Driving assistance system, driving assistance program, and driving assistance method

Abstract

A processor of a driving assistance system is configured to determine a driving trajectory of an avoidance control period (Pa) and control a steering angle (θ) and a braking force (Fb) in accordance with the driving trajectory. The determination of the driving trajectory includes: selecting a control mode for matching a response characteristic estimated in the avoidance control period (Pa) from between a singular control mode (Ms) for controlling a turning orientation of a host vehicle (2) in the avoidance control period (Pa) via singular adjustment of the steering angle (θ), and a cooperative control mode (Mc) for controlling the turning orientation in the avoidance control period (Pa) via cooperation of the steering angle (θ) and the braking force (Fb); determining a driving trajectory so as to define a requested yaw rate (Yr) for the control achieved via singular adjustment of the steering angle (θ) in the singular control mode (Ms); and determining a driving trajectory so as to define a requested yaw rate (Yr) for the control achieved via cooperation of the steering angle (θ) and the braking force (Fb) in the cooperative control mode (Mc).

Description

Driving assistance system, driving assistance program, driving assistance method CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is based on Patent Application No. 2023-190330 filed in Japan on November 7, 2023, and the contents of the original application are incorporated by reference in their entirety.

[0002] The present disclosure relates to a driving assistance technology that assists a vehicle driver in avoiding a collision with a target.

[0003] The technology disclosed in Patent Document 1 controls the steering torque of a vehicle to avoid collision with a target.

[0004] Japanese Patent Application Laid-Open No. 2021-11227

[0005] However, in the technology disclosed in Patent Document 1, the target steering angle is simply set in accordance with the amount of lateral movement on the traveling trajectory required to avoid a predicted collision, even when the vehicle is decelerated by braking. As a result, with control that only adjusts the steering torque for providing the target steering angle in accordance with the amount of lateral movement, there is a concern that the responsiveness of the entire vehicle may be limited and affect collision avoidance depending on the traveling environment.

[0006] An object of the present disclosure is to provide a driving assistance system that is effective for avoiding a collision between a vehicle and a target. Another object of the present disclosure is to provide a driving assistance program that is effective for avoiding a collision between a vehicle and a target. Yet another object of the present disclosure is to provide a driving assistance method that is effective for avoiding a collision between a vehicle and a target.

[0007] The technical means of the present disclosure for solving the problems will be described below.

[0008] A first aspect of the present disclosure is a driving assistance system having a processor that assists in avoiding a collision with a target when driving a host vehicle, wherein the processor is configured to: determine a driving trajectory of the host vehicle during an avoidance control period in which the host vehicle is controlled to avoid a collision; and control the steering angle and braking force applied to the wheels of the host vehicle in accordance with the driving trajectory, respectively; wherein determining the driving trajectory includes: selecting a control mode that matches a response characteristic estimated for the host vehicle during the avoidance control period from an independent control mode in which the turning attitude of the host vehicle during the avoidance control period is controlled by adjusting the steering angle alone, and a cooperative control mode in which the turning attitude during the avoidance control period is controlled by adjusting the steering angle and braking force together; determining the driving trajectory in the independent control mode so as to specify a required yaw rate required to control the turning attitude by adjusting the steering angle alone; and determining the driving trajectory in the cooperative control mode so as to specify a required yaw rate required to control the turning attitude by adjusting the steering angle and braking force together.

[0009] A second aspect of the present disclosure is a driving assistance program stored in a storage medium for assisting a host vehicle in avoiding a collision with a target when driving, and including instructions for causing a processor to execute the assistance, the program including instructions for executing: determining a driving trajectory of the host vehicle during an avoidance control period in which the host vehicle is controlled to avoid a collision; and controlling the steering angle and braking force applied to the wheels of the host vehicle in accordance with the driving trajectory, respectively; wherein determining the driving trajectory includes: selecting a control mode that matches the response characteristics estimated for the host vehicle during the avoidance control period from an independent control mode in which the turning attitude of the host vehicle during the avoidance control period is controlled by adjusting the steering angle alone, and a cooperative control mode in which the turning attitude during the avoidance control period is controlled by adjusting the steering angle and braking force together; determining the driving trajectory in the independent control mode so as to specify a required yaw rate required to control the turning attitude by adjusting the steering angle alone; and determining the driving trajectory in the cooperative control mode so as to specify a required yaw rate required to control the turning attitude by adjusting the steering angle and braking force together.

[0010] A third aspect of the present disclosure is a driving assistance method executed by a processor to assist in avoiding a collision with a target when driving a host vehicle, the method including: determining a driving trajectory of the host vehicle during an avoidance control period in which the host vehicle is controlled to avoid the collision; and controlling the steering angle and braking force applied to wheels of the host vehicle in accordance with the driving trajectory, respectively; wherein determining the driving trajectory includes: selecting a control mode that matches a response characteristic estimated for the host vehicle during the avoidance control period from an independent control mode in which the turning attitude of the host vehicle during the avoidance control period is controlled by adjusting the steering angle alone, and a cooperative control mode in which the turning attitude during the avoidance control period is controlled by adjusting the steering angle and braking force together; determining the driving trajectory in the independent control mode to specify a required yaw rate required to control the turning attitude by adjusting the steering angle alone; and determining the driving trajectory in the cooperative control mode to specify a required yaw rate required to control the turning attitude by adjusting the steering angle and braking force together.

[0011] In these first to third modes, during the avoidance control period in which the host vehicle is controlled to avoid a collision with a target, the steering angle and braking force applied to the wheels of the host vehicle are controlled in accordance with the driving trajectory of the host vehicle. Therefore, during the avoidance control period of the first to third modes, the driving trajectory of the host vehicle is determined so as to define the required yaw rate.

[0012] Specifically, in determining a driving trajectory according to the first to third aspects, a control mode that matches the response characteristics estimated for the host vehicle during the avoidance control period is selected. As a result, in a driving environment in which the turning attitude of the host vehicle to avoid a collision can be controlled by adjusting the steering angle alone, an independent control mode that matches the estimated response characteristics during the avoidance control period is selected, and the required yaw rate for controlling the turning attitude by this independent adjustment can be reflected in the driving trajectory. On the other hand, in a driving environment in which control of the turning attitude to avoid a collision needs to be performed in a short period of time through coordination of the steering angle and braking force, a cooperative control mode that matches the estimated response characteristics during the avoidance control period is selected, and the required yaw rate for controlling the turning attitude by coordination can be reflected in the driving trajectory. As a result of the above, it is possible to provide driving assistance to the host vehicle according to a driving trajectory that is effective in avoiding a collision with a target regardless of the driving environment.

[0013] FIG. 1 is a block diagram showing the physical configuration of a driving assistance system according to a first embodiment. FIG. 2 is a schematic diagram showing a traveling environment of a host vehicle to which the first embodiment is applied. FIG. 3 is a block diagram showing the functional configuration of a driving assistance system according to the first embodiment. FIG. 4 is a flowchart showing a driving assistance flow according to the first embodiment. FIG. 5 is a graph for explaining the driving assistance flow according to the first embodiment. FIG. 6 is a schematic diagram for explaining the driving assistance flow according to the first embodiment. FIG. 7 is a flowchart showing a driving assistance flow according to a second embodiment. FIG. 8 is a flowchart showing an arbitration subroutine according to the second embodiment. FIG. 9 is a graph for explaining the arbitration subroutine according to the second embodiment.

