JP2009051349A - Travel support device and travel support method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress a driver's incompatible feeling accompanied by control. <P>SOLUTION: An avoidance intention detection part 37 detects a situation as a stable avoidance intention. When the stable avoidance intention is detected, correction processing for correcting control by a vehicle control part 39 is carried out by a control amount correcting part 38. In this case, in a situation where steering is returned in a neutral direction after it is carried out in a first steering direction as a primary avoidance operation, the avoidance intention detection part 37 detects as the stable avoidance intention as the situation where steering torque is generated in a first direction and the steering torque is larger than steering torque in normal traveling. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a travel support apparatus and method for supporting travel of a vehicle.

  Conventionally, a method for supporting driving of a vehicle is known. For example, Patent Document 1 discloses a vehicle operation support device that can obtain a necessary assist torque when performing an obstacle avoidance operation while minimizing a driver's uncomfortable feeling due to the assist torque.

Specifically, when a collision avoidance operation by the driver is determined, an avoidance momentum necessary for the host vehicle to avoid an obstacle is calculated, and the target assist current is corrected based on the avoidance momentum. Accordingly, when the absolute value of the yaw rate deviation is equal to or less than the threshold value and the vehicle behavior is stable, the target assist current is reduced, so that the driver's uncomfortable feeling due to excessive assist can be eliminated. Moreover, the reduction amount of the target assist current is set smaller when the collision avoidance operation by the driver is determined than when it is not determined. Therefore, it becomes difficult to reduce the target assist current in an emergency in which a collision avoidance operation is performed, and obstacles can be reliably avoided.
Japanese Patent Laid-Open No. 2007-8402

  However, according to the conventional method, depending on the driver's intention to operate, there is an inconvenience that a steering discomfort greatly different from that during normal driving occurs due to the assist torque by the system.

  The present invention has been made in view of such circumstances, and an object thereof is to suppress a driver's uncomfortable feeling associated with control.

  In order to solve such a problem, the present invention provides a vehicle control means for controlling the motion state of a vehicle based on an avoidance control amount determined so as to follow an avoidance trajectory and a driver. Intention avoidance detection for detecting a state where the primary avoidance operation is being executed as a stable avoidance intention in consideration of a secondary avoidance operation for maintaining the stability of the vehicle after the primary avoidance operation for avoiding And a correction means for performing a correction process for correcting the control by the vehicle control means when the intention to avoid the stability is detected by the avoidance intention detection means. Here, the avoidance intention detection means generates the steering torque in the first direction in a situation where the steering is returned to the neutral direction after steering in the first steering direction as a primary avoidance operation, and the steering torque Is detected as intention to avoid stability

  According to the present invention, it is possible to determine whether or not the driver has an intention of avoiding stability even when avoidance control is intervening, so that it is possible to reduce a sense of incongruity with respect to control.

(First embodiment)
FIG. 1 is a configuration diagram schematically showing a main part of a steering apparatus for a vehicle to which a driving support apparatus according to an embodiment of the present invention is applied. When the handle 1 is operated by the driver, the operation is transmitted to the wheel (for example, the front wheel) 2 via the steering device. The steering device of the present embodiment is an electric power steering device that assists the driver's steering with the power from the assist motor 3 that is an actuator.

  In this steering apparatus, the steering system between the steering wheel 1 and the wheels 2 is mechanically connected. The steering system mainly includes a steering shaft 4, a pinion shaft 5, a rack 6, and a tie rod 7. It is configured. A steering wheel 1 is attached to the upper end of the steering shaft 4, and a pinion shaft 5 is attached to the lower end thereof. The lower end of the pinion shaft 5, that is, the pinion meshes with a rack 6 that extends in the vehicle width direction. By this rack and pinion mechanism, the rotational movement of the handle 1 (the steering shaft 4 and the pinion shaft 5) is converted into the straight movement (translational movement) of the rack 6. A knuckle arm (not shown) provided on the wheel 2 is connected to both ends of the rack 6 via a tie rod 7, and the rack 6 moves in a horizontal direction (translational movement), whereby a steering angle is applied to the wheel 2. Is given.

  Further, the steering device is provided with an assist motor 3, and the power from the assist motor 3 is transmitted to a steering system (for example, the rack 6), whereby an assist torque for assisting the driver's steering is applied. . That is, the assist torque from the assist motor 3 is applied to the steering system in addition to the steering torque from the driver.

