Vehicle driving assistance systems

Abstract

To eliminate the need of steering override and obtain high convenience when a driver drives under a circumstance matching with a corner where the steering override was performed in the past.SOLUTION: A driving support control unit 11 includes a driving support control section 11a and a storage section 11b. When steering wheel operation of a driver during cornering travel is determined to be steering override when steering wheel operation of a driver during cornering travel is determined to be steering override, the driving support control section 11a acquires various situation data including curvature data of corners in time-sequence and causes the storage section 11b to store the data as cornering data this time. When an own vehicle M is determined to be presently approaching a corner or during a cornering travel, the driving support control section checks whether or not the curvature data matching with a curvature of the corner exists in past situation data stored in the storage section 11b, and when the matched curvature data exists, corrects an instructed target steering angle with situation data having the matched curvature data and sets a corrected target steering angle as an instructed target steering angle this time.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a vehicle driving support device that stores various situation data when a driver performs a steering override operation during traveling under automatic steering control, and corrects an instructed target steering angle based on the stored situation data when traveling in the same situation.

Background Art

[0002] Conventionally, various driving support devices have been proposed to reduce the driver's burden and enable comfortable and safe driving, and some have already been put into practical use. This type of driving support includes an Adaptive Cruise Control (ACC) function and an Active Lane Keep Bouncing (ALKB) control function with a lane departure suppression function, so that the host vehicle can be automatically driven along a target travel path set in the center of the travel lane while maintaining the vehicle-to-vehicle distance from the preceding vehicle.

[0003] Also, in automatic driving support, when a driver inputs a destination using a car navigation system mounted on the host vehicle, the car navigation system detects the current position of the host vehicle based on position information received from positioning satellites such as Global Navigation Satellite System (GNSS) satellites, and constructs a travel route from the host vehicle position to the destination by matching with road map information. Then, in a section where automatic driving is possible in the constructed travel route, the automatic driving support device sets the target travel path for the host vehicle to travel in the center of the travel lane, and autonomously drives the host vehicle along the target travel path on behalf of the driver (navigation-linked route travel).

[0004] Furthermore, if the driver assistance system detects steering intervention by the driver (steering override), the ongoing driver assistance is deactivated, and control of the vehicle is handed over to the driver. In contrast, for example, Patent Document 1 (Japanese Patent Application Publication No. 2012-51441) discloses a technology in which the system stops autonomous driving when it detects a steering override by the driver, but resumes autonomous driving when no steering override is detected.

[0005] Furthermore, Patent Document 1 discloses a technology for generating a target route for autonomous driving by taking into account past steering override information stored in a database. Specifically, in this document, surrounding environment information and vehicle information are stored in a database as past steering override information, and when matching conditions (similar scenes) are detected, a correction value for the target route is calculated from the surrounding environment information and vehicle information of those matching conditions, and this target route is corrected with the correction value to generate a new target route. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2012-51441 [Overview of the project] [Problems that the invention aims to solve]

[0007] However, the override disclosed in the aforementioned literature is a brake override caused by the driver applying the brakes while cornering. Therefore, the subsequent correction value for the target path under matching conditions is simply calculated by comparing the change in speed during corner entry with the change in speed along the target path, and determining the speed correction amount from the difference in speed changes.

[0008] Therefore, if steering override is detected while driving through a corner, even if matching conditions are subsequently detected, the automatic steering control will not reflect the change in steering angle caused by the driver's steering wheel operation in the target path. This means that when driving through a corner with matching conditions, the driver will have to repeatedly perform a steering override, which will be inconvenient.