[0014] Hereinafter, multiple embodiments of the present disclosure will be described with reference to the drawings. Note that corresponding components in each embodiment are designated by the same reference numerals, and redundant description may be omitted. Furthermore, when only a portion of the configuration is described in each embodiment, the configuration of another previously described embodiment may be applied to the remaining portions of the configuration. Furthermore, in addition to the combinations of configurations explicitly stated in the description of each embodiment, configurations of multiple embodiments may be partially combined together even if not explicitly stated, provided that there is no particular problem with the combination.

[0015] (First Embodiment) A driving assistance system 1 of a first embodiment shown in FIG. 1 assists in driving a host vehicle 2. At least a portion of the driving assistance system 1 is mounted on the host vehicle 2. The host vehicle 2 to which the driving assistance system 1 is applied may be capable of achieving a level of automated driving specified in, for example, SAE J3016, at which a manual driving assistance task exists that assists an operator in performing manual driving operations, along with an automated driving task. Such a host vehicle 2 is a road user, such as a car or a truck, and may also be referred to as an ego-vehicle. As described above, the driving assistance system 1, as the operator of the host vehicle 2, provides driving assistance to a driver who is aboard the host vehicle 2 and is capable of performing manual driving operations.

[0016] As shown in FIG. 2 , the driving environment in which the host vehicle 2 travels includes at least one of the following types of targets 3 other than the host vehicle 2: other road users, obstacles, and structures. The other road users include non-vulnerable road users and vulnerable road users. The non-vulnerable road users are at least one type of moving body with a human on board, such as a car, truck, motorcycle, or bicycle. The vulnerable users are, for example, pedestrians. The obstacles include at least one type of construction signboard, work signboard, or fallen object. The structures include at least one type of building, road structure, traffic light, or road sign.

[0017] 1, a host vehicle 2 is equipped with an actuator system 4, a sensor system 5, a communication system 6, a map database (DB) 7, and an information presentation system 8, along with at least a part of a driving assistance system 1. However, FIG. 1 representatively shows an example in which the entire driving assistance system 1 implemented in the form of a processing circuit (e.g., a processing ECU) or a semiconductor device (e.g., a semiconductor chip) is equipped in the host vehicle 2.

[0018] The actuator system 4 is configured to be able to control the driving behavior of the host vehicle 2 based on control commands from the driving assistance system 1. As shown in Fig. 3, the actuator system 4 includes at least one type of power train actuator 40, such as an internal combustion engine or a motor-generator-motor. The actuator system 4 also includes at least one type of steering actuator 42, such as a power steering unit. The actuator system 4 also includes at least one type of braking actuator 44, such as a brake unit.

[0019] 2, the host vehicle 2 has a plurality of wheels 20 including front wheels 20fl, 20fr and rear wheels 20rl, 20rr. The brake actuator 44 independently adjusts the braking forces Fb applied to the front wheels 20fl, 20fr and the rear wheels 20rl, 20rr as braking forces (see FIGS. 5 and 6, described later) to be applied to the host vehicle 2. This allows the host vehicle 2 to control the left-right and front-rear distribution of the braking forces Fb.

[0020] On the other hand, the steering actuator 42 adjusts at least one of the steering angle θ common to the front wheels 20fl, 20fr and the steering angle θ common to the rear wheels 20rl, 20rr as the steering angle (see FIGS. 5 and 6 described below) to be applied to the host vehicle 2. The common steering angle θ of the front wheels 20fl, 20fr and the common steering angle θ of the rear wheels 20rl, 20rr may be adjusted independently of each other, and in this case, the host vehicle 2 can control the front / rear distribution of these common steering angles θ.

[0021] 1 , the sensor system 5 senses the external and internal environments of the host vehicle 2 to obtain sensing information that can be used in the driving assistance system 1. To this end, the sensor system 5 includes an external sensor 50 and an internal sensor 52.

[0022] The external sensor 50 senses targets 3 that exist in the external world of the host vehicle 2. The target sensing type external sensor 50 is at least one type of sensor selected from the group consisting of an image sensor (i.e., an on-board camera), a LiDAR (light detection and ranging / laser imaging detection and ranging), a laser sensor, a millimeter wave sensor, and a sonar sensor. The target sensing type external sensor 50 may be implemented by combining multiple types of sensors so as to be capable of sensing the front, side, and rear directions of the host vehicle 2.

[0023] The internal sensor 52 senses a specific physical quantity of motion related to vehicle motion in the internal environment of the host vehicle 2. The internal sensor 52 of the motion sensing type is at least one of, for example, a speed sensor, an acceleration sensor, a gyro sensor, etc. The internal sensor 52 may sense the operation or state of occupants, including the driver, riding in the internal environment of the host vehicle 2. The internal sensor 52 of the occupant sensing type is at least one of, for example, an accelerator pedal sensor, a steering angle sensor, a steering torque sensor, a brake pedal sensor, a shift sensor, an occupant camera, a steering switch, a biosensor, a seating sensor, and an in-vehicle device switch, etc.

[0024] The communication system 6 acquires communication information usable in the driving assistance system 1 via wireless communication. The communication system 6 may receive positioning signals from satellites of a global navigation satellite system (GNSS) present in the external world of the host vehicle 2. The positioning-type communication system 6 is, for example, a GNSS receiver. The communication system 6 may transmit and receive communication signals to and from a V2X system present in the external world of the host vehicle 2. The V2X communication-type communication system 6 is, for example, at least one of a dedicated short range communications (DSRC) communication device and a cellular V2X (C-V2X) communication device. The communication system 6 may transmit and receive communication signals to and from a mobile terminal present in the internal world of the host vehicle 2. The terminal communication-type communication system 6 is, for example, at least one of a Bluetooth (registered trademark) device, a Wi-Fi (registered trademark) device, an infrared communication device, etc.

[0025] The map DB 7 stores map information that can be used in the driving assistance system 1. The map DB 7 includes at least one type of non-transitory tangible storage medium, such as a semiconductor memory, a magnetic medium, or an optical medium. The map DB 7 may be a DB of a locator that estimates the self-position of the host vehicle 2. The map DB may be a DB of a navigation unit that navigates the driving route of the host vehicle 2. The map DB 7 may be constructed by combining multiple types of DBs.

[0026] The map DB 7 acquires and stores the latest map information, for example, through V2X communication with an external center via the communication system 6. The map information is converted into two-dimensional or three-dimensional data as information representing the external environment in which the host vehicle 2 is traveling. Digital data of a high-precision map may be used as the three-dimensional map information. The map information includes road information representing at least one of the following: the position, shape, and road surface condition of a road structure. The map information may also include structure information representing at least one of the following: the position, shape, and other information of buildings and traffic lights facing the road. The map information may also include marking information representing at least one of the following: the position, shape, and other information of signs and lane markings attached to the road.

