Intervention operation determination device

Abstract

To provide an intervention operation determination device that can promptly and accurately determine an intervention operation of a steering by a driver during controlling a steering angle of a vehicle without operation by the driver.SOLUTION: An intervention operation determination device includes: a steering part to be operated by a driver; a steering wheel configured to turn along with the operation of the steering part; and a detector configured to detect an amount of operation of the steering part when operation force for turning the steering wheel is generated, and is configured to determine that the driver has operated the steering part during an automatic operation in which traveling is performed by controlling an actuator without operation of the steering part by the driver. The intervention operation determination device includes a controller configured to control the actuator. The controller determines based on a deviation Δθ between a target steering angle during the automatic operation and an actual steering angle θr based on the amount of operation detected by the detector whether an intervention operation in which the steering part is operated by the driver has been performed.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to an intervention operation determination device that determines that a driver has intervened and performed a steering operation while the steering angle is controlled and the vehicle is running without the driver performing a steering operation.

Background Art

[0002] In Patent Document 1, when there is a steering intervention by a driver while an automatic driving control for changing the steering angle of a vehicle without the driver performing a steering operation is being executed, a steering control device is configured to switch to a control different from the automatic driving control. This steering control device is configured to determine the presence or absence of a steering intervention by the driver based on the steering torque during the automatic driving control. Specifically, the steering control device stores the steering torque at the time when the change rate of the steering torque detected by a torque sensor becomes equal to or greater than a predetermined change rate. Subsequently, when a torque equal to or greater than the stored steering torque is continuously detected for a predetermined time, the steering control device determines that there has been a steering intervention by the driver. On the contrary, when the torque drops below the stored steering torque within a predetermined time, the steering control device determines that the detected value of the torque sensor has changed due to an external disturbance and is not changed by the driver's steering intervention.

[0003] Also, in Patent Document 2, when an automatic driving control for changing the steering angle of a vehicle without the driver performing a steering operation is being executed, the movement of the driver's hand and eyes is detected by a camera provided in the vehicle, and when it is detected based on the detection result that the driver is trying to hold the steering wheel, a traveling control device is configured to switch to a normal control for changing the steering angle of the vehicle based on the driver's steering operation.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

[0005] According to the steering control device described in Patent Document 1, steering intervention by the driver is determined when a predetermined time has elapsed after the rate of change of the steering torque exceeds a predetermined rate of change. In other words, from the time the driver actually performs a steering operation until the steering intervention is determined, the control that was in place before the steering operation continues. Normally, automatic driving control is not configured to perform control in response to the driver's steering operation, so when the driver performs a steering operation and the steering angle changes, it is determined that the driving path has changed due to some factor, and a target steering angle to return to the normal driving path is determined, and the output torque of the actuator is controlled with that target steering angle as the target value. The output torque of such an actuator increases as the deviation between the current steering angle and the target steering angle increases. Therefore, from the time the driver actually performs a steering operation until the steering intervention is determined, the output torque of the actuator increases in proportion to the amount of steering operation, which may reduce the operating feel or cause discomfort to the driver.

[0006] Furthermore, according to the driving control device described in Patent Document 2, it is configured to determine whether the driver is trying to hold the steering wheel based on the driver's hand and eye movements, and to switch from automatic driving control to normal control based on that determination. However, there is a possibility that the driver will not hold the steering wheel, or even if the driver holds the steering wheel, they may not actually operate the steering wheel. In such cases, after switching to normal control, it becomes necessary to switch back to automatic driving control, which not only complicates the control but also creates a period during which the vehicle cannot be controlled temporarily, requiring the driver to take control of the vehicle, which may be troublesome for the driver.

[0007] This invention was made in view of the above-mentioned technical problems, and aims to provide an intervention operation determination device that can determine early and accurately whether the driver has intervened in the steering when the steering angle of the vehicle is being controlled without the driver's input. [Means for solving the problem]

[0008] To achieve the above objective, this invention provides an intervention operation determination device that determines whether the driver has operated the steering unit during automatic driving, in which the vehicle is driven by controlling the actuator without the driver operating the steering unit, and further comprises a controller that controls the actuator, the controller determining the deviation between the target steering angle during automatic driving and the actual steering angle based on the amount of operation detected by the detection unit. If the absolute value of the difference is greater than or equal to a predetermined difference, and the direction of the target steering angle relative to a predetermined reference steering angle and the direction of the actual steering angle relative to the reference steering angle are in opposite directions, It is determined that the driver intervened by operating the steering unit. It is characterized by the following:

