Motor control device

Abstract

To provide a motor control device that is able to reduce discomfort of a driver when switching a target traveling lane.SOLUTION: In a drive assist mode, a manual steering command value calculation unit is configured to calculate a manual steering command value by using a motion equation of a reference model of a steering device. When a direction change command is input by driver operation or when a predetermined lane change approval condition is satisfied thereafter, an automatic steering command value for causing the vehicle to travel along a current lane is set to an automatic steering command value for causing the vehicle to travel along an adjacent lane corresponding to the direction change command. In a pre-switching and post-switching period including a point in time that the automatic steering command value is switched, the manual steering command value calculation unit sets a virtual spring reaction force in the motion equation to zero and calculates a manual steering command value.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to a motor control device. [Background technology]

[0002] In the lane keeping device described in Patent Document 1 below, in automatic steering mode, a target steering angle for driving the vehicle along a target line is calculated, and a control command is output to a motor to obtain this target steering angle.

[0003] When changing the target driving lane, it is determined whether or not to change lanes based on the lane deviation amount, which is the deviation amount in the vehicle width direction between the target line and the vehicle's driving line. If it is determined that the lane should be changed, the target driving lane is changed. Then, a lane change control gain (see FIG. 5 of Patent Document 1) is set such that the control gain gradually decreases from a peak at the point where it is determined that the lane should be changed. Note that the larger the control gain, the stronger the force that returns the vehicle to the target line. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2005-162015 A [Patent Document 2] International Publication No. 2023 / 286169 Summary of the Invention [Problem to be solved by the invention]

[0005] In the lane keeping device described in Patent Document 1, when the target driving lane is changed, the direction of the steering assist force by the system is reversed, which may cause the driver to feel uncomfortable, such as torque loss.

[0006] An object of the present disclosure is to provide a motor control device that can reduce the discomfort felt by the driver when the target driving lane is changed. [Means for solving the problem]

[0007] One embodiment of the present disclosure is a motor control device for driving and controlling an electric motor of a steering device, the motor control device including: a manual steering command value calculation unit that calculates a manual steering command value using a torsion bar torque; an integrated angle command value calculation unit that adds the manual steering command value to an automatic steering command value for driving assistance to calculate an integrated angle command value; and a motor control unit that controls the electric motor based on the integrated angle command value, wherein in a driving assistance mode, the manual steering command value calculation unit is configured to calculate the manual steering command value by utilizing an equation of motion of a reference model of the steering device, and when a predetermined lane change approval condition is satisfied after a direction change command is input by a driver operation, the automatic steering command value for driving a vehicle along a current lane is switched to an automatic steering command value for driving a vehicle along an adjacent lane in accordance with the direction change command, and during a period before and after switching including a time point at which the automatic steering command value is switched, the manual steering command value calculation unit sets a virtual spring reaction force in the equation of motion to zero to calculate the manual steering command value.

[0008] This configuration can reduce the discomfort felt by the driver when the target driving lane is changed.

[0009] The above and other objects, features and advantages of the present disclosure will become apparent from the following detailed description of the embodiments with reference to the accompanying drawings. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a schematic diagram showing a schematic configuration of an electric power steering system to which a motor control device according to an embodiment of the present disclosure is applied. [Diagram 2] FIG. 2 is a block diagram for explaining the electrical configuration of the motor control ECU. [Diagram 3]FIG. 3 is a graph showing an example of setting the assist torque command value Tas relative to the torsion bar torque Ttb. [Figure 4] FIG. 4 is a schematic diagram showing an example of a reference EPS model. [Diagram 5] FIG. 5 is a block diagram showing the configuration of the manual steering command value calculation unit. [Figure 6] FIG. 6 is a block diagram showing the configuration of the angle control unit. [Figure 7] FIG. 7 is a schematic diagram showing a configuration example of a physical model of an electric power steering system. [Figure 8] FIG. 8 is a block diagram showing the configuration of the disturbance torque estimating unit. [Figure 9] FIG. 9 is a schematic diagram showing the configuration of the torque control unit. [Figure 10A] FIG. 10A is a flowchart showing a part of the procedure of the command value selection process performed by the host ECU. [Figure 10B] FIG. 10B is a flowchart showing a part of the procedure of the command value selection process performed by the host ECU. [Figure 11] FIG. 11 is a graph showing an example of setting the first resistance spring constant kre1(el, el_brinker) with respect to (el-el_brinker). [Figure 12] FIG. 12 is a graph showing an example of setting the first guide spring constant kgu1(el, el_change) with respect to (el-el_change). [Figure 13] FIG. 13 is a graph showing an example of setting the second resistance spring constant kre2(el, el_brinker) with respect to (el-el_brinker). [Figure 14] FIG. 14 is a graph showing an example of setting the second guide spring constant kgu2(el, el_change) with respect to (el-el_change). [Figure 15A] FIG. 15A is a flowchart showing a part of the procedure of the spring constant setting process performed by the spring constant setting unit. [Figure 15B]FIG. 15B is a flowchart showing a part of the procedure of the spring constant setting process performed by the spring constant setting unit. [Figure 16] FIG. 16 is a block diagram showing a first modified example of the motor control ECU. [Figure 17] FIG. 17 is a block diagram showing mainly the configuration of the manual steering command value calculation unit. [Figure 18] FIG. 18 is a block diagram showing the configuration of the second manual steering command value calculation unit. [Figure 19] FIG. 19 is a graph showing an example of setting the first resistance spring reaction force Ttb,d_re1(el,el_brinker) relative to (el-el_brinker). [Figure 20] FIG. 20 is a graph showing an example of setting the first guidance spring reaction force Ttb,d_gu1(el,el_change) with respect to (el-el_change). [Figure 21] FIG. 21 is a graph showing an example of setting the second resistance spring reaction force Ttb,d_re2(el,el_brinker) relative to (el-el_brinker). [Figure 22] FIG. 22 is a graph showing an example of setting the second guidance spring reaction force Ttb,d_gu2(el,el_change) with respect to (el-el_change). [Figure 23A] FIG. 23A is a flowchart showing a part of the procedure of the constant / reaction force setting process performed by the spring constant / target virtual spring reaction force setting unit. [Figure 23B] FIG. 23B is a flowchart showing a part of the procedure of the constant / reaction force setting process performed by the spring constant / target virtual spring reaction force setting unit. [Figure 24A] FIG. 24A is a flowchart showing a part of the procedure of the constant / reaction force setting process performed by a first modified example of the spring constant / target virtual spring reaction force setting section. [Figure 24B] FIG. 24B is a flowchart showing a part of the procedure of the constant / reaction force setting process performed by the first modified example of the spring constant / target virtual spring reaction force setting section. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] [Description of the embodiments of the present disclosure] One embodiment of the present disclosure is a motor control device for driving and controlling an electric motor of a steering device, the motor control device including: a manual steering command value calculation unit that calculates a manual steering command value using a torsion bar torque; an integrated angle command value calculation unit that adds the manual steering command value to an automatic steering command value for driving assistance to calculate an integrated angle command value; and a motor control unit that controls the electric motor based on the integrated angle command value, wherein in a driving assistance mode, the manual steering command value calculation unit is configured to calculate the manual steering command value by utilizing an equation of motion of a reference model of the steering device, and when a predetermined lane change approval condition is satisfied after a direction change command is input by a driver operation, the automatic steering command value for driving a vehicle along a current lane is switched to an automatic steering command value for driving a vehicle along an adjacent lane in accordance with the direction change command, and during a period before and after switching including a time point at which the automatic steering command value is switched, the manual steering command value calculation unit sets a virtual spring reaction force in the equation of motion to zero to calculate the manual steering command value.

[0012] This configuration can reduce the discomfort felt by the driver when the target driving lane is changed.

[0013] In one embodiment of the present disclosure, the virtual spring reaction force in the equation of motion is a virtual spring reaction force that is set using a spring constant of a virtual spring.

[0014] In one embodiment of the present disclosure, a target virtual spring reaction force that changes depending on the lateral position of the vehicle reference position with respect to the driving lane is used as the virtual spring reaction force in the equation of motion.

[0015] In one embodiment of the present disclosure, during the period from when the direction change command is input until the automatic steering command value is switched, the manual steering command value calculation unit calculates the manual steering command value using a target virtual spring reaction force that changes depending on the lateral position of the vehicle reference position relative to the driving lane, as the virtual spring reaction force in the equation of motion, and at least immediately after the automatic steering command value is switched, the manual steering command value calculation unit calculates the manual steering command value using a virtual spring reaction force that is set using a spring constant of a virtual spring, as the virtual spring reaction force in the equation of motion.

[0016] Detailed Description of the Embodiments of the Present Disclosure Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

[0017] FIG. 1 is a schematic diagram showing a schematic configuration of an electric power steering system to which a motor control device according to an embodiment of the present disclosure is applied.

[0018] The electric power steering system 1 includes a steering wheel (handle) 2 as a steering member for steering a vehicle, a steering mechanism 4 for steering steered wheels 3 in conjunction with the rotation of the steering wheel 2, and a steering assist mechanism 5 for assisting the driver in steering. The steering wheel 2 and the steering mechanism 4 are mechanically connected via a steering shaft 6 and an intermediate shaft 7.

[0019] 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 capable of relative rotation.

[0020] A torque sensor 12 is disposed near the torsion bar 10. The torque sensor 12 detects a torsion bar torque (steering torque) T applied to the steering wheel 2 based on the amount of relative rotational displacement between the input shaft 8 and the output shaft 9. tb In this embodiment, the torsion bar torque Ttb For example, the torque for steering to the right is detected as a positive value, and the torque for steering to the left is detected as a negative value. The larger the absolute value of the torque, the greater the torsion bar torque T tb The magnitude of is assumed to be large.

[0021] The steering mechanism 4 is composed of a rack-and-pinion mechanism including a pinion shaft 13 and a rack shaft 14 as a steering shaft. The steered 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.

[0022] The rack shaft 14 extends linearly in the left-right direction of the vehicle. A rack 17 that meshes with the pinion 16 is formed in the middle of the rack shaft 14 in the axial direction. The pinion 16 and the rack 17 convert the rotation of the pinion shaft 13 into the axial movement of the rack shaft 14. The steered wheels 3 can be steered by moving the rack shaft 14 in the axial direction.

[0023] 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. As a result, the steered wheels 3 are steered.

[0024] The steering assist mechanism 5 includes an electric motor 18 for generating a steering assist force (assist torque), and a reducer 19 for amplifying the output torque of the electric motor 18 and transmitting it to the steering mechanism 4. The reducer 19 is made up of a worm gear mechanism including a worm gear 20 and a worm wheel 21 meshing with the worm gear 20. The reducer 19 is accommodated in a gear housing 22 serving as a transmission mechanism housing. In the following, the reduction ratio (gear ratio) of the reducer 19 may be represented as N. The reduction ratio N is determined by the rotation angle θ of the worm wheel 21.ww Rotation angle θ of the worm gear 20 relative to wg The ratio θ wg / θ ww It is defined as:

[0025] The worm gear 20 is rotationally driven by the electric motor 18. In addition, the worm wheel 21 is connected to the output shaft 9 so as to be integrally rotatable therewith.

[0026] When the worm gear 20 is rotationally driven by the electric motor 18, the worm wheel 21 is rotationally driven, and motor torque is applied to the steering shaft 6, causing the steering shaft 6 (output shaft 9) to rotate. The rotation of the steering shaft 6 is then 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.

[0027] This causes the steered wheels 3 to turn. That is, by driving the worm gear 20 to rotate by the electric motor 18, it becomes possible for the electric motor 18 to provide steering assistance and turn the steered wheels 3. The electric motor 18 is provided with a rotation angle sensor 23 for detecting the rotation angle of the rotor of the electric motor 18.

[0028] The torque applied to the output shaft 9 (one example of a drive target of the electric motor 18) includes motor torque by the electric motor 18 and disturbance torque other than the motor torque. Disturbance torque T lc Torsion bar torque T tb , Road reaction torque (road load torque) T rl , friction torque T f etc. are included.

[0029] Torsion bar torque T tb is the torque applied to the output shaft 9 from the steering wheel 2 side by the force applied to the steering wheel 2 by the driver, the force generated by steering inertia, etc.

[0030] Road reaction torque T rlis the torque applied to the output shaft 9 from the steered wheels 3 via the rack shaft 14 due to the self-aligning torque generated in the tires, forces generated by the suspension and tire / wheel alignment, frictional force of the rack and pinion mechanism, etc.

[0031] The vehicle is equipped with a CCD (Charge Coupled Device) camera 25 that photographs the road ahead in the direction of travel of the vehicle, a GPS (Global Positioning System) 26 for detecting the vehicle's position, a radar 27 for detecting road shapes and obstacles, a map information memory 28 that stores map information, a vehicle speed sensor 29 that detects the vehicle speed V, a direction change input device 30, and the like.

[0032] The CCD camera 25, GPS 26, radar 27, map information memory 28, vehicle speed sensor 29, and direction change input device 30 are connected to a host ECU (Electronic Control Unit) 201 for performing driving assistance control and automatic driving control. The host ECU 201 recognizes the surrounding environment, estimates the vehicle's position, plans a route, and so on, based on the information obtained by the CCD camera 25, GPS 26, radar 27, vehicle speed sensor 29, and direction change input device 30 and map information, and determines control target values ​​for steering and drive actuators.

[0033] In this embodiment, the host ECU 201 controls the automatic steering command value θ ad In this embodiment, the automatic steering control is, for example, a control for driving the vehicle along a target driving line. ad is the target value of the steering angle for automatically driving the vehicle along the target driving line (the center line of the lane).

