JP7347193B2 - Driving support device - Google Patents

Description

The present invention relates to a driving support device.

Conventionally, Japanese Patent Application Publication No. 2013-218429 is known as a technical document regarding driving support devices. This publication states that in a driving support system that supports deceleration of a vehicle when the vehicle is predicted to stop at a predetermined stop position, if the distance to the stop position and the vehicle speed do not satisfy predetermined conditions, deceleration support ( It is shown that deceleration support is not performed if predetermined conditions are met.

Japanese Patent Application Publication No. 2013-218429

By the way, while the vehicle deceleration support is being performed for a traffic light with a red light, it is conceivable that the traffic light switches to a green light. Even when a traffic light changes to green, traffic participants, such as pedestrians who are crossing the street, may not be able to respond immediately to the change in the traffic light. In such a case, if the deceleration support is suddenly terminated due to the traffic light switching to green, there is a risk that the driver will be required to perform a brake operation due to the termination of the deceleration support.

One aspect of the present invention is a driving support device that supports deceleration of a vehicle in response to a traffic light in front of the vehicle, which includes: a traffic light state determination unit that determines whether the traffic light is in a passing permission state; Start condition determination for determining whether a preset deceleration support start condition is satisfied based at least on the distance between the own vehicle and the traffic light when the state determination unit determines that the traffic light is not in a passing permission state. and when the start condition determination unit determines that the deceleration support start condition is satisfied, the vehicle starts deceleration support for the traffic signal, and the traffic light status determination unit determines that the traffic light is in a passing permission state, or a driving support unit that does not start deceleration support for the host vehicle at the traffic light if the start condition determination unit does not determine that the deceleration support start condition is satisfied, and the driving support unit is configured to perform deceleration support for the traffic light while the deceleration support is being executed. If the traffic light state determining unit determines that the traffic light is in a passing permission state, deceleration support is temporarily continued for a preset time.

According to one aspect of the present invention, when it is determined that the traffic light is in a passing permission state while deceleration support is being executed for the traffic light, deceleration support is temporarily continued for a set time, so sudden deceleration support is not performed. It is possible to suppress the necessity of the driver's brake operation due to the termination.

FIG. 1 is a block diagram showing a driving support device according to an embodiment. 12 is a flowchart illustrating an example of a process for starting deceleration support for traffic lights. (a) It is a flowchart which shows an example of a traffic light switching process during execution of deceleration support. (b) It is a flowchart which shows an example of the temporary continuation process of deceleration support.

Embodiments of the present invention will be described below with reference to the drawings.

The driving support device 100 shown in FIG. 1 is a device that is mounted on a vehicle such as a passenger car (self-vehicle) and supports the driving of the own vehicle by a driver. The driving support device 100 provides deceleration support for the own vehicle under predetermined conditions when a deceleration target such as a preceding vehicle or a traffic light is detected in front of the own vehicle. A deceleration target is a target for deceleration support. Targets for deceleration include preceding vehicles, traffic lights, and stop lines. Targets for deceleration may include pedestrians, bicycles, etc. in addition to the vehicle in front, and in addition to traffic lights and stop lines, objects to be decelerated include curves, crosswalks, fallen objects, construction items, structures, etc. It's okay.

Deceleration support is driving support that decelerates the own vehicle to a preset target vehicle speed. The target vehicle speed is not particularly limited, and may be 0 km/h or 10 km/h. The target vehicle speed may be determined depending on the type of object to be decelerated. When the deceleration target is a traffic light, the target vehicle speed for deceleration support may be changed depending on the lighting state of the traffic light (lighting state of a green light, yellow light, red light, etc.). When the object to be decelerated is a moving object such as a preceding vehicle, the target vehicle speed is not limited to the speed of the own vehicle, but may be the relative speed between the own vehicle and the object to be decelerated.

[Configuration of driving support device]
The configuration of a driving support device 100 according to an embodiment will be described with reference to the drawings. As shown in FIG. 1, the driving support device 100 includes a driving support ECU (Electronic Control Unit) 10 that comprehensively manages the device. The driving support ECU 10 is an electronic control unit that includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and the like. The driving support ECU 10 realizes various functions by, for example, loading a program stored in a ROM into a RAM and executing the program loaded into the RAM by a CPU. The driving support ECU 10 may be composed of a plurality of electronic units.

