Vibration presentation method and vibration presentation device

Abstract

By providing vibrational stimulation to the driver, the system encourages the driver to enter a mental state suitable for safe driving. [Solution] In the vibration presentation method, a vibration actuator is used to vibrate a component inside the vehicle that the driver comes into contact with, generating vibrations that simulate heartbeat vibrations (S5). Risks in the vehicle's driving environment are detected (S1). In accordance with the detected risks, the heart rate or intensity of the heartbeat vibrations simulated by the vibration actuator is changed (S3, S6, S7).

Description

Technical Field

[0001] The present invention relates to a vibration presentation method and a vibration presentation device.

Background Art

[0002] Patent Document 1 describes a warning device including one or more environmental sensors that detect objects around a vehicle, and an actuator system that tactually notifies a driver of warning information regarding the positions of the objects detected by the environmental sensors.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The tactile warning described in Patent Document 1 is effective in improving the driver's spatial recognition ability and awareness of the risk of urgency, but it cannot lead the driver to a mental state suitable for safe driving of the vehicle. As a result, if the driver makes mistakes due to being in an inappropriate mental state, there is a risk that the situation cannot be improved even if a warning is output. An object of the present invention is to prompt a driver to a mental state suitable for safe driving of a vehicle by applying a vibration stimulus to the driver.

Means for Solving the Problems

[0005] In a vibration presentation method according to an aspect of the present invention, vibrations simulating a heartbeat are generated by a vibration actuator that vibrates a member inside the vehicle with which a driver of the vehicle comes into contact, a risk in a driving environment of the vehicle is detected, and according to the detected risk, the heart rate or intensity of the heartbeat vibration simulated by the vibration actuator is changed.

Effects of the Invention

[0006] According to the present invention, by providing the driver with vibrational stimulation, it is possible to encourage the driver to enter a mental state suitable for safe driving of the vehicle. [Brief explanation of the drawing]

[0007] [Figure 1] This is a schematic diagram of an example of a vibration presentation device according to an embodiment. [Figure 2] (a) and (b) are examples of heart rate signals presented to the driver by a vibration display device. [Figure 3] (a) is an explanatory diagram of an example of setting parameters for the heart rate signal, and (b) is an explanatory diagram of updating the heart rate based on the setting parameters in (a). [Figure 4] (a) to (c) are diagrams illustrating an example of the updating of the vibration intensity of the heart rate signal in a dangerous situation. [Figure 5] (a) to (c) are diagrams illustrating another example of updating the vibration intensity of the heart rate signal in a dangerous situation. [Figure 6] (a) and (b) are diagrams illustrating an example of updating the vibration intensity of the heart rate signal in an emergency scenario. [Figure 7] This is a flowchart of an example of a vibration presentation method according to the embodiment. [Figure 8] This is a flowchart illustrating an example of the target scene detection process. [Figure 9] This is a flowchart illustrating an example of a vibration intensity update process. [Modes for carrying out the invention]

[0008] Embodiments of the present invention will be described below with reference to the drawings. Note that the drawings are schematic and may differ from actual ones. Furthermore, the embodiments of the present invention described below are illustrative examples of devices and methods for realizing the technical concept of the present invention, and the technical concept of the present invention is not limited to the structure, arrangement, etc., of the components described below. The technical concept of the present invention can be modified in various ways within the technical scope defined by the claims described in the patent claims.

[0009] (composition) Figure 1 is a schematic diagram of an example of a vibration presentation device according to an embodiment. The vehicle 1 is equipped with a vibration presentation device 10 that provides vibration stimuli to the driver. The vibration presentation device 10 comprises a map database (map DB) 11, a positioning device 12, an on-board sensor 13, a biosensor 14, a tactile actuator (tactile ACTR) 15, and a controller 20. The map database 11 stores road map data. For example, the map database 11 may store navigation map data (hereinafter simply referred to as "navigation map"). The map database 11 may also store high-precision map data suitable for use as map information for autonomous driving (hereinafter simply referred to as "high-precision map").

