JP2005112130A - Vehicular steering control device and control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicular steering control device and a control method capable of accurately exhibiting occupant restraint performance of an airbag device provided on a steering wheel. <P>SOLUTION: A pre-crash ECU11 determines whether a vehicle and a collision object collide or not by utilizing an input signal from sensors 12, 13, 14. If it is determined that they collide, a steer-by-wire ECU21 requests a reaction force actuator ECU22 to turn a steering wheel 41 to the expansion deployment position. When the steering wheel 41 is turned to the expansion deployment position, it requests an electric lock ECU23 to lock the steering wheel 41 at the expansion deployment position. The ECU21 requests an airbag ECU30 to deploy the airbag, and the ECU30 expands and deploys the airbag at the expansion deployment position of the steering wheel 41. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a vehicle steering control device and a vehicle steering control method, and more particularly to a steering control device including an airbag device and a steering device control method including an airbag device.

  Conventionally, for example, as shown in Patent Document 1 below, a steering wheel including an airbag module is known. This conventional steering wheel includes a steering wheel main body including a hub, spokes, and a steering wheel rim, and an airbag module that is rotatably assembled to the steering wheel main body. The airbag module is assembled in an eccentric state with respect to the rotating shaft of the steering wheel body, and a weight is attached in the eccentric direction. For this reason, when the steering wheel is rotated by the driver, the airbag module is prevented from rotating integrally with the steering wheel. Thus, the airbag is always inflated and deployed at the same rotational direction position even when the steering wheel is rotated, so that the effect of occupant protection can be reliably ensured.

  Conventionally, for example, as shown in Patent Document 2 below, an airbag apparatus is also known. In this conventional airbag device, the airbag is divided into two or more, and vent holes for discharging gas are provided in each of the divided airbags. By appropriately setting the hole diameter of the vent hole, it is possible to adjust the damping force of each airbag when the airbag is inflated and deployed to protect the occupant. For this reason, according to the part (head, chest, and abdomen) where the occupant comes into contact with the airbag, the occupant is protected from the impact of the collision.

  Furthermore, conventionally, as shown in Patent Document 3 below, for example, a steering angle correction device in a power steering device is also known. This steering wheel angle correction device detects a steering wheel angle that represents the detected turning angle of the steering wheel and a tire cutting angle that represents the steering wheel turning angle. Then, the target handle angle, which is the normal handle angle, is calculated from the tire turning angle, and if the deviation between the handle angle and the target handle angle exceeds the allowable amount, the handle turning operation is idled to correct the handle angle. It is supposed to be.

  However, in the steering wheel provided with the conventional airbag module, for example, when a foreign object is caught between the steering wheel body and the airbag module, the steering wheel body and the airbag module rotate integrally. there is a possibility. In addition, since the position of the airbag module in the rotation direction is maintained by gravity, that is, the rotation is not mechanically restricted by gravity, there is a possibility that an unexpected rotation is caused by a reaction force when the airbag is inflated and deployed. is there.

  Further, in the above-described conventional airbag device, since the portion where the occupant and the airbag are in contact is specified, for example, when the airbag device is provided on the steering wheel, the inflated and deployed airbag is the occupant's airbag. It is necessary to hold the steering wheel at a predetermined position where it contacts at a specific part. For this reason, even if, for example, the conventional steering angle correction device is applied to the conventional airbag device, the steering wheel cannot be automatically rotated and held. For this reason, when the airbag is inflated and deployed, there is a possibility that the steering wheel will not return even if it attempts to return to a predetermined position.

JP 2000-514016 A JP 2000-16229 A JP 2003-11841 A

  SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a vehicle steering control device and a control method therefor that can accurately demonstrate the occupant restraining performance of an airbag device provided on a steering wheel. Is to provide.

  A feature of the present invention is that a vehicle steering control device includes a rotation driving unit that rotates a steering wheel to a specific rotation position, and an occupant when the vehicle is assembled to the steering wheel and inflated and deployed at the specific rotation position. The airbag having a shape that improves the restraining force is provided with an airbag deploying means that inflates and deploys at the specific rotation position. Further, in this case, a rotation position detection unit that detects a rotation position of the steering wheel is provided, and the rotation drive unit is configured to detect the rotation position from the rotation position detected by the rotation position detection unit to the specific rotation position. It is good to turn the steering wheel. The specific rotation position may be a rotation position where the form after the steering wheel is rotated is substantially the same as the form at the neutral position of the steering wheel.

