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 control the electric motor on the basis of the integrated angle command value. A manual steering command value calculation unit uses, as a virtual spring reaction force in an equation of motion, a virtual spring reaction force obtained by superimposing a virtual spring reaction force corresponding to an automatic steering command value on a virtual spring reaction force corresponding to a manual steering command value. And calculates a manual steering command value.

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] The electric motor is controlled by the first control when the driving mode is a manual driving mode. On the other hand, the electric motor is controlled by the second control when a driving assistance mode in which a driving assistance such as a lane centering assistance (LCA) control is performed.

[0004] Patent Document 1: International Publication No. 2023 / 286169

[0005] In the first control described in Patent Document 1, when the driver performs a steering operation on the steering wheel, the steering operation angle attempts to return to around zero degrees corresponding to the neutral position of the output shaft by a return torque. On the other hand, in the second control, when the vehicle deviates from the target travel route due to the driver's steering operation intervention, the system attempts to return the vehicle to the target travel route by a driving assistance force corresponding to the automatic steering operation command value. Such a driving assistance force has a force of the return torque or more, so the steering operation angle will pass zero degrees and attempt to return to the opposite direction.

[0006] Such a driving assistance force has a concern that it negatively affects the driver's steering operation feeling. In particular, in the case where the vehicle is traveling forward, the driver's steering operation feeling is easily deteriorated. SUMMARY

[0007] An object of the present application is to provide a motor control device that can improve the driver's steering operation feeling in a driving assistance mode.

[0008] 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 calculates the manual steering manipulation command value using a virtual spring reaction force obtained by superimposing a virtual spring reaction force corresponding to the automatic steering manipulation command value on a virtual spring reaction force corresponding to the manual steering manipulation command value as a virtual spring reaction force in the motion equation.

[0009] In this configuration, it is possible to improve the steering manipulation feeling of the driver in the drive assist mode.

[0010] 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

[0011] Figure 1 is a schematic diagram showing a brief configuration of an electric power steering system to which a motor control device of an embodiment of the present application is applied.

[0012] Figure 2 is a block diagram for explaining an electric configuration of a motor control ECU.

[0013] Figure 3 is a graph showing a setting example of an assist torque command value T as for a torsion bar torque T tb .

[0014] Figure 4 is a schematic diagram showing one example of a reference EPS model.

[0015] Figure 5 is a block diagram showing a configuration of a manual steering manipulation command value arithmetic unit.

[0016] Figure 6 is a block diagram showing a configuration of an angle control unit.

[0017] Figure 7 is a schematic diagram showing a configuration example of a physical model of an electric power steering system.

[0018] Figure 8is a block diagram showing the structure of the disturbance torque estimation section.

[0019] Figure 9 is a schematic diagram showing the structure of the torque control section.

[0020] Figure 10 is a flowchart showing the steps of the weight setting process by the weight setting section.

[0021] Figure 11 is a block diagram showing a modification of the manual steering command value calculation section.

[0022] Figure 12 is a block diagram showing a modification of the motor control ECU.

[0023] Figure 13 is a flowchart showing the steps of the weight setting process by Figure 12 the weight setting section. DETAILED DESCRIPTION

[0024] [Explanation of Embodiments of the Invention]

[0025] One embodiment of the present application provides a motor control device for drive controlling an electric motor of a steering apparatus, including: a manual steering command value calculation section that calculates a manual steering command value using a torsion bar torque; a comprehensive angle command value calculation section that adds an automatic steering command value for drive assist to the manual steering command value to calculate a comprehensive angle command value; and a control section that drive controls the electric motor based on the comprehensive angle command value, wherein in a drive assist mode, the manual steering command value calculation section is configured to calculate the manual steering command value using a motion equation of a reference model of the steering apparatus, and the manual steering command value calculation section calculates the manual steering command value using, as a virtual spring reaction force in the motion equation, a virtual spring reaction force obtained by superimposing a virtual spring reaction force corresponding to the manual steering command value on a virtual spring reaction force corresponding to the automatic steering command value.

[0026] In this structure, it is possible to improve the steering feeling of the driver in the drive assist mode.

[0027] In one embodiment of the present application, the manual steering command value calculation section, when calculating the manual steering command value, uses, as a virtual damper reaction force in the motion equation, a virtual damper reaction force obtained by superimposing a virtual damper reaction force corresponding to a differential value of the manual steering command value on a virtual damper reaction force corresponding to a differential value of the automatic steering command value.

[0028] In one embodiment of the application, the manual steering operation command value calculation section described above uses the torsion bar torque or the surrounding environment information to weight the virtual spring reaction force corresponding to the automatic steering operation command value.

[0029] [Detailed Description of Embodiments of the Invention]

[0030] Embodiments of the application will be described in detail below with reference to the accompanying drawings.

[0031] Figure 1 is a schematic diagram showing the brief structure of an electric power steering system to which a motor control device according to one embodiment of the application is applied.

[0032] The electric power steering system 1 is provided with a steering wheel 2 as a steering operation member for steering a vehicle, a steering mechanism 4 that turns a steered wheel 3 in conjunction with the rotation of the steering wheel 2, and a steering operation assist mechanism 5 for assisting the steering operation of a driver. The steering wheel 2 and the steering mechanism 4 are mechanically linked via a steering shaft 6 and an intermediate shaft 7.

[0033] 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 that allows relative rotation via a torsion bar 10.

[0034] A torque sensor 12 is disposed in the vicinity of the torsion bar 10. The torque sensor 12 detects the torsion bar torque (steering operation torque) T tb In this embodiment, the torsion bar torque T tb For example, the torque for steering in the right direction is detected as a positive value, and the 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 .

[0035] The steering mechanism 4 is composed of a rack and pinion mechanism including a pinion shaft 13 and a rack shaft 14 as a steering shaft. The steered wheels 3 are 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 the steering operation of the steering wheel 2. A pinion 16 is linked to the front end of the pinion shaft 13.

