Motor control device

Abstract

This motor control device includes: an assist torque command value generation unit that generates an assist torque command value using steering torque; a manual steering command value generation unit that generates a manual steering command value using the steering torque and the assist torque command value; 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 switching unit that, when in a driving assistance mode, switches in accordance with the steering torque between a first control mode for controlling an electric motor on the basis of the assist torque command value or the manual steering command value and a second control mode for controlling the electric motor on the basis of the integrated angle command value.

Description

[Technical Field]

[0001] The present invention relates to a control device for an electric motor for steering angle control. [Background technology]

[0002] The following Patent Document 1 discloses a technology for a driving assistance device that, in a steering assistance mode, determines whether the driver is gripping the steering wheel, and cancels steering assistance when it is determined that the driver is not holding the steering wheel for a predetermined time or longer, and sets the predetermined time according to the driving conditions of the vehicle. Specifically, the lower the vehicle speed and the smaller the lateral deviation between the center of the traveling lane and the vehicle, the longer the predetermined time is set. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-120374 Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present invention is to provide a motor control device that can switch between a first control mode, in which an electric motor is controlled based on an assist torque command value or a manual steering command value, and a second control mode, in which an electric motor is controlled based on an integrated angle command value, which is the sum of an automatic steering command value for driving assistance and a manual steering command value, depending on the steering torque. [Means for solving the problem]

[0005] One embodiment of the present invention provides a motor control device for drive control of an electric motor for steering angle control, including an assist torque command value generation unit that generates an assist torque command value using steering torque, a manual steering command value generation unit that generates a manual steering command value using the steering torque and the assist torque command value, an integrated angle command value calculation unit that calculates an integrated angle command value by adding the manual steering command value to an automatic steering command value for driving assistance, and a switching unit that, in a driving assistance mode, switches between a first control mode in which the electric motor is controlled based on the assist torque command value or the manual steering command value and a second control mode in which the electric motor is controlled based on the integrated angle command value, depending on the steering torque.

[0006] In this configuration, it is possible to switch between a first control mode in which the electric motor is controlled based on an assist torque command value or a manual steering command value, and a second control mode in which the electric motor is controlled based on an integrated angle command value, which is the sum of an automatic steering command value for driving assistance and a manual steering command value, depending on the steering torque.

[0007] The above and other objects, features and advantages of the present invention will become apparent from the following description of the embodiments with reference to the accompanying drawings. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic diagram showing the general configuration of an electric power steering system to which a motor control device according to one embodiment of the present invention is applied. [Figure 2] FIG. 2 is a block diagram showing the electrical configuration of the motor control ECU. [Figure 3] FIG. 3 is a graph showing an example of setting the assist torque command value Tas relative to the torsion bar torque Td. [Figure 4] FIG. 4 is a schematic diagram showing an example of a reference EPS model used in the manual steering command value generating unit. [Figure 5] FIG. 5 is a block diagram showing the configuration of the angle control unit. [Figure 6] FIG. 6 is a schematic diagram showing an example of the configuration of a physical model of an electric power steering system. [Figure 7] FIG. 7 is a block diagram showing the configuration of the disturbance torque estimating unit. [Figure 8] FIG. 8 is a schematic diagram showing the configuration of the torque control unit. [Figure 9] FIG. 9 is a flowchart showing the procedure of the weight setting process performed by the weight setting unit in the driving assistance mode. [Figure 10] FIG. 10 is a flowchart showing the procedure of another example of the weight setting process performed by the weight setting unit in the driving assistance mode. [Figure 11] FIG. 11 is a flowchart showing the procedure of yet another example of the weight setting process performed by the weight setting unit in the driving assistance mode. [Figure 12] FIG. 12 is a flowchart showing the procedure of yet another example of the weight setting process performed by the weight setting unit in the driving assistance mode. [Figure 13] FIG. 13 is a block diagram for explaining a modified example of the motor control ECU. [Figure 14] FIG. 14 is a flowchart showing the procedure of the weight setting process performed by the second weight setting unit in the driving assistance mode. [Figure 15] FIG. 15 is a flowchart showing the procedure of another example of the weight setting process performed by the second weight setting unit in the driving assistance mode. [Figure 16] FIG. 16 is a flowchart showing the procedure of another example of the weight setting process performed by the second weight setting unit in the driving assistance mode. [Figure 17] FIG. 17 is a flowchart showing the procedure of yet another example of the weight setting process performed by the second weight setting unit in the driving assistance mode. [Figure 18] FIG. 18 is a block diagram for explaining another modified example of the motor control ECU. DETAILED DESCRIPTION OF THE INVENTION

[0009] [Description of the embodiment of the present invention] One embodiment of the present invention provides a motor control device for drive control of an electric motor for steering angle control, including an assist torque command value generation unit that generates an assist torque command value using steering torque, a manual steering command value generation unit that generates a manual steering command value using the steering torque and the assist torque command value, an integrated angle command value calculation unit that calculates an integrated angle command value by adding the manual steering command value to an automatic steering command value for driving assistance, and a switching unit that, in a driving assistance mode, switches between a first control mode in which the electric motor is controlled based on the assist torque command value or the manual steering command value and a second control mode in which the electric motor is controlled based on the integrated angle command value, depending on the steering torque.

[0010] In this configuration, it is possible to switch between a first control mode in which the electric motor is controlled based on an assist torque command value or a manual steering command value, and a second control mode in which the electric motor is controlled based on an integrated angle command value, which is the sum of an automatic steering command value for driving assistance and a manual steering command value, depending on the steering torque.

[0011] In one embodiment of the present invention, the proportion of the second control mode increases as the steering torque increases.

[0012] In one embodiment of the present invention, the proportion of the second control mode decreases as the steering torque increases.

[0013] In one embodiment of the present invention, the switching unit is configured to switch between the first control mode and the second control mode based on a steering involvement amount that increases when the steering torque is equal to or greater than a predetermined threshold and decreases when the steering torque is less than the predetermined threshold.

[0014] In one embodiment of the present invention, the switching unit includes a first weighting unit that performs a first weighting process on the assist torque command value based on the steering torque, a second weighting unit that performs a second weighting process on the integrated angle command value based on the steering torque, and a motor torque command value calculation unit that calculates a motor torque command value based on the assist torque command value after the first weighting process and the integrated angle command value after the second weighting process.

[0015] In one embodiment of the present invention, the switching unit includes a third weighting unit that performs a third weighting process on the automatic steering command value based on the steering torque, and a motor torque command value calculation unit that calculates a motor torque command value based on the automatic steering command value after the third weighting process and the manual steering command value.

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

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

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

[0019] The steering shaft 6 includes an input shaft 8 connected to the steering wheel 2 and an output shaft 9 connected to the intermediate shaft 7. The input shaft 8 and the output shaft 9 are connected via a torsion bar 10 so as to be capable of relative rotation.

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

[0021] The steering mechanism 4 is made up of a rack-and-pinion mechanism including a pinion shaft 13 and a rack shaft 14 as a steering shaft. The steered wheels 3 are connected to each end of the rack shaft 14 via tie rods 15 and knuckle arms (not shown). The pinion shaft 13 is connected to the intermediate shaft 7. The pinion shaft 13 rotates in conjunction with the steering of the steering wheel 2. A pinion 16 is connected to the tip of the pinion shaft 13.

