Motor control device

Abstract

A control unit according to the present invention includes a target driver torque calculation unit that calculates a target driver torque that is to be inputted to a steering member by a driver, a target integrated driver torque calculation unit that can calculate a post-add-on target driver torque that is obtained by adding a target add-on reaction torque to the target driver torque, a feedback control unit that calculates a feedback control torque by performing torque feedback control such that steering torque tracks the target integrated driver torque, a target manual steering angle calculation unit that calculates a target manual steering angle on the basis of the feedback control torque and the steering torque, and an angle control unit that calculates a target motor torque by performing angle feedback control such that an actual steering angle tracks a target integrated steering angle that is obtained by adding a target automatic steering angle to the target manual steering angle.

Description

Motor control device

[0001] This disclosure relates to a motor control device.

[0002] Patent Document 1 discloses a motor control ECU comprising: an integrated angle command value calculation unit that calculates an integrated angle command value by adding an automatic steering command value to a manual steering command value; and a switching unit that switches between a first control that controls the electric motor based only on an assist torque command value and a second control that controls the electric motor based on an integrated angle command value, based on a switching signal.

[0003] Patent Document 2 discloses a steering control device comprising: a basic assist component calculation unit that calculates a basic assist component by torque feedback control to make the steering torque follow a torque command value; an angle command value calculation unit that calculates an angle command value based on the basic assist component, steering torque, and pinion angle; and an angle feedback control unit that calculates an assist command value by angle feedback control to make the pinion angle follow an angle command value.

[0004] International Publication No. 2023 / 286169, International Publication No. 2019 / 087864, International Publication No. 2024 / 218852, Japanese Patent Publication No. 2019-182393

[0005] In the motor control ECU described in Patent Document 1, the relationship between steering torque and control steering angle is uniquely determined by a manual steering command value generation unit, etc. On the other hand, in hierarchical architecture, there is no structure that allows an arbitrary steering reaction force to be given to the motor control ECU by a higher-level domain ECU, and the steering reaction force cannot be controlled by the higher-level domain ECU.

[0006] The purpose of this disclosure is to provide a motor control device that enables the steering reaction force to be controlled by a control device higher than the motor control device.

[0007] [Amendment under Rule 91 28.11.2025] One embodiment of the present disclosure comprises a steering mechanism mechanically connected to a steering member for steering the steering wheels of a vehicle; an electric motor for applying motor torque to the steering mechanism; and a control unit that calculates a target motor torque based on an external input and controls the electric motor, the input including steering torque, a target automatic steering angle and a target add-on reaction torque to assist the driver's operation, the control unit comprising a target driver torque calculation unit for calculating a target driver torque to be input by the driver to the steering member, and a target integrated torque which is the target driver torque plus the target add-on reaction torque. A motor control device is provided, which includes a target integrated driver torque calculation unit capable of calculating the steering torque; a feedback control unit that calculates a feedback control torque by performing torque feedback control so that the steering torque follows the target integrated driver torque; a target manual steering angle calculation unit that calculates a target manual steering angle based on the feedback control torque and the steering torque; and an angle control unit that calculates the target motor torque by performing angle feedback control so that the actual steering angle follows the target integrated steering angle obtained by adding the target automatic steering angle to the target manual steering angle.

[0008] In this configuration, steering reaction force can be controlled by a control device that is higher in level than the motor control device.

[0009] [Correction based on Rule 91 28.11.2025] One embodiment of the present disclosure includes a steering mechanism mechanically separated from a steering member and for steering the steering wheels of a vehicle; a reaction motor control device for controlling a reaction motor that applies reaction torque to the steering member; and a steering motor control device for controlling a steering motor that drives the steering mechanism, wherein the reaction motor control device comprises a control unit that controls the reaction motor by calculating a target motor torque based on an external input, the input including steering torque and a target automatic steering angle and target add-on reaction torque to assist the driver's operation, wherein the control unit comprises a target driver torque calculation unit that calculates a target driver torque to be input by the driver to the steering member, and the target driver The motor control device is provided, which includes: a target integrated driver torque calculation unit capable of calculating a target integrated driver torque by adding the target add-on reaction torque to the liver torque; a feedback control unit that calculates a feedback control torque by performing torque feedback control so that the steering torque follows the target integrated driver torque; a target manual steering angle calculation unit that calculates a target manual steering angle based on the feedback control torque and the steering torque; and an angle control unit that calculates the target motor torque by performing angle feedback control so that the actual steering angle follows the target integrated steering angle obtained by adding the target automatic steering angle to the target manual steering angle.

[0010] In this configuration, steering reaction force can be controlled by a control device that is higher in level than the motor control device.

[0011] The above-mentioned or further other purposes, features, and effects of this disclosure will be made apparent by the following description of embodiments with reference to the accompanying drawings.

[0012] Figure 1 is a schematic diagram showing the general configuration of a steering system according to an embodiment of the present disclosure. Figure 2 is a block diagram illustrating the electrical configuration of the reaction force ECU. Figure 3 is a schematic diagram showing an example of a reference EPS model used in the first manual steering angle command value calculation unit. Figure 4 is a block diagram illustrating the electrical configuration of the steering ECU. Figure 5 is a schematic diagram showing the general configuration of a steering system to which the motor control device according to the second embodiment of the present disclosure is applied. Figure 6 is a block diagram illustrating the electrical configuration of the motor control ECU.

[0013] [Amendment under Rule 91 28.11.2025] [Description of Embodiments of the Disclosure] One embodiment of the Disclosure comprises a steering mechanism mechanically connected to a steering member for steering the steering wheels of a vehicle, an electric motor for applying motor torque to the steering mechanism, and a control unit that calculates a target motor torque based on an external input and controls the electric motor, the input including steering torque, a target automatic steering angle and a target add-on reaction torque to assist the driver's operation, the control unit comprising a target driver torque calculation unit for calculating a target driver torque to be input by the driver to the steering member, and a target integrated driver torque which is the target driver torque plus the target add-on reaction torque. A motor control device is provided, which includes a target integrated driver torque calculation unit capable of calculating the steering torque; a feedback control unit that calculates a feedback control torque by performing torque feedback control so that the steering torque follows the target integrated driver torque; a target manual steering angle calculation unit that calculates a target manual steering angle based on the feedback control torque and the steering torque; and an angle control unit that calculates the target motor torque by performing angle feedback control so that the actual steering angle follows the target integrated steering angle obtained by adding the target automatic steering angle to the target manual steering angle.

[0014] In this configuration, steering reaction force can be controlled by a control device that is higher in level than the motor control device.

[0015] [Correction based on Rule 91 28.11.2025] One embodiment of the present disclosure includes a steering mechanism mechanically separated from a steering member and for steering the steering wheels of a vehicle; a reaction motor control device for controlling a reaction motor that applies reaction torque to the steering member; and a steering motor control device for controlling a steering motor that drives the steering mechanism, wherein the reaction motor control device comprises a control unit that controls the reaction motor by calculating a target motor torque based on an external input, the input including steering torque and a target automatic steering angle and target add-on reaction torque to assist the driver's operation, wherein the control unit comprises a target driver torque calculation unit that calculates a target driver torque to be input by the driver to the steering member, and the target driver The motor control device is provided, which includes: a target integrated driver torque calculation unit capable of calculating a target integrated driver torque by adding the target add-on reaction torque to the liver torque; a feedback control unit that calculates a feedback control torque by performing torque feedback control so that the steering torque follows the target integrated driver torque; a target manual steering angle calculation unit that calculates a target manual steering angle based on the feedback control torque and the steering torque; and an angle control unit that calculates the target motor torque by performing angle feedback control so that the actual steering angle follows the target integrated steering angle obtained by adding the target automatic steering angle to the target manual steering angle.