[0036] The rack shaft 14 extends linearly 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. The rotation of the pinion shaft 13 is converted to the axial movement of the rack shaft 14 by the pinion 16 and the rack 17. The steered wheels 3 are turned by moving the rack shaft 14 in the axial direction.

[0037] If the steering wheel 2 is subjected to a steering operation (rotation), the rotation is transmitted to the pinion shaft 13 via the steering shaft 6 and the intermediate shaft 7. Also, the rotation of the pinion shaft 13 is converted into the axial movement of the rack shaft 14 by the pinion 16 and the rack 17. Thereby, the steered wheels 3 are steered.

[0038] The steering assist mechanism 5 includes an electric motor 18 for generating a steering assist force (assist torque), and a reduction gear 19 for amplifying the output torque of the electric motor 18 and transmitting it to the steering mechanism 4. The reduction gear 19 is constituted by a worm gear mechanism including a worm 20 and a worm wheel 21 engaged with the worm 20. The reduction gear 19 is housed in a gear housing 22 which is a transmission mechanism housing.

[0039] Hereinafter, N denotes the reduction ratio (transmission ratio) of the reduction gear 19. The 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 / the rotational angle of the worm wheel 21, i.e., the worm wheel angle θ ww .

[0040] The worm 20 is rotationally driven by the electric motor 18. Also, the worm wheel 21 is linked to the output shaft 9 in a manner that it can integrally rotate.

[0041] If the worm 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 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 rotational angle sensor 23 for detecting the rotational angle of the rotor of the electric motor 18.

[0042] 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. The disturbance torque T lc other than the motor torque includes a torsion bar torque T tb , a road reaction force torque (road load torque) T rl , a friction torque T f , and the like.

[0043] The torsion bar torque T tbis a torque applied to the output shaft 9 from the steering wheel 2 side through a force applied by the driver to the steering wheel 2, a force generated by steering inertia, and the like.

[0044] Road reaction force torque T rl is a torque applied to the output shaft 9 from the steering wheel 3 side via the rack shaft 14 through a righting moment generated by the tires, a force generated by the suspension, tire wheel alignment, friction of the rack and pinion mechanism, and the like.

[0045] A CCD (Charge Coupled Device) camera 25 that photographs a road ahead of a traveling direction of the vehicle, a GPS (Global Positioning System) 26 that detects a position of the vehicle, a radar 27 that detects a road shape and an obstacle, and a map information storage 28 that stores map information are mounted on the vehicle. The vehicle also mounts two mode switches 31 and 32 for manually switching steering control modes.

[0046] As described later, the steering control modes include a manual steering control mode in which steering is performed by manual driving, and a coordinated steering control mode in which steering is performed based on both manual driving and automatic driving.

[0047] 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 that performs driving assist control and automatic driving control. The higher-level ECU 201 performs surrounding environment recognition, 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 determines a control target value of a steering control and a drive actuator.

[0048] 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 (target track). 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.

[0049] In this embodiment, the automatic steering control instruction value θ ad is expressed as a positive value, and a rotational amount in a right steering direction from the neutral position is expressed as a negative value. The automatic steering control instruction value θ adFor example, it is set based on the vehicle speed, the lateral deviation with respect to the target travel line (in this embodiment, the lane center line), and the yaw deviation of the vehicle with respect to the target travel line. Such an automatic steering control command value θ ad The processing is well known, so detailed description is omitted here.

[0050] Further, the automatic steering control (driving assist control) can also be, for example, a lane centering assist (LCA) control that assists the steering control in such a manner that the vehicle travels in the center of the travel lane, a lane keeping assist (LKA) control that assists the steering control in such a manner that the vehicle is maintained within the travel lane, or the like.

[0051] Further, the host ECU 201 outputs the curvature p of the travel lane in which the vehicle travels. The curvature p is p = 1 / r when r denotes the radius of curvature of the travel lane in which the vehicle travels. The greater the curvature p (the smaller the radius of curvature r), the greater the degree of curvature of the curved road. The curvature p is one example of the "surrounding environment information" of the present application.

[0052] Further, the host ECU 201 outputs a steering control mode signal S mode indicating whether the steering control mode (driving mode) is the manual steering control mode (manual driving mode) or the coordinated steering control mode (driving assist mode) based on the operation of the first mode switch 31 and the second mode switch 32.

[0053] Specifically, when the first mode switch 31 is turned on by the driver, the host ECU 201 outputs a steering control mode signal S mode indicating that the steering control mode is the manual steering control mode. On the other hand, when the second mode switch 32 is turned on by the driver, the host ECU 201 outputs a steering control mode signal S mode indicating that the steering control mode is the coordinated steering control mode.

[0054] The automatic steering control command value θ ad , the curvature p, and the steering control mode signal S mode are imparted to the motor control ECU 202 via the in-vehicle network. The output signal of the torsion bar torque T tb sensor 12 and the rotation angle sensor 23 are input to the motor control ECU 202. The motor control ECU 202 controls the electric motor 18 based on the above input signals and the information imparted from the host ECU 201.

[0055] Figure 2 is a block diagram for explaining the electrical structure of the motor control ECU 202.

[0056] The motor control ECU 202 includes a microcomputer 50, a drive circuit (inverter circuit) 41 that is controlled by the microcomputer 50 and supplies electric power to the electric motor 18, and a current detection circuit 42 that detects a current (hereinafter referred to as "motor current I m " ) flowing to the electric motor 18.

[0057] The microcomputer 50 includes 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 command value setting section 51, a weight setting section 52, a manual steering operation command value operation section 53, a comprehensive angle command 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.

[0058] The assist torque command value setting section 51 sets a target value of the assist torque required for manual operation, that is, an assist torque command value T as . The assist torque command value setting section 51 sets the assist torque command value T tb based on the torsion bar torque T as detected by the torque sensor 12.

[0059] Figure 3 is a graph showing an example of setting of the assist torque command value T tb with respect to the torsion bar torque T as .

