Vehicle driver assistance devices and vehicle driver assistance systems

Abstract

To provide a driving support system for a vehicle, capable of ensuring sufficient safety even when an oncoming vehicle or the like suddenly enters a travel lane of an own vehicle.SOLUTION: A travel_ECU 14o of an oncoming moving body O calculates, every set cycle, distances from division lines defining an oncoming lane to the side ends of the oncoming moving body O as lateral positions a and b relative to the division lines, calculates a risk degree R with respect to the oncoming moving body O on the basis of the history of the lateral positions relative to the division lines calculated within a preset time, and transmits, via a transceiver 38o, the calculated risk degree R to a surrounding area. Meanwhile, a travel_ECU 14m of an own vehicle M receives, via a transceiver 38m, the risk degree R transmitted from the oncoming moving body O, recognizes the oncoming moving body O as an obstacle according to the risk degree R, and performs preliminary collision avoidance control prior to emergency collision avoidance control, with respect to the oncoming moving body O recognized as the obstacle.SELECTED DRAWING: Figure 12

Description

Technical Field

[0001] The present invention relates to a driving support device for a vehicle having a function of performing collision avoidance control against an obstacle, and a vehicle driving support system.

Background Art

[0002] Conventionally, in vehicles such as automobiles, a driving support device for assisting a driver's driving operation has been put into practical use for the purpose of reducing the burden of the driver's driving operation and realizing an improvement in safety. In this type of driving support device, as driving modes, for example, a manual driving mode in which steering and acceleration / deceleration are performed according to the driver's main driving operation, a driving support mode in which steering assistance control and acceleration / deceleration control are performed on the premise of the driver's main driving operation, and a driving support mode for driving the vehicle without requiring the driver's driving operation (so-called, automatic driving mode) are set.

[0003] The driving support control in each driving support mode is basically realized by including a following inter-vehicle distance control (ACC: Adaptive Cruise Control) function, a lane center maintenance control (ALKC: Active Lane Keep Centering) function, and the like. And by such driving support control, the vehicle can be driven along the traveling lane while maintaining the inter-vehicle distance from the preceding vehicle.

[0004] In addition, as a technology related to the active safety of the driving support device, various technologies for performing collision avoidance control with an obstacle existing in front of the traveling path of the host vehicle have been proposed (for example, see Patent Document 1). In the technology of Patent Document 1, the collision prediction unit specifies a collision assumed area in the obstacle from the traveling trajectory (target traveling path) of the host vehicle, the position, shape, moving direction, etc. of the obstacle. Also, the collision prediction unit integrates the collision probability values with the obstacle in the collision assumed area. And when the integrated value of the collision probability values becomes large in any of one or more collision assumed areas specified at a plurality of time points, the collision determination unit generates a warning signal.

Prior Art Documents

[0005] [Patent Document 1] Japanese Patent Publication No. 2016-224501 [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] However, oncoming vehicles traveling in the opposing lane adjacent to the vehicle's lane are generally located at a distance in the width direction relative to the vehicle's target path. Therefore, oncoming vehicles may not be subject to collision avoidance control. In this case, for example, if an oncoming vehicle suddenly enters the vehicle's lane due to inattention by the driver of the oncoming vehicle, it may become difficult to achieve sufficient collision avoidance control for that oncoming vehicle.

[0007] In particular, when oncoming vehicles are traveling on curves or other areas with poor visibility, it may become more difficult to achieve sufficient collision avoidance control for those oncoming vehicles.

[0008] The present invention aims to provide a vehicle driving assistance device that can ensure sufficient safety even when an oncoming vehicle or the like suddenly enters the vehicle's lane, and a vehicle driving assistance device. [Means for solving the problem]

[0009] A vehicle driving assistance system according to one aspect of the present invention relates to an oncoming moving object moving on an oncoming lane adjacent to the driving lane of the vehicle with a velocity component in the opposite direction to the direction of travel of the vehicle, and includes a receiving unit that receives a risk degree calculated based on the history of the lateral position relative to the lane markings, which is the distance from the lane markings defining the oncoming lane to the oncoming moving object, via communication with the outside of the vehicle; an emergency collision avoidance control unit that performs emergency collision avoidance control to avoid a collision with an obstacle when it is determined that there is a high probability that the vehicle will collide with the obstacle; and a preliminary collision avoidance control unit that recognizes the oncoming moving object as an obstacle according to the risk degree and performs preliminary collision avoidance control prior to the emergency collision avoidance control for the oncoming moving object recognized as an obstacle. The pre-collision avoidance control unit shall not execute the pre-collision avoidance control if the risk degree set for the opposing moving object is 0 and the risk level indicating the control permitted for the opposing moving object is 0, and shall execute the pre-collision avoidance control according to the risk level if the risk degree is greater than 0, the risk level is greater than 0 and less than or equal to the risk degree. It is.

[0010] Furthermore, a vehicle driving assistance device according to one aspect of the present invention includes: a lateral position calculation unit that calculates the distance from the lane markings that define the vehicle's driving lane to the vehicle as the lateral position relative to the lane markings at set intervals; a risk level calculation unit that calculates the risk level for the vehicle based on the history of the lateral position relative to the lane markings within a set time; and a transmission unit that transmits the risk level to an oncoming moving object moving on an oncoming lane adjacent to the vehicle's driving lane with a speed component in the opposite direction to the vehicle's direction of travel.

[0011] A vehicle driving assistance system according to one aspect of the present invention relates to an oncoming moving object that moves outside the vehicle on an oncoming lane adjacent to the vehicle's driving lane, with a velocity component in the opposite direction to the vehicle's direction of travel, and comprises: a lateral position calculation unit that calculates the distance from the lane marking the oncoming lane to the oncoming moving object as the lateral position relative to the lane marking at set intervals; a risk degree calculation unit that calculates the risk degree for the oncoming moving object based on the history of the lateral position relative to the lane marking within a set time; a transmission unit that transmits the risk degree to the vehicle; a receiving unit mounted on the vehicle that receives the risk degree; an emergency collision avoidance control unit mounted on the vehicle that performs emergency collision avoidance control to avoid a collision with an obstacle when it is determined that there is a high probability that the vehicle will collide with the obstacle; and a preliminary collision avoidance control unit mounted on the vehicle that recognizes the oncoming moving object as an obstacle according to the risk degree and performs preliminary collision avoidance control prior to the emergency collision avoidance control for the oncoming moving object recognized as an obstacle. Prepare, The pre-collision avoidance control unit does not execute the pre-collision avoidance control if the risk level set for the opposing moving object is 0 and the risk level indicating the control permitted for the opposing moving object is 0, and executes the pre-collision avoidance control according to the risk level if the risk level is greater than 0, the risk level is greater than 0 and less than or equal to the risk level. It is. [Effects of the Invention]

[0012] According to the present invention, sufficient safety can be ensured even when an oncoming vehicle or the like suddenly enters the vehicle's lane. [Brief explanation of the drawing]

[0013] [Figure 1] Schematic diagram of the driver assistance system [Figure 2] Schematic diagram of the driver assistance system [Figure 3] Diagram illustrating the monitoring areas of the stereo camera and radar. [Figure 4] An explanatory diagram showing obstacles located ahead of the target path of the vehicle. [Figure 5] Diagram illustrating an oncoming moving object located in the opposite lane. [Figure 6] Diagram showing the vehicle's position relative to the lane markings. [Figure 7] An explanatory diagram showing the vehicle's behavior pattern. [Figure 8] Explanatory drawing showing the behavior pattern of the host vehicle [Figure 9] Explanatory drawing showing the behavior pattern of the host vehicle [Figure 10] Explanatory drawing showing the risk determination map [Figure 11] Flowchart showing the risk degree calculation routine [Figure 12] Flowchart showing the pre - collision avoidance control routine <00000!87>Flowchart showing the risk degree upper limit processing sub - routine [Figure 14] Flowchart showing the risk degree down - processing sub - routine [Figure 15] Flowchart showing the forced control intervention determination sub - routine [Figure 16] Explanatory drawing exemplifying a case where the risk degree of an oncoming moving object increases due to factors other than fluctuations [Figure 17] Explanatory drawing exemplifying a case where the risk degree of an oncoming moving object increases due to factors other than fluctuations [Figure 18] Explanatory drawing exemplifying a case where the risk degree of an oncoming moving object increases due to factors other than fluctuations [Figure 19] Explanatory drawing showing the control content of the pre - collision avoidance control

Mode for Carrying Out the Invention

[0014] Hereinafter, an embodiment of one aspect of the present invention will be described in detail while referring to the drawings. In the drawings used in the following description, the scale is made different for each component in order to make each component recognizable on the drawing. Therefore, the present invention is not limited only to the quantity of the components described in these drawings, the shape of the components, the ratio of the sizes of the components, and the relative positional relationship of each component.