[0010] The positioning device 12 is equipped with a Global Navigation Satellite System (GNSS) receiver and measures the current position of the vehicle 1 by receiving radio waves from multiple navigation satellites. The GNSS receiver may be, for example, a GPS receiver. The positioning device 12 may also be, for example, an inertial navigation device. The in-vehicle sensor 13 includes an external sensor that detects ambient environment information, which is information about the surrounding environment of the vehicle 1, and a vehicle sensor that detects various information (vehicle information) obtained from the vehicle 1. The external sensor system includes multiple different types of object detection sensors mounted on the vehicle 1, such as laser radar, millimeter-wave radar, cameras, and LIDAR (Light Detection and Ranging, Laser Imaging Detection and Ranging), which detect objects around the vehicle 1.

[0011] Vehicle sensors include, for example, a vehicle speed sensor for detecting the vehicle speed of vehicle 1, a wheel speed sensor for detecting the rotational speed of the vehicle's tires, a three-axis acceleration sensor (G sensor) for detecting the acceleration (including deceleration) of vehicle 1 in three axes, a steering angle sensor for detecting the steering angle (including turning angle), a gyro sensor for detecting the angular velocity occurring in vehicle 1, a yaw rate sensor for detecting the yaw rate, an accelerator sensor for detecting the accelerator opening of vehicle 1, and a brake sensor for detecting the amount of brake operation by the driver.

[0012] The biosensor 14 is a sensor that detects the driver's biological information. For example, the biosensor 14 may be a heart rate sensor that detects the driver's heart rate as biological information. Alternatively, the biosensor 14 may be a sensor that detects at least one of the driver's brain waves, cerebral blood flow, respiratory rate, and sweat volume as biological information of the driver.

[0013] The tactile actuator 15 is an actuator used to output vibration stimuli (tactile signals) to the driver by vibrating components inside the vehicle that the driver of the vehicle 1 comes into contact with, in accordance with a control signal from the controller 20. For example, the tactile actuator 15 may be a steering wheel actuator capable of generating vibrations of the steering wheel, a pedal actuator capable of generating vibrations of the accelerator pedal or brake pedal, a seat actuator capable of generating vibrations of the driver's seat, or a seat belt actuator capable of generating vibrations of the seat belt.

[0014] The controller 20 is an electronic control unit (ECU: Electronic Control Unit) that controls the vibration stimulus (haptic signal) applied to the driver by the haptic actuator 15. The controller 20 includes a processor and peripheral components such as a storage device. The processor may be, for example, a CPU (Central Processing Unit) or an MPU (Micro-Processing Unit). The storage device may include a semiconductor storage device, a magnetic storage device, an optical storage device, etc. The storage device may include memories such as registers, cache memories, a ROM (Read Only Memory) and a RAM (Random Access Memory) used as a main storage device. The functions of the controller 20 described below are realized, for example, when a processor executes a computer program stored in the storage device.

[0015] Note that the controller 20 may be formed by dedicated hardware for executing each information processing described below. For example, the controller 20 may include a functional logic circuit set in a general-purpose semiconductor integrated circuit. For example, the controller 20 may have a programmable logic device (PLD) such as a field-programmable gate array (FPGA).

[0016] Hereinafter, an outline of the vibration presentation method of the embodiment will be described.The vibration presentation method of the embodiment is based on the synchronization phenomenon of human physiological activities (heart rate, respiration rate, skin conductivity) existing in human-to-human communication. Such a synchronization phenomenon is known as a phenomenon in which biological rhythms such as heartbeat fluctuations and breathing with an interaction partner mutually synchronize (such as the periods of two or more periodic motions being the same) (Palumbo, Richard V., et al. "Interpersonal autonomic physiology: A systematic review of the literature.", Personality and Social Psychology Review 21.2 (2017): 99-141).

[0017] Also, it is known that the mental state can be calmed by lowering the heart rate, and the concentration can be increased or a highly vigilant mental state can be induced by raising the heart rate. Therefore, by controlling the driver's heart rate using the above-described synchronization phenomenon, an effect of leading the driver's mental state to a state suitable for the safe driving of the vehicle can be expected.

[0018] Therefore, in the vibration presentation method of the embodiment, the vehicle 1 is anthropomorphized as an interaction partner with the driver, and the driver's heartbeat vibration is synchronized with the heartbeat vibration of the vehicle 1 by giving the driver a vibration that simulates the heartbeat vibration of the anthropomorphized vehicle 1. At this time, based on the surrounding environment of the vehicle 1 detected by the in-vehicle sensor 13, a mental state suitable for safe driving is determined, and the heartbeat vibration corresponding to the determined mental state is given to the driver as the heartbeat vibration of the vehicle 1.

