JP4249111B2 - Vehicle steering control device - Google Patents

Description

  The present invention relates to a steering control device for a vehicle that can automatically steer wheels during parking.

  Developed as a steering control device that automatically performs the steering operation during parking, an actuator such as an electric motor is added to the steering mechanism that steers the wheels, and the actuator is controlled according to a program stored in advance. (For example, refer to Patent Document 1).

In this conventional steering control device, the relationship between the relative position change amount from the reference position (for example, the garage entry start position) and the turning angle of the vehicle is stored in advance in the form of a map, and proceeds from the reference position to the target position. In the meantime, the actuator is controlled so as to reduce the deviation between the target turning angle obtained by referring to the map and the actual turning angle.
Japanese Patent No. 3266828

  However, in this conventional steering control device, the control means calls a map recorded in advance and reproduces the turning angle faithfully to the map value. There is a possibility that the vehicle may be steered in the direction unexpected by the driver when an incorrect map is called, the steering direction instruction is reversed, or when a failure occurs in the electric motor. It is done.

  Accordingly, the present invention is intended to provide a steering control device for a vehicle that can prevent the vehicle from being steered in a direction unexpected by the driver.

In order to achieve the above object, the invention described in claim 1 includes a turning mechanism for turning a wheel (for example, a turning mechanism 3 in an embodiment described later) and a turning actuator for driving the turning mechanism. (For example, the electric motor 4 in the embodiment described later) and the turning angle data with respect to the moving distance that is the standard route of the vehicle from the reference position to the target position are stored in advance and called as necessary, or A normative route setting unit (for example, a normative route setting unit 30 in an embodiment described later) and a control unit (for example, controlling the steering actuator so that the vehicle travels along the normative route). a control unit 31) will be described in the exemplary embodiment, the steering control apparatus for a vehicle having a, the output of the steering actuator turning angle of the vehicle exceeds the output inhibition area Output inhibiting means for stopping (e.g., output prohibiting means 32 will be described in the exemplary embodiment) is provided, the output inhibition area, sets a turning angle along the norms path as an area exceeding a predetermined steering angle range to the reference I did it.

In the case of the present invention, when the reference route is set by the reference route setting means and the steering control is started, the vehicle is basically steered along the reference route by the control of the turning actuator by the control means. However, if the vehicle greatly deviates from the reference route for any reason and exceeds the output prohibition region , the output prohibiting means prohibits the output of the steering actuator. As a result, a large shift of the steering angle with respect to the reference route of the vehicle is prevented.

The invention according to claim 2 is based on at least one of the output time and the output frequency even when the turning angle of the vehicle exceeds the output prohibition region in the invention according to claim 1. The output prohibiting means does not prohibit the output of the steering actuator while the allowable conditions set in the above are satisfied.

In this case, even if the turning angle of the vehicle may temporarily exceed the output prohibition region , the output of the steering actuator is not prohibited while the setting allowable condition is satisfied. It is possible to eliminate the problem that the steering control stops due to the deviation of the turning angle.

  According to the first aspect of the present invention, since a large shift in the turning angle of the vehicle can be restricted by the output prohibiting means, it is possible to prevent the driver from unexpectedly moving the vehicle.

  In addition, according to the second aspect of the present invention, it is possible to prevent the steering control from being stopped each time due to a temporary shift of the turning angle due to an external factor or the like, so that the convenience of the driver can be further improved.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 2 is a schematic configuration diagram of a vehicle 100 to which the steering control device according to the present invention is applied. In FIG. 2, Wf and Wr are front and rear wheels of the vehicle, and 1 is a steering wheel. The steering wheel 1 is linked to the left and right front wheels Wf via a steering shaft 2 and a steering mechanism 3 including a gear mechanism, a tie rod, and the like. The steering mechanism 3 is an actuator that drives the mechanism 3. An electric motor 4 is attached. Further, the steering shaft 2 is provided with a torque sensor 5 for detecting a steering torque by a driver. The torque sensor 5 constitutes an electric power steering together with the electric motor 4. The electric motor 4 is controlled by a controller (electronic control unit) 6 and basically functions as a drive source for electric power steering. However, the drive source of a steering control device that performs automatic steering during parking by switching by a switch operation described later. Also works. Also in this case, the electric motor 4 is controlled by the same controller 6.