  FIG. 2 is a block diagram showing a configuration of the driving support apparatus 10 according to the embodiment of the present invention. The driving support device 10 is a device that performs driving support by controlling an actuator and controlling a motion state of a vehicle in a scene such as avoiding a collision with an obstacle, and includes a detection system, a controller 30, an actuator 40, and the like. It is mainly composed.

  The detection system has a function of detecting various types of information necessary for driving support, and includes various types of sensors. Information detected by the detection system is input to the controller 30.

  The radar 20 detects distance information to an object in the traveling direction of the vehicle, and a laser radar, a millimeter wave radar, or the like can be used. The camera 21 outputs a captured image by capturing a scene in the traveling direction of the vehicle. The captured image output from the camera 21 is input to the image processing device 22. The image processing device 22 detects object identification information for identifying an object in the traveling direction of the vehicle by performing image processing on the captured image. The radar 20, the camera 21, and the image processing device 22 constitute a traveling environment detection unit that detects a traveling environment around the vehicle.

  The yaw rate sensor 23 detects the yaw rate (yaw angular velocity) of the vehicle, that is, the speed of change in the rotation angle about the vertical axis passing through the center of gravity of the vehicle. 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 the wheel 2. The yaw rate sensor 23, the G sensor 24, and the wheel speed sensor 25 constitute a motion state detection means for detecting the motion state of the vehicle.

  The steering angle sensor 8 is attached to the steering shaft 4 shown in FIG. 1, and detects the rotation angle of the handle 1 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 1 corresponding to the straight traveling. The steering torque sensor 9 is attached to the steering shaft 4 shown in FIG. 1 and 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 1 corresponding to the straight traveling. The brake sensor 26 is a sensor that detects whether or not the driver operates the brake pedal as brake information. The steering angle sensor 8 and the steering torque sensor 9 constitute an operation detecting means for detecting a driver's driving operation including de-steering.

  FIG. 3 is a block diagram illustrating a functional configuration of the controller 30. As the controller 30, a microcomputer mainly composed of a CPU, a ROM, a RAM, and an I / O interface can be used. When the controller 30 grasps this functionally, the traveling environment detection unit 31, a traveling environment recognition unit (traveling environment recognition unit) 32, a motion state detection unit 33, and an avoidance track generation unit (avoidance track generation unit). 34, an operation amount detection unit 35, an avoidance trajectory selection unit (avoidance trajectory selection unit) 36, an avoidance intention detection unit (avoidance intention detection unit) 37, a control amount correction unit (correction unit) 38, and a vehicle control unit (Vehicle control means) 39.

  The traveling environment detection unit 31 reads the detection signal from the radar 20 and the processing result from the image processing device 22. Information read by the travel environment detection unit 31 is output to the travel environment recognition unit 32. The travel environment recognition unit 32 recognizes an object that may collide with the host vehicle as an obstacle based on the travel environment around the vehicle. The recognition result by the traveling environment recognition unit 32 is mainly output to the avoidance track generation unit 34. The motion state detection unit 33 reads detection signals from the yaw rate sensor 23, the G sensor 24 and the wheel speed sensor 25 and outputs this information to the avoidance trajectory generation unit 34. The avoidance trajectory generation unit 34 generates a plurality of avoidance trajectories for avoiding a collision with an obstacle based on the traveling environment around the vehicle and the motion state of the vehicle. The plurality of avoidance trajectories generated by the avoidance trajectory generation unit 34 are output to the avoidance trajectory selection unit 36. The operation amount detection unit 35 reads detection signals from the steering angle sensor 8, the steering torque sensor 9, and the brake sensor 26 and outputs this information to the avoidance trajectory selection unit 36 and the avoidance intention detection unit 37. The avoidance trajectory selection unit 36 selects an avoidance trajectory that matches the driving operation of the driver from among the plurality of generated avoidance trajectories based on the driving operation of the driver. The avoidance trajectory selected by the avoidance trajectory selection unit 36 is output to the vehicle control unit 39. The avoidance intention detector 37 detects a stable avoidance intention and outputs the detection result to the control amount correction unit 38. Here, the intention of avoiding the stability is that the driver performs the primary avoidance operation in consideration of the secondary avoidance operation for maintaining the stability of the vehicle after the primary avoidance operation for avoiding the obstacle. It is in a state of being. The control amount correction unit 38 performs a correction process for correcting the control by the vehicle control unit 39 when the intention of avoiding stability is detected. The vehicle control unit 39 controls the motion state of the vehicle by controlling the actuator 40 based on the avoidance control amount determined so as to follow the avoidance track selected by the avoidance track selection unit 36. (Avoidance control).