[0015] As shown in FIG. 1, the driving support system 100 of the present embodiment includes a host vehicle M and an oncoming vehicle (oncoming moving object O) as a plurality of vehicles capable of wireless communication with each other.

[0016] Both the vehicle M and the opposing moving object O are equipped with a driver assistance device 1.

[0017] Next, the configuration of the driver assistance device 1 installed in the vehicle M will be described with reference to Figures 2 and 3. The driver assistance device 1 is configured to include, for example, a camera unit 10 fixed to the center of the front and upper part of the passenger compartment of the vehicle (the vehicle) M.

[0018] This camera unit 10 is composed of a stereo camera 11, an image processing unit (IPU) 12, an image recognition unit (image recognition ECU) 13, and a driving control unit (driving ECU) 14.

[0019] The stereo camera 11 includes a main camera 11a and a sub-camera 11b. The main camera 11a and sub-camera 11b are made of, for example, a CMOS sensor. These main camera 11a and sub-camera 11b are positioned symmetrically on either side of the center in the vehicle width direction.

[0020] The main camera 11a and the sub-camera 11b stereo-image the driving environment in the area Af (see Figure 3) in front of the vehicle from different viewpoints. The imaging cycles of the main camera 11a and the sub-camera 11b are synchronized with each other.

[0021] The IPU 12 processes the driving environment image captured by the stereo camera 11 according to a predetermined method. This allows the IPU 12 to detect the edges of various objects represented in the image, such as three-dimensional objects and road markings. The IPU 12 then calculates distance information from the positional displacement of corresponding edges in the left and right images. Based on this, the IPU 12 generates image information (distance image information) that includes distance information.

[0022] The image recognition ECU13 determines the road curvature [1 / m] of the lane markings that demarcate the left and right sides of the lane in which the vehicle M is traveling (the vehicle's path), and the width between the left and right lane markings (lane width), based on distance image information received from the IPU12. The image recognition ECU13 also determines the road curvature and the width between the left and right lane markings of adjacent lanes to the lane in which the vehicle M is traveling. Various methods are known for determining these road curvatures and lane widths. For example, the image recognition ECU13 performs a luminance-based binarization process on each pixel in the distance image. This allows the image recognition ECU13 to extract candidate points for lane markings on the road. The image recognition ECU13 then performs a curve approximation using the least squares method or the like on the extracted sequence of candidate points for lane markings. This allows the image recognition ECU13 to determine the curvature of the left and right lane markings for each predetermined section. Furthermore, the image recognition ECU13 calculates the lane width from the difference in curvature between the left and right lane markings.

[0023] The image recognition ECU13 then calculates the lane center and the vehicle's lateral position deviation based on the curvature of the left and right lane markings and the lane width. Here, the vehicle's lateral position deviation is the distance from the lane center to the center of the vehicle M in the vehicle width direction.

[0024] Furthermore, the image recognition ECU13 performs predetermined pattern matching on the distance image information. This allows the image recognition ECU13 to recognize three-dimensional objects such as guardrails, curbs, median strips, and surrounding vehicles along the road. In this recognition of three-dimensional objects by the image recognition ECU13, for example, the type of object, the distance to the object, the speed of the object, and the relative speed between the object and the vehicle M are recognized.

[0025] The various pieces of information recognized by the image recognition ECU13 are output to the driving ECU14 as driving environment information.

[0026] Thus, in this embodiment, the image recognition ECU 13, together with the stereo camera 11 and the IPU 12, corresponds to a specific example of a driving environment recognition unit that recognizes information about the driving environment outside the vehicle.

[0027] The ECU14 is a control unit for the overall control of the driver assistance system 1.

[0028] This driving ECU14 is connected to various control units, including the cockpit control unit (CP_ECU)21, the engine control unit (E / G_ECU)22, the transmission control unit (T / M_ECU)23, the brake control unit (BK_ECU)24, and the power steering control unit (PS_ECU)25, via an in-vehicle communication line such as CAN (Controller Area Network).

[0029] Furthermore, the driving ECU14 is connected to various sensors, including the locator unit 36, the left front side sensor 37lf, the right front side sensor 37rf, the left rear side sensor 37lf, and the right rear side sensor 37rr.

[0030] Furthermore, a transceiver 38 is connected to the driving ECU 14 for wireless communication between the vehicle M and the outside world.

[0031] The CP_ECU21 is connected to a Human-Machine Interface (HMI)31 located around the driver's seat. The HMI31 includes, for example, operation switches for setting and executing various driver assistance controls, a mode switch for switching between driver assistance modes, a steering touch sensor for detecting the driver's steering state, a turn signal switch, a driver monitoring system (DMS) for driver facial recognition and gaze detection, a touch panel display, a combination meter, and a speaker.

[0032] When CP_ECU21 receives a control signal from Driving_ECU14, it appropriately notifies the driver of various information such as various warnings for the preceding vehicle, the status of driver assistance control implementation, and the driving environment of its own vehicle M, through displays and voice prompts via HMI31.

[0033] Furthermore, the CP_ECU25 outputs various input information to the Driving_ECU14, such as the on or off operation status of various driver assistance controls input by the driver via the HMI31, the set vehicle speed (set speed) Vs for the vehicle M, and the operation status of the turn signal switch.

[0034] The output side of the E / G_ECU22 is connected to the throttle actuator 32 of the electronically controlled throttle, etc. Various sensors, such as an accelerator sensor (not shown), are connected to the input side of the E / G_ECU22.

[0035] The E / G_ECU22 controls the throttle actuator 32 based on control signals from the Driving_ECU14 or detection signals from various sensors. This allows the E / G_ECU22 to adjust the amount of intake air for the engine and generate the desired engine output. The E / G_ECU22 also outputs signals such as the accelerator opening angle detected by the various sensors to the Driving_ECU14.

[0036] The output side of T / M_ECU23 is connected to the hydraulic control circuit 33. Various sensors, such as a shift position sensor (not shown), are connected to the input side of T / M_ECU23. Based on the engine torque signal estimated by E / G_ECU22 and the detection signals from the various sensors, T / M_ECU23 performs hydraulic control on the hydraulic control circuit 33. As a result, T / M_ECU23 operates the friction engagement elements and pulleys provided in the automatic transmission to shift the engine output to the desired gear ratio. T / M_ECU23 also outputs signals such as the shift position detected by the various sensors to the driving_ECU14.

[0037] A brake actuator 34 is connected to the output side of the BK_ECU24. The brake actuator 34 adjusts the brake fluid pressure output to the brake wheel cylinders located on each wheel. Various sensors, such as a brake pedal sensor, yaw rate sensor, longitudinal acceleration sensor, and vehicle speed sensor (not shown), are connected to the input side of the BK_ECU24.

[0038] The BK_ECU24 controls the brake actuator 34 based on control signals from the Driving_ECU14 or detection signals from various sensors. This allows the BK_ECU24 to appropriately generate braking force on each wheel for forced braking control and yaw rate control of the vehicle M. The BK_ECU24 also outputs signals such as brake operation status, yaw rate, longitudinal acceleration, and vehicle speed (vehicle speed) detected by various sensors to the Driving_ECU14.

[0039] The output side of the PS_ECU25 is connected to an electric power steering motor 35. The electric power steering motor 35 applies steering torque to the steering mechanism through the rotational force of the motor. Various sensors, such as a steering torque sensor and a steering angle sensor, are connected to the input side of the PS_ECU25.

[0040] The PS_ECU25 controls the electric power steering motor 35 based on control signals from the driving_ECU14 or detection signals from various sensors. This causes the PS_ECU25 to generate steering torque for the steering mechanism. The PS_ECU25 also outputs signals such as the steering torque and steering angle detected by the various sensors to the driving_ECU14.

[0041] The locator unit 36 ​​is comprised of a GNSS sensor 36a and a high-precision road map database (road map DB) 36b.

[0042] The GNSS sensor 36a determines the position of the vehicle M (latitude, longitude, altitude, etc.) by receiving positioning signals transmitted from multiple positioning satellites.

[0043] The road map DB36b is a large-capacity storage medium such as an HDD. This road map DB36b stores high-precision road map information (dynamic map). The road map information includes, for example, lane data necessary for autonomous driving, such as lane width data, lane center position coordinate data, lane direction angle data, and speed limit data. The lane data is stored at intervals of several meters for each lane on the road map. For example, based on a request signal from the driving_ECU14, the road map DB36b outputs road map information for a set range based on the vehicle's position determined by the GNSS sensor 36a as driving environment information to the driving_ECU14.