  According to this, the rotation drive means rotates the steering wheel to the specific rotation position. The airbag deployment means inflates and deploys the airbag that has a shape that improves the restraining force of the occupant when the airbag is inflated and deployed at the specific rotation position. For this reason, the restraint performance of the airbag made into the shape which improves a passenger | crew's restraining force can be exhibited exactly, and a passenger | crew can be protected from the impact of a collision exactly. Further, by detecting the rotation position of the steering wheel, the steering wheel can be reliably rotated to the specific rotation position. In addition, by setting the specific rotation position to a position that is substantially the same as the configuration at the neutral position of the steering wheel, it is possible to simplify the inflated and deployed shape of the airbag, which is preferable.

  According to another aspect of the present invention, when the steering wheel is turned to the specific turning position by the turning drive means, the steering wheel of the vehicle is returned to the straight traveling state. There is also a configuration provided with steering wheel control means. Another feature of the present invention is that when the steering wheel is rotated to the specific rotation position by the rotation driving means, the steering wheel and the steering wheel of the vehicle are There is also a configuration including a cooperation prohibiting means for prohibiting the cooperation.

  According to these, in order to bring the steering wheel to a straight traveling state as the steering wheel turns to the specific turning position, the impact force due to the collision can be transmitted to and supported by the vehicle body via the steering wheel. it can. For this reason, the impact force which acts on a passenger | crew can be reduced effectively. Further, when the steering wheel is turned to a specific turning position, in order to prohibit cooperation between the steering wheel and the steering wheel, for example, when the steering wheel is being steered to avoid a collision, the state Can be maintained. This also can effectively reduce the impact force acting on the occupant. Further, by prohibiting the cooperation between the steering wheel and the steering wheel, for example, even when the steering wheel is rotated due to a collision with a collision target, the steering wheel can be prevented from rotating. Therefore, the steering wheel is not rotated from the specific rotation position by the impact of the collision, and the occupant can be restrained accurately by inflating and deploying the airbag at the specific rotation position.

  Another feature of the present invention is that the rotation driving unit rotates the steering wheel to the specific rotation position from a phase side close to the specific rotation position. According to this, the rotation time to the specific rotation position of the steering wheel can be shortened, the airbag can be inflated and deployed accurately, and the occupant can be restrained accurately.

  In another aspect of the present invention, the rotation driving unit rotates the steering wheel to the specific rotation position with a torque larger than a rotation operation torque for rotating the steering wheel of the occupant. There is also. According to this, even if the steering wheel is held by an occupant (driver), the steering wheel can be reliably rotated to the specific rotation position, and the airbag is inflated and deployed at the specific rotation position accurately. can do. Therefore, the passenger can be restrained accurately.

  Another feature of the present invention is a steering wheel fixing means for fixing the steering wheel at the specific rotation position when the steering wheel is rotated to the specific rotation position by the rotation driving means. It is also provided. According to this, since the steering wheel is fixed at the specific rotation position, for example, the steering wheel can be prevented from being rotated by an occupant (driver), and the steering wheel is rotated by the inflation and deployment of the airbag. It can be prevented from moving. Therefore, the airbag can be inflated and deployed accurately, and the occupant can be restrained accurately.

  According to another aspect of the present invention, there is provided a collision state detection unit that detects a collision state of the vehicle, and the rotation driving is performed when the vehicle collision mode detected by the collision state detection unit is an offset collision mode. The means may also be configured to rotate the steering wheel toward the collision occurrence side of the vehicle from the specific rotation position. According to this, the specific rotation position can be adjusted as appropriate according to the collision mode, the airbag can be inflated and deployed accurately, and the occupant can be restrained accurately.

  Furthermore, another feature of the present invention is that a collision prediction means for predicting a collision possibility between the vehicle and a collision object existing ahead of the vehicle, the vehicle and the collision object predicted by the collision prediction means. There is also provided cooperation state changing means for changing the cooperation state of the steering wheel and the steering wheel of the vehicle based on the possibility of collision with the vehicle. According to this, by changing the cooperation state of the steering wheel and the steered wheel (for example, connection with a gear, etc.) according to the possibility of collision (for example, increasing the gear ratio), the steering wheel is quickly turned to a specific rotation. It can be rotated to the moving position. Also by this, the airbag can be inflated and deployed accurately, and the occupant can be restrained accurately.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram schematically showing a steering control system A according to the present embodiment. The steering control system A includes a pre-crash determination device 10 that predicts a collision of a vehicle and determines the possibility of a collision, and a steer-by-wire control device 20 that controls the steering wheel of the vehicle based on an electrical signal. .

