WO2011070645A1

WO2011070645A1 - Behavior control device for sway suppression of combination vehicle

Info

Publication number: WO2011070645A1
Application number: PCT/JP2009/070501
Authority: WO
Inventors: 梶田尚志; 井上玄
Original assignee: トヨタ自動車株式会社
Priority date: 2009-12-07
Filing date: 2009-12-07
Publication date: 2011-06-16

Abstract

Provided is a behavior control device for sway suppression of a combination vehicle including a tractor and a trailer configured in such a manner that some degree of sway suppression effect can be ensured within a range where operation of an operator is not influenced unduly even if rolling of the vehicle body caused by surface disturbance or the like and sway state of the trailer cannot be determined easily. A behavior control device carries out behavior control for sway suppression with a low amount of control even if a determination is not made that the possibility of occurrence of sway state in the trailer of a combination vehicle is high from the relationship between the amount of vibration state in the yaw rate of the tractor and the lateral acceleration of the tractor or the amount of vibration state in the body slip angular speed.

Description

Behavior control device for sway control of articulated vehicles

The present invention relates to behavior control of a vehicle such as an automobile. More specifically, the present invention relates to suppression of a sway state (also referred to as snake motion or trailer pendulum motion) in a coupled vehicle in which a tractor pulls a trailer. Further, the present invention relates to a behavior control device for stabilizing vehicle behavior.

In a connected vehicle of the full trailer or semi-trailer type, generally, a trailer to be pulled by a tractor is pivotally connected by a pin or a coupler provided at a rear portion of the tractor. During travel of this type of connected vehicle, the trailer “sway”, i.e. the trailer against the tractor, due to various factors such as sudden steering, excessive vehicle speed, crosswind or imbalance in load distribution, etc. Thus, a state of swinging or vibrating in the yaw direction around the pin or coupler (pivot axis) may be caused (see FIG. 2A). When such a trailer sway state occurs, the tractor also vibrates in the yaw direction, and the vehicle behavior becomes unstable. Therefore, various vehicle behavior stabilization control devices for suppressing such a sway state have been proposed and put into practical use. For example, in Patent Document 1, when the connecting angle (hitch angle) between the tractor and the trailer reaches a predetermined angle, the trailer brake is operated, and thereby the hitch angle is reduced in the trailer by the braking force of the trailer. A control device that generates a yaw moment in a direction is disclosed. Further, Patent Document 2 detects the occurrence of the sway state by monitoring whether the yaw rate of the frequency band in the sway state, the lateral acceleration of the vehicle has reached a predetermined value, and It discloses that the sway state is suppressed by generating a yaw moment having a phase opposite to the phase of the yaw rate and / or the lateral acceleration by the braking force distribution control. Further, in Patent Document 3, in the stabilization control for suppressing the sway state, the sway state is evaluated by the deviation between the yaw rate detected by the tractor when the trailer is pulled and the yaw rate based on the vehicle model. In addition, it is proposed that when the yaw rate deviation, the lateral frequency deviation and the phase deviation are large, the identification that the sway state has occurred is prohibited, and the running stabilization control is not performed.
JP-A-10-236289 International Publication 2001/002227 International Publication 2004/041612

When the sway state is detected, the behavior control device for suppressing the sway state of the connected vehicle as described above automatically executes behavior control such as deceleration of the vehicle by generation of braking force and generation of anti-yaw moment. To do. Therefore, in order to avoid unnecessarily executing the application of braking force unrelated to the driving operation of the driver, it is preferable to improve the accuracy of detection of the sway state as much as possible. In this regard, the detection of the sway state usually involves increasing the amplitude of the component of the sway vibration band of the physical characteristic value that reflects the magnitude and frequency of the vehicle shake such as the yaw rate and lateral acceleration accompanying the increase of the sway vibration. It is done by detecting. However, the increase in the amplitude of the component of the sway vibration band may occur even when the vehicle body only shakes due to road disturbance, that is, the road surface is rough, in which case the sway vibration is not increased. Regardless, there is a case where deceleration of the vehicle or generation of an anti-yaw moment due to application of braking force is executed. Therefore, in the past, in order to avoid unnecessary or premature start of the operation of the sway state suppression control, measures such as increasing the yaw rate or the lateral acceleration amplitude threshold for determining the occurrence of the sway state have been taken. (Naturally, in such a case, the start of the sway state suppression control operation may be delayed.) When the sway condition occurs, the vibration state of the yaw rate (vibration frequency, frequency, period, etc.) and the vibration state of the lateral acceleration or the vehicle body slip angular velocity are substantially the same. When this occurs, it is found that the vibration state of the yaw rate is different from the vibration state of the lateral acceleration or the vehicle body slip angular velocity. Based on this knowledge, the vibration state of the yaw rate and the lateral acceleration or the vehicle body slip angular velocity is compared. When it is determined that the possibility of occurrence of the sway state is low based on the result, a control method has been proposed that makes it difficult to decelerate the vehicle or apply an anti-yaw moment (for example, the international patent application PCT by the present applicant). / JP2000 / 67500).

However, a sway condition may also occur when a vehicle body shake due to road surface disturbance or the like occurs. When the contribution of the vehicle body vibration due to road surface disturbance or the like is relatively large, the sway vibration actually In spite of the occurrence of sway, it may be determined that the possibility of the occurrence of the sway state is low in the comparison result of the vibration state between the yaw rate and the lateral acceleration or the vehicle body slip angular velocity. Therefore, it is determined that the possibility of occurrence of the sway state is low based on the difference between the vibration state of the yaw rate and the vibration state of the lateral acceleration or the vehicle body slip angular velocity, and the vehicle deceleration or anti-yaw moment for suppressing the sway state is determined. If it is difficult to apply the sway state, the sway state suppression control may be delayed when the vehicle body shake due to road disturbance or the like is large.

Thus, one object of the present invention is a behavior control device for suppressing the sway state of a connected vehicle, even when it is difficult to determine the body roll due to road surface disturbance or the like and the sway state of the trailer. An object of the present invention is to provide an apparatus configured to reduce the effect of delay in sway state suppression control.

Another object of the present invention is an apparatus as described above, which suppresses the sway state at least to some extent within a range that does not excessively affect the operation of the driver when the vehicle body rolls. It is providing the apparatus comprised so that an effect could be ensured.