[0034] In this embodiment, the automatic steering command value θ ad is expressed by the amount of rotation (rotation angle) of the output shaft 9 from the neutral position, the amount of rotation from the neutral position to the right steering direction is expressed as a positive value, and the amount of rotation from the neutral position to the left steering direction is expressed as a negative value. adis set based on, for example, the vehicle speed, the lateral deviation from the target driving line (the center line of the lane), and the yaw deviation of the vehicle from the target driving line. ad The process of setting is well known, so a detailed description will be omitted here.

[0035] In addition, the automatic steering control (driving assistance control) may be, for example, lane centering assist (LCA) control, which assists in steering so that the vehicle travels along the center line of the lane, or lane keeping assist (LKA) control, which assists in steering so that the vehicle stays within the driving lane.

[0036] In this embodiment, the host ECU 201 controls the automatic steering command value θ ad The first automatic steering command value θ ad1 and the second automatic steering command value θ ad2 and the third automatic steering command value θ ad3 Set the following.

[0037] First automatic steering command value θ ad1 is an automatic steering command value for driving the vehicle along the center line of the lane in which the vehicle is currently traveling (hereinafter referred to as the "current lane"). ad2 is an automatic steering command value for driving the vehicle along the center line of the lane to the right of the current lane (hereinafter referred to as the "right lane"). ad3 is an automatic steering command value for driving the vehicle along the center line of the lane to the left of the current lane (hereinafter referred to as the "left lane"). In other words, the automatic steering command value θ ad1 ,θ ad2 ,θ ad3 is the target steering angle for automatically driving the vehicle along the center line of each lane.

[0038] In addition, when there is no lane to the right of the current lane, the second automatic steering command value θ ad2 Similarly, when there is no left lane for the current lane, the third automatic steering command value θ ad3 is not set.

[0039] In addition, the host ECU 201 detects the lateral deviation e l In this embodiment, the lateral deviation e l is the distance from the currently set target driving line (lane center line) to the reference position of the vehicle (hereinafter referred to as the "vehicle reference position"). The vehicle reference position is set at a predetermined position in the center of the vehicle width.

[0040] In this embodiment, the lateral deviation e l is 0 (e l = 0), and when the vehicle reference position is on the right side of the target driving line in the direction of travel, it becomes a positive value (e l >0), and if the vehicle reference position is to the left of the target driving line in the direction of travel, it becomes a negative value (e l <0).

[0041] The direction change input device 30 includes, for example, a turn signal lever for operating a turn signal. When turning right or left or changing lanes, the driver operates the turn signal lever to input a direction change command. When the driver operates the turn signal lever, a rightward direction change command or a leftward direction change command is input. When the turn signal lever is tilted from the turn signal off position, which is the normal position, to the turn signal on position, the input of the direction change command is started, and when the turn signal lever is returned to the turn signal off position, the input of the direction change command is stopped. In other words, the direction change command is continuously input while the turn signal lever is tilted to the turn signal on position.

[0042] The host ECU 201 receives a direction change command I NG In this embodiment, the direction change command I NG shall take the values ​​0, 1, or 2. NG =0 indicates that the turn signal lever is not operated. NG=1 indicates that a rightward direction change command has been input. NG =2 indicates that a left direction change command has been input.

[0043] The host ECU 201 uses a direction change command or the like to set an automatic steering command value θ ad1 ,θ ad2 ,θ ad3 The automatic steering command value θ ad Let's just say that.

[0044] In addition, the host ECU 201 generates a steering mode signal S indicating whether the steering mode (driving mode) is a manual steering mode (manual driving mode) or a cooperative steering mode (driving assistance mode) based on the operation of the first mode switch 31 and the second mode switch 32. mode Specifically, when the first mode switch 31 is turned on by the driver, the host ECU 201 outputs a steering mode signal S mode On the other hand, when the second mode switch 32 is turned on by the driver, the host ECU 201 outputs a steering mode signal S mode Output.

[0045] Automatic steering command value θ ad , lateral deviation e l , the lateral deviation e immediately after the lane change, which will be described later l_change , vehicle speed V, direction change command I NG and steering mode signal S mode is provided to the motor control ECU 202 via the in-vehicle network. tb An output signal of 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 host ECU 201.

[0046] FIG. 2 is a block diagram for explaining the electrical configuration of motor control ECU 202. As shown in FIG.

[0047] The motor control ECU 202 includes a microcomputer 50, a drive circuit (inverter circuit) 41 controlled by the microcomputer 50 to supply power to the electric motor 18, and a current flowing through the electric motor 18 (hereinafter, “motor current I m The power supply 41 includes a current detection circuit 42 for detecting a current that is applied to the power supply 41.

[0048] The microcomputer 50 includes a CPU and memory (ROM, RAM, non-volatile memory, etc.), and functions as a plurality of functional processing units by executing a predetermined program.

[0049] The multiple functional processing units include an assist torque command value setting unit 51, a spring constant setting unit 52, a manual steering command value calculation unit 53, an integrated angle command value calculation unit 54, an angle control unit 55, a first switch 56, a second switch 57, an addition unit 58, and a torque control unit (current control unit) 59.

[0050] The assist torque command value setting unit 51 sets the assist torque command value T as The assist torque command value setting unit 51 sets the assist torque command value based on the vehicle speed V given by the host ECU 201 and the torsion bar torque T detected by the torque sensor 12. tb Based on this, the assist torque command value T as Set the torsion bar torque T tb Assist torque command value T as An example of the configuration is shown in Figure 3.

[0051] Assist torque command value T as is set to a positive value when the electric motor 18 is to generate a steering assist force for steering in the right direction, and is set to a negative value when the electric motor 18 is to generate a steering assist force for steering in the left direction. asis the torsion bar torque T tb For positive values ​​of , the torsion bar torque T tb For negative values ​​of , it is negative.

[0052] Assist torque command value T as is the torsion bar torque T tb The larger the absolute value of , the larger the absolute value of , and the larger the vehicle speed V, the smaller the absolute value of .

[0053] The assist torque command value setting unit 51 determines the torsion bar torque T tb The assist torque command value T as may be calculated.

[0054] The spring constant setting unit 52 determines the spring constant k of the virtual spring used in the manual steering command value calculation unit 53. s The operation of the spring constant setting unit 52 will be described in detail later.

[0055] When the driver operates the steering wheel 2 in the cooperative steering mode, the manual steering command value calculation unit 53 calculates a steering angle (more precisely, a rotation angle θ of the output shaft 9) according to the steering wheel operation. c ) is the manual steering command value θ md In this embodiment, the manual steering command value calculation unit 53 is provided to set the torsion bar torque T tb and the spring constant k set by the spring constant setting unit 52. s and the viscous damping coefficient c of the virtual damper that is set in advance, md The manual steering command value calculation unit 53 will be described in detail later.

[0056] The integrated angle command value calculation unit 54 calculates the automatic steering command value θ ad , manual steering command value θ md Adding this, the integrated angle command value θ cmdCalculate the following.

[0057] The angle control unit 55 calculates an integrated angle command value θ cmd Based on this, the motor torque command value T com The angle control unit 55 will be described in detail later.

[0058] The first switch 56 and the second switch 57 are connected to the steering mode signal S mode Specifically, the steering mode signal S indicating that the steering mode is the manual steering mode is mode is input, the first switch 56 is turned on and the second switch 57 is turned off.

[0059] On the other hand, the steering mode signal S mode is input, the first switch 56 is turned off and the second switch 57 is turned on.

[0060] When the first switch 56 is in the ON state and the second switch 57 is in the OFF state, that is, when the steering mode is the manual steering mode, the adder 58 calculates the assist torque command value T as The motor torque command value T m,cmd (=T as ) when the steering mode is the manual steering mode. Therefore, the electric motor 18 outputs the assist torque command value T as The drive control is based only on the above.

[0061] On the other hand, when the second switch 57 is in the ON state and the first switch 56 is in the OFF state, that is, when the steering mode is the cooperative steering mode, the adder 58 calculates the integrated motor torque command value T com The motor torque command value T m,cmd (=T com ) when the steering mode is the cooperative steering mode. Therefore, the electric motor 18 outputs the integrated motor torque command value T com The drive is controlled based on the above.

[0062] The motor torque command value T m,cmd is provided to the torque control section 59.

[0063] The torque control unit 59 controls the motor torque of the electric motor 18 to a motor torque command value T m,cmd The torque control unit 59 drives the drive circuit 41 so that the torque approaches the torque saturation value saturation. The torque control unit 59 will be described in detail later.

[0064] The manual steering command value calculation unit 53 will be described in detail. First, the manual steering command value θ md This section explains how to set this up.

[0065] The manual steering command value generator calculates the manual steering command value θ md The reference EPS model in FIG. 4 is an example of the "reference model for the steering device" of the present disclosure.

[0066] This reference EPS model is a single inertia model including a lower column. The lower column corresponds to the output shaft 9 and the worm wheel 21. In FIG. md is the inertia of the lower column, and θ col is the rotation angle of the lower column, and T tb is the torsion bar torque. The lower column has a torsion bar torque T tb , the torque N·T acting on the output shaft 9 from the electric motor 18 m and road reaction torque (virtual reaction force) T rl is given.

[0067] Road reaction torque T rl is expressed by the following equation (1) using the spring constant k of the virtual spring and the viscous damping coefficient c of the virtual damper.

[0068]

number

[0069] The spring constant k and the viscous damping coefficient c are determined in advance through experiments, analysis, etc. In the following, k·θ col is called the virtual spring reaction force, and c(dθ col / dt) is sometimes called the virtual damper reaction force.

[0070] The equation of motion of the reference EPS model is expressed by the following equation (2).

[0071]

number

[0072] In equation (2), J md d 2 θ col / dt 2 is the moment of inertia acting on the lower column.

[0073] The manual steering command value generator is T tb The torsion bar torque T detected by the torque sensor 12 is tb Substituting, T m The assist torque command value T as By substituting and solving the differential equation (2), the rotation angle θ of the lower column is col Then, the manual steering command value generating unit calculates the obtained rotation angle θ col Manual steering command value θ md In this way, the manual steering command value θ md The method for generating the above will be called the comparison method.

[0074] The equation of motion in equation (2) is T m T as and θ col θ md This is equivalent to the equation of motion in which

[0075] In this embodiment, the manual steering command value calculation unit 53 calculates the manual steering command value θ by using the motion equation (2) of the reference EPS model described above. md Specifically, in this embodiment, the manual steering command value calculation unit 53 calculates the manual steering command value θ based on a motion equation obtained by modifying the motion equation (2) of the reference EPS model described above. md Calculate the following.

[0076] FIG. 5 is a block diagram showing the configuration of the manual steering command value calculation unit 53.

[0077] In Figure 5, J md is the inertia of the lower column (hereinafter referred to as "column inertia"). The lower column corresponds to the output shaft 9 and the worm wheel 21. s is a differential operator. θ md is the manual steering command value, and the rotation angle θ of the lower column in the comparison method col c is the viscous damping coefficient of the virtual damper, which is obtained in advance through experiments, analysis, etc. s is the spring constant set by the spring constant setting unit 52.

[0078] The manual steering command value calculation unit 53 includes an addition / subtraction unit 101, an inertia division unit 102, a first integration unit 103, a second integration unit 104, a virtual damper reaction force calculation unit 105, and a virtual spring reaction force calculation unit 106.

[0079] The addition / subtraction unit 101 receives the torsion bar torque T tb and the virtual damper reaction force c·dθ given by the virtual damper reaction force calculation unit 105. md / dt and the virtual spring reaction force k given by the virtual spring reaction force calculation unit 106 s θ md and is entered.

[0080] The addition / subtraction unit 101 calculates the torsion bar torque T tb From the above, the virtual damper reaction force c dθ md / dt and virtual spring reaction force k s θ md As a result, the adder / subtractor unit 101 subtracts J on the left side of the above equation (2).col d 2 θ c / dt 2 The moment of inertia J corresponds to md d 2 θ md / dt 2 (=T tb -k s θ md -c dθ md / dt).

[0081] The inertia division unit 102 divides the moment of inertia J calculated by the addition / subtraction unit 101. md d 2 θ md / dt 2 Column inertia J md By dividing by , the manual steering command value θ md The second derivative d 2 θ md / dt 2 Calculate the following.

[0082] The first integration unit 103 calculates the manual steering command value θ md The second derivative d 2 θ md / dt 2 By integrating, the manual steering command value θ md The first derivative dθ md Calculate / dt.

[0083] The second integration unit 104 integrates the manual steering command value θ md The first derivative dθ md By integrating / dt, the manual steering command value θ md This manual steering command value θ md is output from the manual steering command value calculation unit 53.

[0084] The virtual damper reaction force calculation unit 105 calculates the manual steering command value θ md The first derivative dθ md / dt is multiplied by the viscous damping coefficient c to obtain the virtual damper reaction force c dθ md / dt is calculated. This virtual damper reaction force c dθ md / dt is fed back to the addition / subtraction unit 101 .

[0085] The virtual spring reaction force calculation unit 106 calculates the manual steering command value θ md The spring constant k set by the spring constant setting unit 52 s By multiplying by k, we obtain the virtual spring reaction force k s θ md This virtual spring reaction force k s θ md is fed back to the addition / subtraction unit 101.

[0086] That is, the manual steering command value calculation unit 53 calculates the manual steering command value θ based on the equation of motion shown in the following equation (3). md Calculate the following.

[0087]

number

[0088] In equation (3), J md d 2 θ md / dt 2 is the moment of inertia. c dθ md / dt is the virtual damper reaction force. k s θ md is the virtual spring reaction force.

[0089] In this embodiment, the manual steering command value calculation unit 53 calculates the N·T m (=N T as ) is set to 0, and the virtual spring reaction force k θ in the equation of motion in the above formula (2) is md As k s θ md Using the above, the manual steering command value θ md Calculate the following.

