JP4020012B2 - Vehicle steering system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a vehicle steering apparatus including a first actuator and a second actuator that provide a steering force to a steering mechanism. Such a vehicle steering apparatus is configured to drive a steering mechanism that does not have a mechanical coupling to the operation member based on the operation of an operation member such as a steering wheel to steer the steering wheel (so-called steering). An electric power for providing a steering assist force for assisting a steering force by the operation member to the steering mechanism. You may have the structure as a steering device.
[0002]
[Prior art]
The mechanical connection between the steering wheel and the steering mechanism for steering the steering wheel is eliminated, and the steering wheel operation direction and operation amount are detected. On the basis of the detection result, the steering mechanism is steered by an electric motor or the like. A vehicle steering device (so-called steer-by-wire system) in which a driving force from an actuator is applied has been proposed.
[0003]
By adopting such a configuration, it is possible to freely change the ratio (gear ratio) between the rotation amount of the steering wheel and the steering wheel according to the traveling state of the vehicle, and the movement of the vehicle. The performance can be improved. In addition, the configuration as described above also has an advantage that the steering wheel can be prevented from being pushed up at the time of a collision, and an advantage that the degree of freedom of the arrangement position of the steering wheel is increased.
In such a steer-by-wire system, the first and second electric motors for applying driving force to the steered shaft coupled to the steering wheel are provided, and the individual electric motors can be reduced in size. It has been proposed that even when a failure occurs in one electric motor, the steering mechanism can be driven by the driving force of the other electric motor (see, for example, Patent Document 1 below).
[0004]
[Patent Document 1]
Japanese Patent Laid-Open No. 10-218000
[Problems to be solved by the invention]
The first and second electric motors are driven and controlled by, for example, first and second electronic control units, respectively.
In this case, if a failure occurs in the first electric motor and a failure also occurs in the second electronic control unit, even if the second electric motor is normal and the first electronic control unit Even if is normal, both the first and second electric motors become uncontrollable. A similar situation occurs when a failure occurs in the second electric motor and a failure occurs in the first electronic control unit. Therefore, in these cases, there is a possibility that the driving force for turning the steering wheel cannot be applied to the steering mechanism.
[0006]
SUMMARY OF THE INVENTION An object of the present invention is to provide a vehicle steering apparatus that can transmit a driving force of first and second actuators to a steering mechanism as much as possible to ensure a steerable state.
[0007]
[Means for Solving the Problems and Effects of the Invention]
In order to achieve the above object, according to the first aspect of the present invention, there is provided a first actuator (51M) for applying a driving force for steering to the steering mechanism (10), and a driving force for steering to the steering mechanism. The second actuator (51S), the first rotation angle sensor (52M) for detecting the rotation angle of the first actuator, and the second rotation angle sensor (52S) for detecting the rotation angle of the second actuator A first control means (U1) capable of driving and controlling the first actuator and the second actuator; a second control means (U2) capable of driving and controlling the first actuator and the second actuator; and the first control. First switching means (60M) for switching the actuator controlled by the means between the first actuator and the second actuator; Second switching means (60S) for switching the actuator controlled by the second control means between the first actuator and the second actuator, the first actuator, the second actuator, the first control means, and the second control means When there is no failure, the first switching means and the second switching means are controlled so that the first control means controls the first actuator and the second control means controls the second actuator. , One of the first control means and the second control means fails, the other is normal, and one of the first actuator and the second actuator fails, and the other is normal Sometimes, the other of the first control means and the second control means is performed by the first controller. Chueta and second switching control means (U1, U2) for controlling the first switching means and second switching means so that the other is controlled within the actuator and only including said first control means, the internal Is compared with the output of the first rotation angle sensor to determine whether or not the first actuator has failed. The second control means includes a control signal generated internally and The vehicle steering apparatus is characterized in that the output of the second rotation angle sensor is compared to determine whether or not the second actuator has failed . The alphanumeric characters in parentheses indicate corresponding components in the embodiments described later. The same applies hereinafter.
[0008]
According to the above configuration, even if a failure occurs in both the first control unit and the first actuator, the state in which the second actuator is controlled by the second control unit is maintained. The driving force can be given.
In addition, if a failure occurs in both the first control means and the second actuator, the correspondence relationship between the control means and the actuator is switched so that the first actuator is controlled by the second control means. The steering mechanism can be given a driving force for steering.
