Parking assistance device

Abstract

This parking assistance device includes: a target trajectory generation unit that generates a target trajectory to a target parking position in a target parking frame; and an automatic steering angle command value calculation unit that calculates an automatic steering angle command value for causing a host vehicle to travel automatically along the target trajectory generated by the target trajectory generation unit and move to the target parking position in the target parking frame. The target trajectory generation unit has a function of, when a steering intervention is performed during automatic traveling, performing first target trajectory update processing in which another parking frame different from a current target parking frame is set as a new parking frame candidate on the basis of information relating to the steering intervention and peripheral information of the host vehicle, a travel trajectory into the new parking frame candidate is generated, and the target trajectory is updated from the current target trajectory to the travel trajectory into the new parking frame candidate.

Description

Parking assist system

[0001] This disclosure relates to a parking assistance device.

[0002] Patent Document 1 discloses a system in which the driver selects one parking position from a plurality of parking position candidates displayed on a touch panel to determine the target parking position. It also discloses a system in which the drivable area is reset based on driver steering intervention information and driving history information.

[0003] Japanese Patent Publication No. 2020-62940, International Publication No. 2023 / 286169

[0004] The purpose of this disclosure is to provide a parking assistance device that, in parking assistance mode, can change the target parking space from the current target parking space to another parking space based on information regarding steering intervention, etc.

[0005] One embodiment of the present disclosure provides a parking assistance device that includes a target trajectory generation unit that generates a target trajectory to a target parking position within a target parking space, and an automatic steering angle command value calculation unit that calculates an automatic steering angle command value for the vehicle to automatically travel along the target trajectory generated by the target trajectory generation unit to move to the target parking position within the target parking space, wherein the target trajectory generation unit has a function to perform a first target trajectory update process that, when steering intervention is performed during the automatic driving, sets a parking space other than the current target parking space as a new parking space candidate according to information about the steering intervention and information about the vehicle's surroundings, generates a driving trajectory to the new parking space candidate, and updates the target trajectory from the current target trajectory to a driving trajectory to the new parking space candidate.

[0006] In this configuration, when in parking assist mode, the target parking space can be changed from the current target parking space to another parking space based on information regarding steering intervention, etc.

[0007] The above-mentioned or further other purposes, features, and effects of this disclosure will be made apparent by the following description of embodiments with reference to the accompanying drawings.

[0008] Figure 1 is a schematic diagram showing the general configuration of an electric power steering system to which a parking assist device according to one embodiment of the present disclosure is applied. Figure 2 is a block diagram illustrating the electrical configuration of the motor control ECU. Figure 3 is a block diagram showing a part of the configuration of the higher-level ECU. Figure 4 is a flowchart showing an example of the operation of the target trajectory generation unit. Figure 5 is a schematic diagram illustrating examples of new parking space candidates in the first target trajectory update process and new parking position candidates in the second target trajectory update process. Figure 6 is a flowchart showing another example of the operation of the target trajectory generation unit. Figure 7 is a flowchart showing yet another example of the operation of the target trajectory generation unit. Figure 8 is a flowchart showing yet another example of the operation of the target trajectory generation unit.

[0009] [Description of Embodiments of the Present Disclosure] One embodiment of the present disclosure provides a parking assistance device that includes a target trajectory generation unit that generates a target trajectory to a target parking position within a target parking space, and an automatic steering angle command value calculation unit that calculates an automatic steering angle command value for the vehicle to automatically travel along the target trajectory generated by the target trajectory generation unit to the target parking position within the target parking space, wherein the target trajectory generation unit has a function to perform a first target trajectory update processing that, when steering intervention is performed during the automatic driving, sets a parking space other than the current target parking space as a new parking space candidate according to information about the steering intervention and information about the vehicle's surroundings, generates a driving trajectory to the new parking space candidate, and updates the target trajectory from the current target trajectory to a driving trajectory to the new parking space candidate.

[0010] In this configuration, when in parking assist mode, the target parking space can be changed from the current target parking space to another parking space based on information regarding steering intervention, etc.

[0011] In one embodiment of the present disclosure, when steering intervention is performed during automatic driving, the second target trajectory update process is defined as the process of setting a new parking position candidate other than the current target parking position within the current target parking space according to information related to the steering intervention and information about the vehicle's surroundings, generating a driving trajectory to the new parking position candidate, and updating the target trajectory to the driving trajectory from the current target parking position to the new parking position candidate. When steering intervention is performed during automatic driving, the target trajectory generation unit determines whether to perform a target trajectory update using the first target trajectory update process, perform a target trajectory update using the second target trajectory update process, or maintain the current target trajectory, based on whether a driving trajectory into the new parking space candidate can be generated and whether a driving trajectory to the new parking position candidate can be generated.

[0012] In one embodiment of the present disclosure, if it is not possible to generate a driving trajectory within the candidate new parking space, but it is possible to generate a driving trajectory to the candidate new parking position, the target trajectory generation unit performs a target trajectory update by the second target trajectory update process.

[0013] In one embodiment of the present disclosure, if a driving trajectory into the candidate new parking space can be generated and a driving trajectory to the candidate new parking position can be generated, the target trajectory generation unit determines, based on the information regarding the steering intervention, whether to perform a target trajectory update by the first target trajectory update process or a target trajectory update by the second target trajectory update process.

[0014] In one embodiment of the present disclosure, when steering intervention occurs during automatic driving, the second target trajectory update process is defined as the process of setting a new parking position candidate other than the current target parking position within the current target parking space according to information related to the steering intervention and information about the vehicle's surroundings, generating a driving trajectory to the new parking position candidate, and updating the target trajectory to the driving trajectory from the current target parking position to the new parking position candidate. The target trajectory generation unit then determines whether to perform the first target trajectory update process or the second target trajectory update process based on the distance between the new parking space candidate and the vehicle when steering intervention occurs during automatic driving.

[0015] In one embodiment of the present disclosure, when steering intervention is performed during the automated driving, if the distance between the new parking space candidate and the vehicle is greater than or equal to a predetermined distance, the target trajectory generation unit executes the first target trajectory update process, and if the distance between the new parking space candidate and the vehicle is less than the predetermined distance, the target trajectory generation unit executes the second target trajectory update process.

[0016] In one embodiment of the present disclosure, when steering intervention is performed during the automated driving, if the distance between the new parking space candidate and the vehicle is greater than or equal to a predetermined first distance, the target trajectory generation unit executes the first target trajectory update process; if the distance between the new parking space candidate and the vehicle is less than a predetermined second distance which is shorter than the first distance, the target trajectory generation unit executes the second target trajectory update process; and if the distance between the new parking space candidate and the vehicle is greater than or equal to the second distance and less than the first distance, the target trajectory generation unit determines, based on information regarding the steering intervention, whether to execute the first target trajectory update process or the second target trajectory update process.

[0017] [Detailed Description of Embodiments of the Disclosure] Embodiments of the Disclosure will be described in detail below with reference to the accompanying drawings.

[0018] Figure 1 is a schematic diagram showing the general configuration of an electric power steering system to which a parking assist device according to one embodiment of the present disclosure is applied.

[0019] The electric power steering system 1 comprises a steering wheel (handle) 2 as a steering member for steering the vehicle, a steering mechanism 4 that steers the steering wheels 3 in conjunction with the rotation of the steering wheel 2, and a steering assist mechanism 5 for assisting the driver's steering. The steering wheel 2 and the steering mechanism 4 are mechanically connected via a steering shaft 6 and an intermediate shaft 7.

[0020] The steering shaft 6 includes an input shaft 8 connected to the steering wheel 2 and an output shaft 9 connected to the intermediate shaft 7. The input shaft 8 and the output shaft 9 are connected via a torsion bar 10 so as to be rotatable relative to each other.

[0021] A torque sensor 12 is positioned near the torsion bar 10. The torque sensor 12 measures the torsion bar torque (steering torque) T applied to the steering wheel 2 based on the relative rotational displacement of the input shaft 8 and the output shaft 9. ｔｂ The torsion bar torque T detected by the torque sensor 12 is detected. In this embodiment, the torsion bar torque T is detected by the torque sensor 12. ｔｂ For example, the torque for steering to the left is detected as a positive value, and the torque for steering to the right is detected as a negative value, and the larger the absolute value, the greater the torsion bar torque T. ｔｂ Assume that the size of will increase.

[0022] The steering mechanism 4 consists of a rack and pinion mechanism including a pinion shaft 13 and a rack shaft 14 as the steering axis. Steering wheels 3 are connected to each end of the rack shaft 14 via tie rods 15 and knuckle arms (not shown). The pinion shaft 13 is connected to the intermediate shaft 7. The pinion shaft 13 rotates in conjunction with the steering of the steering wheel 2. A pinion 16 is connected to the tip of the pinion shaft 13.

