JP2015151048A - Vehicle trajectory control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicle trajectory control device capable of meeting a driver's demand for correcting a trajectory without requiring a change in a target trajectory and a large number of operations.SOLUTION: A vehicle trajectory control device: sets a target trajectory of a vehicle on the basis of information on a road ahead of the vehicle; calculates a target pinion angle θplkat corresponding to a target steering angle of a steering wheel to drive the vehicle along the target trajectory; and controls the steering angle of the steering wheel so that the same coincides with the target steering angle. When the vehicle is under trajectory control and all the wheels are in a grip state (S10 and S40), the vehicle trajectory control device: calculates a target yaw rate Yrt on the basis of at least steering operation of a driver (S60); and corrects the target pinion angle θplkat by a correction amount Δθp on the basis of a variation ΔYr between the actual yaw rate Yr and the target yaw rate Yrt of the vehicle so that an actual yaw rate Yr comes close to the target yaw rate Yrt (S70 and S80).

Description

  The present invention relates to a trajectory control device that automatically controls the steering angle of a steered wheel so that a vehicle travels along a target trajectory.

  The trajectory control device sets a target trajectory of the vehicle based on an image in front of the vehicle captured by the in-vehicle camera, calculates a target rudder angle of the steered wheels for causing the vehicle to travel along the target trajectory, Trajectory control is performed by controlling the rudder angle to be the target rudder angle. In the trajectory control, it is determined that it is preferable that the vehicle does not travel along the currently set target trajectory, such as when there is an obstacle ahead of the vehicle or when the driver changes the course of the vehicle. And the target locus is changed by resetting.

  For example, in Patent Document 1 below, when an obstacle is detected around the vehicle, the vehicle generates a plurality of target trajectories for avoiding the obstacle, and based on the driver's steering operation from the plurality of target trajectories. A trajectory control device that performs trajectory control by selecting one target trajectory is described. According to this type of trajectory control device, it is possible to avoid an obstacle while continuing the trajectory control even in a situation where the vehicle needs to avoid the obstacle.

JP2013-129328A

[Problems to be Solved by the Invention]
The target trajectory in the trajectory control device is set as a trajectory along which the vehicle travels along the center of the travel lane. Therefore, a driver who prefers the vehicle to pass inside or outside the turn with respect to the target trajectory may be steered so that the vehicle travels in a lateral direction with respect to the target trajectory, particularly on a curved road.

  Since the magnitude of the steering amount and the steering speed when the vehicle is going to travel in a state shifted laterally with respect to the target trajectory on the curved traveling path in this way, in the conventional trajectory control device, It is not determined that the driver is going to change the target locus. For this reason, even if the driver steers the vehicle to move laterally with respect to the target locus, the vehicle does not travel along the locus desired by the driver, and the driver's request for locus correction is not satisfied.

  In order to cope with the above problem, it is conceivable to satisfy the driver's request for correcting the locus with the technique described in Patent Document 1. In that case, since there are no obstacles around the vehicle, a plurality of target trajectories are always calculated without the driver's steering operation. One target locus must be selected from the target locus according to the steering operation. Therefore, not only the calculation load of the device for calculating the target locus becomes excessive, but it is very difficult to calculate and select the target locus that matches the driver's request for locus correction. Therefore, the technique described in Patent Document 1 cannot satisfy the driver's request for various trajectory corrections.

  The present invention calculates the target rudder angle of the steered wheels for causing the vehicle to travel along the target trajectory and controls the above-described problems in the conventional trajectory control device for controlling the steered angle of the steered wheels to be the target rudder angle. It was made in view of the above. And the main subject of this invention is providing the locus | trajectory control apparatus which can satisfy | fill the request | requirement of a driver | operator's locus | trajectory correction, without requiring the change of a target locus | trajectory and a big calculation.