[0009]
Furthermore, even if a failure occurs in both the second control means and the second actuator, the state in which the first actuator is controlled by the first control means is maintained, so that a driving force for steering is given to the steering mechanism. be able to.
Furthermore, the correspondence relationship between the control means and the actuator is switched so that the second control means is controlled by the first control means even if a failure occurs in both the second control means and the first actuator. Therefore, a driving force for steering can be given to the steering mechanism.
[0010]
Thus, one of the first and second control means, one of the first and second actuators even when the fail simultaneously, it is possible to provide a driving force for steering the steering mechanism Therefore, a steerable state can be ensured more reliably.
The switching control of the first switching means is performed by the first control means, and the switching control of the second switching means is performed by the second control means, and the switching control is performed by the functions of the first and second control means. The function of the means may be realized. Of course, the switching control means may be constituted by control means different from the first and second control means.
The invention according to claim 2 is the vehicle steering apparatus according to claim 1, further comprising an overall control electronic control unit that performs overall control of the first control means and the second control means.
According to a third aspect of the present invention, the first control means can control the first switching means and the second switching means, and the second control means includes the first switching means and the second switching means. The vehicle steering device according to claim 1, wherein the vehicle steering device is controllable.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is a conceptual diagram for explaining a basic configuration of a vehicle steering apparatus according to an embodiment of the present invention. The vehicle steering device is provided with a steering mechanism 10 for causing a pair of steering wheels (usually front wheels) W and W to perform a steering operation, and without mechanical coupling to the steering mechanism 10. And a steering wheel 30.
[0012]
In this vehicle steering apparatus, the steering drive system for driving the steering mechanism 10 is a double system. The first steering drive system includes a first steering actuator 51M and a first rotation angle sensor 52M for detecting the rotation angle of the first steering actuator 51M. On the other hand, the second steering drive system includes a second steering actuator 51S and a second rotation angle sensor 52S for detecting the rotation angle of the second steering actuator 51S. Each of the first steering actuator 51M and the second steering actuator 51S is constituted by, for example, an electric motor (for example, a three-phase brushless motor).
[0013]
The steering mechanism 10 includes a steered shaft 11 that extends in the left-right direction of the vehicle body, and a knuckle arm that is coupled to both ends of the steered shaft 11 via tie rods 12 and 12 and supports the steered wheels W and W. 13 and 13. The steered shaft 11 is supported by the housing 14 so as to be slidable in the axial direction, and a first steering actuator 51M and a second steering actuator 51S are coaxially incorporated in the middle portion thereof.
[0014]
With this configuration, when the first steering actuator 51M and / or the second steering actuator 51S is driven, the rotation of the first steering actuator 51M and / or the second steering actuator 51S is rotated by a motion conversion mechanism including a ball screw. The steering wheel 11 is converted to sliding, and the steering wheels W and W are steered by the sliding of the steering shaft 11.
A reaction force actuator 40 for applying a reaction force corresponding to a road surface reaction force to the steering wheel 30 is coupled to the steering wheel 30.
[0015]
The reaction force actuator 40 is constituted by an electric motor (for example, a three-phase brushless motor) having a shaft 23 coupled to the steering wheel 30 as a rotation axis, and a casing thereof is fixed at an appropriate position of the vehicle body. The reaction force actuator 40 is provided with a torque sensor 41 for detecting the steering torque input from the steering wheel 30 and an operation angle sensor 42 for detecting the operation angle of the steering wheel 30.
[0016]
The first steering actuator 51M can be connected to the first electronic control unit (ECU) U1 via the first switching circuit 60M, and can be connected to the second electronic control unit U2 via the second switching circuit 60S. Similarly, the second steering actuator 51S can be connected to the first electronic control unit U1 via the first switching circuit 60M, and can be connected to the second electronic control unit U2 via the second switching circuit 60S. Accordingly, the first steering actuator 51M can be driven and controlled by either the first electronic control unit U1 or the second electronic control unit U2, and the second steering actuator 51S is similarly operated by the first electronic control unit U1 or the second electronic control unit U1. Drive control by either of the two electronic control units U2 is possible. That is, the first steering actuator 51M and the second steering actuator 51S receive a drive current from the drive circuit built in the first or second electronic control unit U1, U2.
[0017]
The reaction force actuator 40 is driven and controlled by the reaction force electronic control unit U3, and a drive current is supplied from a drive circuit built in the reaction force electronic control unit U3.