[0009] The present invention aims to provide a vehicle driving assistance device that eliminates the need for the driver to perform a steering override when driving in a situation that coincides with a corner in which the driver has previously performed a steering override, thereby providing high convenience. [Means for solving the problem]

[0010] The present invention relates to a vehicle driving assistance device comprising: a driving environment information acquisition unit that acquires driving environment information in front of the vehicle; a vehicle state detection unit that detects the state of the vehicle; a storage unit that stores various data; and a driving assistance control unit that sets an instructed target steering angle to drive the vehicle along a target path set in front of the vehicle and performs steering control according to the instructed target steering angle, wherein the driving assistance control unit comprises: a steering override determination unit that checks whether the driver's steering operation during cornering is a steering override; a situation data acquisition unit that, if the steering override determination unit determines that there is a steering override, acquires various situation data, including corner curvature data, in a time series and stores it in the storage unit as the current cornering data; and based on the driving environment information acquired by the driving environment information acquisition unit or the target path, the current vehicle proceeds to the corner. The system includes: a cornering operation determination unit that checks whether the vehicle is entering or cornering; a curvature data matching determination unit that, if the cornering operation determination unit determines that the vehicle is currently entering or cornering, checks whether there is any curvature data in the situation data stored in the storage unit that matches the curvature of the corner determined based on the driving environment information acquired by the driving environment information acquisition unit or the target path; a target steering angle setting unit that, if the curvature data matching determination unit determines that there is any matching curvature data in the situation data stored in the storage unit, corrects the indicated target steering angle with the past situation data having the matching curvature data and sets the corrected target steering angle; and a steering control unit that, if the corrected target steering angle is set in the target steering angle setting unit, sets the said target steering angle as the current indicated target steering angle. The situation data acquired by the situation data acquisition unit includes external environmental elements that affect the vehicle and internal environmental elements related to the vehicle, and the target steering angle setting unit includes an element detection unit that detects the internal environmental elements and the external environmental elements, an environmental element comparison unit that compares the internal and external environmental elements of the situation data with the current external and internal environmental elements detected by the element detection unit, and a corrected target steering angle setting unit that calculates a steering override correction amount according to the results of the comparison by the environmental element comparison unit, corrects the indicated target steering angle with the steering override correction amount, and sets the corrected target steering angle. Equipped with The driving support control unit further includes a driving control unit that controls the speed of the vehicle, and the target steering angle setting unit further includes a deceleration instruction unit that outputs a deceleration instruction to the driving control unit to reduce the current vehicle speed of the vehicle if the ratio of the yaw rate calculated based on the indicated target steering angle and the yaw rate calculated based on the corrected target steering angle exceeds a preset threshold. . [Effects of the Invention]

[0011] According to the present invention, if the driver's steering input during cornering is determined to be a steering override, various situational data, including the curvature data of the corner, are acquired in a time series and stored in the memory as the current cornering data. Furthermore, if it is determined that the vehicle is currently entering a corner or cornering, the system checks whether curvature data matching the curvature of the current corner exists in the past situational data stored in the memory. If matching curvature data exists, the system corrects the target steering angle using the situational data containing this matching curvature data and sets the corrected target steering angle as the current target steering angle. As a result, when driving in a situation that matches a corner in which the driver has previously performed a steering override, the driver does not need to perform a steering override, thus providing high convenience. [Brief explanation of the drawing]

[0012] [Figure 1] Schematic diagram of the driver assistance system [Figure 2] flowchart showing the automatic steering control routine [Figure 3] Flowchart showing the routine for acquiring situation data during steering override. [Figure 4] Flowchart showing the subroutine for setting the corrected target steering angle. [Figure 5] This time chart shows the state after correcting the target steering angle during cornering using the steering angle correction amount. [Figure 6] Conceptual diagram of the deceleration setting table [Figure 7] An overhead view showing the basic target steering angle and the corrected target steering angle during cornering. [Figure 8] Figure 7 is an overhead view showing the basic target steering angle and the corrected target steering angle when passing an oncoming vehicle. [Figure 9] An overhead view showing the basic target steering angle and the corrected target steering angle when cornering through a series of curves. [Modes for carrying out the invention]

[0013] An embodiment of the present invention will be described below with reference to the drawings. In this embodiment, for convenience, the road will be described as one where left-hand traffic is permitted. Therefore, on roads where right-hand traffic is permitted, the left and right lanes will be reversed and applied accordingly.

