JP5369931B2 - Steering control device, angle detection device, and vehicle with steering control device - Google Patents

Description

  The present invention relates to an angle detection device that detects a steered absolute angle of a steered wheel, a steering control device, and a vehicle with a disturbance control device.

  As this type of technology, the technology described in Patent Document 1 below is disclosed. In this publication, when the steering member from the left steering limit position to the right steering limit position is steered, three periodic waveform signals are output, respectively, n times (n + 1) times and (n + 2) times. A device that calculates an absolute steering angle using a difference in signal output values of a resolver is disclosed.

JP 2007-333657 A

  In a steering device that controls steering of a steered wheel according to the steering angle of the steering wheel, the steered angle of the steered wheel is detected, and the detected steered angle becomes an angle according to the steering angle of the steering wheel. Therefore, it is necessary to detect the turning angle. In particular, in a steering device that performs variable steering angle ratio control that varies the steering angle ratio, which is the ratio of the steering angle of the steering wheel and the steering angle of the steering wheel, the steering angle on the steering wheel side and the steering wheel side Since the ratio to the steered angle is not constant, it is necessary to provide angle detection means on each of the steering wheel side and the steered wheel side. The steering wheel side angle (steering angle) detecting means can be installed in the vehicle interior to detect the steering wheel angle, while the steering wheel side angle detecting means is the steering wheel side angle (steering wheel). Angle) must be detected and cannot be installed in the vehicle cabin. Therefore, the steering wheel side angle detection means is installed outside the vehicle room, which is not as good as the vehicle room in terms of environmental temperature, waterproofing and dustproofing.

  By the way, an encoder (a sensor for detecting a digital signal), which is one of the angle detection means, is vulnerable to high temperatures, water, and dust because electronic components are used. On the other hand, since a resolver (sensor that detects an analog signal), which is also one of angle detection means, does not use electronic components, it is superior to an encoder in terms of high temperature resistance, water resistance, and dust resistance. Therefore, a resolver is often used as the angle detection means installed on the steering side. Here, in order to detect an absolute angle using a resolver, it is necessary to install three resolvers as in the above-described prior art, which may increase the cost.

  The present invention has been made paying attention to the above-mentioned problem, and the object of the present invention is to reduce the number of resolvers installed on the steered wheel side and to detect the steering angle, To provide a vehicle with an angle detection device and a steering control device.

  To achieve the above object, according to the present invention, the sum of the steering absolute angle detected by the steering absolute angle detection means, the deviation between the steering absolute angle stored in the deviation storage means and the steering absolute angle, and the steering wheel The difference between the turning angle detection means that detects the angle within the turning angle range at a plurality of cycles and the initial value detected at the start of control is obtained as an offset amount, and the turning angle and offset amount detected by the turning angle detection means Was calculated as the absolute steering angle.

  Therefore, it is not necessary to provide an angle sensor capable of detecting the absolute angle on the steered side, the number of resolvers can be reduced, and the cost can be suppressed.

1 is an overall configuration diagram of a vehicle to which a vehicle steering apparatus according to a first embodiment is applied. It is a graph which shows the relationship between the electrical angle which the resolver type sensor with the number of pole pairs of Example 1 detects, and an actual angle. FIG. 3 is a control block diagram according to the first embodiment. FIG. 3 is a control block diagram of a turning angle command value calculation unit according to the first embodiment. 2 is a variable steering angle ratio map according to the first embodiment. 3 is a flowchart illustrating a flow of a steering absolute angle calculation process performed in a steering absolute angle calculation unit according to the first embodiment. It is a flowchart which shows the flow of the turning absolute angle calculation process performed in the turning absolute angle calculation part of Example 1. FIG. 6 is a flowchart illustrating a flow of a steering absolute angle-steering absolute angle deviation acquisition process according to the first embodiment. 3 is a flowchart illustrating a flow of steered absolute angle estimated value calculation processing according to the first embodiment. It is a flowchart which shows the flow of steering absolute angle calculation of Example 1. FIG. It is a flowchart which shows the flow of the steering absolute angle estimated value correction process of Example 1. FIG. It is a flowchart which shows the flow of the deviation memory process performed in the deviation memory | storage part of Example 1. FIG. It is a flowchart which shows the flow of the deviation memory invalidation process performed in the deviation memory | storage part of Example 1. FIG. 3 is a flowchart illustrating a flow of switching processing between steer-by-wire control and backup mode according to the first embodiment. It is a graph which shows the relationship between the steering angle sensor value of Example 1, and a steering absolute angle. It is a graph which shows the relationship between the steering absolute angle of Example 1, a steering absolute angle, and a vehicle speed.

[Example 1]
A configuration of the vehicle steering apparatus 2 according to the first embodiment will be described.
〔overall structure〕
FIG. 1 is an overall configuration diagram of a vehicle 1 to which a vehicle steering device 2 according to a first embodiment is applied. The vehicle 1 is a steered wheel in which the front wheels 3FL and 3FR of the front wheels 3FL and 3FR and the rear wheels 4RL and 4RR are steered. The vehicle steering apparatus 2 according to the first embodiment is a so-called steer-by-wire system in which the steering wheel 5 and the front wheel 3 are mechanically separated. Further, the vehicle steering apparatus 2 according to the first embodiment variably controls the steering angle ratio, which is the ratio of the steering angle to the steering angle.

(Steering mechanism)
The vehicle steering apparatus 2 according to the first embodiment has a steering wheel 5 that is steered by a driver, a steering shaft 6 that is connected to the steering wheel 5, and a steering angle of the steering wheel 5 that is steered by the driver as a steering-side mechanism. A steering absolute angle sensor 7 (steering absolute angle detection means) for detecting (absolute angle) and a torque (that is, a steering torque of the driver) input to the steering shaft 6 when the steering wheel 5 is steered by the driver. A steering torque sensor 8 to be detected, a reaction force motor 9 connected to the steering wheel 5 via the steering shaft 6, and applying rotational torque (steering reaction force) to the steering wheel 5 via the steering shaft 6, and a reaction force Reaction force motor rotation angle sensor 10 for detecting the rotation angle of the motor 9 The has.

  The steering absolute angle sensor 7 is an encoder-type sensor that outputs a digital signal, and includes an electronic component (arithmetic circuit) that processes the digital signal, and is a sensor that can detect an absolute angle. The steering absolute angle sensor 7 is installed in the living room of the vehicle 1 near the steering wheel 5. The reaction force motor rotation angle sensor 10 is a resolver type sensor that outputs an analog signal, and does not require an electronic component (arithmetic circuit) that processes a digital signal, such as an encoder type sensor.

(Steering mechanism)
The vehicle steering apparatus 2 according to the first embodiment includes a steered motor 11 that steers the front wheels 3, a steered motor rotation angle sensor 12 that detects the angle of the steered motor 11, and steered as a steered side mechanism. A pinion gear 14 connected to the end of the motor shaft 13 of the motor 11, a rack 16 having a rack gear 15 meshing with the pinion gear 14, a tie rod 17 for transmitting the axial force of the rack 16 to the front wheels 3 as a turning force, A steering reaction force sensor 18 that detects a force input in the axial direction of the rack 16 as a steering reaction force acting on the front wheels 3 from the road surface is provided.
The steered motor rotation angle sensor 12 is a resolver type sensor that outputs an analog signal, and does not require an electronic component (arithmetic circuit) that processes a digital signal, such as an encoder type sensor. The steered motor rotation angle sensor 12 is installed in the vicinity of the steered motor 11.

(Backup mechanism)
A vehicle steering apparatus 2 according to the first embodiment is a backup mechanism of a steer-by-wire system. A clutch 19 (connection / disconnection portion) that can mechanically connect and disconnect the steering wheel 5 and the front wheel 3, and a steering wheel via the clutch 19. 5, a pinion shaft 20 that transmits a steering torque of 5, a pinion gear 21 that meshes with the rack gear 15 of the rack 16, and a pinion rotation angle sensor 22 that detects the rotation angle of the pinion gear 21 (steering). Angle detection means).

