaining setting of a first upper limit speed according to a depth level. [Figure 7] 13 is a diagram for explaining an example of a release timing when the release condition is a drowsiness improvement condition. FIG. [Figure 8] 13 is a diagram for explaining an example of a release timing when the release condition is a stop time condition. FIG. [Figure 9] 13 is a diagram for explaining an example of a release timing when the release condition is a release operation condition. FIG. [Figure 10] 13A and 13B are diagrams illustrating an example of a screen for turning on and off a settable function. [Figure 11] FIG. 11 is a diagram for explaining combination patterns of function activation settings in the first embodiment. [Figure 12] FIG. 13 is a diagram for explaining state transition during a stoppage. [Figure 13] FIG. 13 is a diagram for explaining state transition in a monitoring mode in the case of pattern 1. [Figure 14] 13 is a diagram for explaining state transitions in a monitoring mode in the cases of patterns 2 and 4. FIG. [Figure 15] FIG. 13 is a diagram for explaining state transition in a monitoring mode in the case of pattern 6. [Figure 16] FIG. 1 is a diagram illustrating an example of a schematic configuration of a vehicle system. [Figure 17] FIG. 1 is a diagram illustrating an example of a schematic configuration of a driving assistance device. [Figure 18] 13A and 13B are diagrams illustrating an example of a screen for turning on and off a settable function. [Figure 19] FIG. 11 is a diagram for explaining combination patterns of function activation settings in the second embodiment. [Figure 20] FIG. 13 is a diagram for explaining state transition in a monitoring mode in the case of pattern 10. [Figure 21]FIG. 1 is a diagram illustrating an example of a schematic configuration of a vehicle system. [Figure 22] FIG. 1 is a diagram illustrating an example of a schematic configuration of a driving assistance device. [Figure 23] FIG. 1 is a diagram illustrating an example of a schematic configuration of a vehicle system. [Figure 24] FIG. 1 is a diagram illustrating an example of a schematic configuration of a driving assistance device. [Diagram 25] 13 is a diagram for explaining speed suppression by a first speed suppression function in the fourth embodiment. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] A number of embodiments for disclosure will be described with reference to the drawings. For convenience of description, in a number of embodiments, parts having the same functions as parts shown in the drawings used in the previous description may be given the same reference numerals and their description may be omitted. For parts given the same reference numerals, the description in other embodiments may be referred to.

[0013] (Embodiment 1) <Overall configuration of vehicle system 1> Hereinafter, a first embodiment of the present disclosure will be described with reference to the drawings. A vehicle system 1 shown in FIG. 1 can be used in a vehicle. As shown in FIG. 1, the vehicle system 1 includes a driving assistance device 10, a locator 11, a map database (hereinafter, map DB) 12, a vehicle state sensor 13, an engine ECU 14, a brake ECU 15, an interior camera 16, a biosensor 17, a presentation device 18, a user input device 19, and an HCU (Human Machine Interface Control Unit) 20. For example, the driving assistance device 10, the locator 11, the map DB 12, the vehicle state sensor 13, the engine ECU 14, the brake ECU 15, and the HCU 20 may be configured to be connected to an in-vehicle LAN (see the LAN in FIG. 1). Although a vehicle using the vehicle system 1 is not necessarily limited to an automobile, the following description will be given taking an example of a case where the system is used in an automobile. In this embodiment, a configuration example in which the driving assistance device 10 is built into a vehicle at the time of vehicle manufacture will be described.

[0014] A vehicle using the vehicle system 1 may be a vehicle capable of autonomous driving (hereinafter, autonomous driving vehicle). As the stage of autonomous driving of an autonomous driving vehicle (hereinafter, automation level), there may be a plurality of levels, as defined by, for example, SAE. The automation levels are, for example, classified into LV0 to 5 as follows.

[0015] LV0 is the level at which the driver performs all driving tasks without the system intervening. The driving task may be rephrased as a dynamic driving task. The driving task may be, for example, steering, acceleration / deceleration, and surrounding monitoring. LV0 corresponds to so-called manual driving. LV1 is the level at which the system assists with either steering or acceleration / deceleration. LV1 corresponds to so-called driving assistance. LV2 is the level at which the system assists with both steering and acceleration / deceleration. LV2 corresponds to so-called partial driving automation. Note that LV1-2 are also considered to be part of autonomous driving.

[0016] For example, LV1-2 autonomous driving is autonomous driving in which the driver has a duty to monitor safe driving (hereinafter, simply referred to as the duty to monitor). In other words, it corresponds to autonomous driving with a duty to monitor. Driving at LV0-LV2 corresponds to driving with a duty to monitor. The duty to monitor includes visual monitoring of the surroundings. Autonomous driving at LV1-2 can be rephrased as autonomous driving in which a second task is not permitted. A second task is an act other than driving that is permitted for the driver, and is a specific act that is specified in advance. A second task can also be rephrased as a secondary activity, other activity, etc. It is considered that a second task must not prevent the driver from responding to a request from the autonomous driving system to take over driving operations. As an example, actions such as watching content such as videos, operating a smartphone, reading, and eating are assumed to be second tasks.

[0017] LV3 autonomous driving is a level where the system can perform all driving tasks under certain conditions, and the driver takes over driving operations in an emergency. In LV3 autonomous driving, the driver is required to be able to respond quickly when the system requests a handover of driving. This handover of driving can also be said to be the transfer of the responsibility of monitoring the surroundings from the vehicle's system to the driver. LV3 corresponds to so-called conditional driving automation. LV4 autonomous driving is a level where the system can perform all driving tasks, except under certain circumstances such as incompatible roads and extreme environments. LV4 corresponds to so-called high driving automation. LV5 autonomous driving is a level where the system can perform all driving tasks in any environment. LV5 corresponds to so-called full driving automation. For example, autonomous driving at LV3 or higher is autonomous driving where the driver does not have the responsibility of monitoring.

[0018] When a vehicle using the vehicle system 1 is an autonomous vehicle, the vehicle may be an autonomous vehicle with an automation level of 2 or lower. A vehicle using the vehicle system 1 is preferably a vehicle with an automation level of 0. In other words, it is preferably a manually driven vehicle. This is because, in a manually driven vehicle in which the driver performs all driving tasks, the driving assistance device 10, which will be described later, has a greater effect of preventing drowsiness at the wheel.

[0019] Locator 11 includes a GNSS (Global Navigation Satellite System) receiver and an inertial sensor. The GNSS receiver receives positioning signals from a plurality of positioning satellites. The inertial sensor includes, for example, a gyro sensor and an acceleration sensor. Locator 11 sequentially determines the vehicle position of the vehicle (hereinafter, the vehicle position) by combining the positioning signals received by the GNSS receiver with the measurement results of the inertial sensor. The vehicle position may be expressed, for example, in latitude and longitude coordinates. Note that the vehicle position may also be determined using a travel distance calculated from a signal sequentially output from a vehicle speed sensor mounted on the vehicle.

[0020] The map DB 12 is a non-volatile memory, and stores map data used for route guidance in the navigation device. The map data used for route guidance includes link data, node data, etc. The link data includes a link ID that identifies a link, a link length that indicates the length of the link, a link direction, a link travel time, shape information of the link, node coordinates (latitude / longitude) of the start and end of the link, and road attributes. The road attributes include a road name, a road type, a road width, the number of lanes, and a speed limit value. The speed limit value corresponds to the legal upper and lower speed limits. The node data includes a node ID that is a unique number assigned to each node on the map, a node coordinate, a node name, a node type, a connecting link ID that describes the link ID of the link connecting to the node, an intersection type, and other data. The map DB 12 may store high-precision map data. The high-precision map data is map data with a higher precision than the map data used for route guidance. High-precision map data includes information that can be used for driving assistance, such as three-dimensional road shape information, information on the number of lanes, and information indicating the permitted traveling direction for each lane.

[0021] The vehicle state sensor 13 is a group of sensors for detecting various states of the vehicle. The vehicle state sensor 13 includes a vehicle speed sensor, an accelerator stroke sensor, a brake stroke sensor, a steering sensor, and the like. The vehicle speed sensor detects the speed. The accelerator stroke sensor detects the amount of depression of the accelerator pedal. In other words, it detects the accelerator opening. The brake stroke sensor detects the amount of depression of the brake pedal. The steering sensor detects the steering angle of the steering wheel. The vehicle state sensor 13 outputs the detected sensing information to an in-vehicle LAN. The sensing information detected by the vehicle state sensor 13 may be configured to be output to the in-vehicle LAN via an ECU mounted in the vehicle.

[0022] The engine ECU 14 is an electronic control device that controls the acceleration of the vehicle. In this embodiment, the vehicle uses an internal combustion engine as a driving source, but the present invention is not limited to this. If the vehicle uses a motor as a driving source, a power unit control ECU may be used instead of the engine ECU 14. The brake ECU 15 is an electronic control device that controls the acceleration of the vehicle.

[0023] The indoor camera 16 captures an image of a predetermined range in the vehicle cabin. The indoor camera 16 captures an image of at least an area including the driver's seat of the vehicle. The indoor camera 16 is composed of, for example, a near-infrared light source and a near-infrared camera, and a control unit that controls them. The indoor camera 16 captures an image of the driver irradiated with near-infrared light by the near-infrared light source using the near-infrared camera. The image captured by the near-infrared camera is analyzed by the control unit. The control unit analyzes the captured image to detect the driver's posture, drowsiness level, and other conditions. The drowsiness level may be detected by the degree of opening and closing of the eyelids, blinking, eye movement, and the like. The drowsiness level may be referred to as the level of dozing. The indoor camera 16 sequentially outputs the detected state of the driver to the HCU 20.

[0024] The drowsiness level may be, for example, in accordance with the evaluation criteria for drowsiness and dozing described in the basic design document for the driver monitoring (drowsiness and dozing detection) system of the Ministry of Land, Infrastructure, Transport and Tourism's Automobile Bureau. Drowsiness levels are classified into D1, which is not drowsy, D2 to D5, which are drowsy, and S, which is dozing. D2 to D5 are classified into D2, D3, D4, and D5 in order of decreasing drowsiness. In the following, the drowsiness levels are represented by the above-mentioned D1 to D5 and S. Dozing is considered to be a sleeping state, not a state of drowsiness. Drowsiness is a state of decreased alertness due to factors such as monotony of the driving environment, fatigue, and lack of sleep. In this embodiment, drowsiness and dozing are classified differently from the abnormal state of the driver. The abnormal state is considered to be a state corresponding to a sudden change in physical condition that is difficult to predict in advance. Examples include sudden cerebrovascular disease, heart disease, digestive disease, fainting, etc.

[0025] The biosensor 17 measures the bioinformation of the driver. The biosensor 17 sequentially outputs the measured bioinformation to the HCU 20. The biosensor 17 may be configured to be provided in the vehicle. The biosensor 17 may be configured to be provided in a wearable device worn by the driver. When the biosensor 17 is provided in the vehicle, it may be provided on, for example, a steering wheel, a seat, or the like. When the biosensor 17 is provided in a wearable device, it may be configured to have the HCU 20 acquire the measurement results of the biosensor 17 by using, for example, short-range wireless communication. Examples of bioinformation measured by the biosensor 17 include respiration, pulse, heart rate, and the like. Note that the biosensor 17 may be configured to measure bioinformation other than respiration, pulse, and heart rate. For example, the biosensor 17 may measure brain waves, heart rate fluctuations, sweating, body temperature, blood pressure, skin conductance, and the like.