  The pre-crash determination device 10 includes a pre-crash electronic control unit 11 (hereinafter simply referred to as a pre-crash ECU 11). The pre-crash ECU 11 includes a microcomputer including a CPU, a ROM, a RAM, a timer, an interface, and the like as main components. Then, the pre-crash ECU 11 acquires each signal supplied from the vehicle speed sensor 12, the yaw rate sensor 13, and the radar sensor 14, and executes the program of FIG.

  The vehicle speed sensor 12 outputs a pulse signal to the pre-crash ECU 11 at a cycle according to the vehicle speed. Based on the output pulse signal, the pre-crash ECU 11 detects the vehicle speed V. The yaw rate sensor 13 outputs a signal corresponding to the rotational angular velocity around the center of gravity of the vehicle. Based on the output signal, the pre-crash ECU 11 detects the yaw rate γ of the vehicle. The radar sensor 14 is configured by a radar device using millimeter waves or infrared rays, and outputs a signal corresponding to the distance to the collision target existing in front of the vehicle and the relative speed. Based on the output signals, the pre-crash ECU 11 detects the distance L and the relative speed VR between the vehicle and the collision target.

  The steer-by-wire control device 20 is communicably connected to the pre-crash determination device 10 via the bus K. The steer-by-wire control device 20 includes a steer-by-wire electronic control device 21 (hereinafter simply referred to as a steer-by-wire ECU 21), a reaction force actuator electronic control device 22 (hereinafter simply referred to as a reaction force actuator ECU 22), and an electric lock electronic control device 23 (hereinafter referred to as “steering-wire actuator ECU 22”). It is simply comprised of an electric lock ECU 23).

  The steer-by-wire ECU 21 includes a microcomputer including a CPU, a ROM, a RAM, a timer, an interface, and the like as main components, and controls the steering operation of the steering device 40 adopting the steer-by-wire system. That is, the steer-by-wire ECU 21 acquires a signal representing the steering angle output from the steering angle sensor 42 when the driver rotates the steering wheel 41 of the steering device 40. Then, the steer-by-wire ECU 21 detects the steering angle δ based on the acquired signal, and operates a steering actuator that rotates a steering wheel (front wheel of the vehicle) (not shown) by a predetermined amount so as to reflect this steering angle δ. Control. Further, as will be described later, the steer-by-wire ECU 21 cooperates with the reaction force actuator ECU 22 and the electric lock ECU 23 to execute the program of FIG.

  The reaction force actuator ECU 22 also includes a microcomputer including a CPU, a ROM, a RAM, a timer, an interface, and the like as main components. And reaction force actuator ECU22 controls the action | operation of the reaction force actuator 43 which generate | occur | produces a predetermined reaction force with respect to rotation operation of the steering wheel 41 by a driver | operator. Here, since the steering device 40 employs a steer-by-wire system, the steering wheel 41 and the steered wheels are not mechanically coupled via a mechanism such as a rack and pinion, for example. Therefore, the reaction force actuator ECU 22 reacts with the reaction force actuator 43 (specifically, the drive motor 43) so that a virtual reaction force is generated in the steering wheel 41 based on the steering angle δ supplied from the steer-by-wire ECU 21. ) Is controlled.

  The electric lock ECU 23 also includes a microcomputer including a CPU, a ROM, a RAM, a timer, an interface, and the like as main components. The electric lock ECU 23 controls the operation of the electric lock 44 for prohibiting the turning operation of the steering wheel 41. That is, when the electric lock 44 is locked by the electric lock ECU 23, the turning operation of the steering wheel 41 is prohibited, and when the electric lock 44 is unlocked, the turning operation of the steering wheel 41 is allowed. Is done.

  Further, the steering control system A includes an airbag electronic control device 30 (hereinafter simply referred to as an airbag ECU 30). The airbag ECU 30 also includes a microcomputer including a CPU, a ROM, a RAM, a timer, and the like as main components, and comprehensively controls inflating and unfolding operations of an airbag device (not shown) assembled to the steering wheel 41. Here, the inflated and deployed shape of the airbag of the airbag apparatus will be described with reference to FIG.

