Vehicle control system

Abstract

To provide a technique that enables a driver to operate a vehicle with improved comfort.SOLUTION: A vehicle control system controls the vehicle by using a sensor mounted on the vehicle to measure the driver's psychological fatigue level. When an operating condition is met, including the psychological fatigue level exceeding a first threshold, the vehicle control system outputs relaxation sounds through a speaker mounted on the vehicle to alleviate the driver's psychological fatigue.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a technique for controlling a vehicle.

Background Art

[0002] Patent Document 1 discloses an electric vehicle capable of pseudo-reproducing a manual shifting operation of a manual transmission vehicle (MT vehicle).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Mental fatigue of a vehicle driver is not preferable from the viewpoint of appropriate driving. A technique that allows a driver to drive a vehicle more comfortably is desired.

Means for Solving the Problems

[0005] A first aspect relates to a vehicle control system that controls a vehicle. The vehicle control system includes one or more processors. The one or more processors acquire a degree of mental fatigue of a driver of the vehicle using sensors mounted on the vehicle. When an operating condition including at least that the degree of mental fatigue exceeds a first threshold is satisfied, the one or more processors output a relaxation sound for reducing the degree of mental fatigue through a speaker mounted on the vehicle.

[0006] A second aspect relates to a vehicle control system that controls an electric vehicle that uses an electric motor as a driving power device. The electric vehicle is provided with a pseudo clutch pedal and a pseudo shift device. The pseudo clutch pedal is operated during the operation of the pseudo shift device. The driving mode of the electric vehicle is a three-pedal mode in which the output of the electric motor with respect to the operation of the accelerator pedal is changed according to the operation of the pseudo clutch pedal and the operation of the pseudo shift device, and a two-pedal mode that does not require the operation of the pseudo clutch pedal are included. The vehicle control system includes one or more processors. The one or more processors acquire the mental fatigue level of the driver of the electric vehicle using sensors mounted on the electric vehicle. When a mode switching condition including at least that the mental fatigue level exceeds a threshold value during the three-pedal mode is satisfied, the one or more processors switch the driving mode from the three-pedal mode to the two-pedal mode.

Advantages of the Invention

[0007] According to the first aspect, when an operating condition including at least that the mental fatigue level of the driver exceeds a threshold value is satisfied, a relaxation sound for reducing the mental fatigue is output from a speaker mounted on the vehicle. Thereby, the mental fatigue of the driver is reduced. As a result, the driver can drive the vehicle more comfortably.

[0008] According to the second aspect, the electric vehicle is provided with a pseudo clutch pedal and a pseudo shift device, and its driving mode includes a three-pedal mode that pseudo-reproduces the manual shifting operation of a manual transmission vehicle. When a mode switching condition including at least that the mental fatigue level of the driver exceeds a threshold value during the three-pedal mode is satisfied, the driving mode of the electric vehicle switches from the three-pedal mode that requires the operation of the pseudo clutch pedal to the two-pedal mode that does not require the operation of the pseudo clutch pedal. Thereby, since the driver is released from the operation of the pseudo clutch pedal, the mental fatigue of the driver is reduced. As a result, the driver can drive the vehicle more comfortably.

Brief Description of the Drawings

[0009]

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Embodiments for Carrying Out the Invention

[0010] Embodiments of the present disclosure will be described with reference to the accompanying drawings.

[0011] 1. First Embodiment 1-1. Overview FIG. 1 is a conceptual diagram showing a vehicle 10 and a vehicle control system 100 according to the present embodiment. The vehicle 10 may be an engine vehicle that uses an internal combustion engine as a driving power device, or an electric vehicle that uses an electric motor as a driving power device. The vehicle 10 may be a manual transmission vehicle (MT vehicle).

[0012] The vehicle control system 100 controls the vehicle 10. The entire vehicle control system 100 may be mounted on the vehicle 10. As another example, at least a part of the vehicle control system 100 may be included in a management server that can communicate with the vehicle 10. That is, the vehicle control system 100 may remotely control the vehicle 10. The vehicle control system 100 may be distributed between the vehicle 10 and the management server.

[0013] Generally speaking, the vehicle control system 100 includes one or more processors 101 (hereinafter simply referred to as the processor 101) and one or more storage devices 102 (hereinafter simply referred to as the storage device 102). The processor 101 executes various processes. Examples of the processor 101 include general-purpose processors, application-specific processors, CPUs (Central Processing Units), GPUs (Graphics Processing Units), ASICs (Application Specific Integrated Circuits), FPGAs (Field-Programmable Gate Arrays), integrated circuits, conventional circuits, and / or combinations thereof. The processor 101 can also be referred to as circuitry or processing circuitry. The circuitry is hardware programmed to implement the described functions or hardware that executes the functions. The storage device 102 stores (stores) various information. Examples of the storage device 102 include volatile memory, non-volatile memory, HDDs (Hard Disk Drives), SSDs (Solid State Drives), etc. The functions of the vehicle control system 100 are realized by the cooperation of the processor 101 and the storage device 102.

[0014] One or more vehicle control programs 105 (hereinafter simply referred to as the vehicle control program 105) are computer programs executed by the processor 101. The functions of the vehicle control system 100 may be realized by the cooperation of the processor 101 that executes the vehicle control program 105 and the storage device 102. The vehicle control program 105 is stored in the storage device 102. Alternatively, the vehicle control program 105 may be recorded on a computer-readable recording medium.

[0015] The driver of vehicle 10 may feel mental fatigue. For example, when another vehicle suddenly cuts in front of vehicle 10, or when the speed at which vehicle 10 is moving is slow due to traffic congestion, the driver may accumulate stress. As another example, when vehicle 10 is a MT vehicle, operating the clutch pedal for a long time requires the driver to maintain concentration and attention for a long time, which may stress the driver. Such mental fatigue of the driver is not preferable from the perspective of proper driving. A technology that allows the driver to drive vehicle 10 more comfortably is desired.

[0016] Therefore, according to the present embodiment, a sensor 70 for detecting the mental fatigue of the driver is mounted on vehicle 10. Further, a speaker 2 for outputting a relaxation sound for reducing the mental fatigue of the driver is mounted on vehicle 10. The relaxation sound is stored in the storage device 102. The details of the relaxation sound will be described later.