[Means for Solving the Problems and Effects of the Invention]
According to the present invention, the main problem described above is that a target locus of a vehicle is set based on information on a traveling path ahead of the vehicle, and a target steering angle of a steered wheel for causing the vehicle to travel along the target locus is calculated. In the vehicle trajectory control apparatus that performs trajectory control for controlling the steering angle of the steered wheels to be the target rudder angle, when the trajectory control is performed and all the wheels are in the grip state, at least the steering operation of the driver Based on the difference between the target turning state amount and the actual turning state amount so that the actual turning state amount of the vehicle approaches the target turning state amount. This is achieved by a vehicle trajectory control device characterized by correcting a corner.

  According to the above configuration, the target turning state amount of the vehicle calculated based on at least the driver's steering operation is calculated as a turning state amount when the vehicle travels along the trajectory desired by the driver. Further, the target rudder angle of the steered wheels is corrected based on the deviation between the target turning state amount and the actual turning state amount so that the actual turning state amount of the vehicle approaches the target turning state amount. Furthermore, since the target rudder angle of the steered wheels is corrected without changing the target trajectory, it is not necessary to change the target trajectory or calculate a plurality of target trajectories. Therefore, the target rudder angle of the steered wheels can be corrected so that the actual trajectory of the vehicle approaches the trajectory desired by the driver, thereby correcting the trajectory of the driver without requiring a change of the target trajectory or a large amount of calculation. Can meet the demands of.

  In addition, when there is a wheel in a non-grip state, the driver does not necessarily want the actual trajectory of the vehicle even if the target rudder angle of the steered wheel is corrected based on the deviation between the target turning state amount and the actual turning state amount. It is impossible to get close to the trajectory. On the other hand, according to the above configuration, the correction of the target rudder angle of the steered wheel based on the deviation between the target turning state amount and the actual turning state amount is performed by trajectory control, and all the wheels are brought into the grip state. It is done when there is. Therefore, compared with the case where it is not considered whether all the wheels are in the grip state, the actual trajectory of the vehicle can be appropriately brought closer to the trajectory desired by the driver.

It is a schematic structure figure showing a locus control device for vehicles concerning an embodiment of the present invention. It is a flowchart which shows the main routine of the locus | trajectory control in embodiment. It is a flowchart which shows the calculation routine of the target pinion angle | corner (theta) plkat of the locus | trajectory control performed in step 20 of FIG. 6 is a map for calculating a target pinion angle θplkat for trajectory control based on a target lateral acceleration Gyt and a vehicle speed V. It is a figure which shows the example of the target locus | trajectory in the curved driving | running | working path, and the various driving | running | working locus | trajectory which a driver | operator desires. It is a figure which shows the relationship between the absolute value of the lateral acceleration Gy of a vehicle, and the absolute value of the slip angle (beta) v of a vehicle.

  Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 shows a vehicle trajectory control device 10 according to an embodiment of the present invention mounted on a vehicle 12. The trajectory control device 10 includes a steering angle varying device 14 and an electronic control device 16 that controls the steering angle varying device 14. The vehicle 12 has left and right front wheels 18FL and 18FR that are steering wheels, and left and right rear wheels 18RL and 18RR that are non-steering wheels. The left and right front wheels 18FL and 18FR are steered via a rack bar 24 and tie rods 26L and 26R by an electric power steering device (EPS) 22 driven in response to an operation of the steering wheel 20 by a driver.

  A steering wheel 20 as a steering input device is connected to a pinion shaft 34 of the power steering device 22 via an upper steering shaft 28, a steering angle varying device 14, a lower steering shaft 30 and a universal joint 32. The rudder angle varying device 14 includes an electric motor 36 for turning driving. The electric motor 36 is connected to the lower end of the upper steering shaft 28 on the housing 14A side, and is connected to the upper end of the lower steering shaft 30 via a speed reduction mechanism (not shown) on the rotor 14B side.