[0023] The rack shaft 14 extends linearly along the left-right direction of the vehicle. A rack 17 that meshes with the pinion 16 is formed in the axial middle portion of the rack shaft 14. The rotation of the pinion shaft 13 is converted into axial movement of the rack shaft 14 by the pinion 16 and the rack 17. By moving the rack shaft 14 in the axial direction, the steering wheels 3 can be steered.

[0024] When the steering wheel 2 is steered (rotated), this rotation is transmitted to the pinion shaft 13 via the steering shaft 6 and the intermediate shaft 7. The rotation of the pinion shaft 13 is then converted into axial movement of the rack shaft 14 by the pinion 16 and the rack 17. This causes the steering wheel 3 to turn.

[0025] The steering assist mechanism 5 includes an electric motor 18 for generating a steering assist force (assist torque) and a speed reducer 19 for amplifying the output torque of the electric motor 18 and transmitting it to the steering mechanism 4. The speed reducer 19 consists of a worm gear mechanism including a worm gear 20 and a worm wheel 21 meshing with the worm gear 20. The speed reducer 19 is housed in a gear housing 22 as a transmission mechanism housing.

[0026] In the following, the reduction ratio (gear ratio) of the speed reducer 19 is represented by N. The reduction ratio N is the ratio of the worm gear angle θ ｗｗ which is the rotation angle of the worm gear 20 to the worm wheel angle θ ｗｇ which is the rotation angle of the worm wheel 21 (θ ｗｇ / θ ｗｗ ).

[0027] The worm gear 20 is rotationally driven by the electric motor 18. Also, the worm wheel 21 is connected to the output shaft 9 so as to be integrally rotatable.

[0028] When the worm gear 20 is rotationally driven by the electric motor 18, the worm wheel 21 is rotationally driven, motor torque is applied to the steering shaft 6, and the steering shaft 6 (output shaft 9) rotates. Then, the rotation of the steering shaft 6 is transmitted to the pinion shaft 13 via the intermediate shaft 7. The rotation of the pinion shaft 13 is converted into the axial movement of the rack shaft 14. Thereby, the steering wheel 3 is steered. That is, by rotationally driving the worm gear 20 by the electric motor 18, steering assist by the electric motor 18 and steering of the steering wheel 3 become possible. A rotation angle sensor 23 for detecting the rotation angle of the rotor of the electric motor 18 is provided in the electric motor 18.

[0029] As the torque applied to the output shaft 9 (an example of the drive target of the electric motor 18), there are the motor torque by the electric motor 18 and the disturbance torque T ｌｃ other than the motor torque. The disturbance torque T ｌｃ other than the motor torque includes the torsion bar torque T ｔｂ , the road surface reaction torque (road surface load torque) T ｒｌ , the friction torque Tｆ This includes, etc.

[0030] Torsion bar torque T ｔｂ This is the torque applied from the steering wheel 2 to the output shaft 9 by the force applied to the steering wheel 2 by the driver, the force generated by the steering wheel inertia, etc.

[0031] Road surface reaction torque T ｒｌ This is the torque applied to the output shaft 9 via the rack shaft 14 from the steering wheel 3 side, due to the self-aligning torque generated in the tires, the force generated by the suspension and tire-wheel alignment, the frictional force of the rack and pinion mechanism, etc.

[0032] The vehicle is equipped with a CCD (Charge Coupled Device) camera 25 for photographing the road ahead in the direction of travel, a GPS (Global Positioning System) 26 for detecting the vehicle's position, a radar 27 for detecting road shape and obstacles, and a sonar 28 for detecting obstacles. The vehicle is also equipped with two mode switches 31 and 32 for manually switching between driving modes (steering modes).

[0033] The CCD camera 25, GPS 26, radar 27, and sonar 28 are connected to a higher-level ECU (Electronic Control Unit) 201 for performing driver assistance control and autonomous driving control. The higher-level ECU 201 receives information from, for example, the CCD camera 25, GPS 26, radar 27, and sonar 28, and information from the motor control ECU 202 (for example, the manual steering angle command value θ, which will be described later). ＭＤ Based on these factors, the system performs ambient environment recognition, vehicle position estimation, and route planning to determine control target values ​​for steering and drive actuators.

[0034] In this embodiment, the higher-level ECU 201 sets the automatic steering angle command value θ for automatic steering. ＡＤ Set the following. In this embodiment, automatic steering control is, for example, control to drive the vehicle along a target trajectory. Automatic steering angle command value θ ＡＤThis is the target value for the steering angle required to automatically drive the vehicle along a target trajectory.

[0035] In this embodiment, the automatic steering angle command value θ ＡＤ This is expressed as the amount of rotation (rotation angle) from the neutral position of the output shaft 9, with a positive value representing rotation in the left steering direction from the neutral position, and a negative value representing rotation in the right steering direction from the neutral position.

[0036] In this embodiment, the driver assistance control (automatic steering control) is a parking assistance control (automatic parking control) that assists in steering the vehicle so that it moves from its current position to the target parking position.

[0037] Furthermore, the higher-level ECU 201, based on the operation of the first mode switch 31 and the second mode switch 32, etc., provides a driving mode signal S indicating whether the driving mode is manual driving mode or parking assist mode. ｍｏｄｅ Outputs.

[0038] In principle, when the first mode switch 31 is turned on by the driver, the higher-level ECU 201 sends an operating mode signal S indicating that the operating mode is manual operating mode. ｍｏｄｅ It outputs the following. On the other hand, when the second mode switch 32 is turned on by the driver, the higher-level ECU 201 outputs a driving mode signal S indicating that the driving mode is parking assist mode. ｍｏｄｅ Outputs.

[0039] Auto steering angle command value θ ＡＤ and operating mode signal S ｍｏｄｅ This is provided to the motor control ECU 202 via the in-vehicle network. Torsion bar torque T detected by torque sensor 12 ｔｂ The output signal from the rotation angle sensor 23 is input to the motor control ECU 202. The motor control ECU 202 controls the electric motor 18 based on these input signals and information provided by the higher-level ECU 201.

[0040] Figure 2 is a block diagram illustrating the electrical configuration of the motor control ECU 202.

[0041] The motor control ECU 202 includes a microcomputer 50, a drive circuit (inverter circuit) 41 controlled by the microcomputer 50 that supplies power to the electric motor 18, and the current (hereinafter referred to as "motor current I") that flows through the electric motor 18. ｍ It is equipped with a current detection circuit 42 for detecting the following:

[0042] The microcomputer 50 is equipped with a CPU and memory (ROM, RAM, non-volatile memory, etc.) and functions as multiple function processing units by executing a predetermined program. The multiple function processing units include a reduction ratio multiplication unit 51, a rotation angle calculation unit 52, a reduction ratio division unit 53, an assist torque command value setting unit 54, a manual steering angle command value calculation unit 55, an integrated angle command value calculation unit 56, an angle control unit 57, a first switch 58, a second switch 59, an addition unit 60, and a torque control unit (current control unit) 61.

[0043] The reduction ratio multiplication unit 51 multiplies the motor torque command value T output from the addition unit 60. ｍ，ｃｍｄ By multiplying this by the reduction ratio N, the motor torque command value T is obtained. ｍ，ｃｍｄ Output shaft torque command value T ｐ，ｃｍｄ Convert to.

[0044] The rotation angle calculation unit 52 calculates the rotor rotation angle θ of the electric motor 18 based on the output signal of the rotation angle sensor 23. ｍ The reduction ratio division unit 53 calculates the rotor rotation angle θ. ｍ By dividing by the reduction ratio N, the rotor rotation angle θ is obtained. ｍ The rotation angle (actual steering angle) of the output shaft 9 is θ ｐ Convert to the actual steering angle θ. In this embodiment, the actual steering angle θ ｐ This is expressed as the amount of rotation (rotation angle) from the neutral position of the output shaft 9, with a positive value representing rotation in the left steering direction from the neutral position, and a negative value representing rotation in the right steering direction from the neutral position.

[0045] The assist torque command value setting unit 54 sets the assist torque command value T, which is the target value of the assist torque required for manual operation. ａｓ The torsion bar torque T is set. The assist torque command value setting unit 54 sets the torsion bar torque T ｔｂBased on this, the assist torque command value T ａｓ Set it.

