CN117500707A

CN117500707A - Vehicle motion control device, vehicle and system

Info

Publication number: CN117500707A
Application number: CN202280042386.5A
Authority: CN
Inventors: 平田淳一; 中野勇大
Original assignee: NTN Corp
Current assignee: NTN Corp
Priority date: 2021-06-15
Filing date: 2022-06-08
Publication date: 2024-02-02
Also published as: WO2022264897A1; JP2022191100A

Abstract

A vehicle motion control device (100) is provided with: a sideslip angular velocity estimator (150); a yaw acceleration calculator (170); a roll moment calculator (110) that calculates and outputs a roll moment command value in a manner that the roll motion and yaw motion of the vehicle in the turn are linked, based on at least the product of the vehicle speed and the yaw angular velocity estimation value of the vehicle (1) and the product of the vehicle speed and the yaw angular acceleration calculation value; and an actuator control mechanism (130) that controls the actuator (400) that generates the roll moment based on the roll moment command value. Calculating a yaw rate acceleration of the vehicle (1) from the vehicle speed and the steering angle, and performing differential calculation on an output of a yaw rate sensor provided in the vehicle (1) to output a yaw rate acceleration actual measurement value; setting the ratio of the yaw rate acceleration actual measurement value to the yaw rate acceleration calculation value; the yaw rate calculation value is calculated from the ratio of the yaw rate estimation value to the yaw rate actual measurement value, and the ratio is set based on the vehicle speed and the steering angle.

Description

Vehicle motion control device, vehicle and system

RELATED APPLICATIONS

The priority of JP patent application 2021-099771, filed on 6/15 of 2021, is claimed and incorporated herein by reference in its entirety.

Technical Field

The present invention relates to a vehicle motion control device, a vehicle, and a system that control roll motion of a vehicle during turning.

Background

There is a development in the market of technology for improving the riding comfort and driving convenience of a vehicle by controlling the roll motion (appropriately, also referred to as roll angle or simply roll) that occurs when the vehicle turns. As such a technique, for example, the following prior art 1 and prior art 2 are known.

The related art 1 is a technique of controlling a roll angle caused by lateral acceleration and a pitch angle caused by front-rear acceleration by changing a damping force of a damper of a suspension by an actuator, and by changing the damping force of the damper based on a differential value of the lateral acceleration, a differential value of the front-rear acceleration, and a damper speed, thereby improving responsiveness of the roll angle control and the pitch angle control (patent document 1).

A conventional art 2 is a roll angle control technique of a vehicle equipped with an active stabilizer and a damper capable of changing a damping force, which performs control to estimate a roll angle generated in the vehicle body from a detected vehicle speed and rudder angle, change a damping characteristic or a spring characteristic of a suspension according to a deviation from a roll angle constituting a target, suppress a roll occurring in accordance with a lateral acceleration, and reduce a time difference between occurrence of the lateral acceleration and occurrence of the roll or keep the same (patent document 2).

Prior art literature

Patent literature

Patent document 1: JP 2006-069527A

Patent document 2: JP patent publication No. 2007-106257

Disclosure of Invention

Problems to be solved by the invention

In general, the timing at which the yaw rate of the vehicle occurs and the timing at which the lateral acceleration occurs after the driver operates the steering wheel vary according to the vehicle speed. For example, when the vehicle is running at a low speed, the yaw rate is generated with a slight delay after the lateral acceleration is generated in the vehicle in response to the steering operation of the driver. The occurrence of the lateral acceleration is delayed due to the influence of the moment of inertia of the spring and the damping force of the suspension, so that the roll occurs later than the yaw rate. When the vehicle is running at a high speed, a lateral acceleration delay occurs after a yaw rate occurs in the vehicle in response to a steering operation by the driver. The roll occurs further later in time than the lateral acceleration due to the effects of the moment of inertia of the spring and the damping force of the suspension.

In the above-described prior arts 1 and 2, the roll generation amount and the time difference until the roll is generated are controlled with respect to the lateral acceleration generated in the vehicle during turning, but since the yaw rate is not considered, the occurrence timing of the roll depends on the lateral acceleration. That is, the yaw motion and the roll motion, which are rotational motions of the vehicle, occur at different times. Therefore, the driver perceives yaw and roll as separate motions, and the sense of unity with respect to the vehicle motion cannot be obtained.

An object of the present invention is to provide a vehicle motion control device, a vehicle, and a system that enable a driver to obtain an integrated feeling with a vehicle motion to solve the above-described problems of the related art.

Technical proposal for solving the problems

In order to achieve the above object, a vehicle motion control device according to the present invention is a vehicle motion control device mounted on a vehicle, the vehicle motion control device including: a side slip angular velocity estimator for estimating a side slip angular velocity of the vehicle and outputting a side slip angular velocity estimation value; a yaw acceleration calculator that calculates a yaw acceleration of the vehicle and outputs a yaw acceleration calculation value; a roll moment calculator that calculates and outputs a roll moment command value so that a roll motion and a yaw motion of the vehicle at the time of turning are linked, based on at least a product of a vehicle speed of the vehicle and the sideslip angular velocity estimated value and a product of the vehicle speed and the yaw angular acceleration calculated value; and an actuator control mechanism that controls an actuator mounted on the vehicle, the actuator causing the vehicle body to generate a roll moment, based on the roll moment command value,

The yaw acceleration calculator includes: a yaw acceleration estimating unit that estimates a yaw acceleration of the vehicle from the vehicle speed and the steering angle and outputs a yaw acceleration estimated value; a differential operation unit that performs differential calculation on a yaw rate actual measurement value that is an output of a yaw rate sensor provided in the vehicle, and outputs a yaw rate acceleration actual measurement value; a ratio setting unit that sets a ratio of the yaw rate acceleration actual measurement value to the yaw rate acceleration calculation value; and a yaw acceleration calculation unit that calculates and outputs a yaw acceleration calculation value based on the yaw acceleration estimation value, the yaw acceleration actual measurement value, and the ratio;

the ratio setting unit sets the ratio based on the vehicle speed and the steering angle.

