JP7534852B2 - Vehicle control device - Google Patents

Description

The present invention relates to a vehicle control device.

Conventionally, there is known technology that detects a preceding vehicle ahead of the vehicle and avoids a collision with the preceding vehicle (collision avoidance control) or controls driving to maintain a safe distance from the preceding vehicle (for example, Patent Document 1).

Patent No. 3349060

However, when the driver is in a relatively high tension state, there is a risk that the driver will operate the device more, for example by turning the steering wheel at a larger angle, than in a normal state when the driver's tension is relatively low. Therefore, even when driving control is being performed, it is desirable to perform driving control according to the driver's tension.

In view of these problems, the present invention aims to provide a vehicle control device that can perform appropriate driving control according to the driver's level of tension.

In order to solve the above problems, the vehicle control device of the present invention comprises a biosensor provided on a steering wheel that detects biometric information from the driver's hands gripping the steering wheel, a tension determination unit that determines the driver's level of tension based on the detection results by the biosensor, and a driving control unit that performs driving control based on the driver's level of tension, wherein the biosensor is a load sensor that detects the grip force with which the driver grips the steering wheel as the biometric information , and the tension determination unit learns in advance the grip force of the driver detected by the biosensor during steady driving as the driver's reference grip force, and determines the driver's level of tension based on whether the grip force detected by the biosensor during current driving is higher than the driver's reference grip force by a predetermined value or more.

In order to solve the above problem, the vehicle control device of the present invention comprises a biosensor provided on a steering wheel that detects biometric information from the driver's hands gripping the steering wheel, a tension determination unit that determines the driver's level of tension based on the detection result by the biosensor, a driving control unit that performs driving control based on the driver's level of tension, and an exterior environment recognition unit that identifies the driving lane in which the vehicle is traveling, wherein the biosensor is a load sensor that detects the grip force with which the driver grips the steering wheel as the biometric information, the tension determination unit determines whether the driver is in a tense state in which his/her level of tension is high or a normal state in which his/her level of tension is low, and when the driving control unit determines that the driver is in the tense state, it sets a control width narrower than the normal state on the inside of the driving lane as driving control that is safer than the normal state, and controls the vehicle to travel inside the control width.

The tension level determination unit may pre-learn the grip force of the driver detected by the biosensor during steady driving as the driver's reference grip force, and determine the driver's tension level based on whether the grip force detected by the biosensor during current driving is higher than the driver's reference grip force by a predetermined value or more .

The tension determination unit may determine whether the driver is in a high tension state or a normal state in which the driver is in a low tension state, and the driving control unit may perform driving control that is safer than the normal state when it is determined that the driver is in the high tension state.

The vehicle may be equipped with an exterior environment recognition unit that identifies the lane in which the vehicle is traveling, and when the driving control unit determines that the vehicle is in a tense state , the driving control unit may set a control width inside the lane in which the vehicle is traveling that is narrower than the normal state, and control the vehicle to travel inside the control width .

The vehicle may be provided with an external environment recognition unit that identifies a preceding vehicle, and the driving control unit may control the vehicle to maintain a greater distance to the preceding vehicle than in the normal state when the vehicle is determined to be in the tense state.

When it is determined that the vehicle is in the tense state, the driving control unit may control the vehicle speed to be slower than in the normal state.

The present invention makes it possible to perform appropriate driving control according to the driver's level of tension.

1 is a schematic diagram showing a schematic configuration of a vehicle on which a vehicle control device is mounted; FIG. 2 is a diagram illustrating a functional configuration of a control unit. FIG. 2 is a diagram illustrating a steering control. FIG. 13 is a diagram illustrating a tracking control. 13 is a flowchart showing the flow of a travel process.

The following describes in detail an embodiment of the present invention with reference to the attached drawings. The dimensions, materials, and other specific values shown in the embodiment are merely examples to facilitate understanding of the invention, and do not limit the present invention unless otherwise specified. In this specification and drawings, elements that have substantially the same function and configuration are given the same reference numerals to avoid duplicated explanations, and elements that are not directly related to the present invention are not illustrated.

Figure 1 is a schematic diagram showing the general configuration of a vehicle 1 equipped with a vehicle control device 100. As shown in Figure 1, the vehicle 1 is equipped with a vehicle control device 100. The vehicle control device 100 is equipped with an engine 10, a transmission 12, a power transmission system 14, wheels 16, an accelerator pedal 18, a brake pedal 20, a master cylinder 22, a hydraulic control unit 24, a brake 26, a steering wheel 28, a power steering mechanism 30, an accelerator sensor 32, a brake sensor 34, a steering angle sensor 36, a vehicle speed sensor 38, an acceleration sensor 40, a biosensor 42, an imaging device 44, an exterior environment recognition unit 46, and a control unit 48.