[0019] In other words, the mental state suitable for safe driving determined based on the surrounding environment is set as the mental state of the anthropomorphized vehicle 1, and the mental state of the vehicle 1 is transmitted to the driver through the above-described synchronization phenomenon of heartbeat fluctuations. Thereby, through the synchronization phenomenon of heartbeat fluctuations, the driver's mental state can be brought closer to the mental state of the anthropomorphized vehicle 1 and led to a state suitable for the safe driving of the vehicle.

[0020] In the following explanation, vibrations that simulate the heartbeat vibration of the anthropomorphic vehicle 1 will be referred to as "heartbeat signals." The vibration presentation device 10 presents the heartbeat signals to the driver by vibrating the in-vehicle components that the driver comes into contact with (for example, the steering wheel, accelerator pedal, brake pedal, driver's seat, and seat belt) using the tactile actuator 15. Figures 2(a) and 2(b) show examples of heart rate signals presented to the driver by the vibration display device 10. Figure 2(a) shows an example of heart rate oscillation to encourage a higher level of vigilance in the driver when the driving environment of vehicle 1 is detected to be a high-risk driving environment, and the driver is in a resting state that is not suitable for recognizing the surrounding risks and is not suitable for safe driving. Reference numeral T indicates the heart rate interval (RR interval), which is the interval between one heartbeat and the next.

[0021] At the start of outputting the heart rate signal, the controller 20 initially outputs a heart rate signal (a heart rate signal with a relatively low heart rate) that represents heart rate oscillations corresponding to a resting state. Subsequently, it gradually increases the heart rate of the heart rate signal, changing it to a heart rate signal (a heart rate signal with a relatively high heart rate) corresponding to a highly alert and anxious state (a stressed state).

[0022] In other words, at the start of outputting the heart rate signal, the anthropomorphic vehicle 1 outputs a heart rate signal that represents a resting state (a heart rate signal with a relatively low heart rate), and then gradually changes to a heart rate signal that represents a stressed state (a heart rate signal with a relatively high heart rate). This allows a driver who is in a resting state at the time of risk detection to be gradually guided into a highly alert and anxious state by synchronizing with the heart rate signal of vehicle 1, thereby promoting a mental state suitable for safe driving in high-risk driving environments.

[0023] Figure 2(b) shows an example of heart rate oscillating to promote calmness in a driver when they are in an excessively stressed state and unsuitable for safe driving immediately after performing an emergency driving action (for example, emergency braking or steering to avoid a collision with an obstacle). At the start of outputting the heart rate signal, the controller 20 initially outputs a heart rate signal (a heart rate signal with a relatively high heart rate) that represents heart rate variability corresponding to a stressed state. Subsequently, it gradually decreases the heart rate of the heart rate signal, changing it to a heart rate signal (a heart rate signal with a relatively low heart rate) corresponding to a calm state.

[0024] In other words, at the start of outputting the heart rate signal, the heart rate signal for when the anthropomorphic vehicle 1 is in a high-stress state (a heart rate signal with a relatively high heart rate) is output, and then it gradually changes to the heart rate signal for when vehicle 1 is in a calm state (a heart rate signal with a relatively low heart rate). This allows the driver, who was under stress immediately after an emergency driving operation, to gradually calm down by synchronizing with the heart rate signal of vehicle 1, thereby promoting a mental state suitable for safe driving in low-risk driving environments.

[0025] Next, the functional configuration of the controller 20 will be described. Refer to Figure 1. The controller 20 functions as a risk assessment unit 30, an emergency driving operation determination unit 31, a scene detection unit 32, a parameter setting unit 33, a heart rate signal generation unit 34, a parameter update unit 35, and a stop condition determination unit 36. The risk assessment unit 30 detects risks in the driving environment of vehicle 1 based on surrounding environment information detected by the external sensors of the on-board sensors 13, vehicle information detected by the vehicle sensors, and road map data stored in the map database 11.

[0026] For example, the risk assessment unit 30 may detect the time to collision (TTC) between the vehicle 1 and surrounding obstacles as a direct risk. Furthermore, the risk assessment unit 30 may detect potential risks, such as vehicle 1 traveling at high speed towards an intersection with poor visibility.