[0016] In this configuration, steering reaction force can be controlled by a control device that is higher in level than the motor control device.

[0017] In one embodiment of the present disclosure, the target automatic steering angle and the target add-on reaction torque are provided by a control device higher than the motor control device.

[0018] In one embodiment of the present disclosure, the steering mechanism includes a rack shaft, the motor control device includes a rack shaft force estimation unit that estimates the rack shaft force acting on the rack shaft via the steering wheels, and the target driver torque calculation unit calculates the target driver torque using the rack shaft force estimated by the rack shaft force estimation unit.

[0019] [Detailed Description of Embodiments of the Disclosure] Embodiments of the Disclosure will be described in detail below with reference to the accompanying drawings.

[0020] Figure 1 is a schematic diagram showing the general configuration of a steering system to which the motor control device according to the first embodiment of this disclosure is applied.

[0021] The steering system 1 includes a steering wheel (handle) 2 as a steering member for steering the vehicle, a steering mechanism 4 for steering the steering wheels 3, and a steering shaft 5 connected to the steering wheel 2. However, there is no mechanical connection between the steering shaft 5 and the steering mechanism 4 that transmits torque, rotation, or other motion.

[0022] The steering shaft 5 includes a first shaft 7 with one end connected to the steering wheel 2, a torsion bar 8 with one end connected to the other end of the first shaft 7, and a second shaft 9 with one end connected to the other end of the torsion bar 8.

[0023] A torque sensor 11 is positioned near the torsion bar 8. The torque sensor 11 determines the torsion bar torque (steering torque) T applied to the steering wheel 2 based on the relative rotational displacement of the first shaft 7 and the second shaft 9. ｔｂ The torsion bar torque T detected by the torque sensor 11 is detected. In this embodiment, the torsion bar torque T is detected by the torque sensor 11. ｔｂ For example, the torque for steering to the left is detected as a positive value, and the torque for steering to the right is detected as a negative value, and the larger the absolute value, the greater the torsion bar torque T. ｔｂ Assume that the size of will increase.

[0024] A reaction motor 13 is connected to the second shaft 9 via a reduction gear 12 to control the rotation angle of the second shaft 9 (hereinafter sometimes referred to as the "actual steering angle"). The reaction motor 13 is an electric motor that applies a reaction torque to the second shaft 9.

[0025] The reduction gear 12 consists of a worm gear mechanism including a worm shaft (not shown) that is integrally rotatably connected to the output shaft of the reaction motor 13, and a worm wheel (not shown) that meshes with the worm shaft and is integrally rotatably connected to the second shaft 9. The reaction motor 13 is provided with a rotation angle sensor 14 for detecting the rotation angle of the reaction motor 13.

[0026] The steering mechanism 4 consists of a rack and pinion mechanism including a pinion shaft 15 and a rack shaft 16. Steering wheels 3 are connected to each end of the rack shaft 16 via tie rods 17 and knuckle arms (not shown). The pinion shaft 15 is connected to the output shaft of the steering motor 19 via a reduction gear 18. The reduction gear 18 consists of a worm gear mechanism including a worm shaft (not shown) that is integrally rotatably connected to the output shaft of the steering motor 19, and a worm wheel (not shown) that meshes with this worm shaft and is integrally rotatably connected to the pinion shaft 15. A pinion 15A is connected to the tip of the pinion shaft 15. The steering motor 19 is provided with a rotation angle sensor 20 for detecting the rotation angle of the steering motor 19.

[0027] In the following, the reduction ratio of the speed reducer 12 (hereinafter referred to as the "first reduction ratio") may be represented by N1, and the reduction ratio of the speed reducer 18 (hereinafter referred to as the "second reduction ratio") may be represented by N2. The reduction ratio is the worm wheel angle θ, which is the rotation angle of the worm wheel. ｗｗ The worm gear angle θ is the rotation angle of the worm gear relative to the given value. ｗｇ The ratio θ ｗｇ / θ ｗｗ It is defined as follows.

[0028] The rack shaft 16 extends linearly along the left-right direction of the vehicle. A rack 16A is formed on the rack shaft 16 that meshes with the pinion 15A. When the steering motor 19 rotates, its rotational force is transmitted to the pinion shaft 15 via the reduction gear 18. Then, the rotation of the pinion shaft 15 is converted into axial movement of the rack shaft 16 by the pinion 15A and the rack 16A. As a result, the steering wheel 3 is steered.

[0029] The vehicle is equipped with a CCD (Charge Coupled Device) camera 25 for photographing the road ahead of the vehicle in the traveling direction, a GPS (Global Positioning System) 26 for detecting the position of the host vehicle, a radar 27 for detecting road shapes and obstacles, a map information memory 28 storing map information, and a vehicle speed sensor 29 for detecting vehicle speed V.

[0030] The CCD camera 25, GPS 26, radar 27, map information memory 28, and vehicle speed sensor 29 are connected to an ADAS domain ECU 201 for performing driving support control and a vehicle motion domain ECU 202. The driving support control may be, for example, Lane Centering Assist (LCA) control that assists steering so that the vehicle travels in the center of the driving lane, Lane Keeping Assist (LKA) control that assists steering so that the vehicle maintains within the driving lane, or the like.

[0031] The actual steering angle θ is provided to the ADAS domain ECU 201 via the in-vehicle network from a reaction force ECU 203 described later. ｒｐ The actual turning angle is also provided to the ADAS domain ECU 201 via the in-vehicle network from a turning ECU 204 described later. ｓｐ

[0032] The ADAS domain ECU 201 obtains information from the CCD camera 25, GPS 26, radar 27, map information memory 28, and vehicle speed sensor 29, the actual steering angle θ ｒｐ , the actual turning angle θ ｓｐ , and the like, and calculates the target curvature K and the target add-on reaction torque T for driving support control based on such information. It should be noted that the information obtained from the CCD camera 25, GPS 26, radar 27, map information memory 28, and vehicle speed sensor 29 may include an actual curvature. ｃａｄｄ

[0033] The target curvature K calculated by the ADAS domain ECU 201 is provided to the vehicle motion domain ECU 202 via the in-vehicle network. The target add-on reaction torque T calculated by the ADAS domain ECU 201 ｃａｄｄThis is supplied to the reaction force ECU 203 via the in-vehicle network.

[0034] The vehicle motion domain ECU 202 uses information obtained from, for example, the CCD camera 25, GPS 26, radar 27, map information memory 28, and vehicle speed sensor 29, along with the target curvature K, to determine the target automatic steering angle θ corresponding to the target curvature K. ａｒ and target automatic steering angle θ ａｓ The target automatic steering angle θ is calculated. ａｒ This is the target value of the steering angle required to automatically drive the vehicle along the target driving line. Target automatic steering angle θ ａｓ This is the target value for the steering angle required to automatically drive the vehicle along the target driving line.

[0035] Target auto steering angle θ ａｒ The vehicle speed V is provided from the vehicle motion domain ECU 202 to the reaction force ECU 203 via the in-vehicle network. Target automatic steering angle θ ａｓ The vehicle speed V is provided to the steering ECU 204 from the vehicle motion domain ECU 202 via the in-vehicle network. The reaction force ECU 203 is an ECU for controlling the reaction force motor 13, and the steering ECU 204 is an ECU for controlling the steering motor 19.

