JP2008080866A - Vehicular automatic operation device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicular automatic operation device which correctly completes the automatic operation control when a vehicle is deviated from a target moving locus during the automatic operation control or when a driver applies the steering force to a steering wheel. <P>SOLUTION: In the automatic scanning device, the automatic operation control is completed when the deviation between the steering angle θ detected by a steering angle detection means and the target steering angle θref corresponding to the target moving locus satisfies a predetermined condition, or when the steering torque of a steering wheel detected by the steering torque detection means satisfies a predetermined determination condition while a steering actuator control means performs the automatic operation control for driving a steering actuator based on the target moving locus set by a moving locus setting means. In this condition, the steering actuator control means changes the predetermined determination condition according to the steering state of the wheel (whether the steering wheel is in a rotating state or in a fixed state), and any trouble wherein the automatic operation control to be continued is ended or the automatic operation control to be ended is continued is eliminated. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a steering actuator for steering a vehicle wheel, a movement locus setting means for setting a target movement locus of the vehicle to a target position, and a steering actuator control means for driving and controlling the steering actuator based on the target movement locus. And an automatic steering device for a vehicle that terminates automatic steering control when a driver operates a steering wheel during automatic steering control.

  The control mode of the electric motor of the power steering device can be switched between a normal power steering mode for assisting the steering operation of the driver and an automatic steering mode for performing garage entry and parallel parking by automatic steering. In the steering mode, a technique for performing automatic steering control based on a relationship between a movement distance of a vehicle and a steering angle of a wheel stored in advance is known from Patent Document 1 below.

In such a conventional automatic steering device, when the deviation between the actual steering angle of the steering wheel and the target steering angle exceeds a predetermined value during execution of the automatic steering control and the vehicle deviates from the target movement locus, During the execution, for example, when the driver operates the steering wheel to avoid an obstacle and a steering torque greater than a predetermined value is detected, the automatic steering control is terminated and the normal electric power steering control is restored. It has become.
JP-A-9-193691

  By the way, in the above-mentioned conventional one, if the judgment condition for terminating the automatic steering control is too strict, the vehicle slightly deviates from the target movement locus during the execution of the automatic steering control, or the driver mistakenly moves the steering handle. The automatic steering control may end just by touching, and conversely, if the judgment condition for ending the automatic steering control is too gentle, the vehicle greatly deviates from the target movement locus during the execution of the automatic steering control. In addition, there is a possibility that the automatic steering control does not end even when the driver spontaneously operates the steering wheel.

  The present invention has been made in view of the above-described circumstances, and accurately terminates automatic steering control when a vehicle deviates from a target movement locus during automatic steering control or when a driver applies a steering force to a steering wheel. The purpose is to let you.

  In order to achieve the above object, according to the first aspect of the present invention, a steering actuator for steering a vehicle wheel, a movement trajectory setting means for setting a target movement trajectory of the vehicle to a target position, and the target Steering actuator control means for driving and controlling the steering actuator based on a movement trajectory, and steering angle detection means for detecting the steering angle of the steering wheel, and the steering actuator control means is the steering detected by the steering angle detection means. In the automatic steering device for a vehicle that terminates drive control of the steering actuator when a deviation between the angle and a target steering angle corresponding to the target movement locus satisfies a predetermined determination condition, the steering actuator control means includes the steering The predetermined according to the steering state of the steering wheel Automatic steering apparatus for a vehicle and changes the determination condition is proposed.

  According to the invention described in claim 2, the steering actuator for steering the wheels of the vehicle, the movement trajectory setting means for setting the target movement trajectory of the vehicle to the target position, and the steering based on the target movement trajectory. Steering actuator control means for driving and controlling the actuator, and steering force detection means for detecting a steering force for the driver to steer the steering handle. The steering actuator control means has the steering force detected by the steering force detection means. In a vehicle automatic steering apparatus that terminates drive control of the steering actuator when a predetermined determination condition is satisfied, the steering actuator control means changes the predetermined determination condition according to a steering state of the steering handle. Automatic steering system for vehicles characterized by There is proposed.

