JP3858485B2 - Vehicle control device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a vehicle control device.
[0002]
[Prior art]
In some vehicles, it is proposed that the vehicle is driven along a predetermined target locus by automatic steering, for example, to avoid contact with a preceding vehicle. Japanese Patent Laid-Open No. 9-156258 discloses a mechanism in which a motor for automatic steering is separately incorporated in a mechanism for linking a steering wheel and a steering handle, and the motor is driven and controlled so as to reduce a lateral deviation with respect to a target locus of the vehicle. Proposed. Japanese Patent Laid-Open No. 9-156522 discloses that a steering handle and a mechanism for applying a steering force to a steered wheel are separately provided, that is, automatic steering and manual steering by a driver are cut off from each other. There has been proposed one that prevents interference.
[0003]
[Problems to be solved by the invention]
By the way, when performing automatic steering, as shown in the above-mentioned JP-A-9-156522, a steering handle operated by a driver and a steering force applying mechanism for applying a steering force to the steered wheels are separately provided. If it is present, when steering wheels are steered by automatic steering, applying a steering reaction force to the steering wheel informs the driver that the direction of the vehicle will be changed, and driving the driving direction is changed. It is preferable for prompting the person. In this case, from the viewpoint of automatic steering, the provision of steering force is fundamental, and the provision of steering reaction force is incidental according to the provision of steering force.
[0004]
It has been discovered that when the steering reaction force is applied as it is with the steering force applied in automatic steering, the driver may feel uncomfortable. To elaborate on this point, the driver usually steers by manual operation, but at this time, the steering operation is performed first, and the feeling that the traveling direction of the vehicle is changed later than this is felt. It has something to do with it. On the other hand, in the case of automatic steering, since the steering force is applied regardless of the driver's will, the driver recognizes the applied steering reaction force through the steering handle. The timing at which the driver recognizes such a steering reaction force would be uncomfortable.
[0005]
In addition, when automatic steering is performed, how to set the steering reaction force becomes a big problem. In other words, if the driver cannot recognize the magnitude of the steering reaction force according to the traveling direction change state (behavior) of the vehicle that occurs when automatic steering is performed, the driver is anxious about automatic steering. It will give you a sense of incongruity and discomfort. In particular, even when the same steering force is applied during automatic steering, the behavior of the vehicle traveling direction change may differ considerably depending on the traveling state of the vehicle at that time. How to set it becomes a problem.
[0006]
The present invention has been made in view of the foregoing circumstances and has as its object, when performing automatic steering control apparatus for a vehicle to more appropriately set the timing of the steering reaction force applied to the driver Is to provide.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, and in particular to optimize the timing for applying the steering reaction force, the present invention adopts the following first solution. That is, as described in claim 1 in the claims,
A steering unit operated by a driver;
A steering unit configured to be steered from the steering unit;
Steering reaction force applying means for applying a steering reaction force to the steering unit;
Steering force application means for applying a steering force to the steering unit;
Control means for controlling the steering force application means with a first control target value determined for automatic steering, and for controlling the steering reaction force application means with a second control target value when automatic steering is performed. When,
With
The control of the steering force applying means and the steering reaction force applying means by the control means, steering force of application to the steering wheel is performed as the predetermined delayed than the steering reaction force imparted to said steering unit Rutotomoni, When the steering speed is large, the degree of delay is changed to be smaller than when the steering speed is small.
Ru Citea so.
[0008]
In order to achieve the above object, and in particular to optimize the timing for applying the steering reaction force, the present invention adopts the following second solution. That is, as described in claim 2 in the scope of claims,
A steering unit operated by a driver;
A steering unit configured to be steered from the steering unit;
Steering reaction force applying means for applying a steering reaction force to the steering unit;
Steering force application means for applying a steering force to the steering unit;
Control means for controlling the steering force application means with a first control target value determined for automatic steering, and for controlling the steering reaction force application means with a second control target value when automatic steering is performed. When,
With
The control of the steering force application unit and the steering reaction force application unit by the control unit is performed such that the application of the steering force to the steering wheel is delayed by a predetermined amount from the application of the steering reaction force to the steering unit. When the amount is small, the delay is changed so that the degree of delay is smaller than when the steering amount is large.
Ru Citea so.
[ 0009 ]
A preferred mode based on the first solution technique or the second solution technique is as described in claim 3 and subsequent claims.