[0044] Thus, in this embodiment, the road map DB36b, together with the GNSS sensor 36a, constitutes a specific example of a driving environment recognition unit that recognizes information about the driving environment outside the vehicle.

[0045] The left front side sensor 37lf and the right front side sensor 37rf are, for example, composed of millimeter-wave radar. These left front side sensor 37lf and the right front side sensor 37rf are, for example, located on the left and right sides of the front bumper, respectively. The left front side sensor 37lf and the right front side sensor 37rf detect three-dimensional objects in the left and right diagonally forward and lateral regions Alf and Arf (see Figure 3) of the vehicle M, which are difficult to recognize with the image from the stereo camera 11, as driving environment information.

[0046] The left rear side sensor 37lr and the right rear side sensor 37rr are, for example, composed of millimeter-wave radar. These left rear side sensor 37lr and the right rear side sensor 37rr are, for example, located on the left and right sides of the rear bumper, respectively. The left rear side sensor 37lf and the right rear side sensor 37rf detect three-dimensional objects in the left and right diagonal side and rear areas Alr and Arr (see Figure 3) of the vehicle M, which are difficult to recognize with the left front side sensor 37lf and the right front side sensor 37rf, as driving environment information.

[0047] In this case, if each radar is composed of millimeter-wave radar, the millimeter-wave radar primarily detects three-dimensional objects such as vehicles traveling alongside and following vehicles by analyzing the reflected waves from objects in response to the emitted radio waves. Specifically, each radar detects information about the three-dimensional object, such as the width of the object, the position of a representative point of the object (relative position to the vehicle M), and its speed.

[0048] Thus, in this embodiment, the left front side sensor 37lf, the right front side sensor 37rf, the left rear side sensor 37lr, and the right rear side sensor 37rr correspond to specific examples of a driving environment recognition unit that recognizes driving environment information outside the vehicle.

[0049] Furthermore, the coordinates of each external object included in the driving environment information recognized by the image recognition_ECU13, locator unit 36, left front side sensor 37lf, right front side sensor 37rf, left rear side sensor 37lf, and right rear side sensor 37rr are all converted by the driving_ECU14 into coordinates in a three-dimensional coordinate system (see Figure 3) with the center of the vehicle M as the origin.

[0050] The transceiver 38 performs various communications with the outside of the vehicle. Specifically, the transceiver 38 performs, for example, vehicle-to-vehicle communication with surrounding vehicles and vehicle-to-infrastructure communication with infrastructure installed around the road. As information to be transmitted to other vehicles and infrastructure around the vehicle M, the transceiver 38 transmits, for example, the position of the vehicle M on a road map (latitude, longitude, altitude, etc.), the vehicle speed V of the vehicle M, the direction of movement of the vehicle M, and the risk level R (described later) when the vehicle M is traveling in the driving lane.

[0051] Furthermore, the transceiver 38 receives information from other vehicles and infrastructure in the vicinity of its own vehicle M, such as the location of other vehicles on a road map (latitude, longitude, altitude, etc.), the speed of other vehicles, the direction of movement of other vehicles, and the risk level R when other vehicles are driving.

[0052] Thus, in this embodiment, the transceiver 38 corresponds to a specific example of a transmitting unit and a receiving unit.

[0053] The driving ECU14 has several driving modes: a manual driving mode, a first driving control mode and a second driving control mode, and a stow mode. These driving modes can be selectively switched in the driving ECU14 based on, for example, the operation status of the mode switching switch provided on the HMI31.

[0054] Here, manual driving mode refers to a driving mode that requires the driver to maintain steering. In other words, manual driving mode is a driving mode in which the vehicle M is driven according to driving operations such as steering, accelerating, and braking performed by the driver.

[0055] The first driving control mode is also a driving mode that requires the driver to maintain steering. In other words, the first driving control mode is a semi-autonomous driving mode that drives the vehicle M while reflecting the driver's driving operations. This first driving control mode is realized, for example, by the driving_ECU14 outputting various control signals to the E / G_ECU22, BK_ECU24, and PS_ECU25. In the first driving control mode, adaptive cruise control (ACC), active lane keep centering (ALKC), active lane departure prevention control (Active Lane Keep Bouncing), and lane change control are mainly performed in appropriate combinations. As a result, the vehicle M can drive along the target driving path. Furthermore, in the first driving control mode, lane change control can also be performed when the turn signal switch is operated by the driver.

[0056] Here, the adaptive cruise control is basically performed based on driving environment information input from the image recognition ECU13, etc.

[0057] To explain in more detail, the Driving ECU14, for example, if a preceding vehicle is recognized in front of the vehicle M by the Image Recognition ECU13, performs follow-up driving control as part of follow-up distance control. In this follow-up driving control, the Driving ECU14 sets a target distance Lt and target speed Vt based on the speed Vl of the preceding vehicle. Then, the Driving ECU14 performs acceleration and deceleration control for the vehicle M based on the target distance Lt and target speed Vt. As a result, the Driving ECU14 basically maintains the distance L at the target distance Lt and the speed V at the target speed Vt, causing the vehicle M to follow the preceding vehicle.

[0058] On the other hand, if, for example, the image recognition ECU14 does not recognize a preceding vehicle in front of the vehicle M, the driving ECU14 performs constant speed driving control as part of the follow distance control. In this constant speed driving control, the driving ECU14 sets the set vehicle speed Vs input by the driver as the target vehicle speed Vt. Then, the driving ECU14 performs acceleration and deceleration control for the vehicle M based on the target vehicle speed Vt. As a result, the driving ECU14 maintains the vehicle speed V of the vehicle M at the set vehicle speed Vs.

[0059] Furthermore, lane centering control and lane departure prevention control are basically performed based on driving environment information input from at least one of the image recognition ECU 13 and the locator unit 36. That is, the driving ECU 14 sets a target path Rm along the left and right lane markings in the center of the vehicle's driving lane, based on lane marking information included in the driving environment information, for example. Then, based on the target path Rm, the driving ECU 14 maintains the vehicle M in the center of the lane by performing feedforward control and feedback control for steering. In addition, when the driving ECU 14 determines that there is a high possibility that the vehicle M will deviate from its driving lane due to the effects of crosswinds or road banking, it suppresses lane departure by forcibly controlling the steering.

[0060] Furthermore, lane change control is basically performed based on driving environment information input from the image recognition ECU 13, left front side sensor 37lf, right front side sensor 37rf, left rear side sensor 37lr, and right rear side sensor 37rr. This lane change control is executed, for example, when the driver operates the turn signal switch. That is, the driving ECU 14 recognizes the adjacent lane in the direction of operation of the turn signal switch based on the driving environment information. The driving ECU 14 also recognizes whether there is a vehicle or other object on the adjacent lane that would obstruct the lane change. Then, when the driving ECU 14 determines that there is space on the adjacent lane where a lane change is possible, it performs a lane change to the adjacent lane. This lane change control is performed in cooperation with the following distance control.

[0061] The second driving control mode is a driving mode that allows the vehicle M to move without requiring steering, acceleration, or braking by the driver. In other words, the second driving control mode is an autonomous driving mode that allows the vehicle M to move autonomously without requiring driver operation. This second driving control mode is realized, for example, by the driving_ECU14 outputting various control signals to the E / G_ECU22, BK_ECU24, and PS_ECU25. In the second driving control mode, the following of the preceding vehicle control, lane centering control, and lane departure prevention control are mainly performed in appropriate combinations. As a result, the vehicle M can travel according to the target route (route map information). Furthermore, lane change control is also possible in the second driving control mode. In the second driving control mode, lane change control is performed automatically as appropriate, not only when the turn signal switch is operated by the driver, but also according to the driving route to the destination set for the vehicle M and driving environment information.

[0062] The escape mode is a mode for automatically stopping the vehicle M on the roadside or elsewhere. This escape mode is executed, for example, when driving in the second driving control mode becomes impossible to continue and it is not possible to take over driving control to the driver (i.e., it is not possible to transition to manual driving mode or the first driving control mode).

[0063] Furthermore, in each of the above-mentioned driving modes, the driving ECU14 appropriately performs emergency collision avoidance control for obstacles such as vehicles that are highly likely to collide with the vehicle M. This emergency collision avoidance control includes, for example, emergency braking control (collision damage mitigation braking (AEB: Autonomous Emergency Braking)) and emergency steering control.

[0064] Emergency braking control is basically a control system that uses braking to avoid collisions with obstacles located ahead of the vehicle M on its target path Rm. When emergency braking control is performed, the driving ECU 14 sets a target travel area Am in front of the vehicle M, for example, as shown in Figure 4. This target travel area Am has a predetermined width (for example, greater than or equal to the width of the vehicle M) centered on the target travel path Rm. The driving ECU 14 also detects obstacles such as preceding vehicles or stationary vehicles located on the target travel area Am based on driving environment information. Furthermore, the driving ECU 14 calculates the predicted collision time (longitudinal collision time) TTCz for the vehicle M in the longitudinal direction as the predicted collision time with the obstacle. This longitudinal collision time TTCz is calculated based on the relative speed and relative distance between the vehicle M and the obstacle.

