JP5531455B2 - Vehicle travel control device and vehicle travel control method - Google Patents

Description

  The present invention relates to a vehicle travel control device and a control method therefor.

2. Description of the Related Art Conventionally, there has been known a method for controlling the movement state of a vehicle (running control) in order to avoid the vehicle from coming into contact with an obstacle according to the traveling state of the vehicle and the operation state of the driver.
Further, as a similar technique, there is also known a method for controlling the vehicle motion state (travel control) so that the vehicle travels along a lane. In the case of changing the direction of the vehicle in the middle of driving control to follow the lane, since the person becomes the driving subject, there is also a method configured to allow intervention by the driver's intention even during driving control It is known (see, for example, Patent Document 1). According to such a method, in order to provide information suitable for driving from the system side in a form that the driver can easily recognize, information necessary for the vehicle to travel along the lane is obtained from the steering force and the steering angle. Convert it into a shape and tell the driver. As a result, the driver can drive the vehicle with his / her own intention while taking these information into consideration.

Japanese Patent No. 3569587

  However, in traveling control for avoiding contact, when the method disclosed in Patent Document 1 is applied, there is a concern about the following inconveniences. For example, there may be a gap between the driver's steering according to the external situation recognized by the driver himself and the steering by the control intervention, and in this case, the driver may feel uncomfortable. is there. In order to eliminate such a sense of incongruity, it may be possible to suppress steering by control intervention depending on the situation, but even in this case, it is also important to guide to an appropriate avoidance path.

  The present invention has been made in view of such circumstances, and an object of the present invention is to reduce an uncomfortable feeling given to the driver and avoid an avoidance track when performing a travel control for avoiding the vehicle from contacting an obstacle. It is to guide to appropriately.

In order to solve such a problem, the present invention controls traveling of the host vehicle based on an avoidance track that matches the operation of the driver. At this time, with the avoidance trajectory as a processing target, the possibility of contact with an obstacle in a predetermined range extending in a direction substantially orthogonal to the avoidance trajectory is calculated as a risk based on the detection result of the obstacle and the motion state. In this case, the smaller the calculated risk is, the more the travel control is suppressed, and the steering reaction force against the driver's steering operation is adjusted according to the traveling state of the vehicle with respect to the avoidance track.

  According to the present invention, even if there is a deviation between the actual trajectory and the selected avoidance trajectory, if the risk is small, the amount of control suppression increases, so the steering intervention amount due to travel control decreases. Therefore, a gap generated between the steering of the driver according to the external situation recognized by the driver and the steering by the control intervention is suppressed. Thereby, it is possible to reduce the uncomfortable feeling that the driver learns. Even when traveling control with such a sense of incongruity is performed, by adjusting the steering reaction force according to the traveling state of the vehicle with respect to the selected avoidance track, the avoidance track can be provided to the driver through the steering reaction force. Can be recognized.

Explanatory drawing which shows typically the vehicle to which the traveling control apparatus 10 of the vehicle concerning 1st Embodiment was applied. The block diagram which shows the functional structure of the controller 30 The flowchart which shows the traveling control method concerning 1st Embodiment. Illustration of avoidance trajectory Explanatory diagram of risk in a predetermined range extending in the direction perpendicular to the orbit Explanatory diagram showing the relationship between the risk and the correction amount for the command torque Explanatory diagram showing the relationship between the risk and the correction amount for the command torque Explanatory drawing showing the relationship between steering reaction force and steering angle deviation The block diagram which shows the structure of the traveling control apparatus 10 of the vehicle concerning 2nd Embodiment. The flowchart which shows the traveling control method concerning 2nd Embodiment. The flowchart which shows the traveling control method concerning 3rd Embodiment.

(First embodiment)
FIG. 1 is an explanatory diagram schematically showing a vehicle to which a vehicle travel control device 10 according to a first embodiment of the present invention is applied. This vehicle travel control device 10 is a device for controlling the vehicle motion state (running control) in order to avoid the vehicle from coming into contact with an obstacle, and mainly comprises a detection system, a controller 30 and actuators 40 and 41. It is configured.

  The radar 20 detects the distance and position to the object in the traveling direction of the vehicle. As the radar 20, a laser radar, a millimeter wave radar, or the like can be used. For example, when a laser radar is used as the radar 20, the radar 20 irradiates laser light in front of the vehicle and receives reflected light from an object existing in front by a light receiving system. The radar 20 detects the distance and position between the vehicle and the object by detecting the time difference between the laser emission time and the reflected light reception time.