[0046] As the assist torque command value setting unit 54, for example, the assist torque command value setting unit (51) shown in Figure 2 of International Publication No. 2023 / 286169 (Patent Document 2) can be used. In that case, the torsion bar torque T ｔｂ Assist torque command value T ａｓ As an example of the settings, the example shown in Figure 3 of International Publication No. 2023 / 286169 can be used. The assist torque command value setting unit 54 is set to the torsion bar torque T ｔｂ And the assist torque command value T takes into account the vehicle speed. ａｓ The setting may also be configured. In addition, the assist torque command value setting unit 54 sets the torsion bar torque T ｔｂ By multiplying by a preset constant, the assist torque command value T is obtained. ａｓ You may perform the calculation.

[0047] The manual steering angle command value calculation unit 55 calculates the steering angle (more precisely, the rotation angle θ of the output shaft 9) corresponding to the steering wheel operation when the driver operates the steering wheel 2 in parking assist mode. ｐ ) to the manual steering angle command value θ ＭＤ It is provided for setting as follows. The manual steering angle command value calculation unit 55 calculates the torsion bar torque T detected by the torque sensor 12. ｔｂ The assist torque command value T set by the assist torque command value setting unit 54. ａｓ And, the virtual load spring stiffness coefficient k ｍｄ And the virtual load viscous damping coefficient c ｍｄ The manual steering angle command value θ is used with ＭＤ Generates the virtual load spring stiffness coefficient k. ｍｄ and virtual load viscous damping coefficient c ｍｄ This is pre-configured.

[0048] As the manual steering angle command value calculation unit 55, for example, the manual steering command value generation unit (52) shown in Figure 2 of International Publication No. 2023 / 286169 (Patent Document 2) can be used. In that case, the manual steering angle command value calculation unit 55 calculates the manual steering angle command value θ by solving the differential equation (1) below. ＭＤ Perform the calculation.

[0049] J ｐ d ２ θ ＭＤ / dt ２ = T ｔｂ +T ａｓ -k ｍｄ θ ＭＤ -c ｍ (dθ ＭＤ / dt) ... (1) In equation (1), J ｐ For example, the inertia of the lower column, including the output shaft 9 and the worm wheel 21, can be used.

[0050] The manual steering angle command value θ calculated by the manual steering angle command value calculation unit 55 ＭＤ This value is provided to the integrated angle command value calculation unit 56, and also to the higher-level ECU 201 via the in-vehicle network.

[0051] The integrated angle command value calculation unit 56 calculates the automatic steering angle command value θ. ＡＤ The manual steering angle command value θ ＭＤ Adding this, the integrated angle command value θ ｃｍｄ Perform the calculation.

[0052] The angle control unit 57 controls the integrated angle command value θ ｃｍｄ The actual steering angle θ is calculated by the reduction ratio division unit 53. ｐ The output shaft torque command value T is calculated by the reduction ratio multiplication unit 51. ｐ，ｃｍｄ Based on this, the integrated angle command value θ ｃｍｄ The corresponding integrated motor torque command value T ｃｍｄThe angle control unit 57 can be, for example, a configuration in which the reduction ratio multiplication unit (68), rotation angle calculation unit (69), and reduction ratio division unit (70) are removed from the angle control unit (54) shown in Figure 5 of International Publication No. 2023 / 286169 (Patent Document 2). The reason for removing the reduction ratio multiplication unit (68), rotation angle calculation unit (69), and reduction ratio division unit (70) is that the reduction ratio multiplication unit (68), rotation angle calculation unit (69), and reduction ratio division unit (70) correspond to the reduction ratio multiplication unit 51, rotation angle calculation unit 52, and reduction ratio division unit 53 in Figure 2 of this application, respectively.

[0053] Note that θ in Figure 5 of International Publication No. 2023 / 286169 ｓｉｎｔ θ, N・T ｍ and T ｍｉｎｔ These are the θ values ​​in Figure 2 of the present application, respectively. ｃｍｄ , θ ｐ , T ｐ，ｃｍｄ and T ｃｍｄ It corresponds to this.

[0054] The first switch 58 and the second switch 59 receive the operating mode signal S from the higher-level ECU 201. ｍｏｄｅ It is turned on or off accordingly. Specifically, the driving mode signal S indicates that the driving mode is manual driving mode. ｍｏｄｅ If this is entered, the first switch 58 is turned on and the second switch 59 is turned off.

[0055] On the other hand, the driving mode signal S indicates that the driving mode is parking assist mode. ｍｏｄｅ If this is entered, the first switch 58 is turned off and the second switch 59 is turned on.

[0056] When the first switch 58 is ON and the second switch 59 is OFF, the adder 60 sets the assist torque command value T ａｓ The motor torque command value T ｍ，ｃｍｄ (=T ａｓ ) is output as ). On the other hand, when the second switch 59 is ON and the first switch 58 is OFF, the adder 60 outputs the integrated motor torque command value T from the angle control unit 57. ｃｍｄ motor torque command value T ｍ，ｃｍｄ (=Tｃｍｄ Output as).

[0057] The motor torque command value T, which is the output of the addition unit 60 ｍ，ｃｍｄ is given to the torque control unit 61.

[0058] The torque control unit 61 drives the drive circuit 41 so that the motor torque of the electric motor 18 approaches the motor torque command value T ｍ，ｃｍｄ For example, the torque control unit 61 can use the torque control unit (55) shown in FIGS. 2 and 8 of International Publication No. 2023 / 286169 (Patent Document 2). In that case, the torque control unit 61 divides the motor torque command value T ｍ，ｃｍｄ given to the torque control unit 61 by the torque coefficient of the electric motor 18 to calculate the current command value. Then, the torque control unit 61 performs feedback control so that the motor current I ｍ [[ID=[]] ｍｏｄｅ detected by the current detection circuit 42 approaches the current command value.

[0059] FIG. 3 is a block diagram showing a part of the configuration of the upper ECU 201. In FIG. 3, only the configuration related to the control of the motor control ECU 202 among the configurations of the upper ECU 201 is shown.

[0060] The upper ECU 201 is composed of a microcomputer. The microcomputer includes a CPU and a memory (ROM, RAM, non-volatile memory, etc.), and functions as a plurality of functional processing units by executing a predetermined program. The plurality of functional processing units include an operation mode signal generation unit 71 and a parking support control unit 72.

[0061] Basically, the operation mode signal generation unit 71 generates an operation mode signal S ｍｏｄｅ indicating whether the operation mode is a manual operation mode or a parking support mode based on the operations of the first mode switch 31 and the second mode switch 32. Note that the operation mode signal generation unit 71 may switch the operation mode to the manual operation mode when receiving a parking support completion notification from the parking support control unit 72 during the parking support mode.<[[]]

[0062] When in parking assistance mode, the parking assistance control unit 72 automatically controls the steering angle command value θ so that the vehicle moves from its current position to the target parking position. ＡＤ Perform the calculation.

[0063] The parking assistance control unit 72 includes a target trajectory generation unit 73 and an automatic steering angle command value calculation unit 74. The target trajectory generation unit 73 generates a target trajectory to a target parking position within a target parking space. In this embodiment, the target trajectory is a trajectory that moves the vehicle from its current position to the target parking position within the target parking space by reversing the vehicle.

[0064] The automatic steering angle command value calculation unit 74 calculates the automatic steering angle command value θ for moving the vehicle to the target parking position (automatic driving) along the target trajectory generated by the target trajectory generation unit 73. ＡＤ Perform the calculation.

[0065] The target trajectory generation unit 73 and the automatic steering angle command value calculation unit 74 will be described in more detail below.

[0066] The target trajectory generation unit 73 includes an initial target trajectory generation unit 75, a target trajectory update unit 76, a target trajectory switching unit 77, and a parking assistance completion determination unit 78. Although not shown in the figures, a touch panel may be connected to the target trajectory generation unit 73.

[0067] The initial target trajectory generation unit 75 first determines the coordinates of one or more parking space candidates based on information obtained, for example, from a CCD camera 25, GPS 26, radar 27, and sonar 30. The coordinates of a parking space candidate consist, for example, the X and Y coordinates in an absolute coordinate system and the orientation of the parking space candidate.

[0068] Next, the initial target trajectory generation unit 75 presents the driver with parking space candidates and has the driver select one parking space candidate as the target parking space.

[0069] Next, the initial target trajectory generation unit 75 generates a target trajectory from the current position to the target parking position within the target parking frame. In this case, the target parking position within the target parking frame is the reference parking position within the target parking frame. The reference parking position within the target parking frame may be set, for example, at a position on the width center line within the target parking frame and a first predetermined distance forward from the rear end of the target parking frame. For example, referring to FIG. 5, the reference parking position within the parking frame P3 is set at the position indicated by reference numeral 81.