  The steering angle varying device 14 turns the left and right front wheels 18FL and 18FR relative to the steering wheel 20 by rotating the upper steering shaft 28 and the lower steering shaft 30 relative to each other. Therefore, the steering angle varying device 14 functions as a steering gear ratio varying device (VGRS) that changes the steering gear ratio (the reciprocal of the steering transmission ratio). Further, the rudder angle varying device 14 automatically steers the front wheels by changing the rudder angles of the left and right front wheels regardless of whether the driver performs a steering operation. As will be described in detail later, the steering angle varying device 14 is controlled by a steering angle control unit of the electronic control device 16.

  In the illustrated embodiment, the electric power steering device 22 is a rack coaxial type electric power steering device, for example, a ball that converts the rotational torque of the electric motor 40 and the electric motor 40 into a force in the reciprocating direction of the rack bar 24. And a screw-type conversion mechanism 42. The electric power steering device 22 is controlled by the EPS control unit of the electronic control device 16. The electric power steering device 22 reduces the steering burden on the driver and assists the operation of the steering angle varying device 14 by generating an auxiliary steering force that drives the rack bar 24 relative to the housing 44. It functions as a steering assist force generator.

  The steering angle varying device 14 and the steering assist force generating device cooperate with each other to change the steering angle of the left and right front wheels or change the rotation angle of the steering wheel 20 regardless of the steering operation of the driver. As long as it is possible, the apparatus may have any configuration. Although the illustrated steering input device is the steering wheel 20, the steering input device may be a joystick type steering lever.

  The braking force of each wheel is controlled by controlling the pressure in the wheel cylinders 54FL, 54FR, 54RL and 54RR, that is, the braking pressure, by the hydraulic circuit 52 of the braking device 50. Although not shown in FIG. 1, the hydraulic circuit 52 includes an oil reservoir, an oil pump, various valve devices, and the like, and the braking pressure of each wheel cylinder is normally driven according to the depression operation of the brake pedal 56 by the driver. The master cylinder 58 is controlled. Furthermore, the braking pressure of each wheel cylinder is individually controlled by the hydraulic circuit 52 being controlled by the braking force control unit of the electronic control unit 16 as necessary. The braking device 50 can individually control the braking force of each wheel independently of the driver's braking operation.

  The upper steering shaft 28 is provided with a steering angle sensor 60 that detects the rotation angle of the upper steering shaft as the steering angle MA. The pinion shaft 34 is provided with a steering torque sensor 62 that detects the steering torque MT. The steering angle varying device 14 is provided with a rotation angle sensor 64 that detects the rotation angle of the lower steering shaft 30 with respect to the upper steering shaft 28 as a relative rotation angle θre. The steering angle sensor 60, the steering torque sensor 62, and the rotation angle sensor 64 detect the steering angle MA, the steering torque MT, and the relative rotation angle θre, respectively, when the steering or turning in the left turn direction of the vehicle is positive.

  The signal indicating the steering angle MA, the signal indicating the steering torque MT, and the signal indicating the relative rotation angle θre are a signal indicating the vehicle speed V detected by the vehicle speed sensor 66 and a steering angle control unit and an EPS control unit of the electronic control device 16. And input to the travel control unit. A signal indicating the lateral acceleration Gy and yaw rate Yr of the vehicle detected by the lateral acceleration sensor 68 and the yaw rate sensor 70, respectively, is input to the traveling control unit of the electronic control device 16, and the shift position is indicated by the transmission 72. A signal is input. The rotation angle of the lower steering shaft 30 may be detected, and the relative rotation angle θre may be obtained as a difference between the steering angle MA and the rotation angle of the lower steering shaft 30.

  The EPS control unit of the electronic control device 16 controls the EPS 22 based on the steering torque MT and the like, thereby reducing the steering burden on the driver and controlling the front wheel steering angle by the steering angle varying device 14 and the steering wheel 20. Assist in controlling the rotational position.