The driving support ECU 10 is connected to an external sensor 1, an internal sensor 2, an HMI [Human Machine Interface] 3, and an actuator 4.

The external sensor 1 is a detection device that detects the surrounding situation of the host vehicle. The external sensor 1 includes at least one of a camera and a radar sensor. A camera is an image capturing device that captures an image of the external situation of the own vehicle. The camera is provided, for example, on the back side of the windshield of the own vehicle, and images the area in front of the own vehicle. The camera transmits imaged information regarding the external situation of the host vehicle to the driving support ECU 10. The camera may be a monocular camera or a stereo camera.

A radar sensor is a detection device that detects objects around the host vehicle using radio waves (for example, millimeter waves) or light. Radar sensors include, for example, millimeter wave radar or lidar (LIDAR: Light Detection and Ranging). A radar sensor detects an object by transmitting radio waves or light around the vehicle and receiving radio waves or light reflected by the object. The radar sensor transmits information about the detected object to the driving support ECU 10. Objects include fixed obstacles such as guardrails and buildings, as well as moving obstacles such as pedestrians, bicycles, and other vehicles.

The internal sensor 2 is a detection device that detects the running state of the own vehicle. Internal sensor 2 includes a vehicle speed sensor, an acceleration sensor, and a yaw rate sensor. The vehicle speed sensor is a detector that detects the speed of the own vehicle. As the vehicle speed sensor, for example, a wheel speed sensor is used, which is installed on the wheels of the own vehicle or on a drive shaft that rotates integrally with the wheels, and detects the rotational speed of the wheels. The vehicle speed sensor transmits detected vehicle speed information (wheel speed information) to the driving support ECU 10.

The acceleration sensor is a detector that detects the acceleration of the own vehicle. The acceleration sensor includes, for example, a longitudinal acceleration sensor that detects the longitudinal acceleration of the own vehicle, and a lateral acceleration sensor that detects the lateral acceleration of the own vehicle. For example, the acceleration sensor transmits acceleration information of the own vehicle to the driving support ECU 10. The yaw rate sensor is a detector that detects the yaw rate (rotational angular velocity) around the vertical axis of the center of gravity of the host vehicle. For example, a gyro sensor can be used as the yaw rate sensor. The yaw rate sensor transmits detected yaw rate information of the host vehicle to the driving support ECU 10.

The HMI 3 is an interface for inputting and outputting information between the driving support device 100 and the driver. The HMI 3 includes, for example, a display and speakers. The HMI 3 outputs images from a display and audio from a speaker in response to control signals from the driving support ECU 10. The display may be a HUD (Head Up Display).

The actuator 4 is a device used to control the own vehicle. The actuator 4 includes at least a drive actuator and a brake actuator. Actuator 4 may include a steering actuator. The drive actuator controls the amount of air supplied to the engine (throttle opening) according to a control signal from the driving support ECU 10, and controls the driving force of the own vehicle. Note that when the host vehicle is a hybrid vehicle, in addition to the amount of air supplied to the engine, a control signal from the driving support ECU 10 is input to the motor as a power source to control the driving force. When the host vehicle is an electric vehicle, a control signal from the driving support ECU 10 is input to a motor as a power source to control the driving force. The motor serving as the power source in these cases constitutes the actuator 4.

The brake actuator controls the brake system according to a control signal from the driving support ECU 10, and controls the braking force applied to the wheels of the own vehicle. As the brake system, for example, a hydraulic brake system can be used. The steering actuator controls driving of an assist motor that controls steering torque in the electric power steering system in accordance with a control signal from the driving support ECU 10. Thereby, the steering actuator controls the steering torque of the host vehicle.

Next, the functional configuration of the driving support ECU 10 will be explained. As shown in FIG. 1, the driving support ECU 10 includes a deceleration target detection section 11, a relative situation recognition section 12, a traffic light state determination section 13, a start condition determination section 14, a driving support section 15, and a notification section 16. . Note that some of the functions of the driving support ECU 10 described below may be executed in a server that can communicate with the host vehicle.