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

[0023] When the steering wheel 2 is steered (rotated), this rotation is transmitted to the pinion shaft 13 via the steering shaft 6 and the intermediate shaft 7. The rotation of the pinion shaft 13 is then converted into axial movement of the rack shaft 14 by the pinion 16 and the rack 17. As a result, the steered wheels 3 are steered.

[0024] The steering assist mechanism 5 includes an electric motor 18 for generating a steering assist force (assist torque), and a reducer 19 for amplifying the output torque of the electric motor 18 and transmitting it to the steering mechanism 4. The reducer 19 is made up of a worm gear mechanism including a worm gear 20 and a worm wheel 21 that meshes with the worm gear 20. The reducer 19 is housed in a gear housing 22 that serves as a transmission mechanism housing.

[0025] In the following, the reduction ratio (gear ratio) of the reducer 19 may be expressed as N. The reduction ratio N is determined by the rotation angle of the worm wheel 21, that is, the worm wheel angle θ ww The worm gear angle θ is the rotation angle of the worm gear 20 relative to the wg The ratio (θ wg / θ ww )

[0026] The worm gear 20 is rotationally driven by an electric motor 18. In addition, the worm wheel 21 is connected to the output shaft 9 so as to be integrally rotatable therewith.

[0027] When the worm gear 20 is rotationally driven by the electric motor 18, the worm wheel 21 is rotationally driven, and motor torque is applied to the steering shaft 6, causing the steering shaft 6 (output shaft 9) to rotate. The rotation of the steering shaft 6 is then transmitted to the pinion shaft 13 via the intermediate shaft 7. The rotation of the pinion shaft 13 is converted into axial movement of the rack shaft 14, thereby turning the steered wheels 3. In other words, by rotating the worm gear 20 with the electric motor 18, steering assistance by the electric motor 18 and steering of the steered wheels 3 become 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.

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

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

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

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

[0032] The CCD camera 25, GPS 26, radar 27, map information memory 28, and vehicle speed sensor 29 are connected to a host ECU (Electronic Control Unit) 201 for performing driving assistance control. Based on the information obtained by the CCD camera 25, GPS 26, radar 27, and vehicle speed sensor 29 and map information, the host ECU 201 performs surrounding environment recognition, vehicle position estimation, route planning, etc., and determines control target values ​​for steering and drive actuators.

[0033] In this embodiment, there are two driving modes: a normal mode and a driving assistance mode. In the driving assistance mode, the host ECU 201 controls the automatic steering command value θ adacIn this embodiment, the driving assistance is a lane centering assist (LCA) for maintaining the vehicle position in the center of the lane. adac is the target value of the steering angle for driving the vehicle along the center of the lane. adac is set based on, for example, the vehicle speed, the lateral deviation of the vehicle with respect to the target driving line, and the yaw deviation of the vehicle with respect to the target driving line. adac The process of setting the value is well known, so a detailed description will be omitted here.

[0034] The host ECU 201 also outputs a mode signal S indicating whether the driving mode is the normal mode or the driving assistance mode. mode The mode signal S mode and automatic steering command value θ adac is given to the motor control ECU 202 via the in-vehicle network. d The output signal of the rotation angle sensor 23 is input to the motor control ECU 202. The motor control ECU 202 controls the electric motor 18 based on these input signals and information provided by the host ECU 201.

[0035] FIG. 2 is a block diagram showing the electrical configuration of the motor control ECU 202. As shown in FIG.

[0036] The following mainly describes the operation when the driving mode is the driving assistance mode.

[0037] The motor control ECU 202 includes a microcomputer 40, a drive circuit (inverter circuit) 31 controlled by the microcomputer 40 and supplying power to the electric motor 18, and a current detection circuit 32 for detecting the current flowing through the electric motor 18 (hereinafter referred to as "motor current I").

[0038] The microcomputer 40 includes a CPU and memory (ROM, RAM, nonvolatile memory, etc.), and functions as a plurality of functional processing sections by executing a predetermined program. The plurality of functional processing sections include an assist torque command value setting section 41, a manual steering command value generating section 42, an integrated angle command value calculating section 43, an angle control section 44, a first weight multiplying section 45, a second weight multiplying section 46, an adding section 47, a torque control section (current control section) 48, and a weight setting section 49.

[0039] In this embodiment, the weight setting unit 49 and the first weight multiplication unit 45 are an example of a "first weighting unit" in the present invention. The weight setting unit 49 and the second weight multiplication unit 46 are an example of a "second weighting unit" in the present invention. The adder 47 is an example of a "motor torque command value calculation unit" in the present invention. The weight setting unit 49, the first weight multiplication unit 45, the second weight multiplication unit 46, and the adder 47 are an example of a "switching unit" in the present invention.

[0040] The assist torque command value setting unit 41 sets the assist torque command value T as The assist torque command value setting unit 41 sets the torsion bar torque T d Based on this, the assist torque command value T as Set the torsion bar torque T d Assist torque command value T as An example of the configuration is shown in Figure 3.

[0041] Assist torque command value T as is set to a positive value when the electric motor 18 is to generate a steering assist force for steering to the left, and is set to a negative value when the electric motor 18 is to generate a steering assist force for steering to the right. as is the torsion bar torque T d The torsion bar torque T d The assist torque command value T asis the torsion bar torque T d The larger the absolute value of , the larger the absolute value is set.

[0042] The assist torque command value setting unit 41 acquires the vehicle speed from the host ECU 201 and calculates the vehicle speed and the torsion bar torque T d Based on this, the assist torque command value T as In this case, the assist torque command value T as is the torsion bar torque T d The higher the vehicle speed V, the higher the assist torque command value T as is set so that the absolute value of

[0043] The assist torque command value setting unit 41 determines the torsion bar torque T d is multiplied by a preset constant to obtain the assist torque command value T as may be calculated.

[0044] When the driver operates the steering wheel 2, the manual steering command value generating unit 42 generates a steering angle (more precisely, a rotation angle θ of the output shaft 9) corresponding to the steering wheel operation as a manual steering command value θ mdac The manual steering command value generating unit 42 is provided to set the torsion bar torque T d and the assist torque command value T set by the assist torque command value setting unit 41. as and the manual steering command value θ mdac The manual steering command value generating unit 42 will be described in detail later.

[0045] The integrated angle command value calculation unit 43 calculates the automatic steering command value θ set by the host ECU 201. adac , manual steering command value θ mdac The integrated angle command value θ sint Calculate the following.

[0046] The angle control unit 44 calculates the integrated angle command value θ sintBased on this, the integrated angle command value θ sint The integrated motor torque command value T mint The angle control unit 44 will be described in detail later.

[0047] The first weight multiplier 45 multiplies the assist torque command value T as The second weight multiplier 46 multiplies the integrated motor torque command value T mint is multiplied by the second weight W2. The first weight W1 and the second weight W2 are set by the weight setting unit 49. The operation of the weight setting unit 49 will be described in detail later.

[0048] The adder 47 calculates the assist torque command value W1·T after multiplication by the first weight (after the first weighting process). as and the integrated motor torque command value W2·T after multiplication by the second weight (after second weighting processing) mint By adding these, the motor torque command value T m Calculate the following.

[0049] The torque control unit 48 controls the motor torque of the electric motor 18 to be equal to the motor torque command value T m The driving circuit 31 is driven so that the value approaches .