[0036] The ADAS domain ECU 201 and the vehicle motion domain ECU 202 are higher-level ECUs than the reaction force ECU 203 and the steering ECU 204, so these domain ECUs 201 and 202 may be collectively referred to as higher-level ECUs. "ADAS domain ECU 201 and vehicle motion domain ECU 202" are examples of "higher-level control devices" in this disclosure. The reaction force ECU 203 is an example of a "reaction force motor control device" in this disclosure. The steering ECU 204 is an example of a "steering motor control device" in this disclosure.

[0037] In this embodiment, the target automatic steering angle θ ａｒ and the first target manual steering angle θ, which will be described later. ｍｒ This is expressed as the amount of rotation (rotation angle) from the neutral position of the second axis 9, with a positive value representing rotation in the left steering direction from the neutral position, and a negative value representing rotation in the right steering direction from the neutral position. Furthermore, the target automatic steering angle θ is also expressed. ａｓand the second target manual steering angle θ, which will be described later. ｍｓ This is expressed as the amount of rotation (angle of rotation) of the pinion shaft 15 from the neutral position, with a positive value representing the amount of rotation in the left steering direction from the neutral position, and a negative value representing the amount of rotation in the right steering direction from the neutral position.

[0038] Torsion bar torque T detected by torque sensor 11 ｔｂ The output signal from the rotation angle sensor 14 is input to the reaction force ECU 203. The reaction force ECU 203 receives these input signals and the target add-on reaction force torque T provided from the ADAS domain ECU 201. ｃａｄｄ , the target automatic steering angle θ given by the vehicle motion domain ECU 202 ａｒ and the vehicle speed V and the rack axial force F provided by the steering ECU 204. ｒ The reaction motor 13 is controlled based on this.

[0039] The output signal from the rotation angle sensor 20 is input to the steering ECU 204. The steering ECU 204 receives the output signal from the rotation angle sensor 20 and the target automatic steering angle θ provided by the vehicle motion domain ECU 202. ａｓ and the torsion bar torque T provided by the vehicle speed V and reaction force ECU 203. ｔｂ The steering motor 19 is controlled based on this.

[0040] Figure 2 is a block diagram illustrating the electrical configuration of the reaction force ECU 203.

[0041] The reaction force ECU 203 includes a microcomputer 40, a drive circuit (inverter circuit) 31 controlled by the microcomputer 40 that supplies power to the reaction force motor 13, and the current (hereinafter referred to as "motor current I") that flows through the reaction force motor 13. ｒｍ It includes a current detection circuit 32 for detecting the following:

[0042] The microcomputer 40 is equipped with a CPU and memory (ROM, RAM, non-volatile memory, etc.) and functions as multiple function processing units by executing a predetermined program. These multiple function processing units include a rotation angle calculation unit 41, a reduction ratio division unit 42, a steering wheel steering state determination unit 43, a multiplication unit 44, a target driver torque calculation unit 45, an addition unit 46, a torque deviation calculation unit 47, a PD control unit (torque feedback control unit) 48, a first target manual steering angle calculation unit 49, a target integrated steering angle calculation unit 50, and a first angle control unit 51.

[0043] The rotation angle calculation unit 41 calculates the rotor rotation angle θ of the reaction motor 13 based on the output signal of the rotation angle sensor 14. ｒｍ The reduction ratio division unit 42 calculates the rotor rotation angle θ. ｒｍ By dividing by the first reduction ratio N1, the rotor rotation angle θ ｒｍ The rotation angle (actual steering angle) of the second axis 9 is θ ｒｐ Convert to actual steering angle θ. ｒｐ This is provided to the target driver torque calculation unit 45 and the steering wheel steering state determination unit 43, as well as to the ADAS domain ECU 201.

[0044] The steering state determination unit 43 determines the torsion bar torque T detected by the torque sensor 11. ｔｂ and the actual steering angle θ ｒｐ Based on this, the steering state determination unit 43 determines whether the driver is in a hands-on state, gripping the steering wheel 2, or in a hands-off state (hands off), gripping the steering wheel 2. The steering state determination unit 43 outputs 1 if it determines that the driver is in a hands-on state, and outputs 0 if it determines that the driver is in a hands-off state.

[0045] As the steering wheel steering state determination unit 43, for example, the steering wheel steering state determination unit (42) shown in Figures 2 and 3 of Japanese Patent Application Publication No. 2019-182393 (Patent Document 4) can be used. In this case, the actual steering angle θ calculated by the reduction ratio division unit 42 is used as the worm wheel angle θww in Japanese Patent Application Publication No. 2019-182393. ｒｐIt can also be used. Furthermore, the torsion bar torque T of Japanese Patent Publication No. 2019-182393 can be used. ｔｂ The torsion bar torque T detected by the torque sensor 11 is used as the torque. ｔｂ You can use it.

[0046] The multiplication unit 44 receives the target add-on reaction torque T from the ADAS domain ECU 201. ｃａｄｄ The output of the steering steering state determination unit 43 is multiplied by this. Therefore, when the determination result of the steering steering state determination unit 43 is a hands-on state, the multiplier unit 44 is the target add-on reaction torque T ｃａｄｄ The multiplication unit 44 outputs 0 when the steering steering state determination unit 43 determines that the hands-off state is determined.

[0047] Furthermore, the steering wheel steering state determination unit 43 determines the target add-on reaction torque T ｃａｄｄ If the absolute value of is less than a predetermined threshold α, the system becomes inactive, and the standard add-on reaction torque T ｃａｄｄ The steering steering state determination unit 43 may be controlled to become active when the absolute value of is greater than or equal to α. However, α is a real number greater than 0. In this case, when the steering steering state determination unit 43 is inactive, the output of the steering steering state determination unit 43 will be 0.

[0048] The target driver torque calculation unit 45 calculates the rack axial force F supplied from the steering ECU 204. ｒ Using this, the target driver torque T that the driver should input to the steering shaft 5 (steering wheel 2) is determined. ｄ The target driver torque calculation unit 45 calculates the actual steering angle θ calculated by the reduction ratio division unit 42. ｒｐ Torsion bar torque T detected by torque sensor 11 ｔｂ , the rack axial force F supplied from the steering ECU 204 ｒ The vehicle speed V, provided by the vehicle motion domain ECU 202, is input. Based on these inputs, the target driver torque calculation unit 45 calculates the target driver torque T ｄ Perform the calculation.

[0049] The target driver torque calculation unit 45 may, for example, perform the base target torque calculation process M20, the compensation amount calculation process M21, and the addition process M22 shown in Figure 3 of International Publication No. 2024 / 218852 (Patent Document 3). In this case, the target driver torque calculation unit 45 calculates the rack axial force F ｒ Based on the vehicle speed V, the target basic driver torque T is the basic value of the target driver torque that the driver should input to the steering shaft 5 via the steering wheel 2. ｄｂ The calculation is performed. In addition, the target driver torque calculation unit 45 calculates the actual steering angle θ. ｒｐ Based on the vehicle speed V, the target basic driver torque T ｄｂ Compensation amount T to compensate for ｄｒ Next, the target driver torque calculation unit 45 calculates the target basic driver torque T ｄｂ Compensation amount T ｄｒ By adding this, the target driver torque T ｄ Perform the calculation.

[0050] The target driver torque calculation unit 45 calculates the target basic driver torque T ｄｂ Target driver torque T ｄ It may also be used as such.