[0027] The information presentation system 8 presents notification information to occupants, including the driver, of the host vehicle 2. The information presentation system 8 presents notification information by stimulating the vision of the occupants in the host vehicle 2. The information presentation system 8 of the visual information presentation type is, for example, at least one of an in-vehicle monitor, a head-up display (HUD), a combination meter, a navigation unit, and an illumination unit. The information presentation system 8 may present notification information by stimulating the auditory sense of the occupants. The information presentation system 8 of the auditory information presentation type is, for example, at least one of a speaker, a buzzer, and a vibration unit. The information presentation system 8 may present notification information by stimulating the cutaneous sense of the occupants. The information presentation system 8 of the cutaneous sense information presentation type is, for example, at least one of a vibration unit, a reaction force unit, and an air conditioning unit.

[0028] The driving assistance system 1 is connected to an actuator system 4, a sensor system 5, a communication system 6, a map DB 7, and an information presentation system 8 via at least one of, for example, a local area network (LAN), a wire harness, an internal bus, or a wireless communication line. The driving assistance system 1 is configured to include at least one dedicated computer.

[0029] The dedicated computer constituting the driving assistance system 1 may be an integrated ECU (electronic control unit) that integrates the driving control of the host vehicle 2. The dedicated computer constituting the driving assistance system 1 may be a sensing ECU that processes sensing information in the driving control of the host vehicle 2. The dedicated computer constituting the driving assistance system 1 may be a recognition ECU that recognizes the external world in the driving control of the host vehicle 2. The dedicated computer constituting the driving assistance system 1 may be a locator ECU that estimates the self-position of the host vehicle 2.

[0030] The dedicated computer constituting the driving assistance system 1 may be a planning ECU that plans driving control of the host vehicle 2. The dedicated computer constituting the driving assistance system 1 may be a navigation ECU that navigates a driving route in driving control of the host vehicle 2. The dedicated computer constituting the driving assistance system 1 may be an actuator ECU that controls the actuator system 4 as part of driving control of the host vehicle 2.

[0031] The dedicated computer constituting the driving assistance system 1 may be an information management ECU that controls the information presentation system 8 as part of driving control of the host vehicle 2. The dedicated computer constituting the driving assistance system 1 may also be at least one external computer that constitutes, for example, an external center or a mobile terminal that can communicate via the communication system 6.

[0032] The dedicated computer constituting the driving assistance system 1 has at least one memory 10 and one processor 12. The memory 10 is at least one type of non-transitory tangible storage medium, such as a semiconductor memory, a magnetic medium, or an optical medium, that non-temporarily stores computer-readable programs and data. The processor 12 includes at least one type of core, such as a central processing unit (CPU), a graphics processing unit (GPU), or a reduced instruction set computer (RISC)-CPU.

[0033] The processor 12 executes a plurality of instructions included in a driving assistance program stored as software in the memory 10. In this way, the driving assistance system 1 constructs a plurality of functional blocks for carrying out driving assistance processing for the host vehicle 2. The plurality of functional blocks constructed by the driving assistance system 1 in this way include an operation judgment block 100, a trajectory generation block 120, and a driving control block 140 shown in FIG.

[0034] The operation determination block 100 acquires sensing information from the sensor system 5. The operation determination block 100 generates operation data by determining the driver's manual driving operation of the host vehicle 2 based on the acquired sensing information. The operation data related to the manual driving operation may represent at least one type of operation parameter corresponding to the driver's operation, such as the accelerator pedal operation amount, steering operation angle, steering operation torque, brake pedal operation amount, and shift operation position.

[0035] The trajectory generation block 120 acquires sensing information from the sensor system 5. The trajectory generation block 120 acquires communication information from the communication system 6. The trajectory generation block 120 acquires map information from the map DB 7. The trajectory generation block 120 acquires data of past control commands to the host vehicle 2 from the driving control block 140. The trajectory generation block 120 processes this acquired information and data individually and then fuses them to generate recognition data that recognizes the external environment and internal environment of the host vehicle 2. In this way, the recognition data generated by the trajectory generation block 120 represents the state of the external environment and internal environment recognized for each driving scene in which the host vehicle 2 travels.

[0036] Specifically, the trajectory generation block 120 may generate the recognition data by localization that recognizes the self-state of the host vehicle 2. The recognition data regarding the self-state may represent at least one type of physical quantity of motion, such as position, velocity, acceleration, jerk, yaw rate, and yaw angle, which appear in the host vehicle 2 in accordance with a control command from the driving control block 140, which will be described in detail later. The trajectory generation block 120 may generate the recognition data by recognizing a target 3 in the external world of the host vehicle 2. The recognition data regarding the target 3 may represent at least one type of physical quantity of motion, such as separation distance, direction of motion, relative velocity, relative acceleration, and time to collision (TTC) with the host vehicle 2.

[0037] The trajectory generation block 120 plans a target driving trajectory Td (see FIG. 2) for future driving of the host vehicle 2 based on the generated recognition data. The driving trajectory Td specifies time-series changes for each control cycle expected in the future beyond the present regarding motion parameters that are targets for the host vehicle 2's own state. Specifically, the driving trajectory Td may represent position coordinates for each control cycle of a trajectory that the host vehicle 2 is to follow in the future. Furthermore, the driving trajectory Td may represent at least one type of physical quantity of motion, such as speed, acceleration, jerk, yaw rate, and yaw angle, as motion parameters to be revealed for each control cycle on such a trajectory.

[0038] The driving control block 140 acquires operation data from the operation judgment block 100. The driving control block 140 acquires data on the driving trajectory Td from the trajectory generation block 120, along with the recognition data. The driving control block 140 acquires data on past control commands to the host vehicle 2 by reading it from the memory 10. The driving control block 140 generates control commands for controlling the driving behavior of the host vehicle 2 based on this acquired data. At this time, a control command is generated to be issued to the actuator system 4 so as to control a driving task corresponding to the autonomous driving level adjusted to suit the driving scene, out of the autonomous driving task and the manual driving assistance task in the host vehicle 2. The control command generated in this manner is stored in the memory 10.

[0039] Examples of driving tasks corresponding to the autonomous driving level include adaptive cruise control (ACC), autonomous emergency braking (AEB), and lane keeping assist (LKA). Therefore, adjusting the autonomous driving level may include a handover in which the driving task is transferred between the driving assistance system 1 and the driver by transitioning the driving mode between the autonomous driving task and the manual driving assistance task. Such a handover is realized at least at one of the following times: a driver's request for handover; a move toward or away from an autonomous driving operational design domain (ODD); and a required time for a minimum risk maneuver (MRM).

[0040] (Driving Assistance Flow) In the first embodiment, a driving assistance flow that realizes a driving assistance method for assisting driving of the host vehicle 2 is repeatedly executed according to Fig. 4 by cooperation of multiple blocks 100, 120, and 140. Note that in the following explanation, each "S" in the driving assistance flow refers to multiple steps that are executed by multiple commands included in the driving assistance program.