  The camera 21 outputs a captured image to the image processing device 22 by imaging the front of the vehicle. The image processing device 22 processes the captured image from the camera 21 to detect traveling environment information such as an object existing ahead and a road environment.

  The yaw rate sensor 23 detects the yaw rate generated in the vehicle 1. The G sensor 24 detects acceleration in the longitudinal direction (vehicle length direction) of the vehicle (hereinafter referred to as “longitudinal acceleration”) and also detects acceleration in the lateral direction (vehicle width direction) of the vehicle (hereinafter referred to as “lateral acceleration”). To do. The wheel speed sensor 25 detects the speed (vehicle speed) of the vehicle by detecting the rotational speed of each wheel of the vehicle 1.

  The steering angle sensor 26 detects the rotation angle of the handle operated by the driver as the steering angle. The steering angle is detected together with the steering direction such as the left direction or the right direction with reference to the neutral state of the handle corresponding to the straight traveling. The steering torque sensor 27 detects the steering torque applied by the driver's steering operation. The steering torque is detected together with the steering direction such as the left direction or the right direction with reference to the neutral state of the handle corresponding to the straight traveling.

  FIG. 2 is a block diagram illustrating a functional configuration of the controller 30. The controller 30 has a function of controlling the entire system in an integrated manner, and performs traveling control for avoiding obstacles by operating according to the control program. As the controller 30, a microcomputer mainly composed of a CPU, a ROM, a RAM, and an I / O interface can be used. The controller 30 performs various calculations based on various types of information detected by the detection system, and outputs a control signal corresponding to the calculation result to the actuators 40 and 41, thereby controlling the motion state of the vehicle ( Run control).

  When the controller 30 grasps this functionally, the obstacle detection unit 31, the movement state detection unit 32, the driving operation detection unit 33, the avoidance trajectory generation unit 34, the avoidance trajectory selection unit 35, the risk calculation unit 36, the control suppression Part 37, steering reaction force adjusting part 38, and travel control part 39.

  The obstacle detection unit 31 reads a detection signal from the radar 20 and reads a processing result from the image processing device 22. The obstacle detection unit 31 detects an object that may come into contact with the host vehicle as an obstacle based on the read information (obstacle detection means). The detection result by the obstacle detection unit 31 is output to the avoidance trajectory generation unit 34, the risk calculation unit 36, and the control suppression unit 37, respectively.

  The motion state detection unit 32 reads detection signals from the yaw rate sensor 23, the G sensor 24, and the wheel speed sensor 25, respectively. The motion state detection unit 32 detects the motion state of the vehicle from each read information (motion state detection means). The detection result by the movement state detection unit 32 is output to the avoidance trajectory generation unit 34 and the risk calculation unit 36, respectively.

  The driving operation detection unit 33 reads detection signals from the steering angle sensor 26 and the steering torque sensor 27, respectively. The driving operation detection unit 33 detects a driving operation by the driver based on the read information (driving operation detection means). The detection result by the driving operation detection unit 33 is output to the avoidance trajectory selection unit 35 and the steering reaction force adjustment unit 38, respectively.

  The avoidance trajectory generation unit 34 generates a plurality of avoidance trajectories for avoiding contact with the obstacle based on the obstacle detection result and the vehicle motion state (avoidance trajectory generation means). The multiple avoidance trajectories generated by the avoidance trajectory generation unit 34 are output to the avoidance trajectory selection unit 35.

  The avoidance trajectory selection unit 35 selects an avoidance trajectory that matches the driving operation of the driver from among the plurality of avoidance trajectories generated based on the driving operation of the driver (avoidance trajectory selection means). The avoidance trajectory selected by the avoidance trajectory selection unit 35 is output to the risk calculation unit 36, the steering reaction force adjustment unit 38, and the travel control unit 39, respectively.

  The risk calculation unit 36 calculates a risk based on the obstacle detection result and the vehicle motion state (risk calculation means). This risk is an index indicating the possibility of contact with an obstacle in a predetermined range extending in a direction substantially orthogonal to the traveling direction of the host vehicle (avoidance track) (hereinafter referred to as “track orthogonal direction”). In the present embodiment, the risk calculation unit 36 calculates a risk corresponding to the avoidance trajectory selected by the avoidance trajectory selection unit 35. The risk corresponding to the avoidance trajectory calculated by the risk calculation unit 36 is output to the control suppression unit 37.