[0070] The target trajectory is the traveling trajectory of the reference position of the host vehicle. The reference position of the host vehicle is set, for example, at a predetermined position on the width center line of the host vehicle. The reference position of the host vehicle may be set, for example, at a position on the width center line of the host vehicle and a second predetermined distance forward from the rear end of the host vehicle. For example, referring to FIG. 5, the reference position of the host vehicle 300 is set at the position indicated by reference numeral 301.

[0071] When a driver's steering intervention is performed during automatic driving under parking support control, for example, the target trajectory update unit 76 performs processing for updating the current target traveling trajectory based on information regarding the steering intervention and surrounding information of the host vehicle. Information regarding the steering intervention is, in this embodiment, the manual steering angle command value θ ＭＤ In this case, the surrounding information of the host vehicle is acquired based on information obtained by, for example, the CCD camera 25, GPS 26, radar 27, and sonar 30.

[0072] Even when a driver's steering intervention is performed during automatic driving under parking support control, depending on the position of the host vehicle, the surrounding information of the host vehicle, and the information regarding the steering intervention, it may not be possible to update the target traveling trajectory. In that case, the current target trajectory is maintained.

[0073] Note that the information regarding the steering intervention may be the torsion bar torque T ｔｂ or the deviation of the host vehicle position with respect to the target trajectory.

[0074] In this embodiment, whether or not a driver's steering intervention has been performed is determined based on the absolute value of the amount of change per predetermined time of the manual steering angle command value θ ＭＤ (hereinafter, “manual steering angle command value change amount Δθ ＭＤThis is determined by whether the value of the manual steering angle command value change amount Δθ is greater than or equal to a predetermined first threshold α1. α1 is a real number greater than 0. ＭＤ If the value is above the first threshold α1, it is determined that steering intervention has occurred.

[0075] Whether or not steering intervention by the driver has occurred can be determined, for example, as follows: That is, as shown by the dashed lines in Figures 1 to 3, the torsion bar torque T is controlled from the motor control ECU 102. ｔｂ The command is then provided to the higher-level ECU 201. The target trajectory updating unit 76 then controls the torsion bar torque T ｔｂ The absolute value of the amount of change per predetermined time (hereinafter referred to as "torsion bar torque change ΔT") ｔｂ The determination is made based on whether the torsion bar torque change ΔT is greater than or equal to a predetermined first threshold β1. β1 is a real number greater than 0. In this case, the torsion bar torque change ΔT ｔｂ If the value is above the first threshold β1, it is determined that steering intervention has been performed.

[0076] Whether or not steering intervention by the driver has occurred may be determined by whether the absolute value of the deviation of the vehicle's position from the target trajectory (e.g., lateral deviation) is greater than or equal to a predetermined first threshold γ1. γ1 is a real number greater than 0. In this case, if the absolute value of the deviation of the vehicle's position from the target trajectory is greater than or equal to the first threshold γ1, it is determined that steering intervention has occurred.

[0077] The target trajectory updating unit 76 may perform a first target trajectory updating process, a second target trajectory updating process, or select to perform either the first or second target trajectory updating process when steering intervention is performed.

[0078] The first target trajectory update process is a process in which, when steering intervention is performed during automatic driving, the target trajectory update unit 76 sets a new parking space candidate that is different from the current target parking space, according to information about the steering intervention and information about the vehicle's surroundings, generates a driving trajectory into the new parking space candidate, and updates the target trajectory from the current target trajectory to a driving trajectory into the new parking space candidate.

[0079] The second target trajectory update process is performed when steering intervention is performed during automatic driving. The target trajectory update unit 76 sets a new parking position candidate, which is different from the current target parking position, within the current target parking space, in accordance with information regarding the steering intervention and information about the vehicle's surroundings. The unit generates a driving trajectory to the new parking position candidate and updates the target trajectory to the driving trajectory from the current target parking position to the new parking position candidate.

[0080] The target trajectory update unit 76 may also be configured to determine, when steering intervention is performed during automatic driving, whether it is possible to generate a driving trajectory into a candidate new parking space or a driving trajectory to a candidate new parking position, whether to perform a target trajectory update using a first target trajectory update process, whether to perform a target trajectory update using a second target trajectory update process, or whether to maintain the current target trajectory, based on whether it is possible to generate a driving trajectory into a candidate new parking space or a driving trajectory to a candidate new parking position.

[0081] The target trajectory updating unit 76 may determine whether to perform the first target trajectory updating process or the second target trajectory updating process based on the distance between the new parking space candidate and the vehicle when steering intervention is performed.

[0082] When the driving mode is set to parking assistance mode, the target trajectory switching unit 77 is controlled to select and output the target trajectory set by the initial target trajectory generation unit 75. In parking assistance mode, after the target trajectory set by the initial target trajectory generation unit 75 has been updated by the target trajectory update unit 76, the target trajectory switching unit 77 is controlled to select and output the target trajectory set by the target trajectory update unit 76. The target trajectory output from the target trajectory switching unit 77 is provided to the automatic steering angle command value calculation unit 74.

[0083] Although not shown in the diagram, the parking assistance completion determination unit 78 is also provided with information obtained from the CCD camera 25, GPS 26, radar 27, and sonar 30. The parking assistance completion determination unit 78 determines whether the vehicle has reached the target parking position relative to the target trajectory selected by the target trajectory switching unit 77, and outputs a parking assistance completion notification when the vehicle has reached the target parking position. The parking assistance completion notification is provided to the driving mode signal generation unit 71.

[0084] The automatic steering angle command value calculation unit 74 calculates an automatic steering angle command value θ for driving its own vehicle along the target trajectory, based on the target trajectory provided by the target trajectory switching unit 77. ＡＤ The automatic steering angle command value calculation unit 74 calculates the automatic steering angle command value θ based on, for example, the lateral deviation of the vehicle relative to the target trajectory and the yaw angle deviation (direction deviation or azimuth angle deviation) of the vehicle relative to the target trajectory. ＡＤ The automatic steering angle command value calculation unit 74 calculates the automatic steering angle command value θ based on the curvature of the target trajectory. ＡＤ You may perform the calculation.

[0085] Figure 4 is a flowchart showing an example of the operation of the target trajectory generation unit 73.

[0086] When the driving mode is set to parking assist mode (step S1: YES), the target trajectory generation unit 73 performs target parking space determination processing (step S2). Specifically, the target trajectory generation unit 73 displays parking space candidates on a touch panel, for example, based on information about the vehicle's surroundings. The driver performs an operation on the touch panel to select one parking space candidate. The target trajectory generation unit 73 determines the parking space candidate selected by the driver as the target parking space. When the driving mode is set to parking assist mode, the first switch 58 (see Figure 2) in the motor control ECU 202 is turned off, and the second switch 59 is turned on.

[0087] Next, the target trajectory generation unit 73 generates a target trajectory from the vehicle's current position to the target parking position within the target parking space (in this case, the reference parking position) (step S3). The target trajectory generated by the target trajectory generation unit 73 is provided to the automatic steering angle command value calculation unit 74. The automatic steering angle command value calculation unit 74 then calculates the automatic steering angle command value θ for moving the vehicle along the target trajectory. ＡＤ The calculations are performed and provided to the motor control ECU 202. Furthermore, the vehicle's movement begins through drive control by the higher-level ECU 201 (for example, control of the engine ECU by the higher-level ECU 201). As a result, the vehicle automatically travels along the target trajectory.

[0088] Next, the target trajectory generation unit 73 determines whether or not the vehicle has reached the target parking position (step S4). If the vehicle has not reached the target parking position (step S4: NO), the target trajectory generation unit 73 determines whether or not steering intervention has been performed by the driver (step S5). This determination is made, for example, by the change amount Δθ of the manual steering angle command value. ＭＤ This is done based on whether or not the first threshold α1 is greater than or equal to it.

[0089] If it is determined that no steering intervention has been performed by the driver (Step S5: NO), the target trajectory generation unit 73 returns to Step S4.

[0090] In step S4, if it is determined that the vehicle has reached the target parking position (step S4: YES), the target trajectory generation unit 73 sends a parking assistance completion notification to the driving mode signal generation unit 71 (step S6). Upon receiving the parking assistance completion notification, the driving mode signal generation unit 71 switches the driving mode to manual driving mode. If it is determined that the vehicle has reached the target parking position, the vehicle is stopped by braking control by the higher-level ECU 201 (for example, control of the brake ECU by the higher-level ECU 201). After the processing in step S6 is completed, the target trajectory generation unit 73 returns to step S1.

