JP2008213651A - Steering support system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a steering support system capable of reducing a response delay of a vehicle to target lateral acceleration without deteriorating the stability of a vehicle. <P>SOLUTION: A steering support device 1 is equipped with a camera 9 for imaging a traveling road in front of a vehicle, a G sensor 11 for detecting vehicle lateral G and an ECU 12. The ECU 12 is provided with a travel information acquisition part 13 for acquiring shape information of a traveling road or the like by inputting a pickup image of the camera 9, a target lateral acceleration computing part 14 for obtaining target lateral G to travel own vehicle along the traveling road on the basis of the shape information of a traveling road or the like, a lateral acceleration compensation part 15 for detecting a delay of vehicle actual lateral G to the target lateral G by inputting a detection value of the G sensor 11 so as to obtain a lateral G correction value to eliminate the delay, a demand steering torque generation part 16 for obtaining demand steering assist torque by employing the target lateral G and lateral G correction value and a motor drive control part 17 for controlling an electric motor 8 in response to the demand steering assist torque. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a steering assist device mounted on a vehicle including, for example, an electric power steering (EPS).

As a conventional steering assist device, for example, a vehicle steering control device described in Patent Document 1 is known. The vehicle steering control device detects a travel path based on a captured image in front of the vehicle, calculates a curvature of the travel path, calculates a basic steering assist torque from the curvature, and based on a captured image in front of the vehicle. A parameter related to the position of the vehicle with respect to the travel path is obtained, and a corrected steering assist torque is calculated from the parameter. Then, by adding the basic steering assist torque and the corrected steering assist torque, an output steering assist torque for causing the vehicle to travel along the lane center line of the travel path is obtained, and an electric motor is obtained in accordance with the output steering assist torque. To control.
JP 2001-10518 A

  By the way, in the lane keeping system to which the above-described conventional technology is applied, the target lateral acceleration is calculated based on the information on the travel route on which the vehicle travels, and the steering assist torque is obtained from the target lateral acceleration. However, since the vehicle response for achieving the target lateral acceleration is delayed due to unknown characteristics such as friction existing between the vehicle and an actuator such as EPS, the actual lateral acceleration (actual lateral acceleration) of the vehicle and the target Deviation occurs with the lateral acceleration. In order to eliminate the response delay of the actual lateral acceleration with respect to the target lateral acceleration, simply increasing the feedback constant (gain) of the feedback control system related to the position of the vehicle with respect to the travel path causes the vehicle behavior to change drastically. Stability may be deteriorated.

  An object of the present invention is to provide a steering assist device capable of reducing a response delay of a vehicle with respect to a target lateral acceleration without impairing the stability of the vehicle.

  The steering assist device according to the present invention includes a travel path information acquisition unit that acquires information on a travel path on which the host vehicle travels, and a target lateral acceleration that causes the host vehicle to travel along the travel path based on the information on the travel path. Target lateral acceleration calculating means for calculating the required steering torque setting means for obtaining the required steering torque for making the lateral acceleration of the host vehicle the target lateral acceleration, and steering for controlling the steering system of the host vehicle in accordance with the required steering torque Control means, lateral acceleration delay detection means for detecting the actual lateral acceleration delay of the host vehicle with respect to the target lateral acceleration, and lateral acceleration correction value for reducing the delay of the actual lateral acceleration of the host vehicle with respect to the target lateral acceleration The required steering torque setting means includes correction means for correcting the required steering torque in accordance with the lateral acceleration correction value.

  In such a steering assist device of the present invention, the delay of the actual lateral acceleration of the host vehicle with respect to the target lateral acceleration is detected, a lateral acceleration correction value that reduces the delay is obtained, and the lateral acceleration of the host vehicle is determined as the target lateral acceleration. The required steering torque for making the acceleration is corrected according to the lateral acceleration correction value, and the steering system of the host vehicle is controlled according to the corrected required steering torque. Therefore, even if the feedback constant (gain) of the feedback control system is not particularly increased, the delay of the actual lateral acceleration of the host vehicle with respect to the target lateral acceleration is reduced. Thereby, the response delay of the vehicle with respect to the target lateral acceleration can be reduced while ensuring the behavior stability of the vehicle.

