JP2006256482A - Vehicular steering device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicular steering device finely assisting releasing of steering wheel lock when starting operation and steering wheel lock when finishing operation. <P>SOLUTION: An electric motor 15 assists the rotating operation of a steering wheel 11 by rotations thereof. A steering lock mechanism 14 locks the steering wheel 11 by making a lock bar enter a lock groove provided on an outer peripheral surface of a steering shaft 12. The electric motor 15 is actuated to rotate the shaft 12 immediately after pulling out an ignition key IGK, thereby certainly making the lock bat enter the lock groove. The electric motor 15 is actuated to rotate the shaft 12 immediately after inserting the key IGK, thereby assisting pulling out the rock bar from the lock groove. A locking state and a lock releasing state of the steering lock mechanism 14 is determined on the basis of rotation angle speed ω accompanied with the operation of the electric motor 15. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a vehicle steering apparatus that assists steering operation of a steering wheel by rotation of an electric motor.

  Conventionally, for example, as shown in Patent Document 1 below, a lock groove provided at one or a plurality of locations along the circumferential direction on the outer peripheral surface of the steering shaft and a lock groove of the steering shaft are provided. A lock bar that is opposed to the outer peripheral surface of the shaft at an axial position and is urged radially inward by a steering shaft by a spring, and a lock bar that is interlocked with the rotation of an ignition key inserted in the key cylinder Steering mechanism that restricts or permits the displacement of the steering shaft inward in the radial direction of the steering shaft and prohibits rotation of the handle in the locked state and allows rotation of the handle in the unlocked state Is well known.

  In this steering lock mechanism, when the ignition key is inserted into the key cylinder and rotated in the direction to turn on the ignition switch, the cam mechanism displaces the lock bar radially outward of the steering shaft and steers the tip of the lock bar. The lock is held at the unlock position located away from the outer peripheral surface of the shaft, and the handle is allowed to turn. On the other hand, when the key is rotated in the opposite direction from the rotation position in order to pull out the ignition key from the key cylinder, the cam mechanism releases the holding of the lock bar at the lock release position, and the lock bar steering is released. Since the shaft is allowed to move inward in the radial direction, the lock bar enters the lock groove by the biasing force of the spring, and the rotation of the handle is prohibited.

  However, in the above-described conventional apparatus, even if the driver finishes driving the vehicle and rotates the ignition key in the direction opposite to the direction in which the ignition switch is turned on and then withdraws it from the key cylinder, If the front end face does not face the lock groove, the front end face of the lock bar contacts the outer peripheral surface of the steering shaft, and the front end of the bar does not enter the lock groove, so the handle is not locked completely. . If the handle is rotated in this state, when the lock groove provided on the steering shaft rotates to the position of the tip of the lock bar, the tip of the lock bar enters the lock groove and the handle is completely locked. This prevents the vehicle from being stolen. However, the steering wheel turning operation as described above is troublesome for the driver.

  On the other hand, when the driver inserts the ignition key into the key cylinder and rotates the vehicle to start the vehicle, the outer peripheral surface of the lock bar and the inner peripheral wall of the lock groove are in a state where the lock bar has entered the lock groove. Due to the contact friction, a slight force may be required for the turning operation of the ignition key in order to pull out the lock bar from the lock groove, and there is a problem that the turning operation of the key becomes heavy. In such a case, the handle can be easily unlocked by turning the ignition key while turning the handle slightly. However, such an operation is troublesome for the driver and is easy to operate. There is also the problem of being bad.

In response to these problems, the applicant of the present application has proposed an electric power steering device for a vehicle shown in Patent Document 2 below, for example. According to the electric power steering apparatus, the steering shaft is rotated by rotating the electric motor at the end of the operation, and the lock bar and the lock groove of the steering lock mechanism are engaged. Further, the engagement state between the lock bar and the lock groove is determined by detecting the steering torque acting on the steering shaft, and the electric motor is driven to rotate so that the steering torque becomes substantially “0”. Yes. As a result, the steering lock mechanism can be reliably operated without requiring any special operation by the driver, and the steering wheel can be completely locked. Further, by setting the steering torque acting on the steering shaft to almost “0”, it is possible to reduce the contact friction force caused by the contact between the lock bar and the lock groove, and it is very easy to change the lock state of the handle. It can be canceled.
Japanese Patent Laid-Open No. 11-43017 Japanese Patent No. 3531560

  However, the steering torque sensor for detecting the steering torque generally has a detection range, that is, a dead zone, in which the steering torque cannot be detected properly even within the detection range of the steering torque. For this reason, in the dead zone of the steering torque sensor, there is a possibility that the engagement state between the lock bar and the lock groove of the steering lock mechanism, more specifically, the contact state between the lock bar and the lock groove may not be determined. For this reason, there is a possibility that the locked state of the handle cannot be reliably determined, and there is a possibility that the contact friction force between the lock bar and the lock groove cannot be reliably reduced. Therefore, it is eager to be able to determine the engagement state between the lock bar and the lock groove of the steering lock mechanism more accurately.

  The present invention has been made to cope with the above-described problems, and an object of the present invention is to make a steering operation that disables the turning operation of the handle in the locked state and permits the turning operation of the handle in the unlocked state. In a vehicle steering apparatus having a lock mechanism and an electric motor for assisting a rotation operation of the handle, the handle can be easily unlocked at the start of the vehicle operation, and the handle is completely at the end of the vehicle operation. An object of the present invention is to provide a vehicle steering apparatus that is locked to the vehicle.

  In order to achieve the above object, a structural feature of the present invention is that a steering lock mechanism that disables the turning operation of the handle in the locked state and permits the turning operation of the handle in the unlocked state, and the handle In a vehicle steering apparatus provided with an electric motor for assisting the rotation operation, a rotation state detecting means for detecting a rotation state of the electric motor, and rotation control of the electric motor based on the detected rotation state Thus, there is provided a lock release auxiliary control means for assisting release of the lock state in the steering lock mechanism.

  In this case, the unlocking auxiliary control unit is configured to perform normal rotation control based on a first command current value for rotating the electric motor in a predetermined direction, and the normal rotation control by the rotation state detection unit. Reverse rotation control for detecting reverse rotation based on a second command current value for rotating the electric motor in a direction opposite to the predetermined direction when detecting a state in which the rotation of the electric motor in the predetermined direction by the means is detected And a rotation stop control means for stopping the rotation of the electric motor after the electric motor is reversely rotated by a predetermined amount by the reverse rotation control means. The reverse rotation control means changes the electric motor stepwise from the first command current value to the second command current value according to the rotation state of the electric motor detected by the rotation state detection means. It is preferable to perform reverse rotation control.