[0065] Then, the driving ECU14 performs primary brake control when the longitudinal collision prediction time TTCz becomes smaller than a preset first threshold Tth1. When primary brake control is initiated, the driving ECU14 decelerates the vehicle M using a preset first target deceleration a1 (for example, 0.4G).

[0066] Furthermore, when the longitudinal collision prediction time TTCz becomes smaller than a preset second threshold value Tth2 (where Tth2 < Tth1), the traveling ECU 14 executes secondary braking control. When the secondary braking control is started, the traveling ECU 14 decelerates the host vehicle M using a preset second target deceleration a2 (for example, 1G) until the relative speed with the obstacle becomes "0".

[0067] The emergency steering control is a control for avoiding a collision with an obstacle existing ahead on the target traveling path of the host vehicle M by steering. When it is determined that the traveling ECU 14, for example, cannot avoid a collision with an obstacle by the secondary braking control, the traveling ECU 14 executes the emergency steering control instead of or in combination with the emergency braking control.

[0068] Specifically, when the longitudinal collision prediction time TTCz becomes smaller than a preset third threshold value Tth3 (where Tth3 < Tth2), the traveling ECU 14 executes the emergency steering control (for example, refer to the host vehicle M' in FIG. 4).

[0069] During this emergency steering control, the traveling ECU 14 sets a target lateral position to the side of the obstacle. Also, the traveling ECU 14 sets a new target traveling path Ravo until the host vehicle M reaches the target lateral position. This new target traveling path Ravo is set by dividing it, for example, into an extension section for avoiding the host vehicle M to the side of the obstacle and a return section for restoring the posture of the host vehicle M in the direction along the host vehicle traveling path. Then, the traveling ECU 14 executes steering control along the new target traveling path Ravo.

[0070] Note that the traveling ECU 14 can also variably set the first to third threshold values Tth1 to Tth3 according to the wrap ratio in the vehicle width direction of the obstacle with respect to the host vehicle M. This wrap ratio Rr is calculated, for example, based on the intrusion amount of the obstacle into the target traveling area Am. Then, the traveling ECU 14 sets, for example, using a preset map or the like, such that the first to third threshold values Tth1 to Tth3 increase as the wrap ratio Rr increases.

[0071] Incidentally, when the vehicle M is traveling on a road without a median strip, it is conceivable that an oncoming moving object O on the opposite lane may suddenly enter the vehicle M's lane. In this embodiment, the oncoming moving object O refers to an oncoming vehicle (including motorcycles) or pedestrian, etc., moving with a velocity component in the opposite direction to the direction of travel of the vehicle M. In order to avoid collisions with such oncoming moving objects O, the driving ECU 14 of this embodiment extends and applies emergency collision avoidance control to oncoming moving objects O that enter the vehicle M's lane from the opposite lane on a road without a median strip.

[0072] Prior to the emergency collision avoidance control targeting the oncoming moving object O, the driving ECU 14 performs preliminary collision avoidance control (preliminary collision avoidance control) as needed. This preliminary collision avoidance control is a control system designed to suppress the risk of collision between the vehicle M and the oncoming moving object O in advance.

[0073] In order to perform pre-collision avoidance control, the driving ECU 14 receives information about various moving objects, such as other vehicles, that are present around its own vehicle M via the transceiver 38. Specifically, the driving ECU 14 receives information about other vehicles, such as the position of other vehicles on a road map (latitude, longitude, altitude, etc.), the speed of other vehicles, the direction of movement of other vehicles, and the risk level R when other vehicles are traveling.

[0074] Furthermore, the driving ECU14 calculates the risk level R of its own vehicle M as information to be transmitted to other vehicles in the vicinity of the vehicle M. Specifically, the driving ECU14 calculates the distance from the left and right lane markings that define the driving lane in which the vehicle M is traveling to the vehicle M (for example, the distance from the left and right lane markings to the left and right sides of the vehicle M), as the left and right lateral positions relative to the lane markings. This calculation of the lateral positions relative to the lane markings is performed, for example, based on driving environment information. The calculation of the lateral positions relative to the lane markings is performed at pre-set calculation cycles. Then, the driving ECU14 calculates the risk level R based on the history of the lateral positions relative to the lane markings calculated at set cycles within a pre-set time period.

[0075] To explain in more detail, the driving ECU14 calculates the distance from the left and right lane markings that define the driving lane of the vehicle M to the vehicle M itself, and expresses this distance as the left and right lateral positions a and b relative to the lane markings, respectively (see Figure 6). The driving ECU14 then stores the calculated left and right lateral positions a and b relative to the lane markings as history for a predetermined time of 3T (seconds).

[0076] Furthermore, the driving ECU14 calculates the median risk value for the oncoming moving object O based on the history of the lateral positions a and b of the left and right lane markings for each pre-set section.

[0077] In this embodiment, the intermediate risk values ​​are calculated, for example, based on the history of the lateral positions a and b of the left and right opposing boundary lines each time the opposing moving object O moves for T seconds.

[0078] In calculating this median risk level, the driving ECU14 calculates the average value a_ave of the left-side horizontal position a relative to the lane marking and the average value b_ave of the right-side horizontal position b relative to the lane marking over the past T seconds.

[0079] Furthermore, the driving_ECU14 calculates the difference Δx (=a_ave-b_ave) between the average values ​​of the lateral positions of the left and right opposing lane markings over the past T seconds. Based on this, the driving_ECU14 determines the direction of movement of the opposing moving object O in the road width direction over the past T seconds. That is, for example, if the difference Δx between the average values ​​is a negative value, the driving_ECU14 determines that the direction of movement of its own vehicle M is to the left. On the other hand, for example, if the difference Δx between the average values ​​is a positive value, the driving_ECU14 determines that the direction of movement of its own vehicle M is to the right.

[0080] The driving ECU14 determines that the vehicle M is moving in the direction described above when the absolute value of the difference between each average value |Δx| (=|a_ave-b_ave|) is greater than a preset threshold Δxth. On the other hand, the driving ECU14 determines that the vehicle M is not moving in the direction of the road width when the absolute value of the difference between each average value |Δx| (=|a_ave-b_ave|) is less than or equal to a preset threshold Δxth.

[0081] As a result, the driving ECU14 sequentially recognizes the direction of movement of its own vehicle M between the past 3T seconds and the past 2T seconds (timing t-2), the direction of movement of its own vehicle M between the past 2T seconds and the past T seconds (timing t-1), and the direction of movement of its own vehicle M from the past T seconds to the present (timing t).

[0082] The combinations of the vehicle M's behavior at timings t-2, t-1, and t are classified into one of 27 patterns, for example, as shown in Figures 7 to 9. The driving ECU 14 calculates intermediate risk values ​​Rt-2, Rt-1, and Rt at each timing based on the classified vehicle M behavior patterns. These intermediate risk values ​​Rt-2, Rt-1, and Rt can be calculated by referring to the map shown in Figure 9, for example. The driving ECU 14 then calculates the final risk level R for the vehicle M by summing the calculated intermediate risk values ​​Rt-2, Rt-1, and Rt.

[0083] The driving ECU 14 then transmits the calculated risk level R of its own vehicle M, along with information such as the vehicle M's position on the road map (latitude, longitude, altitude, etc.), the vehicle speed V of the vehicle M, and the direction of movement of the vehicle M, to other moving objects such as other vehicles in the vicinity of the vehicle M via the transceiver 38.

[0084] Thus, in this embodiment, the driving ECU14 is capable of mutually sending and receiving information such as the risk level R with other vehicles.

[0085] To perform pre-collision avoidance control, the Driving ECU 14 determines, based on driving environment information, whether or not a median strip exists on the road separating the vehicle M's lane from the oncoming lane. If there is no median strip on the road on which the vehicle M is traveling, the Driving ECU 14 detects, for example, an oncoming moving object O moving in the oncoming lane (see Figure 5). This detection of the oncoming moving object O is basically performed based on information received from various moving objects such as other vehicles. That is, the Driving ECU 14 extracts moving objects present in the oncoming lane based on the positional information of various moving objects such as other vehicles on the road map. The Driving ECU 14 then detects a moving object moving in the oncoming lane with a velocity component in the opposite direction to the direction of movement of the vehicle M as the oncoming moving object O. In addition, when detecting the oncoming moving object O, the Driving ECU 14 can also use the driving environment information recognized by the Image Recognition ECU 13.

