Motor control device

Abstract

The invention relates to a motor control device. The motor control device includes: 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 and calculates an integrated angle command value; and a control unit that drives and controls the electric motor on the basis of the integrated angle command value, in the driving assistance mode, the manual steering command value calculation unit is configured so as to calculate a manual steering command value using an equation of motion of a reference model of the steering device, and the manual steering command value calculation unit calculates the manual steering command value using the equation of motion of the reference model of the steering device at least under predetermined conditions. A manual steering command value is calculated using a target virtual spring reaction force corresponding to a lateral position of a vehicle reference position with respect to a travel lane as the virtual spring reaction force in the equation of motion.

Description

TECHNICAL FIELD

[0001] The present application relates to a control device of an electric motor for cornering control. BACKGROUND

[0002] A motor control device is disclosed in Patent Document 1 below, which has an assist torque command value setting section that generates an assist torque command value using a torsion bar torque, a manual steering operation command value generation section that generates a manual steering operation command value using the torsion bar torque and the assist torque command value, a comprehensive angle command value operation section that adds the manual steering operation command value to an automatic steering operation command value to operate a comprehensive angle command value, and a switching section that switches between a first control that controls the electric motor based on only the assist torque command value and a second control that controls the electric motor based on the comprehensive angle command value, based on a switching signal.

[0003] Patent Document 1: International Publication No. 2023 / 286169

[0004] In the second control described in Patent Document 1, the manual steering operation command value generation section generates the manual steering operation command value using a motion equation of a reference model of a steering operation device. The motion equation of the reference model of the steering operation device includes an inertial moment, a virtual spring reaction force, and a virtual damper reaction force. As the virtual spring reaction force, a value obtained by multiplying a spring constant of a virtual spring by a caster roll angle (the manual steering operation command value) is used. Therefore, even if a value corresponding to a lateral position of a vehicle reference position is used as the spring constant, a torque corresponding to the vehicle reference position cannot be set as the virtual spring reaction force. Therefore, in the second control described in Patent Document 1, the virtual spring reaction force becomes a reaction force that is left to develop. SUMMARY

[0005] An object of the present application is to provide a motor control device that can set a virtual spring reaction force corresponding to a lateral position of a vehicle reference position at least under a prescribed condition.

[0006] An embodiment of the present application provides a motor control device for drive controlling an electric motor of a steering manipulation device, including: a manual steering manipulation command value arithmetic unit that uses a torsion bar torque to calculate a manual steering manipulation command value; a comprehensive angle command value arithmetic unit that adds an automatic steering manipulation command value for drive assist to the manual steering manipulation command value to calculate a comprehensive angle command value; and a control unit that drive controls the electric motor based on the comprehensive angle command value, wherein in a drive assist mode, the manual steering manipulation command value arithmetic unit is configured to calculate the manual steering manipulation command value using a motion equation of a reference model of the steering manipulation device, and the manual steering manipulation command value arithmetic unit uses, as a virtual spring reaction force in the motion equation, a target virtual spring reaction force corresponding to a lateral position of a vehicle reference position with respect to a travel lane, at least under a prescribed condition, to calculate the manual steering manipulation command value.

[0007] In this structure, at least under a prescribed condition, a virtual spring reaction force corresponding to a lateral position of a vehicle reference position can be applied to a driver.

[0008] The above and other objects, features and effects of the present application will become clearer from the following description of the embodiments with reference to the attached drawings. BRIEF DESCRIPTION OF DRAWINGS

[0009] Figure 1 is a schematic diagram showing a brief structure of an electric power steering system using a motor control device of an embodiment of the present application.

[0010] Figure 2 is a block diagram for explaining an electric structure of a motor control ECU.

[0011] Figure 3 is a graph showing a setting example of an assist torque command value T tb for a torsion bar torque T as .

[0012] Figure 4 is a graph showing a setting example of a target virtual spring reaction force T l for a lateral deviation e tb，d (e l ).

[0013] Figure 5 is a schematic diagram showing one example of a reference EPS model.

[0014] Figure 6 is a block diagram showing a structure of a manual steering manipulation command value arithmetic unit.

[0015] Figure 7 is a block diagram showing a structure of an angle control unit.

[0016] Figure 8 is a schematic diagram showing a configuration example of a physical model of an electric power steering system.

[0017] Figure 9 is a block diagram showing a structure of an interference torque estimation section.

[0018] Figure 10 is a schematic diagram showing a structure of a torque control section.

[0019] Figure 11 is a block diagram showing a first modification example and a second modification example of a motor control ECU.

[0020] Figure 12 is a block diagram showing a structure of a manual steering operation command value calculation section used in the first modification example of the motor control ECU.

[0021] Figure 13A is a part of a flowchart for explaining the operation of the LKA target virtual spring reaction force / weight setting section.

[0022] Figure 13B is a part of a flowchart for explaining the operation of the LKA target virtual spring reaction force / weight setting section.

[0023] Figure 14 is a graph for explaining the operation of the LKA target virtual spring reaction force / weight setting section.

[0024] Figure 15 is a block diagram showing a structure of a manual steering operation command value calculation section used in the second modification example of the motor control ECU.

[0025] Figure 16 is a block diagram showing a third modification example of a motor control ECU.

[0026] Figure 17 is a graph showing a setting example of an LCA target virtual spring reaction force T l for a lateral deviation e tb，d_LCA (e l ), and an initial characteristic of an LKA target virtual spring reaction force T tb，d_LKA (e l ).

[0027] Figure 18 is a block diagram showing a structure of a manual steering operation command value calculation section used in the third modification example of the motor control ECU. DETAILED DESCRIPTION

[0028] [EXPLANATION OF EMBODIMENTS OF THE INVENTION]

[0029] One embodiment of the present application provides a motor control device for drive controlling an electric motor of a steering operation device, including: a manual steering operation command value arithmetic unit that uses a torsion bar torque to calculate a manual steering operation command value; a comprehensive angle command value arithmetic unit that adds an automatic steering operation command value for drive assist to the manual steering operation command value to calculate a comprehensive angle command value; and a control unit that drive controls the electric motor based on the comprehensive angle command value, wherein in a drive assist mode, the manual steering operation command value arithmetic unit is configured to calculate the manual steering operation command value using a motion equation of a reference model of the steering operation device, and the manual steering operation command value arithmetic unit calculates the manual steering operation command value using, as a virtual spring reaction force in the motion equation, a target virtual spring reaction force corresponding to a lateral position of a vehicle reference position with respect to a travel lane, at least under a prescribed condition.

[0030] In this configuration, at least under the prescribed condition, the virtual spring reaction force corresponding to the lateral position of the vehicle reference position can be applied to the driver.

[0031] In one embodiment of the present application, when the drive assist mode is a lane keeping assist mode that assists steering operation in such a way as to maintain the vehicle within the travel lane, the manual steering operation command value arithmetic unit calculates the manual steering operation command value using, as the virtual spring reaction force in the motion equation, the target virtual spring reaction force corresponding to the lateral position of the vehicle reference position with respect to the travel lane.

[0032] In one embodiment of the present application, as the drive assist mode, there are the lane keeping assist mode and another drive mode different from the lane keeping assist mode, and when migrating from the other drive mode different from the lane keeping assist mode to the lane keeping assist mode, the target virtual spring reaction force is set in such a way as to coincide with the torsion bar torque immediately before the migration from the other drive mode to the lane keeping assist mode.

[0033] In one embodiment of the application, the other driving mode described above is a lane centering assist mode in which the above-described vehicle is assisted in steering in a manner to travel in the center of the travel lane, the driving mode is set to the above-described lane centering assist mode when the above-described vehicle reference position is within a range from the center of the travel lane to a prescribed distance, the driving mode is set to the above-described lane keeping assist mode when the above-described vehicle reference position is outside the range from the center of the travel lane to the prescribed distance, in the above-described lane centering assist mode, the above-described manual steering operation command value calculation portion calculates the above-described manual steering operation command value as a virtual spring reaction force in the above-described equation of motion using a virtual spring reaction force set using a spring constant of a virtual spring, and the above-described target virtual spring reaction force at the time of transition from the above-described lane centering assist mode to the above-described lane keeping assist mode is set in a manner to coincide with the torsion bar torque immediately before the transition.

[0034] [Detailed Description of Embodiments of the Invention]

[0035] Hereinafter, embodiments of the application will be described in detail with reference to the drawings.

[0036] Figure 1 is a schematic diagram showing a brief structure of an electric power steering system to which a motor control device according to one embodiment of the application is applied.

[0037] The electric power steering system 1 is provided with a steering wheel (steering handle) 2 as a steering operation member for steering a vehicle, a steering mechanism 4 that turns a steering wheel 3 in conjunction with rotation of the steering wheel 2, and a steering operation assist mechanism 5 for assisting steering operation by a driver. The steering wheel 2 and the steering mechanism 4 are mechanically linked via a steering shaft 6 and an intermediate shaft 7.

[0038] The steering shaft 6 includes an input shaft 8 linked to the steering wheel 2 and an output shaft 9 linked to the intermediate shaft 7. The input shaft 8 and the output shaft 9 are linked in a manner to be relatively rotatable via a torsion bar 10.

[0039] A torque sensor 12 is disposed in the vicinity of the torsion bar 10. The torque sensor 12 detects a torsion bar torque (steering operation torque) T tb In this embodiment, the torsion bar torque T tb For example, a torque for steering in the right direction is detected as a positive value, and a torque for steering in the left direction is detected as a negative value, and the greater the absolute value, the greater the magnitude of the torsion bar torque T tb .

[0040] The steering mechanism 4 is constituted by a rack and pinion mechanism including a pinion shaft 13 and a rack shaft 14 as a steering shaft. Steering wheels 3 are linked to each end portion of the rack shaft 14 via tie rods 15 and knuckle arms (not shown). The pinion shaft 13 is linked to the intermediate shaft 7. The pinion shaft 13 rotates in conjunction with steering operation of the steering wheel 2. A pinion 16 is linked to the front end of the pinion shaft 13.

[0041] The rack shaft 14 extends in a straight line in the left-right direction of the vehicle. A rack 17 that engages with the pinion 16 is formed in the intermediate portion in the axial direction of the rack shaft 14. Rotation of the pinion shaft 13 is converted to axial movement of the rack shaft 14 by the pinion 16 and the rack 17. By moving the rack shaft 14 in the axial direction, the steering wheels 3 are steered.

[0042] If the steering wheel 2 is subjected to steering operation (rotation), the rotation is transmitted to the pinion shaft 13 via the steering shaft 6 and the intermediate shaft 7. Furthermore, rotation of the pinion shaft 13 is converted to axial movement of the rack shaft 14 by the pinion 16 and the rack 17. Thus, the steering wheels 3 are steered.

[0043] The steering assist mechanism 5 includes an electric motor 18 for generating a steering assist force (assist torque), and a speed reducer 19 for amplifying the output torque of the electric motor 18 and transmitting it to the steering mechanism 4. The speed reducer 19 is constituted by a worm and gear mechanism including a worm 20 and a gear 21 that engages with the worm 20. The speed reducer 19 is housed in a gear housing 22 as a transmission mechanism housing.

[0044] Hereinafter, the speed reduction ratio (transmission ratio) of the speed reducer 19 will be represented by N. The speed reduction ratio N is defined as the ratio (θ wg / θ ww ) of the rotational angle of the worm 20, i.e., the worm angle θ wg / θ ww ).

[0045] The worm 20 is rotationally driven by the electric motor 18. In addition, the gear 21 is linked to the output shaft 9 in a manner that allows it to rotate integrally.

[0046] If the worm gear 20 is rotationally driven by the electric motor 18, the worm wheel 21 is rotationally driven, a motor torque is applied to the steering shaft 6, and the steering shaft 6 (output shaft 9) is rotated. Also, the rotation of the steering shaft 6 is transmitted to the pinion shaft 13 via the intermediate shaft 7. The rotation of the pinion shaft 13 is converted into the axial movement of the rack shaft 14. Thereby, the steered wheels 3 are steered. That is, by rotationally driving the worm gear 20 by the electric motor 18, the steering assist by the electric motor 18, the steering of the steered wheels 3 becomes possible. 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.

[0047] As the torque applied to the output shaft 9 (one example of the drive object of the electric motor 18), there are a motor torque generated by the electric motor 18, and a disturbance torque T lc other than the motor torque. lc The disturbance torque T tb other than the motor torque includes a rack torque T rl , a road reaction force torque (road load torque) T f , a friction torque T tb , and the like.