  The actuator 40 has a function of adjusting the motion state of the vehicle, and is a brake actuator that applies braking force (longitudinal acceleration) to the vehicle, and a steering that applies lateral force to the tire (that is, applies lateral acceleration to the vehicle). It is composed of an actuator or the like. Here, as shown in FIG. 1, the assist motor 3 constituting the steering device is also included in the steering actuator.

  FIG. 4 is a flowchart showing a procedure of the driving support method according to the first embodiment of the present invention. The process shown in this flowchart is called when the ignition switch of the vehicle is turned on, and is executed at a predetermined cycle.

  In step 10 (S10), the traveling environment recognition unit 32 recognizes the traveling environment. Specifically, the traveling environment recognition unit 32 recognizes an area (traveling path) where the vehicle can travel and an object existing in the traveling path. The travel environment recognition unit 32 recognizes the travel environment based on information read by the travel environment detection unit 31, that is, distance information in the vehicle traveling direction and object identification information in the vehicle traveling direction.

  In step 11 (S11), the traveling environment recognition unit 32 determines whether there is an obstacle with a possibility of collision among the recognized objects. This determination is performed by comparing the vehicle position after a predetermined time and the object position after the predetermined time. 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 processing after step 12 is skipped and the routine is exited.

  In step 12, the traveling environment recognition unit 32 calculates a time Tttc (hereinafter referred to as “collision prediction time”) until the vehicle collides with the obstacle. The collision prediction time Tttc is uniquely determined based on a preset arithmetic expression in consideration of the vehicle speed, the distance to the obstacle, the vehicle deceleration, and the like.

  In step 13 (S13), the avoidance trajectory generation unit 34 determines whether or not the collision prediction time Tttc is shorter than the first determination time Tth1. If the estimated collision time Tttc is long, that is, it takes a long time for the host vehicle to reach the obstacle, the collision with the obstacle is avoided by the driving operation of the driver, and the possibility of the collision is low. The need for avoidance control is low. Therefore, in step 13, it is determined whether or not it is a situation in which driving assistance should be performed by comparing the collision prediction time Tttc with the first determination time Tth1. When an affirmative determination is made in step 13, that is, when the collision prediction time Tttc is smaller than the first determination time Tth1 (Tttc <Tth1), the process proceeds to step 14 (S14). On the other hand, when a negative determination is made in step 13, that is, when the collision prediction time Tttc is equal to or longer than the first determination time Tth1 (Tttc ≧ Tth1), the processing after step 14 is skipped and the routine is exited.

  FIG. 5 is an explanatory diagram of the avoidance trajectory. In step 14, the avoidance trajectory generation unit 34 generates a plurality of avoidance trajectories for avoiding a collision with the obstacle Ob based on the traveling environment and the motion state of the vehicle. As shown in the figure, the avoidance trajectory generating unit 34 includes an avoidance trajectory Le1 that is suitable when the driver steers leftward, an avoidance trajectory Le2 that is suitable when the driver steers rightward, and the driver The avoidance trajectory Le3 suitable for braking is generated. In this case, when the avoidance track does not fit in the travel path or when it is determined that the obstacle Ob cannot be avoided by the driver's operation, the avoidance track is not generated.

  When generating the avoidance trajectory Le3 suitable for the braking operation, the avoidance trajectory generation unit 34 first calculates whether or not the collision with the obstacle Ob can be avoided by braking by the driver (that is, the deceleration). The avoidance trajectory generation unit 34 generates an avoidance trajectory for deceleration only when collision avoidance is possible, and generates the minimum necessary lateral force on the wheel 2 when collision avoidance is impossible. Thus, an avoidance trajectory that can avoid a collision with the obstacle Ob is generated. In this case, an upper limit value in consideration of tire characteristics is set in advance, and an avoidance track is not generated when a lateral force that exceeds the tire limit is required.