[0060] The assist torque command value T as is set to a positive value when the steering operation assist force for right direction steering operation from the electric motor 18 should be generated, and is set to a negative value when the steering operation assist force for left direction steering operation from the electric motor 18 is generated. The assist torque command value T as is taken as positive with respect to the positive value of the torsion bar torque T tb , and is taken as negative with respect to the negative value of the torsion bar torque T tb . Further, the assist torque command value T as is set to be larger in absolute value as the absolute value of the torsion bar torque T tb is larger.

[0061] Further, the assist torque command value setting section 51 can also operate the assist torque command value T tb by multiplying the torsion bar torque T as by a constant set in advance. In addition, the assist torque command value T as may also be set in consideration of the vehicle speed.

[0062] The weight setting section 52 sets a weight based on the torsion bar torque T tband the curvature p imparted from the upper ECU 201, to set the weight W used in the manual steering operation command value calculation section 53 (refer to Figure 5 ). Details of the weight setting section 52 will be described later.

[0063] The manual steering operation command value calculation section 53, in the coordinated steering operation mode, in the case where the driver operates the steering wheel 2, sets the steering operation angle (more accurately, the rotation angle θ c of the output shaft 9) corresponding to this steering wheel operation as the manual steering operation command value θ md is set. The manual steering operation command value calculation section 53 generates the manual steering operation command value θ tb using the torsion bar torque T as detected by the torque sensor 12, the assist torque command value T ad set by the assist torque command value setting section 51, the automatic steering operation command value θ md imparted from the upper ECU 201, and the weight W set by the weight setting section 52. Details of the manual steering operation command value calculation section 53 will be described later.

[0064] The integrated angle command value calculation section 54 adds the automatic steering operation command value θ ad set by the upper ECU 201 to the manual steering operation command value θ md , to calculate the integrated angle command value θ cmd .

[0065] The angle control section 55 calculates the integrated motor torque command value T cmd based on the integrated angle command value θ com . Details of the angle control section 55 will be described later.

[0066] The first switch 56 and the second switch 57 are opened or closed according to the steering operation mode signal S mode input. Specifically, in the case where the steering operation mode signal S mode indicating that the steering operation mode is the manual steering operation mode is input, the first switch 56 is opened and the second switch 57 is closed.

[0067] On the other hand, in the case where the steering operation mode signal S mode indicating that the steering operation mode is the coordinated steering operation mode is input, the first switch 56 is closed and the second switch 57 is opened.

[0068] 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 T m，cmd (= Tas On the other hand, when the second switch 57 is in the open state and the first switch 56 is in the closed state, the addition unit 58 will output the combined motor torque command value T output by the angle control unit 55. com As the motor torque command value T m，cmd (=T) com Output.

[0069] The output of the adder 58 is the motor torque command value T. m，cmd It is assigned to the torque control unit 59.

[0070] The torque control unit 59 uses the motor torque of the electric motor 18 and the motor torque command value T. m，cmd The drive circuit 41 is driven in a similar manner. Details of the torque control unit 59 will be described later.

[0071] The manual steering control command value calculation unit 53 is explained in detail.

[0072] First, regarding the manual steering command value θ of the manual steering command value generation unit described in Patent Document 1 (International Publication No. 2023 / 286169) md The setup method will be explained.

[0073] Manual steering control command value generation unit uses Figure 4 The reference EPS model is used to generate manual steering command values ​​θ. md . Figure 4 The reference EPS model is an example of the "reference model of steering control device" of the present invention.

[0074] This reference EPS model is a single inertial model including the lower column. The lower column corresponds to the output shaft 9 and the worm gear 21. However, this model is an example, and it could also be an inertial model including structures other than those described above (e.g., rack and pinion). Figure 4 In the middle, J md It is the inertia of the lower column (hereinafter referred to as "column inertia"). θ col It is the rotation angle of the lower column, T tb It is a torsion bar torque. A torsion bar torque T is applied to the lower column. tb The torque N·T acting on the output shaft 9 from the electric motor 18 m And the road surface reaction torque (virtual reaction force) T rl .

[0075] Road reaction torque T rl Using the spring constant k of a virtual spring md and the viscous damping coefficient c of the virtual shock absorber md ), is represented by the following formula (1).

[0076] [Math. 1]

[0077]

[0078] spring constant k md and viscous damping coefficient c md is obtained by preliminary experiments, analysis, etc. Hereinafter, k md · θ col is called virtual spring reaction force, and c md (dθ col / dt) is called virtual shock absorber reaction force.

[0079] The motion equation of the reference EPS model is represented by the following equation (2).

[0080] [Math. 2]

[0081]

[0082] In equation (2), J md · d 2 θ col / dt 2 is the moment of inertia force acting on the lower column.

[0083] 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 col of the lower column as the manual steering operation command value θ md . In this way, the method of setting the manual steering operation command value θ md is called a comparison method.

[0084] The motion equation of equation (2) is equivalent to a motion equation in which T m is replaced by T as , and θ col is replaced by θ md .

[0085] In the present embodiment, the manual steering operation command value operation section 53 operates the manual steering operation command value θ mdSpecifically, 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 .

[0086] Figure 5 This is a block diagram showing the structure of the manual steering control command value calculation unit 53.

[0087] exist Figure 5 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 k is the viscous damping coefficient of the virtual shock absorber. md This is the spring constant of the virtual spring. The viscous damping coefficient c of the virtual shock absorber. md And the spring constant k of the virtual spring md It is determined through prior experiments and analysis.

[0088] The manual steering control command value calculation unit 53 includes a reduction ratio multiplication unit 101, an addition and subtraction unit 102, an inertia division unit 103, a first integration unit 104, a second integration unit 105, a first virtual shock absorber reaction force calculation unit 106, a differential unit 107, a second virtual shock absorber reaction force calculation unit 108, a first weight multiplication unit 109, a first addition unit 110, a first virtual spring reaction force calculation unit 111, a second virtual spring reaction force calculation unit 112, a second weight multiplication unit 113, and a second addition unit 114.

[0089] The reduction ratio multiplier 101 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 to the auxiliary torque command value N·T for output shaft 9 as .

