JP2019116140A - Behavior control device - Google Patents

Abstract

To provide a vehicle behavior control device that controls braking means so that a yaw moment is applied to a vehicle, which can suppress a strong feeling of control intervention and a feeling of strangeness from being provided to a driver by applying a yaw monet in consideration of magnitude of lateral acceleration..SOLUTION: In a vehicle behavior control device equipped with a braking control system 18 that can apply different braking force to left and right wheels, typically a PCM 14, when a steering angle decreases, sets a yaw moment in a direction opposite to a yaw rate generated in a vehicle as a target yaw moment which should be applied to the vehicle and the brake control system 18 so that target yaw moment is applied to the vehicle, where the PCM 14 makes the target yaw moment smaller as lateral acceleration becomes lower.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a vehicle behavior control device, and more particularly to a vehicle behavior control device provided with braking means capable of applying different braking forces to left and right wheels.

  2. Description of the Related Art In the past, there have been known devices for controlling the behavior of a vehicle in a safe direction (such as a skid prevention device) when the behavior of the vehicle becomes unstable due to a slip or the like. Specifically, there is known one that detects occurrence of understeer or oversteer behavior in the vehicle at the time of cornering of the vehicle, etc., and applies appropriate deceleration to the wheels so as to suppress them. ing.

  Also, unlike the control for improving the safety in the running state where the behavior of the vehicle becomes unstable as described above, acceleration and deceleration linked to the steering wheel operation from the daily driving range are automatically performed, and the limit There is known a motion control device for a vehicle that reduces skidding in a driving range (see, for example, Patent Document 1). In particular, Patent Document 1 discloses a motion control device of a vehicle provided with a first mode for controlling acceleration / deceleration in the longitudinal direction of the vehicle and a second mode for controlling a yaw moment of the vehicle. There is.

JP, 2010-162911, A

  As described above, in the technology disclosed in Patent Document 1, the yaw moment is applied to the vehicle in the second mode. There is no problem if the control to apply this yaw moment is performed when the lateral acceleration of the vehicle is large, but if it is performed when the lateral acceleration of the vehicle is small, the driver can easily feel that this control intervenes Tend to give the driver a sense of discomfort (relatively strong control intervention). In particular, in the technology disclosed in Patent Document 1, a yaw moment is applied to the vehicle according to the magnitude of the lateral jerk (corresponding to the steering speed) of the vehicle, but the lateral jerk is large even when the lateral acceleration is small. In such a case, the yaw moment is increased to give the driver a strong sense of control intervention.

  The present invention has been made to solve the above-mentioned problems of the prior art, and in the vehicle behavior control device for controlling the braking means to apply a yaw moment to the vehicle, the magnitude of the lateral acceleration is taken into consideration. An object of the present invention is to provide a driver with a strong sense of control intervention and a sense of discomfort by applying a yaw moment.

In order to achieve the above object, it is a behavior control device of a vehicle provided with braking means capable of applying different braking forces to left and right wheels, which comprises steering angle detecting means for detecting a steering angle, and lateral acceleration. Target acceleration setting means for setting a yaw moment reverse to the yaw rate generated in the vehicle as a target yaw moment to be applied to the vehicle based on the lateral acceleration detection means and the steering angle, and the target yaw moment for the vehicle Control means for controlling the braking means to be applied to the target yaw moment setting means, wherein the target yaw moment setting means reduces the target yaw moment as the lateral acceleration decreases.
In the present invention configured as described above, when a yaw moment reverse to the yaw rate generated in the vehicle is set as a target yaw moment, and the braking means is controlled to apply the target yaw moment to the vehicle. The smaller the lateral acceleration of the vehicle, the smaller the target yaw moment. As a result, when the lateral acceleration is small, it is possible to appropriately suppress the driver from feeling uncomfortable due to the control of applying the yaw moment to the vehicle, specifically, giving the driver a strong sense of control intervention. On the other hand, when the lateral acceleration is large, the control effect of applying the yaw moment to the vehicle can be appropriately secured.