[0050] In this embodiment, the manual steering command value generating unit 42 uses the reference EPS model to calculate the manual steering command value θ mdac Set.

[0051] FIG. 4 is a schematic diagram showing an example of a reference EPS model used in the manual steering command value generating unit 42.

[0052] This reference EPS model is a single-inertia model including a lower column. The lower column corresponds to the output shaft 9 and the worm wheel 21. In FIG. 4, J c is the inertia of the lower column, and θ c is the rotation angle of the lower column, and T dis the torsion bar torque. The lower column has a torsion bar torque T d , torque N·T acting on the output shaft 9 from the electric motor 18 m and road load torque T rl is given. Road load torque T rl is the spring constant k s and the viscous damping coefficient c, it is expressed by the following equation (1).

[0053] T rl =-k s θ c -c(dθ c / dt) …(1) In this embodiment, the spring constant k s As the viscous damping coefficient c, predetermined values ​​obtained in advance through experiments, analysis, etc. are set.

[0054] The equation of motion of the reference EPS model is expressed by the following equation (2).

[0055] J c ·d 2 θ c / dt 2 =T d +N·T m -k s θ c -c(dθ c / dt) …(2) The manual steering command value generating unit 42 is T d The torsion bar torque T detected by the torque sensor 12 is d Substituting, T m The assist torque command value T set by the assist torque command value setting unit 41 is as By substituting and solving the differential equation (2), the rotation angle θ of the lower column is c Then, the manual steering command value generating unit 42 calculates the obtained rotation angle θ of the lower column. c The manual steering command value θ mdac Generate it as:

[0056] FIG. 5 is a block diagram showing the configuration of the angle control unit 44.

[0057] The angle control unit 44 calculates the integrated angle command value θ sint Based on this, the integrated motor torque command value T mint The angle control unit 44 includes a low-pass filter (LPF) 51, a feedback control unit 52, a feedforward control unit 53, a disturbance torque estimating unit 54, a torque adding unit 55, a disturbance torque compensating unit 56, a first reduction ratio dividing unit 57, a reduction ratio multiplying unit 58, a rotation angle calculating unit 59, and a second reduction ratio dividing unit 60.

[0058] The reduction ratio multiplication unit 58 multiplies the motor torque command value T m is multiplied by the reduction ratio N of the reducer 19 to obtain the motor torque command value T m is the output shaft torque command value N·T acting on the output shaft 9 (worm wheel 21). m Convert to.

[0059] The rotation angle calculation unit 59 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 60 calculates the rotor rotation angle θ calculated by the rotation angle calculation unit 59. m By dividing by the reduction ratio N, the rotor rotation angle θ m is converted into the rotation angle (actual steering angle) θ of the output shaft 9.

[0060] The low-pass filter 51 calculates the integrated angle command value θ sint The integrated angle command value θ after low-pass filtering is sin is given to the feedback control section 52 and the feedforward control section 53.

[0061] The feedback control unit 52 converts the steering angle estimated value ^θ calculated by the disturbance torque estimating unit 54 into an integrated angle command value θ after low-pass filtering. sin The feedback control unit 52 includes an angle deviation calculation unit 52A and a PD control unit 52B. The angle deviation calculation unit 52A calculates an integrated angle command value θ sin and the deviation Δθ(=θsin The angle deviation calculation unit 52A calculates the integrated angle command value θ sin and the deviation (θ sin -θ) may be calculated as the angle deviation Δθ.

[0062] The PD control unit 52B performs a PD calculation (proportional differential calculation) on the angle deviation Δθ calculated by the angle deviation calculation unit 52A, thereby obtaining a feedback control torque T fb Calculate the feedback control torque T fb is given to the torque adder 55.

[0063] The feedforward control unit 53 is provided to compensate for a delay in response due to the inertia of the electric power steering system 1, thereby improving the response of the control. The feedforward control unit 53 includes an angular acceleration calculation unit 53A and an inertia multiplication unit 53B. The angular acceleration calculation unit 53A calculates an integrated angle command value θ sin By taking the second derivative, the target angular acceleration d 2 θ sin / dt 2 Calculate the following.

[0064] The inertia multiplication unit 53B multiplies the target angular acceleration d calculated by the angular acceleration calculation unit 53A by 2 θ sin / dt 2 is multiplied by the inertia J of the electric power steering system 1 to obtain the feedforward control torque T ff (=J·d 2 θ sin / dt 2 The inertia J can be calculated from, for example, a physical model (see FIG. 6) of the electric power steering system 1, which will be described later. The feedforward control torque T ff is given to the torque adder 55 as an inertia compensation value.

[0065] The torque adder 55 calculates the feedback control torque T fb to the feedforward control torque T ffBy adding fb +T ff ) is calculated.

[0066] The disturbance torque estimating unit 54 is provided to estimate a nonlinear torque (disturbance torque: torque other than motor torque) that occurs as a disturbance in the plant (the object to be controlled by the electric motor 18). The disturbance torque estimating unit 54 estimates the output shaft torque command value N·T m and the actual steering angle θ, the disturbance torque (disturbance load) T lc , steering angle θ and steering angle differential value (angular velocity) dθ / dt are estimated. lc , the estimated values ​​of the steering angle θ and the steering angle differential (angular velocity) dθ / dt are respectively ^T lc , ^θ and d^θ / dt. The disturbance torque estimating unit 54 will be described in detail later.

[0067] The disturbance torque estimated value ^T calculated by the disturbance torque estimator 54 lc is given as a disturbance torque compensation value to the disturbance torque compensator 56. The steering angle estimated value ^θ calculated by the disturbance torque estimator 54 is given to the angle deviation calculator 52A.

[0068] The disturbance torque compensator 56 calculates the basic torque command value (T fb +T ff ) to the estimated disturbance torque ^T lc By subtracting sint (=T fb +T ff -^T lc ) is calculated. As a result, the integrated steering torque command value T sint (torque command value for output shaft 9) is obtained.

[0069] Integrated steering torque command value T sint is given to the first reduction ratio division unit 57. The first reduction ratio division unit 57 calculates the integrated steering torque command value T sint By dividing by the reduction ratio N, the integrated motor torque command value T mint This integrated motor torque command value Tmint is given to the second weight multiplication unit 46 (see FIG. 2).

[0070] The disturbance torque estimation unit 54 will be described in detail. The disturbance torque estimation unit 54 uses, for example, a physical model 101 of the electric power steering system 1 shown in FIG. 6 to estimate the disturbance torque T lc , and a disturbance observer that estimates the steering angle θ and the angular velocity dθ / dt.

[0071] This physical model 101 includes a plant (an example of a motor-driven object) 102 including an output shaft 9 and a worm wheel 21 fixed to the output shaft 9. The plant 102 receives a torsion bar torque T d is applied, and a road load torque T rl is given.

[0072] Furthermore, the plant 102 receives an output shaft torque command value N·T via a worm gear 20. m is given, and friction torque T f is given.

[0073] When the inertia of the plant 102 is J, the equation of motion for the inertia of the physical model 101 is expressed by the following equation (3).

[0074]

number

[0075] d 2 θ / dt 2 is the angular acceleration of the plant 102. N is the reduction ratio of the reducer 19. T lc represents a disturbance torque other than the motor torque applied to the plant 102. In this embodiment, the disturbance torque T lc is the torsion bar torque T d and road load torque T rl and friction torque Tf However, in reality, the disturbance torque T lc includes torques other than these.