  The vehicle 12 is provided with a CCD camera 74 for photographing the front of the vehicle and a selection switch 76 operated by a vehicle occupant. The selection switch 76 is used to select whether or not to perform trajectory control (also referred to as “LKA (lane keep assist) control”) that causes the vehicle to travel along the travel path. A signal indicating image information ahead of the vehicle and a signal indicating the position of the selection switch 76 taken by the CCD camera 74 are input to the travel control unit of the electronic control device 16. The CCD camera 74 is preferably a stereo camera capable of measuring the distance between an object in front of the vehicle and the host vehicle, and image information and travel path information in front of the vehicle are acquired by means other than the CCD camera. May be.

  When the selection switch 76 is on, the steering mode is set to the automatic steering mode, and the trajectory control is performed according to the flowcharts shown in FIGS. On the other hand, when the selection switch 76 is OFF, the steering mode is set to the manual steering mode, and the steering angle of the front wheels is controlled according to the rotational position of the steering wheel 20.

  Each control unit of the electronic control device 16 includes a CPU, a ROM, a RAM, and an input / output port device, which are connected to each other via a bidirectional common bus. You may have. The traveling control unit of the electronic control device 16 controls the steering angle control unit, the EPS control unit, the braking force control unit, and the driving force control unit as necessary.

  Next, trajectory control in the embodiment will be described with reference to the flowcharts shown in FIGS. Trajectory control according to the flowcharts shown in FIGS. 2 and 3 is repeatedly executed at predetermined time intervals by the travel control unit of the electronic control device 16.

<Main routine> (Fig. 2)
First, prior to step 10, a signal or the like indicating the steering angle MA detected by the steering angle sensor 60 is read. In step 10, it is determined whether or not the trajectory control is being performed by determining whether or not the selection switch 76 is on, for example. When a negative determination is made, the control is temporarily terminated, and when an affirmative determination is made, the control proceeds to step 20.

  In step 20, the target locus is set according to the flowchart shown in FIG. 3, and the target pinion angle θplkat, ie, the pinion shaft 34, is set as a value corresponding to the target rudder angle of the front wheels for driving the vehicle along the target locus. The target rotation angle is calculated.

  In step 30, the actual pinion angle θp is calculated based on the steering angle MA and the relative rotation angle θre detected by the steering angle sensor 60 and the rotation angle sensor 64, respectively. Further, it is determined whether or not the absolute value of the difference between the actual pinion angle θp and the target pinion angle θplkat is equal to or less than a reference value Δθp0 (a positive constant close to 0). That is, it is determined whether or not the actual pinion angle θp is substantially the same as the target pinion angle θplkat and the front wheel steering angle is substantially the target steering angle for trajectory control. When a positive determination is made, it is estimated that the driver is not actively performing the steering operation and the vehicle desires to travel along the target locus, so the control proceeds to step 90. On the other hand, when a negative determination is made, it is estimated that the driver is actively steering and the vehicle desires to travel along a trajectory different from the target trajectory. Advances to step 40.

  In step 40, it is determined whether or not the four wheels are in the grip state. When an affirmative determination is made, control proceeds to step 60, and when a negative determination is made, control proceeds to step 50.

In this case, Gy0, Yr0, and θpd0 may be positive constants close to 0, respectively, and when all of the following conditions a to d are satisfied, it may be determined in step 40 that all wheels are in the grip state. Θpd is the actual change rate of the pinion angle θp, that is, the rotational speed of the pinion shaft 34 corresponding to the rudder angular speed of the front wheels. Strictly speaking, the following condition d is not related to the grip state of the wheel, but when the vehicle is moving backward, the target yaw rate Yrt of the vehicle cannot be calculated based on the vehicle model. This is because it is excluded.
a. ｜ Gy | ≦ Gy0
b. | Yr | ≦ Yr0
c. | Θpd | ≦ θpd0
d. Shift position is not reverse

  In a situation where all of the above conditions a to d are satisfied, all the wheels are in a grip state. For example, as shown in FIG. 6, the absolute value of the vehicle slip angle βv is the absolute value of the lateral acceleration Gy of the vehicle. It has a linear relationship with the value. Therefore, the affirmative determination in step 40 is not in the region in which the vehicle is likely to be in a spin state or a drift-out state when the vehicle traveling state is in the linear region and not in the nonlinear region, that is, in a state where the road surface friction coefficient is low. Means that. In FIG. 6, the broken line indicates the relationship between the absolute value of the lateral acceleration Gy of the vehicle and the slip angle βv of the vehicle with respect to the vehicle model. As the absolute value of the acceleration Gy increases, it increases.