Further, in the present invention, preferably, the target yaw moment setting means sets the target yaw moment continuously using the lateral acceleration acquired by the lateral acceleration detection means when starting the control by the control means.
In the present invention thus configured, the target yaw moment is set by continuously using the lateral acceleration acquired when starting the control for applying the yaw moment to the vehicle. As a result, it is possible to suppress the control from becoming unstable by changing the target yaw moment at any time according to the lateral acceleration during the control for applying the yaw moment.

In the present invention, preferably, the value representing the turning state is a steering speed calculated based on the steering angle. The target yaw moment setting means determines that the steering angle (absolute value) decreases. The target yaw moment is set according to the value representing the turning state of the vehicle obtained based on the above, and the target yaw moment obtained by multiplying this target yaw moment by the gain according to the lateral acceleration is supplied to the control means The smaller the lateral acceleration, the smaller the gain.
In the present invention thus configured, processing for multiplying the target yaw moment obtained by this logic by the gain is performed without modifying the logic for setting the target yaw moment according to the value representing the turning state. By doing this, it is possible to apply an appropriate yaw moment to the vehicle according to the lateral acceleration.

In the present invention, preferably, the value representing the turning state is a steering speed calculated based on the steering angle.
According to the present invention configured as described above, a yaw moment having a magnitude corresponding to the speed of the driver's steering operation can be applied in the direction to suppress turning of the vehicle, and the vehicle can be quickly responsive to the driver's steering operation. The behavior can be stabilized.

In the present invention, preferably, the value representing the turning state is a change speed of the difference between the actual yaw rate actually occurring in the vehicle and the target yaw rate calculated based on the steering angle.
According to the present invention configured as described above, for example, when the steering wheel is operated on a low μ road such as a snowy road, the sudden change of the yaw rate difference caused by the response delay of the actual yaw rate is immediately performed. A yaw moment in a direction to suppress turning can be applied to the vehicle, and in a situation before the behavior of the vehicle becomes unstable, the behavior of the vehicle can be quickly stabilized according to the steering operation of the driver.

  According to the present invention, in the vehicle behavior control device that applies the yaw moment to the vehicle by controlling the braking means, by applying the yaw moment taking into consideration the magnitude of the lateral acceleration, the driver feels strong control intervention and discomfort Can be appropriately suppressed.

BRIEF DESCRIPTION OF THE DRAWINGS It is a block diagram which shows the whole structure of the vehicle carrying the behavior control apparatus of the vehicle by embodiment of this invention. FIG. 1 is a block diagram showing an electrical configuration of a vehicle behavior control device according to an embodiment of the present invention. It is a flowchart of the behavior control process which the behavior control apparatus of the vehicle by embodiment of this invention performs. It is a flowchart of an additional deceleration setting process in which the vehicle behavior control device according to the embodiment of the present invention sets an additional deceleration. It is the map which showed the relationship between steering speed and the addition deceleration. It is a flowchart of an additional deceleration setting process in which the vehicle behavior control device according to the embodiment of the present invention sets a target yaw moment. It is the map which specified the gain used in order to set up target yaw moment in an embodiment of the present invention. It is a time chart which shows the time change of the various parameters in connection with behavior control when making the vehicle carrying the behavior control device of the vehicle by the embodiment of the present invention turn.

  Hereinafter, a behavior control device for a vehicle according to an embodiment of the present invention will be described with reference to the accompanying drawings.

  First, a vehicle equipped with the behavior control device for a vehicle according to the embodiment of the present invention will be described with reference to FIG. FIG. 1 is a block diagram showing an overall configuration of a vehicle equipped with a vehicle behavior control device according to an embodiment of the present invention.

  In FIG. 1, the code | symbol 1 shows the vehicle carrying the behavior control apparatus of the vehicle by this embodiment. A drive control system 4 for driving the drive wheels 2 (the front wheels on the left and right in the example of FIG. 1) is mounted on the front portion of the vehicle body of the vehicle 1. As the drive control system 4, an internal combustion engine such as a gasoline engine or a diesel engine or a motor can be used. Although the details will be described later, at least a part of the drive control system 4 functions as a drive unit and a drive control unit.