[0026] The presentation device 18 is provided in the vehicle and presents information to the interior of the vehicle. That is, the presentation device 18 presents information to the driver of the vehicle. The presentation device 18 presents information in accordance with an instruction from the HCU 20. The presentation device 18 includes a display device 181 and a speaker 182.

[0027] The display device 181 presents information by displaying information. For example, a meter MID (Multi Information Display), a CID (Center Information Display), a HUD (Head-Up Display), etc. can be used as the display device 181. The meter MID is a display device provided in front of the driver's seat inside the vehicle. As an example, the meter MID may be configured to be provided in a meter panel. The CID is a display device arranged in the center of the instrument panel of the vehicle. The HUD is provided in the vehicle interior, for example, on the instrument panel. The HUD projects a display image formed by a projector onto a projection area that is predefined on the front windshield as a projection member. The HUD may be configured to project a display image onto a combiner provided in front of the driver's seat instead of the front windshield. The speaker 182 presents information by outputting sound. The sound output from the speaker 182 may include voice.

[0028] The user input device 19 accepts input from a passenger of the vehicle. The user input device 19 may be an operation device that accepts operation input from the passenger. The operation device may be a mechanical switch or a touch switch integrated with the display device 181. Note that the user input device 19 is not limited to an operation device that accepts operation input, so long as it is a device that accepts input from the passenger. For example, the user input device 19 may be a voice input device that accepts voice command input from the passenger.

[0029] The HCU 20 is mainly composed of a computer including, for example, a processor, a volatile memory, a non-volatile memory, an I / O, and a bus connecting these. The HCU 20 executes various processes related to the interaction between the occupant and the vehicle's system by executing a control program stored in the non-volatile memory. The HCU 20 acquires information input from the occupant via the user input device 19. The HCU 20 causes the presentation device 18 to present information. The HCU 20 acquires the driver's state detected by the indoor camera 16. The HCU 20 identifies the driver's abnormal state from the sensing result of the biosensor 17. The abnormal state is defined as a state corresponding to a sudden change in physical condition that is difficult to predict in advance, as described above. The HCU 20 acquires the driver's drowsiness level detected by the indoor camera 16. The HCU 20 may identify the driver's drowsiness level from an image captured by the indoor camera 16. In other words, the HCU 20 may take on part of the function of the control unit of the indoor camera 16. The HCU 20 may identify the drowsiness level of the driver from the sensing result of the vehicle state sensor 13. For example, the HCU 20 may identify the drowsiness level from the amount of change in the accelerator operation, the brake operation, and the steering operation.

[0030] The driving assistance device 10 is mainly configured with a computer including, for example, a processor, a volatile memory, a non-volatile memory, an I / O, and a bus connecting these. The driving assistance device 10 executes a control program stored in the non-volatile memory to perform processing related to preventing the driver from falling asleep at the wheel. This driving assistance device 10 corresponds to a doze prevention device. In addition, this control program corresponds to a doze prevention program. The configuration of the driving assistance device 10 will be described in detail below.

[0031] <General Configuration of Driving Assistance Device 10> Next, a schematic configuration of the driving support device 10 will be described with reference to Fig. 2. As shown in Fig. 2, the driving support device 10 includes an HCU communication unit 101, a presentation instruction unit 102, a speed suppression unit 103, and a release determination unit 104 as functional blocks. The execution of the processing of each functional block of the driving support device 10 by a computer corresponds to the execution of a dozing prevention method. Note that some or all of the functions executed by the driving support device 10 may be configured as hardware using one or more ICs or the like. Also, some or all of the functional blocks included in the driving support device 10 may be realized by a combination of software execution by a processor and hardware members.

[0032] The HCU communication unit 101 mediates the exchange of information between the driving assistance device 10 and the HCU 20. The HCU communication unit 101 performs an output process of information to the HCU 20. The HCU communication unit 101 performs an acquisition process of information from the HCU 20. The HCU communication unit 101 acquires information of input received by the user input device 19. The HCU communication unit 101 includes a drowsiness state acquisition unit 111 and a driver abnormality acquisition unit 112 as sub-functional blocks.

[0033] The drowsiness state acquisition unit 111 acquires the drowsiness level of the driver from the HCU 20. The drowsiness state acquisition unit 111 only needs to acquire at least the presence or absence of drowsiness of the driver. In other words, it only needs to acquire the drowsiness state, which is a state related to the drowsiness of the driver of the vehicle. The drowsiness state acquisition unit 111 preferably acquires a depth level, which is a degree of the depth of drowsiness. This enables detailed processing according to the degree of the depth of drowsiness. For example, the depth level corresponds to the drowsiness levels D1 to D5. The driver abnormality acquisition unit 112 acquires the abnormal state of the driver identified by the HCU 20. When the abnormal state can be identified by the HCU 20, the driver abnormality acquisition unit 112 only needs to acquire this abnormal state. The driver abnormality acquisition unit 112 only needs to acquire dozing, which is a drowsiness level S, as an abnormal state. In the following, a case where the drowsiness state is a depth level will be described as an example. The processing by the drowsiness state acquisition unit 111 corresponds to a drowsiness state acquisition step.

[0034] The presentation instruction unit 102 indirectly controls the presentation of information by the presentation device 18 by sending an instruction to the HCU 20 via the HCU communication unit 101. That is, the presentation instruction unit 102 causes information to be presented to the driver of the vehicle. It is preferable that the presentation instruction unit 102 causes a warning to be issued to the driver in response to the depth level acquired by the drowsiness state acquisition unit 111 indicating that the driver is drowsy. This warning is hereinafter referred to as a drowsiness warning. The state indicating that the driver is drowsy may be, for example, drowsiness levels D2 to D5. An example of the drowsiness warning will be described later. Note that, hereinafter, a state indicating that drowsiness is present is referred to as a drowsy state. On the other hand, a state in which the driver is not drowsy is referred to as a no drowsiness state.

[0035] The speed suppression unit 103 switches the operating state of a speed suppression function that suppresses the speed of the vehicle from exceeding a set upper limit speed. The upper limit speed is set to be greater than 0. In other words, the speed suppression unit 103 does not perform stop control of the vehicle. The speed suppression function may be realized by disabling the operation of the accelerator pedal. The speed suppression function may be realized by applying a reaction force against the operation of the accelerator pedal. The speed suppression function may be realized by intervening in the control of the driving source for traveling. In the following, the explanation will be continued by taking as an example a case where the speed suppression function is realized by disabling the operation of the accelerator pedal. The speed suppression unit 103 includes a first speed suppression unit 131 and a second speed suppression unit 132 as sub-functional blocks.

[0036] The first speed suppression unit 131 activates the speed suppression function in response to the depth level acquired by the drowsiness state acquisition unit 111 being a drowsy state. The speed suppression function activated by the first speed suppression unit 131 is hereinafter referred to as the first speed suppression function. The first speed suppression unit 131 corresponds to the drowsy speed suppression unit. The first speed suppression function of the first embodiment corresponds to the drowsy speed suppression function. The upper limit speed used in the first speed suppression function is hereinafter referred to as the first upper limit speed. This first upper limit speed corresponds to the set upper limit speed. According to the above configuration, in response to the driver's drowsiness, the acceleration of the vehicle to the speed intended by the driver through the driver's operation is suppressed. Therefore, the driver feels uncomfortable about this suppression, which makes it easier for the driver's drowsiness to be relieved. This suppression is a looser measure than stopping the vehicle, so it is possible to prevent the driver from falling asleep while making it difficult to impair the comfort of the driver. In addition, this suppression also makes it possible to encourage the driver to stop the vehicle through driving operation and take a break from driving operation, thereby relieving the driver's drowsiness. This stop is due to the driver's driving operation and not due to stop control, so it is unlikely to impair the comfort of the driver. As a result, even if drowsiness of the driver is detected, it is possible to prevent the driver from falling asleep while making it difficult to impair the comfort of the driver. In addition, even if the driver continues driving despite feeling drowsy, the speed is limited, making it easier to avoid approaching obstacles. The processing in the first speed suppression unit 131 corresponds to the drowsy speed suppression process.

[0037] The second speed suppression unit 132 activates a speed suppression function that suppresses the vehicle from exceeding an upper limit speed set according to a legal upper limit speed, regardless of whether the driver is drowsy. The speed suppression function activated by the second speed suppression unit 132 is hereinafter referred to as the second speed suppression function. The upper limit speed used in the second speed suppression function is hereinafter referred to as the second upper limit speed. This second upper limit speed corresponds to the legal upper limit speed. The second speed suppression unit 132 corresponds to the legal speed suppression unit. In addition, the second speed suppression function corresponds to the legal speed suppression function. The legal upper limit speed is a legal upper limit speed set for the road on which the vehicle is traveling. The legal upper limit speed may be specified by the speed suppression unit 103 from the vehicle position measured by the locator 11 and the map data of the map DB 12. The speed suppression unit 103 may specify the legal upper limit speed by performing image recognition of a speed sign included in an image captured by a surrounding monitoring camera of the vehicle. As described above, the second upper limit speed is an upper limit speed set according to the legal upper limit speed. That is, the second upper limit speed is an upper limit speed that varies according to the legal upper limit speed. The second upper limit speed may be the legal upper limit speed or may be a speed having a certain amount of offset with respect to the legal upper limit speed. This offset is for adjusting the difference between the speed acquired by the vehicle state sensor 13 and presented to the driver by the presentation device 18 and the actual vehicle speed, for example, to set the second upper limit speed to a value at which the actual vehicle speed does not substantially exceed the legal upper limit speed. The offset may be set by the driver, and is assumed to be reset, for example, after changing tires. According to the above configuration, it is possible to suppress the vehicle from exceeding the legal upper limit speed regardless of whether the driver is drowsy or not. Note that the upper limit value of the value that can be taken as the first upper limit speed may be configured to be a value lower than the second upper limit speed, or may be configured to be the same value as the second upper limit speed.

[0038] It is preferable that the instruction presentation unit 102 issues an activation warning when the first speed suppression unit 131 activates the first speed suppression function. It is preferable that the instruction presentation unit 102 issues an activation warning when the second speed suppression unit 132 activates the second speed suppression function. The activation warning is a warning that notifies the driver that the speed suppression function has been activated, and is a warning of a different category from the drowsiness warning. Hereinafter, the activation warning when the first speed suppression function is activated is referred to as a first activation warning. Also, the activation warning when the second speed suppression function is activated is referred to as a second activation warning. An example of the first activation warning is a voice output or text display such as "For safety, the accelerator operation has been restricted." An example of the second activation warning is a voice output or text display such as "The legal speed has been exceeded. The accelerator operation has been restricted."

[0039] It is preferable that the instruction and presentation unit 102 notifies the driver that the first speed suppression function is automatically activated due to the driver's drowsiness before the vehicle starts to move, as the information presentation. This makes it easier for the driver to recognize the intention of the first speed suppression function being activated, and drowsiness is improved more smoothly. The notification that the first speed suppression function is automatically activated due to the driver's drowsiness is hereinafter referred to as an explanatory notification. The instruction and presentation unit 102 may perform the explanatory notification when the power switch of the vehicle is turned on, for example. The power switch is a switch for starting the internal combustion engine or the motor generator of the vehicle. When the driving source of the vehicle is an internal combustion engine, the ignition switch corresponds to the power switch. An example of the explanatory notification is a voice output or a text display such as "A function to limit accelerator operation when drowsiness is detected is enabled."