According to the present invention, in order to achieve the above-described problem, a behavior control device that applies a braking force to at least one wheel in order to suppress a sway state of a connected vehicle including a tractor and a trailer pulled by the tractor. A device is provided in which the braking force applied to the at least one wheel is changed based on the relationship between the vibration state quantity of the tractor yaw rate and the vibration state quantity of the tractor lateral acceleration or the vehicle body slip angular velocity. . In this case, the control achieved by the braking force applied to at least one wheel is specifically the deceleration of the vehicle or the generation of a yaw moment (anti-yaw moment) in a direction to suppress the sway state. It may be. The braking force applied to the wheels may basically be the braking force applied by the braking device of each wheel, but a part of the decrease in the output of the vehicle drive device (reduction of the throttle opening of the engine, It should be understood that it may be generated by regenerative braking or the like. Further, the “vibration state quantity” may be an arbitrary index value representing the vibration speed of each physical quantity, for example, the frequency, frequency, period, etc. of vibration.

As already mentioned, the possibility of sway vibration of the trailer at the time when the amplitude of the component of the tractor yaw rate or lateral acceleration or vehicle body slip angular velocity in the frequency band of the sway vibration of the trailer is generated is fundamental. Specifically, it can be estimated by referring to the relationship between the vibration state of the yaw rate and the vibration state of the lateral acceleration or the vehicle body slip angular velocity. However, when the road surface disturbance is relatively large, the rolling of the vehicle body is strongly reflected in the relationship between the vibration state of the yaw rate and the vibration state of the lateral acceleration or the vehicle body slip angular velocity, and the presence / absence of sway vibration is highly accurate. Judgment becomes difficult. When it is determined that the possibility of occurrence of sway vibration is low based on the relationship between the vibration state of the yaw rate and the vibration state of the lateral acceleration or the vehicle body slip angular velocity, the behavior control is not performed or is difficult to be performed. If there is, a delay in the suppression effect may occur. On the other hand, it responds only to the increase in the amplitude of the tractor yaw rate or the lateral acceleration or the vehicle slip angular velocity component in the sway vibration frequency band without using the relationship between the yaw rate and the vibration state of the lateral acceleration (or vehicle slip angular velocity). Therefore, it is not preferable to perform behavior control for suppressing the sway state because excessive braking force can be applied independently of the driver's operation. Therefore, as described above, the behavior control apparatus of the present invention controls behavior control for sway state suppression based on the relationship between the vibration state quantity of the tractor yaw rate and the vibration state quantity of the tractor lateral acceleration or the vehicle body slip angular velocity. The amount of braking force applied to at least one wheel is changed, thereby avoiding excessive application of braking force due to behavior control for suppressing the sway state, and relatively preventing road disturbance and the like. Even when a sway state occurs when the value is large, an attempt is made to minimize the delay of the suppression effect.

In the above, as a more specific configuration for minimizing the delay in the suppression effect even when a sway condition occurs when the road surface disturbance or the like is relatively large, the apparatus of the present invention provides a vibration state quantity of the yaw rate. If the possibility of occurrence of a sway state is not determined to be high based on the relationship between the acceleration and the lateral acceleration or the vibration state quantity of the vehicle body slip angular velocity, than if it is determined that the possibility of occurrence of the sway state is high Alternatively, the behavior control for suppressing the sway state may be executed with a low control amount. That is, when the road surface disturbance is relatively large, and it is determined that the possibility of occurrence of the sway condition is indeterminate (previously, the possibility of occurrence of the sway condition is low). However, by executing the behavior control for suppressing the sway state with a certain control amount, the vehicle can be stabilized and the progress of the sway state can be suppressed.

As already described, when the vibration state of the yaw rate in the frequency band of the sway vibration of the trailer is substantially different from the vibration state of the lateral acceleration or the vehicle body slip angular velocity, the sway state is basically generated. (“Substantially different” means that there is a significant difference in the two vibrational state quantities, and “substantially equal” means two This means that there is no significant difference in the two vibrational state quantities.) Therefore, when the vibration state quantity of the tractor yaw rate component and the vibration state quantity of the tractor lateral acceleration or vehicle slip angular velocity component in the frequency band of the sway vibration of the trailer are substantially different, The behavior control may be executed with a lower control amount than when the two vibration state quantities are substantially equal. In that case, specifically, in the configuration in which the sway state is suppressed by generating an anti-yaw moment, the tractor yaw rate is attenuated by a low braking force, and the sway state is suppressed by deceleration of the vehicle. The vehicle is decelerated at a low target deceleration.

In the above-described embodiment of the present invention, the behavior control device is configured such that the tractor yaw rate or the lateral acceleration or the amplitude of the vehicle slip angular velocity component in the frequency band of the sway vibration of the trailer is greater than a predetermined value for a predetermined time. Means for applying a braking force to at least one wheel so that the target deceleration is achieved when continued, wherein the vibration state quantity of the tractor yaw rate and the vibration state quantity of the tractor lateral acceleration or vehicle body slip angular velocity are substantially When the vibration state quantity of the tractor yaw rate and the vibration state quantity of the tractor lateral acceleration or the vehicle body slip angular velocity are substantially equal, the braking force may be reduced. As a result, when the possibility of occurrence of the sway state is high, it is expected that the sway state is quickly suppressed by a relatively high braking force, while it is determined that the occurrence of the sway state is indeterminate. Even so, it is possible to ensure a certain degree of control effect for suppressing the sway state.

In addition, when performing the slip state suppression behavior control, in the form of setting the target deceleration and decelerating the vehicle, as one aspect, the behavior control device of the present invention includes the vibration state quantity of the tractor yaw rate. And the tractor lateral acceleration or the vehicle body slip angular velocity vibration state quantity are substantially equal, the vehicle is decelerated at the first target deceleration, and the tractor yaw rate vibration state quantity and the tractor lateral acceleration or vehicle body slip angular velocity When the vibration state quantity is substantially different, the vehicle may be configured to decelerate at a second target deceleration lower than the first target deceleration.