  According to these, when the driver inserts the ignition key into the key cylinder and rotates to start the vehicle, the steering lock mechanism is in the locked state, that is, the lock bar has entered the lock groove, and the lock Even if the outer peripheral surface of the bar is in contact with the inner peripheral wall of the lock groove, the lock release auxiliary control means can automatically release the contact between the lock bar and the lock groove by controlling the rotation of the electric motor. . Specifically, the forward rotation control means of the lock release auxiliary control means first rotates the electric motor forward based on the first command current value. When the rotation state detecting means detects a state where the rotation of the electric motor is stopped, in other words, a state where the lock bar and the lock groove are in contact with each other, the reverse rotation control means of the lock release auxiliary control means Is rotated in reverse by a predetermined amount. Accordingly, the electric motor can be reversely rotated with reference to the position where the lock bar and the lock groove are in contact with each other. By rotating the lock bar and the lock groove in a direction away from each other, the lock bar and the lock groove can be rotated. Can be reliably released. Then, the rotation stop control means of the lock release auxiliary control means stops the reverse rotation of the electric motor in a state where the contact between the lock bar and the lock groove is released.

  Therefore, the driver can easily unlock the steering wheel by rotating the ignition key with a small force without rotating the ignition key while rotating the steering wheel. The operability is improved. In addition, whether or not the outer peripheral surface of the lock bar and the inner peripheral wall of the lock groove are in contact with each other is grasped based on the stopped state of the electric motor rather than the rotating state of the electric motor. Therefore, the engagement state between the lock bar and the lock groove can be reliably determined.

  Further, the reverse rotation control means of the lock release auxiliary control means can change the second command current value stepwise based on the rotation state of the electric motor detected by the rotation state detection means. Therefore, the electric motor can be operated accurately regardless of the influence of the environment (for example, outside air temperature) in which the electric motor operates, and as a result, the steering lock mechanism can be favorably released from the locked state. Can do. Further, since it is not necessary to consider in advance the influence of the environment on the operation of the electric motor, for example, it is not necessary to prepare a temperature sensor or a table for correcting the second command current value, and the steering device itself is simplified. You can also.

  In addition, another structural feature of the present invention is that a variable gear mechanism is provided for changing a gear ratio interposed in a steering shaft located between the handle and the electric motor, and the lock release auxiliary control means includes Based on the detection of the rotation state by the rotation state detection means, when controlling the rotation of the electric motor to assist the release of the lock state in the steering lock mechanism, the variable gear mechanism is controlled to There is also the fact that the amount of rotation is made small. According to this, even if the electric motor is rotated in order to release the locked state in the steering lock mechanism, the amount of rotation of the handle can be reduced by controlling the variable gear mechanism. The feeling of strangeness can be eliminated.

  Another structural feature of the present invention is a steering lock mechanism that disables the turning operation of the handle in the locked state and allows the turning operation of the handle in the unlocked state, and the turning operation of the handle. In a vehicle steering apparatus comprising an electric motor for assisting the vehicle, a rotation state detecting means for detecting a rotation state of the electric motor, and the steering by controlling the rotation of the electric motor based on the detected rotation state A lock assist control means for assisting the setting of the lock state in the lock mechanism is provided.

  In this case, the lock assist control unit is configured to control rotation of the electric motor based on a command current value for rotating the electric motor in a predetermined direction. When detecting a state in which the rotation in the predetermined direction is stopped, a lock determination unit for determining that the handle is locked, and when the lock determination unit determines that the handle is locked, the rotation of the electric motor is stopped. It is good to comprise from the rotation stop control means to control.

  According to these, when the driver turns the ignition key in a direction opposite to the direction in which the ignition key is turned on and then pulls out from the key cylinder to stop the operation of the vehicle, the front end surface of the lock bar does not face the lock groove. Since the lock assist control means assists the setting of the lock state in the steering lock mechanism by controlling the rotation of the electric motor, the distal end portion of the lock bar can enter the lock groove and completely lock the handle. Specifically, when the rotation control means of the lock auxiliary control means rotates the electric motor in a predetermined direction, the lock groove provided in the steering shaft rotates to a position facing the front end surface of the lock bar. The tip part enters the lock groove. As described above, after the lock bar has entered the lock groove, the electric motor detected by the rotation state detection means is detected by the rotation assist detection means when the lock bar is further displaced and comes into contact with the inner peripheral wall of the lock groove. Based on the stop state, it can be determined that the handle is completely locked. Then, the rotation stop control means of the lock auxiliary control means stops the rotation of the electric motor.

  Therefore, even after the driver removes the ignition key from the key cylinder, the steering wheel is always completely locked without turning the steering wheel. It is also safer against theft. In addition, whether or not the outer peripheral surface of the lock bar and the inner peripheral wall of the lock groove are in contact with each other is grasped based on the stopped state of the electric motor rather than the rotating state of the electric motor. Therefore, the engagement state between the lock bar and the lock groove can be reliably determined. This ensures that the steering wheel is locked by the steering lock mechanism. In addition, since the rotation of the electric motor is stopped after it is determined that the handle is completely locked, the electric motor is not unnecessarily rotated.

  In addition, another structural feature of the present invention is that a variable gear mechanism is provided for varying a gear ratio interposed in a steering shaft located between the handle and the electric motor, and the lock auxiliary control means includes: Based on the detection of the rotation state by the rotation state detection means, the rotation of the handle is controlled by controlling the variable gear mechanism when controlling the rotation of the electric motor to assist the setting of the lock state in the steering lock mechanism. I also tried to make the amount small. According to this, even if the electric motor is rotated in order to set the lock state in the steering lock mechanism, the amount of rotation of the handle can be reduced by controlling the variable gear mechanism. The feeling of strangeness can be eliminated.

  Furthermore, another structural feature of the present invention is that the rotational state detecting means detects the rotational state of the electric motor based on, for example, the rotational angular velocity of the electric motor. Further, handle rotation angle detection means for detecting the rotation angle of the handle is provided, and the rotation state detection means is based on a change amount of the rotation angle accompanying the rotation of the electric motor detected by the handle rotation angle detection means. The rotational state of the electric motor may be detected. According to these, the rotation state detection means can detect the rotation state of the electric motor using a sensor that is also used for other control in the vehicle, such as a rotary encoder or a steering angle sensor. it can. For this reason, the configuration of the steering device itself can be simplified, and the manufacturing cost can be reduced as compared with the case where a separate sensor is provided.