According to the above-described aspect, the vehicle motion control apparatus of the present invention includes: a roll moment calculator that calculates and outputs a roll moment command value so that the roll motion and the yaw motion of the vehicle during turning are linked; and an actuator control means for controlling an actuator that generates a roll moment on the vehicle body based on the roll moment command value, linking the roll motion with the yaw motion, calculating a yaw acceleration calculation value based on the yaw acceleration estimation value, the yaw acceleration actual measurement value, and the ratio, and setting the ratio based on the vehicle speed and the steering angle, whereby it is possible to compensate for a delay due to suspension damping or the like, reduce the delay until a roll angle is generated after the occurrence of the yaw rate (reduce a phase delay of the roll motion relative to the yaw motion), and thus the driver can generate a sense of unity for the motion of the vehicle.

The ratio setting portion may set the ratio in accordance with whether or not the vehicle posture determined based on the vehicle speed and the steering angle is in any of the following states including: steady state, transitional state, or a quasi-transitional state between steady state and transitional state. In this way, the vehicle posture is divided into the steady state, the transition state, and the quasi-transition state, and the ratio is set, so that the ratio can be adjusted to be appropriate for each state, and thus, the sense of incongruity brought about by the driver under the roll control can be suppressed.

The vehicle posture may be determined from the yaw acceleration estimated value calculated from the vehicle speed and the steering angle. By using the yaw acceleration estimated value calculated from the vehicle speed and the steering angle in this way, the vehicle posture reflecting the steering intention of the driver and the influence of the vehicle speed can be determined.

The vehicle posture may be determined from the vehicle speed and a steering angular velocity obtained by performing a time-differential calculation of at least the steering angle. By using the vehicle speed and at least the steering angular velocity in this way, it is possible to determine the vehicle posture reflecting the steering intention of the driver and the influence of the vehicle speed, and the calculation load is reduced as compared with the case of using the yaw acceleration estimated value.

In the ratio setting unit, the ratio may be set to zero when it is determined that the vehicle posture is in the steady state. In this way, in the steady state in which the change in the behavior of the vehicle is small, the noise component included in the roll moment command value can be reduced, and thus, the sense of incongruity brought about by the control to the driver can be suppressed.

In the ratio setting unit, the ratio may be set to 1 when it is determined that the vehicle posture is in the transient state. In this way, in the transient state in which the change in behavior of the vehicle is large, the yaw acceleration actual measurement value corresponding to the actual vehicle behavior can be reflected in the roll moment command value, and therefore the roll moment command value can be calculated appropriately.

In the ratio setting unit, when it is determined that the vehicle posture is in the quasi-transient state, the ratio may be closer to 1 as the vehicle posture approaches the transient state. Thus, when the vehicle posture is in the quasi-transient state between the steady state and the transient state, the effect of reducing the noise component included in the roll moment command value and the effect of reflecting the roll moment command value on the yaw angle acceleration actual measurement value according to the actual vehicle behavior (both effects can be achieved) can be appropriately adjusted by making the ratio closer to 1 as the vehicle posture approaches the transient state.

The vehicle according to the present invention is equipped with the vehicle motion control device according to any one of the above aspects. The system of the present invention is configured by the vehicle motion control device and the actuator according to any one of the above-described aspects.

According to the above aspect, since the vehicle and the system of the present invention are equipped with the functions described above, the effects described above can be achieved, and at least the roll moment calculator that calculates and outputs the roll moment command value in such a manner that the roll motion and the yaw motion of the vehicle during the turning are linked; an actuator control means for controlling an actuator that generates a roll moment on a vehicle body based on the roll moment command value, and for linking the roll motion with the yaw motion, and further calculating a yaw acceleration calculation value based on the yaw acceleration estimation value, the yaw acceleration actual measurement value, and the ratio, and setting the ratio based on the vehicle speed and the steering angle, it is possible to compensate for a delay due to suspension damping or the like, and reduce a delay from the generation of the yaw angular velocity to the generation of the roll angle (reduce a phase delay of the roll motion relative to the yaw motion), and thereby the driver can generate a sense of unity to the motion of the vehicle.

Any combination of at least two configurations disclosed in the claims and/or the specification and/or the drawings is included in the present invention. In particular, any combination of two or more of each of the claims is included in the invention.

Drawings

The invention will be more clearly understood from the following description of the preferred embodiments with reference to the accompanying drawings. However, the examples and drawings are for illustration and description only and are not intended to limit the scope of the invention. The scope of the invention is defined by the claims. In the drawings, like numerals designate identical or corresponding parts throughout the several views.

Fig. 1 is a schematic diagram showing a configuration of a vehicle in which a vehicle motion control device according to embodiment 1 of the present invention is mounted.