In the above configuration, whether the vibration state quantity of the yaw rate and the vibration state quantity of the lateral acceleration or the vehicle body slip angular velocity are substantially equal may be determined by a ratio or difference between the two vibration state quantities. As an example of the vibration state quantity, when the vibration period of the corresponding physical quantity is adopted, the change of the braking force applied to at least one wheel is determined by the vibration period of the tractor yaw rate and the lateral acceleration of the tractor or the vehicle body. It may be based on the ratio or difference between the slip angular velocity and the vibration period. Further, as another example of the vibration state quantity, when the number of vibrations (frequency of vibration) exceeding the predetermined magnitude in the predetermined time of the corresponding physical quantity is adopted, it is given to at least one wheel. The braking force may be changed based on the ratio or difference between the number of vibrations of the tractor yaw rate and the number of vibrations of the lateral acceleration of the tractor or the vehicle body slip angular velocity in a predetermined time. Typically, the vibration state quantity of the tractor yaw rate component in the trailer sway vibration frequency band and the vibration state quantity of the tractor lateral acceleration or vehicle slip angular velocity component in the trailer sway vibration frequency band When the ratio or difference between the two is not within a predetermined range (when the vibration state quantity of the tractor yaw rate is substantially different from the vibration state quantity of the tractor's lateral acceleration or vehicle body slip angular velocity), at least one of them is required for behavior control. When the braking force applied to one of the wheels is within the predetermined range (the tractor yaw rate vibration state quantity is substantially equal to the tractor lateral acceleration or the vehicle body slip angular speed vibration state quantity). It may be set lower than (when equal). Here, the “predetermined range” is determined that there is no significant difference in the vibration state quantity of the yaw rate and the lateral acceleration of the tractor or the vehicle body slip angular velocity if the difference or ratio of the vibration state quantity is within the range. Determined in scope. When it is determined that the possibility of occurrence of the sway state is uncertain, or when the vibration state quantity of the tractor yaw rate and the vibration state quantity of the tractor lateral acceleration or the vehicle body slip angular velocity are substantially different, Alternatively, the degree of behavior control (applying braking force) executed when the ratio or difference between the vibration state quantity of the yaw rate and the vibration state quantity of the component of the lateral acceleration or the vehicle body slip angular velocity is not within a predetermined range is, for example, It may be the extent that the brake lamp of the vehicle does not light up. This is to prevent the driver of another vehicle behind the vehicle from being surprised by the lighting of the brake lamp accompanying the behavior control executed when it is determined that the possibility of occurrence of the sway state is low. It is.

Thus, according to the above-described apparatus of the present invention, the control amount in the behavior control for suppressing the sway state is changed with reference to the relationship between the vibration state of the yaw rate and the vibration state of the lateral acceleration or the vehicle body slip angular velocity. Therefore, even when it is difficult to determine the rolling of the vehicle body and the sway state of the trailer due to road disturbance etc., excessive execution of braking force application independent of the driver's operation and start of control Both the delay and the delay can be reduced. In the configuration of the present invention described above, when a state where the amplitude of the component of the yaw rate or the lateral acceleration or the vehicle body slip angular velocity in the frequency band of the sway vibration of the trailer is larger than a predetermined value continues for a predetermined time, Even if it is not determined that the possibility of the occurrence of the sway state is high from the relationship of the vibration state quantity, the behavior control is not stopped completely, but the behavior is controlled by a certain control quantity. Since it is possible to execute the control, it is possible to secure the sway state suppression effect at least in a range where the driver's operation is not excessively affected, and the sway state suppression control is excessive or premature. It is expected that the delay in starting the control due to measures for avoiding the execution will be eliminated, and the behavior stability and safety of the connected vehicle will be improved. Further, according to the apparatus of the present invention, the sway state suppression control is used for the operation of the normal behavior control apparatus without using a dedicated sensor means (for example, a sensor for detecting the hitch angle of the connecting pin). This is advantageous in that the increase in cost can be suppressed because it can be executed using the parameters detected from the sensor group.

Other objects and advantages of the present invention will be in part apparent and pointed out below.

FIG. 1A is a schematic side view of a vehicle on which a behavior control device for suppressing a sway state, which is a preferred embodiment of the present invention, is mounted. FIG. 1B is a schematic plan view of the vehicle showing the signal flow of the vehicle braking system and the electronic control unit that controls the braking system. FIG. 1C shows the internal configuration of a device that executes sway state suppression behavior control, which is a preferred embodiment of the present invention, in the form of a control block. FIG. 2A is a schematic plan view of an example of a vehicle when a sway state occurs. FIG. 2 (B) shows the time change (a) of the yaw rate and the lateral acceleration in the frequency band of the sway vibration when the sway state occurs, the time change (b) of the yaw rate vibration period and the lateral acceleration vibration period, FIG. 2C shows the change (c) in the cumulative number of vibrations exceeding the predetermined threshold value of the lateral acceleration. FIG. 2C shows the yaw rate and lateral force in the frequency band of the sway vibration when the vehicle body rolls due to road disturbance or the like. These are the time variation of acceleration (a), the time variation of the vibration cycle of the yaw rate and the vibration cycle of the lateral acceleration (b), and the change of the cumulative number of vibrations exceeding the predetermined threshold values of the yaw rate and lateral acceleration (c). FIGS. 3A, 3B, and 3C are phase diagrams showing a state in which the probability of occurrence of the sway state is high with the vibration state quantity of the yaw rate and the vibration state quantity of the lateral acceleration as variables. In the drawing, since the probability of occurrence of the sway state is high in the hatched region, behavior control for suppressing the sway state is executed when the amplitude of the yaw rate or the lateral angle is large. On the other hand, outside the shaded area, the contribution of the body shake due to road disturbances is high, but since the occurrence of the sway state cannot be completely denied, behavior control can be performed with a lower control amount than when the state is in the shaded area. Executed. FIG. 4A shows the target deceleration G _A (when the possibility of occurrence of the sway state is high) and G _B (when the occurrence of the sway state is uncertain) in the form of suppressing the sway state by deceleration of the vehicle. It is a figure showing the time change of). FIG. 4B shows the target anti-yaw moment Y _A (when the possibility of occurrence of the sway state is high) and Y _B (when the occurrence of the sway state is uncertain) in the form of suppressing the sway state by the generation of the anti-yaw moment. It is a figure showing a time change when it is.

DESCRIPTION OF SYMBOLS 10 ... Vehicle 10a ... Tractor 10b ... Trailer 12fl, fr ... Tractor front wheel 12rl, rr ... Tractor rear wheel 12tl, tr ... Trailer wheel 14a ... Connecting pin 30bl, br, btl, btr ... Brake lamp 40 ... Braking system device 42fl, fr , Rl, rr ... wheel cylinder 42tl, tr ... trailer wheel braking device 44 ... brake pedal 45 ... brake valve or master cylinder 46 ... fluid pressure circuit (tractor)
46t ... brake device (trailer)
50 ... Electronic control device 60 ... Lateral acceleration / deceleration sensor, yaw rate sensor (tractor)

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. In the figure, the same reference numerals indicate the same parts.

