Vehicle driving control device

Abstract

To reduce a risk of contacting and collision by a following vehicle, by taking a position of the following vehicle into consideration at the time of executing risk minimization control.SOLUTION: A vehicle travelling control device has a function of executing in-lane automatic travelling, while maintaining a set vehicle speed if there is no precedent vehicle on a travelling lane of an own vehicle and while maintaining a set inter-vehicle distance if there is a precedent vehicle, and an MRM function of executing risk minimization control including control of decelerating and stopping the own vehicle on the travelling lane, if a system failure occurs during execution of the inter-lane automatic travelling function or if operation is not turned over to a driver when the system failure occurs, which determines a direction of corrective steering on the basis of a position in a lateral direction of the following vehicle on the travelling lane of the own vehicle, during execution of the MRM function, and executes the corrective steering during deceleration of the own vehicle.SELECTED DRAWING: Figure 8

Description

[Technical Field]

[0001] The present invention relates to a vehicle cruise control device, and more particularly to a risk minimization function during operation of an automatic lane keeping system. [Background technology]

[0002] Various driving control systems aimed at reducing the burden on drivers and supporting safe driving are being put into practical use and international standardization is underway. For example, driving control systems such as the already-in-use Acceleration Control System (ACCS) and Lane Keeping Assist System (LKAS), as well as a combination of these, the Partially Automated In-Lane Driving System (PADS), are being put into practical use. Of these, regulations have been formulated for the Automated Lane Keeping System (ALKS), which applies to automated driving within a single lane under specific conditions, such as when the vehicle is traveling at speeds below 60 km / h and on expressways with a physical separator between the oncoming lane and other lanes.

[0003] In such an automated lane keeping system, if a serious failure occurs in the system or if the driver is unable to respond to a request to take over control, the system will switch to risk minimization control (Minimal Risk Maneuver, MRM).On the other hand, if a collision with another vehicle is predicted, emergency avoidance control (EM) will be activated, and the system will avoid the collision by slowing down at maximum deceleration or stop the vehicle in its lane.

[0004] For example, Patent Document 1 discloses that when a predetermined condition is met while the vehicle is traveling that makes it difficult for the vehicle control system or the driver to continue traveling, an automatic stopping mode is executed to stop the vehicle within a predetermined stopping area, and the lateral distance from other vehicles traveling alongside the vehicle is increased. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2020-158090 Summary of the Invention [Problem to be solved by the invention]

[0006] However, when a vehicle is slowed down and stopped, the vehicle behind may not be able to avoid the vehicle that has slowed down and stopped due to a delay in the vehicle's detection or braking, which may result in contact or collision with the vehicle behind.

[0007] The present invention has been made in consideration of the above-described circumstances, and its purpose is to reduce the risk of contact or collision with a rear vehicle by taking into account the position of the rear vehicle when risk minimization control is activated. [Means for solving the problem]

[0008] In order to solve the above problems, the present invention provides: an environmental state estimation unit including a surroundings recognition function for recognizing the current lane, adjacent lanes, other vehicles on each lane, and the surrounding environment, and a function for acquiring the current vehicle motion state; a route generation unit that generates a target route based on information acquired by the environmental state estimation unit; a vehicle control unit that performs speed control and steering control so as to make the host vehicle follow the target route; A vehicle driving control device comprising: A function that maintains the set vehicle speed when there is no preceding vehicle in the vehicle's lane, and automatically drives within the lane while maintaining the set vehicle distance when there is a preceding vehicle. An MRM function that executes risk minimization control, including slowing down and stopping the vehicle within the lane, when a system failure occurs during operation of the in-lane autonomous driving function or when operation is not handed over to the driver when a system failure occurs; In those having When the MRM function is activated, There is a vehicle behind Lateral position of rear vehicle However, if the vehicle is deviated to the left or right relative to its running position, or if the vehicle is deviated to the left or right within the lane, the vehicle will move in the opposite direction to the deviation. The method is characterized by determining the direction of corrective steering and executing corrective steering during deceleration. [Effects of the Invention]

[0009] As described above, when the MRM function is activated, the vehicle driving control device of the present invention determines the direction of corrective steering based on the lateral position of the rear vehicle in the vehicle's lane and performs corrective steering during deceleration, which is advantageous in reducing the risk of contact or collision with the rear vehicle. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a schematic diagram illustrating a vehicle cruise control system. [Figure 2] FIG. 2 is a schematic plan view showing a group of external sensors of the vehicle. [Figure 3] FIG. 1 is a block diagram showing a vehicle cruise control system. [Figure 4] FIG. 2 is a state transition diagram of control in the cruise control system. [Figure 5] 3 is a flowchart showing a control process according to an embodiment of the present invention. [Figure 6] FIG. 2 is a schematic plan view showing an example of the relative positional relationship between the host vehicle and a following vehicle when MRM is activated. [Figure 7] FIG. 10 is a schematic plan view showing another example of the relative positional relationship between the host vehicle and a following vehicle when MRM is activated. [Figure 8] 10 is a flowchart showing a corrective steering direction determination when MRM is activated. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In FIG. 1, a vehicle 1 equipped with a cruise control system according to the present invention includes, in addition to typical automobile components such as an engine and a body, external sensors 21 that detect the environment around the vehicle, internal sensors 22 that detect vehicle information, a group of controllers / actuators for speed control and steering control, an ACC controller 14 for controlling the distance between vehicles, an LKA controller 15 for lane keeping control, and an autonomous driving controller 10 that controls these components to implement partially automated driving within a lane (PADS) and automated driving within a single lane (ALKS).