[0090] The manual steering command value calculation unit 53 calculates the assist torque command value T as By multiplying by the reduction ratio N, N·T as Calculate the result N Tas In this case, the addition / subtraction unit 101 may provide the torsion bar torque T tb To N.T. as The virtual damper reaction force c dθ is calculated from the sum. md / dt and virtual spring reaction force k s θ md In this case, the manual steering command value calculation unit 53 subtracts N·T from the right side of the above equation (3). as Based on the equation of motion to which md The following calculation is performed:

[0091] FIG. 6 is a block diagram showing the configuration of angle control unit 55.

[0092] The angle control unit 55 calculates an integrated angle command value θ cmd Based on this, the integrated motor torque command value T com The angle control unit 55 includes a low pass filter (LPF) 61, a feedback control unit 62, a feedforward control unit 63, a disturbance torque estimating unit 64, a torque adding unit 65, a disturbance torque compensating unit 66, a first reduction gear ratio dividing unit 67, a reduction gear ratio multiplying unit 68, a rotation angle calculating unit 69, and a second reduction gear ratio dividing unit 70.

[0093] The reduction ratio multiplication unit 68 multiplies the motor torque command value T m,cmd By multiplying this by the reduction ratio N of the reducer 19, the motor torque command value T m,cmd The output shaft torque command value N·T acting on the output shaft 9 (worm wheel 21) m,cmd Convert to.

[0094] The rotation angle calculation unit 69 calculates the rotor rotation angle θ of the electric motor 18 based on the output signal of the rotation angle sensor 23. m The second reduction ratio division unit 70 calculates the rotor rotation angle θ m By dividing by the reduction ratio N, the rotor rotation angle θ m The rotation angle of the output shaft 9 (actual steering angle) θ c Convert to.

[0095] In this embodiment, the actual steering angle θ c is expressed as the amount of rotation (rotation angle) from the neutral position of the output shaft 9, with the amount of rotation from the neutral position in the right steering direction being expressed as a positive value and the amount of rotation from the neutral position in the left steering direction being expressed as a negative value.

[0096] The low-pass filter 61 calculates the integrated angle command value θ cmd The integrated angle command value θ cmdl is provided to the feedback control section 62 and the feedforward control section 63.

[0097] The feedback control unit 62 converts the steering angle estimated value ^θ calculated by the disturbance torque estimation unit 64 into an integrated angle command value θ after low-pass filtering. cmdl The feedback control unit 62 includes an angle deviation calculation unit 62A and a PD control unit 62B. The angle deviation calculation unit 62A calculates an integrated angle command value θ cmdl and the estimated steering angle ^θ c Deviation Δθ(=θ cmdl -^θ c The angle deviation calculation unit 62A calculates the integrated angle command value θ cmdl and the actual steering angle θ calculated by the second reduction ratio division unit 70. c Deviation from (θ cmdl -θ c ) may be calculated as the angle deviation Δθ.

[0098] The PD control unit 62B performs a PD calculation (proportional differential calculation) on the angle deviation Δθ calculated by the angle deviation calculation unit 62A, thereby obtaining a feedback control torque T fb Calculate the feedback control torque T fb is provided to the torque adder 65.

[0099] The feedforward control unit 63 is provided to compensate for a delay in response due to the inertia of the electric power steering system 1, thereby improving the response of the control. The feedforward control unit 63 includes an angular acceleration calculation unit 63A and an inertia multiplication unit 63B. The angular acceleration calculation unit 63A calculates an integrated angle command value θ cmdl By differentiating it twice, the target angular acceleration d 2 θ cmdl / dt 2 Calculate the following.

[0100] The inertia multiplication unit 63B multiplies the target angular acceleration d calculated by the angular acceleration calculation unit 63A by 2 θ cmdl / dt 2 is multiplied by the inertia J of the electric power steering system 1 to obtain the feedforward control torque T ff (=J d 2 θ cmdl / dt 2 The inertia J can be calculated, for example, from a physical model (see FIG. 7) of the electric power steering system 1, which will be described later. The feedforward control torque T ff is provided to the torque adder 65 as an inertia compensation value.

[0101] The torque addition unit 65 calculates the feedback control torque T fb The feedforward control torque T ff By adding fb +T ff ) is calculated.

[0102] The disturbance torque estimating unit 64 is provided to estimate a nonlinear torque (disturbance torque: torque other than the motor torque) that occurs as a disturbance in the plant (the object to be controlled by the electric motor 18). The disturbance torque estimating unit 64 estimates the output shaft torque command value N·T m,cmd and the actual steering angle θ c Based on this, the disturbance torque (disturbance load) T lc , steering angle θ and steering angle differential value (angular velocity) dθ c / dt is estimated. Disturbance torque T lc , steering angle θ cand steering angle differential (angular velocity) dθ c The estimates of / dt are lc , ^θ c and d^θ c The disturbance torque estimation unit 64 will be described in detail later.

[0103] The disturbance torque estimated value ^T calculated by the disturbance torque estimator 64 lc is given to the disturbance torque compensator 66 as a disturbance torque compensation value. The steering angle estimated value ^θ calculated by the disturbance torque estimator 64 c is provided to the angle deviation calculation unit 62A.

[0104] The disturbance torque compensation unit 66 calculates the basic torque command value (T fb +T ff ) to the estimated disturbance torque ^T lc By subtracting co (=T fb +T ff -^T lc ) is calculated. This results in the integrated torque command value T co (torque command value for output shaft 9) is obtained.

[0105] Integrated torque command value T co is provided to a first reduction ratio division unit 67. The first reduction ratio division unit 67 calculates an integrated torque command value T co By dividing by the reduction ratio N, the integrated motor torque command value T com (torque command value for the electric motor 18). This integrated motor torque command value T com is provided to the second switch 57 (see FIG. 2).

[0106] The disturbance torque estimation unit 64 will now be described in detail. The disturbance torque estimation unit 64 uses, for example, a physical model 300 of the electric power steering system 1 shown in FIG. lc , steering angle θ c and angular velocity dθ c It consists of a disturbance observer that estimates / dt.

[0107] This physical model 300 includes a plant (an example of a motor-driven object) 301 including an output shaft 9 and a worm wheel 21 fixed to the output shaft 9. The plant 301 receives a torsion bar torque T tb is applied, and a road reaction torque T rl is given.

[0108] Furthermore, the plant 301 is supplied with an output shaft torque command value N·T via a worm gear 20. m,cmd is given, and friction torque T f is given.

[0109] If the inertia of the plant 301 is J, the equation of motion for the inertia of the physical model 300 is expressed by the following equation (4).

[0110]

number

[0111] d 2 θ c / dt 2 is the angular acceleration of the plant 301. N is the reduction ratio of the reducer 19. T lc indicates a disturbance torque other than the motor torque applied to the plant 301. In this embodiment, the disturbance torque T lc is the torsion bar torque T tb and road reaction torque T rl and friction torque T f However, in reality, the disturbance torque T lc includes torques other than these.

[0112] The state equation for the physical model 300 in FIG.

[0113]

number

[0114] In the above formula (5), x is a state variable vector, u1 is a known input vector, u2 is an unknown input vector, and y is an output vector (measurement value). Also, in the above formula (5), A is a system matrix, B1 is a first input matrix, B2 is a second input matrix, C is an output matrix, and D is a direct feedthrough matrix.

[0115] The state equation is expanded to a system including the unknown input vector u2 as one of the states. The state equation of the expanded system (expanded state equation) is expressed by the following equation (6).

[0116]

number

[0117] In the formula (6), x e is the state variable vector of the extended system and is expressed by the following equation (7).

[0118]

number

[0119] In the formula (6), A e is the system matrix of the expanded system, B e is the known input matrix of the extended system, C e is the output matrix of the augmented system.

[0120] From the extended state equation of the above formula (6), a disturbance observer (extended state observer) expressed by the following formula (8) is constructed.

[0121]

number

[0122] In equation (8), ^x e x erepresents the estimated value of . Also, L is the observer gain. Also, ^y represents the estimated value of y. ^x e is expressed by the following equation (9).

[0123]

number

[0124] In equation (9), ^θ c is θ c is an estimate of ^T lc is T lc is an estimate.

[0125] The disturbance torque estimation unit 64 calculates the state variable vector ^x based on the above equation (8). e Calculate the following.

[0126] FIG. 8 is a block diagram showing the configuration of the disturbance torque estimating unit 64. As shown in FIG.

[0127] The disturbance torque estimation unit 64 includes an input vector input unit 81, an output matrix multiplication unit 82, a first adder unit 83, a gain multiplication unit 84, an input matrix multiplication unit 85, a system matrix multiplication unit 86, a second adder unit 87, an integration unit 88, and a state variable vector output unit 89.

[0128] The output shaft torque command value N·T calculated by the reduction ratio multiplication unit 68 (see FIG. 6) m,cmd is provided to an input vector input unit 81. The input vector input unit 81 outputs an input vector u1.

[0129] The output of the integrator 88 is the state variable vector ^x e (See equation (9) above.) At the start of the calculation, the state variable vector ^x e The initial value is given as the state variable vector ^x e The initial value of is, for example, 0.

[0130] The system matrix multiplication unit 86 multiplies the state variable vector ^x e In the system matrix Ae The output matrix multiplication unit 82 multiplies the state variable vector ^x e to the output matrix C e Multiply by.

[0131] The first adder 83 calculates the output (C e ^x e That is, the first adder 83 subtracts the output vector y from the output vector estimate ^y (=C e ^x e ) to calculate the difference (y-^y). The gain multiplication unit 84 multiplies the output (y-^y) of the first addition unit 83 by the observer gain L (see equation (8) above).

[0132] The input matrix multiplication unit 85 multiplies the input vector u1 output from the input vector input unit 81 by the input matrix B e The second adder 87 multiplies the output of the input matrix multiplier 85 (B e u1) and the output of the system matrix multiplication unit 86 (A e ^x e ) and the output of the gain multiplication unit 84 (L(y-^y)), the differential value d^x of the state variable vector is obtained. e The integrator 88 calculates the output of the second adder 87 (d^x e / dt), the state variable vector ^x e The state variable vector output unit 89 calculates the state variable vector ^x e Based on this, the disturbance torque estimate ^T lc , steering angle estimate ^θ c and the estimated angular velocity d^θ c Calculate / dt.

[0133] Unlike the above-mentioned extended state observer, a general disturbance observer is composed of an inverse model of the plant and a low-pass filter. The equation of motion of the plant is expressed by equation (3) as mentioned above. Therefore, the inverse model of the plant is expressed by the following equation (10).

[0134]

number

[0135] The input to a typical disturbance observer is J d 2 θ c / dt 2 and N.T. m,cmd and the actual steering angle θ c Since the second-order differential value of is used, it is significantly affected by noise from the rotation angle sensor 23. In contrast, the extended state observer of the above-described embodiment estimates the disturbance torque in an integral manner, so that it is possible to reduce the influence of noise due to differentiation.

[0136] The disturbance torque estimating unit 64 may be a general disturbance observer that is configured with an inverse model of the plant and a low-pass filter.

[0137] FIG. 9 is a schematic diagram showing the configuration of the torque control unit 59.

[0138] The torque control unit 59 (see FIG. 2) includes a motor current command value calculation unit 91, a current deviation calculation unit 92, a PI control unit 93, and a PWM (Pulse Width Modulation) control unit 94.

[0139] The motor current command value calculation unit 91 calculates the motor torque command value T m,cmd The torque constant K of the electric motor 18 t The motor current command value I m,cmd Calculate the following.

[0140] The current deviation calculation unit 92 calculates the motor current command value I m,cmd and the motor current I detected by the current detection circuit 42. m Deviation ΔI (=I m,cmd -I m ) is calculated.

[0141] The PI control unit 93 performs a PI calculation (proportional integral calculation) on the current deviation ΔI calculated by the current deviation calculation unit 92 to calculate the motor current I flowing through the electric motor 18 as a motor current command value I m,cmd The PWM control unit 94 generates a PWM control signal having a duty ratio corresponding to the drive command value, and supplies the PWM control signal to the drive circuit 41. As a result, power corresponding to the drive command value is supplied to the electric motor 18.

[0142] In the following, the operation when the steering mode is the cooperative steering mode will be described.

[0143] The command value selection process performed by the host ECU 201 will be described.

[0144] 10A and 10B are flowcharts showing the procedure of command value selection processing performed by host ECU 201.

[0145] In the following, changing the target driving line may be referred to as "lane change."

[0146] First, the host ECU 201 sets a first automatic steering angle θ for driving the vehicle along the center line of the current lane. ad1 The automatic steering angle θ ad (step S1).

[0147] Next, the host ECU 201 issues a direction change command I ND It is determined whether or not the direction change command I is 0 (step S2). ND If the direction change command I is not 0 (step S2: NO), the host ECU 201 returns to step S2. ND If it is 0 (step S2: YES), the host ECU 201 proceeds to step S3.

[0148] In step S3, the host ECU 201 receives a direction change command I ND Determine whether or not the direction change command I is 1. NDIf it is not 1 (step S3: NO), the host ECU 201 outputs the direction change command I ND It is determined whether the direction change command I is 2 (step S4). ND If it is not 2 (step S4: NO), the host ECU 201 returns to step S3.

[0149] In step S3, a direction change command I ND If it is determined that the value is 1 (step S3: YES), that is, if a rightward direction change command is input, the host ECU 201 proceeds to step S5. Note that, if a rightward direction change command is input, a direction indicator corresponding to the right direction is caused to blink (not shown).

[0150] In step S5, the host ECU 201 detects the current lateral deviation e l The lateral deviation e at the time when the direction change command is input l-brinker and sets a first count value T1 to zero in order to determine the time requirement for whether or not to perform a lane change.

[0151] After that, the host ECU 201 determines whether or not a first predetermined time for updating the first count value T1 has elapsed (step S6). If the first predetermined time has not elapsed (step S6: NO), the host ECU 201 returns to step S6.