Based on the detection result of the external sensor 1, the deceleration target detection unit 11 determines whether or not a deceleration target that is a deceleration target ahead of the host vehicle is detected. The deceleration target is the deceleration target that is first detected in a state where deceleration support is not being executed. The deceleration target detection unit 11 recognizes the type of deceleration target (type of preceding vehicle, traffic light, stop line, etc.). The deceleration target detection unit 11 detects the deceleration target and determines the type by performing pattern matching using image patterns for each type stored in advance, based on an image taken in front of the own vehicle by a camera, for example. Recognize. The deceleration target detection unit 11 may recognize the type of deceleration target based on object information from a radar sensor.

The relative situation recognition unit 12 recognizes the relative situation between the host vehicle and the object to be decelerated. The relative situation includes at least the distance between the own vehicle and the object to be decelerated (the distance in the longitudinal direction or the traveling direction of the own vehicle). The relative situation may include the relative speed between the own vehicle and the object to be decelerated.

The relative situation recognition unit 12 recognizes the relative situation between the host vehicle and the object to be decelerated, based on the detection result of the external sensor 1, for example. When the object to be decelerated is a vehicle that can communicate with the own vehicle, the relative situation recognition unit 12 may recognize the relative situation between the own vehicle and the object to be decelerated using information acquired through the inter-vehicle communication. The relative situation recognition unit 12 may recognize the relative speed between the host vehicle and the deceleration target, for example, based on the speed of the deceleration target obtained through inter-vehicle communication and the speed of the host vehicle.

For example, when the deceleration target detection unit 11 recognizes a traffic light as a deceleration target, the traffic light state determination unit 13 determines whether the traffic light is in a passing permission state based on the detection result of the external sensor 1 (for example, an image captured by a camera). Determine whether Here, the passage permission state means a state in which passage is permitted in the traveling direction of the own vehicle's travel lane. The direction of travel of the own vehicle in the travel lane can be recognized from image recognition of an arrow (arrow painted on the road surface) shown on the road surface of the travel lane or image recognition of a sign indicating the travel direction of the travel lane. The traveling direction of the driving lane of the own vehicle may be recognized from the position of the own vehicle and map information (map information having traveling direction information for each lane).

For example, if the traffic light is a traffic light with a left-turn arrow and the lane in which the own vehicle is traveling is a left-turn exclusive lane, the traffic light state determination unit 13 determines that the vehicle is in a passing permission state when the left-turn arrow is lit. The traffic light state determining unit 13 does not determine that the vehicle is in a pass-permitted state even if the left turn arrow is lit when the vehicle is traveling in a straight-ahead lane. The traffic light state determining unit 13 determines that the vehicle is in a passing permission state when the traffic light is green or when the straight ahead arrow of the traffic light is lit when the vehicle is traveling in a straight-ahead lane.

When the traffic light state determining unit 13 cannot recognize the direction of travel of the own vehicle, the traffic light state determining unit 13 determines whether or not the traffic light is in a passing permission state based on the lighting state of the traffic light. In this case, the traffic light state determining unit 13 may determine that the traffic light is in the passing permission state when the lighting state of the traffic light is a green light. Hereinafter, a state in which the traffic light prohibits the vehicle from passing through the lane in which the own vehicle is traveling will be referred to as a "passing prohibited state", and a state in the middle of transition from a passing permitted state to a passing prohibited state will be referred to as a "transition state". An example of the prohibited passage state is a red light. An example of the transition state is a yellow light.

The start condition determining unit 14 determines whether a deceleration support start condition for the deceleration target is satisfied. The deceleration support start condition is a condition set in advance for use in determining whether to start deceleration support. The start condition determination unit 14 determines whether the deceleration support start condition is satisfied based on at least the distance between the own vehicle and the object to be decelerated.

The deceleration support start conditions are changed depending on the type of deceleration target. For example, when the type of deceleration target is a preceding vehicle, the start condition determination unit 14 determines whether the deceleration support start condition for the preceding vehicle is satisfied based on the relative situation between the own vehicle and the deceleration target (for example, TTC). judge.