  In step 50, it is determined whether or not the trajectory control should be ended by determining whether or not a predetermined trajectory control end condition is satisfied. In this case, it is determined that the trajectory control should be terminated when the speed of the steering operation by the driver is greater than or equal to a reference value or when the magnitude of the driver's steering operation over several cycles is greater than or equal to the reference value. May be. Further, when the wheels are in a non-grip state and the behavior of the vehicle is no longer stable, vehicle behavior stabilization control by controlling the braking / driving force of the wheels may be executed.

In step 60, the target yaw rate Yrt of the vehicle based on the driver's steering operation is calculated based on the steering angle MA and the vehicle speed V. For example, the target yaw rate Yrt is calculated according to the following equation (1), where the steering gear ratio is N, the vehicle wheelbase is L, the stability factor is Kh, and the steering-yaw rate transient transfer function is H (s). May be.
Yrt = V · (MA / N) · {L (1 + Kh · V ² )} · H (s) (1)

  In step 70, a deviation ΔYr (= Yrt−Yr) between the target yaw rate Yrt and the actual yaw rate Yr of the vehicle detected by the yaw rate sensor 70 is calculated. Further, a pinion angle correction amount Δθplkat for making the actual yaw rate Yr close to the target yaw rate Yrt is calculated based on the yaw rate deviation ΔYr. In this case, the correction amount Δθplkat is calculated to 0 when the magnitude of the yaw rate deviation ΔYr is equal to or less than the reference value ΔYr0 (positive constant).

  In step 80, the target pinion angle θplkat is corrected with the correction amount Δθplkat by adding the correction amount Δθplkat to the target pinion angle θplkat calculated in step 20. However, as in the case of step 50, the guard processing may be performed so that the target pinion angle θplkat does not change with an excessive change amount.

  In step 90, the rudder angle varying device 14 and the EPS 22 are controlled so that the pinion angle θp becomes the target pinion angle θplkat, whereby the trajectory control for running the vehicle along the target trajectory is executed, so that the front wheels 18FL and 18FR are executed. Is controlled.

<Target pinion angle θplkat calculation routine> (Fig. 3)
Next, the trajectory control target pinion angle θplkat calculation routine executed in step 20 will be described in detail with reference to FIG.

  First, in step 22, a traveling lane is identified by analyzing image information in front of the vehicle photographed by the CCD camera 74, and a target locus of the vehicle along the traveling lane is set as a line passing through the center of the traveling lane, for example. Is done. Furthermore, the curvature R (reciprocal of the radius) of the target locus, the lateral deviation Y of the vehicle with respect to the target locus, and the yaw angle φ of the vehicle are calculated.

  Note that the identification of the travel path and the determination of the target trajectory may be performed based on information from a navigation device not shown in the figure, and based on a combination of analysis of image information and information from the navigation device. It may be done. The curvature R of the target trajectory is a parameter necessary for performing trajectory control for causing the vehicle to travel along the target trajectory. However, the calculation procedure does not form the gist of the present invention. The parameter may be calculated in an arbitrary manner.

  In step 24, the target lateral acceleration Gylkat is calculated as the target turning state quantity of the vehicle for causing the vehicle to travel along the target locus based on the parameters (R, Y and φ) of the locus control. The target lateral acceleration Gylkat may be calculated by a function of the trajectory control parameter, and a map showing the relationship between the trajectory control parameter and the target lateral acceleration Gylkat is set, and based on the trajectory control parameter, the target lateral acceleration Gylkat is calculated. The acceleration Gylkat may be calculated. Further, the target turning state amount of the vehicle for causing the vehicle to travel along the target locus may be a target yaw rate.