[0048] The rack torque T tb is a torque applied from the steering wheel 2 side to the output shaft 9 by a force applied to the steering wheel 2 by the driver, a force generated by the steering inertia, and the like.

[0049] The road reaction force torque T rl is a torque applied from the steered wheels 3 side to the output shaft 9 via the rack shaft 14 by a restoring moment generated by the tires, a force generated by the suspension, the tire wheel alignment, the friction of the rack and pinion mechanism, and the like.

[0050] The vehicle is equipped with a CCD (Charge Coupled Device) camera 25 that photographs a road ahead of the traveling direction of the vehicle, a GPS (Global Positioning System) 26 that detects the position of the vehicle, a radar 27 that detects the road shape, the obstacle, and a map information storage 28 that stores map information. The vehicle is also equipped with two mode switches 31, 32 for manually switching the steering control mode.

[0051] As described later, the steering control mode has a manual steering control mode in which the steering control is performed by the manual driving, and a coordinated steering control mode in which the steering control based on both the manual driving and the automatic driving is possible.

[0052] The CCD camera 25, the GPS 26, the radar 27, and the map information storage 28 are connected to a higher-level ECU (ECU: Electronic Control Unit) 201 for performing driving assist control, automatic driving control. The higher-level ECU 201 performs surrounding environment recognition, own vehicle position estimation, path planning, and the like based on information obtained by the CCD camera 25, the GPS 26, and the radar 27, and map information, and performs steering control, determination of a control target value of a drive actuator.

[0053] In this embodiment, the higher-level ECU 201 sets an automatic steering control instruction value θ ad In this embodiment, the automatic steering control is, for example, control for causing the vehicle to travel along a target travel route. The automatic steering control instruction value θ ad is a target value of a steering angle for causing the vehicle to automatically travel along the target travel route.

[0054] In this embodiment, the automatic steering control instruction value θ ad is expressed as a positive value, and a rotation amount in a right steering direction from the neutral position is expressed as a negative value. The automatic steering control instruction value θ ad is set, for example, based on a vehicle speed, a lateral deviation with respect to a target travel route (lane center line), and a yaw deviation of the vehicle with respect to the target travel route. The processing of setting such an automatic steering control instruction value θ ad is well known, and thus detailed description thereof is omitted here.

[0055] Further, the automatic steering control (driving assist control) can also be, for example, a lane keeping assist (LKA) control that assists steering in such a manner that the vehicle is maintained within a travel lane, a lane centering assist (LCA) control that assists steering in such a manner that the vehicle travels in the center of the travel lane, or the like.

[0056] In addition, the higher-level ECU 201 outputs a lateral deviation e l In this embodiment, the lateral deviation e l is a distance from the currently set target travel route (lane center line) to a reference position of the vehicle (hereinafter, referred to as "vehicle reference position"). The vehicle reference position is set to a prescribed position in the center of the width of the vehicle.

[0057] In this embodiment, the lateral deviation e l In a case where the vehicle reference position is on the target travel route, it becomes 0 (e l= 0), in a case where the vehicle reference position is located on the right side of the target travel route in the advancing direction, becomes a positive value (e l > 0), in a case where the vehicle reference position is located on the left side of the target travel route in the advancing direction, becomes a negative value (e l < 0).

[0058] In addition, the upper ECU 201 outputs a steering manipulation mode signal S mode indicating whether the steering manipulation mode (driving mode) is the manual steering manipulation mode (manual driving mode) or the coordinated steering manipulation mode (driving assist 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 upper ECU 201 outputs the steering manipulation mode signal S mode indicating that the steering manipulation mode is the manual steering manipulation mode.

[0059] The automatic steering manipulation instruction value θ ad , the lateral deviation e l , and the steering manipulation mode signal S mode are imparted to the motor control ECU 202 via the in-vehicle network. The output signal of the rotation angle sensor 23 and the torsion bar torque T tb detected by the torsion bar torque sensor 12 are input to the motor control ECU 202. The motor control ECU 202 controls the electric motor 18 based on the above-mentioned input signals and information imparted from the upper ECU 201.

[0060] Figure 2 is a block diagram for explaining the electric structure of the motor control ECU 202.

[0061] The motor control ECU 202 is provided with a microcomputer 50, a drive circuit (inverter circuit) 41 controlled by the microcomputer 50 and supplying electric power to the electric motor 18, and a current detection circuit 42 for detecting a current (hereinafter referred to as "motor current I m " ) flowing to the electric motor 18.

[0062] The microcomputer 50 is provided with a CPU and a memory (ROM, RAM, nonvolatile memory, etc.) and functions as a plurality of functional processing sections by executing a prescribed program. The plurality of functional processing sections include an assist torque instruction value setting section 51, a target virtual spring reaction force setting section 52, a manual steering manipulation instruction value operation section 53, a comprehensive angle instruction value operation section 54, an angle control section 55, a first switch 56, a second switch 57, an addition section 58, and a torque control section (current control section) 59.

[0063] The auxiliary torque command value setting unit 51 sets the target value of the auxiliary torque required for manual operation, i.e., the auxiliary torque command value T. as The auxiliary torque command setting unit 51 is based on the torsion bar torque T detected by the torque sensor 12. tb To set the auxiliary torque command value T as .

[0064] Figure 3 This indicates the torque T of the torsion bar. tb Assist torque command value T as The diagram shows the configuration example.

[0065] Assist torque command value T as When the electric motor 18 should generate steering assist force for right-hand steering, a positive value is set; when the electric motor 18 should generate steering assist force for left-hand steering, a negative value is set. Assist torque command value T as Relative to the torsion bar torque T tb The positive value is taken as positive, relative to the torsion bar torque T. tb Negative values ​​are taken as negative. Furthermore, the auxiliary torque command value T... as Set as torsion bar torque T tb The larger the absolute value, the larger its absolute value.

[0066] Furthermore, the auxiliary torque command value setting unit 51 can also set the torsion bar torque T. tb The auxiliary torque command value T is calculated by multiplying it by a pre-set constant. as Additionally, the auxiliary torque command value T as You can also consider the vehicle speed when setting it.

[0067] When coordinating the steering control mode, the target virtual spring reaction force setting unit 52 is based on the lateral deviation e given by the upper ECU 201. l To set the target virtual spring reaction force T tb，d (e) l ).

[0068] Figure 4 This indicates that the lateral deviation e l Target virtual spring reaction force T tb，d (e) l The diagram shows the setting example.

[0069] In lateral deviation e l In -e l，s (where e) l，s >0) ~e l，s Within the range, the target virtual spring reaction force T tb，d (e)l ) is set to T tb，d，s (where T tb，d，s > 0) to T tb，d，s , the larger the lateral deviation e l is, the larger it is. In this example, the target virtual spring reaction force T tb，d (e l ) is linearly changed, but it can be changed nonlinearly.

[0070] In the range of the lateral deviation e l，s ~ e l，m (where e l，m > e l，s ), the target virtual spring reaction force T tb，d (e l ) is set to T tb，d，s to T tb，d，m (where T tb，d，m > T tb，d，s ), the larger the lateral deviation e l is, the larger it is, and the inclination of the straight line is set to be larger than that in the range of the lateral deviation e l in the range of -e l，s ~ e l，s . In this example, the target virtual spring reaction force T tb，d (e l ) is linearly changed, but it can be changed nonlinearly. In the range of the lateral deviation e l larger than e l，m , the target virtual spring reaction force T tb，d (e l ) is set to T tb，d，m .

[0071] In the range of the lateral deviation e l in the range of -e l，s ~ -e l，m (where -e l，m < -e l，s ), the target virtual spring reaction force T tb，d (e l ) is set to -T tb，d，s to -T tb，d，m (where -T tb，d，m < -T tb，d，s ), the smaller the lateral deviation e l is, the smaller it is, and the inclination of the straight line is set to be larger than that in the range of the lateral deviation e l in the range of -e l，s ~ e l，s . In this example, the target virtual spring reaction force T tb，d (e l) can also be changed non-linearly. In the range of e l < e l，m , the target virtual spring reaction force T tb，d (e l ) is set to -T tb，d，m .

[0072] The manual steering manipulation command value arithmetic unit 53, when the cooperative steering manipulation mode is coordinated, is provided to set the steering manipulation angle (more accurately, the rotation angle θ c of the output shaft 9) corresponding to the steering wheel 2 operation to the manual steering manipulation command value θ md in the case where the driver operates the steering wheel 2. The manual steering manipulation command value arithmetic unit 53 generates the manual steering manipulation command value θ tb using the torsion bar torque T tb，d (e l ) detected by the torque sensor 12 and the target virtual spring reaction force T md set by the target virtual spring reaction force setting unit 52. Details of the manual steering manipulation command value arithmetic unit 53 will be described later.

[0073] The integrated angle command value arithmetic unit 54 adds the automatic steering manipulation command value θ ad set by the upper ECU 201 to the manual steering manipulation command value θ md to calculate the integrated angle command value θ cmd .

[0074] The angle control unit 55 calculates the integrated motor torque command value T cmd based on the integrated angle command value θ com . Details of the angle control unit 55 will be described later.

[0075] The first switch 56 and the second switch 57 are opened or closed according to the steering manipulation mode signal S mode input. Specifically, in the case where the steering manipulation mode signal S mode indicating that the steering manipulation mode is the manual steering manipulation mode is input, the first switch 56 is opened and the second switch 57 is closed.

[0076] On the other hand, in the case where the steering manipulation mode signal S mode indicating that the steering manipulation mode is the cooperative steering manipulation mode is input, the first switch 56 is closed and the second switch 57 is opened.

[0077] In the case where the first switch 56 is in the open state and the second switch 57 is in the closed state, the adder 58 outputs the assist torque command value T as as the motor torque command value Tm，cmd (=T as ) is output. On the other hand, in a case where the second switch 57 is in an open state and the first switch 56 is in a closed state, the addition section 58 outputs the integrated motor torque command value T com (=T m，cmd ) output from the angle control section 55 to the torque control section 59. com (=T m，cmd ) is output.

[0078] The output of the addition section 58, that is, the motor torque command value T m，cmd is given to the torque control section 59.

[0079] The torque control section 59 drives the drive circuit 41 in a manner that the motor torque of the electric motor 18 approaches the motor torque command value T md . Details of the torque control section 59 will be described later.

[0080] The manual steering operation command value calculation section 53 will be described in detail.

[0081] First, the setting method of the manual steering operation command value θ md of the manual steering operation command value generation section described in Patent Document 1 will be described.

[0082] The manual steering operation command value generation section generates the manual steering operation command value θ Figure 5 using a reference EPS model of md . The reference EPS model of col is one example of the "reference model of a steering operation device" of the present application.

[0083] The 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. However, this model is one example, and can be an inertia model including structures other than the above (for example, a rack bar, etc.). In the reference EPS model, J tb is an inertia of the lower column (hereinafter, referred to as "column inertia"), θ tb is a rotation angle of the lower column, and T m is a torsion bar torque. The torsion bar torque T rl is applied to the lower column, a torque N•T rl acted on the output shaft 9 from the electric motor 18, and a road reaction force torque (virtual reaction force) T md .

[0084] The road reaction force torque T md is represented by the following equation (1) using a spring constant k md of a virtual spring and a viscous damping coefficient c md of a virtual shock absorber.

[0085] Math. 1

[0086]

[0087] spring constant k md and viscous damping coefficient c md is obtained by preliminary experiments, analysis, etc. Hereinafter, k md • θ col is called a virtual spring reaction force, and c md (dθ col / dt) is called a virtual shock absorber reaction force.

[0088] The equation of motion with reference to the EPS model is represented by the following equation (2).

[0089] Math. 2

[0090]

[0091] In equation (2), J md • d 2 θ col / dt 2 is the moment of inertia of the lower column.

[0092] The manual steering operation command value generation section solves the differential equation of equation (2) by substituting the torsion bar torque T tb detected by the torque sensor 12 into T tb and substituting the assist torque command value T as set by the assist torque command value setting section 51 into T m , to calculate the rotation angle θ col of the lower column. Also, the manual steering operation command value generation section generates the obtained rotation angle θ md of the lower column as the manual steering operation command value θ col . In this way, the method of setting the manual steering operation command value θ md is called a comparison method.