[0051] The addition unit 46 controls the target driver torque T. ｄ The output of the multiplication unit 44 (T ｃａｄｄ By adding (or 0), the target integrated driver torque T ｄｉ (=T ｄ or (T ｄ +T ｃａｄｄ The addition unit 46 calculates the target integrated driver torque.

[0052] The torque deviation calculation unit 47 calculates the target integrated driver torque T ｄｉ Torsion bar torque T ｔｂ Torque deviation ΔT(=T ｄｉ -T ｔｂ The PD control unit 48 calculates the feedback control torque T by performing a PD calculation (proportional-derivative calculation) on the torque deviation ΔT. ｄｆｂ Perform the calculation.

[0053] Basically, when a driver operates the steering wheel 2, the first target manual steering angle calculation unit 49 calculates the steering angle corresponding to the steering wheel operation (more precisely, the rotation angle θ of the second shaft 9 ｒｐ ) to be set as the first target manual steering angle θ ｍｒ .

[0054] In this embodiment, the first target manual steering angle calculation unit 49 calculates the first target manual steering angle θ ｍｒ using a reference EPS model.

[0055] FIG. 3 is a schematic diagram illustrating an example of the reference EPS model used in the first target manual steering angle calculation unit 49.

[0056] This reference EPS model is a single inertia model including a lower column. The lower column corresponds to, for example, the second shaft 9 and the worm wheel of the reduction gear 12. In FIG. 3, J ｃ is the inertia of the lower column (hereinafter referred to as "column inertia"), θ ｃ is the rotation angle of the lower column, and T ｔｂ is torsion bar torque. The torsion bar torque T ｔｂ , the torque N1·T acting on the second shaft 9 from the reaction force motor 13 ｍ and the road surface reaction torque T ｒｌ are applied to the lower column.

[0057] The road surface reaction torque T ｒｌ is expressed by the following equation (1) using the spring constant k of a virtual spring and the viscous damping coefficient c of a virtual damper.

[0058] T ｒｌ =−k·θ ｃ −c(dθ ｃ / dt)...(1)

[0059] The equation of motion of the reference EPS model is expressed by the following equation (2).

[0060] J ｃ ·d ２ θ c / dt ２ =T ｔｂ +N1·T ｍ −k·θｃ −c(dθ ｃ / dt)... (2)

[0061] In equation (2), J ｃ ·d ２ θ ｃ / dt ２ is the moment of inertia acting on the lower column.

[0062] The first target manual steering angle calculation unit 49 substitutes the torsion bar torque T detected by the torque sensor 11 into T ｔｂ detected by the torque sensor 11 into T ｔｂ , substitutes the feedback control torque T calculated by the PD control unit 48 into N1·T ｍ calculated by the PD control unit 48 into T ｄｆｂ , substitutes the preset first spring constant k1 as k, and substitutes the preset first viscous damping coefficient c1 as c, then solves the differential equation of equation (2) to calculate the rotation angle θ of the lower column ｃ . Then, the first target manual steering angle calculation unit 49 sets the obtained rotation angle θ of the lower column ｃ as the first target manual steering angle θ ｍｒ .

[0063] That is, the first target manual steering angle calculation unit 49 replaces N1·T ｍ , θ ｃ , k and c in equation (2) with T ｄｆｂ , θ ｍｒ , k1 and c1 respectively, then solves the differential equation of the following equation (3) to calculate the first target manual steering angle θ ｍｒ .

[0064] J ｃ ·d ２ θ ｍｒ / dt ２ =T ｔｂ +T ｄｆｂ −k1·θ ｍｒ −c1(dθ ｍｒ / dt)... (3)

[0065] The target integrated steering angle calculation unit 50 adds the target automatic steering angle θ ｍｒ to the first target manual steering angle θ ａｒ , and calculates the target integrated steering angle θ ｉｒ .

[0066] The first angle control unit 51 controls the target integrated steering angle θ ｉｒ Based on this, the reaction motor 13 is angle-controlled. Specifically, the first angle control unit 51 controls the actual steering angle θ ｒｐ (The rotation angle of the second axis 9) is the target integrated steering angle θ ｉｒ The drive circuit 31 is controlled to follow this.

[0067] For example, the first angle control unit 51 first determines the target integrated steering angle θ ｉｒ and the actual steering angle θ ｒｐ The angular deviation (θ) ｉｒ -θ ｒｐ Next, the first angle control unit 51 calculates the target torque for the second shaft 9 by performing a PD calculation (proportional-derivative calculation) on the first shaft 9. Next, the first angle control unit 51 calculates the target motor torque for the reaction motor 13 by dividing the target second shaft torque by the first reduction ratio N1. Next, the first angle control unit 51 calculates the target motor current for the reaction motor 13 by dividing the target motor torque by the torque coefficient of the reaction motor 13. Next, the first angle control unit 51 calculates the target motor current and the motor current I detected by the current detection circuit 32. ｒｍ The drive command value is calculated by performing PID calculation (proportional-integral-derivative calculation) on the current deviation. Finally, the first angle control unit 51 generates a PWM signal with a duty cycle corresponding to the drive command value and supplies it to the drive circuit 31.

[0068] The first angle control unit 51 controls the target second axis torque and the actual steering angle θ. ｒｐ Based on this, the system may include a disturbance torque estimation unit that estimates the nonlinear torque (disturbance torque: torque other than motor torque) that occurs as a disturbance in the object driven by the reaction force motor 13. In that case, the first angle control unit 51 may calculate the target second shaft torque with the disturbance torque compensated by subtracting the disturbance torque estimated by the disturbance torque estimation unit from the target second shaft torque, and then calculate the target motor torque by dividing the obtained target second shaft torque after disturbance torque compensation by the first reduction ratio N1.

[0069] Figure 4 is a block diagram illustrating the electrical configuration of the steering ECU 204.

[0070] The steering ECU 204 includes a microcomputer 70, a drive circuit (inverter circuit) 61 controlled by the microcomputer 70 that supplies power to the steering motor 19, and the current (hereinafter referred to as "motor current I") that flows through the steering motor 19. ｓｍ It includes a current detection circuit 62 for detecting the following:

[0071] The microcomputer 70 is equipped with a CPU and memory (ROM, RAM, non-volatile memory, etc.) and functions as multiple function processing units by executing a predetermined program. These multiple function processing units include a rotation angle calculation unit 71, a reduction ratio division unit 72, a steering angle conversion value calculation unit 73, a rack axis force estimation unit 74, a second target manual steering angle calculation unit 75, a target integrated steering angle calculation unit 76, and a second angle control unit 77.

[0072] The rotation angle calculation unit 71 calculates the rotor rotation angle θ of the steering motor 19 based on the output signal of the rotation angle sensor 20. ｓｍ The reduction ratio division unit 72 calculates the rotor rotation angle θ. ｓｍ By dividing by the second reduction ratio N2, the rotor rotation angle θ is obtained. ｓｍ The rotation angle (actual steering angle) of the pinion shaft 15 is θ ｓｐ Convert to actual steering angle θ. ｓｐ This value is provided to the steering angle conversion calculation unit 73 and also to the ADAS domain ECU 201.

[0073] The steering angle conversion value calculation unit 73 calculates the actual steering angle θ ｓｐ By dividing this by a virtual gear ratio (VGR: ratio of steering angle to steering angle) set according to the vehicle speed V, the actual steering angle θ is obtained. ｓｐ The steering angle equivalent value θ is defined by and VGR. ｒｐｃｏｎ The steering angle conversion value θ is calculated. ｒｐｃｏｎ This is provided to the rack axial force estimation unit 74.