  The vehicle 1 also includes a steering angle sensor (steering angle detection means) 8 that detects a steering angle as a rotation angle of a steering column (not shown) connected to the steering wheel 6, a vehicle speed sensor 10 that detects a vehicle speed, and a yaw rate The yaw rate sensor 12 detects the Each of these sensors outputs the detection value of each to PCM14 (Power-train Control Module).

In addition, the vehicle 1 is provided with a brake control system 18 that supplies a brake fluid pressure to the wheel cylinders and brake calipers of the brake device 16 provided on each wheel. The brake control system 18 calculates the hydraulic pressure supplied independently to each of the wheel cylinder and the brake caliper of each wheel based on the yaw moment command value input from the PCM 14, and controls the pump according to the hydraulic pressure. Do. The brake control system 18 stores in advance a control map that defines in accordance with the yaw moment command value how much the hydraulic pressure of the brake device 16 for each wheel is to be increased when the yaw moment command value is input. . The brake control system 18 refers to the control map when the yaw moment command value is input from the PCM 14, and the hydraulic pressure supplied independently to each of the brake devices 16 for each wheel increases according to the yaw moment command value. Control the pump to do so.
At least a part of the brake control system 18 functions as a braking means and a control means in the present invention.

Next, the electrical configuration of the vehicle behavior control device according to the embodiment of the present invention will be described with reference to FIG. FIG. 2 is a block diagram showing an electrical configuration of the vehicle behavior control device according to the embodiment of the present invention.
The PCM 14 is a component (for example, a throttle valve, a turbocharger, or the like) of the drive control system 4 based on detection signals of the above-described sensors and detection signals output from various sensors that detect the operating state of the drive A control signal is output to control the variable valve mechanism, the igniter, the fuel injection valve, the EGR device, the remaining amount of battery, and the like.

The PCM 14 sets an additional deceleration setting unit 20 that sets an additional deceleration to be added to the vehicle 1 in relation to a change in steering angle, and sets a target yaw moment to be applied to the vehicle 1 in relation to a change in steering angle. And a yaw moment setting unit 22.
Each component of the PCM 14 includes a CPU, various programs to be interpreted and executed on the CPU (including a basic control program such as an OS, and an application program activated on the OS to realize a specific function), and It is comprised by the computer provided with internal memories, such as ROM for storing various data, and RAM.
Although the details will be described later, the PCM 14 corresponds to the behavior control device of the vehicle in the present invention, and functions as a lateral acceleration detection means, a target yaw moment setting means and a control means.

Next, the process which the behavior control apparatus of a vehicle performs is demonstrated using FIGS. 3-6.
FIG. 3 is a flow chart of behavior control processing executed by the vehicle behavior control apparatus according to the embodiment of the present invention, and FIG. 4 is an addition reduction for setting the additional deceleration by the vehicle behavior control apparatus according to the embodiment of the present invention FIG. 5 is a flow chart of the speed setting process, and FIG. 5 is a map showing the relationship between the steering speed and the addition deceleration degree. FIG. 6 is a diagram showing that the vehicle behavior control device according to the embodiment of the present invention sets a target yaw moment It is a flowchart of an additional deceleration setting process. The map shown in FIG. 5 is prepared in advance and stored in a memory or the like.

The behavior control process of FIG. 3 is started when the ignition of the vehicle 1 is turned on and the vehicle behavior control device is powered on, and is repeatedly executed in a predetermined cycle (for example, 50 ms).
When the behavior control process is started, as shown in FIG. 3, the PCM 14 acquires various information of the vehicle 1 in step S1. Specifically, the PCM 14 acquires detection signals output from the various sensors described above, including the steering angle detected by the steering angle sensor 8, the vehicle speed detected by the vehicle speed sensor 10, the yaw rate detected by the yaw rate sensor 12, and the like.

Next, in step S 2, the additional deceleration setting unit 20 of the PCM 14 executes an additional deceleration setting process to set an additional deceleration to be added to the vehicle 1.
Subsequently, in step S3, the yaw moment setting unit 22 of the PCM 14 executes target yaw moment setting processing to set a target yaw moment to be applied to the vehicle 1.

