WO2014148087A1

WO2014148087A1 - Power steering device and controller of power steering device

Info

Publication number: WO2014148087A1
Application number: PCT/JP2014/050988
Authority: WO
Inventors: 輝幸大西; 木村　誠
Original assignee: 日立オートモティブシステムズステアリング株式会社
Priority date: 2013-03-19
Filing date: 2014-01-20
Publication date: 2014-09-25
Also published as: JPWO2014148087A1

Abstract

In this steering device, the consumed power is reduced as much as possible when ignition is off. Provided are steering operation detection devices (first and second Hall switches) (14a, 14b) for detecting the steering operation of a steering wheel when the ignition of the vehicle is off or when an accessory switch is off. When the steering operation detection devices (14a, 14b) detect a steering operation of the steering wheel while the ignition is off or the accessory switch is off, a current is conducted to a steering angle detection device (a motor rotation angle sensor) (13) in a wake-up circuit (24) to make a transition to normal steering angle detection by the steering angle detection device.

Description

POWER STEERING DEVICE AND CONTROL DEVICE FOR POWER STEERING DEVICE

The present invention relates to a power steering apparatus and its control apparatus, and more particularly to a steering angle detection method for steering.

In order to detect a steering angle in a car, a system has been constructed which can be detected using an existing sensor without newly providing a dedicated sensor. For example, the sensor for detecting the steering angle of the steering wheel is omitted by converting the rotation angle of the motor detected by the motor rotation angle sensor into an absolute steering angle which is a steering angle from the neutral state of the steering.

As a technique of detecting an absolute steering angle of a steering wheel using a motor rotation angle sensor, the following patent document 1 is disclosed.

JP 2011-201451 A

However, when converting the absolute steering angle of the steering wheel using the motor rotation angle, it must be a mechanism that can store the absolute steering angle even when the ignition is off and can always detect the rotation angle of the motor. Therefore, it is necessary to operate the motor rotation angle sensor even when the ignition is off, which causes a problem of consuming power.

The present invention has been made in view of such technical problems, and it is an object of the steering apparatus to reduce the power consumption when the ignition is off.

The present invention is provided with a steering operation detection device capable of detecting a steering operation of a steering wheel when ignition of the vehicle or accessory switch is off, and when the steering operation detection device detects steering operation of the steering wheel when ignition is off or accessory switch is off In the wake-up circuit, the steering angle detection device is energized to shift to the normal steering angle detection by the steering angle detection device.

According to the present invention, in the steering apparatus, it is possible to reduce the power consumption when the ignition is off.

It is a schematic diagram showing a power steering device in an embodiment. It is a schematic diagram showing a steering angle detection device and a steering operation detection device in an embodiment. It is a graph which shows the output signal of hall switch. It is a graph showing intermittent operation of a hall switch. It is a graph which shows the latch function of the output signal of Hall switch. It is a graph which shows the detectable range of a Hall switch. It is a circuit block diagram of ECU in an embodiment. It is the schematic which shows the other example of a magnet. It is the schematic which shows the other example of the arrangement | positioning method of a GMR element and a Hall switch. It is the schematic which shows the other example of the arrangement | positioning method of a GMR element and a Hall switch. It is the schematic which shows the other example of a power steering apparatus. It is the schematic which shows the other example of a power steering apparatus.

Hereinafter, embodiments of a power steering apparatus and a control apparatus therefor according to the present invention will be described in detail based on FIGS. 1 to 12.

[Embodiment]
FIG. 1 is a schematic view showing a power steering apparatus according to the present embodiment. In the power steering apparatus shown in FIG. 1, a basic steering mechanism is configured by a steering wheel SW, a steering shaft 1 as a steering shaft 1, a torsion bar (not shown), a pinion shaft 2 and a rack shaft 3. In this steering mechanism, when the steering wheel SW is turned by the driver, the steering shaft 1 is rotated and the torsion bar is twisted, and the elastic deformation of the torsion bar which is generated based on the torsion deformation of the torsion bar The pinion shaft 2 rotates. The rotational movement of the pinion shaft 2 is converted into the linear movement of the rack shaft 3, and the left and right steered wheels W, W connected to both ends of the rack shaft 3 are steered. That is, the rack shaft 3 is formed with rack teeth in which the pinion shaft 2 is engaged, and a conversion mechanism configured to convert the rotation of the steering shaft 1 into turning operation by meshing the rack teeth and the pinion shaft is configured. .

The housing of the pinion shaft 2 is provided with a torque sensor (not shown) for detecting the steering angle of the steering wheel SW, and a control device based on the output signal of the torque sensor and the output signal of the motor rotation sensor and vehicle speed information The electric current control of the electric motor M is performed by an ECU 4 (hereinafter referred to as an ECU), and a steering assist force is applied to the rack shaft 3 from the electric motor M via a reduction gear (not shown).

The electric motor M is a brushless motor, and includes a rotor, a stator, and a motor rotation angle sensor that detects the rotational position of the rotor.

