JP2008080892A - Vehicular steering device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicular steering device capable of reducing various inconvenience caused by collision of a vehicle by a simple constitution by not forecasting the collision with an obstacle but operating a steering actuator based on the detection result of the collision with the obstacle to execute automatic steering. <P>SOLUTION: A control means detects existence of the collision, emits braking instruction for quickly braking the vehicle when it is determined that the collision exists, determines that the collision occurs at any one side, and controls the steering actuator so as to perform steering in an opposite direction to a side where the collision occurs. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention includes a steering actuator capable of applying a steering force to a steering mechanism that operates to steer a steering wheel in accordance with an operation of the steering member regardless of the operation of the steering member. The present invention relates to a vehicle steering apparatus.

  Steering of a vehicle is performed by transmitting an operation of a steering member such as a steering wheel to a steering mechanism via a steering shaft, and steering wheels (generally, left and right front wheels) are steered by the operation of the steering mechanism. Is called. As a steering apparatus for performing such steering, there is a steering apparatus provided with a steering actuator that can apply a steering force to a steering mechanism regardless of operation of a steering member in recent years.

  For example, Patent Document 1 includes a variable ratio transmission mechanism capable of changing a rotation transmission ratio in the middle of a steering shaft that communicates between a steering member and a steering mechanism, and steering from the steering member is performed by the operation of the variable ratio transmission mechanism. A vehicle steering apparatus has been proposed in which transmission to the mechanism is performed by changing the rotation transmission ratio steplessly.

  The variable ratio transmission mechanism disclosed in Patent Document 1 is provided with an input sun gear that is provided around the input shaft on the steering member side, and an output sun shaft that is provided on the output side on the steering mechanism side, and is arranged coaxially with the input sun gear. An output sun gear, an input planetary gear and an output planetary gear meshed with the input sungear and the output sungear, respectively, and a carrier that supports these planetary gears via a common support shaft. Is provided with a speed change motor that rotates the shaft around the axis.

  According to this configuration, when the transmission motor is in a non-driven state and the carrier is fixed, the rotation of the input shaft input to the input sun gear is determined by the rotation transmission ratio determined by the number of teeth of the input / output sun gear and the input / output planetary gear. The operation amount of the steering member and the operation amount of the steering mechanism are maintained in a certain correspondence relationship.

  On the other hand, when the carrier is rotated by driving the transmission motor, the rotation of the input shaft input to the input sun gear is transmitted to the output sun gear and output shaft via the input planetary gear and output planetary gear that revolve with the carrier. The rotation transmission ratio between the input and output shafts can be changed steplessly according to the increase or decrease of the rotation speed of the carrier driven by the speed change motor, and the operation amount of the steering member and the operation amount of the steering mechanism The correspondence relationship can be freely changed.

  In this steering device, the speed change motor can be used as a steering actuator that applies a steering force to the steering mechanism. By operating the speed change motor regardless of the operation of the steering member, for example, for a vehicle that is running Corrective steering can be performed to prevent unstable vehicle behavior caused by crosswinds acting on the road, slipping of wheels on the road surface, and the like.

  In Patent Document 2, a steering member inside the vehicle compartment is mechanically separated from a steering mechanism outside the vehicle compartment, and a steering motor is attached to a part of the steering mechanism, and the steering motor is attached to the steering member. A so-called steer-by-wire type steering apparatus has also been proposed that is configured to perform steering by applying a steering force to a steering mechanism and controlling the vehicle according to the above operation.

  Further, an electric power steering apparatus widely known as a vehicle steering apparatus includes a steering assist motor that applies a steering assist force to a steering mechanism, and controls the steering assist motor in accordance with an operation of a steering member. Therefore, the operation force applied to the steering member is reduced, and a good steering feeling is realized.

  Also in these steering devices, the steering motor or the steering assist motor can be used as a steering actuator that applies a steering force to the steering mechanism, and operates the steering motor or the steering assist motor regardless of the operation of the steering member. Thus, it is possible to execute the correction steering for preventing the unstable vehicle behavior due to the above-described cross wind and slip.