[0040] The first speed suppression unit 131 may activate the first speed suppression function on condition that the depth level is a drowsiness state even after the drowsiness warning is started. The depth level is acquired by the drowsiness state acquisition unit 111. In this way, if the driver's drowsiness is relieved by the drowsiness warning, it is not necessary to activate the first speed suppression function. Therefore, even if the driver is drowsy, a grace period is provided for activating the first speed suppression function, making it less likely that the comfort of the driver will be impaired.

[0041] It is preferable that the instruction display unit 102 causes a step-by-step warning to be issued as a drowsiness warning before the first speed suppression function is activated in response to the depth level being a drowsiness state. The step-by-step warning is a step-by-step warning. That is, the step-by-step warning is a warning in which the intensity increases with the later stage. According to the above configuration, by increasing the intensity of the warning, drowsiness is easily improved before the first speed suppression function is activated.

[0042] In the present embodiment, the step-by-step warning is described by taking an example of a two-step warning. The second-step drowsiness warning is a warning including a warning to activate the first speed suppression function. The second-step drowsiness warning is hereinafter referred to as a warning warning. An example of a warning warning is a voice output or text display such as "For safety, accelerator operation will be restricted after a while." The first-step drowsiness warning is a warning prior to the warning warning. The first-step drowsiness warning is hereinafter referred to as a pre-warning warning. The pre-warning warning may be a warning that notifies the driver of drowsiness and encourages the driver to rest. An example of a pre-warning warning is a voice output or text display such as "Drowsiness has been detected. Please take a rest." If the pre-warning warning is repeated, the warning may be changed to "You are still drowsy. Please take a rest." The pre-warning warning is stronger than the pre-warning warning in that the pre-warning warning is a promotion while the pre-warning warning is a warning to call attention. Alternatively, the second stage drowsiness warning may be made stronger than the first stage drowsiness warning by adjusting the size, volume, etc. of the display.

[0043] It is preferable that the first speed suppression unit 131 continues to perform the following process on condition that the depth level is in the drowsiness state even after the drowsiness warning is started. The first speed suppression unit 131 may accelerate the timing of activating the first speed suppression function after the drowsiness warning is started as the depth level increases. This timing is hereinafter referred to as the activation timing. Note that the activation timing is the timing of activating the first speed suppression function after the drowsiness warning is started when the first speed suppression function is activated. According to the above configuration, the greater the drowsiness is and the less likely improvement is expected by the drowsiness warning, the earlier the timing of activating the first speed suppression function can be. Therefore, it is possible to easily improve the driver's drowsiness while reducing the waste of continuing the drowsiness warning.

[0044] The indicator of the activation timing may be the distance traveled by the vehicle from the start of the drowsiness warning, the elapsed time, or a combination of these. The first speed suppression unit 131 may be configured to change the activation timing successively even after the start of the drowsiness warning in response to a change in the depth level. According to this, when the drowsiness is improving, it is possible to extend the activation timing and wait for the drowsiness to be eliminated without activating the first speed suppression function. Also, when the drowsiness is worsening, the activation timing is shortened to make it easier to eliminate the drowsiness before it becomes difficult to eliminate it. Note that the first speed suppression unit 131 may be configured to set the activation timing before the start of the drowsiness warning, and not change the activation timing after the start of the drowsiness warning.

[0045] It is preferable that the first speed suppression unit 131 continues to perform the following process on condition that the depth level is in the drowsiness state even after the advance warning starts. The first speed suppression unit 131 may activate the first speed suppression function a specified time after the advance warning starts. This allows the first speed suppression function to be activated at a fixed time after the advance warning starts, regardless of the speed of the vehicle. Therefore, the time from the start of the advance warning to the activation of the first speed suppression function does not vary significantly depending on the speed of the vehicle, making it difficult to confuse the driver. The specified time may be a relatively short time, for example, less than a few minutes. The specified time may be arbitrarily set.

[0046] It is preferable that the indication / instruction unit 102 performs the following process on the condition that the depth level continues to be in the drowsiness state even after the pre-warning has started. The indication / instruction unit 102 may cause the advance warning to be issued after the distance traveled by the vehicle after the pre-warning has started has reached a specified distance. According to this, the faster the vehicle speed is, the earlier the timing of the advance warning is. Therefore, the faster the vehicle speed is despite drowsiness and the greater the need to eliminate drowsiness sooner, the earlier the advance warning can be issued. As a result, the greater the need to eliminate drowsiness sooner, the easier it is to eliminate drowsiness sooner. The specified distance may be set arbitrarily.

[0047] Here, an example of the timing of the operation of the first speed suppression function and various warnings will be described with reference to FIG. 3. FIG. 3 shows an example in which the vehicle is traveling. The symbols in FIG. 3 will be described. DS indicates the actual state of drowsiness of the driver. DD indicates whether the depth level acquired by the drowsiness state acquisition unit 111 is a drowsy state or a non-drowsy state. In the figure, the drowsy state is represented by ON, and the non-drowsy state is represented by OFF. DLV indicates the depth level acquired by the drowsiness state acquisition unit 111. DN shown in FIG. 3 is a depth level that is greater than D1 and smaller than DNc. DNc may be a depth level that is estimated to be highly likely to cause a problem in driving. DNc may be arbitrarily set. For example, DNc may be D5. W indicates a warning to be performed by the presentation instruction unit 102. NBW indicates a pre-warning warning. NW indicates a warning warning. FAW indicates a first operation warning. SSF indicates the operation state of the first speed suppression function. In the figure, an operating state is represented by ON, and a non-operating state is represented by OFF. VS indicates the driving state of the vehicle. The driving state may be moving or stopped. DAT indicates the timing at which the driver begins to become aware of drowsiness. DTT indicates the timing at which the depth level acquired by the drowsiness state acquisition unit 111 becomes a drowsy state. NBWT indicates the timing at which a pre-warning starts. NWT indicates the timing at which a warning starts. FAT indicates the timing at which the first speed suppression function becomes active. The same symbols are used in figures other than FIG. 3.

[0048] As shown in FIG. 3, when the depth level acquired by the drowsiness state acquisition unit 111 becomes a drowsy state, the advance warning NBW is started. The advance warning NBW may be configured to be periodically repeated as shown in FIG. 3. As an example, it may be configured to be performed every 5 minutes. As shown in FIG. 3, when the depth level is constant and the mileage after the start of the advance warning NBW reaches a specified distance, the advance warning NW is started. The constant state here refers to a state in which a depth level larger than D1 and smaller than DNc is maintained. Next, the first speed suppression function is activated after a specified time from the start of the advance warning NW. When the first speed suppression function is activated, the first activation warning FAW is started.

[0049] Here, an example of a warning display will be described with reference to FIG. 4. FIG. 4 shows an example in which the first operation warning FAW is performed. The symbols in FIG. 4 will be described. DDG indicates a gauge (hereinafter, depth gauge) that represents the depth level of the driver's drowsiness. SD indicates a display (hereinafter, status display) that notifies the driver that the accelerator operation of the vehicle is being restricted. BFD indicates a display that encourages rest (hereinafter, rest promotion display). As shown in FIG. 4, the first operation warning FAW may display text such as "Accelerator operation has been restricted for safety." In this case, the status display SD may display text such as "Accelerator operation is being restricted." Also, as shown in FIG. 4, the rest promotion display BFD may display text such as "Let's take a break" or an icon. Alternatively, the depth gauge DDG may be displayed. When a drowsiness warning is displayed, the first operation warning FAW may be replaced with a drowsiness warning. In this case, the status display SD may be omitted. Note that, when the driver is not in a drowsy state, the depth gauge DDG is displayed, but the warning display, the status display SD, and the rest promotion display BFD may be omitted.

[0050] The indication instruction unit 102 may cause the advance warning to be issued even before the travel distance of the host vehicle after the start of the advance warning reaches a specified distance. Specifically, the advance warning may be issued on condition that the depth level has deteriorated beyond a threshold. This threshold may be the above-mentioned DNc. The first speed suppression unit 131 may also activate the first speed suppression function even before the travel distance of the host vehicle after the start of the advance warning reaches a specified distance. Specifically, the first speed suppression function may be activated on condition that the depth level has deteriorated beyond a threshold. In this case, the first speed suppression function may be activated on condition that a specified time has elapsed since the start of the advance warning due to the deterioration of the depth level described above.

[0051] Here, an example of the timing of the operation of the first speed suppression function due to the deterioration of the depth level and various warnings will be described with reference to FIG. 5. FIG. 5 is an example of a case where the vehicle is traveling. Symbols in FIG. 5 that are different from those in FIG. 3 will be described. DWT indicates the timing when the depth level deteriorates beyond a threshold. DNw shown in FIG. 5 is a depth level equal to or higher than DNc. As shown in FIG. 5, the advance warning NW is started at the timing when the depth level deteriorates beyond a threshold even before the mileage after the advance warning NW is started reaches a specified distance. Then, the first speed suppression function is activated after a specified time from the start of the advance warning NW. The timing of the first speed suppression function being activated may be before the mileage after the advance warning NBW is started reaches a specified distance.

[0052] The instruction display unit 102 may set the number of stages of the gradual warning before starting the gradual warning. The instruction display unit 102 may set the number of stages of the gradual warning to be greater as the depth level increases. In this way, the number of stages of the drowsiness warning is increased as the state becomes difficult to eliminate drowsiness, making it easier to eliminate drowsiness before the first speed suppression function is activated. The upper limit of the number of stages of the gradual warning is not limited to the above-mentioned two stages, and may be three or more stages.

[0053] Before starting the gradual warning, the indication instruction unit 102 may set a start stage, which is the stage at which the gradual warning is to be started. The indication instruction unit 102 may set the start stage to a later stage of the gradual warning as the depth level increases. In this way, as the driver is in a state where it is difficult to eliminate drowsiness, the indication instruction unit 102 starts the drowsiness warning at a stronger stage, making it easier to eliminate drowsiness before the first speed suppression function is activated.

[0054] The first speed suppression unit 131 may lower the first upper limit speed as the depth level increases. The lower the first upper limit speed, the greater the deviation from the speed intended by the driver. Therefore, as the depth of drowsiness increases, the driver becomes more likely to feel uncomfortable, and the driver's drowsiness is more likely to be relieved.

[0055] When a legal lower limit speed is set for the road on which the vehicle is traveling, the first speed suppression unit 131 may set the first upper limit speed according to the depth level not to fall below the legal lower limit speed. The legal lower limit speed may be specified by the speed suppression unit 103 from the vehicle position measured by the locator 11 and the map data in the map DB 12. For example, when the road on which the vehicle is traveling is a Japanese expressway, the legal lower limit speed may be set to 50 km / h. With the above configuration, even if the first upper limit speed is lowered as the depth of drowsiness decreases, traffic is not impeded on the road on which the legal lower limit speed is set.

[0056] Here, the setting of the first upper limit speed according to the depth level will be described with reference to FIG. 6. The graph in FIG. 6 shows an example of the first upper limit speed according to the depth levels D1 to D5. Depth level D1 is a state where the user is not drowsy, so the first upper limit speed is not set. Depth levels D2 to D5 are a state where the user is drowsy, so the first upper limit speed is set. The first upper limit speed is set to a lower value in the order of the depth levels D2, D3, D4, and D5. The lowest first upper limit speed is set for depth level D5, which is the deepest. As shown in FIG. 6, even the lowest first upper limit speed is set so as not to be equal to or lower than the legal lower limit speed.