As shown in FIG. 2, the motor rotation angle sensor includes a multipolar magnet 12 attached to the end of a motor shaft 11 which is a rotation shaft of the electric motor M, and a motor rotation angle sensor IC mounted on a substrate 15 ( In the present embodiment, the GMR element: hereinafter referred to as a GMR element) 13 is provided. In the present embodiment, the magnet 12 is configured of two poles, and configured such that the N pole 180 ° and the S pole 180 ° in the direction around the axis of the motor shaft 11. The GMR element 13 (steering angle detection device) is mounted on the opposite side of the magnet 12 via an air gap. The motor rotation angle sensor detects the rotational position of the motor shaft 11 based on the change of the magnetic field of the magnet 12.

The ECU 4 is provided with: rotation angle information of the motor shaft 11 which is an output signal of the GMR element 13; and rotation number information obtained by counting how many rotations of the motor shaft 11 have made in a clockwise direction or a counterclockwise direction. Based on this, an absolute steering angle which is a steering angle from the neutral state of the steering wheel SW is calculated. Thus, the motor rotation angle sensor is also used as a steering angle detection device, and absolute angle information of the steering wheel SW can be obtained without providing a steering angle sensor capable of detecting an absolute steering angle.

Further, as shown in FIG. 2, around the GMR element 13 of the substrate 15, first and

second Hall switches

14a and 14b as a detection unit are mounted. The first and

second hall switches

14a and 14b are disposed around the axis of the motor shaft 11 with a magnetic angle of 90 degrees out of phase with each other. The magnet 12 and the first and second hall switches 14a and 14b constitute a steering operation detection device.

As shown in FIG. 3, the first and second Hall switches 14 a and 14 b output a high signal or a low signal according to a change in magnetic flux density, and detect the rotational position of the motor shaft 11. In this embodiment, since the magnet 12 has two poles and an N pole 180 ° and an S pole 180 °, the output signals of the first and

second Hall switches

14a and 14b are 180 high and low signals. It is output alternately every °, and one cycle becomes 360 °.

Since the first and

second hall switches

14a and 14b are arranged with a phase difference of 90 degrees in magnetic angle, four combinations of high and low signals of the first and

second hall switches

14a and 14b can be made. Therefore, it is possible to detect which area among the areas obtained by dividing the range of 360 degrees by 90 degrees by the output signals of the first and

second Hall elements

14a and 14b.

Further, among the signals outputted by the first and

second hall switches

14a and 14b, the motor shaft 11 is produced based on both the rising of the high signal to the low signal and the falling of the low signal to the high signal. Since the rotational position is detected, the amount of information is doubled as compared to the case where only one of rising and falling is considered, and the rotational position of the motor shaft 11 can be detected finely. Furthermore, the rotation direction of the motor shaft 11 can also be detected by a combination of rising and falling of the output signals of the first and

second hall switches

14a and 14b.

As shown in FIG. 4, the first and

second Hall switches

14a and 14b are intermittently operated by a pulse drive method. The first in this embodiment, the second Hall switch 14a, the 14b, as shown in FIG. 4, a large current value capable of detecting the magnetic flux density is the period the supply of t _op as the operation time, the sampling of the magnetic flux density Is done. Thereafter, a small current value is supplied as a standby time during a period of t _stb , and sampling of the magnetic flux density is not performed in this standby period. After that, similarly, the operation time and the waiting time are repeated, and the intermittent operation is performed.

However, the signals output from the first and

second hall switches

14a and 14b maintain the output signal of the previous operation time even in the standby time in which sampling is not performed. Therefore, it is possible to obtain an output signal as a provisional value even in a standby time in which sampling is not performed.

As a result, as shown in FIG. 5, when the magnetic field (for example, the N pole) of the magnet approaches the first and

second Hall switches

14a and 14b and the magnetic flux density exceeds B _op , the first and second Hall switches 14a , maintaining the value of 14b output V _Q is low signal switched from a high signal to a low signal, the magnetic field of the magnet (for example, N pole) away from the first,

second Hall switch

14a, 14b, magnetic flux density B becomes lower than _rp, first, second Hall switch 14a, the output V _Q of 14b maintains a high signal switched from low signal to high signal.

Further, as shown in FIG. 6, the first and

second hall switches

14a and 14b can detect 180 ° clockwise and counterclockwise, respectively, when the magnet 12 has two poles, Detection can be performed in a total range of 360 °. On the other hand, when the rotational position changes beyond the range of 360 ° (± 180 °), the rotational position of the motor shaft 11 is 360 ° (± 180 °) in the first and

second hall switches

14a and 14b. It can not be determined if it has changed within the range or if it has changed 360 ° from there.

Therefore, the waiting time is set to be shorter than the shortest possible time required for the motor shaft 11 to rotate 180 degrees. Thus, the rotational position of the motor shaft 11 can be detected before the motor shaft 11 rotates 180 degrees or more.

Further, the first and

second Hall switches

14a and 14b are controlled so that the current value becomes large in a cycle shorter than the rotation of the rotary shaft by 90 degrees of magnetic angle. That is, by setting the standby time to the shortest possible period of time required for the motor shaft 11 to rotate 90 °, the motor shaft 11 may change in angle by 90 ° or more during the standby time. Thus, the change in the rotational position of the motor shaft 11 can be reliably reflected on the output signals of the first and second hall switches 14a and 14b.