[0041] In S10 shown in FIG. 4 , the trajectory generation block 120 determines whether a collision avoidance condition, which requires the host vehicle 2 to avoid a collision with the target 3 in future traveling, is met. The collision avoidance condition is met when the collision risk between the host vehicle 2 and the target 3 increases to a collision avoidance range that requires the host vehicle 2 to avoid a collision. Therefore, whether the collision risk has reached the collision avoidance range is determined based on the recognition data generated by the trajectory generation block 120. In this case, the collision risk may be determined to have reached the collision avoidance range when the TTC is equal to or less than a threshold time (e.g., 2 seconds). The collision risk may also be determined to have reached the collision avoidance range when, in addition to these TTC requirements, the probability of collision avoidance, for example, by changing lanes, is equal to or greater than a threshold.

[0042] If a negative determination is made in S10 because the collision avoidance conditions are not met, the current driving assistance flow ends. On the other hand, if a positive determination is made in S10 because the collision avoidance conditions are met, the current driving assistance flow proceeds to S20. In S20, the trajectory generation block 120 sets an avoidance control period Pa to perform emergency control of the host vehicle 2 to avoid a collision.

[0043] In the next S30, the trajectory generation block 120 determines a driving trajectory Td to be traced by the host vehicle 2 over the avoidance control period Pa in order to avoid a collision with the target 3 in the future traveling of the host vehicle 2. At this time, the driving trajectory Td is planned so as to define, for each control cycle, the time-series change in the target yaw rate Yt shown in Figures 5 and 6 in addition to the trajectory representing the time-series change in position coordinates as a motion parameter to be targeted in the future traveling of the host vehicle 2. Note that, although the sign of the target yaw rate Yt in Figures 5 and 6 is defined around the yaw axis of the host vehicle 2 in a top view such that the counterclockwise direction is positive and the clockwise direction is negative, it is of course also possible to define the opposite relationship.

[0044] When specifying the target yaw rate Yt for planning such a driving trajectory Td, a time-series change in the target lateral acceleration may be specified for each control cycle as a motion parameter to be targeted in the future traveling of the host vehicle 2. Furthermore, the target longitudinal acceleration Ag shown in Figures 5 and 6 may be specified for each control cycle as a motion parameter to be targeted in the future traveling of the host vehicle 2, so that the driving trajectory Td can be planned including the target longitudinal acceleration Ag. Note that, although the sign of the target longitudinal acceleration Ag in Figures 5 and 6 is defined as negative in the backward traveling direction of the host vehicle 2, it may of course be defined as positive.

[0045] Specifically, the trajectory generation block 120 in the trajectory planning of S30 first estimates the response characteristics expected of the host vehicle 2 during the avoidance control period Pa. At this time, the response characteristics estimated may be the ground contact loads of at least the front wheels 20fl, 20fr of the wheels 20. The response characteristics estimated may be the maximum yaw moment that can be generated in the host vehicle 2.

[0046] Next, the trajectory generation block 120 in the trajectory planning of S30 selects a control mode to match the response characteristics of the host vehicle 2 estimated during the avoidance control period Pa. As shown in Figures 5 and 6, the control modes include an independent control mode Ms for the steering angle θ and a cooperative control mode Mc for the steering angle θ and braking force Fb. Note that the sign of the steering angle θ in Figures 5 and 6 is defined as positive in the counterclockwise direction and negative in the clockwise direction around the yaw axis based on the longitudinal axis of the host vehicle 2 in a top view, but it is of course possible to define an inverse relationship. Also, the sign of the braking force Fb in Figures 5 and 6 is defined as negative in the reverse direction of the host vehicle 2, but it is of course possible to define it as a positive sign.

[0047] The independent control mode Ms shown in Fig. 5 (see also the dashed-two-dot line graph in Fig. 6 ) is one control mode of turning attitude control (i.e., so-called yawing control) that controls the turning attitude of the host vehicle 2 by independently adjusting the steering angle θ of at least the front wheels 20fl, 20fr among the wheels 20 during the avoidance control period Pa. On the other hand, the cooperative control mode Mc shown in Fig. 6 is another control mode of turning attitude control that controls the turning attitude of the host vehicle 2 by coordinating the steering angle θ and braking force Fb of at least the front wheels 20fl, 20fr among the wheels 20 during the avoidance control period Pa. In particular, in this cooperative control mode Mc, the left / right distribution of the braking force Fb is coordinated with a common steering angle θ for the left and right for at least the front wheels 20fl, 20fr among the wheels 20, so that the turning attitude of the host vehicle 2 during the avoidance control period Pa is optimally controlled to avoid a collision.

[0048] In the mode selection at S30, for response characteristics that are positively estimated to enable left / right distribution of the braking force Fb of at least the front wheels 20fl, 20fr among the wheels 20 during the avoidance control period Pa within the limited range ΔF as shown in Fig. 6, a coordinated control mode Mc that matches the response characteristics is selected. In other words, for response characteristics that are negatively estimated to enable left / right distribution within the limited range ΔF regarding the braking force Fb of at least the front wheels 20fl, 20fr among the wheels 20 during the avoidance control period Pa, a separate control mode Ms that matches the response characteristics is selected.

[0049] Therefore, when selecting a mode in S30, the availability of left / right allocation may be determined in accordance with the ground load estimated as a response characteristic.When selecting a mode in S30, the availability of left / right allocation may be determined in accordance with the maximum yaw moment estimated as a response characteristic.When selecting a mode in S30, the availability of left / right allocation may be determined in consideration of limit values ​​for the longitudinal acceleration and / or longitudinal jerk (jerk) of the host vehicle 2.

[0050] The trajectory generation block 120 in the trajectory planning of S30 further sets the target yaw rate Yt, shown in Figures 5 and 6, among the motion parameters of the driving trajectory Td, for each selected control mode. In this case, in the cooperative control mode Mc shown by the solid line graph in Figure 6, the phase of the target yaw rate Yt is adjusted more to the advance side than in the independent control mode Ms shown by the two-dot chain line graph in the same figure (see also Figure 5). At the same time, in the cooperative control mode Mc shown by the solid line graph in Figure 6, the absolute value of the differential value, which is the gradient over time of the target yaw rate Yt, i.e., the magnitude of the yaw angular acceleration ηc equivalent to this gradient, is adjusted to be larger than the magnitude of the yaw angular acceleration ηs in the independent control mode Ms shown by the two-dot chain line graph in the same figure (see also Figure 5).

[0051] These advance adjustments and increase adjustments are based on the fact that the response speed of the actual yaw rate to a control command in the host vehicle 2 is higher when the steering angle θ and braking force Fb are coordinated compared to when the steering angle θ is adjusted independently. Therefore, the phase advance time δsc due to the advance adjustment and the increase adjustment factor between the magnitudes of the yaw angular accelerations ηs and ηc are set according to, for example, the minimum speed difference among the response speed differences between the actual yaw rates estimated based on the response characteristics in each of the coordinated control mode Mc and the independent control mode Ms. In this case, for example, at least one of the ground load and maximum yaw moment estimated as response characteristics, and the limit values ​​of the longitudinal acceleration and / or longitudinal jerk (jerk) may be reflected in the setting of the advance time δsc and the increase adjustment factor.