  As shown by a solid line in FIG. 4, the air bag of the air bag device is inflated and deployed in an inflated and deployed shape X when the vehicle collides. The inflated and deployed shape X is asymmetric with respect to the axis of the steering wheel 41. For this reason, the airbag is inflated and deployed in an inflated and deployed shape X when the steering wheel 41 is in a specific rotation position where the airbag is inflated and deployed (hereinafter, this position is referred to as an inflated and deployed position). Here, the inflated and deployed position is a rotational direction position that is the same as the form of the steering wheel position for moving the vehicle straight. In this way, the airbag is inflated and deployed in the inflated and deployed shape X, so that compared to the conventional inflated and deployed shape X ′ (symmetric with respect to the axis of the steering wheel 41) as shown by the broken line in FIG. The contact area between the airbag and the driver can be greatly increased, and the restraining force of the driver can be greatly improved.

  Next, the operation of the steering control system A according to the embodiment configured as described above will be described. When the ignition switch (not shown) is turned on, the pre-crash ECU 11 repeatedly executes the collision prediction program of FIG. 2 at predetermined time intervals. Begin to. The execution of the collision prediction program is started in step S10. In step S11, the vehicle speed V is detected based on the pulse signal from the vehicle speed sensor 12, and whether or not the vehicle speed V is equal to or higher than a predetermined vehicle speed Vo. By determining whether or not the vehicle is in a traveling state. If the vehicle speed V is less than the predetermined vehicle speed Vo, it is determined as “No” in step S11, the process proceeds to step S17, and the execution of the program is temporarily terminated.

  On the other hand, when the vehicle starts traveling and “Yes”, that is, when the vehicle speed V is determined to be equal to or higher than the predetermined vehicle speed Vo in step S11, the pre-crash ECU 11 executes the processing from step S12 onward. In step S <b> 12, the pre-crash ECU 11 detects the distance L from the vehicle front end to the collision target based on the output signal from the radar sensor 14. Then, the detected value is input, set as a current relative distance Lnew representing an input distance by execution of the current program, and the process proceeds to step S13. In step S13, the pre-crash ECU 11 detects the relative speed VR between the vehicle and the collision target based on the output signal from the radar sensor 14. Then, the detected value is input and set as the current relative speed VRnew representing the input relative speed by the current program, and the process proceeds to step S14.

  In step S14, the pre-crash ECU 11 determines whether or not the current relative speed VRnew input in step S13 is positive. If the relative speed VRnew is not positive this time, it is determined as “No”, the process proceeds to step S17, and the execution of the program is temporarily ended. This means that if the relative speed VRnew is not positive this time, the distance L from the front end of the vehicle to the collision object does not change or increases, and in this case, the vehicle becomes the collision object. This is because there is no possibility of collision, so there is no need to predict collision.

  On the other hand, if the current relative speed VRnew is positive, “Yes” is determined in step S14, and the process proceeds to step S15. In step S15, the pre-crash ECU 11 compares the distance calculated by multiplying the predetermined time Tc and the current relative speed VRnew with the current relative distance Lnew, and determines whether or not the vehicle and the collision object collide. judge. That is, the pre-crash ECU 11 predicts the travel distance of the vehicle by multiplying a predetermined time Tc determined in advance based on the time required for collision avoidance and the current relative speed VRnew. Then, by comparing the predicted moving distance of the vehicle with the current relative distance Lnew, a collision between the vehicle and the collision object is predicted.

  If the current relative distance Lnew is greater than the predicted movement distance, the pre-crash ECU 11 determines “No”, proceeds to step S17, and temporarily ends the execution of the program. This is because a collision can be avoided by a collision avoidance operation (for example, a turning operation or a braking operation of the vehicle) by the driver. On the other hand, if the current relative distance Lnew is smaller than the predicted moving distance, the pre-crash ECU 11 determines “Yes” and proceeds to step S16.

  In step S16, the pre-crash ECU 11 supplies the steer-by-wire ECU 21 with collision information indicating that collision avoidance between the vehicle and the collision target is impossible. More specifically, the pre-crash ECU 11 supplies collision information to the steer-by-wire ECU 21 via the bus K when it is predicted that the vehicle and the collision object will collide by the determination process in step S15. Then, after the collision information supply process of step S16, the pre-crash ECU 11 proceeds to step S17 and ends the execution of the collision prediction program.

  The steer-by-wire ECU 21 acquires the collision information supplied in step S16 via the bus K and the interface. Then, the steer-by-wire ECU 21 executes the steering device control program shown in FIG. 3 in cooperation with the reaction force actuator ECU 22 and the electric lock ECU 23.

