Driving control device

Abstract

To provide a travelling control device that can reduce an anxiety of a driver.SOLUTION: A travelling control device according to one embodiment in the disclosure comprises: an anxiety-level estimating part that estimates an anxiety level; a friction coefficient estimating part that estimates a friction coefficient of a road surface; an analyzing part that calculates a ratio of straight lines in a scheduled travelling route; and a travelling control part that controls travelling of a vehicle. The travelling control part performs first control processing when the friction coefficient is lower than a first predetermined value, in an automatic operation mode. The travelling control part performs first processing for performing travelling control by correcting a turning speed and braking timing, when the anxiety level is higher than a predetermined level and the ratio of the straight lines is lower than a predetermined ratio; performs second processing for performing travelling control by correcting an upper limit speed and upper limit acceleration, when the anxiety level is higher than the predetermined level and the ratio of the straight lines is higher than the predetermined ratio; and performs third processing for switching an operation mode to a manual operation mode, when the anxiety level is lower than the predetermined level.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a driving control device that controls driving of a vehicle. [Background technology]

[0002] Some vehicles are capable of switching between an automatic driving mode and a manual driving mode. For example, Patent Document 1 discloses a system that controls switching of driving modes based on the driver's anxiety level. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-64773 Summary of the Invention [Problem to be solved by the invention]

[0004] For example, when switching the driving mode from an automatic driving mode to a manual driving mode, it is desirable to reduce the driver's anxiety, and further reduction in driver anxiety is expected.

[0005] It is desirable to provide a cruise control device that can reduce the driver's anxiety. [Means for solving the problem]

[0006] A cruise control device according to an embodiment of the present disclosure includes an anxiety level estimation unit, a friction coefficient estimation unit, an analysis unit, and a cruise control unit. The anxiety level estimation unit estimates an anxiety level indicating a degree of anxiety felt by a driver of the vehicle based on detection results from a sensor that detects biological information of the driver. The friction coefficient estimation unit estimates a friction coefficient of a road surface on which the vehicle is traveling. The analysis unit calculates a straight line ratio indicating a proportion of the length of a straight line in a planned travel route based on the planned travel route of the vehicle. The cruise control unit operates in one of an autonomous driving mode and a manual driving mode, and controls the travel of the vehicle. In the autonomous driving mode, the cruise control unit performs a first control process when the friction coefficient is lower than a first predetermined value. In the first control process, the cruise control unit reduces the steering speed when the anxiety level is higher than a predetermined level and the straight line ratio is lower than the predetermined ratio. The steering speed is corrected to lower the Brake timing Braking timing should be adjusted to make it faster. a first process for correcting the steering speed and the brake timing, and performing vehicle travel control in an autonomous driving mode using the corrected steering speed and the corrected brake timing; and a second process for correcting the upper limit speed when the anxiety level is higher than a predetermined level and the straight line ratio is higher than a predetermined ratio. The upper limit speed is corrected to lower the Upper limit acceleration Set the upper acceleration limit to A second process is performed in which the vehicle's driving is controlled in autonomous driving mode using the corrected upper limit speed and the corrected upper limit acceleration, and a third process is performed in which the driving mode is switched from autonomous driving mode to manual driving mode when the anxiety level is lower than a predetermined level. [Effects of the Invention]

[0007] According to the cruise control device according to an embodiment of the present disclosure, it is possible to reduce the anxiety of the driver. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a block diagram illustrating an example configuration of a vehicle equipped with a cruise control device according to an embodiment of the present disclosure. [Figure 2] 2 is a state transition diagram illustrating an example of the operation of the driving control unit illustrated in FIG. 1. [Figure 3A]2 is a flowchart illustrating an example of the operation of the driving control unit illustrated in FIG. 1. [Figure 3B] 10 is another flowchart illustrating an example of the operation of the traveling control unit shown in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings.

[0010] <Embodiment> [Configuration example] 1 shows an example of the configuration of a vehicle 1 equipped with a cruise control device according to an embodiment. The vehicle 1 includes an exterior environment detection unit 11, a biological information detection unit 12, a navigation unit 13, and a cruise control device 20.

[0011] The exterior environment detection unit 11 is configured to detect the environment around the vehicle 1. The exterior environment detection unit 11 is configured using, for example, an image sensor, a distance sensor, etc. The image sensor is configured to capture, for example, images in front of and behind the vehicle 1. The image sensor may be, for example, a stereo camera. The distance sensor is configured to detect the distance to an object around the vehicle 1. The distance sensor may be, for example, a LiDAR (light detection and ranging) device.