[0014] In Figure 1, the driver assistance device 1 installed in the vehicle M (see Figures 7 to 9) has a driver assistance control unit 11. Furthermore, this driver assistance control unit 11 includes a driver assistance control unit 11a that performs necessary driver assistance such as vehicle speed control and steering control during autonomous driving, and a storage unit 11b that stores various data such as driving data indicating the driving state of the vehicle M when the driver performs a steering override, and surrounding environment data.

[0015] Furthermore, the forward driving environment recognition unit 21d, which is provided in the driver assistance control unit 11a and the camera unit 21 (described later as a driving environment information acquisition unit), is composed of a microcontroller equipped with a CPU, RAM, ROM, rewritable non-volatile memory (flash memory or EEPROM), and peripheral devices. The ROM stores programs and fixed data necessary for the CPU to execute various processes. The RAM is provided as the CPU's work area, and various data from the CPU is temporarily stored there. The CPU is also called an MPU (Microprocessor) or processor. Alternatively, a GPU (Graphics Processing Unit) or GSP (Graph Streaming Processor) may be used instead of a CPU. Alternatively, a selective combination of CPU, GPU, and GSP may be used.

[0016] Furthermore, systems and sensors necessary for performing autonomous driving are connected to the input side of the driver assistance control unit 11. These systems and sensors include a camera unit 21, a car navigation system 22, and a vehicle speed sensor 23, a steering angle sensor 24, a yaw rate sensor 25, a steering torque sensor 26, etc., and each of these sensors 23 to 26 corresponds to the vehicle state detection unit of the present invention, which detects the state of the vehicle M.

[0017] Here, the camera unit 21 is fixed to the upper center of the front part inside the vehicle cabin of the host vehicle M, and includes an in-vehicle camera (stereo camera) composed of a main camera 21a and a sub-camera 21b disposed at symmetrical positions on both sides of the center in the vehicle width direction (vehicle width center), an image processing unit (IPU) 21c, and a forward driving environment recognition unit 21d.

[0018] This camera unit 21 captures reference image data with the main camera 21a and comparative image data with the sub-camera 21b. Then, these two image data are subjected to predetermined image processing by the IPU 21c. The forward driving environment recognition unit 21d reads the reference image data and the comparative image data that have been subjected to image processing by the IPU 21c, and calculates distance information data (distance from the host vehicle M to the object) of the same object in both images based on the parallax thereof using the principle of triangulation.

[0019] Next, well-known grouping processing is performed on this distance information, and the grouped distance information is compared (pattern matching) with three-dimensional road shape data, solid object data, etc. stored in advance. Thereby, forward driving environment information such as curvature data of a corner, road shape data such as an intersection, lane line data partitioning the left and right of a lane, and moving object data including an oncoming vehicle is extracted.

[0020] Further, the car navigation system 22 has a positioning radio wave receiving unit (not shown). The car navigation system 22 acquires position information (coordinates such as latitude, longitude, altitude, etc.) of the host vehicle M based on a position signal from a positioning satellite such as GNSS received by this positioning radio wave receiving unit. Then, the car navigation system 22 displays a driving route to a destination set by the driver on a high-precision road map information (dynamic map) stored in the high-precision road map database 22a, and superimposes the current position of the host vehicle M on the coordinates of the acquired vehicle position. Such road map information includes the shape of roads and structures, lane information, etc. required when automatically driving the host vehicle M.

[0021] Furthermore, the vehicle speed sensor 23 detects the vehicle speed (own vehicle speed) of the vehicle M from the average value of the wheel speeds detected by the wheel speed sensors installed on the four wheels. The steering angle sensor 24 detects the steering angle of the steering wheels. The yaw rate sensor 25 detects the yaw rate acting on the vehicle M. The steering torque sensor 26 detects the steering torque generated by the driver's steering wheel operation.

[0022] On the other hand, the output side of this driver assistance control unit 11 is connected to a brake drive unit 31, an electric power steering motor drive unit (EPS drive unit) 32, an acceleration / deceleration control unit 33, and a notification device 34 such as a monitor and speaker that notifies the driver of information to alert them.