  In a vehicle steering apparatus having such a steering actuator, it has also been proposed to use the operation of the steering actuator that applies a steering force to the steering mechanism in order to avoid a collision accident of the vehicle (for example, Patent Documents). 3).

In the invention disclosed in Patent Document 3, the presence / absence of an obstacle on the front / rear, left / right of the vehicle is detected, the occurrence of a collision accident with respect to the detected obstacle is predicted, and the result of this prediction is notified to the driver by an alarm. On the other hand, when an operation for avoiding danger is not performed in response to this warning, automatic steering is performed by operating a steering assist motor of the electric power steering apparatus.
JP 2005-344757 A Japanese Patent Laid-Open No. 10-218000 Japanese Patent Laid-Open No. 2003-40061

  However, the invention described in Patent Document 3 is an invention related to an accident analysis device for estimating a damage situation after the occurrence of an accident and enabling quick countermeasures. The detection means for detecting left and right obstacles has a complicated configuration using a radar and a camera, and moreover, complicated processing including image processing is required for prediction of a collision based on these detection results. Furthermore, there is no specific description of the procedure of automatic steering based on the prediction result, and only an insufficient configuration that cannot be put into practical use is disclosed.

  In recent years, a steering control device that automatically performs garage entry and parallel parking using automatic steering by the operation of a steering actuator has been put into practical use. In this apparatus, a movement path is determined based on an analysis result of a peripheral image captured by a camera mounted on a vehicle, and a steering actuator is operated to perform steering along this path.

  In a vehicle equipped with this device, interrupt steering by operating a steering member is made possible in order to cope with an unexpected obstacle intervention during automatic steering, but the driver is appropriate for a sudden operation during automatic steering. There is a risk that a collision with the obstacle may be promoted by causing an incorrect operation to be performed and causing a problem such as damage to the vehicle body.

  The present invention has been made in view of such circumstances, and does not predict a collision with an obstacle, but performs automatic steering by operating a steering actuator based on a detection result of the collision with an obstacle. Accordingly, an object of the present invention is to provide a vehicle steering apparatus that can reliably reduce various problems caused by a vehicle collision with a simple configuration.

  A vehicle steering apparatus according to a first aspect of the present invention includes a steering mechanism that performs a steering operation for turning a steering wheel in response to an operation of a steering member of the vehicle, a steering actuator that applies a steering force to the steering mechanism, and In the vehicle steering apparatus comprising: a collision detection unit that detects a collision with an obstacle of the vehicle including a direction of the collision; and the collision detected by the steering actuator according to the detection by the collision detection unit. Control means for controlling the steering mechanism to apply a steering force in the opposite direction to the steering mechanism.

  The vehicle steering apparatus according to a second aspect of the present invention is characterized in that the control means according to the first aspect executes braking control for suddenly braking the vehicle during the control operation of the steering actuator.

  Furthermore, the vehicle steering apparatus according to a third aspect of the present invention is characterized in that the collision detection means in the first or second aspect is configured to detect the collision based on a change in lateral acceleration or yaw rate of the vehicle. And

  In the vehicle steering apparatus according to the first aspect of the present invention, the steering actuator is configured to cause the steering to be performed in the direction opposite to the direction in which the collision occurs by the operation of the control unit according to the collision detection by the collision detection unit. Therefore, automatic steering is performed so as to move away from the obstacle, and the occurrence of problems such as damage due to the collision can be reduced.

  In the vehicle steering system according to the second aspect of the invention, the control means executes the braking control in conjunction with the control of the steering actuator and suddenly brakes the vehicle. The occurrence of malfunctions can be reduced more effectively.

  Further, in the vehicle steering apparatus according to the third aspect of the invention, since the collision with the obstacle is detected based on the change in the lateral acceleration or the yaw rate, the lateral acceleration sensor or the yaw rate sensor necessary for various control of the vehicle is used. The present invention has an excellent effect that, for example, automatic steering when a collision occurs can be executed with a simple configuration that does not require complicated processing.