[0012] The controller / actuator group for speed control and steering control includes an EPS (electric power steering) controller 31 for steering control, an engine controller 32 for acceleration / deceleration control, and an ESP / ABS controller 33. ESP (registered trademark; Electronic Stability Program) includes ABS (anti-lock braking system) to form a stability control system (vehicle behavior stabilization control system).

[0013] The external environment sensor 21 consists of multiple detection means for inputting the presence and relative distance of road dividing lines that define the current lane and adjacent lanes, other vehicles, obstacles, people, etc. around the current vehicle as external environment data such as image data or point cloud data to the automatic driving controller 10.

[0014] 2, vehicle 1 is equipped with a millimeter-wave radar (211) and a camera (212) as forward detection means 211, 212, LIDAR (laser image detection / ranging) as front-side detection means 213 and rear-side detection means 214, and a camera (back camera) as rear detection means 215, which cover 360 degrees around the vehicle and can detect the positions and distances of vehicles and obstacles within a predetermined range in the front, rear, left and right directions of the vehicle, as well as the positions of lane markings in the vehicle's lane and adjacent lanes. Note that millimeter-wave radar (or LIDAR) can also be added as rear detection means.

[0015] The internal sensor 22 is composed of a plurality of detection means for measuring physical quantities that represent the vehicle's motion state, such as a vehicle speed sensor, a yaw rate sensor, and an acceleration sensor. As shown in FIG. 3, each measurement value is input to the autonomous driving controller 10, the ACC controller 14, the LKA controller 15, and the EPS controller 31, and is processed together with the input from the external sensor 21.

[0016] The autonomous driving controller 10 includes an environmental state estimation unit 11, a route generation unit 12, and a vehicle control unit 13, and is composed of a computer for performing the functions described below, namely, a ROM that stores programs and data, a CPU that performs arithmetic processing, a RAM that reads the programs and data and stores dynamic data and arithmetic processing results, and an input / output interface.

[0017] The environmental state estimation unit 11 acquires the absolute position of the vehicle by matching the vehicle position information obtained by a positioning means 24 such as a GPS with map information 23, and estimates the positions of the lane markings of the vehicle and adjacent lanes, and the positions and speeds of other vehicles, based on external data such as image data and point cloud data acquired by an external sensor 21. It also acquires the motion state of the vehicle from internal data measured by an internal sensor 22. It also acquires the state of the driver from a driver status monitor 25.

[0018] The route generation unit 12 generates a target route from the vehicle position to the destination estimated by the environmental state estimation unit 11. In addition, based on the adjacent lane marking positions, other vehicle positions and speeds, and the vehicle's motion state estimated by the environmental state estimation unit 11, the route generation unit 12 generates a target route from the vehicle position to the destination point during automated driving, such as lane keeping, lane changing, or course change.

[0019] The vehicle control unit 13 calculates a target vehicle speed and a target steering angle based on the target route generated by the route generation unit 12, and transmits a speed command for constant speed driving or vehicle-to-vehicle distance maintenance / following driving to the ACC controller 14, and transmits a steering angle command for route following to the EPS controller 31 via the LKA controller 15.

[0020] The vehicle speed is also input to the EPS controller 31 and the ACC controller 14. Because the steering reaction force changes depending on the vehicle speed, the EPS controller 31 refers to a steering angle-steering torque map for each vehicle speed and sends a torque command to the steering mechanism 41. The engine controller 32, the ESP / ABS controller 33, and the EPS controller 31 control the engine 42, the brakes 43, and the steering mechanism 41, thereby controlling the longitudinal and lateral movements of the vehicle 1.

[0021] (Outline of partially automated driving system within lanes) Next, we will provide an overview of the Partially Automated in-lane Driving System (PADS).

[0022] The partially automated driving system (PADS) is a system that combines an adaptive cruise control system (ACCS) and a lane keeping assistance system (LKAS), and can be executed when the ACC controller 14, which constitutes the adaptive cruise control system (ACC) together with the autonomous driving controller 10, and the LKAS controller 15, which constitutes the lane keeping assistance system (LKAS), are both operating.

[0023] At the same time as the in-lane partially automated driving system is activated, the automated driving controller 10 (route generation unit 12) generates a target route and target vehicle speed within a single lane based on external information (lane, vehicle position, position and speed of other vehicles traveling in the lane in which the vehicle is traveling and adjacent lanes) acquired by the environmental state estimation unit 11 through the external sensor 21, and internal information (vehicle speed, yaw rate, acceleration) acquired by the internal sensor 22.