[0057] When the first upper limit speed has changed, the presentation instruction unit 102 may output a first notification sound notifying the driver that the first upper limit speed has changed. The first notification sound may be, for example, an alarm sound. When the second upper limit speed has changed, the presentation instruction unit 102 may output a second notification sound notifying the driver that the second upper limit speed has changed. The second notification sound may be, for example, an alarm sound of a different type from the first notification sound. It is preferable that the presentation instruction unit 102 outputs the second notification sound in a manner that is less annoying than the first notification sound. Examples of a manner that is less annoying include reducing the volume or lowering the frequency. According to the above configuration, it is possible to further reduce the annoyance of a change in the upper limit speed that is not related to drowsiness. Therefore, a driver who is not drowsy is less likely to feel annoyed by the notification of the change in the second upper limit speed. The first notification sound and the second notification sound may be output as audio. For example, the first notification sound may be output as a voice saying, "For safety, the speed limit for accelerator operation has been lowered to XX km / h." In this case, it is desirable to explicitly notify the first speed limit XX km / h after the change in a specific numerical value. The second notification sound may be output as a voice saying, "The legal speed limit of the road you are traveling on has changed to YY km / h. If you exceed the legal speed limit YY km / h, accelerator operation will be limited." In this case, it is also desirable to explicitly notify the second speed limit YY km / h after the change in a specific numerical value. In order to output the second notification sound in a manner that is less annoying than the first notification sound, for example, the first notification sound may be output as a voice in addition to an alarm sound, and the second notification sound may be output as an alarm sound without any voice output. Alternatively, the first notification sound may be output as a voice in addition to an alarm sound, and the second notification sound may be output as a voice without an alarm sound.

[0058] The release determination unit 104 determines whether or not a release condition for releasing the first speed suppression function is satisfied when the first speed suppression function is in an active state. The first speed suppression unit 131 releases the first speed suppression function when the release determination unit 104 determines that the release condition is satisfied. When the first speed suppression function is released, the presentation instruction unit 102 may issue a notification indicating that the first speed suppression function has been released. This notification is hereinafter referred to as a release report. An example of the release report is a text display or audio output such as "Restriction on accelerator operation has been released." Alternatively, a unique electronic sound may be output at the time of release.

[0059] The cancellation conditions include, for example, three cancellation conditions. The first cancellation condition is that the drowsiness level acquired by the drowsiness state acquisition unit 111 has reached a state indicating that the driver's drowsiness has been eliminated. In the example of this embodiment, it may be that the depth level has reached D1. This first cancellation condition is hereinafter referred to as a drowsiness improvement condition. The second cancellation condition is that the vehicle has stopped and a set time or more has elapsed. The set time may be a time estimated to be required for drowsiness improvement, and can be set arbitrarily. The set time may be changed so as to be set longer as the depth level increases. The stopping of the vehicle may be limited to parking, or may not be limited to parking. This second cancellation condition is hereinafter referred to as a stop time condition. The third cancellation condition is that the vehicle has received a cancellation operation that is predetermined as an operation for canceling the operation state of the first speed suppression function. An example of the cancellation operation will be described later. This third cancellation condition is referred to as a cancellation operation condition.

[0060] The release determination unit 104 may set at least one of the drowsiness improvement condition, the stop time condition, and the release operation condition as the release condition. Then, when any one of the release conditions is satisfied, it may determine that the release condition for releasing the operation state of the first speed suppression function is satisfied. This makes it possible to release the operation state of the first speed suppression function. When the drowsiness improvement condition is set as the release condition, the operation state of the first speed suppression function can be released when the driver's drowsiness is relieved. When the stop time condition is set as the release condition, the operation state of the first speed suppression function can be released when it is estimated that the drowsiness has been relieved by stopping the vehicle and taking a rest. When the release operation condition is set as the release condition, the operation state of the first speed suppression function can be released in response to a request from the driver whose drowsiness has been relieved.

[0061] The release operation condition makes it possible to release the operation state of the first speed suppression function when the drowsiness improvement condition and the stop time condition are not satisfied but acceleration is necessary due to traffic conditions. The release operation can be rephrased as a non-steady override. Examples of the release operation include the following. Note that this release operation may also be configured to be applied to the release of the operation state of the second speed suppression function.

[0062] The release operation may be performed by depressing the accelerator pedal by a predetermined amount or more multiple times. The multiple times may be, for example, 5 times or more. The amount of depression of the accelerator pedal may be detected by an accelerator stroke sensor. The predetermined amount may be a value that can be set arbitrarily. In this way, it is preferable that the release operation is a driving operation multiple times or more. This makes it more difficult to release the function than when the release operation is a single driving operation. When the release operation is a single driving operation, the function is released by a simpler operation, and therefore it is less likely to lead to improvement in drowsiness due to the operation of the first speed suppression function. In contrast, by performing the release operation multiple times or more, the driver is more likely to receive improvement in drowsiness due to the first speed suppression function. The release operation may be performed by depressing the accelerator pedal by a predetermined amount or more for several seconds or more. The several seconds may be, for example, 5 seconds or more. The predetermined amount may be a value that can be set arbitrarily. In order to suppress sudden acceleration after release, the output value of the accelerator opening to the engine ECU 14 may be adjusted so that it changes gradually with respect to the actual depression amount.

[0063] The release operation may be an operation of a release button as a touch switch on the screen of the display device 181. The release button may be, for example, a dedicated button display for releasing the operating state of the first speed suppression function. The operation of the release button may be accepted via the user input device 19. The release operation may be a combination of the operation of a wiper switch and a washer switch. The release operation is preferably a combination of a plurality of types of operations in the vehicle. An example of a combination of a plurality of types of operations is a combination of an accelerator operation and a washer switch operation. This makes the release more difficult than when the release operation is a single type of operation in the vehicle. Therefore, the driver is more likely to receive the improvement in drowsiness due to the first speed suppression function.

[0064] Here, an example of the timing of canceling the operation state of the first speed suppression function will be described with reference to Figs. 7 to 9. First, an example of the timing of canceling when the cancel condition is a drowsiness improvement condition will be described with reference to Fig. 7. Fig. 7 shows an example of a case where drowsiness is eliminated by the operation of the first speed suppression function while the host vehicle continues to travel. Symbols in Fig. 7 that are different from those in the previously described drawings will be described. DI indicates the timing when drowsiness is eliminated. RLR shown in Fig. 7 indicates a cancellation report. As shown in Fig. 7, when drowsiness is eliminated after the operation of the first speed suppression function, the operation state of the first speed suppression function is cancelled. Furthermore, when the operation state of the first speed suppression function is cancelled, a cancellation report RLR is started. When drowsiness is eliminated, the operation state of the first speed suppression function is cancelled even if the host vehicle continues to travel.

[0065] Next, an example of the release timing when the release condition is a stop time condition will be described with reference to FIG. 8. FIG. 8 shows an example of a case where the vehicle is stopped until a set time is reached after the first speed suppression function is activated. Symbols in FIG. 8 that are different from those in the previously described drawings will be described. ST indicates the timing when the vehicle starts to stop. As shown in FIG. 8, when the vehicle is stopped until a set time is reached after the first speed suppression function is activated, the activation state of the first speed suppression function is released. In addition, when the activation state of the first speed suppression function is released, a release report RLR is started. When the vehicle is stopped, the detection of drowsiness may be paused or may be continued. FIG. 8 shows an example of a case where the detection of drowsiness is paused while the vehicle is stopped.

[0066] Next, an example of the release timing when the release condition is a release operation condition will be described with reference to FIG. 9. FIG. 9 shows an example of a case where a release operation is performed after the first speed suppression function is activated. Symbols in FIG. 9 that are different from those in the previously described drawings will be described. CPI indicates the timing at which the release operation is performed. As shown in FIG. 9, when a release operation is performed after the first speed suppression function is activated, the activated state of the first speed suppression function is released. In addition, when the activated state of the first speed suppression function is released, a release report RLR is initiated. When a release operation is performed, the activated state of the first speed suppression function is released even if the host vehicle continues to travel.

[0067] The driving assistance device 10 may be configured to set various parameters. The parameter settings may be configured to be accepted via the user input device 19. The settable parameters include the above-mentioned set time. The set time may be set within a range of, for example, 15 minutes to 30 minutes. The settable parameters include the cancellation operation condition. The cancellation operation condition may be set to one or more of the above-mentioned examples. The settable parameters include a first notification sound and a second notification sound. The first notification sound may be set to an alarm sound and a voice with a sound level of, for example, seven levels from LV0 to LV6. The second notification sound may be set to an alarm sound and a voice with a sound level of, for example, four levels from LV0 to LV3. LV0 may be a level equivalent to no sound output. The lower the sound level, the less annoying the driver the sound is output. Examples of the less annoying aspects include lowering the volume and lowering the frequency. The settable parameters may be parameters other than those described above. For example, the first and second upper speed limits may be set according to the driver's preference. The settable parameters include the offset of the second upper speed limit described above. Similarly, for the first upper speed limit, an offset that adjusts the difference between the speed acquired by the vehicle state sensor 13 and presented to the driver by the presentation device 18 and the actual vehicle speed may be set as a settable parameter.

[0068] <Function activation settings in the first embodiment> Next, the switching settings of functions that can be switched between enabled and disabled will be described with reference to Figs. 10 and 11. The switching setting between enabled and disabled will be referred to as a function enable setting below. A function that can be enabled will be referred to as a configurable function below. Enabled settable functions will be referred to as on, and disabled settable functions will be referred to as off below. In this embodiment, the drowsiness monitoring function, the first speed suppression function, and the second speed suppression function are settable functions. The drowsiness monitoring function is a function that identifies a drowsiness level.

[0069] The settable functions may be turned on and off by operating a touch switch on the screen of the display device 181. FIG. 10 shows an example of a display screen for turning on and off the settable functions in the first embodiment. In the example of FIG. 10, the first speed suppression function is displayed as a suppression function when drowsiness is detected. In the example of FIG. 10, the second speed suppression function is displayed as a suppression function when exceeding the legal speed limit. Sb in FIG. 10 shows a button display for switching on and off the settable functions. The settable functions are switched on and off by operating the button display for each function. The screen for turning on and off the settable functions displays buttons for switching on and off the drowsiness monitoring function, the first speed suppression function, and the second speed suppression function.

[0070] Next, the combination patterns of the function activation settings will be described with reference to FIG. 11. In FIG. 11, the drowsiness monitoring function is indicated by DMF. In FIG. 11, the first speed suppression function is indicated by DDASF. In FIG. 11, the second speed suppression function is indicated by SEASF. Pattern 1 is a pattern in which the drowsiness monitoring function, the first speed suppression function, and the second speed suppression function are all on. Pattern 2 is a pattern in which the drowsiness monitoring function and the first speed suppression function are off, and the second speed suppression function is on. Pattern 3 is a pattern in which the drowsiness monitoring function, the first speed suppression function, and the second speed suppression function are all off. Pattern 4 is a pattern in which the drowsiness monitoring function and the second speed suppression function are on, and the first speed suppression function is off. Pattern 5 is a pattern in which the drowsiness monitoring function is on, and the first speed suppression function and the second speed suppression function are off. Pattern 6 is a pattern in which the drowsiness monitoring function, the first speed suppression function, and the second speed suppression function are off.

[0071] It is not possible to set a pattern combination in which the drowsiness monitoring function is off, and the first speed suppression function and the second speed suppression function are on.It is not possible to set a pattern combination in which the drowsiness monitoring function and the second speed suppression function are off, and the first speed suppression function is on.In other words, the first speed suppression function can be set to on only when the drowsiness monitoring function is on.