Diagram of the apparatus. 1 (A) of the vehicle 10 to a preferred embodiment of a device for executing the behavior control for the suppression of swaying state of the combination vehicle according to the present invention is mounted schematically shown. The vehicle 10 is shown in the figure by, for example, a connected vehicle that pulls any type of trailer, that is, a tractor 10a having a pair of front wheels 12f and a pair of rear wheels 12r, and a connector 14a provided at the rear of the tractor 10a. And a trailer 10b having at least a pair of wheels 12t that are pivotably connected in the direction of the arrow. In the drawing, the vehicle is illustrated as a connected vehicle in which a passenger vehicle pulls a center axle type light trailer (such as a camping trailer, a cargo trailer, and a boat trailer) as an example. Can be applied to vehicles of any type of truck (which may be a full trailer type or a semi-trailer type), a bus, etc. It should be understood that such a case also belongs to the scope of the present invention.

The braking of each wheel of the tractor 10a of the connected vehicle 10 is performed by a braking system device 40 that can independently control the braking force of each wheel, as schematically shown in FIG. In short, the braking system device 40 is typically an electronically controlled pneumatic braking system device, an air / hydraulic (combined) braking system device or a hydraulic braking system device, and the front wheel of the tractor 10a. A fluid pressure circuit 46 is provided for adjusting the brake pressure in the wheel cylinders 42fl, fr, rl, rr equipped on the 12fl, fr and the rear wheels 12rl, rr, that is, the braking force of each wheel of the tractor. In the fluid pressure circuit 46 of the tractor 10a, the wheel cylinder of each wheel is selectively transferred to an air compressor, an air tank, a braking force booster, an oil pump, an oil reservoir, etc. (not shown) in a normal manner. Various valves (a modulator, a fluid pressure holding valve, a pressure reducing valve, etc.) that communicate with each other are provided, and in a normal braking operation, a brake valve (or master cylinder) 45 in response to the depression of the brake pedal 44 by the driver. , And the pressure of the air tank, the brake booster or the master cylinder is supplied to the respective wheel cylinders 42i (i = fl, fr, rl, rr, and so on), and the braking force is generated simultaneously for each wheel. However, in order to execute ABS control, motion control such as VSC, control for suppressing a sway state by the behavior control device of the present invention (sway suppression behavior control), or any other braking force distribution control, control of each wheel is performed. When the power is adjusted individually or independently, the various valves are operated based on the command of the electronic control unit 50 so that the brake pressure in the wheel cylinder of each wheel matches the target pressure. It is controlled individually. Brake lamps 30bl and br are provided at the rear of the tractor, and the ramps are provided with a predetermined deceleration when the brake pedal is depressed or when behavior control or other automatic braking force is applied. Lights when the value becomes larger than.

Optionally, a braking system device for braking each wheel of the trailer 10b may be provided. The brake system device of the trailer 10b may be an electromagnetic, inertial or fluid pressure type brake system device. For example, based on a command from the electronic control device 50, the brake lamps 30bl and br of the tractor are turned on / off. Correspondingly, the braking devices 42tl, tr equipped on the trailer wheels 12tl, tr are actuated so that a braking force is generated at each wheel (the braking force of each wheel can be selected selectively). It may be adjusted to (but not limited to).) It should be understood that the trailer 10b may not be equipped with a braking system, and such a case also belongs to the scope of the present invention. Brake lamps 30btl and btr are also provided behind the trailer and light up together with the brake lamps of the tractor.

The electronic control unit 50 may include a microcomputer having a CPU, a ROM, a RAM, and an input / output port unit connected to each other by a bidirectional common bus and a driving circuit. Brake pedal depression amount θb from a given depression amount sensor (not shown), wheel speed Vwi from a wheel speed sensor (not shown) provided for each wheel, and in the wheel cylinder of each wheel from a wheel cylinder pressure sensor The detected values such as the pressure Pbi, the lateral G sensor provided in the tractor, the lateral acceleration Gy from the yaw rate sensor 60, and the tractor yaw rate γ are input. In addition to what is illustrated, various detection signals representing various parameter values necessary for various controls to be executed in the vehicle of the present embodiment, such as longitudinal acceleration, may be input. (The brake pedal depression amount sensor and the wheel cylinder pressure sensor for each wheel may not be provided.)

FIG. 1C shows the sway state suppression behavior control device of the present invention incorporated in the electronic control device 50 in the form of a block diagram. Referring to the figure, in the sway state suppression behavior control device according to the present invention, in brief, the lateral acceleration Gy detected by the lateral G sensor and the yaw rate γ detected by the yaw rate sensor are respectively converted into the sway. The vibration state quantity (vibration state quantity calculation unit 50c) of the lateral acceleration Gy calculated from each of the components obtained by passing the signals through the bandpass filters (BPF) 50a and 50b that transmit signals in the vibration frequency band, and the yaw rate γ The vibration state quantity (vibration state quantity calculation unit 50d) is compared (comparison determination unit 50e), and based on the comparison result, the amplitude (amplitude detection unit 50f) detected from the component obtained by passing through the BPF 50b of the yaw rate γ. ) Is large, it is determined whether or not the possibility of occurrence of a sway state is high (see notes 1 and 2 below). When the possibility of occurrence of the sway state is determined to be high and the vehicle speed (which may be determined by an arbitrary method from the wheel speed value of each wheel. The vehicle speed determination unit 50g) exceeds the predetermined speed, the sway state Target deceleration (braking force) or anti-yaw moment (yaw moment generated in antiphase with respect to yaw rate vibration) is determined (sway suppression behavior control unit 50h), target deceleration or anti-yaw moment Therefore, the braking force distribution is determined (braking force control unit 50i), and a control command is given to each braking device 46.
(Note 1) The frequency range of sway vibration varies depending on the weight and arrangement of the load, vehicle speed, acceleration / deceleration, etc. (usually 0.1 to 2 Hz). Therefore, the transmission band of the BPF may be set so as to cover frequencies that may occur.
(Note 2) In detecting the occurrence of the sway state, a component of the vehicle body slip angular velocity β ′ may be used instead of the component of the lateral acceleration Gy. The vehicle body slip angular velocity β ′ is calculated by β ′ = Gy / V−γ.

On the other hand, when the amplitude of the yaw rate γ in the frequency band of the sway vibration is large, the vibration state quantity of the lateral acceleration Gy (or the vehicle body slip angular velocity β ′) output from the vibration state quantity calculation unit 50c and the vibration state quantity calculation unit 50d. When it is not determined that the possibility of occurrence of the sway state is high in the comparison result with the vibration state amount of the output yaw rate γ, the possibility of occurrence of the sway state is high in the sway suppression behavior control unit 50h. A control amount lower than the time, that is, a low target deceleration or a small anti-yaw moment is determined, and braking force distribution is determined to achieve the target deceleration or anti-yaw moment (braking force control unit 50i). A control command is given to the fluid pressure circuit 46.