  The pinion rotation angle sensor 22 is a resolver type sensor and does not have an electronic component (arithmetic circuit). The pinion rotation angle sensor 22 is installed in the vicinity of the pinion gear 21, that is, in the vicinity of the rack 16 (outside the vehicle room). The turning angle of the front wheel 3 is uniquely determined by the rotation angle of the pinion gear 21 and the gear ratio between the rack gear 15 of the rack 16 and the pinion gear 21. Therefore, in the first embodiment, when simply described as “steering angle”, the rotation angle of the pinion gear 21 is shown.

(Resolver type sensor)
The resolver type sensor used for the reaction force motor rotation angle sensor 10, the steering motor rotation angle sensor 12, and the pinion rotation angle sensor 22 will be described. FIG. 2 is a graph showing the relationship between the electrical angle detected by the resolver sensor with 2 pole pairs and the actual angle. The resolver type sensor having the number of pole pairs of 2 can detect a range of 180 ° in the range of electrical angle of 360 °. Here, in FIG. 2, since the electrical angle is 0 ° when the angle is 0 °, the electrical angles of 0 °, 180 °, and 360 ° are 0 ° as the detection value (sensor value) of the resolver type sensor. , 90 °, 180 °. In the following, for simplicity of explanation, sensor values are used instead of electrical angles.

  In addition, as described above, since the resolver sensor with the pole pair number 2 can detect the range of the angle 180 °, for example, when the actual angle is in the range of −720 ° to 720 °, This is 8 cycles. That is, -720 ° to -540 ° for one cycle, -540 ° to -360 ° for two cycles, -360 ° to -180 ° for three cycles, -180 ° to 0 ° for four cycles, 0 ° to 180 ° 5 cycles, 180 ° to 360 ° 6 cycles, 360 ° to 540 ° 7 cycles, 540 ° to 720 ° 8 cycles. Therefore, when the sensor value is 90 °, the actual angle must be either -630 °, -450 °, -270 °, -90 °, 0 °, 90 °, 270 °, 450 °, 630 ° I understand. In other words, the pole pair number resolver type sensor can detect in the range of 180 degrees, but when the sensor value is 90 degrees, the absolute angle is -630 degrees, -450 degrees, -270 degrees, -90 degrees, It is impossible to detect which angle is 0 °, 90 °, 270 °, 450 ° or 630 °.

(Control mechanism)
The vehicle steering apparatus according to the first embodiment includes a reaction force controller 30 that controls the reaction motor 9 and the clutch 19, and a steering controller 40 that controls the steering motor 11 and the clutch 19, as control mechanisms of the devices. ing. The reaction force controller 30 and the turning controller 40 are connected by a communication circuit 24 so that information input by each can be shared.

The reaction force controller 30 performs control of the reaction force motor 9, control of the clutch 19, calculation of a turning angle command value, calculation of the steering absolute angle of the steering wheel 5, and the like.
The reaction force controller 30 includes a rotation angle of the reaction force motor 9 from the reaction force motor rotation angle sensor 10, a turning reaction force from the turning reaction force sensor 18, a vehicle speed from the vehicle speed sensor 23, and a reaction force from the reaction force motor 9. Enter the motor monitor value. The reaction force motor monitor value indicates the drive current, temperature, and the like of the reaction force motor 9.

  The reaction force controller 30 calculates a steering reaction force command value to be applied to the steering wheel 5 based on the steering reaction force detected by the steering reaction force sensor 18, and based on the calculated steering reaction force command value. By controlling the motor 9, the steering reaction force is controlled on the steering wheel 5. The reaction force controller 30 outputs an engagement command to the clutch 19 when the reaction force motor 9 cannot apply the steering reaction force to the steering wheel 5 or when the steering motor 11 cannot perform the steering control of the front wheels 3. .

  Further, the reaction force controller 30 calculates a turning angle command value based on the steering absolute angle detected by the steering absolute angle sensor 7 and the vehicle speed detected by the vehicle speed sensor 23, and converts the turning angle command value. Output to the rudder controller. The reaction force controller 30 determines the steering absolute angle of the steering wheel 5 based on the steering angle detected by the steering absolute angle sensor 7 and the rotation angle of the reaction force motor 9 detected by the reaction force motor rotation angle sensor 10. Calculate and output to the turning controller 40. The steering absolute angle sensor includes, for example, a magnetized rotor provided on the rotation shaft of the steering wheel 5 and an arithmetic circuit that calculates an absolute rotation angle based on a magnetic change accompanying the rotation of the rotor. For example, it is a known magnetic encoder described in Japanese Patent Application Laid-Open No. 2008-224283.

  The turning controller 40 performs control of the turning motor 11, control of the clutch 19, and calculation of the turning absolute angle. The steering controller 40 includes a rotation angle of the steering motor 11 from the steering motor rotation angle sensor 12, a rotation angle of the pinion gear 21 from the pinion rotation angle sensor 22, a steering torque of the steering wheel 5 from the steering torque sensor 8, A steering motor monitor value is input from the steering motor 11, and a steering absolute angle and a steering angle command value are input from the reaction force controller 30. The steered motor monitor value indicates the drive current, temperature, and the like of the steered motor 11.

The turning controller 40 (drive control means) calculates the turning absolute angle based on the steering absolute angle calculated by the reaction force controller 30 and the rotation angle of the pinion gear 21 calculated by the pinion rotation angle sensor 22. Further, the turning controller 40 outputs a turning motor drive current to the turning motor 11 (drive means) based on the deviation between the turning angle command value calculated by the reaction force controller 30 and the calculated turning absolute angle. and, drive controls the steering motor 11 as the steering angle command value and the steering absolute angle matches. When the steered motor monitor value or the reaction force motor monitor value becomes a value indicating abnormality, the steered controller 40 outputs an engagement command to the clutch 19. At this time, the turning controller 40 controls the turning motor 11 so as to assist the driver's steering torque based on the steering torque of the steering wheel 5 detected by the steering torque sensor 8.

[Control block]
FIG. 3 is a control block diagram of the first embodiment. In the control block diagram of FIG. 3, the reaction force controller 30 describes the calculation of the steering absolute angle of the steering wheel 5, and the turning controller 40 describes the control of the turning motor 11 and the calculation of the turning absolute angle.

(Reaction force controller)
The reaction force controller 30 includes a steering absolute angle calculation unit 31 and a steering angle command value calculation unit 32 (steering angle ratio variable means). The steering absolute angle calculation unit 31 inputs the steering absolute angle θh_abs detected by the steering absolute angle sensor 7 and the rotation angle θh_mot of the reaction force motor 9 detected by the reaction force motor rotation angle sensor 10 to input the steering absolute angle. θh is calculated.

  The turning angle command value calculation unit 32 inputs the vehicle speed V detected by the vehicle speed sensor 23 and the steering absolute angle θh calculated by the steering absolute angle calculation unit 31, and calculates a turning angle command value θp_cmd. FIG. 4 is a control block diagram of the turning angle command value calculation unit 32. The turning angle command value calculation unit 32 includes a variable steering angle ratio map 32a and a multiplication unit 32b. FIG. 5 is a variable steering angle ratio map 32a. The steering angle ratio is the ratio of the steering angle to the steering angle. FIG. 5 shows a mechanical steering angle ratio that is a constant steering angle ratio regardless of the vehicle speed, and a variable steering angle ratio that makes the steering angle ratio variable according to the vehicle speed. As shown in FIG. 5, the variable steering angle ratio is set such that the steering angle ratio is set high when the vehicle speed is low, and the steering angle ratio is set lower as the vehicle speed increases. The multiplication unit 32b multiplies the steering absolute angle θh by the steering angle ratio obtained from the variable steering angle ratio map. The multiplied value is output as a turning angle command value θp_cmd.