[0074] The rack axial force estimation unit 74 estimates, for example, the steering angle equivalent value θ. ｒｐｃｏｎ Based on the vehicle speed V, the rack axial force F acts on the rack shaft 16 via the steering wheels 3. ｒ Specifically, the rack axial force estimation unit 74 estimates the steering angle equivalent value θ.ｒｐｃｏｎ２ The larger the absolute value of F, the greater the rack axial force. ｒ The absolute value of increases, and the greater the vehicle speed V, the greater the rack axial force F. ｒ The rack axial force F increases in absolute value. ｒ The rack axial force F is calculated. ｒ This is applied to the reaction force ECU 203.

[0075] The second target manual steering angle calculation unit 75 basically calculates the steering angle (more precisely, the rotation angle θ of the pinion shaft 15) corresponding to the steering wheel operation when the driver operates the steering wheel 2. ｓｐ ) is the second target manual steering angle θ ｍｓ It is provided for setting it as such.

[0076] The operation of the second target manual steering angle calculation unit 75 is almost the same as the operation of the first target manual steering angle calculation unit 49. However, the low column of the reference EPS model in Figure 3 corresponds, for example, to the pinion shaft 15 and the worm wheel of the reduction gear 18. In addition, the low column has a torsion bar torque T detected by the torque sensor 11. ｔｂ Torque N2·T acting from the steering motor 19 to the pinion shaft 15 ｍ and road surface reaction torque T ｒｌ It is given.

[0077] The second target manual steering angle calculation unit 75 calculates T in equation (2) above. ｔｂ Torsion bar torque T detected by torque sensor 11 ｔｂ Substitute N1・T ｍ By substituting 0 for k, substituting the pre-set second spring constant k2 for k, and substituting the pre-set second viscous damping coefficient c2 for c, and solving the differential equation (2), the rotation angle θ of the lower column can be found. ｃ The second target manual steering angle calculation unit 75 then calculates the rotation angle θ of the lower column obtained. ｃ The second target manual steering angle θ ｍｓ Set it as follows.

[0078] In other words, the second target manual steering angle calculation unit 75 is N1・T in equation (2). ｍ , θ ｃ , k and c are set to 0 and θ respectively.ｍｓ By solving the differential equation (4) below, with k2 and c2 substituted, the second target manual steering angle θ can be found. ｍｓ Perform the calculation.

[0079] J ｃ d ２ θ ｍｓ / dt ２ = T ｔｂ -k²θ ｍｓ -c²(dθ) ｍｓ / dt) ... (4)

[0080] Note that J in equation (4) ｃ For example, the inertia of the pinion shaft 15 and the worm wheel of the reduction gear 18 can be used.

[0081] The target integrated steering angle calculation unit 76 calculates the second target manual steering angle θ. ｍｓ The target automatic steering angle θ is given by the vehicle motion domain ECU 202. ａｓ Adding this, the target integrated steering angle θ ｉｓ Perform the calculation.

[0082] The second angle control unit 77 controls the target integrated steering angle θ. ｉｓ Based on this, the steering motor 19 is angle-controlled. Specifically, the second angle control unit 77 controls the actual steering angle θ ｓｐ (The rotation angle of the pinion shaft 15) is the target integrated steering angle θ ｉｓ The drive circuit 61 is controlled to follow the movement.

[0083] For example, the second angle control unit 77 first determines the target integrated steering angle θ ｉｓ and the actual steering angle θ ｓｐ The angular deviation (θ) ｉｓ -θ ｓｐNext, the second angle control unit 77 calculates the target torque for the pinion shaft 15 by performing a PD calculation (proportional-derivative calculation) on the target pinion shaft 15. Next, the second angle control unit 77 calculates the target motor torque for the steering motor 19 by dividing the target pinion shaft torque by the second reduction ratio N2. Next, the second angle control unit 77 calculates the target motor current for the steering motor 19 by dividing the target motor torque by the torque coefficient of the steering motor 19. Next, the second angle control unit 67 calculates the target motor current and the motor current I detected by the current detection circuit 52. ｓｍ The drive command value is calculated by performing PID calculation (proportional-integral-derivative calculation) on the current deviation. Finally, the second angle control unit 77 generates a PWM signal with a duty cycle corresponding to the drive command value and supplies it to the drive circuit 61.

[0084] The second angle control unit 77 controls the target pinion shaft torque and the actual steering angle θ. ｓｐ Based on this, the steering motor 19 may be equipped with a disturbance torque estimation unit that estimates a nonlinear torque (disturbance torque: torque other than motor torque) that occurs as a disturbance in the object it drives. In that case, the second angle control unit 77 may calculate the target pinion shaft torque with the disturbance torque compensated by subtracting the disturbance torque estimated by the disturbance torque estimation unit from the target pinion shaft torque, and then calculate the target motor torque by dividing the obtained target pinion shaft torque after disturbance torque compensation by the second reduction ratio N2.

[0085] In Figure 4, the steering angle conversion value calculation unit 73 calculates the actual steering angle θ. ｓｐ By dividing by VGR, the steering angle equivalent value θ is obtained. ｒｐｃｏｎ It is calculating the target integrated steering angle θ, as shown by the dashed line in Figure 4. ｉｓ By dividing by VGR, the steering angle equivalent value θ is obtained. ｒｐｃｏｎ The steering angle conversion value calculation unit 73 may calculate the second target manual steering angle θ. ｍｓ Target automatic steering angle θ ａｓ The target integrated steering angle θ obtained by adding these values ｉｓ The steering angle equivalent value θ is defined by the VGR.ｒｐｃｏｎ Perform the calculation.

[0086] In the first embodiment described above, when the driver is gripping the steering wheel 2, the target driver torque T is calculated by the target driver torque calculation unit 45 in the reaction force ECU 203. ｄ The add-on reaction torque T is supplied from the ADAS domain ECU 201. ｃａｄｄ When added, the target integrated driver torque T ｄｉ The calculation is performed. Then, the torsion bar torque T ｔｂ Target integrated driver torque T ｄｉ Feedback control is performed to make it follow, resulting in a feedback-controlled torque T ｄｆｂ The calculation is performed.

[0087] Feedback-controlled torque T ｄｆｂ Torsion bar torque T ｔｂ Based on this, the first target manual steering angle θ ｍｒ The following is calculated: First target manual steering angle θ ｍｒ The target automatic steering angle θ is given by the vehicle motion domain ECU 202. ａｒ When added, the target integrated steering angle θ ｉｒ The calculation is performed, and then the actual steering angle θ is calculated. ｒｐ The target integrated steering angle θ ｉｒ The drive circuit 31 of the reaction motor 13 is controlled to follow this movement.

[0088] Therefore, in the first embodiment described above, the torsion bar torque (steering torque) T ｔｂ While maintaining control of the steering angle in accordance with the steering torque, it becomes possible to control the steering reaction force by an ECU (ADAS domain ECU 201) that is higher in level than the reaction force ECU 203 and the steering ECU 204. In other words, in the first embodiment described above, it becomes possible to control the steering reaction force by a control device higher in level than the motor control devices (ECUs 203 and 204) while maintaining control of the steering angle in accordance with the steering torque.