[0076] The state equation for the physical model 101 in FIG. 6 is expressed by the following equation (4).

[0077]

number

[0078] In the above formula (4), 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). Also, in the above formula (4), A is a system matrix, B1 is a first input matrix, B2 is a second input matrix, C is an output matrix, and D is a direct feedthrough matrix.

[0079] The state equation is expanded to a system including the unknown input vector u2 as one of the states. The state equation of the expanded system (expanded state equation) is expressed by the following equation (5).

[0080]

number

[0081] In the formula (5), x e is the state variable vector of the extended system and is expressed by the following equation (6).

[0082]

number

[0083] In the formula (5), A e is the system matrix of the extended system, B e is the known input matrix of the extended system, and Ce is the output matrix of the extended system.

[0084] From the extended state equation of the above formula (5), a disturbance observer (extended state observer) expressed by the following formula (7) is constructed.

[0085]

number

[0086] In equation (7), ^x e x e represents the estimated value of . Also, L is the observer gain. Also, ^y represents the estimated value of y. ^x e is expressed by the following equation (8).

[0087]

number

[0088] In equation (8), ^θ is the estimated value of θ, and ^T lc is T lc is an estimate of

[0089] The disturbance torque estimation unit 54 calculates the state variable vector ^x based on the equation (7). e Calculate the following.

[0090] FIG. 7 is a block diagram showing the configuration of the disturbance torque estimating section 54. As shown in FIG.

[0091] The disturbance torque estimation unit 54 includes an input vector input unit 71, an output matrix multiplication unit 72, a first addition unit 73, a gain multiplication unit 74, an input matrix multiplication unit 75, a system matrix multiplication unit 76, a second addition unit 77, an integration unit 78, and a state variable vector output unit 79.

[0092] The output shaft torque command value N·T calculated by the reduction ratio multiplication unit 58 (see FIG. 5) m is given to the input vector input unit 71. The input vector input unit 71 outputs the input vector u1.

[0093] The output of the integrator 78 is the state variable vector ^xe (See equation (8) above.) At the start of calculation, the state variable vector ^x e The initial value is given as the state variable vector ^x e The initial value of is, for example, 0.

[0094] The system matrix multiplication unit 76 multiplies the state variable vector ^x e In the system matrix A e The output matrix multiplication unit 72 multiplies the state variable vector ^x e into the output matrix C e Multiply by.

[0095] The first adder 73 calculates the output (C e ^x e ) is subtracted from the output vector y. That is, the first adder 73 subtracts the output vector estimate ^y(=C e ^x e The gain multiplication unit 74 multiplies the output (y-^y) of the first addition unit 73 by the observer gain L (see equation (7) above).

[0096] The input matrix multiplication unit 75 multiplies the input vector u1 output from the input vector input unit 71 by the input matrix B e The second adder 77 multiplies the output (B e u1) and the output of the system matrix multiplication unit 76 (A e ^x e ) and the output (L(y-^y)) of the gain multiplication unit 74, the differential value d^x of the state variable vector is obtained. e The integrator 78 calculates the output (d^x e / dt), the state variable vector ^x e The state variable vector output unit 79 calculates the state variable vector ^x e Based on this, the disturbance torque estimate ^T lc , the steering angle estimated value ^θ and the angular velocity estimated value d^θ / dt are calculated.

[0097] Unlike the extended state observer described above, a general disturbance observer consists of an inverse model of the plant and a low-pass filter. The equation of motion of the plant is expressed by equation (3) as described above. Therefore, the inverse model of the plant is expressed by the following equation (9).

[0098]

number

[0099] The input to a typical disturbance observer is J d 2 θ / dt 2 and N.T. m and uses the second-order differential value of the actual steering angle θ, so it is significantly affected by noise from the rotation angle sensor 23. In contrast, the extended state observer of the above-described embodiment estimates the disturbance torque in an integral manner, so it is possible to reduce the influence of noise due to differentiation.

[0100] The disturbance torque estimating unit 64 may be a general disturbance observer that is configured from an inverse model of the plant and a low-pass filter.

[0101] FIG. 8 is a schematic diagram showing the configuration of the torque control unit 48.

[0102] The torque control unit 48 (see FIG. 2) includes a motor current command value calculation unit 81, a current deviation calculation unit 82, a PI control unit 83, and a PWM (Pulse Width Modulation) control unit 84.

[0103] The motor current command value calculation unit 81 calculates the motor torque command value T m The torque constant K of the electric motor 18 t By dividing by, the motor current command value I cmd Calculate the following.

[0104] The current deviation calculation unit 82 calculates the motor current command value I obtained by the motor current command value calculation unit 81. cmdand the deviation ΔI (=I cmd -I).

[0105] The PI control unit 83 performs a PI calculation (proportional integral calculation) on the current deviation ΔI calculated by the current deviation calculation unit 82, thereby controlling the motor current I flowing through the electric motor 18 to a motor current command value I cmd The PWM control unit 84 generates a PWM control signal with a duty ratio corresponding to the drive command value and supplies it to the drive circuit 31. As a result, power corresponding to the drive command value is supplied to the electric motor 18.

[0106] FIG. 9 is a flowchart showing the procedure of the weight setting process performed by the weight setting unit 49 in the driving assistance mode.

[0107] When the driving mode is changed to the driving assistance mode, the weight setting unit 49 performs an initial setting (step S1). In the initial setting, the weight setting unit 49 sets the operation involvement amount D e_norm , counter value k and previous counter value k prev The weight setting unit 49 sets the first weight W1 to 1 and the second weight W2 to 0. e_norm takes a value in the range 0 to 1.

[0108] When the driving mode is changed to the driving assistance mode, the host ECU 201 controls the automatic steering command value θ adac is set, and the automatic steering command value θ adac is given to the motor control ECU 202.

[0109] Next, the weight setting unit 49 calculates the torsion bar torque T d Absolute value of |T d | is a predetermined first threshold T th1 It is determined whether or not it is equal to or greater than this (step S2).

[0110] |T d |≧Tth1 If so (step S2: YES), the weight setting unit 49 sets the current counter value k to the previous counter value k prev After storing the result as k, the weight setting unit 49 increments the counter value k by 1 (+1) (step S3). Then, the weight setting unit 49 proceeds to step S5.

[0111] In step S2, |T d | <T th1 If it is determined that the current counter value k is equal to the previous counter value k (step S2: NO), the weight setting unit 49 sets the current counter value k to the previous counter value k prev After storing the result as k, the weight setting unit 49 decrements the counter value k by 1 (-1) (step S4). Then, the weight setting unit 49 proceeds to step S5.

[0112] In step S5, the operation involvement amount D e_norm is calculated based on the following equation (10).

[0113] if 0 <X<1 then D e_norm =X if X≧1 then D e_norm =1 if X≦0 then D e_norm =0 X=k Δt / D e_base …(10) In equation (10), Δt is the calculation period [sec], and D e_base is the operation involvement reference time [sec]. The processing of steps S2 to S8 in Fig. 9 is repeatedly executed at predetermined time intervals. This predetermined time is the calculation cycle Δt.