[0027] The emergency driving operation determination unit 31 determines whether an emergency driving operation (for example, an emergency braking operation or emergency steering operation to avoid a collision with an obstacle) has been performed in the vehicle 1, based on the surrounding environment information detected by the external sensors of the on-board sensors 13 and the vehicle information detected by the vehicle sensors. For example, the emergency driving operation determination unit 31 may determine that an emergency driving operation has been performed if the TTC between the vehicle 1 and the objects around the vehicle 1 falls below a predetermined value, and either a braking operation with a deceleration of a predetermined deceleration or greater is performed, or a steering operation with a steering speed of a predetermined steering speed or greater is performed.

[0028] The scene detection unit 32 determines whether the current driving scene (i.e., driving conditions) of vehicle 1 is a target scene in which a heart rate signal should be presented to the driver. For example, the scene detection unit 32 may detect a scene in which the risk in the driving environment of vehicle 1 increases as a target scene. In the following description, a scene in which the risk in the driving environment of vehicle 1 increases may be referred to as a "dangerous scene". For example, the scene detection unit 32 may detect the current driving scene as a dangerous scene if the direct or potential risks detected by the risk assessment unit 30 are increasing. For example, the scene detection unit 32 may detect the current driving scene as a dangerous scene if these risks increase from a value below the on-threshold Thon to a value above the on-threshold Thon.

[0029] For example, the scene detection unit 32 may detect a scene as a target scene in which an emergency driving operation of vehicle 1 occurs, and subsequently the risk in the driving environment of vehicle 1 decreases. In the following description, a scene in which an emergency driving operation of vehicle 1 occurs, and subsequently the risk in the driving environment of vehicle 1 decreases, may be referred to as an "emergency scene".

[0030] For example, the scene detection unit 32 may detect the current driving scene as an emergency scene when the emergency driving operation determination unit 31 determines that an emergency driving operation has been performed. This is because, under normal circumstances, the subsequent risk decreases after an emergency driving operation is performed. Alternatively, the scene detection unit 32 may also detect the current driving scene as an emergency scene when the emergency driving operation determination unit 31 determines that an emergency driving operation has been performed, and the direct and potential risks subsequently detected by the risk assessment unit 30 have decreased.

[0031] When the scene detection unit 32 detects a target scene, the parameter setting unit 33 sets setting parameters for determining the heart rate Hr and vibration intensity I of the heart rate signal presented (output) from the tactile actuator 15, according to the detected target scene. Figure 3(a) is an explanatory diagram of an example of setting parameters for the heart rate signal. For example, the setting parameters may include the heart rate Hi at the time the heart rate signal output starts and the heart rate Ht corresponding to the target driver's mental state in the target scene detected by the scene detection unit 32.

[0032] In the following explanation, the heart rate Hi at the point when the heart rate signal output begins (output start time ts) will be referred to as the "initial heart rate," and the heart rate Ht corresponding to the target driver's mental state in the target scenario will be referred to as the "target heart rate." For example, if the scene detection unit 32 detects a dangerous scene, the parameter setting unit 33 may set the heart rate of a person in a resting state (relatively low heart rate) who is not suitable for recognizing the surrounding risks as the initial heart rate Hi, and set the heart rate of a person in a highly alert, anxious state (stressed state) (relatively high heart rate) as the target heart rate Ht.

[0033] For example, if the target scene detected by the scene detection unit 32 is an emergency scene, the parameter setting unit 33 may set the heart rate of a person in a stressed state (a relatively high heart rate) as the initial heart rate Hi, and the heart rate of a person in a calm state (a relatively high heart rate) as the target heart rate Ht.

[0034] The parameter setting unit 33 may estimate the driver's mental state based on the biological information detected by the biosensor 14. The parameter setting unit 33 may set the heart rate corresponding to the mental state estimated based on the biological information detected by the biosensor 14 as the initial heart rate Hi. In this case, the heart rate signal generation unit 34, described later, generates a heart rate signal starting with an initial heart rate of Hi corresponding to a resting state if the target scene detected by the scene detection unit 32 is a dangerous scene and the driver's mental state estimated by the parameter setting unit 33 is a "resting state" that is not suitable for recognizing the risks around them. However, if the driver's mental state estimated by the parameter setting unit 33 is a mental state suitable for safe driving in a dangerous scene (for example, a highly alert and anxious state (stressed state)), the heart rate signal does not need to be generated.