[0089] In the first embodiment described above, the rack axial force estimation unit 74 calculates the steering angle equivalent value θ. ｒｐｃｏｎ Based on the vehicle speed V, the rack axial force Fｒ It estimates the target pinion shaft torque (target integrated steering angle θ) calculated by the second angle control unit 77. ｉｓ and the actual steering angle θ ｓｐ The angular deviation (θ) ｉｓ -θ ｓｐ Based on the target pinion shaft torque obtained by performing PD calculation on ), the rack shaft force F ｒ It is also possible to estimate the rack axial force. Furthermore, the rack axial force estimation unit 74 should be one capable of estimating the rack axial force, and may be one capable of estimating the rack axial force using a method different from the one described above.

[0090] Figure 5 is a schematic diagram showing the general configuration of a steering system to which the motor control device according to the second embodiment of this disclosure is applied. In Figure 5, parts corresponding to each part in Figure 1 are denoted by the same reference numerals as in Figure 1.

[0091] The steering system 101 includes a steering wheel 102 as a steering member for steering the vehicle, a steering mechanism 104 that steers the steering wheels 103 in conjunction with the rotation of the steering wheel 102, and a steering assist mechanism 105 for assisting the driver's steering. The steering wheel 102 and the steering mechanism 104 are mechanically connected via a steering shaft 106 and an intermediate shaft 107.

[0092] The steering shaft 106 includes an input shaft 108 connected to the steering wheel 102 and an output shaft 109 connected to the intermediate shaft 107. The input shaft 108 and the output shaft 109 are connected via a torsion bar 110 so as to be rotatable relative to each other.

[0093] A torque sensor 112 is positioned near the torsion bar 110. The torque sensor 112 measures the torsion bar torque (steering torque) T applied to the steering wheel 102 based on the relative rotational displacement of the input shaft 108 and the output shaft 109. ｔｂ The torsion bar torque T detected by the torque sensor 112 is detected. In this embodiment, the torsion bar torque T is detected by the torque sensor 112. ｔｂFor example, the torque for steering to the left is detected as a positive value, and the torque for steering to the right is detected as a negative value, and the larger the absolute value, the greater the torsion bar torque T. ｔｂ Assume that the size of will increase.

[0094] The steering mechanism 104 consists of a rack and pinion mechanism including a pinion shaft 113 and a rack shaft 114 as the steering axis. Steering wheels 103 are connected to each end of the rack shaft 114 via tie rods 115 and knuckle arms (not shown). The pinion shaft 113 is connected to an intermediate shaft 107. The pinion shaft 113 rotates in conjunction with the steering of the steering wheel 102. A pinion 116 is connected to the tip of the pinion shaft 113.

[0095] The rack shaft 114 extends linearly along the left-right direction of the vehicle. A rack 117 that meshes with a pinion 116 is formed in the axial middle portion of the rack shaft 114. The rotation of the pinion shaft 113 is converted into axial movement of the rack shaft 114 by the pinion 116 and rack 117. By moving the rack shaft 114 in the axial direction, the steering wheels 103 can be steered.

[0096] When the steering wheel 102 is steered (rotated), this rotation is transmitted to the pinion shaft 113 via the steering shaft 106 and the intermediate shaft 107. The rotation of the pinion shaft 113 is then converted into axial movement of the rack shaft 114 by the pinion 116 and the rack 117. This causes the steering wheel 103 to turn.

[0097] The steering assist mechanism 105 includes an electric motor 118 for generating steering assist force (assist torque) and a reduction gear 119 for amplifying the output torque of the electric motor 118 and transmitting it to the steering mechanism 104. The reduction gear 119 consists of a worm gear mechanism including a worm gear 120 and a worm wheel 121 that meshes with the worm gear 120.

[0098] In the following, the reduction ratio (gear ratio) of the reducer 119 is denoted by N. The reduction ratio N is equal to the worm wheel angle θ, which is the rotation angle of the worm wheel 121.ｗｗ The worm gear angle θ is the rotation angle of the worm gear 120 relative to [the specified value]. ｗｇ The ratio (θ) ｗｇ / θ ｗｗ ) is defined as.

[0099] The worm gear 120 is rotationally driven by the electric motor 118. The worm wheel 121 is also integrally rotatably connected to the output shaft 109.

[0100] When the worm gear 120 is rotationally driven by the electric motor 118, the worm wheel 121 is rotationally driven, applying motor torque to the steering shaft 106 and causing the steering shaft 106 (output shaft 109) to rotate. The rotation of the steering shaft 106 is then transmitted to the pinion shaft 113 via the intermediate shaft 107. The rotation of the pinion shaft 113 is converted into axial movement of the rack shaft 114. This causes the steering wheel 103 to turn. In other words, by rotationally driving the worm gear 120 with the electric motor 118, steering assistance by the electric motor 118 and steering of the steering wheel 103 become possible. The electric motor 118 is equipped with a rotation angle sensor 123 for detecting the rotation angle of the rotor of the electric motor 118.

[0101] The vehicle is equipped with a CCD camera 25, GPS 26, radar 27, map information memory 28, and vehicle speed sensor 29, similar to the first embodiment. These are connected to the ADAS domain ECU 201 and the vehicle motion domain ECU 202 for driver assistance control. The ADAS domain ECU 201 receives the actual steering angle θ from the motor control ECU 205, which will be described later. ｐ It is provided via the in-vehicle network.

[0102] The ADAS domain ECU 201 receives information from, for example, a CCD camera 25, GPS 26, radar 27, map information memory 28, and vehicle speed sensor 29, as well as the actual steering angle θ. ｐ Based on these factors, the target curvature K and target add-on reaction torque T for driver assistance control are determined. ｃａｄｄ Perform the calculation.

[0103] The target curvature K calculated by the ADAS domain ECU 201 is provided to the vehicle motion domain ECU 202 via the in-vehicle network. The target add-on reaction torque T is calculated by the ADAS domain ECU 201. ｃａｄｄ This is provided to the motor control ECU 205 via the in-vehicle network.

[0104] The vehicle motion domain ECU 202 uses information obtained from, for example, the CCD camera 25, GPS 26, radar 27, map information memory 28, and vehicle speed sensor 29, along with the target curvature K, to determine the target automatic steering angle θ corresponding to the target curvature K. ａｄ The target automatic steering angle θ is calculated. ａｄ This is the target value for the steering angle required to automatically drive the vehicle along the target driving line.

[0105] Target auto steering angle θ ａｄ The vehicle speed V is provided from the vehicle motion domain ECU 202 to the motor control ECU 205 via the in-vehicle network. The motor control ECU 205 is an ECU for controlling the electric motor 118. The motor control ECU 205 is an example of a “motor control device” in this disclosure. The ADAS domain ECU 201 and the vehicle motion domain ECU 202 are examples of “higher-level control devices” in this disclosure.

[0106] Figure 6 is a block diagram illustrating the electrical configuration of the motor control ECU 205.

[0107] The motor control ECU 205 includes a microcomputer 80, a drive circuit (inverter circuit) 78 controlled by the microcomputer 80 that supplies power to the electric motor 118, and the current (hereinafter referred to as "motor current I") that flows through the electric motor 118. ｍ It includes a current detection circuit 79 for detecting the following:

[0108] The microcomputer 80 is equipped with a CPU and memory (ROM, RAM, non-volatile memory, etc.) and functions as multiple function processing units by executing a predetermined program. These multiple function processing units include a rotation angle calculation unit 81, a reduction ratio division unit 82, a rack axis force estimation unit 83, a steering wheel steering state determination unit 84, a multiplication unit 85, a target drive torque calculation unit 86, an addition unit 87, a torque deviation calculation unit 88, a PD control unit (torque feedback control unit) 89, a target manual steering angle calculation unit 90, a target integrated steering angle calculation unit 91, and an angle control unit 92.

