JP5459002B2 - Vehicle control device - Google Patents

Description

  The present invention relates to a vehicle control device.

  Conventionally, as a technical document in such a field, JP-A-2004-106673 is known. This publication discloses a technique for calculating a risk level based on a predicted collision time (TTC) and performing driving assistance (brake control, steering control intervention, etc.) according to the risk level.

JP 2004-106673 A

  Even when the TTC is large, the TTC may rapidly decrease depending on the collision target. In such a case, the collision target may not be detected (sensor lost). In the above-described conventional technology, there is a possibility that appropriate driving assistance cannot be performed when such sensor lost occurs.

  The present invention has been made to solve such a problem, and an object of the present invention is to provide a vehicle control device that can perform driving support with high safety even when a sensor lost of a collision target occurs. And

  A vehicle control device according to the present invention is a vehicle control device that performs driving assistance for avoiding a risk target around a vehicle for a driver of the vehicle, and includes a risk target detection unit that repeatedly detects a risk target; A risk degree calculating means for calculating a risk degree for the vehicle of the risk object detected by the risk object detecting means; a collision prediction time acquiring means for acquiring a collision prediction time for the risk object detected by the risk object detecting means; The support content determination unit includes: a support content determination unit that determines driving support content based on the collision prediction time acquired by the collision prediction time acquisition unit and the risk level calculated by the risk level calculation unit; When the risk object detection means becomes unable to detect the risk object, the immediately preceding risk object is detectable To continue the determined driving support content.

  In this vehicle control device, when the risk target cannot be detected, the assistance content determination means maintains the immediately preceding driving assistance content, so that high safety of driving assistance can be realized.

  Further, the support content determination means is when the risk object detection means has become unable to detect the risk object, the collision prediction time is shorter than a predetermined time, and the risk level of the risk object is at a predetermined level. The aspect of maintaining the driving assistance content determined when the immediately preceding risk target is in a detectable state may be used. When the collision prediction time is short and the risk level is high, high safety is ensured particularly effectively.

  ADVANTAGE OF THE INVENTION According to this invention, even when the sensor lost of the collision target arises, the vehicle control apparatus which can perform driving assistance with high safety is provided.

FIG. 1 is a diagram showing the details of driving assistance provided until a vehicle collides. FIG. 2 is a diagram showing driving assistance in the information provision stage. FIG. 3 is a diagram showing driving assistance in the avoidance guidance stage. FIG. 4 is a diagram illustrating driving assistance in the avoidance control stage. FIG. 5 is a schematic configuration diagram of the vehicle control device according to the embodiment of the present invention. FIG. 6 is a diagram showing an assumed scene of each risk degree in the embodiment of the present invention. FIG. 7 is a diagram showing a support form map used when the vehicle control device of FIG. 5 determines the content of driving support.

  Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the accompanying drawings. In addition, the same code | symbol is attached | subjected about the same or equivalent element, and the description is abbreviate | omitted when description overlaps.

  Prior to the description of the embodiment of the present invention, the contents of various driving assistances provided by the vehicle control device according to the present embodiment will be described with reference to FIGS.

As shown in FIG. 1, the driving assistance provided by the vehicle control device includes (a) an information provision stage, (b) an avoidance guidance stage, and (c) an avoidance control stage, depending on the time until the vehicle collides. In each stage, predetermined driving assistance is performed. Hereinafter, the content of these driving assistance is demonstrated.
(A) Information provision stage

In the information provision stage, the predicted time until the collision is relatively long (for example, 4.0 seconds), and the vehicle control device performs driving support for the purpose of driving away from danger based on the driver's own judgment. . That is, as shown in FIG. 2, an object (risk target) that has a possibility of collision existing ahead is detected by a radar or a camera, and the presence is notified to the driver. In the aspect shown in FIG. 2, a roadside object B1, a preceding vehicle B2, and a pedestrian B3 are present in front of the vehicle. That is, the driver is notified of three risk targets B1, B2, and B3.
(B) Avoidance guidance stage

In the avoidance guidance stage, the predicted time until the collision is short (for example, 2.5 seconds), and the vehicle control device performs driving support for the purpose of inviting the driver's own avoidance operation. That is, as shown in FIG. 3, the collision risk is calculated based on the risk target information, and the recommended course D and the optimum vehicle speed of the own vehicle are generated from the smallest area of the collision risk target B2. These “recommended route” and “optimum vehicle speed” are combined to define a “target route”. When the actual route of the vehicle is more than a predetermined value with respect to the target route, driving assistance for guiding the steering direction so as to approach the target route (for example, input of a single steering torque or Slow deceleration control).
(C) Avoidance control stage

  In the avoidance control stage, the predicted time until the collision is extremely short (for example, 1.0 second), and the vehicle control device performs driving support for the purpose of avoiding the collision by intervening in the driving operation of the driver. That is, as shown in FIG. 4B, in order to avoid a collision with the risk target B, the vehicle control device performs intervention control (steer / brake cooperative control) of deceleration (brake) and trajectory change (steer). Do. Conventionally, only brake control has been performed (see FIG. 4A).