[0035] Furthermore, if the target scene detected by the scene detection unit 32 is an emergency scene and the driver's mental state estimated by the parameter setting unit 33 is a stressed state, a heart rate signal starting with an initial heart rate of Hi corresponding to the stressed state is generated. However, if the driver's mental state estimated by the parameter setting unit 33 is a mental state suitable for safe driving in an emergency scene (e.g., a calm state), a heart rate signal does not need to be generated.

[0036] Furthermore, the setting parameters may include a transition time Htr that gradually changes the heart rate Hr of the heart rate signal from the initial heart rate Hi to the target heart rate Ht. The transition time Htr is the time from the start of outputting the heart rate signal ts until the heart rate Hr reaches the target heart rate Ht. The setting parameter may also include a duration Ttd, which is the period from the start time ts of heart rate signal output to the stop time te of heart rate signal output. The setting parameters may also include a fade-out time Tf, which is the transition time during which the oscillation intensity I of the heart rate signal is gradually reduced to 0 when the presentation (output) of the heart rate signal ends.

[0037] When the scene detection unit 32 detects a target scene, the heart rate signal generation unit 34 generates an operation signal for the tactile actuator 15 and outputs (presents) a heart rate signal from the tactile actuator 15. First, the heart rate signal generation unit 34 sets the heart rate Hr of the heart rate signal at the start of output ts to the initial heart rate Hi, and sets the vibration intensity I of the heart rate signal at the start of output ts to an initial value. For example, the initial value of vibration intensity I may be a predetermined fixed value or a maximum value Imax. In the following explanation, the heart rate (Hr) and vibration intensity (I) of the heart rate signal may be referred to as "pulsation parameters."

[0038] The heart rate signal generation unit 34 converts the pulsation parameters into operating signals for the tactile actuator 15, causing the tactile actuator 15 to generate a heart rate signal (heart rate vibration) with a set heart rate Hr and vibration intensity I. During the period after the output start time ts, the parameter update unit 35 updates the heart rate signal pulse parameters (heart rate Hr and vibration intensity I) based on the setting parameters set by the parameter setting unit 33 (for example, transition time Htr, duration Ttd, and fade-out time Tf) and the risk in the driving environment of vehicle 1 detected by the risk assessment unit 30.

[0039] For example, the parameter update unit 35 may define a monotonically decreasing profile or a monotonically increasing profile that gradually changes from an initial heart rate Hi to a target heart rate Ht, and update the heart rate Hr to change gradually according to these profiles. For example, the parameter update unit 35 may calculate the rate of change (time rate of change) for gradually changing the heart rate Hr from the initial heart rate Hi to the target heart rate Ht based on the transition time Htr, and update the heart rate Hr so that it changes gradually at the calculated rate of change.

[0040] Figure 3(b) is an explanatory diagram of an example of updating the heart rate Hr. The parameter update unit 35 updates the heart rate Hr at update time tui (i=1, 2…) so that it matches the value of the monotonically increasing profile defined by the set parameter. For example, the update interval T of the heart rate Hr by the parameter update unit 35 (i.e., the interval between time tui and time tu(i+1)) may be the heart rate interval (RR interval) described above, referring to Figure 2. The heart rate signal generation unit 34 converts the pulsation parameters updated by the parameter update unit 35 into an operating signal for the tactile actuator 15, causing the tactile actuator 15 to generate a heart rate signal (heart rate vibration) with a set heart rate Hr and vibration intensity I.

[0041] Alternatively, the parameter update unit 35 may update the vibration intensity I based on the risk in the driving environment of the vehicle 1 detected by the risk assessment unit 30. Figures 4(a) to 4(c) are explanatory diagrams illustrating an example of updating the vibration intensity I of the heart rate signal in a dangerous scene. Figure 4(a) is a time chart of the risk R detected by the risk assessment unit 30, Figure 4(b) is a time chart of the vibration intensity I updated by the parameter update unit 35, and Figure 4(c) is a schematic diagram of the heart rate signal presented by the tactile actuator 15.