[0017] The vehicle control system 100 (processor 101) uses the sensor 70 mounted on vehicle 10 to obtain the mental fatigue degree M of the driver. The mental fatigue degree M quantitatively represents the degree of mental fatigue of the driver. The operating conditions for outputting the relaxation sound include at least that the mental fatigue degree M of the driver exceeds the first threshold value Mth1. The vehicle control system 100 (processor 101) determines whether or not the operating conditions are satisfied based on at least the mental fatigue degree M. When the operating conditions are satisfied, the vehicle control system 100 (processor 101) outputs a relaxation sound for reducing the mental fatigue degree through the speaker 2 mounted on vehicle 10. Thereby, the mental fatigue of the driver is reduced. As a result, the driver can drive vehicle 10 more comfortably.

[0018] 1-2. Examples of sensors FIG. 2 is a diagram showing an example of the sensor 70. The sensor 70 includes at least one of one or more electrocardiographs 71 that detect the driver's heartbeat data and one or more sweating sensors 72 that detect the driver's sweating amount. For example, the electrocardiograph 71 is installed at a position where the driver's heartbeat can be detected, that is, on a device (e.g., steering wheel HD, seat belt SB) used by the driver during the driving operation. For example, the sweating sensor 72 is installed at a position where the driver's palm touches, that is, on a device (e.g., steering wheel HD) used by the driver during the driving operation. Note that the driver's sweating amount may be detected by the sweating sensor 72 mounted on a wearable terminal (e.g., smartwatch) worn by the driver.

[0019] The vehicle control system 100 acquires the mental fatigue degree M based on at least one of the driver's heartbeat data detected by the electrocardiograph 71 and the driver's sweating amount detected by the sweating sensor 72.

[0020] Let's consider an example of calculating the mental fatigue degree M based on the driver's heartbeat data. As shown in (A) in FIG. 3, the driver's heartbeat data includes data on the heartbeat interval (R-R interval (RRI (RR Interval))) indicating the time difference between the occurrence time of the R wave and the occurrence time of the next R wave. The mental fatigue degree M is calculated, for example, based on the magnitude of the area S of the Lorenz plot generated from the data on the driver's heartbeat interval (R-R interval).

[0021] As shown in (B) of FIG. 3, the Lorenz plot plots the value of the n-th (RRI(n)) of the R-R intervals on the horizontal axis (x-axis) and the value of the (n + 1)-th (RRI(n+1)) consecutive to the n-th on the vertical axis (y-axis). That is, the point (x, y) = (RRI(n), RRI(n+1)) consisting of two consecutive R-R intervals is plotted on the graph. The area S of the Lorenz plot is calculated by approximating the region of the set of plots with an ellipse. The area S of the Lorenz plot indicates the range of the spread of the plots. The area S of the Lorenz plot is one of the indicators showing whether the driver's heartbeat is stable or unstable. It is known that when the area S of the Lorenz plot is large, it is a relaxed state, and when the area S is small, it is a stressed state. Therefore, the mental fatigue degree M can be calculated based on the magnitude of the area S of the Lorenz plot. For example, the smaller the area S of the Lorenz plot, the higher the mental fatigue degree M is calculated.

[0022] Consider an example of calculating the mental fatigue degree M based on the sweating amount of the driver. The sweating amount of the driver is represented by, for example, the graph shown in (C) of FIG. 3. For example, as shown in (C) of FIG. 3, when the vehicle 10 is caught in a traffic jam or when another vehicle suddenly cuts in front of the vehicle 10, the sweating amount increases. Therefore, the mental fatigue degree M changes according to the sweating amount of the driver. The higher the sweating amount of the driver, the higher the mental fatigue degree M. The sweating amount of the driver may be directly used as the mental fatigue degree M.

[0023] In addition, the mental fatigue degree M may be estimated based on the recognition result of the driver's face (expression) by the camera mounted on the vehicle 10 in addition to the method described above.

[0024] When an operating condition that at least includes the mental fatigue degree M exceeding the first threshold value Mth1 is satisfied, the vehicle control system 100 outputs a relaxation sound that reduces the mental fatigue degree M of the driver.

[0025] The relaxation sound is a sound for reducing the mental fatigue level M. Specifically, the relaxation sound is a sound that increases the area S of the Lorenz plot. Alternatively, the relaxation sound is a sound that gives the driver a sense of relaxation in order to reduce the amount of sweating. Examples of relaxation sounds include natural sounds such as the sound of a river. The relaxation sound may be selected in advance. By outputting the relaxation sound, a sense of relaxation can be given to the driver, and the mental fatigue of the driver can be reduced. As a result, the driver can drive the vehicle 10 more comfortably.

[0026] 1-3. Functional Configuration Example and Processing Example FIG. 4 is a block diagram showing a functional configuration example of a vehicle control system 100 according to the first embodiment. The vehicle control system 100 includes, as functional blocks, a fatigue level acquisition unit 110, an operating condition determination unit 120, a relaxation sound control unit 130, and an end condition determination unit 140. These functional blocks may be realized by the cooperation of a processor 101 that executes a vehicle control program 105 and a storage device 102. Some of the functional blocks may be included in a management server that can communicate with the vehicle 10.

[0027] FIG. 5 is a flowchart showing a processing example by the vehicle control system 100 according to the first embodiment. Hereinafter, with reference to FIGS. 4 and 5, the processing example by the vehicle control system 100 will be described.

[0028] In step S110, the fatigue level acquisition unit 110 acquires sensor detection information indicating the detection result by a sensor 70 mounted on the vehicle 10. When the fatigue level acquisition unit 110 is included in the management server, the fatigue level acquisition unit 110 communicates with the vehicle 10 to acquire the sensor detection information. The fatigue level acquisition unit 110 acquires the mental fatigue level M of the driver based on the sensor detection information.

[0029] For example, the fatigue level acquisition unit 110 includes a heartbeat data acquisition unit 111 and a sweating amount acquisition unit 112. The heartbeat data acquisition unit 111 acquires the driver's heartbeat data detected by the electrocardiograph 71 (see FIG. 2). The sweating amount acquisition unit 112 acquires the driver's sweating amount detected by the sweating sensor 72 (see FIG. 2). The driver's heartbeat data and sweating amount correspond to the sensor detection information. Then, the fatigue level acquisition unit 110 acquires the mental fatigue level M based on at least one of the driver's heartbeat data and sweating amount. In this case, the smaller the area S of the Lorentz plot generated based on the driver's heartbeat data, or the larger the driver's sweating amount, the higher the mental fatigue level M. Note that the driver's sweating amount may be directly used as the mental fatigue level M.