[0109] The rotation angle calculation unit 81 calculates the rotor rotation angle θ of the electric motor 118 based on the output signal of the rotation angle sensor 123. ｍ The reduction ratio division unit 82 calculates the rotor rotation angle θ. ｍ By dividing by the reduction ratio N, the rotor rotation angle θ is obtained. ｍ Output 109 rotation angle (actual steering angle) θ ｐ Convert to actual steering angle θ. ｐ This is provided to the rack axial force estimation unit 83, the target driver torque calculation unit 86, and the steering wheel steering state determination unit 84, as well as to the ADAS domain ECU 201.

[0110] The rack axial force estimation unit 83 calculates the actual steering angle θ ｐ Based on the vehicle speed V, the rack axial force F acts on the rack shaft 114 via the steering wheel 103. ｒ Specifically, the rack axial force estimation unit 74 estimates the actual steering angle θ. ｐ The larger the absolute value of F, the greater the rack axial force. ｒ The absolute value of increases, and the greater the vehicle speed V, the greater the rack axial force F. ｒ The rack axial force F increases in absolute value. ｒ The rack axial force F is calculated. ｒ This is provided to the target driver torque calculation unit 86.

[0111] The steering state determination unit 84 determines the torsion bar torque T detected by the torque sensor 112. ｔｂ and the actual steering angle θ ｐBased on this, the steering wheel steering state determination unit 84 determines whether the driver is in a hands-on state, gripping the steering wheel 102, or in a hands-off state (hands-free state), not gripping the steering wheel 102. The steering wheel steering state determination unit 84 outputs 1 if it determines that the driver is in a hands-on state, and outputs 0 if it determines that the driver is in a hands-off state. The operation of the steering wheel steering state determination unit 84 is the same as that of the steering wheel steering state determination unit 43 in the first embodiment.

[0112] The multiplication unit 85 receives the target add-on reaction torque T from the ADAS domain ECU 201. ｃａｄｄ The output of the steering state determination unit 84 is multiplied by this. Therefore, when the determination result of the steering state determination unit 84 is a hands-on state, the multiplier unit 85 is the target add-on reaction torque T ｃａｄｄ The multiplication unit 85 outputs 0 when the steering steering state determination unit 84 determines that the hands-off state is determined.

[0113] Furthermore, the steering wheel steering state determination unit 84 determines the target add-on reaction torque T ｃａｄｄ If the absolute value of is less than a predetermined threshold α, the system becomes inactive, and the target add-on reaction torque T ｃａｄｄ The system may be controlled to become active when the absolute value of is α or greater. In this case, when the steering state determination unit 84 is inactive, the output of the steering state determination unit 84 will be 0.

[0114] The target driver torque calculation unit 86 calculates the rack axial force F estimated by the rack axial force estimation unit 83. ｒ Using this, the target driver torque T that the driver should input to the steering shaft 106 (steering wheel 102) is used. ｄ The target driver torque calculation unit 86 calculates the actual steering angle θ calculated by the reduction ratio division unit 82. ｐ Torsion bar torque T detected by torque sensor 112 ｔｂ , the rack axial force F estimated by the rack axial force estimation unit 83 ｒThe vehicle speed V, provided by the vehicle motion domain ECU 202, is input. Based on these inputs, the target driver torque calculation unit 86 calculates the target driver torque T ｄ The calculation is performed. The operation of the target driver torque calculation unit 86 is the same as the operation of the target driver torque calculation unit 45 in the first embodiment, so its explanation is omitted.

[0115] The addition unit 87 controls the target driver torque T ｄ The output of the multiplication unit 44 (T ｃａｄｄ By adding (or 0), the target integrated driver torque T ｄｉ (=T ｄ or (T ｄ +T ｃａｄｄ The addition unit 87 calculates the target integrated driver torque. The addition unit 87 is an example of the "target integrated driver torque calculation unit" in this disclosure.

[0116] The torque deviation calculation unit 88 calculates the target integrated driver torque T ｄｉ Torsion bar torque T ｔｂ Torque deviation ΔT(=T ｄｉ -T ｔｂ The PD control unit 89 calculates the feedback control torque T by performing a PD calculation (proportional-derivative calculation) on the torque deviation ΔT. ｄｆｂ Perform the calculation.

[0117] The target manual steering angle calculation unit 90 basically calculates the steering angle (more precisely, the rotation angle θ of the output shaft 109) corresponding to the steering wheel operation when the driver operates the steering wheel 102. ｐ ) Target manual steering angle θ ｍｄ It is provided for setting it as such.

[0118] The operation of the target manual steering angle calculation unit 90 is substantially the same as the operation of the first target manual steering angle calculation unit 49 in Figure 2. However, the low column of the reference EPS model in Figure 3 corresponds, for example, to the output shaft 109 and the worm wheel 121 of the reduction gear 119. In addition, the low column has a torsion bar torque T detected by the torque sensor 112. ｔｂ Torque N.T acting from the electric motor 118 to the output shaft 109 ｍ and road surface reaction torque T ｒｌIt is given.

[0119] The target manual steering angle calculation unit 90 is T in equation (2). ｔｂ Torsion bar torque T detected by torque sensor 112 ｔｂ Substitute N1・T ｍ The feedback control torque T calculated by the PD control unit 89 ｄｆｂ By substituting the values, substituting the predetermined third spring constant k3 as k, and substituting the predetermined third viscous damping coefficient c3 as c, and solving the differential equation (2), the rotation angle θ of the lower column can be found. ｃ The calculation is performed. Then, the target manual steering angle calculation unit 90 calculates the rotation angle θ of the lower column obtained. ｃ Target manual steering angle θ ｍｄ Set it as follows.

[0120] In other words, the target manual steering angle calculation unit 90 is N1・T in equation (2). ｍ , θ ｃ , k and c are T ｄｆｂ , θ ｍｄ By solving the differential equation (5) below, with k3 and c3 substituted, the target manual steering angle θ can be found. ｍｄ Perform the calculation.

[0121] J ｃ d ２ θ ｍｄ / dt ２ = T ｔｂ +T ｄｆｂ -k1・θ ｍｄ -c1(dθ ｍｄ / dt) ... (5)

[0122] Note that J in equation (5) ｃ For example, the inertia of the output shaft 109 and the worm wheel 121 can be used.

[0123] The target integrated steering angle calculation unit 91 calculates the target manual steering angle θ ｍｄ The target automatic steering angle θ ａｄ Adding this, the target integrated steering angle θ ｉ Perform the calculation.

[0124] The angle control unit 92 controls the target integrated steering angle θ ｉBased on this, the electric motor 118 is angle-controlled. Specifically, the angle control unit 92 controls the actual steering angle θ ｐ (The rotation angle of the output shaft 109) is the target integrated steering angle θ ｉ The drive circuit 78 is controlled to follow this.

[0125] For example, the angle control unit 92 first determines the target integrated steering angle θ ｉ and the actual steering angle θ ｐ The angular deviation (θ) ｉ -θ ｐ Next, the angle control unit 92 calculates the target output shaft torque, which is the target torque for the output shaft 109, by performing a PD calculation (proportional-derivative calculation) on the output shaft 109. Next, the angle control unit 92 calculates the target motor torque, which is the target torque for the electric motor 118, by dividing the target output shaft torque by the reduction ratio N. Next, the angle control unit 92 calculates the target motor current for the electric motor 118 by dividing the target motor torque by the torque coefficient of the electric motor 118. Next, the angle control unit 92 calculates the target motor current and the motor current I detected by the current detection circuit 79. ｍ The drive command value is calculated by performing PID calculation (proportional-integral-derivative calculation) on the current deviation. Finally, the angle control unit 92 generates a PWM signal with a duty cycle corresponding to the drive command value and supplies it to the drive circuit 78.