  Preferably, the required steering torque setting means stores in advance a torque map indicating the relationship between the target lateral acceleration and the required steering torque when the steering operation is increased or decreased, and the correcting means is the lateral acceleration correction value. Accordingly, the required steering torque corresponding to the target lateral acceleration in the torque map is corrected. In this case, the required steering torque for making the lateral acceleration of the host vehicle the target lateral acceleration can be easily obtained using the torque map. Further, when correcting the required steering torque according to the lateral acceleration correction value, the configuration for correcting the required steering torque is simplified by correcting the characteristics of the torque map according to the lateral acceleration correction value. be able to.

  Preferably, on the basis of information on the traveling road, the traveling road shape determining means for determining whether the shape of the traveling road is a specific shape, and the traveling road shape determining means that the shape of the traveling road is the specific shape. Learning means for learning a delay of the actual lateral acceleration of the host vehicle with respect to the target lateral acceleration when it is determined. In this case, after learning the delay of the actual lateral acceleration of the host vehicle relative to the target lateral acceleration, a lateral acceleration correction value that reduces the delay is obtained, and the lateral acceleration of the host vehicle is set to the target lateral acceleration. The required steering torque is corrected according to the lateral acceleration correction value. By performing the learning of the delay in this way, a more appropriate lateral acceleration correction value can be obtained, so that the response delay of the vehicle with respect to the target lateral acceleration can be further reduced.

  At this time, it is preferable that the specific shape is a straight line. When the host vehicle travels on a straight line, the reproducibility of the vehicle response to the target lateral acceleration is higher than when the host vehicle travels on a curve. Therefore, when the travel path is a straight line, the learning accuracy can be improved by learning the delay of the actual lateral acceleration of the host vehicle with respect to the target lateral acceleration.

  Preferably, the vehicle further comprises torque resistance determination means for determining whether or not the driver of the host vehicle feels resistance to the steering torque applied to the steering system, and the correction means is configured to detect the vehicle by the torque resistance determination means. When it is determined that the driver feels resistance, the required steering torque according to the lateral acceleration correction value is not corrected. In this case, the uncomfortable feeling of the steering operation by the driver can be effectively reduced, and the driving feeling of the driver can be improved.

  Further, preferably, the apparatus further comprises disturbance influence determining means for determining whether or not the host vehicle is affected by disturbance of the traveling road, and the correcting means is affected by the disturbance of the traveling road by the disturbance influence determining means. When it is determined that the required steering torque is not corrected according to the lateral acceleration correction value. In this case, since the behavior of the vehicle is prevented from being deteriorated due to the influence of the disturbance on the traveling road, the behavior stability of the vehicle can be sufficiently ensured.

  Preferably, the correction means does not correct the required steering torque according to the lateral acceleration correction value when the target lateral acceleration is smaller than a predetermined value. In this case, when the target lateral acceleration of the vehicle is close to 0 because the vehicle is running almost straight, the behavior of the vehicle becomes unstable by correcting the required steering torque according to the lateral acceleration correction value. This prevents the vehicle from hunting.

  According to the present invention, the response delay of the vehicle with respect to the target lateral acceleration can be reduced without impairing the stability of the vehicle. Thereby, when the present invention is applied to the lane keeping system, the vehicle can be run while being maintained at the center of the lane.

  DESCRIPTION OF EMBODIMENTS Hereinafter, a preferred embodiment of a steering assist device according to the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a configuration diagram showing a first embodiment of a steering assist device according to the present invention. In the figure, a steering assist device 1 of this embodiment is mounted on a vehicle equipped with an electric power steering (EPS) 2 and assists a steering operation.

  The electric power steering 2 includes a steering wheel 3 and a gear box 5 connected to the steering wheel 3 via a steering shaft 4. The gear box 5 is connected to the left and right wheels 7 via tie rods 6, respectively. The electric power steering 2 is provided with an electric motor 8 for applying a steering assist force (assist torque).

  The steering assist device 1 includes a camera 9 that images a road (traveling road) ahead of the vehicle, a vehicle speed sensor 10 that detects the traveling speed (vehicle speed) of the vehicle, and a G sensor 11 that detects lateral acceleration (lateral G) of the vehicle. And an ECU (Electronic Control Unit) 12 for inputting a sensed image of the camera 9, detection values of the vehicle speed sensor 10 and the G sensor 11, performing a predetermined process related to steering assistance, and controlling the electric motor 8.

  The ECU 12 includes a travel information acquisition unit 13, a target lateral acceleration calculation unit 14, a lateral acceleration compensation unit 15, a required steering torque generation unit 16, and a motor drive control unit 17.