  In addition to the torque sensor 5 being connected to the input side of the controller 6, the steering angle sensor 25 for detecting the turning angle of the front wheel Wf from the rotation angle of the steering wheel 1 and the shift lever are selected. A shift position sensor 7 that detects the shift range (“D” range, “R” range, “N” range, “P” range, etc.) and a brake switch 8 that is linked to whether or not the brake is depressed are connected. On the other hand, on the output side, in addition to the electric motor 4, a voice teaching speaker 9 is connected to assist the operation of the driver by voice guidance or to alert the driver. Further, the controller 6 is connected to a wiring of an operation panel 11 which will be described later, in which a monitor 10 (see FIG. 1) is integrated, and to a power switch 12 of the steering device. The power switch 12 also functions as an emergency stop switch during automatic steering.

  Although wiring is omitted in the figure, the input side of the controller 6 further includes a rotation angle sensor 19 for detecting the rotation angle of the front and rear wheels Wf and Wr, and an obstacle that is disposed on both front and rear sides of the vehicle. Is connected to an obstacle detection means 13 for detecting the image of the vehicle with an ultrasonic wave, a radar or the like, and an imaging means 14 for taking images of the front and rear of the vehicle.

  As shown in FIG. 5, in addition to the monitor 10, the operation panel 11 includes mode selection switches 15a to 15d for setting a parking mode (a left / right rear parallel parking mode and a parallel parking mode), and a start for starting automatic steering. A switch 16, a warning lamp 17, a buzzer 18, and the like are provided, and the driver's intention to operate is reflected in the controller 6 by a switch operation. To inform the person.

  Further, in the storage unit 6a of the controller 6, data of the turning angle corresponding to the moving distance of the vehicle 100 for each of the four types of parking modes (left / right rear side parallel parking mode and left / right parallel parking mode). (Reference route) is stored, and these are read out as needed during steering control.

  FIG. 3 shows a reference route that the vehicle 100 travels in the left side parallel parking. For example, in this left side parallel parking, the vehicle 100 is moved from the parking reference position of (1) to the final parking position of (3 ′) through the folding position of (2 ′). The map (steering angle data) referred to by the control unit is as shown in FIG. The parking reference position (1) is a position close to the parking frame 21 where the center G of the vehicle 100 is positioned on the center line of the parking frame 21 in a posture in which the vehicle 100 is orthogonal to the parking frame 21. Say. 3 and 4, (2) shows the first target position at the time of advance ahead of the turn-back position (2 ′), and (3) is before the final parking position (3 ′). The 2nd target position at the time of retreating is shown.

  Here, the map of FIG. 4 will be described. This map is a plot of the turning angle corresponding to the moving distance of the vehicle 100 from the parking reference position (1), and the final parking position from the parking reference position (1). The characteristic line connecting the plot points up to (3 ′) means the following vehicle behavior.

That is, when the vehicle 100 starts moving forward from the state of the parking reference position (1), the turning angle is increased rightward at the beginning of the movement, and the state is maintained when the set turning angle is reached. . Thereafter, the steering is gradually returned to the neutral direction, and when the vehicle 100 reaches the first target position (2), the turning angle becomes 0 °, and the turning is continued until the turning position (2 ′) is reached. The rudder angle is maintained. When the vehicle 100 starts to move backward from the turn-back position (2 ′), the turning angle is maintained at 0 ° until the vehicle 100 reaches the first target position (2), and then the first target position. The steering angle is increased in the left direction from the point exceeding (2). When the turning angle reaches the set turning angle, the turning angle is maintained for a while, and then the turning is returned to the neutral direction, and the vehicle 100 turns when the vehicle 100 reaches the second target position (3). The rudder angle becomes 0 °. This turning angle is maintained until the vehicle moves back to the final parking position (3 ′).
The series of behaviors of the vehicle 100 described above draws a reference path targeted by the vehicle 100.