(Steering controller)
The steering controller 40 includes a steering absolute angle calculation unit 41, a deviation storage unit 42 (deviation storage unit), a steering angle servo control unit 43, a current control driver 44, and a backup mode switching unit 45. doing. The turning absolute angle calculation unit 41 stores the steering absolute angle θh calculated by the steering absolute angle calculation unit 31, the turning angle sensor value θpsens detected by the pinion rotation angle sensor 22, and the deviation storage unit 42. The deviation Δθ is input, and the turning absolute angle θp is calculated. The deviation storage unit 42 inputs the steering absolute angle θh calculated by the steering absolute angle calculation unit 31 and the steering absolute angle θp calculated by the steering absolute angle calculation unit 41, and the steering absolute angle−steering absolute Stores Δθ which is a deviation of the angle. The deviation storage unit 42 has a nonvolatile memory that can retain the stored contents even when the ignition switch is turned off, and the deviation Δθ is stored in the nonvolatile memory.

  The turning angle servo control unit 43 inputs the turning angle command value θp_cmd calculated by the turning angle command value calculation unit 32 and the turning absolute angle θp calculated by the turning absolute angle calculation unit 41. The current command value Ip_cmd corresponding to the deviation between the turning absolute angle θp and the turning angle command value θp_cmd is calculated. The current control driver 44 inputs the current command value Ip_cmd calculated by the steering angle servo control unit 43 and the drive actual current Ip_real which is the steered motor monitor value of the steered motor 11, and the drive actual current Ip_real is The drive current Ip_dri supplied to the steered motor 11 is controlled so that the current command value Ip_cmd is obtained.

  The backup mode switching unit 45 inputs the turning absolute angle θp calculated by the turning absolute angle calculating unit 41, and when the turning absolute angle θp cannot be calculated by the turning absolute angle calculating unit 41, the turning angle The servo control unit 43 instructs to stop the steer-by-wire control and outputs an engagement command to the clutch 19.

[Steering absolute angle calculation processing]
FIG. 6 is a flowchart showing the flow of the steering absolute angle calculation process performed in the steering absolute angle calculation unit 31.

In step S1, it is determined whether or not the ignition switch is ON. When the ignition switch is ON, the process proceeds to step S2, and when the ignition switch is OFF, the process of step S1 is repeated.
In step S2, it is determined whether or not the calculation of the steering absolute angle offset Δθh_ofs is completed. When the calculation of the steering absolute angle offset Δθh_ofs is completed, the process proceeds to step S5, and the calculation of the steering absolute angle offset Δθh_ofs is completed. If not, the process proceeds to step S3.

In step S3, the steering absolute angle θh_abs detected by the steering absolute angle sensor 7 and the rotation angle θh_mot of the reaction force motor 9 detected by the reaction force motor rotation angle sensor 10 are acquired, and the process proceeds to step S4. The steering absolute angle θh_abs and the rotation angle θh_mot of the reaction force motor 9 acquired here are values immediately after the ignition switch is turned on.
In step S4, the steering angle offset θh_ofs is calculated by the following equation (1), and the process proceeds to step S2.
Δθh_ofs = θh_abs-θh_mot… (1)

In step S5, the rotation angle θh_mot of the reaction force motor 9 detected by the reaction force motor rotation angle sensor 10 is acquired, and the process proceeds to step S6. The rotation angle θh_mot of the reaction force motor 9 acquired here is a value acquired after step S3.
In step S6, the steering absolute angle θh is calculated by the following equation (2), and the process ends.
θh = θh_mot + θh_ofs… (2)

Steering absolute angle calculation process is a process for causing improve the steering absolute angle accuracy of the steering wheel 5 which is detected by the steering absolute angle sensor 7, the steering absolute angle when the resolution of the steering absolute angle sensor 7 is high enough The detection value of the sensor 7 may be used as it is.

[Steering absolute angle calculation processing]
FIG. 7 is a flowchart showing the flow of the turning absolute angle calculation process performed in the turning absolute angle calculation unit 41.

In step S11, it is determined whether or not the ignition switch is ON. When the ignition switch is ON, the process proceeds to step S12. When the ignition switch is OFF, the process of step S11 is repeated.
In step S12, a steering absolute angle-steering absolute angle deviation acquisition process described later is performed, and the process proceeds to step S13.

In step S13, a steered absolute angle estimated value calculation process described later is performed, and the process proceeds to step S13.
In step S14, a steered absolute angle calculation process described later is performed, and the process ends.

(Steering absolute angle-Steering absolute angle deviation acquisition process)
FIG. 8 is a flowchart showing a flow of the steering absolute angle-steering absolute angle deviation acquisition process.
In step S21, it is determined whether or not the steering absolute angle-steering absolute angle deviation Δθ is normally stored in the deviation storage unit 42. When the steering absolute angle-steering absolute angle deviation Δθ is normally stored, the process proceeds to step S22. If not, the process proceeds to step S23. The steering absolute angle-steering absolute angle deviation Δθ is a deviation Δθ between the steering absolute angle and the steering absolute angle recorded in the deviation storage unit 42. When the deviation Δθ is not stored in the deviation storage unit 42, it is determined that the steering absolute angle−steering absolute angle deviation Δθ cannot be normally acquired.

In step S22, steering absolute angle−steering absolute angle deviation Δθ is acquired, and the process ends.
In step S23, it is recorded that the steering absolute angle-steering absolute angle deviation Δθ could not be acquired, and the process is terminated.

(Steering absolute angle estimated value calculation processing)
FIG. 9 is a flowchart showing the flow of the steering absolute angle estimated value calculation process.
In step S31, it is determined whether or not the steering absolute angle-steering absolute angle deviation Δθ can be normally acquired. If the deviation Δθ can be normally acquired, the process proceeds to step S32. If the deviation Δθ cannot be normally acquired, the process proceeds to step S33. Migrate to

In step S32, it is determined whether or not the steering absolute angle sensor 7 is normal. When the steering absolute angle sensor 7 is normal, the process proceeds to step S33, and when it is abnormal, the process proceeds to step S35.
In step S33, the steering absolute angle θh calculated by the steering absolute angle calculation unit 31 is acquired, and the process proceeds to step S34.

In step S34, the steered absolute angle estimated value θp * is calculated by the following equation (3), and the process ends.
θp * = θh + Δθ… (3)
In step S35, the fact that the steered absolute angle estimated value θp * cannot be calculated is recorded, and the process ends.

FIG. 10 is a flowchart showing a flow of turning absolute angle calculation.
In step S41, the calculation result of the steered absolute angle estimated value θp * is determined. If the steered absolute angle estimated value θp * has not yet been calculated, the process of step S41 is repeated. When the calculation of the steered absolute angle estimated value θp * is completed, the process proceeds to step S42, and when the steered absolute angle estimated value θp * cannot be calculated, the process proceeds to step S47.

In step S42, it is determined whether or not the pinion rotation angle sensor 22 is normal. If the pinion rotation angle sensor 22 is normal, the process proceeds to step S43. If the pinion rotation angle sensor 22 is abnormal, the process proceeds to step S49.
In step S43, it is determined whether or not the calculation of the pinion rotation angle sensor value offset Δθp has been completed. If the calculation of the offset Δθp has not been completed, the process proceeds to step S44, and the calculation of the offset Δθp has been completed. Control goes to step S47.
In step S44, the steering angle sensor value θpsens detected by the pinion rotation angle sensor 22 is acquired, and the process proceeds to step S45. The steered angle sensor value θpsens acquired here is a value (initial value) immediately after the ignition switch is turned on.