  The travel information acquisition unit 13 captures an image captured by the camera 9 and performs image processing to extract a road dividing line (white line) on which the host vehicle travels, and based on the extraction result and the detection value of the vehicle speed sensor 10. Thus, the information on the shape (straight line, curve, etc.) of the traveling road and the position information of the own vehicle with respect to the traveling road are acquired.

  The target lateral acceleration calculation unit 14 is a target lateral acceleration (hereinafter referred to as “running”) that causes the host vehicle to travel along the travel path based on the shape information of the travel path obtained by the travel information acquisition unit 13 and the position information of the host vehicle. , The target lateral G).

  The lateral acceleration compensation unit 15 takes in the target lateral G obtained by the target lateral acceleration calculation unit 14 and the detected value of the G sensor 11, and the actual lateral acceleration of the host vehicle with respect to the target lateral G (hereinafter referred to as vehicle actual lateral G). ) And a lateral acceleration correction value (hereinafter referred to as a lateral G correction value) that eliminates the delay is obtained.

  FIG. 2 is a flowchart showing a processing procedure of the lateral acceleration compensation unit 15. In the figure, it is first determined whether or not a flag (delay determination flag) for determining whether or not there is a delay of the actual vehicle lateral G with respect to the target lateral G is OFF (step 51). Note that the delay determination flag is set to OFF in the initial state. When it is determined that the delay determination flag is OFF, it is determined whether or not the actual vehicle lateral G is delayed with respect to the target lateral G (step 52), and the actual vehicle lateral G is delayed with respect to the target lateral G. If so, the delay judgment flag is turned on (step 53).

  On the other hand, when it is determined in step 51 that the delay determination flag is ON instead of OFF, it is determined whether or not there is no delay in the actual lateral G with respect to the target lateral G (step 54). When the lateral G delay is eliminated, the delay judgment flag is turned OFF (step 55).

  Thereafter, it is determined whether or not the delay determination flag is ON (step 56), and when it is determined that the delay determination flag is ON, the size (absolute value) of the target lateral G is subsequently a predetermined value or more. It is determined whether or not there is (step 57). The predetermined value here is set to a value R (see FIG. 6) close to neutral (0) in a torque map characteristic described later.

When it is determined that the size of the target lateral G is equal to or greater than a predetermined value, a difference G _com between the target lateral G and the actual vehicle lateral G is obtained, and this difference G _com is output as a lateral G correction value (step 58). ). At this time, as the output form of the lateral G correction value, the calculated lateral G correction value G _com is not output immediately as it is, but the lateral G correction value gradually increases from 0 as shown in FIG. The lateral G correction value reaches G _com after a predetermined time has elapsed.

  On the other hand, if it is determined in step 56 that the delay determination flag is OFF instead of ON, and if it is determined in step 57 that the size of the target lateral G is not equal to or greater than the predetermined value, the lateral G correction value is not output. This process is terminated.

The details of the processing procedure of step 52 are shown in FIG. In the figure, first, it is determined whether or not the direction of the actual vehicle lateral G matches the direction of the target lateral G (step 61). It is then determined whether the absolute value of the difference between the target lateral G and the actual vehicle lateral G is greater than the threshold value ΔG _ON (step 62).

At this time, when it is determined that the absolute value of the difference between the target lateral G and the actual vehicle lateral G is larger than the threshold value ΔG _ON , the variable _ION is incremented (step 63). Note that the variable _ION is set to 0 in the initial state. Then, it is determined whether or not the variable _ION is larger than the threshold value _CON for determining that the actual vehicle side G is delayed from the target side G (step 64), and the variable _ION is greater than the threshold value _CON . Is larger, the delay judgment flag is turned ON in step 53, and then the process proceeds to step 56.

On the other hand, if it is determined in step 62 that the absolute value of the difference between the target lateral G and the actual vehicle lateral G is not larger than the threshold value ΔG _ON , the variable _ION is reset to 0 (step 66), and the above step 56 Move on.

Details of the processing procedure of step 54 shown in FIG. 2 are shown in FIG. In the figure, it is first determined whether or not the absolute value of the difference between the target lateral G and the actual vehicle lateral G is smaller than a threshold value ΔG _OFF (step 71).