[0052] In addition to the above-described trajectory planning, in S30 shown in FIG. 4, the trajectory generation block 120 further corrects the set target yaw rate Yt to define a requested yaw rate Yr required of the host vehicle 2 for each control cycle of the avoidance control period Pa. At this time, as shown in FIGS. 5 and 6, the phase of the requested yaw rate Yr is adjusted to be more advanced than the phase of the target yaw rate Yt according to the planned driving trajectory Td in both control modes Ms and Mc. The phase advance time δr resulting from this advance adjustment is common between the control modes Ms and Mc and is set to, for example, the maximum delay time among the response delay times predicted for the actuator system 4. Note that, although the sign of the requested yaw rate Yr in FIGS. 5 and 6 is defined such that the counterclockwise direction is positive and the clockwise direction is negative around the yaw axis of the host vehicle 2 in a top view, it is of course also possible to define the opposite relationship.

[0053] According to S30 described in detail up to this point, in the cooperative control mode Mc shown by the solid line graph in Fig. 6, the phase of the required yaw rate Yr is advanced in accordance with the target yaw rate Yt by a lead time δsc compared to the independent control mode Ms shown by the two-dot chain line graph in the same figure (see also Fig. 5). At the same time, according to S30, in the cooperative control mode Mc shown by the solid line graph in Fig. 6, the magnitude of the yaw angular acceleration ηc, which is the gradient over time of the required yaw rate Yr in accordance with the target yaw rate Yt, is increased compared to the magnitude of the yaw angular acceleration ηs in the independent control mode Ms shown by the two-dot chain line graph in the same figure (see also Fig. 5).

[0054] As a result of S30, the driving trajectory Td is determined so as to define the required yaw rate Yr for controlling the turning attitude of the host vehicle 2 during the avoidance control period Pa by adjusting the steering angle θ alone in the independent control mode Ms. On the other hand, as a result of S30, the driving trajectory Td is determined so as to define the required yaw rate Yr for controlling the turning attitude of the host vehicle 2 during the avoidance control period Pa by adjusting the steering angle θ and the braking force Fb together in the cooperative control mode Mc.

[0055] 4, the driving control block 140 generates control commands to the actuator system 4 to control the steering angle θ and the braking force Fb according to the driving trajectory Td obtained as data from the trajectory generation block 120 after execution of S20 and S30. In particular, the control commands for the steering actuator 42 and the braking actuator 44 are generated in correspondence with the required yaw rate Yr for each control mode selected in S30, among the motion parameters defined by the driving trajectory Td. Note that, although not described below, in the first embodiment, when the host vehicle 2 is in a driver override state due to manual driving operation, the control commands may be corrected based on the operation data from the operation determination block 100.

[0056] Specifically, when generating a control command in the independent control mode Ms, the braking yaw moment Bm to be exerted on the host vehicle 2 by the independent adjustment of the braking force Fb is set to a value of 0, as shown in Fig. 5. Therefore, the control command in the independent control mode Ms is generated as shown in Fig. 5 (also see the two-dot chain line graph in Fig. 6) so as to control the braking force Fb of at least the front wheels 20fl, 20fr of the wheels 20 to a value that is substantially common to the left and right, i.e., a left and right distribution command value that is substantially 1:1, in accordance with the target longitudinal acceleration Ag and the braking yaw moment Bm. Note that, although the sign of the braking yaw moment Bm in Figs. 5 and 6 is defined such that the counterclockwise direction is positive and the clockwise direction is negative about the yaw axis of the host vehicle 2 in a top view, it may of course be defined in the opposite relationship.

[0057] At the same time, the control command in the independent control mode Ms is generated so as to control only the steering angle θ of at least the front wheels 20fl, 20fr among the wheels 20 to an angle command value that conforms to the required yaw rate Yr. At this time, the angle command value of the steering angle θ is preferably adjusted to satisfy the lateral force control value Fy that follows changes in the required yaw rate Yr, as shown in Figure 5 (see also the two-dot chain line graph in Figure 6). Note that the sign of the lateral force control value Fy in Figures 5 and 6 is defined as positive in the left direction and negative in the right direction relative to the longitudinal axis of the host vehicle 2 in a top view, but it is of course also possible to define the opposite relationship.

[0058] On the other hand, when generating a control command in cooperative control mode Mc, as shown in Fig. 6, the braking yaw moment Bm to be generated in the host vehicle 2 by braking force Fb alone is set in accordance with the advance angle of the required yaw rate Yr. Therefore, the control command in cooperative control mode Mc is generated as shown by the solid and dashed line graphs in Fig. 6 so as to control the braking force Fb of at least the front wheels 20fl, 20fr of the wheels 20 to a left / right distribution command value that simultaneously satisfies the target longitudinal acceleration Ag and braking yaw moment Bm. The solid line graph in Fig. 6 indicates the braking force Fb of the left front wheel 20fl, and the dashed line graph in Fig. 6 indicates the braking force Fb of the right front wheel 20fr.

[0059] At the same time, the control command for the cooperative control mode Mc is generated so as to control the steering angle θ of at least the front wheels 20fl, 20fr of the wheels 20 to an angle command value that satisfies the required yaw rate Yr in cooperation with the left / right distribution command value of the braking force Fb. At this time, the angle command value for the steering angle θ is preferably adjusted to satisfy the lateral force control value Fy that is correlated with the change in the required yaw rate Yr by offsetting the change due to the emergence of the braking yaw moment Bm, as shown by the solid line graph in Figure 6.

[0060] As shown in Fig. 4, in S50 following S40, the driving control block 140 determines whether the avoidance control period Pa in the current driving assistance flow has completed. As a result, if a negative determination is made during the avoidance control period Pa, S40 is repeated, and the next control cycle in the current driving assistance flow is started. On the other hand, if a positive determination is made upon completion of the avoidance control period Pa, the current driving assistance flow ends. According to the driving assistance flow described above, in the cooperative control mode Mc illustrated in Fig. 7, it is possible to avoid a collision with the target 3 in a short time during the avoidance control period Pa, compared to the independent control mode Ms illustrated in Fig. 2.

[0061] (Operations and Effects) Operations and effects of the first embodiment described above will be described below.

[0062] In the first embodiment, during an avoidance control period Pa in which the host vehicle 2 is controlled to avoid a collision with the target 3, the steering angle θ and braking force Fb applied to the wheels 20 of the host vehicle 2 are each controlled in accordance with the driving trajectory Td of the host vehicle 2. Therefore, during the avoidance control period Pa of the first embodiment, the driving trajectory Td of the host vehicle 2 is determined so as to define the required yaw rate Yr.

[0063] Specifically, in determining the driving trajectory Td according to the first embodiment, a control mode that matches the response characteristics estimated for the host vehicle 2 during the avoidance control period Pa is selected. As a result, in a driving environment in which the turning attitude of the host vehicle 2 toward collision avoidance can be controlled by adjusting the steering angle θ alone, the independent control mode Ms that matches the estimated response characteristics during the avoidance control period Pa is selected, and the required yaw rate Yr for controlling the turning attitude through this independent adjustment can be reflected in the driving trajectory Td. On the other hand, in a driving environment in which control of the turning attitude toward collision avoidance is required in a short period of time through coordination of the steering angle θ and the braking force Fb, the cooperative control mode Mc that matches the estimated response characteristics during the avoidance control period Pa is selected, and the required yaw rate Yr for controlling the turning attitude through coordination can be reflected in the driving trajectory Td. As a result of the above, it is possible to provide driving assistance to the host vehicle 2 in accordance with a driving trajectory Td that is effective in avoiding a collision with the target 3 regardless of the driving environment.