[0030] In step S120, the operating condition determination unit 120 determines whether a predetermined operating condition is satisfied. If the predetermined operating condition is not satisfied (step S120; No), the processing in the current cycle ends. On the other hand, if the predetermined operating condition is satisfied (step S120; Yes), the processing proceeds to step S130.

[0031] In the examples shown in FIGS. 4 and 5, the predetermined operating condition includes a first condition and a second condition. The first condition is that the mental fatigue level M exceeds the first threshold value Mth1. The second condition is that the driver has approved the output of the relaxation sound. In order to determine whether each of the first condition and the second condition is satisfied, the operating condition determination unit 120 includes a fatigue level determination unit 121 and a driver intention confirmation unit 122. At least one of the fatigue level determination unit 121 and the driver intention confirmation unit 122 may be included in a management server that can communicate with the vehicle 10.

[0032] In step S121, the fatigue level determination unit 121 determines whether the mental fatigue level M exceeds the first threshold value Mth1, that is, whether the first condition is satisfied. If the first condition is not satisfied (step S121; No), the operating condition is not satisfied. On the other hand, if the first condition is satisfied (step S121; Yes), the processing proceeds to step S122.

[0033] In step S122, the driver intention confirmation unit 122 determines whether the driver has approved the output of the relaxation sound, that is, whether the second condition is satisfied. More specifically, the vehicle 10 is equipped with an HMI (Human-Machine Interface) 90 (see FIG. 1). The HMI 90 includes an output device and an input device. Examples of the output device include a touch panel, a display, a speaker, etc. Examples of the input device include a touch panel, buttons, etc. The driver intention confirmation unit 122 inquires of the driver through the output device of the HMI 90 whether it is okay to output the relaxation sound. The inquiry message may be displayed on the display, notified from the speaker, or both. In response to the inquiry message, the driver inputs "approval" or "rejection" using the input device of the HMI 90. The driver intention confirmation unit 122 can determine whether the second condition is satisfied based on the input from the driver. If the second condition is not satisfied (step S122; No), the operating condition is not satisfied. On the other hand, if the second condition is satisfied (step S122; Yes), and the operating condition is satisfied (step S120; Yes), the process proceeds to step S130.

[0034] In step S130, the relaxation sound control unit 130 acquires the relaxation sound stored in the storage device 102 and outputs the relaxation sound through the speaker 2. When outputting the relaxation sound, the relaxation sound control unit 130 may notify the driver through the output device of the HMI 90 that the relaxation sound is being output.

[0035] In step S140, the end condition determination unit 140 determines whether the end condition is satisfied. For example, the end condition is that the mental fatigue level M of the driver becomes equal to or lower than the first threshold value Mth1. As another example, the end condition may be that a certain period of time has elapsed since the relaxation sound was output. As still another example, the end condition may be that the driver instructs to stop the output of the relaxation sound through the HMI 90. When the end condition is not satisfied (step S140; No), the process returns to step S130 and the output of the relaxation sound continues. On the other hand, when the end condition is satisfied (step S140; Yes), the process proceeds to step S145.

[0036] In step S145, the relaxation sound control unit 130 stops the output of the relaxation sound.

[0037] 1-4. Modification The predetermined operating condition may not include the second condition. In that case, step S122 is omitted.

[0038] 2. Second Embodiment 2-1. Overview When an operation of a clutch pedal is required, it may impose stress on the driver. The stress caused by such an operation of the clutch pedal is also a kind of mental fatigue of the driver. The second embodiment proposes a technique capable of reducing the stress caused by the operation of the clutch pedal.

[0039] The vehicle 10 assumed in the second embodiment is, for example, a manual transmission vehicle (MT vehicle) equipped with a clutch pedal. As another example, the vehicle 10 may be an electric vehicle capable of pseudo-reproducing the manual shifting operation of an MT vehicle (see Patent Document 1). Hereinafter, the case where the vehicle 10 is an electric vehicle capable of pseudo-reproducing the manual shifting operation of an MT vehicle will be considered. The same applies to the case where the vehicle 10 is a normal MT vehicle.

[0040] FIG. 6 is a conceptual diagram for explaining the outline of the second embodiment. The vehicle 10 includes an accelerator pedal 22, a brake pedal 23, a pseudo clutch pedal 28, and a pseudo shift lever 27 (pseudo shift device).

[0041] The pseudo shift lever 27 has a structure that simulates the shift lever of a MT vehicle. The arrangement and operating feel of the pseudo shift lever 27 are equivalent to those of an actual MT vehicle. The pseudo shift lever 27 is provided with positions corresponding to each gear stage such as first gear, second gear, third gear, fourth gear, fifth gear, sixth gear, reverse, and neutral.

[0042] The pseudo clutch pedal 28 has a structure that simulates the clutch pedal of a MT vehicle. The arrangement and operating feel of the pseudo clutch pedal 28 are equivalent to those of an actual MT vehicle. The pseudo clutch pedal 28 is operated when the pseudo shift lever 27 is operated. That is, when the driver wants to change the gear stage setting with the pseudo shift lever 27, the driver depresses the pseudo clutch pedal 28, and when the gear stage setting change is completed, releases the depression and returns the pseudo clutch pedal 28 to its original position.

[0043] The driving mode of the vehicle 10 (electric vehicle) includes a "three-pedal mode" that simulates the manual shifting operation and driving characteristics of a MT vehicle. In the three-pedal mode, the output of the electric motor in response to the operation of the accelerator pedal 22 is changed according to the operations of the pseudo clutch pedal 28 and the pseudo shift lever 27. The method for realizing the three-pedal mode in an electric vehicle will be described in detail in Section 6 later.