  The control suppression unit 37 calculates a control suppression amount based on the calculated risk and the obstacle detection result (a suppression unit). The control suppression amount is a control amount necessary to suppress this when the travel control unit 39 described later performs travel control for following the selected avoidance path. The control suppression amount calculated by the control suppression unit 37 is output to the travel control unit 39.

  The steering reaction force adjusting unit 38 adjusts the steering reaction force for the steering operation of the driver according to the traveling state of the host vehicle with respect to the selected avoidance track (steering reaction force adjusting means). Specifically, the steering reaction force adjusting unit 38 calculates a control amount for applying a steering reaction force according to the traveling state of the host vehicle with respect to the selected avoidance track.

  The traveling control unit 39 automatically selects the avoidance trajectory selected based on the selected avoidance trajectory, the control suppression amount calculated by the control suppression unit 37, and the control amount calculated by the steering reaction force adjustment unit 38. A travel control amount for the vehicle to travel is calculated. Then, the travel control unit 39 controls the actuators 40 and 41 based on the travel control amount to control the travel control, that is, the motion state of the vehicle (travel control means).

  The steering actuator 40 is an actuator that applies lateral force to the wheels (that is, applies lateral acceleration to the vehicle), and includes, for example, an assist motor that applies assist torque that assists the driver's steering. The steering actuator 40 can perform a steering operation of the vehicle by giving an arbitrary steering angle to the wheels, and can adjust a steering reaction force to the driver.

  FIG. 3 is a flowchart illustrating the travel control method according to the first embodiment. The process shown in this flowchart is called when the ignition switch of the vehicle is turned on, and is executed by the controller 30 at a predetermined cycle.

  In step 10 (S10), the obstacle detection unit 31 includes an area in which the vehicle can travel (hereinafter referred to as “traveling road”) and a traveling path based on input information from the radar 20 and the image processing device 22. Detects existing objects. Note that a method for detecting a traveling road or the like is already known at the time of filing of the present application, and thus detailed description thereof is omitted. About the detection method of a traveling path, since it is disclosed by the patent 3521860 gazette, please refer if necessary.

  In step 11 (S11), the obstacle detection unit 31 determines based on the detection result in step 10 whether or not there is an object (hereinafter referred to as “obstacle”) that may come into contact with the vehicle in the travel path. Is determined. In addition, since the detection method of an obstruction is already well-known at the time of the application of this application, detailed description is abbreviate | omitted. The obstacle detection method is disclosed in, for example, Japanese Patent Application Laid-Open No. 2000-207693, so refer to it if necessary. If an affirmative determination is made in step 11, that is, if there is an obstacle, the process proceeds to step 12 (S12). On the other hand, if a negative determination is made in step 11, that is, if there is no obstacle, the process returns to step 10.

  In step 12, the obstacle detection unit 31 makes contact with the obstacle confirmed by the processing in step 11 based on the distance between the obstacle and the own vehicle and the relative speed between the obstacle and the own vehicle. The time until this is calculated as the predicted contact time Tttc. The distance between the obstacle and the host vehicle can be calculated from input information from the radar 20, and the relative speed between the host vehicle and the obstacle can be calculated by, for example, differentiating the calculated distance with time.

  In step 13 (S13), the avoidance trajectory generation unit 34 determines whether or not the predicted contact time Tttc is equal to or shorter than a preset first determination time Tth1. If an affirmative determination is made in step 13, that is, if the predicted contact time Tttc is equal to or shorter than the first determination time Tth1, the process proceeds to step 14 (S14). On the other hand, if a negative determination is made in step 13, that is, if the predicted contact time Tttc is not equal to or shorter than the first determination time Tth1, the process returns to step 10.

  If the predicted contact time Tttc is not less than or equal to the first determination time Tth1, in other words, if the time until the host vehicle is in contact with the obstacle is relatively long, the obstacle is generally caused by subsequent vehicle operation by the driver. May be avoided. Therefore, there is a high possibility that there is no need to execute travel control for avoiding contact. As a result, it is possible to suppress the execution of travel control, which will be described later, even though the scene does not require execution of travel control. Therefore, the processing load on the controller 30 can be reduced. Therefore, in the determination process in step 13, the first determination time Tth1 for making such a determination is set through experiments and simulations.