[0072] <State transition in vehicle system 1> Next, an example of state transition in the vehicle system 1 will be described. First, an example of state transition when the vehicle is stopped will be described with reference to FIG. 12. FIG. 12 is a diagram for explaining state transition when the vehicle is stopped. The default state when the vehicle is stopped is the non-monitoring mode. The non-monitoring mode is a state in which the vehicle is stopped and is not in the setting mode. The non-monitoring mode can be rephrased as a standby state. In the non-monitoring mode, when the setting mode button is operated (see t1 in FIG. 12), a transition to the setting mode occurs. The setting mode button is a button for switching to the setting mode. The setting mode button may be, for example, a touch switch on the screen of the display device 181.

[0073] The setting mode is a mode that accepts the settings of the various parameters described above. In the setting mode, when the setting completion button is operated (see t2 in FIG. 12), a transition to the non-monitoring mode occurs. The setting completion button is a button for completing the setting mode. The setting completion button may be, for example, a touch switch on the screen of the display device 181. In the setting mode, when the vehicle starts traveling (see t2 in FIG. 12), a transition to the non-monitoring mode also occurs. In this case, the profile being set is discarded, and then the transition to the non-monitoring mode is forcibly made.

[0074] In addition, in the non-monitoring mode, when the vehicle starts to travel (see t3 in FIG. 12), the mode transitions to the monitoring mode, which will be described later. On the other hand, in the monitoring mode, when the vehicle stops (see t4 in FIG. 12), the mode transitions to the non-monitoring mode.

[0075] Next, an example of state transition in the monitoring mode when the combination of function activation settings is pattern 1 will be described with reference to FIG. 13. The monitoring mode is the mode when the vehicle is traveling. FIG. 13 is a diagram for explaining state transition in the monitoring mode in the case of pattern 1. The NDS in FIG. 13 shows a state when the driver's drowsiness is not identified. This state is called a no-drowsiness state. Drowsiness can be identified by the driving assistance device 10 from the depth level of the drowsiness level acquired by the drowsiness state acquisition unit 111. The same applies below.

[0076] When the vehicle starts traveling (see t11 in FIG. 13), the vehicle transitions to the no-limit state of this no-drowsiness state as a default state. The no-limit state is a state in which the driver's drowsiness is not identified and the vehicle has not reached the legal upper limit speed. When the vehicle reaches the legal upper limit speed in the no-limit state (see t12 in FIG. 13), the vehicle transitions to the legal speed limit state of the no-drowsiness state. The legal speed limit state is a state in which the second speed suppression function is activated. In other words, the legal speed limit state corresponds to a state in which the second speed suppression function is activated. On the other hand, when the vehicle falls below the legal upper limit speed in the legal speed limit state (see t13 in FIG. 13), the vehicle transitions to the no-limit state.

[0077] In the no drowsiness state, if drowsiness less than the above-mentioned DNc is identified (see t14 in FIG. 13), the state transitions to the alert 1 state. DNc is a depth level estimated to be highly likely to cause a hindrance to driving. The alert 1 state is a state in which the above-mentioned advance warning is performed. In the alert 1 state, if no drowsiness is identified (see t15 in FIG. 13), the state transitions to the no drowsiness state. That is, if drowsiness is eliminated by the advance warning, the state transitions to the no drowsiness state. On the other hand, in the alert 1 state, if the travel distance of the vehicle after the start of the advance warning reaches a specified distance (see t16 in FIG. 13), the state transitions to the alert 2 state. In addition, in the alert 1 state, if drowsiness equal to or greater than DNc is identified (see t16 in FIG. 13), the state transitions to the alert 2 state. Drowsiness equal to or greater than DNc does not include dozing at level S, which is not drowsiness. In addition, in the no drowsiness state, if drowsiness equal to or greater than DNc is identified (see t17 in FIG. 13), the state transitions to the alert 2 state.

[0078] The alert 2 state is a state in which the advance warning is given. In the alert 2 state, if it is determined that the driver is not drowsy (see t18 in FIG. 13), the state transitions to the no drowsiness state. In other words, if the driver's drowsiness is relieved by the advance warning, the state transitions to the no drowsiness state. On the other hand, in the alert 2 state, if a specified time has elapsed since the start of the advance warning (see t19 in FIG. 13), the state transitions to the alert 3 state.

[0079] The alert 3 state is a state in which the first speed suppression function is activated. In other words, the alert 3 state corresponds to an activation state of the first speed suppression function. The alert 3 state is also a state in which the above-mentioned first activation warning is issued. In the alert 3 state, if the release condition is satisfied (see t20 in FIG. 13), the state transitions to the no drowsiness state. In a configuration in which the release condition includes a stop time condition, the state transitions to the provisional monitoring mode without transitioning to the non-monitoring mode when the vehicle is stopped. The provisional monitoring mode may transition to the alert 3 state when the vehicle resumes traveling. Then, the state transitions to the no drowsiness state when the stop time condition is satisfied. In addition, in the monitoring mode, when the vehicle stops, the state transitions to the non-monitoring mode, with some exceptions. In some exceptions, the alert 3 state may be set in a configuration in which the release condition includes a stop time condition.

[0080] Next, an example of state transition in the monitoring mode when the combination of function activation settings is pattern 2 and 4 will be described with reference to Fig. 14. Fig. 14 is a diagram for explaining state transition in the monitoring mode when the combination is pattern 2 and 4. Note that the state transition when the vehicle is stopped may be the same as that shown in Fig. 12 even in the case of pattern 2 and 4.

[0081] In the monitoring mode for patterns 2 and 4, when the host vehicle starts traveling (see t21 in FIG. 14), the default state is transitioned to the no limit state. The no limit state is the same as described above. In the no limit state, when the host vehicle reaches the legal upper limit speed (see t22 in FIG. 14), the state transitions to the legal speed limit state. The legal speed limit state is the same as described above. On the other hand, in the legal speed limit state, when the host vehicle falls below the legal upper limit speed (see t23 in FIG. 14), the state transitions to the no limit state. Also, when the host vehicle stops in the monitoring mode, the state transitions to the non-monitoring mode.

[0082] Next, an example of state transition in the monitoring mode when the combination of function activation settings is pattern 6 will be described with reference to Fig. 15. Fig. 15 is a diagram for explaining state transition in the monitoring mode in the case of pattern 6. Note that the state transition when the vehicle is stopped may be the same as that shown in Fig. 12 even in the case of pattern 6.

[0083] When the vehicle starts traveling (see t31 in FIG. 15), the state transitions to the no-restriction state as a default state. The no-restriction state here is a state in which the driver's drowsiness is not specified. In the no-restriction state, when drowsiness less than the above-mentioned DNc is specified (see t32 in FIG. 15), the state transitions to the alert 1 state. The alert 1 state is the same as described above. In the alert 1 state, when no drowsiness is specified (see t33 in FIG. 15), the state transitions to the no-restriction state. On the other hand, in the alert 1 state, when the travel distance of the vehicle after the start of the advance warning reaches a specified distance (see t34 in FIG. 15), the state transitions to the alert 2 state. Also, in the alert 1 state, when drowsiness equal to or greater than DNc is specified (see t34 in FIG. 15), the state transitions to the alert 2 state. The alert 2 state is the same as described above. Also, in the no-restriction state, when drowsiness equal to or greater than DNc is specified (see t35 in FIG. 15), the state transitions to the alert 2 state.

[0084] In the alert 2 state, if it is determined that the driver is not drowsy (see t36 in FIG. 15), the state transitions to the no-restriction state. On the other hand, in the alert 2 state, if a specified time has elapsed since the start of the advance warning (see t37 in FIG. 15), the state transitions to the alert 3 state. The alert 3 state is the same as described above. In the alert 3 state, if the release condition is satisfied (see t38 in FIG. 15), the state transitions to the no-restriction state. In the case of a configuration in which the release condition includes a stop time condition, the state transitions to the provisional monitoring mode, as described above. The provisional monitoring mode may transition to the alert 3 state when the vehicle resumes traveling. Then, when the stop time condition is satisfied, the state transitions to the no-restriction state. In the monitoring mode, with some exceptions, when the vehicle stops, the state transitions to the non-monitoring mode. With some exceptions, the state transitions to the alert 3 state in a configuration in which the release condition includes a stop time condition.

[0085] Next, an example of state transition when the combination of function activation settings is pattern 3 and pattern 5 will be described. The default state when stopped is the standby state. The standby state is a state in which the vehicle is stopped and is not in the setting mode. When the setting mode button described above is operated in the standby state, the vehicle transitions to the setting mode described above. On the other hand, when the setting completion button described above is operated in the setting mode, the vehicle transitions to the standby state. When the vehicle starts to travel in the setting mode, the vehicle transitions to the standby state as well. In this case, the profile being set may be discarded and the vehicle may be forcibly transitioned to the standby state. Also, when the vehicle starts to travel in the standby state, the vehicle transitions to the unrestricted state described above. On the other hand, when the vehicle stops in the unrestricted state, the vehicle transitions to the standby state.

[0086] In addition, when an abnormal state of the driver is identified during driving in the monitoring mode in the cases of patterns 1 to 2, 4, and 6 and in the cases of patterns 3 and 5, a transition to an abnormality response state may be made. The abnormality may be identified when the driving support device 10 acquires an abnormality state by the driver abnormality acquisition unit 112. The abnormality response state is a state in which an abnormality response process, which is a process corresponding to an abnormal state of the driver, is performed. The abnormality response process may be the process shown in the timing chart on page 13 of the basic design document for the driver abnormality response system (deceleration stop type) of the Ministry of Land, Infrastructure, Transport and Tourism's Automobile Bureau. For example, the vehicle may be automatically stopped after a warning that the brakes are automatically applied. In the abnormality response state, if the vehicle stops automatically, a transition to the non-monitoring mode may be made. In the abnormality response state, if a release operation is performed, a transition may be made to return to the state before the transition to the abnormality response state of the monitoring mode. The release operation in this case may be the same as the release operation shown in the timing chart on page 13 of the basic design document for the driver abnormality response system (deceleration stop type) described above.

[0087] Furthermore, in an unrestricted state, when the continuous driving time from the start of driving reaches a certain period of time, a notification encouraging a rest may be issued. This notification is hereinafter referred to as a rest promotion notification. The certain period of time may be a period during which a rest is estimated to be desirable. The rest promotion notification may be issued by the presentation instruction unit 102. An example of the rest promotion notification is a voice output or a text display such as "It's been two hours since you started driving. Would you like to take a break?"

[0088] (Embodiment 2) In the first embodiment, the drowsiness monitoring function, the first speed suppression function, and the second speed suppression function are settable functions, but this is not necessarily limited to this. The first speed suppression function may not be included in the settable functions (hereinafter, the second embodiment). An example of the configuration of the second embodiment will be described below with reference to the drawings. <Schematic configuration of vehicle system 1a> Hereinafter, the second embodiment of the present disclosure will be described with reference to the drawings. As shown in Fig. 16, the vehicle system 1a includes a driving assistance device 10a, a locator 11, a map DB 12, a vehicle state sensor 13, an engine ECU 14, a brake ECU 15, an interior camera 16, a biosensor 17, a presentation device 18, a user input device 19, and an HCU 20. The vehicle system 1a is similar to the vehicle system 1 of the first embodiment, except that the vehicle system 1a includes the driving assistance device 10a instead of the driving assistance device 10.