  In step 26, the target pinion angle θplkat for trajectory control is calculated from the map shown in FIG. 4 based on the target lateral acceleration Gylkat and the vehicle speed V of the vehicle.

  Next, the operation of the embodiment will be described separately for the driver's steering operation situation and the wheel grip state. In the following description of the operation, FIG. 5 showing examples of target trajectories and various travel trajectories on a curved travel path will be referred to as appropriate.

  In FIG. 5, 100 indicates a traveling lane, and a solid line 102 indicates a target locus set so as to pass through the center of the traveling lane 100. A broken line 104 indicates a travel locus when the vehicle travels along the target locus 102, and alternate long and short dash lines 106 and 108 indicate a travel locus when the vehicle travels toward the inside of the turn and toward the outside of the turn, respectively. Show. An alternate long and two short dashes line 110 indicates a travel locus when the driver performs a relatively abrupt steering operation so that the vehicle greatly deviates from the target locus 102.

A. <When the driver is not actively steering>
When the front wheels 18FL and 18FR are automatically steered by the trajectory control, the steering wheel 20 rotates corresponding to the steering of the front wheels. “When the driver is not actively performing the steering operation” refers to a case where the driver puts his hand on the steering wheel 20 and moves his / her arm according to the rotation of the steering wheel without countering the rotation of the steering wheel.

  Since the driver is not actively steering, the steering angle of the front wheels is the same as the target steering angle of the trajectory control. Therefore, an affirmative determination is made in step 30, and control proceeds to step 90 without executing steps 40 to 80. Therefore, the target pinion angle θplkat is not corrected, and the trajectory control is executed by controlling the pinion angle based on the target pinion angle θplkat calculated in step 20. Since the vehicle travels along the target locus 102, the traveling locus of the vehicle is a locus indicated by a broken line 104 in FIG.

B. <When the driver is actively steering and all wheels are in grip>
When the four wheels are in the grip state, the running state of the vehicle is stable, so the relationship between the lateral acceleration Gy of the vehicle and the slip angle βv of the vehicle is in the linear region of FIG. Therefore, “when the driver actively performs steering operation and all wheels are in the grip state” means that the driver performs a gentle steering operation in a state where all the wheels are in the grip state. It is.

  Since the driver actively performs the steering operation, the rudder angle of the front wheels is different from the target rudder angle of the trajectory control, and a negative determination is made in step 30. Further, since all the wheels are in the grip state, an affirmative determination is made in step 40. Accordingly, steps 60 to 80 are executed. That is, in step 60, the target yaw rate Yrt of the vehicle based on the driver's steering operation is calculated. In step 70, based on the deviation ΔYr between the target yaw rate Yrt and the actual yaw rate Yr, a pinion angle correction amount Δθplkat for bringing the actual yaw rate Yr closer to the target yaw rate Yrt is calculated. Further, in step 80, the target pinion angle θplkat calculated in step 20 is corrected with the correction amount Δθplkat.

  For example, as indicated by a one-dot chain line 106 in FIG. 5, when the driver desires to travel closer to the inside of the turn with respect to the target locus, the magnitude of the steering angle MA at the curved portion of the traveling path. Is smaller than the value when the vehicle travels along the target locus 102. As a result, the target yaw rate Yrt calculated based on the steering angle MA and the vehicle speed V is smaller than the value when the vehicle travels along the target locus 102. Therefore, the correction amount Δθplkat of the pinion angle is calculated so as to be a correction amount in the left turn direction that brings the actual yaw rate Yr closer to the target yaw rate Yrt, and the target pinion angle θplkat is reduced so that the steering angle of the front wheels decreases. It is corrected with the correction amount Δθplkat.