[0023] Here, the brake drive unit 31 drives a brake actuator (not shown) and adjusts the brake fluid pressure supplied to the wheel cylinders of the brake calipers on each wheel, thereby forcibly decelerating the vehicle M to a predetermined speed. The EPS drive unit 32 drives an EPS motor to control the steering of the vehicle M while it is driving. The acceleration / deceleration control unit 33 controls the driving force of the drive source (engine, electric motor, etc.) (engine braking or regenerative braking) and, in coordinated control with the brake drive unit 31, converges the vehicle speed to the target speed while it is driving.

[0024] Incidentally, in autonomous driving, the target path is basically set to the center of the driving lane. Therefore, even when cornering using autonomous driving, the driver assistance control unit 11a sets the target path to the center of the driving lane, which is divided into left and right sections by lane markings. For this reason, the driver assistance control unit 11a transmits a drive signal to the EPS drive unit 32 that corresponds to the instructed target steering angle (see Figures 7 to 9) for tracing the target path.

[0025] However, depending on the driver's steering feel, they may feel uncomfortable driving their vehicle M along the center of the lane when cornering. In other words, as shown by the dashed line in Figure 7, drivers who prefer to drive their vehicle M on the inside of the lane when cornering will find that their vehicle M is traveling on a trajectory different from what they envisioned, forcing them to oversteer each time.

[0026] Therefore, the driver assistance control unit 11a learns the driver's preferences when cornering, and when cornering in a similar environment and on a similar road shape, it learns and corrects the pre-stored basic target route to the driver's preferred route, and sets an instructed target steering angle to trace the new target route.

[0027] The learning correction performed by the driver assistance control unit 11a during cornering is processed in the automatic steering control routine shown in Figure 2.

[0028] In this routine, first, in step S1, it is checked whether the vehicle M is in autonomous driving mode. For example, if the autonomous driving switch (not shown) is ON and the current driving route constructed by the car navigation system 22 satisfies the driving conditions for autonomous driving (such as driving in an autonomous driving section), it is determined that the vehicle is in autonomous driving mode and the process proceeds to step S2. If the autonomous driving switch is OFF, or if the current driving route is not an autonomous driving section, the routine is exited.

[0029] In step S2, it is checked whether the vehicle M is performing a cornering maneuver (entering a corner or driving while cornering). Whether the vehicle M is performing a cornering maneuver is determined, for example, based on the road curvature of the driving route in front of the vehicle M set from the driving route, the road curvature set from the road shape (road curvature) in front of the vehicle M acquired by the camera unit 21, or the change in steering angle detected by the steering angle sensor 24. Note that the processing in this step S2 corresponds to the cornering maneuver determination unit of the present invention.

[0030] Then, if the driver assistance control unit 11a determines that the vehicle M is performing a cornering maneuver, it proceeds to step S3. If it determines that the vehicle M is not performing a cornering maneuver, it jumps to step S9.

[0031] Step S3 checks for steering override caused by the driver's intentional steering input. Whether or not the driver is performing a steering override is determined, for example, by comparing the steering torque detected by the steering torque sensor 26 with a preset override determination threshold. This process in step S3 corresponds to the steering override determination unit of the present invention.

[0032] If the steering torque is less than the steering torque threshold, the driver assistance control unit 11a determines that the driver has not performed an intentional steering operation and proceeds to step S4. If the steering torque is equal to or greater than the steering torque threshold, the driver assistance control unit 11a determines that the driver has intentionally performed a steering override and branches to step S5.

[0033] In step S5, it is determined whether the steering override is due to a transient steering action, such as the driver attempting to avoid an obstacle, or to a continuous steering action during cornering. Whether the steering action is transient or not is determined, for example, based on the duration for which the steering torque detected by the steering torque sensor 26 is above the steering torque threshold.

[0034] If the duration is equal to or greater than the judgment time (for example, 0.5 to 1.0 [sec]), it is determined to be a continuous steering override, and the process proceeds to step S6. If the duration is less than the judgment time, it is determined to be a transient steering override, and the process branches to step S7.