[0064] In the cooperative control mode Mc according to the first embodiment, a required yaw rate Yr is defined for controlling the turning attitude of the host vehicle 2 by coordinating the left / right distribution of the braking force Fb with the steering angle θ. Accordingly, even in a driving environment where short-term control of the turning attitude is required to avoid a collision, by selecting the cooperative control mode Mc that matches the estimated response characteristics during the avoidance control period Pa, the driving trajectory Td that defines the required yaw rate Yr by coordinating the left / right distribution of the braking force Fb with the steering angle θ can be adapted to the driving environment. Therefore, it is possible to assist the host vehicle 2 in avoiding a collision with the target 3 according to the driving trajectory Td that is effective regardless of the driving environment.

[0065] According to the first embodiment, for response characteristics for which the left / right distribution of the braking force Fb within the limited range ΔF during the avoidance control period Pa is positively estimated, a coordinated control mode Mc that matches that response characteristic is selected. Accordingly, in a driving environment in which short-term control of the turning attitude is required to avoid a collision, the stability of the host vehicle 2 can be ensured when tracing a driving trajectory Td that defines the required yaw rate Yr by coordinating the left / right distribution with the steering angle θ by selecting a coordinated control mode Mc that matches the response characteristics that allow the left / right distribution of the braking force Fb within the limited range ΔF. Therefore, it is possible to increase the reliability of driving assistance for the host vehicle 2 in accordance with a driving trajectory Td that is effective in avoiding a collision with the target 3 regardless of the driving environment.

[0066] According to the first embodiment, in the cooperative control mode Mc, the phase of the required yaw rate Yr is adjusted to be more advanced than in the independent control mode Ms. As a result, even in a driving environment where short-term control of the turning attitude is required to avoid a collision, the required yaw rate Yr with the phase advanced can be reflected in the driving trajectory Td in the cooperative control mode Mc, which matches the estimated response characteristics that are expected to provide a high response speed to the actual yaw rate through coordination of the braking force Fb and the steering angle θ during the avoidance control period Pa. Therefore, it is possible to increase the reliability of driving assistance for the host vehicle 2 in accordance with the driving trajectory Td that is effective in avoiding a collision with the target 3 regardless of the driving environment.

[0067] According to the first embodiment, the magnitude of the yaw angular acceleration ηc, which is the gradient of the required yaw rate Yr, in the cooperative control mode Mc is adjusted to be larger than the magnitude of the yaw angular acceleration ηs in the independent control mode Ms. This allows the requested yaw rate Yr, with the gradient of the requested yaw rate Yr adjusted to be larger, to be reflected in the driving trajectory Td in the cooperative control mode Mc, which matches the estimated response characteristics that are expected to provide a high response speed to the actual yaw rate through the coordination of the braking force Fb and the steering angle θ during the avoidance control period Pa, even in a driving environment where short-term control of the turning attitude is required to avoid a collision. Therefore, it is possible to increase the reliability of driving assistance for the host vehicle 2 according to a driving trajectory Td that is effective in avoiding a collision with the target 3 regardless of the driving environment.

[0068] 8 and 9, in the driving assistance flow of the second embodiment, steps S2041 to S2045 of an arbitration subroutine are executed in step S2040, which replaces step S40 in the first embodiment. This arbitration subroutine is added so as to define the required yaw rate Yr by limiting the response sensitivity for steering operations in an override state in the host vehicle 2.

[0069] Specifically, in S2041 of the arbitration subroutine shown in Figure 9, the trajectory generation block 120 determines whether the host vehicle 2 is in an override state, where the host vehicle 2 has been overridden by the driver's manual driving operation, based on the operation data from the operation judgment block 100. As a result, if a negative determination is made for the host vehicle 2 during the automated driving task because the driver is not in an override state, the arbitration subroutine proceeds to S2042. In S2042, the driving control block 140 generates a control command to the actuator system 4 (excluding corrections in an override state) in accordance with S40 of the first embodiment. The arbitration subroutine proceeds to S50 upon completion of execution of S2042.

[0070] On the other hand, if a positive determination is made in S2041, the arbitration subroutine proceeds to S2043. In S2043, the trajectory generation block 120 performs low-pass filtering as shown in Fig. 10. Specifically, the low-pass filtering in S2043 increases the attenuation rate of the frequency component of the steering angle ψ input by the driver, which is passed as the requested yaw rate Yr, as the frequency component increases.

[0071] 10, the low-pass filter processing in S2043 regulates the required yaw rate Yr so that it changes more slowly with time (see the solid line graph in the same figure) than the steering angle ψ, even if the steering angle ψ changes suddenly (see the two-dot chain line graph in the same figure). That is, the response sensitivity of the required yaw rate Yr to the steering angle ψ is subjected to a first-stage restriction by the low-pass filter processing.

[0072] In step S2044 following the arbitration subroutine shown in FIG. 9, the trajectory generation block 120 performs dead-band processing as shown in FIG. 11. Specifically, the dead-band processing of S2044 forces the correction gain G to the minimum gain (0x here) for the absolute value when the absolute value of the requested yaw rate Yr after low-pass filtering falls within the dead range ΔYd. On the other hand, the dead-band processing gradually increases the correction gain G from the minimum gain to the maximum gain (1x here) as the absolute value increases when the absolute value of the requested yaw rate Yr after low-pass filtering falls outside the dead range ΔYd within the limited range ΔYl. Furthermore, the dead-band processing fixes the correction gain G for the absolute value to the maximum gain when the absolute value of the requested yaw rate Yr after low-pass filtering falls outside the limited range ΔYl. In the dead band process, the correction gain G may be adjusted based on the yaw angular acceleration, which is the differential value of the required yaw rate Yr, instead of the absolute value of the required yaw rate Yr.

[0073] 11, the required yaw rate Yr is regulated so that the output value of the required yaw rate Yr after low-pass filtering is reduced and corrected by the correction gain G while the magnitude of the output value is small. That is, the response sensitivity of the required yaw rate Yr to the steering operation is subject to a second-stage limitation by the dead-band processing.

[0074] As described above, the driving trajectory Td in the driver override state is determined so as to define the required yaw rate Yr that has been subjected to low-pass filtering and dead-band processing. At this time, the motion parameters of the driving trajectory Td other than the required yaw rate Yr may be defined to the planned value determined by S30 or a value obtained by correcting the planned value based on the required yaw rate Yr that has been subjected to low-pass filtering and dead-band processing.