[0024] The automatic driving controller 10 (vehicle control unit 13) calculates the yaw rate γ and lateral acceleration (d 2 y / dt 2 ) the vehicle speed, posture, and lateral displacement after Δt seconds are estimated from the relationship, and a steering angle command that will result in lateral displacement of yt after Δt seconds is given to the EPS controller 31 via the LKA controller 15, and a speed command that will result in speed Vt after Δt seconds is given to the ACC controller 14.

[0025] The ACC controller 14, LKA controller 15, EPS controller 31, engine controller 32, and ESP / ABS controller 33 operate independently of automatic steering, but can also be operated by command input from the automatic driving controller 10 when the partially automated driving system (PADS), automatic lane keeping system (ALKS), and partially automated lane change system (PALS) are in operation.

[0026] The ESP / ABS controller 33, which receives a deceleration command from the ACC controller 14, issues a hydraulic command to an actuator and controls the braking force of the brakes 43, thereby controlling the vehicle speed. Furthermore, the engine controller 32, which receives an acceleration / deceleration command from the ACC controller 14, controls the actuator output (throttle opening) to issue a torque command to the engine 42, thereby controlling the driving force and thereby controlling the vehicle speed.

[0027] The ACC function (ACCS) functions as a combination of hardware and software, such as a millimeter wave radar as forward detection means 211 constituting the external sensor 21, the ACC controller 14, the engine controller 32, and the ESP / ABS controller 33.

[0028] In other words, if there is no preceding vehicle, the vehicle will travel at a constant speed with the ACC set speed (set speed) as the target vehicle speed, and if the vehicle catches up with the preceding vehicle (if the preceding vehicle speed is below the ACC set speed), the vehicle will follow the preceding vehicle while maintaining a distance (set distance) according to the set time gap (time between vehicles = distance between vehicles / vehicle speed) in accordance with the speed of the preceding vehicle.

[0029] The LKA function (LKAS) detects lane markings and the vehicle's position using the environmental state estimation unit 11 of the autonomous driving controller 10 based on image data acquired by the external sensor 21 (cameras 212, 215), and performs steering control using the EPS controller 31 via the LKA controller 15 so that the vehicle can travel in the center of the lane.

[0030] That is, upon receiving a steering angle command from the LKA controller 15, the EPS controller 31 refers to a map of vehicle speed-steering angle-steering torque, issues a torque command to the actuator (EPS motor), and gives the steering mechanism 41 the target front wheel steering angle.

[0031] The partially automated driving system (PADS) is implemented by combining the longitudinal control (speed control, inter-vehicle distance control) by the ACC controller 14 and the lateral control (steering control, lane keeping control) by the LKA controller 15 as described above.

[0032] (System status monitoring) During operation of the partially automated driving system (PADS) within a lane, the environmental state estimation unit 11 constantly monitors whether the vehicle's driving state, surrounding environmental conditions, and driver state are maintained within the system's operational design domain (ODD), based on external information acquired through the external sensor 21, vehicle information acquired by the internal sensor 22, and the driver's state acquired by the driver status monitor 25.

[0033] If the environmental state estimation unit 11 determines that the system operating conditions have deviated, or if it detects an abnormality or failure in the system, and determines that automatic driving cannot be continued stably, a Transition Demand (TD) is notified to the driver.

[0034] If the driver takes over driving operations within a predetermined time (for example, 10 seconds) after the driver's takeover request (TD), the vehicle will transition from partially automated driving within the lane to manual driving. The driver's takeover is detected by a steering torque sensor and a steering wheel grip sensor. On the other hand, if the driver does not take over driving operations within the predetermined time, the Minimal Risk Maneuver (MRM) will be activated and risk minimization control will be implemented.

[0035] (Risk minimization control when operation handover is not carried out) Minimal Risk Maneuver (MRM) refers to a function that automatically transitions to a minimal risk condition when a change in the external driving environment or a system failure occurs and the driver is notified of a takeover request (TD) but is unable to take over. Specifically, it includes control (safe stop) by the autonomous driving controller 10 to decelerate and stop within the lane.

[0036] As mentioned above, the external sensor 21 is composed of multiple sensors, and the autonomous driving controller 10 is designed to be redundant so that if an abnormality occurs in any of the sensors or detection means, a minimal risk maneuver (MRM) can be performed using other sensors or detection means.

[0037] (Emergency avoidance control when a collision is predicted) On the other hand, if a collision with another vehicle is predicted for some reason while the partially automated driving system (PADS) is operating, the emergency maneuver (EM) will be activated and emergency avoidance control will be carried out. The emergency avoidance control (EM) includes the activation of automatic emergency braking (AEB) to mitigate collision damage.