In step S45, a steered absolute angle estimated value correction process described later is performed, and the process proceeds to step S46.
In step S46, the pinion rotation angle sensor value offset Δθp is calculated by the following equation (4) using the steering angle sensor value θpsens detected by the pinion rotation angle sensor 22 for the turning absolute angle θp * corrected in step S45. And the process proceeds to step S43.
Δθp = θp *-θpsens… (4)
In step S47, the steering angle sensor value θpsens detected by the pinion rotation angle sensor 22 is acquired, and the process proceeds to step S48. The steered angle sensor value θpsens acquired here is a value acquired after step S44.

In step S48, the turning absolute angle θp is calculated by the following equation (5) using the turning angle sensor value θpsens and the pinion rotation angle sensor value offset Δθp calculated in step S45, and the process is terminated.
θp = θpsens + Δθp… (5)
In step S49, the fact that the turning absolute angle θp could not be calculated is recorded and the process is terminated.

FIG. 11 is a flowchart showing the flow of the steering absolute angle estimated value correction process.
In step S51, a pinion rotation angle converted value θp * conv obtained by converting the steering absolute angle estimated value θ * into a detectable angle range of the pinion rotation angle sensor 22 by the following equation (6) is calculated, and the process proceeds to step S52. Here, n represents the number of pole pairs of the pinion rotation angle sensor.
The remainder of θp * conv = [θp * / (360 / n)] (6)

In step S52, it is determined whether or not the pinion rotation angle conversion value θp * conv is negative. If the pinion rotation angle conversion value θp * conv is negative, the process proceeds to step S53. Migrate to
In step S53, 360 / n is added to θp * conv, and the process proceeds to step S54.

In step S54, the steering absolute angle estimated value correction amount Δθp * is calculated using the following equation (7), and the process proceeds to step S55.
Δθp * = θp * conv-θpsens… (7)
In step S55, it is determined whether or not the turning absolute angle estimated value correction amount Δθp * is larger than 360 / 2n. If the turning absolute angle estimated value correction amount Δθp * is larger than 360 / 2n, the process proceeds to step S57. If it is 360 / 2n or less, the process proceeds to step S56.

In step S56, it is determined whether or not the steering absolute angle estimated value correction amount Δθp * is smaller than −360 / 2n. If Δθp * is smaller than −360 / 2n, the process proceeds to step S58, and −360 / 2n. If so, the process proceeds to step S59.
In step S57, 360 / n is subtracted from the steering absolute angle estimated value correction amount Δθp *, and the process proceeds to step S59.
In step S58, 360 / n is added to the steering absolute angle estimated value correction amount Δθp *, and the process proceeds to step S59.

In step S59, the corrected steering absolute angle estimated value θp * is calculated using the following equation (8).
θp * = θp *-Δθp *… (8)

[Deviation memory processing]
FIG. 12 is a flowchart showing a flow of the deviation storing process performed in the deviation storing unit 42.
In step S61, the steering absolute angle θh calculated by the steering absolute angle calculation unit 31 and the steering absolute angle θp calculated by the steering absolute angle calculation unit 41 are acquired, and the process proceeds to step S62.

In step S62, the steering absolute angle-steering absolute angle deviation Δθ is calculated using the following equation (9), and the process proceeds to step S63.
Δθ = θh-θp… (9)
In step S63, it is determined whether or not the variable steering angle ratio control is stopped. When the variable steering angle ratio control is stopped, the process proceeds to step S64, and when the variable steering angle ratio control is not stopped, the process returns to step S61. The stop of the variable steering angle ratio control indicates a state where the clutch 19 is engaged or a state where the ignition switch is turned off.
In step S64, steering absolute angle−steering absolute angle deviation Δθ is stored, and the process ends.

[Deviation memory invalidation processing]
FIG. 13 is a flowchart showing a flow of the deviation storage invalidation process performed in the deviation storage unit 42.
In step S71, it is determined whether or not the variable steering angle ratio control is started. If the variable steering angle ratio control is started, the process proceeds to step S72, and if the variable steering angle ratio control is not started. The determination in step S71 is repeated. Whether or not the variable steering angle ratio control has been started may be determined based on whether or not the clutch 19 has been released.
In step S72, the stored deviation Δθ is invalidated and the process is terminated.

[Backup mode switching process]
FIG. 14 is a flowchart showing a flow of a switching process between the steer-by-wire control and the backup mode.
In step S81, the calculation result of the turning absolute angle θp is determined. If the turning absolute angle θp has been calculated, the process proceeds to step S82. If the turning absolute angle θp cannot be calculated, step S81 is performed. The process proceeds to S83, and when the steered absolute angle θp has not yet been calculated, the process of step S81 is repeated.

In step S82, the steering angle command value calculation unit 32 is instructed to perform steer-by-wire control, and the process ends.
In step S83, the steering angle command value calculation unit 32 is instructed to shift to the backup mode, and an engagement command is output to the clutch 19, and the process ends.
In steer-by-wire control, variable steering angle ratio control is performed, and in the backup mode, fixed steering angle ratio (mechanical steering angle ratio) control is performed.

[Steering absolute angle calculation processing operation]
When the ignition switch is ON and the calculation of the steering angle offset Δθh_ofs is not completed, the process proceeds from step S1 to step S2 to step S3 to step S4 in the flowchart of FIG. In step S4, a steering angle offset Δθh_ofs is calculated. When the calculation of the steering angle offset Δθh_ofs is completed, the process proceeds from step S1 to step S2 to step S5 to step S6 in the flowchart of FIG. In step S6, the steering absolute angle θh is calculated.

[Operation of turning absolute angle calculation]
When the ignition switch is ON, the process proceeds from step S11 to step S12 in the flowchart of FIG. In step S12, the steering absolute angle-steering absolute angle deviation acquisition process of FIG. 8 is performed.

  When the steering absolute angle-steering absolute angle deviation Δθ is normally stored in the deviation storage unit 42, the process proceeds from step S21 to step S22 in the flowchart of FIG. 8 to acquire the deviation Δθ. When the deviation Δθ is not normally stored, the process proceeds from step S21 to step S23 in the flowchart of FIG. 8 to record that the deviation Δθ cannot be acquired.

  When the steering absolute angle-steering absolute angle deviation acquisition process ends, the process returns to the flowchart of FIG. 7 and proceeds from step S12 to step S13. In step S13, the steered absolute angle estimated value calculating means process of FIG. 9 is performed.

  When the steering absolute angle-steering absolute angle deviation Δθ is normally acquired and the steering absolute angle sensor 7 is normal, the process proceeds from step S31 to step S32 to step S33 to step S34 in the flowchart of FIG. In step S33, the steering absolute angle θh calculated by the steering absolute angle calculation unit 31 is acquired. In step S34, the steering absolute angle estimated value is calculated based on the steering absolute angle θh and the deviation Δθ stored in the deviation storage unit 42. Calculate θp *. When the steering absolute angle-steering absolute angle deviation Δθ cannot be acquired normally, or when the steering absolute angle sensor 7 is abnormal, the routine proceeds to step S31 → (step S32 →) step S35 to estimate the steering absolute angle. Record that the value θp * cannot be calculated.

  When the steered absolute angle estimated value calculation process ends, the process returns to the flowchart of FIG. 7 and proceeds from step S13 to step S14. In step S14, the turning absolute angle calculation process of FIG. 10 is performed.

  When the calculation of the steering absolute angle estimated value θp * is completed and the pinion rotation angle sensor 22 is normal and the calculation of the pinion rotation angle sensor value offset Δθp is not completed, step S41 → step in the flowchart of FIG. The process proceeds from S42 to step S43 to step S44 to step S45. In step S44, the turning angle sensor value θpsens detected by the pinion rotation angle sensor 22 is acquired. In step S45, the turning absolute angle estimated value correction process of FIG. 11 is performed.