At this time, if it is determined that the absolute value of the difference between the target lateral G and the actual vehicle lateral G is smaller than the threshold value ΔG _OFF , the variable I _OFF is incremented (step 72). Note that the variable I _OFF is set to 0 in the initial state. Then, it is determined whether or not the variable I _OFF is larger than the threshold value C _OFF for determining that the delay of the actual vehicle lateral G with respect to the target lateral G has disappeared (step 73), and the variable I _OFF is larger than the threshold value C _OFF. If larger, the delay judgment flag is turned off in step 55, and then the process proceeds to step 56.

On the other hand, when it is determined in step 71 that the absolute value of the difference between the target lateral G and the actual vehicle lateral G is not smaller than the threshold value ΔG _OFF , the variable I _OFF is reset to 0 (step 75), and the above step 56 Move on.

  Returning to FIG. 1, the requested steering torque generation unit 16 uses the target lateral G obtained by the target lateral acceleration calculation unit 14 and the lateral G correction value obtained by the lateral acceleration compensation unit 15 to use the lateral acceleration of the host vehicle. The required steering assist torque for obtaining the target lateral G is obtained.

  Specifically, a basic torque map as shown in FIG. 6 is stored in advance in the memory of the required steering torque generator 16. The basic torque map shows the relationship between the target lateral G and the required steering assist torque. In this basic torque map, a thick solid line P indicates a characteristic when the steering wheel 3 is increased and a thin solid line Q indicates a characteristic when the steering wheel 3 is switched back. Further, the target lateral G on the horizontal axis in the basic torque map is set to be positive (+) when the steering wheel 3 is turned to the right, and negative (−) when the steering wheel 3 is turned to the left. ing.

  The required steering torque generation unit 16 calculates the required steering assist torque according to such a basic torque map. A processing procedure of the required steering torque generation unit 16 is shown in FIG.

  In the figure, first, it is determined whether or not the lateral G correction value obtained by the lateral acceleration compensator 15 is input (step 81). When the lateral G correction value is input, it is determined according to the lateral G correction value. The value (characteristic) of the basic torque map is corrected (step 82). Specifically, as indicated by a broken line in FIG. 6, the characteristics of the basic torque map are shifted by an amount corresponding to the lateral G correction value. Then, a required steering assist torque corresponding to the added value of the target lateral G and the lateral G correction value is generated from the corrected torque map characteristic and output (step 83). As a result, the required steering assist torque is corrected for the target lateral G.

  At this time, since the lateral G correction value is set to gradually increase from 0 as described above (see FIG. 3), the required steering assist torque according to the lateral G correction value is also gradually corrected. . Thereby, it is possible to reduce the impact received by the driver due to the rapid correction of the required steering assist torque.

  Note that the torque map characteristic shown in FIG. 6 shows only the correction when the right-side increase operation is performed, but the left-side increase operation, the right-side return operation, and the left-side operation are performed. The correction during the returning operation is performed in the same manner.

  On the other hand, when the lateral G correction value is not input in step 81, the required steering assist torque corresponding to the target lateral G is generated and output using the basic torque map without correction (step 84).

  Returning to FIG. 1, the motor drive controller 17 supplies the electric motor 8 with a current signal corresponding to the required steering assist torque obtained by the required steering torque generator 16.

  In the above, the travel information acquisition part 13 of the camera 9, the vehicle speed sensor 10, and ECU12 comprises the travel path information acquisition means which acquires the information regarding the travel path on which the own vehicle travels. The target lateral acceleration calculation unit 14 of the ECU 12 constitutes a target lateral acceleration calculation unit that calculates a target lateral acceleration that causes the host vehicle to travel along the travel path based on information on the travel path. The required steering torque generation unit 16 of the ECU 12 constitutes required steering torque setting means for obtaining required steering torque for setting the lateral acceleration of the host vehicle to the target lateral acceleration. The motor drive control part 17 of ECU12 comprises the steering control means which controls the steering system 2 of the own vehicle according to a request | requirement steering torque. The processing of steps 51 and 52 (see FIG. 2) in the lateral acceleration compensator 15 of the G sensor 11 and the ECU 12 constitutes lateral acceleration delay detection means for detecting the delay of the actual lateral acceleration of the host vehicle with respect to the target lateral acceleration. The processing of steps 56 to 58 (see FIG. 2) in the lateral acceleration compensation unit 15 of the ECU 12 constitutes lateral acceleration compensation means for obtaining a lateral acceleration correction value that reduces the delay of the actual lateral acceleration of the host vehicle with respect to the target lateral acceleration. To do. Further, the processing in steps 81 to 83 (see FIG. 7) in the required steering torque generation unit 16 of the ECU 12 constitutes a correcting unit that corrects the required steering torque in accordance with the lateral acceleration correction value.