[0012] Furthermore, this invention comprises a steering unit operated by a driver, steering wheels that steer in conjunction with the operation of the steering unit, and actuators that generate steering force to steer the steering wheels, and is an intervention operation determination device that determines whether the driver has operated the steering unit during automatic driving in which the vehicle is driven by controlling the actuator without the driver operating the steering unit, and comprises a controller that controls the actuator, the controller determines the deviation between the target lateral position and the actual lateral position in the automatic driving. When the absolute value of the difference is greater than or equal to a predetermined difference, and the direction of the yaw angle based on the target lateral position relative to a predetermined reference yaw angle is opposite to the direction of the actual yaw angle relative to the reference yaw angle, This system is characterized by determining whether an intervention operation involving the steering unit has occurred. [Effects of the Invention]

[0016] In this invention, the system determines whether an intervention operation by the driver has occurred by operating the steering unit, based on the deviation between the target steering angle during autonomous driving and the actual steering angle based on the amount of operation detected by the detection unit. Therefore, the intervention operation can be determined before the steering force output from the actuator increases in order to make the actual steering angle follow the target steering angle. As a result, it is possible to suppress the steering force corresponding to the target steering angle from acting in opposition to the steering force of the driver, thereby improving the driver's feel of the steering unit and preventing the driver from experiencing discomfort. [Brief explanation of the drawing]

[0017] [Figure 1] This is a schematic diagram illustrating an example of an electric power steering system that can be targeted by this invention. [Figure 2] This is a block diagram illustrating the configuration of the EPS-ECU. [Figure 3] This block diagram shows an example of a configuration that determines intervention based on the deviation between the actual steering angle and the target steering angle. [Figure 4] This is a flowchart illustrating an example of control performed by the intervention operation determination device in this embodiment of the invention. [Figure 5] This is a time chart showing the changes in actual steering angle, target steering angle, steering angle deviation, steering torque, whether or not a judgment was made by the normal steering judgment unit, and whether or not a judgment was made by the early steering judgment unit when the steering wheel is operated in the leftward turning direction while the vehicle is driving in a straight line under autonomous driving. [Figure 6] This is a time chart showing the changes in actual steering angle, target steering angle, steering angle deviation, steering torque, steering speed, deviation speed, presence or absence of judgment by the normal steering judgment unit, presence or absence of judgment based on deviation by the early steering judgment unit, and presence or absence of judgment based on deviation speed by the early steering judgment unit when the target steering angle changes in the left turning direction while the vehicle is driving in a straight line under autonomous driving. [Figure 7]A time chart showing changes in the target steering angle when driving straight by automatic driving and changing in the left turning direction, as well as the actual steering angle, target steering angle, steering angle deviation, steering torque, steering speed, deviation speed, presence or absence of determination by the normal steering determination unit, presence or absence of determination based on deviation by the early steering determination unit, and presence or absence of determination based on deviation speed by the early steering determination unit when the steering wheel is held. [Figure 8] A block diagram showing an example of a configuration for determining an intervention operation based on the deviation between the actual operation angle and the target steering angle and the direction of the target steering angle and the actual steering angle. [Figure 9] A block diagram showing an example of a configuration for determining an intervention operation based on the rate of change of the deviation between the actual operation angle and the target steering angle. [Figure 10] A time chart showing changes in the actual steering angle, target steering angle, steering angle deviation, steering torque, steering speed, deviation speed, presence or absence of determination by the normal steering determination unit, presence or absence of determination based on deviation by the early steering determination unit, and presence or absence of determination based on deviation speed by the early steering determination unit when the steering wheel is operated in the left turning direction while driving straight by automatic driving. [Figure 11] A block diagram showing an example of a configuration for determining an intervention operation based on the rate of change of the deviation between the actual operation angle and the target steering angle and the rate of change of the actual steering angle. [Figure 12] A block diagram showing an example of a configuration for determining an intervention operation based on the difference between the target lateral position and the actual lateral position. [Figure 13] A block diagram showing an example of a configuration for determining an intervention operation based on the difference between the target lateral position and the actual lateral position and the direction of the target yaw angle and the actual yaw angle. [Figure 14] A block diagram showing an example of a configuration for determining an intervention operation based on the rate of change of the difference between the target lateral position and the actual lateral position and the rate of change of the actual lateral position.

Embodiments for Carrying Out the Invention

[0018] Hereinafter, embodiments of the present invention will be described while referring to the drawings. Note that the embodiments described below are merely examples of implementing the present invention and do not limit the present invention.

[0019] The intervention operation determination device in the embodiment of the present invention targets a vehicle that can automatically drive by controlling the steering angle without the driver performing a steering operation. An example of a steering device capable of automatically controlling such a steering angle is shown in FIG. 1. The steering device shown in FIG. 1 is an electric power steering device (EPS) 1 configured to be able to electrically control the torque for changing the steering angle (hereinafter referred to as steering torque), and to control the assist torque for adding or subtracting the driver's steering torque, and its schematic configuration is shown.