Vehicle 1 is an automobile that runs using power output from engine 10 as a drive source. Vehicle 1 may also be a hybrid automobile equipped with engine 10 and a motor as drive sources. Vehicle 1 may also be an electric automobile equipped with a motor as a drive source.

The power output from the engine 10 is transmitted to the wheels 16 via the transmission 12 and the power transmission system 14. The transmission 12 changes the torque and rotation speed of the power output from the engine 10 and transmits it to the power transmission system 14. The power transmission system 14 includes a differential gear and a drive shaft, and transmits the power transmitted from the transmission 12 to the wheels 16.

The accelerator pedal 18 accepts accelerator operation by the driver. The brake pedal 20 accepts brake operation by the driver.

The master cylinder 22 is connected to the brake pedal 20 via a booster (not shown). The master cylinder 22 is also connected to the brake 26 via a hydraulic control unit 24. The master cylinder 22 generates hydraulic pressure according to the amount of operation of the brake pedal 20. The hydraulic pressure generated by the master cylinder 22 is supplied to the brake 26 via the hydraulic control unit 24.

The hydraulic pressure control unit 24 can adjust the hydraulic pressure supplied to the brakes 26. Specifically, the hydraulic pressure control unit 24 has devices such as a pump and a control valve, and by controlling the operation of these devices, the brake hydraulic pressure of the brakes 26 is controlled. This controls the braking force applied to the wheels 16.

The brakes 26 apply braking force to the wheels 16 using hydraulic pressure supplied from the hydraulic control unit 24.

The steering wheel 28 receives steering input from the driver. The steering wheel 28 is connected to the steering wheels (wheels) via a steering mechanism (not shown). The steering mechanism changes the direction of the wheels 16 according to the rotation of the steering wheel 28.

The power steering mechanism 30 assists the driver in steering using the steering wheel 28. For example, the power steering mechanism 30 has an electric motor capable of outputting power to rotate the steering wheel 28. In this case, assistance to the driver's steering is achieved by driving the electric motor.

The accelerator sensor 32 detects the amount of operation of the accelerator pedal 18, i.e., the amount of depression. The brake sensor 34 detects the amount of operation of the brake pedal 20, i.e., the amount of depression. The steering angle sensor 36 detects the steering angle indicating the rotation angle of the steering wheel 28. The vehicle speed sensor 38 detects the speed (vehicle speed) of the vehicle 1. The acceleration sensor 40 detects the acceleration of the vehicle 1.

The biosensor 42 is, for example, a strain gauge type or voltage type load sensor. The biosensor 42 is provided at a position on the steering wheel 28 where the driver grips the steering wheel 28. The biosensor 42 detects bioinformation from the driver's hands gripping the steering wheel 28. Specifically, the biosensor 42 detects the force with which the driver grips the steering wheel 28 (grip force).

For example, two imaging devices 44 are provided. The two imaging devices 44 are arranged spaced apart from each other in the approximately horizontal direction. The imaging devices 44 capture images of the environment outside the vehicle 1 in the traveling direction of the vehicle 1. Specifically, the imaging devices 44 capture images of objects present in the detection area in front of the vehicle 1, and continuously generate luminance images that include at least luminance information.

The vehicle exterior environment recognition unit 46 derives parallax information based on the luminance image generated by the imaging device 44, and generates a distance image including the parallax information. The vehicle exterior environment recognition unit 46 identifies the type of specific object that the target in the detection area is based on the luminance image and the distance image. The specific object may be, but is not limited to, a preceding vehicle, a white line on the road, a traffic light, etc. In this way, the vehicle exterior environment recognition unit 46 recognizes the vehicle exterior environment in the traveling direction of the vehicle 1.

The vehicle exterior environment recognition unit 46 also identifies the driving lane based on the positional relationship between the identified specific object and the vehicle 1. Specifically, when there is a specific object (such as a white line or a guard rail) on the left or right of the vehicle 1 whose distance from the vehicle 1 is within a predetermined range, the vehicle exterior environment recognition unit 46 identifies the area between these specific objects as the driving lane.

The control unit 48 is composed of a semiconductor integrated circuit including a central processing unit (CPU), a ROM in which programs and the like are stored, and a RAM as a work area.

Figure 2 is a diagram explaining the functional configuration of the control unit 48. As shown in Figure 2, the control unit 48 executes a program to function as a data acquisition unit 50, a manual driving control unit 52, an automatic driving control unit (travel control unit) 54, and a tension level determination unit 56.