[0012] The biological information detection unit 12 is configured to detect the biological information of the driver. The biological information detection unit 12 is configured using, for example, an image sensor, a blood pressure sensor, a heart rate sensor, a sweat sensor, a temperature sensor, a microphone, etc. For example, the image sensor is configured to capture an image of the driver. The blood pressure sensor is configured to detect the blood pressure of the driver. The heart rate sensor is configured to detect the heart rate of the driver. The sweat sensor is configured to detect the amount of sweat of the driver. The temperature sensor is configured to detect the body temperature of the driver. The microphone is configured to detect the voice emitted by the driver.

[0013] The navigation unit 13 is configured to determine a route (planned driving route) to a destination along which the vehicle 1 should travel and to provide information to the driver so as to guide the vehicle 1 along the determined route. The navigation unit 13 has, for example, a map information database containing information about road maps and determines the planned driving route using this map information database. Note that this is not limited to this. For example, the navigation unit 13 may not have a map information database, but may acquire information about road maps by communicating with a network server (not shown) and determine the planned driving route based on the acquired information. The navigation unit 13 acquires the terrestrial position of the vehicle 1 using a Global Navigation Satellite System (GNSS) such as a Global Positioning System (GPS). The navigation unit 13 also has a user interface, such as a display panel, a touch panel, and various buttons. As a result, the navigation unit 13 determines a planned driving route to the destination based on information about the destination input by the driver operating this user interface, and provides information about the determined route to the driver using this user interface.

[0014] The driving control device 20 has an anxiety level estimation unit 21, a road surface friction coefficient estimation unit 22, a planned driving route analysis unit 23, and a driving control unit 24. The driving control device 20 is configured, for example, with one or more processors that execute programs, one or more RAMs (Random Access Memories) that temporarily store processed data, one or more ROMs (Read Only Memories) that store programs, etc.

[0015] The anxiety level estimation unit 21 is configured to estimate the driver's anxiety level A based on the detection result of the biometric information detection unit 12. In this example, the anxiety level A is a value greater than or equal to 0, and the more anxious the driver feels, the higher the value. The anxiety level estimation unit 21 can estimate the driver's anxiety level A by, for example, analyzing the driver's gaze movement frequency, gaze direction, blink frequency, facial expression, and facial and body movements based on the image captured by the image sensor of the biometric information detection unit 12. The anxiety level estimation unit 21 can also estimate the driver's anxiety level A by, for example, analyzing the detection results of the blood pressure sensor, heart rate sensor, sweat sensor, and temperature sensor of the biometric information detection unit 12. The anxiety level estimation unit 21 can also estimate the driver's anxiety level A by, for example, analyzing the driver's remarks and tone of voice based on audio data acquired by a microphone. The anxiety level estimation unit 21 then supplies information about the estimated anxiety level A to the driving control unit 24.

[0016] The road surface friction coefficient estimation unit 22 is configured to estimate the friction coefficient μ of the road surface with respect to the vehicle 1. The friction coefficient μ is a value equal to or greater than 0, and the less slippery the road is, the larger the value is. The road surface friction coefficient estimation unit 22 estimates the friction coefficient μ by, for example, checking the tire slip state based on information about the rotational speed of the tires of the vehicle 1. Note that this is not limited to this, and the friction coefficient μ may be estimated by, for example, checking the driving state of the vehicle 1 using an image captured by an image sensor of the exterior environment detection unit 11 or a GNSS of the navigation unit 13. The road surface friction coefficient estimation unit 22 then supplies information about the estimated friction coefficient μ to the driving control unit 24.

[0017] The planned driving route analysis unit 23 is configured to analyze the planned driving route determined by the navigation unit 13. In this example, the planned driving route analysis unit 23 calculates a straight line ratio R, which is the ratio of the length of straight driving roads in the driving roads of the planned driving route. Then, the planned driving route analysis unit 23 supplies information about this straight line ratio R to the driving control unit 24.

[0018] The driving control unit 24 is configured to control the driving of the vehicle 1. Specifically, the driving control unit 24 controls the operation of a driving force generating unit such as an engine or a motor, controls the operation of a braking device that slows down or stops the vehicle 1, and controls the operation of a steering device that changes the direction of travel of the vehicle 1. The driving control unit 24 can also control the driving of the vehicle 1 while stabilizing the behavior of the vehicle. In this example, the driving control unit 24 has functions such as an ABS (Anti-lock Breaking System) and a VDC (Vehicle Dynamics Control), for example.