[0020] EPS1 is mounted on the vehicle 2 and is configured to steer a steering wheel 3 such as a front wheel that changes the direction (turns) of the vehicle 2. A steering wheel 4 is provided as a steering unit for performing this operation. The steering wheel 4 is connected to a steering linkage 6 via a steering shaft 5 and is configured to steer the steering wheel 3 according to the rotation angle of the steering wheel 4. The steering linkage 6 has, as an example, a rack 7 that moves back and forth in the width direction of the vehicle 2, a pinion 8 that meshes with the rack 7, and a tie rod 9 that connects the rack 7 and the steering wheel 3, and the above-mentioned steering shaft 5 is connected to the pinion 8. Therefore, when the steering wheel 4 is rotated to the right or left, the pinion 8 rotates and the rack 7 moves to the right or left, and accordingly the steering wheel 3 steers. That is, the steering wheel 3 steers in conjunction with the operation of the steering wheel 4.

[0021] In the embodiment described here, the steering wheel 4 used to move the vehicle 2 straight is defined as a steering angle of "0 degrees". From this position, the steering amount measured to the left is defined as a "positive" steering angle, and the steering amount measured to the right is defined as a "negative" steering amount. Therefore, operating the steering wheel 4 to turn the vehicle 2 to the left increases the steering angle, and conversely, operating the steering wheel 4 to turn the vehicle 2 to the right decreases the steering angle.

[0022] A motor 10 is provided to generate steering torque and to assist the steering torque performed by the driver. The motor 10 is configured to apply or remove torque to the steering wheel 4 and steering shaft 5, or to apply or remove forward / reverse power to the rack 7, that is, to generate steering force that turns the steering wheels 3. In the example shown in Figure 1, the motor 10 is connected to the steering shaft 5 via a reduction gear 11. This motor 10 corresponds to the "actuator" in this embodiment of the invention.

[0023] Furthermore, a torque sensor 12 for detecting the torque acting on the steering shaft 5 and a steering angle sensor 13 for detecting the steering angle (amount of operation), which is the rotation angle of the steering shaft 5, are provided. These sensors 12 and 13 input detection signals to an electronic control unit (EPS-ECU) 14 for the electric power steering system (EPS). The steering angle sensor 13 corresponds to the "detection unit" in this embodiment of the invention, and the EPS-ECU 14 corresponds to the "controller" in this embodiment of the invention.

[0024] Figure 2 shows a block diagram illustrating the configuration of the EPS-ECU14. The EPS-ECU14 shown in Figure 2 is mainly composed of a microcomputer and is configured to determine the command signal to be output to the motor 10 based on the input signal and pre-stored calculation formulas and maps.

[0025] This EPS-ECU14 is configured to enable autonomous driving, where the motor 10 controls the vehicle to follow a predetermined driving route (including its position within the driving lane) without the driver operating the steering wheel 4. In addition to a mode in which autonomous driving is performed without the driver operating the steering wheel 4 (hereinafter referred to as the first mode), the system is configured to allow the driver to operate the steering wheel 4 as appropriate during autonomous driving (hereinafter referred to as the second mode). Specifically, in the second mode, if the driver operates the steering wheel 4 during autonomous driving, the system prioritizes the driver's intention, and if the steering wheel 4 is not operated, it automatically controls the steering angle to follow the driving route. The first mode and the second mode can be selected by the driver as appropriate by operating an operating part such as a switch (not shown) provided on the vehicle 2.

[0026] In the example shown in Figure 2, an automatic driving controller 15 is provided in the EPS-ECU 14 to control the output torque of the motor 10 for performing the automatic driving described above. The automatic driving controller 15 is equipped with a steering control unit 16 that calculates the torque for controlling the steering angle of the vehicle 2 without the driver operating the steering wheel 4. This steering control unit 16 is configured to sequentially calculate the steering torque for driving the vehicle 2 along a driving route, for example. Therefore, the automatic driving controller 15 shown in Figure 2 receives signals from sensors that identify surrounding information such as cameras and map information, as well as current location information. The steering control unit 16 is configured to calculate the amount of deviation between the current position of the vehicle 2, which is identified based on the camera and map information, and a pre-formed driving route, calculate a target steering angle θt to correct that amount of deviation, and calculate a target steering torque from the deviation Δθ between the target steering angle θt and the actual steering angle θr detected by the steering angle sensor 13.

[0027] The discrepancy between the driving route described above and the current position of vehicle 2 is caused by external factors affecting vehicle 2, such as wind force and road surface conditions, as well as internal factors such as the rotation of the steering wheel 4.

[0028] The steering control unit 16 includes a first steering control unit 16a that calculates the target steering torque when the first mode is selected, and a second steering control unit 16b that calculates the target steering torque when the second mode is selected. The feedback gain for calculating the target steering torque by multiplying it by the deviation Δθ between the target steering angle θt and the actual steering angle θr is set to be larger for the first steering control unit 16a than for the second steering control unit 16b. In other words, when the target steering torque is determined by the first steering control unit 16a, the vehicle 2 can be returned to the driving route more quickly than when the target steering torque is determined by the second steering control unit 16b.