  Next, in step S4, the drive control system 4 applies an actuator (a fuel injection device of an engine, an igniter, an intake / exhaust system, a motor, etc.) to add the additional deceleration set in step S2 to the vehicle 1. Control. Specifically, the drive control system 4 reduces the output torque of the engine or motor so as to apply the set additional deceleration to the vehicle 1.

  Further, in step S4, the brake control system 18 controls an actuator (such as a pump) to apply the target yaw moment set in step S3 to the vehicle 1. For example, the brake control system 18 stores in advance a map that defines the relationship between the yaw moment command value and the rotational speed of the pump, and is set in the target yaw moment setting process of step S3 by referring to this map. The pump is operated at the rotation speed corresponding to the yaw moment command value, and the valve units provided in the hydraulic pressure supply line to the brake device 16 of each wheel are individually controlled to adjust the braking force of each wheel.

  After the step S4 described above, the PCM 14 ends the behavior control process.

Next, the additional deceleration setting process will be described with reference to FIG.
As shown in FIG. 4, when the additional deceleration setting process is started, in step S11, the additional deceleration setting unit 20 calculates the steering speed based on the steering angle acquired in step S1 of the behavior control process of FIG. Do.

Next, in step S12, additional deceleration setting unit 20, whether during turning operation of the steering wheel 6 (i.e. the steering angle (absolute value) in the increase) of and the steering speed is a predetermined threshold value S ₁ or more judge.
As a result, when the operation in and steering speed cut is the threshold value S ₁ or more, the process proceeds to step S13, additional deceleration setting unit 20 sets the deceleration with based on the steering speed. The additional deceleration is a deceleration that should be added to the vehicle 1 in response to the steering operation in order to accurately realize the vehicle behavior intended by the driver.

Specifically, the additional deceleration setting unit 20 sets the additional deceleration corresponding to the steering speed calculated in step S11 based on the relationship between the steering speed and the additional deceleration shown in the map of FIG.
The horizontal axis in FIG. 5 indicates the steering speed, and the vertical axis indicates the additional deceleration. As shown in FIG. 5, when the steering speed is less than the threshold value S _1, the additional deceleration corresponding zero. That is, when the steering speed is less than the threshold value S _1, PCM 14 does not perform the control for adding the deceleration of the vehicle 1 based on the steering operation (specifically, reduction of the output torque of the engine or motor).
On the other hand, when the steering speed is equal to or higher than the threshold value S ₁ , the additional deceleration corresponding to the steering speed gradually _{approaches the} predetermined upper limit value D _max as the steering speed increases. That is, the additional deceleration increases as the steering speed increases, and the rate of increase in the amount of increase decreases. The upper limit value D _max is set to such a degree that the driver does not feel that there is control intervention even if the vehicle 1 is decelerated according to the steering operation (for example, 0.5 m / s ² 0 0 .05G).
Further, when the steering speed is high threshold S ₂ or more than the threshold S _1, the additional deceleration is maintained at the upper limit value D _max.
After step S13, the additional deceleration setting unit 20 ends the additional deceleration setting process and returns to the main routine.

Also, not in turning operation of the steering wheel 6 in step S12 (i.e. in constant or decreasing steering angle) or, if the steering speed is less than the threshold value S _1, the additional deceleration setting unit 20 adds the deceleration setting process Exit and return to the main routine.

  The drive control system 4 reduces the output torque of the engine or motor in step S4 of the behavior control process of FIG. 3 so as to realize the additional deceleration set based on the increase speed of the steering angle in the above-mentioned additional deceleration setting process. Let As described above, when the steering wheel 6 is cut, the vertical load of the front wheel 2 is increased by reducing the output torque of the engine or motor based on the steering speed, which is favorable for the driver's cutting operation. The behavior of the vehicle 1 can be controlled with various responsiveness.