  The control unit 22 of the embodiment corresponds to the steering actuator control unit of the present invention, the storage unit 23 of the embodiment corresponds to the movement trajectory setting unit of the present invention, and the steering torque detection unit Sb of the embodiment includes Corresponding to the steering force detecting means of the present invention, the steering torque T and the steering load F of the embodiment correspond to the steering force of the present invention, and the front wheel Wf of the embodiment corresponds to the wheel of the present invention. The reference steering angle θref corresponds to the target steering angle of the present invention.

  According to the configuration of the first aspect, the steering angle detected by the steering angle detection means while the steering actuator control means performs the automatic steering control for driving the steering actuator based on the target movement locus set by the movement locus setting means. When the deviation from the target steering angle corresponding to the target movement trajectory satisfies a predetermined determination condition, the automatic steering control ends. At that time, the steering actuator control means changes the predetermined determination condition in accordance with the steering state of the steering handle, so that the automatic steering control to be continued or the automatic steering control to be terminated is continued. Can be eliminated.

  According to the second aspect of the present invention, the steering force detected by the steering force detection means while the steering actuator control means performs the automatic steering control for driving the steering actuator based on the target movement locus set by the movement locus setting means. When the predetermined determination condition is satisfied, the automatic steering control ends. At that time, the steering actuator control means changes the predetermined determination condition in accordance with the steering state of the steering handle, so that the automatic steering control to be continued or the automatic steering control to be terminated is continued. Can be eliminated.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

  1 to 4 show an embodiment of the present invention. FIG. 1 is an overall configuration diagram of a vehicle equipped with an automatic steering device, FIG. 2 is an explanatory diagram of the operation of a back parking / left mode, and FIG. FIG. 4 is a flowchart showing the end determination of the automatic steering control.

  As shown in FIG. 1, the vehicle V includes a pair of front wheels Wf, Wf and a pair of rear wheels Wr, Wr. Steering handle 1 and front wheels Wf and Wf, which are steered wheels, are rotated integrally with steering handle 1, steering shaft 2, pinion 3 provided at the lower end of steering shaft 2, rack 4 meshing with pinion 3, and rack 4 Are connected by left and right tie rods 5, 5 provided at both ends, and left and right knuckles 6, 6 connected to tie rods 5, 5. A steering actuator 7 made of an electric motor is connected to the steering shaft 2 via a worm gear mechanism 8 in order to assist the driver's operation of the steering handle 1 or to perform automatic steering for a garage to be described later.

  The steering control device 21 includes a control unit 22 and a storage unit 23, and the control unit 22 includes a steering angle detection unit Sa that detects a steering angle θ that is a rotation angle of the steering handle 1, and a steering handle 1. Steering torque detection means Sb for detecting the steering torque T, wheel rotation angle detection means Sc for detecting the rotation angle of the wheels Wf, Wf; Wr, Wr, and brake operation amount detection means for detecting the operation amount of the brake pedal 9. A signal is input from Sd and the shift range detection means Se that detects the shift range (“D” range, “R” range, “N” range, “P” range, etc.) selected by the select lever 10. .

  As is apparent when referring to FIG. 3, the mode selection switch Sf and the automatic parking start switch Sg operated by the driver are connected to the control unit 22. The mode selection switch Sf is operated when selecting one of four types of parking modes to be described later, that is, back parking / right mode, back parking / left mode, parallel parking / right mode, and parallel parking / left mode. With buttons. The automatic parking start switch Sg is operated when starting automatic parking in any mode selected by the mode selection switch Sf.

  The storage unit 23 stores the data of the four types of parking modes, that is, the relationship of the reference steering angle θref with respect to the movement distance X of the vehicle V in advance as a table (see FIG. 2B). The moving distance X of the vehicle V is obtained by multiplying the known outer peripheral lengths of the wheels Wf, Wf; Wr, Wr by the rotation angles of the wheels Wf, Wf; Wr, Wr detected by the wheel rotation angle detection means Sc. It is done. For the calculation of the movement distance X, the high select value, low select value, or average value of the output of the wheel rotation angle detection means Sc... Is used.

  Based on the signals from the detection means Sa to Se and the switches Sf and Sg and the parking mode data stored in the storage unit 23, the control unit 22 operates the steering actuator 7, the liquid crystal monitor, and the speaker. , The operation of the operation stage teaching device 11 including a lamp, a chime, a buzzer and the like are controlled.