[0029] Furthermore, the automatic driving controller 15 is further equipped with a steering reaction force control unit 17 for calculating a reaction torque that counteracts the steering torque when the steering wheel 4 is operated. This steering reaction force control unit 17 is configured to calculate the reaction torque by multiplying the torque value detected by the torque sensor 12 by a predetermined gain. This is because, during automatic driving, the driver may inadvertently steer the steering wheel 4 or operate the steering wheel 4 intentionally, and the steering wheel 4 operation feel and other settings are configured to respond to such situations.

[0030] The steering reaction force control unit 17 comprises a first steering reaction force control unit 17a that calculates the reaction force torque when the first mode is selected, and a second steering reaction force control unit 17b that calculates the reaction force torque when the second mode is selected. The gain for calculating the reaction force torque by multiplying it by the steering torque detected by the torque sensor 12 is set to be larger for the first steering reaction force control unit 17a than for the second steering reaction force control unit 17b. In other words, the gain of the first steering reaction force control unit 17a is set to be smaller than that of the second steering reaction force control unit 17b. Therefore, when the reaction force torque is determined by the first steering reaction force control unit 17a, the torque required to rotate the steering wheel 4 is greater than when the reaction force torque is determined by the second steering reaction force control unit 17b.

[0031] The automatic driving controller 15 shown in Figure 2 is configured to select control units 16a and 16b for determining the target steering torque according to the set control mode among the first and second modes, and similarly to select control units 17a and 17b for determining the reaction torque according to the set control mode. Furthermore, when the first mode is set, if the steering determination unit 23 (described later) receives a signal indicating that the steering wheel 4 has been operated, the system is configured to determine the target steering torque using the second steering control unit 16b and the reaction torque using the second steering reaction force control unit 17b. The automatic driving controller 15 is provided with a steering control switching unit 18 for switching the control unit for determining the target steering torque and a steering reaction force control switching unit 19 for switching the control unit for determining the reaction torque.

[0032] The automatic driving controller 15 is configured to add the target steering torque determined by the steering control unit 16 and the reaction torque determined by the steering reaction force control unit 17, and then output an electrical signal to the motor 10 to generate the added torque.

[0033] Furthermore, the EPS-ECU14 is equipped with a steering detection unit 20 for determining whether the driver has operated the steering wheel 4 during autonomous driving. This steering detection unit 20 includes a normal steering detection unit 21 that determines the intervention operation when the steering wheel 4 is operated at a relatively low speed, and a fast steering detection unit 22 that determines the intervention operation when the steering wheel 4 is operated at a relatively high speed.

[0034] The steering determination unit 21 is configured to determine whether or not a steering operation has occurred based on the steering torque detected by the torque sensor 12. Specifically, it calculates the deviation between the minimum and maximum values ​​of the steering torque detected by the torque sensor 12 within a predetermined time, and determines that a steering operation has occurred if the deviation exceeds a predetermined threshold torque. This is because, when the vehicle is running with the motor torque calculated by the automatic driving controller 15, when the driver operates the steering wheel 4, a torque acting on the steering wheel 4 in a direction opposite to or greater than the motor torque acts on the steering wheel 4, and this becomes a reaction torque that is detected by the torque sensor 12.

[0035] The normal steering determination unit 21 described above determines the driver's steering operation from the torque sensor 12's detection value over a predetermined period of time, and an unavoidable delay occurs before the determination is made. Therefore, the steering determination device 20 shown in Figure 2 is equipped with an early steering determination unit 22 to determine intervention operations early when the steering wheel 4 is operated at high speed.

[0036] The early steering determination unit 22 receives signals of the actual steering angle θr, which is the value detected by the steering angle sensor 13, and the target steering angle θt, which is calculated by the automatic driving controller 15. It is configured to determine whether the driver has performed a steering operation based on the actual steering angle θr and the target steering angle θt. For example, as shown in Figure 3, the deviation Δθ is obtained by subtracting the target steering angle θt from the actual steering angle θr. It is then determined whether this deviation Δθ is greater than or equal to a predetermined difference Δθ1, or less than or equal to a predetermined difference Δθ2. If either of these determinations is positive, it is determined that the driver has performed a steering operation. In other words, it is determined that the driver has performed a steering operation if the absolute value of the deviation between the target steering angle θt and the actual steering angle θr is greater than or equal to a predetermined difference. As mentioned above, the angle at which the steering wheel 4 is steered to the left is considered "positive," so the deviation Δθ can take either a positive or negative value. Therefore, in the above determination, the predetermined difference Δθ1 is set to a positive value, and the predetermined difference Δθ2 is set to a negative value.