  DESCRIPTION OF EMBODIMENTS Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 schematically shows a vehicle steering apparatus according to the embodiment.

  This steering device is an electric power steering device, and includes a steering shaft 12 connected to the handle 11 so that the upper end thereof is integrally rotated. The lower end of the shaft 12 is integrally rotated with a pinion gear 13 a of the rack and pinion mechanism 13. It is connected to the. Connected to both ends of the rack bar 13b of the rack and pinion mechanism 13 are left and right front wheels FW1 and FW2 that are steered left and right in accordance with the axial displacement of the bar 13b.

  A steering lock that prohibits rotation of the handle 11 by engaging a lock groove provided on the shaft 12 and a lock bar provided on a support member side that rotatably supports the shaft 12 at an upper portion of the steering shaft 12. A mechanism 14 is assembled. The steering lock mechanism 14 has a known configuration and includes a cam mechanism that displaces the lock bar in conjunction with the rotation of the ignition key IGK in addition to the lock groove and the lock bar. The lock grooves are provided on the outer peripheral surface of the steering shaft 12 at one or a plurality of locations along the circumferential direction. The lock bar is provided on a fixed side with respect to the vehicle body and is incorporated in a support member that supports the steering shaft 12 so as to be rotatable about the axis, and the shaft 12 is provided at an axial position where the lock groove of the steering shaft 12 is provided. Is constantly biased toward the radially inner side of the shaft 12 by a spring. When the ignition key IGK inserted in the key cylinder is rotated in a direction to turn on the ignition switch 25, the cam mechanism displaces the lock bar outward in the radial direction against the biasing force of the spring, and The front end surface is held at an unlocked position that is positioned away from the outer peripheral surface of the steering shaft 12, and is rotated in the opposite direction from the rotational position where the ignition switch 25 is turned on in order to pull out the ignition key IGK from the key cylinder. When moved, the lock bar is released from being held in the unlocked position, and the urging force of the spring allows the lock bar to be displaced inward in the radial direction.

  An electric motor 15 is assembled to the steering shaft 12 at a position between the pinion gear 13 a and the steering lock mechanism 14. The electric motor 15 is composed of a direct current motor, and applies an assisting force to the turning operation of the handle 11 according to the rotation thereof. The rotation is transmitted to the steering shaft 12 via the speed reducer 16. It is like that.

  An electric control device 20 is electrically connected to the electric motor 15, and a vehicle speed sensor 21, a steering torque sensor 22, and a rotary encoder 23 are connected to the electric control device 20. The vehicle speed sensor 21 detects the vehicle speed V and supplies a detection signal representing the vehicle speed V to the electric control device 20. The steering torque sensor 22 detects a difference in rotational displacement between both ends of an elastic torsion member such as a torsion bar constituting a part of the steering shaft 12 at a position between the steering lock mechanism 14 and the speed reducer 16. Then, a signal proportional to the difference is supplied to the electric control device 20 as a signal representing the steering torque TM. The steering torque TM corresponds to a reaction force against the turning operation of the handle 11, and the steering torque TM is represented by positive and negative depending on the rotation direction. The rotary encoder 23 is assembled to the drive shaft of the electric motor 15 and counts pulses detected at every predetermined rotation of the drive shaft, whereby a detection signal indicating the rotation angular velocity ω of the electric motor 15 is sent to the electric control device 20. Supply.

  As shown in FIG. 2, the electric control device 20 is connected to a battery 17 whose negative voltage terminal (−) is grounded. The positive voltage terminal (+) of the battery 17 is connected to a first relay switch 24 a and an ignition. One end of each of the switch 25, the key insertion detection switch 26, and the second relay switch 27a is connected.

  The first relay switch 24a is kept off when the first relay coil 24b controlled by the first relay control circuit 44 described later is not energized, and kept on when the first relay coil 24b is energized. The battery voltage is supplied to the drive circuit 30. The drive circuit 30 causes a drive current to flow through the electric motor 15 and is formed of a bridge circuit having four sides of switching elements 31 to 34 such as FETs. One of a pair of opposite diagonal positions of the bridge circuit is connected to the other end of the relay switch 24a via a shunt resistor 35, and the other of the same pair of diagonal positions is grounded via a shunt resistor 36. Yes. Further, both terminals of the electric motor 15 are connected to the other diagonal position of the bridge circuit.

  The ignition switch 25 is turned on when the ignition key IGK is inserted into the key cylinder and rotated in one direction, and is turned off in other states. The other end of the ignition switch 25 is connected to the microcomputer 40, the drive control circuit 41, the current detection circuit 42, the voltage detection circuit 43, and the first relay control circuit 44 via the diode 28a, and the switch 25 is in the ON state. The battery voltage is supplied to each of the circuits 40-44. The battery voltage from the first relay switch 24a is also supplied to the cathode side of the diode 28a via the diode 28b. Further, the potential at the connection point between the other end of the ignition switch 25 and the diode 28 a is also supplied to the microcomputer 40.

  The microcomputer 40 inputs the vehicle speed V, the steering torque TM, and the rotational angular velocity ω from the vehicle speed sensor 21, the steering torque sensor 22, and the rotary encoder 23 by executing the built-in program shown in the flowcharts of FIGS. A command current value I * for flowing through the electric motor 15 is calculated according to the vehicle speed V, the steering torque TM, and the rotational angular velocity ω, and a control signal corresponding to the calculated command current value I * is output to the drive control circuit 41. At the same time, the first and second relay control circuits 44 and 45 are controlled. The drive control circuit 41 performs on / off control of the switching elements 31 to 34 in the drive circuit 30 according to the control signal from the microcomputer 40.

  The current detection circuit 42 is connected to both ends of the shunt resistor 36, and outputs a detection signal representing the drive current value Im flowing through the electric motor 15 to the microcomputer 40 based on the voltage across the resistor 36. The voltage detection circuit 43 is connected to both ends of the electric motor 15, and outputs a detection signal indicating a voltage value Vm between terminals of the motor 15 to the microcomputer 40. The first relay control circuit 44 controls energization and de-energization of the first relay coil 24b according to a control signal from the microcomputer 40.