[0152] When it is determined in step S6 that the first predetermined time has elapsed (step S6: YES), the host ECU 201 increments the first count value T1 by 1 (step S7). lim1 It is then determined whether or not the number of the first and second digits has reached the threshold (step S8).

[0153] The first count value T1 is the first time limit T lim1If it has not reached (step S8: NO), the upper ECU 201 determines whether the first lane change approval condition is satisfied (step S9). In this embodiment, if a predetermined value L1 greater than 0 is used as the first threshold value, the upper ECU 201 determines whether ((e l -e l_brinker ) ≥ L1), which is the first lane change approval condition, is satisfied. In other words, after the upper ECU 201 determines that the rightward direction change command was input in step S3, it determines whether the first lane change approval condition that the vehicle has moved rightward by the first threshold value L1 or more is satisfied.

[0154] If the first lane change approval condition is not satisfied ((e l -e l_brinker ) < L1) (step S9: NO), the upper ECU 201 returns to step S6. In this case, in step S6, the upper ECU 201 determines whether the first predetermined time has elapsed since the first count value T1 was incremented by 1 in the previous step S7.

[0155] In step S8, if it is determined that the first count value T1 has reached the first limit time T lim1 (step S8: YES), the upper ECU 201 returns to step S1. In this case, the lane change is not performed.

[0156] In step S9, if it is determined that the first lane change approval condition is satisfied ((e l -e l_brinker ) ≥ L1) (step S9: YES), the upper ECU 201 selects the second automatic steering angle θ ad2 for running the vehicle along the center line of the adjacent lane (right lane) on the right side of the current lane as the automatic steering angle θ ad (step S10). As a result, the automatic steering command value θ ad is switched. That is, the lane change is performed.

[0157] Then, the host ECU 201 sets the right lane as the current lane, sets the lane to the left of the newly set current lane as the left lane, and sets the lane to the right of the newly set current lane as the right lane (step S11). That is, the current lane, the left lane, and the right lane are updated.

[0158] In addition, the host ECU 201 determines the lateral deviation e l The lateral deviation e from the center line of the current lane after updating l (Step S12). Then, the host ECU 201 detects the lateral deviation e l The lateral deviation e immediately after lane change l_change (step S13).

[0159] The upper ECU 201 updates the lateral deviation e l When the motor control ECU 202 is first sent l Not only that, but also the lateral deviation immediately after lane change l_change to the motor control ECU 202. Then, the host ECU 201 returns to step S1.

[0160] In step S4, a direction change command I ND If it is determined that the value is 2 (step S4: YES), that is, if a leftward direction change command is input, the host ECU 201 proceeds to step S14. Note that, if a leftward direction change command is input, a direction indicator corresponding to the left direction is caused to blink (not shown).

[0161] In step S14, the host ECU 201 determines the current lateral deviation e l The lateral deviation e at the time when the direction change command is input l_brinker and sets the first count value T1 to zero.

[0162] After that, the host ECU 201 determines whether or not a first predetermined time for updating the first count value T1 has elapsed (step S15). If the first predetermined time has not elapsed (step S15: NO), the host ECU 201 returns to step S15.

[0163] When it is determined in step S15 that the first predetermined time has elapsed (step S15: YES), the host ECU 201 increments the first count value T1 by 1 (step S16). lim1 It is then determined whether or not the number of the first and second digits has reached the threshold (step S17).

[0164] The first count value T1 is the first time limit T lim1 If the e has not been reached (step S17: NO), the host ECU 201 determines whether the second lane change approval condition is satisfied (step S18). l -e l_brinker In other words, after it is determined in step S3 that a leftward direction change command has been input, the host ECU 201 determines whether or not the second lane change approval condition, that is, the vehicle has moved leftward by the first threshold value L1 or more, is satisfied.

[0165] If the second lane change approval condition is not met (e l -e l_brinker If L1)>-L2) (step S18: NO), the host ECU 201 returns to step S15. In this case, in step S15, the host ECU 201 determines whether or not a first predetermined time has elapsed since the first count value T1 was incremented by 1 in the previous step S16.

[0166] In step S17, the first count value T1 is equal to or greater than the first time limit T lim1If it is determined that the threshold value has been reached (step S17: YES), the host ECU 201 returns to step S1 In this case, no lane change is performed.

[0167] In step S18, the second lane change approval condition is satisfied (e l -e l_brinker If it is determined that the current lane is adjacent to the current lane (left lane), the host ECU 201 sets a third automatic steering angle θ ad3 The automatic steering angle θ ad (Step S19). As a result, the automatic steering command value θ ad In other words, a lane change is performed.

[0168] Then, the host ECU 201 sets the left lane as the current lane, sets the lane to the left of the newly set current lane as the left lane, and sets the lane to the right of the newly set current lane as the right lane (step S20). That is, the current lane, the left lane, and the right lane are updated.

[0169] In addition, the host ECU 201 determines the lateral deviation e l The lateral deviation e from the center line of the current lane after updating l (Step S21). Then, the host ECU 201 detects the lateral deviation e l The lateral deviation e immediately after the lane change l_change (step S22).

[0170] The upper ECU 201 updates the lateral deviation e l When the motor control ECU 202 is first sent l Not only that, but also the lateral deviation immediately after lane change l_change to the motor control ECU 202. Then, the host ECU 201 returns to step S1.

[0171] Although not shown, the torsion bar torque T tb If the direction of the vehicle changes from right to left, the host ECU 201 returns to step S1. In other words, if the driver turns the steering wheel leftward after the rightward direction change command is input and before a positive determination is made in step S9 or step S8, no lane change is performed.

[0172] Similarly, after the leftward direction change command is input in step S4, the torsion bar torque T tb If the direction of the vehicle changes from the left to the right, the host ECU 201 returns to step S1. In other words, if the driver turns the steering wheel to the right after the left direction change command is input and before a positive determination is made in step S18 or step S17, a lane change is not performed.

[0173] The spring constant setting unit 52 is described in detail below. The spring constant setting unit 52 determines the spring constant k s A spring constant setting process is performed to set the spring constant.

[0174] The spring constant k set by the spring constant setting unit 52 s As for the LCA spring constant k LCA , spring constant k for the first resistance re1 (e l ,e l_brinker ), the spring constant k for the first guidance gu1 (e l ,e l_change ), the spring constant k for the second resistance re2 (e l ,e l_brinker ) and the spring constant k for the second guidance gu2 (e l ,e l_change ) is available.

[0175] Spring constant k for LCA LCA is the spring constant for lane centering assist control and is the basic spring constant used in the cooperative steering mode. Spring constant k for LCA LCA is a preset fixed value and is stored in memory (non-volatile memory).

[0176] Spring constant k for the first resistance re1 (e l ,e l_brinker ) is the spring constant used during the period from when a rightward direction change command is input until the target driving lane is changed from the current lane to the right lane (hereinafter referred to as the "first resistance period"). The first resistance spring constant k re1 (e l ,e l_brinker ) is the lateral deviation e when a rightward direction change command is input. l_brinker and lateral deviation e l It is set based on.

[0177] Figure 11 shows the (e l -e l_brinker ) spring constant k for the first resistance re1 (e l ,e l_brinker ) is a graph showing an example of setting.

[0178] Spring constant k for the first resistance re1 (e l ,e l_brinker ) is (e l -e l_brinker ) is in the range of 0 or more and less than a predetermined value A (A>0), a first predetermined value k s_1 The spring constant for the first resistance, k re1 (e l ,e l_brinker ) is (e l -e l_brinker ) is greater than or equal to A and less than a certain value B greater than A, k s_1 to 0, (e l -e l_brinker ) is set to be smaller as el -e l_brinker ) in the range of B or more, the spring constant k for the first resistor re1 (e l ,e l_brinker ) is set to 0.

[0179] The predetermined value B is set to a value smaller than the first threshold value L1. l -e l_brinker ) reaches B until it reaches the first threshold L1, the first resistance spring constant k re1 (e l ,e l_brinker ) is set to 0. In other words, after the vehicle moves to the right by B after the rightward direction change command is input, the first resistance spring constant k re1 (e l ,e l_brinker ) is set to 0.

[0180] As shown in FIG. l -e l_brinker ) spring constant k for the first resistance re1 (e l ,e l_brinker A map representing the characteristics of the ) is stored in a memory (non-volatile memory).

[0181] First guidance spring constant k gu1 (e l ,e l_change ) is the spring constant used during the period from when the target lane is switched from the current lane to the right lane until the distance between the lane reference position and the center line of the current lane after the target lane is switched becomes equal to or less than the second threshold L2 (where L2>0) (hereinafter referred to as the "first guidance period"). The first guidance spring constant k gu1 (e l ,e l_change ) is the lateral deviation e immediately after the lane change that is set immediately after the target lane is changed from the current lane to the right lane. l_change and the lateral deviation e relative to the current lane after switching l It is set based on.

[0182] Figure 12 shows the l -e l_change ) spring constant k for the first guidance gu1 (e l ,e l_change ) is a graph showing an example of setting.

[0183] First guidance spring constant k gu1 (e l ,e l_change ) is (e l -e l_change When the first guidance spring constant k is equal to or greater than 0 and less than a predetermined value C (C>0), the first guidance spring constant k is set to 0. gu1 (e l ,e l_change ) is (e l -e l_change ) is equal to or greater than C and is less than a predetermined value D greater than C, the range is from 0 to a second predetermined value k s_2 Until then, (e l -e l_change In this embodiment, the second predetermined value k s_2 is the first predetermined value k s_1 It is set to a value smaller than (e l -e l_change ) in the range of D or more, the first guidance spring constant k gu1 (e l ,e l_change ) is k s_2 is set to.

[0184] The predetermined value C is set to a value smaller than the second threshold value L2. Therefore, after the target driving lane is switched from the current lane to the right lane, (e l -e l_change ) reaches a predetermined value C, the first guidance spring constant k gu1 (e l ,e l_change ) is set to 0. In other words, from when the lane change to the right lane is made until the vehicle moves to the right by C, the first guidance spring constant k gu1 (e l ,e l_change ) is set to 0.

[0185] As shown in FIG. l -e l_change ) spring constant k for the first guidance gu1 (e l ,e l_change A map representing the characteristics of the ) is stored in a memory (non-volatile memory).

[0186] Spring constant k for the second resistance re2 (e l ,e l_brinker ) is the spring constant used during the period from when a leftward direction change command is input until the target lane is changed from the current lane to the left lane (hereinafter referred to as the "second resistance period"). re2 (e l ,e l_brinker ) is the lateral deviation e when a leftward direction change command is input. l_brinker and lateral deviation e l It is set based on.

[0187] Figure 13 shows the l -e l_brinker ) spring constant k for the second resistance re2 (e l ,e l_brinker ) is a graph showing an example of setting.

[0188] Spring constant k for the second resistance re2 (e l ,e l_brinker ) is (e l -e l_brinker ) is less than or equal to 0 and greater than -A, k s_1 The spring constant for the second resistance, k re2 (e l ,e l_brinker ) is (e l -e l_brinker ) is less than or equal to -A and greater than -B, k s_1 to 0, (e l -e l_brinker ) is set to be smaller as el -e l_brinker ) in the range below -B, the spring constant k for the second resistance re2 (e l ,e l_brinker ) is set to 0.

[0189] -B is a value greater than -L. Therefore, (e l -e l_brinker ) during the period from when it reaches -B to when it reaches -L, the spring constant k re2 (e l ,e l_brinker ) is set to 0. In other words, after the leftward direction change command is input, the vehicle moves to the left by B until the lane change is performed, and the second resistance spring constant k re2 (e l ,e l_brinker ) is set to 0.

[0190] As shown in FIG. l -e l_brinker ) spring constant k for the second resistance re2 (e l ,e l_brinker A map representing the characteristics of the ) is stored in a memory (non-volatile memory).

[0191] Second guidance spring constant k gu2 (e l ,e l_change ) is the spring constant used during the period from when the target lane is switched from the current lane to the left lane until the distance between the lane reference position and the center of the current lane after the target lane is switched becomes the second threshold value L2 (where L2>0) (hereinafter referred to as the "second guidance period"). gu2 (e l ,e l_change ) is the lateral deviation e immediately after the lane change that is set immediately after the target lane is switched from the current lane to the left lane. l_change and the lateral deviation e relative to the current lane after switching l It is set based on.

[0192] Figure 14 shows the l -e l_change ) spring constant k for the second guidance gu2 (e l ,e l_change ) is a graph showing an example of setting.

[0193] Second guidance spring constant k gu2 (e l ,e l_change ) is (e l -e l_change ) is set to 0 when it is less than 0 and greater than -C. The second guidance spring constant k gu2 (e l ,e l_change ) is (e l -e l_change ) is in the range of -C or less and -D or more, from 0 to k s_2 Until then, (e l -e l_change ) is set to be larger as e l -e l_change ) in the range below -D, the spring constant k for the second guidance gu2 (e l ,e l_change ) is k s_2 is set to.

[0194] -C is set to a value larger than -L2. Therefore, after the target lane is switched from the current lane to the left lane, (e l -e l_change ) reaches -C, the spring constant k gu2 (e l ,e l_change ) is set to 0. In other words, from when the lane change to the left lane is made until the vehicle moves to the left by C, the second guidance spring constant k gu2 (e l ,e l_change ) is set to 0.

[0195] As shown in FIG. l -e l_change ) spring constant k for the second guidance gu2(e l ,e l_change A map representing the characteristics of the ) is stored in a memory (non-volatile memory).

[0196] 15A and 15B are flowcharts showing the procedure of the spring constant setting process performed by the spring constant setting unit 52.

[0197] The spring constant setting unit 52 first calculates the LCA spring constant k LCA Let the spring constant k s (Step S31). Therefore, the manual steering command value calculation unit 53 sets the spring constant k s As the spring constant k for LCA LCA Using the manual steering command value θ md Calculate the following.