  Next, the operation of the embodiment of the present invention having the above-described configuration will be described.

  During normal times when automatic parking is not performed (when the mode selection switch Sf is not operated), the steering control device 21 is in a power steering mode in which it functions as a general power steering control device. Specifically, when the driver operates the steering handle 1 to turn the vehicle V, the steering torque detection means Sb detects the steering torque T input to the steering handle 1, and the control unit 22 determines the steering torque T. Based on this, the driving of the steering actuator 7 is controlled. As a result, the left and right front wheels Wf, Wf are steered by the driving force of the steering actuator 7, and the driver's steering operation is assisted.

  Next, the content of the automatic steering control will be described by taking back parking / left mode (a mode in which parking is performed while backing to the parking position on the left side of the vehicle V) as an example.

  First, as shown in FIG. 2 (A), the vehicle V is moved to the vicinity of the garage where parking is to be performed by the driver's own steering operation, and the door is opened with the left side of the vehicle body as close as possible to the garage entrance line. The vehicle V is stopped at the position where the mark M (see FIG. 1) provided on the inner side coincides with the center line of the garage (start position (1). Then, the mode selection switch Sf is operated to set the back parking / left mode. When the automatic parking start switch Sg is selected and the automatic parking start switch Sg is turned on, the automatic steering control is started from the power steering mode and the automatic steering control is started. Current position, surrounding obstacles, parking position, target movement trajectory of the vehicle from the start position (1) to the target position (3), turn-back position (2) for switching from forward to reverse, etc. In addition, various instructions and warnings such as operation of the select lever 10 at the folding position (2) are given to the driver by voice from the speaker.

  A door mirror may be used instead of the mark M provided on the inside of the door, and the mark M and the door mirror may be aligned with the end of the garage instead of being aligned with the center line of the garage.

  The automatic steering control allows the driver to release the brake pedal 9 and creep the vehicle V, without operating the steering handle 1, based on the back parking / left mode data selected by the mode selection switch Sf. The front wheels Wf, Wf are automatically steered. That is, while the vehicle V moves forward from the start position (1) to the turn-back position (2), the front wheels Wf and Wf are automatically steered to the right, while the vehicle V moves backward from the turn-back position (2) to the target position (3). The front wheels Wf, Wf are automatically steered to the left.

  As apparent from FIG. 2 (B), during the automatic steering control, the control unit 22 inputs the reference parking angle θref of the back parking / left mode read from the storage unit 23 and the steering angle detection means Sa. A deviation E (= θref−θ) is calculated based on the steering angle θ, and the operation of the steering actuator 7 is controlled so that the deviation E becomes zero. At this time, since the data of the reference steering angle θref is set corresponding to the movement distance X of the vehicle V, the vehicle V always moves on the target movement locus even if there is a slight fluctuation in the vehicle speed of the creep travel. It will be.

  The automatic steering control ends when the driver turns off the mode selection switch Sf, but when the driver returns the select lever 10 to the “P” range, the driver takes his / her foot from the brake pedal 9. When the vehicle is released, when the vehicle speed exceeds a predetermined value, or when the driver applies a steering torque T higher than the predetermined value to the steering handle 1, the deviation E between the reference steering angle θref and the steering angle θ becomes higher than the predetermined value. If it is, the process returns to normal power steering control.

  Next, the automatic steering control is terminated when the driver applies a steering torque T greater than or equal to a predetermined value to the steering handle 1 and when the deviation E between the reference steering angle θref and the steering angle θ exceeds a predetermined value. The operation in this case will be described based on the flowchart of FIG.

  First, in step S1, the rotational speed dθ / dt (steering angular speed) of the steering handle 1 is compared with a threshold value of 10 deg / sec. The rotational speed dθ / dt of the steering handle 1 can be obtained by time differentiation of the steering angle θ detected by the steering angle detection means Sa. When the rotational speed dθ / dt is equal to or higher than the threshold value 10 deg / sec and the steering handle 1 is rapidly rotated, that is, when the steering handle 1 is in the steering state 1 (rotation state), the process proceeds to step S2.