[0037] Then, the signals determined by the normal steering determination unit 21 and the rapid steering determination unit 22 are input to the steering determination unit 23, which inputs a signal to the steering control switching unit 18 and the steering reaction force control switching unit 19 indicating whether or not the driver has performed a steering operation, as determined by at least one of the determination units 21 and 22. Accordingly, the steering control switching unit 18 and the steering reaction force control switching unit 19 are controlled based on these input signals to determine the motor torque.

[0038] Figure 4 is a flowchart illustrating an example of the control performed by the EPS-ECU14 described above. In the example shown in Figure 4, first, it is determined whether or not the vehicle is in autonomous driving mode (step S1). Since the intervention operation determination device in this embodiment of the invention determines whether or not the driver has performed an intervention operation while the vehicle is in autonomous driving mode, if it is determined negatively in step S1 because the vehicle is not in autonomous driving mode, this routine is terminated.

[0039] Conversely, if it is determined positively in step S1 that the vehicle is in autonomous driving mode, the first steering control unit 16a or the second steering control unit 16b calculates the target steering torque based on the selected control mode (step S2), and the first steering reaction force control unit 17a or the second steering reaction force control unit 17b calculates the reaction force torque (step S3).

[0040] Next, the system reads signals to determine whether or not the driver has performed an intervention. Specifically, it first reads a signal regarding the presence or absence of an intervention from the normal steering determination unit 21 (step S4), and then reads a signal regarding the presence or absence of an intervention from the early steering determination unit 22 (step S5).

[0041] Then, it is determined whether or not an intervention operation occurred (step S6). That is, it is determined whether or not a signal indicating that an intervention operation occurred was input to the steering determination unit 23 from at least one of the normal steering determination unit 21 and the early steering determination unit 22.

[0042] If an intervention operation is positively judged in step S6, the torque obtained by adding the steering torque determined by the second steering control unit 16b and the reaction torque determined by the second steering reaction force control unit 17b is output as a command signal to the motor 10 (step S7). In other words, when the first mode is set, if the driver operates the steering wheel 4 to avoid an obstacle in an emergency, the steering torque determined by the first steering control unit 16a is switched to the steering torque determined by the second steering control unit 16b, and the reaction torque determined by the first steering reaction force control unit 17a is switched to the reaction torque determined by the second steering reaction force control unit 17b. In other words, when the first mode is set, if an intervention operation occurs, the control mode is switched to the second mode.

[0043] Furthermore, while the driver is operating the steering wheel 4 and driving, unnecessary controls are deactivated (step S8). Specifically, emergency brake control, control to maintain a distance of more than a predetermined distance from adjacent vehicles, and control to automatically change driving lanes are deactivated. In addition, the hands-on display is switched on to inform or prompt the driver that the vehicle will be driven in response to the driver's operation of the steering wheel 4. Moreover, when the EPS-ECU14 is driving autonomously without the driver operating the steering wheel 4, it is configured to determine malfunctions based on the deviation between the instructed value and the measured value, and to improve controllability. In other words, the EPS-ECU14 is configured to perform learning control based on the deviation between the instructed value and the measured value. Therefore, when the driver operates the steering wheel 4, the steering angle is changed by the driver's operation, so the steering angle is excluded from the malfunction determination conditions.

[0044] On the other hand, if a negative judgment is made in step S5 due to the absence of intervention, the routine is terminated by outputting a command signal to the motor 10 (step S9) that adds up the steering torque determined by the first steering control unit 16a or the second steering control unit 16b based on the set control mode and the reaction torque determined by the first steering reaction force control unit 17a or the second steering reaction force control unit 17b. Specifically, if the first mode is selected, the command signal to the motor 10 is output as the sum of the motor torque calculated by the first steering control unit 16a and the reaction torque calculated by the first steering reaction force control unit 17a. If the second mode is selected, the command signal to the motor 10 is output as the sum of the motor torque calculated by the second steering control unit 16b and the reaction torque calculated by the second steering reaction force control unit 17b.

[0045] Figure 5 shows a time chart illustrating the timing of intervention decisions by the normal steering determination unit 21 and the early steering determination unit 22 when the driver turns the steering wheel 4 counterclockwise while the driver is driving straight without operating the steering wheel 4. In the example shown in Figure 5, at time t0, the actual steering angle θr (actual) and the target steering angle θt (dashed line) are both at the reference value of "0". At time t1, the driver has started operating the steering wheel 4, and consequently, the actual steering angle θr and the deviation Δθ (solid line) begin to increase. As a result, at time t2, the deviation Δθ becomes greater than or equal to a predetermined difference Δθ1 (determination threshold), and the early steering determination unit 22 determines that an intervention has occurred.