Fig. 2 is a block diagram showing the construction of the vehicle motion control apparatus of fig. 1;

fig. 3 is a block diagram showing the configuration of a yaw rate acceleration calculator included in the vehicle motion control device of fig. 1;

fig. 4 is a waveform diagram for explaining the characteristics of the ratio α;

fig. 5 is a diagram for explaining turning travel of the vehicle in a J-shape;

fig. 6 is a waveform diagram of each of the roll angle, the roll moment command value, and the like of the vehicle in which the vehicle motion control device of fig. 1 is not mounted and the vehicle in which the vehicle motion control device of fig. 1 is mounted;

Fig. 7 is a waveform diagram of a yaw rate estimated value, a yaw rate measured value, a yaw rate acceleration calculation value, a roll moment command value, and the like of the vehicle in which the vehicle motion control device of fig. 1 is mounted;

fig. 8 is another waveform diagram of a yaw rate acceleration estimated value, a yaw rate acceleration measured value, a yaw rate acceleration calculation value, a roll moment command value, and the like of the vehicle in which the vehicle motion control device of fig. 1 is mounted;

fig. 9 is a block diagram showing another configuration of a yaw rate acceleration calculator included in the vehicle motion control device of fig. 1;

fig. 10 is a waveform diagram illustrating other characteristics of the ratio α;

fig. 11 is a further waveform diagram of a yaw rate acceleration estimated value, a yaw rate acceleration actual measurement value, a yaw rate acceleration calculation value, a roll moment command value, and the like of the vehicle on which the vehicle motion control device of fig. 1 is mounted;

fig. 12 is a waveform diagram of further other waveforms of a yaw rate acceleration estimated value, a yaw rate acceleration measured value, a yaw rate acceleration calculation value, a roll moment command value, and the like of the vehicle on which the vehicle motion control device of fig. 1 is mounted;

fig. 13 is a waveform diagram illustrating still another characteristic of the ratio α;

FIG. 14 is a schematic diagram showing the vertical forces generated by the vehicle and the suspension link configuration, etc.;

fig. 15 is a schematic view showing a configuration of a vehicle on which a vehicle motion control device according to embodiment 2 of the present invention is mounted;

fig. 16 is a block diagram showing the structure of the vehicle motion control apparatus of fig. 15;

fig. 17 is a schematic view showing a vertical force generated by a vehicle, a suspension link arrangement, and the like.

Detailed Description

The following vehicle motion control apparatuses 100 (100A [ fig. 1], 100B [ fig. 15 ]) according to the following embodiments 1 and 2 of the present invention are mounted on a vehicle 1 (1A [ fig. 1], 1B [ fig. 15 ]), and the vehicle 1 has an actuator 400 (for example, an active suspension 17[ fig. 1], a hub motor 19[ fig. 15 ]). The vehicle motion control apparatus 100 has a yaw rate estimator 150, a yaw rate acceleration calculator 170, a roll moment calculator 110, and an actuator control mechanism 130 (130A [ fig. 2], 130B [ fig. 16 ]) of fig. 2, 16.

< embodiment 1 >

As shown in fig. 1, for example, the vehicle motion control device 100A of the present embodiment is mounted on a vehicle 1A described below, and the vehicle 1A includes active suspensions 17 that are actuators capable of generating roll moment and are mounted on 4 wheels 10 of the vehicle via knuckles 11, suspension arms 15, and the like. The vehicle 1A includes a vehicle speed sensor 271 that detects a vehicle speed, a steering angle sensor 250 that detects a steering angle, an acceleration sensor 230 that detects acceleration in the vehicle front-rear-left-right direction, a yaw rate sensor 210 that detects a yaw rate, the above-described vehicle motion control device 100A that controls roll motion, a suspension control device 330 that controls the active suspension 17, and an ECU (electronic control unit) 270 (not shown in fig. 15) that controls basic operations of the vehicle. The respective outputs (vehicle speed, steering angle, lateral acceleration actual value, yaw rate actual value) of the vehicle speed sensor 271, the steering angle sensor 250, the acceleration sensor 230, and the yaw rate sensor 210 are input to the vehicle motion control device 100A.

Fig. 2 shows a block diagram of the vehicle motion control device 100A. The vehicle motion control device 100A includes a side-slip angular velocity estimator 150, a yaw acceleration calculator 170, a roll moment calculator 110, and an actuator control mechanism 130A. The yaw rate estimator 150 estimates the yaw rate of the vehicle 1A using the input output signals of the sensors, and outputs the estimated yaw rate to the roll moment calculator 110. The side-slip angular velocity may be estimated using a vehicle model that is a linear or nonlinear tire model. For example, when the side slip angular velocity is estimated in a two-wheel model using a linear tire model, the side slip angular velocity is calculated according to the following expression (3) using, for example, a steering angle and a vehicle speed. The yaw acceleration calculator 170 calculates the yaw acceleration of the vehicle 1A using the input output signals of the sensors (excluding the actual lateral acceleration values), and outputs the calculated yaw acceleration value to the roll moment calculator 110.

The roll moment calculator 110 calculates a roll moment command value from the vehicle speed, the yaw angular velocity estimation value, and the yaw angular acceleration calculation value, and outputs the calculated roll moment command value to the actuator control mechanism 130A. As an input signal receivable by the suspension control device 330, the actuator control mechanism 130A converts the roll moment command value into a vertical force command value, for example, and outputs the same to the suspension control device 330.

Each block is further described. The sideslip angular velocity estimator 150 estimates the value β of the sideslip angular velocity using, for example, a two-wheel model describing translational motion in the vehicle transverse direction and rotational motion about the vertical axis _est ". The basic formula of the two-wheeled model is shown below. In the coordinate system, the x-axis is the front-rear direction of the vehicle, the front is positive, the y-axis is the left-right direction, the left direction is positive, the z-axis is the up-down direction, and the up-direction is positive.

[ mathematical formula 1]

m represents a vehicle mass; v represents the vehicle speed;indicating a sideslip angular velocity of the vehicle; r represents yaw rate; y is Y _f Representing the lateral force of the front wheel; y is Y _r Represents the lateral force of the rear wheel; i _z Representing yaw moment of inertia of the vehicle; />Representing yaw acceleration; l (L) _f Representing the distance between the center of gravity point of the vehicle and the front axle; l (L) _r The distance between the center of gravity of the vehicle and the rear axle is indicated.