[0038] That is, the environmental state estimation unit 11 constantly calculates the predicted time to collision (TTC) based on information (inter-vehicle distance, relative speed) of the preceding vehicle (or obstacle) detected by the external sensor 21 and the vehicle speed of the vehicle itself acquired by the internal sensor 22, and when it is determined that there is a high possibility of collision, such as when the predicted time to collision is less than a predetermined value, it issues a brake request (hydraulic command) to the actuator of the brake 43 and performs automatic braking (automatic emergency braking).

[0039] (Outline of the partial automatic lane change system) Next, we will explain the overview of the Partially Automated Lane Change System (PALS), assuming a lane change from partially automated driving within a lane (PADS driving) on ​​a highway with two or more lanes in each direction and a median strip.

[0040] The Partial Automated Lane Change System (PALS) automatically changes lanes at the system's discretion or in response to the driver's instructions or approval, and is implemented by combining longitudinal control (speed control, vehicle-to-vehicle distance control) and lateral control (target path tracking control using automatic steering) by the autonomous driving controller 10.

[0041] At the same time as the partial automated lane change system is operating, the automatic driving controller 10 (route generation unit 12) constantly generates a target route for changing lanes from the lane in which the vehicle is currently traveling to an adjacent lane, based on external information (lane markings of the vehicle's own lane and adjacent lanes, positions and speeds of other vehicles traveling in the vehicle's own lane and adjacent lanes) acquired by the environmental state estimation unit 11 through the external sensor 21, and internal information (vehicle speed, yaw rate, acceleration) acquired by the internal sensor 22.

[0042] This automatic lane change target route is a route that leads to a state in which the vehicle changes lanes from the lane in which the vehicle is currently traveling and travels in the center of the adjacent lane.The future positions and speeds of other vehicles traveling in the adjacent lane are predicted, and when it is determined that no other vehicles are present within a specified area in front of, behind, or to the side of the adjacent lane, which is set according to the vehicle speed, the system determines that an automatic lane change is performed using automatic steering.

[0043] Even during a lane change, the surroundings of the vehicle continue to be monitored using external information acquired by the environmental state estimation unit 11 through the external sensor 21, and if it is confirmed that another vehicle has entered (cut in) a specified area in front, behind, or to the side, the automatic driving controller 10 determines whether to continue or cancel the lane change based on the position of the vehicle during the lane change.

[0044] If it is determined that the lane change cannot be continued and the lane change is to be canceled, the automatic driving controller 10 (route generation unit 12) changes the tracking target to the center line of the lane in which the vehicle was traveling before the lane change began (original lane) and regenerates the target route and vehicle speed, and the vehicle control unit 13 gives a steering angle command to the EPS controller 31 and a speed command to the ACC controller 14 to make the vehicle follow the regenerated target route, and returns to the original lane by automatic steering (automotive lane return function).

[0045] Even if it is confirmed that another vehicle has entered (cut in) into the specified area ahead, the specified area behind, or the specified area to the side, if the vehicle has almost moved into the adjacent lane, for example, if three or more of the four wheels have crossed the dividing line and entered the adjacent lane, the lane change will not be stopped but will continue.

[0046] On the other hand, if it is determined that it is difficult to continue the lane change, the system notifies the driver of a takeover request (TD), cancels the automated lane change, and transfers authority to the driver. If the driver takes over, the vehicle transitions to manual driving, but if the driver is unable to take over, the Minimal Risk Maneuver (MRM) is activated.

[0047] (Outline of partially automated driving system within lanes) Next, we will explain the outline of the Automatically Lane Keeping System (ALKS) assuming a situation where a vehicle is operating in partially automated driving mode (PADS) on a highway with a median strip.

[0048] The Automated Lane Keeping System (ALKS) is a system that combines an Acceleration Control System (ACCS) and a Lane Keeping Assist System (LKAS), similar to the Partially Automated Driving System (PADS), and is executed when the ACC controller 14 that constitutes the Acceleration Control System (ACCS) and the Lane Keeping Assist System (LKAS) are both operating together with the autonomous driving controller 10, but can only be executed at speeds of 60 km / h or less.

[0049] When the automatic lane keeping system (ALKS) is operating, the automatic lane change function is stopped and the vehicle maintains a single lane while automatically driving. In addition to the above, the automatic lane keeping system (ALKS) can be executed when the driver status monitor 25 confirms that the driver is ready to take over driving in response to a takeover request, and the driver is not required to pay close attention to the driving situation as long as the driver is seated in the driver's seat and has their seatbelt fastened.

[0050] Because the minimum speed on expressways is set at 50 km / h, if a vehicle is following a vehicle ahead using partially automated driving systems (PADS) and the expressway becomes congested and the vehicle's speed drops below 50 km / h, or if the vehicle catches up with a vehicle ahead that is traveling at less than 50 km / h due to congestion, the vehicle will switch from partially automated driving systems (PADS) to automated lane keeping systems (ALKS).