[0044] In the three-pedal mode, the vehicle control system 100 acquires the mental fatigue level M of the driver using the sensor 70 mounted on the vehicle 10. For example, the sensor 70 includes an electrocardiograph 71 and a sweating sensor 72. The sweating sensor 72 may be mounted on the pseudo shift lever 27 operated by the driver in the three-pedal mode. In this case, the vehicle control system 100 can acquire the mental fatigue level M based on the amount of sweating of the driver detected by the sweating sensor 72 mounted on the pseudo shift lever 27.

[0045] The operating conditions for outputting the relaxation sound include at least that the mental fatigue level M of the driver exceeds the first threshold value Mth1. When the operating conditions are satisfied, the vehicle control system 100 (processor 101) outputs the relaxation sound through the speaker 2.

[0046] By outputting the relaxation sound, the stress on the driver caused by the operation of the pseudo clutch pedal 28 is reduced. As a result, the driver can drive the vehicle 10 more comfortably. In particular, the driver can drive the vehicle 10 comfortably while enjoying the three-pedal mode.

[0047] 2-2. Example of functional configuration and processing example FIG. 7 is a flowchart showing an example of processing by the vehicle control system 100 according to the second embodiment. Descriptions overlapping with those of the above-described first embodiment are appropriately omitted. Also, the block diagram showing an example of the functional configuration of the vehicle control system 100 according to the second embodiment is the same as that of the first embodiment described above.

[0048] In step S100, the vehicle control system 100 determines whether the driving mode of the vehicle 10 (electric vehicle) is the three-pedal mode. If the driving mode is not the three-pedal mode (step S100; No), the processing in the current cycle ends. On the other hand, if the driving mode is the three-pedal mode (step S100; Yes), the processing proceeds to step S110. Note that when the vehicle 10 is a normal MT vehicle, step S100 is omitted.

[0049] Steps S110, S120, S130, and S140 are the same as those in the first embodiment. In step S130, the relaxation sound control unit 130 acquires the relaxation sound stored in the storage device 102 and outputs the relaxation sound through the speaker 2.

[0050] 2-3. Variation The predetermined operating conditions may not include the second condition. In that case, step S122 is omitted.

[0051] 3. Third Embodiment 3-1. Overview FIG. 8 is a conceptual diagram for explaining the overview of the third embodiment. The vehicle 10 assumed in the third embodiment uses an electric motor as a driving power device and is an electric vehicle equipped with a pseudo clutch pedal 28 and a pseudo shift device 27. The driving modes of the vehicle 10 (electric vehicle) include the above-mentioned "three-pedal mode". The three-pedal mode requires the operation of the pseudo clutch pedal 28 and simulates the manual shifting operation and driving characteristics of an MT vehicle based on the operation of the pseudo clutch pedal 28.

[0052] The driving modes of the vehicle 10 (electric vehicle) further include a "two-pedal mode" that does not require the operation of the pseudo clutch pedal 28. The two-pedal mode includes, for example, an EV mode in which the vehicle 10 is driven as a normal electric vehicle. As another example, the two-pedal mode may include an AT mode that simulates the driving characteristics of an automatic transmission vehicle (AT vehicle). As still another example, the two-pedal mode may include a sequential shift mode that simulates the manual shifting operation and driving characteristics of a sequential shift type MT vehicle. The method for realizing the sequential shift mode in an electric vehicle will be described in detail in section 6 later.

[0053] During the three-pedal mode, the vehicle control system 100 (processor 101) determines whether a predetermined mode switching condition is satisfied. The predetermined mode switching condition includes at least that the mental fatigue level M of the driver exceeds a second threshold value Mth2. The second threshold value Mth2 may be the same as the first threshold value Mth1 or different from the first threshold value Mth1. When the predetermined mode switching condition is satisfied during the three-pedal mode, the vehicle control system 100 (processor 101) switches the driving mode from the three-pedal mode that requires operation of the pseudo clutch pedal 28 to the two-pedal mode that does not require operation of the pseudo clutch pedal 28. As a result, the driver is released from the operation of the pseudo clutch pedal 28, so that the mental fatigue of the driver is reduced. As a result, the driver can drive the vehicle 10 more comfortably.

[0054] Note that the two-pedal mode may include a sequential shift mode and other modes (at least one of an AT mode and an EV mode). In this case, the vehicle control system 100 may gradually switch the driving mode within the two-pedal mode. For example, when the mental fatigue level M exceeds the second threshold value Mth2, the vehicle control system 100 switches the driving mode from the three-pedal mode to the sequential shift mode. If the mental fatigue level M does not become equal to or less than the second threshold value Mth2 even after a certain period of time has elapsed since the start of the sequential shift mode, the vehicle control system 100 may switch the driving mode from the sequential shift mode to the AT mode or the EV mode.

[0055] 3-2. Functional Configuration Example and Processing Example FIG. 9 is a block diagram showing a functional configuration example of the vehicle control system 100 according to the third embodiment. The vehicle control system 100 includes, as functional blocks, a fatigue level acquisition unit 110, a mode switching condition determination unit 150, and a mode switching unit 160. These functional blocks may be realized by the cooperation of a processor 101 that executes a vehicle control program 105 and a storage device 102. Some of the functional blocks may be included in a management server that can communicate with the vehicle 10.

[0056] Figure 10 is a flowchart showing an example of processing by the vehicle control system 100 according to the third embodiment. Hereinafter, an example of processing by the vehicle control system 100 will be described with reference to FIGS. 9 and 10.

[0057] In step S100, the vehicle control system 100 determines whether the driving mode of the vehicle 10 (electric vehicle) is the three-pedal mode. If the driving mode is not the three-pedal mode (step S100; No), the processing in this cycle ends. On the other hand, if the driving mode is the three-pedal mode (step S100; Yes), the processing proceeds to step S110.

[0058] In step S110, the fatigue degree acquisition unit 110 acquires sensor detection information indicating the detection result by the sensor 70 mounted on the vehicle 10. When the fatigue degree acquisition unit 110 is included in the management server, the fatigue degree acquisition unit 110 communicates with the vehicle 10 to acquire the sensor detection information. The fatigue degree acquisition unit 110 acquires the mental fatigue degree M of the driver based on the sensor detection information.

[0059] In step S150, the mode switching condition determination unit 150 determines whether a predetermined mode switching condition is satisfied. If the predetermined mode switching condition is not satisfied (step S150; No), the processing in this cycle ends. On the other hand, if the predetermined mode switching condition is satisfied (step S150; Yes), the processing proceeds to step S160.