[0089] <General configuration of driving assistance device 10a> Next, a schematic configuration of the driving support device 10a will be described with reference to FIG. 17. As shown in FIG. 17, the driving support device 10a includes an HCU communication unit 101, a presentation instruction unit 102, a speed suppression unit 103a, and a release determination unit 104 as functional blocks. The driving support device 10a is similar to the driving support device 10 of the first embodiment, except that the driving support device 10a includes the speed suppression unit 103a instead of the speed suppression unit 103. The driving support device 10a corresponds to a dozing prevention device. Also, the control program stored in the non-volatile memory of the driving support device 10a corresponds to a dozing prevention program. Also, the execution of the processing of each functional block of the driving support device 10a by a computer corresponds to the execution of a dozing prevention method.

[0090] The speed suppression unit 103a includes a second speed suppression unit 132a as a sub-functional block. The speed suppression unit 103a does not include the first speed suppression unit 131. The speed suppression unit 103a includes the second speed suppression unit 132a instead of the second speed suppression unit 132. Except for these points, the speed suppression unit 103a is similar to the speed suppression unit 103 of the first embodiment.

[0091] The second speed suppression unit 132a is similar to the second speed suppression unit 132 of the first embodiment, except for some differences in processing. The second speed suppression unit 132a performs the same processing as the second speed suppression unit 132. The second speed suppression unit 132a performs different processing in addition to the processing of the second speed suppression unit 132. This different processing will be described below.

[0092] The second speed suppression unit 132a activates the second speed suppression function in response to the depth level acquired by the drowsiness state acquisition unit 111 being a drowsy state. That is, in the second embodiment, the second upper limit speed corresponds to the set upper limit speed. In the second embodiment, the second speed suppression unit 132a also serves as a drowsy speed suppression unit. The second speed suppression function in the second embodiment also serves as a drowsy speed suppression function. The processing in the second speed suppression unit 132a corresponds to a drowsy speed suppression step. Even with the above configuration, even if the driver's drowsiness is detected, it is possible to prevent the driver from falling asleep while making it difficult for the driver's comfort to be impaired. In addition, even if the driver continues to drive while feeling drowsy, the speed is limited, making it easier to avoid approaching obstacles. Note that the second speed suppression unit 132a may be configured not to activate the second speed suppression function when the vehicle does not meet the condition that the vehicle has reached the legal upper limit speed even in the case of a drowsy state.

[0093] <Function activation settings in the second embodiment> Next, a function activation setting in the second embodiment will be described with reference to Fig. 18 and Fig. 19. In this embodiment, it is assumed that the drowsiness monitoring function and the second speed suppression function are settable functions.

[0094] Fig. 18 shows a display example of a screen for turning on and off the settable functions in embodiment 2. In the example of Fig. 18, the second speed suppression function is displayed as a suppression function when exceeding the legal speed limit. The screen for turning on and off the settable functions in embodiment 2 displays buttons for switching on and off the drowsiness monitoring function and the second speed suppression function.

[0095] Next, the combination patterns of function activation settings in the second embodiment will be described with reference to Fig. 19. Pattern 7 is a pattern in which both the drowsiness monitoring function and the second speed suppression function are on. Pattern 8 is a pattern in which the drowsiness monitoring function is off and the second speed suppression function is on. Pattern 9 is a pattern in which both the drowsiness monitoring function and the second speed suppression function are off. Pattern 10 is a pattern in which the drowsiness monitoring function is on and the second speed suppression function is off.

[0096] <Regarding state transition in the vehicle system 1a> Next, an example of state transition in the vehicle system 1a will be described. First, an example of state transition in the monitoring mode when the combination of function activation settings is pattern 10 will be described with reference to FIG. 20. FIG. 20 is a diagram for explaining state transition in the monitoring mode in the case of pattern 10. The LWS in FIG. 20 shows a state waiting for the second speed suppression function to be activated. This state is called a restriction waiting state. Note that the state transition when the vehicle is stopped may be the same as that shown in FIG. 12 even in the case of pattern 10.

[0097] When the vehicle starts traveling (see t41 in FIG. 20), the vehicle transitions to the no-limit state as a default state. The no-limit state here is a state in which the driver's drowsiness is not specified and the vehicle has not reached the legal upper limit speed. In this no-limit state, when drowsiness less than the above-mentioned DNc is specified (see t42 in FIG. 20), the vehicle transitions to the alert 1 state. The alert 1 state is the same as described above. In the alert 1 state, when no drowsiness is specified (see t43 in FIG. 20), the vehicle transitions to the no-limit state as a default state. On the other hand, in the alert 1 state, when the travel distance of the vehicle after the start of the advance warning reaches a specified distance (see t44 in FIG. 20), the vehicle transitions to the alert 2 state. In addition, in the alert 1 state, when drowsiness equal to or greater than DNc is specified (see t44 in FIG. 20), the vehicle transitions to the alert 2 state. The alert 2 state is the same as described above. Also, in the no-limit state as the default state, if drowsiness of DNc or ​​more is identified (see t45 in FIG. 20), a transition to the alert 2 state occurs.

[0098] In the alert 2 state, if no drowsiness is identified (see t46 in FIG. 20), the state transitions to the no-restriction state as the default state. On the other hand, in the alert 2 state, if a specified time has elapsed since the start of the advance warning (see t47 in FIG. 20), the state transitions to the limit waiting state. In the limit waiting state, if the vehicle reaches the legal upper limit speed (see t48 in FIG. 20), the state transitions from the no-restriction state of the limit waiting state to the legal speed limit state. The legal speed limit state is the same as that described above. That is, in the case of pattern 9, even if the second speed suppression function is off, if drowsiness is identified, the second speed suppression function is automatically turned on. On the other hand, in the legal speed limit state, if the vehicle falls below the legal upper limit speed (see t49 in FIG. 20), the state transitions to the no-restriction state of the limit waiting state. Also, in the monitoring mode, if the vehicle stops, the state transitions to the non-monitoring mode.

[0099] Next, an example of state transition when the combination of function enable settings is patterns 7 to 9 will be described. When the combination of function enable settings is patterns 7 and 8, the same as the above-mentioned patterns 2 and 4 may be applied. When the combination of function enable settings is pattern 9, the same as the above-mentioned patterns 3 and 5 may be applied.

[0100] In addition, if an abnormal state of the driver is identified in the monitoring mode in the cases of patterns 7 to 8 and 10, and while driving in the case of pattern 9, the vehicle may transition to the abnormality response state described above. Also, if the vehicle stops automatically in the abnormality response state, the vehicle may transition to the non-monitoring mode.

[0101] (Embodiment 3) In the above embodiment, the speed suppression by the speed suppression function does not include the speed suppression by the braking control, but this is not necessarily limited to this. In the following, the speed suppression by the speed suppression function may include the speed suppression by the braking control (hereinafter, the third embodiment). In the following, an example of the configuration of the third embodiment will be described with reference to the drawings. <Schematic configuration of vehicle system 1b> Hereinafter, the third embodiment of the present disclosure will be described with reference to the drawings. As shown in Fig. 21, the vehicle system 1b includes a driving assistance device 10b, a locator 11, a map DB 12, a vehicle state sensor 13, an engine ECU 14, a brake ECU 15, an interior camera 16, a biosensor 17, a presentation device 18, a user input device 19, and an HCU 20. The vehicle system 1b is similar to the vehicle system 1 of the first embodiment, except that the vehicle system 1b includes the driving assistance device 10b instead of the driving assistance device 10.

[0102] <Schematic configuration of driving assistance device 10b> Next, a schematic configuration of the driving support device 10b will be described with reference to FIG. 22. As shown in FIG. 22, the driving support device 10b includes an HCU communication unit 101, a presentation instruction unit 102, a speed suppression unit 103b, and a release determination unit 104 as functional blocks. The driving support device 10b is similar to the driving support device 10 of the first embodiment, except that the driving support device 10b includes a speed suppression unit 103b instead of the speed suppression unit 103. This driving support device 10b corresponds to a dozing prevention device. Also, the control program stored in the non-volatile memory of the driving support device 10b corresponds to a dozing prevention program. Also, the execution of the processing of each functional block of the driving support device 10b by a computer corresponds to the execution of a dozing prevention method.

[0103] The speed suppression unit 103b includes a first speed suppression unit 131b and a second speed suppression unit 132b as sub-functional blocks. The speed suppression unit 103b includes a first speed suppression unit 131b and a second speed suppression unit 132b instead of the first speed suppression unit 131 and the second speed suppression unit 132. Except for this point, the speed suppression unit 103b is similar to the speed suppression unit 103 of the first embodiment.

[0104] The first speed suppression unit 131b is similar to the first speed suppression unit 131 of the first embodiment, except for some differences in processing. The differences will be described below. The first speed suppression unit 131b performs the following processing when the first speed suppression function is in an active state, the vehicle speed of the host vehicle exceeds the first upper limit speed, and the depression amount of the brake pedal is 0. The first speed suppression unit 131b causes the brake ECU 15 to apply braking so that the vehicle speed falls below the first upper limit speed. That is, while the first speed suppression function did not intervene in the brake control in the first embodiment, it does intervene in the brake control in the third embodiment.

[0105] According to the above configuration, even if the speed cannot be suppressed by only intervening in the accelerator control, it is possible to suppress the speed by intervening in the brake control. As a result, it is possible to more easily prevent the driver from falling asleep while making it difficult for the driver's comfort to be impaired. This first speed suppression unit 131b also corresponds to a drowsy speed suppression unit. Moreover, the processing in the first speed suppression unit 131b also corresponds to a drowsy speed suppression process. Note that the first speed suppression unit 131b preferably performs gradual deceleration so that the deceleration amount per unit time during braking does not become too large. The deceleration amount per unit time may be set arbitrarily.

[0106] The second speed suppression unit 132b is similar to the second speed suppression unit 132 of the first embodiment, except for some differences in processing. The differences will be described below. The second speed suppression unit 132b performs the following processing when the second speed suppression function is in an active state, the vehicle speed of the host vehicle exceeds the second upper limit speed, and the depression amount of the brake pedal is zero. The second speed suppression unit 132b causes the brake ECU 15 to apply braking so that the vehicle speed falls below the second upper limit speed. It is preferable that the second speed suppression unit 132b slowly decelerates the vehicle so that the deceleration amount per unit time during braking does not become too large. The deceleration amount per unit time may be set arbitrarily.

[0107] In the third embodiment, the second speed suppression unit 132 of the first embodiment may be used in place of the second speed suppression unit 132b. The configuration of the third embodiment may be combined with the configuration of the second embodiment.

[0108] (Embodiment 4) In the above-described embodiment, the driving support devices 10, 10a, and 10b are installed in the vehicle when the vehicle is manufactured. However, this is not necessarily limited to this. Hereinafter, an example of the configuration of the fourth embodiment will be described with reference to the drawings. <Schematic configuration of vehicle system 1c> Hereinafter, the fourth embodiment of the present disclosure will be described with reference to the drawings. As shown in FIG. 23, the vehicle system 1c includes a driving assistance device 10c, a locator 11, a map DB 12, a vehicle state sensor 13, an engine ECU 14, a brake ECU 15, an interior camera 16, a biosensor 17, a presentation device 18, a user input device 19, and an HCU 20. The vehicle system 1c is similar to the vehicle system 1 of the first embodiment, except that the vehicle system 1c includes the driving assistance device 10c instead of the driving assistance device 10. The driving assistance device 10c is assumed to be added to the vehicle after the vehicle is manufactured. In other words, the driving assistance device 10c is a retrofit device.