[0035] If the process proceeds to step S6, the steering override data acquisition flag Fovr is set (Fovr←1), and the process jumps to step S9. Alternatively, if the process branches to step S7, the automatic driving is deactivated and the routine is exited. When deactivating automatic driving, the notification device 34 notifies the driver in advance that automatic driving will be deactivated and the system will switch to manual driving.

[0036] The value of the steering override data acquisition flag Fovr, as described above, is read in the steering override situation data acquisition routine shown in Figure 3.

[0037] Now, we will interrupt the explanation of the automatic steering control routine shown in Figure 2 and explain the processing in the routine shown in Figure 3. Note that the processing in this routine corresponds to the status data acquisition unit of the present invention.

[0038] In this routine, first, in step S11, the value of the steering override data acquisition flag Fovr is checked. If Fovr=0, which indicates a transient override, the routine is exited. If Fovr=1, which indicates a continuous steering override, the process proceeds to step S12, where the difference between the target steering angle (instructed target steering angle) that traces the basic target path during cornering, as set by the driver assistance control unit 11a, and the actual steering angle (actual steering angle) detected by the steering angle sensor 24 is calculated at each calculation cycle. This records the driver's steering pattern during a steering override.

[0039] Next, the process proceeds to step S13, where various current situation data are acquired. The situation data acquired includes autonomous driving elements, override elements, external environment elements, internal environment elements, etc. Data for autonomous driving elements includes the vehicle speed detected by the vehicle speed sensor 23, corner curvature data obtained from road map information read by the car navigation system 22 or forward driving environment information extracted by the camera unit 21, lateral position data of the vehicle M relative to the basic target route, and the presence or absence of oncoming vehicles.

[0040] Override elements include the actual steering angle detected by the steering angle sensor 24. External environmental elements are those that affect the vehicle M, such as road surface μ and weather information. Here, road surface μ and weather information are acquired from external devices of the vehicle M via the car navigation system 22 through vehicle-to-vehicle communication, vehicle-to-infrastructure communication, information distribution communication, etc. Alternatively, they are estimated from the forward driving environment information of the camera unit 21.

[0041] Furthermore, internal environmental factors are elements related to the vehicle M itself, and include the number of occupants, load weight (sprung weight), tire pressure, tire condition, etc. Here, the number of occupants is analyzed by analyzing voice collected by a hands-free microphone equipped in the car navigation system 22, for example. The load weight is estimated based on the differential value of the vehicle speed (acceleration) detected by the vehicle speed sensor at the time of starting and the change in output of the drive source (engine or electric motor), for example.

[0042] Furthermore, the tire pressure checks whether the air pressure is low or not, while the tire condition checks whether the tires have been replaced and the degree of tire wear. These are estimated, for example, by calculating the distance traveled per rotation from the rotation speed and distance traveled of each tire detected by each wheel speed sensor, and comparing it with a preset reference distance.

[0043] Next, the process proceeds to step S14, where the driver assistance control unit 11a checks whether the driver's steering override has ended. The end of the steering override is determined by whether the steering torque detected by the steering torque sensor 26 has fallen below the steering torque threshold. If the steering torque is equal to or greater than the steering torque threshold, it is determined that the steering override is continuing, and the process returns to step S12. If the steering torque is below the steering torque threshold, it is determined that the steering override has ended, and the process proceeds to step S15.

[0044] In step S15, various situational data, including the difference between the current target steering angle and the actual steering angle, are acquired in chronological order and stored as the current cornering data at a predetermined address in non-volatile memory, before proceeding to step S16. In step S16, the steering override data acquisition flag Fovr is cleared and the routine is exited.