[0198] Next, the spring constant setting unit 52 receives a direction change command I ND It is determined whether or not the direction change command I is 0 (step S32). ND If the direction change command I is not 0 (step S32: NO), the spring constant setting unit 52 returns to step S32. ND If it is 0 (step S32: YES), the spring constant setting unit 52 proceeds to step S33.

[0199] In step S33, the spring constant setting unit 52 receives the direction change command I ND Determine whether or not the direction change command I is 1. ND If it is not 1 (step S33: NO), the spring constant setting unit 52 sets the direction change command I ND It is determined whether the direction change command I is 2 (step S34). ND If is not 2 (step S34: NO), the spring constant setting unit 52 returns to step S32.

[0200] In step S33, a direction change command I ND If it is determined that the command is 1 (step S33: YES), that is, if a rightward direction change command has been input, the spring constant setting unit 52 proceeds to step S35.

[0201] In step S35, the spring constant setting unit 52 calculates the current lateral deviation e l The lateral deviation e at the time when the direction change command is input l-brinker Then, the spring constant setting unit 52 stores the first resistance spring constant k re1 (e l ,e l_brinker ) with the spring constant k s and the first time limit T lim1 A first count value T1 for timing is set to zero (step S36).

[0202] Spring constant k for the first resistance re1 (e l ,e l_brinker ) is the lateral deviation e set in step S35 l-brinker and the current lateral deviation e l The host ECU 201 calculates the value of e set in step S5 of FIG. l_brinker to the motor control ECU 202. In that case, the spring constant setting unit 52 receives the e l_brinker , e l_brinker It may also be used as.

[0203] As a result, the manual steering command value calculation unit 53 calculates the spring constant k s Let the spring constant k for the first resistance be re1 (e l ,e l_brinker ) to obtain the manual steering command value θ md Calculate the following.

[0204] After that, the spring constant setting unit 52 determines whether or not a first predetermined time for updating the first count value T1 has elapsed (step S37). If the first predetermined time has not elapsed (step S37: NO), the spring constant setting unit 52 returns to step S37.

[0205] When it is determined in step S37 that the first predetermined time has elapsed (step S37: YES), the spring constant setting unit 52 increments the first count value T1 by 1 (step S38). Then, the spring constant setting unit 52 determines whether the first count value T1 has reached the first limit time T lim1 (step S39).

[0206] If the count value T has not reached the first limit time T lim1 (step S39: NO), the spring constant setting unit 52 determines whether the first lane change approval condition is satisfied (step S40). In this embodiment, the spring constant setting unit 52 determines whether the first lane change approval condition that (e l - e l_brinker ) ≥ L1 is satisfied.

[0207] If the first lane change approval condition is not satisfied ((e l - e l_brinker ) < L1) (step S40: NO), the spring constant setting unit 52 returns to step S37. In this case, in step S37, the spring constant setting unit 52 determines whether the first predetermined time has elapsed since the first count value T1 was incremented by 1 in the previous step S38.

[0208] In step S39, when it is determined that the first count value T1 has reached the first limit time T lim1 (step S39: YES), the spring constant setting unit 52 returns to step S31. In this case, the lane change by the upper ECU 201 is not performed.

[0209] In step S40, when it is determined that the first lane change approval condition is satisfied ((e l - e l_brinker ) ≥ L1) (step S40: YES), the spring constant setting unit 52 acquires the lateral deviation e l with respect to the current lane after the lane change and the lateral deviation e l_change immediately after the lane change from the upper ECU 201 (step S41).

[0210] Specifically, the spring constant setting unit 52 calculates the lateral deviation e l and lateral deviation e immediately after lane change l_change The ECU 201 waits for the lateral deviation e l and lateral deviation e immediately after lane change l_change When these are transmitted from the host ECU 201, they are acquired.

[0211] After this, the spring constant setting unit 52 sets the first guidance spring constant k gu1 (e l ,e l_change ) with the spring constant k s (Step S42). The first guidance spring constant k gu1 (e l ,e l_change ) is the current lateral deviation e l and lateral deviation e immediately after lane change l_change In this way, the manual steering command value calculation unit 53 sets the first guidance spring constant k gu1 (e l ,e l_change ) into the spring constant k s The manual steering command value θ md Such an operation of the manual steering command value calculation unit 53 will be referred to as a first guidance operation.

[0212] Next, the spring constant setting unit 52 sets a second time limit T lim2 A second count value T2 for measuring the time is set to zero (step S43).

[0213] After that, the spring constant setting unit 52 determines whether or not a second predetermined time for updating the second count value T2 has elapsed (step S44). If the second predetermined time has not elapsed (step S44: NO), the spring constant setting unit 52 returns to step S44.

[0214] When it is determined in step S44 that the second predetermined time has elapsed (step S44: YES), the spring constant setting unit 52 increments the second count value T2 by 1 (step S45). lim2 It is then determined whether or not the number of the first and second digits has reached the threshold (step S46).

[0215] The second count value T2 is the second time limit T lim2 If the e has not been reached (step S46: NO), the spring constant setting unit 52 determines whether or not the first guidance operation end condition is satisfied (step S47). l In other words, the spring constant setting unit 52 determines whether the first guidance operation end condition that the vehicle reference position reaches within a range from the center line of the current lane after the target driving lane is switched to the right lane from the current lane to the second threshold value L2 is satisfied.

[0216] If the first guidance operation end condition is not satisfied (step S47: NO), the spring constant setting unit 52 returns to step S44. In this case, in step S44, the spring constant setting unit 52 determines whether or not a second predetermined time has elapsed since the second count value T2 was incremented by 1 in the previous step S45.

[0217] In step S46, the second count value T2 is equal to or greater than the second time limit T lim2 If it is determined that the spring constant has been reached (step S46: YES), the spring constant setting unit 52 returns to step S31.

[0218] If it is determined in step S47 that the first guidance operation ending condition is satisfied (step S47: YES), the spring constant setting unit 52 returns to step S31.

[0219] In step S34, a direction change command IND If it is determined that the value is 2 (step S34: YES), that is, if a direction change command to the left has been input, the spring constant setting unit 52 proceeds to step S48.

[0220] In step S48, the spring constant setting unit 52 calculates the current lateral deviation e l is the lateral deviation e when the direction change command is input. l-brinker Then, the spring constant setting unit 52 stores the second resistance spring constant k re2 (e l ,e l_brinker ) with the spring constant k s and the first time limit T lim1 A first count value T1 for timing is set to zero (step S49).

[0221] Spring constant k for the second resistance re2 (e l ,e l_brinker ) is the lateral deviation e set in step S48 l-brinker and the current lateral deviation e l The calculation is performed using e l_brinker As described above, the value may be obtained from the host ECU 201.

[0222] As a result, the manual steering command value calculation unit 53 calculates the spring constant k s As the spring constant for the second resistance, k re2 (e l ,e l_brinker ) to obtain the manual steering command value θ md Calculate the following.

[0223] After that, the spring constant setting unit 52 determines whether or not a first predetermined time for updating the first count value T1 has elapsed (step S50). If the first predetermined time has not elapsed (step S50: NO), the spring constant setting unit 52 returns to step S50.

[0224] When it is determined in step S50 that the first predetermined time has elapsed (step S50: YES), the spring constant setting unit 52 increments the first count value T1 by 1 (step S51). lim1 It is then determined whether or not the number of the first and second digits has reached the threshold (step S52).

[0225] The count value T is the first time limit T lim If the difference between the first lane change approval condition and the second lane change approval condition is not met (step S52: NO), the spring constant setting unit 52 determines whether the second lane change approval condition is met (step S53). l -e l_brinker It is determined whether a second lane change approval condition, that is, whether the lane change speed is greater than or equal to -L1, is satisfied.

[0226] If the second lane change approval condition is not met (e l -e l_brinker )>-L1) (step S53: NO), the spring constant setting unit 52 returns to step S50. In this case, in step S50, the spring constant setting unit 52 determines whether or not a first predetermined time has elapsed since the first count value T1 was incremented by 1 in the previous step S51.

[0227] In step S52, the first count value T1 is equal to or smaller than the first time limit T lim1 If it is determined that the maximum lane width is reached (step S52: YES), the spring constant setting unit 52 returns to step S31. In this case, the host ECU 201 does not perform a lane change.

[0228] In step S53, the second lane change approval condition is satisfied (e l -e l_brinker If it is determined that the lateral deviation e )≦-L1) (step S53: YES), the spring constant setting unit 52 calculates the lateral deviation e l and lateral deviation e immediately after lane change l_changeis acquired from the host ECU 201 (step S54).

[0229] Specifically, the spring constant setting unit 52 calculates the lateral deviation e l and lateral deviation e immediately after lane change l_change The ECU 201 waits for the lateral deviation e l and lateral deviation e immediately after lane change l_change When these are transmitted from the host ECU 201, they are acquired.

[0230] After this, the spring constant setting unit 52 sets the second guidance spring constant k gu2 (e l ,e l_change ) with the spring constant k s (Step S55). The second guidance spring constant k gu2 (e l ,e l_change ) is the current lateral deviation e l and lateral deviation e immediately after lane change l_change In this way, the manual steering command value calculation unit 53 sets the second guidance spring constant k gu2 (e l ,e l_change ) into the spring constant k s The manual steering command value θ md Such an operation of the manual steering command value calculation unit 53 will be referred to as a second guidance operation.

[0231] Next, the spring constant setting unit 52 sets a second time limit T lim2 A second count value T2 for timing is set to zero (step S56).

[0232] After that, the spring constant setting unit 52 determines whether or not a second predetermined time for updating the second count value T2 has elapsed (step S57). If the second predetermined time has not elapsed (step S57: NO), the spring constant setting unit 52 returns to step S57.

[0233] When it is determined in step S57 that the second predetermined time has elapsed (step S57: YES), the spring constant setting unit 52 increments the second count value T2 by 1 (step S58). lim2 It is then determined whether or not the number of the first and second digits has been reached (step S59).

[0234] The second count value T2 is the second time limit T lim2 If the e has not been reached (step S59: NO), the spring constant setting unit 52 determines whether or not the second guidance operation end condition is satisfied (step S60). l In other words, the spring constant setting unit 52 determines whether the second guidance operation end condition, that is, after the target driving lane is switched from the current lane to the left lane, the vehicle reference position reaches within a range from the center line of the current lane after the switch to the second threshold value L2, is satisfied.

[0235] If the second guidance operation end condition is not satisfied (step S60: NO), the spring constant setting unit 52 returns to step S57. In this case, in step S57, the spring constant setting unit 52 determines whether or not a second predetermined time has elapsed since the second count value T2 was incremented by 1 in the previous step S58.

[0236] In step S59, the second count value T2 is equal to or greater than the second time limit T lim2 If it is determined that the spring constant has been reached (step S59: YES), the spring constant setting unit 52 returns to step S31.

[0237] In step S60, when it is determined that the second guidance operation ending condition is satisfied (step S60: YES), the spring constant setting unit 52 returns to step S31.

[0238] In the above embodiment, when the target lane is switched from the current lane to the right lane, the operation is as follows: s As the spring constant k for LCA LCA When a rightward direction change command is input, the LCA spring constant k LCA to the spring constant k for the first resistance re1 (e l ,e l_brinker ) with spring constant k s can be switched.

[0239] Spring constant k for the first resistance re1 (e l ,e l_brinker ) has the characteristics shown in FIG. 11, so the absolute value of the virtual spring reaction force |k s θ md |(=|k re1 (e l ,e l_brinker )·θ md |) becomes relatively large immediately after the rightward direction change command is input, and (e l -e l_brinker ) reaches a certain value A and then decreases. Then, the absolute value of the virtual spring reaction force |k s θ md |(=|k re1 (e l ,e l_brinker )·θ md |) is (e l -e l_brinker ) becomes zero when it reaches a certain value B, and (e l -e l_brinker ) remains zero even if it is greater than or equal to B.

[0240] (e l -e l_brinker After the vehicle moves to the right after the lane change approval condition (e l -e l_brinker ) ≧ L1) is satisfied, the spring constant k s is the spring constant k for the first resistance re1 (e l ,e l_brinker ) to the first guidance spring constant k gu1 (el ,e l_change ) can be switched to.

[0241] First guidance spring constant k gu1 (e l ,e l_change ) has the characteristics shown in FIG. 12, so the absolute value of the virtual spring reaction force |k s θ md |(=|k gu1 (e l ,e l_change )·θ md |) remains zero even after the lane change. And, (e l -e l_brinker When the virtual spring reaction force |k s θ md |(=|k gu1 (e l ,e l_change )·θ md |) gradually grows. And (e l -e l_brinker When the virtual spring reaction force |k s θ md |(=|k gu1 (e l ,e l_change )·θ md |) becomes almost constant.

[0242] (e l -e l_brinker After the vehicle moves to the right after the first guidance operation end condition (e l ≧-L2) is satisfied, the spring constant k s is the spring constant k for the first guidance gu1 (e l ,e l_change ) to obtain the spring constant k for LCA LCA can be switched to.

[0243] In this way, when the target lane is switched from the current lane to the right lane, the virtual spring reaction force k in the equation of motion (3) is s θ mdis set to zero. This can reduce the discomfort felt by the driver when the target driving lane is changed.

[0244] When the target lane is changed from the current lane to the left lane, the operation is as follows. The spring constant k s As the spring constant k for LCA LCA When a leftward direction change command is input, the spring constant k s is the spring constant k for LCA LCA to the spring constant k for the second resistance re2 (e l ,e l_brinker ) can be switched to.