[0090] Input the torsion bar torque T into the addition / subtraction unit 102 tb The auxiliary torque command value N·T for output shaft 9 as The virtual shock absorber reaction force (c) imparted by the first additive part 110 md ·dθ md / dt+W·c md ·dθ ad / dt), the virtual spring reaction force (k) given by the second addition part 114 md ·θ md +W·k md ·θ ad).

[0091] The addition and subtraction section 102 pairs of torsion bar torque T tb Adding the auxiliary torque command value N·T for output shaft 9 as Subtract the virtual damper reaction force (c) from the summation result. md ·dθ md / dt+W·c md ·dθ ad / dt) and virtual spring reaction force (k md ·θ md +W·k md ·θ ad Therefore, the addition / subtraction part 102 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 - (k) md ·θ md +W·k md ·θ ad ) - (c md ·dθ md / dt+W·c md ·dθ ad / dt)).

[0092] The inertial division unit 103 calculates the inertial torque J by the addition and subtraction unit 102. 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 .

[0093] The first integrator 104 measures the manual steering control 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.

[0094] The second integrator 105 measures the manual steering control command value θ mdThe 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.

[0095] The first virtual shock absorber reaction force calculation unit 106 calculates the manual steering control command value θ calculated by the first integrator 104. md The first differential value dθ md / dt multiplied by the viscous decay coefficient c md To calculate the reaction force c of the first virtual shock absorber. md ·dθ md / dt.

[0096] Differential section 107 corresponds to the automatic steering control command value θ ad The second virtual shock absorber reaction force calculation unit 108 performs differentiation on the automatic steering control command value θ calculated by the differentiation unit 107. ad The differential value dθ ad / dt multiplied by the viscous decay coefficient c md To calculate the reaction force c of the second virtual shock absorber. md ·dθ ad / dt.

[0097] The first weighted multiplication part 109 reacts to the second virtual shock absorber c. md ·dθ ad / dt is multiplied by the weight W (0≤W≤1) set by the weight setting unit 52.

[0098] The first additive unit 110 applies the reaction force c of the first virtual shock absorber. md ·dθ md The second virtual shock absorber reaction force W·c after adding the weighted multiplication to / dt md ·dθ ad / dt, to calculate the virtual shock absorber reaction force (c md ·dθ md / dt+W·c md ·dθ ad / dt). The virtual shock absorber reaction force (c) md ·dθ md / dt+W·c md ·dθ ad / dt) is fed back to the addition and subtraction department 102.

[0099] The first virtual spring reaction force calculation unit 111 calculates the manual steering command value θ calculated by the second integrator 105. md Multiplied by the spring constant k mdTo calculate the first virtual spring reaction force k md ·θ md .

[0100] The second virtual spring reaction force calculation unit 112 calculates the automatic steering control command value θ. ad Multiplied by the spring constant k md To calculate the second virtual spring reaction force k md ·θ ad .

[0101] The second weighted multiplication part 113 reacts to the second virtual spring force k. md ·θ ad Multiply by the weight W (0≤W≤1) set by the weight setting unit 52.

[0102] The second addition unit 114 applies the reaction force k of the first virtual spring. md ·θ md The second virtual spring reaction force W·k after weighted multiplication md ·θ ad To calculate the virtual spring reaction force (k) md ·θ md +W·k md ·θ ad The virtual spring reaction force (k) md ·θ md +W·k md ·θ ad The result was fed back to the addition and subtraction department 102.

[0103] That is, the manual steering command value calculation unit 53 calculates the manual steering command value θ based on the motion equation of the following formula (3). md .

[0104] [Mathematical Expression 3]

[0105]

[0106] In equation (3), (k md ·θ md +W·k md ·θ ad (c) is the virtual spring reaction force. md ·dθ md / dt+c md ·dθ ad / dt) is the virtual shock absorber reaction force.

[0107] That is, the manual steering command value calculation unit 53 calculates the virtual spring reaction force k in the above formula (2). md ·θ col And the reaction force c of the virtual shock absorbermd ·dθ col / dt, respectively using (k md ·θ md +W·k md ·θ ad ) and (c md ·dθ md / dt+W·c md ·dθ ad / dt), to calculate the manual steering control command value θ md .

[0108] The manual steering command value calculation unit 53 has such a structure that by changing the weight W, the vehicle's following ability to the target driving route can be adjusted. The reason for this will be explained later.

[0109] Figure 6 This is a block diagram showing the structure of the angle control unit 55.

[0110] Angle control unit 55 based on comprehensive angle command value θ cmd To calculate the overall motor torque command value T com The angle control unit 55 includes a low-pass filter (LPF) 61, a feedback control unit 62, a feedforward control unit 63, an interference torque inference unit 64, a torque addition unit 65, an interference torque compensation unit 66, a first reduction ratio division unit 67, a reduction ratio multiplication unit 68, a rotation angle calculation unit 69, and a second reduction ratio division unit 70.

[0111] The reduction ratio multiplier 68 passes through the adder 58 (see reference). Figure 2 The motor torque command value T calculated m，cmd Multiply by the reduction ratio N of reducer 19 to get the motor torque command value T. m，cmd This is converted into the output shaft torque command value N·T acting on output shaft 9 (worm gear 21). m，cmd .

[0112] The rotation angle calculation unit 69 calculates the rotor rotation angle θ of the electric motor 18 based on the output signal of the rotation angle sensor 23. m The second reduction ratio division unit 70 calculates the rotor rotation angle θ by the rotation angle calculation unit 69. m Divide by the reduction ratio N, and the rotor rotation angle θ m Converted to the rotation angle (actual steering control angle) of output shaft 9 θ c .

[0113] In this embodiment, the actual steering angle θ cThe rotation amount (rotation angle) is represented by the amount of rotation from the neutral position of the output shaft 9. The rotation amount that turns right from the neutral position to the control direction is represented as a positive value, and the rotation amount that turns left from the neutral position to the control direction is represented as a negative value.

[0114] Low-pass filter 61 combines the angle command value θ cmd Low-pass filtering is performed. The resulting composite angle command value θ is obtained after low-pass filtering. cmdl It is assigned to the feedback control unit 62 and the feedforward control unit 63. Alternatively, the low-pass filter 61 may not be provided.