In addition to the braking force distribution control described above, control for reducing the output of the drive device (engine, motor, etc.) may be executed for the purpose of decelerating the vehicle. In this case, when it is determined that the possibility of occurrence of the sway state is high, a signal is given from the sway suppression behavior control unit 50h to the driving force control 50j, and an instruction to reduce the output of the driving device is given. On the other hand, when it is not determined that the possibility of occurrence of the sway state is high, the output reduction of the driving device is not executed.

It should be understood that the above-described units 50a to 50j are realized by processing operations of the CPU and other elements in accordance with a program stored in advance in a storage device such as a memory in the electronic control unit 50. .

FIG. 2A illustrates the principle of the apparatus due to various factors such as sudden steering, excessive vehicle speed, crosswind, or imbalance in load distribution while the coupled vehicle 10 is traveling as illustrated in FIG. As described above, the trailer 10b may swing or vibrate like a pendulum in the yaw direction with the coupler 14a of the tractor 10a as a fulcrum (sway vibration). Such sway vibration of the trailer causes coupled vibration of the tractor 10a, the amplitudes of the yaw rate γ and the lateral acceleration Gy (or the vehicle body slip angular velocity β ′) of the tractor 10a are increased, and the stability of the vehicle is deteriorated. . Therefore, in general, in the sway state suppression behavior control device, the amplitude of the sway vibration frequency band component of the tractor yaw rate γ or lateral acceleration Gy (or vehicle body slip angular velocity β ′) is monitored, and the amplitude increases. Sometimes, it is determined that a sway state (a state in which sway vibration is occurring) has occurred, and the vehicle is decelerated, or the tractor yaw rate or lateral acceleration Gy (or vehicle body slip angular velocity β ′) is suppressed in a direction to suppress vibration ( That is, the sway state is suppressed by the generation of the yaw moment (in the opposite phase) (see cited document 2).

Regarding the detection of the sway state, as described above, the amplitude of the frequency band component of the sway vibration of the yaw rate γ or the lateral acceleration Gy (or the vehicle body slip angular velocity β ′) of the tractor is the same even if the sway state does not occur. For example, since it increases even when the vehicle body rolls due to road surface disturbance or the like, simply monitoring the amplitude of the yaw rate γ or the lateral acceleration Gy (or the vehicle body slip angular velocity β ′) makes it possible to detect the sway state. It has been found difficult to detect the occurrence. In a vehicle in which a sway condition occurs, the vibration speed of the sway vibration frequency band component of the yaw rate γ of the tractor and the lateral acceleration Gy (or the vehicle body slip angular velocity β ′), that is, the vibration frequency, Where the vibration period and the like are substantially equal (see FIG. 2 (B) a), if the vehicle is rolling rather than sway vibration, the tractor yaw rate γ and lateral acceleration Gy or vehicle body slip angular velocity Although the amplitude of β ′ can be increased, it has been found that the vibration speeds of yaw rate γ and lateral acceleration Gy (or vehicle body slip angular velocity β ′) are different from each other (see FIG. 2 (C) a). . Therefore, in the international patent application PCT / JP2009 / 67500, when the index value (vibration state quantity) indicating the vibration speed of the yaw rate γ and the lateral acceleration Gy (or the vehicle body slip angular velocity β ′) is substantially equal. , It is determined that a trailer sway condition has occurred, behavior control for suppressing the sway condition is executed, and an index value representing the vibration speed of the yaw rate γ and the lateral acceleration Gy (or the vehicle body slip angular velocity β ′). When the (vibration state quantities) are substantially different, it has been proposed that it is determined that a trailer sway state has not occurred, and behavior control is not executed, or behavior control becomes difficult to execute.

However, even when a sway condition occurs in the vehicle, the amplitude and frequency of the roll of the vehicle body caused by road disturbance, etc. when the vehicle is traveling on a relatively rough road surface In the high state, the vibration state quantities of the yaw rate γ and the lateral acceleration Gy (or the vehicle body slip angular velocity β ′) can be substantially different from each other due to the influence of the vehicle body roll caused by the road surface disturbance or the like. That is, when the vibration state quantities of the yaw rate γ and the lateral acceleration Gy (or the vehicle body slip angular velocity β ′) are substantially different, it cannot be said that the sway state is not always generated. When the vibration state quantities of the yaw rate γ and the lateral acceleration Gy (or the vehicle body slip angular velocity β ′) are substantially different, a delay in the sway suppression effect occurs when the behavior control is prohibited or suppressed. There is. However, the frequency band component of the sway vibration of the yaw rate γ or the lateral acceleration Gy (or the vehicle body slip angular velocity β ′) without referring to the relationship between the vibration state quantities of the yaw rate γ and the lateral acceleration Gy (or the vehicle body slip angular velocity β ′). When the execution of behavior control is started only based on the increase in the amplitude of the vehicle, even when there is no sway vibration, the behavior control including the application of braking force independent of the driver's operation is high. This is not preferable because it may be unnecessarily affected by the operation of the driver or the surroundings of the vehicle.

Therefore, the apparatus according to the present embodiment has the yaw rate γ and the lateral acceleration Gy (or the vehicle body slip angular velocity β ′) when the amplitude of the component of the frequency band of the sway vibration of the yaw rate γ or the lateral acceleration Gy (or the vehicle body slip angular velocity β ′) increases. ) Is substantially equal (that is, when the possibility of occurrence of the sway state is high), behavior control is executed with a normal control amount (target deceleration and / or anti-yaw moment), and the yaw rate is When the vibration state quantities of γ and lateral acceleration Gy (or vehicle body slip angular velocity β ′) are substantially different (that is, when the occurrence of the sway state is uncertain), the control amount is changed to a weaker magnitude than usual. And configured to execute behavior control. According to such a configuration, even when the vibration state quantities of the yaw rate γ and the lateral acceleration Gy (or the vehicle body slip angular velocity β ′) are substantially different, that is, even in the presence of the vehicle body rolling due to road disturbance or the like. When the behavior control is executed at a weak level, for example, at least at a minimum level, and the sway vibration is generated, it is expected that the development is suppressed and the operation is performed. Since the degree of behavior control executed independently of the driver's operation is weaker than usual, it is advantageous in that the influence on the driver's operation or the surroundings of the vehicle can be reduced.

The behavior control for detecting the possibility of occurrence of the sway state of the operation trailer of the apparatus and for suppressing the sway state may be roughly divided into the following processes.
(I) Calculation and comparison of vibration state quantity of yaw rate γ and lateral acceleration Gy or vehicle body slip angular velocity β ′ (ii) Amplitude detection of yaw rate (iii) Behavior control for sway state suppression Each process is described in detail below. Explained.