Here, the wake-up function of the steering apparatus in the present embodiment will be described based on the block diagram of FIG. 7. The ECU 4 comprises a substrate 15, a power supply 21 for constantly supplying power even when the ignition is off, first and second hall switches 14a and 14b which are the steering operation detecting devices, and first and second hall switches 14a and 14b. A wake-up circuit 24 for activating the power IC 22 based on the signal, a power IC 22 which is a main power source and does not supply power when the ignition is off, a microcomputer for calculating a command signal for driving and controlling the electric motor M (hereinafter referred to as MPU and And a GMR element (motor rotation angle sensor IC) 13, 13. The power supply 21 and the power supply IC 22 constitute a power supply circuit. The power supply 21 is for operating only the first and second hall switches 14a and 14b and the wakeup circuit 24 and has a small capacity. The power is supplied from the power supply IC 22 to the MPU 25 and the GMR element 13.

After the ignition is turned off, there is no change in the steering angle for a predetermined time, and if the changes in the first and second hall switches 14a and 14b are not detected, the sleep mode is entered to turn off the power supply IC 22 of the ECU 4 to reduce power consumption. At this time, the absolute steering angle based on the output signal of the GMR element 13 is stored in the storage circuit 26 of the MPU 25. The power supply 21 supplies power to the first and second hall switches 14a and 14b and the wakeup circuit 24.

In the sleep mode, when the motor shaft 11 is rotated by steering of the steering wheel SW and the output signals of the first and second hall switches 14a and 14b change, the wakeup circuit 24 activates the power supply IC 22, and the MPU 25 and GMR element The electric power is supplied to 13, and the rotational position detection of the motor shaft 11 by the GMR element 13 and the absolute steering angle calculation of the steering wheel SW are restarted.

In the absolute steering angle calculation of the steering wheel SW, the absolute steering angle of the steering shaft 11 stored in the storage circuit 26 of the MPU 25 when the ignition is off, and the rotation of the motor shaft 11 detected by the first and second hall switches 14a and 14b. Based on the corners, estimate the current steering angle.

As described above, according to the power steering apparatus of this embodiment, when the ignition is off, the first and second hall switches 14a and 14b, which consume relatively low power, are energized to perform steering operation. By energizing the GMR element 13, it is possible to obtain steering angle information in consideration of the steering operation performed during the ignition off time while the power consumption is suppressed while the ignition is on.

The first and second hall switches 14a and 14b and the wakeup circuit 24 are supplied with power from a power supply 21 different from the power supply IC 22 for supplying power to the ECU 4. When sharing the same power supply as the ECU 4 that consumes a large current, it is necessary to flow a large current to supply power to the first and second Hall switches 14a and 14b while the ignition is off, but it is different from the ECU 4 side By supplying power from the power supply 21 to the first and second hall switches 14a and 14b, it is possible to suppress power consumption during ignition off.

In addition, since the first and second hall switches 14a and 14b used as the steering operation detection device in the embodiment are elements performing intermittent operation, power consumption can be suppressed for the standby time, which is significantly larger than that of the always-on type. Power consumption can be reduced.

Further, since the GMR element 13 and the first and second hall switches 14a and 14b share the same magnet 12, the apparatus can be simplified. Furthermore, since the steering operation detection device is configured by at least two poles (one each of N and S) and a pair of Hall switches, the steering operation detection device can be configured inexpensively.

Further, in the present embodiment, the magnet 12 having two poles has been described, but the number of poles of the magnet 12 is not limited to two. For example, as shown in FIG. 8, the magnet 12 may be arranged in four poles around the axis of the motor shaft 11. In FIG. 8, the S pole and the N pole are alternately arranged at every magnetic angle of 90 ° around the axis of the motor shaft 11. As described above, when the magnet 12 is configured with four poles, resolution twice as high as that with two poles can be obtained. That is, when the magnet 12 has two poles, the output signals of the first and second hall switches 14a and 14b have one cycle of 360 °, and the high signal and the low signal are repeated every 180 °, When the magnet 12 has four poles, the output signals of the first and second Hall switches 14a and 14b have one cycle of 180 °, and repeat high and low signals every 90 °. Therefore, detection accuracy equal to or more than that of two Hall switches can be realized, and cost reduction can be expected by reducing the number of parts.

Further, since the GMR element 13 and the first and second hall switches 14a and 14b are disposed on the same surface (the magnet 12 side) of the substrate 15, the mountability (assembling ability) of the elements and sensors on the substrate 12 is improved. Do.

Further, as shown in FIG. 9, the GMR element 13 and the first and second Hall switches 14a and 14b may be disposed on the back surface of the substrate 15 (the opposite side of the magnet 12).