In embodiments 1 and 2, the slip angular velocity of the vehicle is also written as β "·". Similarly, in each embodiment, after the time derivative operation is performed on the variable X, the term X "·" is written in addition to the description form of the side point (·) on the upper portion of the character X.

The transfer function of the slip angular velocity β "·" with respect to the rudder angle δ in the two-wheeled model is the following expression (3). Estimating the sideslip angular velocity estimated value β using the transfer function of equation (3) _est “·”。

[ mathematical formula 2]

Wherein s represents a Laplace operator;indicating a sideslip angle gain constant; t (T) _β A constant indicating a sideslip angle; />A decay ratio representing yaw response of the vehicle relative to rudder angle; omega _n Representing the amount of natural vibration of the yaw response of the vehicle relative to the rudder angle; delta _h Representing the steering angle; n represents the steering gear ratio.

Fig. 3 shows a block diagram of the yaw acceleration calculator 170. The yaw acceleration calculator 170 calculates a yaw acceleration calculation value using the signals of the sensors, and outputs the calculated yaw acceleration value to the roll moment calculator. The yaw acceleration calculator 170 includes a yaw acceleration estimating unit 171, a differential calculating unit 173, a ratio setting unit 175, and a yaw acceleration calculating unit 177. The yaw acceleration estimating unit 171 calculates (estimates) a yaw acceleration as a yaw acceleration estimated value r from the inputted vehicle speed and the inputted steering angle _est ". For example, when a two-wheel model is used, the yaw acceleration r "·" transfer function with respect to the rudder angle δ is the following expression (5). Calculating a yaw acceleration estimated value r by using a transfer function of (5) _est “·”。

[ mathematical formula 3]

Wherein,representing yaw rate constant; t (T) _r The yaw rate time constant is indicated.

The differential operation unit 173 differentiates the yaw rate actual measurement value, which is the output of the yaw rate sensor 210, as the yaw rate acceleration actual measurement value r _act ". The ratio setting unit 175 uses the yaw rate acceleration estimated value r _est "·" the ratio α is set according to a predetermined condition. Specifically, the ratio setting unit 175 uses a yaw acceleration estimated value r estimated from the vehicle speed and the steering angle _est As an index, "·" is used, in the present embodiment, the ratio setting portion 175 sets the ratio α according to whether the vehicle posture is in the steady state, the quasi-transient state, or the transient state, according to a predetermined condition. The ratio alpha is the yaw acceleration measured value r _act "·" and a yaw acceleration calculation value r described later _cal Ratio of "·". The yaw rate acceleration calculation value is a yaw rate acceleration estimation value r _est ". And yaw acceleration actual measurement value r _act The weighted average value of "·" is calculated by the yaw acceleration calculation unit 177 as the yaw acceleration estimated value r based on the above-described yaw acceleration _est ", yaw acceleration actual measurement r _act Values calculated as "·" and ratio α.

The ratio α is obtained by estimating the yaw rate acceleration estimated value r, for example, as shown in the graph of fig. 4 _est The absolute value of "·" is set as an indicator. Yaw acceleration estimation value r _est The absolute value of "·" is zero for the ratio α below the threshold As. Yaw acceleration estimation value r _est When the absolute value of "·" exceeds the threshold value As and is equal to or lower than the threshold value Ae, the yaw rate acceleration estimated value r _est The greater the absolute value of "·", the closer the ratio α is from zero to 1. Yaw angular acceleration estimation value r _est The ratio α when the absolute value of "·" exceeds the threshold Ae is 1. As described above, the yaw acceleration calculation unit 177 estimates the value r from the yaw acceleration _est ". And yaw acceleration actual measurement value r _act "The rate alpha is calculated by the following formula (6) and the calculated value r of the yaw acceleration is output _cal “·”。

[ mathematical formula 4]

The roll moment calculator 110 calculates the roll moment generated by the actuator 17 in the vehicle body 1A by the following (7), and uses the calculated roll moment as the roll moment command value M _φ And output.

[ mathematical formula 5]

Here, hs denotes a distance between the vehicle center of gravity G and a roll axis (axis connecting the front roll center A1 and the rear roll center A2) ls shown in fig. 14, kΦ denotes roll rigidity, and cΦ denotes a roll damping coefficient.

The rolling moment command value mΦ will be described. Let the lateral acceleration of the vehicle in the two-wheeled model be a _y . Equation (1) shows the relationship between the yaw rate β "· of the vehicle, the yaw rate r, and the lateral force generated by the vehicle during turning, and therefore, from this equation (1), the yaw rate β" · the yaw rate r, and the lateral acceleration a can be seen _y The relation of (2) is represented by the following formula (8).

[ mathematical formula 6]

The above formula (8) represents the lateral acceleration a of the vehicle _y The lateral acceleration generated by the side-slip angular velocity β "·" of the vehicle and the lateral acceleration generated by the yaw rate r. At the time of steady turning, the slip angle β ". Cndot.", of the vehicle is zero, but at the transition state of turning, the slip angle β of the vehicle is changed to generate the slip angle β ". Cndot.", so at the vehicle speed V, the side is due to the fact thatSlip angular velocity beta ". Cndot., lateral acceleration a _y Only to the extent of the lateral acceleration vβ "·". As a specific example, fig. 6 shows changes in the respective values when the J-turn travel (J-turn travel) shown in fig. 5 is performed at a constant vehicle speed during high-speed travel. The change is a change in the J-turn travel described above from the first straight section shown by the solid line in fig. 5 to the halfway point CR in the following turn section.