[0091] If it is determined in step S5 that steering intervention has been performed by the driver (step S5: YES), the target trajectory generation unit 73 proceeds to step S7.

[0092] In step S7, the target trajectory generation unit 73 determines a candidate for a new parking space in the first target trajectory update process and a candidate for a new parking position in the second target trajectory update process based on information regarding the steering intervention and information about the vehicle's surroundings. In this embodiment, for the sake of simplicity, it is assumed that one candidate for a new parking space in the first target trajectory update process and one candidate for a new parking position in the second target trajectory update process are determined.

[0093] Examples of new parking space candidates in the first target track update process and new parking position candidates in the second target track update process, determined by step S7, will be explained with reference to Figure 5.

[0094] In Figure 5, 300 indicates the vehicle itself, and 301 indicates the vehicle's reference position. P1 to P4 each indicate parking spaces. Parking space P3 is set as the current target parking space, and the reference parking position 81 within parking space P3 is set as the current target parking position. The dashed line 80 is the currently set target trajectory.

[0095] If, at the vehicle's position shown in Figure 5, steering intervention is performed on the vehicle 300 in the leftward direction, the target trajectory generation unit 73 will, for example, set the parking space P2 adjacent to the left of the current target parking space P3 as a candidate for a new parking space in the first target trajectory update process. The target trajectory generation unit 73 will also, for example, set a predetermined position 82 to the left of the current target parking position 81 within the current target parking space P3 as a candidate for a new parking position in the second target trajectory update process.

[0096] Assuming that steering intervention is performed to the right relative to the vehicle 300 at the vehicle's position shown in Figure 5, the target trajectory generation unit 73 sets the parking space P4 to the right of the current target parking space P3 as a candidate for the new parking space in the first target trajectory update process. The target trajectory generation unit 73 also sets a predetermined position 83 to the right of the current target parking position 81 within the current target parking space P3 as a candidate for the new parking position in the second target trajectory update process.

[0097] Next, the target trajectory generation unit 73 attempts to generate a driving trajectory from the current vehicle position to the reference parking position within the new parking space candidate determined in step S7 (hereinafter referred to as "first driving trajectory A") and a driving trajectory from the current vehicle position to the new parking space candidate determined in step S7 (hereinafter referred to as "second driving trajectory B") (step S8).

[0098] In Figure 5, examples of the first and second travel trajectories A and B when the steering intervention direction is to the left are shown by the dashed-dotted line A1 and the dashed-dotted line B1, respectively. In Figure 5, examples of the first and second travel trajectories when the steering intervention direction is to the right are shown by the dashed-dotted line A2 and the dashed-dotted line B2, respectively.

[0099] Next, the target trajectory generation unit 73 determines whether or not it has been able to generate the first travel trajectory A (step S9). If it is determined that the first travel trajectory A has been generated (step S9: YES), the target trajectory generation unit 73 sets the first travel trajectory A as the new target trajectory (step S10). This updates the target trajectory. The updated target trajectory is provided to the automatic steering angle command value calculation unit 74. The automatic steering angle command value calculation unit 74 then sets an automatic steering angle command value θ to move the vehicle along the target trajectory. ＡＤ The calculation is performed and provided to the motor control ECU 202. When the processing in step S10 is completed, the target trajectory generation unit 73 returns to step S4.

[0100] If it is determined in step S9 that the first travel trajectory A could not be generated (step S9: NO), the target trajectory generation unit 73 determines whether or not the second travel trajectory B could be generated (step S11).

[0101] If it is determined that the second travel trajectory B has been generated (step S11: YES), the target trajectory generation unit 73 sets the second travel trajectory B as the new target trajectory (step S12). This updates the target trajectory. The updated target trajectory is provided to the automatic steering angle command value calculation unit 74. The automatic steering angle command value calculation unit 74 then sets an automatic steering angle command value θ to move the vehicle along the target trajectory. ＡＤ The calculation is performed and provided to the motor control ECU 202. When the processing in step S12 is completed, the target trajectory generation unit 73 returns to step S4.

[0102] If it is determined in step S11 that the second travel trajectory B could not be generated (step S11: NO), the target trajectory generation unit 73 returns to step S4.

[0103] In step S5 of Figure 4, the target trajectory generation unit 73 determines whether or not steering intervention has occurred by measuring the torsion bar torque change ΔT. ｔｂThe determination may also be made by whether or not the value is greater than or equal to the first threshold β1. Alternatively, in step S5 of Figure 4, the target trajectory generation unit 73 may determine whether or not steering intervention has been performed by whether or not the absolute value of the deviation of the vehicle's position relative to the target trajectory is greater than or equal to the first threshold γ1.

[0104] The target trajectory generation unit 73 may determine only new parking space candidates in step S7. In this case, the target trajectory generation unit 73 attempts to generate only the first travel trajectory A in step S8. If it is determined in step S9 that the first travel trajectory A has been generated, the target trajectory generation unit 73 sets the first travel trajectory A as the target trajectory. On the other hand, if it is determined in step S9 that the first travel trajectory A could not be generated, the target trajectory generation unit 73 returns to step S4. When this processing is performed, steps S11 and S12 are unnecessary.

[0105] According to the embodiment described above, in parking assistance mode, if steering intervention occurs during automatic driving, the target parking space can be automatically changed from the current target parking space to another parking space in accordance with information regarding the steering intervention and information about the vehicle's surroundings, and the vehicle can be automatically moved into the changed target parking space.

[0106] Furthermore, according to the above-described embodiment, when steering intervention occurs during automatic driving in parking assistance mode, the target parking position can be automatically changed to a different parking position within the current target parking space, depending on the information regarding the steering intervention and the surrounding information of the vehicle, and the vehicle can be automatically moved to the changed target parking position.

[0107] Furthermore, according to the above-described embodiment, when steering intervention occurs during automatic driving in parking assistance mode, it becomes possible to automatically determine whether to automatically update the target trajectory based on a change in the target parking space or to automatically update the target trajectory based on a change in the target parking position within the current target parking space.

[0108] In the embodiment described above, step S7 in Figure 4 determines one candidate new parking space in the first target trajectory update process and one candidate new parking position in the second target trajectory update process. However, multiple candidates for new parking spaces may be set in the first target trajectory update process, and multiple candidates for new parking positions may be set in the second target trajectory update process.

[0109] In this case, in step S8 of Figure 4, the target trajectory generation unit 73 attempts to generate a driving trajectory for each of the multiple new parking space candidates, and also attempts to generate a driving trajectory for each of the multiple new parking position candidates.

[0110] In step S9 of Figure 4, the target trajectory generation unit 73 determines whether or not it was able to generate a first travel trajectory A for each of the multiple new parking space candidates. If, in step S9, it is determined that a first travel trajectory A was generated for one or more new parking space candidates, the target trajectory generation unit 73 proceeds to step S10 of Figure 4 and performs the following processing.

[0111] In other words, if in step S9 it is determined that a first travel trajectory A has been generated for only one new parking space candidate, the target trajectory generation unit 73 sets the said first travel trajectory A as the target trajectory. If in step S9 it is determined that a first travel trajectory A has been generated for two or more new parking space candidates, the target trajectory generation unit 73 first selects one of the multiple first travel trajectories A generated in step S8, for example, based on information regarding steering intervention and information about the vehicle's surroundings. Then, the target trajectory generation unit 73 sets the selected first travel trajectory A as the target trajectory.

[0112] If, in step S9, it is determined that the first travel trajectory A could not be generated for all of the multiple new parking space candidates, the target trajectory generation unit 73 proceeds to step S11 in Figure 4 to determine whether or not the second travel trajectory B could be generated for each of the multiple new parking position candidates. If, in step S11, it is determined that the second travel trajectory B could be generated for one or more new parking position candidates, the target trajectory generation unit 73 proceeds to step S12 in Figure 4 to perform the following processing.

[0113] In other words, if it is determined in step S11 that a second travel trajectory B has been generated for only one new parking position candidate, the target trajectory generation unit 73 sets the said second travel trajectory B as the target trajectory. If it is determined in step S11 that a second travel trajectory B has been generated for two or more new parking position candidates, the target trajectory generation unit 73 first selects one of the multiple second travel trajectories B generated in step S8, for example, based on information regarding steering intervention and information about the vehicle's surroundings. Then, the target trajectory generation unit 73 sets the selected second travel trajectory B as the target trajectory.

[0114] If, in step S11, a second travel trajectory B cannot be generated for all of the multiple new parking position candidates, the target trajectory generation unit 73 returns to step S4 in Figure 4.