Furthermore, as shown in FIG. 10, the GMR element 13 and the first and second Hall switches 14a and 14b may be disposed on different surfaces of the substrate 15. Thereby, the mounting range of the GMR element 13 and the first and second Hall switches 14a and 14b on the projection surface of the substrate 15 is suppressed without overlapping the mounting positions of the GMR element 13 and the first and second Hall switches 14a and 14b. can do. As a result, the magnet 12 can be miniaturized.

Further, the timing of storing the absolute steering angle in the storage circuit 26 may be set as the time when the door of the vehicle is locked. Even after the ignition is turned off, the steering operation may be performed as long as the driver is in the vehicle, but after the door lock, the possibility of the steering operation is extremely low, so the absolute steering angle at this time The accuracy of absolute steering angle information at reignition ON can be improved by storing

Further, the timing at which the absolute steering angle is stored in the storage circuit 26 may be a time when there is no steering operation for a predetermined time after the ignition is turned off. If the steering operation is not performed for a predetermined time after the ignition is turned off, there is a high possibility that the steering operation will not be performed after that. Therefore, by storing the absolute steering angle at this time, Accuracy can be improved.

Further, by storing the absolute steering angle at ignition OFF and the motor rotation angle at ignition OFF in the storage circuit, the absolute steering angle can be maintained even when the battery is removed.

Further, when the steering operation is performed while the ignition is off, the ECU 4 may store information of the steering angle detected by the GMR element 13 in the storage circuit 26. The GMR element 13 activated by the wakeup circuit 24 is also deenergized when the steering operation is not performed for a predetermined time again, and power consumption can be suppressed. By storing the steering angle information at this time in the storage circuit 26, it is possible to obtain steering angle information in consideration of the steering operation amount during ignition off when the reignition is on.

Further, since both the GMR element (steering angle detection device) 13 and the first and second hall switches (steering operation detection device) 14a and 14b can detect the steering angle, an ignition switch or accessory switch of the vehicle is used. When the difference between the two steering angles is large, the abnormality of the device can be detected by comparing the steering angles based on the output signals of the GMR element 13 and the first and second hall switches 14a and 14b when the switch is on. it can.

Further, in the embodiment, the first and second hall switches are applied to the steering operation detection device, but the present invention is also applicable to a GMR sensor, an AMR sensor, a TMR sensor, or a hall sensor. With the GMR sensor, it is possible to detect one rotation of the rotating shaft. With the AMR sensor, it is possible to detect a half rotation of the rotation shaft.

In the embodiment, the first and second hall switches 14a and 14b are provided in addition to the GMR element 13, and the steering operation at the time of ignition off is detected by the first and second hall switches 14a and 14b. The GMR element 13 may detect a steering operation when the ignition is off. In this case, it is desirable to supply power to the GMR element 13 from a small-capacity power supply different from the power supply IC 22. Further, the steering shaft rotation angle is greatly decelerated from the relationship of the reduction ratio with respect to the motor rotation angle, and the angle change can be detected from the slight change of the steering shaft rotation angle.

Alternatively, an IC in which the first and second Hall switches 14a and 14b and the GMR element 13 are integrated may be used. In this case, the layout can be improved, the number of parts can be reduced, and the cost can be reduced.

Further, the ECU 4 of the present embodiment corrects the steering angle to 0 when it is determined that the vehicle is traveling straight. As a determination condition of the straight traveling state of the vehicle, when the traveling speed of the vehicle is equal to or more than a predetermined speed, when the rotational speed difference between the left and right steered wheels W is equal to or less than a predetermined amount, or when the steering torque is equal to or less than a predetermined value Can be mentioned. As described above, it can be determined whether or not the vehicle is traveling straight according to the traveling condition of the vehicle. When the steering angle when it is determined to be in the straight ahead state is equal to or more than a predetermined angle, the accuracy of the steering angle information can be enhanced by correcting the steering angle to the 0 side. As a result, the steering angle information can be improved even if the power steering apparatus does not have a sensor capable of independently detecting the absolute steering angle. For example, the first and second hall switches 14a and 14b are not activated as well. The steering angle can be set even when the steering operation is performed in the state where the battery is removed.

Further, as in the present embodiment, in the electromechanical integrated structure in which the ECU 4 and the electric motor M are integrated, the first and second hall switches 14a and 14b and the wakeup circuit 24 are integrated with the control board 15 of the ECU 4. By doing this, the number of parts can be reduced and the layout can be improved. .
FIG. 11 is a schematic view showing a power steering apparatus for steering by wire. As shown in FIG. 11, in the steering-by-wire power steering apparatus, the steering wheel SW and the rack bar 3 are not connected, and the steering wheel SW and the steered wheels W and W operate independently. When the steering wheel SW is rotationally steered, the steering angle of the steering wheel SW is detected by the torque sensor TS, and the ECU 4 controls the current of the electric motor M based on the output signal of the torque sensor TS. The steering force is applied via (not shown). The power steering device of this steering by wire applies a steering force only by the output from the electric motor M, and steers the steered wheels W, W. The present invention is also applicable to such a steering by wire steering apparatus.