  If the state where the deviation E is 60 deg or more continues in step S2 for 0.5 sec or more, it is determined that there is a high possibility that an abnormality has occurred in the automatic steering control and the vehicle V has deviated from the target movement locus, and step S3 Then, the automatic steering control is finished. Further, when the state where the steering torque T detected by the steering torque detection means Sb is 5 Nm or more continues for 0.1 sec or more, or when the steering torque T is 3 Nm or more continues for 0.3 sec or more, the driver It is determined that the steering handle 1 has been operated, and the automatic steering control is terminated in step S3. If the condition of step S2 is not satisfied, the process returns to step S1 without terminating the automatic steering control.

  If the rotational speed dθ / dt of the steering wheel 1 is less than the threshold value 10 deg / sec in step S1, whether or not the movement distance X of the vehicle V is within the range in which the standard steering angle θref changes in step S4, that is, FIG. It is determined whether or not the vehicle is in the region b, d, f, h in B). If it is in the region b, d, f, h, it is determined in step S5 whether the vehicle V is stopped. Whether or not the vehicle V is stopped can be determined based on the rotation angles per unit time of the wheels Wf, Wf; Wr, Wr detected by the wheel rotation angle detection means Sc. If the vehicle V is not stopped in step S5, it is determined in step S2 whether or not the automatic steering control is to be terminated.

  If the moving distance X of the vehicle V is within the range in which the reference steering angle θref does not change in step S4 (when it is in the areas a, c, e, g, i in FIG. 2B), or in step S5 When the vehicle V is stopped, that is, when the steering handle 1 is in the steering state 2 (fixed state), the process proceeds to step S6.

  When the state where the deviation E is 20 deg or more continues in step S6 for 0.5 sec or more, it is determined that there is a high possibility that an abnormality has occurred in the automatic steering control and the vehicle V has deviated from the target movement locus, and step S3 Then, the automatic steering control is finished. When the state where the steering torque T detected by the steering torque detection means Sb is 5 Nm or more continues for 0.1 sec or more, it is determined that the driver has operated the steering handle 1, and the automatic steering control is terminated in step S3. . If the condition of step S6 is not satisfied, the process returns to step S1 without terminating the automatic steering control.

  The meaning of the flowchart will be further described. The steering state of the steering wheel 1 includes a steering state 1 (rotation state) in step S2 and a steering state 2 (fixed state) in step S6. The “rotation state” is obtained by changing the steering angle θ to the change in the reference steering angle θref. The steering handle 1 is rotating to follow, and the “fixed state” is a state where the steering handle 1 is fixed because the reference steering angle θref does not change.

  In the “rotation state”, the steering angle θ is made to follow the reference steering angle θref by feedback control. Therefore, there is a certain deviation E between the reference steering angle θref and the steering angle θ even in the normal state. On the other hand, in the “fixed state”, since the steering angle θ coincides with the constant reference steering angle θref, there is almost no deviation E in the normal state. Therefore, in the “rotation state”, the threshold value for determining the abnormality and terminating the automatic steering control is set gently (60 deg is 0.5 sec or more), and in the “fixed state”, the abnormality is determined and the automatic steering control is terminated. By setting a strict threshold value (20 deg is 0.5 sec or more), the automatic steering control can be reliably ended in an abnormal state while avoiding unnecessary automatic steering control from being ended in a normal state.

  Further, when the driver spontaneously operates the steering handle 1 and the steering torque T is detected during the automatic steering control, there is no difference between the “rotation state” and the “fixed state”. However, in the “rotation state”, if the driver unintentionally touches the steering handle 1, the hand is rubbed against the rotating steering handle 1 and a relatively small steering torque T is detected. Will occur. On the other hand, such a phenomenon does not occur in the “fixed state”.

  Accordingly, if the threshold value of the steering torque T for ending the automatic steering control is set to be large, the automatic steering control is not ended when the driver's hand rubs against the steering handle 1 in the “rotation state”, and the driver's hand is There is a possibility that the steering handle 7 is rubbed against the steering wheel 1 and the rotation of the steering wheel 1 by the steering actuator 7 is obstructed, and the accuracy of the automatic steering control is lowered.