(I) Calculation and comparison of vibration state quantity of yaw rate γ and lateral acceleration Gy (or vehicle body slip angular velocity β ′) As described above, the speed of vibration of yaw rate γ and the lateral acceleration Gy or vehicle body slip in the sway vibration frequency band. When the angular velocity β ′ substantially matches the vibration speed, there is a high possibility that a trailer sway state has occurred (see FIG. 2B) a). Therefore, in the apparatus of the present invention, the vibration state quantity representing the speed of each vibration in the sway vibration frequency band is calculated and compared from the yaw rate value γ and the lateral acceleration value Gy (or the vehicle body slip angular velocity value β ′). It is determined whether or not the trailer sway state is highly likely to occur. As the vibration state quantity, the vibration period of each component or the number of vibrations within a predetermined time may be used.

When using a vibration period as the vibration state quantity, first, the lateral acceleration value Gy (or the vehicle body slip angular velocity value β ′) and the yaw rate value γ are passed through the

BPF

50a and 50b, respectively, and the frequency band components of each sway vibration are extracted. The extracted components are given to the vibration state

quantity calculation units

50c and 50d, respectively. The vibration state quantity calculation unit measures a time interval in which the value of the input component passes through 0 point, that is, a half cycle of vibration, and outputs the value. Then, when the vibration of the yaw rate value γ and the vibration of the lateral acceleration value Gy (or the vehicle body slip angular velocity value β ′) are caused by the sway vibration, as illustrated in FIG. The vibration period of the acceleration Gy (or the vehicle body slip angular velocity β ′) and the vibration period of the yaw rate γ change substantially equally. On the other hand, when the vibration of the yaw rate value γ and the vibration of the lateral acceleration value Gy (or the vehicle body slip angular velocity value β ′) are caused by the vehicle body rolling due to a road surface disturbance, as illustrated in FIG. The vibration cycle of the lateral acceleration Gy (or the vehicle body slip angular velocity β ′) and the vibration cycle of the yaw rate γ are substantially different. Therefore, as will be described later, by referring to the comparison results of these vibration periods, sway vibration may occur when an increase in yaw rate amplitude is detected in the process (ii) described later. Whether or not the property is high can be determined.

When the number of vibrations within a predetermined time is used as the vibration state quantity, first, similarly to the above, the lateral acceleration value Gy (or the vehicle body slip angular velocity value β ′) and the yaw rate value γ are respectively passed through the

BPFs

50a and 50b. Sway vibration frequency band components are extracted, and the extracted components are given to the vibration state

quantity calculation units

50c and 50d, respectively. In the vibration state quantity calculation unit, the cumulative number when the value of the input component exceeds a predetermined threshold (that is, the cumulative number of occurrences of large amplitude) is counted and the cumulative number is output (the cumulative number) Is reset when the value of the component input over a predetermined time does not exceed a predetermined threshold value). Then, when the vibration of the yaw rate value γ and the vibration of the lateral acceleration value Gy (or the vehicle body slip angular velocity value β ′) are caused by the sway vibration, as illustrated in FIG. The frequency of acceleration Gy (or vehicle body slip angular velocity β ′) (cumulative number exceeding the threshold) and the frequency of yaw rate γ (cumulative number exceeding the threshold value) increase substantially equally, whereas the vibration of yaw rate value γ and When the vibration of the lateral acceleration value Gy (or the vehicle body slip angular velocity value β ′) is caused by the vehicle body rolling due to a road surface disturbance, as illustrated in FIG. A substantial deviation occurs. Therefore, as will be described later, by comparing these frequencies, it is highly possible that sway vibration has occurred when an increase in yaw rate amplitude is detected in the process (ii) described later. It can be determined whether or not.

Thus, when the vibration state quantities of the yaw rate γ and the lateral acceleration Gy (or the vehicle body slip angular velocity β ′), that is, the vibration period or frequency are calculated, those values are given to the comparison determination unit 50e. In the comparison / determination unit 50e, the deviation of the vibration state quantity is inspected, and the high possibility of occurrence of the sway state is determined. Specifically, when any of the following conditions is satisfied, it may be determined that the possibility of occurrence of the sway state is high.
(A) The ratio of the vibration state quantity S (γ) of the yaw rate γ to the vibration state quantity S (Gy) of the lateral acceleration Gy (or the vibration state quantity S (β ′) of the vehicle body slip angular velocity β ′) is a predetermined value including 1. When in the range Spb-Spt, that is,
Spb <S (γ) / S (Gy) <Spt (1)
Or
Spb <S (γ) / S (β ′) <Spt (1a)
[Where 0 <Spb <1 <Spt]
(When the state enters the shaded area in FIG. 3A)
(B) The magnitude of the difference between the vibration state quantity S (γ) of the yaw rate γ and the vibration state quantity S (Gy) of the lateral acceleration Gy (or the vibration state quantity S (β ′) of the vehicle body slip angular velocity β ′) is predetermined. When the magnitude falls below Sdo, that is,
| S (γ) −S (Gy) | <Sdo (2)
Or
| S (γ) −S (β ′) | <Sdo (2a)
(When the state enters the shaded area in FIG. 3B)
(C) The difference between the vibration state quantity S (γ) of the yaw rate γ and the vibration state quantity S (Gy) of the lateral acceleration Gy (or the vibration state quantity S (β ′) of the vehicle body slip angular velocity β ′) is less than the predetermined value Sdo. When
S (γ) −S (Gy) <Sdo (3)
Or
S (γ) −S (β ′) <Sdo (3a)
(When the state enters the shaded area in FIG. 3C)
In any case, the conditions (a) to (c) described above are the vibration state quantity S (γ) of the yaw rate γ and the vibration state quantity S (Gy) of the lateral acceleration Gy (or the vibration state of the vehicle body slip angular velocity β ′. This is a condition for determining that the amount S (β ′)) is not substantially different. In the comparison / determination unit 50e, which of the above conditions (a) to (c) is adopted may be appropriately selected by a designer, and both cases belong to the present invention. Each value, Sdo, Spb, Spt is set experimentally or theoretically according to the type and specification of the vehicle.

Thus, when the comparison / determination unit 50e determines that the possibility of the occurrence of the sway state is high, a signal indicating this is given to the sway suppression behavior control unit 50h.