[0086] When an opposing moving object O is detected, the driving ECU 14 calculates the longitudinal velocity component Voz and the lateral velocity component Vox, which correspond to the longitudinal and lateral directions of the vehicle M, based on the moving speed of the opposing moving object O (hereinafter referred to as speed Vo).

[0087] Furthermore, the driving ECU14 calculates the predicted collision time with an oncoming moving object O, specifically the longitudinal collision prediction time (TTCz) for the vehicle M in the front-rear direction and the lateral collision prediction time (TTCx) for the vehicle M in the width direction.

[0088] In other words, the driving ECU14 calculates the longitudinal collision prediction time TTCz by dividing the longitudinal relative velocity, which is calculated from the vehicle speed V of the vehicle M and the longitudinal velocity component Voz of the opposing moving object O, by the longitudinal relative distance between the vehicle M and the opposing moving object O.

[0089] Furthermore, the driving ECU14 calculates the predicted lateral collision time TTCx by, for example, dividing the lateral velocity component Vx of the opposing moving object O by the distance from the opposing moving object O to the target travel area Am. When calculating this predicted lateral collision time TTVx, it is desirable that the distance from the opposing moving object O to the target travel area Am be corrected based on the width of the opposing moving object O and the entry angle of the moving object O relative to the target travel area Am (predicted collision angle).

[0090] Furthermore, the driving ECU 14 determines, based on the risk level R received from the oncoming moving object O, whether or not the oncoming moving object O is an obstacle that could potentially collide with the vehicle M. If the oncoming moving object O is recognized as an obstacle, the driving ECU 14 appropriately executes preliminary collision avoidance control for the oncoming moving object O, prior to emergency collision avoidance control.

[0091] In this embodiment, the configuration of the driver assistance device 1 mounted on the opposing mobile body O is the same as the configuration of the driver assistance device 1 mounted on the vehicle M. Therefore, a detailed explanation of the configuration of the driver assistance device 1 mounted on the opposing mobile body O will be omitted. In the following explanation, when it is necessary to distinguish between the driver assistance device 1 and its components relating to the vehicle M and the driver assistance device 1 and its components relating to the opposing mobile body O, the denominator "m" or "o" will be added to the end of the reference numeral as appropriate.

[0092] Thus, in this embodiment, the driving_ECU14 corresponds to one specific example of an emergency collision avoidance control unit, a risk determination area setting unit, a risk degree calculation unit, and a pre-collision avoidance control unit. The transceiver 38 corresponds to one specific example of a transmitter and a receiver. More specifically, when considering the pre-collision avoidance control performed by the vehicle M as a reference, the driving_ECU14m corresponds to one specific example of an emergency collision avoidance control unit and a pre-collision avoidance control unit. The transceiver 38m corresponds to one specific example of a receiver. On the other hand, the driving_ECU14o corresponds to one specific example of a lateral position calculation unit and a risk degree calculation unit. The transceiver 38o corresponds to one specific example of a transmitter.

[0093] Next, prior to a detailed explanation of the pre-collision avoidance control, we will explain the calculation of the risk level R performed in other vehicles, etc., following the flowchart of the risk level calculation routine shown in Figure 11. Note that this calculation of the risk level R is performed in various mobile bodies equipped with the driver assistance device 1, but here we will explain the calculation of the risk level R by the driving ECU 14o of the opposing mobile body O.

[0094] When the routine starts, in step S001, the driving ECU14o recognizes the front wheels of the opposing moving object O if it is a four-wheeled vehicle or a two-wheeled vehicle.

[0095] In the following step S002, the driving_ECU14o determines the center of the opposing moving object O. That is, for example, if the opposing moving object O is a four-wheeled vehicle, the driving_ECU14o determines the center of the front wheel tread recognized in step S001 as the center of the opposing moving object O. Also, for example, if the opposing moving object O is a two-wheeled vehicle, the driving_ECU14o determines the position of the front wheel recognized in step S001 as the center of the opposing moving object O.

[0096] In the following step S003, the driving ECU14o recognizes the width of the opposing moving object O.

[0097] In the following step S004, the driving ECU14o calculates the distances from the left and right lane lines that demarcate the opposing lane to the side edge of the opposing moving object O as lane line lateral positions a and b. The driving ECU14o then stores the calculated lane line lateral positions a and b as the movement history of the opposing moving object O.

[0098] In the following step S005, the driving ECU14o clears the stored lateral position a and b relative to the lane markings that were prior to the last 3 turns.

[0099] In the following step S006, the driving ECU14o reads the movement history of the opposing moving object O over the past 3T seconds and calculates the average values ​​a_ave and b_ave of the left and right lateral positions a and b of the opposing lane lines for each past T seconds.

[0100] In the subsequent step S007, the driving ECU 14o determines the behavior of the opposing moving object O at each timing t-2, t-1, and t based on the average values ​​a_ave and b_ave of the left and right opposing lane line lateral positions a and b over the past T seconds. That is, the driving ECU 14o calculates the difference Δx between the average values ​​a_ave and b_ave for each interval over the past T seconds, and recognizes the behavior of the opposing moving object O at each timing t-2, t-1, and t based on the sign and absolute value of this difference Δx.

[0101] In the following step S008, the driving ECU14o sequentially calculates the intermediate risk values ​​Rt-2, Rt-1, and Rt for the opposing moving object O at each timing t-2, t-1, and t by referring to a pre-set map, etc.

[0102] Then, in step S009, the driving ECU14o calculates the current risk level R for the opposing moving object O by adding the calculated intermediate risk levels Rt-2, Rt-1, and Rt.

[0103] In the following step S010, the driving ECU 14o transmits information such as the calculated risk degree R, the position of the opposing mobile object O (latitude, longitude, altitude, etc.), the speed Vo of the opposing mobile object O, and the direction of movement of the opposing mobile object O (mobile object information) to the surrounding area via the transceiver 38.

[0104] Next, the details of the pre-collision avoidance control for the vehicle M will be explained according to the flowchart of the pre-collision avoidance control routine shown in Figure 12. This pre-collision avoidance control routine is repeatedly executed at set intervals by the driving_ECU14m when the vehicle M is traveling on a road without a median strip.

[0105] When the routine starts, in step S101, the driving ECU 14 receives mobile object information transmitted from various surrounding mobile objects via the transceiver 38m. Then, based on the mobile object information received from each mobile object, the driving ECU 14m detects an opposing mobile object O present in the vicinity of its own vehicle M.

[0106] In the following step S102, the driving ECU14m checks whether or not there is an oncoming moving object O in the oncoming lane.

[0107] Then, in step S102, if it is determined that there is no opposing moving object O in the opposing lane (step S102: NO), the driving_ECU14m exits the routine.

[0108] On the other hand, if it is determined in step S102 that there is an opposing moving object O in the opposing lane (step S102: YES), the driving ECU14m proceeds to step S103.

[0109] In step S103, the driving ECU14m calculates the predicted longitudinal collision time TTCz and the predicted lateral collision time TTCx with respect to the opposing moving object O.

[0110] When the system proceeds from step S103 to step S104, the driving ECU14m performs upper limit processing on the risk degree R. This upper limit processing is performed to prevent the risk degree R from becoming unnecessarily large due to factors other than the swaying of the opposing moving body O.

[0111] In this upper limit processing, the driving_ECU14m limits the risk level R to, for example, "4" or less if it is anticipated that the risk level R will increase due to factors other than the swaying of the opposing moving body O.

[0112] This upper limit processing for the risk level R is performed, for example, according to the flowchart of the risk level upper limit processing subroutine shown in Figure 13.

[0113] When the subroutine starts, the driving_ECU14m checks in step S201 whether the opposing moving object O is moving along a straight path with good visibility.

[0114] Then, in step S201, if it is determined that the opposing moving object O is not moving in a straight line (step S201: NO), the driving_ECU14m exits the subroutine.

[0115] On the other hand, if it is determined in step S201 that the opposing moving object O is moving in a straight line (step S201: YES), the driving ECU 14m proceeds to step S202.

[0116] In step S202, the driving_ECU14m obtains the target route Rm set for its own vehicle M.

[0117] In the following step S203, the driving ECU14m calculates the predicted path Ro of the opposing moving object O based on the current speed and direction of movement of the opposing moving object O.

[0118] In the following step S204, the driving_ECU14m calculates the predicted collision point Pc and collision angle θc between the vehicle M and the oncoming moving object O. For example, assuming that the oncoming moving object O moves along the predicted path Ro (see O' in Figure 5), the driving_ECU14m calculates the point where both the predicted longitudinal collision time TTCz and the predicted lateral collision time TTCx are "0" or less as the predicted collision point Pc between the vehicle M and the oncoming moving object O (see Figure 5). Furthermore, assuming that the oncoming moving object O has moved to the predicted collision point Pc, the driving_ECU14m calculates the collision angle θc based on the relative angle between the oncoming moving object O' after the move and the vehicle M.