The solid line in the graph of fig. 6 shows the change in each value when the vehicle motion control device of each embodiment is not operated, that is, the roll moment of the vehicle motion control device 100 (formula (7)) is not generated, steering is started at time t1 until the steering angle δh increases (fig. 6 (a)). After steering is started, the yaw rate r (fig. 6 (b)) and the yaw rate β "·" (fig. 6 (d)) are generated later _y The degree of the lateral acceleration phase generated by the lateral side slip angular velocity β "·" of the vehicle shown in the formula (8) is delayed with respect to the yaw rate r "·" phase ((c) of fig. 6). Further, the vehicle roll angle phi is set to be relative to the lateral acceleration a based on the damping characteristics of the suspension and the roll moment of the vehicle _y The roll angle phi of (c) is delayed (fig. 6 (f)). In this way, a delay is generated from the generation of the yaw rate (yaw motion) to the generation of the roll angle (roll motion) of the vehicle at the time of turning.

By lateral acceleration a acting on the centre of gravity of the vehicle _y The roll angle phi is generated for the vehicle, and if the two-wheeled model is expanded, the roll angle phi is expressed by the following formula (9). Assuming that the unsprung mass is sufficiently small relative to the vehicle mass, the sprung mass of the vehicle is equal to the vehicle mass m.

[ mathematical formula 7]

The 1 st right term of the above equation (7) as a calculation equation of the roll moment command value mΦ is a term for canceling the roll moment generated by the lateral acceleration caused by the yaw rate β "·" of the vehicle, and the 2 nd right term is a term for compensating for the delay (delay from the roll moment generated by the lateral acceleration caused by the yaw rate r acting on the vehicle body until the roll angle is generated) generated due to the influence of the damping characteristics of the suspension. By causing the vehicle to generate the roll moment of item 1 on the right side of the equation (7), only the lateral acceleration generated by the yaw rate r acts on the vehicle as the roll moment, and therefore the yaw motion (yaw rate) and the roll motion (roll angle) are linked. Further, by making the vehicle generate the roll moment of the right 2 nd item of the formula (7), the delay from the generation of the yaw motion (yaw rate) to the generation of the roll motion (roll angle) becomes small. That is, the roll moment, which is the roll moment command value mΦ of the expression (7), is generated on the vehicle by the actuator, and the delay from the generation of the yaw rate r to the generation of the roll angle Φ can be reduced.

As an example of the case where the roll moment is generated on the vehicle body by the actuator 400, in the graph of fig. 6, the roll moment command value mΦ ((e) of fig. 6) and the roll angle Φ ((f) of fig. 6) are indicated by broken lines, which are the roll moment command value mΦ ((7)) at the time of operation of the vehicle motion control device 100 as in the respective embodiments. Fig. 7 shows a yaw rate acceleration estimated value r in the vehicle motion control device 100 in this case _est "·" (fig. 7 (b)), yaw acceleration actual measurement value r _act "·" (fig. 7 (c)), the ratio α (fig. 7 (d)), the yaw rate acceleration calculation value r _cal Graph of values of "·" (fig. 7 (e)). From the steering start time t1 to time t2, the yaw rate acceleration estimating unit 171 calculates a yaw rate acceleration estimated value r by changing the steering angle δh (fig. 7 (a)) _est ". The differential operation unit 173 differentiates the yaw rate actual measurement value output from the yaw rate sensor and outputs the yaw rate acceleration actual measurement value r _act ". The steering angle δh is angle (position) information, but since the yaw rate actual measurement value is angular velocity (speed) information, the yaw rate actual measurement value is generally an output signal of a sensor, and noise increases. Therefore, the yaw-rate acceleration actual value r obtained by differentiating the yaw-rate actual value is calculated _act As shown in FIG. 7, "& gt is related to the yaw rate acceleration estimated value r _est Noise becomes larger than "·".

The ratio setting unit 175 uses the yaw acceleration estimated value r calculated from the vehicle speed and the steering angle _est "·" is used as an index, and the value r is estimated from the yaw rate acceleration according to the condition shown in fig. 4 _est "·", relationship between the threshold As and the threshold Ae in fig. 4, the ratio α is set. At the yaw acceleration estimated value r as an index _est When the absolute value of "·" is equal to or less than the threshold value As, the vehicle posture is in a steady state, the ratio α is zero, and the yaw rate acceleration estimated value r _est When the absolute value of "·" exceeds the threshold Ae, the vehicle posture is in the transition state, and the ratio α is 1. In addition, at the yaw acceleration estimated value r _est When the absolute value of "·" exceeds the threshold value As and is equal to or smaller than the threshold value Ae, the vehicle posture is in a quasi-transient state of a state between the steady state and the transient state, and the yaw angle acceleration estimation value r _est The larger the absolute value of ". Cndot.", the larger the ratio α is in the range of 0 to 1. In fig. 4, a yaw acceleration estimated value r is calculated when the vehicle posture is in a quasi-transient state _est When the absolute value of "·" exceeds the threshold value As and is below the threshold value Ae, the ratio α is expressed As an estimated value r relative to the yaw acceleration _est The first order function of the absolute value of "·" may be expressed as a function of a second order or more, an exponential function, or the like, as long as it is an increasing function.

By setting the ratio α as shown in fig. 4, it is possible to reduce the yaw rate acceleration calculation value r when the vehicle posture in which the change in the steering angle δh becomes small is in a steady state as in straight running or steady turning _cal Noise contained in "·". Therefore, in the roll moment calculator 110, the yaw rate acceleration calculation value r is used in the expression (7) _cal The noise component contained in the roll moment command value mΦ calculated by "·" also becomes smaller in straight running and in steady turning. When the vehicle posture is in a steady state, since the change in the vehicle behavior is small, the driver easily and sensitively feels the small vehicle posture change due to the control. As described above, the value r is calculated by using the yaw-rate acceleration _cal ",", by reducing the occurrence of roll moment due to noise components, it is possible to reduce the occurrence of roll moment during straight running or steady turningAnd a sense of incongruity to the driver. In addition, by using the yaw rate acceleration estimated value r in setting the ratio α _est "·" can reflect the steering meaning of the driver. Due to yaw acceleration estimate r _est Since "·" is calculated using the steering angle, only when the driver steers, the roll moment by the control can be generated, and the yaw rate acceleration actual measurement value r can be eliminated _act The cross wind, the unevenness of the road surface, and the inclination of the road surface.