Specifically, a case where the object to be decelerated is a traffic light will be explained. When the traffic light state determination unit 13 determines that the traffic light is not in a passing permission state, the start condition determination unit 14 determines whether deceleration support start conditions for the traffic light are satisfied based at least on the distance between the own vehicle and the traffic light. Determine. Note that one of the conditions for starting deceleration support may be that the traffic light is not in a passing permission state.

The start condition determination unit 14 determines that the deceleration support start condition is satisfied, for example, when the distance between the vehicle and the traffic light is less than the distance threshold. The distance threshold is a threshold of a preset value. Here, as the position of the traffic light used to calculate the distance between the own vehicle and the traffic light, the position of the traffic light itself may be used, or the position of a stop line in front of the traffic light may be used. When the external sensor 1 cannot detect the stop line in front of the traffic light due to rubbing of the white line of the stop line, etc., the start condition determination unit 14 assumes that the stop line exists at a certain distance before the traffic light. It may also be used to calculate the distance between the host vehicle and the traffic light.

Further, the start condition determination unit 14 may determine the deceleration support start condition using the TTC [Time To Collusion] between the host vehicle and the traffic light instead of the distance between the host vehicle and the traffic light. For example, when the TTC between the own vehicle and the traffic light is less than the TTC threshold, the start condition determination unit 14 determines that the deceleration support start condition for the traffic light is satisfied. TTC is calculated by dividing the distance between the own vehicle and the traffic light by the vehicle speed of the own vehicle. The TTC threshold is a threshold of a preset value.

When the start condition determination unit 14 determines that the deceleration support start condition is satisfied, the driving support unit 15 starts deceleration support as driving support for the host vehicle. The driving support unit 15 supports the deceleration of the own vehicle by transmitting a control signal to the actuator 4 . The driving support unit 15 provides deceleration support so that the own vehicle decelerates to a preset target speed, based on, for example, the distance between the own vehicle and the deceleration target and the speed of the own vehicle.

The driving support unit 15 executes deceleration support using, for example, a target vehicle speed that is preset according to the type of object to be decelerated. When the type of deceleration target is a traffic light in a prohibited state, the driving support unit 15 sets the target vehicle speed for deceleration support to the target vehicle speed for stopping (for example, 0 km/h). Note that the target vehicle speed for stopping does not necessarily have to be 0 km/h, and may be a value around 0 km/h.

On the other hand, the driving support unit 15 does not start deceleration support if the start condition determination unit 14 does not determine that the deceleration support start condition is satisfied. In addition, when the deceleration target is a traffic light, the driving support unit 15 does not start deceleration support when the traffic light state determining unit 13 determines that the traffic light is in a passing permission state.

The driving support unit 15 ends the deceleration support when the driver performs an operation to cancel the deceleration support while the deceleration support is being executed. The deceleration support canceling operation includes, for example, turning off the driving support function, operating the accelerator pedal more than a certain amount, or operating the steering wheel more than a certain amount.

Further, when the own vehicle is stopped due to deceleration support, the driving support unit 15 ends the deceleration support. The driving support unit 15 terminates the deceleration support when the deceleration support start conditions are no longer satisfied (for example, when the distance between the host vehicle and the preceding vehicle increases due to the acceleration of the preceding vehicle). Good too. Note that the conditions for ending deceleration support may be different from the conditions for starting deceleration support.

When the deceleration target is a traffic light, the driving support unit 15 determines that the traffic light is in a pass-permitted state by the traffic light state determination unit 13 during execution of deceleration support (the traffic light changes from a pass-prohibited state or a transition state to a pass-permitted state). state), it is determined whether the arrival time to the traffic light is less than a time threshold. The time required to reach the traffic light is calculated based on the distance between the vehicle and the traffic light and the speed of the vehicle. The time required to reach the traffic light may be calculated based on the deceleration of the own vehicle. The time threshold is a threshold of a preset value.