Next, the target yaw moment setting process will be described with reference to FIG.
As shown in FIG. 6, when the target yaw moment setting process is started, in step S21, the yaw moment setting unit 22 determines the target yaw rate and the vehicle speed based on the steering angle and the vehicle speed acquired in step S1 of the behavior control process of FIG. Calculate the target cross jerk.
Specifically, the yaw moment setting unit 22 calculates the target yaw rate by multiplying the steering angle by a coefficient according to the vehicle speed. Further, the yaw moment setting unit 22 calculates a target lateral acceleration from the target yaw rate and the vehicle speed, and calculates the target lateral jerk by differentiating the target lateral acceleration in time.

  Next, in step S22, the yaw moment setting unit 22 determines the difference between the yaw rate (actual yaw rate) detected by the yaw rate sensor 12 acquired in step S1 of the behavior control process of FIG. 3 and the target yaw rate calculated in step S21 (yaw rate Difference) Calculate Δγ.

  Next, in step S23, the yaw moment setting unit 22 sets the gain used to set the target yaw moment based on the lateral acceleration of the vehicle. In this case, the yaw moment setting unit 22 uses, for example, the lateral acceleration calculated based on the vehicle speed detected by the vehicle speed sensor 10 and the yaw rate detected by the yaw rate sensor 12 or the like. The setting of the gain will be specifically described with reference to FIG.

  FIG. 7 is a map defining the gains used to set the target yaw moment in the embodiment of the present invention. This map is prepared in advance and stored in a memory or the like. In FIG. 7, the horizontal axis indicates the lateral acceleration, and the vertical axis indicates the gain. The gain is set to a value corresponding to the lateral acceleration, and is used to multiply the target yaw moment calculated by the method described later. That is, the value obtained by multiplying the gain is used as the target yaw moment to be finally applied.

  As shown in FIG. 7, the gain decreases as the lateral acceleration decreases. In other words, as the lateral acceleration increases, the gain increases. According to such a gain, the target yaw moment decreases as the lateral acceleration decreases. In other words, the target yaw moment increases as the lateral acceleration increases. By this, when the lateral acceleration is large, the control effect of applying the yaw moment to the vehicle 1 can be appropriately secured, while when the lateral acceleration is small, the control of applying the yaw moment to the vehicle 1 It is possible to appropriately suppress giving the driver a feeling of strangeness, specifically, a strong sense of control intervention.

  The yaw moment setting unit 22 reads the map stored in the memory as shown in FIG. 7 and acquires the gain corresponding to the lateral acceleration. Specifically, when the yaw moment setting unit 22 starts the control to apply the yaw moment to the vehicle 1, typically when the steering angle starts to decrease (that is, the steering wheel 6 is turned back) The gain is set from the lateral acceleration at the start), and this gain is used continuously in setting the target yaw moment. That is, when performing control to apply the yaw moment to the vehicle 1, the yaw moment setting unit 22 does not change the gain according to the change of the lateral acceleration during control, but the gain according to the lateral acceleration at the start of control. Be used consistently throughout the control. By doing this, the gain to be applied during the control for applying the yaw moment to the vehicle 1 fluctuates, and the control is prevented from becoming unstable.

Returning to FIG. 6, the description of the processes after step S24 is resumed. In step S24, the yaw moment setting unit 22 is in the process of turning back the steering wheel 6 (ie, the steering angle (absolute value) is decreasing), and the yaw rate difference obtained by time differentiating the yaw rate difference Δγ It is determined whether the rate of change Δγ ′ is equal to or greater than a predetermined threshold Y ₁ .
As a result, when the switching back operation is performed and the change rate Δγ ′ of the yaw rate difference is equal to or more than the threshold Y ₁ , the process proceeds to step S25, and the yaw moment setting unit 22 sets the change rate Δγ ′ of the yaw rate difference in step S23. Based on the gain, a yaw moment reverse to the actual yaw rate of the vehicle 1 is set as the target yaw moment. Specifically, the yaw moment setting unit 22 multiplies the change rate Δγ ′ of the yaw rate difference by a predetermined coefficient C _m1 to calculate the magnitude of the target yaw moment serving as a reference, and the target yaw moment serving as the reference is Is multiplied by the gain to calculate the magnitude of the target yaw moment to be applied to the vehicle 1.