[0046] Therefore, at time t2, the steering torque is determined by the second steering control unit 16b, and the reaction torque is determined by the second steering reaction force control unit 17b. As described above, the gain multiplied by the deviation between the target steering angle θt and the actual steering angle θr in the second steering control unit 16b is set to be smaller than that of the first steering control unit 16a, and similarly, the gain multiplied by the steering torque in the second steering reaction force control unit 17b is set to be smaller than that of the second steering reaction force control unit 17a. As a result, at time t2, the torque required by the driver to rotate the steering wheel 4 is smaller than when the steering torque and reaction torque are determined by the first steering control unit 16a and the first steering reaction force control unit 17a. As a result, the load on the driver when operating the steering wheel 4 is reduced, which improves the operating feel, such as allowing the driver to fine-tune the rotation angle of the steering wheel 4.

[0047] In contrast, at time t2, the target steering angle θt has not changed from time t0 because the deviation between the predetermined driving route and the actual position of vehicle 2 is small. Therefore, the steering torque determined by the first steering control unit 16a is maintained at a small value. As a result, the normal steering determination unit 21 does not determine an intervention operation. Therefore, if the early steering determination unit 22 is not provided, the steering torque and reaction torque are determined by the first steering control unit 16a and the first steering reaction force control unit 17a even after time t2. Then, at time t3, as the position of vehicle 2 deviates from the driving route, the target steering angle θt is output in the negative direction (right turn direction), and the steering torque (dashed line) begins to increase accordingly. In this case, the steering torque is in the opposite direction to the direction in which the driver rotates the steering wheel 4, so the torque value detected by the torque sensor 12 begins to increase. Furthermore, the direction of operation of the steering wheel 4, which is operated by the driver, and the direction of the steering torque output from the motor 10 to follow the target steering angle θt are opposite, and the steering torque increases as the deviation Δθ of the steering angle increases. Therefore, from time t3 onwards, the torque required by the driver to rotate the steering wheel 4 increases.

[0048] As described above, the steering torque increases, allowing the normal steering determination unit 21 to determine an intervention operation at time t4. Therefore, the second steering control unit 16b determines the steering torque, and the second steering reaction force control unit 17b determines the reaction force torque. For convenience, Figure 5 shows the steering angle deviation Δθ and the magnitude of the steering torque in the same column, and the scale is adjusted so that the predetermined difference Δθ1 that the early steering determination unit 22 determines as an intervention operation and the threshold that the normal steering determination unit 21 determines as an intervention operation are in the same position in Figure 5.

[0049] As shown in Figure 5, during autonomous driving, if the steering wheel 4 is operated so that the deviation Δθ between the target steering angle θt and the actual steering angle θr exceeds a predetermined difference Δθ1 before the position of the vehicle 2 deviates to an extent that corrects the discrepancy between the driving route and the position of the vehicle 2, the early steering determination unit 22 can determine an intervention operation earlier than the normal steering determination unit 21. As a result, it is possible to suppress the application of a large motor torque in opposition to the steering torque of the driver's steering wheel 4, thereby improving the driver's operating feel of the steering wheel 4 and suppressing discomfort for the driver.

[0050] As described above, if intervention is determined solely by the deviation Δθ between the actual steering angle θr and the target steering angle θt, then when the target steering angle θt changes rapidly, such as to avoid an obstacle during autonomous driving, as shown in Figure 6, the deviation Δθ may exceed a predetermined difference Δθ1 or fall below a predetermined difference Δθ2. Furthermore, as shown in Figure 7, when the steering angle changes due to autonomous driving control, if the steering wheel 4 is held in a manner that minimizes the amount of change in the steering angle, the deviation Δθ may exceed a predetermined difference Δθ1 or fall below a predetermined difference Δθ2.

[0051] On the other hand, the intervention operation determination device in this embodiment of the invention determines an intervention operation in a situation where the steering torque of the steering wheel 4 by the driver becomes large. Therefore, it is preferable to suppress the misidentification of sudden changes in the target steering angle or holding the steering wheel 4 as an intervention operation during autonomous driving as described above. In other words, it is configured to determine an intervention operation when the direction of the target steering angle relative to the actual steering angle (reference steering angle θb) from a predetermined time ago and the direction of the current actual steering angle relative to the reference steering angle are in opposite directions.

[0052] Therefore, in order to prevent the system from mistakenly determining that an intervention operation has occurred when the steering wheel 4 is not being operated or is being held, the early steering determination unit 22 may be configured, as shown in Figure 8, to determine that an intervention operation has occurred when the deviation Δθ is greater than or equal to a predetermined difference Δθ1 and the value obtained by subtracting the reference steering angle θb from the actual steering angle θr is positive and the value obtained by subtracting the reference steering angle θb from the target steering angle θt is negative, or when the deviation Δθ is less than or equal to a predetermined difference Δθ2 and the value obtained by subtracting the reference steering angle θb from the actual steering angle θr is negative and the value obtained by subtracting the reference steering angle θb from the target steering angle θt is positive. By determining an intervention operation based on the direction between the target steering angle and the actual steering angle in this way, it is possible to determine that an intervention operation has occurred only when the driver intentionally rotates the steering wheel 4, thereby preventing the above-mentioned misdetermined results from occurring.