  The key insertion detection switch 26 is turned on when the ignition key IGK is inserted into the key cylinder, and turned off when the ignition key IGK is pulled out from the key cylinder. The other end of the key insertion detection switch 26 is grounded via a resistor 46, and the potential at the connection point between the switch 26 and the resistor 46 is supplied to the microcomputer 40 and the second relay control circuit 45. ing.

  The second relay switch 27a is kept off when the second relay coil 27b controlled by the second relay control circuit 45 is not energized, and is kept on when the second relay coil 27b is energized. Yes, the other end of the switch 27a is grounded via a resistor 47. The connection point of the second relay switch 27a and the resistor 47 is connected to both cathodes of the diodes 28a and 28b via the diode 28c. When the switch 27a is turned on, the battery voltage is applied to the microcomputer 40 and the drive control. The circuit 41, the current detection circuit 42, the voltage detection circuit 43, and the first relay control circuit 44 are supplied.

  The second relay control circuit 45 is connected between the other end of the second relay coil 27b connected at one end to the positive voltage terminal (+) of the battery 17 and the other end of the resistor 48 having one end grounded. Yes. The second relay control circuit 45 is constituted by a flip-flop circuit, a switching circuit, etc., and starts energization of the second relay coil 27b when the potential at the connection point between the key insertion detection switch 26 and the resistor 46 rises. The energization is canceled by a control signal from the microcomputer 40.

  Next, the operation of the embodiment configured as described above will be described. In order to start the vehicle, when the driver inserts the ignition key IGK into the key cylinder and rotates in the direction in which the ignition switch 25 is turned on, the ignition key IGK is inserted into the key cylinder and the key insertion is detected at the time. The switch 26 is turned on. When the key insertion detection switch 26 is turned on, the potential at the connection point between the switch 26 and the resistor 46 increases. In response to this increase in potential, the second relay control circuit 45 starts energizing the second relay coil 27b, so that the second relay switch 27a is turned on, and the battery voltage is changed via the switch 27a and the diode 28c. The microcomputer 40, the drive control circuit 41, the current detection circuit 42, the voltage detection circuit 43, and the first relay control circuit 44 start to be supplied.

  When the supply of the battery voltage is started, the microcomputer 40 starts operation and starts executing the initial control program of FIG. 3 in step S100. After starting the execution of the initial control program, the microcomputer 40, in step S102, the microcomputer 40 itself including the CPU, ROM, RAM, interface circuit, and the like, the electric motor 15, the vehicle speed sensor 21, the steering torque sensor 22, and the rotary encoder. 23, the drive circuit 30, the drive control circuit 41, the current detection circuit 42, the voltage detection circuit 43, the first and second relay control circuits 44 and 45, and the like are subjected to an initial check for confirming the normal operation of the entire system. If any part of the system is abnormal, it is determined as “No” in step S104, information on the abnormality is displayed on a display (not shown) in step S106, and the nonvolatile in the microcomputer 40 is displayed. After the information is written in the volatile memory portion, the execution of the initial control program is terminated in step S126.

  On the other hand, if the overall system is normal as a result of the initial check, it is determined as “Yes” in step S104, and a control signal is output to the first relay control circuit 44 in step S108. 24b is energized and controlled. By energizing the first relay coil 24b, the first relay switch 24a is turned on, and the battery voltage from the battery 17 is supplied to the drive circuit 30.

  After the process of step S108, the microcomputer 40 sets the command current value I * to the predetermined current value Ir1 in step S110. Here, the predetermined current value Ir1 is, for example, a driving current of the electric motor 15 that can rotate the shaft 12 against a reaction force input to the steering shaft 12 from the road surface via the left and right front wheels FW1 and FW2. Set to value Im or higher. The predetermined current value Ir1 is set to rotate the electric motor 15 in one of the left and right directions. For example, the predetermined current value Ir1 is expressed as a positive value when the steering shaft 12 is rotated leftward. At the same time, it is represented by a negative value when it is rotated rightward. In the following description, it is assumed that the predetermined current value Ir1 is represented by an absolute value.

  When the command current value I * is set in step S110 as described above, the microcomputer 40 drives and controls the electric motor 15 in step S112. That is, the microcomputer 40 inputs the drive current value Im of the electric motor 15 from the current detection circuit 42, and the drive control signal is such that the drive current value Im becomes the set command current value I *, that is, the predetermined current value Ir1. Is output to the drive control circuit 41. As a result, the drive control circuit 41 controls on / off of the switching elements 31 to 34 of the drive circuit 30 according to the drive control signal. Accordingly, the rotation of the electric motor 15 is controlled so that the rotational torque is proportional to the command current value I *.

  After the rotation control process in step S112, the microcomputer 40 inputs the rotation angular velocity ω of the electric motor 15 from the rotary encoder 23 in step S114. Then, the microcomputer 40 determines whether or not the absolute value of the input rotational angular velocity ω is greater than “0”. This determination process determines whether the outer peripheral surface of the lock bar is in contact with the inner peripheral wall of the lock groove in the steering lock mechanism 14 and the load for pulling out the lock bar from the lock groove is large.

  That is, the electric motor 15 is rotated by the drive current value Im corresponding to the command current value I * (predetermined current value Ir1) set in step S110, and this rotation is steered via the speed reducer 16. It is transmitted to the shaft 12. At this time, if the steering shaft 12 is in a locked state where the lock bar and the lock groove in the steering lock mechanism 14 are engaged, there is a clearance between the outer peripheral surface of the lock bar and the inner peripheral wall of the lock groove. It is possible to rotate by this clearance. In other words, the steering shaft 12 is prohibited from rotating in the other direction of the lock bar when one side of the outer peripheral surface of the lock bar is in contact with the inner peripheral wall of the lock groove. Therefore, if rotation of the steering shaft 12 is prohibited, the electric motor 15 does not rotate depending on the drive current value Im corresponding to the command current value I * (predetermined current value Ir1) set in step S110. That is, the rotational angular velocity ω is “0”. For this reason, when the rotational angular velocity ω of the electric motor 15 is “0”, the outer peripheral surface of the lock bar of the steering lock mechanism 14 and the inner peripheral wall of the lock groove are in contact with each other. The frictional force between is increased. As a result, the load for pulling out the lock bar from the lock groove is large.