[0109] <Schematic configuration of driving assistance device 10c> Next, a schematic configuration of the driving support device 10c will be described with reference to FIG. 24. As shown in FIG. 24, the driving support device 10c includes an HCU communication unit 101, a presentation instruction unit 102, a speed suppression unit 103c, and a release determination unit 104 as functional blocks. The driving support device 10c is similar to the driving support device 10 of the first embodiment, except that the driving support device 10c includes the speed suppression unit 103c instead of the speed suppression unit 103. This driving support device 10c corresponds to a dozing prevention device. Also, the control program stored in the non-volatile memory of the driving support device 10c corresponds to a dozing prevention program. Also, the execution of the processing of each functional block of the driving support device 10c by a computer corresponds to the execution of a dozing prevention method.

[0110] The speed suppression unit 103c includes a first speed suppression unit 131c and a second speed suppression unit 132c as sub-functional blocks. The speed suppression unit 103c includes a first speed suppression unit 131c and a second speed suppression unit 132c instead of the first speed suppression unit 131 and the second speed suppression unit 132. Except for this point, the speed suppression unit 103c is similar to the speed suppression unit 103 of the first embodiment. The following describes this difference.

[0111] The speed suppression unit 103c is interposed between an accelerator stroke sensor of the vehicle state sensor 13 and the engine ECU 14. That is, the first speed suppression unit 131c and the second speed suppression unit 132c are interposed between the accelerator stroke sensor and the engine ECU 14. The accelerator stroke sensor of the vehicle state sensor 13 corresponds to an accelerator signal generating unit. The engine ECU 14 corresponds to a driving force control device. When the host vehicle uses a motor as a driving source, a power unit control ECU may be used instead of the engine ECU 14. A device that outputs an accelerator signal indicating the amount of operation of the accelerator pedal other than the accelerator stroke sensor may be used as the accelerator signal generating unit.

[0112] The first speed suppression unit 131c suppresses the speed in the first speed suppression function as follows. The first speed suppression unit 131c converts the accelerator signal input from the accelerator stroke sensor into an accelerator signal indicating an accelerator pedal operation amount smaller than the input signal. Then, the converted accelerator signal is output to the engine ECU 14. This realizes the suppression of the speed. According to the above configuration, even when the driving support device 10c is added to the vehicle after the vehicle is manufactured, it is possible to more easily realize the suppression of the speed. And, even when the drowsiness of the driver is detected, it is possible to prevent the driver from falling asleep while making it difficult for the driver's comfort to be impaired. This first speed suppression unit 131c also corresponds to a drowsy speed suppression unit. Moreover, the processing in the first speed suppression unit 131c also corresponds to a drowsy speed suppression process.

[0113] Here, the speed suppression by the first speed suppression function in the fourth embodiment will be described with reference to FIG. 25. The graph in FIG. 25 shows the change in the output value of the accelerator opening and the vehicle speed of the host vehicle. AOO in FIG. 25 shows the output value of the accelerator opening. UO in FIG. 25 is the output value of the accelerator opening from the first speed suppression unit 131c to the engine ECU 14. Until the vehicle speed of the host vehicle exceeds the first upper limit speed, the accelerator opening output to the engine ECU 14 is the same as the value input from the accelerator stroke sensor. On the other hand, when the vehicle speed of the host vehicle exceeds the first upper limit speed, the accelerator opening output from the first speed suppression unit 131c to the engine ECU 14 becomes a suppression value that is suppressed more than the value input from the accelerator stroke sensor. The suppression value may be, for example, an accelerator opening of 0.

[0114] The second speed suppression unit 132c may suppress the speed with the second speed suppression function as follows. The second speed suppression unit 132c converts the accelerator signal input from the accelerator stroke sensor into an accelerator signal indicating an accelerator pedal operation amount smaller than the input. Then, the converted accelerator signal is output to the engine ECU 14. In this way, the speed suppression is realized.

[0115] When the driving assistance device 10c is added to the vehicle after the vehicle is manufactured, it is assumed that a display device other than a built-in display will be used as the display device 181. Examples of the non-built-in display device include a multi-function mobile phone or a tablet terminal carried by the driver. Other examples include a display device that is added later. In order to facilitate the use of the non-built-in display device, the driving assistance device 10c may include a communication module that communicates with the non-built-in display device. For communication between the non-built-in display device and the driving assistance device 10c, short-range wireless communication in accordance with a short-range communication standard may be used. As an example, short-range wireless communication in accordance with Bluetooth (registered trademark) Low Energy may be used.

[0116] The configuration of embodiment 4 may be combined with the configurations of embodiments 2 and 3. When the configuration of embodiment 4 is combined with the configuration of embodiment 3, the following may be performed. The first speed suppression unit 131c may set the brake signal input from the brake stroke sensor to a predetermined value that slowly decelerates the host vehicle, and output the set value to the brake ECU 15.

[0117] (Embodiment 5) In the above embodiment, the driving support devices 10, 10a, 10b, and 10c are configured to correspond to the driving prevention device, but this is not necessarily limited to this. For example, an ECU other than the driving support devices 10, 10a, 10b, and 10c may be configured to correspond to the driving prevention device.

[0118] The present disclosure is not limited to the above-described embodiment, and various modifications are possible within the scope of the claims. The embodiments obtained by appropriately combining the technical means disclosed in the different embodiments are also included in the technical scope of the present disclosure. The control unit and the method described in the present disclosure may be realized by a dedicated computer constituting a processor programmed to execute one or more functions embodied by a computer program. Alternatively, the device and the method described in the present disclosure may be realized by a dedicated hardware logic circuit. Alternatively, the device and the method described in the present disclosure may be realized by one or more dedicated computers configured by a combination of a processor that executes a computer program and one or more hardware logic circuits. The computer program may be stored in a computer-readable non-transient tangible recording medium as instructions executed by the computer.

[0119] (Disclosed technical idea) This specification discloses multiple technical ideas described in the following multiple dependent claims. Some of the claims may be described in a multiple dependent form, where the subsequent claim alternatively refers to the preceding claim. Furthermore, some of the claims may be described in a multiple dependent form, where the subsequent claim alternatively refers to the preceding claim. The claims described in these multiple dependent forms define multiple technical ideas.

[0120] (Technical thought 1) A driver's drowsiness prevention device that can be used in a vehicle, A drowsiness state acquisition unit (111) that acquires a drowsiness state, which is a state related to the drowsiness of a driver of the vehicle; and a drowsiness speed suppression unit (131, 132a, 131b, 131c) that activates a drowsiness speed suppression function that suppresses the vehicle speed from exceeding a set upper limit speed, which is an upper limit speed that is set greater than 0, when the drowsiness state acquired by the drowsiness state acquisition unit indicates that the driver is drowsy.

[0121] (Technical thought 2) A driver's drowsiness prevention device according to Technical Idea 1, A presentation instruction unit (102) is provided for presenting information to the driver, the presentation instruction unit causes a warning to be given to the driver as the information presentation in response to the drowsiness state acquired by the drowsiness state acquisition unit being a state indicating that the driver is drowsy; and The drowsiness speed suppression unit continues to activate the drowsiness speed suppression function even after the warning has been initiated by the presentation instruction unit, provided that the drowsiness state acquired by the drowsiness state acquisition unit is a state indicating that the driver is drowsy.

[0122] (Technical Thought 3) A driver's drowsiness prevention device according to Technical Concept 2, the instruction presentation unit causes the drowsiness speed suppression unit to perform a step-by-step warning as the warning, until the drowsiness speed suppression function is activated in the drowsiness speed suppression unit, in response to the drowsiness state acquired by the drowsiness state acquisition unit being a state indicating that the driver is drowsy, The drowsiness speed suppression unit continues to activate the drowsiness speed suppression function even after the presentation instruction unit has started the final stage of the staged warnings, provided that the drowsiness state acquired by the drowsiness state acquisition unit is a state indicating that the driver is drowsy. This is an anti-drowsiness device.

[0123] (Technical Thought 4) A driver's drowsiness prevention device according to Technical Concept 3, The drowsiness state acquisition unit acquires a depth level, which is a degree of depth of drowsiness, as the drowsiness state, The presentation instruction unit sets the number of stages of the gradual warning before starting the gradual warning, and the drowsiness prevention device sets the number of stages of the gradual warning to be higher as the depth level acquired by the drowsiness state acquisition unit increases.

[0124] (Technical Thought 5) A driving prevention device according to Technical Idea 3 or 4, The drowsiness state acquisition unit acquires a depth level, which is a degree of depth of drowsiness, as the drowsiness state, The presentation instruction unit sets a start stage, which is the stage at which the graduated warning should be started, before starting the graduated warning, and the start stage is set to a later stage of the graduated warning as the depth level acquired by the drowsiness state acquisition unit increases.

[0125] (Technical Thought 6) A driving prevention device according to any one of technical concepts 2 to 5, The drowsiness state acquisition unit acquires a depth level, which is a degree of depth of drowsiness, as the drowsiness state, The drowsiness speed suppression unit, on condition that the drowsiness state acquired by the drowsiness state acquisition unit continues to indicate that the driver is drowsy even after the warning has been initiated by the warning instruction unit, advances the timing of activating the drowsiness speed suppression function after the start of the warning in accordance with the increase in the depth level acquired by the drowsiness state acquisition unit.

[0126] (Technical Thought 7) A driving prevention device according to any one of technical concepts 2 to 6, The instruction unit is configured to at least provide a warning including a warning of activating the drowsiness speed suppression function as the warning, The drowsiness speed suppression unit activates the drowsiness speed suppression function a specified time after the start of the advance warning by the presentation instruction unit, on condition that the drowsiness state acquired by the drowsiness state acquisition unit continues to be a state indicating that the driver is drowsy.

[0127] (Technical Thought 8) A driver's drowsiness prevention device according to Technical Concept 7, the instruction presentation unit causes the drowsiness speed suppression unit to perform a step-by-step warning as the warning, until the drowsiness speed suppression function is activated in the drowsiness speed suppression unit, in response to the drowsiness state acquired by the drowsiness state acquisition unit being a state indicating that the driver is drowsy, The staged warning includes a warning including a warning of activating the drowsiness speed suppression function, and a pre-warning, which is a warning at an earlier stage than the warning, The presentation instruction unit continues to issue the advance warning after the advance warning has started and the drowsiness state acquired by the drowsiness state acquisition unit indicates that the driver is drowsy, and the advance warning is issued after the vehicle's mileage after the advance warning has started reaches a specified distance.

[0128] (Technical Thought 9) A driving prevention device according to any one of technical concepts 1 to 8, The drowsiness state acquisition unit acquires a depth level, which is a degree of depth of drowsiness, as the drowsiness state, The drowsiness speed suppression unit is configured to lower the set upper limit speed as the depth level acquired by the drowsiness state acquisition unit increases.

[0129] (Technical Thought 10) A driver's drowsiness prevention device according to Technical Idea 9, The drowsiness speed suppression unit is a drowsiness prevention device that, if a legal minimum speed limit is set for the road on which the vehicle is traveling, prevents the set upper limit speed corresponding to the depth level from falling below this legal minimum speed.