  As described above, in the present embodiment, when there is a delay of the actual vehicle lateral G with respect to the target lateral G, a lateral G correction value that eliminates the delay is obtained, and this lateral G correction value is obtained. Accordingly, the required steering assist torque is corrected by shifting the value (characteristic) of the basic torque map, and the electric motor 8 is controlled according to the corrected required steering assist torque. Will be reduced. At this time, it is not particularly necessary to increase the feedback constant (gain) of the feedback control system. For this reason, even when a delay of the actual vehicle lateral G with respect to the target lateral G occurs due to unknown characteristics existing between the vehicle and the electric motor 8, the vehicle lateral G with respect to the target lateral G is stabilized while the behavior of the vehicle is stabilized. Response performance can be improved. As a result, when the steering assist device 1 of the present embodiment is applied to the lane keeping system, the host vehicle can travel along the center of the lane.

  When the target lateral G is within the range close to 0, even if there is a delay of the actual lateral G with respect to the target lateral G, the required steering assist torque is not corrected according to the lateral G correction value. Therefore, when the host vehicle is running almost straight, it is possible to prevent the behavior of the vehicle from becoming unstable and causing hunting.

  Furthermore, the required steering assist torque can be corrected without depending on the speed of the host vehicle by shifting the characteristics of the basic torque map in accordance with the lateral G correction value. Therefore, the configuration for correcting the required steering assist torque can be simplified.

  FIG. 8 is a block diagram showing a second embodiment of the steering assist device according to the present invention. In the figure, the same or equivalent elements as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  In the same figure, the steering assistance apparatus 20 of this embodiment is provided with the camera 9, the vehicle speed sensor 10, the G sensor 11, and ECU12 similarly to 1st Embodiment. The ECU 12 includes a lateral acceleration compensation unit 21 instead of the lateral acceleration compensation unit 15 described above.

  FIG. 9 is a flowchart showing a processing procedure of the lateral acceleration compensator 21. In the figure, first, it is determined whether or not the road on which the vehicle is traveling is not a straight line from the travel path shape information obtained by the travel information acquisition unit 13 (step 91), and the road is not a straight line (a curve). ), Steps 51 to 58 are executed as in the first embodiment.

On the other hand, when it is determined in step 91 that the road is a straight line, it is determined whether or not there is an effect of correcting the required steering assist torque according to the current (latest) lateral G correction value (step 92). The determination of this effect may be performed by comparing the absolute value of the difference between the target lateral G and the actual lateral vehicle G with the threshold value ΔG _ON , for example, as in step 62 shown in FIG. An index may be used.

  At this time, if it is determined that there is no effect of correcting the required steering assist torque in accordance with the current lateral G correction value, it is determined whether there is a request for learning the delay of the actual lateral G with respect to the target lateral G. For this purpose, a flag (learning request flag) is turned ON (step 93). Note that the learning request flag is set to OFF in the initial state. Then, learning of the delay of the vehicle actual lateral G with respect to the target lateral G is executed (step 94), and then the process proceeds to step 56.

  On the other hand, when it is determined in step 92 that there is an effect of correcting the required steering assist torque in accordance with the current lateral G correction value, the learning request flag is turned OFF (step 95), and then the process proceeds to step 56.

  The details of the learning processing procedure in step 94 are shown in FIG. Here, four learning divisions are configured by combining the increase and cut-off and the right side and the left side in the basic torque map (described above).

  In the figure, first, it is determined whether or not the number of learnings k has reached n times (design value) (step 101). When the number of learnings k has not reached n times, the following formula is calculated. (Step 102) When the number of learnings k reaches n, the number of learnings k is set to 0 (Step 103), and then the following equation is calculated.

_{G k = G k-1 +} L (E k -E k-1) ... (A)
k = k + 1 (B)
Here, L is a learning coefficient (design value), and G ₋₁ = 0 and E ₋₁ = 0. The above formula (A) is obtained from the following evaluation index.

Then, it sets the value of _{G k} obtained from the above formula (A) in the transverse G correction value _{G com} (step 104). Thereafter, the process proceeds to steps 56 to 58 shown in FIG. 9, and the lateral G correction value _Gcom is output.