[0115] The feedback control unit 62 combines the steering angle estimation value ^θ calculated by the disturbance torque estimation unit 64 with the comprehensive angle command value θ after low-pass filtering. cmdl The setting is based on proximity. The feedback control unit 62 includes an angle deviation calculation unit 62A and a PD control unit 62B. The angle deviation calculation unit 62A calculates the comprehensive angle command value θ. cmdl Inferred value of steering angle ^θ c The deviation Δθ (=θ) cmdl -^θ c Furthermore, 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.

[0116] 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.

[0117] 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 .

[0118] 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 7 The feedforward control torque T is then calculated. ff The torque addition part 65 is assigned as an inertia compensation value.

[0119] 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 ).

[0120] The interference torque estimation unit 64 is provided to estimate the nonlinear torque (interference torque: torque other than motor torque) generated as interference on 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 (disturbing load) T lc Steering angle θ and its derivative (angular velocity) dθ c / dt. Use ^T respectively. lc ,^θ c and d^θ c / dt represents the disturbance torque T lc Steering angle θ c And the differential value of the steering angle (angular velocity) dθ c The inferred value of / dt. Details of the interference torque inference unit 64 will be described later.

[0121] The interference torque inference value ^T calculated by the interference torque inference unit 64 lc The interference torque compensation value is assigned to the interference torque compensation unit 66. The steering angle estimation value ^θ calculated by the interference torque estimation unit 64 is... c It is assigned to the angle deviation calculation unit 62A.

[0122] The interference torque compensation unit 66 obtains the basic torque command value (T) from the basic torque command value. fb +T ff Subtract the inferred value of the disturbance torque ^T lc To calculate the comprehensive torque command value T co (=T) fb +T ff -^T lc Thus, the comprehensive torque command value T, which compensates for the disturbance torque, is obtained. co (Torque command value for output shaft 9).

[0123] The integrated torque command value T co is given to the first reduction ratio division section 67. The first reduction ratio division section 67 calculates the integrated motor torque command value T co by dividing the integrated torque command value T com by the reduction ratio N. This integrated motor torque command value T com is given to the second switch 57 (refer to Figure 2 ).

[0124] The disturbance torque estimation section 64 will be described in detail. The disturbance torque estimation section 64 is constituted, for example, by a disturbance observer which estimates the disturbance torque T Figure 7 using the physical model 300 of the electric power steering system 1 shown in Fig. 1. The disturbance torque estimation section 64 estimates the disturbance torque T lc , the steering angle θ c , and the angular velocity dθ c / dt.

[0125] The physical model 300 includes a device (one example of a motor drive object) 301 having an output shaft 9 and a worm wheel 21 fixed to the output shaft 9. A 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.

[0126] Further, 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 the friction between the worm wheel 21 and the worm gear 20.

[0127] If the inertia of the device 301 is assumed to be J, the motion equation with respect to the inertia of the physical model 300 is represented by the following equation (4).

[0128] [Mathematical expression 4]

[0129]

[0130] 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 represents the disturbance torque other than the motor torque applied to the device 301. In this embodiment, the disturbance torque T lc is represented as the torsion bar torque T tb , the road reaction force torque T rl , and the friction torque T fand, but actually disturbance torque T lc include these.

[0131] for Figure 7 The state equation of the physical model 300 is represented by the following equation (5).

[0132] [Equation 5]

[0133]

[0134] In the above equation (5), x is a state variable vector, ui 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, Bi is a first input matrix, B2 is a second input matrix, C is an output matrix, and D is a direct matrix.

[0135] The above state equation is extended to a system including the unknown input vector u2 as one of the states. The state equation of the extended system (extended state equation) is represented by the following equation (6).

[0136] [Equation 6]

[0137]

[0138] In the above equation (6), x e is a state variable vector of the extended system, and is represented by the following equation (7).

[0139] [Equation 7]

[0140]

[0141] In the above 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.

[0142] According to the extended state equation of the above equation (6), a disturbance observer (extended state observer) represented by the following equation (8) is constructed.

[0143] [Equation 8]

[0144]

[0145] 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).

[0146] [Math. 9]

[0147]

[0148] In Equation (9), ^θ c is an estimated value of θ c , and ^T lc is an estimated value of T lc .

[0149] The disturbance torque estimation section 64 operates the state variable vector ^x e based on the equation of Equation (8) described above.

[0150] Figure 8 is a block diagram representing the structure of the disturbance torque estimation section 64.

[0151] 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.

[0152] The output shaft torque command value N·T m，cmd operated by the reduction ratio multiplication section 68 (refer to Figure 6 ) is given to the input vector input section 81. The input vector input section 81 outputs an input vector u1.

[0153] The output of the integration section 88 becomes the state variable vector ^x e (Equation (9) described above). At the start of operation, an initial value is given as the state variable vector ^x e . The initial value of the state variable vector ^x e is, for example, 0.

[0154] The system matrix multiplication section 86 multiplies the state variable vector ^x e by the system matrix A e . The output matrix multiplication section 82 multiplies the state variable vector ^x e by the output matrix C e .

[0155] The first addition section 83 subtracts the output (C e ·^x e ) of the output matrix multiplication section 82 from the actual steering angle θ c operated by the second reduction ratio division section 70 (refer to Figure 6 ), that is, the output vector (measured value) y. That is, the first addition section 83 operates the output vector y and the output vector estimated value ^y (= C e ·^x eThe difference (y - ^y). The output (y - ^y) of the gain multiplier 84 to the first adder 83 is multiplied by the observer gain L (refer to equation (8) above).

[0156] 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 c and the inferred angular velocity d^θ c / dt.

[0157] 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).

[0158] [Mathematical Expression 10]

[0159]

[0160] 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.

[0161] 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.

[0162] Figure 9 This is a schematic diagram showing the structure of the torque control unit 59.

[0163] Torque control unit 59 (reference)Figure 2 ) includes a motor current command value calculation section 91, a current deviation calculation section 92, a PI control section 93, and a PWM (Pulse Width Modulation) control section 94.