[0060] In the examples shown in FIGS. 9 and 10, the predetermined mode switching condition includes a first condition and a second condition. The first condition is that the mental fatigue degree M exceeds the second threshold value Mth2. The second condition is that the driver has approved the switching from the three-pedal mode to the two-pedal mode. In order to determine whether each of the first condition and the second condition is satisfied, the mode switching condition determination unit 150 includes a fatigue degree determination unit 151 and a driver intention confirmation unit 152. At least one of the fatigue degree determination unit 151 and the driver intention confirmation unit 152 may be included in a management server capable of communicating with the vehicle 10.

[0061] In step S151, the fatigue determination unit 151 determines whether the mental fatigue level M exceeds the second threshold value Mth2, that is, whether the first condition is satisfied. If the first condition is not satisfied (step S151; No), the mode switching condition is not satisfied. On the other hand, if the second condition is satisfied (step S151; Yes), the process proceeds to step S152.

[0062] In step S152, the driver intention confirmation unit 152 determines whether the driver has approved the switching from the three-pedal mode to the two-pedal mode, that is, whether the second condition is satisfied. More specifically, the driver intention confirmation unit 152 inquires of the driver through the output device of the HMI90 whether it is possible to switch the driving mode from the three-pedal mode to the two-pedal mode. The inquiry message may be displayed on the display, notified from the speaker, or both. In response to the inquiry message, the driver inputs "approve" or "reject" using the input device of the HMI90. The driver intention confirmation unit 152 can determine whether the second condition is satisfied based on the input from the driver. If the second condition is not satisfied (step S152; No), the operating condition is not satisfied. On the other hand, if the second condition is satisfied (step S152; Yes), and the operating condition is satisfied (step S150; Yes), the process proceeds to step S160.

[0063] In step S160, the mode switching unit 160 switches the driving mode from the three-pedal mode to the two-pedal mode. When switching the driving mode, the mode switching unit 160 may notify the driver of the switching of the driving mode through the output device of the HMI90.

[0064] 3-3. Variation The predetermined mode switching condition may not include the second condition. In that case, step S152 is omitted.

[0065] 4. Fourth Embodiment The fourth embodiment is a combination of the above-described second embodiment and third embodiment. FIG. 11 is a block diagram showing a functional configuration example of a vehicle control system 100 according to the fourth embodiment. The vehicle control system 100 includes, as functional blocks, a fatigue level acquisition unit 110, an operation condition determination unit 120, a relaxation sound control unit 130, an end condition determination unit 140, a mode switching condition determination unit 150, and a mode switching unit 160. The fatigue level acquisition unit 110, the operation condition determination unit 120, and the relaxation sound control unit 130 are the same as those in the above-described second embodiment. The mode switching condition determination unit 150 and the mode switching unit 160 are the same as those in the above-described third embodiment.

[0066] The operation condition determination unit 120 and the mode switching condition determination unit 150 may operate independently of each other. That is, the vehicle control system 100 may determine in parallel whether the operation condition is satisfied and whether the mode switching condition is satisfied.

[0067] Alternatively, the operation condition determination unit 120 and the mode switching condition determination unit 150 may operate in cooperation. That is, the vehicle control system 100 may determine serially whether the operation condition is satisfied and whether the mode switching condition is satisfied.

[0068] In the example shown in FIG. 12, first, the operation condition determination unit 120 determines whether the operation condition is satisfied. When the operation condition is satisfied (step S120; Yes), the relaxation sound control unit 130 outputs a relaxation sound (step S130). Thereafter, the mode switching condition determination unit 150 determines whether the mode switching condition is satisfied. When the mode switching condition is satisfied (step S150; Yes), the mode switching unit 160 switches the driving mode from the three-pedal mode to the two-pedal mode (step S160).

[0069] In the example shown in FIG. 13, first, the mode switching condition determination unit 150 determines whether the mode switching condition is satisfied. When the mode switching condition is satisfied (step S150; Yes), the mode switching unit 160 switches the driving mode from the three-pedal mode to the two-pedal mode (step S160). Thereafter, the operation condition determination unit 120 determines whether the operation condition is satisfied. When the operation condition is satisfied (step S120; Yes), the relaxation sound control unit 130 outputs a relaxation sound (step S130).

[0070] 5. Fifth Embodiment Any combination of the first embodiment and any one of the second to fourth embodiments is also possible.

[0071] 6. Details of MT Mode An electric motor used as a driving power device in a general electric vehicle has significantly different torque characteristics from an internal combustion engine that has been used as a driving power device in a conventional vehicle (CV: Conventional Vehicle). Due to the difference in the torque characteristics of the power devices, a CV requires a transmission, while a general electric vehicle generally does not have a transmission. Of course, a general electric vehicle does not have a manual transmission (MT) that switches the gear ratio by the driver's manual operation. For this reason, there is a significant difference in the driving feeling between the operation of a conventional vehicle with an MT (hereinafter referred to as an MT vehicle) and the operation of an electric vehicle.

[0072] On the other hand, an electric motor can relatively easily control torque by controlling the applied voltage and field excitation. Therefore, in an electric motor, it is possible to obtain desired torque characteristics within the operating range of the electric motor by implementing appropriate control. Taking advantage of this feature, the torque of an electric vehicle can be controlled to simulate the torque characteristics peculiar to an MT vehicle. Also, a pseudo shifter can be provided in the electric vehicle so that the driver can obtain a driving feeling like that of an MT vehicle. By these means, it becomes possible to simulate an MT vehicle in an electric vehicle.

[0073] That is, the electric vehicle controls the output of the electric motor so as to simulate the driving characteristics (torque characteristics) peculiar to MT vehicles. The driver operates the pseudo-shifter to perform a pseudo-manual shifting operation. In response to the pseudo-manual shifting operation by the driver, the electric vehicle changes the driving characteristics (torque characteristics) by simulating an MT vehicle. As a result, the driver of the electric vehicle can obtain a feeling as if driving an MT vehicle. Hereinafter, the control mode of the electric motor for simulating the driving characteristics and the manual shifting operation of the MT vehicle is referred to as the "manual mode" or the "MT mode".