[0114] In the procedure of FIG. 9, the operation involvement reference time D e_base is the change from the state where the first weight W1 is 1 and the second weight W2 is 0 to the state where the steering wheel 2 is being operated (|T d |≧T th1 The state of the time D e_base The operation involvement reference time D is a predetermined time for setting the first weight W1 to 0 and the second weight W2 to 1 when the operation involvement reference time D has continued for more than 10 seconds. e_baseis the change from the state where the first weight W1 is 0 and the second weight W2 is 1 to the state where the steering wheel 2 is not being operated (|T d | <T th1 The state of the time D e_base This is also the time for setting the first weight W1 to 1 and the second weight W2 to 0 when the above continues.

[0115] Next, the weight setting unit 49 determines whether or not the saturation condition of X≦0 or X≧1 is satisfied (step S6). If the saturation condition is satisfied (step S6: YES), the weight setting unit 49 sets the previous counter value k prev The weight setting unit 49 sets the pre-update count value k stored as k (step S7). If it is determined that the saturation condition is satisfied, the count value k is returned to the count value before being updated in step S3 or S4. Then, the weight setting unit 49 proceeds to step S8.

[0116] If it is determined in step S6 that the saturation condition is not satisfied (step S6: NO), the weight setting unit 49 proceeds to step S8.

[0117] In step S8, the weight setting unit 49 calculates the first weight W1 and the second weight W2 based on the following equation (11), sets the obtained first weight W1 in the first weight multiplication unit 45, and sets the obtained second weight W2 in the second weight multiplication unit 46. Then, the weight setting unit 49 returns to step S2.

[0118] W1=1-D e_norm W2=D e_norm …(11) When the driving mode is the normal mode, the weight setting unit 49 sets the first weight W1 to 1 and the second weight W2 to 0. Therefore, in the normal mode, the assist torque command value T as The electric motor 18 is controlled based only on the above.

[0119] In the procedure of Fig. 9, the driver's operational involvement De_norm When becomes larger, the assist torque command value T as The first weight W1 for the integrated motor torque command value T mint On the other hand, the second weight W2 for the driver's operation involvement D e_norm When becomes smaller, the assist torque command value T as The first weight W1 for the integrated motor torque command value T mint The second weight W2 for

[0120] This allows the driver to recognize that the driving assistance (LCA in this embodiment) will be canceled if the steering wheel is not operated. This encourages the driver to maintain steering wheel operation in the driving assistance mode. It also prevents the driving assistance (LCA in this embodiment) function from being activated when the steering wheel is not being operated, allowing for safer driving even when the reliability of the driving assistance system is low.

[0121] Furthermore, a driver who is aware that the driving assistance will be cancelled if the steering wheel is not operated will actively operate the steering wheel 2. However, in a typical vehicle, if the torsion bar torque becomes large, the driving assistance will be cancelled by an override. In this embodiment, when the steering wheel operation is continued, the integrated motor torque command value T mint Since the electric motor 18 is driven and controlled based on the steering wheel operation, steering based on the driver's steering wheel operation is possible. Therefore, in this embodiment, there is no need to cancel the driving assistance based on the driver's steering wheel operation, and therefore cancellation (override) of the driving assistance based on the steering wheel operation is not performed.

[0122] FIG. 10 is a flowchart showing the procedure of another example of the weight setting process performed by the weight setting unit in the driving assistance mode.

[0123] In FIG. 10, steps that are the same as those in FIG. 9 are denoted by the same step numbers as those in FIG.

[0124] In the procedure of Figure 10, the operation involvement reference time D e_base The first operation reference time D for changing the first weight W1 from 1 to 0 (the second weight W2 from 0 to 1) is e_base_AD and the second operation reference time D for changing the first weight W1 from 0 to 1 (the second weight W2 from 1 to 0). e_base_MD are preset.

[0125] D e_base_AD is the change from the state where the first weight W1 is 1 (the second weight W2 is 0) to the state where the steering wheel 2 is being operated (|T d |≧T th1 The state of the time D e_base_AD This is the time for setting the first weight W1 to 0 (and the second weight W2 to 1) when the time has elapsed since the start of the test, and is set in advance. e_base_MD is the change from the state where the first weight W1 is 0 (the second weight W2 is 1) to the state where the steering wheel 2 is not being operated (|T d | <T th1 The state of the time D e_base_MD This is the time for setting the first weight W1 to 1 (and the second weight W2 to 0) when the current continues for more than this period, and is set in advance.

[0126] In the procedure in Figure 10, D e_base_AD is the amount of operation involved D e_norm is the time set when the value is increasing, and D e_base_MD is the amount of operation involved D e_norm This is the time set when the value is decreasing.

[0127] In step S2, |T d |≧T th1 If it is determined that the operation participation amount D e_norm The operation involvement reference time D used to calculate e_base As the first operation involvement reference time D e_base_AD(Step S21). Then, the weight setting unit 49 proceeds to Step S3.

[0128] On the other hand, in step S2, |T d | <T th1 If it is determined that the operation participation amount D e_norm The operation involvement reference time D used to calculate e_base As the second operation involvement reference time D e_base_MD (Step S22). Then, the weight setting unit 49 proceeds to Step S4. The steps other than Step S21 and Step S22 are the same as those in FIG.

[0129] When driving assistance is emphasized, the first operation involvement reference time D e_base_AD The second operation reference time D e_base_MD In this case, the torsion bar torque T tb is the first threshold T th1 Once this is reached, the driving assistance is activated immediately. tb is the first threshold T th1 Even if the vehicle is in a state where the vehicle is not moving, driving assistance will continue to be provided to a certain extent.

[0130] When the driver's steering wheel operation is emphasized, the second operation involvement reference time D e_base_MD The first operation reference time D e_base_AD In this case, the torsion bar torque T tb is the first threshold T th1 If it falls below this level, the driver assistance is quickly disabled.

[0131] The procedure in FIG. 10 also provides the same effect as the procedure in FIG.

[0132] FIG. 11 is a flowchart showing the procedure of yet another example of the weight setting process performed by the weight setting unit 49 in the driving assistance mode.

[0133] When the driving mode is changed to the driving assistance mode, the weight setting unit 49 performs an initial setting (step S101). In the initial setting, the weight setting unit 49 sets the operation involvement amount D e_norm is set to 0, and the counter value k and the previous counter value k prev The weight setting unit 49 sets the first weight W1 to 0 and the second weight W2 to 1. e_norm takes a value in the range 0 to 1.

[0134] When the driving mode is changed to the driving assistance mode, the host ECU 201 controls the automatic steering command value θ adac is set, and the automatic steering command value θ adac is given to the motor control ECU 202.

[0135] Next, the weight setting unit 49 calculates the torsion bar torque T d Absolute value of |T d | is a predetermined second threshold T th2 It is determined whether or not it is equal to or greater than this (step S102).

[0136] |T d |≧T th2 If so (step S102: YES), the weight setting unit 49 sets the current counter value k to the previous counter value k prev After saving the result as k, the weight setting unit 49 increments the counter value k by 1 (+1) (step S103). Then, the weight setting unit 49 proceeds to step S105.

[0137] In step S102, |T d | <T th2 If it is determined that the current counter value k is equal to the previous counter value k (step S102: NO), the weight setting unit 49 sets the current counter value k to the previous counter value k prev After storing the result as k, the weight setting unit 49 decrements the counter value k by 1 (-1) (step S104). Then, the weight setting unit 49 proceeds to step S105.