[0093] The equation of motion of equation (2) is equivalent to the equation of motion in which T m is replaced by T as , and θ col is replaced by θ md .

[0094] In the comparison method, as the virtual spring reaction force, the spring constant k md of the virtual spring is multiplied by the rotation angle θ md of the lower column J col (manual steering operation command value θ mdThe value obtained is from the lateral position corresponding to the vehicle's reference position. Therefore, even if the value corresponding to the lateral position is used as the spring constant k, md Furthermore, it is impossible to set the torque corresponding to the lateral position of the vehicle's reference position as the virtual spring reaction force. Therefore, in the comparison method, in the coordinated control mode, the virtual spring reaction force k... md •θ col (=k) md •θ md This becomes a counterforce that allows things to develop unchecked.

[0095] In this embodiment, the manual steering command value calculation unit 53 calculates the manual steering command value θ 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 modified motion equation (2) of the aforementioned reference EPS model. md .

[0096] Figure 6 This is a block diagram showing the structure of the manual steering control command value calculation unit 53.

[0097] exist Figure 6 In the middle, J md It represents cylindrical inertia. s is the differential operator. θ md It is the manual steering control command value, equivalent to the rotation angle θ of the lower pillar in the comparison method. col c md It is the viscous damping coefficient of the virtual shock absorber, which is obtained through prior experiments and analysis.

[0098] The manual steering control command value calculation unit 53 includes: an addition and subtraction unit 101, an inertial division unit 102, a first integration unit 103, a second integration unit 104, and a virtual shock absorber reaction force calculation unit 105.

[0099] Input the torsion bar torque T into the addition / subtraction unit 101 tb Target virtual spring reaction force T tb，d (e) l ), and the virtual shock absorber reaction force c given by the virtual shock absorber reaction force calculation unit 105. md •dθ md / dt.

[0100] Addition and subtraction section 101 from torsion bar torque T tb Subtract the target virtual spring reaction force T tb，d (e) l ) and the virtual shock absorber reaction force c md •dθ md / dt. Therefore, the addition / subtraction part 101 operation is equivalent to J on the left side of the above equation (2). md •d 2 θ col / dt 2 Inertial torque J md •d 2 θ md / dt 2 (=T) tb -c md •dθ md / dt-T tb，d (e) l )).

[0101] The inertial division unit 102 calculates the inertial torque J by the addition and subtraction unit 101. md •d 2 θ md / dt 2 Divided by the column inertia J md To calculate the manual steering control command value θ md The second-order differential value d 2 θ md / dt 2 .

[0102] The first integrator 103 controls the manual steering command value θ md The second-order differential value d 2 θ md / dt 2 Integrating the values ​​of the manual steering commands (θ) to calculate the value of the manual steering command. md The first differential value dθ md / dt.

[0103] The second integrator 104 processes the manual steering control command value θ md The first differential value dθ md Integrating / dt to calculate the manual steering command value θ md The manual steering control command value θ md The value of the control command is output by the calculation unit 53, which switches from manual to control.

[0104] The virtual shock absorber reaction force calculation unit 105 calculates the manual steering control command value θ calculated by the first integrator unit 103. md The first differential value dθ md / dt multiplied by the viscosity decay coefficient c md To calculate the virtual shock absorber reaction force c md •dθ md / dt. The virtual shock absorber reaction force c md •dθ md / dt is fed back to the addition and subtraction department 101.

[0105] That is, the manual steering manipulation command value operation section 53 operates the manual steering manipulation command value θ based on a motion equation represented by the following equation (3) md .

[0106] Mathematical expression 3

[0107]

[0108] In the equation (3), J md • dθ 2 / dt is the virtual damper reaction force. T md (e 2 ) is the target virtual spring reaction force. md • dθ md / dt is the virtual damper reaction force. T tb，d (e l ) is the target virtual spring reaction force.

[0109] In the present embodiment, the manual steering manipulation command value operation section 53 sets N•T m (= N•T as ) in the motion equation of the above equation (2) to 0, and operates the manual steering manipulation command value θ md as the virtual spring reaction force k•θ l in the motion equation of the above equation (2), using the target virtual spring reaction force T tb，d (e l ) corresponding to the lateral deviation e md .

[0110] Further, the manual steering manipulation command value operation section 53 can also operate N•T as by multiplying the assist torque command value T as by the reduction ratio N, and supply the obtained N•T as to the addition / subtraction section 101. In this case, the addition / subtraction section 101 subtracts the virtual damper reaction force c tb • dθ as / dt and the target virtual spring reaction force T md (e md ) from the value obtained by adding N•T tb，d to the torsion bar torque T l . In this case, the manual steering manipulation command value operation section 53 operates the manual steering manipulation command value θ as based on the motion equation with N•T md added to the right side of the above equation (3).

[0111] Figure 7 is a block diagram showing the structure of the angle control section 55.

[0112] The angle control section 55 operates an integrated motor torque command value T cmd based on the integrated angle command value θ com . The angle control section 55 includes a low-pass filter (LPF) 61, a feedback control section 62, a feedforward control section 63, a disturbance torque estimation section 64, a torque addition section 65, a disturbance torque compensation section 66, a first reduction ratio division section 67, a reduction ratio multiplication section 68, a rotation angle operation section 69, and a second reduction ratio division section 70.

[0113] The reduction ratio multiplication section 68 converts the motor torque command value T Figure 2 operated by the addition section 58 (refer to m，cmd ) into an output shaft torque command value N•T m，cmd that acts on the output shaft 9 (worm 21) by multiplying the motor torque command value T m，cmd by the reduction ratio N of the reduction gear 19.

[0114] The rotation angle operation section 69 operates the rotor rotation angle θ m of the electric motor 18 based on the output signal of the rotation angle sensor 23. The second reduction ratio division section 70 converts the rotor rotation angle θ m operated by the rotation angle operation section 69 into the rotation angle (actual steering angle) θ m of the output shaft 9 by dividing the rotor rotation angle θ c by the reduction ratio N.

[0115] In this embodiment, the actual steering angle θ c is represented by the amount of rotation (rotation angle) from the neutral position of the output shaft 9, and the amount of rotation in the right steering direction from the neutral position is represented as a positive value, and the amount of rotation in the left steering direction from the neutral position is represented as a negative value.

[0116] The low-pass filter 61 performs low-pass filter processing on the integrated angle command value θ cmd . The integrated angle command value θ cmdl after the low-pass filter processing is given to the feedback control section 62 and the feedforward control section 63. Note that the low-pass filter 61 can not be provided.

[0117] The feedback control section 62 is provided in order to cause the steering angle estimation value ^θ cmdl operated by the disturbance torque estimation section 64 to approach the integrated angle command value θ cmdl after the low-pass filter processing. The feedback control section 62 includes an angle deviation operation section 62A and a PD control section 62B. The angle deviation operation section 62A operates the deviation Δθ (= θ c - ^θ cmdl of the integrated angle command value θ cFurthermore, the angle deviation calculation unit 62A can also calculate the comprehensive angle command value θ. cmdl The actual steering angle θ calculated by the second reduction ratio divider 70 c deviation (θ) cmdl -θ c The angle deviation Δθ is used for calculation.

[0118] The PD control unit 62B calculates the feedback control torque T by performing PD calculation (proportional-derivative calculation) on the angle deviation Δθ calculated by the angle deviation calculation unit 62A. fb Feedback control torque T fb The torque addition part is given 65.

[0119] The feedforward control unit 63 is provided to compensate for the responsiveness delay caused by the inertia of the electric power steering system 1 and to improve the control responsiveness. 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 the angular acceleration by processing the combined angle command value θ. cmdl Perform a second-order differential to calculate the target angular acceleration d. 2 θ cmdl / dt 2 .

[0120] The inertial multiplication unit 63B calculates the target angular acceleration d from the angular acceleration calculation unit 63A. 2 θ cmdl / dt 2 Multiply by the inertia J of the electric power steering system 1 to calculate the feedforward control torque T. ff (=J•d) 2 θ cmdl / dt 2 Inertia J, for example, is based on the physical model of the electric power steering system 1 described later (see reference). Figure 8 The feedforward control torque T is then calculated. ff The torque addition part 65 is assigned as an inertia compensation value.

[0121] The torque addition unit 65 controls the feedback torque T fb Plus feedforward control torque T ff To calculate the basic torque command value (T) fb +T ff ).

[0122] The interference torque estimation unit 64 is provided to estimate the nonlinear torque (interference torque: torque other than motor torque) generated as interference in the device (the controlled object of the electric motor 18). The interference torque estimation unit 64 is based on the output shaft torque command value N•T. m，cmd and the actual steering angle θ c, to infer the disturbance torque (disturbance load) T lc , the steering angle θ, and the steering angle differential value (angular velocity) dθ c / dt. The inferred values of the disturbance torque T lc , the steering angle θ c , and the steering angle differential value (angular velocity) dθ c / dt are represented by ^T lc , ^θ c , and d^θ c / dt, respectively. Details of the disturbance torque inferring section 64 will be described later.

[0123] The disturbance torque inferred value ^T lc calculated by the disturbance torque inferring section 64 is given to the disturbance torque compensating section 66 as a disturbance torque compensation value. The steering angle inferred value ^θ c calculated by the disturbance torque inferring section 64 is given to the angle deviation calculating section 62A.

[0124] The disturbance torque compensating section 66 calculates the integrated torque command value T fb by subtracting the disturbance torque inferred value ^T ff from the basic torque command value (T lc + T co ) (= T fb + T ff - ^T lc ). Thus, the integrated torque command value T co (= T co + T co - ^T com ) that compensates for the disturbance torque (torque command value for the output shaft 9) is obtained.

[0125] The integrated torque command value T co is given to the first reduction ratio dividing section 67. The first reduction ratio dividing section 67 calculates the integrated motor torque command value T co (= T com ) by dividing the integrated torque command value T com by the reduction ratio N. This integrated motor torque command value T lc is given to the second switch 57 (refer to Figure 2 ).

[0126] The disturbance torque inferring section 64 will be described in detail. The disturbance torque inferring section 64 is constituted, for example, by a disturbance observer that infers the disturbance torque T c , the steering angle θ c , and the angular velocity dθ tb / dt using the physical model 300 of the electric power steering system 1 shown in FIG. 6.

[0127] The physical model 300 includes a device (one example of a motor-driven object) 301 having an output shaft 9 and a worm gear 21 fixed to the output shaft 9. A steering column torque T tb is applied to the device 301 from the steering wheel 2 via the torsion bar 10, and a road reaction force torque T rl is applied to the device 301 from the steering wheel 3 side.

[0128] And, an output shaft torque command value N•T m，cmd is applied to the device 301 via the worm gear 20, and a friction torque T f is applied to the device 301 by friction between the worm gear 21 and the worm gear 20.

[0129] If the inertia of the device 301 is set to J, a motion equation with respect to the inertia of the physical model 300 is represented by the following equation (4).

[0130] Mathematical equation 4

[0131]

[0132] d 2 θ c / dt 2 is the angular acceleration of the device 301. N is the reduction ratio of the reduction gear 19. T lc A disturbance torque other than the motor torque applied to the device 301 is shown. In this embodiment, the disturbance torque T lc is expressed as the sum of the steering column torque T tb , the road reaction force torque T rl , and the friction torque T f , but in fact the disturbance torque T lc includes torques other than these.

[0133] The state equation of the physical model 300 with respect to Figure 8 is represented by the following equation (5).

[0134] Mathematical equation 5

[0135]

[0136] In the above equation (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 (measured value). In the above equation (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 matrix.

[0137] The above state equation is extended to a system in which the unknown input vector u2 is included as one of the states. The state equation of the extended system (extended state equation) is represented by the following equation (6).

[0138] Math. 6

[0139]

[0140] In the above-described equation (6), x e is a state variable vector of the extended system, which is represented by the following equation (7).

[0141] Math. 7

[0142]

[0143] In the above-described equation (6), A e is a system matrix of the extended system, B e is a known input matrix of the extended system, and C e is an output matrix of the extended system.

[0144] According to the extended state equation of the above-described equation (6), a disturbance observer (extended state observer) represented by the following equation (8) is constructed.

[0145] Math. 8

[0146]

[0147] In equation (8), ^x e represents an estimated value of x e . In addition, L is an observer gain. In addition, ^y represents an estimated value of y. ^x e is represented by the following equation (9).