[0042] If the risk R detected by the risk assessment unit 30 exceeds the on threshold Thon at time ts, the scene detection unit 32 detects the current running scene as a dangerous scene. As a result, the heart rate signal generation unit 34 starts generating a heart rate signal from time ts. The parameter update unit 35 maintains the vibration intensity I at a constant value as long as the risk R detected by the risk assessment unit 30 is greater than or equal to the off threshold Thoff. For example, in the example in Figure 4(b), it is maintained at the maximum value Imax. At the subsequent time point te, if the stop condition described later is met, the heart rate signal generation unit 34 terminates the generation of the heart rate signal and the vibration intensity I becomes 0. As a result, as shown in Figure 4(c), a heart rate signal is generated in which the vibration intensity I is kept constant between the start time ts and the end time te.

[0043] Figures 5(a) to 5(c) illustrate another example of updating the vibration intensity I of the heart rate signal in a dangerous situation. Figure 5(a) is a time chart of the risk R detected by the risk assessment unit 30, Figure 5(b) is a time chart of the vibration intensity I updated by the parameter update unit 35, and Figure 5(c) is a schematic diagram of the heart rate signal presented by the tactile actuator 15. If the risk R detected by the risk assessment unit 30 exceeds the on-threshold Thon at time ts, the scene detection unit 32 detects the current running scene as a dangerous scene. As a result, the heart rate signal generation unit 34 starts generating a heart rate signal from time ts.

[0044] When the risk R detected by the risk assessment unit 30 at time t1 falls below the off-threshold Thoff, the parameter update unit 35 decreases the vibration intensity I from its value at time t1 (Imax in the example of Figure 5(b)) to 0 over a fade-out period Tf. When the vibration intensity I reaches 0 at the subsequent time te = t1 + Tf, the heart rate signal generation unit 34 terminates the generation of the heart rate signal. As a result, as shown in Figure 5(c), a heart rate signal is generated in which the vibration intensity I gradually decreases to 0 when the risk R falls below the off-threshold Thoff.

[0045] Figures 6(a) and 6(b) illustrate an example of updating the vibration intensity I of the heart rate signal in an emergency scenario. Figure 6(a) is a time chart of the vibration intensity I updated by the parameter update unit 35, and Figure 6(b) is a schematic diagram of the heart rate signal presented by the tactile actuator 15. When an emergency driving operation occurs for vehicle 1, and the risk in the vehicle 1's driving environment subsequently decreases, the scene detection unit 32 detects the current driving scene as an emergency scene. As a result, the heart rate signal generation unit 34 starts generating a heart rate signal from time ts.

[0046] At time point t2, when the remaining time until the duration Ttd expires becomes less than or equal to the fade-out time Tf, the parameter update unit 35 performs a gradual reduction process to decrease the vibration intensity I from its value at time point t1 (Imax in the example of Figure 6(a)) to 0 over the fade-out time Tf. As a result, as shown in Figure 6(b), a heart rate signal is generated in which the oscillation intensity I gradually decreases to 0 from time t2 to the end time te of the duration Ttd.

[0047] The stop condition determination unit 36 ​​determines whether or not the stop condition, which is the condition for stopping the presentation (output) of the heart rate signal, is met. For example, it may be determined that the stop condition is met if any of the following conditions (C1) to (C3) are met. (C1) If the scene detection unit 32 detects a dangerous scene, the risk R detected by the risk assessment unit 30 will be less than the off threshold Thoff. (C2) Vehicle 1 comes to a stop. (C3) The shift position of vehicle 1 is set to park. For example, the parameter update unit 35 may gradually decrease the vibration intensity I to 0 when the stop condition (C1) is met, and when the vibration intensity I reaches 0, the heart rate signal generation unit 34 may stop presenting (outputting) the heart rate signal. Alternatively, for example, the heart rate signal generation unit 34 may immediately stop presenting (outputting) the heart rate signal when the stop condition (C2) or (C3) is met.

[0048] (operation) Figure 7 is a flowchart of an example of a vibration presentation method according to the embodiment. In step S1, the vibration presentation device 10 performs target scene detection processing. Figure 8 is a flowchart of an example of the target scene detection process. In step S10, the emergency driving operation determination unit 31 determines whether or not an emergency driving operation occurred in vehicle 1. If no emergency driving operation occurred (step S10:N), the process proceeds to step S12. If an emergency driving operation occurred (step S10:Y), the process proceeds to step S11.