[0019] 2 shows a state transition diagram of the driving control unit 24. The driving control unit 24 has an automatic driving mode MA and a manual driving mode MB.

[0020] In the autonomous driving mode MA, the driving control unit 24 performs steering control, speed control, braking control, and the like of the vehicle 1 based on the detection results of the external environment detection unit 11. For example, the driving control unit 24 may control the vehicle 1 based on the detection results of the external environment detection unit 11 under specific conditions that can ensure safety. Specifically, for example, the driving control unit 24 can control the vehicle 1 to follow a preceding vehicle while maintaining the vehicle's lane. Furthermore, the driving control unit 24 can control the vehicle 1 to overtake a preceding vehicle on a highway or merge at a junction, for example.

[0021] In the manual driving mode MB, the driving control unit 24 performs steering control, speed control, braking control, etc. of the vehicle 1 based on the driver's steering operation, acceleration operation, deceleration operation, braking operation, etc.

[0022] The driving control unit 24 can switch the driving mode from the automatic driving mode MA to the manual driving mode MB, or from the manual driving mode MB to the automatic driving mode MA, based on, for example, an instruction from the driver.

[0023] Furthermore, when the cruise control unit 24 is controlling the vehicle 1 in the autonomous driving mode MA and determines that it is difficult to continue controlling the vehicle 1 in the autonomous driving mode MA, the cruise control unit 24 can switch the driving mode from the autonomous driving mode MA to the manual driving mode MB. Specifically, for example, when it is snowing and the exterior environment detection unit 11 cannot accurately detect lane markings, the cruise control unit 24 switches the driving mode from the autonomous driving mode MA to the manual driving mode MB. In such a case, if the cruise control unit 24 suddenly switches the driving mode from the autonomous driving mode MA to the manual driving mode MB, the driver may feel uneasy. Therefore, the cruise control unit 24 continues to maintain the driving mode in the autonomous driving mode MA until the driver's uneasiness is alleviated, and corrects various cruise control parameters in the autonomous driving mode MA to alleviate the driver's uneasiness. The cruise control parameters include, for example, the steering speed, braking timing, upper limit speed, and upper limit acceleration. The steering speed is the speed of change in the steering angle when changing the direction of travel of the vehicle 1, and is expressed in units of, for example, [rad / s] or [deg / s]. The braking timing is a parameter that indicates how far in advance the braking operation of the vehicle 1 should commence, for example, when the vehicle 1 approaches a roadway where it must travel at a low speed, such as a curve. In this example, the braking timing indicates the distance from the point where the braking operation commences to the curve, and is expressed in units of, for example, [m]. The upper speed limit is the upper limit of the speed of the vehicle 1, and is expressed in units of, for example, [km / h]. The upper acceleration limit is the upper limit of the acceleration of the vehicle 1, and is expressed in units of, for example, [m / s 2 The driving control unit 24 corrects these driving control parameters so as to ease the driver's anxiety. After the driver's anxiety has eased to a certain extent, the driving mode is switched from the automatic driving mode MA to the manual driving mode MB.

[0024] Here, the anxiety level estimation unit 21 corresponds to a specific example of an "anxiety level estimation unit" in the present disclosure. The anxiety level A corresponds to a specific example of an "anxiety level" in the present disclosure. The road surface friction coefficient estimation unit 22 corresponds to a specific example of a "friction coefficient estimation unit" in the present disclosure. The friction coefficient μ corresponds to a specific example of a "friction coefficient" in the present disclosure. The planned driving route analysis unit 23 corresponds to a specific example of an "analysis unit" in the present disclosure. The straight line ratio R corresponds to a specific example of a "straight line ratio" in the present disclosure. The driving control unit 24 corresponds to a specific example of a "driving control unit" in the present disclosure. The autonomous driving mode MA corresponds to a specific example of an "autonomous driving mode" in the present disclosure. The manual driving mode MB corresponds to a specific example of a "manual driving mode" in the present disclosure.

[0025] [Actions and Actions] Next, the operation and function of the vehicle 1 of this embodiment will be described.