FIG. 12 is a schematic view showing a steering device of an electric and mechanical unit. As shown in FIG. 12, the steering device of the machine-electric separate unit is one in which the ECU 4 and the electric motor M are not integrally but separately provided. The present invention is also applicable to such an electric and mechanical separate steering apparatus. In the power steering apparatus of this machine-electric separate body, if the steering operation detection device (first and second hall switches 14a and 14b) and the wakeup circuit 24 are mounted on the electric motor M side, there is no connection between the ECU 4 and the electric motor M In addition, the wakeup mode can be activated by the steering angle fluctuation.

In addition, a motor rotation angle sensor may be applied to the steering operation detection device. As a result, the steering shaft rotation angle is largely decelerated from the reduction ratio with respect to the motor rotation angle, so that it is possible to detect an angle change from a slight change in the rotation angle of the steering shaft.

Further, in the present embodiment, the steering angle detection device (GMR element) 13 and the steering operation detection devices (first and second hall switches) 14a and 14b are provided in the electric motor M, but a configuration provided in the steering mechanism is also applicable It is.

Here, the technical ideas to be understood from the above-described embodiments and effects other than those described in the claims will be described below.

(A) In the power steering apparatus according to claim 4, the first and second Hall elements are drive-controlled such that the current value becomes larger in a cycle shorter than that when the rotary shaft rotates 90 degrees. The power steering apparatus according to claim 4, characterized in that:

According to the technical concept described in (a), it is possible to prevent the rotational axis from being angularly changed by 90 degrees or more in a state where the current value is small.

(B) In the power steering device according to (a), the first and second Hall switches maintain and output the previous value of the output signal in the state in which the current value is large in the state in which the current value is small. Power steering device characterized by

According to the technical idea described in (b), even when the current value is small, an output signal as a provisional value can be continuously obtained.

(C) In the power steering device according to claim 3, a steering angle based on an output signal of the steering angle detection device, provided in the control device, when an ignition switch or accessory switch of the vehicle is on, and the steering operation What is claimed is: 1. A power steering apparatus comprising: an abnormality detection unit configured to detect an abnormality of the device by comparing a steering angle based on an output signal of the detection device;

According to the technical idea described in (c), both the steering angle detection device and the steering operation detection device can detect a change in steering angle. By comparing the output signals of the two, if the difference is large, it is possible to detect an abnormality of the device.

(D) In the power steering apparatus according to claim 3, the electric motor is a brushless motor including a rotor, a stator, and a motor rotation angle sensor for detecting a rotational position of the rotor.
The motor rotation angle sensor includes the magnet of the steering operation detection device, and a rotation angle sensor which is provided to face the magnet and detects the rotational position of the rotation shaft based on a change in the magnetic field of the magnet. Power steering apparatus characterized in that

According to the technical concept described in (d), the device can be simplified by combining the magnet of the steering operation detection device and the magnet of the motor rotation angle sensor.

(E) In the power steering apparatus according to claim 3, the control device comprises a microcomputer for calculating a command signal for driving and controlling the electric motor, and a substrate on which the microcomputer is mounted.
The electric motor is a brushless motor including a rotor, a stator, and a motor rotation angle sensor that detects a rotational position of the rotor.
The motor rotation angle sensor is composed of a magnet provided on the rotation shaft, and a rotation angle sensor provided to face the magnet and detecting a rotation position of the rotation shaft based on a change in the magnetic field of the magnet. And
A power steering apparatus, wherein the first and second Hall switches and the rotation angle sensor are disposed on the same side of the substrate.

(E) According to the technical concept described above, the mountability (assembling ability) of the element or sensor on the substrate is improved.

(F) In the power steering device according to claim 3, the control device comprises a microcomputer for calculating a command signal for driving and controlling the electric motor, and a substrate on which the microcomputer is mounted.
The electric motor is a brushless motor including a rotor, a stator, and a motor rotation angle sensor that detects a rotational position of the rotor.
The motor rotation angle sensor is composed of a magnet provided on the rotation shaft, and a rotation angle sensor provided to face the magnet and detecting a rotation position of the rotation shaft based on a change in the magnetic field of the magnet. And
A power steering apparatus, wherein the first and second Hall switches and the rotation angle sensor are disposed on the opposite side of the substrate.

According to the technical idea described in (f), it is possible to suppress the mounting ranges of the first and second Hall switches on the substrate and the projection plane of the rotation angle sensor. Further, the mounting positions do not interfere with each other between the first and second Hall elements and the rotation angle sensor.

(G) In the power steering device according to claim 3, the steering operation detection device is a signal that changes from a high signal to a low signal among signals output from the first and second hall switches, and a low signal. A power steering apparatus characterized by detecting which one of the four divided areas is located on the basis of both rising edges changing from a high signal to a high signal.

According to the technical idea described in (g), by considering both the rise and the fall, the amount of information is doubled as compared with the case where only one of the fall or the rise is considered, and The direction of rotation of can also be detected.

(H) In the power steering apparatus according to claim 3, the steering operation detection apparatus is configured to be supplied with power from a power supply different from a power supply for supplying power to the control apparatus. Power steering device.

(H) According to the technical concept described, when sharing the same power supply as a control device that consumes a large current, it is necessary to flow a large current to supply power to the steering operation detection device while the ignition is off. By using a power supply different from the microcomputer side, it is possible to suppress the power consumption during the ignition off.