[0053] Furthermore, the early steering determination unit 22 may determine that an intervention operation has occurred when the rate of change (or speed of change) R of the deviation Δθ is greater than or equal to a predetermined rate of change R1, or less than or equal to a predetermined rate of change R2, as shown in Figure 9. Figure 10 shows the speed of change (steering speed) of the actual steering angle θr and the speed of change of the deviation Δθ when the steering wheel 4 is operated, similar to Figure 5. By determining an intervention operation based on the rate of change R of the deviation Δθ (dashed line), an intervention operation can be determined as soon as the steering wheel 4 is started to be operated, as shown in Figure 10. As a result, an intervention operation can be determined even earlier than when an intervention operation is determined when the deviation Δθ is greater than or equal to a predetermined difference Δθ1, or less than or equal to a predetermined difference Δθ2.

[0054] The rate of change R of the above-mentioned deviation Δθ may be obtained by differentiating the deviation Δθ with respect to time, or by dividing the difference between the deviation Δθ obtained in the previous control routine (previous value) and the deviation Δθ obtained in the current control routine (current value) by the control cycle time. In other words, since the control cycle is constant, instead of the rate of change of the deviation Δθ, the presence or absence of an intervention operation may be determined based on the difference in deviation Δθ for each control routine. Similarly, the rate of change in the following explanation is not limited to the value obtained by differentiating with respect to time.

[0055] Even when determining intervention operations based on the rate of change R of the deviation Δθ as described above, there is a possibility of incorrectly determining that an intervention operation has occurred when the steering wheel 4 is not being operated or is being held, similar to the above. Therefore, in the intervention operation determination device in this embodiment of the invention, as shown in Figure 11, it may be determined that a driver intervention operation has occurred when the rate of change R of the deviation Δθ is greater than or equal to a predetermined rate of change R1 and the rate of change Rθ of the steering angle θ is greater than or equal to a predetermined rate of change Rθ1, or when the rate of change R of the deviation Δθ is less than or equal to a predetermined rate of change R2 and the rate of change Rθ of the steering angle θ is less than or equal to a predetermined rate of change Rθ2. Note that the predetermined rate of change Rθ1 may be set to a positive value and the predetermined rate of change Rθ2 may be set to a negative value.

[0056] By determining whether or not an intervention operation is performed based on the rate of change Rθ of the steering angle θ, in addition to the rate of change Rθ of the deviation Δθ, it is possible to determine the intervention operation early and to suppress the occurrence of a false judgment that an intervention operation has been performed when the driver has not performed an operation to rotate the steering wheel 4.

[0057] Furthermore, the intervention operation determination device in this embodiment of the invention is not limited to determining an intervention operation based on the steering angle, but may also determine it based on the position of the vehicle 2. Figure 12 is a functional block diagram illustrating an example of determining an intervention operation based on the position of the vehicle 2. In the example shown in Figure 12, first, the difference (lateral deviation) D between the target lateral position on the driving route determined by the automatic driving control and the current lateral position (actual lateral position) of the vehicle 2 obtained from cameras, map information, etc. is calculated. Then, if the lateral deviation D is greater than or equal to a predetermined difference D1, or less than or equal to a predetermined difference D2, that is, if the absolute value of the lateral deviation D is greater than or equal to a predetermined difference, it is determined that an intervention operation has occurred. Here, a positive value is assumed to be to the left on the map information.

[0058] Furthermore, similar to the method for determining intervention operations according to the steering angle described above, the system is configured to suppress false determinations that an intervention operation has occurred when the steering wheel 4 is not being operated or is being held. In other words, the system may be configured to determine that an intervention operation has occurred when the absolute value of the lateral deviation D is greater than or equal to a predetermined difference, and the direction of the target yaw angle Yt relative to the actual yaw angle (reference yaw angle Yb) from a predetermined time ago is in the opposite direction to the direction of the current actual yaw angle (actual yaw angle) Yr relative to the reference yaw angle Yb. Specifically, as shown in Figure 13, the system may be configured to determine that an intervention operation has occurred when the lateral deviation D is greater than or equal to a predetermined difference D1, and the value obtained by subtracting the reference yaw angle Yb from the actual yaw angle Yr is positive and the value obtained by subtracting the reference yaw angle Yb from the target yaw angle Yt is negative, or when the lateral deviation D is less than or equal to a predetermined deviation D2, and the value obtained by subtracting the reference yaw angle Yb from the actual yaw angle Yr is negative and the value obtained by subtracting the reference yaw angle Yb from the target yaw angle Yt is positive.