[0026] (Overview of overall operation) First, the operation of the vehicle 1 will be described with reference to FIG. 1. The exterior environment detection unit 11 detects the environment around the vehicle 1. The biometric information detection unit 12 detects the driver's biometric information. The navigation unit 13 determines a route (planned driving route) to a destination to which the vehicle 1 should travel, and provides information to the driver to guide the vehicle 1 along the determined route. The anxiety level estimation unit 21 of the driving control device 20 estimates the driver's anxiety level A based on the detection results of the biometric information detection unit 12. The road surface friction coefficient estimation unit 22 estimates the friction coefficient μ of the road surface with respect to the vehicle 1. The planned driving route analysis unit 23 calculates a straight line ratio R, which is the ratio of the length of a straight line in the driving path of the planned driving route, based on the planned driving route determined by the navigation unit 13. The driving control unit 24 switches the driving mode from an automatic driving mode MA to a manual driving mode MB, or from the manual driving mode MB to the automatic driving mode MA, for example, based on an instruction from the driver. In the automatic driving mode MA, the driving control unit 24 performs steering control, speed control, braking control, etc. of the vehicle 1 based on the detection results of the exterior environment detection unit 11. In the manual driving mode MB, the driving control unit 24 performs steering control, speed control, braking control, etc. of the vehicle 1 based on the driver's steering operation, acceleration operation, deceleration operation, braking operation, etc.

[0027] (Detailed operation) When the driving control unit 24 is controlling the driving of the vehicle 1 in the automatic driving mode MA, if it determines that it is difficult to continue the driving control in the automatic driving mode MA, the driving control unit 24 switches the driving mode from the automatic driving mode MA to the manual driving mode MB. This operation will be described in detail below.

[0028] 3A and 3B show an example of the operation of the driving control unit 24. FIG.

[0029] First, the driving control unit 24 checks whether the driving mode is the automatic driving mode MA (step S101). If the driving mode is not the automatic driving mode MA ("N" in step S101), the driving control unit 24 repeats the process of step S101 until the driving mode becomes the automatic driving mode MA.

[0030] In step S101, if the driving mode is the automatic driving mode MA ("Y" in step S101), the driving control unit 24 checks whether the friction coefficient μ estimated by the road surface friction coefficient estimation unit 22 is equal to or less than a predetermined threshold μth1 (μ≦μth1) (step S102). Here, the threshold μth1 is a threshold value used by the driving control unit 24 to determine whether or not to change the driving control parameters so that the vehicle 1 can travel more safely in a slippery environment. That is, for example, if the friction coefficient μ becomes low, the tires of the vehicle 1 become more slippery. Therefore, the driving control unit 24 starts operation in a low friction coefficient driving mode and changes the driving control parameters so that the driving control of the automatic driving mode MA can be performed more safely in a slippery environment. The driving control unit 24 determines whether or not to change the driving control parameters by checking whether the friction coefficient μ is equal to or less than the threshold μth1. If the friction coefficient μ is not equal to or less than the threshold μth1 ("N" in step S102), the driving control unit 24 repeats the processing of step S102 until the friction coefficient μ satisfies this condition. That is, in this case, the driving control unit 24 determines that the environment is not slippery, and repeats the process of step S102.

[0031] In step S102, if the friction coefficient μ is equal to or less than the threshold value μth1 ("Y" in step S102), the cruise control unit 24 determines that the environment is slippery and starts operation in the low friction coefficient travel mode (step S103). The cruise control unit 24 calculates the steering speed, braking timing, upper limit speed, and upper limit acceleration to be used in this low friction coefficient travel mode (step S104). Then, the cruise control unit 24 starts cruise control of the vehicle 1 using the steering speed, braking timing, upper limit speed, and upper limit acceleration calculated in step S104 (step S105).

[0032] For example, the travel control unit 24 calculates the steering speed to be used in the low friction coefficient travel mode using the following equation. Steering speed = Steering speed base value - (μstd - μ) × β Here, the base value of the steering speed is the value of the steering speed in a normal case where the friction coefficient μ is not low. μstd is the reference value of the friction coefficient, for example, 0.8 on a dry road surface, 0.1 on an icy road surface, and 0.4 on a snowy road surface. β is a coefficient. For example, the smaller the estimated friction coefficient μ, the smaller the value of the steering speed calculated by the above formula. Therefore, in the low friction coefficient driving mode, the driving control unit 24 controls the driving of the vehicle 1 so that the direction of travel of the vehicle 1 changes more slowly.