[0245] Spring constant k for the second resistance re2 (e l ,e l_brinker ) has the characteristics shown in FIG. 13, so the absolute value of the virtual spring reaction force |k s θ md |(=|k re2 (e l ,e l_brinker )·θ md |) becomes relatively large immediately after the left direction change command is input, and (e l -e l_brinker ) reaches -A and then decreases. Then, the absolute value of the virtual spring reaction force |k s θ md |(=|k re2 (e l ,e l_brinker )·θ md |) is (e l -e l_brinker ) reaches -B and becomes zero, and (e l -e l_brinker ) remains zero even if it is less than -B.

[0246] (e l -e l_brinker After the vehicle moves left after the lane change approval condition (e l -e l_brinker ) ≦-L1) is satisfied, the spring constant k s is the spring constant k for the second resistancere2 (e l ,e l_brinker ) to the spring constant k for the second guidance gu2 (e l ,e l_change ) can be switched to.

[0247] Second guidance spring constant k gu2 (e l ,e l_change ) has the characteristics shown in FIG. 14, so the absolute value of the virtual spring reaction force |k s θ md |(=|k gu2 (e l ,e l_change )·θ md |) remains zero even after the lane change. And, (e l -e l_brinker When the virtual spring reaction force |k s θ md |(=|k gu2 (e l ,e l_change )·θ md |) gradually grows. And (e l -e l_brinker ) reaches -D, the absolute value of the virtual spring reaction force |k s θ md |(=|k gu2 (e l ,e l_change )·θ md |) becomes almost constant.

[0248] (e l -e l_brinker After the vehicle moves leftward after the first guidance operation end condition (e l ≦L2) is satisfied, the spring constant k s is the spring constant k for the second guidance gu2 (e l ,e l_change ) to obtain the spring constant k for LCA LCA can be switched to.

[0249] Even when the target lane is switched from the current lane to the left lane, the virtual spring reaction force k in the equation of motion (3) is s θ md is set to zero. This can reduce the discomfort felt by the driver when the target driving lane is changed.

[0250] The following describes modified examples of the motor control ECU 202. In the following modified examples of the motor control ECU 202, the operation in the manual steering mode is similar to that in the above-described embodiment, so the operation in the cooperative steering mode will be mainly described.

[0251] Fig. 16 is a block diagram showing a modified example of the motor control ECU, in which the same reference numerals as in Fig. 2 are used to denote parts corresponding to those in Fig. 2 described above.

[0252] A motor control ECU 202A in FIG. 16 differs from the motor control ECU 202 in FIG. 2 in the following (1) and (2). (1) The configuration of the manual steering command value calculation unit 53A is different from the configuration of the manual steering command value calculation unit 53 in FIG. (2) A spring constant / target virtual spring reaction force setting unit (hereinafter referred to as "constant / reaction force setting unit 52A") is used instead of the spring constant setting unit 52 in FIG.

[0253] FIG. 17 is a block diagram showing mainly the configuration of the manual steering command value calculation unit 53A.

[0254] The manual steering command value calculation unit 53A calculates a first manual steering command value θ md1 A first manual steering command value calculation unit 501 that calculates a second manual steering command value θ md2 A second manual steering command value calculation unit 502 that calculates a first manual steering command value θ md1 and the second manual steering command value θ md2 Select one of the two and set the manual steering command value θ md and a command value switching unit 503 that outputs the command value as

[0255] The configuration of the first manual steering command value calculation unit 501 is the same as the configuration of the manual steering command value calculation unit 53 in FIG. s is set by the constant / reaction force setting unit 52A. The first manual steering command value calculation unit 501 calculates the manual steering command value θ md The first manual steering command value θ md1 The output is as follows.

[0256] FIG. 18 is a block diagram showing the configuration of the second manual steering command value calculation unit 502.

[0257] In FIG. 18, T tb,d is the target virtual spring reaction force set by the constant / reaction force setting unit 52A.

[0258] The second manual steering command value calculation unit 502 includes an addition / subtraction unit 111, an inertia division unit 112, a first integration unit 113, a second integration unit 114, and a virtual damper reaction force calculation unit 115. The second manual steering command value calculation unit 502 does not include the virtual spring reaction force calculation unit 106 of FIG.

[0259] The addition / subtraction unit 111 receives the torsion bar torque T tb and the target virtual spring reaction force T set by the constant / reaction force setting unit 52A. tb,d and the virtual damper reaction force c·dθ given by the virtual damper reaction force calculation unit 115. md Enter / dt.

[0260] The addition / subtraction unit 111 calculates the torsion bar torque T tb From the target virtual spring reaction force T tb,d and virtual damper reaction force c md dθ md In this way, the adder / subtractor 111 subtracts J on the left side of the formula (2). col d 2 θ c / dt 2 The moment of inertia J corresponds to md d 2 θ md / dt 2 (=Ttb -c dθ md / dt-T tb,d ) is calculated.

[0261] The inertia division unit 112 divides the moment of inertia J calculated by the addition / subtraction unit 111. md d 2 θ md / dt 2 Column inertia J md By dividing by , the manual steering command value θ md The second derivative d 2 θ md / dt 2 Calculate the following.

[0262] The first integration unit 113 calculates the manual steering command value θ md The second derivative d 2 θ md / dt 2 By integrating, the manual steering command value θ md The first derivative dθ md Calculate / dt.

[0263] The second integration unit 114 integrates the manual steering command value θ md The first derivative dθ md By integrating / dt, the manual steering command value θ md This manual steering command value θ md is the second manual steering command value θ md2 is output from the second manual steering command value calculation unit 502 as

[0264] The virtual damper reaction force calculation unit 115 calculates the manual steering command value θ md The first derivative dθ md / dt is multiplied by the viscous damping coefficient c to obtain the virtual damper reaction force c dθ md / dt is calculated. This virtual damper reaction force c dθ md / dt is fed back to the addition / subtraction unit 111 .

[0265] That is, the second manual steering command value calculation unit 502 calculates the manual steering command value θ based on the equation of motion shown in the following equation (11). mdCalculate the following.

[0266]

number

[0267] In equation (11), J md d 2 θ md / dt 2 is the moment of inertia. c dθ md / dt is the virtual damper reaction force. T tb,d is the target virtual spring reaction force (virtual spring reaction force).

[0268] In this modified example, the second manual steering command value calculation unit 502 calculates the N·T m (=N T as ) is set to 0, and the virtual spring reaction force k θ in the equation of motion in the above formula (2) is col as the target virtual spring reaction force tb,d Using the above, the manual steering command value θ md Then, the second manual steering command value calculation unit 502 calculates the obtained manual steering command value θ md The second manual steering command value θ md2 The output is as follows:

[0269] The second manual steering command value calculation unit 502 calculates the assist torque command value T as By multiplying by the reduction ratio N, N·T as Calculate the result N T as In this case, the torsion bar torque T tb To N.T. as The virtual damper reaction force c dθ is calculated from the sum. md / dt and target virtual spring reaction force tb,d In this case, the second manual steering command value calculation unit 502 subtracts N·T from the right side of the above-mentioned equation (11). as Based on the equation of motion to which md The following calculation is performed:

[0270] The constant / reaction force setting unit 52A determines the spring constant k s and a target virtual spring reaction force used in the second manual steering command value calculation unit 502. tb,d In addition, a constant / reaction force setting process is performed to control the command value switching unit 503.

[0271] The spring constant k set by the constant / reaction force setting unit 52A s As for the LCA spring constant k LCA There is a spring constant k for LCA. LCA is the spring constant for lane centering assist control and is the basic spring constant used in the cooperative steering mode. Spring constant k for LCA LCA is a preset fixed value and is stored in memory (non-volatile memory).

[0272] The target virtual spring reaction force T set by the constant / reaction force setting unit 52A tb,d The spring reaction force for the first resistance T tb,d_re1 (e l ,e l_brinker ), First guidance spring reaction force T tb,d_gu1 (e l ,e l_change ), spring reaction force for second resistance T tb,d_re2 (e l ,e l_brinker ) and the second guidance spring reaction force T tb,d_gu2 (e l ,e l_change ) is available.

[0273] Spring reaction force T for the first resistance tb,d_re1 (e l ,e l_brinker ) is the target virtual spring reaction force adopted in the first resistance period. The spring reaction force for the first resistance T tb,d_re1 (e l ,e l_brinker ) is the lateral deviation e when a rightward direction change command is input. l_brinker and lateral deviation e l It is set based on.

[0274] Figure 19 shows the l -e l_brinker ) spring reaction force T for the first resistance tb,d_re1 (e l ,e l_brinker ) is a graph showing an example of setting.

[0275] Spring reaction force T for the first resistance tb,d_re1 (e l ,e l_brinker ) is (e l -e l_brinker ) is in the range of 0 or more and less than the predetermined value E (E>0), tb,d_3 (However, T tb,d_3 >0), (e l -e l_brinker The larger the spring reaction force for the first resistance T tb,d_re1 (e l ,e l_brinker ) is (e l -e l_brinker ) is equal to or greater than E and is less than a certain value F that is greater than E, T tb,d_1 to 0, (e l -e l_brinker ) is set to be smaller as e l -e l_brinker ) in the range of F or more, the first resistance spring reaction force T tb,d_re1 (e l ,e l_brinker ) is (e l -e l_brinker ) is set to 0.

[0276] The predetermined value F is set to a value smaller than the first threshold value L1. l -e l_brinker During the period from when the force F reaches the first threshold L1, the first resistance spring reaction force T tb,d_re1 (e l ,e l_brinker ) is set to 0. In other words, after the vehicle moves to the right by F after the input of the rightward direction change command, the first resistance spring reaction force T tb,d_re1 (el ,e l_brinker ) is set to 0.

[0277] As shown in FIG. l -e l_brinker ) spring reaction force T for the first resistance tb,d_re1 (e l ,e l_brinker A map representing the characteristics of the ) is stored in a memory (non-volatile memory).

[0278] First guidance spring reaction force T tb,d_gu1 (e l ,e l_change ) is the target virtual spring reaction force used in the first guidance period. The first guidance spring reaction force T tb,d_gu1 (e l ,e l_change ) is the lateral deviation e immediately after the lane change that is set immediately after the target lane is changed from the current lane to the right lane. l_change and the lateral deviation e relative to the current lane after switching l It is set based on.

[0279] Figure 20 shows the l -e l_change ) the first guidance spring reaction force T tb,d_gu1 (e l ,e l_change ) is a graph showing an example of setting.

[0280] First guidance spring reaction force T tb,d_gu1 (e l ,e l_change ) is (e l -e l_change When the first guidance spring reaction force T is in the range of 0 or more and less than a predetermined value G (G>0), it is set to 0. tb,d_gu1 (e l ,e l_change ) is (e l -e l_change ) is greater than or equal to G and less than a certain value H greater than G, tb,d_4 (However, T tb,d_4 is a fourth predetermined value greater than 0.l -e l_change ) is set to be smaller as T tb,d_4 is T tb,d_3 The first guidance spring reaction force T tb,d_gu1 (e l ,e l_change ) is (e l -e l_change ) is equal to or greater than H and is less than a predetermined value I that is greater than H, -T tb,d_4 to 0, (e l -e l_change ) is set to be larger as e l -e l_change ) in the range of I or more, the first guidance spring reaction force T tb,d_gu1 (e l ,e l_change ) is set to 0.

[0281] The predetermined value G is set to a value smaller than the second threshold value L2. Therefore, after the target driving lane is switched from the current lane to the right lane, (e l -e l_change Until the first guidance spring reaction force T tb,d_gu1 (e l ,e l_change ) is set to 0. In other words, after the lane change to the right lane is made, the first guidance spring reaction force T tb,d_gu1 (e l ,e l_change ) is set to 0.

[0282] As shown in FIG. l -e l_change ) the first guidance spring reaction force T tb,d_gu1 (e l ,e l_change A map representing the characteristics of the ) is stored in a memory (non-volatile memory).

[0283] Spring reaction force T for second resistance tb,d_re2 (e l ,e l_brinker) is the target virtual spring reaction force adopted in the second resistance period. The spring reaction force for the second resistance T tb,d_re2 (e l ,e l_brinker ) is the lateral deviation e when a leftward direction change command is input. l_brinker and lateral deviation e l It is set based on.

[0284] Figure 21 shows the l -e l_brinker ) the second resistance spring reaction force T tb,d_re2 (e l ,e l_brinker ) is a graph showing an example of setting.

[0285] Spring reaction force T for second resistance tb,d_re2 (e l ,e l_brinker ) is (e l -e l_brinker ) is less than or equal to 0 and greater than -E, from 0 to -T tb,d_3 Until then, (e l -e l_brinker The smaller the second resistance spring reaction force T tb,d_re2 (e l ,e l_brinker ) is (e l -e l_brinker ) is less than or equal to -E and greater than -F, -T tb,d_3 to 0, (e l -e l_brinker ) is set to be larger as e l -e l_brinker ) in the range below -F, the second resistance spring reaction force T tb,d_re2 (e l ,e l_brinker ) is set to 0.

[0286] -F is set to a value smaller than -L1. Therefore, (e l -e l_brinker During the period from when the load reaches -F to when the load reaches -L1, the second resistance spring reaction force T tb,d_re2 (e l,e l_brinker ) is set to 0. In other words, after the vehicle moves to the left by F after the input of the leftward direction change command, the second resistance spring reaction force T tb,d_re2 (e l ,e l_brinker ) is set to 0.

[0287] As shown in FIG. l -e l_brinker ) the second resistance spring reaction force T tb,d_re2 (e l ,e l_brinker A map representing the characteristics of the ) is stored in a memory (non-volatile memory).

[0288] Second guidance spring reaction force T tb,d_gu2 (e l ,e l_change ) is the target virtual spring reaction force adopted in the second guidance period. The second guidance spring reaction force T tb,d_gu2 (e l ,e l_change ) is the lateral deviation e immediately after the lane change that is set immediately after the target lane is switched from the current lane to the left lane. l_change and the lateral deviation e relative to the current lane after switching l It is set based on.