  Execution of the steering device control program is started in step S50, and in step S51, the steer-by-wire ECU 21 returns the steering wheel 41 to the inflated and deployed position. In general, when it is predicted that collision avoidance between the vehicle and the collision target is impossible, the steering wheel 41 is rotated by the driver to avoid collision with the collision target. In this case, since there is a high possibility that the vehicle and the object to be collided with each other, the airbag of the airbag device is effectively deployed in order to protect the driver from the impact caused by the collision with the steering wheel 41. There is a need to. Incidentally, the airbag of the airbag device mounted on the vehicle is asymmetric with respect to the axis of the steering wheel 41, and the driver is effectively restrained by returning the steering wheel 41 to the inflated and deployed position. It is like that.

  For this reason, the steer-by-wire ECU 21 supplies the steering angle information representing the steering angle δ detected based on the signal from the steering angle sensor 42 to the reaction force actuator ECU 22 and sets the steering wheel 41 to the expansion and deployment position. Request to rotate. The reaction force actuator ECU 22 acquires the steering angle information supplied from the steer-by-wire ECU 21, and controls the rotational drive so that the steering wheel 41 is in the inflated and deployed position based on the request. The rotation drive control of the reaction force actuator ECU 22 will be specifically described.

  The reaction force actuator ECU 22 checks the amount of rotation of the steering wheel 41 using the steering angle δ represented by the steering angle information. Here, the steering wheel 41 can be rotated a plurality of times between a position (lock-to-lock) that stops when the steering wheel 41 rotates to the left from a position that stops when the steering wheel 41 rotates to the right.

  Therefore, the reaction force actuator ECU 22 determines the closest expansion / deployment position from the current steering angle δ, and determines the rotation direction that can return the earliest to the determined expansion / deployment position. The reaction force actuator ECU 22 supplies the reaction force actuator 43 with information indicating the determined expansion / deployment position and rotation direction, and instructs the steering wheel 41 to rotate. The reaction force actuator 43 rotates the steering wheel 41 in the determined rotation direction up to the determined expansion / deployment position in accordance with the instruction. At this time, the reaction force actuator 43 rotationally drives the steering wheel 41 with a torque larger than the force (steering torque) at which the driver holds the steering wheel 41.

  Here, even when the reaction force actuator ECU 22 rotates the steering wheel 41 to the inflated and deployed position as described above, the steering direction of the steered wheels is not returned to the linear direction. That is, since the steering device 40 employs the steer-by-wire system, the steering wheel 41 and the steering wheel are not mechanically coupled. For this reason, the steer-by-wire ECU 21 requests the reaction force actuator ECU 22 to turn the steering wheel 41 to the inflated and deployed position, while maintaining the current drive state for the steering actuator. To control. Thereby, even if the steering wheel 41 is rotated to the inflating and deploying position, the steering wheel is maintained in the direction in which the current direction is maintained, that is, the collision with the collision target is avoided.

  Further, the reaction force actuator ECU 22 supplies information representing the determined expansion / deployment position to the steer-by-wire ECU 21. The steer-by-wire ECU 21 acquires information representing the supplied inflated / deployed position, temporarily stores it in a RAM (not shown), and proceeds to step S52.

  In step S52, the steer-by-wire ECU 21 determines whether or not the steering wheel 41 has been rotated to the inflated / deployed position based on information representing the inflated / deployed position. More specifically, the steer-by-wire ECU 21 detects the current steering angle δ of the steering wheel 41 based on the signal output from the steering angle sensor 42. Then, the steer-by-wire ECU 21 determines whether or not the steering wheel 41 has been rotated to the inflated and deployed position using the information indicating the inflated and deployed position stored in the RAM in step S51 and the detected steering angle δ. judge.

  If the steering wheel 41 has not been rotated to the inflated and deployed position, the steer-by-wire ECU 21 determines “No” and repeats the process until the steering wheel 41 is rotated to the inflated and deployed position. On the other hand, if the steering wheel 41 has been rotated to the inflated and deployed position, it is determined as “Yes”, and the process proceeds to step S53.

  In step S53, the steer-by-wire ECU 21 requests the electric lock ECU 23 to lock the steering wheel 41 at the inflated / deployed position. More specifically, the steer-by-wire ECU 21 supplies lock request information indicating that the rotation of the steering wheel 41 is prohibited to the electric lock ECU 23 via the bus K. The electric lock ECU 23 acquires lock request information via the bus K and the interface. Then, the electric lock ECU 23 places the electric lock 44 in the locked state. Thereby, the steering wheel 41 is prohibited from rotating with respect to the driver's rotation operation. As described above, when the lock request information is supplied to the electric lock ECU 23, the steer-by-wire ECU 21 proceeds to step S54.