[0119] In the following step S205, the driving ECU14m checks whether the turn signal of the opposing moving object O is flashing.

[0120] Then, in step S205, if it is determined that the turn signal of the opposing moving object O is flashing (step S205: YES), the driving ECU14m proceeds to step S209.

[0121] In step S209, the driving_ECU14m performs an upper limit process, for example, to set the risk level R to "4" or less, and then exits the subroutine.

[0122] In other words, as shown in Figure 16, for example, one case in which the risk degree R of an oncoming moving object O increases due to factors other than swaying is when the oncoming moving object O turns towards the lane of the vehicle M while flashing its turn signal. In such a case, it is assumed that the driver of the oncoming moving object O has a clear intention and is fully aware of the vehicle M. Therefore, in such a case, it is unlikely that the oncoming moving object O would suddenly enter the lane of the vehicle M at a time when there is a high probability of collision with the vehicle M, and the control content is limited by the upper limit processing.

[0123] On the other hand, if in step S205 it is determined that the turn signal of the opposing moving object O is not flashing (step S205: NO), the driving ECU14m proceeds to step S206.

[0124] In step S206, the driving ECU14m checks whether the behavior of the opposing moving object O has changed in a favorable direction compared to the previous time, making it possible to avoid a collision with the vehicle M. That is, the driving ECU14m checks whether the predicted path Ro of the opposing moving object O calculated in step S203, and the predicted collision point Pc and collision angle θc with the opposing moving object O calculated in step S204, have changed in a favorable direction. Here, for example, if the lateral velocity component Vox of the opposing moving object O starts to decrease, the predicted path Ro of the opposing moving object O generally tilts towards the vehicle M. Also, for example, if the lateral velocity component Vox of the opposing moving object O starts to decrease, the predicted collision point Pc of the opposing moving object O generally moves towards the vehicle M. Also, for example, if the lateral velocity component Vox of the opposing moving object O starts to decrease, the collision angle θc changes to an increasing direction. Therefore, the driving ECU14m determines that the behavior of the opposing moving object O has changed to a favorable side when at least one of the following conditions is met: the predicted path Ro tilts toward the vehicle M side, the predicted collision point Pc moves toward the vehicle M side, or the collision angle θc changes to an increasing side.

[0125] Then, if the driving ECU14m determines that the behavior of the opposing moving object O has changed to a favorable side (step S206: YES), it proceeds to step S209.

[0126] When the process proceeds to step S209, the driving_ECU14m performs an upper limit process, for example, to set the risk level R to "4" or less, and then exits the subroutine.

[0127] On the other hand, if it is determined in step S206 that the behavior of the opposing moving body O has changed to an unfavorable state (step S206: NO), the driving ECU14m proceeds to step S207.

[0128] In step S207, the driving ECU14m checks whether there is a stationary object such as a parked vehicle in the vicinity of the oncoming moving object O on the opposite lane.

[0129] Then, in step S207, if it is determined that there is a parked vehicle or the like in the oncoming lane (step S207: YES), the driving ECU14m proceeds to step S209.

[0130] When the process proceeds to step S209, the driving_ECU14m performs an upper limit process, for example, to set the risk level R to "4" or less, and then exits the subroutine.

[0131] In other words, as shown in Figure 17, for example, one case in which the risk degree R of an oncoming moving object O increases due to factors other than swaying is when the oncoming moving object O avoids a stationary object such as a parked vehicle in the oncoming lane. In such a case, it is assumed that the driver of the oncoming moving object O has a clear intention and is fully aware of the vehicle M. In addition, in such a case, it is assumed that the risk degree R calculated based on the risk judgment area will increase initially and then quickly decrease. Therefore, in such a case, it is unlikely that the oncoming moving object O will suddenly enter the vehicle M's lane at a time when there is a high probability of collision with the vehicle M, and the control content is limited by the upper limit processing.

[0132] On the other hand, if step S207 determines that there are no parked vehicles or other objects in the oncoming lane (step S207: NO), then the driving ECU14m proceeds to step S208.

[0133] In step S208, the driving ECU14m checks whether the opposing moving object O is merging from the branching road into the opposing lane.

[0134] Then, in step S208, if it is determined that the opposing moving object O is merging from a branch road (step S208: YES), the driving ECU 14m proceeds to step S209.

[0135] When the process proceeds to step S209, the driving_ECU14m performs an upper limit process, for example, to set the risk level R to "4" or less, and then exits the subroutine.

[0136] In other words, as shown in Figure 18, for example, a case in which the risk degree R of an oncoming moving object O increases due to factors other than swaying is when the oncoming moving object O enters the oncoming lane from a branch road or the like. In such a case, it is assumed that the driver of the oncoming moving object O has a clear intention and is fully aware of the vehicle M. In addition, in such a case, it is assumed that the risk degree R calculated based on the risk judgment area will increase initially and then quickly decrease. Therefore, in such a case, it is unlikely that the oncoming moving object O will suddenly enter the vehicle M's lane at the time of collision, so the control content is limited by the upper limit processing.

[0137] On the other hand, if step S208 determines that the opposing moving object O is not merging from the branch road (step S208: NO), then the driving_ECU14m exits the subroutine.

[0138] In the main routine shown in Figure 12, when the system proceeds from step S104 to step S105, the driving_ECU14m performs a down process for the risk degree R. This down process is designed to appropriately lower the risk level LV of the pre-collision avoidance control (described later), which is permissible according to the risk degree R, based on the relative relationship between the vehicle M and the oncoming moving object O. For example, even if the oncoming moving object O is swaying significantly and the risk degree R of the oncoming moving object O entering the driving lane of the vehicle M is high, if the oncoming moving object O is far away, the possibility of the vehicle M colliding with the oncoming moving object O is low. In such cases, the driving_ECU14m lowers the risk level LV of the pre-collision avoidance control, which is permissible according to the risk degree R, in order to prevent excessive pre-collision avoidance control from being executed.

[0139] This down process is executed, for example, according to the flowchart of the down process subroutine shown in Figure 14.

[0140] When the subroutine starts, at step S301, the traveling ECU 14m checks whether the vertical collision prediction time TTCz with respect to the oncoming moving object O is less than a previously set fourth threshold value Tth4 (where Tth1 < Tth4).

[0141] And, at step S301, when it is determined that the vertical collision prediction time TTCz is greater than or equal to the fourth threshold value Tth4 (step S301: NO), the traveling ECU 14m proceeds to step S302.

[0142] At step S302, after the traveling ECU 14m permits the pre - collision avoidance control corresponding to when the risk level R is "2" or less, it exits the subroutine. As a result, the traveling ECU 14m permits up to the pre - collision avoidance control corresponding to when the risk level R is "2", even if the current risk level R is "9". Also, for example, when the current risk level R is "2", the traveling ECU 14m permits the pre - collision avoidance control corresponding to when the risk level R is "2". In this embodiment, the pre - collision avoidance control corresponding to when the risk level R is "2" or less is the collision avoidance control with a risk level LV = 1 associated with the "caution area" in the risk determination area.

[0143] On the other hand, at step S301, when it is determined that the vertical collision prediction time TTCz is less than the fourth threshold value Tth4 (step S301: YES), the traveling ECU 14m proceeds to step S303.

[0144] At step S303, the traveling ECU 14m checks whether the vertical collision prediction time TTCz is less than a previously set fifth threshold value Tth5 (where Tth1 ≤ Tth5 < Tth4).

[0145] And, at step S303, when it is determined that the vertical collision prediction time TTCz is greater than or equal to the fifth threshold value Tth5 (step S303: NO), the traveling ECU 14m proceeds to step S304.

[0146] In step S304, the driving_ECU14m permits the corresponding pre-collision avoidance control when the risk level R is "4" or less, and then exits the subroutine. As a result, even if the current risk level R is "9", the driving_ECU14m permits the pre-collision avoidance control corresponding to the risk level R being "4". Also, if the current risk level R is "4", the driving_ECU14m permits the pre-collision avoidance control corresponding to the risk level R being "4". In this embodiment, the pre-collision avoidance control corresponding to the risk level R being greater than "2" and "4" or less is a collision avoidance control with a risk level of LV=2, which is associated with the "warning area" in the risk determination area.

[0147] On the other hand, if in step S303 it is determined that the longitudinal collision prediction time TTCz is smaller than the fifth threshold Tth5 (step S303: YES), then the driving ECU14m proceeds to step S305.