[0115] Figure 6 is a flowchart showing another example of the operation of the target trajectory generation unit 73. In Figure 6, the steps corresponding to each step in Figure 4 are indicated with the same step numbers as in Figure 4.

[0116] Steps S1, S2, S3, S4, S5, S6, S7, and S8 in Figure 6 are the same as steps S1, S2, S3, S4, S5, S6, S7, and S8 in Figure 4, respectively, so their explanations will be omitted.

[0117] When the processing in step S8 is completed, the target trajectory generation unit 73 proceeds to step S21. In step S21, the target trajectory generation unit 73 determines whether or not it has been able to generate at least one of the first travel trajectory A and the second travel trajectory B.

[0118] If neither the first travel trajectory A nor the second travel trajectory B can be generated (step S21: NO), the target trajectory generation unit 73 returns to step S4.

[0119] If it is determined in step S21 that at least one of the first travel trajectory A and the second travel trajectory B has been generated (step S21: YES), the target trajectory generation unit 73 proceeds to step S22.

[0120] In step S22, the target trajectory generation unit 73 determines whether it was able to generate both the first trajectory A and the second trajectory B, only the first trajectory A, or only the second trajectory B.

[0121] In step S22, if it is determined that both the first travel trajectory A and the second travel trajectory B have been generated, the target trajectory generation unit 73 determines the change amount Δθ of the manual steering angle command value at the time of steering intervention. ＭＤ However, it is determined whether the value is greater than or equal to a second threshold α2, which is greater than a first threshold α1 used to determine whether or not steering intervention has occurred (step S23).

[0122] Change in manual steering angle command value Δθ during steering intervention ＭＤ If the value is greater than or equal to the second threshold α2 (step S23: YES), the target trajectory generation unit 73 sets the first travel trajectory as the new target trajectory (step S24). This updates the target trajectory. The updated target trajectory is provided to the automatic steering angle command value calculation unit 74. The automatic steering angle command value calculation unit 74 then calculates the automatic steering angle command value θ to move the vehicle along the target trajectory. ＡＤ The calculation is performed and provided to the motor control ECU 202. When the processing in step S24 is completed, the target trajectory generation unit 73 returns to step S4.

[0123] In step S23, the amount of change in the manual steering angle command value Δθ during steering intervention. ＭＤ If it is determined that the value is less than the second threshold α2 (step S23: NO), the target trajectory generation unit 73 sets the second travel trajectory as the new target trajectory (step S25). This updates the target trajectory. The updated target trajectory is provided to the automatic steering angle command value calculation unit 74. The automatic steering angle command value calculation unit 74 then calculates the automatic steering angle command value θ to move the vehicle along the target trajectory. ＡＤ The calculation is performed and provided to the motor control ECU 202. When the processing in step S25 is completed, the target trajectory generation unit 73 returns to step S4.

[0124] If it is determined in step S22 that only the first travel trajectory A has been generated, the process proceeds to step S24.

[0125] If it is determined in step S22 that only the second travel trajectory B has been generated, the process proceeds to step S25.

[0126] In step S5 of Figure 6, the target trajectory generation unit 73 determines whether or not steering intervention has occurred by using the change in torsion bar torque ΔT at the time of steering intervention. ｔｂ The determination may also be made based on whether or not it is greater than or equal to the first threshold β1. In this case, in step S23 of Figure 6, the target trajectory generation unit 73 determines the torsion bar torque change amount ΔT during steering intervention. ｔｂ It is determined whether the value is greater than or equal to the second threshold β2, which is greater than the first threshold β1.

[0127] Furthermore, in step S5 of Figure 6, the target trajectory generation unit 73 may determine whether steering intervention has been performed based on whether the absolute value of the deviation of the vehicle's position relative to the target trajectory is greater than or equal to a first threshold γ1. In this case, in step S23 of Figure 6, the target trajectory generation unit 73 determines whether the absolute value of the deviation of the vehicle's position relative to the target trajectory is greater than or equal to a second threshold γ2, which is greater than the first threshold γ1.

[0128] In the embodiment described above, step S7 in Figure 6 determines one candidate new parking space in the first target trajectory update process and one candidate new parking position in the second target trajectory update process. However, multiple candidates for new parking spaces may be set in the first target trajectory update process, and multiple candidates for new parking positions may be set in the second target trajectory update process.

[0129] In this case, in step S8 of Figure 4, the target trajectory generation unit 73 attempts to generate a first travel trajectory A for each of the multiple new parking space candidates, and also attempts to generate a second travel trajectory for each of the multiple new parking position candidates.

[0130] In step S21 of Figure 6, the target trajectory generation unit 73 determines whether at least one travel trajectory was generated in step S8, considering the first travel trajectory A and the second travel trajectory B as a single travel trajectory. If no travel trajectory was generated at all, the target trajectory generation unit 73 returns to step S4.

[0131] If it is determined in step S21 that at least one travel trajectory has been generated, the target trajectory generation unit 73 proceeds to step S22.

[0132] In step S22, if in step S8 one or more first travel trajectories A and one or more second travel trajectories B are generated, the target trajectory generation unit 73 determines that both the first travel trajectory A and the second travel trajectory B have been generated.

[0133] In step S8, if one or more first travel trajectories A were generated, but no second travel trajectories B were generated at all, the target trajectory generation unit 73 determines that only first travel trajectories A were generated.

[0134] In step S8, if one or more second travel trajectories B were generated, but no first travel trajectories A were generated at all, the target trajectory generation unit 73 determines that only second travel trajectories B were generated.

[0135] If it is determined in step S22 that both the first travel trajectory A and the second travel trajectory B have been generated, the target trajectory generation unit 73 proceeds to step S23.

[0136] In step S23, the amount of change in the manual steering angle command value Δθ during steering intervention. ＭＤ If it is determined that the value is greater than or equal to the second threshold α2, the target trajectory generation unit 73 proceeds to step S24 and performs the following processing (hereinafter referred to as "first processing").

[0137] In other words, if the number of first travel trajectories A generated in step S8 is 1, the target trajectory generation unit 73 sets that one first travel trajectory A as the new target trajectory. If the number of first travel trajectories A generated in step S8 is 2 or more, the target trajectory generation unit 73 first selects one of the first travel trajectories A based, for example, on information regarding steering intervention and information about the vehicle's surroundings. Then, the target trajectory generation unit 73 sets the selected one first travel trajectory A as the target trajectory.

[0138] In step S23, the amount of change in the manual steering angle command value Δθ during steering intervention. ＭＤIf it is determined that the value is less than the second threshold α2, the target trajectory generation unit 73 proceeds to step S25 and performs the following processing (hereinafter referred to as the "second processing").

[0139] In other words, if the number of second travel trajectories B generated in step S8 is 1, the target trajectory generation unit 73 sets that one second travel trajectory B as the new target trajectory. If the number of second travel trajectories B generated in step S8 is 2 or more, the target trajectory generation unit 73 first selects one of the second travel trajectories B based, for example, on information regarding steering intervention and information about the vehicle's surroundings. Then, the target trajectory generation unit 73 sets the selected one second travel trajectory B as the target trajectory.

[0140] If it is determined in step S22 that only the first travel trajectory A has been generated, the target trajectory generation unit 73 proceeds to step S24 and performs the same processing as the first process described above.

[0141] If it is determined in step S22 that only the second travel trajectory B has been generated, the target trajectory generation unit 73 proceeds to step S25 and performs the same processing as the second process described above.

[0142] Figure 7 is a flowchart showing yet another example of the operation of the target trajectory generation unit 73. In Figure 7, the steps corresponding to each step in Figure 4 are indicated with the same step numbers as in Figure 4.

[0143] Steps S1, S2, S3, S4, S5, S6, and S7 in Figure 7 are the same as steps S1, S2, S3, S4, S5, S6, and S7 in Figure 4, respectively, so their explanations will be omitted.

[0144] When the processing in step S7 is completed, the target trajectory generation unit 73 proceeds to step S31. In step S31, the target trajectory generation unit 73 determines whether the distance d between the new parking space candidate determined in step S7 and the vehicle is greater than or equal to a predetermined threshold δ. More specifically, the target trajectory generation unit 73 determines, for example, whether the distance between the center of the width of the rear end of the vehicle and the center of the width of the entrance to the new parking space candidate is greater than or equal to δ.

[0145] In order to generate a driving trajectory for moving your vehicle into a new parking space candidate, the distance d between the new parking space candidate and your vehicle must be a predetermined distance d ｍｉｎ If the above is necessary, then δ is d ｍｉｎ It is set to a predetermined value that is greater than [a certain value].