The data acquisition unit 50 is connected to the accelerator sensor 32, the brake sensor 34, the steering angle sensor 36, the vehicle speed sensor 38, the acceleration sensor 40, and the biosensor 42. The data acquisition unit 50 acquires the detection results of these sensors at predetermined intervals.

The data acquisition unit 50 is also connected to the vehicle exterior environment recognition unit 46. The data acquisition unit 50 acquires information identified by the vehicle exterior environment recognition unit 46.

The vehicle 1 is provided with a manual driving mode and an automatic driving mode as driving modes. For example, the vehicle 1 is provided with an input device (e.g., a switch or a button) for selecting whether the manual driving mode or the automatic driving mode is to be executed. The driver can select the manual driving mode or the automatic driving mode by operating the input device.

The manual driving mode is a driving mode in which the acceleration/deceleration and steering angle of the vehicle 1 are controlled according to the driver's driving operations (i.e., accelerator operation, brake operation, and steering operation). The automatic driving mode is a driving mode in which the acceleration/deceleration and steering angle of the vehicle 1 are automatically controlled without depending on the driver's driving operations.

When the manual driving mode is set, the manual driving control unit 52 controls each device so that the acceleration/deceleration and steering angle correspond to the driving operation of the driver. Specifically, the manual driving control unit 52 controls the engine 10 so that power is output according to the amount of depression of the accelerator pedal 18. The manual driving control unit 52 also controls the hydraulic control unit 24 (brake 26) so that a braking force corresponding to the amount of depression of the brake pedal 20 is applied. The manual driving control unit 52 also controls the power steering mechanism 30 so that a torque in a direction that matches the rotation direction of the steering wheel 28 is applied to the steering wheel 28.

When the automatic driving control unit 54 is set to the automatic driving mode, it performs driving control, i.e., adaptive cruise control. For example, when there is no preceding vehicle ahead of the vehicle 1, the automatic driving control unit 54 performs constant speed control to control the engine 10 so that the vehicle 1 travels at a vehicle speed preset by the driver. When there is a preceding vehicle ahead of the vehicle 1, the automatic driving control unit 54 performs following control to control the engine 10 and the hydraulic control unit 24 (brakes 26) so that the vehicle follows the preceding vehicle while maintaining a distance to the preceding vehicle. When the driving lane is specified, the automatic driving control unit 54 performs steering control to control the power steering mechanism 30 so that the vehicle 1 does not deviate from the driving lane.

The tension level determination unit 56 determines the tension level of the driver based on the detection results of the biosensor 42. Specifically, the tension level determination unit 56 learns the driver's grip force detected by the biosensor 42 during steady driving where the vehicle speed is within a predetermined range (e.g., 30 km/h to 50 km/h) and the acceleration is equal to or lower than a predetermined value, as a reference grip force.

The tension determination unit 56 determines the driver's level of tension by comparing the driver's grip force detected by the biosensor 42 with a reference grip force, since the grip force increases as the driver's level of tension increases. For example, if the driver's grip force is higher than the reference grip force by a predetermined value or more, the tension determination unit 56 determines that the driver is in a highly tense state. On the other hand, if the driver's grip force is not higher than the reference grip force plus a predetermined value, the tension determination unit 56 determines that the driver is in a normal state with a low level of tension.

The tension determination unit 56 may determine that the driver is in a high tension state when the ratio of the driver's grip force to the reference grip force is equal to or greater than a predetermined threshold, and may determine that the driver is in a low tension normal state when the ratio of the driver's grip force to the reference grip force is less than the predetermined threshold. In other words, the tension determination unit 56 may determine whether the driver is in a high tension state or a low tension normal state.

The driver of vehicle 1 experiences changes in tension depending on changes in the environment and his/her psychological state. For example, when driving at night, when the weather is bad, or when vehicle 1 is traveling at high speed, the driver is likely to be in a state of high tension compared to normal conditions.

When the driver is in a relatively high state of tension, there is a risk that the driver will operate a greater amount of equipment, for example, by turning the steering wheel at a greater angle, than in a normal state where the driver's level of tension is relatively low.

The autonomous driving control unit 54 changes the control amount (control method) of the constant speed control, steering control, and tracking control in the autonomous driving mode based on the driver's level of tension, i.e., whether the driver is in a normal state or a tense state. If the autonomous driving control unit 54 determines that the driver is in a normal state, it controls the driving of the vehicle 1 in the first autonomous driving mode as the autonomous driving mode. Furthermore, if the autonomous driving control unit 54 determines that the driver is in a tense state, it controls the driving of the vehicle 1 in the second autonomous driving mode, which is considered safer than the first autonomous driving mode.