[0148] In step S305, the driving_ECU14m permits the corresponding pre-collision avoidance control when the risk level R is "9" or less, and then exits the subroutine. As a result, the driving_ECU14m permits the pre-collision avoidance control corresponding to all risk levels R. That is, for example, if the current risk level R is "9", the driving_ECU14m permits the pre-collision avoidance control corresponding to when the risk level R is "9". Also, for example, if the current risk level R is "4", the driving_ECU14m permits the pre-collision avoidance control corresponding to when the risk level R is "4". In this embodiment, the pre-collision avoidance control corresponding when the risk level R is greater than "4" and the risk level R is "9" or less is a collision avoidance control with a risk level LV=3 that corresponds to the "dangerous area" in the risk determination area.

[0149] In the main routine shown in Figure 12, when the process proceeds from step S105 to step S106, the driving ECU 14m makes a determination to perform a forced control intervention with respect to the oncoming moving object O. This forced control intervention is a determination to forcibly execute a pre-collision avoidance control with a risk level of LV=3 in an emergency situation, such as when the oncoming moving object O continues to move directly toward the vehicle M.

[0150] This mandatory control intervention determination is performed, for example, according to the mandatory control intervention determination subroutine shown in Figure 15.

[0151] When the subroutine starts, in step S401, the driving_ECU14m checks whether the condition in which the opposing moving object O is directly moving toward its own vehicle M has continued for a set time (for example, a predetermined frame).

[0152] Then, in step S401, if it is determined that the opposing moving object O is not directly approaching the vehicle M (step S401: NO), the driving_ECU14m exits the subroutine.

[0153] On the other hand, if in step S401 it is determined that the opposing moving object O is moving directly toward the vehicle M (step S401: YES), the driving ECU 14m proceeds to step S402.

[0154] In step S402, the driving_ECU14m corrects the risk level R for the opposing moving object O to "9" and corrects the allowable risk level LV for the opposing moving object O to "3", and then exits the subroutine.

[0155] In the main routine shown in Figure 12, when the vehicle proceeds from step S106 to step S107, the driving ECU 14m determines what preliminary collision avoidance action should be taken with respect to the oncoming moving object O. This preliminary collision avoidance action is determined, for example, based on the currently permissible risk level LV for the oncoming moving object O and the currently set risk degree R for the oncoming moving object O.

[0156] Here, for example, as shown in Figure 19, if the current risk level R for the oncoming moving object O is "0", then "0" is set as the risk level for the oncoming moving object O. When the risk level LV=0, the driving_ECU14m prohibits outputting warnings or other alerts to notify the driver of the presence of the oncoming moving object O. Also, when the risk level LV=0, the driving_ECU14m prohibits avoidance control in the longitudinal direction (front-to-back direction of the vehicle M) for the oncoming moving object O. Furthermore, when the risk level LV=0, the driving_ECU14m prohibits avoidance control in the lateral direction (vehicle width direction of the vehicle M) for the oncoming moving object O.

[0157] Furthermore, as shown in Figure 19, for example, if the risk level R is greater than "0" and control up to risk level LV=1 is permitted for the oncoming moving object O, the driving ECU 14m will prohibit the output of warnings or other signals to inform the driver of the presence of the oncoming moving object O.

[0158] Furthermore, if the risk level R is greater than "0" and control up to risk level LV=1 is permitted for the oncoming moving object O, the driving ECU14m permits a first acceleration suppression control as a longitudinal (front-to-back direction of the vehicle M) avoidance control for the oncoming moving object O, for example, instead of brake control. In this first acceleration suppression control, for example, the first acceleration suppression amount is set appropriately only when the vehicle M is accelerating (including when it is about to accelerate). The first acceleration suppression amount is set to increase as the longitudinal collision prediction time TTCz decreases, for example, based on a pre-set map.

[0159] Furthermore, if the risk level R is greater than "0" and control up to risk level LV=1 is permitted for the oncoming moving object O, the driving ECU14m permits steering control as lateral avoidance control (in the vehicle width direction of the vehicle M) for the oncoming moving object O, for example, within the range that does not deviate from the driving lane in which the vehicle M is traveling. In this steering control, the amount of avoidance by steering is set appropriately. The amount of avoidance is set to increase as the predicted lateral collision time TTCx decreases, for example, based on a pre-set map. It is desirable that the steering speed permitted for this steering control be limited to, for example, about 10 deg / s.

[0160] Furthermore, for example, as shown in Figure 19, if the risk level R is greater than "2" and control up to risk level LV=2 is permitted for the oncoming moving object O, the driving ECU 14m sets an alarm or the like to notify the driver of the presence of the oncoming moving object O.

[0161] Furthermore, if the risk level R is greater than "2" and control up to risk level LV=2 is permitted for the oncoming moving object O, the driving ECU14m will allow a second acceleration suppression control instead of brake control as longitudinal avoidance control for the oncoming moving object O. In this second acceleration suppression control, for example, the second acceleration suppression amount is set appropriately only when the vehicle M is accelerating (including when it is about to accelerate). The second acceleration suppression amount is set to increase as the longitudinal collision prediction time TTCz decreases, for example, based on a pre-set map. The second acceleration suppression amount is set to be greater than the first acceleration suppression amount. For example, the upper limit of the second acceleration suppression amount is set to the deceleration (suppression amount) obtained when the driver releases the accelerator.

[0162] Furthermore, if the risk level R is greater than "2" and control up to risk level LV=2 is permitted for the oncoming moving object O, the driving ECU14m permits steering control as lateral avoidance control for the oncoming moving object O, for example, until the vehicle M straddles the lane markings. In this steering control, the amount of avoidance by steering is set appropriately. The amount of avoidance is set to increase as the predicted lateral collision time TTCx decreases, for example, based on a pre-set map. It is desirable that the steering speed permitted for this steering control be limited to, for example, about 80 deg / s.

[0163] Furthermore, for example, as shown in Figure 19, if the risk level R is greater than "4" and control up to risk level LV=3 is permitted for the oncoming moving object O, the driving ECU 14m sets an alarm or the like to notify the driver of the presence of the oncoming moving object O.

[0164] Furthermore, if the risk level R is greater than "4" and control up to risk level LV=3 is permitted for the oncoming moving object O, the driving ECU14m will allow brake control as longitudinal avoidance control for the oncoming moving object O. In this brake control, for example, the amount of brake is set appropriately. The amount of brake is set to increase as the collision prediction time TTCz decreases, based on a pre-set map, etc. It is desirable that this amount of brake be set to a limit of the first target deceleration a1 (e.g., 0.4G) in the emergency collision avoidance control described above.

[0165] Furthermore, if the risk level R is greater than "4" and control up to risk level LV=3 is permitted for the oncoming moving object O, the driving ECU14m permits steering control as lateral avoidance control for the oncoming moving object O, for example, until the vehicle M crosses the lane markings. In this steering control, for example, the amount of avoidance by steering is set appropriately. The amount of avoidance is set to increase as the predicted lateral collision time TTCx decreases, for example, based on a pre-set map. It is desirable that the steering speed permitted for this steering control be limited to, for example, about 240 deg / s.

[0166] When the process proceeds from step S107 to step S108, the driving ECU 14m checks whether control intervention is necessary for the opposing moving body O, that is, whether a predetermined control amount was set in step S107 described above.

[0167] Then, if it is determined in step S108 that control intervention is unnecessary (step S108: NO), the driving_ECU14m exits the routine.

[0168] On the other hand, if it is determined in step S108 that control intervention is necessary (step S108: YES), the driving ECU14m proceeds to step S109.

[0169] In step S109, the driving ECU14m checks whether the opposing moving object O has entered the target travel area Am of its own vehicle M.

[0170] Then, in step S109, if it is determined that the opposing moving object O is outside the target travel area Am of the vehicle M (step S109: NO), the driving ECU 14m proceeds to step S110.

[0171] In step S110, the driving_ECU14m executes preliminary collision avoidance control and then exits the routine. That is, the driving_ECU14m executes preliminary collision avoidance control based on the control amount set in step S107.

[0172] On the other hand, if in step S109 it is determined that the opposing moving object O is within the target travel area Am of the vehicle M (step S109: YES), the driving ECU 14m proceeds to step S111.

[0173] In step S111, the driving ECU14m switches its control over the oncoming moving object O from pre-collision avoidance control to emergency collision avoidance control, and then exits the routine.