  Hereinafter, the present invention will be described in detail with reference to the drawings illustrating embodiments thereof. FIG. 1 is a schematic diagram showing the overall configuration of a vehicle steering apparatus according to the present invention, in which a rotation operation of a steering wheel 1 as a steering member is transmitted to a steering mechanism 3 via a steering shaft 2, and the steering mechanism 3 By the operation, the steering wheels 30, 30 arranged on the left and right of the vehicle body are steered.

  The steering mechanism 3 includes a rack shaft 32 that is supported so as to be movable in the axial direction in a rack housing 31 that extends in the left-right direction of a vehicle body (not shown), and a pinion housing 33 that crosses the rack housing 31 in the middle. This is a known rack and pinion type steering mechanism having a pinion shaft 34 rotatably supported therein. Needless to say, the characteristic configuration of the present invention described below can be applied to a vehicle including a steering mechanism other than the rack and pinion type.

  Both ends of the rack shaft 32 projecting outward from both sides of the rack housing 31 are connected to the left and right steering wheels 30, 30 via separate tie rods 35, 35, and projecting from the top of the pinion housing 33 The upper end of the pinion shaft 34 is connected to the steering shaft 2 via the intermediate shaft 36. A pinion (not shown) is provided in the lower half portion of the pinion shaft 34 extending into the pinion housing 33, and the pinion is formed on the outer surface of the rack shaft 32 at an appropriate length at the intersection with the rack housing 31. Meshed with the rack.

  The steering shaft 2 is rotatably supported inside a cylindrical column housing 20, and is attached to the interior of a vehicle compartment (not shown) while maintaining an inclined posture with the front facing down. The steering shaft 2 is divided into two shafts, an upper input shaft 2a and a lower output shaft 2b (see FIG. 2), inside the column housing 20, and the steering shaft 2 ( The steering wheel 1 is fixed to the projecting end of the input shaft 2a), and the projecting end of the steering shaft 2 (output shaft 2b) downward is connected to the pinion shaft 34 as described above.

  With the above configuration, when the steering wheel 1 is rotated for steering, this rotation is transmitted to the pinion shaft 34 via the steering shaft 2 and the pinion shaft 34 rotates. Motion is converted at the meshing portion of the rack and transmitted to the rack shaft 32, and the rack shaft 32 moves in the axial direction, and by this movement, the other tie rods 35, 35 are pushed and pulled, and the wheels 30, 30 Is steered.

  The illustrated vehicle steering apparatus includes a variable ratio transmission mechanism 4 in the middle of the column housing 20 that supports the steering shaft 2. This variable ratio transmission mechanism 4 is a mechanism for continuously transmitting rotation from the upper part to the lower part of the steering shaft 2, that is, from the input shaft 2a to the output shaft 2b, by changing the rotation transmission ratio in a stepless manner. Has been.

  A variable speed transmission mechanism 4 and a reaction force motor 6 are attached to the variable ratio transmission mechanism 4. The speed change motor 5 is rotationally driven in response to an operation command given to a drive circuit (not shown) from a steering control unit 7 using a microprocessor, and acts on the variable ratio transmission mechanism 4 as will be described later, whereby the variable ratio transmission mechanism. The operation of changing the rotation transmission ratio by 4 steplessly is performed. Similarly, the reaction force motor 6 is rotationally driven in accordance with an operation command given from the steering control unit 7 and acts on the variable ratio transmission mechanism 4 as will be described later to apply a rotational force to the steering wheel 1 via the input shaft 2a. Thus, an operation for complementing the steering reaction force that changes in accordance with the change in the rotation transmission ratio is performed.

  The steering control unit 7 is configured to issue an operation command (braking command) to a vehicle braking control device (not shown). The braking control device to which the braking command is given operates to operate brakes attached to the respective wheels in order to suddenly brake the vehicle.

  The steering control unit 7 includes a detection result of the input rotation sensor 21 that detects the rotation angle of the steering shaft 2, that is, the input shaft 2 a above the variable ratio transmission mechanism 4, and a lower position than the variable ratio transmission mechanism 4. And the detection result of the output rotation sensor 22 for detecting the rotation angle of the steering shaft 2, that is, the output shaft 2b.