Figure 3 is a diagram explaining steering control. Figure 3(a) is a diagram explaining steering control in the first automatic driving mode. Figure 3(b) is a diagram explaining steering control in the second automatic driving mode.

As shown in FIG. 3(a), when the autonomous driving control unit 54 is in the first autonomous driving mode, when the driving lane 60 is identified, it sets a control width W2 that is inside both ends of the driving lane 60 and narrower than the width W1 of the driving lane 60. The control width W2 may be set by multiplying the width W1 of the driving lane 60 by a predetermined value less than 1, or may be set to a width that is a predetermined distance away from both ends of the driving lane 60. The center of the control width W2 in the width direction is set to coincide with or approximately coincide with the center of the width W1 of the driving lane.

When the vehicle 1 deviates outside the control width W2 in the first automatic driving mode, the automatic driving control unit 54 performs steering control to return the vehicle 1 to within the control width W2. On the other hand, even if the driver operates the steering wheel 28, the automatic driving control unit 54 does not perform steering control unless the vehicle 1 deviates from the control width W2. Therefore, even in the first automatic driving mode, the driver can move the vehicle 1 within the control width W2 by operating the steering wheel 28.

As shown in FIG. 3(b), in the second automatic driving mode, when the automatic driving control unit 54 identifies the driving lane 60, it sets a control width W3 that is inside both ends of the control width W2 and is narrower than the control width W2. The control width W3 may be set by multiplying the width W1 of the driving lane 60 by a value smaller than that in the first automatic driving mode, or may be set to a width that is further away from both ends of the driving lane 60 than in the first automatic driving mode. The center of the control width W3 in the width direction is set to coincide with or approximately coincide with the center of the width W1 of the driving lane 60 in the width direction.

When the vehicle 1 deviates outside the control width W3 in the second automatic driving mode, the automatic driving control unit 54 performs steering control to return the vehicle 1 to within the control width W3. On the other hand, even if the driver operates the steering wheel 28, the automatic driving control unit 54 does not perform steering control unless the vehicle 1 deviates from the control width W3.

In this way, when the driver is in a state of high tension, the automatic driving control unit 54 controls the vehicle 1 to travel closer to the inside of the driving lane 60 than in the normal state. This allows the vehicle control device 100 to reduce the vehicle 1's departure from the driving lane 60 even if the amount of change in the steering wheel 28 becomes large when the driver is in a state of tension. On the other hand, the vehicle control device 100 can tolerate a certain degree of operation of the steering wheel 28 when in the normal state. In this way, the vehicle control device 100 can perform appropriate driving control according to the driver's level of tension.

Figure 4 is a diagram explaining the tracking control. Figure 4(a) is a diagram explaining the tracking control in the first automatic driving mode. Figure 3(b) is a diagram explaining the tracking control in the second automatic driving mode.

As shown in FIG. 4(a), in the first automatic driving mode, when the preceding vehicle 62 is identified, the automatic driving control unit 54 sets a control distance L1 from the vehicle 1 to the preceding vehicle 62. The control distance L1 may be set according to the vehicle speed or may be a constant value.

Then, when the autonomous driving control unit 54 is in the first autonomous driving mode, it performs following control so that the distance to the preceding vehicle 62 becomes the control distance L1.

On the other hand, as shown in FIG. 4(b), in the second automatic driving mode, when a preceding vehicle 62 is identified, the automatic driving control unit 54 sets the control distance L2 from the vehicle 1 to the preceding vehicle 62 to a distance longer than the control distance L1. Note that the control distance L2 may be set by multiplying the control distance L1 by a value greater than 1, or may be set by adding a predetermined value to the control distance L1.

Then, when the autonomous driving control unit 54 is in the second autonomous driving mode, it performs following control so that the distance to the preceding vehicle 62 becomes the control distance L2.

In this way, the automatic driving control unit 54 maintains a greater distance to the preceding vehicle 62 than in a normal state when the driver is in a tense state, which is considered to be tense. This allows the vehicle control device 100 to make it difficult to get close to the preceding vehicle 62 when the driver is in a tense state, and makes it possible to prevent a collision with the preceding vehicle 62 even if the accelerator pedal 18 is suddenly pressed for some reason. On the other hand, when the vehicle control device 100 is in a normal state, it can maintain an optimal control distance L1. In this way, the vehicle control device 100 can perform appropriate driving control according to the driver's level of tension.

In addition, in the first automatic driving mode, the automatic driving control unit 54 performs steady-state control at a vehicle speed preset by the driver when the preceding vehicle 62 has not been identified. On the other hand, in the second automatic driving mode, the automatic driving control unit 54 performs steady-state control to maintain a vehicle speed slower than the vehicle speed preset by the driver when the preceding vehicle 62 has not been identified. This allows the vehicle control device 100 to suppress anxiety caused to the driver when the driver is in a tense state.