On the other hand, if the steering wheel 6 is not turned back at step S24 (i.e., the steering angle is constant or increasing), the process proceeds to step S26 and the yaw moment setting unit 22 determines that the change rate .DELTA..gamma. It is determined whether the actual yaw rate is larger than the target yaw rate (ie, the direction in which the behavior of the vehicle 1 is oversteered) and the change rate Δγ ′ of the yaw rate difference is equal to or greater than the threshold Y ₁ . Specifically, the yaw moment setting unit 22 increases the yaw rate difference when the target yaw rate is smaller than the actual yaw rate or when the target yaw rate is smaller than the actual yaw rate. When it is determined, the change rate Δγ ′ of the yaw rate difference is determined to be in the direction in which the actual yaw rate becomes larger than the target yaw rate.

As a result, when the change rate Δγ ′ of the yaw rate difference is such that the actual yaw rate becomes larger than the target yaw rate and the change rate Δγ ′ of the yaw rate difference is the threshold Y ₁ or more, the process proceeds to step S25 and the yaw moment setting unit 22 In the same manner as described above, based on the change rate Δγ ′ of the yaw rate difference and the gain set in step S23, the yaw moment reverse to the actual yaw rate of the vehicle 1 is set as the target yaw moment.

After step S25, or if the change rate Δγ in the yaw rate difference 'change rate Δγ if yaw rate difference actual yaw rate is not larger direction than the target yaw rate' is less than the threshold value Y ₁ at step S26, the process proceeds to step S27 , yaw moment setting unit 22 is a switch-back during operation of the steering wheel 6 (i.e. the steering angle (in absolute value) is decreased), and the steering speed is determined whether a predetermined threshold S ₃ or more .

As a result, if and steering speed in the switch-back is the threshold value S ₃ or more, the process proceeds to step S28, yaw moment setting unit 22, on the basis the target lateral jerk calculated in step S21, the gain set in step S23, A yaw moment reverse to the actual yaw rate of the vehicle 1 is set as a second target yaw moment.
Specifically, the yaw moment setting unit 22 multiplies the target transverse jerk by a predetermined coefficient C _m2 to calculate the magnitude of a second target yaw moment as a reference, and the second target as the reference. By further multiplying the yaw moment by the gain, the magnitude of the second target yaw moment to be applied to the vehicle 1 is calculated.

After step S28, or, if cut is not being returning operation (i.e. the steering angle is in constant or increased) or steering speed of the steering wheel 6 is less than the threshold value S ₃ in step S27, the process proceeds to step S29, yaw The moment setting unit 22 sets the larger one of the target yaw moment set in step S25 and the second target yaw moment set in step S28 as the yaw moment command value.
After step S29, the yaw moment setting unit 22 ends the target yaw moment setting process, and returns to the main routine.

  Next, with reference to FIG. 8, the operation of the vehicle behavior control device according to the embodiment of the present invention will be described. FIG. 8 is a time chart showing temporal changes in various parameters related to behavior control when the vehicle 1 equipped with the behavior control device for a vehicle according to the embodiment of the present invention is cornered.

  In FIG. 8, chart (a) shows the steering angle, chart (b) shows lateral acceleration, chart (c) shows lateral jerk, and chart (d) the gain used to set the target yaw moment. And the chart (e) shows the target yaw moment (corresponding to the yaw moment command value input from the PCM 14 to the brake control system 18). In the charts (b) to (e), solid lines indicate various parameters when the lateral acceleration is relatively large, and broken lines indicate various parameters when the lateral acceleration is relatively small.

As shown in FIG. 8, when the steering operation is switched from the turning operation to the switching back operation (see chart (a)), the target yaw moment starts to change at time t1 (see chart (e)). That is, at time t1, a target yaw moment for controlling the behavior of the vehicle is set, and control to apply the yaw moment to the vehicle 1 is started. In a typical example, a steering operation switching back operation, and, in condition that the steering speed is the threshold value S ₃ or more is satisfied (step of FIG. 6 S27: Yes), the yaw moment setting unit 22, the target A (second) target yaw moment is set based on the lateral jerk (step S28 in FIG. 6).