  In the above, the process of step 91 in the lateral acceleration compensation unit 21 (see FIG. 9) constitutes a traveling road shape determining unit that determines whether or not the shape of the traveling road is a specific shape based on the information related to the traveling road. . The processing of steps 92 to 94 (see FIG. 9) learns the delay of the actual lateral acceleration of the host vehicle with respect to the target lateral acceleration when the traveling road shape determining means determines that the shape of the traveling road is a specific shape. The learning means is configured.

  In the present embodiment as described above, when the host vehicle travels on a curve, the required steering assist torque is corrected similarly to the first embodiment, and when the host vehicle travels on a straight line, the current lateral G correction is performed. The effect of correcting the required steering assist torque according to the value is evaluated, and the delay of the actual vehicle lateral G with respect to the target lateral G is learned according to the evaluation result, and a lateral G correction value that eliminates the delay is obtained. Since the optimal lateral G correction value is obtained by performing such learning, the delay of the actual lateral G with respect to the target lateral G is further reduced. At this time, since the reproducibility of the vehicle response to the target lateral G can be obtained by performing learning when the host vehicle travels on a straight line, the learning accuracy increases. Therefore, the lateral G response performance of the vehicle with respect to the target lateral G can be further improved.

  FIG. 11 is a configuration diagram showing a third embodiment of the steering assist device according to the present invention. In the figure, the same or equivalent elements as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  In the figure, a steering assist device 30 of the present embodiment includes a torque sensor 31 that detects a steering torque generated by a steering operation, and a steering angle of a steering wheel 3 in addition to a camera 9, a vehicle speed sensor 10, a G sensor 11, and an ECU 12. And a rudder angle sensor 32 for detecting.

  The ECU 12 has a lateral acceleration compensation unit 33 instead of the lateral acceleration compensation unit 15 described above. FIG. 12 is a flowchart showing a processing procedure of the lateral acceleration compensation unit 33. This processing procedure is different from the processing procedure shown in FIG. 2 in that steps 111 and 112 are added between step 56 and step 57.

  Specifically, when it is determined in step 56 that the delay determination flag is ON, the host vehicle is influenced by the disturbance of the road from the shape information of the travel road obtained by the travel information acquisition unit 13 subsequently. It is judged whether it is not (step 111). Examples of the disturbance of the road include that the road surface of the road is inclined and the road surface of the road is uneven.

  When it is determined that the host vehicle is not affected by road disturbance, the driver further resists the steering torque during the steering operation based on the detection values of the torque sensor 31 and the steering angle sensor 32. Is judged (step 112). Examples of resistance to such steering torque include resistance felt when the host vehicle is forcibly stopped by the road. At this time, when it is determined that the driver does not feel resistance with respect to the steering torque, the processing of steps 57 and 58 is executed, and then this processing is terminated.

  On the other hand, if it is determined in step 111 that the host vehicle is affected by road disturbance, and if it is determined in step 112 that the driver feels resistance to the steering torque, the lateral G correction value is determined. Is not output and this processing is terminated. As a result, the required steering assist torque is not corrected according to the lateral G correction value.

  In the above, the processing of step 111 in the camera 9, the travel information acquisition unit 13 and the lateral acceleration compensation unit 33 of the ECU 12 constitutes a disturbance influence determination unit that determines whether or not the host vehicle is affected by the disturbance of the travel path. . The torque sensor 31, the rudder angle sensor 32, and the process of step 112 in the lateral acceleration compensation unit 33 of the ECU 12 are torque resistors that determine whether the driver of the host vehicle feels resistance to the steering torque applied to the steering system. A determination unit is configured.

  In the present embodiment as described above, when the host vehicle is traveling under the influence of a road disturbance, the correction of the required steering assist torque according to the lateral G correction value is stopped. No longer becomes unstable. In addition, when the driver feels resistance to the steering torque during the steering operation, the correction of the required steering assist torque according to the lateral G correction value is stopped, so that the uncomfortable feeling of the steering operation is reduced and the driver can drive It becomes easy to do.

  In the third embodiment, it goes without saying that the learning function implemented in the second embodiment described above may be combined.