  In the turning absolute angle estimated value calculation process of FIG. 9, the turning absolute angle estimated value θp * is calculated based on the steering absolute angle θh and the steering absolute angle−the turning absolute angle deviation Δθ. The steering absolute angle θh is a value calculated based on the detected value on the steering side, and the steering absolute angle−steering absolute angle deviation Δθ is a value stored at the end of the previous variable steering angle ratio control. The estimation accuracy of this steered absolute angle estimated value θp * is not sufficient. Therefore, in the turning absolute angle estimated value correction process of FIG. 11, the turning absolute angle estimated value θ * is calculated using the turning angle sensor value θpsens detected by the pinion rotation angle sensor 22 that is the detected value on the turning side. I am trying to correct it.

  In the flowchart of FIG. 11, the process proceeds from step S51 to step S52 to (step S53) to step S54. In step S51, a pinion rotation angle converted value θp * conv is calculated by converting the steering absolute angle estimated value θp * into a value within a detectable range of the pinion rotation angle sensor 22. The relationship between the turning angle sensor value θpsens detected by the pinion rotation angle sensor 22 and the turning absolute angle θp will be described. FIG. 15 is a graph showing the relationship between the turning angle sensor value θpsens detected by the pinion rotation angle sensor 22 and the turning absolute angle θp. It is assumed that the number of pole pairs of the pinion rotation angle sensor 22 is 2. The pinion rotation angle sensor 22 having the number of pole pairs of 2 can detect an angle range from 0 ° to 360 ° / 2 (= 180 °). For example, if the steered absolute angle estimated value is 240 °, the steered angle sensor value corresponding to the steered absolute angle 240 ° is 60 °.

  In subsequent steps S52 and S53, the pinion rotation angle converted value θp * conv calculated in step S51 is processed to be a positive value. In step S54, a steered absolute angle estimated value correction amount Δθp * is calculated.

  Subsequently, the process proceeds from step S55 → step S56 → step S59, or step S55 → step S57 → step S59, or step S55 → step S56 → step S58 → step S59. In steps S55 to S58, when the difference between the pinion rotation angle converted value θp * conv and the turning angle sensor value θpsens is larger than 360 ° / 2n, the turning absolute angle estimated value θp * is determined as the pinion rotation angle sensor 22. The steering absolute angle estimated value correction amount [Delta] [theta] p * is calculated. In step S59, a corrected steering absolute angle estimated value θp * is obtained based on the steering absolute angle estimated value correction amount Δθp * before correction and the steering absolute angle estimated value correction amount Δθp *.

  Here, the flow of the steering absolute angle estimated value correction process will be described with reference to specific numerical values and FIG. For example, the steered angle absolute angle estimated value θp * is set to 240 °, and the steered angle sensor value θpsens is set to 70 °. In step S51, the remainder of the pinion rotation angle converted value θp * conv = [240 ° / (360 ° / 2)] = 60 ° is calculated.

  Next, in step S51, since the pinion rotation angle converted value θp * conv = 60 ° ≧ 0, the process proceeds to step S54. In step S54, the steering absolute angle estimated value correction amount Δθp * = 60 ° −70 ° = −10 ° is calculated.

  Next, in step S55, since the steering absolute angle estimated value correction amount Δθp * = − 10 ° ≦ 360 ° / 2 · 2 = 90 °, the process proceeds to step S56. In Step S56, since the steering absolute angle estimated value correction amount Δθp * = − 10 ° ≧ −360 ° / 2 · 2 = −90 °, the process proceeds to Step S59. In step S59, the corrected steering absolute angle estimated value θp * = 240 ° − (− 10 °) = 250 ° is calculated.

  As another specific numerical example, the steered angle absolute angle estimated value θp * is also set to 240 °, and the steered angle sensor value θpsens is set to 160 °. At this time, in step S54, the steering absolute angle estimated value correction amount Δθp * = 60 ° −160 ° = −100 ° is calculated. In step S56, since the steering absolute angle estimated value correction amount Δθp * = − 100 ° <−360 ° / 2 · 2 = −90 °, the process proceeds to step S58 and the steering absolute angle estimated value correction amount Δθp *. Calculated as = -100 ° + 360 ° / 2 = 80 °. In step S59, a corrected steering absolute angle estimated value θp * = 240 ° -80 ° = 160 ° is calculated.

  That is, in step S55 to step S58, among the turning absolute angle corresponding to the turning angle sensor value θpsens, a value close to the uncorrected turning absolute angle estimated value θp * is a corrected turning absolute angle estimated value θp. It is used as *.

  When the steered absolute angle estimated value correction process is completed, the process returns to FIG. 10 and proceeds to step S46. In step S46, the pinion rotation angle sensor value offset value Δθp is calculated based on the corrected turning absolute angle estimated value θ * and the turning angle sensor value θpsens.

  When the calculation of the pinion rotation angle sensor value offset Δθp is completed, the process proceeds from step S47 to step S48. In step S47, the turning angle sensor value θpsens detected by the pinion rotation angle sensor 22 is acquired. In step S48, the turning absolute angle θp is determined based on the pinion rotation angle sensor value offset Δθp and the turning angle sensor value θpsens. calculate.

[Deviation memory processing operation]
When the variable steering angle ratio control is stopped, the process proceeds from step S61 to step S62 to step S63 to step S64 in the flowchart of FIG. In step S62, the steering absolute angle−steering absolute angle deviation Δθ is calculated based on the steering absolute angle θh and the steering absolute angle θp acquired in step S61. In step S <b> 64, the steering absolute angle−steering absolute angle deviation Δθ is stored in the deviation storage unit 42.

[Deviation memory invalidation processing operation]
After the variable rudder angle ratio control is started and when the steering absolute angle-steering absolute angle deviation Δθ has already been acquired in step S22 of the steering absolute angle-steering absolute angle deviation acquisition process (FIG. 8), The process proceeds from step S71 to step S72 to step S73. In step S73, the stored deviation Δθ is invalidated.

[Backup mode switching processing operation]
In the backup mode switching process (FIG. 14), when the calculation of the turning absolute angle θp is completed, the process proceeds from step S81 to step S82. In step S82, steer-by-wire control is performed. When the calculation of the turning absolute angle θp is impossible, the process proceeds from step S81 to step S83. In step S83, the mode is switched to the backup mode.

[Action]
Since the vehicle steering apparatus 2 according to the first embodiment performs variable steering angle ratio control, the ratio between the steering angle and the steering angle is not constant, and it is necessary to detect the steering angle and the steering angle, respectively. Since the steering absolute angle sensor 7 can be provided immediately behind the steering wheel 5, the steering absolute angle sensor 7 can be disposed in the cabin of the vehicle 1. On the other hand, the pinion rotation angle sensor 22 that detects the turning angle is installed in the vicinity of the pinion gear 21. The vicinity of the pinion gear 21 is close to the engine, and water or dust may enter from the lower part of the vehicle 1, which is an unfavorable environment compared to the interior of the vehicle 1 in terms of environmental temperature, waterproofing, dustproofing, and the like. As an angle sensor for detecting an absolute angle, a magnetic encoder using a magnetoresistive element or an optical encoder using a phototransistor is widely used. However, as described above, in terms of environmental temperature, waterproofing, dustproofing, etc. In the vicinity of the pinion gear 21 which is an inferior environment, a sensor including an electronic component (arithmetic circuit) such as an encoder cannot be arranged.

  For this reason, it is conceivable to use, as the pinion rotation angle sensor 22, a resolver that is superior to the encoder in terms of high temperature resistance, water resistance, and dust resistance. For example, as disclosed in JP-A-2007-333657, When the absolute angle is detected using a resolver, the number of resolvers increases, which may increase the cost.