  In the present embodiment, as shown in chart (d), a gain corresponding to the magnitude of the lateral acceleration is set, and as shown in chart (e), a target yaw moment to which such a gain is applied is set. Ru. As described above, the gain according to the magnitude of the lateral acceleration at the start of the control for applying the yaw moment (that is, at time t1) is consistently applied in the setting of the target yaw moment during the control (in other words, Then, the gain once set is fixed and not changed during control to apply the yaw moment). More specifically, as shown by the solid and broken lines in charts (d) and (e), when the lateral acceleration is small, a gain having a smaller value is set than in the case where the lateral acceleration is large, and thus smaller. A target yaw moment (absolute value) having a value is set.

  Thereafter, when the turning back operation of the steering wheel 6 ends (see chart (a)), at time t2, the target yaw moment is set to 0, and the control of applying the yaw moment to the vehicle 1 is ended.

  Next, the effects of the vehicle behavior control device according to the embodiment of the present invention will be described.

  According to the present embodiment, when the yaw moment reverse to the yaw rate generated in the vehicle 1 is set as the target yaw moment and the brake device 16 is controlled to apply the target yaw moment to the vehicle 1. The smaller the lateral acceleration of the vehicle 1, the smaller the target yaw moment. As a result, when the lateral acceleration is small, it is possible to appropriately suppress giving the driver a sense of discomfort, specifically a strong sense of control intervention, by the control of applying the yaw moment to the vehicle 1. On the other hand, when the lateral acceleration is large, the control effect of applying the yaw moment to the vehicle 1 can be appropriately secured.

  In addition, not only lateral acceleration but also yaw rate occurs in the vehicle 1 while turning, but the driver is particularly easy to sense lateral acceleration, so it is better to perform behavior control considering the magnitude of lateral acceleration as described above. is there. That is, although it is preferable to perform behavior control in consideration of the magnitude of the yaw rate, it is more preferable to perform behavior control in consideration of the magnitude of the lateral acceleration than to perform behavior control in consideration of the magnitude of the yaw rate. It is effective.

  Further, according to the present embodiment, the target yaw moment is set by continuously using the lateral acceleration acquired when the control for applying the yaw moment to the vehicle 1 is started. As a result, it is possible to suppress the control from becoming unstable by changing the target yaw moment at any time according to the lateral acceleration during the control for applying the yaw moment.

  Further, according to the present embodiment, a target yaw moment is set according to a value (a yaw rate, a steering speed, a lateral acceleration, a lateral jerk, etc.) representing a turning state of the vehicle obtained based on a steering angle. On the other hand, the target yaw moment obtained by multiplying the gain according to the lateral acceleration is used. Thus, according to the lateral acceleration, the target yaw moment obtained by this logic is simply multiplied by the gain without correcting the logic for setting the target yaw moment according to the value representing the turning state. It is possible to apply an appropriate yaw moment to the vehicle 1.

  Further, according to the present embodiment, the steering speed calculated based on the steering angle can be used as a value representing the turning state. Thus, a yaw moment having a magnitude corresponding to the speed of the driver's steering operation can be applied in the direction to suppress turning of the vehicle 1, and the vehicle behavior can be quickly stabilized according to the driver's steering operation. .

  Further, according to the present embodiment, the change speed of the difference between the actual yaw rate actually occurring in the vehicle 1 and the target yaw rate calculated based on the steering angle can be used as a value representing the turning state. Thus, for example, when the steering wheel is operated on a low μ road such as a snowy road, the yaw moment in the direction to suppress turning immediately according to the rapid change of the yaw rate difference caused by the response delay of the actual yaw rate In the situation before the behavior of the vehicle 1 becomes unstable, the vehicle behavior can be rapidly stabilized according to the steering operation of the driver.

  Next, a modification of the present embodiment will be described.