[0289] Figure 22 shows the l -e l_change ) the second guidance spring reaction force T tb,d_gu2 (e l ,e l_change ) is a graph showing an example of setting.

[0290] Second guidance spring reaction force T tb,d_gu2 (e l ,e l_change ) is (e l -e l_change When the second guidance spring reaction force T is less than or equal to 0 and greater than −G (G>0), it is set to 0. tb,d_gu2 (e l ,e l_change ) is (e l -el_change ) is less than or equal to -G and greater than -H, 0 to T tb,d_4 Until then, (e l -e l_change The smaller the second guidance spring reaction force T tb,d_gu2 (e l ,e l_change ) is (e l -e l_change ) is less than -H and greater than -I, T tb,d_4 to 0, (e l -e l_change ) is set to be smaller as e l -e l_change ) in the range of -I or less, the second guidance spring reaction force T tb,d_gu2 (e l ,e l_change ) is set to 0.

[0291] -G is set to a value smaller than -L2. Therefore, after the target lane is switched from the current lane to the left lane, (e l -e l_change Until the second guidance spring reaction force T tb,d_gu2 (e l ,e l_change ) is set to 0. In other words, from when the lane change to the left lane is made until the vehicle moves to the left by G, the second guidance spring reaction force T tb,d_gu2 (e l ,e l_change ) is set to 0.

[0292] As shown in FIG. l -e l_change ) the second guidance spring reaction force T tb,d_gu2 (e l ,e l_change A map representing the characteristics of the ) is stored in a memory (non-volatile memory).

[0293] 23A and 23B are flowcharts showing the procedure of the constant / reaction force setting process performed by constant / reaction force setting unit 52 A. In Fig. 23A and Fig. 23B, the same steps as in Fig. 15A and Fig. 15B are denoted by the same step numbers as in Fig. 15A and Fig. 15B.

[0294] In the following, the first manual steering command value θ ad1 is the manual steering command value θ ad The switching control mode for controlling the command value switching unit 503 so as to output the command value as a first control mode C mode1 The second manual steering command value θ ad2 is the manual steering command value θ ad The switching control mode for controlling the command value switching unit 503 so as to output the command value as a second control mode C mode2 Let's just say that.

[0295] The constant / reaction force setting unit 52A first selects the switching control mode C. mode First control mode C mode1 and set the LCA spring constant k LCA Let the spring constant k s (Step S31A). Therefore, the manual steering command value calculation unit 53A sets the spring constant k s As the spring constant k for LCA LCA Using the above, the manual steering command value θ md Calculate the following.

[0296] Next, the constant / reaction force setting unit 52A receives a direction change command I ND It is determined whether or not the direction change command I is 0 (step S32). ND If the direction change command I is not 0 (step S32: NO), the constant / reaction force setting unit 52A returns to step S32. ND If it is 0 (step S32: YES), the constant / reaction force setting unit 52A proceeds to step S33.

[0297] In step S33, the constant / reaction force setting unit 52A receives the direction change command I ND Determine whether or not the direction change command I is 1. NDIf it is not 1 (step S33: NO), the constant / reaction force setting unit 52A sets the direction change command I ND It is determined whether the direction change command I is 2 (step S34). ND If is not 2 (step S34: NO), the constant / reaction force setting unit 52A returns to step S33.

[0298] In step S33, a direction change command I ND If it is determined that the command is 1 (step S33: YES), that is, if a rightward direction change command has been input, the constant / reaction force setting unit 52A proceeds to step S35.

[0299] In step S35, the constant / reaction force setting unit 52A calculates the current lateral deviation e l The lateral deviation e at the time when the direction change command is input l-brinker Then, the constant / reaction force setting unit 52A stores the switching control mode C mode The second control mode C mode2 and set the target virtual spring reaction force T tb,d The spring reaction force T for the first resistance tb,d_re1 (e l ,e l_brinker ) and set the first time limit T lim1 A first count value T1 for timing is set to zero (step S36A).

[0300] Spring reaction force T for the first resistance tb,d_re1 (e l ,e l_brinker ) is the lateral deviation e set in step S35 l-brinker and the current lateral deviation e l The host ECU 201 calculates the value of e set in step S5 of FIG. l_brinker may be transmitted to the motor control ECU 202. In that case, the constant / reaction force setting unit 52A receives e l_brinker , e l_brinker It may also be used as.

[0301] As a result, the manual steering command value calculation unit 53A calculates the manual steering command value θ tb,d using the first resistance spring reaction force T tb,d_re1 as the target virtual spring reaction force T in Equation (11). l (e l_brinker , e md ).

[0302] After that, the constant / reaction force setting unit 52A determines whether or not a first predetermined time for updating the first count value T1 has elapsed (step S37). If the first predetermined time has not elapsed (step S37: NO), the constant / reaction force setting unit 52A returns to step S37.

[0303] If it is determined in step S37 that the first predetermined time has elapsed (step S37: YES), the constant / reaction force setting unit 52A increments the first count value T1 by 1 (step S38). Then, the constant / reaction force setting unit 52A determines whether or not the first count value T1 has reached the first limit time T lim1 (step S39).

[0304] If the count value T has not reached the first limit time T lim1 (step S39: NO), the constant / reaction force setting unit 52A determines whether or not the first lane change approval condition is satisfied (step S40). In this modification, the constant / reaction force setting unit 52A determines whether or not the first lane change approval condition of (e l - e l_brinker ) ≥ L1 is satisfied.

[0305] If the first lane change approval condition is not satisfied ((e l - e l_brinker ) < L1) (step S40: NO), the constant / reaction force setting unit 52A returns to step S37. In this case, in step S37, the constant / reaction force setting unit 52A determines whether or not the first predetermined time has elapsed since the first count value T1 was incremented by 1 in the previous step S38.

[0306] In step S39, the first count value T1 is equal to or greater than the first time limit T lim1 If it is determined that the threshold value has been reached (step S39: YES), the constant / reaction force setting unit 52A returns to step S31 A. In this case, the host ECU 201 does not perform a lane change.

[0307] In step S40, the first lane change approval condition is satisfied (e l -e l_brinker If it is determined that L1) is greater than or equal to L2 (step S40: YES), the constant / reaction force setting unit 52A calculates the lateral deviation e l and lateral deviation e immediately after lane change l_change is acquired from the host ECU 201 (step S41).

[0308] After this, the constant / reaction force setting unit 52A calculates the first guidance spring reaction force T tb,d_gu1 (e l ,e l_change ) is the target virtual spring reaction force T tb,d (Step S42A). The first guidance spring reaction force T tb,d_gu1 (e l ,e l_change ) is the current lateral deviation e l and lateral deviation e immediately after lane change l_change As a result, the manual steering command value calculation unit 53A calculates the first guidance spring reaction force T tb,d_gu1 (e l ,e l_change ) to the target virtual spring reaction force T tb,d The manual steering command value θ md Such an operation of the manual steering command value calculation unit 53A will be referred to as a first guidance operation.

[0309] Next, the constant / reaction force setting unit 52A sets a second time limit T lim2 A second count value T2 for measuring the time is set to zero (step S43).

[0310] Thereafter, the constant / reaction force setting unit 52A determines whether or not a second predetermined time for updating the second count value T2 has elapsed (step S44). If the second predetermined time has not elapsed (step S44: NO), the constant / reaction force setting unit 52A returns to step S44.

[0311] When it is determined in step S44 that the second predetermined time has elapsed (step S44: YES), the constant / reaction force setting unit 52A increments the second count value T2 by 1 (step S45). lim2 It is then determined whether or not the number of the first and second digits has reached the threshold (step S46).

[0312] The second count value T2 is the second time limit T lim2 If e has not been reached (step S46: NO), the constant / reaction force setting unit 52A determines whether the first guidance operation end condition is satisfied (step S47). l In other words, constant / reaction force setting unit 52A determines whether the first guidance operation end condition that the target driving lane is switched from the current lane to the right lane and the vehicle reference position reaches within a range from the center line of the current lane after the switch to the second threshold value L2 is satisfied.

[0313] If the first guidance operation end condition is not satisfied (step S47: NO), constant / reaction force setting unit 52A returns to step S44. In this case, in step S44, constant / reaction force setting unit 52A determines whether or not a second predetermined time has elapsed since the second count value T2 was incremented by 1 in the previous step S45.

[0314] In step S46, the second count value T2 is equal to or greater than the second time limit T lim2 If it is determined that the constant / reaction force setting unit 52A has reached the predetermined value (step S46: YES), the constant / reaction force setting unit 52A returns to step S31A.

[0315] In step S47, when it is determined that the first guidance operation ending condition is satisfied (step S47: YES), constant / reaction force setting unit 52A returns to step S31A.

[0316] In step S34, a direction change command I ND If it is determined that the leftward direction change command is input (step S34: YES), the constant / reaction force setting unit 52A proceeds to step S48.

[0317] In step S48, the constant / reaction force setting unit 52A calculates the current lateral deviation e l is the lateral deviation e when the direction change command is input. l-brinker Then, the constant / reaction force setting unit 52A stores the switching control mode C mode The second control mode C mode2 and the second resistance spring reaction force T tb,d_re2 (e l ,e l_brinker ) is the target virtual spring reaction force T tb,d_ The first time limit T lim1 A first count value T1 for timing is set to zero (step S49A).

[0318] Spring reaction force T for second resistance tb,d_re2 (e l ,e l_brinker ) is the lateral deviation e set in step S48 l-brinker and the current lateral deviation e l The calculation is performed using e l_brinker As described above, the value may be obtained from the host ECU 201.

[0319] As a result, the manual steering command value calculation unit 53A calculates the target virtual spring reaction force T tb,d The second resistance spring reaction force T tb,d_re2 (e l ,e l_brinker ) to obtain the manual steering command value θ md Calculate the following.

[0320] Thereafter, the constant / reaction force setting unit 52A determines whether or not a first predetermined time for updating the first count value T1 has elapsed (step S50). If the first predetermined time has not elapsed (step S50: NO), the constant / reaction force setting unit 52A returns to step S50.

[0321] When it is determined in step S50 that the first predetermined time has elapsed (step S50: YES), the constant / reaction force setting unit 52A increments the first count value T1 by 1 (step S51). lim1 It is then determined whether or not the number of the first and second digits has reached the threshold (step S52).

[0322] The count value T is the first time limit T lim If it is not reached (step S52: NO), the constant / reaction force setting unit 52A determines whether the second lane change approval condition is satisfied (step S53). l -e l_brinker It is determined whether a second lane change approval condition, that is, whether the lane change speed is greater than or equal to -L1, is satisfied.

[0323] If the second lane change approval condition is not met (e l -e l_brinker )>-L1) (step S53: NO), the constant / reaction force setting unit 52A returns to step S50. In this case, in step S50, the constant / reaction force setting unit 52A determines whether or not a first predetermined time has elapsed since the first count value T1 was incremented by 1 in the previous step S51.

[0324] In step S52, the first count value T1 is equal to or smaller than the first time limit T lim1 If it is determined that the threshold value has been reached (step S52: YES), the constant / reaction force setting unit 52A returns to step S31 A. In this case, the host ECU 201 does not perform a lane change.

[0325] In step S53, the second lane change approval condition is satisfied (e l -e l_brinker If it is determined that the lateral deviation e with respect to the current lane after the lane change is equal to or less than -L1 (step S53: YES), the constant / reaction force setting unit 52A calculates the lateral deviation e with respect to the current lane after the lane change. l and lateral deviation e immediately after lane change l_change is acquired from the host ECU 201 (step S54).

[0326] After this, the constant / reaction force setting unit 52A calculates the second guidance spring reaction force T tb,d_gu2 (e l ,e l_change ) is the target virtual spring reaction force T tb,d (Step S55A). The second guidance spring reaction force T tb,d_gu2 (e l ,e l_change ) is the current lateral deviation e l and lateral deviation e immediately after lane change l_change As a result, the manual steering command value calculation unit 53A calculates the second guidance spring reaction force T tb,d_gu2 (e l ,e l_change ) to the target virtual spring reaction force T tb,d The manual steering command value θ md Such an operation of the manual steering command value calculation unit 53A is referred to as a second guidance operation.

[0327] Next, the constant / reaction force setting unit 52A sets a second time limit T lim2 A second count value T2 for timing is set to zero (step S56).

[0328] Thereafter, the constant / reaction force setting unit 52A determines whether or not a second predetermined time for updating the second count value T2 has elapsed (step S57). If the second predetermined time has not elapsed (step S57: NO), the constant / reaction force setting unit 52A returns to step S57.

[0329] When it is determined in step S57 that the second predetermined time has elapsed (step S57: YES), the constant / reaction force setting unit 52A increments the second count value T2 by 1 (step S58). lim2 It is then determined whether or not the number of the first and second digits has been reached (step S59).

[0330] The second count value T2 is the second time limit T lim2 If the e has not been reached (step S59: NO), the constant / reaction force setting unit 52A determines whether the second guidance operation end condition is satisfied (step S60). l In other words, constant / reaction force setting unit 52A determines whether the second guidance operation end condition, that is, after the target driving lane is switched from the current lane to the left lane, the vehicle reference position reaches within a range from the center line of the current lane after the switch to the second threshold value L2, is satisfied.

[0331] If the second guidance operation end condition is not satisfied (step S60: NO), constant / reaction force setting unit 52A returns to step S57. In this case, in step S57, constant / reaction force setting unit 52A determines whether or not a second predetermined time has elapsed since the second count value T2 was incremented by 1 in the previous step S58.

[0332] In step S59, the second count value T2 is equal to or greater than the second time limit T lim2 If it is determined that the constant / reaction force setting unit 52A has reached the predetermined value (step S59: YES), the constant / reaction force setting unit 52A returns to step S31A.