  On the other hand, when generating avoidance trajectories Le1 and Le2 suitable for the steering operation, the avoidance trajectory generation unit 34 sets a lateral acceleration in consideration of the motion state of the vehicle, tire characteristics, and the like, and performs vehicle control to add the lateral acceleration. The realized trajectory is generated as an avoidance trajectory. In this case, even if it is possible to avoid a collision without applying braking, it is safer to pass as close as possible when the vehicle passes near the obstacle Ob. A trajectory realized by vehicle control may be generated as an avoidance trajectory.

  In step 15 (S15), the avoidance trajectory selection unit 36 determines whether any operation has been performed by the driver. Specifically, the avoidance trajectory selection unit 36 refers to the information read by the operation amount detection unit 35, that is, the steering angle and the brake information, and determines whether or not there is an operation by the driver. If a negative determination is made in step 15, that is, if no operation is performed 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 the operation is performed by the driver, the process of step 16 is skipped and the process proceeds to step 17 (S17).

  In step 16, the avoidance trajectory selection unit 36 determines whether or not the collision prediction time Tttc is smaller than the second determination time Tth2. As shown in FIG. 8, the second determination time Tth2 is the collision prediction time to the obstacle Ob when the latest avoidance trajectory Le1 to Le3 reaches the point P1 where the avoidance control is started the latest. It is. If a negative determination is made in step 16, that is, if the predicted collision time Tttc is greater than or equal to the second determination time Tth2 (Tttc ≧ Tth2), the process proceeds to step 17 (S17). On the other hand, if an affirmative determination is made in step 16, that is, if the collision prediction time Tttc is smaller than the second determination time Tth2 (Tttc <Tth2), the processing returns to step 15.

  In step 17, the avoidance trajectory selection unit 36 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 36 selects an avoidance trajectory that matches the driver's operation from the candidates of the avoidance trajectories Le1 to Le3. 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 Ob than the control start point regarding any of the avoidance tracks Le1 to Le3. The avoidance trajectory whose control start point is closest to the obstacle Ob is selected from the candidates of ~ Le3.

  In step 18 (S18), the vehicle control unit 39 starts avoidance control, and controls the actuator 40 to follow the avoidance path based on the selected avoidance path. For example, the vehicle control unit 39 controls the assist motor 3 to apply assist torque that follows the avoidance path to the steering system.

  In step 19 (S19), the traveling environment recognition unit 32 determines whether the avoidance has ended and the possibility of a collision with the obstacle Ob has been eliminated. If an affirmative determination is made in step 19, that is, if there is no possibility of a collision, the process proceeds to step 20 (S20). On the other hand, if a negative determination is made in step 19, that is, if there is a possibility of a collision, the processing after step 20 is skipped and the routine is exited.

  In step 20, the avoidance intention detection unit 37 identifies the steering angular velocity and the steering torque based on the information read by the operation amount detection unit 35, that is, the steering angle and the steering torque. Specifically, the steering angular velocity is specified as a change amount of the steering angle per unit time, and the read value of the steering torque is specified as it is.

  In step 21 (S21), the avoidance intention detection unit 37 determines whether or not the driver's steering status is returning steering. Here, the return steering is performed in the neutral direction (for example, after the first maximum steering angle) after steering in the first steering direction (for example, left direction) as a primary avoidance operation. , To the right). If an affirmative determination is made in step 21, that is, if return steering is being performed, the routine proceeds to step 22 (S22). On the other hand, if a negative determination is made in step 21, that is, if the return steering is not reached, the process returns to step 19.

  In step 22, the avoidance intention detection unit 37 determines whether the steering torque has a determination condition. Specifically, the avoidance intention detection unit 37 determines whether or not a steering torque larger than the determination torque Trq is generated in a direction opposite to the steering angular velocity. This determination torque Trq is a determination value for determining whether or not the current steering torque is larger than the steering torque during normal driving (that is, during non-avoidance control), and is calculated by the arithmetic expression shown below.

(Formula 1)
Trq = J x θacc
Here, J is a moment of inertia acting on a system on the opposite side of the assist motor 3 with respect to the steering torque sensor 9 in the steering system. θacc is the steering angular acceleration.