(Ii) Yaw Rate Amplitude Detection In detecting the increase in the yaw rate amplitude, the yaw rate value γ obtained from the yaw rate sensor is first passed through the BPF 50b to extract the frequency band component of the yaw rate sway vibration, and the amplitude It is input to the detection unit 50f. The amplitude detection unit 50f includes a counter that counts the number of times that the magnitude of the input yaw rate component exceeds a predetermined threshold within a predetermined time (that is, the number of occurrences of large amplitude). When the predetermined number of times is reached, that is, when the amplitude of the yaw rate component increases over a predetermined period, a signal indicating this is generated. When such a signal is given to the sway suppression behavior control unit 50h, behavior control for suppression of the sway state is executed as will be described later. The amplitude detector 50f changes the “predetermined threshold value” and / or the “predetermined number of times” according to the presence / absence of a signal indicating that the possibility of occurrence of the sway state is high from the comparison / determination unit 50e. It may be. That is, when a signal indicating that the possibility of occurrence of a sway state is high is received, the above-mentioned “predetermined threshold” and / or “predetermined number of times” are set lower than when such a signal is not received. The With this configuration, when the comparison determination unit 50e determines that the possibility of occurrence of the sway state is high, the yaw rate component of the frequency band of the sway vibration is more quickly (before the amplitude of the yaw rate component becomes considerably large). An increase in amplitude is detected. Note that when the sway state of the trailer occurs, the amplitude of the lateral acceleration or the vehicle body slip angular velocity also increases. Therefore, instead of detecting the increase in the yaw rate amplitude, an increase in the amplitude of the lateral acceleration Gy or the vehicle body slip angular velocity β ′ is detected. It may be like this.

(Iii) Behavior Control for Sway State Suppression In a state in which the comparison determination unit 50e is emitting a signal indicating that the possibility of occurrence of the sway state is high, the amplitude detection unit 50f has a frequency of sway vibration of the tractor yaw rate. When an increase in the amplitude of the band component is detected, it can be determined that a trailer sway state has occurred. On the other hand, when the comparison determination unit 50e does not issue a signal indicating that the possibility of occurrence of the sway state is high, that is, the vibration state quantity S (γ) of the yaw rate γ and the vibration state quantity S (Gy) ( Alternatively, when the amplitude of the frequency band component of the sway vibration of the yaw rate of the tractor increases in a state where the vibration state quantity S (β ′)) of the vehicle body slip angular velocity β ′ is substantially different, the increase in the amplitude is It cannot be determined whether it is due to sway vibration or due to rolling of the vehicle body caused by road disturbance. Therefore, the sway suppression behavior control unit 50h refers to the signal from the comparison determination unit 50e and the signal from the amplitude detection unit 50f, and detects a signal and amplitude detection from the comparison determination unit 50e indicating that the possibility of occurrence of the sway state is high. When a signal indicating an increase in the amplitude of the yaw rate value is received from the unit 50f, the execution of behavior control for suppressing the sway state using the first control amount is instructed, and the sway state can be generated from the comparison determination unit 50e. When a signal indicating an increase in the amplitude of the yaw rate value is received from the amplitude detection unit 50f in a state where a signal indicating high performance is not received, a sway using a second control amount lower than the first control amount is received. Instructs execution of behavior control for state suppression. However, when the vehicle speed is lower than the predetermined speed, the behavior control may not be executed in any case. Specifically, the behavior control for suppressing the sway state may be executed by deceleration of the vehicle and / or generation of an anti-yaw moment.

When the sway state suppression is executed by the deceleration of the vehicle, the sway suppression behavior control unit 50h generates a sway state from the comparison determination unit 50e in response to receiving a signal indicating an increase in the amplitude of the yaw rate value from the amplitude detection unit 50f. when the potential is receiving a signal indicating a high that sets a target deceleration G _a such is illustrated in FIG. 4 (a), so that the target deceleration G _a is reached, the braking force The controller 50i is instructed to increase the braking force of each wheel, or at the same time, the driving force control unit 50j of the vehicle is reduced in driving output (reduction in throttle opening or torque output). Instruct. On the other hand, when the sway suppression behavior control unit 50h receives a signal indicating an increase in the amplitude of the yaw rate value from the amplitude detection unit 50f, the sway suppression behavior control unit 50h receives a signal indicating that a sway state is highly likely to occur from the comparison determination unit 50e. when not, set the illustrated such that the target deceleration G _B in FIG. 4 (a), such that the target deceleration G _B is achieved, the increase in the wheel braking force to the braking force control unit 50i (The drive output suppression may not be executed). Here, as shown in the figure, the target decelerations G _A and G _B are:
G _A > G _B (4)
Is set to hold. G _A is the vehicle speed, based on the amplitude or the like of the yaw rate value may be set by any method. When G _A is required as the target deceleration, the generation of swaying state is assumed to be substantially reliable, G _A is as soon as possible the swaying state converges while ensuring the safety of the vehicle traveling It is preferable to set the size sufficiently large. On the other hand, when the G _B is required as the target deceleration, causes the amplitude of the increase in the yaw rate value is a roll of the vehicle body due to road surface disturbance or the like, occurrence of sway oscillations is uncertain. Thus, G _B is operation of the driver, is preferably set to lower excessive impact on the surrounding vehicle of about beyond the value (> 0). For example, G _B, the brake lamp degree of may be set to a value (which is not lit, giving unnecessary warnings to the driver of a vehicle traveling behind the host vehicle is avoided. Such deceleration processing May be continued until the signal indicating the increase in the amplitude of the yaw rate from the amplitude detector disappears.

When the sway state suppression is executed by the generation of the anti-yaw moment, when the sway suppression behavior control unit 50h receives a signal indicating an increase in the yaw rate amplitude from the amplitude detection unit 50f, the sway state suppression frequency control component 50h Referring to this, a target value of anti-yaw moment having an opposite phase to that component is calculated, and the value is transmitted to braking force control unit 50i. At that time, when receiving a signal indicating a high likelihood of sway state generated from the comparison determination unit 50e is set to a value The illustrated such anti yaw moment Y _A in FIG. 4 (B), comparing when not receiving a signal indicative of the determination unit 50e is likely sway condition occurs, a small Y _B amplitude is set than the anti-yaw moment Y _a. As with the target deceleration, when the anti-yaw moment Y _A is required, since the occurrence of swaying state is assumed to be substantially reliable, the amplitude of Y _A is after securing the safety of the vehicle traveling It is preferable that the amplitude is set to a magnitude that is sufficient for the sway state to converge as quickly as possible. When the anti-yaw moment Y _B is required, the presence or absence of occurrence of sway vibration is uncertain. The amplitude of _B is preferably set to a low amplitude (> 0) that does not excessively affect the driver's operation and the surroundings of the vehicle. Thus, when the target value of the anti-yaw moment is received, the braking force control unit 50i determines the braking force distribution of each wheel to achieve the anti-yaw moment, and controls the braking device 46 according to the determined braking force distribution. A command is given and an anti-yaw moment is generated. The generation of the anti-yaw moment may be continued until the signal indicating the increase in the amplitude of the yaw rate from the amplitude detector disappears. Note that the behavior control by the anti-yaw moment also has an effect of suppressing instability of the vehicle due to road surface disturbance or the like, so even if it is executed with Y _A as the target value regardless of the presence or absence of a signal from the comparison determination unit 50e. Good.