[0138] In step S105, the operation involvement amount De_norm is calculated based on the following equation (12).

[0139] if 0 <X<1 then D e_norm =X if X≧1 then D e_norm =1 if X≦0 then D e_norm =0 X=k Δt / D e_base …(12) In equation (12), Δt is the calculation period [sec], and D e_base is the operation involvement reference time [sec]. The processing of steps S102 to S108 in Fig. 11 is repeatedly executed at predetermined time intervals. This predetermined time is the calculation cycle Δt.

[0140] In the procedure of FIG. 11, the operation involvement reference time D e_base is the change from the state where the first weight W1 is 0 and the second weight W2 is 1 to the state where the steering wheel 2 is being operated (|T d |≧T th2 The state in which e_base The operation involvement reference time D is a predetermined time for setting the first weight W1 to 1 and the second weight W2 to 0 when the operation involvement reference time D has continued for more than 10 seconds. e_base is the change from the state where the first weight W1 is 1 and the second weight W2 is 0 to the state where the steering wheel 2 is not being operated (|T d | <T th2 The state in which e_base This is also the time for setting the first weight W1 to 0 and the second weight W2 to 1 when the above continues.

[0141] Next, the weight setting unit 49 determines whether or not the saturation condition of X≦0 or X≧1 is satisfied (step S106). If the saturation condition is satisfied (step S106: YES), the weight setting unit 49 sets the previous counter value k prevThe weight setting unit 49 sets the pre-update count value k stored as k (step S107). If it is determined that the saturation condition is satisfied, the count value k is returned to the count value before being updated in step S103 or S104. Then, the weight setting unit 49 proceeds to step S108.

[0142] If it is determined in step S106 that the saturation condition is not satisfied (step S106: NO), the weight setting unit 49 proceeds to step S108.

[0143] In step S108, the weight setting unit 49 calculates the first weight W1 and the second weight W2 based on the following equation (13), sets the obtained first weight W1 in the first weight multiplication unit 45, and sets the obtained second weight W2 in the second weight multiplication unit 46. Then, the weight setting unit 49 returns to step S102.

[0144] W1=D e_norm W2=1-D e_norm …(13) When the driving mode is the normal mode, the weight setting unit 49 sets the first weight W1 to 1 and the second weight W2 to 0. Therefore, in the normal mode, the assist torque command value T as The electric motor 18 is controlled based only on the above.

[0145] In the procedure of Fig. 11, the driver's operational involvement D e_norm When becomes larger, the assist torque command value T as The first weight W1 for the integrated motor torque command value T mint On the other hand, the second weight W2 for the driver's operation involvement D e_norm When becomes smaller, the assist torque command value T as The first weight W1 for the integrated motor torque command value T mint The second weight W2 for

[0146] This allows the driver to substantially disable (override) the driving assistance when performing steering intervention (manual driving) in the driving assistance mode. This makes it easier to perform steering intervention in the driving assistance mode. Note that, since the procedure in FIG. 11 substantially disables the driving assistance when the driver is performing steering intervention in the driving assistance mode, it is important to detect that the driver is certainly involved in steering wheel operation. Therefore, the second threshold T th2 is the first threshold T th1 It is preferable to set it to a value greater than

[0147] In addition, when the driver is not intervening in the operation, the driving assistance is enabled, so if the reliability of the driving assistance system is high, the vehicle can be driven safely even when the driver is not involved in the operation.

[0148] FIG. 12 is a flowchart showing the procedure of yet another example of the weight setting process performed by the weight setting unit in the driving assistance mode.

[0149] In FIG. 12, steps that are the same as those in FIG. 11 are denoted by the same step numbers as those in FIG.

[0150] In the procedure of Fig. 12, the operation involvement reference time D e_base The first operation reference time D for changing the first weight W1 from 1 to 0 (the second weight W2 from 0 to 1) is e_base_AD and the second operation reference time D for changing the first weight W1 from 0 to 1 (the second weight W2 from 1 to 0). e_base_MD are preset.

[0151] D e_base_MD is the change from the state where the first weight W1 is 0 (the second weight W2 is 1) to the state where the steering wheel 2 is being operated (|T d |≧T th2 The state of the time D e_base_MDThis is the time for setting the first weight W1 to 1 (and the second weight W2 to 0) when the time has continued for more than this period, and is set in advance. e_base_AD is the change from the state where the first weight W1 is 1 (the second weight W2 is 0) to the state where the steering wheel 2 is not being operated (|T d | <T th2 The state of the time D e_base_AD This is the time for setting the first weight W1 to 0 (and the second weight W2 to 1) when the current continues for more than this period, and is set in advance.

[0152] In the procedure in Figure 12, e_base_MD is the amount of operation involved D e_norm is the time set when the value is increasing, and D e_base_AD is the amount of operation involved D e_norm This is the time set when the value is decreasing.

[0153] In step S102, |T d |≧T th2 If it is determined that the operation participation amount D e_norm The operation involvement reference time D used to calculate e_base As the second operation involvement reference time D e_base_MD (step S121). Then, the weight setting unit 49 proceeds to step S103.

[0154] On the other hand, in step S102, |T d | <T th2 If it is determined that the operation participation amount D e_norm The operation involvement reference time D used to calculate e_base As the first operation involvement reference time D e_base_AD (step S122). Then, the weight setting unit 49 proceeds to step S104. The steps other than steps S121 and S122 are the same as those in FIG.

[0155] When driving assistance is emphasized, the first operation involvement reference time D e_base_AD The second operation reference time De_base_MD In this case, the torsion bar torque T tb is the second threshold T th2 When the torque reaches below this value, the driving assistance is activated immediately. tb is the second threshold T th2 Even in the above situations, driving assistance continues to a certain extent.

[0156] When the driver's steering wheel operation is emphasized, the second operation involvement reference time D e_base_MD The first operation reference time D e_base_AD In this case, the torsion bar torque T tb is the second threshold T th2 If this happens, the driving assistance will be quickly disabled. tb is the second threshold T th2 Even if the vehicle is in a state where the vehicle is not in a safe state, the driving assistance will remain disabled to some extent.

[0157] The procedure in FIG. 12 also provides the same effect as the procedure in FIG.

[0158] Fig. 13 is a block diagram for explaining a modified example of motor control ECU 202. In Fig. 13, parts corresponding to those in Fig. 2 described above are denoted by the same reference numerals as those in Fig. 2.

[0159] In this motor control ECU 202, the automatic steering command value θ adac A third weight multiplication unit 50 is provided between the input terminal (not shown) of the integrated angle command value calculation unit 43 and the integrated angle command value calculation unit 43 .

[0160] Automatic steering command value θ given by the host ECU 201 adac is input to the third weight multiplication unit 50. The third weight multiplication unit 50 multiplies the automatic steering command value θ adac is multiplied by the third weight W3. The automatic steering command value W3·θ after multiplication by the third weight adac is given to the integrated angle command value calculation unit 43. The integrated angle command value calculation unit 43 calculates the automatic steering command value W3·θ after multiplication by the third weight. adac, the manual steering command value θ generated by the manual steering command value generating unit 42 mdac The integrated angle command value θ sint The angle control unit 44 calculates the integrated angle command value θ sint Based on this, the integrated angle command value θ sint The integrated motor torque command value T mint Calculate the following.