[0049] In step S11, the scene detection unit 32 determines that the current driving scene is an emergency scene. After that, the target scene detection process ends. In step S12, the risk assessment unit 30 detects the current driving environment of vehicle 1. In step S13, the risk assessment unit 30 predicts the operation of vehicle 1 in the current driving environment. In step S14, the risk assessment unit 30 estimates the risk R of vehicle 1 in the driving environment based on the predicted operation of vehicle 1 and the current driving environment.

[0050] In step S15, the scene detection unit 32 determines whether the risk R exceeds the on threshold Thon. If the risk R does not exceed the on threshold Thon (step S15:N), the process proceeds to step S17. If the risk R exceeds the on threshold Thon (step S15:Y), the process proceeds to step S16. In step S16, the scene detection unit 32 determines that the current driving scene is a dangerous scene. After that, the target scene detection process ends. In step S17, the scene detection unit 32 determines that the current driving scene is not the target scene. After that, the target scene detection process ends.

[0051] Refer to Figure 7. In step S2, the parameter setting unit 33 determines whether or not the target scene has been detected. If no target scene is detected (step S2:N), the process terminates. If a target scene is detected (step S2:Y), the process proceeds to step S3.

[0052] In step S3, the parameter setting unit 33 sets the setting parameters (initial heart rate Hi, target heart rate Ht, transition time Htr, duration Ttd, fade-out time Tf). The heart rate signal generation unit 34 sets the heart rate signal pulse parameters (heart rate Hr, vibration intensity I) based on the setting parameters.

[0053] In step S4, the heart rate signal generation unit 34 converts the pulsation parameters into operating signals for the tactile actuator 15. In step S5, the heart rate signal generation unit 34 transmits an operation signal to the tactile actuator 15, causing the tactile actuator 15 to generate a heart rate signal (heart rate vibration).

[0054] In step S6, the parameter update unit 35 updates the heart rate Hr of the heart rate signal based on the transition time Htr. In step S7, the parameter update unit 35 executes a vibration intensity update process to update the vibration intensity I. Figure 9 is a flowchart of an example of the vibration intensity update process.

[0055] In step S20, the parameter update unit 35 determines whether the current driving scene is a dangerous scene. If the current driving scene is not a dangerous scene (step S20:N), the process proceeds to step S24. If the current driving scene is a dangerous scene (step S20:Y), the process proceeds to step S21. In step S21, the parameter update unit 35 determines whether the risk R estimated by the risk assessment unit 30 has fallen below the off-threshold Thoff.

[0056] If the risk R is less than the off-threshold Thoff (step S21:Y), the process proceeds to step S23. If the risk R is greater than or equal to the off-threshold Thoff (step S21:N), the process proceeds to step S22. In step S22, the parameter update unit 35 maintains the current vibration intensity I. After that, the vibration intensity update process is terminated.

[0057] In step S23, the parameter update unit 35 reduces the vibration intensity I according to the fade-out time Tf. After that, the vibration intensity update process is terminated. In step S24, the parameter update unit 35 determines whether the current driving scene is an emergency scene. If the current driving scene is not an emergency scene (step S24:N), the vibration intensity update process is terminated. If the current driving scene is an emergency scene (step S24:Y), the process proceeds to step S25.

[0058] In step S25, the parameter update unit 35 determines whether the remaining period until the duration Ttd expires is less than or equal to the fade-out time Tf. If the remaining period is less than or equal to the fade-out time Tf (step S25:Y), the process proceeds to step S27. If the remaining period is longer than the fade-out time Tf (step S25:N), the process proceeds to step S26. In step S26, the parameter update unit 35 maintains the current vibration intensity I. After that, the vibration intensity update process is terminated.

[0059] In step S27, the parameter update unit 35 reduces the vibration intensity I according to the fade-out time Tf. After that, the vibration intensity update process is terminated. Refer to Figure 7. In step S8, the heart rate signal generation unit 34 determines whether the duration Ttd has elapsed. The stop condition determination unit 36 ​​determines whether the stop condition for the heart rate signal is met. If the duration Ttd has not elapsed and the stop condition is not met (step S8:N), the process returns to step S4. If the duration Ttd has elapsed or the stop condition is met (step S8:Y), the process ends.