Unlike fig. 7, at the yaw acceleration estimated value r _est ". And yaw acceleration actual measurement value r _act When "·" is different in magnitude, for example, as shown in fig. 8, the yaw acceleration actual measurement value is larger than the yaw acceleration estimated value r in absolute value _est R of " _act1 When "·" or when the absolute value is smaller than r of the yaw-angle acceleration estimation value rest "·" _act2 In "·" (fig. 8 (c)), the yaw rate acceleration calculation value r _cal " _cal1 " _cal2 "·" changes (fig. 8 (e)), reflecting the actual vehicle behavior. Therefore, the roll moment command value mΦ can be made to be appropriate while reflecting the actual vehicle behavior, as in the case of mΦ1 or mΦ2 (fig. 8 (g)). Further, when the vehicle posture is in the transition state or the quasi-transition state close to the transition state, the yaw rate β generated in the vehicle increases, and the yaw rate acceleration calculation value r in the roll moment command value mΦ is calculated by the equation (7) _cal The influence of the noise component of "·" is relatively small, and the vehicle behavior change itself is also large, so that the yaw rate acceleration calculation value r during the vehicle behavior change is relatively small _cal The effect of the noise component of "·" is relatively small. Therefore, when the vehicle posture is in the transition state and the quasi-transition state close to the transition state, the yaw rate acceleration calculation value r _cal Measured yaw acceleration r in "·" _act Even if the ratio α of "·" is close to 1, the possibility of giving the driver an uncomfortable feeling can be suppressed.

As another example of estimating the side slip angular velocity in the present embodiment, the following expression (10) after the deformation of expression (8) estimated using the actual lateral acceleration value output from the acceleration sensor, the vehicle speed V output from the vehicle speed sensor, and the actual yaw rate value r output from the yaw rate sensor is shown. In this case, the expression (10) may be used instead of the expression (8).

[ mathematical formula 8]

The vehicle motion control device according to the present embodiment described above can cause the roll motion to be linked with the yaw motion, compensate for the delay caused by the suspension damping and the like, and reduce the delay from the occurrence of the yaw angular velocity to the occurrence of the roll angle (reduce the phase delay of the roll motion with respect to the yaw motion), so that the driver can obtain a sense of unity with respect to the motion of the vehicle.

Fig. 9 is a block diagram of a yaw rate acceleration calculator 170A, which is a modification of the yaw rate acceleration calculator 170 in the present embodiment. The yaw rate accelerator operator 170A of fig. 9 also includes a yaw rate acceleration estimating unit 171, a differential calculating unit 173, and a yaw rate acceleration calculating unit 177, but in the example of fig. 3, the input of the ratio setting unit 175 is a yaw rate acceleration estimated value, whereas the example of fig. 9 is different in that: the inputs of the ratio setting portion 175A are the vehicle speed and the steering angle. The ratio setting portion 175A of fig. 9 sets the ratio α according to whether the vehicle posture is in a steady state or a quasi-transitional state or a transitional state, according to a condition predetermined using the vehicle speed and the steering angle as indexes.

The ratio α in the ratio setting unit 175A is set as in the graph shown in fig. 10, for example. In fig. 10, the characteristics (waveforms) of the ratio α may be different between the case of the vehicle speed V1 and the case of the vehicle speed V2 (V1 < V2). First, when the absolute value of the steering angular velocity δh "·" as the steering angular derivative value is equal to or smaller than the threshold value Bs1 for the vehicle speed V1, the vehicle posture is in a steady state, the ratio α is zero, when the absolute value of the steering angular velocity δh "·" exceeds the threshold value Bs1 and is equal to or smaller than the threshold value Be1, the vehicle posture is in a quasi-transient state, the larger the absolute value of the steering angular velocity δh "·" is, the larger the ratio α is in the range of 0 to 1, and when the absolute value of the steering angular velocity δh "·" exceeds the threshold value Be1, the vehicle posture is in a transient state, and the ratio α is 1. Similarly, even at the vehicle speed V2, when the absolute value of the steering angular velocity δh "·" as the steering angular derivative value is equal to or smaller than the threshold value Bs2, the vehicle posture is in a steady state, the ratio α is zero, when the absolute value of the steering angular velocity δh "·" exceeds the threshold value Bs2 and is equal to or smaller than the threshold value Be2, the vehicle posture is in a quasi-transient state, the larger the absolute value of the steering angular velocity δh "·" is, the larger the ratio α is in the range of 0 to 1, and when the absolute value of the steering angular velocity δh "·" exceeds the threshold value Be2, the vehicle posture is in a transient state, and the ratio α is 1. The threshold values have a relationship of Bs 1.gtoreq.Bs2 and Be 1.gtoreq.Be2, respectively.