[0045] Now, let's return to the routine shown in Figure 2. Moving from step S3 to step S4 in Figure 2, it is checked whether past situation data, including corner curvature data that matches the curvature of the corner being entered or already entered, is stored in the non-volatile memory. This corner curvature data is obtained from road map information, or the corner curvature is calculated based on the forward driving environment information of the camera unit. Furthermore, this degree of match does not need to be perfect; it is sufficient if it falls within a preset ± tolerance value. Note that the processing in step S4 corresponds to the curvature data matching determination unit of the present invention.

[0046] If no matching curvature data exists, the process jumps to step S9. If matching curvature data exists in the past, the process proceeds to step S8, where the corrected target steering angle (corrected target steering angle) for cornering is set based on the past situation data with matching curvature data. This corrected target steering angle is set in the corrected target steering angle setting subroutine shown in Figure 4. Note that the processing in Figure 4 corresponds to the target steering angle setting unit of the present invention.

[0047] In this subroutine, first, in step S21, situational data including the curvature data of the matching corner is read from non-volatile memory. Next, the process proceeds to step S22, where the current internal environmental elements of the vehicle M (number of occupants, load weight, tire pressure, tire condition, etc.) and external environmental elements (road surface μ, weather information, etc.) are detected. The method for detecting these internal and external environmental elements has been described previously, so the explanation is omitted here. Note that the processing in step S22 corresponds to the element detection unit of the present invention.

[0048] Subsequently, the process proceeds to step S23, where the internal and external environmental elements included in past situation data are compared with the internal and external environmental elements detected in the current step. If the compared environmental elements match, the process branches to step S24. If at least one of the internal and external environmental elements does not match, the process proceeds to step S25. Note that the processing in step S23 corresponds to the environmental element comparison unit of the present invention.

[0049] Proceeding to step S24, the system corrects the instructed target steering angle set for the corner based on the autonomous driving elements and override elements of the situation data read from the non-volatile memory, and sets a new target steering angle (corrected target steering angle) (see Figures 7-9), and then proceeds to step S9 in Figure 2.

[0050] On the other hand, proceeding to step S25, the internal and external environmental elements of the current situation are compared with the internal and external environmental elements of the situation data, and the degree of influence is calculated when the target steering angle is corrected as is based on the autonomous driving elements and override elements stored in past situation data.

[0051] For example, regarding external environmental factors, if the weather is rainy or snowy and the road surface μ is lower than the road surface μ in the situation data, if the cornering driving is performed using the road surface μ in the situation data as is, there is a possibility that the behavior of the vehicle M will become unstable, i.e., the impact will be higher. Also, regarding internal environmental factors, if the load weight in this case is higher than the load weight in the situation data, if the target steering angle is corrected using the steering angle in the situation data as is, there is a possibility that the steering angle will be insufficient to complete the corner (steering override), i.e., the impact will be higher.

[0052] Next, the process proceeds to step S26, where a steering override correction amount is calculated according to the aforementioned degree of influence. For example, if the road surface μ in this case is lower than the road surface μ in the situation data, the actual steering angle of the override element read in this case (override steering angle due to the driver's steering wheel operation) is corrected by a correction amount determined in advance from experiments, etc., to set the steering override correction amount. In this case, it is also acceptable to steer at a gradual angular velocity until the target steering angle is reached. Furthermore, for example, if the load weight in this case has increased compared to the load weight in the situation data, a correction amount (steering override correction amount) that corrects the override amount, determined in advance from experiments, etc., is set according to the increase.

[0053] As a result, the target steering angle shown by the solid line in Figure 5 is not directly corrected by the steering angle included in the override element shown by the dashed line (override steering angle), but is corrected by a steering override correction amount (dashed line) that limits it.

[0054] Next, the process proceeds to step S27, where the indicated target steering angle is corrected by the steering override correction amount to set a new target steering angle (corrected target steering angle) (see Figures 7 to 9), and then the process proceeds to step S28. Note that the processing in step S27 corresponds to the corrected target steering angle setting unit of the present invention.

[0055] In step S28, the ratio R is calculated between the yaw rate A, obtained by differentiating the target steering angle with respect to time, and the yaw rate B, obtained by differentiating the corrected target steering angle with respect to time (R = (B / A) * 100 [%]). Next, in step S29, this ratio R is compared with a pre-set threshold C. The threshold C is the upper limit of the level at which driving stability during cornering is not compromised, and is determined and set in advance through experiments, etc.