[0148] Math. 9

[0149]

[0150] In equation (9), ^θ c is an estimated value of θ c , and ^T lc is an estimated value of T lc .

[0151] The disturbance torque estimation section 64 operates the state variable vector ^x e based on the above-described equation (8).

[0152] Figure 9 is a block diagram representing the structure of the disturbance torque estimation section 64.

[0153] The disturbance torque estimation section 64 includes an input vector input section 81, an output matrix multiplication section 82, a first addition section 83, a gain multiplication section 84, an input matrix multiplication section 85, a system matrix multiplication section 86, a second addition section 87, an integration section 88, and a state variable vector output section 89.

[0154] From the reduction ratio multiplication part 68 (refer to) Figure 7 The output shaft torque command value N•T calculated by the operation m，cmd The input vector is assigned to the input vector input section 81. The input vector input section 81 outputs the input vector u1.

[0155] The output of the integrator 88 becomes the state variable vector ^x e (Refer to equation (9) above). At the start of the operation, the state variable vector ^x e Assign initial values. State variable vector ^x e The initial value is, for example, 0.

[0156] The system matrix multiplication part has 86 pairs of state variable vectors ^x e Multiply by system matrix A e The output matrix multiplication part 82 pairs the state variable vector ^x e Multiply by the output matrix C e .

[0157] The first addition section 83 is derived from the second reduction ratio division section 70 (see reference). Figure 7 The actual steering angle θ calculated c That is, the output vector (measured value) y minus the output of the output matrix multiplication unit 82 (C e •^x e That is, the output vector y of the first addition unit 83 and the inferred value ^y (=C) of the output vector. e •^x e The difference (y-^y) is calculated by multiplying the output (y-^y) of the first adder 83 by the gain multiplier 84. The gain multiplier 84 multiplies the output (y-^y) of the first adder 83 by the observer gain L (refer to equation (8) above).

[0158] 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 addition unit 87 inputs the matrix multiplication unit 85's output (B... e •u1), the output of the system matrix multiplication unit 86 (A) e •^x e The differential value d^x of the state variable vector is calculated by adding the output of the gain multiplication unit 84 (L(y-^y)) and the output of the gain multiplication unit 84. e / dt. The integral part 88 outputs (d^x) to the second addition part 87. e Integrate / dt to compute the state variable vector ^x e The state variable vector output unit 89 is based on the state variable vector ^x. e To calculate the inferred value of the disturbance torque ^T lc , Steering angle inference value ^θ cand the inferred angular velocity d^θ c / dt.

[0159] Unlike the extended state observer described above, the ordinary interference observer consists of the device's inverse model and a low-pass filter. As mentioned above, the device's equation of motion is represented by equation (3). Therefore, the device's inverse model becomes equation (10).

[0160] Mathematical formula 10

[0161]

[0162] The input for a typical interference observer is J•d 2 θ c / dt 2 and N•T m，cmd Because the actual steering angle θ is used c The second derivative value is therefore significantly affected by the noise from the rotation angle sensor 23. In contrast, in the extended state observer of the above embodiment, since the disturbance torque is inferred using an integral form, the noise influence of the derivative can be reduced.

[0163] In addition, as the interference torque inference unit 64, a common interference observer consisting of the inverse model of the device and a low-pass filter can also be used.

[0164] Figure 10 This is a schematic diagram showing the structure of the torque control unit 59.

[0165] Torque control unit 59 (refer to) Figure 2 It 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.

[0166] The motor current command value calculation unit 91 calculates the current by adding the value from the addition unit 58 (see reference). Figure 2 The calculated motor torque command value T m，cmd Divide by the torque constant K of the electric motor 18 t To calculate the motor current command value I m，cmd .

[0167] The current deviation calculation unit 92 calculates the motor current command value I obtained by the motor current command value calculation unit 91. m，cmd The motor current I detected by the current detection circuit 42 m The deviation ΔI (=I m，cmd -I m ).

[0168] The PI control section 93 generates a drive command value for the motor current I flowing to the electric motor 18 by performing PI operation (proportional integral operation) with respect to the current deviation ΔI calculated by the current deviation operation section 92. The PWM control section 94 generates a PWM control signal of a duty ratio corresponding to the above-described drive command value, and supplies it to the drive circuit 41. Thereby, power corresponding to the drive command value is supplied to the electric motor 18. m，cmd The PWM control section 94 generates a PWM control signal of a duty ratio corresponding to the above-described drive command value, and supplies it to the drive circuit 41. Thereby, power corresponding to the drive command value is supplied to the electric motor 18.

[0169] Hereinafter, the operation of the present embodiment will be described with reference to Figure 2 to the drawings.

[0170] In the present embodiment, the manual steering operation mode refers to a steering operation mode in which the electric motor 18 is controlled based on only the assist torque command value T as The coordinated steering operation mode refers to a steering operation mode in which the electric motor 18 is controlled based on a comprehensive angle command value θ ad that takes into account both the automatic steering operation command value θ md and the manual steering operation command value θ cmd

[0171] In a case where the steering operation mode is set to the manual steering operation mode, the first switch 56 is turned on, and the second switch 57 is turned off. In a case where the steering operation mode is set to the coordinated steering operation mode, the first switch 56 is turned off, and the second switch 57 is turned on. That is, the motor control ECU 202 can switch the steering operation mode between the manual steering operation mode and the coordinated steering operation mode by the driver's operation of the mode switches 31, 32.

[0172] Further, although the switching of the steering operation mode is performed by the mode switches 31, 32, the upper ECU 201 can also switch the steering operation mode in accordance with an on / off signal of a driving assistance function or an automatic driving function, an obstacle, a driver's state, a driver's operation of an accelerator / brake, and a running state of the vehicle. In this case, the upper ECU 201 generates a mode setting signal in accordance with the on / off signal of the driving assistance function or the automatic driving function, the obstacle, the driver's state, the driver's operation of the accelerator / brake, and the running state of the vehicle, and gives it to the motor control ECU 202.

[0173] For example, in a case where a lane keeping assistance control for maintaining the vehicle within a lane is performed, the upper ECU 201 can also automatically switch the steering operation mode as follows.

[0174] Referring to Figure 4 , the lateral deviation e l is in the range of -e l，s ~e​l，s When the lateral deviation e l，s ~ e l，s is within the range of -e tb，d ~ e l , the upper ECU 201 sets the steering operation mode to the manual steering operation mode. By this, the first switch 56 is opened, and the second switch 57 is closed. In this case, since the second switch 57 is closed, the target virtual spring reaction force T l (e l，s ) is not reflected as the steering operation reaction force.

[0175] On the other hand, when the lateral deviation e l，s is outside the range of -e l，s ~ e l，s , the upper ECU 201 sets the steering operation mode to the cooperative steering operation mode. By this, the second switch 57 is opened, and the first switch 56 is closed. In this case, since the second switch 57 is opened, the target virtual spring reaction force T tb，d (e l ) outside the range of -e l ~ e l，s is reflected as the steering operation reaction force.

[0176] In the case of automatically switching the steering operation mode as such, under the condition that the lateral deviation e l，s is outside the range of -e md ~ e l , the manual steering operation command value operation section 53 operates the manual steering operation command value θ tb，d as the virtual spring reaction force k • θ l in the motion equation of the above-described equation (2), using the target virtual spring reaction force T md (e cmd ) corresponding to the lateral deviation e as .

[0177] In the above-described embodiment, it is possible to switch between the cooperative steering operation mode in which the electric motor 18 is controlled based on the integrated angle command value θ cmd , and the manual steering operation mode in which the electric motor 18 is controlled based on only the assist torque command value T as .

[0178] That is, in the electric power steering system 1 in which the electric motor 18 is controlled based on the integrated angle command value θ as , it is possible to control the electric motor 18 based on only the assist torque command value T md .

[0179] In the above implementation, in manual steering mode, since it is based solely on the auxiliary torque command value T as This controls the electric motor 18, so the driver can accept the actual road reaction torque.

[0180] In the above embodiment, when coordinating the steering control mode, the manual steering control command value calculation unit 53 calculates the virtual spring reaction force k•θ in the motion equation of the above equation (2). md Using lateral deviation e l The corresponding target virtual spring reaction force T tb，d (e) l ), to calculate the manual steering control command value θ md Therefore, when coordinating steering control modes, it is possible to control the lateral deviation e. l The corresponding steering reaction force is applied to the driver. As a result, the driver can easily perceive the distance from the center of the driving lane or the distance to the lane.

[0181] Furthermore, in the above implementation, based on the comprehensive angle command value θ cmd To calculate the basic torque command value (T) fb +T ff ), and the interference torque inference value ^T calculated by the interference torque inference unit 64 lc To correct the basic torque command value (T) fb +T ff Therefore, it can suppress the influence of disturbance torque on angle control performance. As a result, high-precision angle control can be achieved.

[0182] The following describes a variation of the motor control ECU 202. In the following variation of the motor control ECU 202, the operation in manual steering mode is the same as in the above embodiment, so the operation in coordinated steering mode will be described below.

[0183] Figure 11 This is a block diagram representing a first modified example of an ECU for motor control. Figure 11 In the middle, to and Figure 2 The corresponding part markings and Figure 2 Same reference numerals as shown in the attached figures.

[0184] exist Figure 11 In the motor control ECU202A, in the following (1) and (2), with Figure 2 The motor control ECU202 is different.

[0185] (1) The structure of the manual steering control command value calculation unit 53A and Figure 2 The structure of the manual steering control command value calculation unit 53 is different.

[0186] (2) Instead of Figure 2 the target virtual spring reaction force setting section 52, a target virtual spring reaction force / weight setting section 52A for LKA (hereinafter, referred to as "reaction force / weight setting section 52A") is used.

[0187] The reaction force / weight setting section 52A sets the target virtual spring reaction force T tb，d_LKA (e l ) for LKA used for the lane keeping assist, and sets the first weight W1 and the second weight W2 described later. In addition to the lateral deviation e l , the torsion rod torque T tb is also given to the reaction force / weight setting section 52A.

[0188] The torsion rod torque T tb and the target virtual spring reaction force T tb，d_LKA (e l ) set by the reaction force / weight setting section 52A are given to the manual steering manipulation command value operation section 53A. Also, the assist torque command value T as set by the assist torque command value setting section 51 and the first weight W1 and the second weight W2 set by the reaction force / weight setting section 52A are given to the manual steering manipulation command value operation section 53A.

[0189] Figure 12 is a block diagram showing the structure of the manual steering manipulation command value operation section 53A. In Figure 12 , the same reference numerals are attached to the parts corresponding to the respective parts of the above Figure 6 . Figure 6

[0190] In Figure 12 , k md is a spring constant of the virtual spring, and is found by a preliminary experiment, analysis, or the like. T as is the assist torque command value T as set by the assist torque command value setting section 51.

[0191] The manual steering manipulation command value operation section 53A includes a reduction ratio multiplication section 131, a subtraction / addition section 101, an inertia division section 102, a first integration section 103, a second integration section 104, a virtual damper reaction force operation section 105, a virtual spring reaction force operation section 106, a first weight multiplication section 107, a first addition section 108, a second weight multiplication section 109, and a second addition section 110.

[0192] The reduction ratio multiplication section 131 multiplies the assist torque command value T as ​Multiply by the reduction ratio N of the reducer 19, and then use the auxiliary torque command value T for the rotating shaft of the electric motor 18. as Converted into an auxiliary torque command value N•T for output shaft 9. as The auxiliary torque command value N•T for the output shaft 9 is calculated by the reduction ratio multiplication unit 131. as It is assigned to the addition and subtraction section 101, and to the first addition section 108.

[0193] The addition and subtraction section 101 is given a torsion bar torque T. tb The auxiliary torque command value N•T for the output shaft 9 is calculated by the reduction ratio multiplication unit 131. as The virtual shock absorber reaction force c assigned by the virtual shock absorber reaction force calculation unit 105 md •dθ md The sum of / dt and the result X of the second addition part 110.

[0194] Addition and subtraction section 101 torsion bar torque T tb In addition, the auxiliary torque command value N•T for output shaft 9 as And subtract the virtual damper reaction force θ from the summation result. md •dθ md / dt and X. Therefore, the addition / subtraction part 101 operation is equivalent to J on the left side of the above equation (2). md •d 2 θ col / dt 2 Inertial torque J md •d 2 θ md / dt 2 (=T) tb +N•T as -c md •dθ md / dt-X).