  If an affirmative determination is made in step 22, that is, if the steering torque is greater than the determination torque Trq, the routine proceeds to step 22. On the other hand, if a negative determination is made in step 22, that is, if the steering torque is equal to or less than the determination torque, the process returns to step 19.

  In step 23 (S23), the control amount correction unit 38 causes the vehicle control unit 39 to stop the avoidance control, thereby stopping the application of the assist torque that follows the avoidance track (correction process).

  In step 24 (S24), the control amount correction unit 38 sets the assist torque control characteristic to the vehicle control unit 39 so that the characteristic of the steering torque according to the steering angle is faster than that during normal driving. A change is instructed (correction process). Specifically, as shown in FIG. 6, the dead zone of the steering torque in the vicinity of the neutral steering position is narrower than that during normal traveling, and the generation amount of steering torque corresponding to the steering angle is larger than that during normal traveling. Change the assist torque control characteristics. As a result, after this process, the vehicle control unit 39 applies the assist torque so that the steering torque characteristic Sr is faster than the steering torque characteristic Ss during normal driving.

  In step 25 (S25), the traveling environment recognition unit 32 determines whether the avoidance has ended and the possibility of a collision with the obstacle Ob has been eliminated. If the determination in step 25 is affirmative, that is, if there is no possibility of collision, the routine is exited. In this case, the control amount correction unit 38 instructs the vehicle control unit 39 to change the changed assist torque characteristic to the assist torque characteristic Ss during normal travel (see FIG. 6). On the other hand, if a negative determination is made in step 25, that is, if there is a possibility of a collision, the process returns to step 25 after a predetermined time and the same determination is made.

  Thus, in this embodiment, the avoidance intention detection unit 37 also considers a secondary avoidance operation for the driver to maintain the stability of the vehicle after the primary avoidance operation for avoiding the obstacle Ob. Then, the state in which the primary avoidance operation is being executed is detected as the intention to avoid the stability. When the intention of avoiding stability is detected, a correction process for correcting the control by the vehicle control unit 39 is performed by the control amount correction unit 38. In this case, the avoidance intention detection unit 37 generates steering torque in the first direction in a situation where the steering is returned to the neutral direction after steering in the first steering direction as a primary avoidance operation, and this steering is performed. A situation where the torque is larger than the steering torque during normal driving is detected as an intention to avoid stability.

  According to such a configuration, it is possible to determine whether or not the driver has an intention of avoiding stability even when the avoidance control is intervening, and it is possible to reduce a sense of incongruity with respect to the control (1, 6).

  FIG. 7 is an explanatory diagram showing the relationship between the steering angle and the steering torque in the case where the driving support of this embodiment is not performed. In the figure, the upper stage shows the time series transition of the steering angle, and the lower stage shows the time series transition of the steering torque. In the upper part of the figure, the steering angle transition Ls3 (dashed line) is the target steering angle corresponding to the avoidance trajectory generated to avoid the collision with the obstacle Ob, and the vehicle control unit 39 performs step 19 (FIG. 4). After the start of control in (see), assist torque corresponding to the target steering angle is applied to the steering system. On the other hand, in the upper part of the figure, the steering angle transition Ls1 (broken line) and the steering angle transition Ls2 indicate the transition of the steering angle corresponding to the operation actually performed by the driver. When the driver is late in finding the obstacle Ob, the urgency of avoidance steering increases, so as shown in the steering angle transition Ls1, the steering angle, the large steering angle, and the steering angle are kept constant. It becomes a steering pattern that can hardly be seen. On the other hand, when the driver recognizes the obstacle Ob from the near side, the steering operation is predicted to the traveling track after avoiding the obstacle Ob, and therefore, the steering operation is indicated by the steering angle transition Ls2. The steering pattern is as follows.

  If the steering pattern indicated by the steering angle transition Ls1 occurs, if it is an avoidance operation that only considers avoiding the immediately preceding obstacle Ob, an assist torque for avoiding a collision with the obstacle Ob is applied. Continuing will support the driver's avoidance operation. Further, if the driver has recognized the obstacle Ob from the front, the direction of the steering operation and the direction in which the steering torque is generated can be determined even if the assist torque for avoiding the collision with the obstacle Ob is continuously generated. It occurs in almost the same direction as during normal operation. For this reason, even if there is a difference in the magnitude of the steering reaction force compared to the normal steering operation, it is less likely to give a sense of discomfort that adversely affects the driver's operation.