[0146] If the distance d between the new parking space candidate and the vehicle is δ or greater (step S31: YES), the target trajectory generation unit 73 generates a driving trajectory (hereinafter referred to as "first driving trajectory A") from the current position of the vehicle to the reference parking position within the new parking space candidate determined in step S7, and sets the first driving trajectory A as the new target trajectory (step S32). This updates the target trajectory. The updated target trajectory is provided to the automatic steering angle command value calculation unit 74. The automatic steering angle command value calculation unit 74 then sets an automatic steering angle command value θ to move the vehicle along the target trajectory. ＡＤ The calculation is performed and provided to the motor control ECU 202. When the processing in step S32 is completed, the target trajectory generation unit 73 returns to step S4.

[0147] In step S31, if it is determined that the distance d between the new parking space candidate and the vehicle is less than δ (step S31: NO), the target trajectory generation unit 73 generates a driving trajectory from the current vehicle position to the new parking space candidate determined in step S7 (hereinafter referred to as "second driving trajectory B"), and sets the first driving trajectory A as the new target trajectory (step S33). This updates the target trajectory. The updated target trajectory is provided to the automatic steering angle command value calculation unit 74. The automatic steering angle command value calculation unit 74 then sets an automatic steering angle command value θ to move the vehicle along the target trajectory. ＡＤ The calculation is performed and provided to the motor control ECU 202. When the processing in step S33 is completed, the target trajectory generation unit 73 returns to step S4.

[0148] The target trajectory generation unit 73 may also determine only new parking space candidates in step S7. In this case, if it is determined in step S31 that the distance d between the new parking space candidate and the vehicle is δ or greater, the target trajectory generation unit 73 proceeds to step S32 to generate a first travel trajectory A and sets the first travel trajectory A as the new target trajectory. On the other hand, if it is determined in step S31 that the distance d between the new parking space candidate and the vehicle is less than δ, the target trajectory generation unit 73 returns to step S4. When this type of processing is performed, the processing in step S33 is unnecessary.

[0149] In the example shown in Figure 7, step S7 determines one candidate for a new parking space in the first target trajectory update process and one candidate for a new parking position in the second target trajectory update process. However, multiple candidates for new parking spaces may be set in the first target trajectory update process, and multiple candidates for new parking positions may be set in the second target trajectory update process.

[0150] In this case, in step S31 of Figure 7, the target trajectory generation unit 73 determines whether the distance condition that the distance between the candidate new parking space and the vehicle is δ or greater is met for each of the multiple candidate new parking spaces. If there is one or more candidate new parking spaces that meet the distance condition, the target trajectory generation unit 73 proceeds to step S32 and performs the following processing.

[0151] In other words, if there is only one candidate new parking space that satisfies the distance condition, the target trajectory generation unit 73 generates a first travel trajectory A from the current position of the vehicle to a reference parking position within the candidate new parking space, and sets the first travel trajectory A as the new target trajectory.

[0152] If there are two or more new parking space candidates that meet the distance conditions, the target trajectory generation unit 73 selects one of them based, for example, on information regarding steering intervention and information about the vehicle's surroundings. The target trajectory generation unit 73 then generates a first travel trajectory A from the current position of the vehicle to a reference parking position within the selected new parking space candidate, and sets the first travel trajectory A as the new target trajectory.

[0153] If, in step S31, it is determined that there are no new parking space candidates that satisfy the distance conditions, the target trajectory generation unit 73 proceeds to step S33 and, for example, based on information regarding steering intervention and information about the vehicle's surroundings, selects one of the multiple new parking position candidates determined in step S7. The target trajectory generation unit 73 then generates a second travel trajectory B from the current vehicle position to the selected new parking position candidate and sets the second travel trajectory B as the new target trajectory.

[0154] Figure 8 is a flowchart showing yet another example of the operation of the target trajectory generation unit 73. In Figure 8, the steps corresponding to each step in Figure 4 are indicated with the same step numbers as in Figure 4.

[0155] Steps S1, S2, S3, S4, S5, S6, and S7 in Figure 8 are the same as steps S1, S2, S3, S4, S5, S6, and S7 in Figure 4, respectively, so their explanations will be omitted.

[0156] Once the processing in step S7 is completed, the target trajectory generation unit 73 proceeds to step S41. In step S41, the target trajectory generation unit 73 determines whether the distance d between the new parking space candidate determined in step S7 and the vehicle is greater than or equal to a predetermined first threshold δ1. More specifically, the target trajectory generation unit 73 determines, for example, whether the distance between the center of the width of the rear end of the vehicle and the center of the width of the entrance to the new parking space candidate is greater than or equal to the first threshold δ1.

[0157] In order to generate a driving trajectory for moving your vehicle into a new parking space candidate, the distance d between the new parking space candidate and your vehicle must be a predetermined distance d ｍｉｎ If the above is necessary, then δ1 is d ｍｉｎ It is set to a predetermined value that is greater than [a certain value].

[0158] If the distance d between the new parking space candidate and the vehicle is greater than or equal to the first threshold δ1 (step S41: YES), the target trajectory generation unit 73 generates a driving trajectory (hereinafter referred to as "first driving trajectory A") from the current position of the vehicle to the reference parking position within the new parking space candidate determined in step S7, and sets the first driving trajectory A as the new target trajectory (step S42). This updates the target trajectory. The updated target trajectory is provided to the automatic steering angle command value calculation unit 74. The automatic steering angle command value calculation unit 74 then generates an automatic steering angle command value θ to move the vehicle along the target trajectory. ＡＤ The calculation is performed and provided to the motor control ECU 202. When the processing in step S42 is completed, the target trajectory generation unit 73 returns to step S4.

[0159] In step S41, if it is determined that the distance d between the new parking space candidate and the vehicle is less than the first threshold δ1 (step S41: NO), the target trajectory generation unit 73 determines whether the distance between the new parking space candidate and the vehicle is less than the second threshold δ2, which is smaller than the first threshold δ1 (step S43). δ2 is d ｍｉｎ It is set to a predetermined value that is greater than or less than δ1.

[0160] If the distance d between the new parking space candidate and the vehicle is less than the second threshold δ2 (step S43: YES), the target trajectory generation unit 73 generates a driving trajectory from the current vehicle position to the new parking space candidate determined in step S7 (hereinafter referred to as "second driving trajectory B"), and sets the second driving trajectory B as the new target trajectory (step S44). This updates the target trajectory. The updated target trajectory is provided to the automatic steering angle command value calculation unit 74. The automatic steering angle command value calculation unit 74 then generates an automatic steering angle command value θ to move the vehicle along the target trajectory. ＡＤ The calculation is performed and provided to the motor control ECU 202. When the processing in step S44 is completed, the target trajectory generation unit 73 returns to step S4.

[0161] In step S43, if it is determined that the distance d between the new parking space candidate and the vehicle is greater than or equal to the second threshold δ2, that is, if the distance d between the new parking space candidate and the vehicle is greater than or equal to the second threshold δ2 and less than the first threshold δ1 (step S43: NO), the target trajectory generation unit 73 proceeds to step S45.

[0162] In step S45, the target trajectory generation unit 73 generates the change amount Δθ of the manual steering angle command value during steering intervention. ＭＤ However, it is determined whether the value is greater than or equal to a second threshold α2, which is greater than a first threshold α1 used to determine whether or not steering intervention has occurred.

[0163] Change in manual steering angle command value Δθ during steering intervention ＭＤ However, if the second threshold α2 is greater than or equal to (step S45: YES), the target trajectory generation unit 73 proceeds to step S42. In this case, the target trajectory generation unit 73 generates a first travel trajectory A from the current position of the vehicle to the reference parking position within the new parking space candidate determined in step S7, and sets the first travel trajectory A as the new target trajectory.

[0164] In step S45, the amount of change Δθ in the manual steering angle command value during steering intervention. ＭＤ However, if it is determined that the value is less than the second threshold α2 (step S45: NO), the target trajectory generation unit 73 proceeds to step S44. In this case, the target trajectory generation unit 73 generates a second travel trajectory B from the current vehicle position to the new parking position candidate determined in step S7, and sets the second travel trajectory B as the new target trajectory.

[0165] In step S5 of Figure 8, the target trajectory generation unit 73 determines whether or not steering intervention has occurred by using the change in torsion bar torque ΔT at the time of steering intervention. ｔｂ The determination may also be made based on whether or not it is greater than or equal to the first threshold β1. In this case, in step S45 of Figure 8, the target trajectory generation unit 73 determines the torsion bar torque change amount ΔT during steering intervention. ｔｂ It is determined whether the value is greater than or equal to the second threshold β2, which is greater than the first threshold β1.