[0060] (Effects of the embodiment) (1) In the vibration presentation method of the embodiment, vibrations simulating heartbeat vibrations are generated by a vibration actuator that vibrates the interior components of the vehicle that the driver comes into contact with, risks in the vehicle's driving environment are detected, and the heart rate or intensity of the heartbeat vibrations simulated by the vibration actuator is changed according to the detected risks. This allows the driver's mental state to be guided to a state suitable for safe driving in the current driving environment, depending on the detected risk.

[0061] (2) When a decrease in risk is detected, the heart rate of the heart rate vibration simulated by the vibration actuator may be gradually reduced. For example, the heart rate of the heart rate vibration simulated by the vibration actuator may be gradually reduced over a predetermined period of time from an initial value that simulates the heart rate of a person in a stressed state to a target value that simulates the heart rate of a person in a calm state. This allows the driver's mental state to be guided to a calm state when the current driving environment is low-risk and does not require a high level of vigilance. As a result, it prevents the driver from becoming unnecessarily stressed and guides them to a state suitable for safe driving.

[0062] (3) If a potential risk is detected and the detected potential risk increases, the heart rate of the heart rate vibration simulated by the vibration actuator may be gradually increased. For example, the heart rate of the heart rate vibration simulated by the vibration actuator may be gradually increased over a predetermined period of time from an initial value that simulates the heart rate of a person in a resting state to a target value that simulates the heart rate of a person in a stressed state. This can encourage drivers to be more vigilant when potential risks are increased, leading them to a state suitable for safe driving.

[0063] (4) Before stopping the generation of vibrations simulating heartbeat vibrations by the vibration actuator, a gradual reduction process may be performed to gradually decrease the intensity of the vibrations. This allows the vibrations simulating heartbeat oscillations to stop naturally, thus avoiding any impact on the driver due to the cessation of vibrations. [Explanation of Symbols]

[0064] 1...Vehicle, 10...Vibration display device 10, 11...Map database, 12...Positioning device, 13...In-vehicle sensor, 14...Biometric sensor, 15...Tactile actuator, 20...Controller, 30...Risk assessment unit, 31...Emergency driving operation determination unit, 32...Scene detection unit, 33...Parameter setting unit, 34...Heart rate signal generation unit, 35...Parameter update unit, 36...Stop condition determination unit

Claims

1. By using vibration actuators that vibrate the interior components of the vehicle that the driver comes into contact with, vibrations that simulate heartbeat vibrations are generated. To detect risks in the driving environment of the aforementioned vehicle, Depending on the detected risk, the heart rate or intensity of the heart rate vibration simulated by the vibration actuator is changed. A vibration presentation method characterized by the above.

2. The vibration presentation method according to claim 1, characterized in that when a decrease in the aforementioned risk is detected, the heart rate of the heart rate vibration simulated by the vibration actuator is gradually reduced.

3. The vibration presentation method according to claim 2, characterized in that the heart rate of the heart rate vibration simulated by the vibration actuator is gradually reduced over a predetermined period of time from an initial value that simulates the heart rate of a person in a stressed state to a target value that simulates the heart rate of a person in a calm state.

4. The vibration presentation method according to claim 1, characterized in that it detects the potential risk and, when the detected potential risk increases, gradually increases the heart rate of the heart rate vibration simulated by the vibration actuator.

5. The vibration presentation method according to claim 4, characterized in that the heart rate of the heart rate vibration simulated by the vibration actuator is gradually increased over a predetermined period of time from an initial value that simulates the heart rate of a person in a resting state to a target value that simulates the heart rate of a person in a stressed state.

6. The vibration presentation method according to any one of claims 1 to 5, characterized in that a gradual reduction process is performed to gradually decrease the intensity of the vibration before stopping the generation of vibrations simulating heartbeat vibrations by the vibration actuator.

7. A vibration actuator that vibrates the interior components of a vehicle that the driver comes into contact with, A controller that generates vibrations simulating heartbeat vibrations using the vibration actuator, detects risks in the vehicle's driving environment, and changes the heart rate or intensity of the heartbeat vibrations simulated by the vibration actuator according to the detected risks, A vibration presentation device characterized by comprising the following features.

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