[0033] For example, the driving control unit 24 calculates the brake timing to be used in the low friction coefficient driving mode using the following equation. Brake timing = Brake timing base value + (μstd - μ) × α Here, the base value of the brake timing is the value of the brake timing in a normal case where the friction coefficient is not low. α is a coefficient. For example, the smaller the estimated friction coefficient μ, the larger the value of the brake timing calculated by the above formula. Therefore, in the low friction coefficient driving mode, the driving control unit 24 controls the driving of the vehicle 1 so that the braking operation is initiated at a point earlier, for example, before approaching a curve.

[0034] For example, the travel control unit 24 calculates the upper limit speed to be used in the low friction coefficient travel mode using the following formula. Upper speed limit = Upper speed limit base value - (μstd - μ) × γ Here, the base value of the upper limit speed is the value of the upper limit speed in a normal case where the friction coefficient is not low. γ is a coefficient. For example, the smaller the estimated friction coefficient μ, the smaller the value of the upper limit speed calculated by the above formula. Therefore, in the low friction coefficient traveling mode, the traveling control unit 24 performs traveling control of the vehicle 1 so as to lower the upper limit value of the traveling speed of the vehicle 1.

[0035] For example, the driving control unit 24 calculates the upper limit acceleration to be used in the low friction coefficient driving mode using the following formula. Upper limit acceleration = Upper limit acceleration base value - (μstd - μ) × ρ Here, the base value of the upper limit acceleration is the value of the upper limit acceleration in a normal case where the friction coefficient is not low. ρ is a coefficient. For example, the smaller the estimated friction coefficient μ, the smaller the value of the upper limit acceleration calculated by the above formula. Therefore, in the low friction coefficient traveling mode, the traveling control unit 24 controls the traveling of the vehicle 1 so as to lower the upper limit value of the acceleration of the traveling speed of the vehicle 1.

[0036] Next, the driving control unit 24 checks whether the friction coefficient μ estimated by the road surface friction coefficient estimation unit 22 is greater than a predetermined threshold μth2 (μ>μth2) (step S106). Here, the threshold μth2 is a threshold used by the driving control unit 24 to determine whether the driver should drive. That is, for example, as the friction coefficient μ decreases, the tires of the vehicle 1 become more slippery, so the vehicle 1 can travel safely according to the situation if the driver drives it himself. The threshold μth2 is lower than the threshold μth1 in step S102. The driving control unit 24 checks whether the friction coefficient μ is greater than the threshold μth2 to determine whether the low friction coefficient driving mode should be maintained or whether the driver should drive it himself. If the friction coefficient μ is greater than the threshold μth2 ("Y" in step S106), the driving control unit 24 repeats the processing of step S106 until the friction coefficient μ no longer satisfies this condition. That is, in this case, the traveling control unit 24 determines that the low friction coefficient traveling mode should be maintained, and repeats the processing of step S106.

[0037] In step S106, if the friction coefficient μ is less than or equal to the threshold value μth2 ("N" in step S106), the driving control unit 24 determines that the vehicle 1 can travel safely according to the situation if the driver drives it himself, and begins preparations to transition from automatic driving mode MA to manual driving mode MB (step S107).

[0038] Next, the driving control unit 24 checks whether the driver's anxiety level A estimated by the anxiety level estimation unit 21 is equal to or greater than a predetermined threshold value Ath (A≦Ath) (step S108). Here, the threshold value Ath is a threshold value used by the driving control unit 24 to determine whether to switch the operation mode from the automatic driving mode MA to the manual driving mode MB. That is, for example, if the driver's anxiety level A is high, when the driving control unit 24 switches the operation mode from the automatic driving mode MA to the manual driving mode MB, the driver will drive while feeling anxious. Therefore, the driving control unit 24 checks whether the anxiety level A is equal to or greater than the threshold value Ath to determine whether to maintain the automatic driving mode MA or to switch the driving mode from the automatic driving mode MA to the manual driving mode MB.

[0039] In step S108, if the driver's anxiety level A is lower than the threshold value Ath ("N" in step S108), the driving control unit 24 determines that the driver is not feeling anxious and switches the driving mode from the automatic driving mode MA to the manual driving mode MB (step S109). Then, the process returns to step S101.