[0051] 4 shows the state transition of the control in the automated lane keeping system (ALKS). Even when the automated lane keeping system (ALKS) is operating (100), the environmental state estimation unit 11 constantly monitors the vehicle's driving state, the surrounding environmental conditions, and the driver's state. If it determines that the system activation conditions are not met or if a system fault (excluding a serious malfunction, which will be described later) is detected, the system notifies the driver of a request to take over (TD) (120). If the driver takes over driving operations within a predetermined time (for example, 10 seconds), the system transitions from automated lane keeping driving to manual driving (140).

[0052] On the other hand, if the driving operation is not taken over within a predetermined time, the Minimal Risk Maneuver (MRM) is activated and the risk minimization control (130) is executed. Note that if the environmental state estimation unit 11 determines that a serious malfunction has occurred in the system (such as a drop in engine oil pressure, an increase in engine water temperature, or a brake system abnormality that could cause an accident or fire) while the Automated Lane Keeping System (ALKS) is in operation, the operation takeover request (TD) is not made, and the Minimal Risk Maneuver (MRM) is immediately activated and the risk minimization control (130) is executed.

[0053] Furthermore, if a collision is predicted for some reason while the Automated Lane Keeping System (ALKS) is operating (100), such as another vehicle cutting in, a sudden deceleration or collision of a preceding vehicle, or an obstacle (falling object), and the conditions for operating the emergency avoidance control are met, the Emergency Maneuver (EM) is activated and the Automatic Emergency Braking (AEB) is executed as the emergency avoidance control (100).

[0054] In addition, the automated driving systems described above are capable of being overridden by driver intervention, not only when the automated lane keeping system (ALKS) is in operation, but also when the motorway risk minimization control (MRM) or emergency avoidance control (EM) is in operation. In other words, when an override is performed by the driver through acceleration / deceleration intervention (accelerator OR, brake OR) or steering intervention (steering OR), each of the automated driving functions described above is stopped and the system transitions to manual driving by the driver.

[0055] When the risk minimization control (MRM) is activated, the hazard lamps are turned on, the vehicle maintains its lane, and the vehicle decelerates at a predetermined rate (for example, 4.0 m / s 2 However, if the vehicle behind is late in noticing the vehicle and braking, contact or a collision with the vehicle behind may occur.

[0056] (Improved Risk Minimization Control) Therefore, the automatic driving controller 10 according to the present invention is configured to perform corrective steering taking into account the position of the rear vehicle when the risk minimization control (MRM) is activated, and in order to perform such corrective steering, the driving position of the rear vehicle is constantly monitored as follows.

[0057] That is, the environmental state estimation unit 11 constantly detects lane markings, the vehicle's position, and, if a vehicle behind is present within a predetermined distance behind the vehicle's lane, its lateral position within that lane, based on image data acquired by the external sensor 21 (cameras 212, 215).

[0058] For example, as shown in Fig. 6, when a rear vehicle 3 is present within a predetermined distance behind the own vehicle lane, the lateral position y3 of the rear vehicle 3 is detected as the lateral deviation amount (relative deviation amount) and the deviation direction, either left or right, of the center 3c of the rear vehicle 3 relative to the center line 215c of the rear detection area of ​​the vehicle 1. The lateral position y3 of the rear vehicle 3 can also be detected based on the lateral distances y3R, y3L from the lane markings 5R, 5L to the rear vehicle 3. At night, the center 3c can be detected from the left and right headlights of the rear vehicle 3.

[0059] The specified distance behind the vehicle in the own lane is set based on the braking distance at maximum deceleration and the free running distance (reaction distance of the vehicle behind + braking recovery distance) at the same speed as the vehicle behind, assuming that the vehicle behind 3 is following the vehicle behind 1 at the same speed. However, if a distance measurement means (such as millimeter wave radar) is added as a rear detection means, the specified distance behind the vehicle behind 3 may be set based on the estimated vehicle speed of the vehicle behind 3.

[0060] Furthermore, the environmental state estimation unit 11 constantly monitors the presence of adjacent lanes and effective road shoulders that can serve as evacuation spaces for the vehicle 1 and the rear vehicle 3, based on the detection information of the external sensors 21 (212, 213). Note that an effective road shoulder is, for example, a road shoulder with a pavement structure that is 1.75 m or more wide, which is generally provided on expressways, and does not include protected road shoulders that have no pavement structure.

[0061] When the risk minimization control (MRM) is activated, corrective steering is performed in parallel with deceleration as follows:

[0062] FIG. 8 is a flowchart showing the determination of the corrective steering direction when the risk minimization control (MRM) is activated, and corresponds to the search for an evacuation route for the rear vehicle (step 134) in FIG. 5. When the risk minimization control (MRM) is activated (step 133), first, the presence of a rear vehicle is confirmed (step 1341), and if a rear vehicle exists (step 1341; YES), the lateral position of the rear vehicle is referenced (step 1342).