It is a lineblock diagram showing a 1st embodiment of a steering support device concerning the present invention. It is a flowchart which shows the process sequence of the lateral acceleration compensation part shown in FIG. It is a figure which shows the output form of the lateral G correction value obtained by the lateral acceleration compensation part shown in FIG. It is a flowchart which shows the detail of the process sequence of step 52 shown in FIG. It is a flowchart which shows the detail of the process sequence of step 54 shown in FIG. It is a figure which shows the basic torque map memorize | stored in the memory of the request | requirement steering torque production | generation part shown in FIG. It is a flowchart which shows the process sequence of the request | requirement steering torque production | generation part shown in FIG. It is a block diagram which shows 2nd Embodiment of the steering assistance device concerning this invention. It is a flowchart which shows the process sequence of the lateral acceleration compensation part shown in FIG. It is a flowchart which shows the detail of the process sequence of step 94 shown in FIG. It is a block diagram which shows 3rd Embodiment of the steering assistance device concerning this invention. It is a flowchart which shows the process sequence of the lateral acceleration compensation part shown in FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Steering assistance apparatus, 2 ... Electric power steering (steering system), 9 ... Camera (traveling path information acquisition means, disturbance influence determination means), 11 ... G sensor (lateral acceleration delay detection means), 12 ... ECU, 13 ... Traveling information acquisition unit (traveling path information acquisition unit, disturbance influence determination unit), 14 ... target lateral acceleration calculation unit (target lateral acceleration calculation unit), 15 ... lateral acceleration compensation unit (lateral acceleration delay detection unit, lateral acceleration compensation unit) , 16 ... required steering torque generation unit (requested steering torque setting means), 17 ... motor drive control part (steering control means), 20 ... steering assist device, 21 ... lateral acceleration compensation part (lateral acceleration delay detection means, lateral acceleration compensation) Means, travel road shape determination means, learning means), 30 ... steering assist device, 31 ... torque sensor (torque resistance determination means), 32 ... steer angle sensor (torque resistance determination means), 33 ... lateral acceleration compensation (Lateral acceleration lag detection means, the lateral acceleration compensation means, the torque resistance determining means, disturbance effects determining means).

Claims (7)

Traveling road information acquisition means for acquiring information related to the traveling road on which the host vehicle travels;
A target lateral acceleration calculating means for calculating a target lateral acceleration that causes the host vehicle to travel along the travel path based on the information on the travel path;
Requested steering torque setting means for obtaining required steering torque for setting the lateral acceleration of the host vehicle to the target lateral acceleration;
Steering control means for controlling a steering system of the host vehicle according to the required steering torque;
Lateral acceleration delay detection means for detecting a delay of the actual lateral acceleration of the host vehicle with respect to the target lateral acceleration;
Lateral acceleration compensation means for obtaining a lateral acceleration correction value that reduces a delay of the actual lateral acceleration of the host vehicle with respect to the target lateral acceleration,
The required steering torque setting means includes a correction means for correcting the required steering torque in accordance with the lateral acceleration correction value. The required steering torque setting means stores in advance a torque map indicating a relationship between the target lateral acceleration and the required steering torque when the steering operation is increased or decreased.
The steering assist device according to claim 1, wherein the correction unit corrects the required steering torque corresponding to the target lateral acceleration in the torque map in accordance with the lateral acceleration correction value. Based on the information on the travel path, a travel path shape determination unit that determines whether the shape of the travel path is a specific shape;
Learning means for learning a delay of the actual lateral acceleration of the host vehicle with respect to the target lateral acceleration when the traveling road shape determining means determines that the shape of the traveling road is a specific shape. The steering assist device according to claim 1 or 2.   The steering assist device according to claim 3, wherein the specific shape is a straight line. Torque resistance determination means for determining whether or not the driver of the host vehicle feels resistance to the steering torque applied to the steering system;
The correction means does not correct the required steering torque according to the lateral acceleration correction value when the torque resistance determination means determines that the driver of the host vehicle feels resistance. The steering assist device according to any one of claims 1 to 4, wherein Disturbance influence determination means for determining whether or not the host vehicle is affected by disturbance on the travel path,
The correction means does not correct the required steering torque according to the lateral acceleration correction value when the disturbance influence determination means determines that the host vehicle is affected by the disturbance of the travel path. The steering assist device according to any one of claims 1 to 5, wherein the steering assist device is configured as described above.   The correction means does not correct the required steering torque in accordance with the lateral acceleration correction value when the target lateral acceleration is smaller than a predetermined value. The steering assist device according to one item.

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