  Next, the vehicle control apparatus 1 according to the embodiment will be described with reference to FIG. This vehicle control device 1 is a device that provides driving assistance for avoiding a risk target around the vehicle to the driver of the host vehicle, and detects and detects an obstacle (risk target) that becomes a risk when the vehicle travels. The driver is provided with driving assistance according to a predicted collision time (TTC [Time To Collision]) until the obstacle collides with the vehicle.

  The vehicle control device 1 includes a CPU [Central Processing Unit] that performs arithmetic processing, a ROM [Read Only Memory] and a RAM [Random Access Memory] that are storage units, an input signal circuit, an output signal circuit, a power supply circuit, and the like. It has a vehicle control ECU [Electric Control Unit] 2 for overall control of the apparatus. The vehicle control ECU 2 is electrically connected to each of the white line detection unit 3, the obstacle detection unit (risk target detection means) 4, the vehicle speed sensor 5, and the yaw rate sensor 6. Further, the vehicle control ECU 2 is electrically connected to each of an HMI [Human Machine Interface] 7 and a vehicle control unit 8.

  The white line detection unit 3 includes a camera for recognizing the position of the white line in front of the vehicle, and is attached to the front of the vehicle so that the optical axis direction thereof coincides with the traveling direction of the vehicle. The camera of the white line detection unit 3 has a wide imaging range in the left-right direction that can sufficiently image a running road. The white line detection unit 3 transmits the captured image ahead of the vehicle and the position of the white line recognized from the image to the vehicle control ECU 2 as white line recognition information.

  The obstacle detection unit 4 includes a radar for detecting obstacles around the vehicle using radio waves. The radar includes a front radar having a fan-shaped detection range extending in front of the vehicle, and detection of the front radar. It is composed of a front side wide-angle short-range radar having a fan-shaped detection range that is closer and wider than the range. The obstacle detection unit 4 repeatedly performs detection (for example, at a constant cycle), and transmits the detected position and size of the obstacle to the vehicle control ECU 2 as obstacle information.

  The vehicle speed sensor 5 is a sensor that detects the vehicle speed of the vehicle. The vehicle speed sensor 5 is attached to a wheel, for example, and detects the vehicle speed from the rotational speed of the wheel. The vehicle speed sensor 5 transmits the detected vehicle speed to the vehicle control ECU 2 as vehicle speed information. The yaw rate sensor 6 is a sensor that detects the yaw rate of the vehicle. The yaw rate sensor 6 is attached to the vehicle body, for example. The yaw rate sensor 6 transmits the detected yaw rate of the vehicle to the vehicle control ECU 2 as yaw rate information.

  The HMI 7 is an interface for exchanging information between the device and the driver. The HMI 7 includes a display panel and speakers for providing information to the driver. When an information provision command is transmitted from the vehicle control ECU 2, the HMI 7 provides information to the driver as driving assistance.

  The vehicle control unit 8 is a part that controls the vehicle according to various commands transmitted from the vehicle control ECU 2. When the avoidance guidance command is transmitted from the vehicle control ECU 2, the vehicle control unit 8 performs avoidance guidance for the driver. The avoidance guidance is driving assistance that guides the avoidance operation of the driver by driving the vehicle handle, the brake pedal, and the accelerator pedal in a direction in which the vehicle avoids the obstacle. Driving the steering wheel or the like during avoidance guidance does not affect the running of the vehicle. Moreover, the vehicle control part 8 performs avoidance control of a vehicle, when the avoidance control command is transmitted from vehicle control ECU2. The avoidance control is driving assistance in which the vehicle control unit 8 intervenes in driving to forcibly stop or change the course of the vehicle.

  The vehicle control ECU 2 includes a departure allowance time calculation unit 9, a collision prediction time calculation unit (collision prediction time acquisition unit) 10, and a risk degree calculation unit (risk degree calculation unit) 11. Further, the vehicle control ECU 2 includes an information provision calculation unit 12, a vehicle control target value calculation unit 13, and a support determination unit (support content determination means) 14.