  Therefore, in step S114, the microcomputer 40 has the absolute value of the rotational angular velocity ω greater than “0”, that is, the lock bar and the lock groove of the steering lock mechanism 14 are not in contact with each other, and the electric motor 15 In a situation where can be rotated, “Yes” is determined, and the process proceeds to step S116. In step S116, the command current value I * is set to “0”, and the rotation control of the electric motor 15 is stopped. On the other hand, in step S114, the microcomputer 40 is in a situation where the absolute value of the rotational angular velocity ω is “0”, that is, the lock bar of the steering lock mechanism 14 is in contact with the lock groove and the electric motor 15 cannot rotate. , "No" is determined, the process proceeds to step S118, and the "unlock assist routine" is executed. The “unlock assist routine” will be described in detail below.

  The “unlock assist routine” is executed in step S200 as shown in the flowchart of FIG. The microcomputer 40 resets the values of parameters described later in the initial setting process in step S202, and then executes the processes in steps S204 to S210 to separate the lock groove from the lock bar of the steering lock mechanism 14. By rotating relatively in the direction, the contact state between the outer peripheral surface of the lock bar and the inner peripheral wall of the lock groove is released.

  That is, in step S204, the microcomputer 40 gradually reduces the value calculated by Io * G from the predetermined current value Ir1 set in step S110, and sequentially sets the command current value I * stepwise. To do. Here, Io is a predetermined current value (constant) set in advance, and is positive if the predetermined current value Ir1 is a positive value, and negative if the predetermined current value Ir1 is a negative value. Value. G is a coefficient parameter for reducing the predetermined current value Ir1, and is incremented by a count-up process in step S208 described later. Then, the microcomputer 40 inputs the drive current value Im of the electric motor 15 from the current detection circuit 42 based on the command current value I * set in the step S204 in the same manner as the step S112. The rotation of the electric motor 15 is controlled so that the value Im becomes equal to the determined command current value I *.

  Subsequently, in step S208, the microcomputer 40 determines whether or not the electric motor 15 has been driven, in other words, whether or not the absolute value of the rotational angular velocity ω of the electric motor 15 is greater than “0”. If the absolute value of the rotational angular velocity ω is still “0” by this determination processing, it is determined “No”, the predetermined coefficient parameter G is incremented by the count-up processing in step S210, and the command current in step S204 is again performed. Executes the setting process for the value I *. In this way, by incrementing the predetermined coefficient G and executing the setting process in step S204 again, the value of the predetermined current value Ir1 is gradually decreased stepwise, and finally the electric motor 15 is reversed. The command current value I * to be driven is set. As a result, the electric motor 15 performs rotation control in the direction opposite to the rotation control by the processing of Steps S110 and S112. In step S208, the processes of step S204 to step S210 are repeated until the absolute value of the rotational angular velocity ω is greater than “0”.

  Here, as described above, by repeatedly executing the processing of step S204 to step S210, for example, it is possible to eliminate the influence of an increase in viscosity due to a change in the outside air temperature of the lubricant applied to each rotating portion, and to ensure In addition, the contact between the outer peripheral surface of the lock bar of the steering lock mechanism 14 and the inner peripheral wall of the lock groove can be released. That is, for example, in a state where the outside air temperature is low, the viscosity of the lubricant applied to each rotating portion such as the steering shaft 12, the electric motor 15, and the speed reducer 16 increases, so that the resistance to rotation increases. In such a situation, the rotational torque required to rotate the steering shaft 12 varies greatly.

  For this reason, when the electric motor 15 is uniquely controlled for reverse rotation using the preset command current value I *, the electric motor 15 cannot generate the necessary rotational torque, and the steering shaft 12 is rotated. May not be possible. Therefore, in this case, in order to generate an appropriate rotational torque in the electric motor 15, it is necessary to provide a temperature sensor, a table for correcting the drive current value Im, and the like separately. On the other hand, as described above, step S204 to step S210 are repeatedly executed to set the command current value I * in a stepwise manner, thereby generating the rotational torque necessary for the electric motor 15 to reversely rotate. Therefore, the reverse rotation can be reliably controlled.

  If the absolute value of the rotational angular velocity ω is greater than “0” in step S208, the microcomputer 40 determines “Yes” and proceeds to step S212. Here, if the absolute value of the rotational angular velocity ω is greater than “0” in step S208, the electric motor 15 is in a reverse rotation state. In step S212, the microcomputer 40 increments the time parameter T for rotating the electric motor 15, and in step S214, whether or not the incremented time parameter T is greater than a predetermined time To set in advance. Determine whether. Here, the predetermined time To is determined in consideration of, for example, a clearance amount determined by the width dimension of the lock bar and the width dimension of the lock groove of the steering lock mechanism 14. Then, the microcomputer 40 repeats “No” determination in step S214 until the time parameter T becomes larger than the predetermined time To, and executes step S212 and step S214. As a result, the steering shaft 12 rotates by a predetermined amount, in other words, the lock groove rotates by a predetermined amount with respect to the lock bar of the steering lock mechanism 14 in the direction of releasing the contact.

  If the time parameter T becomes larger than the predetermined time To in step S214, the microcomputer 40 determines “Yes” and proceeds to step S216. Thus, the contact state between the lock bar and the lock groove of the steering lock mechanism 14 is released by rotating the electric motor 15 reversely for a predetermined time To. In step S216, the microcomputer 40 sets the command current value I * to Ir1-Io * (G-1) in order to stop the rotation of the electric motor 15 that is currently reversely controlled. That is, as described above, in order to release the contact state between the lock bar and the lock groove of the steering lock mechanism 14, the electric motor 15 causes the command current value I * set in stages, in other words, Ir1− Reverse rotation control is performed based on Io * G. At this time, the electric motor 15 which is reversely controlled based on the command current value I * represented by Ir1-Io * G is in a state where it finally shifts from the stop state to the reverse rotation state. For this reason, if the value of the coefficient parameter G is reduced by “1”, the command current value I * for rotating the electric motor 15 in the reverse direction decreases, and the electric motor 15 is again stopped. Therefore, the reverse rotation drive of the electric motor 15 can be stopped by setting the command current value I * to Ir1-Io * (G-1). Then, after the drive stop process in step S216, the microcomputer 40 ends the execution of the “unlock assist routine” in step S218.

  Returning to the flowchart of FIG. 3 again, the microcomputer 40 sets the command current value I * to “0” in step S116 after executing the “unlock assist routine”, and stops the rotation control of the electric motor 15. To do. Since the process consisting of steps S110 to S116 is repeated until the ignition switch 25 is turned on by turning the ignition key IGK, the frictional force acting between the lock bar and the lock groove is eliminated. Or it is reduced. Therefore, the driver can rotate the ignition key IGK with a small force in the direction in which the ignition switch 25 is turned on, and the lock bar is pulled out from the lock groove by this rotation, and the steering lock mechanism 14 locks the handle 11. Since the state can be released, the operability of the steering lock mechanism 14 is improved.