[0161] The adder 47 calculates the integrated motor torque command value W2·T after the second weighting addition. mint , the assist torque command value W1·T after the first weighting is added as By adding m Calculate the following.

[0162] The first weight W1 and the second weight W2 are set by the first weight setting unit 49 A. The third weight W3 is set by the second weight setting unit 49 B. When the driving mode is the driving assistance mode, the first weight setting unit 49 A sets the first weight W1 to 0 and the second weight W2 to 1.

[0163] The operation of the second weight setting unit 49B will be described.

[0164] Fig. 14 is a flowchart showing the procedure of the weight setting process performed by the second weight setting unit 49B in the driving assistance mode. The procedure in Fig. 14 is similar to the procedure in Fig. 9. In Fig. 14, the same steps as those in Fig. 9 are assigned the same step numbers as those in Fig. 9.

[0165] 14 differs from FIG. 9 in that step S1A corresponds to step S1 in FIG. 9 and step S8A corresponds to step S8 in FIG.

[0166] In step S1A, the second weight setting unit 49B calculates the operation involvement amount D e_norm , counter value k and previous counter value k prev The second weight setting unit 49B sets the third weight W3 to 0.

[0167] In step S8A, the second weight setting unit 49B calculates the third weight W3 based on the following equation (14) and sets it in the third weight multiplication unit 50.

[0168] W3=D e_norm …(14) In the driving assistance mode, the assist torque command value T as The first weight W1 for the integrated motor torque command value T mint The second weight W2 for the driver's operation involvement D e_norm When becomes larger, the automatic steering command value θ adac On the other hand, the third weight W3 for the driver's operation involvement D e_norm When becomes smaller, the automatic steering command value θ adac The third weight W3 for

[0169] This allows the driver to recognize that the driving assistance (LCA in this embodiment) will be canceled if there is no steering wheel operation. This encourages the driver to maintain steering wheel operation in the driving assistance mode. It also prevents the driving assistance (LCA in this embodiment) function from being activated when there is no steering wheel operation, allowing for safer driving even when the reliability of the driving assistance system is low.

[0170] When the driving mode is the normal mode, the first weight setting unit 49A sets the first weight W1 to 1 and the second weight W2 to 0. The second weight setting unit 49B sets the third weight W3 to 0 or 1. As a result, in the normal mode, the assist torque command value T as The electric motor 18 is controlled based only on the above.

[0171] In the normal mode, the first weight setting unit 49A may set the first weight W1 to 0, the second weight W2 to 1, and the second weight setting unit 49B may set the third weight W3 to 0. In this way, in the normal mode, the manual steering command value θ set by the manual steering command value setting unit 42 mdacThe electric motor 18 is controlled based on the angle control according to the above.

[0172] In the driving assistance mode, the second weight setting unit 49B may set the third weight W3 according to the procedure shown in Fig. 15. The procedure in Fig. 15 is similar to the procedure in Fig. 10. In Fig. 15, steps that are the same as those in Fig. 10 are assigned the same step numbers as those in Fig. 10.

[0173] However, D e_base_AD is the state where the third weight W3 is 0, and the state where the steering wheel 2 is being operated (|T d |≧T th1 The state of the time D e_base_AD This is the time for setting the third weight W3 to 1 when the time has continued for more than this period, and is set in advance. e_base_MD is the change from the state where the third weight W3 is 1 to the state where the steering wheel 2 is not being operated (|T d | <T th1 The state of the time D e_base_MD This is the time for setting the third weight W3 to 0 if the occurrence of a fault continues for more than this period, and is set in advance.

[0174] That is, D e_base_AD is the amount of operation involved D e_norm is the time set when the value is increasing, and D e_base_MD is the amount of operation involved D e_norm This is the time set when the value is decreasing.

[0175] 15 differs from FIG. 10 in step S1A corresponding to step S1 in FIG. 10 and step S8A corresponding to step S8 in FIG.

[0176] In step S1A, the second weight setting unit 49B calculates the operation involvement amount D e_norm , counter value k and previous counter value k prev The second weight setting unit 49B sets the third weight W3 to 0.

[0177] In step S8A, the second weight setting unit 49B calculates the third weight W3 based on the above equation (14) and sets it in the third weight multiplication unit 50.

[0178] The procedure in FIG. 15 also provides the same effect as the procedure in FIG.

[0179] Fig. 16 is a flowchart showing the procedure of yet another example of the weight setting process performed by the second weight setting unit 49B in the driving assistance mode. The procedure of Fig. 16 is similar to the procedure of Fig. 11 described above. In Fig. 16, the same steps as those in Fig. 11 are assigned the same step numbers as those in Fig. 11.

[0180] 16 differs from FIG. 11 in step S101A corresponding to step S101 in FIG. 11 and step S108A corresponding to step S108 in FIG.

[0181] In step S101A, the second weight setting unit 49B calculates the operation involvement amount D e_norm is set to 0, and the counter value k and the previous counter value k prev The second weight setting unit 49B sets the third weight W3 to 1.

[0182] In step S108A, the second weight setting unit 49B calculates the third weight W3 based on the following equation (15) and sets it in the third weight multiplication unit 50.

[0183] W3=(1-D e_norm ) …(15) In the driving assistance mode, the assist torque command value T as The first weight W1 for the integrated motor torque command value T mint The second weight W2 for the driver's operation involvement D e_norm When becomes larger, the automatic steering command value θ adac On the other hand, the third weight W3 for the driver's operation involvement D e_norm When becomes smaller, the automatic steering command value θ adacThe third weight W3 for

[0184] This allows the driver to substantially disable (override) the driving assistance when performing steering intervention (manual driving) in the driving assistance mode. This makes it easier to perform steering intervention in the driving assistance mode. Note that, since the procedure in FIG. 16 substantially disables the driving assistance when the driver is intervening in steering in the driving assistance mode, it is important to detect that the driver is certainly involved in steering wheel operation. Therefore, the second threshold T th2 is the first threshold T th1 It is preferable to set it to a value greater than

[0185] In addition, when the driver is not intervening in the operation, the driving assistance is enabled, so if the reliability of the driving assistance system is high, the vehicle can be driven safely even when the driver is not involved in the operation.

[0186] When the driving mode is the normal mode, the first weight setting unit 49A sets the first weight W1 to 1 and the second weight W2 to 0. The second weight setting unit 49B sets the third weight W3 to 0 or 1. As a result, in the normal mode, the assist torque command value T as The electric motor 18 is controlled based only on the above.

[0187] In the normal mode, the first weight setting unit 49A may set the first weight W1 to 0, the second weight W2 to 1, and the second weight setting unit 49B may set the third weight W3 to 0. In this way, in the normal mode, the manual steering command value θ set by the manual steering command value setting unit 42 mdac The electric motor 18 is controlled based on the angle control according to the above.

[0188] In the driving assistance mode, the second weight setting unit 49B may set the third weight W3 according to the procedure shown in Fig. 17. The procedure in Fig. 17 is similar to the procedure in Fig. 12. In Fig. 17, steps that are the same as those in Fig. 12 are assigned the same step numbers as those in Fig. 12.