  Therefore, in the turning absolute angle calculation unit 41 of the first embodiment, the sum of the steering absolute angle θh calculated by the steering absolute angle calculation unit 31 and the steering absolute angle−steering absolute angle deviation Δθ stored in the deviation storage unit 42 is calculated. The difference between the turning angle sensor value θpsens detected by the pinion rotation angle sensor 22 at the start of control is obtained as the pinion rotation angle sensor value offset Δθp, and the sum of the turning angle detected by the pinion rotation angle sensor 22 and the offset Δθp is changed. The rudder absolute angle θp is calculated.

  That is, the steering absolute angle sensor 7 capable of detecting the absolute angle provided on the steering side (steering wheel 5 side) and the angle within the steering angle range provided on the steering side (front wheel (steering wheel) 3 side) The turning absolute angle θp is obtained by using a pinion rotation angle sensor 22 that is detected at a plurality of cycles. For this reason, it is not necessary to provide an angle sensor capable of detecting an absolute angle on the steered side, and the number of resolvers can be reduced.

Further, in the turning absolute angle calculation unit 41 of the first embodiment, the steering absolute angle θh calculated by the steering absolute angle calculation unit 31 at the start of control and the steering absolute angle stored in the deviation storage unit 42−the turning absolute angle deviation Δθ. The sum is obtained as the estimated absolute steering angle value θ p *. Then, a value obtained by converting the steering absolute angle estimated value θ p * into a detection angle range of the pinion rotation angle sensor 22 and an initial value of the steering angle sensor value θpsens detected by the pinion rotation angle sensor 22 at the start of control. The difference is obtained as the steering absolute angle estimated value correction amount Δθp *. Further, the difference between the steering absolute angle θh calculated by the steering absolute angle calculation unit 31 and the steering absolute angle−steering absolute angle deviation Δθ stored in the deviation storage unit 42 and the correction amount Δθp * is calculated as the steering absolute angle. It was calculated as θp.
Therefore, the turning absolute angle θp can be calculated by the pinion rotation angle sensor 22 provided on the turning side, and the calculation accuracy of the turning absolute angle θp can be improved.

Further, when the turning absolute angle calculation unit 41 of the first embodiment stops the variable steering angle ratio control, the deviation storage unit 42 stores the deviation Δθ between the steering absolute angle θh and the turning absolute angle θp.
FIG. 16 is a graph showing the relationship between the steering absolute angle θh, the turning absolute angle θp, and the vehicle speed V. In FIG. 16, the solid line indicates the steering absolute angle, the dotted line indicates the steering absolute angle θp when the variable steering angle ratio control is performed, and the alternate long and short dash line indicates that the variable steering angle ratio control is not performed (mechanical steering angle). Ratio) is the absolute steering angle θp. As shown in FIG. 16, since the steering angle ratio changes according to the vehicle speed V when the variable steering angle ratio control is performed, the relationship between the steering absolute angle θh and the steering absolute angle θp is always monitored. There is a need. On the other hand, when the variable steering angle ratio control is not performed, the steering angle ratio is constant regardless of the vehicle speed V. Therefore, the deviation Δθ between the correct steering absolute angle θh and the steering absolute angle θp can be stored.

In the first embodiment, the clutch 19 that connects and disconnects the force transmission between the steering wheel 5 and the front wheel 3 is provided, and the deviation storage unit 42 transmits the force between the steering wheel 5 and the front wheel 3. When connected, the deviation Δθ between the steering absolute angle θh and the turning absolute angle θp is stored.
When the clutch 19 connects the transmission of force between the steering wheel 5 and the front wheel 3, the variable steering angle ratio control is not performed and the steering angle ratio is constant regardless of the vehicle speed V. The deviation Δθ from the absolute angle θp can be stored.

In the first embodiment, the deviation storage unit 42 invalidates the storage of the steering absolute angle-steering absolute angle deviation Δθ when the steering angle command calculation unit 32 starts variable control of the steering angle ratio. did.
When the variable steering angle ratio control is started, the relationship between the steering absolute angle θh and the steering absolute angle θp changes, so that the steering absolute angle-steering absolute angle deviation Δθ stored in the deviation storage unit 42 is used. If the turning absolute angle θp is calculated, an incorrect value is calculated. Therefore, when the variable steering angle ratio control is started, it is possible to prevent the erroneous calculation of the absolute turning angle θp by invalidating the storage of the deviation Δθ.

Further, in the first embodiment, the deviation storage unit 42 calculates the steering absolute angle of the steering wheel 5 and the steering absolute angle of the front wheel 3 when the clutch 19 releases the transmission of force between the steering wheel 5 and the front wheel 3. The memory of deviation was disabled.
When the clutch 19 connects and disconnects the force transmission between the steering wheel 5 and the front wheel 3, the variable steering angle ratio control is performed. Therefore, by invalidating the memory of the deviation Δθ, the erroneous steering absolute angle θp is set. It is possible to prevent calculation.

The turning angle command value calculation unit 32 fixes the steering angle ratio when the turning absolute angle calculation unit 41 cannot acquire the steering absolute angle−the turning absolute angle deviation Δθ from the deviation storage unit 41.
If the steering absolute angle θp is calculated in a state where the steering absolute angle-steering absolute angle deviation Δθ cannot be obtained, an incorrect value is calculated and variable steering angle ratio control cannot be performed. Therefore, it is possible to fix the rudder angle ratio and prevent the variable rudder angle ratio control from being performed with an incorrect turning absolute angle θp.

Further, in the first embodiment, the clutch 19 that connects and disconnects the force transmission between the steering wheel 5 and the front wheel 3 is provided, and the clutch 19 is operated by the steering absolute angle calculation unit 32 to steer the steering wheel 5 from the deviation storage unit. When the deviation between the absolute angle and the absolute turning angle of the front wheel 3 could not be obtained, the clutch 19 connects the transmission of force between the steering wheel 5 and the front wheel 3.
By connecting the transmission of force between the steering wheel 5 and the front wheel 3 by the clutch 19, it is possible to prevent the variable steering angle ratio control from being performed with an incorrect steering absolute angle θp.

〔effect〕
The effects of Example 1 are listed below.

  (1) A steering motor 11 that steers the steered wheels, a steering absolute angle sensor 7 that detects a steering absolute angle of the steering wheel 5 provided on the room side of the vehicle 1, and a front wheel 3 side. A pinion rotation angle sensor 22 that detects an angle within a turning angle range of the front wheel 3 over a plurality of periods, and a deviation storage unit that stores a deviation between a steering absolute angle of the steering wheel 5 and a turning absolute angle of the front wheel 3 42, the difference between the sum of the steering absolute angle detected by the steering absolute angle sensor 7 and the deviation stored in the deviation storage unit 42 and the initial value detected by the pinion rotation angle sensor 22 at the start of control is calculated as the pinion rotation angle sensor offset. And a turning absolute angle calculation unit 41 that calculates the sum of the turning angle sensor value detected by the pinion rotation angle sensor 22 and the offset amount as the turning absolute angle of the front wheels 3 is provided.

  Therefore, the steering absolute angle sensor 7 capable of detecting the absolute angle provided on the steering side (steering wheel 5 side) and the pinion rotation angle sensor 22 provided on the steered side (front wheel (steering wheel) 3 side) are used. It becomes possible to obtain the turning absolute angle. For this reason, it is not necessary to provide an angle sensor capable of detecting the absolute angle on the steered side, the number of resolvers can be reduced, and the cost can be reduced.

(2) The turning absolute angle calculation unit 41 converts the sum of the steering absolute angle calculated by the steering absolute angle sensor 7 at the start of control and the deviation stored in the deviation storage unit 42 into the detection angle range of the pinion rotation angle sensor 22. A difference between the calculated value and the initial value detected by the pinion rotation angle sensor 22 at the start of control as a correction amount, and the sum of the steering absolute angle detected by the steering absolute angle sensor 7 and the deviation stored in the deviation storage means; The difference from the correction amount is calculated as the absolute turning angle of the front wheel 3.
Therefore, the turning absolute angle θp can be calculated by the pinion rotation angle sensor 22 provided on the turning side, and the calculation accuracy of the turning absolute angle θp can be improved.