  On the other hand, as indicated by a one-dot chain line 108 in FIG. 5, when the driver desires to travel outside the turn with respect to the target locus, the steering angle MA at the curved portion of the traveling path is large. This is larger than the value when the vehicle travels along the target locus 102. As a result, the target yaw rate Yrt is larger than the value when the vehicle travels along the target locus 102. Therefore, the correction amount Δθplkat of the pinion angle is calculated so as to be a correction amount in the right turn direction that brings the actual yaw rate Yr closer to the target yaw rate Yrt, and the target pinion angle θplkat increases the size of the steering angle of the front wheels. It is corrected with the correction amount Δθplkat.

  Therefore, when the driver actively performs a steering operation in a state where all the wheels are in the grip state and tries to correct the traveling locus of the vehicle to a locus that deviates from the target locus, Based on this, the target rudder angle of the front wheels can be corrected. Therefore, even if the driver prefers to drive inwardly or outwardly with respect to the target trajectory, or prefers to inflate and travel outward before turning, the target trajectory is not changed. Trajectory control can be performed so that the driver's preference regarding travel is reflected.

C. <When the driver is actively steering and there are non-grip wheels>
When there are non-grip wheels, the relationship between the lateral acceleration Gy of the vehicle and the slip angle of the vehicle is in the non-linear region of FIG. Therefore, “when the driver actively performs steering operation and there is a non-grip wheel” means that the driver performs a relatively quick steering operation or a steering operation with a relatively large amount of operation, This is the case when at least one wheel is in a non-grip state.

  Since the driver is actively steering, the steering angle of the front wheels is different from the target steering angle of the trajectory control as in the case of B, and a negative determination is made in step 30. However, since there is a non-grip wheel, a negative determination is made in step 40, thereby executing step 50. That is, it is determined whether or not the trajectory control should be terminated.

  When it is determined that the trajectory control should be terminated, the trajectory control is terminated and the steering mode is shifted to the manual mode. When it is determined that the trajectory control should not be terminated, the trajectory control is continued, but the target pinion angle θplkat is not corrected in steps 60 to 80. In this case as well, the driver can cause the vehicle to travel other than traveling along the target locus by a steering operation.

  For example, as shown by a two-dot chain line 110 in FIG. 5, when the driver desires to travel actively deviating from the target locus 102, the driver moves the steering wheel 20 relatively. Operate at high steering speeds and relatively large rotation angles. Therefore, a negative determination is made in steps 30 and 40, and a negative determination is also made in step 50. As a result, the trajectory control is continued, but the target pinion angle θplkat is not corrected based on the deviation ΔYr between the target yaw rate Yrt and the actual yaw rate Yr.

  As can be understood from the above description, according to the above-described embodiment, when the steering operation is performed by the driver and all the wheels are in the grip state, the yaw rate deviation is adjusted so that the actual yaw rate Yr approaches the target yaw rate Yrt. The rudder angle of the front wheels is corrected with the correction amount based on ΔYr. Therefore, the driver can perform the trajectory control by reflecting the driver's preference regarding the turning without changing the target trajectory or setting a plurality of target trajectories by performing the steering operation even during the trajectory control. Can do. Further, it is possible to prevent the rudder angle of the front wheels from being unnecessarily corrected in a situation where the driver is not performing the steering operation. Furthermore, when an emergency situation occurs or the course is changed, the driver actively performs a fast steering operation to end the trajectory control, and the vehicle travel trajectory is determined based on the steering operation. Can be controlled.

  Further, according to the above-described embodiment, it is determined in step 30 whether or not the steering operation is performed by the driver, and if the steering operation is not performed by the driver, in step 30 Since a positive determination is made, steps 40 to 80 are not executed. Therefore, even if the yaw rate deviation ΔYr having a magnitude greater than or equal to the reference value ΔYr0 occurs, the steering angle of the front wheels can be prevented from being unnecessarily corrected with the correction amount based on the yaw rate deviation ΔYr.