  In this embodiment, the part that calls the data in the controller 6a constitutes the reference path setting means 30 in the present invention (see FIG. 1).

  On the other hand, as shown in FIG. 1, the processing function section in the controller 6 is configured with a control means 31. When the automatic steering is started at the time of parking, the control means 31 corresponds to the selected parking mode. The map is called from the storage unit 6a, and the output of the electric motor 4 is controlled so that the turning angle when the vehicle 100 moves always approaches the map value. Specifically, the controller 6 always detects the moving distance and turning angle of the vehicle 100 from the parking reference position (1), and refers to the map value for the target turning angle corresponding to the moving distance at that time. The output of the electric motor 4 is controlled so that the deviation between the target turning angle and the actual turning angle is zero. Here, the travel distance of the vehicle 100 from the parking reference position (1) is obtained by the product of the known circumference of the front wheel Wf and the rotation angle of the wheel detected by the rotation angle sensor 19, and the actual turning angle is determined by turning. It is obtained from the detection value of the angle sensor 25.

  Further, in the storage unit 6a of the controller 6, in addition to the above-mentioned correspondence data of the moving distance of the vehicle 100 and the turning angle (hereinafter referred to as “output data”), the rotation for prohibiting the output to the electric motor 4 is prohibited. Data on the steering angle area (hereinafter referred to as “prohibited data”) is stored for each parking mode, and these prohibited data are also read as needed during steering control.

For example, the prohibition data is stored in the form of a map as shown by hatching in FIG. In the example of the left rear side parallel parking shown in FIG. 4, an area where output is prohibited is set according to the movement position of the vehicle 100 as follows.
<Moving position between reference parking position (1) and first target position (2)>
A region where the left turning angle exceeds a ° with respect to the neutral position.
<Moving position between the first target position (2) and the folding position (2 ')>
A region where the left turning angle exceeds a ° with respect to the neutral position and a region where the right turning angle exceeds a °.
<Movement position between the folding position (2 ') and the second target position (3)>
The region where the right turning angle exceeds a ° with respect to the neutral position.
<Moving position between second target position (3) and final parking position (3 ')>
A region where the left turning angle exceeds a ° with respect to the neutral position and a region where the right turning angle exceeds a °.

  In addition, the processing function unit in the controller 6 is provided with an output prohibiting unit 32 in addition to the above-described reference path setting unit 30 and the control unit 31. The output prohibiting means 32 refers to the map of the prohibition data described above, and outputs an output prohibition signal to the electric motor 4 when the turning angle of the vehicle 100 exceeds the prohibition area during the steering control, and the control means 31. A reset signal is output to fix the deviation between the target turning angle and the actual turning angle at 0 °.

  Next, the operation when the steering control is performed at the time of parking will be described taking the left rear side parallel parking as an example.

  First, the driver directly operates the steering wheel 1 to move the vehicle 100 to the parking reference position (1) while performing visual confirmation. Therefore, the driver once stops the vehicle 100, selects the left side parallel parking mode among the mode selection switches 15a to 15d on the operation panel 11, and then presses the start switch 16, the start switch 16 is turned on. Steering control is started.

  When the steering control is started, a map of output data and a map of prohibition data corresponding to the parking mode are read in the controller 6 and the electric motor 4 is controlled by the control means 31.

  The vehicle 100 moves forward by releasing the depression of the brake pedal or by an accelerator operation, and controls the turning angle so as to follow the map value of the output data. As a result, the vehicle 100 moves forward while changing its posture in the right direction as shown in FIG. 3, and the steering is maintained in a neutral state when the vehicle reaches the first target position (2). When the controller 6 determines that the vehicle 100 has passed the first target position (2) and the moving distance of the vehicle 100 from the parking reference position (1) has exceeded the set value, the display on the monitor 10 The driver is informed that the vehicle 100 should be stopped by an instruction from the voice teaching speaker 9. Thus, when the driver depresses the brake pedal and the vehicle 100 stops at the turn-back position (2 ′), the driver is informed that the shift range should be switched to R by an instruction from the voice teaching speaker 9.