  In step 14, the avoidance trajectory generation unit 34 generates a plurality of travel trajectories as avoidance trajectories for avoiding contact with the obstacle based on the detected obstacle and the detected motion state of the host vehicle. calculate. In the present embodiment, the avoidance trajectory generation unit 34 generates an avoidance trajectory that avoids contact with an obstacle by steering. Specifically, as shown in FIG. 4, an avoidance trajectory R1 that avoids contact with an obstacle by steering in the left direction and an avoidance trajectory R2 that avoids contact with the obstacle by steering in the right direction. Generate each. In the figure, “C” indicates the own vehicle, and “O” indicates an obstacle moving in the direction of the arrow (direction perpendicular to the track).

  When generating the individual avoidance tracks R1 and R2, the avoidance track generation unit 34 assigns the avoidance track generation unit 34 to the own vehicle in order to avoid contact with an obstacle based on the motion state of the own vehicle and the tire characteristics of the own vehicle. Set the lateral acceleration. Then, the avoidance trajectory generation unit 34 determines whether or not contact with an obstacle can be avoided by the set lateral acceleration. When the avoidance trajectory generation unit 34 determines that the contact can be avoided by the lateral acceleration, the avoidance trajectory generation unit 34 calculates an avoidance trajectory corresponding to the lateral acceleration within the range of the travel path. In this case, the avoidance trajectory generation unit 34 does not generate an avoidance trajectory that is out of the range of the travel path. On the other hand, the avoidance trajectory generation unit 34 does not generate an avoidance trajectory when it is determined that contact cannot be avoided due to the lateral acceleration.

  In step 15 (S15), the avoidance trajectory selection unit 35 determines whether or not there is any operation by the driver. The avoidance trajectory selection unit 35 refers to the operation amount detected by the driving operation detection unit 33, specifically, the steering angle, and determines whether or not a steering operation by the driver has been performed. The method for determining the presence or absence of the steering operation is, for example, detecting whether the steering angle has changed in either the left or right direction from the steering angle at the timing at which the avoidance trajectory was calculated in step 14. Further, it may be determined whether or not a change in the steering angle has occurred by a predetermined threshold value or more based not only on the steering direction but also on the steering angle at the timing when the avoidance track is calculated. Further, instead of the change in the steering angle, it may be determined that the steering angular velocity or the steering angular acceleration has changed by a predetermined threshold value or more. If a negative determination is made in step 15, that is, if there is no operation by the driver, the process proceeds to step 16 (S16). On the other hand, if an affirmative determination is made in step 15, that is, if there is an operation by the driver, the process proceeds to step 17 (S17).

  In step 16, the avoidance trajectory selection unit 35 determines whether or not the predicted contact time Tttc calculated by the processing in step 12 is equal to or longer than the predicted contact time Tth2. Here, as shown at points P1 and P2 in FIG. 4, the control start point for performing the traveling control following each avoidance track differs depending on the avoidance track. The predicted contact time Tth2 described above is the predicted contact time when the vehicle arrives at the control start point of the avoidance trajectory where the control start point is closest to the obstacle (in the example shown in FIG. 4, the point P2 Predicted contact time). If an affirmative determination is made in step 16, that is, if the predicted contact time Tttc is greater than or equal to the predicted contact time Tth2, the process returns to step 15. On the other hand, if a negative determination is made in step 16, that is, if the predicted contact time Tttc is smaller than the predicted contact time Tth2, the process proceeds to step 17.

  In step 17, the avoidance trajectory selection unit 35 selects an avoidance trajectory from among the plurality of avoidance trajectories that have been generated. Specifically, when the operation is performed by the driver, the avoidance trajectory selection unit 35 selects an avoidance trajectory that matches the driver's operation from the plurality of avoidance trajectories R1 and R2. For example, when the driver is steering in the right direction, the avoidance track R2 that matches the steering in the right direction is selected. On the other hand, when the operation is not performed by the driver, the point at which the driver starts the operation is closer to the obstacle than the control start points P1 and P2 regarding any of the avoidance tracks R1 and R2. Therefore, the avoidance trajectory selection unit 35 selects an avoidance trajectory whose control start points P1 and P2 are closest to the obstacle from the plurality of avoidance trajectories R1 and R2.