  The steering control unit 7 is also provided with the detection result of the lateral acceleration applied to the vehicle body by the lateral G sensor 23, the detection result of the yaw rate acting on the vehicle body by the yaw rate sensor 24, and the detection result of the traveling speed by the vehicle speed sensor 25. ing. The steering control unit 7 uses the lateral G sensor 23 and the yaw rate sensor 24 as collision detection means for detecting the collision of the vehicle including the direction, and in response to the detection of the collision, the shift motor 5 of the variable ratio transmission mechanism 4 is used. An automatic steering control operation described later is performed as a control target.

  Further, the steering control unit 7 is given a detection result of the traveling direction of the vehicle by the traveling direction sensor 26. The traveling direction sensor 26 may be any sensor that can detect whether the vehicle is moving forward or backward. For example, a sensor that detects a shift stage of the transmission, a front-rear G that detects longitudinal acceleration applied to the vehicle, and the like. A sensor or the like can be used. Furthermore, the vehicle speed sensor 25 can also be used. The traveling direction of the vehicle detected by the traveling direction sensor 26 is used to determine the steering direction in automatic steering control described later.

  Further, GPS (Global Positioning System) information received by the GPS sensor 27 is given to the steering control unit 7. The GPS information is information for specifying the position of the vehicle based on reception results of radio waves emitted from a plurality of dedicated satellites on the satellite orbit. The steering control unit 7 includes GPS information sequentially given from the GPS sensor 27, By comparing with the map information given from the navigation device that does not, the position of the vehicle on the road can be recognized including the speed. The position information recognized in this way is used to determine a travel route in automatic steering control described later.

  FIG. 2 is a longitudinal sectional view schematically showing the configuration of the variable ratio transmission mechanism 4. As shown in the figure, the input shaft 2a and the output shaft 2b constituting the steering shaft 2 are supported so as to be rotatable on the same axis with their front ends abutted on each other. 41 and the output sun gear 42 are integrally formed. As shown in the figure, the input sun gear 41 and the output sun gear 42 have an appropriate outer diameter difference, and the number of teeth provided on the outer periphery thereof is different.

  The input sun gear 41 is engaged with two input planetary gears 43 and 43 at positions facing each other in the radial direction, and the output sun gear 42 is similarly engaged with two output planetary gears 44 and 44. The input planetary gear 43 and the output planetary gear 44 meshing at the same position are provided around the outer periphery of a common support shaft 45 and surround the outside of the input sun gear 41 and the output sun gear 42 via the support shaft 45. It is supported inside a hollow cylindrical carrier 46. The carrier 46 has a support hole penetrating the axial center of the end walls on both sides, and is externally fitted to the input shaft 2a and the output shaft 2b via separate bearings, and is rotated relative to the two shafts 2a and 2b on the same axis. It is supported freely.

  On the outer periphery of the carrier 46, a transmission gear 47 is formed over the entire circumference, and the transmission gear 47 meshes with the output gear 50 of the transmission motor 5 driven for changing the rotation transmission ratio and for automatic steering. I'm allowed. The transmission motor 5 is rotationally driven in accordance with the operation command given from the steering control unit 7 as described above. When the transmission motor 5 is rotationally driven, the carrier 46 is rotated via the transmission gear 47 meshed with the output gear 50. It is done.

  The rotation of the transmission motor 5 is transmitted to the carrier 46 via a transmission gear 47 meshing with the output gear 50. The input planetary gears 43 and 43 and the output planetary gears 44 and 44 supported by the carrier 46 are connected to the input shaft 2a. And revolves on the same axis as the output shaft 2b, and rotates in unison around the axes of the separate support shafts 45 and 45 at each position on the revolution circumference.

  Further, a reaction force gear 48 is fitted and fixed to the input shaft 2 a of the variable ratio transmission mechanism 4, and the reaction force gear 47 is engaged with the output gear 60 of the reaction force motor 6. The reaction force motor 6 is rotationally driven in accordance with the operation command given from the steering control unit 7 as described above, and when the reaction force motor 6 is rotationally driven, the reaction force motor 48 meshes with the output gear 60 via the input force gear 48. A rotational force is applied to 2a, and this rotational force is applied to the steering wheel 1 fixed to the upper end of the input shaft 2a.