[ 0010 ]
【The invention's effect】
According to the first aspect, after the driver feels the steering reaction force through the steering unit, the traveling direction of the vehicle is changed by the automatic steering. Therefore, it is possible to prevent the driver from feeling uncomfortable with the automatic steering. Is preferable. Further, the degree of delay can be appropriately set according to the steering speed.
[0011]
According to the second aspect, after the driver feels the steering reaction force through the steering unit, the traveling direction of the vehicle is changed by the automatic steering, so that it is possible to prevent the driver from feeling uncomfortable with the automatic steering. Is preferable. Further, the degree of delay can be appropriately set according to the steering amount.
[ 0012 ]
According to the third aspect , the effect corresponding to the first or second aspect can be obtained when the automatic steering is for causing the vehicle to travel along a predetermined target locus.
According to claim 4 , a specific method for determining the first control target value and the second control target value is provided.
[ 0013 ]
According to the fifth to seventh aspects, the degree of delay can be set more appropriately according to the steering torque, the yaw rate, or the road surface μ.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
In FIG. 1, reference numeral 1 denotes a vehicle (automobile), which is an FF vehicle in the embodiment. The traveling lane is indicated by reference numeral 2, the left boundary line (white line) thereof is indicated by reference numeral 2L, and the right boundary line is indicated by reference numeral 2R. Although not displayed in the actual travel lane 2, the center line of the travel lane 2 is indicated by a one-dot chain line and denoted by reference numeral 2C. The vehicle 1 is automatically steered with the center line 2C as a target locus. In FIG. 1, the vehicle 1 is slightly deflected to the right with respect to the center line 2C, and the front of the vehicle body is slightly inclined to the right. Is shown. In the state of FIG. 1, during automatic steering, a steering force is applied so that the left and right front wheels 3 as steering wheels are directed to the left, and a steering reaction force of a left operation is applied to the steering handle 4 as a steering unit. .
[0015]
A steering system and a control system of the vehicle 1 are shown in FIG. In FIG. 2, left and right front wheels 3 as steering wheels are mechanically connected to each other via a pair of left and right knuckle arms 11, a pair of left and right tie rods 12, and a drive mechanism (reduction gear mechanism) 13 that connects the left and right tie rods 12. Are linked together. Each of the constituent elements 11, 12, and 13 constitutes a steering mechanism as a steering section, and the drive mechanism 13 is provided with a motor (actuator) 14 as a steering force applying means. The handle 4 is configured separately and independently from the steering mechanisms 11 to 13, and a motor 15 is provided as a steering reaction force applying means for a steering shaft 4 a attached to the handle 4.
[0016]
During automatic steering, as will be described in detail later, a steering torque (steering force) is applied to the left and right front wheels 3 by the motor 14, while a steering reaction force is applied to the handle 4 by the motor 15. Note that, during normal manual steering that is not automatic steering, that is, during steering that the driver manually operates the handle 4, the motor 14 is driven in accordance with the steering amount or steering torque of the handle 4 to operate the handle 4. The front wheel 3 is steered and a steering reaction force corresponding to the steering amount or the steering torque is given by the motor 15.
[0017]
Each of the motors 14 and 15 is controlled by a controller U configured using a microcomputer. The controller U receives signals from various sensors and the like, and detects (or calculates) the following various states. Various states to be detected (or calculated) are as follows. First, the position of the center line 2C of the travel lane 2 as the target locus is detected as yc using a camera mounted on the vehicle 1, for example. Further, the current lateral deviation between the center line 2C in the front-rear direction and the center line 2C of the vehicle 1 is detected as yo using the camera, for example. The current vehicle speed is detected as v by the vehicle speed sensor. The yaw angle of the vehicle 1 is detected as yw using the camera, for example. The yaw rate of the vehicle 1 is detected as r by the yaw rate sensor. The road surface friction coefficient is detected as μ. The steering amount (actual steering amount of the front wheels 3) is detected as θ by the steering angle sensor. The steering speed (actual steering speed of the front wheels 3) is detected as θ ′, for example, by differentiating θ. The curvature (curvature radius) of the traveling lane 2 is detected using the camera or the navigation system. It should be noted that conventionally known appropriate methods can be adopted as the above-described various state detection methods.