If the driving support unit 15 determines that the time taken to reach the traffic light is not less than the time threshold, the driving support unit 15 ends the deceleration support. On the other hand, if the driving support unit 15 determines that the time taken to reach the traffic light is less than the time threshold, the driving support unit 15 temporarily continues deceleration support for a set time. The set time is a preset time. The setting time is not particularly limited, but may be 3 seconds or 5 seconds. Temporary continuation of deceleration support means to temporarily continue the content of deceleration support that is performed when it is determined that the traffic light is not in a passing permission state.

The driving support unit 15 determines whether or not a set time has elapsed during temporary continuation of deceleration support. If the driving support unit 15 determines that the set time has elapsed, it ends the deceleration support.

The notification unit 16 notifies the driver of the own vehicle regarding driving support. The notification unit 16 sends a control signal to the HMI 3 to provide notification including at least one of the image output of the display and the audio output of the speaker. The notification unit 16 may notify the start of deceleration support when the start condition determination unit 14 determines that the deceleration support start condition is satisfied. The deceleration support start notification is a notification for informing the driver of the start of deceleration support. The contents of the deceleration support start notification are not particularly limited.

When temporarily continuing deceleration support, the notification unit 16 may notify the driver that deceleration support will be temporarily continued. In this case, the notification unit 16 may notify the driver that the traffic light has entered the passing permission state, or may notify the driver of the remaining time for temporary continuation of deceleration support.

[Processing of driving support device]
Next, the processing of the driving support device 100 of this embodiment will be explained with reference to the drawings. Here, a case where the deceleration target is a traffic light will be explained. FIG. 2 is a flowchart illustrating an example of a process for starting deceleration support for traffic lights. This deceleration support start process is performed when a traffic light as a deceleration target is detected when the driving support function is turned on.

As shown in FIG. 2, the driving support ECU 10 of the driving support device 100 causes the deceleration target detection unit 11 to recognize a traffic light in S10. The deceleration target detection unit 11 recognizes the lighting state of the traffic light based on the detection result of the external sensor 1 (for example, an image captured by a camera). At this time, the deceleration target detection unit 11 may recognize the traveling direction of the own vehicle's travel lane based on the detection result of the external sensor 1 (for example, an image captured by a camera).

In S12, the driving support ECU 10 uses the traffic light state determination unit 13 to determine whether the traffic light is not in a passing permission state. The traffic light state determination unit 13 performs the above determination based on, for example, the lighting state of the traffic light and the traveling direction of the vehicle's travel lane. When the driving support ECU 10 determines that the traffic light is not in a passing permission state (S12: YES), the process proceeds to S14. When the driving support ECU 10 determines that the traffic light is in a passing permission state (S12: NO), it ends the current process. After that, the driving support ECU 10 repeats the process from S10 again after a certain period of time has elapsed.

In S14, the driving support ECU 10 uses the start condition determination unit 14 to determine whether the deceleration support start condition for the traffic light is satisfied. The start condition determining unit 14 makes the above determination based on at least the distance between the own vehicle and the traffic light. When the driving support ECU 10 determines that the deceleration support start condition for the traffic light is satisfied (S14: YES), the process proceeds to S16. If the deceleration support start condition for the traffic light is satisfied (S14: NO), the driving support ECU 10 ends the current process. After that, the driving support ECU 10 repeats the process from S10 again after a certain period of time has elapsed.

In S16, the driving support ECU 10 causes the driving support unit 15 to start deceleration support for the traffic light. The driving support unit 15 supports the deceleration of the own vehicle by transmitting a control signal to the actuator 4 .

Next, FIG. 3(a) is a flowchart showing an example of a traffic light switching process during execution of deceleration support. The traffic light switching process is performed during execution of deceleration support for the traffic light.

As shown in FIG. 3(a), in S20, the driving support ECU 10 uses the traffic light state determination unit 13 to determine whether the traffic light has been switched to the pass permission state. The traffic light state determination unit 13 performs the above determination based on, for example, the lighting state of the traffic light and the traveling direction of the vehicle's travel lane. When the driving support ECU 10 determines that the traffic light has switched to the passing permission state (S20: YES), the process proceeds to S22. If the driving support ECU 10 does not determine that the traffic light has switched to the pass permission state (S20: NO), it ends the current process. Thereafter, if the deceleration support for the traffic light continues, the driving support ECU 10 repeats the process from S20 again after a certain period of time has elapsed.