[0164] The motor current command value calculation section 91 calculates a motor current command value I Figure 2 by dividing a motor torque command value T m，cmd calculated by the addition section 58 (refer to t to a torque constant K m，cmd of the electric motor 18.

[0165] The current deviation calculation section 92 calculates a deviation ΔI (= I m，cmd - I m ) of the motor current command value I m，cmd obtained by the motor current command value calculation section 91 from a motor current I m detected by the current detection circuit 42.

[0166] The PI control section 93 generates a drive command value for guiding the motor current I m，cmd flowing to the electric motor 18 to the motor current command value I md by performing a PI operation (proportional integral operation) with respect to the current deviation ΔI calculated by the current deviation calculation 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.

[0167] Next, a weight setting process performed by the weight setting section 52 will be described.

[0168] First, a case where followability of the vehicle to the target travel route varies depending on the magnitude of the weight W of the manual steering manipulation command value calculation section 53 will be described.

[0169] As described above, the manual steering manipulation command value calculation section 53 calculates the manual steering manipulation command value θ md · θ col and the virtual damper reaction force c md · dθ col / dt of the above-described formula (2) using (k md · θ md + W · k md · θ ad ) and (c md · dθ md / dt + W · c md · dθ ad / dt), respectively. md

[0170] Reference Figure 2 as well as Figure 6 When coordinating steering control modes, for example, using the actual steering angle θ c Follow the overall angle command value θ cmd The electric motor 18 is controlled in this manner. If we assume the actual steering angle θ... c Completely follows the composite angle command value θ cmd , then θ md =θ c -θ ad This relationship is valid.

[0171] In this case, the first virtual spring reaction force k in the above equation (3) md ·θ md (and manual steering command value θ) md The corresponding virtual spring reaction force is represented by the following formula (11).

[0172] [Mathematical Expression 11]

[0173]

[0174] Similarly, the first virtual shock absorber reaction force c in equation (3) above md ·dθ md / dt (compared to the manual steering command value θ) md The corresponding virtual shock absorber reaction force is represented by the following formula (12).

[0175] [Mathematical Expression 12]

[0176]

[0177] That is, the first virtual spring reaction force k md ·θ md Includes the actual steering angle θ c The corresponding actual steering angle component k md ·θ c and the automatic steering control command value θ ad The corresponding automatic steering control component -k md ·θ ad Similarly, the reaction force c of the first virtual shock absorber md ·dθ md / dt includes the actual steering angle θ c The actual steering angle component c corresponding to the first derivative md ·dθ c / dt, and the automatic steering control command value θ ad The first derivative corresponds to the automatic steering control component -cmd ·dθ ad / dt.

[0178] If we assume that equations (11) and (12) are true, then the above equation (3) is as shown in equation (13).

[0179] [Mathematical Expression 13]

[0180]

[0181] When W=0, equation (13) becomes equivalent to equation (2). Therefore, in coordinating the steering control mode, the comparison method is the same as that used with the automatic steering control command value θ. ad The corresponding driving assistance forces are activated. That is, the vehicle's ability to follow the target driving route becomes higher.

[0182] On the other hand, when W=1, the above equation (13) becomes the following equation (14).

[0183] [Mathematical Expression 14]

[0184]

[0185] That is, when W=1, the virtual spring reaction force becomes k. md ·θ c , and the automatic steering control command value θ ad The corresponding automatic steering control component -k md ·θ ad It becomes zero. Similarly, when W=1, the virtual damper reaction force becomes c. 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 becomes zero. That is, when W=1, it is related to the automatic steering command value θ. ad The corresponding driving assistance forces are ineffective. That is, the vehicle loses its ability to follow the target driving route.

[0186] When W is in the range of 0 < W < 1, based on the fundamental characteristic of W=0, coordinated control is implemented to reduce the vehicle's following of the target driving route. In this case, the larger W is, the weaker the vehicle's following of the target driving route.

[0187] Figure 10 This is a flowchart illustrating the steps of the weight setting process performed by the weight setting unit 52. Figure 10 The processing is repeated in units of a specified number of operation cycles. Furthermore, the initial value of W is 0.

[0188] First, the weight setting section 52 discriminates whether the torsion bar torque T tb is equal to or less than a prescribed threshold value A (A > 0) (step S1). The threshold value A is a threshold value for determining whether the driver is holding the steering wheel (hand holding state) or not holding the steering wheel (hand off state).

[0189] In the case where the torsion bar torque T tb is equal to or less than the threshold value A (step S1: YES), the weight setting section 52 determines that the hand off state is present, and sets the weight W to zero (step S2). That is, in the case where the hand off state is present, W is set in such a manner that the followability of the vehicle to the target travel route becomes high. The reason for this is that if the followability of the vehicle to the target travel route is weakened in the case where the hand off state is present, the vehicle cannot follow the target travel route.

[0190] Further, in step S1, in the case where the torsion bar torque T tb is equal to or less than the threshold value A, W can be set to a value equal to or greater than zero that is close to zero. The weight setting section 52 ends the processing of this operation cycle if the processing of step S2 is performed.

[0191] Further, in step S1, a sensor that determines the presence or absence of contact by the driver can be installed to the steering wheel, and it can be discriminated whether the contact surface pressure or the contact time is equal to or less than a prescribed threshold value B (B > 0).

[0192] In step S1, in the case where the torsion bar torque T tb is greater than the threshold value A (step S1: NO), the weight setting section 52 determines that the hand holding state is present, and discriminates whether the travel lane is a straight road (step S3). In this embodiment, the weight setting section 52 discriminates that the travel lane is a straight road if the curvature p is equal to or less than a prescribed threshold value C (C > 0), and discriminates that the travel lane is a curved road if the curvature p is greater than the threshold value C.