[0056] If R > C, it is determined that cornering with the newly set target steering angle will compromise driving stability, and the process proceeds to step S30. If R ≤ C, the process proceeds to step S9 in Figure 2.

[0057] In step S30, a target vehicle speed is set such that the ratio R becomes the threshold C, and the driving control unit (not shown) provided in the driving support control unit 11a outputs an instruction for the set target vehicle speed. Next, in step S31, a deceleration is set according to the difference Δ1 between the ratio R and the threshold C. That is, in this step S31, the deceleration setting table is referred to based on the difference Δ1. Figure 6 shows the concept of the deceleration setting table. As shown in the figure, the deceleration (negative acceleration) a is set such that the absolute value of the deceleration (negative acceleration) increases as the difference Δ1 increases, and is set to remain constant at a predetermined difference Δ1.

[0058] In step S31, the deceleration setting table is referenced to set the deceleration (negative acceleration) a required to reduce the current vehicle speed to the target vehicle speed, and a deceleration instruction is output to the driving control unit (not shown) provided in the driving support control unit 11a, before proceeding to step S9 in Figure 2. Note that the processing in steps S28 to S31 corresponds to the deceleration instruction unit of the present invention.

[0059] The driving control unit operates the brake drive unit 31 and the acceleration / deceleration control unit 33 to decelerate the vehicle M to the target speed at the instructed deceleration rate. By reducing the vehicle speed, the corrected target steering angle set in this instance can be maintained almost, allowing the vehicle M to corner along the trajectory envisioned by the driver. Furthermore, by limiting the deceleration rate, sudden deceleration can be avoided, reducing discomfort for the passengers.

[0060] When the process proceeds from step S6 or step S8 to step S9 in Figure 2, the driver assistance control unit 11a continues automatic steering and exits the routine.

[0061] In other words, when proceeding from step S6 to step S9, the driver assistance control unit 11a maintains the automatic steering function while executing steering control that prioritizes steering override by the driver's steering wheel operation and exits the routine. Then, when the driver's steering override ends, the driver assistance control unit 11a continues steering control by automatic steering at the indicated target steering angle. On the other hand, when proceeding from step S8 to step S9, the driver assistance control unit 11a sets the corrected target steering angle to the current indicated target steering angle and continues steering control by automatic steering. Note that the processing in step S9 corresponds to the steering control unit of the present invention.

[0062] Thus, when the vehicle M enters or is driving through a corner, if the driver performs a steering override, the driver assistance control unit 11a sequentially stores various situational data at that time as a single cornering driving data in non-volatile memory. Subsequently, when the vehicle M enters or is driving through a corner, it checks whether past situational data, including corner curvature data matching the curvature of the corner, is stored in the non-volatile memory.

[0063] Then, if past situation data with matching corner curvature is stored in non-volatile memory, the target steering angle is corrected based on the data stored in that situation data, and the corrected target steering angle is set. In this embodiment, this corrected target steering angle is set as the current target steering angle, and the vehicle is made to continuously drive through the corner with automatic steering. Therefore, when driving in a situation that matches a corner where the driver has previously performed a steering override, the driver does not need to perform a steering override, resulting in high convenience.

[0064] Furthermore, even if the curvature of the corners matches, the degree of influence will differ if the internal and external environmental factors are different. to Accordingly, the steering override correction amount is calculated and the override steering angle is corrected. Therefore, even if the situation changes slightly, the vehicle M can be driven through corners by automatic steering while maintaining stable behavior.

[0065] Furthermore, the ratio R (=(B / A)·100[%]) of the yaw rate A due to the instructed target steering angle and the yaw rate B due to the corrected target steering angle is compared with a threshold C. If R > C, driving stability is compromised, so the target vehicle speed is reduced to allow cornering without changing the corrected target steering angle. This makes it possible to corner the vehicle M along the trajectory imagined by the driver, even in situations where driving stability is easily compromised.