  In the embodiment described above, the gain corresponding to the lateral acceleration is applied in both the setting of the target yaw moment in step S25 of FIG. 6 and the setting of the target yaw moment in step S28 of FIG. That is, in both of the case where the target yaw moment is set according to the change speed of the difference between the actual yaw rate and the target yaw rate, and the case where the target yaw moment is set according to the target lateral jerk (corresponding to the steering speed), The gain according to the acceleration was applied. In another example, the gain according to the lateral acceleration may be applied only when the target yaw moment is set according to the target lateral jerk without applying the gain in both of these cases. In the configuration in which a yaw moment according to the lateral jerk is applied to the vehicle 1, the lateral jerk may become large even when the lateral acceleration is small, in which case the yaw moment becomes large, giving the driver a strong sense of control intervention. It will be. Therefore, by applying a gain corresponding to the lateral acceleration to a configuration that applies a yaw moment particularly to the lateral jerk, it is possible to effectively suppress a strong sense of control of the control to apply the yaw moment to the vehicle 1. is there.

  In the above embodiment, it has been described that the rotation angle of the steering column connected to the steering wheel 6 is used as the steering angle, but various states in the steering system may be used instead of the rotation angle of the steering column or together with the rotation angle of the steering column An amount (a rotation angle of a motor for applying assist torque, a displacement of a rack in a rack and pinion, etc.) may be used as the steering angle.

1 Vehicle 2 Drive Wheel (Front Wheel)
4 drive control system 6 steering wheel 8 steering angle sensor 10 vehicle speed sensor 12 yaw rate sensor 14 PCM
16 brake device 18 brake control system 20 additional deceleration setting unit 22 yaw moment setting unit

In order to achieve the above object, the vehicle behavior control device is provided with braking means capable of applying different braking forces to left and right wheels, and corresponds to a steering wheel operated by a driver and operation of the steering wheel. Occurs in the vehicle when the steering wheel turn-back operation is determined based on the steering angle detection means for detecting the steering angle, the lateral acceleration detection means for detecting the lateral acceleration, and the steering angle detected by the steering angle detection means Target yaw moment setting means for setting a yaw moment reverse to the current yaw rate as a target yaw moment to be applied to the vehicle; control means for controlling the braking means to apply the target yaw moment to the vehicle; The target yaw moment setting means reduces the target yaw moment as the lateral acceleration decreases. And butterflies.
In the present invention configured as described above, when a yaw moment reverse to the yaw rate generated in the vehicle is set as a target yaw moment, and the braking means is controlled to apply the target yaw moment to the vehicle. The smaller the lateral acceleration of the vehicle, the smaller the target yaw moment. As a result, when the lateral acceleration is small, it is possible to appropriately suppress the driver from feeling uncomfortable due to the control of applying the yaw moment to the vehicle, specifically, giving the driver a strong sense of control intervention. On the other hand, when the lateral acceleration is large, the control effect of applying the yaw moment to the vehicle can be appropriately secured.

Claims (5)

A vehicle behavior control device comprising braking means capable of applying different braking forces to left and right wheels.
Steering angle detection means for detecting a steering angle;
Lateral acceleration detection means for detecting lateral acceleration;
Target yaw moment setting means for setting, as a target yaw moment to be applied to the vehicle, a yaw moment reverse to the yaw rate generated in the vehicle, based on the steering angle;
Control means for controlling the braking means to apply the target yaw moment to the vehicle;
Have
The target yaw moment setting means reduces the target yaw moment as the lateral acceleration decreases.   The target yaw moment setting means sets the target yaw moment using the lateral acceleration continuously obtained by the lateral acceleration detecting means when starting control by the control means. Vehicle behavior control device. The target yaw moment setting means sets the target yaw moment according to a value representing the turning state of the vehicle obtained based on the steering angle when the steering angle is decreasing, and the target yaw moment is set for the target yaw moment. A target yaw moment obtained by multiplying a gain corresponding to the lateral acceleration is supplied to the control means;
The vehicle behavior control device according to claim 1, wherein the gain is smaller as the lateral acceleration is smaller.   The vehicle behavior control device according to claim 3, wherein the value representing the turning state is a steering speed calculated based on the steering angle.   The vehicle behavior control according to claim 3 or 4, wherein the value representing the turning state is a change speed of a difference between an actual yaw rate actually occurring in the vehicle and a target yaw rate calculated based on the steering angle. apparatus.

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