[0126] The angle control unit 92 controls the target output shaft torque and the actual steering angle θ. ｐ Based on this, the system may include a disturbance torque estimation unit that estimates the nonlinear torque (disturbance torque: torque other than motor torque) that occurs as a disturbance in the object driven by the electric motor 118. In that case, the angle control unit 92 may calculate the target output shaft torque with the disturbance torque compensated by subtracting the disturbance torque estimated by the disturbance torque estimation unit from the target output shaft torque, and then calculate the target motor torque by dividing the obtained target output shaft torque after disturbance torque compensation by the reduction ratio N.

[0127] In the second embodiment described above, when the driver is gripping the steering wheel 102, the target driver torque T is calculated by the target driver torque calculation unit 86 of the motor control ECU 205. ｄThe add-on reaction torque T is supplied from the ADAS domain ECU 201. ｃａｄｄ When added, the target integrated driver torque T ｄｉ The calculation is performed. Then, the torsion bar torque T ｔｂ Target integrated driver torque T ｄｉ Feedback control is performed to make it follow, resulting in a feedback-controlled torque T ｄｆｂ The calculation is performed.

[0128] Feedback-controlled torque T ｄｆｂ Torsion bar torque T ｔｂ Based on this, the target manual steering angle θ ｍｄ The target manual steering angle θ is calculated. ｍｄ The target automatic steering angle θ is given by the vehicle motion domain ECU 202. ａｄ When added, the target integrated steering angle θ ｉ The calculation is performed, and then the actual steering angle θ is calculated. ｐ The target integrated steering angle θ ｉ The drive circuit 78 of the electric motor 118 is controlled to follow this.

[0129] Therefore, in the second embodiment described above, the torsion bar torque (steering torque) T ｔｂ While maintaining control of the steering angle in accordance with the steering torque, it becomes possible to control the steering reaction force by an ECU (ADAS domain ECU 201) that is higher in level than the motor control ECU 205. In other words, in the second embodiment described above, it becomes possible to control the steering reaction force by a control device higher in level than the motor control device while maintaining control of the steering angle in accordance with the steering torque.

[0130] In the second embodiment described above, the rack axial force estimation unit 83 determines the actual steering angle θ ｐ Based on the vehicle speed V, the rack axial force F ｒ It is estimated that the target integrated steering angle θ ｉ Based on the vehicle speed V, the rack axial force F ｒ It is also possible to estimate this.

[0131] Furthermore, the rack axial force estimation unit 83 calculates the target output shaft torque (target integrated steering angle θ) calculated by the angle control unit 92. ｉand the actual steering angle θ ｐ The angular deviation (θ) ｉ -θ ｐ Based on the target output axis torque obtained by performing PD calculation on ), the rack axial force F ｒ It is also possible to estimate the rack axial force. Furthermore, the rack axial force estimation unit 83 may be any unit capable of estimating the rack axial force, and may be any unit capable of estimating the rack axial force using a method different from the one described above.

[0132] In the first embodiment described above, as shown in Figure 2, the reaction force ECU 203 includes a handle operation state determination unit 43 and a multiplication unit 44, but the reaction force ECU 203 does not have to include these. In that case, the add-on reaction force torque T ｃａｄｄ This is given to the addition unit 46.

[0133] Similarly, in the second embodiment described above, as shown in Figure 6, the motor control ECU 205 includes a handle operation state determination unit 84 and a multiplication unit 85, but the motor control ECU 205 does not need to include these. In that case, the add-on reaction torque T ｃａｄｄ This is supplied to the addition unit 87.

[0134] While embodiments of this disclosure have been described in detail, these are merely examples used to illustrate the technical content of this disclosure, and this disclosure should not be construed as being limited to these examples. The scope of this disclosure is limited only to the attached claims.

[0135] 13... Reaction motor, 11... Torque sensor, 19... Steering motor, 41, 61, 81... Rotation angle calculation unit, 42, 62, 82... Reduction ratio division unit, 43, 84... Steering wheel steering state determination unit, 44, 85... Multiplication unit, 45, 86... Target driver torque calculation unit, 46, 87... Addition unit, 47, 88... Torque deviation calculation unit, 48, 89... PD control unit, 49... First target manual steering angle calculation unit, 50, 91... Target integrated steering angle calculation unit, 51... First angle control unit, 90... Target manual steering angle calculation unit, 92... Angle control unit, 74, 83... Rack axis force estimation unit, 201... ADAS domain ECU, 202... Vehicle motion domain ECU, 203... Reaction force ECU, 204... Steering ECU, 205... Motor control ECU

Claims

1. [Correction based on Rule 91 28.11.2025] A steering mechanism mechanically connected to a steering member to steer the steering wheels of a vehicle; an electric motor that applies motor torque to the steering mechanism; and a control unit that calculates a target motor torque based on an external input and controls the electric motor, wherein the input includes steering torque and a target automatic steering angle and target add-on reaction torque to assist the driver's operation, the control unit comprising: a target driver torque calculation unit that calculates a target driver torque to be input by the driver to the steering member; a target integrated driver torque calculation unit capable of calculating a target integrated driver torque by adding the target add-on reaction torque to the target driver torque; a feedback control unit that calculates a feedback control torque by performing torque feedback control so that the steering torque follows the target integrated driver torque; and a target manual steering angle calculation unit that calculates a target manual steering angle based on the feedback control torque and the steering torque, A motor control device including an angle control unit that calculates the target motor torque by performing angle feedback control so that the actual steering angle follows a target integrated steering angle obtained by adding the target manual steering angle to the target automatic steering angle.

2. [Correction based on Rule 91 28.11.2025] Includes a steering mechanism mechanically separated from a steering member and for steering the steering wheels of a vehicle; a reaction motor control device for controlling a reaction motor that applies reaction torque to the steering member; and a steering motor control device for controlling a steering motor that drives the steering mechanism, wherein the reaction motor control device comprises a control unit that calculates a target motor torque based on an external input and controls the reaction motor, the input includes steering torque and a target automatic steering angle and target add-on reaction torque to assist the driver's operation, the control unit comprises a target driver torque calculation unit that calculates a target driver torque that the driver should input to the steering member; a target integrated driver torque calculation unit that can calculate a target integrated driver torque by adding the target add-on reaction torque to the target driver torque; and a feedback control unit that calculates a feedback control torque by performing torque feedback control so that the steering torque follows the target integrated driver torque. A motor control device including: a target manual steering angle calculation unit that calculates a target manual steering angle based on the feedback control torque and the steering torque; and an angle control unit that calculates a target motor torque by performing angle feedback control so that the actual steering angle follows a target integrated steering angle obtained by adding the target automatic steering angle to the target manual steering angle.

3. The motor control device according to claim 1 or 2, wherein the target automatic steering angle and the target add-on reaction torque are provided by a control device higher than the motor control device.

4. The motor control device according to claim 1 or 2, wherein the steering mechanism includes a rack shaft, the motor control device includes a rack shaft force estimation unit that estimates the rack shaft force acting on the rack shaft via the steering wheels, and the target driver torque calculation unit calculates the target driver torque using the rack shaft force estimated by the rack shaft force estimation unit.

Images