[0075] 9 , the driving control block 140 generates control commands for the actuator system 4 to control the steering angle θ and the braking force Fb according to the driving trajectory Td obtained from the trajectory generation block 120 after execution of S2043 and S2044. In particular, the control commands for the steering actuator 42 and the braking actuator 44 are generated in correspondence with the requested yaw rate Yr, which has limited response sensitivity to the driver's steering operation, among the motion parameters defined by the driving trajectory Td. The arbitration subroutine proceeds to S50 upon completion of execution of S2045. From the above, it can be said that the arbitration subroutine arbitrates the driving control in the override state by S2045 against the driving control in the non-override state by S2042.

[0076] (Operations and Effects) Operations and effects specific to the second embodiment described above will be described below.

[0077] According to the second embodiment, the driving trajectory Td is determined so as to define the requested yaw rate Yr by limiting the response sensitivity to the steering operation of the driver in an override state in the host vehicle 2. In this way, in an override state in which the driver's steering operation is prone to fluctuate, the requested yaw rate Yr can be reflected in the driving trajectory Td by limiting the response sensitivity to the fluctuation, thereby making it possible to increase the robustness of the driving control.

[0078] (Other Embodiments) Although multiple embodiments have been described above, the present disclosure should not be construed as being limited to those embodiments, and can be applied to various embodiments and combinations within the scope that does not deviate from the gist of the present disclosure.

[0079] In a modified example, the dedicated computer constituting the driving assistance system 1 may have at least one of a digital circuit and an analog circuit as a processor. Here, the digital circuit is at least one of an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), a system on a chip (SOC), a programmable gate array (PGA), and a complex programmable logic device (CPLD). Furthermore, such a digital circuit may have a memory that stores a program.

[0080] In a modified example, the operator who manually drives the host vehicle 2 to which the driving assistance system 1 is applied may be a remote operator who remotely controls the driving of the host vehicle 2 from an external center. In a modified example, the driving assistance system 1 may be configured to be capable of realizing only automated driving tasks, without any manual driving assistance tasks that assist the operator in manual driving operations.

[0081] In the modified S30, with respect to the required yaw rate Yr in the cooperative control mode Mc, only one of the phase advance adjustment and the increase adjustment between the magnitudes of the yaw angular accelerations ηs, ηc that form the gradient may be performed. In the modified S30, in addition to the limited range ΔF of the braking force Fb, at least one of the following may be taken into consideration as conditions for the response characteristics that match with the selected control mode: constraints on the operation of the actuator system 4 based on temperature, etc.; whether or not the actuators 40, 42, 44 in the actuator system 4 can be cooperatively operated; and road surface conditions.

[0082] In the modified cooperative control mode Mc, the required yaw rate Yr is specified in S30 with the steering angles of the front wheels 20fl, 20fr and the rear wheels 20rl, 20rr as the objects of coordination among the wheels 20, and an actual yaw moment following the braking yaw moment Bm may also be generated by the rear wheels 20rl, 20rr in S40 and S2042.

[0083] (Additional Remarks) This specification discloses the following technical ideas and their combinations. Note that the reference symbols in parentheses in this Additional Remarks section indicate the correspondence with the specific means described in the above detailed embodiments, and do not limit the technical scope of the present disclosure.

[0084] (Technical Idea 1) A driving assistance system having a processor (12) for assisting in avoidance of a collision with a target (3) during driving of a host vehicle (2), wherein the processor is configured to execute the following: determining a driving trajectory (Td) of the host vehicle during an avoidance control period (Pa) for controlling the host vehicle to avoid the collision; and controlling a steering angle (θ) and a braking force (Fb) to be applied to wheels (20) of the host vehicle in accordance with the driving trajectory, respectively; the determination of the driving trajectory is performed by selecting a control mode that matches a response characteristic estimated for the host vehicle during the avoidance control period from among an individual control mode (Ms) for controlling a turning attitude of the host vehicle during the avoidance control period by adjusting the steering angle alone, and a cooperative control mode (Mc) for controlling the turning attitude during the avoidance control period by adjusting the steering angle and the braking force together; and determining the driving trajectory in the individual control mode so as to specify a required yaw rate (Yr) required to control the turning attitude by adjusting the steering angle alone; In the cooperative control mode, determining the driving trajectory so as to specify the required yaw rate required to control the turning attitude by coordination of the steering angle and the braking force.

[0085] (Technical Idea 2) The driving assistance system according to Technical Idea 1, wherein the determination of the driving trajectory includes, in the cooperative control mode, specifying the required yaw rate for controlling the turning attitude by coordinating the left / right distribution of the braking force with the steering angle.

[0086] (Technical Idea 3) The driving assistance system according to Technical Idea 2, wherein the determination of the driving trajectory includes selecting the cooperative control mode that matches the response characteristics for which the left / right distribution within the limited range (ΔF) of the braking force during the avoidance control period is positively estimated.

[0087] (Technical Idea 4) The driving assistance system according to any one of Technical Ideas 1 to 3, wherein the determination of the driving trajectory includes adjusting the phase of the required yaw rate in the cooperative control mode to be more advanced than in the independent control mode.

[0088] (Technical Idea 5) The driving assistance system according to any one of Technical Ideas 1 to 4, wherein the determination of the driving trajectory includes adjusting the magnitude of the yaw angular acceleration (ηc), which is the gradient of the requested yaw rate, in the cooperative control mode to be larger than that in the independent control mode.

[0089] (Technical Idea 6) A driving assistance system according to any one of Technical Ideas 1 to 5, wherein the determination of the driving trajectory includes determining the driving trajectory so as to define the required yaw rate by limiting response sensitivity to steering operations by a driver who is in an override state in the host vehicle.

[0090] The above-mentioned technical concepts 1 to 6 may be understood as the respective technical concepts of the program and method.

Claims

1. A driver assistance system having a processor (12) that assists in avoiding collisions with targets (3) during the operation of a host vehicle (2), The aforementioned processor, The operation trajectory (Td) of the host vehicle during the avoidance control period (Pa) in which the host vehicle is controlled to avoid the collision is determined, The host vehicle is configured to control the steering angle (θ) and braking force (Fb) applied to the wheels (20) according to the driving trajectory, respectively. The determination of the aforementioned operating track is The control mode is selected from among a single control mode (Ms) in which the turning posture of the host vehicle during the avoidance control period is controlled by the independent adjustment of the steering angle, and a coordinated control mode (Mc) in which the turning posture during the avoidance control period is controlled by the coordinated adjustment of the steering angle and the braking force, and which matches the response characteristics estimated for the host vehicle during the avoidance control period. In the aforementioned standalone control mode, the driving trajectory is determined such that the required yaw rate (Yr) is defined to control the turning attitude by independently adjusting the rudder angle, The cooperative control mode includes determining the driving trajectory such that the required yaw rate is defined in order to control the turning attitude by the coordination of the steering angle and the braking force, The determination of the aforementioned operating track is A driving assistance system that includes defining the required yaw rate for controlling the turning posture by coordinating the left-right distribution of the braking force with the steering angle in the aforementioned cooperative control mode.

2. The determination of the aforementioned operating track is The driving assistance system according to claim 1, further comprising selecting a cooperative control mode that matches the response characteristics in which the left-right distribution within the limit range (ΔF) of the braking force is affirmed during the avoidance control period.