  In step S54, the steer-by-wire ECU 21 requests the airbag ECU 30 to start the airbag device. More specifically, the steer-by-wire ECU 21 supplies start-up request information representing a start request to prepare for deploying the airbag to the airbag ECU 30 via the bus K in preparation for a vehicle collision. The airbag ECU 30 acquires activation request information via the bus K and the interface. The airbag ECU 30 appropriately uses an airbag device such as an ignition timing of an airbag device provided on the steering wheel 41 (specifically, a timing of energizing an ignition device of an inflator (not shown)) and a drive voltage. Start preparing to start.

  The airbag ECU 30 immediately inflates and deploys the airbag of the airbag device immediately after detecting the collision between the vehicle and the collision target. As a result, as shown in FIG. 5, the airbag develops in an inflated and deployed shape X between the driver H and the steering wheel 41 to restrain the driver H, causing the driver H to collide with the steering wheel 41. Accurately protects against impacts caused by After the activation request process in step S54, the steer-by-wire ECU 21 proceeds to step S55 and ends the execution of the steering device control program.

  As can be understood from the above description, in this embodiment, the steer-by-wire ECU 21, the reaction force actuator ECU 22, and the reaction force actuator 43 rotate the steering wheel 41 to the inflated and deployed position. The airbag ECU 30 inflates and deploys the airbag having an inflated and deployed shape X that improves the restraining force of the occupant when inflated and deployed at the inflated and deployed position. For this reason, the restraint performance of the airbag made into the shape which improves a passenger | crew's restraining force can be exhibited exactly, and a passenger | crew can be protected from the impact of a collision exactly. In addition, by setting the inflated and deployed position to a position that is substantially the same as the configuration at the neutral position of the steering wheel 41, the inflated and deployed shape X of the airbag can be simplified, which is preferable.

  Further, when the steering wheel 41 is rotated to the inflated and deployed position, the steering wheel 41 and the steered wheel are prohibited from cooperating. When the steered wheel is being steered by the steering actuator in order to avoid a collision, That state can be maintained. This also can effectively reduce the impact force acting on the occupant. Further, by prohibiting the cooperation between the steering wheel 41 and the steering wheel, for example, even when the steering wheel is rotated due to a collision with a collision target, the steering wheel 41 can be prevented from rotating. it can. Therefore, the steering wheel 41 is not rotated from the inflated and deployed position due to the impact of the collision, and the passenger can be restrained accurately by inflating and deploying the airbag at the inflated and deployed position. In addition, by determining the closest inflated and deployed position from the current steering angle δ, the rotation time to the inflated and deployed position of the steering wheel 41 can be shortened, and the airbag can be inflated and deployed accurately. The occupant can be restrained accurately.

  Further, since the reaction force actuator 43 rotates the steering wheel with a torque larger than the steering torque of the driver, even if the steering wheel is held by the driver, the steering wheel can be reliably rotated to the inflated and deployed position. Can do. For this reason, the airbag can be inflated and deployed accurately at the inflated and deployed position. Therefore, the passenger can be restrained accurately. Furthermore, since the steering wheel 41 is fixed at the inflated and deployed position by the electric lock 44, the steering wheel can be prevented from being turned by the driver, and the steering wheel 41 is turned by the inflated and deployed air bag. Can be prevented. Therefore, the airbag can be inflated and deployed accurately, and the occupant can be restrained accurately.

  In the above embodiment, the steering control system A adopts the steer-by-wire system, and the steering wheel is maintained in the collision avoidance direction with the collision object even when the steering wheel 41 is in the inflated and deployed position. Implemented. Instead of this, it is also possible to carry out the steering wheel in a straight traveling state in conjunction with the rotation of the steering wheel 41 to the expansion and deployment position. In other words, when the steer-by-wire ECU 21 detects that the steering wheel 41 has started to rotate toward the inflated and deployed position by the reaction force actuator 43, the steer-by-wire ECU 21 instructs the steering actuator to bring the steered wheels straight. The steering actuator is driven so that the steering wheel is in a straight traveling state in accordance with the instruction.