  In step 18 (S18), the traveling control unit 39 starts traveling control based on the selected avoidance track. Specifically, the travel control unit 39 starts the control of the steering actuator 40.

  In step 19 (S19), the travel control unit 39 calculates a target steering angle for the vehicle to follow the avoidance track using, for example, a two-wheel model, based on the selected avoidance track. Then, the traveling control unit 39 detects a deviation (steering angle deviation) between the target steering angle and the current steering angle, and calculates a command torque for the steering actuator 40 as a control amount for reducing the steering angle deviation. . There are various methods for calculating the command torque to follow the target steering angle, and since they are already known at the time of filing of the present application, detailed description thereof is omitted. Note that the target steering angle may be calculated approximately from the selected avoidance trajectory using only the input information from the yaw rate sensor 23 and the wheel speed sensor 25 of the vehicle. Further, the selected avoidance trajectory may be the target steering angle from the beginning.

  In step 20 (S20), the risk calculation unit 36 calculates a risk corresponding to the selected avoidance route based on the detection result of the obstacle and the detection result of the motion state of the vehicle. As described above, this risk is an index indicating the possibility of contact with an obstacle in a predetermined range extending in the direction orthogonal to the trajectory, and is a small value in a range where there is no obstacle ahead, and a range where there is an obstacle ahead. Is set to a large value. For example, when the normalized risk is used, 0 is set for the risk in the range without the obstacle, and 1 is set for the risk in the range with the obstacle. In the range between them, for example, as shown in FIGS. 7A and 7B, the risk may be set so as to appropriately connect “0” and “1”.

  In step 21 (S21), the control suppression unit 37 calculates the relative position of the vehicle with respect to the obstacle using the detection result of the obstacle detection unit 31. Then, the control suppression unit 37 obtains the current risk by comparing with the calculated risk positional relationship, and based on this risk, the control amount, specifically, the correction amount for the command torque calculated in step 19 (specifically In step S19, a correction amount for suppressing the command torque in step 19 is calculated. Specifically, the control suppression unit 37 calculates a larger correction amount for the command torque so that the lower the risk, the weaker the command torque that follows the target steering angle. As a result, in a low-risk scene, the driver can correct the trajectory of the vehicle. On the other hand, the control suppression unit 37 calculates a smaller correction amount for the command torque so that the command torque that follows the target steering angle does not become weaker as the risk increases. In a high-risk scene, it is difficult for the driver to correct the vehicle trajectory. From such a viewpoint, the correction amount with respect to the command torque is set so as to decrease as the risk increases. For example, as shown in FIG. 6, the correction amount (Tta) for the command torque may be linearly changed according to the risk (R). Further, as shown in FIG. 7A, the correction amount (Tta) for the command torque changes nonlinearly according to the risk (R), but satisfies the above condition by changing inversely. It may be. Further, as shown in FIG. 7B, the correction amount (Tta) for the command torque is a constant correction amount within a certain risk (R) range, but this gradually decreases as the risk increases. It may be a thing.

  In step 22 (S22), the steering reaction force adjusting unit 38 corrects the command torque calculated in step 19 (specifically, the steering torque) so that the driver can recognize the vehicle follow-up state with respect to the selected avoidance track. A correction amount (control amount) for adjusting the reaction force is calculated. Normally, the travel control unit 39 uses the rotation position when the wheel steering angle corresponds to the target steering angle as a reference position, and steers the steering reaction force so that the steering reaction force increases as the steering angle increases from the reference position. The reaction force is controlled. The steering reaction force adjusting unit 38 increases the steering reaction force in accordance with the increase in the steering angle from the reference position as the deviation of the current steering angle (steering angle deviation) with respect to the target steering angle in the calculation of step 19 increases. The correction amount is calculated so that the amount is larger than normal. As a result, when the steering angle deviation is large, the driver can be recognized to be out of the selected avoidance track. On the other hand, when the steering angle deviation is small, the steering reaction force does not become too large compared to that in the normal state. As a result, the driver can be allowed to perform a free steering operation, so that the driver feels uncomfortable. From this point of view, the steering reaction force is set to be proportional to the deviation with respect to the target steering angle, with the rotational position when the steering angle of the wheel corresponds to the target steering angle as a reference position. For example, as shown in FIG. 8, the steering reaction force may be in a relationship that changes linearly according to the deviation of the target steering angle.