[0195] The inertial division unit 102 calculates the inertial torque J by the addition and subtraction unit 101. md •d 2 θ md / dt 2 Divided by the column inertia J md To calculate the manual steering control command value θ md The second-order differential value d 2 θ md / dt 2 .

[0196] The first integrator 103 controls the manual steering command value θ md The second-order differential value d 2 θ md / dt2 Integrating the values ​​of the manual steering commands (θ) to calculate the value of the manual steering command. md The first differential value dθ md / dt.

[0197] The second integrator 104 processes the manual steering control command value θ md The first differential value dθ md The / dt unit is used to calculate the manual steering control command value θ. md The manual steering control command value θ md The output of the operation command value calculation unit 53A is switched from manual to control.

[0198] The virtual shock absorber reaction force calculation unit 105 calculates the manual steering control command value θ calculated by the first integrator 103. md The first differential value dθ md / dt multiplied by the viscosity decay coefficient c md To calculate the virtual shock absorber reaction force c md •dθ md / dt. The virtual shock absorber reaction force c md •dθ md / dt is fed back to the addition and subtraction department 101.

[0199] The virtual spring reaction force calculation unit 106 calculates the manual steering control command value θ calculated by the second integrator 104. md Multiply by the spring constant k md To calculate the virtual spring reaction force k md •θ md .

[0200] The first weighted multiplication part 107 relates to the virtual spring reaction force k. md •θ md Multiply by the first weight W1.

[0201] The first addition section 108 uses the target virtual spring reaction force T on LKA. tb，d_LKA (e) l Add the auxiliary torque command value N•T for the output shaft 9 calculated by the reduction ratio multiplier 131. as The result of the operation (T) of the second weighted multiplication unit 109 on the first addition unit 108. tb，d_LKA (e) l ) + N•T as Multiply by the second weight W2.

[0202] The second addition unit 110 performs the operation of the first weighted multiplication unit 107 on the result W1•k. md •θ md The result of the operation of the second weighted multiplication unit 109 is W2•(T)tb，d_LKA (e l ) + N • T as are added. The addition result of the second adding section 110 {W1 • k md • θ md + W2 • (T tb，d_LKA (e l ) + N • T as ) is fed back as X to the adding / subtracting section 101.

[0203] With reference to Figure 14 , let e l，q be a prescribed value greater than zero and less than 1 / 2 of the width of the travel lane. In the present embodiment, as will be described later, in the case where the lateral deviation e l is greater than -e l，q and less than e l，q , the drive assist mode becomes a lane centering assist mode (LCA mode), the first weight W1 is set to 1, and the second weight W2 is set to zero.

[0204] On the other hand, in the case where the lateral deviation e l is -e l，q or more or is e l，q or less, the drive assist mode becomes a lane keeping assist mode (LKA mode), the first weight W1 is set to 0, and the second weight W2 is set to 1.

[0205] In the LCA mode, the addition result X of the second adding section 110 becomes k md • θ md . Therefore, the operation result of the adding / subtracting section 101 becomes (T tb + N • T as - c md • dθ md / dt - k md • θ md ).

[0206] Therefore, in the LCA mode, the manual steering manipulation command value operation section 53A operates the manual steering manipulation command value θ md based on the motion equation of the following formula (11).

[0207] Mathematical formula 11

[0208]

[0209] In formula (11), J md • d 2 θ md / dt 2 is the moment of inertia. c md • dθ mdk md • θ md is the virtual spring reaction force k md • θ col corresponding to the above-described equation (2).

[0210] That is, in the LCA mode, the manual steering manipulation command value operation section 53A operates the manual steering manipulation command value θ md based on the same equation of motion as the above-described equation (2).

[0211] In the LKA mode, the addition result X of the first addition section 108 becomes (T tb，d_LKA (e l ) + N • T as ). Therefore, the operation result of the adder-subtracter 101 becomes {T tb - c md • dθ md / dt - T tb，d_LKA (e l )}.

[0212] Therefore, in the LKA mode, the manual steering manipulation command value operation section 53A operates the manual steering manipulation command value θ md based on the same equation of motion as the above-described equation (3), that is, the following equation (12).

[0213] Mathematical equation 12

[0214]

[0215] In the equation (12), J md • d 2 θ md / dt 2 is the moment of inertia. c md • dθ md / dt is the virtual damper reaction force. T tb，d_LKA (e l ) is the LKA target virtual spring reaction force.

[0216] That is, in the LKA mode, the manual steering manipulation command value operation section 53A sets N • T m (= N • T as ) in the equation of motion of the above-described equation (2) to 0, and uses the LKA target virtual spring reaction force T md (e col ) corresponding to the lateral deviation (e l ) as the virtual spring reaction force k tb，d_LKA • θ l of the above-described equation (2).To calculate the manual steering control command value θ md .

[0217] Furthermore, the manual steering control command value calculation unit 53A may not need to provide N•T to the first addition unit 108. as In this case, in LKA mode, the manual steering command value calculation unit 53A adds N•T to the right side of the above equation (12). as The subsequent equation of motion is used to calculate the manual steering command value θ. md .

[0218] Figure 13A as well as Figure 13B This is a flowchart illustrating the operation of the reaction force / weight setting unit 52A.

[0219] When the power is turned on, the reaction force / weight setting unit 52A performs initial settings (step S1). Specifically, the reaction force / weight setting unit 52A resets the flag F used to store whether the driving assistance mode is LCA mode or LKA mode (F=0). In addition, the reaction force / weight setting unit 52A sets the first weight W1 to 1 and the second weight W2 to 0.

[0220] Additionally, when the reaction force / weight setting unit 52A is set to store the LKA mode, it is used to calculate the target virtual spring reaction force T for LKA. tb，d_LKA (e) l The initial expression or mapping table of initial properties is used. In this variation, the initial expression is set. The initial expression can also be stored in a pre-defined memory.

[0221] In addition, the F flag is set (F=1) if the driving assistance mode is LCA mode, and reset (F=0) if the driving assistance mode is LKA mode.

[0222] The calculation method for the initial expression is explained below.

[0223] Figure 14 The dashed line L0 represents the target virtual spring reaction force T of LKA. tb，d_LKA (e) l A schematic diagram of the initial characteristics of ).

[0224] In lateral deviation (e l ) is e l，q In the above cases, LKA uses the target virtual spring reaction force T tb，d_LKA (e) l ), in lateral deviation (e l ) is e l，q The time is set to zero, in the lateral deviation (e le l，max is set to the maximum value T tb，d_LKA，max . When the lateral deviation (e l ) is in the range of e l，q ~ e l，max , the LKA target virtual spring reaction force T tb，d_LKA (e l ) is set from 0 to T tb，d_LKA，max , the greater the lateral deviation (e l ) is, the greater it is.

[0225] When the lateral deviation (e l ) is -e l，q or less, the LKA target virtual spring reaction force T tb，d_LKA (e l ) is set to zero when the lateral deviation (e l ) is -e l，q , and is set to -T l when the lateral deviation (e l，max ) is -e tb，d_LKA，max corresponding to the left lane boundary. When the lateral deviation (e l ) is in the range of -e l，q ~ -e l，max , the LKA target virtual spring reaction force T tb，d_LKA (e l ) is set from 0 to -T tb，d_LKA，max , the smaller the lateral deviation (e l ) is, the smaller it is.

[0226] When it is set as { (e l，max - e l，q ) = L}, if the initial characteristic of the LKA target virtual spring reaction force T tb，d_LKA (e l ) is expressed by an equation, it becomes the following equation (13).

[0227] Mathematical equation 13

[0228]

[0229] Next, the reaction force / weight setting section 52A discriminates whether the lateral deviation e l is in the range of -e l，q < e l < e l，q (Step S2). If the lateral deviation e l is in the range of -e l，q < e l < e l，qIf the lateral deviation e l is within the range of -e l，q < e l < e l，q (step S2: YES), the reaction force / weight setting portion 52A sets the flag F (F = 1) (step S3).

[0230] Next, the reaction force / weight setting portion 52A sets the first weight Wl to 1 and sets the second weight W2 to 0 (step S4). Thereby, the drive assist mode is set to the LCA mode.

[0231] Next, the reaction force / weight setting portion 52A sets the LKA-use target virtual spring reaction force T tb，d_LKA (e l ) to zero (step S5).

[0232] Next, the reaction force / weight setting portion 52A sets the current torsion rod torque T tb，before as the actual torsion rod torque value T tb before the drive assist mode is to be shifted from the LCA mode to the LKA mode (step S6). Thereafter, the reaction force / weight setting portion 52A returns to step S2.

[0233] In step S2, in the case where it is determined that the lateral deviation e l is outside the range of -e l，q < e l < e l，q (step S2: NO), the reaction force / weight setting portion 52A discriminates whether the lateral deviation e l is e l，q or more (step S7).

[0234] In the case where the lateral deviation e l is e l，q or more (step S7: YES), the reaction force / weight setting portion 52A discriminates whether the flag F is set (step S8). In the case where the flag F is set (step S8: YES), the reaction force / weight setting portion 52A resets the flag F (F = 0) (step S9).

[0235] Further, the reaction force / weight setting portion 52A sets the first weight Wl to 0 and sets the second weight W2 to 1 (step S10). Thereby, the drive assist mode is switched from the LCA mode to the LKA mode.

[0236] In addition, the reaction force / weight setting portion 52A sets T tb，d_LKA (e l ) as the LKA-use target virtual spring reaction force T tb，before (step Sll). T tb，before is the torsion rod torque T tb before the drive assist mode is to be switched to the LKA mode.

[0237] Next, the reaction force / weight setting portion 52A updates the operation formula for operating the LKA-use target virtual spring reaction force T tb，d_LKA (e l ) (step S12). Specifically, the operation formula for operating the LKA-use target virtual spring reaction force T tb，d_LKA (e l ) is changed to the following formula (14).

[0238] Mathematical formula 14

[0239]

[0240] Figure 14 The solid line L1 shows the characteristics of the LKA-use target virtual spring reaction force T tb，before (e tb1 ) with respect to the lateral deviation e l when T tb，d_LKA (> 0). l

[0241] Further, in step S12, instead of changing the operation formula for operating the LKA-use target virtual spring reaction force T tb，d_LKA (e l ), a map table in which the characteristics of the LKA-use target virtual spring reaction force T l (e tb，d_LKA ) with respect to the lateral deviation e l are stored can be changed.

[0242] After that, the reaction force / weight setting portion 52A returns to step S2.

[0243] In step S8, in the case where it is discriminated that the flag F is reset (step S8: No), the reaction force / weight setting portion 52A sets the first weight Wl to 0 and sets the second weight W2 to 1 (step S13). Thereby, the drive assist mode is set to the LKA mode. Further, at the time when the determination in step S8 is negative, the drive assist mode is sometimes already set to the LKA mode.

[0244] Next, the reaction force / weight setting portion 52A sets the LKA-use target virtual spring reaction force T l (e tb，d_LKA ) on the basis of the currently set operation formula and the lateral deviation e l (step S14). After that, the reaction force / weight setting portion 52A returns to step S2.

[0245] In step S7, in the case where it is discriminated that the lateral deviation e l is not e l，q ​In the above case (step S7: No), the reaction force / weight setting unit 52A determines it to be a lateral deviation e. l If -el, q or below, then determine whether the flag F is set (step S15). If the flag F is set (step S15: yes), the reaction force / weight setting unit 52A resets the flag F (F=0) (step S16).

[0246] Next, the reaction force / weight setting unit 52A sets the first weight W1 to 0 and the second weight W2 to 1 (step S16). As a result, the driving assistance mode is switched from LCA mode to LKA mode.

[0247] Additionally, the reaction force / weight setting unit 52A sets the target virtual spring reaction force T for LKA. tb，d_LKA (e) l ), to set T tb，before (Step S18). T tb，before This refers to the torsion bar torque T before the driver assistance mode is replaced with LKA mode. tb .

[0248] Next, the reaction force / weight setting unit 52A updates the target virtual spring reaction force T used to calculate LKA. tb，d_LKA (e) l The calculation formula for LKA is (step S19). Specifically, the formula used to calculate the target virtual spring reaction force T is... tb，d_LKA (e) l The expression for ) is changed to the following expression (15).