(I) In the power steering apparatus according to claim 2, the rotation shaft of the steering operation detection device includes a magnet disposed around the rotation shaft so as to face the detection unit,
The detection unit of the steering operation detection device is a Hall switch that outputs a high signal or a low signal according to the magnetic flux density, and
The said steering operation detection apparatus detects the rotational position of the said rotating shaft based on the output signal of the said hall | hole switch, The power steering apparatus characterized by the above-mentioned.

(I) According to the technical idea described, resolution twice as high as in the case where the magnet has two poles can be obtained.

(J) The power steering apparatus according to claim 2, wherein the steering operation detecting apparatus is constituted by a GMR sensor or an AMR sensor, a TMR sensor, and a hall sensor.

(J) According to the technical idea described, in the case of a GMR sensor, it is possible to detect one rotation of the rotating shaft. With the AMR sensor, it is possible to detect a half rotation of the rotation shaft.

(K) In the power steering apparatus according to claim 1, the control device has a storage circuit that stores the value of the absolute steering angle when the door is locked when the door of the vehicle is locked. Power steering device that features.

According to the technical concept described in (k), even after the ignition is turned off, the steering operation may be performed as long as the driver is in the vehicle, but the steering operation may be performed after the door is locked. Since the nature is extremely low, storing the absolute steering angle at this time makes it possible to improve the accuracy of the steering angle information when the reignition is on.

(L) In the power steering apparatus according to claim 1, the control device has a memory circuit for storing the value of the absolute steering angle when the predetermined time has elapsed when there is no steering operation for a predetermined time after the ignition is turned off. Power steering device characterized by

(L) According to the technical concept described, when there is no steering operation for a predetermined time after ignition off, there is a high possibility that the steering operation will not be performed after that, so the absolute steering angle at this time should be stored. Thus, the accuracy of the steering angle information when the reignition is on can be enhanced.

(M) In the power steering device according to claim 1, the control device is configured to cause the traveling speed of the vehicle to be a predetermined speed or more, the rotational speed difference between the left and right steered wheels to be a predetermined amount or less, or the steering torque to be a predetermined value or less. A power steering apparatus, which determines that the vehicle is in a straight traveling state based on the condition of and corrects a steering angle detected by the steering angle detection device.

(M) According to the technical concept described, it can be determined whether the vehicle is in a straight ahead state according to the traveling condition of the vehicle, and when the steering angle at this time is a predetermined angle or more, the steering angle is 0 The correction to the side can increase the accuracy of the steering angle information. Therefore, for example, the steering angle information can be obtained even when the steering operation is performed in a state in which the battery is removed so that the steering operation detection device is not activated as well.

(N) In the power steering device according to claim 1, the control device has a storage circuit for storing information of the steering angle detected by the steering angle detection device when the steering operation is performed while the ignition is off. Power steering device characterized by

According to the technical concept described in (n), the steering angle detection device activated by the wakeup circuit is also deenergized when the steering operation is not performed for a predetermined time again, and power consumption can be suppressed. By storing the steering angle information at this time in the storage circuit, it is possible to obtain steering angle information in consideration of the steering operation amount during ignition off when the reignition is on.

(O) In the power steering device according to claim 1, the steering angle detection device is configured of a rotation shaft that rotates in response to a steering operation of a steering wheel, and a rotation angle sensor that detects a rotation angle of the rotation shaft. And
The control device is information on the rotation angle which is an output signal of the rotation angle sensor of the steering angle detection device, and rotation number information obtained by counting how many rotations the rotation shaft rotates clockwise or counterclockwise. And an absolute steering angle which is a steering angle from a neutral state of a steering wheel based on and.

(O) According to the technical concept described above, absolute angle information can be obtained without providing a steering angle sensor capable of detecting an absolute angle. As a result, downsizing and cost reduction of the device can be achieved.

(P) In the power steering device according to claim 1, the electric motor is a brushless motor including a rotor stator and a motor rotation angle sensor for detecting a rotational position of the rotor,
The motor rotation angle sensor includes the magnet of the steering operation detection device, and a rotation angle sensor which is provided to face the magnet and detects the rotational position of the rotation shaft based on a change in the magnetic field of the magnet. And
A power steering apparatus, wherein the control device detects a steering angle changed by a steering operation performed while the ignition is off by using the motor rotation angle sensor.

According to the technical concept described in (p), the motor rotation angle sensor has high angle detection accuracy to control the brushless motor, and therefore, by detecting the steering angle based on this information, highly accurate steering angle information You can get In addition, there is no need to provide a separate sensor.

(Q) In the power steering apparatus according to claim 1, the steering mechanism is configured such that a steering wheel and steered wheels can be operated independently,
The power steering apparatus according to the present invention is characterized in that the steering angle detection device includes a rotation shaft that rotates in response to the turning operation of the steered wheels of the steered wheels, and a rotation angle sensor that detects the rotational position of the rotation shaft. .