3. The determination of the aforementioned operating track is The driving support system according to claim 1 or 2, further comprising adjusting the phase of the requested yaw rate in the cooperative control mode to advance the angle compared to that in the single control mode.

4. The determination of the aforementioned operating track is The driving support system according to claim 1 or 2, further comprising adjusting the magnitude of the yaw angular acceleration (ηc), which is the gradient of the required yaw rate, in the cooperative control mode to be greater than in the single control mode.

5. The determination of the aforementioned operating track is The driving assistance system according to claim 1 or 2, further comprising determining the driving trajectory such that the requested yaw rate is defined by limiting the response sensitivity to steering operations of a driver in an override state in the host vehicle.

6. A driving assistance system having a processor (12) that assists in avoiding collisions with targets (3) during the operation of a host vehicle (2), The aforementioned processor, The operation trajectory (Td) of the host vehicle during the avoidance control period (Pa) in which the host vehicle is controlled to avoid the collision is determined, The host vehicle is configured to control the steering angle (θ) and braking force (Fb) applied to the wheels (20) according to the driving trajectory, respectively. The determination of the aforementioned operating track is The control mode is selected from among a single control mode (Ms) in which the turning posture of the host vehicle during the avoidance control period is controlled by the independent adjustment of the steering angle, and a coordinated control mode (Mc) in which the turning posture during the avoidance control period is controlled by the coordinated adjustment of the steering angle and the braking force, and which matches the response characteristics estimated for the host vehicle during the avoidance control period. In the aforementioned standalone control mode, the driving trajectory is determined such that the required yaw rate (Yr) is defined to control the turning attitude by independently adjusting the rudder angle, The cooperative control mode includes determining the driving trajectory such that the required yaw rate is defined in order to control the turning attitude by the coordination of the steering angle and the braking force, The determination of the aforementioned operating track is A driving assistance system that includes adjusting the phase of the requested yaw rate in the cooperative control mode to advance the angle compared to that in the single control mode.

7. The determination of the aforementioned operating track is The driving support system according to claim 6, further comprising adjusting the magnitude of the yaw angular acceleration (ηc), which is the gradient of the required yaw rate, in the cooperative control mode to be greater than in the single control mode.

8. The determination of the aforementioned operating track is The driving assistance system according to claim 6, which includes determining the driving trajectory such that the requested yaw rate is defined by limiting the response sensitivity to steering operations of a driver in an override state in the host vehicle.

9. A driving assistance system having a processor (12) that assists in avoiding collisions with targets (3) during the operation of a host vehicle (2), The aforementioned processor, The operation trajectory (Td) of the host vehicle during the avoidance control period (Pa) in which the host vehicle is controlled to avoid the collision is determined, The host vehicle is configured to control the steering angle (θ) and braking force (Fb) applied to the wheels (20) according to the driving trajectory, respectively. The determination of the aforementioned operating track is The control mode is selected from among a single control mode (Ms) in which the turning posture of the host vehicle during the avoidance control period is controlled by the independent adjustment of the steering angle, and a coordinated control mode (Mc) in which the turning posture during the avoidance control period is controlled by the coordinated adjustment of the steering angle and the braking force, and which matches the response characteristics estimated for the host vehicle during the avoidance control period. In the aforementioned standalone control mode, the driving trajectory is determined such that the required yaw rate (Yr) is defined to control the turning attitude by independently adjusting the rudder angle, The cooperative control mode includes determining the driving trajectory such that the required yaw rate is defined in order to control the turning attitude by the coordination of the steering angle and the braking force, The determination of the aforementioned operating track is A driving assistance system that includes adjusting the magnitude of the yaw angular acceleration (ηc), which is the gradient of the required yaw rate, in the cooperative control mode to be greater than in the single control mode.

10. The determination of the aforementioned operating track is The driving assistance system according to claim 9, which includes determining the driving trajectory such that the requested yaw rate is defined by limiting the response sensitivity to steering operations of a driver in an override state in the host vehicle.

11. The determination of the aforementioned operating track is The driving assistance system according to any one of claims 7, 8, or 10, further comprising defining the required yaw rate for controlling the turning attitude by coordinating the left-right distribution of the braking force with the steering angle in the aforementioned coordinated control mode.

12. The determination of the aforementioned operating track is The driving assistance system according to claim 11, further comprising selecting a cooperative control mode that matches the response characteristics in which the left-right distribution within the limit range (ΔF) of the braking force is affirmed during the avoidance control period.

13. A driving assistance program that is stored in a storage medium (10) to assist in avoiding collisions with targets (3) during the driving of a host vehicle (2), and includes instructions for causing a processor (12) to perform said assistance, The operation trajectory (Td) of the host vehicle during the avoidance control period (Pa) in which the host vehicle is controlled to avoid the collision is determined, The command includes a command to cause the host vehicle to control the steering angle (θ) and braking force (Fb) applied to the wheels (20) according to the driving trajectory, respectively. The determination of the aforementioned operating track is The control mode is selected from among a single control mode (Ms) in which the turning posture of the host vehicle during the avoidance control period is controlled by the independent adjustment of the steering angle, and a coordinated control mode (Mc) in which the turning posture during the avoidance control period is controlled by the coordinated adjustment of the steering angle and the braking force, and which matches the response characteristics estimated for the host vehicle during the avoidance control period. In the aforementioned standalone control mode, the driving trajectory is determined such that the required yaw rate (Yr) is defined to control the turning attitude by independently adjusting the rudder angle, The cooperative control mode includes determining the driving trajectory such that the required yaw rate is defined in order to control the turning attitude by the coordination of the steering angle and the braking force, The determination of the aforementioned operating track is A driving assistance program that includes defining the required yaw rate for controlling the turning attitude by coordinating the left-right distribution of the braking force with the steering angle in the aforementioned cooperative control mode.

14. A driving assistance method performed by a processor (12) to assist in avoiding collision with a target (3) during the operation of a host vehicle (2), The operation trajectory (Td) of the host vehicle during the avoidance control period (Pa) in which the host vehicle is controlled to avoid the collision is determined, This includes controlling the steering angle (θ) and braking force (Fb) applied to the wheels (20) of the host vehicle according to the driving trajectory, The determination of the aforementioned operating track is The control mode is selected from among a single control mode (Ms) in which the turning posture of the host vehicle during the avoidance control period is controlled by the independent adjustment of the steering angle, and a coordinated control mode (Mc) in which the turning posture during the avoidance control period is controlled by the coordinated adjustment of the steering angle and the braking force, and which matches the response characteristics estimated for the host vehicle during the avoidance control period. In the aforementioned standalone control mode, the driving trajectory is determined such that the required yaw rate (Yr) is defined to control the turning attitude by independently adjusting the rudder angle, The cooperative control mode includes determining the driving trajectory such that the required yaw rate is defined in order to control the turning attitude by the coordination of the steering angle and the braking force, The determination of the aforementioned operating track is A driving assistance method comprising defining the required yaw rate for controlling the turning attitude in the aforementioned cooperative control mode by coordinating the left-right distribution of the braking force with the steering angle.