  Thus, by making the steering wheel go straight, the impact load due to the predicted collision can be transmitted to the vehicle body of the vehicle via the steering wheel (front wheel of the vehicle), and the impact load can be supported by the vehicle body. Thereby, while being able to relieve | impact the impact by the collision given to a passenger | crew, a passenger | crew can be reliably protected by the restraining force of an airbag.

  Moreover, in the said embodiment and modified embodiment, it implemented so that the pre-crash ECU11 might estimate the possibility of a collision. In addition to this, the pre-crash ECU 11 can be implemented so as to predict the form of collision (for example, full-lap collision or offset collision). More specifically, the pre-crash ECU 11 acquires information indicating the position (existing direction) of the collision target existing in front of the vehicle from the radar sensor 14, so that the relative position between the vehicle and the collision target is obtained. Check the relationship. Then, for example, when the pre-crash ECU 11 confirms that the collision target exists in front of the vehicle, the pre-crash ECU 11 predicts the collision form as a full lap collision, and when it confirms that the collision target exists diagonally forward of the vehicle, the collision Predict the shape as an offset collision.

  Thus, when the collision mode is predicted by the pre-crash ECU 11, the steer-by-wire ECU 21 appropriately adjusts the rotational position of the steering wheel 41 from the expansion / deployment position according to the collision mode. This is because the occupant moves toward the collision portion of the vehicle depending on the collision mode of the vehicle. That is, when a collision occurs in the vehicle, a large inertial force acts on the occupant. Due to the generated inertial force, the occupant moves toward the collision portion of the vehicle. For this reason, the steer-by-wire ECU 21 requests the reaction force actuator ECU 22 to turn the steering wheel 41 from the inflated and deployed position toward the collision occurrence site in consideration of the direction in which the occupant moves due to the collision. As a result, the airbag can be inflated and deployed by adjusting the inflated and deployed position of the airbag corresponding to the occupant who has moved due to the collision.

  Furthermore, it goes without saying that various modifications are possible without departing from the object of the present invention. For example, the steering control system A can adopt a steering system with a variable gear mechanism or an electric power steering system. When the steering system with a variable gear mechanism is adopted, the electronic control device that controls the operation of the steering device with the variable gear mechanism based on the collision prediction of the pre-crash ECU 11 is a variable that links the steering wheel 41 and the steering wheel. It is possible to change the gear ratio of the gear mechanism. More specifically, the electronic control unit continuously sets the gear ratio of the variable gear mechanism according to the risk based on the collision prediction of the pre-crash ECU 11 (for example, the frequency that increases as the vehicle speed V of the vehicle increases). Make it bigger.

  Thereby, in preparation for a collision, the steering wheel 41 can be quickly rotated to the inflated and deployed position, and the phase difference between the current steering angle δ and the inflated and deployed position can be reduced. In addition, the steered wheel can be quickly brought straight, and the impact force caused by the collision can be accurately supported by the vehicle body. Therefore, the impact force on the occupant can be reduced.

  Further, when the electric power steering system is adopted, when a vehicle collision is detected, the electronic control device that controls the operation of the electric power steering returns the steering wheel 41 to the inflated and deployed position and sets the steered wheels in a straight traveling state. . As a result, the airbag can be deployed at the inflated and deployed position, and the passenger can be protected accurately. In addition, it is possible to accurately support the impact force caused by the collision with the steering wheel in a straight traveling state. Therefore, the impact force on the occupant can be reduced.

1 is a schematic block diagram illustrating a steering control system according to an embodiment of the present invention. 2 is a flowchart of a collision prediction program executed by a pre-crash ECU in FIG. 1. 2 is a flowchart of steering device control executed by a steer-by-wire ECU in FIG. 1. FIG. 2 is a diagram for explaining an inflated and deployed shape of an airbag that is deployed and controlled by the airbag ECU of FIG. 1. FIG. 2 is a view for explaining a state in which the airbag is restrained by an airbag ECU and the airbag is restrained by an airbag.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Pre-crash determination apparatus, 11 ... Pre-crash ECU, 12 ... Vehicle speed sensor, 13 ... Yaw rate sensor, 14 ... Radar sensor, 20 ... Steer-by-wire control device, 21 ... Steer-by-wire ECU, 22 ... Reaction force actuator ECU, 23 ... Electric lock ECU, 30 ... Airbag ECU, 41 ... Steering wheel, 42 ... Steering angle sensor, 43 ... Reaction force actuator, 44 ... Electric lock, A ... Steering control system

Claims (19)