[0066] Furthermore, the present invention is not limited to the embodiments described above. For example, Figures 7 to 9 illustrate a case where the driver oversteers inward (towards the inside of the lane) during cornering. However, if the driver oversteers outward (towards the outside of the lane), the situation data is stored in non-volatile memory. [Explanation of Symbols]

[0067] 1…Driving assistance system, 11…Driving support control unit, 11a... Driving support control unit, 11b...Storage section, 21...Camera unit, 21a... Main camera, 21b... Sub-camera, 21d...Forward driving environment recognition unit, 22... Car navigation system, 22a... High-precision road map database, 23... Vehicle speed sensor, 24... Steering angle sensor, 25... Yaw rate sensor, 26... Steering torque sensor, 31...Brake drive unit, 32... Electric power steering motor drive unit, 33...Acceleration / deceleration control unit, 34... Notification device, A, B... yaw rate, C...threshold, Fovr... Steering override data acquisition flag, M... Own vehicle, R…Ratio, Δ1…difference

Claims

1. A driving environment information acquisition unit that acquires driving environment information in front of the vehicle, The vehicle status detection unit detects the state of the vehicle, A memory unit that stores various types of data, A driving support control unit sets an instructed target steering angle to drive the vehicle along a target path set in front of the vehicle, and performs steering control according to the instructed target steering angle. In a vehicle driver assistance system equipped with, The aforementioned driver assistance control unit, A steering override determination unit that checks whether the driver's steering input during cornering constitutes a steering override, If the steering override determination unit determines that a steering override has occurred, the situation data acquisition unit acquires various situation data, including corner curvature data, in a time series and stores it in the storage unit as the current cornering data. A cornering operation determination unit, based on the driving environment information acquired by the driving environment information acquisition unit or the target route, determines whether the vehicle is currently entering a corner or performing cornering maneuvers. If the cornering operation determination unit determines that the vehicle is currently entering a corner or is cornering, the curvature data matching determination unit checks whether there is any curvature data in the situation data stored in the storage unit that matches the curvature of the corner determined based on the driving environment information acquired by the driving environment information acquisition unit or the target path, If the curvature data matching determination unit determines that matching curvature data exists in the status data stored in the storage unit, the target steering angle setting unit corrects the indicated target steering angle with the past status data having the matching curvature data and sets the corrected target steering angle. When the target steering angle setting unit sets the corrected target steering angle, the steering control unit sets the target steering angle as the current instructed target steering angle. Equipped with, The situation data acquired by the situation data acquisition unit includes external environmental factors affecting the vehicle and internal environmental factors related to the vehicle. The aforementioned target steering angle setting unit is An element detection unit for detecting the internal environmental elements and the external environmental elements, An environmental element comparison unit compares the internal and external environmental elements of the aforementioned situation data with the current external and internal environmental elements detected by the element detection unit. The environmental element comparison unit calculates a steering override correction amount according to the comparison results, and the corrected target steering angle setting unit corrects the indicated target steering angle with the steering override correction amount to set the corrected target steering angle. Equipped with, The aforementioned driving support control unit further comprises a driving control unit that controls the speed of the vehicle, The target steering angle setting unit outputs a deceleration instruction to the driving control unit to reduce the current vehicle speed if the ratio of the yaw rate calculated based on the indicated target steering angle and the yaw rate calculated based on the corrected target steering angle exceeds a preset threshold. A vehicle driving assistance system characterized by further features.

2. The deceleration instruction unit sets a target vehicle speed such that the ratio is equal to the threshold value, calculates the deceleration based on the difference between the ratio and the threshold value, and outputs a deceleration instruction to the driving control unit to reduce the current vehicle speed of the vehicle to the target vehicle speed using the deceleration. The vehicle driving assistance device according to claim 1.

3. The threshold value is set to the upper limit of the level at which the vehicle's driving stability is not compromised when cornering. The vehicle driving assistance device according to feature 2.

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