  In order to prevent this, if the threshold value of the steering torque T for ending the automatic steering control is set to a small value, the automatic steering can be performed only by applying a small steering torque T that does not affect the accuracy of the automatic steering control in the “fixed state”. As a result, the control ends, and the problem of poor usability occurs.

  Therefore, in the present embodiment, the threshold value of the steering torque T for ending the automatic steering control is changed according to the steering state of the steering handle 1. As a direct determination method of the steering state, if the rotational speed of the steering wheel 1 is 10 deg / sec or more, it is determined as “rotating state”, and if it is less than 10 deg / sec, it is determined as “fixed state”.

  Even if the rotational speed is less than 10 deg / sec, the steering angle θ follows the reference steering angle θref if the reference steering angle θref is in the regions b, d, f, and h in FIG. Therefore, if it is in the region a, c, e, g, i in FIG. 2B where the reference steering angle θref does not change, the steering angle θ follows the reference steering angle θref. Since it does not change, it is determined as “fixed state”.

  However, even if it is determined as “rotation state” here, if the vehicle V is stopped, the movement distance X does not change and the reference steering angle θref does not change, so that it is exceptionally determined as “fixed state”. To do.

  Therefore, in response to the case where the driver spontaneously operates the steering handle 1, for both the “rotation state” and the “fixed state”, a threshold value of 5 Nm for the steering torque T is set to 0.1 sec or more, Corresponding to the case where the driver's hand is rubbed against the steering handle 1, only the “rotation state” is set by adding a threshold of 3Nm of 0.3 sec or more for the steering torque T.

  Thus, even when the driver operates the steering handle 1 spontaneously or when the driver's hand rubs against the steering handle 1, the automatic steering control can be accurately terminated.

  The embodiments of the present invention have been described above, but various design changes can be made without departing from the scope of the present invention.

  For example, in the embodiment, the steering torque T is used as a parameter for determining the end of the automatic steering control. However, the steering load F applied to the steering handle 1 by the driver may be used as a parameter. If the radius of the steering handle 1 is determined. This is because the steering torque T and the steering load F have a one-to-one relationship. In this specification, the steering torque T and the steering load F are defined as steering force.

Overall configuration diagram of a vehicle equipped with an automatic steering device Action diagram of back parking / left mode Diagram showing mode selection switch and automatic parking start switch Flow chart of automatic steering control end determination

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Steering handle 7 Steering actuator 22 Control part (steering actuator control means)
23 storage unit (movement trajectory setting means)
E Deviation Sa Steering angle detection means Sb Steering torque detection means (steering force detection means)
T Steering torque (steering force)
V Vehicle Wf Front wheel (wheel)
θ Steering angle θref Standard steering angle (target steering angle)

Claims (2)

A steering actuator (7) for steering the wheel (Wf) of the vehicle (V);
Movement trajectory setting means (23) for setting a target movement trajectory of the vehicle (V) to the target position;
Steering actuator control means (22) for driving and controlling the steering actuator (7) based on the target movement locus;
Steering angle detection means (Sa) for detecting the steering angle (θ) of the steering handle (1),
The steering actuator control means (22) determines whether a deviation (E) between the steering angle (θ) detected by the steering angle detection means (Sa) and the target steering angle (θref) corresponding to the target movement locus is predetermined. When the condition is satisfied, in the vehicle automatic steering device that terminates the drive control of the steering actuator (7),
The automatic steering apparatus for a vehicle, wherein the steering actuator control means (22) changes the predetermined determination condition according to a steering state of the steering handle (1). A steering actuator (7) for steering the wheel (Wf) of the vehicle (V);
Movement trajectory setting means (23) for setting a target movement trajectory of the vehicle (V) to the target position;
Steering actuator control means (22) for driving and controlling the steering actuator (7) based on the target movement locus;
Steering force detection means (Sb) for detecting a steering force (T, F) for the driver to steer the steering handle (1),
The steering actuator control means (22) ends the drive control of the steering actuator (7) when the steering force (T, F) detected by the steering force detection means (Sb) satisfies a predetermined determination condition. In an automatic vehicle steering system,
The automatic steering apparatus for a vehicle, wherein the steering actuator control means (22) changes the predetermined determination condition according to a steering state of the steering handle (1).

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