[0018]
Since the automatic steering is performed so as to travel along the center line 2C as the target locus, the future lateral deviation amount y1 is determined. This future lateral deviation amount y1 is calculated by taking the center line position yc and the lateral deviation when the vehicle head time, which is the time expected to take until the vehicle 1 reaches the forward gaze point P (see FIG. 1), is T. Based on the quantity yo, the vehicle head time T, the vehicle speed v, and the yaw angle yw, the following equation 1 is used.
[0019]
y1 = yc− (yo + T × v × yw) (1)
[0020]
During automatic steering, the steering torque T2 as the first control target value for determining the steering force and the steering torque T1 as the second control target value for determining the steering reaction force are respectively based on the future lateral deviation amount y1, It is determined as shown in FIG. The steering torque T2 is always larger than the steering torque T1, but the deviation is set so as to increase as the steering torque T2 increases. Each torque T1, T2 is set so as to increase as the future lateral deviation amount y1 increases, but an upper limit value is also set.
[0021]
In FIG. 3, the future lateral deviation amount y1 is mapped as a parameter, and torques T1 and T2 are created and stored in advance. However, based on y1 using a control constant (control gain), FIG. Torques T1 and T2 can also be calculated. That is, as described in the flow chart described later, it is possible to calculate as T1 = k1 × y1 and T2 = k2 × y1 (k1 <k2). The output of the steering torque T2 to the motor 14 is delayed by a predetermined amount t with respect to the output of the steering reaction force T1 to the motor 15, and the degree of delay (delay time) t is changed according to the running state. Is done.
[0022]
The control content of the automatic steering by the controller U will be described with reference to the flowchart of FIG. 5. In the following description, Q indicates a step. First, after the various states shown in FIG. 2 are read (calculated) in Q1, a future lateral deviation amount y1 is calculated in Q2. Based on the future lateral deviation amount y1, the steering torque, that is, the steering reaction torque T1 is calculated with Q3, and the steering torque T2 is calculated with Q4.
[0023]
In Q5, the delay time t is calculated using the steering torque T2, the yaw rate r, the road surface μ, the steering amount θ, the steering speed θ ′, and the vehicle speed v as parameters. After Q5, at Q6, the steering torque T1 is output to the motor 15 (execution of driving by the motor 15 at the magnitude of the torque T1). Thereafter, in Q7, after the delay time t has elapsed from the T1 output, the steering torque T2 is output to the motor 14 in Q8 (execution of driving by the motor 14 at the torque T2).
[0024]
More specifically, the setting of the delay time t in Q5 is as follows. First, the delay time t is set larger as the steering torque T2 is larger (when T2 is larger, the delay time t is set larger than when the steering torque T2 is small). The delay time t is set larger as the yaw rate r is larger (when r is larger, the delay time t is set larger than when it is smaller). The delay time t is set larger as the road surface μ is larger (when μ is larger, the delay time t is set larger than when it is smaller). However, for the road surface μ, when the reference road surface μ0 is set and the actual road surface μ is larger than the reference road surface μ0, the delay time t is increased, and when the actual road surface μ is smaller than the reference road surface μ0, the delay time is increased. t is set to be small.
[0025]
The delay time t is set larger as the steering amount θ is larger (when θ is larger, the delay time t is set larger than when the steering amount is smaller). The delay time t is set smaller as the steering speed θ ′ is larger (when θ ′ is larger, the delay time t is set smaller than when the steering speed is smaller). The delay time t is set smaller as the vehicle speed v increases (the delay time t is set smaller when v is larger than when the vehicle speed v is small).
[0026]
As described above, the delay time t is set with the steering torque T2 as a basic value, and is corrected (changed) in accordance with various traveling states such as the vehicle speed v. The driving state for changing the delay time in Q5 is merely an example, and at least one of the various driving states shown in Q5 is used (including the case where any two or more combinations are used). t can be changed, and the delay time t can be changed in a driving state that is not included in the above description, particularly in a driving state that affects the vehicle behavior during steering (for example, vehicle weight, front-rear load) Distribution, road surface unevenness, etc.).