(3) The deviation storage unit 42 stores the deviation between the steering absolute angle of the steering wheel 5 and the absolute steering angle of the front wheel 3 when the steering angle command value calculation unit 32 stops the variable control of the steering angle ratio. I tried to do it.
Since the steering angle ratio is constant regardless of the vehicle speed V when the variable steering angle ratio control is not performed, the deviation Δθ between the correct steering absolute angle θh and the turning absolute angle θp can be stored.

(4) The clutch 19 that connects and disconnects the force transmission between the steering wheel 5 and the front wheel 3 is provided, and the deviation storage unit 42 connects the force transmission between the steering wheel 5 and the front wheel 3. Sometimes, the deviation between the absolute steering angle of the steering wheel 5 and the absolute steering angle of the front wheel 3 is stored.
When the clutch 19 connects the transmission of force between the steering wheel 5 and the front wheel 3, the variable steering angle ratio control is not performed and the steering angle ratio is constant regardless of the vehicle speed V. The deviation Δθ from the absolute angle θp can be stored.

(5) When the turning angle command value calculation unit 32 starts variable control of the steering angle ratio, the deviation storage unit 42 stores a deviation between the steering absolute angle of the steering wheel 5 and the absolute turning angle of the front wheel 3. I made it invalid.
Therefore, it is possible to prevent the erroneous calculation of the absolute turning absolute angle θp.

(6) The deviation storage unit 42 determines the deviation between the steering absolute angle of the steering wheel 5 and the steering absolute angle of the front wheel 3 when the clutch 19 releases the transmission of force between the steering wheel 5 and the front wheel 3. The memory was invalidated.
Therefore, it is possible to prevent the erroneous calculation of the absolute turning absolute angle θp.

(7) The turning angle command value calculation unit 32 cannot acquire the deviation between the steering absolute angle of the steering wheel 5 and the turning absolute angle of the front wheel 3 from the deviation storage unit 41 in the turning absolute angle calculation unit 41. Sometimes the steering angle ratio was fixed.
Therefore, it is possible to prevent the variable steering angle ratio control from being performed with an incorrect turning absolute angle θp.

(8) The clutch 19 has a clutch 19 for connecting and disconnecting force between the steering wheel 5 and the front wheel 3. The clutch 19 has a steering absolute angle calculation unit 32 that determines the steering absolute angle of the steering wheel 5 from the deviation storage unit. When the deviation from the absolute steering angle of the front wheel 3 could not be acquired, the transmission of force was connected between the steering wheel 5 and the front wheel 3 by the clutch 19.
Therefore, it is possible to prevent the variable steering angle ratio control from being performed with an incorrect turning absolute angle θp.

  (9) The room side of the vehicle 1 having the steering motor 11 that varies the steering angle ratio, which is the ratio between the steering angle of the steering wheel 5 and the steering angle of the front wheels 3 that are steered in accordance with the steering of the steering wheel 5. A steering absolute angle sensor 7 for detecting the steering absolute angle of the steering wheel 5 and a pinion rotation angle sensor 22 for detecting an angle within a turning angle range of the front wheel 3 provided on the front wheel 3 side in a plurality of cycles. A deviation storage unit 42 that stores a deviation between a steering absolute angle of the steering wheel 5 and a steering absolute angle of the front wheel 3, a steering absolute angle detected by the steering absolute angle sensor 7, and a deviation stored in the deviation storage unit 42 And the initial value detected at the start of control by the pinion rotation angle sensor 22 is obtained as a pinion rotation angle sensor offset, and the turning detected by the pinion rotation angle sensor 22 is obtained. The sum of the degree sensor value and the offset amount is provided a steering absolute angle calculating section 41 that calculates a steering absolute angle of the front wheel 3.

  Therefore, the steering absolute angle sensor 7 capable of detecting the absolute angle provided on the steering side (steering wheel 5 side) and the pinion rotation angle sensor 22 provided on the steered side (front wheel (steering wheel) 3 side) are used. It becomes possible to obtain the turning absolute angle. For this reason, it is not necessary to provide an angle sensor capable of detecting an absolute angle on the steered side, and the number of resolvers can be reduced.

  (10) The room side of the vehicle 1 having the steering motor 11 that varies the steering angle ratio, which is the ratio between the steering angle of the steering wheel 5 and the steering angle of the front wheel 3 that steers as the steering wheel 5 is steered. The steering absolute angle sensor 7 for detecting the steering absolute angle of the steering wheel 5 and the pinion rotation angle for detecting the angle within the turning angle range of the front wheel 3 over a plurality of cycles provided on the front wheel 3 side. A deviation between a steering absolute angle of the steering wheel 5 and a steering absolute angle of the front wheel 3, and a deviation stored in the deviation storage unit 42 and a steering absolute angle detected by the steering absolute angle sensor 7. And the difference between the initial value detected by the pinion rotation angle sensor 22 at the start of control is obtained as a pinion rotation angle sensor offset, and the turning angle detected by the pinion rotation angle sensor 22 The sum of the sensor values and the offset amount was calculated as the steering absolute angle of the front wheel 3.

  Therefore, the steering absolute angle sensor 7 capable of detecting the absolute angle provided on the steering side (steering wheel 5 side) and the pinion rotation angle sensor 22 provided on the steered side (front wheel (steering wheel) 3 side) are used. It becomes possible to obtain the turning absolute angle. For this reason, it is not necessary to provide an angle sensor capable of detecting an absolute angle on the steered side, and the number of resolvers can be reduced.

  (11) In the vehicle 1, a steering motor 11 that varies a steering angle ratio that is a ratio between a steering angle of the steering wheel 5 and a steering angle of the front wheels 3 that are steered in accordance with the steering of the steering wheel 5, and the vehicle The steering absolute angle sensor 7 for detecting the steering absolute angle of the steering wheel 5 provided on the room 1 side and the angle within the turning angle range of the front wheel 3 provided on the front wheel 3 side are detected over a plurality of cycles. A pinion rotation angle sensor 22 that performs the deviation, a deviation storage unit 42 that stores a deviation between the steering absolute angle of the steering wheel 5 and the steering absolute angle of the front wheel 3, and a steering absolute angle and deviation storage unit that are detected by the steering absolute angle sensor 7. The difference between the sum of the deviations stored in 42 and the initial value detected by the pinion rotation angle sensor 22 at the start of control is obtained as a pinion rotation angle sensor offset, and the pinion rotation angle sensor is obtained. 22 is provided with steering absolute angle calculating section 41 for calculating a sum of the steering angle sensor value and the offset amounts detected as the steering absolute angle of the front wheel 3.

  Therefore, the steering absolute angle sensor 7 capable of detecting the absolute angle provided on the steering side (steering wheel 5 side) and the pinion rotation angle sensor 22 provided on the steered side (front wheel (steering wheel) 3 side) are used. It becomes possible to obtain the turning absolute angle. For this reason, it is not necessary to provide an angle sensor capable of detecting an absolute angle on the steered side, and the number of resolvers can be reduced.

[Other embodiments]
The best mode for carrying out the present invention has been described based on the first embodiment. However, the specific configuration of the present invention is not limited to the first embodiment and does not depart from the gist of the present invention. Any change in the design of the range is included in the present invention.

  For example, in the first embodiment, the turning angle is detected by the pinion rotation angle sensor 22, but the turning angle may be detected by using the turning motor rotation angle sensor 12. This is because the turning angle of the front wheel 3 is uniquely determined by the rotation angle of the pinion gear 14 and the gear ratio between the rack gear 15 of the rack 16 and the pinion gear 14.