In S22, the driving support ECU 10 uses the driving support unit 15 to determine whether the arrival time to the traffic light is less than a time threshold. When the driving support ECU 10 determines that the arrival time to the traffic light is less than the time threshold (S22: YES), the process proceeds to S24. If the driving support ECU 10 determines that the arrival time to the traffic light is less than the time threshold (S22: NO), the process proceeds to S26.

In S24, the driving support ECU 10 causes the driving support unit 15 to temporarily continue deceleration support. The driving support unit 15 temporarily continues deceleration support for a preset time. In S26, the driving support ECU 10 terminates the deceleration support by the driving support unit 15.

FIG. 3(b) is a flowchart showing an example of a temporary continuation process of deceleration support. As shown in FIG. 3(b), in S30, the driving support ECU 10 determines by the driving support unit 15 whether or not a set time has elapsed. When the driving support ECU 10 determines that the set time has elapsed (S30: YES), the process proceeds to S32. If it is determined that the set time has not elapsed (S30: NO), the driving support ECU 10 ends the current process. After that, the driving support ECU 10 repeats the process from S30 again after a certain period of time has elapsed.

In S32, the driving support ECU 10 causes the driving support unit 15 to end the deceleration support for the traffic light (ends the temporary continuation of the deceleration support).

According to the driving support device 100 according to the present embodiment described above, if it is determined that the traffic light is in a passing permission state while deceleration support is being executed for the traffic light, the deceleration support is temporarily continued for a set time. Therefore, it is possible to prevent the driver from having to perform a brake operation due to sudden termination of deceleration support.

Although the embodiments of the present invention have been described above, the present invention is not limited to the embodiments described above. The present invention can be implemented in various forms including the embodiments described above, with various changes and improvements based on the knowledge of those skilled in the art.

For example, when it is determined that the traffic light is in a passing permission state during execution of deceleration support, the driving support unit 15 does not necessarily need to determine whether the time taken to reach the traffic light is less than the time threshold. The driving support unit 15 may be configured to temporarily continue deceleration support for a set time when it is determined that the traffic light is in a passing permission state while deceleration support is being performed. The set time may be changed depending on the distance between the host vehicle and the traffic light or the time taken to reach the traffic light when it is determined that the traffic light is in a passing permission state. The set time may be set to be longer as the distance between the host vehicle and the traffic light or the time it takes to reach the traffic light is longer.

The traffic light state determination unit 13 does not necessarily need to recognize the traveling direction of the own vehicle's travel lane. The traffic light state determining unit 13 may determine whether or not the traffic light is in a passing permission state based on the lighting state of the traffic light.

1... External sensor, 2... Internal sensor, 3... HMI, 4... Actuator, 10... Driving support ECU, 11... Deceleration target detection section, 12... Relative situation recognition section, 13... Traffic light state determination section, 14... Start condition determination Section, 15...Driving support section, 16...Notification section, 100...Driving support device.

Claims (1)

A driving support device that provides deceleration support for the own vehicle in response to a traffic light in front of the own vehicle,
a traffic light state determination unit that determines whether the traffic light is in a passing permission state;
When the traffic light state determination unit determines that the traffic light is not in the passing permission state, whether or not a preset deceleration support start condition is satisfied based at least on the distance between the own vehicle and the traffic light. a start condition determination unit that determines the
If the start condition determination unit determines that the deceleration support start condition is satisfied, the deceleration support of the host vehicle to the traffic light is started, and the traffic light state determination unit determines that the traffic light is in the passage permission state. a driving support unit that does not start the deceleration support of the own vehicle in response to the traffic light if the start condition determination unit determines that the deceleration support start condition is satisfied;
Equipped with
When the traffic light state determination unit determines that the traffic light is in the pass permission state while performing the deceleration support for the traffic light, the driving support unit provides the deceleration support for a preset time. A driving support device that temporarily continues the operation.

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