  After this, when the driver switches the shift range to R, gradually releases the brake pedal, and performs an accelerator operation as necessary, the vehicle 100 starts to move backward and steer again so as to follow the map value of the output data. Control the corners. As a result, the vehicle 100 moves backward while changing its posture in the left direction, and when the second target position (3) is reached, the steering is maintained in a neutral state, and the vehicle 100 is moved to the second position. When the controller 6 determines that the target position (3) is reached, the driver is informed that the vehicle should be stopped again by the display on the monitor 10 and the instruction from the voice teaching speaker 9. When the driver depresses the brake pedal in accordance with this instruction, the vehicle 100 stops at the final parking position (3 ′).

  The above is the basic left side rear side parallel parking control, but when the turning angle of the vehicle 100 exceeds the output prohibition region shown in FIG. 4 due to a system abnormality or a failure of the electric motor 4 during such parking. The output control means 32 in the controller 6 outputs an output prohibition signal to the electric motor 4 and simultaneously outputs a reset signal to the control means 31. Thereby, the steering control of the vehicle 100 by the electric motor 4 is stopped, and the driver is informed that the steering control is stopped by the display on the monitor 10 and the voice teaching speaker 9. Therefore, in the rearward parallel parking according to the map of FIG. 4, when moving forward from the parking reference position (1) to the first target position (2) and from the first target position (2) to the second target position. During reverse to (3), turning in the opposite direction of a ° or more is prohibited, and between the first target position (2) and the turn-back position (2 '), the second target position (3) and the final parking During the position (3 ′), the steering of a right and left a ° or more of the neutral position is prohibited.

  Therefore, in the vehicle 100 employing this steering control device, it is possible to reliably prevent the vehicle 100 from being greatly steered in a direction unexpected by the driver. In the above, the case of the left side parallel parking has been described as an example, but the same applies to parking in other modes.

Next, another embodiment will be described with reference to FIG.
In this embodiment, the output prohibiting means is configured so that the electric motor is operated as long as the setting allowable conditions such as time and frequency are satisfied even when the turning angle of the vehicle exceeds the output prohibiting region (set steering region). The prohibition of output is not performed, and furthermore, the output prohibition area is divided and the allowable condition is changed according to the division area.

Specifically, in FIG. 6, the output prohibition region is divided into L ₁ , L ₂ , and L ₃ according to the deviation from the neutral steering angle, and the allowable conditions are, for example, continuous 30 msec for L ₁ and for L ₂ continuous 10 msec, are determined as 2msec in _{L 3.} Thus, in this example, output prohibiting means 32 when the turning angle into the L ₁ region is followed by more consecutive 30msec is prohibited the output of the electric motor 4, L ₂ region, the L ₃ region, in these areas The output of the electric motor 4 is prohibited when the turning angle to enter continues for 10 msec or more and 2 msec or more, respectively.

  In this steering control device, even if the turning angle of the vehicle 100 temporarily exceeds the output prohibition region (set steering angle region), the output of the electric motor 4 is not immediately prohibited and the output to the output prohibition region is not performed. The output of the electric motor 4 is prohibited according to the approach depth and the approach duration. For this reason, when the turning angle of the vehicle 100 temporarily changes due to an external factor or the like, or when the turning angle temporarily outputs an abnormal value, the output of the electric motor 4 is not prohibited and is steered. The control is continued, and the output of the electric motor 4 is prohibited only when the possibility that there is an abnormality in the system, the electric motor 4 or the like after the turning beyond the output prohibition region continues for the set time or longer.