  The departure allowance time calculation unit 9 calculates a departure allowance time, which is a time until the running vehicle deviates from the white line, based on various information. The deviation margin time calculation unit 9 is based on the white line recognition information transmitted from the white line detection unit 3, the vehicle speed information transmitted from the vehicle speed sensor 5, and the yaw rate information transmitted from the yaw rate sensor 6. Calculate time. The departure allowance time calculation unit 9 transmits the calculated departure allowance time to the risk degree calculation unit 11 as departure allowance time information.

  The collision prediction time calculation unit 10 calculates a collision prediction time (that is, TTC) that is a time until a traveling vehicle collides with an obstacle based on various information. Based on the obstacle information transmitted from the obstacle detection unit 4, the vehicle speed information transmitted from the vehicle speed sensor 5, and the yaw rate information transmitted from the yaw rate sensor 6, the collision prediction time calculation unit 10 performs TTC by a known method. Is calculated. The collision prediction time calculation unit 10 transmits the calculated TTC to the risk degree calculation unit 11 as TTC information.

  The risk degree calculation unit 11 includes information on the obstacle detected by the obstacle detection unit 4, deviation margin time information transmitted from the deviation margin time calculation unit 9, TTC information transmitted from the collision prediction time calculation unit 10, vehicle speed Based on the vehicle speed information transmitted from the sensor 5 and the yaw rate information transmitted from the yaw rate sensor 6, a risk degree is calculated and a risk map is created.

  Here, the assumed scenes of the risk degrees R0 to R3 will be described with reference to FIG. In the scene shown in FIG. 6, the pedestrian is an obstacle to be risked.

  In the risk degree R0 shown in FIG. 6A, the pedestrian does not enter the course of the own vehicle and there is no traffic rule that can enter the course.

  In the risk degree R1 shown in FIG. 6B, the pedestrian has not entered the course of his / her own vehicle, but has a traffic rule (crosswalk) that can enter the course.

  In the risk level R2 shown in FIG. 6C, the pedestrian has not entered the course of his / her own vehicle, but has a traffic rule (pedestrian crossing) that can enter the course, and other obstacles This is a situation where there is a high possibility of entering the course due to the relationship with objects (other cars).

  In the risk degree R3 shown in FIG. 6 (d), the pedestrian is in a situation where he / she has entered the course of his / her own vehicle, or is in a situation where he / she is about to enter.

  The vehicle control device 1 uses various sensors to grasp the status of the risk target and makes a determination in the vehicle control ECU 2 to determine one risk degree from the risk degrees R0 to R3.

  The risk degree calculation unit 11 performs calculation processing related to the recommended route of the vehicle based on the created risk map, and generates optimal vehicle speed information when traveling on the recommended route. The risk degree calculation unit 11 transmits the generated recommended route information and optimum vehicle speed information to the vehicle control target value calculation unit 13 as target route information used for vehicle control. Further, the risk degree calculation unit 11 transmits the created risk map to the information provision calculation unit 12 and the vehicle control target value calculation unit 13 as risk map information.

  The information provision calculation part 12 performs the calculation regarding the information provision which is one of driving assistance based on various information. Specifically, the information provision calculation unit 12 includes risk map information transmitted from the risk degree calculation unit 11, white line recognition information transmitted from the white line detection unit 3, and obstacle information transmitted from the obstacle detection unit 4. Based on the above, image information to be displayed on the display panel of the HMI 7 as information provision and alarm information to be output from the speaker are generated. The information provision calculation unit 12 transmits the generated image information and alarm information to the support determination unit 14.

  The vehicle control target value calculation unit 13 determines a control target value related to avoidance guidance and avoidance control, which are driving assistance, based on the risk map information and target route information transmitted from the risk degree calculation unit 11. The vehicle control target value calculation unit 13 calculates a control target value for avoidance guidance, that is, a driving amount and a driving direction of a vehicle steering wheel, a brake pedal, and an accelerator pedal for guiding the driver.

  Further, the vehicle control target value calculation unit 13 is based on the risk map information and the target route information transmitted from the risk degree calculation unit 11, and is a control target value in avoidance control, that is, steering control and braking control when intervening in driving. And each target value of acceleration control is calculated. The vehicle control target value calculation unit 13 transmits the calculated control target value in avoidance guidance and the control target value in avoidance control to the support determination unit 14 as control target value information. Further, the vehicle control target value calculation unit 13 transmits the target route information transmitted from the risk degree calculation unit 11 to the support determination unit 14.