[0249] Mathematical formula 15

[0250]

[0251] Figure 14 The solid line L2 shows T tb，before It is T tb2 (<0) relative to the modified lateral deviation e l LKA uses the target virtual spring reaction force T tb，d_LKA (e) l The characteristics of ).

[0252] Furthermore, in step S19, the target virtual spring reaction force T used to calculate LKA can also be changed instead. tb，d_LKA (e) l The formula for the operation is changed, and the storage is modified to target the lateral deviation e. l LKA uses the target virtual spring reaction force T tb，d_LKA (e) l A mapping table of the characteristics of ).

[0253] Then, the reaction force / weight setting unit 52A returns to step S2.

[0254] In step S15, if it is determined that flag F has been reset (step S15: No), the reaction force / weight setting unit 52A sets the first weight W1 to 0 and the second weight W2 to 1 (step S20). Thus, the driving assistance mode is set to LKA mode. Furthermore, when a negative determination is made in step S15, the driving assistance mode has usually already been set to LKA mode.

[0255] Next, the reaction force / weight setting unit 52A sets the reaction force / weight based on the currently set formula and the lateral deviation e. l To set the target virtual spring reaction force T for LKA tb，d_LKA (e) l (Step S21). Furthermore, the reaction force / weight setting unit 52A returns to step S2.

[0256] In this first variation, when the steering control mode is the coordinated steering control mode, the lateral deviation e l In -e l，q <e l <e l，q When the range is within the specified range, the driving assistance mode is set to LCA mode. In this case, the manual steering command value calculation unit 53A calculates the value based on the virtual spring reaction force k. md •θ md The motion equation (11) is used to calculate the manual steering control command value θ. md Therefore, the steering reaction force used to guide the vehicle toward the center of the lane is applied to the driver.

[0257] On the other hand, in the lateral deviation e l In -e l，q <e l <e l，q When the range is outside the specified range, the driving assistance mode is set to LKA mode. In this case, the manual steering control command value calculation unit 53A calculates the value based on the virtual spring reaction force k as shown in the above formula (2). md •θ col The use of lateral deviation (e) l The corresponding LKA uses the target virtual spring reaction force T. tb，d_LKA (e) l The equation of motion (12) is used to calculate the manual steering command value θ. md Therefore, it will be related to the lateral deviation e. l A corresponding virtual spring reaction force is applied to the driver. This allows the driver to easily perceive the distance from the center of the driving lane (distance to the lane).

[0258] Additionally, when switching the driver assistance mode from LCA mode to LKA mode, the target virtual spring reaction force T is used to switch to the LKA mode after the transition. tb，d_LKA (e) l ) and the torsion bar torque T before the relocation tb，before In a consistent manner, set the target virtual spring reaction force T for LKA. tb，d_LKA (e) l And update LKA with the target virtual spring reaction force T. tb，d_LKA (e) l The operational formulas (refer to formulas (14) and (15)).

[0259] Therefore, when switching the driver assistance mode from LCA mode to LKA mode, the torsion bar torque T can be smoothly engaged. tb Therefore, when transitioning from LCA mode to LKA mode, it can suppress situations where the steering feel suddenly becomes lighter and the driver feels a shock.

[0260] Furthermore, when switching the driver assistance mode from LCA mode to LKA mode, the virtual spring reaction force T after the switch can also be used. tb，d_LKA (e) l ) and the virtual spring reaction force k before the migration md •θ md In a consistent manner, set the target virtual spring reaction force T for LKA. tb，d_LKA (e) l ).

[0261] In this case, Figure 13A In step S6, the reaction force / weight setting unit 52A sets the virtual spring reaction force (k) before switching the driving assistance mode from LCA mode to LKA mode. md •θ md -) before To set the current virtual spring reaction force k md •θ md -. Additionally, in Figure 13A Step S11 and Figure 13B In step S18, the reaction force / weight setting unit 52A sets (k) md •θ md -) before Set the target virtual spring reaction force T for LKA tb，d_LKA (e) l ).

[0262] In addition, Figure 13A In step S12, the reaction force / weight setting unit 52A will use the target virtual spring reaction force T for calculating LKA. tb，d_LKA(e) l The operation expression of ) is changed to the following expression (16).

[0263] Mathematical formula 16

[0264]

[0265] In addition, Figure 13B In step S19, the reaction force / weight setting unit 52A will use the target virtual spring reaction force T for calculating LKA. tb，d_LKA (e) l The expression for ) is changed to the following expression (17).

[0266] Mathematical formula 17

[0267]

[0268] It can also replace Figure 11 The manual steering control command value calculation unit 53A, such as Figure 11 As shown by the dotted line, use the further input automatic steering control command value θ. ad The manual steering command value calculation unit 53B is used. Hereinafter, the motor control ECU 202B that uses the manual steering command value calculation unit 53B instead of the manual steering command value calculation unit 53A will be referred to as a second variant of the motor control ECU.

[0269] Figure 15 This is a block diagram showing the structure of the manual steering command value calculation unit 53B. Figure 15 In the middle, regarding the above Figure 12 The corresponding part markings and Figure 12 Same reference numerals as shown in the attached figures.

[0270] The manual steering control command value calculation unit 53B includes: a reduction ratio multiplication unit 131, a first-order differential unit 111, a second-order differential unit 112, an addition and subtraction unit 101, an inertia division unit 102, a first integration unit 103, a second integration unit 104, a first virtual shock absorber reaction force calculation unit 105, a virtual spring reaction force calculation unit 106, a first weight multiplication unit 107, a second virtual shock absorber reaction force calculation unit 113, an inertia multiplication unit 114, a first addition unit 108, a second weight multiplication unit 109, and a second addition unit 110.

[0271] The reduction ratio multiplier 131 controls the auxiliary torque command value T. as Multiply by the reduction ratio N of the reducer 19, and then use the auxiliary torque command value T for the rotating shaft of the electric motor 18. as Converted into an auxiliary torque command value N•T for output shaft 9. asThe auxiliary torque command value N•T for the output shaft 9 is calculated by the reduction ratio multiplication unit 131. as It is assigned to the addition and subtraction section 101, and to the first addition section 108.

[0272] The addition and subtraction section 101 is given a torsion bar torque T. tb The auxiliary torque command value N•T for output shaft 9 as The first virtual shock absorber reaction force c calculated by the first virtual shock absorber reaction force calculation unit 105 md •dθ md The sum of / dt and the result Y of the second addition part 110.

[0273] Addition and subtraction section 101 torsion bar torque T tb In addition, the auxiliary torque command value N•T for output shaft 9 as And subtract the reaction force c of the first virtual shock absorber from the summation result. md •dθ md / dt and Y. Therefore, the addition / subtraction part 101 operation is equivalent to J on the left side of the above equation (2). md •d 2 θ col / dt 2 Inertial torque J md •d 2 θ md / dt 2 (=T) tb +N•T as -c md •dθ md / dt-Y).

[0274] The inertial division unit 102 calculates the inertial torque J by the addition and subtraction unit 101. md •d 2 θ md / dt 2 Divide by the column inertia J md To calculate the manual steering control command value θ md The second derivative value d 2 θ md / dt 2 .

[0275] The first integrator 103 controls the manual steering command value θ md The second-order differential value d 2 θ md / dt 2 Integrating the values ​​of the manual steering commands (θ) to calculate the value of the manual steering command. md The first differential value dθ md / dt.

[0276] The second integrator 104 processes the manual steering control command value θ md The first differential value dθ md Integrating / dt to calculate the manual steering command value θ md The manual steering control command value θ md The output of the operation command value calculation unit 53B is switched from manual to control.

[0277] The first virtual shock absorber reaction force calculation unit 105 calculates the manual steering control command value θ calculated by the first integrator 103. md The first differential value dθ md / dt multiplied by the viscosity decay coefficient c md To calculate the reaction force c of the first virtual shock absorber. md •dθ md / dt. The reaction force c of the first virtual shock absorber. md •dθ md / dt is fed back to the addition and subtraction department 101.

[0278] The virtual spring reaction force calculation unit 106 calculates the manual steering control command value θ calculated by the second integrator 104. md Multiplied by the spring constant k md To calculate the virtual spring reaction force k md •θ md The first weighted multiplication part 107 relates to the virtual spring reaction force k. md •θ md Multiply by the first weight W1.

[0279] The first-order differential part 111 corresponds to the automatic steering control command value θ ad The first-order differential is performed. The second virtual shock absorber reaction force calculation unit 113 calculates the automatic steering control command value θ. ad The first differential value dθ ad / dt multiplied by the viscosity decay coefficient c md To calculate the reaction force c of the second virtual shock absorber. md •dθ ad / dt. Second virtual shock absorber reaction force c md •dθ ad / dt refers to the automatic steering control command value θ ad The reaction force of the virtual shock absorber.

[0280] The second-order differential part 112 corresponds to the automatic steering control command value θ. ad Second-order differentiation is performed. The inertial multiplication unit 114 performs the automatic steering control command value θ... ad The second-order differential value d 2 θ ad / dt 2Multiplied by the column inertia J md To calculate the value θ for the automatic steering control command. ad Inertial torque J md •d 2 θ ad / dt 2 .

[0281] The first addition unit 108 targets the automatic steering control command value θ. ad The virtual shock absorber reaction force (second virtual shock absorber reaction force) c md •dθ ad / dt, plus the automatic steering control command value θ ad Inertial torque J md •d 2 θ ad / dt 2 LKA uses the target virtual spring reaction force T tb，d_LKA (e) l And the auxiliary torque command value N•T for output shaft 9. as .

[0282] The result of the operation of the second weighted multiplication unit 109 on the first addition unit 108 (c) md •dθ ad / dt+J md •d 2 θ ad / dt 2 +T tb，d_LKA (e) l ) + N•T as Multiply by the second weight W2.

[0283] The second addition unit 110 performs the operation of the first weighted multiplication unit 107 on the result W1•k. md •θ md The result of the operation of the second weighted multiplication unit 109 is W2•(c md •dθ ad / dt+J md •d 2 θ ad / dt 2 +T tb，d_LKA (e) l ) + N•T as Add them together. The result of the addition in the second addition part 110 is {W1•k}. md •θ md +W2•(c md •dθ ad / dt+J md •d 2 θ ad / dt 2 +Ttb，d_LKA (e) l ) + N•T as As Y, it is fed back to the addition and subtraction department 101.

[0284] In this modified example, the reaction force / weight setting unit 52A is used. Figure 13A as well as Figure 13B The actions described are the same. However, as mentioned above, when switching the driver assistance mode from LCA mode to LKA mode, the virtual spring reaction force T after the switch can also be used. tb，d_LKA (e) l ) and the virtual spring reaction force k before the migration md •θ md In a consistent manner, set the target virtual spring reaction force T for LKA. tb，d_LKA (e) l ).

[0285] Therefore, in the lateral deviation e l Greater than -e l，q And less than e l，q In this case, the driving assistance mode becomes Lane Centering Assist (LCA mode), setting the first weight W1 to 1 and the second weight W2 to zero.

[0286] On the other hand, in the lateral deviation e l It is -e l，q In the following cases or e l，q In the above situations, the driving assistance mode becomes Lane Keeping Assist (LKA) mode, with the first weight W1 set to 0 and the second weight W2 set to 1.

[0287] In LCA mode, the summation result Y of the second adder 110 is... Figure 12 The manual steering command value calculation unit 53A is the same as that, becoming k md •θ md Therefore, the result Y of the addition / subtraction section 101 becomes T. tb +N•T as ―c md •dθ md / dt―k md •θ md .

[0288] Therefore, in LCA mode, the manual steering command value calculation unit 53B calculates the manual steering command value θ based on the same equation as above (11), namely the following equation (18). md .

[0289] Mathematical formula 18

[0290]

[0291] That is, in the LCA mode, the manual steering manipulation command value operation section 53B operates the manual steering manipulation command value θ using the same equation of motion as the above equation (2) md .

[0292] In the LKA mode, the addition result Y of the second addition section 110 becomes (c md • dθ ad / dt + J md • d 2 θ ad / dt 2 + T tb，d_LKA (e l ) + N • T as ). Therefore, the operation result of the addition / subtraction section 101 becomes T tb - c md • dθ md / dt - c md • dθ ad / dt - J md • d 2 θ ad / dt 2 - T tb，d_LKA (e l ).