  On the other hand, when the steering pattern indicated by the steering angle transition Ls2 occurs, the assist torque is added even though the collision with the obstacle Ob can be avoided by the driver's operation, and the second half of the primary avoidance steering ( In the section (B) in the figure, the direction of steering operation and the direction in which steering torque is generated are reversed, and a feeling of steering discomfort significantly different from that during normal driving occurs. Further, since there is a high possibility that the deviation between the target steering angle of the system and the steering angle intended by the driver will gradually increase, a feeling of steering discomfort during the avoidance operation will be given. Therefore, in the B section in the figure, that is, in a scene where the direction of the steering operation and the direction of the steering torque are reversed, the assist for avoiding the collision with the obstacle Ob is assumed to promote the steering discomfort. Judging that the torque is unnecessary, it is determined that the driver is performing intentional avoidance steering.

  On the other hand, as shown in section A in the figure, when the direction of the steering operation is the same as the direction of the steering torque, an assist torque for avoiding a collision with the obstacle Ob is necessary. Therefore, it is determined that the driver is not performing intentional avoidance steering. Here, even if the driver performs an intentional operation, it is determined that there is little influence on the steering discomfort even if the assist torque is applied.

  Further, according to the present embodiment, the vehicle control unit 39 performs control to apply assist torque to assist the steering of the driver to the steering system. Here, the control amount correction unit 38 stops the control (avoidance control) based on the avoidance control amount as the correction process, and the response characteristic of the steering torque according to the steering angle is faster than that during normal travel. Thus, the control characteristic of the assist torque is changed. Specifically, the assist torque control characteristics are changed so that the steering torque dead zone near the neutral position of the steering is narrower than that during normal driving and the amount of steering torque generated according to the steering angle is larger than that during normal driving. It is done.

  FIG. 8 is an explanatory diagram showing the relationship between the steering angle and the steering torque in the case where the driving support of the present embodiment is performed. As shown in the figure, the steering torque is changed as indicated by the broken line by the correction process accompanying the detection of the intention to avoid stability, so that the uncomfortable feeling of steering given to the driver during the period C can be reduced. Further, by changing the control characteristics of the assist torque so that the response of the steering torque is higher than that during normal driving, it is possible to give the driver a sense of security in operation (2, 3).

  Further, according to the present embodiment, when the intention to avoid stability is not detected, the control by the vehicle control means is not corrected. According to this configuration, an appropriate assist torque can be given to a driver who does not intend to avoid stability (4).

(Second Embodiment)
FIG. 9 is a flowchart showing the procedure of the driving support method according to the second embodiment of the present invention. The driving support device according to the second embodiment is different from that of the first embodiment in the procedure in the driving support method. In addition, the description which overlaps with embodiment mentioned above shall be abbreviate | omitted, and demonstrates below centering on difference.

  In this embodiment, the process of step 26 (S26) is added following the affirmative determination of step 22. In step 26, the control amount correction unit 38 refers to the steering angle read by the operation amount detection unit 35, and determines whether or not the steering angle is in a neutral state. If an affirmative determination is made in step 26, that is, if the steering angle has returned to the neutral state, the routine proceeds to step 23. On the other hand, if a negative determination is made in step 26, that is, if the steering angle has not returned to the neutral state, the process returns to step 19.

  As described above, in the present embodiment, the control amount correction unit 38 performs the correction process on the condition that the steering angle is in the neutral state. According to such a configuration, the correction process is performed at the timing when the steering angle is in the neutral state, so that it is possible to make it difficult for the driver to feel uncomfortable when the control logic is switched (5).

Configuration diagram schematically showing main parts of a steering device for a vehicle to which a driving support device is applied The block diagram which shows the structure of the driving assistance device 10 The block diagram which shows the functional structure of the controller 30 The flowchart which shows the procedure of the driving assistance method concerning 1st Embodiment. Illustration of avoidance trajectory Illustration of steering torque corresponding to steering angle Explanatory drawing which shows the relationship between the steering angle and steering torque in the case where driving assistance is not performed Explanatory drawing which shows the relationship between the steering angle and steering torque in the case which performs driving support The flowchart which shows the procedure of the driving assistance method concerning 2nd Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Handle 2 Wheel 3 Assist motor 4 Steering shaft 5 Pinion shaft 6 Rack 7 Tie rod 8 Steering angle sensor 9 Steering torque sensor 10 Driving support device 20 Radar 21 Camera 22 Image processing device 23 Yaw rate sensor 24 G sensor 25 Wheel speed sensor 26 Brake sensor DESCRIPTION OF SYMBOLS 30 Controller 31 Travel environment detection part 32 Travel environment recognition part 33 Motion state detection part 34 Avoidance track generation part 35 Operation amount detection part 36 Avoidance track detection part 37 Avoidance intention detection part 38 Operation amount correction | amendment part 39 Vehicle control part 40 Actuator