[0063] If the rear vehicle is deviated to either the left or right (step 1342; YES), the direction of corrective steering is determined in the opposite direction (opposite deviation direction) to the lateral deviation of the rear vehicle so that the avoidance width for the rear vehicle to avoid vehicle 1 with as little steering as possible is secured as wide as possible (step 1351).

[0064] For example, as shown in Figure 6, if the rear vehicle 3 is deviated to the right relative to vehicle 1, corrective steering is performed to the left, in the opposite direction to the deviation, so that the rear vehicle 3 can avoid vehicle 1 with less steering and the avoidance width of the rear vehicle 3 is increased.

[0065] The amount of this corrective steering can be, for example, a steering amount that gives a lateral displacement equivalent to the difference between the width of the vehicle 1 and the displacement y3 of the rear vehicle 3 over the travel distance until deceleration and stoppage estimated based on the vehicle speed when the risk minimization control (MRM) is activated, and a corrective steering angle command is given to the EPS controller 31 via the LKA controller 15.

[0066] On the other hand, if the relative lateral deviation of the rear vehicle is equal to or less than a predetermined value (FIG. 8, step 1342; NO), the avoidance action of the rear vehicle cannot be immediately identified, so whether or not a shoulder exists on the adjacent lane or road edge side is checked based on the detection information of the external sensors 21 (212, 213) (step (1343)).

[0067] If an adjacent lane or a valid shoulder is present on either the left or right side of the own lane (step 1343; YES), the direction of corrective steering is determined to be opposite the adjacent lane or shoulder (towards the central reservation) in order to increase the avoidance width for the rear vehicle on those sides (step 1352).

[0068] For example, as shown in Figure 7, if the relative lateral deviation of the rear vehicle 4 is below a predetermined value but there is an effective shoulder (or adjacent lane) on the left side of the vehicle's own lane, corrective steering is performed to the right, in the opposite direction from the shoulder (or adjacent lane), so that a wide avoidance width for the rear vehicle 4 is secured, including the effective shoulder (or adjacent lane).

[0069] Through the process described above, the direction and amount of corrective steering when the risk minimization control (MRM) is activated are determined, and corrective steering is executed in parallel with deceleration at a predetermined deceleration (brake control). This corrective steering is basically executed within the lane, and the amount of steering is minimal, so that the effect on the posture of the vehicle 1 is small, and this can be handled by behavior stabilization control by the ESP / ABS controller 33.

[0070] (Control flow when the automatic lane keeping system is operating) Next, the control flow (FIG. 5) during operation of the automatic lane keeping system will be described.

[0071] (1) Automatic Lane Keeping System (ALKS) operation When the vehicle is following a preceding vehicle using partially automated driving within a lane (PADS driving) and the vehicle speed drops below 60 km / h, the system switches to the automated lane keeping system (ALKS) (step 100).

[0072] (2) Collision possibility determination While the Automated Lane Keeping System (ALKS) is operating, collision possibility determination is always performed (step 101). That is, if the collision prediction time (TTC) becomes equal to or less than a predetermined value due to sudden braking of a preceding vehicle, sudden cutting in of another vehicle, or the appearance of a stopped vehicle or obstacle due to a preceding vehicle changing lanes (steerage avoidance), and it is determined that there is a collision possibility, the system transitions to emergency avoidance control (EM) (step 110).

[0073] (3) Emergency Avoidance Control When the system shifts to emergency avoidance control (EM), the collision determination flag is set (step 111), and at the same time, the automatic emergency brake (AEB) is activated as emergency avoidance control (step 112), and the maximum deceleration (5 m / s 2 Automatic emergency braking is performed when the vehicle is in a state where ...

[0074] (5) Determining whether an override is present during EM operation The determination of whether or not an override is present continues even while emergency avoidance control (automatic emergency braking) is in operation (step 113), and if steering intervention equal to or greater than a predetermined steering override threshold, accelerator operation intervention equal to or greater than a predetermined accelerator override threshold, or brake operation intervention equal to or greater than a predetermined brake override threshold is detected, the automated lane keeping system (ALKS) stops and the vehicle transitions to manual driving (step 140).

[0075] (6) Emergency avoidance control completion determination It is determined whether the emergency avoidance control (EM) has been completed based on the vehicle state and the surrounding environment (step 114). That is, if the imminent risk of a collision has disappeared (due to an emergency stop or a change in the surrounding environment) or if the system has been deactivated by the driver, it is determined that the emergency avoidance control has been completed, the hazard lights are flashed (step 115), and the automated lane keeping system (ALKS) is stopped (step 140).

[0076] (7) Serious failure determination While the Automated Lane Keeping System (ALKS) is operating, the vehicle's self-diagnosis function constantly determines whether a serious malfunction has occurred (step 102). Serious malfunctions include a drop in engine oil pressure, an increase in engine water temperature, and a brake system abnormality, which can lead to an accident or fire. If a serious malfunction is determined to have occurred, a serious malfunction flag is set (step 131), and the system transitions to risk minimization control (MRM) (130).