  Then, when the ignition switch 25 is turned on by the rotation of the ignition key IGK, the potentials of the switch 25 and the diode 28a rise to the battery voltage. In response to this voltage increase, the microcomputer 40 determines that “Yes”, that is, the ignition switch 25 is turned on in step S120, and advances the program to step S122. In step S122, a control signal is output to the second relay control circuit 45 to release the energization of the second relay coil 27b that has been energized so far. Therefore, at this time, power supply to the microcomputer 40 and the like of the battery voltage via the second relay switch 27a is stopped, but the battery voltage is supplied via the ignition switch 25 and the first relay switch 24a.

  After the process of step S122, the execution of the assist control program of FIG. 5 is permitted in step S124, and the execution of the initial control program is terminated in step S126. Thereafter, the microcomputer 40 starts to repeatedly execute the assist control program of FIG. 5 every predetermined short time.

  The execution of the assist control program is started in step S300, and it is determined in step S302 whether or not the lock operation flag ROP is “1”. The lock operation flag ROP is initially set to “0”, and by “1”, the steering lock mechanism 14 is completely locked immediately after the operation of the vehicle is stopped and the ignition key IGK is removed. In this case, the electric motor 15 is operated, and “0” indicates the other state. Therefore, in this case, it is determined in step S302 that “No”, that is, the lock operation flag ROP is not “1”, and the program proceeds to step S304. In step S304, the potential at the connection point between the key insertion detection switch 26 and the resistor 46 is input, and it is determined whether or not the ignition key IGK has been removed from the key cylinder based on whether or not the potential is the ground potential. To do. In this case, since the ignition key IGK is inserted into the key cylinder, it is determined as “No” in step S304, that is, not the ground potential, and the program proceeds to step S306 and subsequent steps.

  In step S306, the vehicle speed V and the steering torque TM are input from the vehicle speed sensor 21 and the steering torque sensor 22. In step S308, the input vehicle speed V and the steering torque TM are input with reference to the conversion table that is stored in the microcomputer 40 and stores the assist current value Ia that changes according to the steering torque TM for each of a plurality of vehicle speed ranges. The assist current value Ia corresponding to is determined. The conversion characteristics of the conversion table are shown in the graph of FIG. 6, whereby the assist current value Ia is determined to increase as the steering torque TM increases and to decrease as the vehicle speed V increases.

  After the process of step S308, the calculated assist current value Ia is set as the command current value I * in step S310, and in step S312, as in the process of step S112, the current detection circuit 42 sends the electric motor 15 And the rotation of the electric motor 15 is controlled so that the drive current value Im becomes equal to the command current value I *. Therefore, the electric motor 15 is controlled such that its rotational torque is proportional to the command current value I *.

  After the process of step S312, execution of the assist control program is terminated in step S328. Then, every time a predetermined time elapses, the processing of step S306 to step S312 is repeatedly executed until the ignition key IGK is extracted. Therefore, the turning operation of the handle 11 is performed according to the steering torque TM and the vehicle speed V. The assist control is performed by the rotational torque of the motor 15.

  On the other hand, when the driver pulls out the ignition key IGK from the key cylinder when the vehicle is driven, the key insertion detection switch 26 is turned off, and the potential at the connection point between the switch 26 and the resistor 46 is reduced to the ground potential. . In response to this, the microcomputer 40 determines “Yes” in step S304, and determines whether the vehicle speed V and the steering torque TM are substantially “0” in steps S314 and 316, respectively. The determination process in steps S314 and 316 is a determination process for ensuring that the driving of the vehicle is finished. If either one of the vehicle speed V and the steering torque TM is not substantially “0”, the program is executed in step S304. Returning to step S304, the determination processing in steps S304, 314, and 316 is repeated. If the ignition key IGK is withdrawn from the key cylinder and both the vehicle speed V and the steering torque TM are substantially “0”, “Yes” is determined in steps S304, 314, and 316, respectively, and the lock operation is performed in step S318. After setting the flag ROP to “1”, the program proceeds to steps S320 and S322. Even in this state, the battery voltage from the battery 17 is supplied to the microcomputer 40 or the like via the first relay switch 24a and the diode 28b, and the operation of the computer 40 or the like is ensured.

  In step S320, command current value I * is set to positive predetermined current value Ir2. In step S322, the drive current value Im of the electric motor 15 is input from the current detection circuit 42, and the drive current value Im becomes equal to the determined command current value I *, as in the processing of steps S112 and 312. Thus, the rotation of the electric motor 15 is controlled. As a result, the electric motor 15 rotates and the steering shaft 12 and the handle 11 are rotated via the speed reducer 16.

  At this time, due to the rotation in the key cylinder before removing the ignition key IGK, in the steering lock mechanism 14, the lock bar is displaced radially inward of the steering shaft 12 from the unlocked position by the biasing force of the spring. However, if the front end surface of the lock bar does not face the lock groove, the bar cannot contact the lock groove and is in contact with the outer peripheral surface of the steering shaft 12. Of course, if the front end surface of the lock bar faces the lock groove, the bar has entered the lock groove.

  However, when the lock shaft provided on the outer peripheral surface of the steering shaft 12 is rotated to a position facing the front end surface of the lock bar due to the rotation of the steering shaft 12 by the process of step S322, the lock bar is biased by the spring. To enter the lock groove. Therefore, the predetermined current value Ir2 is equal to or higher than the drive current value Im of the electric motor 15 that can turn the steering shaft 12 even when the front end surface of the lock bar is pressed against the outer peripheral surface of the steering shaft 12 by the spring. Is set. Accordingly, even if the driver pulls out the ignition key IGK from the key cylinder and the handle 11 is not rotated, the handle 11 is always completely locked, so that the operability of the steering lock mechanism 14 is improved. At the same time, it becomes safer against theft of vehicles.