In general, since the yaw rate acceleration r "·" of 1 vehicle indicates that the vehicle speed V and the steering angular velocity δ are proportional to h, if the condition as in fig. 10 is determined, the yaw rate acceleration calculator 170 of fig. 3 obtains the ratio α by using the yaw rate acceleration estimated value r _est "." set the same effect. That is, by setting the ratio α as shown in fig. 10, the yaw rate acceleration calculation value r is calculated when the change in the steering angle δh is small as in the straight running and the steady turning in which the vehicle posture is in the steady state _cal Noise contained in "·" may be reduced as shown in fig. 11 ((f) of fig. 11). Therefore, in the roll moment calculator 110, the yaw rate acceleration calculation value r is used in the expression (7) _cal Roll moment command value M calculated by "·" _φ The noise component contained in (a) is also reduced in the straight running and in the steady rotation (fig. 11 (h)). In straight running and steady turning, since the vehicle behavior variation is small, it is also sensitive to small vehicle posture variation due to control, but as described above, the value r is calculated by using the yaw angle acceleration _cal By the above, the occurrence of roll moment due to noise components can be reduced, and the sense of incongruity to the driver during straight running or steady turning in which the vehicle posture is in a steady state can be reduced. In addition, by using the steering angular velocity δh "·" in setting the ratio α, the steering intention of the driver can be reflected Therefore, the influence of disturbance such as crosswind or inclined road can be eliminated. In addition, the thresholds Bs and Be of the steering angular velocity δh″ in (b) of fig. 11 are the thresholds Bs1 and Be1 in the vehicle speed V1 of fig. 10, or the thresholds Bs2 and Be2 in the vehicle speed V2.

Unlike fig. 11, at the yaw acceleration estimated value r _est ". And yaw acceleration actual measurement value r _act When "·" is different in magnitude, for example, as shown in fig. 12, the absolute value of the yaw rate acceleration measured value is larger than the yaw rate acceleration estimated value r _est " _ast ", yaw acceleration estimation value r _est In "·" (fig. 12 (d)), the value r is calculated due to the yaw acceleration _cal " _cal1 “·”、r _cal2 As shown in fig. 12 (f), the actual vehicle behavior is reflected when the vehicle posture is in the quasi-transient state or the transient state. Therefore, the roll moment command value mΦ is also as in mΦ1 and mΦ2, respectively (fig. 12 (h)), which can reflect the actual vehicle behavior and have an appropriate value. Further, when the vehicle posture is in the transition state or the quasi-transition state close to the transition state, the yaw-angle acceleration calculation value r out of the roll-moment command value mΦ calculated by the expression (7) increases due to the increase in the side-slip angular velocity β generated in the vehicle _cal The influence of the noise component of "·" is relatively small, and the vehicle behavior change itself is also large, so that the yaw rate acceleration calculation value r during the vehicle behavior change is relatively small _cal The effect of the noise component of "·" is relatively small. Therefore, in the quasi-transition state in which the vehicle posture is in or near the transition state, the yaw tilt acceleration calculation value r _cal Measured yaw acceleration r in "·" _act Even if the ratio α of "·" is close to 1, the possibility of giving the driver an uncomfortable feeling can be suppressed.

The ratio setting units 175 and 175A may use the graphs shown in fig. 13 instead of the graphs of fig. 4 and 10, and set the ratio α according to whether the vehicle posture is in the steady state or in the quasi-transient state or in the transient state. The horizontal axis of the graph of fig. 13 represents the product of the absolute value of the vehicle speed V and the absolute value of the steering angular velocity δh "·". In fig. 13, when the product of the absolute value of the vehicle speed V and the absolute value of the steering angular velocity δh "·" is equal to or less than the threshold Cs, the vehicle posture is in a steady state, the ratio α is set to zero, when the product of the absolute value of the vehicle speed V and the absolute value of the steering angular velocity δh "·" exceeds the threshold Cs and is equal to or less than the threshold Ce, the vehicle posture is in a transitional state, the larger the product of the absolute value of the vehicle speed V and the absolute value of the steering angular velocity δh "·" is in a range of 0 or more and less than 1, and when the product of the absolute value of the vehicle speed V and the absolute value of the steering angular velocity δh "·" exceeds the threshold Ce, the vehicle posture is in a transitional state, and the ratio α is 1.

The roll moment calculator 110 of the present embodiment calculates the roll moment mΦ by the method (7) using the vehicle speed, the yaw angular velocity estimation value, and the yaw angular acceleration calculation value, and outputs the calculated roll moment mΦ to the actuator control unit 130A as the roll moment command value mΦ. In this case, the actuator control mechanism 130A calculates the vertical force command value FS shown in fig. 14 from the roll moment command value mΦ in order to control the vertical force of the active suspension 17 generating the roll moment _i (i=1 to 4) and output to the suspension control device 330. Roll moment command value Mphi and vertical force command value FS _i The relation of (2) is represented by the following formula (11). The active suspension 17 sets the distance between the left and right of the front wheel at the support point where the vehicle body generates vertical force to be ds _f The distance between the left and right of the rear wheel is ds _r 。

[ mathematical formula 9]

For example, in order not to generate pitch and heave, the sum of the vertical forces of the front and rear wheels is set to zero, and if the vertical forces of the diagonally positioned active suspensions 17 are equal and opposite in sign, FS for generating a roll moment satisfying the roll moment command value mΦ _i Can be calculated with the following 4 formulas.

[ mathematical formula 10]

Input of vertical force command value FS _i The suspension control apparatus 330 of (a) generates a roll moment by controlling the vertical force of the active suspension using a driving source not shown in the drawing. The driving source may be of hydraulic type, air pressure type, motor type, or the like. The vehicle 1A is caused to generate a roll moment satisfying the roll moment command value mΦ by the active suspension 17, and the roll motion of the vehicle is linked with the yaw motion while changing the magnitude of the roll motion, so that the driver can obtain an integrated feeling of the motion of the vehicle. In addition, in fig. 1, in order to generate the roll moment, an actuator capable of generating a vertical force on the vehicle body, such as an active stabilizer, may be used instead of the active suspension.