As described above, the vehicle control device 100 performs driving control based on the driver's level of tension. Specifically, when the vehicle control device 100 determines that the driver is in a state of tension, the vehicle control device 100 performs driving control that is considered safer than in a normal state. This allows the vehicle control device 100 to perform appropriate driving control according to the driver's level of tension.

Figure 5 is a flowchart showing the flow of the driving process. As shown in Figure 5, the automatic driving control unit 54 determines whether the automatic driving mode is set (S1). If the automatic driving mode is not set (NO in S1), that is, if the manual driving mode is set, the manual driving control unit 52 controls each device in the manual driving mode (S2).

On the other hand, if the automatic driving mode is set (YES in S1), the tension level determination unit 56 determines the driver's tension level based on the biometric information from the biometric sensor 42 (S3). Then, the automatic driving control unit 54 determines whether the driver's tension level is in a tense state (S4).

If the vehicle is in a tense state (YES in S4), the automatic driving control unit 54 performs driving control in the second automatic driving mode (S5). On the other hand, if the vehicle is not in a tense state (NO in S4), i.e., if the vehicle is in a normal state, the automatic driving control unit 54 performs driving control in the first automatic driving mode (S6).

The above describes a preferred embodiment of the present invention with reference to the attached drawings, but it goes without saying that the present invention is not limited to the above-mentioned embodiment, and various modifications and alterations within the scope of the claims also fall within the technical scope of the present invention.

For example, in the above embodiment, the driver's grip strength is detected as biometric information. However, the biometric information may be the temperature of the driver's hands, pulse, etc.

In addition, the processes described in this specification using flowcharts do not necessarily have to be performed in the order shown in the flowcharts. In addition, additional processing steps may be employed, and some processing steps may be omitted.

The present invention can be used in vehicle control devices.

1 Vehicle 46 Vehicle exterior environment recognition unit 54 Automatic driving control unit (driving control unit)
56 Tension level determination unit 100 Vehicle control device

Claims (6)

a biosensor provided on the steering wheel for detecting biometric information from the driver's hands gripping the steering wheel;
a tension level determination unit that determines a tension level of the driver based on a detection result by the biosensor;
A driving control unit that performs driving control based on the driver's tension level;
Equipped with
the biosensor is a load sensor,
The load sensor detects, as the biometric information, a gripping force of the driver gripping the steering wheel,
The tension level determination unit is
The grip force of the driver detected by the biosensor during steady driving is learned in advance as a reference grip force of the driver,
A vehicle control device that determines a degree of tension of a driver based on whether the grip force detected by the biosensor during a current drive is higher than a reference grip force of the driver by a predetermined value or more . a biosensor provided on the steering wheel for detecting biometric information from the driver's hands gripping the steering wheel;
a tension level determination unit that determines a tension level of the driver based on a detection result by the biosensor;
A driving control unit that performs driving control based on the driver's tension level;
An exterior environment recognition unit that identifies a lane in which the vehicle is traveling;
Equipped with
the biosensor is a load sensor,
The load sensor detects, as the biometric information, a gripping force of the driver gripping the steering wheel,
The tension level determination unit is
determining whether the driver is in a high tension state or a low tension normal state;
The traveling control unit is
When the vehicle is determined to be in a tense state, a vehicle control device sets a control width narrower than the normal state on the inside of the driving lane as driving control that is safer than the normal state, and controls the vehicle to drive inside the control width. The tension level determination unit is
determining whether the driver is in a high tension state or a low tension normal state;
The traveling control unit is
The vehicle control device according to claim 1 , wherein, when it is determined that the vehicle is in the tense state, a driving control that is safer than the normal state is performed. An exterior environment recognition unit that identifies the lane in which the vehicle is traveling,
The traveling control unit is
The vehicle control device according to claim 3 , wherein when it is determined that the vehicle is in the tense state, a control width narrower than that in the normal state is set on the inside of the driving lane, and the vehicle is controlled so as to travel within the control width. An external environment recognition unit is provided to identify a preceding vehicle,
The traveling control unit is
The vehicle control device according to claim 2 , further comprising: when it is determined that the vehicle is in the tense state, control is performed so that a state in which a distance to the preceding vehicle is maintained greater than in the normal state. The traveling control unit is
The vehicle control device according to claim 2 , further comprising: a control unit configured to control a vehicle speed to be slower than that in the normal state when it is determined that the vehicle is in the tense state.

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