[0166] Furthermore, in step S5 of Figure 8, the target trajectory generation unit 73 may determine whether steering intervention has been performed based on whether the absolute value of the deviation of the vehicle's position relative to the target trajectory is greater than or equal to a first threshold γ1. In this case, in step S45 of Figure 8, the target trajectory generation unit 73 determines whether the absolute value of the deviation of the vehicle's position relative to the target trajectory is greater than or equal to a second threshold γ2, which is greater than the first threshold γ1.

[0167] In the example shown in Figure 8, step S7 determines one candidate for a new parking space in the first target trajectory update process and one candidate for a new parking position in the second target trajectory update process. However, multiple candidates for new parking spaces may be set in the first target trajectory update process, and multiple candidates for new parking positions may be set in the second target trajectory update process.

[0168] In this case, in step S41 of Figure 8, the target trajectory generation unit 73 determines whether the first distance condition is met for each of the multiple new parking space candidates set in step S7, namely that the distance d between the new parking space candidate and the vehicle is equal to or greater than a first threshold δ1. If there is one or more new parking space candidates that meet the first distance condition, the target trajectory generation unit 73 proceeds to step S42 and performs the following processing.

[0169] In other words, if there is only one candidate new parking space that satisfies the first distance condition, the target trajectory generation unit 73 generates a first travel trajectory A from the current position of the vehicle to a reference parking position within the candidate new parking space, and sets the first travel trajectory A as the new target trajectory.

[0170] If there are two or more new parking space candidates that satisfy the first distance condition, the target trajectory generation unit 73 selects one of them based, for example, on information regarding steering intervention and information about the vehicle's surroundings. The target trajectory generation unit 73 then generates a first travel trajectory A from the current position of the vehicle to a reference parking position within the selected new parking space candidate, and sets the first travel trajectory A as the new target trajectory.

[0171] If, in step S41, it is determined that there are no new parking space candidates that satisfy the first distance condition, the target trajectory generation unit 73 proceeds to step S43. In step S43, the target trajectory generation unit 73 determines, for each of the multiple new parking space candidates set in step S7, whether or not the second distance condition is satisfied, which is that the distance d between the new parking space candidate and the vehicle is less than the second threshold δ2.

[0172] If all new parking space candidates satisfy the second distance condition, the target trajectory generation unit 73 proceeds to step S44 and performs the following process (hereinafter referred to as the "third process"). Specifically, the target trajectory generation unit 73 selects one of the multiple new parking position candidates determined in step S7, for example, based on information regarding steering intervention and information about the vehicle's surroundings. The target trajectory generation unit 73 then generates a second travel trajectory B from the current vehicle position to the selected new parking position candidate, and sets the second travel trajectory B as the new target trajectory.

[0173] In step S43, if there is one or more new parking space candidates that do not satisfy the second distance condition, the target trajectory generation unit 73 proceeds to step S45. Then, the target trajectory generation unit 73 calculates the change amount Δθ of the manual steering angle command value during steering intervention. ＭＤ This determines whether the value is above the second threshold α2.

[0174] Change in manual steering angle command value Δθ during steering intervention ＭＤ If it is determined that the value is greater than or equal to the second threshold α2, the target trajectory generation unit 73 proceeds to step S42 and performs the following processing.

[0175] In other words, if there is only one parking space candidate that does not satisfy the first distance condition and the second distance condition, the target trajectory generation unit 73 generates a first travel trajectory A from the current position of the vehicle to the reference parking position within the new parking space candidate, and sets the first travel trajectory A as the new target trajectory.

[0176] If there are two or more new parking space candidates that do not satisfy the first distance condition and the second distance condition, the target trajectory generation unit 73 selects one of the new parking space candidates based, for example, on information regarding steering intervention and information about the vehicle's surroundings. The target trajectory generation unit 73 then generates a first travel trajectory A from the current position of the vehicle to a reference parking position within the selected new parking space candidate, and sets the first travel trajectory A as the new target trajectory.

[0177] In step S45, the amount of change Δθ in the manual steering angle command value during steering intervention. ＭＤ If it is determined that the value is less than the second threshold α2, the process proceeds to step S44, and the same process as the third process described above is performed.

[0178] Furthermore, although the above-described embodiments show an example of applying the present disclosure to a column-type EPS, the present disclosure can also be applied to EPS other than the column type. The present disclosure can also be applied to steer-by-wire systems.

[0179] While embodiments of this disclosure have been described in detail, these are merely examples used to illustrate the technical content of this disclosure, and this disclosure should not be construed as being limited to these examples. The scope of this disclosure is limited only to the attached claims.

[0180] 1...Electric power steering system, 3...Steering wheel, 4...Steering mechanism, 18...Electric motor, 50...Microcomputer, 54...Assist torque command value setting unit, 55...Manual steering angle command value calculation unit, 56...Integrated angle command value calculation unit, 57...Angle control unit, 58...First switch, 59...Second switch, 60...Addition unit, 61...Torque control unit, 71...Driving mode signal generation unit, 72...Parking assist control unit, 73...Target trajectory generation unit, 74...Automatic steering angle command value calculation unit, 201...Higher-level ECU, 202...ECU for motor control

Claims

1. A parking assistance device comprising: a target trajectory generation unit that generates a target trajectory to a target parking position within a target parking space; and an automatic steering angle command value calculation unit that calculates an automatic steering angle command value for the vehicle to automatically travel along the target trajectory generated by the target trajectory generation unit to the target parking position within the target parking space, wherein the target trajectory generation unit has a function to perform a first target trajectory update process that, when steering intervention is performed during automatic driving, sets a parking space other than the current target parking space as a new parking space candidate according to information about the steering intervention and information about the vehicle's surroundings, generates a driving trajectory to the new parking space candidate, and updates the target trajectory from the current target trajectory to a driving trajectory to the new parking space candidate.

2. When steering intervention is performed during the automatic driving, the second target trajectory update process is defined as the process of setting a new parking position candidate within the current target parking space that is different from the current target parking position, in accordance with information related to the steering intervention and information about the vehicle's surroundings, generating a driving trajectory to the new parking position candidate, and updating the target trajectory to the driving trajectory from the current target parking position to the new parking position candidate, and the target trajectory generation unit determines, when steering intervention is performed during the automatic driving, whether to perform a target trajectory update using the first target trajectory update process, perform a target trajectory update using the second target trajectory update process, or maintain the current target trajectory, based on whether a driving trajectory into the new parking space candidate can be generated and whether a driving trajectory to the new parking position candidate can be generated.

3. If it is not possible to generate a driving trajectory within the candidate new parking space, but it is possible to generate a driving trajectory to the candidate new parking position, the target trajectory generation unit performs a target trajectory update by the second target trajectory update process, as described in claim 2.

4. The parking assistance device according to claim 3, wherein, if a driving trajectory into the new parking space candidate can be generated and a driving trajectory to the new parking position candidate can be generated, the target trajectory generation unit determines, based on the information regarding the steering intervention, whether to perform a target trajectory update by the first target trajectory update process or a target trajectory update by the second target trajectory update process.

5. When steering intervention is performed during the automatic driving, the second target trajectory update process is defined as the process of setting a new parking position candidate within the current target parking space that is different from the current target parking position, in accordance with information related to the steering intervention and information about the vehicle's surroundings, generating a driving trajectory to the new parking position candidate, and updating the target trajectory to the driving trajectory from the current target parking position to the new parking position candidate, wherein the target trajectory generation unit determines whether to perform the first target trajectory update process or the second target trajectory update process based on the distance between the new parking space candidate and the vehicle when steering intervention is performed during the automatic driving, the parking assistance device according to claim 1.

6. The parking assistance device according to claim 5, wherein when steering intervention is performed during the automatic driving, if the distance between the new parking space candidate and the vehicle is greater than or equal to a predetermined distance, the target trajectory generation unit executes the first target trajectory update process, and if the distance between the new parking space candidate and the vehicle is less than the predetermined distance, the target trajectory generation unit executes the second target trajectory update process.

7. When steering intervention is performed during the automatic driving, if the distance between the new parking space candidate and the vehicle is greater than or equal to a predetermined first distance, the target trajectory generation unit executes the first target trajectory update process; if the distance between the new parking space candidate and the vehicle is less than a predetermined second distance shorter than the first distance, the target trajectory generation unit executes the second target trajectory update process; and if the distance between the new parking space candidate and the vehicle is greater than or equal to the second distance and less than the first distance, the target trajectory generation unit determines, based on information regarding the steering intervention, whether to execute the first target trajectory update process or the second target trajectory update process, as described in claim 5.

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