  Further, according to the above-described embodiment, the traveling lane is specified by analyzing image information in front of the vehicle photographed by the CCD camera 74, and the target locus of the vehicle along the traveling lane is determined. The target pinion angle θplkat corresponding to the target steering angle of the front wheels is calculated based on the curvature R of the target locus, the lateral deviation Y of the vehicle with respect to the target locus, and the yaw angle φ of the vehicle. Therefore, compared with the case where any one of the curvature R of the target locus, the lateral deviation Y of the vehicle with respect to the target locus, and the yaw angle φ of the vehicle is not taken into account, the target is in a state where the vehicle has a preferable relationship with the target locus. It is possible to travel well along the trajectory. Therefore, the driver desires based on the deviation between the target turning state quantity of the vehicle based on the driver's steering operation and the actual turning state quantity, as compared with the case where any one of the curvature R of the target locus is not considered. The correction amount of the target rudder angle can be accurately calculated in accordance with the magnitude of the correction of the travel locus to be performed.

  Although the present invention has been described in detail with respect to specific embodiments, the present invention is not limited to the above-described embodiments, and various other embodiments are possible within the scope of the present invention. This will be apparent to those skilled in the art.

  For example, in the above-described embodiment, when the steering operation is performed by the driver and the vehicle is in a stable running state, the correction amount for correcting the target rudder angle of the front wheels is the target yaw rate Yrt of the vehicle and the actual amount. Calculation is based on the deviation ΔYr from the yaw rate Yr. However, the correction amount for correcting the target steering angle of the front wheels may be calculated based on the deviation ΔGy between the target lateral acceleration Gyt of the vehicle and the actual lateral acceleration Gy. In this case, the target lateral acceleration Gyt of the vehicle may be calculated as a value obtained by dividing the right side of the equation (1) by the vehicle speed V, for example.

  In the above-described embodiment, the target pinion angle θplkat corresponding to the target rudder angle of the front wheels is calculated based on the curvature R of the target locus, the lateral deviation Y of the vehicle with respect to the target locus, and the yaw angle φ of the vehicle. The However, the target pinion angle θplkat, and thus the target rudder angle of the front wheels, may be calculated in any manner as long as the vehicle can travel along the target locus.

  In the above-described embodiment, the target pinion angle θplkat is calculated as a value corresponding to the target steering angle of the front wheels. However, the target steering angle of the front wheel itself may be calculated, or the rotation angle of the steering wheel 20 may be calculated as a value corresponding to the target steering angle of the front wheel.

  In the above-described embodiment, the reference value Δθp0 for determination in step 30 is a constant value. However, since the amount of steering operation performed by the driver for correcting the traveling locus of the vehicle becomes smaller as the vehicle speed V becomes higher, the reference value Δθp0 is variably set according to the vehicle speed so as to become smaller as the vehicle speed V becomes higher, for example. May be.

  Furthermore, in the above-described embodiment, the left and right front wheels, which are steering wheels, are steered by the rudder angle varying device 14 and the EPS 22 that rotationally drive the lower steering shaft 30 relative to the upper steering shaft 28. . However, the driving of the steering wheel for steering the steering wheel may be performed only by the EPS 22, and the steering wheel may be steered by a by-wire type steering device.

  DESCRIPTION OF SYMBOLS 10 ... Vehicle locus control device, 12 ... Vehicle, 14 ... Steering angle variable device, 16 ... Electronic control device, 22 ... Electric power steering device (EPS), 50 ... Braking device, 60 ... Steering angle sensor, 70 ... Yaw rate Sensor, 74 ... CCD camera

Claims (1)

A target trajectory of the vehicle is set based on information on a travel path ahead of the vehicle, a target rudder angle of a steered wheel for causing the vehicle to travel along the target trajectory is calculated, and the rudder angle of the steered wheel becomes the target rudder angle. In the vehicle trajectory control apparatus that performs trajectory control for controlling
When the trajectory control is performed and all the wheels are in the grip state, the target turning state amount of the vehicle is calculated based on at least the driver's steering operation, and the actual turning state amount of the vehicle approaches the target turning state amount. Thus, the vehicle trajectory control apparatus corrects the target rudder angle of the steered wheel based on the deviation between the target turning state quantity and the actual turning state quantity.

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