  After the process of step S322, it is determined in step S324 whether or not the rotational angular velocity ω of the electric motor 15 input from the rotary encoder 23 is “0”. This determination process is to determine that the handle 11 is securely locked, that is, after the lock bar of the steering lock mechanism 14 has entered the lock groove, the outer peripheral surface of the lock bar comes into contact with the inner peripheral wall of the lock groove. Thus, it is determined whether or not the steering shaft 12 cannot rotate and the electric motor 15 cannot rotate. In this way, by determining whether or not the rotational angular velocity ω is “0”, in addition to the inability to rotate the steering shaft 12, the left and right front wheels FW1, FW2 contact the road shoulders, It can also be determined that the electric motor 15 is locked due to reaching the limit (steering end) at which the handle 11 is turned, a system failure including a failure of the electric motor 15, or the like.

  If the rotational angular velocity ω is not “0”, it is determined as “No” in step S324, and the process proceeds to step S328, where the execution of the assist control program is temporarily ended. If a predetermined time elapses after the execution of the assist control program, the program is executed again. However, since the lock operation flag ROP is set to “1”, “Yes” is determined in step S302. Thus, the processing after step S320 is executed, and the rotation of the electric motor 15 continues to be controlled by the processing of steps S320 and 322. When the lock bar of the steering lock mechanism 14 enters the lock groove and the outer peripheral surface of the lock bar comes into contact with the inner peripheral wall of the lock groove and the steering shaft 12 cannot be rotated, “Yes” is determined in step S324. That is, it is determined that the rotational angular velocity ω of the electric motor 15 is “0”, and the program proceeds to step S326. Also, if the electric motor 15 is locked for reasons other than the engagement between the lock bar and the lock groove, “Yes” is determined in step S324, and the program proceeds to step S326.

  In step S326, a control signal for releasing the energization of the first relay coil 24b is output to the first relay control circuit 44, and the control circuit 44 releases the energization of the first relay coil 24b. As a result, the first relay switch 24a is turned off, so that the supply of the battery voltage to the drive circuit 30 and the supply of the battery voltage to the microcomputer 40 and the like via the diode 28b are stopped. At this time, since the ignition switch 25 and the second relay switch 27a are also kept off, the operation of the entire electric power steering system including the operation stop of the electric motor 15 is stopped. In this way, as a result of the operation of the electric motor 15 being stopped, unnecessary rotation control of the motor 15 is eliminated, and the motor 15 is protected.

  As can be understood from the above description, according to the vehicle steering apparatus of the above embodiment, when the driver inserts the ignition key IGK into the key cylinder and rotates to start the vehicle, the steering lock mechanism 14 is Even when the lock bar is in the lock groove and the lock bar is in contact with the outer peripheral surface of the lock bar and the inner peripheral wall of the lock groove, the microcomputer 40 controls reverse rotation of the electric motor 15. Thus, the contact between the lock bar and the lock groove can be automatically released.

  Therefore, the driver can easily unlock the handle 11 by rotating the ignition key IGK with a small force without rotating the ignition key IGK while rotating the handle 11. The operability of the steering lock mechanism 14 is improved. Further, whether or not the outer peripheral surface of the lock bar and the inner peripheral wall of the lock groove are in contact is grasped based on the rotation state of the electric motor 15, in other words, the stop state of the electric motor 15, so that there is no dead zone. It is possible to reliably determine the engagement state between the lock bar and the lock groove.

  Further, according to the vehicle steering apparatus of the above embodiment, when the driver turns the ignition key IGK in the direction opposite to the direction in which the ignition switch 25 is turned on and then pulls it out from the key cylinder, the steering is stopped. Even if the front end surface of the lock bar of the lock mechanism 14 does not face the lock groove, the microcomputer 40 assists in setting the lock state in the steering lock mechanism 14 by controlling the rotation of the electric motor 15. For this reason, the front-end | tip part of a lock bar can penetrate | invade into a lock groove | channel, and can lock the handle | steering-wheel 11 completely.

  Therefore, even if the driver pulls out the ignition key IGK from the key cylinder and the steering wheel 11 is not rotated, the steering wheel 11 is always completely locked, so that the operability of the steering lock mechanism 14 is improved. , It will also be safer against vehicle theft. Further, whether or not the outer peripheral surface of the lock bar and the inner peripheral wall of the lock groove are in contact is grasped based on the rotation state of the electric motor 15, in other words, the stop state of the electric motor 15, so that there is no dead zone. It is possible to reliably determine the engagement state between the lock bar and the lock groove. As a result, the steering lock mechanism 14 securely locks the handle.

  Here, in the above-described embodiment, the insertion of the ignition key IGK into the key cylinder is detected by the key insertion detection switch 26 at the start of operation of the vehicle. However, instead of or in addition to this, the ignition key In a vehicle equipped with an immobilizer system having a function of detecting the insertion of an IGK into a key cylinder, an insertion detection signal of the ignition key IGK into the key cylinder by the immobilizer system may be used. Further, in a vehicle equipped with a key entry system capable of starting the engine by remote operation, the engine start signal of the system may be used instead of or in addition to detection by the detection switch 26. Furthermore, in a vehicle equipped with a smart key system that can receive radio waves from a portable terminal carried by the driver, recognize the driver, and start the engine by pressing the ignition start switch by the driver. The radio waves of the system may be used in place of detection by the detection switch 26.

  In the above embodiment, the determination process in step 304 (or the determination processes in steps 304, 314, and 316) is performed in order to reliably detect the necessity of locking the steering wheel 11 by the steering lock mechanism 14 at the end of driving of the vehicle. ) Was executed. Alternatively or in addition, the door was opened / closed by a door open / close signal, the door was locked by a door lock detection signal, the seat belt was removed by a seat belt wearing / non-detection signal, shift position detection Stop of the vehicle based on the parking position detection signal in the means, stop of the vehicle based on the side brake pull detection signal in the side brake position detection means, release of the hand from the handle 11 by the handle contact sensor, from the anti-theft device The determination may be made by signal detection or the like.

  Further, in the above embodiment, the rotary encoder 23 is provided in the electric motor 15 so that the microcomputer 40 uses the rotational angular velocity ω output from the rotary encoder 23. However, when the steering angle sensor for detecting the rotation angle of the steering wheel 11 by the driver, that is, the steering angle θ, is assembled to the steering shaft 12, the detected steering angle θ from the steering angle sensor is time-differentiated, for example. It is also possible to use the rotational angular velocity ω1. In this case, since the steering shaft 12 and the electric motor 15 are connected to each other via the speed reducer 16, whether or not the electric motor 15 is rotated by using the rotational angular velocity ω1 of the steering shaft 12 is determined. Can be determined. Therefore, even in this case, the steering lock mechanism 14 can be reliably brought into the locked state or the unlocked state without having a dead zone.