[0130] (Technical Thought 11) A driving prevention device according to any one of technical concepts 1 to 10, a deactivation determination unit (104) that determines whether or not a deactivation condition for deactivating the drowsiness speed suppression function is satisfied when the drowsiness speed suppression function is in an activated state, The drowsiness speed suppression unit cancels an operating state of the drowsiness speed suppression function when the cancellation determination unit determines that the cancellation condition is satisfied, The release determination unit sets at least one of the release conditions that the drowsiness state acquired by the drowsiness state acquisition unit has reached a state indicating that the driver's drowsiness has been eliminated, that the vehicle has stopped and a set time or more has elapsed, and that the vehicle has received a release operation that is predetermined as an operation to release the operating state of the drowsiness speed suppression function, and determines that the release condition for releasing the operating state of the drowsiness speed suppression function has been met when any one of these release conditions is satisfied.

[0131] (Technical Thought 12) A driving prevention device according to any one of technical concepts 1 to 11, A presentation instruction unit (102) is provided to present information to the driver, The presentation instruction unit is a drowsiness prevention device that notifies the driver, as the information presentation, that the drowsiness speed suppression function will be automatically activated due to the driver's drowsiness before the vehicle departs.

[0132] (Technical Thought 13) A driver's drowsiness prevention device according to Technical Idea 9, In addition to the drowsiness speed suppression unit, the drowsiness prevention device further includes a legal-related speed suppression unit (132, 132a, 132b, 132c) that activates a legal-related speed suppression function that suppresses the vehicle from exceeding a legal-related upper limit speed, which is an upper limit speed that is set so as not to exceed a legal upper limit speed according to the legal upper limit speed established for the road on which the vehicle is traveling, regardless of whether the driver is drowsy or not.

[0133] (Technical Thought 14) A driver's drowsiness prevention device according to Technical Idea 13, A presentation instruction unit (102) is provided to present information to the driver, the presentation instruction unit outputs at least a sound as the information presentation, The presentation instruction unit outputs a first notification sound to notify the driver that the set upper limit speed has changed when the set upper limit speed has changed, and also outputs a second notification sound to notify the driver that the legal upper limit speed has changed when the legal upper limit speed has changed, and the second notification sound is output in a manner that is less annoying than the first notification sound.

[0134] (Technical Thought 15) A driver's drowsiness prevention device according to any one of technical concepts 1 to 14, The drowsiness speed suppression function that the drowsiness speed suppression unit (131c) activates is a function that suppresses acceleration caused by operation of an accelerator pedal of the vehicle, The drowsiness speed suppression unit is an anti-drowsiness device that is interposed between an accelerator signal generating unit (13) that outputs an accelerator signal, which is a signal indicating the amount of accelerator pedal operation, and a driving force control device (14) that controls the vehicle's driving force in response to the accelerator signal, and converts the accelerator signal input from the accelerator signal generating unit into an accelerator signal indicating an accelerator pedal operation amount that is smaller than the input accelerator signal, and outputs the converted accelerator signal to the driving force control device. [Explanation of symbols]

[0135] 1, 1a, 1b, 1c Vehicle system, 10, 10a, 10b, 10c Driving support device (sleep prevention device), 13 Vehicle state sensor (accelerator signal generating unit), 14 Engine ECU (driving force control device), 102 Presentation instruction unit, 104 Release determination unit, 111 Drowsiness state acquisition unit, 131, 131b, 131c First speed suppression unit (sleepiness speed suppression unit), 132b Second speed suppression unit (sleepiness speed suppression unit)

Claims

1. A driver's drowsiness prevention device that can be used in a vehicle, A drowsiness state acquisition unit (111) that acquires a drowsiness state that is a state related to the drowsiness of a driver of the vehicle; and a drowsiness speed suppression unit (131, 132a, 131b, 131c) that activates a drowsiness speed suppression function that suppresses the vehicle speed from exceeding a set upper limit speed, which is an upper limit speed that is set greater than 0, when the drowsiness state acquired by the drowsiness state acquisition unit indicates that the driver is drowsy.

2. The sleep prevention device according to claim 1, A presentation instruction unit (102) is provided for presenting information to the driver, the presentation instruction unit causes a warning to be given to the driver as the information presentation in response to the drowsiness state acquired by the drowsiness state acquisition unit being a state indicating that the driver is drowsy; and The drowsiness speed suppression unit continues to activate the drowsiness speed suppression function even after the warning has been initiated by the presentation instruction unit, provided that the drowsiness state acquired by the drowsiness state acquisition unit is a state indicating that the driver is drowsy.

3. The sleep prevention device according to claim 2, the instruction presentation unit causes the drowsiness speed suppression unit to perform a step-by-step warning as the warning, until the drowsiness speed suppression function is activated in the drowsiness speed suppression unit, in response to the drowsiness state acquired by the drowsiness state acquisition unit being a state indicating that the driver is drowsy, The drowsiness speed suppression unit continues to activate the drowsiness speed suppression function even after the presentation instruction unit has started the final stage of the staged warnings, provided that the drowsiness state acquired by the drowsiness state acquisition unit is a state indicating that the driver is drowsy. This is an anti-drowsiness device.

4. The sleep prevention device according to claim 3, The drowsiness state acquisition unit acquires a depth level, which is a degree of depth of drowsiness, as the drowsiness state, The presentation instruction unit sets the number of stages of the gradual warning before starting the gradual warning, and the drowsiness prevention device sets the number of stages of the gradual warning to be higher as the depth level acquired by the drowsiness state acquisition unit increases.

5. The sleep prevention device according to claim 3, The drowsiness state acquisition unit acquires a depth level, which is a degree of depth of drowsiness, as the drowsiness state, The presentation instruction unit sets a start stage, which is the stage at which the graduated warning should be started, before starting the graduated warning, and the start stage is set to a later stage of the graduated warning as the depth level acquired by the drowsiness state acquisition unit increases.

6. The sleep prevention device according to claim 2, The drowsiness state acquisition unit acquires a depth level, which is a degree of depth of drowsiness, as the drowsiness state, The drowsiness speed suppression unit, on condition that the drowsiness state acquired by the drowsiness state acquisition unit continues to indicate that the driver is drowsy even after the warning has been started by the presentation instruction unit, advances the timing of activating the drowsiness speed suppression function after the start of the warning in accordance with the increase in the depth level acquired by the drowsiness state acquisition unit.

7. The sleep prevention device according to claim 2, The instruction unit is configured to at least provide a warning including a warning of activating the drowsiness speed suppression function as the warning, The drowsiness speed suppression unit activates the drowsiness speed suppression function a specified time after the start of the advance warning by the presentation instruction unit, on condition that the drowsiness state acquired by the drowsiness state acquisition unit continues to be a state indicating that the driver is drowsy.

8. The sleep prevention device according to claim 7, the instruction presentation unit causes the drowsiness speed suppression unit to perform a step-by-step warning as the warning, until the drowsiness speed suppression function is activated in the drowsiness speed suppression unit, in response to the drowsiness state acquired by the drowsiness state acquisition unit being a state indicating that the driver is drowsy, The staged warning includes a warning including a warning of activating the drowsiness speed suppression function, and a pre-warning warning which is a warning at an earlier stage than the warning, The presentation instruction unit continues to issue the advance warning after the advance warning has started and the drowsiness state acquired by the drowsiness state acquisition unit indicates that the driver is drowsy, and the advance warning is issued after the vehicle's mileage after the advance warning has started reaches a specified distance.

9. The sleep prevention device according to claim 1, The drowsiness state acquisition unit acquires a depth level, which is a degree of depth of drowsiness, as the drowsiness state, The drowsiness speed suppression unit is configured to lower the set upper limit speed as the depth level acquired by the drowsiness state acquisition unit increases.

10. The sleep prevention device according to claim 9, The drowsiness speed suppression unit is a drowsiness prevention device that, if a legal minimum speed limit is set for the road on which the vehicle is traveling, prevents the set upper limit speed corresponding to the depth level from falling below this legal minimum speed.

11. The sleep prevention device according to claim 1, A deactivation determination unit (104) is provided for determining whether or not a deactivation condition for deactivating the drowsiness speed suppression function is satisfied when the drowsiness speed suppression function is in an activated state, The drowsiness speed suppression unit cancels an operating state of the drowsiness speed suppression function when the cancellation determination unit determines that the cancellation condition is satisfied, The release determination unit sets at least one of the release conditions that the drowsiness state acquired by the drowsiness state acquisition unit has reached a state indicating that the driver's drowsiness has been eliminated, that the vehicle has stopped and a set time or more has elapsed, and that the vehicle has received a release operation that is predetermined as an operation to release the operating state of the drowsiness speed suppression function, and determines that the release condition for releasing the operating state of the drowsiness speed suppression function has been met when any one of these release conditions is satisfied.

12. The sleep prevention device according to claim 1, The present invention further includes a display instruction unit (102) for displaying information to the driver, The presentation instruction unit is a drowsiness prevention device that notifies the driver, as the information presentation, that the drowsiness speed suppression function will be automatically activated due to the driver's drowsiness before the vehicle departs.

13. The sleep prevention device according to claim 9, In addition to the drowsiness speed suppression unit, the drowsiness prevention device further includes a legal-related speed suppression unit (132, 132a, 132b, 132c) that activates a legal-related speed suppression function that suppresses the vehicle from exceeding a legal-related upper limit speed, which is an upper limit speed that is set so as not to exceed a legal upper limit speed according to the legal upper limit speed established for the road on which the vehicle is traveling, regardless of whether the driver is drowsy or not.

14. The sleep prevention device according to claim 13, The present invention further includes a display instruction unit (102) for displaying information to the driver, the presentation instruction unit outputs at least a sound as the information presentation, The presentation instruction unit outputs a first notification sound to notify the driver that the set upper limit speed has changed when the set upper limit speed has changed, and also outputs a second notification sound to notify the driver that the legal relevant upper limit speed has changed when the legal relevant upper limit speed has changed, and the second notification sound is output in a manner that is less annoying than the first notification sound.

15. The sleep prevention device according to claim 1, The drowsiness speed suppression function that the drowsiness speed suppression unit (131c) activates is a function that suppresses acceleration due to operation of an accelerator pedal of the vehicle, The drowsiness speed suppression unit is an anti-drowsiness device that is interposed between an accelerator signal generating unit (13) that outputs an accelerator signal, which is a signal indicating the amount of accelerator pedal operation, and a driving force control device (14) that controls the vehicle's driving force in response to the accelerator signal, and converts the accelerator signal input from the accelerator signal generating unit into an accelerator signal indicating an accelerator pedal operation amount that is smaller than the input accelerator signal, and outputs the converted accelerator signal to the driving force control device.

16. A method for preventing drowsiness that can be used in a vehicle, comprising: Executed by at least one processor, a drowsiness state acquiring step of acquiring a drowsiness state related to the drowsiness of the driver of the vehicle; and a drowsiness speed suppression process for activating a drowsiness speed suppression function that suppresses the vehicle speed from exceeding a set upper limit speed, which is an upper limit speed that is set greater than 0, depending on whether the drowsiness state acquired in the drowsiness state acquisition process is a state indicating that the driver is drowsy.

17. A driver's drowsiness prevention program usable in a vehicle, comprising: Computer, A drowsiness state acquisition unit (111) that acquires a drowsiness state that is a state related to the drowsiness of a driver of the vehicle; A drowsiness prevention program for causing a drowsiness speed suppression unit (131, 132a, 131b, 131c) to function as an drowsiness speed suppression unit that activates a drowsiness speed suppression function that suppresses the vehicle speed from exceeding a set upper limit speed, which is an upper limit speed that is set greater than 0, depending on whether the drowsiness state acquired by the drowsiness state acquisition unit is a state indicating that the driver is drowsy.

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