[0189] However, D e_base_MD is the state where the third weight W3 is 1, and the state where the steering wheel 2 is being operated (|T d |≧T th2 The state of the time D e_base_MD This is the time for setting the third weight W3 to 0 when the time has elapsed since the start of the test, and is set in advance. e_base_AD is the change from the state where the third weight W3 is 0 to the state where the steering wheel 2 is not being operated (|T d | <T th2 The state of the time D e_base_AD This is the time for setting the third weight W3 to 1 when the occurrence of a fault continues for more than this period, and is set in advance.

[0190] In the procedure in Figure 17, e_base_MD is the amount of operation involved D e_norm is the time set when the value is increasing, and D e_base_AD is the amount of operation involved D e_norm This is the time set when the value is decreasing.

[0191] 17 differs from FIG. 12 in step S101A corresponding to step S101 in FIG. 12 and step S108A corresponding to step S108 in FIG.

[0192] In step S101A, the second weight setting unit 49B calculates the operation involvement amount D e_norm is set to 0, and the counter value k and the previous counter value k prev The second weight setting unit 49B sets the third weight W3 to 1.

[0193] In step S108A, the second weight setting unit 49B calculates the third weight W3 based on the above equation (15) and sets it in the third weight multiplication unit 50.

[0194] The procedure in FIG. 17 also provides the same effect as the procedure in FIG.

[0195] Second weight setting unit 49B and third weight multiplication unit 50 in Fig. 13 are an example of the "third weighting processing unit" in the present invention. Integrated angle command value calculation unit 43, angle control unit 44, and adder 47 in Fig. 13 are an example of the "motor torque command value calculation unit" in the present invention. Second weight setting unit 49B, third weight multiplication unit 50, integrated angle command value calculation unit 43, angle control unit 44, and adder 47 in Fig. 13 are an example of the "switching unit" in the present invention.

[0196] Figure 18 is a block diagram for explaining another modified example of motor control ECU 202. In Figure 18, parts corresponding to parts in Figure 13 described above are denoted by the same reference numerals as those in Figure 13.

[0197] This motor control ECU 202 does not have the first weight multiplication unit 45, the second weight multiplication unit 45, the adder 47, and the first weight multiplication unit 49A in the motor control ECU 202 of FIG. 13. Also, a weight setting unit 49C is provided instead of the second weight setting unit 49B in FIG. 13. In this modification, the integrated motor torque command value T mint is the motor torque command value T m This becomes:

[0198] The weight setting unit 49C sets the third weight W3. The operation of the weight setting unit 49C in the driving assistance mode is the same as the operation of the second weight setting unit 49B in Fig. 13, and therefore a description thereof will be omitted. In the normal mode, the weight setting unit 49C sets the third weight W3 to 0.

[0199] Second weight setting unit 49C and third weight multiplication unit 50 in Fig. 18 are an example of the "third weighting processing unit" in the present invention. Integrated angle command value calculation unit 43 and angle control unit 44 in Fig. 18 are an example of the "motor torque command value calculation unit" in the present invention. Weight setting unit 49C, third weight multiplication unit 50, and integrated angle command value calculation unit 43 in Fig. 18 are an example of the "switching unit" in the present invention.

[0200] Although the embodiment and the modified examples of the present invention have been described above, the present invention can be embodied in other forms. For example, in the above-described embodiment, in step S2 of Figs. 9, 10, 14 and 15, the torsion bar torque T tb Absolute value of |T tb | is the first threshold T th1 However, when the estimated value of the driver torque acting on the steering wheel 2 is equal to or greater than the first threshold T th1 It may be determined whether the driver torque is equal to or greater than the predetermined value. As the driver torque estimated value, for example, a tri-torque estimated value estimated by the "tri-torque estimating unit" described in Japanese Patent Application Laid-Open No. 2017-114324 can be used. In this case, the driver torque estimated value is an example of the "steering torque" in the "switching unit that switches in accordance with the steering torque" of the present invention.

[0201] Similarly, in the above-described embodiment, in step S102 of FIGS. 11, 12, 16, and 17, the torsion bar torque T tb Absolute value of |T tb | is the second threshold T th2 However, when the estimated value of the driver torque acting on the steering wheel 2 is equal to or greater than the second threshold T th2 It may be determined whether or not the value is equal to or greater than this.

[0202] 2 and 13, the assist torque command value T as is multiplied by the first weight W1, and the assist torque command value after multiplication by the first weight W1·T as is given to the adder 47. However, instead of this, the manual steering command value θ mdacmay be multiplied by a first weight W1, and the manual steering command value after multiplication with the first weight W1 may be provided to the adder 43.

[0203] In the above embodiment, the angle control unit 44 (see FIG. 5) includes the feedforward control unit 53, but the feedforward control unit 53 may be omitted. In this case, the feedback control torque T calculated by the feedback control unit 52 is fb is the basic target torque.

[0204] In addition, although the above-described embodiment shows an example in which the present invention is applied to a column-type EPS, the present invention can also be applied to EPSs other than column types. The present invention can also be applied to steer-by-wire systems.

[0205] Although the embodiments of the present invention have been described in detail, these are merely examples used to clarify the technical contents of the present invention, and the present invention should not be construed as being limited to these examples, and the scope of the present invention is limited only by the appended claims.

[0206] This application corresponds to an international patent application (PCT / JP2021 / 037906) filed with the Japan Patent Office as a receiving office on October 13, 2021, the entire disclosure of which is incorporated herein by reference. [Explanation of symbols]

[0207] 1... electric power steering device, 3... steered wheels, 4... steering mechanism, 18... electric motor, 41... assist torque command value setting unit, 42... manual steering command value generation unit, 43... integrated angle command value calculation unit, 44... angle control unit, 45... first weight multiplication unit, 46... second weight multiplication unit, 47... addition unit, 48... torque control unit, 49, 49A, 49B... weight setting unit, 50... third weight multiplication unit

Claims

1. A motor control device for driving and controlling an electric motor for steering angle control, an assist torque command value generating unit that generates an assist torque command value using the steering torque; a manual steering command value generating unit that generates a manual steering command value using the steering torque and the assist torque command value; an integrated angle command value calculation unit that calculates an integrated angle command value by adding the manual steering command value to an automatic steering command value for driving assistance; a switching unit that switches, in a driving assistance mode, between a first control mode in which the electric motor is controlled based on the assist torque command value or the manual steering command value, and a second control mode in which the electric motor is controlled based on the integrated angle command value, in accordance with the steering torque.

2. The motor control device according to claim 1 , wherein the proportion of the second control mode increases as the steering torque increases.

3. The motor control device according to claim 1 , wherein the proportion of the second control mode decreases as the steering torque increases.

4. 4. The motor control device according to claim 1, wherein the switching unit is configured to switch between the first control mode and the second control mode based on a steering involvement amount that increases when the steering torque is equal to or greater than a predetermined threshold and decreases when the steering torque is less than the predetermined threshold.

5. The switching unit is a first weighting unit that performs a first weighting process on the assist torque command value based on the steering torque; a second weighting unit that performs a second weighting process on the integrated angle command value based on the steering torque; 2. The motor control device according to claim 1, further comprising: a motor torque command value calculation unit that calculates a motor torque command value based on the assist torque command value after the first weighting process and the integrated angle command value after the second weighting process.

6. The switching unit is a third weighting unit that performs a third weighting process on the automatic steering command value based on the steering torque; 2. The motor control device according to claim 1, further comprising: a motor torque command value calculation unit that calculates a motor torque command value based on the automatic steering command value after the third weighting process and the manual steering command value.

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