Thus, according to the above-described device of the present invention, when the occurrence of the sway state is uncertain, considering that the sway state can occur even in the presence of rolling of the vehicle body due to road surface disturbance, etc. In addition, by controlling the behavior for suppressing the sway state at a certain level, when the yaw rate amplitude is increased, the control effect is obtained at least at the minimum level, and the sway vibration is obtained. Attempts are made to reduce the delay in the execution of amplification or behavior control.

Although the present invention has been described in detail with reference to specific embodiments, the present invention is not limited to the above-described embodiments, and various other embodiments are possible within the scope of the present invention. It will be apparent to those skilled in the art.

For example, when the number of vibrations within a predetermined time is used as the vibration state quantity, the number of vibrations exceeding the threshold of the yaw rate γ, the lateral acceleration Gy, or the vehicle body slip angular velocity β ′ is counted in the vibration state quantity calculation unit. Therefore, when the number of vibrations reaches a predetermined number, it may be determined that the amplitude of those values has increased. Therefore, in this case, the sway suppression control may be executed when the comparison determination unit 50e issues a signal (in this case, the vibration detection unit 50f is omitted).

In addition, the condition for determining the vibration state quantity illustrated in the phase diagram in FIG. 3 (the shape of the phase diagram in FIG. 3) is not limited to the illustrated example, and other conditions may be used. It should be understood that such a case also belongs to the scope of the present invention.

Furthermore, the most important feature of the present invention is that the action of the sway state suppression behavior control is changed depending on whether the speed or frequency of vibration of the yaw rate is substantially equal to the speed or frequency of vibration of the lateral acceleration or the vehicle body slip angular velocity. Therefore, the method for determining whether the speed or frequency of the yaw rate vibration and the vibration speed or frequency of the lateral acceleration or the vehicle body slip angular velocity are substantially equal is a method different from that exemplified in the embodiment. Such a case may be included in the scope of the present invention. For example, even if the determination of the occurrence of the sway state or the control of the sway state suppression behavior is performed based on the homology between the frequency distribution (spectrum) of the yaw rate in the sway vibration frequency band component and the lateral acceleration or the vehicle body slip angular velocity frequency distribution. Good.

Claims

A behavior control device for applying a braking force to at least one wheel to suppress a sway state of a connected vehicle including a tractor and a trailer towed by the tractor, wherein the vibration state quantity of the yaw rate of the tractor and the tractor A device in which a braking force applied to the at least one wheel is changed based on a relationship between a lateral acceleration or a vibration state quantity of a vehicle body slip angular velocity.
The apparatus of claim 1, wherein it is not determined that the possibility of occurrence of the sway state is high based on the relationship between the vibration state quantity of the yaw rate and the vibration state quantity of the lateral acceleration or the vehicle body slip angular velocity. An apparatus that executes behavior control for suppressing a sway state with a lower control amount than when it is determined that the possibility of the occurrence of the sway state is high.
2. The apparatus according to claim 1, wherein the braking force applied to the at least one wheel is a vibration state quantity of a yaw rate component of the tractor and a sway vibration of the trailer in a frequency band of the sway vibration of the trailer. When the ratio or difference between the lateral acceleration of the tractor or the vehicle body slip angular velocity component in the frequency band is not within the predetermined range, the ratio or difference is set lower than when the ratio or difference is within the predetermined range. Equipment.
2. The apparatus according to claim 1, wherein the tractor yaw rate or the lateral acceleration or the body slip angular velocity component amplitude in the frequency band of the sway vibration of the trailer is larger than a predetermined value for a predetermined time. Means for applying a braking force to the at least one wheel so that a speed is achieved, wherein a vibration state quantity of the yaw rate of the tractor and a vibration state quantity of a lateral acceleration of the tractor or a vehicle body slip angular velocity are substantially different. An apparatus in which the braking force is reduced as compared with a case where the vibration state quantity of the yaw rate of the tractor and the vibration state quantity of the lateral acceleration of the tractor or the vehicle body slip angular velocity are substantially equal.
2. The apparatus according to claim 1, wherein when the vibration state quantity of the yaw rate of the tractor is substantially equal to the vibration state quantity of the lateral acceleration of the tractor or the vehicle body slip angular velocity, the vehicle is operated at the first target deceleration. When the vibration state amount of the yaw rate of the tractor and the vibration state amount of the lateral acceleration of the tractor or the vehicle body slip angular velocity are substantially different from each other, the second target deceleration is lower than the first target deceleration. A device for decelerating the vehicle.
2. The apparatus according to claim 1, wherein a yaw moment is generated in a direction to suppress the sway state by a braking force applied to the at least one wheel.
2. The apparatus according to claim 1, wherein a part of the braking force applied to the at least one wheel is generated by reducing an output of the driving device of the vehicle.
2. The apparatus according to claim 1, wherein each of the vibration state quantities is a vibration period of a corresponding physical quantity, and a ratio or difference between a vibration period of a yaw rate of the tractor and a vibration period of a lateral acceleration of the tractor or a vehicle body slip angular velocity. The braking force applied to the at least one wheel is changed based on the above.
2. The apparatus according to claim 1, wherein each of the vibration state quantities is a number of vibrations exceeding a predetermined magnitude of a corresponding physical quantity, and the number of vibrations of the yaw rate of the tractor and the lateral acceleration of the tractor over a predetermined time. Alternatively, an apparatus in which a braking force applied to the at least one wheel is changed based on a ratio or difference between the vehicle body slip angular velocity and the number of vibrations.
The apparatus according to claim 1, wherein when the vibration state quantity in the sway vibration frequency band of the yaw rate of the tractor is substantially different from the vibration state quantity in the sway vibration frequency band of the lateral acceleration or the vehicle body slip angular velocity, A device that attenuates the yaw rate of the tractor with a lower braking force than when two vibration state quantities are substantially equal.
The apparatus according to claim 1, wherein when the vibration state quantity in the sway vibration frequency band of the yaw rate of the tractor is substantially different from the vibration state quantity in the sway vibration frequency band of the lateral acceleration or the vehicle body slip angular velocity, An apparatus for decelerating the vehicle at a target deceleration that is lower than when the two vibration state quantities are substantially equal.