[0040] In step S108, if the driver's anxiety level A is equal to or greater than the threshold value Ath ("Y" in step S108), the cruise control unit 24 determines that the driver is feeling anxious and maintains cruise control in the autonomous driving mode MA. The cruise control unit 24 then checks whether the straight line ratio R generated by the planned driving route analysis unit 23 is equal to or less than a predetermined threshold value Rth (R≦Rth) (step S110). The threshold value Rth is a threshold value used by the cruise control unit 24 to determine which of the cruise control parameters should be corrected. That is, for example, if the straight line ratio R is low, the planned driving route has many curves, and therefore the cruise control unit 24 corrects the steering speed and braking timing. On the other hand, for example, if the straight line ratio R is high, the planned driving route has many straight roads, and therefore the cruise control unit 24 corrects the upper limit speed and upper limit acceleration. The cruise control unit 24 checks whether the straight line ratio R is equal to or less than the threshold value Rth to determine which of the cruise control parameters should be corrected.

[0041] In step S110, if the straight line ratio R is equal to or less than the threshold value Rth ("Y" in step S110), for example, because the planned driving route has many curves, the driving control unit 24 calculates the correction amount of the steering speed and the correction amount of the braking timing to be used in the low-friction coefficient driving mode (step S111), and updates the steering speed and the braking timing to be used in the low-friction coefficient driving mode (step S112).Then, the driving control unit 24 starts driving control using the updated steering speed and the braking timing (step S113).

[0042] The cruise control unit 24 corrects the steering speed and braking timing to alleviate the driver's anxiety. For example, the cruise control unit 24 corrects the steering speed and braking timing used in the low friction coefficient traveling mode using the following equations. Steering speed = current steering speed + steering speed correction amount Brake timing = current brake timing + brake timing correction amount The correction amount for the steering speed is a negative value. Therefore, the driving control unit 24 controls the driving of the vehicle 1 so as to reduce the steering speed. In other words, the driving control unit 24 controls the driving of the vehicle 1 so as to change the traveling direction of the vehicle 1 more slowly. Furthermore, the correction amount for the braking timing is a positive value. Therefore, the driving control unit 24 controls the driving of the vehicle 1 so as to initiate a braking operation at an earlier point, for example, before approaching a curve. In other words, the driving control unit 24 controls the driving of the vehicle 1 so as to initiate a braking operation at an earlier timing. Then, the process returns to step S108.

[0043] In step S110, if the straightness ratio R is greater than the threshold value Rth ("N" in step S110), for example, because the planned driving route includes many straight roads, the driving control unit 24 calculates the correction amounts for the upper limit speed and the upper limit acceleration used in the low-friction coefficient driving mode (step S114) and updates the upper limit speed and the upper limit acceleration used in the low-friction coefficient driving mode (step S115).Then, the driving control unit 24 starts driving control using the updated upper limit speed and the upper limit acceleration (step S116).

[0044] The driving control unit 24 corrects the upper speed limit and the upper acceleration limit so as to ease the driver's anxiety. For example, the driving control unit 24 corrects the upper speed limit and the upper acceleration limit used in the low friction coefficient driving mode using the following equations. Upper limit speed = current upper limit speed + upper limit speed correction amount Upper limit acceleration = current upper limit acceleration + upper limit acceleration correction amount The correction amount for the upper limit speed is a negative value. Therefore, the driving control unit 24 controls the driving of the vehicle 1 so as to lower the upper limit speed. In other words, the driving control unit 24 controls the driving of the vehicle 1 so as to prevent the driving speed of the vehicle 1 from increasing. Furthermore, the correction amount for the upper limit acceleration is a negative value. Therefore, the driving control unit 24 controls the driving of the vehicle 1 so as to lower the upper limit acceleration. In other words, the driving control unit 24 controls the driving of the vehicle 1 so as to prevent a sudden change in the driving speed of the vehicle 1. Then, the processing returns to step S108.

[0045] The driving control unit 24 repeats the processes of steps S111 to S113 or steps S114 to S116 until the anxiety level A becomes lower than the threshold value Ath. Then, when the anxiety level A becomes lower than the threshold value Ath ("N" in step S108), the driving control unit 24 switches the driving mode from the automatic driving mode MA to the manual driving mode MB (step S109). Then, the process returns to step S101.

[0046] This completes the flow. Here, threshold value Ath corresponds to a specific example of "predetermined degree" in the present disclosure. Threshold value μth2 corresponds to a specific example of "first predetermined value" in the present disclosure. Threshold value μth1 corresponds to a specific example of "second predetermined value" in the present disclosure. Threshold value Rth corresponds to a specific example of "predetermined ratio" in the present disclosure.