According to the technical concept described in (q), even in a so-called power steering device of a steering by wire, it is possible to detect an absolute angle which is a turning angle of turning wheels.

(R) In the power steering device according to claim 1, the control device sets an initial absolute steering angle in consideration of the movement of the steering angle detected at the time of ignition on / off,
A power steering apparatus characterized in that a steering angle is detected based on an initial absolute steering angle and a detection output of a motor rotation angle sensor when a microcomputer is started.

(R) According to the technical idea described, it is possible to detect a change in the steering angle without maintaining the microcomputer in the activated state during ignition on / off.

(S) A power steering apparatus according to claim 1, wherein a movement of the steering angle when the ignition is off and the steering angle during the ignition off is stored in the storage circuit.

According to the technical concept described in (s), the absolute steering angle can be maintained even when the battery is removed.

(T) A power steering apparatus according to claim 1, wherein an IC in which a steering operation detecting device and a steering angle detecting device are integrated is used.

(T) According to the technical idea described, it is possible to improve the layout performance, reduce the number of parts, and reduce the cost.

(U) The power steering apparatus according to claim 1, wherein the control unit and the electric motor are integrated, and the steering operation detection unit and the wakeup circuit are provided on a substrate of the control unit.

(U) According to the technical idea described, the number of parts can be reduced and the layout can be improved.

(V) The power steering apparatus according to claim 1, wherein the control unit and the electric motor are separated, and the steering operation detecting unit and the wakeup circuit are mounted on the motor side.

According to the technical idea described in (v), the wakeup mode can be activated by the steering angle fluctuation without connection between the control device and the electric motor.