[0293] Therefore, in the LCA mode, the manual steering manipulation command value operation section 53B operates the manual steering manipulation command value θ based on the equation of motion of the following equation (19) md .

[0294] Mathematical expression 19

[0295]

[0296] In the equation (19), (J md • d 2 θ md / dt 2 + J md • d 2 θ ad / dt 2 ) is the inertial moment. (c md • dθ md / dt + c md • dθ ad / dt ) is the virtual damper reaction force. T tb，d_LKA (e l ) is the LKA target virtual spring reaction force.

[0297] That is, in the LKA mode, the manual steering manipulation command value calculation section 53B sets N•T m (=N•T as ) to 0 in the motion equation of the above-described equation (2), and uses (J md •d 2 θ col / dt 2 , the virtual damper reaction force c md •dθ col / dt, and the virtual spring reaction force k md •θ col , respectively, as the inertia moment J md •d 2 θ md / dt 2 + J md •d 2 θ ad / dt 2 , (c md •dθ md / dt + c md •dθ ad / dt), and T tb，d_LKA (e l ), to calculate the manual steering manipulation command value θ md .

[0298] Further, the manual steering manipulation command value calculation section 53B can not impart N•T as to the first addition section 108. In this case, in the LKA mode, the manual steering manipulation command value calculation section 53B calculates the manual steering manipulation command value θ md based on the motion equation in which N•T as is added to the right side of the above-described equation (19).

[0299] In the second modification example, the same effects as those of the above-described first modification example are achieved. In the second modification example, the effect that the driver's discomfort can be reduced in the LKA mode is also achieved. Hereinafter, this point will be described.

[0300] With reference to Figure 11 and Figure 7 , in the coordinated steering manipulation mode, the electric motor 18 is controlled in such a manner that the actual steering angle θ c follows the integrated angle command value θ cmd . If it is assumed that the actual steering angle θ c completely follows the integrated angle command value θ cmd , the relationship θ md = θ c - θ ad is established.

[0301] In this case, the manual steering control command value θ in equation (19) above... md The virtual shock absorber reaction force c md •dθ md / dt is represented by the following formula (20).

[0302] Mathematical formula 20

[0303]

[0304] In addition, the manual steering control command value θ in the above equation (19) md Inertial torque J md •d 2 θ md / dt 2 It is represented by the following formula (21).

[0305] Mathematical expression 21

[0306]

[0307] That is, c md •dθ md / dt includes: the actual rotation angle θ c The actual rotation component c corresponding to the first differential md •dθ c / dt, and the automatic steering control command value θ ad The first derivative corresponds to the automatic steering control component -c md •dθ ad / dt. Similarly, J md •d 2 θ md / dt 2 Includes the actual rotation angle θ c The actual rotation component J corresponding to the second derivative md •d 2 θ c / dt 2 and the automatic steering control command value θ ad The second derivative of the automatic steering control component -J md •d 2 θ ad / dt 2 .

[0308] The above actual rotation component c md •dθ c / dt and J md •d 2 θ c / dt 2It corresponds to the driver's actions, so the driver will not experience discomfort. On the other hand, the aforementioned automatic steering control component -c md •dθ ad / dt and -J md •d 2 θ ad / dt 2 It is unrelated to the driver's behavior, so there is a concern that the driver might experience discomfort. ad The absolute value of / dt is greater than -d 2 θ ad / dt 2 The absolute value, therefore especially the automatic steering component of the virtual shock absorber reaction force -c md •dθ ad / dθ can negatively impact steering feel.

[0309] In the second variation, the equation of motion of the above equation (19) serves as the reaction force of the virtual shock absorber, except for the manual steering command value θ. md The virtual shock absorber reaction force c md •dθ md In addition to / dt, it also includes the automatic steering control command value θ. ad The virtual shock absorber reaction force c md •dθ ad / dt. Furthermore, the equation of motion in the above equation (19) serves as the inertial torque, except for the manual steering command value θ. md Inertial torque J md •d 2 θ md / dt 2 In addition, it also includes the automatic steering control command value θ. ad Inertial torque J md •d 2 θ ad / dt 2 .

[0310] This allows for a reduction in the value θ for manual steering input commands. md The virtual shock absorber reaction force c md •dθ md The automatic steering control component contained in / dt -c md •dθ ad / dt. Similarly, it can reduce the value θ for manual steering input commands. md Inertial torque J md •d 2 θ md / dt 2 The automatic steering control component included - J md •d2 θ ad / dt 2 Therefore, in LKA mode, driver discomfort can be reduced.

[0311] Assuming θ md =θ c -θ ad When such a relationship holds, the equation of motion for equation (19) is shown in equation (22).

[0312] Mathematical expression 22

[0313]

[0314] In this case, compensation c md •dθ md The automatic steering control component contained in / dt -c md •dθ ad / dt, leaving only the actual rotation angle θ c The actual rotation component c md •dθ c / dt, in addition, compensation J md •d 2 θ md / dt 2 The automatic steering control component included - J md •d 2 θ ad / dt 2 Only the actual rotation angle θ remains. c J md •d 2 θ c / dt 2 .

[0315] Figure 16 This is a block diagram representing a third variation of an ECU for motor control. Figure 16 In the middle, to and Figure 11 The corresponding part markings and Figure 11 Same reference numerals as shown in the attached figures.

[0316] exist Figure 16 In the motor control ECU202C, in the following (1) and (2), it is used with Figure 11 The second variation described is different.

[0317] (1) The structure of the manual steering command value calculation unit 53C is the same as the structure of the manual steering command value calculation unit 53B in the second modified example. Figure 15 )different.

[0318] (2) In addition Figure 11In addition to the LKA target virtual spring reaction force / weight setting unit 52A, there is also an LCA target virtual spring reaction force setting unit 52B for setting the target virtual spring reaction force for lane centering assist, i.e., the LCA target virtual spring reaction force.

[0319] The torsion bar torque T is provided to the manual steering control command value calculation unit 53C. tb LKA uses the target virtual spring reaction force T tb，d_LKA (e) l The first weight W1, the second weight W2, and the automatic steering control command value θ ad It also provides the manual steering control command value calculation unit 53C with the LCA target virtual spring reaction force T set by the LCA target virtual spring reaction force setting unit 52B. tb，d_LCA (e) l In this third variation, the auxiliary torque command value T set by the auxiliary torque command value setting unit 51 is not provided to the manual steering control command value calculation unit 53C. as .

[0320] LCA uses a target virtual spring reaction force setting unit 52B based on lateral deviation e l To set the target virtual spring reaction force T for LCA tb，d_LCA (e) l ). Figure 17 The solid line L3 represents the lateral deviation e. l The LCA uses the target virtual spring reaction force T tb，d_LCA (e) l The diagram shows the setting example.

[0321] LCA uses the target virtual spring reaction force T tb，d_LCA (e) l ) in lateral deviation (e l ) greater than e l，q Within the range and lateral deviation (e l Less than -e l，q The value is set to 0 within the specified range. Additionally, the LCA uses the target virtual spring reaction force T. tb，d_LCA (e) l ) in lateral deviation (e l When ) is 0, it is set to 0.

[0322] LCA uses the target virtual spring reaction force T tb，d_LCA (e) l ) in lateral deviation (e l ) is e l，q At that time, it is set to the specified maximum value T. tb，d_LCA，max In lateral deviation (e l ) is -el，q When, it is set to -T tb，d_LCA，max .

[0323] In lateral deviation (e l ) in the range of 0 to e l，q Within the range, LCA uses the target virtual spring reaction force T tb，d_LCA (e) l ) is set to from 0 to T tb，d_LCA，max Lateral deviation (e) l The larger the value, the greater its magnitude. In the lateral deviation e l In the range of 0 to -e l，q Within the range, LCA uses the target virtual spring reaction force T tb，d_LCA (e) l ) is set from 0 to -T tb，d_LCA，max Lateral deviation (e) l The smaller the value, the smaller the value. In this example, LCA uses the target virtual spring reaction force T. tb，d_LCA (e) l Although it changes linearly, it can also change nonlinearly.

[0324] Reaction force / weight setting unit 52A is used. Figure 13A as well as Figure 13B The actions described are roughly the same. However, in Figure 13A The initial formula set in step S1 and in Figure 13A The initial calculation formula described in the text is different. The actions of the reaction force / weight setting unit 52A, other than these, are the same as those described above.

[0325] In this variation, in LKA mode, the target virtual spring reaction force T is used to calculate LKA. tb，d_LKA (e) l The initial characteristics of ) are as follows Figure 17 As shown by the dashed line L4.

[0326] Therefore, in Figure 13A In step S1, the initial operation expression is set as shown in the following formula (23).

[0327] Mathematical expression 23

[0328]

[0329] Figure 18 This is a block diagram showing the structure of the manual steering command value calculation unit 53C. Figure 18 In the middle, regarding the above Figure 15 The corresponding part markings and Figure 15 Same reference numerals as shown in the attached figures.

[0330] The manual steering control command value calculation unit 53C includes: a first-order differential unit 111, a second-order differential unit 112, an addition and subtraction unit 101, an inertial division unit 102, a first integration unit 103, a second integration unit 104, a third addition unit 121, a virtual shock absorber reaction force calculation unit 105, a fourth addition unit 122, a virtual spring reaction force calculation unit 106, a fifth addition unit 123, a first weight multiplication unit 107, a sixth addition unit 124, a second weight multiplication unit 109, a second addition unit 110, and an inertial multiplication unit 125.

[0331] The second-order differential part 112 corresponds to the automatic steering control command value θ. ad Perform a second-order differential. The inertial multiplication unit 125 takes the result d from the differential of the second-order differential unit 112. 2 θ ad / dt 2 Multiplied by the column inertia J md To calculate the value θ for the automatic steering control command. ad Inertial torque J md • 2 θ ad / dt 2 .

[0332] Provide torsion bar torque T to addition / subtraction unit 101 tb Regarding the automatic steering control command value θ ad Inertial torque J md • 2 θ ad / dt 2 The sum Z of the second addition part 110 and the sum Z of the second addition part 110.

[0333] Addition and subtraction section 101 from torsion bar torque T tb Subtract the value θ for the automatic steering control command ad Inertial torque J md • 2 θ ad / dt 2 And Z. Therefore, the addition / subtraction part 101 is equivalent to J on the left side of equation (2) above. md •d 2 θ col / dt 2 Inertial torque J md •d 2 θ md / dt 2 (=T) tb -J md • 2 θ ad / dt 2 -Z).

[0334] The inertial division unit 102 calculates the inertial torque J by the addition and subtraction unit 101. md •d 2 θ md / dt 2 Divide by the column inertia J md To calculate the manual steering control command value θ md The second-order differential value d 2 θ md / dt 2 .

[0335] The first integrator 103 controls the manual steering command value θ md The second-order differential value d 2 θ md / dt 2 Integrating the values ​​of the manual steering commands (θ) to calculate the value of the manual steering command. md The first differential value dθ md / dt.

[0336] The second integrator 104 processes the manual steering control command value θ md The first differential value dθ md Integrating / dt to calculate the manual steering command value θ md The manual steering control command value θ md The output of the operation command value calculation unit 53C is switched from manual to control.

[0337] The first-order differential part 111 corresponds to the automatic steering control command value θ ad Perform the first-order differential. The third addition unit 121 applies the manual steering control command value θ. md The differential value dθ md / dt plus the automatic steering control command value θ ad The differential value dθ ad / dt.

[0338] The virtual shock absorber reaction force calculation unit 105 calculates the result (dθ) of the third adder unit 121. md / dt+dθ ad / dt) multiplied by the viscous decay coefficient c md To calculate the virtual shock absorber reaction force c md •(dθ md / dt+dθ ad / dt).

[0339] The fourth addition unit 122 sets the manual steering control command value θ. md Add automatic steering control command value θ ad The virtual spring reaction force calculation unit 106 calculates the result (θ) of the fourth addition unit 122. md +θad Multiply by the spring constant k md To calculate the virtual spring reaction force k md •(θ) md +θ ad ).

[0340] The fifth addition unit 123 calculates the virtual shock absorber reaction force c calculated by the virtual shock absorber reaction force calculation unit 105. md •(dθ md / dt+dθ ad / dt), the virtual spring reaction force k calculated by the virtual spring reaction force calculation unit 106. md •(θ) md +θ ad ), and the target virtual spring reaction force T of LCA tb，d_LCA (e) l Add them together.