[0047] As described above, the driving control device 20 includes an anxiety level estimation unit 21 that estimates an anxiety level A indicating the degree of anxiety felt by the driver of the vehicle 1 based on the detection results of the biological information detection unit 12 that detects the biological information of the driver of the vehicle 1, a road surface friction coefficient estimation unit 22 that estimates the friction coefficient μ of the road surface on which the vehicle 1 is traveling, a planned driving route analysis unit 23 that calculates a straight line ratio R indicating the ratio of the length of straight driving paths in the driving paths of the planned driving route based on the planned driving route of the vehicle 1, and a driving control unit 24 that operates in one of the driving modes of the automatic driving mode MA and the manual driving mode MB and controls the driving of the vehicle 1. In the automatic driving mode MA, the driving control unit 24 performs a first control process when the friction coefficient μ is lower than a first predetermined value (threshold value μth2). In this first control process, if the anxiety level A is higher than a predetermined level (threshold Ath) and the straight line ratio R is lower than a predetermined ratio (threshold Rth), the cruise control unit 24 corrects the steering speed and braking timing as shown in steps S111 to S113, and performs first processing to control the cruise of the vehicle 1 in the autonomous driving mode MA using the corrected steering speed and the corrected braking timing.Furthermore, in the first control process, if the anxiety level A is higher than a predetermined level (threshold Ath) and the straight line ratio R is higher than the predetermined ratio (threshold Rth), the cruise control unit 24 corrects the upper limit speed and upper limit acceleration as shown in steps S114 to S116, and performs second processing to control the cruise of the vehicle 1 in the autonomous driving mode using the corrected upper limit speed and the corrected upper limit acceleration. Furthermore, in the first control process, if the anxiety level A is lower than a predetermined level (threshold Ath), the cruise control unit 24 performs a third process of switching the driving mode from the automatic driving mode MA to the manual driving mode MB, as shown in step S109. As a result, if the driver feels anxious, the cruise control device 20 does not switch the driving mode from the automatic driving mode MA to the manual driving mode MB, but instead corrects the steering speed, braking timing, upper limit speed, and upper limit acceleration. The cruise control unit 24 can correct these cruise control parameters, for example, to alleviate the driver's anxiety. As a result, the cruise control device 20 can reduce the driver's anxiety.

[0048] Furthermore, when the cruise control device 20 performs the first process or the second process, the cruise control device 20 repeats the first control process until the cruise control device 20 performs the third process. As a result, as shown in steps S108 to S116, the cruise control device 20 repeats the first process or the second process until the anxiety level A becomes lower than the threshold value Ath, thereby repeatedly correcting the steering speed, braking timing, upper limit speed, and upper limit acceleration. In this way, by repeatedly correcting the steering speed, braking timing, upper limit speed, and upper limit acceleration, the driver's anxiety can be alleviated. Then, the cruise control device 20 switches the driving mode from the automatic driving mode MA to the manual driving mode MB after the anxiety level A becomes lower than the threshold value Ath. As a result, the cruise control device 20 can reduce the driver's anxiety.

[0049] Furthermore, in the cruise control device 20, the cruise control unit 24 performs the second control process (cruise control in the low-friction coefficient traveling mode) when the friction coefficient μ is lower than a second predetermined value (threshold μth1) in the automatic driving mode MA, and then performs the second control process when the friction coefficient μ is lower than a first predetermined value (threshold μth2). The second predetermined value (threshold μth1) is higher than the first predetermined value (threshold μth2). In the second control process, the cruise control unit 24 sets the steering speed, braking timing, upper limit speed, and upper limit acceleration based on the friction coefficient μ, as shown in steps S104 and S105. As a result, the cruise control device 20 first performs cruise control in the low-friction coefficient traveling mode, and then performs the first control process when the friction coefficient μ further decreases, thereby reducing the driver's anxiety. [effect] As described above, this embodiment includes an anxiety level estimation unit that estimates an anxiety level indicating the degree of anxiety felt by the vehicle driver based on detection results from a biometric information detection unit that detects biometric information of the vehicle driver; a road surface friction coefficient estimation unit that estimates a friction coefficient of the road surface on which the vehicle is traveling; a planned driving route analysis unit that calculates a straight line ratio indicating the ratio of the length of straight lines in the driving path of the planned driving route based on the planned driving route of the vehicle; and a driving control unit that operates in one of an autonomous driving mode and a manual driving mode and controls driving of the vehicle. In the autonomous driving mode, the driving control unit performs a first control process when the friction coefficient is lower than a first predetermined value. In this first control process, if the anxiety level is higher than a predetermined level and the straight line ratio is lower than a predetermined ratio, the driving control unit corrects the steering speed and braking timing and performs a first process to control driving of the vehicle in the autonomous driving mode using the corrected steering speed and braking timing. In the first control process, the driving control unit performs a second process of correcting the upper limit speed and upper limit acceleration when the anxiety level is higher than a predetermined level and the linear ratio R is higher than a predetermined ratio, and controlling the driving of the vehicle in autonomous driving mode using the corrected upper limit speed and upper limit acceleration. In addition, in the first control process, the driving control unit performs a third process of switching the driving mode from autonomous driving mode to manual driving mode when the anxiety level is lower than a predetermined level. This reduces the driver's anxiety.