[0027]
Although the embodiment has been described above, in order to obtain a configuration corresponding to claim 9 in the claims, the setting of the steering torque T1 (second control target value) is set to the steering torque T2 (first control target value). It may be set based on the running state. The running state at this time can be, for example, at least one of yaw rate, road surface μ, steering amount, steering speed, and vehicle speed, or any combination of two or more. Specifically, the steering torque T1 may be set with a value based on the steering torque T2 as a basic value, and the basic value may be corrected (changed) in the traveling state (for example, a delay at Q5 in FIG. 4). Setting by the same method as setting at time t). In the embodiment shown in FIG. 4, the steering torque T1 having a value corrected in the running state as described above can be used (both claims 1 and 9 in the claims). Is satisfied).
[0028]
The automatic steering in the present invention is not intended to follow the target trajectory, and the purpose (type) of the automatic steering is not particularly limited, for example, automatic steering for avoiding steering to avoid contact with the preceding vehicle. is there. In addition, the automatic steering for tracking the target locus includes a case where automatic steering is performed so as to return to the target locus only when there is a predetermined deviation from the target locus. As the first control target value for automatic steering, a value other than the torque can be set as the target value, such as setting as a target steering amount instead of using the steering torque T2. Various members such as each step or sensor shown in the flowchart can be expressed by adding the name of the means to the high-level expression of the function. Further, the object of the present invention is not limited to what is explicitly stated, but also implicitly includes providing what is substantially preferred or expressed as an advantage. Furthermore, the present invention can also be expressed as a control method.
[Brief description of the drawings]
FIG. 1 is a diagram for explaining automatic steering for tracking a target locus.
FIG. 2 is a diagram showing an example of a steering system and a control system used for automatic steering.
FIG. 3 is a diagram showing a setting example of steering torque and steering torque.
FIG. 4 is a flowchart showing a control example of the present invention.
FIG. 5 is a block diagram showing the configuration of the present invention.
[Explanation of symbols]
1: Vehicle 2: Traveling lane 2C: Center line (target locus yc)
3: Front wheel (steering wheel)
4: Steering handle (steering part)
14: Motor (for steering torque generation)
15: Motor (for steering reaction force generation)
U: Controller y1: Future lateral deviation amount T1: Steering torque (steering reaction force)
T2: Steering torque (steering force)

Claims (7)

A steering unit operated by a driver;
A steering unit configured to be steered from the steering unit;
Steering reaction force applying means for applying a steering reaction force to the steering unit;
Steering force application means for applying a steering force to the steering unit;
Control means for controlling the steering force application means with a first control target value determined for automatic steering, and for controlling the steering reaction force application means with a second control target value when automatic steering is performed. When,
With
The control of the steering force applying means and the steering reaction force applying means by the control means, steering force of application to the steering wheel is performed as the predetermined delayed than the steering reaction force imparted to said steering unit Rutotomoni, When the steering speed is large, the degree of delay is changed to be smaller than when the steering speed is small.
A control apparatus for a vehicle. A steering unit operated by a driver;
A steering unit configured to be steered from the steering unit;
Steering reaction force applying means for applying a steering reaction force to the steering unit;
Steering force application means for applying a steering force to the steering unit;
Control means for controlling the steering force application means with a first control target value determined for automatic steering, and for controlling the steering reaction force application means with a second control target value when automatic steering is performed. When,
With
The control of the steering force application unit and the steering reaction force application unit by the control unit is performed such that the application of the steering force to the steering wheel is delayed by a predetermined amount from the application of the steering reaction force to the steering unit. When the amount is small, the delay is changed so that the degree of delay is smaller than when the steering amount is large.
A control apparatus for a vehicle. In claim 1 or claim 2 ,
The vehicle control apparatus according to claim 1, wherein the first control target value is determined as a value for causing the vehicle to travel along a predetermined target locus. In claim 3 ,
The first control target value is determined based on a predicted lateral deviation amount that is a future predicted lateral deviation amount from the currently traveling lane,
The second control target value is also determined based on the predicted lateral deviation amount.
A control apparatus for a vehicle. In claim 1 or claim 2,
  The vehicle control apparatus characterized in that the degree of the delay is increased when the steering torque is large compared to when the steering torque is small. In claim 1 or claim 2,
  The vehicle control device characterized in that the degree of the delay is increased when the yaw rate is large compared to when the yaw rate is small. In claim 1 or claim 2,
  The vehicle control apparatus characterized in that the degree of the delay is increased when the road surface μ is large compared to when the road surface μ is small.

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