[0077] (8) System startup conditions not met or failure determination While the automated lane keeping system (ALKS) is operating, the environmental state estimation unit 11 constantly determines whether the vehicle's driving state and the surrounding environmental conditions are being maintained within the operational design domain (ODD) of the system, the driver status monitor 25 determines whether the driver is ready to take over driving, and the vehicle's self-diagnosis function determines whether any of the components of the automated lane keeping system have a failure or malfunction (step 103). In addition to road conditions and vehicle speed, the ODD of the automated lane keeping system includes environmental conditions such as strong winds, and system failures and external sensor failures also fall under these conditions.

[0078] If the system activation conditions are not met or a malfunction is determined, a warning to stop the automated lane keeping system (ALKS) and a request to take over (TD) are sent (step 120), and a predetermined time (for example, 10 seconds) is started to count (step 121). (9) Driving transfer decision In step 122, if the takeover of driving operations is confirmed by detecting steering torque or the like within a predetermined time (e.g., 10 seconds), the automated lane keeping system (ALKS) is stopped and the system transitions to manual driving (step 140). On the other hand, if the takeover of driving operations is not confirmed within the predetermined time, the system transitions to risk minimization control (MRM) (130).

[0079] (10) Risk minimization control When transitioning to risk minimization control (MRM), the hazard lights are activated (step 132) and at the same time the minimal risk maneuver (MRM) is activated (step 133), and the autonomous driving controller 10 starts control to decelerate and stop the vehicle at a predetermined deceleration rate (for example, 4.0 m / s2 or less) while maintaining the lane in which the vehicle is traveling.

[0080] (11) Route search to avoid rear vehicles At the same time, the presence or absence of a rear vehicle within a predetermined distance behind is checked, and if a rear vehicle is present, the corrective steering direction is determined based on its lateral position (step 134; Figure 8, steps 1341 to 1353), and corrective steering is performed in parallel with deceleration at a predetermined deceleration (step 135).

[0081] (12) Determining whether or not an override is present during MRM operation The determination of whether or not an override has occurred continues even while the risk minimization control (MRM) is operating (step 136). If a steering intervention equal to or greater than a predetermined steering override threshold, an accelerator operation intervention equal to or greater than a predetermined accelerator override threshold, or a brake operation intervention equal to or greater than a predetermined brake override threshold is detected, the automated lane keeping system (ALKS) is stopped and the vehicle transitions to manual driving (step 140).

[0082] (13) Risk minimization control completion determination It is determined whether or not the risk minimization control (MRM) is complete based on the vehicle state (step 137). That is, if the system is deactivated or the system has stopped the vehicle, it is determined that the risk minimization control is complete, and the automatic lane keeping system (ALKS) is stopped (step 140), the hazard lamps are kept flashing, and all other vehicle systems are stopped.

[0083] (Action and effect) As described above in detail, the vehicle driving control device of the present invention determines the direction of corrective steering based on the lateral position (y3) of the rear vehicle 3 within a specified distance behind the vehicle's own lane when risk minimization control (MRM) is activated, and performs corrective steering during deceleration.Therefore, even if the rear vehicle is slow to notice or brake, an avoidance route for the rear vehicle is secured by corrective steering, which has the advantage of reducing the risk of contact or collision with the rear vehicle.

[0084] For example, as shown in Figure 6, when the risk minimization control (MRM) is activated, vehicle 1 moves to the left side of the lane and stops, as shown by the symbol 1', by corrective steering to the left, opposite to the relative lateral deviation y3 of the rear vehicle 3. Therefore, even if the rear vehicle 3 is slow to notice or brake, and steering to avoid the collision is insufficient, corrective steering will ensure an avoidance route to the right of vehicle 1', approximately in front of the advancing rear vehicle 3', increasing the possibility of avoiding contact or collision with the rear vehicle 3'.

[0085] In this case, corrective steering is performed within the lane in which the vehicle 1 is traveling, which has the advantage that there is no need to consider the movement of vehicles in adjacent lanes, and control can be performed immediately regardless of the movement of vehicles in adjacent lanes.

[0086] In addition, when the risk minimization control (MRM) is activated, if the lateral deviation of the rear vehicle 4 is below a predetermined value, a check is made to see if there is an adjacent lane or an effective shoulder on the road edge side, and if there is an adjacent lane or an effective shoulder that can provide avoidance space for the rear vehicle 4, corrective steering is performed in the opposite direction to widen the avoidance width for the rear vehicle 4, thereby reducing the possibility of vehicle 1 being rear-ended by the rear vehicle 4.

[0087] For example, as shown in Figure 7, if a valid shoulder is detected on the right side of the lane in which vehicle 1 is traveling, corrective steering is performed in the opposite direction to the right, and by moving to the right side of the lane and stopping as shown by symbol 1', a sufficient avoidance width, including the shoulder, is secured on the left side of vehicle 1', and the rear vehicle 3' can move to the avoidance space with relatively little steering, increasing the possibility of avoiding contact or collision with the rear vehicle 3'.