[0050] In this embodiment, when the driving control unit performs the first processing or the second processing, it repeats the first control processing until it performs the third processing, thereby reducing the driver's anxiety.

[0051] In this embodiment, in the autonomous driving mode, the cruise control unit performs the second control process when the friction coefficient is lower than a first predetermined value, and then performs the second control process when the friction coefficient is lower than the second predetermined value. The second predetermined value is higher than the first predetermined value. Then, in the second control process, the cruise control unit sets the steering speed, braking timing, upper limit speed, and upper limit acceleration based on the friction coefficient. This can reduce the driver's anxiety.

[0052] Although the present technology has been described above by giving embodiments, the present technology is not limited to these embodiments and can be modified in various ways.

[0053] For example, in the above embodiment, the steering speed and braking timing are corrected in steps S111 to S113, but this is not limiting and other driving control parameters may also be corrected. Similarly, in steps S114 to S116, the upper limit speed and upper limit acceleration are corrected, but this is not limiting and other driving control parameters may also be corrected.

[0054] The effects described in this specification are merely examples and are not limiting, and other effects may also be present. [Explanation of symbols]

[0055] 1...vehicle, 11...external environment detection unit, 12...biometric information detection unit, 13...navigation unit, 20...driving control device, 21...anxiety level estimation unit, 22...road surface friction coefficient estimation unit, 23...planned driving route analysis unit, 24...driving control unit, MA...autonomous driving mode, MB...manual driving mode, A...anxiety level, Ath...threshold value, R...straight line ratio, Rth...threshold value, μ...friction coefficient, μth1, μth2...threshold values.

Claims

1. an anxiety level estimation unit that estimates an anxiety level indicating a degree of anxiety felt by a driver of a vehicle based on a detection result of a sensor that detects biological information of the driver; a friction coefficient estimation unit that estimates a friction coefficient of a road surface on which the vehicle travels; an analysis unit that calculates a straight line ratio indicating a ratio of a length of a straight line in a travel path of the planned travel route based on the planned travel route of the vehicle; a driving control unit that operates in one of an automatic driving mode and a manual driving mode and controls driving of the vehicle; Equipped with The traveling control unit In the automatic driving mode, a first control process is performed when the friction coefficient is lower than a first predetermined value; In the first control process, the traveling control unit a first process of correcting the steering speed to decrease the steering speed and correcting the brake timing to advance the brake timing when the degree of anxiety is higher than a predetermined degree and the straight line ratio is lower than a predetermined ratio, and performing driving control of the vehicle in the autonomous driving mode using the corrected steering speed and the corrected brake timing; a second process of correcting the upper limit speed to lower the upper limit speed and correcting the upper limit acceleration to lower the upper limit acceleration when the degree of anxiety is higher than the predetermined degree and the linear ratio is higher than the predetermined ratio, and performing driving control of the vehicle in the autonomous driving mode using the corrected upper limit speed and the corrected upper limit acceleration; a third process of switching the driving mode from the automatic driving mode to the manual driving mode when the anxiety level is lower than the predetermined level; Do Driving control device.

2. When the travel control unit has performed the first process or the second process, the travel control unit repeats the first control process until the travel control unit has performed the third process. The cruise control device according to claim 1 .

3. the traveling control unit, in the automatic driving mode, performs a second control process when the friction coefficient is lower than a second predetermined value, and thereafter performs the first control process when the friction coefficient is lower than the first predetermined value; the second predetermined value is higher than the first predetermined value; In the second control process, the traveling control unit sets the steering speed, the braking timing, the upper limit speed, and the upper limit acceleration based on the friction coefficient. The driving control device according to claim 1 or 2.

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