  In step 23 (S23), the travel control unit 39 calculates a final command torque based on the command torque calculated in step 19 and the correction amounts calculated in steps 21 and 22, respectively. Specifically, the traveling control unit 39 calculates the final command torque by adding the command torque and each correction amount. Then, the travel control unit 39 converts the final command torque into a command current necessary for driving the assist motor, and outputs this to the steering actuator 40 as a control command. Steering control is performed by the steering actuator 40 operating according to the control command.

  In step 24 (S24), the obstacle detection unit 31 determines whether or not the avoidance of the obstacle has been completed and the possibility of contact with the obstacle has disappeared. If an affirmative determination is made in step 24, that is, if it is determined that there is no possibility of contact, the process returns to step 10. In this case, the travel control unit 39 ends the travel control for causing the vehicle to follow the avoidance track selected by the avoidance track selection unit 35. On the other hand, if a negative determination is made in step 24, that is, if it is determined that there is a possibility of contact, the process returns to step 19.

  As described above, in the present embodiment, the risk calculation unit 36 calculates the possibility of contact with an obstacle in a predetermined range extending in a direction substantially orthogonal to the avoidance trajectory as a risk, using the selected avoidance trajectory as a processing target. Moreover, the control suppression part 37 suppresses the traveling control by the traveling control part 39 according to the calculated risk. Further, the steering reaction force adjusting unit 38 adjusts the steering reaction force with respect to the driver's steering operation according to the traveling state (specifically, the steering angle deviation) of the host vehicle with respect to the selected avoidance track.

  According to this configuration, even if there is a deviation between the actual trajectory and the selected avoidance trajectory, the amount of control suppression increases when the risk is small, so the steering intervention amount due to travel control decreases. Therefore, a gap generated between the steering of the driver according to the external situation recognized by the driver and the steering by the control intervention is suppressed. Thereby, it is possible to reduce the uncomfortable feeling that the driver learns. Further, even when the travel control with such a sense of incongruity is performed, the avoidance trajectory is provided to the driver via the steering wheel by applying a steering reaction force according to the traveling state of the vehicle with respect to the selected avoidance trajectory. Can be recognized. In addition, the amount of intervention by the driver can be increased by guiding the driver's operation to an avoidance trajectory with a small discomfort.

  In the present embodiment, the travel control unit 39 calculates a target steering angle for the vehicle to follow the avoidance track based on the selected avoidance track, and the calculated target steering angle and the current wheel steering. A command torque (control amount) for reducing the steering angle deviation from the angle is calculated. Then, the traveling control unit 39 controls traveling of the host vehicle based on the calculated command torque. According to such a configuration, since the command torque corresponding to the deviation is applied, the absolute value of the command torque can be reduced, and the uncomfortable feeling that the driver learns can be reduced. Further, in a state where the travel control is suppressed by the control suppression unit 37, the vehicle approaches the avoidance track selected gently. For this reason, the driver feels that he / she is guided to the single avoidance track through the steering operator (steering wheel) without a sense of incongruity, and can obtain a sense of security.

  In the present embodiment, the steering reaction force adjustment unit 38 performs an adjustment such that the greater the steering angle deviation, the greater the increase in the steering reaction force according to the increase in the steering angle from the reference position. According to this configuration, the driver can intuitively recognize the avoidance route from the steering reaction force. Therefore, the driver's operation can be guided to the avoidance path without making the driver feel uncomfortable. Further, since the steering reaction force increases in accordance with the deviation from the target steering angle, an unnecessary steering operation can be suppressed even in a situation where the driver panics.

  In the present embodiment, in the processing of step 10, an object present in the travel road is detected as an obstacle, but it is not considered whether it is in the travel road, for example, within a predetermined area in front of the host vehicle. May be detected as an obstacle.

  Further, the risk calculated in step 20 may be used to calculate the steering reaction force in step S14. In this case, in a low risk range, the steering reaction force may be reduced or set to the steering reaction force possessed by the power steering characteristics. On the other hand, in a high-risk range, the steering reaction force may be made extremely large to make it difficult for the driver to steer, thereby suppressing the steering operation due to the driver's mistake.