[0193] In the case where the travel lane is a straight road (step S3: YES), the weight setting section 52 sets W to a prescribed value a (0 < a < 1) in a range that is greater than 0 and less than 1 (step S4). That is, in this embodiment, the weight setting section 52 sets a value that is greater than the weight set in step S2 to a. In this embodiment, a = 0.7 is set. Thus, the followability of the vehicle to the target travel route is weakened compared to the case where W = 0. In other words, compared to the case where the manual steering manipulation command value q md is generated by the comparison method, the automatic steering manipulation command value q ad corresponding to the driving assistance force is weakened. Thus, the steering manipulation feeling of the driver at the time of the driving assistance mode can be improved.

[0194] Further, in the case where it is discriminated in step S3 that the travel lane is a straight road, W is preferably set to a prescribed value a (0 < a < 1) in a range larger than 0 and smaller than 1, but W can also be set to 1. The weight setting portion 52 ends the processing of this operation cycle if the processing of step S4 is performed.

[0195] In the case where it is discriminated in step S3 that the travel lane is a curved road (step S3: No), the weight setting portion 52 sets W to zero (step S5). That is, in this embodiment, the weight setting portion 52 sets a value smaller than the weight set in step S4 as the weight. That is, in the case where the travel lane is a curved road, W is set in such a manner that the followability of the vehicle to the target travel line becomes high. The reason for this is that in a curved road, the vehicle is likely to deviate from the target travel line due to the centrifugal force acting on the vehicle.

[0196] Further, in the case where it is discriminated in step S3 that the travel lane is a curved road, W can also be set to a value of zero or more close to zero. In addition, in the case where it is discriminated in step S3 that the travel lane is a curved road, a value of the weight set in step S4 or more can also be set as the weight. The weight setting portion 52 ends the processing of this operation cycle if the processing of step S5 is performed.

[0197] Hereinafter, the operation of the present embodiment will be described with reference to Figure 2 The operation of the present embodiment will be described.

[0198] In this 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 . In addition, 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 .

[0199] In the 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 the 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 operation of the driver on the mode switches 31, 32.

[0200] In the above-described embodiment, the coordinated steering operation mode in which the electric motor 18 is controlled based on the comprehensive angle command value θ cmd can be switched between the manual steering operation mode in which the electric motor 18 is controlled based on only the assist torque command value T asIt can switch between manual steering operation modes of the electric motor 18.

[0201] That is, based on the comprehensive angle command value θ cmd In the electric power steering system 1 that can control the electric motor 18, it is possible to control the auxiliary torque command value T based solely on the auxiliary torque command value T. as To control the electric motor 18.

[0202] 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.

[0203] In the above embodiment, when coordinating the steering control mode, the manual steering control command value calculation unit 53 acts as the virtual spring reaction force k in the above formula (2). md ·θ col And the reaction force c of the virtual shock absorber md ·dθ col / dt, respectively using (k md ·θ md +W·k md ·θ ad ) and (c md ·dθ md / dt+W·c md ·dθ ad / dt), to calculate the manual steering control command value θ md .

[0204] Therefore, by changing the weight W, the vehicle's ability to follow the target driving route can be adjusted. This, in turn, improves the driver's steering feel in driver assistance mode.

[0205] In the above embodiment, the reaction force c with the second virtual shock absorber md ·dθ ad The weights W and K, multiplied by / dt, and the reaction force k of the second virtual spring. md ·θ a The weights W of the multiplication are the same. However, the reaction force c of the second virtual damper... md ·dθ ad The weights W and K, multiplied by / dt, and the reaction force k of the second virtual spring. md ·θ a The weights W for multiplication can also be different.

[0206] Furthermore, in the above embodiment, the virtual spring reaction force k in the above formula (2) is... md ·θ col , used (k md ·θ md+W·k md ·θ ad ), and as the virtual shock absorber reaction force c in the above equation (2) md ·dθ col / dt, using virtual damper reaction force (c md ·dθ md / dt+W·c md ·dθ ad / dt). However, the virtual spring reaction force k in the above equation (2) is md ·θ col , used (k md ·θ md +W·k md ·θ ad However, the virtual shock absorber reaction force c in equation (2) above... md ·dθ col / dt, or you can use c md ·dθ md / dt.

[0207] In this case, the manual steering command value calculation unit becomes... Figure 11 The structure shown. In Figure 11 In the middle, regarding the above Figure 5 The corresponding part markings and Figure 5 Same reference numerals as shown in the attached figures.

[0208] Figure 11 The manual steering control command value calculation unit 53A does not have Figure 5 The manual steering command value calculation unit 53 includes a differential unit 107, a second virtual shock absorber reaction force calculation unit 108, a first weight multiplication unit 109, and a first addition unit 110. The first virtual shock absorber reaction force c calculated by the first virtual shock absorber reaction force calculation unit 106... md ·dθ md / dt is fed back to the addition / subtraction unit 102 as the reaction force of the virtual shock absorber.

[0209] In this case, the manual steering command value calculation unit 53A calculates the manual steering command value θ based on the motion equation of the following equation (15). md .

[0210] [Mathematical Expression 15]

[0211]

[0212] In equation (15), k md ·θ md +W·k md ·θ adIt is a virtual spring reaction force. md ·dθ md / dt is the virtual shock absorber reaction force.

[0213] That is, the manual steering command value calculation unit 53A is used as the virtual spring reaction force k in the above formula (2). md ·θ md And the reaction force c of the virtual shock absorber md ·dθ col / dt, respectively using (k md ·θ md +W·k md ·θ ad ) and c md ·dθ md / dt is used to calculate the manual steering control command value θ. md .

[0214] Figure 12 This is a block diagram illustrating a modified example of an ECU for motor control. Figure 12 In the middle, regarding the above Figure 2 The corresponding part markings and Figure 2 Same reference numerals as shown in the attached figures.

[0215] exist Figure 12 In the motor control ECU202B, in the following (1), (2) and (3), with Figure 2 The motor control ECU202 is different.

[0216] (1) No settings Figure 2 The first switch 56, the second switch 57, and the addition unit 58.

[0217] (2) In addition to inputting the torsion bar torque T detected by the torque sensor 12 into the weight setting unit 52B tb In addition to the curvature ρ assigned by the upper ECU201, a steering control mode signal S is also input to it. mode .