  In the vehicle steering apparatus according to the present invention having such a variable ratio transmission mechanism 4, when the steering wheel 1 is rotated for steering, the input shaft 2a connected to the steering wheel 1 rotates and is variable. The input sun gear 41 of the ratio transmission mechanism 4 rotates.

  Here, when the speed change motor 5 is not driven to rotate and the carrier 46 is in a non-rotating state, the input planetary gears 43 and 43 meshing with the input sun gear 41 share the support shafts 45 and 45 with the rotation of the input sun gear 41. The output planetary gears 44 and 44 rotate together, and this rotation adds a rotational force to the output sun gear 42 meshing with the output planetary gears 44 and 44, and the output shaft 2b including the output sun gear 42 rotates. Steering is performed by the operation of the steering mechanism 3 according to the rotation.

  At this time, the rotation transmission from the input shaft 2a to the output shaft 2b is performed at a specific rotation transmission ratio determined by the number of teeth of the input sun gear 41, the input, output planetary gears 43, 44, and the output sun gear 42. 30 and 30 are steered in an operation direction of the steering wheel 1 by an amount corresponding to an angle (steering angle) obtained by multiplying the operation amount (steering angle) of the steering wheel 1 by the rotation transmission ratio.

  On the other hand, when the speed change motor 5 is driven to rotate and the carrier 46 is rotated, the input sun gear 41 rotates together with the input planetary gears 43 and 43 and the output planetary gears 44 and 44 that rotate while revolving together with the carrier 46. As a result, the rotation transmission from the input shaft 2a to the output shaft 2b is performed under a rotation transmission ratio that is small (or large) by the revolution speed due to the rotation of the carrier 46, and the steering wheel 30 is transmitted. , 30 is smaller (or larger) than the steering angle corresponding to the steering wheel 1. By driving the transmission motor 5 in this way, the rotation transmission ratio from the input shaft 2a to the output shaft 2b can be changed.

  The transmission motor 5 is, for example, a steering angle detection value by the input rotation sensor 21 and a steering angle detection value by the output rotation sensor 22 in order to obtain a predetermined rotation transmission ratio based on the vehicle speed detection result by the vehicle speed sensor 25. Is controlled in accordance with an operation command given from the steering control unit 7 as a feedback signal.

  The control operation of the steering control unit 7 for changing the rotation transmission ratio is performed, for example, to drive the transmission motor 5 during low-speed traveling and increase the rotation transmission ratio from the input shaft 2a to the output shaft 2b. This makes it possible to increase the rudder angle of the steering wheels 30 and 30 when driving at low speeds to facilitate driving operations, and to reduce the rudder angle of the steering wheels 30 and 30 when traveling at high speeds. Thus, it is possible to improve the running stability by preventing the unstable behavior of the vehicle due to sudden steering.

  During the above control operation, the steering control unit 7 issues an operation command to the reaction force motor 6 in response to the drive of the speed change motor 5 and performs an operation of driving the reaction force motor 6 to rotate. When the reaction force motor 6 is driven to rotate, the rotation force of the reaction force motor 6 is applied to the steering wheel 1. For example, the reaction force of the steering wheel 1 is increased by increasing the rotation transmission ratio during low-speed traveling. Power can be reduced and a light steering feel can be achieved.

  On the other hand, when the transmission motor 5 is rotationally driven with the input shaft 2 a of the variable ratio transmission mechanism 4 being non-rotating, the carrier 46 is rotated by transmission from the transmission motor 5 and meshes with the input sun gear 41. 43 and 43 revolve together with the output planetary gears 44 and 44, and the output sun gear 42 meshing with the output planetary gears 44 and 44 rotates. This rotation is transmitted to the steering mechanism 3 through the output shaft 2b, and steering is executed by the above-described operation of the steering mechanism 3. At this time, since the steering reaction force is generated on the input shaft 2a by the operation of the steering mechanism 3, the reaction force motor 6 is driven to cancel the steering reaction force and fix the steering wheel 1. Thus, by driving the speed change motor 5 in a state where the steering wheel 1 is not operated, automatic steering using the speed change motor 5 as a steering actuator can be executed.