  In the first embodiment, the absolute steering angle sensor 7 is an encoder type sensor, but a resolver type sensor may be used as long as the absolute angle can be detected.

  Moreover, in Example 1, although the deviation memory | storage part 42 was provided in the steering controller 40, you may provide in the reaction force controller 30, and you may provide in both. When both are provided, redundancy can be provided for maintaining the steering absolute angle-steering absolute angle deviation Δθ.

DESCRIPTION OF SYMBOLS 1 Vehicle 2 Steering device 2 for vehicles Steering wheel 3 Front wheel (steering wheel)
7 Steering absolute angle sensor (steering absolute angle detection means)
19 Clutch (connection / disconnection)
22 Pinion rotation angle sensor (steering angle detection means)
32 Steering angle command value calculation unit (steering angle ratio variable means)
41 Steering absolute angle calculation part (steering absolute angle calculation means)
42 Deviation storage unit (deviation storage means)
45 Backup mode switching part

Claims (11)

Steering absolute angle detection means for detecting a steering absolute angle within the steering angle range of the steering wheel provided on the vehicle interior side;
Steering angle detection means that is provided outside the room of the vehicle and detects an angle within the steering angle range of the steered wheels as a steering detection angle over a plurality of cycles,
Steering absolute angle calculation means for calculating the steering absolute angle of the steered wheels using the steering absolute angle and the steering detection angle;
Deviation storage means for storing said steering absolute angle of the steering wheel is last the phase absolute angle detecting means detects the deviation between the steering absolute angle of the steering wheel is last the steering absolute angle calculating means to calculate and,
Driving means for steering drive the steerable wheels,
Drive control means for controlling the drive means based on the turning angle command value corresponding to the steering absolute angle and the turning absolute angle ;
Have
The steering absolute angle calculating means is
The difference between the sum of the steering absolute angle detected by the steering absolute angle detection means and the deviation stored in the deviation storage means and the initial value detected by the turning angle detection means at the start of control is obtained as an offset amount. ,
A steering control device , wherein a sum of the detected steering angle detected by the steering angle detecting means and the offset amount is calculated as a steered absolute angle of the steered wheel . The steering control device according to claim 1, wherein
The turning absolute angle calculating means is configured to calculate a sum of the steering absolute angle detected by the steering absolute angle detecting means and the deviation stored in the deviation storing means at the start of control of the steering control device. The difference between the value converted into the detected angle range and the initial value detected by the turning angle detecting means at the start of control is obtained as a correction amount, and the absolute steering angle detected by the absolute steering angle detecting means and the deviation memory are obtained. A steering control device, wherein a difference between the sum of the deviation stored in the means and the correction amount is calculated as the turning absolute angle of the steered wheel. In the steering control device according to claim 1 or 2,
The drive control means is means for performing steering angle ratio variable control for making the steering angle of the steered wheels variable with respect to the steering angle of the steering wheel,
It said deviation storage means, when said drive control means stops the steering ratio - variable control, storing the deviation between the steering absolute angle and the steering absolute angle of the steering wheel of the steering wheel A steering control device characterized by that. The steering control means according to claim 3,
A connection part for connecting and disconnecting force transmission between the steering wheel and the steering wheel;
The deviation storage means is configured such that when the connecting / disconnecting portion connects transmission of force between the steering wheel and the steered wheel, the steering absolute angle of the steering wheel and the steered absolute of the steered wheel A steering control device that stores the deviation from an angle. In the steering control device according to claim 3,
It said deviation storage means, when said drive control means starts the steering angle ratio - variable control, storage of the deviation between the steering absolute angle and the steering absolute angle of the steering wheel of the steering wheel A steering control device characterized by being invalidated. The steering control device according to claim 4, wherein
The deviation storage means, when the connecting / disconnecting part releases the transmission of force between the steering wheel and the steered wheel, the steering absolute angle of the steering wheel and the steered absolute of the steered wheel. A steering control device that invalidates storage of the deviation from an angle. The steering control device according to any one of claims 1 to 6,
The drive control means is means for performing steering angle ratio variable control for making the steering angle of the steered wheels variable with respect to the steering angle of the steering wheel,
Said drive control means in the steering absolute angle calculating means, when it does not acquire the deviation between the steering absolute angle and the steering absolute angle of the steering wheel of the steering wheel from the deviation storage means, A steering control device, wherein the steering angle ratio is fixed. The steering control means according to claim 7,
A connection part for connecting and disconnecting force transmission between the steering wheel and the steering wheel;
The disengaging section, at the steering absolute angle calculating means, when it does not acquire the deviation between the steering absolute angle and the steering absolute angle of the steering wheel of the steering wheel from the deviation storage means, A steering control device characterized in that transmission of force is connected between the steering wheel and the steered wheel by the connecting and disconnecting portion. Only set the room inside of the vehicle, the steering absolute angle detection means for detecting a steering absolute angle within the steering angle range of the steering wheel,
Provided room outside of the vehicle, and steering angle detecting means for detecting over a plurality of cycles the angle of the steering angle range of the steering wheel as a steering detection angle,
Steering absolute angle calculation means for calculating the steering absolute angle of the steered wheels using the steering absolute angle and the steering detection angle;
Deviation storage means for storing said steering absolute angle of the steering wheel is last the phase absolute angle detecting means detects the deviation between the steering absolute angle of the steering wheel is last the steering absolute angle calculating means to calculate When,
Have
The steering absolute angle calculating means is
The difference between the sum of the steering absolute angle detected by the steering absolute angle detection means and the deviation stored in the deviation storage means and the initial value detected by the turning angle detection means at the start of control is obtained as an offset amount. ,
Angle detecting device comprising a Turkey to calculate the sum of the steering detection angle and the offset amount in which the steering angle detecting means detects the rotation steering absolute angle of the steering wheel. Only set the room inside of the vehicle, the steering absolute angle detection means for detecting a steering absolute angle within the steering angle range of the steering wheel,
Provided room outside of the vehicle, and steering angle detecting means for detecting over a plurality of cycles the angle of the steering angle range of the steering wheel as a steering detection angle,
Have
In the angle detection method for calculating the steered absolute angle of the steered wheel using the absolute steering angle and the steered detection angle,
Storing the deviation between the steering absolute angle of the steering wheel detected by the previous steering absolute angle detection means and the steering absolute angle of the steered wheel calculated last time ;
Wherein the sum of the steering absolute angle detecting means detects the steering absolute angle and the previous SL deviation, determines the difference between the initial value the steering angle detecting means detects at the start of control as an offset amount,
Angle detection method characterized by calculating the sum of the steering detection angle and the offset amount in which the steering angle detecting means detects the rotation steering absolute angle of the steering wheel. Only set the room inside of the vehicle, the steering absolute angle detection means for detecting a steering absolute angle within the steering angle range of the scan tearing wheel,
Provided room outside of the vehicle, and steering angle detecting means for detecting over a plurality of cycles the angle of the steering angle range of the steering wheel as a steering detection angle,
Steering absolute angle calculation means for calculating the steering absolute angle of the steered wheels using the steering absolute angle and the steering detection angle;
Deviation storage means for storing said steering absolute angle of the steering wheel is last the phase absolute angle detecting means detects the deviation between the steering absolute angle of the steering wheel is last the steering absolute angle calculating means to calculate and,
Driving means for steering drive the steerable wheels,
Drive control means for controlling the drive means based on the turning angle command value corresponding to the steering absolute angle and the turning absolute angle ;
Have
The steering absolute angle calculating means is
The difference between the sum of the steering absolute angle detected by the steering absolute angle detection means and the deviation stored in the deviation storage means and the initial value detected by the turning angle detection means at the start of control is obtained as an offset amount. ,
A vehicle with a steering control device , wherein a sum of the detected steering angle detected by the steering angle detection means and the offset amount is calculated as a steered wheel absolute angle .

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