The detection signals of the torque sensor 41 and the operation angle sensor 42 are input in common to the first and second electronic control units U1, U2 and the reaction force electronic control unit U3. Further, the detection signals of the first rotation angle sensor 52M and the second rotation angle sensor 52S are input in common to the first and second electronic control units U1, U2. Further, in relation to the steered shaft 11, a steered position sensor 15 for detecting the axial position of the steered shaft 11 is provided. The two electronic control units U1 and U2 are input in common. Further, a detection signal of the vehicle speed sensor 70 for detecting the vehicle speed is input in common to the first and second electronic control units U1, U2. The vehicle speed sensor 70 can be constituted by, for example, a wheel speed sensor that detects the rotational speed of a wheel.
[0018]
The first switching circuit 60M switches and supplies the drive current output from the first electronic control unit U1 to the first steering actuator 51M or the second steering actuator 51S. The switching is performed by the first electronic control unit U1. To be controlled. Similarly, the second switching circuit 60S switches and supplies the drive current output from the second electronic control unit U2 to the first steering actuator 51M or the second steering actuator 51S. The switching is performed by the second electronic control. It is controlled by the unit U2. The first electronic control unit U1 controls the first switching circuit 60M so that the drive current from the first electronic control unit U1 is supplied to the first steering actuator 51M during normal times (when there is no failure). Similarly, the second electronic control unit U2 controls the second switching circuit 60S so that the drive current from the second electronic control unit U2 is normally supplied to the second steering actuator 51S.
[0019]
Each of the first electronic control unit U1 and the second electronic control unit U2 performs an abnormality detection process for detecting its own failure, and monitors each other's operation state via the communication line 65. An abnormality detection process is performed to detect the other failure. Further, the first and second electronic control units U1 and U2 monitor the output signals of the first and second rotation angle sensors 52M and 52S, for example, to detect a failure of the first and second steering actuators 51M and 51S. An abnormality detection process for detection is executed. For example, when the first and second steering actuators 51M and 51S are driven equally, whether or not the difference between the drive currents supplied to the first and second steering actuators 51M and 51S exceeds a predetermined threshold value. Based on this, the occurrence of an abnormality in one of the actuators may be detected.
[0020]
The first electronic control unit U1 and the second electronic control unit U2 have a fail-safe function of cutting off a relay (not shown) for cutting off a drive current for driving the actuator when a failure of the first electronic control unit U1 and the second electronic control unit U2 is detected. Each has.
FIG. 2 is a flowchart for explaining the operation of the first electronic control unit U1. The first electronic control unit U1 determines whether or not a failure has occurred in itself (step S11). If the failure has occurred in itself, the power supply to the first electronic control unit U1 is interrupted (step S11). S12), the drive current for driving the actuator is not output.
[0021]
If no failure has occurred in the first electronic control unit U1 itself (NO in step S11), the first electronic control unit U1 next determines whether or not the first steering actuator 51M has failed (step S13). Normally, the first electronic control unit U1 is connected to the first steering actuator 51M via the first switching circuit 60M. For example, the control signal generated by itself and the first rotation angle sensor 52M By comparing with the output, it is possible to determine whether or not the first steering actuator 51M has failed.
[0022]
If there is no failure in the first steering actuator 51M (NO in step S13), the first switching circuit 60M is held in a state where the drive current from the first electronic control unit U1 is supplied to the first steering actuator 51M (step S13). S14).
The first electronic control unit U1 outputs a drive current corresponding to the operation of the steering wheel 30 by the driver based on the outputs of the torque sensor 41, the operation angle sensor 42, and the steered position sensor 15. At this time, the first electronic control unit U2 outputs an appropriate drive current according to the rotation angle of the first steering actuator 51M based on the output signal of the first rotation angle sensor 52M.
[0023]
At this time, the reaction force electronic control unit U3 controls the reaction force actuator 40 on the basis of the operation torque detected by the torque sensor 41 and the operation angle detected by the operation angle sensor 42, so Giving power. As a result, the driver can perform steering with a good feeling while feeling the same road surface reaction force as in the case of a conventional vehicle steering apparatus in which the steering wheel and the steering mechanism are mechanically coupled. .