  The control operation of the steering control unit 7 for automatic steering is performed, for example, to automatically perform garage entry and parallel parking. This control operation recognizes the current position and the parking position of the vehicle, and sets a movement path for moving the vehicle between the current position and the parking position, as is conventionally done. This is realized by determining a steering procedure for moving the vehicle along the road and driving and controlling the transmission motor 5 as a steering actuator so as to perform the steering according to this procedure.

  The GPS information given from the GPS sensor 27 to the steering control unit 7 indicates the current position of the vehicle, and can be used for setting a movement route during automatic steering for parking. This setting of the movement route can be realized, for example, when the position information of the parking position is given in advance or when it is given as map information from the navigation device.

  FIG. 3 is an explanatory diagram of a method for setting a movement route using GPS information. As shown in the figure, the current position A of the vehicle based on GPS information can be handled together with the parking position B as two-dimensional coordinates on a map around the parking position B. The moving path C from the current position A to the parking position B is set at an intermediate position D (generally a plurality) so that interference between the two does not occur in consideration of the size of the vehicle and surrounding obstacles. A curve connecting the position A to the parking position B through the intermediate position D is set. This setting is identification of a curve in a two-dimensional plane obtained by looking down on the current position A and the parking position B from above, and does not require complicated calculation processing. Therefore, the load on the steering control unit 7 can be reduced. And rapid path setting is possible.

  In recent years, the positional accuracy based on GPS information has been increased to around 10 cm, and the setting of a movement route using GPS information can be realized with sufficient practical accuracy. In addition, by referencing GPS information during movement by automatic steering, the current position and moving speed can be sequentially recognized, and by using these as feedback information, highly accurate automatic steering can be executed. It becomes.

  In recent years, many street cameras have been installed mainly for the purpose of crime prevention. Since these street cameras are generally installed so as to capture a bird's-eye view of the road from above, by acquiring and using these image information, it is the same as when using GPS information. Automatic steering can be performed.

  In the above control operation for automatic steering, the steering control unit 7 issues an operation command to the reaction force motor 6 in response to the drive of the transmission motor 5, keeps the reaction force motor 6 in a locked state, and turns the input shaft 2a on. It is desirable to implement a control operation that restricts the rotation to be impossible. By this control operation, the steering wheel 1 fixed to the input shaft 2a is kept in a non-rotating state, so there is no possibility of giving the driver a sense of incongruity during automatic steering, and automatic steering is canceled in an emergency. The operation of the steering wheel 1 can be easily performed.

  In addition, during the execution of the automatic steering as described above, an unexpected collision may occur in the vehicle. The steering control unit 7 performs the following collision control operation when such a collision occurs. FIG. 4 is a flowchart showing the contents of the collision control operation.

  During execution of automatic steering, the steering control unit 7 takes in one or both of the detection results of the lateral G sensor 23 and the yaw rate sensor 24 as collision detection means at a predetermined cycle, and determines the presence or absence of a collision using these. (Step S1). The lateral acceleration detected by the lateral G sensor 23 and the yaw rate detected by the yaw rate sensor 24 are state quantities that indicate the turning state of the vehicle. Sometimes discontinuous and sudden changes occur. The determination in step S1 is made based on whether there is a sudden change in the detection result of the lateral G sensor 23 or the yaw rate sensor 24.

  If it is determined in step S1 that there is a collision (step S1: YES), the steering control unit 7 issues a braking command (step S2). This braking command is given to the vehicle braking control device as described above, and the vehicle is suddenly braked by the operation of this braking control device.

  Next, the steering control unit 7 determines which side of the vehicle the collision occurs on the left and right sides (step S3). If the collision occurs on the left side (step S3: YES), the steering control unit 7 An operation command is issued to the speed change motor 5 to execute steering (step S4), and when a collision occurs on the right side (step S3: NO), an operation command is issued to the speed change motor 5 to execute leftward steering (step S3). Step S5).