  Therefore, according to this steering control device, unnecessary frequent stop of steering control does not occur, and the convenience of the driver is enhanced. In particular, as in this embodiment, when the approach duration to be allowed is set to be longer as the approach depth to the output prohibited area is shallower, while preventing a large shift of the route due to a system abnormality or the like, it is unnecessary. Steering stop can be minimized.

In the above, the output of the electric motor 4 is prohibited when the turning angle of the vehicle enters the output prohibited area continuously for a set time or longer, but the frequency of entering the output prohibited area per predetermined time, The output may be prohibited according to the accumulated time for entering the output prohibited area. That is, continuous in _{L 1} region in the above example 30 msec, _L continuous 10msec in ₂ regions, although the _{L 3} region a continuous 2 msec, for example, _{L 1} region is accumulated during a predetermined period of time (e.g., 1,2Sec) in above 30 msec, L ₂ region 10msec or more, set as the cumulative time that has entered the output inhibition area in the predetermined time so as to disable output if exceeds the set time.
In addition, the speed of the vehicle 100 may be added as a determination factor of the output prohibition control, and the higher the speed of the vehicle 100, the stricter the permissible conditions, and the output of the electric motor 4 may be prohibited earlier. In this case, it is possible to more effectively prevent the vehicle 100 from greatly traveling in an unexpected direction due to an increase in speed.

FIG. 7 is a diagram in which an output map and a prohibition map of still another embodiment are overlapped.
The steering control device according to this embodiment sets the output prohibition region (set turning angle region) with a predetermined width a on the left and right of the turning angle along the reference route for the entire travel range during parking. Yes. When the output prohibition area is set in this way, not only abnormal turning in the reverse direction during turning but also excessive turning in the normal turning direction can be restricted. Can be further enhanced.

In addition, this invention is not limited to the said embodiment, A various design change is possible in the range which does not deviate from the summary. For example, in the above embodiment, the output data and the prohibition data are stored in the form of a map in advance, but it is also possible to obtain a reference path by calculation or store the prohibition area as a threshold value. The map indicating the output prohibition area (set turning angle area) may be fixed for each parking mode, but may be set and adjusted freely according to driving conditions, the specifications of the vehicle 100, and the like.
Further, in the above embodiment, the output data map and the prohibited data map are stored in one controller 6. However, the output data map is stored in the main controller, and the prohibited data map is stored in another controller. You may make it memorize | store in a sub controller. In this case, it is possible to monitor the failure of the main controller by the sub controller, and to more reliably detect the failure of the main controller and prohibit the output.

The functional block diagram of the steering control apparatus which shows one Embodiment of this invention. The schematic block diagram of the vehicle which shows the embodiment. The schematic diagram explaining the action | operation of the embodiment. The figure which overlapped and described the output map and prohibition map of the embodiment. The top view of the operation panel in the embodiment. The figure similar to FIG. 4 which shows other embodiment of this invention. The figure similar to FIG. 4 which shows another embodiment of this invention.

Explanation of symbols

3 Steering mechanism 4 Electric motor (steering actuator)
30: reference path setting means 31: control means 32: output prohibiting means

Claims (2)

A steering mechanism that steers the wheels;
A steering actuator that drives the steering mechanism;
Steering angle data with respect to the travel distance that is the standard path of the vehicle from the reference position to the target position, the standard path setting means for storing in advance and calling or setting by calculation as necessary,
A vehicle steering control apparatus comprising: a control unit that controls the steering actuator so that the vehicle travels along the reference path;
An output prohibiting means for prohibiting the output of the steering actuator in which the turning angle of the vehicle exceeds the output prohibition region ,
The vehicle steering control device , wherein the output prohibition region is set as a region exceeding a predetermined turning angle width based on a turning angle along the reference route . The output prohibiting means is configured so that, even when the turning angle of the vehicle exceeds the output prohibiting region , the steering actuator is in a state where an allowable condition set based on at least one of output time and output frequency is satisfied. The vehicle steering control device according to claim 1, wherein output of the vehicle is not prohibited.

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