[0333] In step S60, when it is determined that the second guidance operation ending condition is satisfied (step S60: YES), constant / reaction force setting unit 52A returns to step S31A.

[0334] In this modified example, the operation when the target driving lane is switched from the current lane to the right lane is as follows. mode is the first control mode C mode1 and the spring constant k s As the spring constant k for LCA LCA When a rightward direction change command is input while the switch control mode C is set, mode is the second control mode C mode2 The first resistance spring reaction force T tb,d_re1 (e l ,e l_briker ) is the target virtual spring reaction force T tb,d is set as:

[0335] Spring reaction force T for the first resistance tb,d_re1 (e l ,e l_briker ) has the characteristics shown in Figure 19, so the absolute value of the virtual spring reaction force |T tb,d |(=|T tb,d_re1 (e l ,e l_briker )|) gradually increases when a rightward direction change command is input, and (e l -e l_brinker ) reaches a certain value E, T tb,d_3 Then, the absolute value of the virtual spring reaction force |T tb,d |(=|T tb,d_re1 (e l ,e l_briker )|) is (e l -e l_brinker ) becomes zero when it reaches a certain value F, and (e l -e l_brinker ) remains zero even if F or higher.

[0336] (e l -e l_brinker After the vehicle moves to the right after the first lane change approval condition (e l -e l_brinker When L1) is satisfied, the target virtual spring reaction force T tb,d The first resistance spring reaction force T tb,d_re1 (e l ,el_briker ) to the first guidance spring reaction force T tb,d_gu1 (e l ,e l_change ) can be switched to.

[0337] First guidance spring reaction force T tb,d_gu1 (e l ,e l_change ) has the characteristics shown in Figure 20, so the absolute value of the virtual spring reaction force |T tb,d |(=|T tb,d_gu1 (e l ,e l_change )|) remains zero even after the lane change. And the absolute value of the virtual spring reaction force |T tb,d |(=|T tb,d_gu1 (e l ,e l_change )|) is (e l -e l_brinker ) gradually increases when it reaches a certain value G, and (e l -e l_brinker ) reaches a certain value H, T tb,d-4 Then, the absolute value of the virtual spring reaction force |T tb,d |(=|T tb,d_gu1 (e l ,e l_change )|) is (e l -e l_brinker ) becomes zero when it reaches a certain value I, and (e l -e l_brinker ) remains zero even if it exceeds a predetermined value I.

[0338] (e l -e l_brinker After the vehicle moves to the right after the first guidance operation completion condition (e l ≧-L2) is satisfied, switching control mode C mode is the second control mode C mode2 to 1st control mode C mode1 and the spring constant k s is the spring constant k for LCA LCA is set to.

[0339] In this way, when the target driving lane is switched from the current lane to the right lane, the target virtual spring reaction force T in the equation of motion (11) is calculated in the period before and after the switching, including the time when the target driving lane is switched. tb,d is set to zero. This can reduce the discomfort felt by the driver when the target driving lane is changed.

[0340] When the target lane is switched from the current lane to the left lane, the operation is as follows. Switching control mode C mode is the first control mode C mode1 and the spring constant k s As the spring constant k for LCA LCA When the left direction change command is input while the switch control mode C is set, mode is the second control mode C mode2 and the second resistance spring reaction force T tb,d_re2 (e l ,e l_briker ) is the target virtual spring reaction force T tb,d is set as:

[0341] Spring reaction force T for second resistance tb,d_re2 (e l ,e l_briker ) has the characteristics shown in FIG. 21, so the absolute value of the virtual spring reaction force |T tb,d |(=|T tb,d_re2 (e l ,e l_briker )|) gradually increases when a leftward direction change command is input, and (e l -e l_brinker ) reaches a certain value -E, T tb,d_3 Then, the absolute value of the virtual spring reaction force |T tb,d |(=|T tb,d_re2 (e l ,e l_briker )|) is (e l -e l_brinker ) becomes zero when it reaches a certain value -F, and (e l -e l_brinker ) remains zero even if F or less.

[0342] (e l -e l_brinker After the vehicle moves to the right after the second lane change approval condition (e l -e l_brinker When the condition -L1 is satisfied, the target virtual spring reaction force T tb,d The second resistance spring reaction force T tb,d_re2 (e l ,e l_briker ) to the second guidance spring reaction force T tb,d_gu2 (e l ,e l_change ) can be switched to.

[0343] Second guidance spring reaction force T tb,d_gu2 (e l ,e l_change ) has the characteristics shown in FIG. 22, so the absolute value of the virtual spring reaction force |T tb,d |(=|T tb,d_gu2 (e l ,e l_change The absolute value of the virtual spring reaction force |T tb,d |(=|T tb,d_gu2 (e l ,e l_change The absolute value of (e l -e l_brinker ) gradually increases when it reaches a certain value -G, and (e l -e l_brinker ) reaches a certain value -H, T tb,d_4 Then, the absolute value of the virtual spring reaction force |T tb,d |(=|T tb,d_gu2 (e l ,e l_change The absolute value of (e l -e l_brinker ) becomes zero when it reaches a predetermined value -I, and remains zero even if it falls below the predetermined value -I.

[0344] (e l -e l_brinker After the vehicle moves to the left after the vehicle reaches -G, the second guidance operation completion condition (e l ≦L2) is satisfied, switch control mode C modeis the second control mode C mode2 to 1st control mode C mode1 and the spring constant k s is the spring constant k for LCA LCA is set to.

[0345] Even when the target driving lane is switched from the current lane to the left lane, the target virtual spring reaction force T in the equation of motion (11) is tb,d is set to zero. This can reduce the discomfort felt by the driver when the target driving lane is changed.

[0346] Hereinafter, a first modified example and a second modified example of the constant / reaction force setting process will be described.

[0347] In the first modification of the constant / reaction force setting process, in the first resistance period, switching control mode C mode is the second control mode C mode2 The target virtual spring reaction force T tb,d The first resistance spring reaction force T tb,d_re1 (e l ,e l_briker In the first guidance period, switching control mode C mode is the first control mode C mode1 and the spring constant k s The spring constant k for the first guidance gu1 (e l ,e l_change ) is set.

[0348] In the second resistance period, switching control mode C mode is the second control mode C mode2 The target virtual spring reaction force T tb,d The second resistance spring reaction force T tb,d_re2 (e l ,e l_briker In the second guidance period, switching control mode C mode is the first control mode C mode1 and the spring constant k sThe spring constant k for the second guidance gu2 e l ,e l_change ) is set.

[0349] 24A and 24B are flowcharts showing the procedure of the constant / reaction force setting process performed by a first modified example of the constant / reaction force setting unit 52A. In Fig. 24A and Fig. 24B, the same steps as in Fig. 23A and Fig. 23B are denoted by the same step numbers as in Fig. 23A and Fig. 23B. In step S42B corresponding to step S42A in Fig. 23A, the constant / reaction force setting unit 52A selects switching control mode C. mode First control mode C mode1 and the spring constant k s The spring constant k for the first guidance gu1 (e l ,e l_change ) to set the

[0350] In step S55B corresponding to step S55A in FIG. 23B, the constant / reaction force setting unit 52A selects switching control mode C. mode First control mode C mode1 and the spring constant k s The spring constant k for the second guidance gu2 (e l ,e l_change The processes performed in other steps are the same as those described with reference to Figures 23A and 23B.

[0351] In the first modified example of the constant / reaction force setting process, the virtual spring reaction force (k s θ md ,T tb,d ) is set to zero. This reduces the discomfort felt by the driver when the target driving lane is changed.

[0352] In the first modified constant / reaction torque setting process, in the first and second resistance periods where adjustment of the reaction torque is important, the virtual spring reaction force (e l -e l_brikerIn addition, after a lane change, it becomes easy to switch to lane centering assist control.

[0353] In the second modification of the constant / reaction force setting process, in the first resistance period, switching control mode C mode is the first control mode C mode1 and the spring constant k s Let the spring constant k for the first resistance be re1 (e l ,e l_briker In the first guidance period, switching control mode C mode is the second control mode C mode2 The target virtual spring reaction force T tb,d The first guidance spring reaction force T tb,d_gu1 (e l ,e l_change ) is used.

[0354] In the second resistance period, switching control mode C mode is the first control mode C mode1 and the spring constant k s As the spring constant for the second resistance, k re2 (e l ,e l_briker In the second guidance period, switching control mode C is set. mode is the second control mode C mode2 The target virtual spring reaction force T tb,d The second guidance spring reaction force T tb,d_gu2 (e l ,e l_change ) is used.

[0355] Specifically, in step S35A of FIG. 23A, the constant / reaction force setting unit 52A selects the switching control mode C. mode First control mode C mode1 and the spring constant k s Let the spring constant k for the first resistance be re1 (e l ,e l_briker ) and set the first time limit T lim1A first count value T1 for timing is set to zero.

[0356] In step S48A of FIG. 23B, the constant / reaction force setting unit 52A selects the switching control mode C. mode First control mode C mode1 and the spring constant k s As the spring constant for the second resistance, k re2 (e l ,e l_briker ) and set the first time limit T lim1 A first count value T1 for timing is set to zero. The processes performed in the other steps are the same as those described in Figures 23A and 23B.

[0357] In the second modified example of the constant / reaction force setting process, the virtual spring reaction force (k s θ md ,T tb,d ) is set to zero. This reduces the discomfort felt by the driver when the target driving lane is changed.

[0358] Although the embodiment of the present disclosure has been described above, the present disclosure can be embodied in other forms.

[0359] In the above embodiment, when a direction change command is input, the lateral deviation e l e l_briker Then, e l_briker In the above embodiment, the lane change is performed when the vehicle moves from the first threshold L1 in the direction corresponding to the direction change command. However, the lane change may be performed when the vehicle reference position reaches a lateral position preset in response to the direction change command after the direction change command is input.

[0360] For example, the lateral deviation corresponding to the lateral position a certain distance to the right from the center line of the current lane is e l_right Then, after a rightward direction change command is input, e l ≧e l_rightSimilarly, the lateral deviation corresponding to the lateral position a predetermined distance to the left from the center line of the current lane may be set as e l_left Then, after a left direction change command is input, e l ≦e l_left A lane change may be performed when the lane change approval condition is satisfied.

[0361] In the above embodiment, the angle control unit 55 (see FIG. 6) includes the feedforward control unit 63, but the feedforward control unit 63 may be omitted. In this case, the feedback control torque T fb is the basic target torque.

[0362] In the above embodiment, the disturbance torque estimator 64 estimates the motor torque command value T m,cmd and the plant rotation angle θ c Based on and the disturbance torque ^T lc However, a motor torque acquisition unit is provided to acquire the motor torque generated by the electric motor 18, and the motor torque acquired by the motor torque acquisition unit is used as the motor torque command value T m,cmd may be used instead of

[0363] In addition, in the above-described embodiment, a case was described in which the manual steering command value and the automatic steering command value are angle command values, but the present disclosure can also be applied to a case in which the manual steering command value and the automatic steering command value are torque command values.

[0364] Further, in the above-described embodiment, an example was shown in which the present disclosure is applied to motor control of a column-type EPS, but the present disclosure can also be applied to motor control of EPS other than the column type.

[0365] Although the embodiments of the present disclosure have been described in detail, these are merely specific examples used to clarify the technical content of the present disclosure, and the present disclosure should not be interpreted as being limited to these specific examples, and the scope of the present disclosure is limited only by the appended claims. [Explanation of symbols]

[0366] 1...electric power steering device, 3...steered wheel, 4...steered mechanism, 18...electric motor, 30...direction change command input device, 51...assist torque command value setting section, 52...spring constant setting section, 52A...spring constant / target virtual spring reaction force setting section, 53, 53A...manual steering command value calculation section, 54...integrated angle command value calculation section, 55...angle control section, 56...first switch, 57...second switch, 582...addition section, 59...torque control section, 201...host ECU, 202, 202A...motor control ECU, 501...first manual steering command value calculation section, 502...first manual steering command value calculation section, 503...command value switching section

Claims

1. A motor control device for controlling the drive of an electric motor of a steering device, a manual steering command value calculation unit that calculates a manual steering command value by using a torsion bar torque; an integrated angle command value calculation unit that calculates an integrated angle command value by adding the manual steering command value to an automatic steering command value for driving assistance; a motor control unit that controls the electric motor based on the integrated angle command value, In a driving assistance mode, the manual steering command value calculation unit is configured to calculate the manual steering command value by utilizing an equation of motion of a reference model of the steering device, when a predetermined lane change approval condition is satisfied after a direction change command is input by a driver's operation, an automatic steering command value for driving the vehicle along a current lane is switched to an automatic steering command value for driving the vehicle along an adjacent lane in response to the direction change command, a manual steering command value calculation unit that calculates the manual steering command value by setting a virtual spring reaction force in the equation of motion to zero during a period before and after switching that includes a time point at which the automatic steering command value is switched.

2. The motor control device according to claim 1 , wherein the virtual spring reaction force in the equation of motion is a virtual spring reaction force that is set using a spring constant of a virtual spring.

3. 2. The motor control device according to claim 1, wherein a target virtual spring reaction force that changes depending on a lateral position of a vehicle reference position with respect to a driving lane is used as the virtual spring reaction force in the equation of motion.

4. During a period from when the direction change command is input until when the automatic steering command value is switched, the manual steering command value calculation unit calculates the manual steering command value by using a target virtual spring reaction force that changes depending on a lateral position of a vehicle reference position with respect to a driving lane as a virtual spring reaction force in the equation of motion, 2. The motor control device according to claim 1, wherein at least immediately after the automatic steering command value is switched, the manual steering command value calculation unit calculates the manual steering command value using a virtual spring reaction force that is set using a spring constant of a virtual spring as a virtual spring reaction force in the equation of motion.

Images