  The determination of the collision direction in step S3 is made based on the direction of change that occurs in the detection results of the lateral G sensor 23 and the yaw rate sensor 24. Such detection including the direction of the collision of the vehicle can be realized by simple processing by monitoring the detection result of one or both of the lateral G sensor 23 and the yaw rate sensor 24. The lateral G sensor 23 and the yaw rate sensor 24 are widely installed in recent automobiles as sensors necessary for various controls, and can detect a collision without requiring a dedicated sensor.

  Note that the lateral acceleration detected by the lateral G sensor 23 always changes in the opposite direction from the side where the collision occurred, whereas the yaw rate detected by the yaw rate sensor 24 is the rotational speed around the center of gravity axis of the vehicle. The direction of the change caused by depends on the traveling direction of the vehicle. Therefore, when the collision detection is performed using the detection result of the yaw rate sensor 24, it is necessary to use the traveling direction of the vehicle detected by the traveling direction sensor 26 as well.

  The steering control unit 7 determines whether or not the vehicle has stopped after issuing an operation command to the speed change motor 5 for right steering or left steering (step S6), and has not stopped (step S6: NO). In such a case, the process returns to step S2 to continue the braking command and the steering command, and when the vehicle stops (step S6: YES), the series of collision control operations is terminated.

  FIG. 5 is an explanatory diagram of the behavior of the vehicle during execution of automatic steering for parking realized by the above-described control operation at the time of collision. When the vehicle 8 traveling backwards collides with the obstacle 9, the steering wheels 30, 30 of the vehicle 8 are automatically steered to the side opposite to the side where the collision occurred due to the drive of the transmission motor 5. The rear vehicle 8 moves away from the obstacle 9 as indicated by a broken line in the figure, and the occurrence of problems such as damage to the vehicle 8 due to the collision can be reduced.

  Further, in the control operation at the time of the collision described above, the steering control unit 7 issues a braking command, and the vehicle is suddenly braked by the operation of the braking control device to which this braking command is given. The vehicle 8 is stopped at a position not far away from the obstacle 9, and the vehicle 8 can be prevented from running away.

  In the above embodiment, the control operation at the time of collision performed during execution of automatic steering for parking has been described. However, the control operation at the time of collision described above is also performed during execution of automatic steering for other purposes. The present invention can be implemented in the same manner, and can also be performed during normal traveling without automatic steering.

  In the above embodiment, the control operation at the time of collision performed with the transmission motor 5 of the variable ratio transmission mechanism 4 as a control target has been described. However, the present invention is attached to the steering mechanism in the steer-by-wire type steering apparatus. Various steering actuators that can apply a steering force to the steering mechanism, such as a steering assist motor that applies a steering assist force to the steering mechanism in a steering motor or an electric power steering apparatus, can be realized as a control target.

1 is a schematic diagram showing an overall configuration of a vehicle steering apparatus according to the present invention. It is a longitudinal cross-sectional view which briefly shows the structure of a variable ratio transmission mechanism. It is explanatory drawing of the setting method of the movement path | route using GPS information. It is a flowchart which shows the content of the control action at the time of a collision. It is explanatory drawing of the behavior of the vehicle implement | achieved by the control action at the time of a collision.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Steering wheel (steering member), 3 Steering mechanism, 5 Shifting motor (steering actuator), 7 Steering control part (control means), 23 Lateral G sensor (collision detection means), 24 Yaw rate sensor (collision detection means), 30 wheels

Claims (3)

In a vehicle steering apparatus comprising: a steering mechanism that performs a steering operation for turning a steering wheel according to an operation of a steering member of the vehicle; and a steering actuator that applies a steering force to the steering mechanism.
Collision detection means for detecting a collision with an obstacle of the vehicle including the direction of the collision;
A vehicle steering apparatus comprising: control means for controlling the steering actuator to apply a steering force in the direction opposite to the detected collision direction to the steering mechanism in response to detection by the collision detection means.   2. The vehicle steering apparatus according to claim 1, wherein the control unit also executes braking control for suddenly braking the vehicle during a control operation of the steering actuator. 3.   The vehicle steering apparatus according to claim 1, wherein the collision detection unit is configured to detect the collision based on a change in a lateral acceleration or a yaw rate of the vehicle.

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