(Second Embodiment)
FIG. 9 is a block diagram showing the configuration of the vehicle travel control apparatus 10 according to the second embodiment. The vehicle travel control device 10 and its control method according to this embodiment differ from those of the first embodiment in that not only steering control but also braking control is performed as travel control. In addition, the description which overlaps with 1st Embodiment shall be abbreviate | omitted, and it demonstrates focusing on difference below. In the present embodiment, a brake actuator 41 is added to the vehicle travel control device 10 in addition to the configuration shown in the first embodiment. The brake actuator 41 is, for example, an actuator that controls a brake fluid pressure supplied to a wheel cylinder of the vehicle. By controlling the brake actuator 41, a braking force is generated on the wheels to perform a braking operation of the vehicle. Can do.

  FIG. 10 is a flowchart illustrating a travel control method according to the second embodiment. In the control method of this embodiment, the process of step 25 (S25) is additionally executed between the process of step 19 and the process of step 20 as compared with the first embodiment.

  In step 25, the traveling control unit 39 sets the necessary deceleration so that the vehicle does not obstruct the lateral force and yaw rate necessary to avoid the obstacle by following the target steering angle. The traveling control unit 39 calculates a hydraulic pressure command value necessary for the set deceleration, and outputs this to the brake actuator 41 as a control command. Braking control is performed by the brake actuator 41 operating in response to a control command.

  According to the present embodiment as described above, by applying the braking control, it is possible to more effectively perform the traveling control for avoiding the obstacle.

  In the process of step 25, the hydraulic pressure command value of the brake actuator 41 may be set to the maximum command value pressure allowed by the actuator. Further, the hydraulic pressure command value of the brake actuator 41 may be set to a certain constant value in order to decelerate.

(Third embodiment)
The vehicle travel control apparatus 10 and its control method according to the third embodiment are different from those of the first embodiment in a method for calculating a steering reaction force. In addition, the description which overlaps with 1st Embodiment shall be abbreviate | omitted, and it demonstrates focusing on difference below. In the present embodiment, the configuration of the vehicle travel control device 10 is the same as that of the first embodiment.

  FIG. 11 is a flowchart illustrating a travel control method according to the third embodiment. In the control method of this embodiment, the process of step 26 (S26) is added compared with 1st Embodiment, This process is performed in parallel with the process from step 19 to step 21. FIG.

  In step 26 (S26), the travel control unit 39 uses the input information from the steering torque sensor 27 detected by the driving operation detection unit 33 to adjust the steering reaction force according to the steering situation of the driver. Specifically, when the steering torque detected by the steering torque sensor 27 is large, the driver may be actively operating the steering wheel, or may want to perform a steering operation sufficiently larger than the target steering angle. It is done. Therefore, the traveling control unit 39 weakens the steering reaction force accordingly. As a result, it is possible to improve the ease of handle operation by the driver. On the other hand, when the steering torque detected by the steering torque sensor 27 is small, it is conceivable that the driver has not operated the steering wheel very much or has performed a steering operation that almost matches the target steering angle. Therefore, the traveling control unit 39 increases the steering reaction force accordingly. Thereby, the driver can obtain a sense of stability of the steering wheel.

  In step 26, the change in the steering reaction force with respect to the steering torque sensor 27 is referred to, but input information from the wheel speed sensor 25 may be used as additional information. For example, the steering reaction force is increased as the wheel speed increases, so that a sense of stability of the steering wheel at a high speed can be realized. As a result, a sense of stability in high-speed traveling can be transmitted to the driver.

  In each embodiment described above, the obstacle detection unit 31 of the controller 30 has a function of detecting an obstacle existing in front of the host vehicle. In a broad sense, the radar 20, the camera 21, and the image processing are performed. The device 22 also functions as a means for performing the same function. The motion state detection unit 32 has a function of detecting the motion state of the host vehicle. In a broad sense, the yaw rate sensor 23, the G sensor 24, and the wheel speed sensor 25 also function as means for performing the same function. . Further, the operation amount detection unit 33 has a function of detecting the operation of the host vehicle by the driver. In a broad sense, the steering angle sensor 26 and the steering torque sensor 27 also function as a unit having the same function.