[0059] Furthermore, as shown in Figure 14, the system may be configured to determine that an intervention operation has occurred if the rate of change RD of the lateral deviation D is greater than or equal to a predetermined rate of change RD1 and the rate of change RYr of the actual yaw angle Yr is greater than or equal to a predetermined rate of change RYr1, or if the rate of change RD of the lateral deviation D is less than or equal to a predetermined rate of change RD2 and the rate of change RYr of the actual yaw angle Yr is less than or equal to a predetermined rate of change RYr2.

[0060] As described above, by determining the presence or absence of an intervention operation based on the lateral position of the vehicle 2, it is possible to determine the intervention operation early when the steering wheel 4 is operated at a relatively high speed. Furthermore, by determining the intervention operation based on the actual yaw angle Yr in addition to the lateral deviation D, it is possible to suppress the occurrence of a false determination that an intervention operation has occurred when the driver has not performed an operation to rotate the steering wheel 4. Moreover, by determining the presence or absence of an intervention operation based on the rate of change RD of the lateral deviation D, it is possible to determine the intervention operation immediately after the steering wheel 4 is operated, enabling even earlier detection of the intervention operation.

[0061] Furthermore, the steering system described above is not limited to the configuration shown in Figure 1; it may also be a so-called steer-by-wire system in which the steering wheel 4 and the steering wheels 3 are not mechanically connected. In addition, in the example described above, the vehicle 2 can be configured to have a first mode in which the driver does not operate the steering wheel 4 during automatic driving, and a second mode in which the driver can operate the steering wheel 4 as appropriate during automatic driving. The system is configured to switch to the second mode when an intervention operation is performed during driving in the first mode, but it may also be configured to switch between automatic driving and manual driving.

[0062] Furthermore, in this invention, the steering mechanism may be a control stick (or joystick) instead of the steering wheel described above. In that case, since the control stick is tilted left and right without rotating, the actual steering angle in the above embodiment can be treated as the actual tilt angle. Therefore, the steering angle in this invention includes the angle of tilt. Furthermore, in the above embodiment, the steering angle to the left was described as a "positive" angle and the steering angle to the right as a "negative" angle, but these "positive" and "negative" may be the opposite of those in the above embodiment, and absolute values ​​may be used without distinguishing between "positive" and "negative". [Explanation of Symbols]

[0063] 1. Electric Power Steering System (EPS) 2 vehicles 3 Steering Wheel 4 Steering Wheel 5. Steering shaft 6. Steering Linkage 7 racks 8 pinion 9 Tie rods 10 motors 11 Reducer 12 Torque Sensor 13. Steering angle sensor 14 Electronic control unit (EPS-ECU) 15. Automatic Driving Controller 16, 16a, 16b Steering control unit 17, 17a, 17b Steering reaction force control unit 18 Steering control switching unit 19. Steering reaction force control switching unit 20 Steering Detector 21 Normal steering determination unit 22 Quick steering determination section 23 Steering Determination Unit

Claims

1. An intervention operation determination device comprising a steering unit operated by a driver, steering wheels that steer in conjunction with the operation of the steering unit, an actuator that generates steering force to steer the steering wheels, and a detection unit that detects the amount of operation of the steering unit, wherein the device determines whether the driver has operated the steering unit during automatic driving in which the vehicle is driven by controlling the actuator without the driver operating the steering unit, The system includes a controller that controls the actuator, The aforementioned controller, If the absolute value of the deviation between the target steering angle during the automated driving and the actual steering angle based on the amount of operation detected by the detection unit is greater than or equal to a predetermined difference, and the direction of the target steering angle relative to a predetermined reference steering angle is opposite to the direction of the actual steering angle relative to the reference steering angle, then it is determined that the driver has performed an intervention operation by operating the steering unit. An intervention operation determination device characterized by the following:

2. An intervention operation determination device comprising a steering unit operated by a driver, steering wheels that steer in conjunction with the operation of the steering unit, and actuators that generate steering force to steer the steering wheels, wherein the device determines whether the driver has operated the steering unit during automatic driving in which the vehicle is driven by controlling the actuators without the driver operating the steering unit, The system includes a controller that controls the actuator, The aforementioned controller, If the absolute value of the deviation between the target lateral position and the actual lateral position in the aforementioned automated driving is greater than or equal to a predetermined difference, and the direction of the yaw angle based on the target lateral position relative to a predetermined reference yaw angle is opposite to the direction of the actual yaw angle relative to the reference yaw angle, then it is determined that an intervention operation by operating the steering unit has occurred. An intervention operation determination device characterized by the following:

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