Claims (6)

In a driving support device that supports driving of a vehicle,
Driving environment detection means for detecting the driving environment around the vehicle;
Based on the detection result of the travel environment detection means, travel environment recognition means for recognizing an object that may collide with the host vehicle as an obstacle,
Motion state detection means for detecting the motion state of the vehicle;
An avoidance trajectory that generates a plurality of avoidance trajectories for avoiding a collision with an obstacle recognized by the travel environment recognition means based on the detection result of the travel environment detection means and the detection result of the motion state detection means. Generating means;
Operation detecting means for detecting a driver's driving operation including steering;
An avoidance trajectory selection means for selecting an avoidance trajectory suitable for the driving operation of the driver from a plurality of avoidance trajectories generated by the avoidance trajectory generation means based on the detection result of the operation detection means;
Vehicle control means for controlling the motion state of the vehicle based on the avoidance control amount determined to travel following the avoidance path selected by the avoidance path selection means;
The state where the driver is executing the primary avoidance operation in consideration of the secondary avoidance operation for maintaining the stability of the vehicle after the primary avoidance operation for avoiding the obstacle is stabilized. Avoidance intention detection means for detecting as avoidance intention;
Correction means for performing correction processing for correcting the control by the vehicle control means when a stable avoidance intention is detected by the avoidance intention detection means,
The avoidance intention detection means generates a steering torque in the first direction and returns the steering torque to the neutral direction after steering in the first steering direction as the primary avoidance operation. A driving support device that detects a situation where the steering torque is larger than the steering torque during normal driving as the intention to avoid the stability. The vehicle control means performs control to apply assist torque to assist the steering of the driver to the steering system,
The correction unit stops the control based on the avoidance control amount by the vehicle control unit as the correction process, and the characteristic of the steering torque according to the steering angle is faster than that during normal travel. The driving assist device according to claim 1, wherein a control characteristic of the assist torque is changed.   The correction means changes a control characteristic of the assist torque so that a dead zone of the steering torque in the vicinity of the neutral steering position is narrower than that during normal traveling and the amount of generated steering torque corresponding to the steering angle is larger than that during normal traveling. The travel support apparatus according to claim 2, wherein   The driving support according to any one of claims 1 to 3, wherein the correction means does not correct the control by the vehicle control means when the intention to avoid the stability is not detected by the avoidance intention detection means. apparatus.   5. The travel support apparatus according to claim 1, wherein the correction unit performs the correction process on the condition that a steering angle is in a neutral state. In a driving support method for supporting driving of a vehicle,
A first step of recognizing an object that may collide with the host vehicle as an obstacle based on a traveling environment around the vehicle;
A second step of generating a plurality of avoidance trajectories for avoiding a collision with an obstacle recognized by the traveling environment recognition means based on a motion state of the vehicle;
A third step of selecting an avoidance trajectory that the vehicle should travel from among the plurality of avoidance trajectories generated based on a driver's driving operation including steering;
A fourth step of controlling the motion state of the vehicle based on the avoidance control amount determined to follow the selected avoidance path;
Detecting the state where the primary avoidance operation is being executed as the intention of stable avoidance in consideration of the secondary avoidance operation for maintaining the stability of the vehicle after the primary avoidance operation for avoiding the obstacle A fifth step to:
A sixth step of correcting the control of the motion state of the vehicle in the fourth step when the stability avoidance intention is detected, and
In the fifth step, the steering torque is generated in the first direction in the situation where the steering is returned to the neutral direction after steering in the first steering direction as the primary avoidance operation, and the steering torque A driving support method characterized in that it is a step of detecting a situation where the steering torque is larger than the steering torque during normal driving as the intention to avoid the stability.

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