[0174] In this embodiment, the driving ECU 14o of the opposing moving object O calculates the distance from the lane markings that demarcate the opposing lane to the side edge of the opposing moving object O as lateral positions a and b to the lane markings at set intervals. The driving ECU 14o also calculates the risk degree R for the opposing moving object O based on the history of lateral positions to the lane markings calculated within a preset time. Furthermore, the driving ECU 14o transmits the calculated risk degree R to the surrounding area via the transceiver 38o. On the other hand, the driving ECU 14m of the own vehicle M receives the risk degree R transmitted from the opposing moving object O via the transceiver 38m. The driving ECU 14m also recognizes the opposing moving object O as an obstacle according to the risk degree R and performs preliminary collision avoidance control prior to emergency collision avoidance control for the opposing moving object O recognized as an obstacle.

[0175] This ensures sufficient safety even when an oncoming vehicle or other moving object O suddenly enters the driving lane of the vehicle M. Specifically, the driving ECU 14 performs preliminary collision avoidance control according to the risk level R for the oncoming moving object O even before it enters the target driving area Am of the vehicle M. Therefore, even when an oncoming moving object O suddenly crosses the lane markings and enters in front of the vehicle M, emergency collision avoidance control can be performed with ample time to spare.

[0176] In this case, the risk level R is calculated outside of the vehicle M. That is, the risk level R is calculated in the driving ECU 14o of the opposing moving object O, which is another vehicle. Therefore, even when the opposing moving object O is moving along a curve with poor visibility that is difficult to recognize by the autonomous sensors of the vehicle M, such as the stereo camera 11, the driving ECU 14m can accurately grasp the behavior of the opposing moving object O.

[0177] Furthermore, the driving ECU14o calculates intermediate risk values ​​Rt-2, Rt-1, and Rt for each timing t-2, t-1, and t for the opposing moving object O, based on the history of the lateral position relative to the lane mark calculated for each pre-set section (for example, every past time T). The driving ECU14o then calculates the sum of the intermediate risk values ​​Rt-2, Rt-1, and Rt as the risk level R. This allows for accurate calculation of the risk level R due to the behavior of the opposing moving object O, such as swaying.

[0178] In this process, the driving ECU14o calculates the lateral positions a and b of the opposing moving object O relative to the left and right lane markings that define the opposing lane. Then, based on the difference Δx between the average values ​​a_ave and b_ave of the lateral positions a and b calculated for each pre-set section, the driving ECU14o calculates the median risk values ​​Rt-2, Tt-1, and Rt at each timing t-2, t-1, and t. Therefore, regardless of the size of the opposing moving object O, the deviation of the opposing moving object O relative to the center of the opposing lane can be recognized with high accuracy.

[0179] In addition, the ECU14m performs upper limit processing on the risk level R. This suppresses unnecessary pre-collision avoidance control.

[0180] Furthermore, the driving ECU14m adjusts the control level (risk level) allowed for pre-collision avoidance control according to the value of the longitudinal collision prediction time TTCz. This enables appropriate pre-collision avoidance control for oncoming moving objects O.

[0181] In the above-described embodiment, the image recognition_ECU13, driving_ECU14, CP_ECU21, E / G_ECU22, T / M_ECU23, BK_ECU24, and PS_ECU25, etc., are composed of a well-known microcomputer equipped with a CPU, RAM, ROM, non-volatile memory, etc., and its peripheral devices. The ROM pre-stores fixed data such as programs executed by the CPU and data tables. Note that all or part of the processor's functions may be composed of logic circuits or analog circuits. Furthermore, the processing of various programs may be realized by electronic circuits such as FPGAs.

[0182] In the embodiment described above, the vehicle M and the opposing moving object O are relative and change depending on the reference vehicle. Therefore, in the following description, it is possible to read "vehicle M" as "opposing moving object O" and "opposing moving object O" as "vehicle M".

[0183] The inventions described in the above embodiments are not limited to those forms, and various modifications can be made in the implementation stage without departing from the gist of the invention. Furthermore, the above embodiments include inventions at various stages, and various inventions can be extracted by appropriate combinations of the multiple constituent elements disclosed.

[0184] For example, the functions of the horizontal position calculation unit, the risk level calculation unit, and the transmission unit can be provided in infrastructure equipment (roadside units, etc.) installed at set intervals along the road. In this case, the infrastructure equipment includes, for example, a configuration corresponding to the camera unit 10 and a configuration corresponding to the transceiver 38.

[0185] Furthermore, if the problem described can be solved and the effects described can be obtained even if some of the constituent elements shown in the above-described form are removed, then the configuration with the removed constituent elements can be extracted as an invention. [Explanation of symbols]

[0186] 1. Driving assistance system 10 ... Camera unit 11… Stereo camera 11a ... Main camera 11b ... Sub-camera 12 … IPU 13 … Image Recognition_ECU 14 … Driving_ECU 21 … CP_ECU 22 … E / G_ECU 23 … T / M_ECU 24 … BK_ECU 25 … PS_ECU 31 … HMI 32… Throttle Actuator 33. Hydraulic control circuit 34… Brake actuator 35… Electric power steering motor 36... Locator Unit 36a ... GNSS sensor 36b ... Road map database 37lf… Left front side sensor 37lr… Left rear side sensor 37rf ... Right front side sensor 37rr... Right rear side sensor 100… Driver assistance systems M... Vehicle (own vehicle) O... Opposing moving object

Claims

1. Regarding an oncoming moving object moving on an oncoming lane adjacent to the vehicle's driving lane with a speed component in the opposite direction to the vehicle's direction of travel, a receiving unit receives a risk level calculated based on the history of the lateral position relative to the lane marking, which is the distance from the lane marking to the oncoming moving object, via communication with the outside of the vehicle. When the vehicle determines that there is a high probability of colliding with an obstacle, an emergency collision avoidance control unit performs emergency collision avoidance control to avoid a collision with the obstacle, The system includes a pre-collision avoidance control unit that recognizes the opposing moving object as an obstacle according to the risk level and performs pre-collision avoidance control prior to the emergency collision avoidance control for the opposing moving object recognized as an obstacle, The pre-collision avoidance control unit is characterized in that it does not perform the pre-collision avoidance control when the risk degree set for the opposing moving body is 0 and the risk level indicating the control permitted for the opposing moving body is 0, and performs the pre-collision avoidance control according to the risk level when the risk degree is greater than 0, the risk level is greater than 0 and less than or equal to the risk degree.

2. A lateral position calculation unit calculates the distance from the lane markings that define the vehicle's driving lane to the vehicle itself as the lateral position relative to the lane markings at set intervals, A risk level calculation unit that calculates the risk level for the vehicle based on the history of the lateral position relative to the lane line within a predetermined time period, A vehicle driving assistance device characterized by comprising: a transmitting unit that transmits the aforementioned risk level to an oncoming moving object moving on an oncoming lane adjacent to the vehicle's driving lane, with a speed component in the opposite direction to the vehicle's direction of travel.

3. Regarding an opposing moving object moving outside of the vehicle on an opposing lane adjacent to the vehicle's driving lane, with a velocity component in the opposite direction to the vehicle's direction of travel, the system includes a lateral position calculation unit that calculates the distance from the lane markings defining the opposing lane to the opposing moving object as the lateral position relative to the lane markings at set intervals, A risk level calculation unit that calculates the risk level for the opposing moving object based on the history of the lateral position of the opposing lane line within a predetermined time period, A transmitting unit that transmits the aforementioned risk level to the vehicle itself, The vehicle includes a receiving unit that is mounted on the vehicle and receives the risk level, An emergency collision avoidance control unit is installed in the vehicle and, when it is determined that there is a high probability of the vehicle colliding with an obstacle, performs emergency collision avoidance control to avoid a collision with the obstacle. The vehicle is equipped with a pre-collision avoidance control unit that recognizes the oncoming moving object as an obstacle according to the risk level and performs pre-collision avoidance control prior to the emergency collision avoidance control for the oncoming moving object recognized as an obstacle, A vehicle driving assistance system characterized in that the pre-collision avoidance control unit does not execute the pre-collision avoidance control when the risk degree set for the opposing moving body is 0 and the risk level indicating the control permitted for the opposing moving body is 0, and executes the pre-collision avoidance control according to the risk level when the risk degree is greater than 0, the risk level is greater than 0 and less than or equal to the risk degree.

4. The vehicle driving support system according to claim 3, characterized in that the risk level calculation unit calculates intermediate risk levels for the opposing moving object based on the history of the lateral position relative to the lane line for each pre-set section, and calculates the sum of the intermediate risk levels as the risk level.

5. The vehicle driving support system according to claim 4, characterized in that the risk level calculation unit performs an upper limit processing on the risk level, with a preset value as the upper limit.

6. The pre-collision avoidance control unit is characterized in that it increases the risk level for which the pre-collision avoidance control is permitted as the predicted collision time in the longitudinal direction of the vehicle, calculated based on the longitudinal relative distance and relative speed of the vehicle and the opposing moving object, decreases. This is a vehicle driving assistance system according to any one of claims 3 to 5.

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