DESCRIPTION OF SYMBOLS 10 ... Traveling control apparatus 20 ... Radar 21 ... Camera 22 ... Image processing apparatus 23 ... Yaw rate sensor 24 ... G sensor 25 ... Wheel speed sensor 26 ... Steering angle sensor 27 ... Steering torque sensor 30 ... Controller 31 ... Obstacle detection part 32 ... Motion state detection unit 33 ... Driving operation detection unit 34 ... Avoidance trajectory generation unit 35 ... Avoidance trajectory selection unit 36 ... Risk calculation unit 37 ... Control suppression unit 38 ... Steering reaction force adjustment unit 39 ... Travel control unit 40 ... Steering actuator 40, 41 ... Actuator 41 ... Brake actuator

Claims (9)

Obstacle detection means for detecting obstacles existing in front of the host vehicle;
Motion state detection means for detecting the motion state of the host vehicle;
An avoidance trajectory generating means for generating a plurality of avoidance trajectories for avoiding contact of the own vehicle with the obstacle with reference to the motion state of the own vehicle;
Driving operation detection means for detecting operation of the vehicle by the driver;
An avoidance trajectory selection means for selecting an avoidance trajectory suitable for the operation of the vehicle by the driver from the plurality of avoidance trajectories;
Travel control means for traveling control of the host vehicle based on the avoidance trajectory selected by the avoidance trajectory selection means;
Based on the detection results of the obstacle detection means and the motion state detection means, the selected avoidance trajectory can be contacted with the obstacle in a predetermined range extending in a direction substantially orthogonal to the avoidance trajectory. Risk calculation means for calculating sex as a risk,
The smaller the risk calculated by the risk calculation means, the lower the suppression means for suppressing the travel control by the travel control means,
A vehicle travel control device comprising: a steering reaction force adjusting means for adjusting a steering reaction force with respect to a driver's steering operation in accordance with a traveling state of the host vehicle with respect to the selected avoidance track.   The travel control means calculates a target steering angle for the vehicle to follow the avoidance track based on the selected avoidance track, and a steering angle between the calculated target steering angle and the current wheel steering angle. The vehicle travel control apparatus according to claim 1, wherein a control amount for reducing the deviation is calculated, and the host vehicle is travel-controlled based on the calculated control amount. The travel control means uses the rotational position when the steering angle of the wheel corresponds to the target steering angle as a reference position, and the steering reaction force so that the steering reaction force increases as the steering angle increases from the reference position. Control
The steering reaction force adjusting means adjusts the steering reaction force by the travel control means so that the greater the steering angle deviation, the greater the increase in the steering reaction force according to the increase in the steering angle from the reference position. The vehicle travel control device according to claim 2, wherein the vehicle travel control device is performed.   The vehicle travel control device according to any one of claims 1 to 3, wherein the travel control unit performs braking control together with steering control. The vehicle travel according to any one of claims 1 to 3, wherein the steering reaction force adjusting means decreases the steering reaction force in accordance with an increase in an operation force of a driver's steering operation. Control device.   The avoidance trajectory generating means generates an avoidance trajectory that avoids contact with an obstacle by steering in the right direction and an avoidance trajectory that avoids contact with an obstacle by steering in the left direction. The vehicle travel control device according to any one of claims 1 to 5. The avoidance trajectory selecting means selects an avoidance trajectory that avoids contact with an obstacle by steering in the right direction when a steering operation in the right direction by the driver is detected by the driving operation detection means,
7. The avoidance trajectory that avoids contact with an obstacle by leftward steering is selected when the leftward steering operation by the driver is detected by the driving operation detection unit. Vehicle travel control device.   8. The vehicle travel according to claim 6, wherein the avoidance trajectory selection unit selects an avoidance trajectory whose control start point is closest to the obstacle when it is determined that there is no operation by the driver. Control device. With reference to the motion state of the vehicle, the avoidance path for avoiding the host vehicle contacts the obstacles generates a plurality,
From among the plurality of avoidance trajectories, select the avoidance route corresponding to the operation of the vehicle by the OPERATION person,
Based on the obstacle and the motion state of the vehicle, the avoidance trajectory is a processing target, and the possibility of contact with the obstacle in a predetermined range extending in a direction substantially orthogonal to the avoidance trajectory is calculated as a risk.
The host vehicle is travel-controlled based on the selected avoidance path, and the travel control is suppressed as the calculated risk is smaller during the travel control, and the driver's steering operation is performed according to the travel control. A vehicle travel control method comprising adjusting a steering reaction force against the vehicle.

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