[0074] Hereinafter, consider the case where the vehicle 10 according to the present disclosure is the electric vehicle 10E equipped with the MT mode. In the MT mode, the electric vehicle 10E may generate a pseudo-engine sound according to the driving operation of the driver and output the pseudo-engine sound via a speaker. Since not only the driving operation of the MT vehicle but also the engine sound of the MT vehicle are reproduced, the satisfaction of the driver who pursues reality is enhanced. Hereinafter, a configuration example of the electric vehicle 10E equipped with the MT mode will be described. Examples of the MT mode include the "sequential shift mode" and the "three-pedal mode".

[0075] 6-1. First Configuration Example (Sequential Shift Mode) FIG. 14 is a block diagram showing a first configuration example of the power control system of the electric vehicle 10E. The electric vehicle 10E includes an electric motor 44, a battery 46, and an inverter 42. The electric motor 44 is a power device for traveling. The battery 46 stores electric energy for driving the electric motor 44. That is, the electric vehicle 10E is a battery electric vehicle (BEV) that travels with the electric energy stored in the battery 46. The inverter 42 converts the DC power input from the battery 46 during acceleration into the driving power of the electric motor 44. Further, the inverter 42 converts the regenerative power input from the electric motor 44 during deceleration into DC power and charges the battery 46.

[0076] The electric vehicle 10E is equipped with an accelerator pedal 22 for the driver to input an acceleration request for the electric vehicle 10E. The accelerator pedal 22 is provided with an accelerator position sensor 32 for detecting the accelerator opening degree.

[0077] The electric vehicle 10E is equipped with a sequential shifter 24. The sequential shifter 24 may be a paddle shifter or a lever-type pseudo shifter.

[0078] The paddle shifter is a dummy different from the original paddle shifter. The paddle shifter has a structure similar to that of the paddle shifter equipped in a clutch pedal-less MT vehicle. The paddle shifter is attached to the steering wheel. The paddle shifter is provided with an upshift switch and a downshift switch for determining the operation position. The upshift switch emits an upshift signal 34u when pulled forward, and the downshift switch emits a downshift signal 34d when pulled forward.

[0079] On the other hand, the lever-type pseudo shifter is also a dummy different from the original shifter, similar to the paddle shifter. The lever-type pseudo shifter has a structure similar to that of the lever shifter equipped in a clutch pedal-less MT vehicle. The lever-type pseudo shifter is configured to output an upshift signal 34u when the shift lever is tilted forward and a downshift signal 34d when the shift lever is tilted backward.

[0080] A wheel speed sensor 36 is provided on the wheel 26 of the electric vehicle 10E. The wheel speed sensor 36 is used as a vehicle speed sensor for detecting the vehicle speed of the electric vehicle 10E. In addition, a rotational speed sensor 38 for detecting the rotational speed is provided on the electric motor 44.

[0081] The electric vehicle 10E is equipped with a control device 50. The control device 50 is typically an electronic control unit (ECU) installed in the electric vehicle 10E. The control device 50 may also be a combination of multiple ECUs. The control device 50 includes an interface, a memory, and a processor. An in-vehicle network is connected to the interface. The memory includes a RAM for temporarily recording data and a ROM for storing programs executable by the processor and various data related to the programs. The program is composed of a plurality of instructions. The processor reads the program and data from the memory and executes them, and generates a control signal based on the signals acquired from each sensor.

[0082] For example, the control device 50 controls the electric motor 44 by PWM control of the inverter 42. Signals from an accelerator position sensor 32, a sequential shifter 24 (when the sequential shifter 24 is a paddle shifter, an upshift switch and a downshift switch), a wheel speed sensor 36, and a rotational speed sensor 38 are input to the control device 50. The control device 50 processes these signals and calculates a motor torque command value for PWM control of the inverter 42.

[0083] The control device 50 includes an automatic mode (EV mode) and a manual mode (MT mode) as control modes. The automatic mode is a normal control mode for driving the electric vehicle 10E as a general electric vehicle. The automatic mode is programmed to continuously change the output of the electric motor 44 according to the operation of the accelerator pedal 22. On the other hand, the manual mode is a control mode for driving the electric vehicle 10E like an MT vehicle. The manual mode is programmed to change the output characteristics of the electric motor 44 with respect to the operation of the accelerator pedal 22 according to the upshift operation and downshift operation with respect to the sequential shifter 24. This manual mode (MT mode) corresponds to the "sequential shift mode". The automatic mode and the manual mode are switchable.

[0084] The control device 50 includes an automatic mode torque calculation unit 54 and a manual mode torque calculation unit 56. Each of the units 54 and 56 may be an independent ECU, or may be the function of an ECU obtained by executing a program recorded in a memory by a processor.

[0085] The automatic mode torque calculation unit 54 has a function of calculating the motor torque when controlling the electric motor 44 in the automatic mode. A motor torque command map is stored in the automatic mode torque calculation unit 54. The motor torque command map is a map that determines the motor torque from the accelerator opening and the rotational speed of the electric motor 44. Signals from the accelerator position sensor 32 and the rotational speed sensor 38 are input to each parameter of the motor torque command map. Motor torque corresponding to these signals is output from the motor torque command map. Therefore, in the automatic mode, even if the driver operates the sequential shifter 24, the operation is not reflected in the motor torque.

[0086] The manual mode torque calculation unit 56 includes an MT vehicle model. The MT vehicle model is a model for calculating the drive wheel torque that should be obtained by operating the accelerator pedal 22 and the sequential shifter 24 when assuming that the electric vehicle 10E is an MT vehicle.

[0087] The MT vehicle model included in the manual mode torque calculation unit 56 will be described with reference to FIG. 15. As shown in FIG. 15, the MT vehicle model includes an engine model 561, a clutch model 562, and a transmission model 563. Note that the engine, clutch, and transmission virtually realized by the MT vehicle model are referred to as a virtual engine, a virtual clutch, and a virtual transmission, respectively. In the engine model 561, the virtual engine is modeled. In the clutch model 562, the virtual clutch is modeled. In the transmission model 563, the virtual transmission is modeled.

[0088] The engine model 561 calculates the virtual engine rotational speed Ne and the virtual engine output torque Teout. The virtual engine rotational speed Ne is calculated based on the rotational speed Nw of the wheels, the overall reduction ratio R, and the slip ratio Rslip of the virtual clutch. For example, the virtual engine rotational speed Ne is represented by the following equation (1). Equation (1): Ne = Nw × R / (1 - Rslip)

[0089] The virtual engine output torque Teout is calculated from the virtual engine rotational speed Ne and the accelerator opening Pap. For the calculation of the virtual engine output torque Teout, as shown in FIG. 15, a map defining the relationship between the accelerator opening Pap, the virtual engine rotational speed Ne, and the virtual engine output torque Teout is used. In this map, the virtual engine output torque Teout with respect to the virtual engine rotational speed Ne is given for each accelerator opening Pap. The torque characteristics shown in FIG. 15 can be set to the characteristics assuming a gasoline engine, or can be set to the characteristics assuming a diesel engine. Also, the characteristics assuming a naturally aspirated engine can be set, or the characteristics assuming a supercharged engine can be set.

[0090] The clutch model 562 calculates the torque transmission gain k. The torque transmission gain k is a gain for calculating the degree of torque transmission of the virtual clutch according to the virtual clutch opening Pc. The virtual clutch opening Pc is normally 0%, and is temporarily opened up to 100% in conjunction with the switching of the virtual gear stage of the virtual transmission. The clutch model 562 has a map as shown in FIG. 15. In this map, the torque transmission gain k is given for the virtual clutch opening Pc. In FIG. 15, Pc0 corresponds to the position where the virtual clutch opening Pc is 0%, and Pc3 corresponds to the position where the virtual clutch opening Pc is 100%. The ranges from Pc0 to Pc1 and from Pc2 to Pc3 are dead zones where the torque transmission gain k does not change depending on the virtual clutch opening Pc. The clutch model 562 calculates the clutch output torque Tcout using the torque transmission gain k. The clutch output torque Tcout is the torque output from the virtual clutch. For example, the clutch output torque Tcout is given by the product of the virtual engine output torque Teout and the torque transmission gain k (Tcout = Teout × k).

[0091] Also, the clutch model 562 calculates the slip ratio Rslip. The slip ratio Rslip is used in the calculation of the virtual engine rotational speed Ne in the engine model 561. For calculating the slip ratio Rslip, a map in which the slip ratio Rslip is given for the virtual clutch opening Pc can be used, similar to the torque transmission gain k.

[0092] The transmission model 563 calculates the gear ratio (shift ratio) r. The gear ratio r is the gear ratio determined by the virtual gear stage GP in the virtual transmission. Upon receiving an upshift operation of the sequential shifter 24, the virtual gear stage GP is shifted up by one stage. On the other hand, upon receiving a downshift operation of the sequential shifter 24, the virtual gear stage GP is shifted down by one stage. The transmission model 563 has a map as shown in FIG. 15. In this map, the gear ratio r is given to the virtual gear stage GP such that the larger the virtual gear stage GP, the smaller the gear ratio r. The transmission model 563 calculates the transmission output torque Tgout using the gear ratio r obtained from the map and the clutch output torque Tcout. For example, the transmission output torque Tgout is given by the product of the clutch output torque Tcout and the gear ratio r (Tgout = Tcout × r). The transmission output torque Tgout changes discontinuously according to the switching of the gear ratio r. This discontinuous change in the transmission output torque Tgout generates a shift shock and gives the impression of a vehicle equipped with a stepped transmission.

[0093] The MT vehicle model calculates the drive wheel torque Tw using a predetermined reduction ratio rr. The reduction ratio rr is a fixed value determined by the mechanical structure from the virtual transmission to the drive wheels. The value obtained by multiplying the reduction ratio rr by the gear ratio r is the aforementioned overall reduction ratio R. The MT vehicle model calculates the drive wheel torque Tw from the transmission output torque Tgout and the reduction ratio rr. For example, the drive wheel torque Tw is given by the product of the transmission output torque Tgout and the reduction ratio rr (Tw = Tgout × rr).

[0094] The control device 50 converts the drive wheel torque Tw calculated by the MT vehicle model into the required motor torque Tm. The required motor torque Tm is the motor torque necessary to achieve the drive wheel torque Tw calculated by the MT vehicle model. The reduction ratio from the output shaft of the electric motor 44 to the drive wheels is used for the conversion of the drive wheel torque Tw to the required motor torque Tm. Then, the control device 50 controls the inverter 42 according to the required motor torque Tm to control the electric motor 44.

[0095] FIG. 16 is a diagram showing the torque characteristics of the electric motor 44 realized by motor control using an MT vehicle model, compared with the torque characteristics of the electric motor 44 realized by normal motor control as an electric vehicle (EV). According to the motor control using the MT vehicle model, as shown in FIG. 19, torque characteristics (solid line in the figure) that simulate the torque characteristics of the MT vehicle can be realized according to the virtual gear stage set by the sequential shifter 24. In FIG. 16, the number of gear stages is six.

[0096] 4-2. Second Configuration Example (3-Pedal Mode) FIG. 17 is a block diagram showing a second configuration example of the power control system of the electric vehicle 10E according to the present embodiment. Here, only the configuration different from the above-described first configuration example will be described. Specifically, in the second configuration example, the electric vehicle 10E includes a pseudo shift lever (pseudo shift device) 27 and a pseudo clutch pedal 28 instead of the sequential shifter 24 provided in the first configuration example. The pseudo shift lever 27 and the pseudo clutch pedal 28 are merely dummies that are different from the original shift lever and clutch pedal.

[0097] The pseudo shift lever 27 has a structure that simulates the shift lever provided in an MT vehicle. The arrangement and operating feeling of the pseudo shift lever 27 are equivalent to those of an actual MT vehicle. The pseudo shift lever 27 is provided with positions corresponding to each gear stage such as first speed, second speed, third speed, fourth speed, fifth speed, sixth speed, reverse, and neutral. The pseudo shift lever 27 is provided with a shift position sensor 27a that detects the gear stage by determining which position the pseudo shift lever 27 is in.