[0088] In addition, if there is no adjacent lane or effective shoulder when the risk minimization control (MRM) is activated, corrective steering is performed toward the edge of the road within the vehicle's own lane, ensuring an avoidance width for the vehicle behind on the opposite side of the road edge, thereby minimizing the possibility of a rear-end collision after decelerating and stopping and the impact on traffic flow.

[0089] (Other Examples) In the above embodiment, the case where corrective steering is performed within the lane in which the vehicle 1 is traveling when the risk minimization control (MRM) is activated has been mainly described. However, corrective steering may also be performed across the dividing lines 5L, 5R between the vehicle 1 and an adjacent lane or road shoulder. Therefore, corrective steering may be performed by at least partially moving the vehicle 1 from the lane in which the vehicle 1 is traveling to the adjacent lane or road shoulder. In particular, if the relative lateral deviation of the rear vehicle is equal to or less than a predetermined value, corrective steering may also be performed by changing lanes to the adjacent lane or road shoulder, provided that it is confirmed that no other vehicles or obstacles exist within a predetermined range before or after the adjacent lane or road shoulder.

[0090] In addition, in the above embodiment, the control state transition during operation of the Automated Lane Keeping System (ALKS) has been mainly described, but the corrective steering control according to the present invention may also be executed when the Risk Minimization Control (MRM) is activated during operation of other automated driving functions, such as the Partially Automated Driving System (PADS) or the Partially Automated Lane Changing System (PALS).

[0091] Although several embodiments of the present invention have been described above, it should be noted that the present invention is not limited to the above-described embodiments, and various modifications and variations are possible within the scope of the present invention. [Explanation of symbols]

[0092] 10 Autonomous Driving Controller 11 Environmental state estimation unit 12 Route generation unit 13 Vehicle control unit 14 ACC controller 15 LKA controller 21 External Sensor 22 Internal Sensors 25 Driver Status Monitor 31 EPS controller 32 Engine Controller 33 ESP / ABS controller 34 Manual steering (handle)

Claims

1. an environmental state estimation unit including a surroundings recognition function for recognizing the current lane, adjacent lanes, other vehicles on each lane, and the surrounding environment, and a function for acquiring the current vehicle motion state; a route generation unit that generates a target route based on information acquired by the environmental state estimation unit; a vehicle control unit that performs speed control and steering control so as to make the host vehicle follow the target route; A vehicle driving control device comprising: A function that maintains the set vehicle speed when there is no preceding vehicle in the vehicle's lane, and automatically drives within the lane while maintaining the set vehicle distance when there is a preceding vehicle. an MRM function that executes risk minimization control, including decelerating and stopping the vehicle within the lane, when a system failure occurs during operation of the in-lane automatic driving function or when operation is not handed over to the driver when a system failure occurs; In those having A vehicle driving control device characterized in that, when the MRM function is activated, if a rear vehicle is present in the vehicle's lane and the lateral position of the rear vehicle is deviated to either the left or right relative to the vehicle's driving position, the direction of corrective steering is determined in the direction opposite to the deviation, and corrective steering is performed during deceleration.

2. 2. A vehicle driving control device according to claim 1, characterized in that, when the MRM function is activated, if a rear vehicle is present in the own lane, the deviation of the lateral position of the rear vehicle is equal to or less than a predetermined value, and there is no adjacent lane or shoulder on the road edge side, the direction of the corrective steering is determined to be toward the road edge side, and if there is an adjacent lane or shoulder on the road edge side, the direction of the corrective steering is determined to be toward the center divider side.

3. An environmental state estimation unit including a surrounding recognition function for recognizing the vehicle's own lane, adjacent lanes, other vehicles on each lane, and the surrounding environment, and a function for acquiring the vehicle's own vehicle motion state; a route generation unit that generates a target route based on information acquired by the environmental state estimation unit; a vehicle control unit that performs speed control and steering control so as to make the host vehicle follow the target route; A vehicle driving control device comprising: A function that maintains the set vehicle speed when there is no preceding vehicle in the vehicle's lane, and automatically drives within the lane while maintaining the set vehicle distance when there is a preceding vehicle. an MRM function that executes risk minimization control, including decelerating and stopping the vehicle within the lane, when a system failure occurs during operation of the in-lane automatic driving function or when operation is not handed over to the driver when a system failure occurs; In those having A vehicle driving control device characterized in that, when the MRM function is activated, if a rear vehicle is present in the vehicle's lane and the lateral position of the rear vehicle is deviated to either the left or right within the lane, the direction of corrective steering is determined in the direction opposite to the deviation, and corrective steering is performed during deceleration.

4. 4. The vehicle cruise control device according to claim 1, wherein the corrective steering when the MRM function is activated is performed within the lane in which the vehicle is traveling.

5. The vehicle driving control device according to any one of claims 1 to 3, characterized in that the corrective steering when the MRM function is activated includes at least a partial movement from the lane in which the vehicle is traveling to an adjacent lane or a shoulder.

Images