[0341] The sum of the first weighted multiplication part 107 and the fifth addition part 123 is {c md •(dθ md / dt+dθ ad / dt)+k md •(θ) md +θ ad )+T tb，d_LCA (e) l Multiply by the first weight W1.

[0342] The sixth addition unit 124 calculates the virtual shock absorber reaction force c calculated by the virtual shock absorber reaction force calculation unit 105. md •(dθ md / dt+dθ ad / dt) and LKA using the target virtual spring reaction force T tb，d_LKA (e) l Add them together.

[0343] The sum of the second weighted multiplication part 109 and the sixth addition part 124 {c md •(dθ md / dt+dθ ad / dt)+T tb，d_LKA (e) l Multiply by the second weight W2.

[0344] The second addition unit 110 performs the operation of the first weighted multiplication unit 107 on the result W1•{c md •(dθ md / dt+dθ ad / dt)+k md •(θ) md +θ ad )+Ttb，d_LCA (e l )} and the operation result W2 • {c md • (dθ md / dt + dθ ad / dt) + T tb，d_LKA (e l )} of the second weight multiplication section 109 are added. The addition result of the second addition section 110, [W1 • {c md • (dθ md / dt + dθ ad / dt) + k md • (θ md + θ ad ) + T tb，d_LCA (e l )} + W2 • {c md • (dθ md / dt + dθ ad / dt) + T tb，d_LKA (e l )}, is fed back to the adder-subtracter 101 as Z.

[0345] In this modification example, in a case where the lateral deviation e l is larger than -e l，q and smaller than e l，q , the drive assist mode becomes a lane centering assist mode (LCA mode), the first weight W1 is set to 1, and the second weight W2 is set to zero.

[0346] On the other hand, in a case where the lateral deviation e l is -e l，q or more or e l，q or less, the drive assist mode becomes a lane keeping assist mode (LKA mode), the first weight W1 is set to 0, and the second weight W2 is set to 1.

[0347] In the LCA mode, the addition result Z of the second addition section 110 becomes {c md • (dθ md / dt + dθ ad / dt) + k md • (θ md + θ ad ) + T tb，d_LCA (e l )}. Therefore, the operation result of the adder-subtracter 101 becomes { (T tb - J md • d 2 θ ad / dt 2 - c md • dθ md / dt - cmd •dθ ad / dt-k md •θ md -k md •θ ad -T tb，d_LCA (e) l )}.

[0348] Therefore, in LCA mode, the manual steering command value calculation unit 53C calculates the manual steering command value θ based on the motion equation of the following formula (24). md .

[0349] Mathematical expression 24

[0350]

[0351] In equation (24), (J md •d 2 θ md / dt 2 +J md •d 2 θ ad / dt 2 (c) is the moment of inertia. md •dθ md / dt+c md •dθ ad / dt) is the virtual shock absorber reaction force. (k md •θ md +k md •θ ad +T tb，d_LCA (e) l )) is the virtual spring reaction force.

[0352] That is, in LCA mode, the manual steering control command value calculation unit 53C calculates N•T in the motion equation of the above formula (2). m (=N•T) as Let J be 0, and let J be the moment of inertia in equation (2) above. md •d 2 θ md / dt 2 Virtual shock absorber reaction force c md •θ col And the virtual spring reaction force k md •θ col , respectively using (J md •d 2 θ md / dt 2 +J md •d 2 θ ad / dt2 ), (c md • dθ md / dt + c md • dθ ad / dt) and (k md • θ md + k md • θ ad + T tb，d_LCA (e l )) are used to calculate the manual steering manipulation command value θ md .

[0353] In the LKA mode, the addition result Z of the second adding section 110 becomes {c md • (dθ md / dt + dθ ad / dt) + T tb，d_LKA (e l )}. Therefore, the calculation result of the adding and subtracting section 101 becomes {T tb - J md • d 2 θ ad / dt 2 - c md • dθ md / dt - c md • dθ ad / dt - T tb，d_LKA (e l )}.

[0354] Therefore, in the LKA mode, the manual steering manipulation command value calculation section 53C calculates the manual steering manipulation command value θ md based on the same equation as the above equation (19), that is, the following equation (25).

[0355] Mathematical equation 25

[0356]

[0357] In the equation (25), (J md • d 2 θ md / dt 2 + J md • d 2 θ ad / dt 2 ) is the inertial moment. (c md • dθ md / dt + c md • dθ ad / dt) is the virtual damper reaction force. T tb，d_LKA (e l ) is the LKA target virtual spring reaction force.

[0358] That is, in LKA mode, the manual steering control command value calculation unit 53C calculates N•T in the motion equation of the above formula (2). m (=N•T) as Let J be 0, and let J be the moment of inertia in equation (2) above. md •d 2 θ col / dt 2 Virtual shock absorber reaction force c md •dθ col / dt and the virtual spring reaction force k md •θ col , respectively using (J md •d 2 θ md / dt 2 +J md •d 2 θ ad / dt 2 ), (c md •dθ md / dt+c md •dθ ad / dt) and T tb，d_LKA (e) l ), to calculate the manual steering control command value θ md .

[0359] Furthermore, the manual steering command value calculation unit 53C can also calculate the auxiliary torque command value T. as Multiply by the reduction ratio N to calculate N•T as The obtained N•T as The torque T is assigned to the addition / subtraction unit 101. In this case, the addition / subtraction unit 101 assigns the torque T to the torsion bar. tb Add N•T as And subtract the value θ for the automatic steering control command from the summation result. ad Inertial torque J md • 2 θ ad / dt 2 And Z.

[0360] In this case, in LCA mode, the manual steering command value calculation unit 53C adds N•T to the right side of the following equation (24). as The subsequent equation of motion is used to calculate the manual steering command value θ. md Additionally, in LKA mode, the manual steering command value calculation unit 53C adds N•T to the right side of the following equation (25). as The subsequent equation of motion is used to calculate the manual steering command value θ.md .

[0361] In the third variation, the same effect as in the second variation is achieved. In the third variation, the effect of reducing driver discomfort is achieved not only in LKA mode but also in LCA mode. This point will be explained below.

[0362] In the third variation, in LCA mode, the value θ used to calculate the manual steering control command is... md The equation of motion (24) serves as the reaction force of the virtual damper, except for the manual steering command value θ. md The virtual shock absorber reaction force c md •dθ md In addition to / dt, it also includes the automatic steering control command value θ. ad The virtual shock absorber reaction force c md •dθ ad / dt.

[0363] In addition, this equation of motion (24) serves as the inertial torque, except for the manual steering control command value θ. md Inertial torque J md •d 2 θ md / dt 2 In addition, it also includes the automatic steering control command value θ. ad Inertial torque J md •d 2 θ ad / dt 2 .

[0364] Furthermore, the equation of motion (24), as a virtual spring reaction force, applies only to the manual steering command value θ. md The virtual spring reaction force k md •dθ md In addition to / dt, it also includes the automatic steering control command value θ. ad The virtual spring reaction force k md •dθ ad / dt.

[0365] Therefore, in LCA mode, the value θ for manual steering input can be reduced. md The virtual shock absorber reaction force c md •dθ md The automatic steering component is contained in / dt. Similarly, it can also reduce the value θ for manual steering commands. md Inertial torque J md •d 2 θ md / dt 2the automatic steering manipulation component. Also, the manual steering manipulation instruction value θ md the virtual spring reaction force k md • dθ md / dt of the automatic steering manipulation component. Thus, in the third modification, the driver's discomfort can be reduced both in the LKA mode and in the LCA mode.

[0366] The above describes the embodiments and modifications of the present application, but the present application can be implemented in other forms.

[0367] In the above-described embodiments, the spring constant k md is obtained in advance through experiments, analysis, or the like. However, the spring constant k md in the above-described equations (11), (18), and (21) can also use the disturbance torque estimation value ^T lc calculated by the disturbance torque estimation section 64 (see Figure 7 ) and the actual steering manipulation angle θ c calculated by the second deceleration ratio division section 70, based on the following equation (26).

[0368] Mathematical equation 26

[0369]

[0370] In the above-described embodiments, the viscous damping coefficient c md in the above-described equations (3), (11), (12), (18), (19), (24), and (25) is obtained in advance through experiments, analysis, or the like.

[0371] However, the viscous damping coefficient c md in the above-described equations (3), (11), (12), (18), (19), (24), and (25) can be calculated based on the following equation (27) using the disturbance torque estimation value ^T lc calculated by the disturbance torque estimation section 64 and the actual steering manipulation angle θ c calculated by the second deceleration ratio division section 70.

[0372] Mathematical equation 27

[0373]

[0374] In the above-described embodiments, the angle control section 55 (see Figure 7 ) includes the feedforward control section 63, but the feedforward control section 63 can be omitted. In this case, the feedback control torque T fb calculated by the feedback control section 62 becomes the basic target torque.

[0375] Further, in the above-described embodiments, although an example in which the application is applied to motor control of a column-type EPS is shown, the application can also be applied to motor control of an EPS other than a column type. Further, the application can also be applied to control of an electric motor for steering angle control of an electric power steering system.

[0376] Although the embodiments of the application have been described in detail, these are merely specific examples for clearly ascertaining the technical contents of the application, the application should not be interpreted as being limited to the above-described specific examples, the scope of the application is defined only by the appended claims.

[0377] Explanation of Reference Signs

[0378] 1 … electric power steering device, 3 … steering wheel, 4 … steering mechanism, 18 … electric motor, 51 … auxiliary torque command value setting portion, 52 … target virtual spring reaction force setting portion, 52A … target virtual spring reaction force / weight setting portion for LKA, 52B … target virtual spring reaction force setting portion for LCA, 53, 53A, 53B, 53C … manual steering operation command value calculation portion, 54 … integrated angle command value calculation portion, 55 … angle control portion, 56, 56A … subtraction portion, 56 … first switch, 57 … second switch, 58 … addition portion, 59 … torque control portion, 201 … upper ECU, 202, 202A, 202B, 202C … motor control ECU.

Claims

1. A motor control device for drive controlling an electric motor of a steering operation device, comprising: a manual steering operation command value arithmetic unit that uses a torque of a torsion bar to calculate a manual steering operation command value; a comprehensive angle command value arithmetic unit that adds an automatic steering operation command value for drive assist to the manual steering operation command value to calculate a comprehensive angle command value; and a control unit that drive controls the electric motor based on the comprehensive angle command value, wherein in a drive assist mode, the manual steering operation command value arithmetic unit is configured to calculate the manual steering operation command value using a motion equation of a reference model of the steering operation device, and wherein the manual steering operation command value arithmetic unit uses, as a virtual spring reaction force in the motion equation, a target virtual spring reaction force corresponding to a lateral position of a vehicle reference position with respect to a travel lane, to calculate the manual steering operation command value at least under a prescribed condition.

2. The motor control device according to claim 1, wherein in a lane keeping assist mode that is the drive assist mode in which steering operation is assisted in such a manner that the vehicle is maintained within the travel lane, the manual steering operation command value arithmetic unit uses, as the virtual spring reaction force in the motion equation, the target virtual spring reaction force corresponding to the lateral position of the vehicle reference position with respect to the travel lane, to calculate the manual steering operation command value.

3. The motor control device according to claim 2, wherein the drive assist mode includes the lane keeping assist mode and another drive mode different from the lane keeping assist mode, and wherein the target virtual spring reaction force is set in conformity with the torque of the torsion bar immediately before the transition from the other drive mode to the lane keeping assist mode, when the transition from the other drive mode to the lane keeping assist mode is made.

4. The motor control device according to claim 3, wherein the other drive mode is a lane centering assist mode in which steering operation is assisted in such a manner that the vehicle travels in the center of the travel lane, and wherein the drive mode is set to the lane centering assist mode when the vehicle reference position is within a range from the center of the travel lane to a prescribed distance, and the drive mode is set to the lane keeping assist mode when the vehicle reference position is outside the range from the center of the travel lane to the prescribed distance, and wherein in the lane centering assist mode, the manual steering operation command value arithmetic unit calculates the manual steering operation command value using a virtual spring reaction force set using a spring constant of a virtual spring, as the virtual spring reaction force in the motion equation, and wherein the target virtual spring reaction force at the time of the transition from the lane centering assist mode to the lane keeping assist mode is set in conformity with the torque of the torsion bar immediately before the transition is made. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​

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