[0218] (3) The operation of the weight setting unit 52B and Figure 2 The weight setting part 52 operates differently.

[0219] In this modified example, the comprehensive motor torque command value T obtained by the angle control unit 55 is... com As the motor torque command value T m，cmd This is then assigned to the torque control unit 59. Therefore, not only in the case where the steering mode is the coordinated steering mode, but also in the case where the steering mode is the manual steering mode, the torque command value T is based on the integrated motor torque command value. com (Comprehensive angle command value θ) cmd), to control the electric motor 18. Further, in this modification, in a case where the steering operation mode is the manual steering operation mode, the automatic steering operation instruction value θ ad is set to zero.

[0220] Figure 13 is a flowchart showing the steps of the weight setting processing by the weight setting section 52B. In Figure 13 , the steps corresponding to each step of Figure 10 are denoted by the same step number as Figure 10 .

[0221] Figure 13 The processing of the weight setting section 52B is repeatedly executed in units of a prescribed operation cycle. Further, the initial value of W is 0.

[0222] The weight setting section 52B first discriminates, based on the steering operation mode signal S mode , whether the steering operation mode is the manual steering operation mode (step Sll).

[0223] In a case where the steering operation mode is the manual steering operation mode (step Sll: YES), the weight setting section 52B sets the weight W to 1 (step S12). That is, in a case where the steering operation mode is the manual steering operation mode, the vehicle does not need to follow the target travel route, so W is set in a manner in which the followability of the vehicle to the target travel route becomes low. The weight setting section 52B ends the processing of this operation cycle if the processing of step S12 is performed.

[0224] In step Sll, in a case where it is discriminated that the steering operation mode is the coordinated steering operation mode (step Sll: NO), the weight setting section 52B moves to step Sl. Then, the weight setting section 52B performs the processing after step Sl using the Figure 10 already explained.

[0225] The above, although the embodiment of the present application and the modification have been explained, the present application can also be implemented in other forms.

[0226] In the above embodiment and the modification, the weight setting section 52, 52B sets the weight W based on the torsion bar torque T tb and the curvature (one example of the surrounding environment information) p. However, the weight setting section 52, 52B can set the weight W based on only the torsion bar torque T tb , or can set the weight W based on only the curvature (one example of the surrounding environment information) p. However, the weight setting section 52, 52B preferably sets the weight based on at least the torsion bar torque T tb and the curvature p. tb

[0227] In the case of setting the weight W based on only the torsion bar torque T​tb In the case where the weight W is set based on the curvature p and the steering operation amount A, in Figure 10 and Figure 13 , steps S3, S5 are omitted. That is, in Figure 10 and Figure 13 , in step S1, in the case where it is discriminated that T tb >A, the weight setting section 52, 52B moves to step S4.

[0228] In the case where the weight W is set based on the curvature p alone, in Figure 10 and Figure 13 , steps S1, S2 are omitted. That is, in Figure 10 , the weight setting section 52 first performs the process of step S3. In Figure 13 , in step S11, in the case where it is discriminated that the steering operation mode is the cooperative steering operation mode, the weight setting section 52B moves to step S3.

[0229] In the above-described embodiment, the spring constant k md in the above-described equations (3), (15) is found through a preliminary experiment, analysis, or the like. However, the spring constant k md in the above-described equations (3), (15) can also be found using the disturbance torque estimation value ^T lc calculated by the disturbance torque estimation section 64 (refer to Figure 6 ) and the actual steering operation angle θ c calculated by the second reduction ratio division section 70, and based on the following equation (16).

[0230] [Equation 16]

[0231]

[0232] In addition, in the above-described embodiment, the viscous damping coefficient c md in the above-described equations (3), (15) is found through a preliminary experiment, analysis, or the like.

[0233] However, the viscous damping coefficient c md in the above-described equations (3), (15) can also be found using the disturbance torque estimation value ^T lc calculated by the disturbance torque estimation section 64 and the actual steering operation angle θ c calculated by the second reduction ratio division section 70, and based on the following equation (17).

[0234] [Equation 17]

[0235]

[0236] In addition, in the above-described embodiment, the angle control section 55 (refer to Figure 6) although the feedforward control section 63 is provided, the feedforward control section 63 is omitted. In this case, the feedback control torque T fb becomes the basic target torque.

[0237] In addition, in the above-described embodiment, 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 the column type. In addition, the application can also be applied to control of an electric motor for steering angle control of an electric power steering system.

[0238] Although the embodiments of the application have been described in detail, these are merely specific examples for clarifying the technical contents of the application, and the application should not be interpreted as being limited to the above-described specific examples, and the scope of the application is only limited by the appended claims.

[0239] This application corresponds to Japanese Patent Application No. 2023-098544 filed with the Japan Patent Office on June 15, 2023, and all disclosures in the above application are incorporated herein by reference.

[0240] Explanation of Reference Numerals

[0241] 1… electric power steering device, 3… steering wheel, 4… steering mechanism, 18… electric motor, 51… assist torque command value setting section, 52, 52B… weight setting section, 53, 53A… manual steering operation command value calculation section, 54… integrated angle command value calculation section, 55… angle control section, 56… first switch, 57… second switch, 58… addition section, 59… torque control section, 201… upper ECU, 202, 202A… 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 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 virtual spring reaction force obtained by superimposing a virtual spring reaction force corresponding to the manual steering operation command value on a virtual spring reaction force corresponding to the automatic steering operation command value.

2. The motor control device according to claim 1, wherein the manual steering operation command value arithmetic unit, when calculating the manual steering operation command value, uses, as a virtual damper reaction force in the motion equation, a virtual damper reaction force obtained by superimposing a virtual damper reaction force corresponding to a differential value of the manual steering operation command value on a virtual damper reaction force corresponding to a differential value of the automatic steering operation command value.

3. The motor control device according to claim 1, wherein the manual steering operation command value arithmetic unit performs a weighting process on the virtual spring reaction force corresponding to the automatic steering operation command value using the torsion bar torque or surrounding environment information. ​ ​ ​ ​ ​ ​ ​

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