Rotation drive means for rotating the steering wheel to a specific rotation position;
An airbag deployment means for inflating and deploying an airbag at the specific rotation position, which is configured to improve the restraining force of an occupant when the airbag is assembled to the steering wheel and inflated and deployed at the specific rotation position; A vehicle steering control device comprising: A rotation position detecting means for detecting a rotation position of the steering wheel;
2. The vehicle steering control device according to claim 1, wherein the rotation driving unit rotates the steering wheel from a rotation position detected by the rotation position detection unit to the specific rotation position. 3. The specific rotation position is
The vehicle steering control device according to claim 1 or 2, wherein a form after the steering wheel is turned is a turning position that is substantially the same as a form at a neutral position of the steering wheel. In the vehicle steering control device according to claim 1 or 2,
A steering control device for a vehicle, comprising steering wheel control means for returning a steering wheel of the vehicle to a straight traveling state when the steering wheel is rotated to the specific rotation position by the rotation driving means. . In the steering wheel control device for a vehicle according to claim 1 or 2,
A vehicle comprising cooperation prohibiting means for prohibiting cooperation between the steering wheel and a steering wheel of the vehicle when the steering wheel is rotated to the specific rotation position by the rotation driving means. Steering control device. The rotation driving means is
The steering control device for a vehicle according to any one of claims 1 to 5, wherein the steering wheel is rotated to the specific rotation position from a phase side close to the specific rotation position. The rotation driving means is
7. The steering wheel according to claim 1, wherein the steering wheel is turned to the specific turning position by a torque larger than a turning operation torque for turning the steering wheel of the occupant. Vehicle steering control device. In the steering control device for a vehicle according to any one of claims 1 to 7,
Steering a vehicle, characterized in that steering wheel fixing means is provided for fixing the steering wheel at the specific rotation position when the steering wheel is rotated to the specific rotation position by the rotation driving means. Control device. In the vehicle steering control device according to claim 1 or 2,
A collision state detecting means for detecting a collision state of the vehicle is provided;
When the vehicle collision mode detected by the collision state detection unit is an offset collision mode, the rotation driving unit rotates the steering wheel to the vehicle collision occurrence side from the specific rotation position. A vehicle steering control device. In the vehicle steering control device according to claim 1 or 2,
A collision prediction means for predicting a collision possibility between the vehicle and a collision target existing in front of the vehicle;
Coordination state changing means for changing the cooperation state of the steering wheel and the steering wheel of the vehicle based on the possibility of collision between the vehicle and the collision object predicted by the collision prediction means is provided. A vehicle steering control device. Detect the turning position of the steering wheel,
Rotating the steering wheel from the detected rotation position to a specific rotation position;
An airbag that is shaped to improve the restraining force of an occupant when it is assembled to the steering wheel and inflated and deployed at the specific rotation position is inflated and deployed at the specific rotation position. A vehicle steering control method. The specific rotation position is
The vehicle steering control method according to claim 11, wherein a form after the steering wheel is turned is a turning position that is the same as a form at a neutral position of the steering wheel. The vehicle steering control method according to claim 11,
A vehicle steering control method, wherein when the steering wheel is rotated to the specific rotation position, the steering wheel of the vehicle is returned to a straight traveling state. The vehicle steering control method according to claim 11,
A vehicle steering control method characterized in that, when the steering wheel is rotated to the specific rotation position, cooperation between the steering wheel and the steering wheel of the vehicle is prohibited.   The vehicle steering control method according to any one of claims 11 to 14, wherein the steering wheel is rotated to the specific rotation position from a phase side close to the specific rotation position.   The steering wheel according to any one of claims 11 to 15, wherein the steering wheel is turned to the specific turning position by a torque larger than a turning operation torque for turning the steering wheel of the occupant. The vehicle steering control method described in 1.   The vehicle according to any one of claims 11 to 16, wherein when the steering wheel is rotated to the specific rotation position, the steering wheel is fixed at the specific rotation position. Steering control method. The vehicle steering control method according to claim 11,
Detecting the collision state of the vehicle,
A steering control method for a vehicle, wherein the steering wheel is rotated from the specific rotation position to the vehicle collision occurrence side when the detected vehicle collision mode is an offset collision mode. The vehicle steering control method according to claim 11,
Predicting the possibility of collision between the vehicle and a collision object existing in front of the vehicle,
A vehicle steering control method, wherein a cooperative state between the steering wheel and a steering wheel of the vehicle is changed based on the predicted possibility of collision between the vehicle and the collision object.

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