[0098] The pseudo clutch pedal 28 has a structure that mimics the clutch pedal of an MT vehicle. The arrangement and operating feel of the pseudo clutch pedal 28 are equivalent to those of an actual MT vehicle. The pseudo clutch pedal 28 is operated when the pseudo shift lever 27 is operated. That is, when the driver wants to change the gear stage setting with the pseudo shift lever 27, the driver depresses the pseudo clutch pedal 28, and when the gear stage setting change is completed, releases the depression and returns the pseudo clutch pedal 28 to its original position. The pseudo clutch pedal 28 is provided with a clutch position sensor 28a for detecting the depression amount of the pseudo clutch pedal 28.

[0099] Signals from the accelerator position sensor 32, the shift position sensor 27a, the clutch position sensor 28a, the wheel speed sensor 36, and the rotational speed sensor 38 are input to the control device 50. The control device 50 processes these signals and calculates a motor torque command value for PWM control of the inverter 42.

[0100] Similar to the first configuration example described above, the control device 50 includes an automatic mode (EV mode) and a manual mode (MT mode) as control modes. The automatic mode is programmed to continuously change the output of the electric motor 44 in response to the operation of the accelerator pedal 22. On the other hand, the manual mode is a control mode for driving the electric vehicle 10E like an MT vehicle. The manual mode is programmed to change the output and output characteristics of the electric motor 44 with respect to the operation of the accelerator pedal 22 according to the operations of the pseudo clutch pedal 28 and the pseudo shift lever (pseudo shift device) 27. This manual mode (MT mode) corresponds to the "three-pedal mode". The automatic mode and the manual mode are switchable.

[0101] The vehicle model equipped with the manual mode torque calculation unit 56 is the same as that shown in Fig. 15. However, the virtual clutch opening Pc is replaced by the depression amount of the pseudo clutch pedal 28 detected by the clutch position sensor 28a. Also, the virtual gear stage GP is determined by the position of the pseudo shift lever 27 detected by the shift position sensor 27a.

Explanation of Signs

[0102] 2…Speaker, 10…Vehicle, 70…Sensor, 71…Electrocardiograph, 72…Sweating sensor, 90…HMI, 100…Vehicle control system, 110…Fatigue degree acquisition unit, 120…Operating condition determination unit, 130…Relaxation sound control unit, 140…End condition determination unit, 150…Mode switching condition determination unit, 160…Mode switching unit

Claims

1. A vehicle control system for controlling a vehicle, comprising one or more processors, wherein the one or more processors acquire the mental fatigue level of the driver of the vehicle using at least sensors mounted on the vehicle, and when an operating condition including at least that the mental fatigue level exceeds a first threshold is satisfied, output a relaxation sound for reducing the mental fatigue level through a speaker mounted on the vehicle. It is configured as a vehicle control system.

2. The vehicle control system according to claim 1, wherein the operating condition further includes that the driver has approved the output of the relaxation sound. A vehicle control system.

3. The vehicle control system according to claim 1, wherein the sensor includes at least one of a device used by the driver during a driving operation or an electrocardiograph and a sweating sensor mounted on a wearable terminal worn by the driver, and the one or more processors are configured to acquire the mental fatigue level based on at least one of the driver's heart rate data detected by the electrocardiograph and the driver's sweating amount detected by the sweating sensor. A vehicle control system.

4. The vehicle control system according to any one of claims 1 to 3, wherein the vehicle is a manual transmission vehicle equipped with a clutch pedal. A vehicle control system.

5. The vehicle control system according to any one of claims 1 to 3, wherein the vehicle is an electric vehicle using an electric motor as a driving power device and is equipped with a pseudo clutch pedal and a pseudo shift device. The pseudo clutch pedal is operated when the pseudo shift device is operated, The driving mode of the electric vehicle includes a three-pedal mode in which the output of the electric motor with respect to the operation of the accelerator pedal is changed according to the operation of the pseudo clutch pedal and the operation of the pseudo shift device, In the three-pedal mode, the one or more processors are configured to acquire the mental fatigue level and output the relaxation sound when the operating condition is satisfied Vehicle control system.

6. The vehicle control system according to claim 5, The sensor is mounted on the pseudo shift device Vehicle control system.

7. The vehicle control system according to claim 5, The driving mode of the electric vehicle further includes a two-pedal mode that does not require the operation of the pseudo clutch pedal, The one or more processors are further configured to switch the driving mode from the three-pedal mode to the two-pedal mode when a mode switching condition is satisfied, the mode switching condition including at least that the mental fatigue level exceeds a second threshold during the three-pedal mode Vehicle control system.

8. The vehicle control system according to claim 7, The mode switching condition further includes that the driver approves the switching from the three-pedal mode to the two-pedal mode Vehicle control system.

9. The vehicle control system according to claim 7, The one or more processors are configured to determine whether the mode switching condition is satisfied after the operating condition is satisfied and the relaxation sound is output Vehicle control system.

10. A vehicle control system for controlling an electric vehicle that uses an electric motor as a driving power device, wherein the electric vehicle includes a pseudo clutch pedal and a pseudo shift device, the pseudo clutch pedal is operated when the pseudo shift device is operated, the driving mode of the electric vehicle is a three-pedal mode in which the output of the electric motor with respect to the operation of the accelerator pedal is changed according to the operation of the pseudo clutch pedal and the operation of the pseudo shift device, and a two-pedal mode that does not require the operation of the pseudo clutch pedal and includes, the vehicle control system includes one or more processors, the one or more processors acquire the mental fatigue degree of the driver of the electric vehicle using sensors mounted on the electric vehicle, and when a mode switching condition including at least that the mental fatigue degree exceeds a threshold during the three-pedal mode is satisfied, the driving mode is configured to be switched from the three-pedal mode to the two-pedal mode Vehicle control system.

11. The vehicle control system according to claim 10, wherein the mode switching condition further includes that the driver has approved the switching from the three-pedal mode to the two-pedal mode Vehicle control system.

12. The vehicle control system according to claim 10 or 11, wherein the sensor includes at least one of a device used by the driver during driving operation or an electrocardiograph and a sweating sensor mounted on a wearable terminal worn by the driver, and the one or more processors are configured to acquire the mental fatigue degree based on at least one of the driver's heartbeat data detected by the electrocardiograph and the driver's sweating amount detected by the sweating sensor Vehicle control system.

13. The vehicle control system according to claim 12, wherein the sensor is mounted on the pseudo shift device Vehicle control system.

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