[0024]
If it is determined that there is a failure in the first steering actuator 51M (YES in step S13), the first electronic control unit U1 generates a failure in the second electronic control unit U2 based on the signal from the communication line 65. It is determined whether or not (step S15). If no failure has occurred in the second electronic control unit U2, the process is returned. On the other hand, when a failure has occurred in the second electronic control unit U2 (YES in step S15), the first electronic control unit U1 outputs the first electronic control unit U1 by controlling the first switching circuit 60M. A driving current is supplied to the second steering actuator 51S (step S16). At this time, the first electronic control unit U1 refers to the output of the second rotation angle sensor 52S and outputs an appropriate drive current according to the rotation angle of the second steering actuator 51S.
[0025]
FIG. 3 is a flowchart for explaining the operation of the second electronic control unit U2. The second electronic control unit U2 determines whether or not a failure has occurred in itself (step S21). If the failure has occurred in itself, the power supply to the second electronic control unit U2 is interrupted (step S21). S22), the drive current for driving the actuator is not output.
If no failure has occurred in the second electronic control unit U2 itself (NO in step S21), the second electronic control unit U2 next determines whether or not the second steering actuator 51S has failed (step S23). Since the second electronic control unit U2 is normally connected to the second steering actuator 51S via the second switching circuit 60S, for example, the control signal generated by itself and the second rotation angle sensor 52S By comparing with the output, it is possible to determine whether or not the second steering actuator 51S has failed.
[0026]
If there is no failure in the second steering actuator 51S (NO in step S23), the second switching circuit 60S is held in a state where the drive current from the second electronic control unit U2 is supplied to the second steering actuator 51S (step). S24).
As in the case of the first electronic control unit U1, the second electronic control unit U2 responds to the operation of the steering wheel 30 by the driver based on the outputs of the torque sensor 41, the operation angle sensor 42, and the turning position sensor 15. Output drive current. At this time, the second electronic control unit U2 outputs an appropriate drive current according to the rotation angle of the second steering actuator 51S based on the output signal of the second rotation angle sensor 52S.
[0027]
At this time, the reaction force electronic control unit U3 controls the reaction force actuator 40 on the basis of the operation torque detected by the torque sensor 41 and the operation angle detected by the operation angle sensor 42, so Giving power.
If it is determined that there is a failure in the second steering actuator 51S (YES in step S23), the second electronic control unit U2 generates a failure in the first electronic control unit U1 based on the signal from the communication line 65. It is determined whether or not (step S25). If no failure has occurred in the first electronic control unit U1, the process is returned. On the other hand, when a failure has occurred in the first electronic control unit U1 (YES in step S25), the second electronic control unit U2 outputs the second electronic control unit U2 by controlling the second switching circuit 60S. A driving current is supplied to the first steering actuator 51M (step S26). At this time, the second electronic control unit U2 refers to the output of the first rotation angle sensor 52M and outputs an appropriate drive current according to the rotation angle of the first steering actuator 51M.
[0028]
Through the above-described processing in the first and second electronic control units U1 and U2, the first electronic control unit U1 drives and controls the first steering actuator 51M and the second electronic control unit U2 normally controls the second steering actuator. The driving force for steering is given to the steered shaft 11 by both the first and second steering actuators 51M and 51S.
On the other hand, when a failure occurs in the first electronic control unit U1, the power source of the first electronic control unit U1 is cut off, so that no drive current is supplied from the first electronic control unit U1. At this time, if both the second electronic control unit U2 and the second steering actuator 51S are normal, the second electronic control unit U2 causes the second switching circuit 60S to drive the drive current from the second electronic control unit U2. Since the control is performed so that the second steering actuator 51S is supplied, a driving force for steering is applied to the steered shaft 11 from the second steering actuator 51S. If a failure has occurred in the second steering actuator 51S, the second electronic control unit U2 sends the second switching circuit 60S to the first steering actuator 51M with the drive current output by the second electronic control unit U2. Control to give state. Therefore, also in this case, a driving force for steering can be applied to the steered shaft 11.
[0029]
On the other hand, when a failure occurs in the second electronic control unit U2, the power supply of the second electronic control unit U2 is cut off, so that no drive current is supplied from the second electronic control unit U2. At this time, if both the first electronic control unit U1 and the first steering actuator 51M are normal, the first electronic control unit U1 sets the first switching circuit 60M so that the drive current from the first electronic control unit U1 is the first. Since the state is controlled so as to be supplied to the first steering actuator 51M, a driving force for steering is applied to the steered shaft 11 from the first steering actuator 51M. If a failure also occurs in the first steering actuator 51M, the first electronic control unit U1 sends the first switching circuit 60M to the second steering actuator 51S and the drive current output by the first electronic control unit U1. Control to give state. Therefore, also in this case, a driving force for steering can be applied to the steered shaft 11.
[0030]
In this manner, even when a failure occurs in one of the first and second electronic control units U1 and U2 and one of the first and second steering actuators 51M and 51S at the same time, the steering shaft 11 is steered. Therefore, it is possible to reliably maintain a situation where steering is possible.
FIG. 4 is an illustrative view for explaining a specific configuration for applying a driving force to the steered shaft 11 by the first and second steering actuators 51M and 51S provided coaxially on the steered shaft 11. It is sectional drawing.
[0031]
The first and second steering actuators 51M and 51S are, for example, electric motors such as brushless motors, are adjacent to each other in the axial direction of the steered shaft 11, and coaxially surround the steered shaft 11. Is arranged in.
The first and second steering actuators 51M and 51S are rotatable via cylindrical stators 72 and 73 fixed to the inner periphery of the housing 14 and bearings 86 and 87; 88 and 89 corresponding to the housing 14, respectively. And rotors 76 and 77 inserted into the corresponding stators 72 and 73. A plurality of exciting phase coils (not shown) are wound around a part of the stators 72 and 73, and the outer circumferences of the rotors 76 and 77 are cylindrical so as to face the stators 72 and 73. A drive magnet is provided. The drive magnet is magnetized so as to alternately form N and S poles in the circumferential direction.
[0032]
Further, the rotation angle sensors 52M and 52S attached to the first and second steering actuators 51M and 51S are made of resolvers, and detect the rotation positions (rotation angles) of the rotors 76 and 77, respectively. The rotation angle sensors 52M and 52S include a stator portion 83 fixed to the housing 14 and a rotor portion 84 fixed to the corresponding rotors 76 and 77 and rotating integrally with the rotors 76 and 77. Since a predetermined voltage is induced in the stator portion 83 according to the rotational position of the rotor portion 84, the rotational position of the rotor portion 84, that is, the rotational position (phase) of the rotors 76 and 77 is measured by measuring this voltage. Can be detected.
[0033]
Based on the rotational positions (phases) of the rotors 76 and 77 output from the rotational angle sensors 52M and 52S, the first and second electronic control units U1 and U2 are the stators of the first and second steering actuators 51M and 51S. Current is sequentially supplied to the excitation phases of coils (not shown) divided in the rotation direction of 72 and 73. As a result, the first and second steering actuators 51M and 51S generate a rotational force.
Between the first and second steering actuators 51M and 51S, a ball screw mechanism 80 is disposed as a motion conversion mechanism for converting rotational motion into linear motion. The ball screw mechanism 80 includes a ball nut 81 as a rotating cylinder that surrounds the periphery of the steered shaft 11. The ball nut 81 is screwed into a ball screw groove 11 a formed in the middle of the steered shaft 11 via a ball 85.
[0034]
Both end portions of the ball nut 81 are press-fitted and fixed to opposite ends of the rotors 76 and 77 of the first and second steering actuators 51M and 51S, respectively. The housing 14 is rotatably supported via 88 and 89.
With such a configuration, when the rotors 76 and 77 are rotationally driven, this rotational motion is converted into a linear motion of the steered shaft 11 by the ball screw mechanism 80 and coupled to both ends of the steered shaft 11. The steered wheels W, W are steered.
[0035]
As mentioned above, although one Embodiment of this invention was described, this invention can also be implemented with another form. For example, in the above embodiment, a steer-by-wire system without mechanical coupling between the steering wheel 30 and the steering mechanism 10 is taken as an example. The steering wheel 30 and the steering mechanism 10 are mechanically coupled by coupling a steering shaft to a pinion that meshes with the rack, and a steering assist force for assisting the steering force applied to the steering wheel 30 is provided. The present invention is also applicable to an electric power steering apparatus configured to be applied to the steered shaft 11 by the first and second steering actuators 51M and 51S.
[0036]
Further, the first and second actuators do not need to be provided on the steered shaft 11. For example, a rack may be provided on the steered shaft 11, and a pinion that meshes with the rack may be driven by one actuator. Good. In the case of the electric power steering apparatus having the above-described configuration, the driving force of one actuator may be applied to the steering shaft.
Furthermore, in the above embodiment, both the first and second steering actuators 51M and 51S are driven in the normal state. For example, in the normal state, only the first steering actuator 51M is driven and the first The second steering actuator 51S may be driven by the second electronic control unit U2 when a failure occurs in either the steering actuator 51M or the first electronic control unit U1. In this case, when the first electronic control unit U1 is normal (that is, the first steering actuator 51M is malfunctioning) and the second electronic control unit U2 is malfunctioning, the drive from the first electronic control unit U1 is performed. The first switching circuit 60M may be switched so as to supply current to the second steering actuator 51S. Further, when the first steering actuator 51M is normal (that is, the first electronic control unit U1 is out of order) and the second steering actuator 51S is out of order, the drive current from the second electronic control unit U2 is changed to the first. The second switching circuit 60S may be switched so as to be supplied to the one steering actuator 51M.
[0037]
Furthermore, in the above embodiment, the first electronic control unit U1 performs the switching control of the first switching circuit 60M, and the second electronic control unit U2 performs the switching control of the second switching circuit 60S. An overall control electronic control unit for overall control of the first electronic control unit U1 and the second electronic control unit U2 is provided, and the first and second electronic control units U1, U2 and the first and second electronic control units are controlled by the overall control electronic control unit. The failure detection of the two steering actuators 51M and 51S may be performed, and switching control of the first and second switching circuits 60M and 60S may be executed based on the detection result.
[0038]
Further, the first electronic control unit U1 may be configured to be capable of switching control of both the first and second switching circuits 60M and 60S. Similarly, the second electronic control unit U2 may be configured to enable switching control of both the first and second switching circuits 60M and 60S.
Further, the first switching circuit 60M may be built in the first electronic control unit U1, and the second switching circuit 60M may be built in the second electronic control unit U2.
[0039]
In the above-described embodiment, the example in which the steering wheel 30 is used as the operation member has been described. However, other operation members such as a lever may be used.
In addition, various design changes can be made within the scope of matters described in the claims.
[Brief description of the drawings]
FIG. 1 is a conceptual diagram for illustrating a configuration of a vehicle steering apparatus according to an embodiment of the present invention.
FIG. 2 is a flowchart for explaining the operation of the first electronic control unit.
FIG. 3 is a flowchart for explaining the operation of a second electronic control unit.
FIG. 4 is an illustrative sectional view for explaining a specific configuration example for applying a driving force to the steered shaft by the first and second steering actuators.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Steering mechanism 11 Steering shaft 14 Housing 15 Steering position sensor 30 Steering wheel 40 Reaction force actuator 41 Torque sensor 42 Operation angle sensor 51M 1st steering actuator 51S 2nd steering actuator 52M 1st rotation angle sensor 52S 2nd rotation angle sensor 60M First switching circuit 60S Second switching circuit 65 Communication line 70 Vehicle speed sensor 80 Ball screw mechanism 81 Ball nut 83 Stator part 84 Rotor part 85 Balls 86 to 89 Bearing U1 First electronic control unit U2 Second electronic control unit U3 Reaction force Electronic control unit W Steering wheel

Claims (3)

A first actuator that applies a steering force to the steering mechanism;
A second actuator that applies a driving force for steering to the steering mechanism;
A first rotation angle sensor for detecting a rotation angle of the first actuator;
A second rotation angle sensor for detecting the rotation angle of the second actuator;
First control means capable of driving and controlling the first actuator and the second actuator;
Second control means capable of driving and controlling the first actuator and the second actuator;
First switching means for switching the actuator controlled by the first control means between the first actuator and the second actuator;
Second switching means for switching the actuator controlled by the second control means between the first actuator and the second actuator;
When there is no failure in the first actuator, the second actuator, the first control means, and the second control means, the first actuator is controlled by the first control means, and the second actuator is controlled by the second control means. The first switching means and the second switching means are controlled to be controlled, one of the first control means and the second control means fails, the other is normal, and the first actuator And when one of the second actuators fails and the other is normal, the other of the first and second actuators is caused by the other of the first control means and the second control means. Switching control means for controlling the first switching means and the second switching means so as to be controlled Only including,
The first control means determines whether or not there is a failure of the first actuator by comparing an internally generated control signal with the output of the first rotation angle sensor.
The second control means determines whether or not the second actuator has failed by comparing an internally generated control signal with the output of the second rotation angle sensor . Steering device.   2. The vehicle steering apparatus according to claim 1, further comprising an overall control electronic control unit that performs overall control of the first control means and the second control means.   The first control means can control the first switching means and the second switching means, and the second control means can control the first switching means and the second switching means. The vehicle steering apparatus according to claim 1.

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