< embodiment 2 >

Fig. 15 shows embodiment 2. Fig. 15 shows an example in which the front-rear force of the in-wheel motor 19 is used for the control of the roll motion. In fig. 15, the difference from fig. 1 is that, instead of the active suspension 17 and the suspension control device 330 of fig. 1, a motor control device 350 is included, and the motor control device 350 includes an in-wheel motor 19 and inverters 351, 353, 355, 357 corresponding to four wheels. Fig. 16 is a block diagram of the vehicle motion control device 100B. Compared with the block diagram of fig. 2, fig. 16 is different in that: the output of the actuator control mechanism 130B is a front-rear force command value, and is output to the motor control device 350. As shown in fig. 17, the links of the suspension SP supported by the suspension arm SA are arranged to have virtual anti-pitchingAngle theta _f Or reverse downtilt angle theta _r In the case of (a), since a vertical force is generated in the vehicle body by the front-rear force of the in-wheel motor 19, the brake, or the like, the vertical force is used for the control of the roll motion. The actuator control means of the vehicle motion control device 100B calculates the front-rear force command value FX by the following equation (19) based on the roll moment command value mΦ according to the following equation (16) _i Output to the motor control device. By using the formulas (16) to (19), the roll moment satisfying the roll moment command value mΦ can be generated with the front-rear forces of four wheels.

[ mathematical formula 11]

In order to generate the roll moment, the braking force of the friction brake may be used instead of the braking force of the in-wheel motor. In addition, the reverse pitch angle θ _f Or reverse downtilt angle theta _r Smaller, but the braking/driving force of the engine or the on-board motor may be used. In addition, they may be combined.

It should be understood that the embodiments of the present disclosure are illustrative in all respects, and not restrictive. The scope of the present invention is indicated by the claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are intended to be embraced therein.

For example, even when the vehicle is changed to a system including a vehicle motion control device and an actuator such as an active suspension, the same operation and effects as those of embodiment 1 are achieved. In addition to the active suspension and the in-wheel motor, the same operation and effects as those of the respective embodiments described above can be achieved even when the actuators of the respective embodiments are changed to an active stabilizer, a four-wheel drive mechanism (including an engine or the on-board 1/2 motors) capable of driving the respective front and rear wheels, and a four-wheel independent control brake mechanism.

As described above, the preferred embodiments have been described with reference to the drawings, but various additions, modifications and deletions can be made without departing from the gist of the present invention. Accordingly, such a case is also included in the scope of the present invention.

Description of the reference numerals:

reference numerals 1, 1A, 1B denote vehicles;

reference numeral 17 denotes an active suspension (actuator);

reference numeral 19 denotes a hub motor (actuator)

Reference numerals 100, 100A, 100B denote vehicle motion control devices;

reference numeral 110 denotes a roll moment calculator;

reference numerals 130, 130A, 130B denote actuator control mechanisms;

reference numeral 150 denotes a sideslip angular velocity estimator;

reference numeral 170 denotes a yaw acceleration calculator;

reference numeral 171 denotes a yaw acceleration estimating unit;

reference numeral 173 denotes a differential operation section;

reference numeral 175 denotes a ratio setting section;

reference numeral 177 denotes a yaw acceleration operation unit;

reference numeral 210 denotes a yaw rate sensor;

reference numeral 250 denotes a steering angle sensor;

reference numeral 271 denotes a vehicle speed sensor;

reference numeral 400 denotes an actuator.

Claims

1. A vehicle motion control apparatus mounted on a vehicle, the vehicle motion control apparatus comprising: a side slip angular velocity estimator for estimating a side slip angular velocity of the vehicle and outputting a side slip angular velocity estimation value; a yaw acceleration calculator that calculates a yaw acceleration of the vehicle and outputs a yaw acceleration calculation value; a roll moment calculator that calculates and outputs a roll moment command value so that a roll motion and a yaw motion of the vehicle at the time of turning are linked, based on at least a product of a vehicle speed of the vehicle and the sideslip angular velocity estimated value and a product of the vehicle speed and the yaw angular acceleration calculated value; and an actuator control mechanism that controls an actuator mounted on the vehicle, the actuator causing the vehicle body to generate a roll moment, based on the roll moment command value,

2. The vehicle motion control apparatus according to claim 1, wherein the ratio setting portion sets the ratio in correspondence with whether or not a vehicle posture determined based on the vehicle speed and the steering angle is in any of the following states including: steady state, transitional state, or a quasi-transitional state between steady state and transitional state.

3. The vehicle motion control apparatus according to claim 2, wherein the vehicle posture is determined based on the yaw acceleration estimated value calculated from the vehicle speed and the steering angle.

4. The vehicle motion control apparatus according to claim 2, wherein the vehicle posture is determined from the vehicle speed and a steering angular velocity obtained by performing a time-differential calculation of at least the steering angle.

5. The vehicle motion control apparatus according to any one of claims 2 to 4, wherein in the ratio setting portion, when it is determined that the vehicle posture is in the steady state, the ratio is set to zero.

6. The vehicle motion control apparatus according to any one of claims 2 to 4, wherein in the ratio setting portion, when it is determined that the vehicle posture is in the transitional state, the ratio is set to 1.

7. The vehicle motion control apparatus according to any one of claims 2 to 4, wherein in the ratio setting portion, when it is determined that the vehicle posture is in the quasi-transitional state, the closer the vehicle posture is to the transitional state, the closer the ratio is to 1.

8. A vehicle mounted with the vehicle motion control apparatus according to any one of claims 1 to 7.

9. A system constituted by the vehicle motion control apparatus according to any one of claims 1 to 7 and the above-described actuator controlled by the vehicle motion control apparatus.