Claims

A steering mechanism having a steering shaft connected to the steering wheel and transmitting a steering operation of the steering wheel to the steered wheels;
An electric motor for applying a steering force to the steering mechanism;
A reduction gear, provided between the steering mechanism and the electric motor, for transmitting the torque of the electric motor to the steering mechanism;
A steering angle detection device provided in the steering mechanism or the electric motor to detect a steering angle of a steering wheel;
A control device that drives and controls the electric motor based on a traveling state of the vehicle;
A steering operation detection device provided in the steering mechanism or the electric motor to detect a steering operation of a steering wheel;
Provided in the control device, the steering angle detection device is energized when the ignition switch or accessory switch of the vehicle is on, and the energization to the steering angle detection device is shut off when the ignition switch or accessory switch is off, and the steering operation detection device is energized. Power supply circuit to perform
The electric power is provided in the control device, and when the vehicle ignition switch or accessory switch is off, and the steering operation detection device detects a steering operation of a steering wheel, the electric power is supplied to the steering angle detection device. A wake up circuit for controlling the supply circuit;
A power steering apparatus comprising:
The steering operation detection device includes a rotation shaft that rotates in response to a steering operation of a steering wheel, and a detection unit that can detect the rotation position of the rotation shaft within a range of 360 degrees.
The power steering apparatus according to claim 1, wherein the wakeup circuit is configured to be able to energize the steering angle detection device until the rotation shaft rotates 180 degrees.
The rotation shaft of the steering operation detection device includes a magnet provided to face the detection unit,
The detection unit of the steering operation detection device is disposed at a phase of 90 degrees in magnetic angle with each other around the rotation axis, and outputs a high signal or a low signal according to the magnetic flux density. Hall switch,
The steering operation detection device is formed by dividing the range of the rotation axis by 360 degrees into four parts by 90 degrees based on a combination of an output signal of the first hall switch and an output signal of the second hall switch. 3. The power steering apparatus according to claim 2, wherein it is possible to detect which region is located.
4. The driving method according to claim 3, wherein the first and second Hall switches are controlled by a pulse driving method in which a state in which a supplied current value is small and a state in which a magnetic flux density can be detected are repeatedly large. Power steering device.
5. The power steering system according to claim 4, wherein the first and second Hall elements are drive-controlled so that the current value is large in a cycle shorter than the rotation of the rotation shaft by 90 degrees. apparatus.
6. The power steering apparatus according to claim 5, wherein the first and second Hall switches maintain and output the previous value of the output signal in a state in which the current value is large in a state in which the current value is small. .
The steering angle based on the output signal of the steering angle detection device is compared with the steering angle based on the output signal of the steering operation detection device provided in the control device and the ignition switch or accessory switch of the vehicle is on The power steering apparatus according to claim 3, wherein an abnormality of the apparatus is detected by performing the process.
The electric motor is a brushless motor including a rotor, a stator, and a motor rotation angle sensor that detects a rotational position of the rotor.
The motor rotation angle sensor includes the magnet of the steering operation detection device, and a rotation angle sensor which is provided to face the magnet and detects the rotational position of the rotation shaft based on a change in the magnetic field of the magnet. The power steering apparatus according to claim 3, characterized in that:
The control device includes a microcomputer for calculating a command signal for driving and controlling the electric motor, and a substrate on which the microcomputer is mounted.
The electric motor is a brushless motor including a rotor, a stator, and a motor rotation angle sensor that detects a rotational position of the rotor.
The motor rotation angle sensor is composed of a magnet provided on the rotation shaft, and a rotation angle sensor provided to face the magnet and detecting a rotation position of the rotation shaft based on a change in the magnetic field of the magnet. And
The power steering apparatus according to claim 3, wherein the first and second Hall switches and the rotation angle sensor are disposed on the same side of the substrate.
The control device includes a microcomputer for calculating a command signal for driving and controlling the electric motor, and a substrate on which the microcomputer is mounted.
The electric motor is a brushless motor including a rotor, a stator, and a motor rotation angle sensor that detects a rotational position of the rotor.
The motor rotation angle sensor is composed of a magnet provided on the rotation shaft, and a rotation angle sensor provided to face the magnet and detecting a rotation position of the rotation shaft based on a change in the magnetic field of the magnet. And
The power steering apparatus according to claim 3, wherein the first and second hall switches and the rotation angle sensor are disposed on the opposite side of the substrate.
The steering operation detection device is selected based on both the falling of the high signal to the low signal and the rising of the low signal to the high signal among the signals output from the first and second hall switches. 4. The power steering apparatus according to claim 3, wherein which one of the divided areas is located is detected.
The power steering apparatus according to claim 3, wherein the steering operation detection device is configured to be supplied with power from a power supply different from a power supply for supplying power to the control device.
The rotation axis of the steering operation detection device includes a magnet disposed around the rotation axis so as to face the detection unit,
The detection unit of the steering operation detection device is a Hall switch that outputs a high signal or a low signal according to the magnetic flux density, and
The power steering apparatus according to claim 2, wherein the steering operation detection device detects a rotational position of the rotational shaft based on an output signal of the hall switch.
The power steering apparatus according to claim 2, wherein the steering operation detection device is configured of a GMR sensor, an AMR sensor, a TMR sensor, and a hall sensor.
The power steering apparatus according to claim 1, wherein the control device includes a storage circuit that stores a value of the absolute steering angle when the door is locked when the door of the vehicle is locked.
The power steering apparatus according to claim 1, wherein the control device includes a storage circuit that stores the value of the absolute steering angle when the predetermined time has elapsed when there is no steering operation for a predetermined time after the ignition is turned off.
The control device determines that the vehicle is traveling straight based on any of the following conditions: the traveling speed of the vehicle is equal to or higher than a predetermined speed, the difference in rotational speed between the left and right steered wheels is equal to or lower than a predetermined amount, or the steering torque is equal to or lower than a predetermined value. The power steering apparatus according to claim 1, wherein the steering angle detected by the steering angle detection device is corrected.
The power steering apparatus according to claim 1, wherein the control device has a storage circuit that stores information on a steering angle detected by the steering angle detection device when a steering operation is performed while the ignition is off. .
The steering angle detection device includes a rotation shaft that rotates in response to a steering operation of a steering wheel, and a rotation angle sensor that detects a rotation angle of the rotation shaft.
The control device is information on the rotation angle which is an output signal of the rotation angle sensor of the steering angle detection device, and rotation number information obtained by counting how many rotations the rotation shaft rotates clockwise or counterclockwise. The power steering apparatus according to claim 1, wherein an absolute steering angle which is a steering angle from a neutral state of the steering wheel is calculated based on and.
The electric motor is a brushless motor including a rotor stator and a motor rotation angle sensor that detects a rotational position of the rotor,
The motor rotation angle sensor includes the magnet of the steering operation detection device, and a rotation angle sensor which is provided to face the magnet and detects the rotational position of the rotation shaft based on a change in the magnetic field of the magnet. And
The power steering apparatus according to claim 1, wherein the control device detects a steering angle changed by a steering operation performed while the ignition is off using the motor rotation angle sensor.
The steering mechanism is configured such that the steering wheel and the steered wheels are independently operable.
The steering angle detection device is characterized by comprising a rotation shaft that rotates in response to a turning operation of the turning wheels of the turning wheels, and a rotation angle sensor that detects a rotation position of the rotation shaft. Power steering device as described.
A control device for driving and controlling a power steering device,
A steering mechanism having a steering shaft connected to the steering wheel and transmitting a steering operation of the steering wheel to the steered wheels;
An electric motor for applying a steering force to the steering mechanism;
A reduction gear, provided between the steering mechanism and the electric motor, for transmitting the torque of the electric motor to the steering mechanism;
A steering angle detection device provided in the steering mechanism or the electric motor to detect a steering angle of a steering wheel;
A control device that drives and controls the electric motor based on a traveling state of the vehicle;
A steering operation detection device provided in the steering mechanism or the electric motor to detect a steering operation of a steering wheel;
Provided in the control device, the steering angle detection device is energized when the ignition switch or accessory switch of the vehicle is on, and the energization to the steering angle detection device is shut off when the ignition switch or accessory switch is off, and the steering operation detection device is energized. Power supply circuit to perform
The electric power is provided in the control device, and when the vehicle ignition switch or accessory switch is off, and the steering operation detection device detects a steering operation of a steering wheel, the electric power is supplied to the steering angle detection device. A wake up circuit for controlling the supply circuit;
A power steering apparatus comprising: