JP2006315658A - Steering device for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To certainly separate a steering wheel and a steered wheel at the start of a system. <P>SOLUTION: The steering device for the vehicle is provided with a steering angle sensor 23; a steering actuator 38; a reaction force actuator 25; a steering actuator control means; a reaction force actuator control means; a planetary gear mechanism 51 provided between the steering wheel 21 and the steering actuator 38; a lock member for mechanically connecting/separating the steering wheel 21 and the steering wheel 35; a lock drive means for driving the lock member; and a lock state determination means for determining the lock/unlock state of the lock member. When the lock state determination means determines that it is in the lock state regardless that the lock member is made in the unlock state by driving the lock drive means, a control amount of the steering actuator 38 is increased. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a vehicle steering apparatus capable of mechanically connecting and separating an operator operated by a driver and a steering actuator for steering a steered wheel.

In a so-called steer-by-wire type steering device in which a steering wheel (operator) operated by a driver and a steered wheel are not mechanically connected, an appropriate steering reaction force when the driver operates the steering wheel. And a steering actuator for turning the steered wheels in accordance with the driver's operation of the steering wheel, each actuator being controlled independently.
Some steer-by-wire steering devices include a backup system to enable steering even when the system is abnormal.

As this backup system, the rotating shaft of the steering wheel and the input shaft of the steering mechanism are connected by a planetary gear mechanism (clutch), and one constituent gear of this planetary gear mechanism can be made non-rotatable by a lock member. (For example, refer to Patent Document 1).
This backup system normally functions as a steer-by-wire steering device by mechanically separating the steering wheel and the input shaft of the steering mechanism by allowing each component gear of the planetary gear mechanism to freely rotate. When the system malfunctions, one gear of the planetary gear mechanism is locked with a lock member to make it non-rotatable, so that the steering wheel and the input shaft of the steering mechanism are mechanically connected and rotated by the steering wheel. It can be made to function as a steering device (non-steer-by-wire type steering device) that directly steers the steered wheels. In this backup system, the locking member is locked even when the system is stopped.
JP-A-2005-29016

However, when the driver applies a force in a direction on the steering wheel when releasing the lock state of the lock member, a twist is generated between the steering wheel and the steered wheel, and the force based on the twist is locked. There is a case where the unlocking operation of the member is obstructed and the lock cannot be released. In particular, when the system is started, the steered wheels are stopped, and a very large load is applied to the steered wheel side of the planetary gear mechanism, so if a force is applied to the steering wheel, the twisting force becomes very large, It becomes difficult to unlock. If the control as the steer-by-wire is started without unlocking the lock member in this way, the operation of the steering mechanism is restricted by the steering wheel, and the driver may feel uncomfortable.
In order to solve this problem, if the unlocking force is increased to cope with this problem, the unlocking device becomes large, and problems such as a reduction in merchantability due to occurrence of shock or abnormal noise during unlocking occur.
Therefore, the present invention provides a vehicle steering apparatus that can reliably form a mechanically separated state between an operating element and a steered wheel when the system is started without causing an increase in the size of the apparatus.

In order to solve the above-mentioned problem, the invention according to claim 1 is directed to an operation element (for example, a steering wheel 21 in an embodiment described later) operated by a driver, and an operation for detecting an operation input amount to the operation element. An input amount detection means (for example, a steering angle sensor 23 in an embodiment described later) and a steered actuator (for example, a steering in an embodiment described later) that steers a steered wheel (for example, a steered wheel 35 in an embodiment described later). Actuator 38), a reaction force actuator that applies a steering reaction force to the operation element (for example, a reaction force actuator 25 in an embodiment described later), and the steering according to the operation input amount detected by the operation input detection means. Steering actuator control means for controlling the actuator (for example, the steering control unit 110 in the embodiment described later and the reaction force actuator) Reaction force actuator control means for performing control (for example, reaction force control unit 120 in the embodiment described later) and a clutch (for example, a planetary gear in the embodiment described later) provided between the operating element and the steering actuator. Mechanism 51), clutch switching means (for example, a lock mechanism 80 in an embodiment to be described later) for switching on / off of the clutch, and clutch state determination means (for example, to be described later) for determining whether the clutch is in a connected state or a disconnected state Steps S103 and 203) in the example, and it is determined that the clutch state determining means is in the clutch connected state even though the clutch switching means is operating to shift the clutch from the connected state to the disconnected state. If this is the case, increase the control amount of the steering actuator, or Vehicle steering apparatus characterized by performing one of control to increase the control amount of the force actuator (e.g., a vehicle steering apparatus 10 in the embodiment) is.
The reason why the clutch cannot be disengaged despite the fact that the clutch switching means is operating to shift the clutch from the connected state to the disconnected state is due to the twisted state between the operating element and the steered wheels. If the control amount of the steering actuator is increased or the control amount of the reaction force actuator is increased, the torsional state can be weakened. As a result, the clutch can be reliably shifted from the connected state to the disconnected state.
Note that the operation input amount of the operation element may be an operation angle or an operation torque (steering torque).

The invention according to claim 2 is an operation element (for example, a steering wheel 21 in an embodiment described later) operated by a driver, and an operation input amount detection means (for example, described later) that detects an operation input amount to the operation element. The steering angle sensor 23) in the embodiment to be turned, the turning actuator (for example, the turning actuator 38 in the embodiment to be described later) for turning the steered wheel (for example, the steered wheel 35 in the embodiment to be described later), and the operation element. And a steering actuator control for controlling the steering actuator in accordance with the operation input amount detected by the operation input detection means. Means (for example, a steering control unit 110 in an embodiment described later) and a reaction force actuator for controlling the reaction force actuator. And a planetary gear mechanism (for example, a planetary gear mechanism 51 in an embodiment to be described later) provided between a data controller (for example, a reaction force control unit 120 in an embodiment to be described later) and the operation element and the steering actuator. ), The constituent members of the planetary gear mechanism in the locked state are made non-rotatable, the operating element and the steered wheel are mechanically connected, and the constituent members are made rotatable in the unlocked state, and the operating element and the A lock member that mechanically separates the steered wheels (for example, a swing arm 82 in an embodiment that will be described later), a lock drive means that drives the lock member (for example, a solenoid 83 in an embodiment that will be described later), and the lock member Lock state determination means (for example, steps S103 and S203 in the embodiments to be described later) for determining whether the state is locked or unlocked. If the lock state determining means determines that the lock member is in the locked state even though the lock driving means is driven to shift the lock member from the locked state to the unlocked state, the control of the steering actuator is performed. A vehicle steering device (for example, a vehicle steering device 10 in an embodiment to be described later) that controls whether to increase the amount or to increase the control amount of the reaction force actuator.
The reason why the lock cannot be released even though the lock driving means is driven to shift the lock member from the locked state to the unlocked state is that the space between the operating element and the steered wheel is twisted. Thus, if the control amount of the steering actuator is increased or the control amount of the reaction force actuator is increased, the torsional state can be weakened. As a result, the lock member can be reliably shifted from the locked state to the unlocked state.
Note that the operation input amount of the operation element may be an operation angle or an operation torque (steering torque).

According to a third aspect of the present invention, in the first or second aspect of the invention, when the control amount is increased, the control amount with respect to the operation input amount until the operation element returns to the neutral position. The ratio is maintained.
By configuring in this way, it is possible to prevent the control amount from changing suddenly when the clutch shifts from the connected state to the disconnected state or when the lock member shifts from the locked state to the unlocked state. it can.

According to the first aspect of the present invention, by increasing the control amount of the steering actuator or increasing the control amount of the reaction force actuator, the torsion between the operating element and the steered wheels is weakened, and the clutch is Since it is possible to reliably shift from the connected state to the disconnected state, steering control by steer-by-wire can be performed without causing the driver to feel uncomfortable. Further, the clutch can be reliably shifted from the connected state to the disconnected state without increasing the size of the clutch switching means.
According to the second aspect of the present invention, by increasing the control amount of the steering actuator or increasing the control amount of the reaction force actuator, the torsion between the operating element and the steered wheels is weakened, and the lock member Can be reliably shifted from the locked state to the unlocked state, and steering control by steer-by-wire can be performed without causing the driver to feel uncomfortable. Further, the lock member can be reliably shifted from the locked state to the unlocked state without increasing the size of the lock driving means.
According to the invention of claim 3, when the clutch shifts from the connected state to the disconnected state, or when the lock member shifts from the locked state to the unlocked state, the control amount is prevented from changing suddenly. Therefore, stable steering control by steer-by-wire can be performed without causing the driver to feel strange, and the steering feeling is improved.

Embodiments of a vehicle steering apparatus according to the present invention will be described below with reference to the drawings of FIGS.
As shown in FIG. 1, the vehicle steering apparatus 10 mechanically separates the steering mechanism 30 from the steering wheel 21 and generates steering power from the steering actuator 38 in accordance with the steering amount of the steering wheel 21. The steering power is transmitted to the steering mechanism 30 to cause the left and right steered wheels 35 and 35 to be steered by the steering mechanism 30, which is a so-called steer-by-wire type steering device.

  The steering mechanism 20 of the vehicle steering device 10 includes a steering wheel (operator) 21 operated by a driver, a steering shaft 22 connected to the steering wheel 21, and a steering angle (operation input amount) of the steering wheel 21. A steering angle sensor (operation input amount detecting means) 23 for detecting, a reaction force actuator 25 for applying a steering reaction force to the steering wheel 21, and a steering torque sensor 29 for detecting a steering torque acting on the steering shaft 22 are provided. . Here, the steering reaction force is an operation resistance that acts in the direction opposite to the rotation direction of the steering wheel 21. The reaction force actuator 25 includes a reaction force motor 24 that generates a steering reaction force (reaction torque), and a reaction force transmission mechanism 26 that transmits the steering reaction force to the steering shaft 22. The reaction force transmission mechanism 26 includes: The worm gear mechanism, that is, a booster mechanism, includes a worm 27 provided on the motor shaft of the reaction force motor 24 and a worm wheel 28 that is coupled to the steering shaft 22 and meshes with the worm 27.

  The steering mechanism 30 includes an input shaft 31 to which a steering force of the steering shaft 22 is input, a rack shaft 34 coupled to the input shaft 31 via a rack and pinion mechanism 33, and left and right rolling at both ends of the rack shaft 34. Tie rods 36 and 36 and knuckles 37 and 37 that connect steered wheels (for example, front wheels) 35 and 35, a steering actuator 38 that applies steering power to the input shaft 31, and a rack shaft position that detects the position of the rack shaft 34 Sensor 42. The rack and pinion mechanism 33 includes a pinion 43 formed on the input shaft 31 and a rack 44 formed on the rack shaft 34. The steering actuator 38 includes a steering motor 45 that generates steering power and a steering power transmission mechanism 46 that transmits the steering power to the input shaft 31. The steering power transmission mechanism 46 is a steering motor 45. The worm gear mechanism, that is, the booster mechanism, includes a worm 47 provided on the motor shaft and a worm wheel 48 that is coupled to the input shaft 31 and meshes with the worm 47.

Further, in the vehicle steering apparatus 10, the steering shaft 22 of the steering mechanism 20 and the input shaft 31 of the steering mechanism 30 include a planetary gear mechanism 51, a first connecting shaft 52, a first universal shaft joint 53, and a second connecting shaft. The shaft 54 and the second universal shaft joint 55 are connected.
The planetary gear mechanism 51 will be described with reference to the schematic diagram of FIG. The planetary gear mechanism 51 meshes a plurality of, for example, three planetary gears 72... With the central sun gear 71, meshes the planetary gear 72. Each carrier 74 is configured to be rotatably attached.

  The sun gear 71, the ring gear 73 and the carrier 74 are arranged concentrically with the first connecting shaft 52 as the center. The ring gear 73 is connected to the steering shaft 22, the carrier 74 is connected to the first connecting shaft 52, the sun gear 71 is supported to be rotatable relative to the first connecting shaft 52, and the planetary gears 72. On the other hand, they are arranged radially at an equal pitch. In FIG. 2, reference numeral 92 denotes a first bearing that supports the steering shaft 22, reference numerals 93 and 93 denote second bearings that support the first connecting shaft 52, and reference numeral 94 denotes a third bearing that supports the ring gear 73.

  Further, the planetary gear mechanism 51 includes a lock mechanism 80 that prevents the sun gear 71 from rotating. The lock mechanism 80 includes a lock gear 81 provided integrally with the sun gear 71, a swing arm (lock member) 82 that can be engaged with the teeth of the lock gear 81, and a state in which the swing arm 82 is locked or unlocked. And a solenoid (lock driving means) 83 for driving the motor. The locking gear 81 is disposed concentrically with the first connecting shaft 52 and is provided to be rotatable relative to the first connecting shaft 52. The swing arm 82 is provided so as to be rotatable about a support shaft 85, and has a lock claw 84 that can be engaged with the teeth of the lock gear 81 at one end. The swing arm 82 is biased by a return spring (not shown) in a rotational direction that causes the lock claw 84 to approach the lock gear 81, and the tip of the push rod 88 of the solenoid 83 is abutted against the other end of the swing arm 82. Yes.

  In the non-excited state of the solenoid 83, the push rod 88 is retracted as shown by the solid line in FIG. 3, and at this time, the swing arm 82 is rotated in the direction approaching the locking gear 81 by the return spring. The locking claw 84 of the arm 82 engages with the teeth of the locking gear 81 (hereinafter, this state is referred to as a locked state), and the rotation of the locking gear 81 is prevented. As a result, the sun gear 71 cannot be rotated. The vehicle steering apparatus 10 is configured such that when the system is stopped, the solenoid 83 is de-energized and the lock mechanism 80 is locked.

  On the other hand, when the solenoid 83 is excited, the push rod 88 moves forward as shown in FIG. 2 (as shown by a two-dot chain line in FIG. 3), and pushes the other end of the swing arm 82 against the elasticity of the return spring. To do. As a result, the swing arm 82 rotates against elasticity, the lock claw 84 is separated from the locking gear 81, and the lock is released (hereinafter, this state is referred to as an unlocked state).

Next, the operation of the planetary gear mechanism 51 will be described.
When an ignition switch (not shown) is ON, the solenoid 83 is normally excited and the lock mechanism 80 is unlocked. At this time, the locking gear 81 can rotate, and the sun gear 71 integrated with the locking gear 81 can also rotate. As a result, the planetary gears 72... And the ring gear 73 can rotate without being restricted from each other, and the steering force is not transmitted from the steering shaft 22 to the input shaft 31. That is, when the lock mechanism 80 is unlocked, the steering torque is interrupted in the planetary gear mechanism 51, and the steering wheel 21 and the steered wheel 35 can be substantially separated. At this time, the reaction force motor 24 and the steering motor 45 are independently controlled by an electronic control unit 61 as will be described later, and the vehicle steering device 10 becomes a steer-by-wire type steering device.

  On the other hand, when the electrical connection between the steering mechanism 20 and the steering mechanism 30 is released due to some factor, or when the ignition switch is turned OFF, the solenoid 83 is in a non-excited state, and the lock mechanism 80 is locked. At this time, the locking gear 81 is made non-rotatable, and the sun gear 71 integrated with the locking gear 81 is also non-rotatable. In this state, when the steering wheel 21 is rotated and the ring gear 73 is rotated, the rotational force is transmitted to the carrier 74 via the planetary gears 72..., The carrier 74 is rotated, and the planetary gears 72. To do. In other words, when the lock mechanism 80 is locked, the steering torque can be transmitted from the steering shaft 22 to the first connecting shaft 52 via the planetary gear mechanism 51, and the steering mechanism 20 and the steering mechanism 30 are connected to the planetary gear 72. .. and mechanically connected via the ring gear 73, and the steering wheel 21 and the steered wheel 35 can be mechanically coupled. As a result, the rotational motion of the steering wheel 21 can be mechanically converted into the axial motion of the rack shaft 9, and the steered wheels 35 can be steered.

That is, at this time, the vehicle steering device 10 is not steer-by-wire, and becomes a steering device capable of manually turning the steered wheels 35. At this time, the reaction force motor 24 is controlled by the electronic control unit 61 so as not to generate a steering reaction force. In this case, the road surface reaction force received by the steered wheels 35, 35 acts on the steering shaft 22 via the steered mechanism 30 and the planetary gear mechanism 51.
That is, the steering wheel 21 and the steered wheel 35 can be mechanically connected when the lock mechanism 80 is locked, and the steering wheel 21 and the steered wheel 35 are substantially separated when the lock mechanism 80 is unlocked. be able to.
That is, in the vehicle steering apparatus 10, the planetary gear mechanism 51 constitutes a clutch, and the lock mechanism 80 constitutes a clutch switching unit that switches between engagement and disengagement of the clutch. The unlocked state of the lock mechanism 80 corresponds to the clutch disengaged state, and the locked state of the lock mechanism 80 corresponds to the clutch connected state.

  Next, control of the reaction force motor 24 and the steering motor 45 will be described. The vehicle steering device 10 includes an electronic control device 61, which outputs signals from the steering angle sensor 23, the steering torque sensor 29, the rack shaft position sensor 42, the vehicle speed sensor 62, and the ignition switch 63. Entered. As described above, when the vehicle steering apparatus 10 is used as a steer-by-wire steering apparatus with the lock mechanism 80 in the unlocked state, the electronic control unit 61 uses the sensors 23, 29. , 42 and 62, the reaction force motor 24 and the steering motor 45 are individually controlled. Since the rack shaft position (rack stroke) detected by the rack shaft position sensor 42 corresponds to the actual turning angle, in the following description, the output signal of the rack shaft position sensor 42 is read as the actual turning angle signal. explain.

  As shown in the block diagram of FIG. 4, the electronic control device 61 includes a turning control unit (steering actuator control unit) 110 that controls the steering motor 45 and a reaction force control unit (reaction force) that controls the reaction force motor 24. (Actuator control means) 120 and a lock release control unit 130 that performs release control of the lock mechanism 80.

  The lock release control unit 130 needs to correct the control amount (target turning angle or target steering reaction force) at the time of starting the system based on the ON / OFF signal of the ignition switch 63 and the steering torque signal from the steering torque sensor 29. When the control amount correction is determined to be necessary, a correction signal is output to the target turning angle setting unit 111 or the target steering reaction force setting unit 121.

The steering control unit 110 is based on a steering angle signal including the steering direction of the steering wheel 2 from the steering angle sensor 23, a vehicle speed signal from the vehicle speed sensor 62, and a correction signal from the lock release control unit 130. To the steering motor 45 in order to make the actual turning angle signal from the rack shaft position sensor 42 coincide with the target turning angle set by the target turning angle setting unit 111. A steering motor control unit 112 for controlling the supply current of the motor.
As a result, the optimum turning angle of the steered wheels 35 is determined with respect to the steering angle (operation amount) given to the steering wheel 21 by the vehicle speed at that time.

The reaction force control unit 120 generates a vehicle speed signal from the vehicle speed sensor 62, an actual turning angle signal from the rack shaft position sensor 42, a steering angle command signal from the steering control unit 110, and a correction signal from the lock release control unit 130. Based on the target steering reaction force setting unit 121 that sets the target steering reaction force based on the target steering reaction force, the output value of the steering torque sensor 29 (that is, the actual steering torque) is set to the target steering reaction force set by the target steering reaction force setting unit 121. And a reaction force motor control unit 122 that controls a supply current to the reaction force motor 24 in order to match. Here, the steering angle command signal from the steering control unit 110 is a deviation between the target steering angle signal output from the target steering angle setting unit 111 and the actual steering angle signal output from the rack shaft position sensor 42. Signal.
As a result, a steering reaction force in a direction opposite to the steering direction of the driver is applied to the steering wheel 21, and a steering feeling as if a torsion bar exists between the steering wheel 21 and the steered wheel 35. Obtainable.

Next, processing when the unlock control unit 130 determines that control amount correction is necessary will be described.
As described above, when the ignition switch is OFF, the lock mechanism 80 is locked, but when the ignition switch is turned ON from this state, the solenoid 83 is excited and the swing arm 82 rotates against the elasticity of the return spring. Then, the lock claw 84 is detached from the locking gear 81 and the lock is released, the lock mechanism 80 is unlocked, and the steering wheel 21 and the steered wheel 35 can be mechanically separated.

  However, if the ignition switch is turned on while applying a force in the direction of the steering wheel 21, the steered wheel 35 is stopped and grounded on the road surface when the ignition switch is turned on. Therefore, since the operation of the steering actuator 38 cannot follow the operation of the steering wheel 21, the steering shaft 22 and the first connecting shaft 52 are twisted, and the lock gear 81 is turned. Bites the lock claw 84, the lock claw 84 cannot be detached from the locking gear 81 (that is, cannot shift to the unlocked state), and the steering wheel 21 and the steered wheel 35 are mechanically separated. There is a possibility that it cannot be done.

  Therefore, in the vehicle steering apparatus 10, when the lock mechanism 80 does not shift from the locked state to the unlocked state even though the solenoid 83 is excited by the lock release command, the control amount of the turning actuator 38 is controlled. The lock claw 84 can be reliably detached from the teeth of the locking gear 81 by executing control that increases the control force of the reaction force actuator 25 or by executing control that increases the control amount of the reaction force actuator 25 more than normal. Thus, the lock mechanism 80 can be reliably shifted from the locked state to the unlocked state.

More specifically, when the control amount of the steering actuator 38 is increased more than usual, a larger turning power than usual can be obtained, so that the torsional state of the steering shaft 22 and the first connecting shaft 52 can be weakened. The lock claw 84 can be reliably detached from the teeth of the lock gear 81.
Further, when the control amount of the reaction force actuator 25 is increased more than usual, the steering reaction force on the steering wheel 21 becomes larger than usual, so that the steering torque acting on the steering shaft 22 can be reduced. As a result, the twisted state of the steering shaft 22 and the first connecting shaft 52 can be weakened, and the lock pawl 84 can be reliably detached from the teeth of the lock gear 81.

  In this embodiment, whether or not the lock mechanism 80 has shifted from the locked state to the unlocked state after the lock release command is determined based on the steering torque value detected by the steering torque sensor 29. That is, when the detected steering torque is greater than a predetermined value, it is determined that the unlocked state has not been reached, and when the detected steering torque is less than the predetermined value, it has been determined that the unlocked state has been reached.

  Next, an unlocking process for facilitating unlocking of the lock mechanism 80 by increasing the control amount of the steering actuator 38 more than usual will be described with reference to the flowchart shown in FIG. 5 and the time chart shown in FIG. Note that the unlock processing routine shown in the flowchart of FIG. 5 is repeatedly executed by the electronic control device 61 at regular intervals. Moreover, the rack stroke in FIG. 6 corresponds to the turning angle, and can be read as the turning angle.

First, in step S101, based on the output signal of the ignition switch 63, it is determined whether or not the system is activated.
If the determination result in step S101 is “YES” (during system startup), the process proceeds to step S102 where a lock release command is issued and current is passed through the solenoid 83 of the lock mechanism 80 to excite it.
In step S103, it is determined whether the steering torque value trq detected by the steering torque sensor 29 is greater than a predetermined threshold th. Here, when the steering torque trq is larger than the threshold th, it is determined that the lock mechanism 80 has not shifted from the locked state to the unlocked state. When the steering torque trq is less than or equal to the threshold th, the lock mechanism 80 is locked. It is determined that the state has shifted to the unlocked state. In this embodiment, the electronic control device 61 executes the process of step S103, thereby realizing a lock state determining means for determining whether the lock member is in a locked state or an unlocked state, and whether the clutch is in a connected state or disconnected. Clutch state determining means for determining whether or not the state is present is realized.

If the determination result in step S103 is “YES” (trq> th), it has not shifted to the unlocked state, so the process proceeds to step S104, and the correction coefficient r is calculated based on the equation (1).
r = (λt + α) / λt (1)
In equation (1), λt is a normal target turning angle set when the lock mechanism 80 is unlocked, and the steering angle detected by the steering angle sensor 23 and the vehicle speed detected by the vehicle speed sensor. Is set based on Further, α is a turning angle corresponding to the increase in control, and a predetermined constant value is set in advance.

Next, the process proceeds from step S104 to step S105, and it is determined whether or not the steering angle θ of the steering wheel 21 detected by the steering angle sensor 23 is “0” (neutral position).
When the determination result in step S105 is “NO” (θ ≠ 0), the process proceeds to step S106, and the corrected target turning angle λtt is calculated based on the equation (2).
λtt = λt · r (2)

Next, the process proceeds to step S107, and the current supplied to the steering motor 45 is controlled so that the corrected target turning angle λtt and the actual turning angle λ detected by the rack shaft position sensor 42 coincide with each other. If the determination result is “YES” (θ = 0), the process proceeds to step S108, the correction coefficient r is set to “1”, and then the process proceeds to step S106.

  That is, when it is determined that the lock mechanism 80 does not shift from the locked state to the unlocked state even though the solenoid 83 of the lock mechanism 80 is excited at the time of system startup, the control for increasing the target turning angle more than usual. As a result, as shown in the time chart of FIG. 6, the steering torque (steering torque) acting on the first connecting shaft 31 is immediately drastically reduced, and the twisted state of the steering shaft 22 and the first connecting shaft 52 is changed. Can weaken rapidly. As a result, the lock claw 84 of the lock mechanism 80 can be detached from the teeth of the lock gear 81, and the lock mechanism 80 is unlocked.

The target turning angle increase control is performed after the lock mechanism 80 is unlocked until the steering wheel 21 returns to the neutral position until the steering ratio (starting angle control amount with respect to the steering angle) is set. The ratio is maintained). Then, when the steering wheel 21 returns to the neutral position, the control for increasing the target turning angle is terminated, and the control returns to the normal steering ratio control.
In this way, the lock mechanism 80 can be reliably unlocked when the system is started up without increasing the size of the solenoid 83 in the lock mechanism 80. In addition, there is no shock or noise when unlocking, and stable steering control by steer-by-wire can be performed without giving the driver a sense of incongruity, improving the merchantability.

  In other words, the clutch (planetary gear mechanism 51) can be reliably shifted from the connected state to the disconnected state when the system is started up without enlarging the clutch switching means (lock mechanism 80). In addition, there is no shock or noise when switching from the clutch connected state to the disconnected state, and stable steering control by steer-by-wire can be performed without giving the driver a sense of incongruity. Will improve.

  In addition, when the determination result in step S101 is “NO” (not at the time of activation) and when the determination result in step S103 is “NO” (trq ≦ th) (that is, the lock mechanism 80 is unlocked). In the case where there is no need to perform the increase control of the target turning angle, the process proceeds to step S105. In these cases, the correction coefficient r is set to the initial value “1”, and the processing in step S106 and subsequent steps is executed.

  Next, an unlocking process for facilitating unlocking of the lock mechanism 80 by increasing the control amount of the reaction force actuator 25 more than usual will be described with reference to the flowchart shown in FIG. Note that the unlocking processing routine shown in the flowchart of FIG. 7 is repeatedly executed by the electronic control device 61 at regular intervals.

First, in step S201, it is determined based on the output signal of the ignition switch 63 whether or not the system is activated.
If the determination result in step S201 is “YES” (during system startup), the process proceeds to step S202, where a lock release command is issued, and current is passed through the solenoid 83 of the lock mechanism 80 to excite it.
In step S203, it is determined whether the steering torque value trq detected by the steering torque sensor 29 is greater than a predetermined threshold th. In this embodiment, the electronic control device 61 executes the process of step S203, thereby realizing a lock state determination unit.

If the determination result in step S203 is “YES” (trq> th), it is determined that the lock mechanism 80 has not shifted from the locked state to the unlocked state, the process proceeds to step S204, and based on equation (3). To calculate the correction coefficient r.
r = (ht + α) / ht Formula (3)
In Expression (3), ht is a normal target steering reaction force set when the lock mechanism 80 is in the unlocked state. The vehicle speed signal from the vehicle speed sensor 62 and the actual steering from the rack shaft position sensor 42 are shown. It is set based on the angle signal and the steering angle command signal (deviation signal between the target turning angle signal and the actual turning angle signal) from the turning control unit 110. Α is a steering reaction force corresponding to the increase in control, and a predetermined constant value is set in advance.

Next, the process proceeds from step S204 to step S205, and it is determined whether or not the steering angle θ of the steering wheel 21 detected by the steering angle sensor 23 is “0” (neutral position).
When the determination result in step S205 is “NO” (θ ≠ 0), the process proceeds to step S206, and the corrected target steering reaction force htt is calculated based on the equation (4).
ht = ht · r (4)

Next, proceeding to step S207, the supply current to the reaction force motor 24 is controlled so that the corrected target steering reaction force htt and the actual steering torque h detected by the steering torque sensor 29 coincide.
On the other hand, if the determination result in step S205 is “YES” (θ = 0), the process proceeds to step S208, the correction coefficient r is set to “1”, and then the process proceeds to step S206.

  That is, when it is determined that the lock mechanism 80 does not shift from the locked state to the unlocked state even though the solenoid 83 of the lock mechanism 80 is excited at the time of system startup, the control that increases the target steering reaction force more than usual. Is executed. As a result, the steering torque acting on the steering shaft 22 can be drastically reduced immediately, and the torsional state of the steering shaft 22 and the first connecting shaft 52 can be rapidly weakened. As a result, the lock claw 84 of the lock mechanism 80 can be detached from the teeth of the lock gear 81, and the lock mechanism 80 is unlocked.

The increase control of the target steering reaction force is performed after the lock mechanism 80 is unlocked until the steering wheel 21 returns to the neutral position until the steering ratio (starting angle control amount with respect to the steering angle) is set. The ratio is maintained). When the steering wheel 21 returns to the neutral position, the target steering reaction force increase control is terminated, and the control returns to the normal steering ratio control.
In this way, the lock mechanism 80 can be reliably unlocked when the system is started up without increasing the size of the solenoid 83 in the lock mechanism 80. In addition, there is no shock or noise when unlocking, and stable steering control by steer-by-wire can be performed without giving the driver a sense of incongruity, improving the merchantability.

  In other words, the clutch (planetary gear mechanism 51) can be reliably shifted from the connected state to the disconnected state when the system is started up without enlarging the clutch switching means (lock mechanism 80). In addition, there is no shock or noise when switching from the clutch connected state to the disconnected state, and stable steering control by steer-by-wire can be performed without giving the driver a sense of incongruity. Will improve.

In addition, when the determination result in step S201 is “NO” (not at the time of activation) and when the determination result in step S203 is “NO” (trq ≦ th) (that is, the lock mechanism 80 is unlocked). In the case where the target steering reaction force does not need to be controlled, the process proceeds to step S205. In these cases, the correction coefficient r is set to the initial value “1”, and the processing in step S206 and subsequent steps is executed.
In this embodiment, the corrected target steering reaction force generated by the reaction force motor 24 is determined based on the equation (4), but the corrected target steering reaction force is equivalent to the steering torque input to the steering wheel 21. It is also possible to determine so as to be in the opposite direction with the size of.

[Other Examples]
The present invention is not limited to the embodiment described above.
For example, the operation element is not limited to the steering wheel 21 and may be a joystick.
In the embodiment described above, the operation input amount to the steering wheel 21 (operator) is used as the operation angle. However, the steering actuator 38 may be controlled using the steering torque (operation state amount) as the operation input amount.
In the above-described embodiment, the lock / unlock state of the lock member is determined based on the steering torque. However, the position of the push rod 88 of the solenoid 83 or the position of the lock claw 84 can be detected by the position sensor. Based on the output of the position sensor, the lock / unlock state of the lock member may be determined.
Further, when the lock mechanism 80 does not shift from the locked state to the unlocked state even though the solenoid 83 is excited, the control amount increase control of the steered actuator 38 and the control amount increase of the reaction force actuator 25 are increased. It is also possible to execute both controls.

  In the above-described embodiment, the clutch is configured by the planetary gear mechanism 51. However, the clutch is not limited to this as long as it can switch transmission / cutoff of the steering torque. For example, the clutch is configured by a meshing clutch. It is also possible. In that case, the clutch switching means is constituted by a hydraulic actuator or the like for driving the clutch.

It is a schematic block diagram in one Example of the vehicle steering device which concerns on this invention. It is a block diagram which shows an example of the planetary gear mechanism in the steering apparatus for vehicles of the said Example. It is a block diagram which shows an example of the stopper mechanism in the steering apparatus for vehicles of the said Example. It is a control block diagram of the steering apparatus for vehicles of the said Example. It is an example of the flowchart which shows the lock release process in the steering apparatus for vehicles of the said Example. It is an example of the time chart at the time of lock release in the vehicle steering device of the embodiment. It is another example of the flowchart which shows the lock release process in the steering apparatus for vehicles of the said Example.

Explanation of symbols

10 Vehicle Steering Device 21 Steering Wheel (Operator)
23 Steering angle sensor (operation input amount detection means)
25 Reaction Force Actuator 35 Steering Wheel 38 Steering Actuator 51 Planetary Gear Mechanism (Clutch)
80 Lock mechanism (clutch switching means)
82 Swing arm (locking member)
83 Solenoid (lock drive means)
110 Steering control unit (steering actuator control means)
120 reaction force control unit (reaction force actuator control means)

Claims (3)

An operator operated by the driver, and
An operation input amount detecting means for detecting an operation input amount to the operation element;
A steering actuator for steering the steered wheels;
A reaction force actuator for applying a steering reaction force to the operation element;
Steered actuator control means for controlling the steered actuator according to the operation input amount detected by the operation input detecting means;
Reaction force actuator control means for controlling the reaction force actuator;
A clutch provided between the operating element and the steering actuator;
Clutch switching means for switching on and off of the clutch;
Clutch state determining means for determining whether the clutch is in a connected state or a disconnected state;
And when the clutch state determining means determines that the clutch is in the clutch connected state even though the clutch switching means is operating to shift the clutch from the connected state to the disconnected state, the steering actuator A vehicle steering apparatus that controls whether to increase the control amount of the reaction force or to increase the control amount of the reaction force actuator. An operator operated by the driver, and
An operation input amount detecting means for detecting an operation input amount to the operation element;
A steering actuator for steering the steered wheels;
A reaction force actuator for applying a steering reaction force to the operation element;
Steered actuator control means for controlling the steered actuator according to the operation input amount detected by the operation input detecting means;
Reaction force actuator control means for controlling the reaction force actuator;
A planetary gear mechanism provided between the operating element and the steering actuator;
In a locked state, a part of the constituent members of the planetary gear mechanism is made non-rotatable to mechanically connect the operating element and the steered wheel, and in an unlocked state, the constituent member is made rotatable so that the operating element and the A locking member that mechanically separates the steered wheels;
Lock driving means for driving the lock member;
Lock state determination means for determining whether the lock member is in a locked state or an unlocked state;
The lock member is driven to shift the lock member from the locked state to the unlocked state. A vehicle steering apparatus that controls whether to increase the control amount of an actuator or to increase the control amount of the reaction force actuator.   3. The vehicle according to claim 1, wherein when the control amount is increased, a ratio of the control amount to the operation input amount is maintained until the operation element returns to a neutral position. Steering device.

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