  In the above embodiment, the drive current value Im of the electric motor 15 can be detected. For this reason, even if the electric motor 15 is not provided with a means for detecting the rotational angular velocity ω, such as the rotary encoder 23, the rotational angular velocity ω of the electric motor 15 may be estimated using the detected drive current value Im. Good. In this case, for example, the rotational speed of the electric motor 15 with respect to the drive current value Im is measured in advance, and the rotational angular velocity ω is estimated and calculated from this rotational speed.

  In the above embodiment, the unlocking or locking of the handle 11 is always assisted by the electric motor 15. However, the assistance is stopped by the changeover switch that is switched by the driver, and the assistance is stopped. You may be allowed to select the case.

  Further, in the above embodiment, the gear ratio is made variable on the steering shaft 12 located between the handle 11 and the electric motor 15 in order to eliminate the uncomfortable feeling of rotation of the handle 11 when the handle 11 is unlocked or locked. A variable gear mechanism may be interposed to control the variable gear mechanism to reduce the rotation amount of the handle 11 when the auxiliary electric motor 15 rotates.

  Furthermore, in the said embodiment, it implemented about the electric power steering device as a vehicle steering device. However, the present invention can also be implemented for other vehicle steering devices, for example, a steering-by-wire vehicle steering device that eliminates the mechanical connection between the steering wheel and the left and right front wheels FW1, FW2. Also in this case, for example, an actuator (electric motor) for applying a reaction force to the handle and an actuator (electric motor) for steering the left and right front wheels FW1, FW2 in accordance with the turning operation of the handle are described in the above embodiment. Similarly to the above, by controlling the rotation based on the rotation state, the same effect as in the above embodiment can be expected.

1 is an overall schematic diagram of an electric power steering device as a vehicle steering device according to an embodiment of the present invention. It is a whole block diagram of the electric control apparatus of FIG. 3 is a flowchart of an initial control program executed by the microcomputer of FIG. 2. 3 is a flowchart of an unlock assist routine executed by the microcomputer of FIG. 2. 3 is a flowchart of an assist control program executed by the microcomputer of FIG. It is a graph which shows the relationship between steering torque and an assist electric current value.

Explanation of symbols

FW1, FW2 ... front left and right wheels, IGK ... ignition key, 11 ... handle, 12 ... steering shaft, 14 ... steering lock mechanism, 15 ... electric motor, 20 ... electric control device, 21 ... vehicle speed sensor, 22 ... steering torque sensor, 23 ... Rotary encoder, 24a, 27a ... Relay switch, 24b, 27b ... Relay coil, 25 ... Ignition switch, 26 ... Key insertion detection switch, 30 ... Drive circuit, 40 ... Microcomputer, 44, 45 ... Relay control circuit

Claims (9)

A steering lock mechanism that disables the turning operation of the handle in the locked state and allows the turning operation of the handle in the unlocked state, and an electric motor for assisting the turning operation of the handle. In the steering device,
Rotation state detection means for detecting the rotation state of the electric motor;
A vehicle steering apparatus, comprising: a lock release auxiliary control unit that controls rotation of the electric motor based on the detected rotation state and assists the release of the lock state in the steering lock mechanism. In the vehicle steering apparatus according to claim 1,
The unlocking auxiliary control means,
Forward rotation control means for performing forward rotation control based on a first command current value for rotating the electric motor in a predetermined direction;
A second command current value for rotating the electric motor in a direction opposite to the predetermined direction when the rotation state detecting unit detects that the rotation of the electric motor in the predetermined direction by the forward rotation control unit is stopped. Reverse rotation control means for performing reverse rotation control based on
A vehicle steering apparatus comprising: a rotation stop control means for stopping the rotation of the electric motor after the electric motor is reversely rotated by a predetermined amount by the reverse rotation control means. In the vehicle steering apparatus according to claim 2,
The reverse rotation control means reversely rotates the electric motor by changing stepwise from the first command current value to the second command current value according to the rotation state of the electric motor detected by the rotation state detection means. A vehicle steering apparatus that controls the vehicle. The vehicle steering apparatus according to any one of claims 1 to 3, further comprising:
A variable gear mechanism is provided for changing a gear ratio interposed in a steering shaft located between the handle and the electric motor,
When the lock release auxiliary control means controls the rotation of the electric motor to assist the release of the lock state in the steering lock mechanism based on the detection of the rotation state by the rotation state detection means, the variable gear mechanism The vehicle steering apparatus is characterized in that the amount of rotation of the steering wheel is reduced by controlling the steering wheel. A steering lock mechanism that disables the turning operation of the handle in the locked state and allows the turning operation of the handle in the unlocked state, and an electric motor for assisting the turning operation of the handle. In the steering device,
Rotation state detection means for detecting the rotation state of the electric motor;
A vehicle steering apparatus comprising: a lock assist control means for assisting in setting a lock state in the steering lock mechanism by controlling the rotation of the electric motor based on the detected rotation state. In the vehicle steering apparatus according to claim 5,
The lock auxiliary control means,
Rotation control means for controlling rotation based on a command current value for rotating the electric motor in a predetermined direction;
A lock determination unit that determines that the handle is locked when the rotation state detection unit detects a state in which the rotation of the electric motor by the rotation control unit is stopped in a predetermined direction;
A vehicle steering apparatus comprising: a rotation stop control means for stopping the rotation of the electric motor when the lock determination means determines that the handle is locked. The vehicle steering apparatus according to claim 5 or 6, further comprising:
A variable gear mechanism is provided for changing a gear ratio interposed in a steering shaft located between the handle and the electric motor,
When the lock auxiliary control means controls the rotation of the electric motor to assist the setting of the lock state in the steering lock mechanism based on the detection of the rotation state by the rotation state detection means, the variable gear mechanism is A steering apparatus for a vehicle, characterized in that the amount of rotation of the steering wheel is controlled to be small. In the vehicle steering apparatus according to any one of claims 1 to 7,
The rotation state detecting means includes
A vehicle steering apparatus that detects a rotation state of the electric motor based on a rotation angular velocity of the electric motor. The vehicle steering apparatus according to any one of claims 1 to 7, further comprising:
A handle rotation angle detection means for detecting the rotation angle of the handle is provided;
The rotation state detecting means includes
A vehicle steering apparatus, wherein a rotation state of the electric motor is detected based on a change amount of a rotation angle accompanying rotation of the electric motor detected by the steering wheel rotation angle detection means.

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