  The support determination unit 14 determines the content and execution timing of driving support based on various information. The contents of driving support include information provision (attention and warning) with different degrees of support, avoidance guidance (driver guidance), and avoidance control (intervention control). The provision of information has the lowest degree of support for the driver, and urges the driver to pay attention to obstacles through the HMI 7. In the avoidance guidance, the degree of support for the driver is the second lowest after information is provided, and the driver's avoidance operation is guided by driving the vehicle handle, the brake pedal, and the accelerator pedal in a direction in which the vehicle avoids the obstacle. The avoidance control has the highest degree of support for the driver, and forcibly stops or changes the course of the vehicle through driving.

  The support determination unit 14 functions as support content determination means, and determines the content of driving support. At this time, a support form map as shown in FIG. 7 is used. In this support form map, T1 (2.5 to 3.5 seconds), T2 (1.8 to 2.5 seconds), and T3 (up to 1.8 seconds) are set as TTC determination conditions. R0 to R3 are set as judgment conditions for the estimated risk level (risk level).

  When the obstacle detection unit 4 detects a risk target, the support determination unit 14 uses the risk target TTC acquired by the collision prediction time calculation unit 10 and the risk level calculated by the risk level calculation unit 11 in FIG. The content of driving assistance is determined with reference to the assistance form map.

  When the support determination unit 14 determines that it is necessary to perform driving support using the support content as information provision, the support determination unit 14 transmits an information provision instruction including image information and alarm information generated by the information provision calculation unit 12 to the HMI 7. When the support determination unit 14 determines that it is necessary to change the support content to avoidance guidance and perform driving support, the assistance determination unit 14 controls the avoidance guidance command including the control target value information generated by the vehicle control target value calculation unit 13. Transmit to unit 8. Further, when the support determination unit 14 determines that it is necessary to change the support content to avoidance control and perform driving support, the assist determination unit 14 transmits an avoidance control command to the vehicle control unit 8.

  However, when the obstacle detection unit 4 becomes unable to detect the risk target, the support determination unit 14 continues the content of the driving support determined when the immediately preceding risk target is in a detectable state. .

  However, it is preferable to adjust the continuation mode of each cancel control in consideration of the past mode transition so that the driver does not feel uncomfortable and does not impair safety.

  Below, the control mode when detection is impossible is defined as the areas A to D in FIG. 7, and the continuation mode of the support content in each mode will be described.

  In the control mode A and the control mode B, when the detection is impossible, the contents of the driving assistance are not continued and the cancellation is immediately performed. However, at the time of transition from the control mode C and the control mode D, the driving support control is extended by using the estimated value of the TTC and the risk degree from the previous time only for a fixed time.

  In the control mode C, when the detection is impossible, the content of the driving support determined last time is extended for a certain time. However, at the time of transition from the control mode D, the control extension time is lengthened.

  In the control mode D, when the detection is impossible, the control is continued and extended with the estimated value of TTC and the risk degree from the previous time.

  According to the vehicle control apparatus 1 described above, when the risk target cannot be detected, the support determination unit 14 maintains the driving support content immediately before it, so that high safety of driving support can be realized.

  The present invention is not limited to the embodiment described above. For example, the support determination unit 14 is in a state where the obstacle detection unit 4 becomes unable to detect an obstacle, the collision prediction time is shorter than a predetermined time, and the risk level of the risk target is When the level is higher than a predetermined level, the driving assistance content determined when the immediately preceding risk target is in a detectable state may be maintained. Under such conditions, high safety is ensured particularly effectively.

  In the above-described embodiment, the obstacle that may collide with the vehicle has been described as the risk object. However, the risk object is not limited to the obstacle. For example, a groove near the roadway or a recess in the road is used as the risk object. May be applied.

  DESCRIPTION OF SYMBOLS 1 ... Vehicle control apparatus, 2 ... Vehicle control ECU, 4 ... Obstacle detection part, 7 ... HMI, 8 ... Vehicle control part, 10 ... Collision prediction time calculation part, 11 ... Risk degree calculation part, 14 ... Support determination part.

Claims (1)

A vehicle control device that provides driving support for a vehicle driver to avoid a risk target around the vehicle,
Risk object detection means for repeatedly detecting the risk object; and
A risk degree calculating means for calculating a risk degree for the vehicle of the risk object detected by the risk object detecting means;
A collision prediction time acquisition unit for acquiring a collision prediction time for the vehicle of the risk target detected by the risk target detection unit;
Support content determination means for determining driving support content based on the collision prediction time acquired by the collision prediction time acquisition means and the risk degree calculated by the risk degree calculation means,
The support content determination means is when the risk object detection means becomes unable to detect the risk object, the collision prediction time is shorter than a predetermined time, and the risk degree of the risk object is A vehicle control device that maintains the driving assistance content determined when the immediately preceding risk target is in a detectable state when the level is higher than a predetermined level .

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