JP2000062594A - Running state detecting device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To high-precisely detect the lateral slide angle of a vehicle. SOLUTION: A reference value βref of a vehicle corrected by multiplying a differential value Δβ0 of a vehicle lateral slide angle computed from a relation formula between a yaw rate, a lateral direction acceleration, and a car speed by a road, a correction value ω according to a road state, such as a bank road and a cant, and a running state, such as a spin, is computed. By integrating the reference value βref, a vehicle lateral slide angle β is estimated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle running state detecting device for detecting the inclination of a road or the sideslip angle of a vehicle from steering angle, yaw rate, lateral acceleration, etc. used for controlling the attitude of the vehicle. .

[0002]

2. Description of the Related Art Conventionally, a vehicle state quantity such as a yaw rate or a steering angle of a running vehicle is detected to prevent sideslip or spin of the vehicle at the time of cornering, when an obstacle is urgently avoided, or when the road condition suddenly changes. Many restraint attitude controls have been proposed.

In this attitude control, it is important to estimate the sideslip angle of the vehicle and the road surface friction coefficient μ.

The road surface friction coefficient μ is estimated based on the time-series changes of the steering steering angle and the lateral acceleration, or the steering steering angle and the yaw rate. For example, on the high μ road for the same steering steering angle. A large vehicle state quantity (lateral acceleration and yaw rate) is obtained, while low μ
Since only a small vehicle state quantity can be obtained on the road, μ is calculated according to the increase or decrease of the ratio.

Further, the estimation of the vehicle sideslip angle is calculated by integrating the time differential component Δβ of the sideslip angle β defined by the relational expression of the yaw rate r, the lateral acceleration y and the vehicle speed v.

In Japanese Patent Laid-Open No. 8-332934, in order to detect the cant (road surface inclination) of the traveling path of the vehicle, the vehicle travels using a formula relating to the rate of change of vehicle speed, yaw rate, lateral acceleration, and lateral speed. It has been proposed to estimate the cant of the road and to estimate the sideslip angle by using a vehicle motion model.

[0007]

However, in the conventional μ estimation, lateral acceleration or yaw rate may occur on a sloped road surface such as a cant or a bank even if the steering angle is zero. If μ is estimated and calculated based on the response of the yaw rate or the lateral acceleration to the steering angle, a large error may occur.

Further, in the conventional estimation of the vehicle sideslip angle β,
Although it can be calculated without being much affected by μ, it is easily affected by the output error of the sensor, and the lateral acceleration and yaw rate can be obtained even if the steering rudder angle is 0 on an inclined road surface such as a cant or a bank. May occur, the calculated value may change suddenly.

The present invention has been made in view of the above-mentioned problems, and an object thereof is to detect a running state of a vehicle capable of accurately detecting an inclination of a running road by suppressing an influence of a sudden behavior change of the vehicle and a road surface friction coefficient μ. It is to provide a device.

Another object of the present invention is to provide a vehicle running state detecting device capable of quickly and highly accurately estimating the sideslip angle of a vehicle by a simple calculation.

[0011]

In order to solve the above-mentioned problems and to achieve the object, a vehicle traveling state detecting device of the present invention has the following constitution. That is, the yaw rate detecting means for detecting the yaw rate of the vehicle, the lateral acceleration detecting means for detecting the lateral acceleration of the vehicle, the yaw rate detected by the yaw rate detecting means, and the lateral acceleration detecting means. And a tilt detecting means for detecting a tilt of the traveling road surface of the vehicle from the reference value.

Also, preferably, the reference value is defined by a parameter applied to a first-order lag variable relating to lateral acceleration and yaw rate.

Further, preferably, the parameters are calculated by identification.

Further, preferably, when the parameter relating to the yaw rate is a and the parameter relating to lateral acceleration is b, the reference value is calculated by b / 1-a.

Further, preferably, the inclination detecting means is
If the reference value is approximately 1, it is determined to be a horizontal road, if the reference value is substantially 0, it is determined to be a bank road, and if the reference value is greater than 1, it is determined to be a cant road.

Further, the vehicle running state detecting device of the present invention has the following configuration. That is, at least a detection means for detecting a steering angle and a vehicle speed of the vehicle, a sideslip angle calculation means for estimating and calculating a sideslip angle of the vehicle from the steering angle and the vehicle speed detected by the detection means, and the sideslip angle calculation means. Correction means for correcting the sideslip angle calculated in step 1 according to the inclination state of the road.

Preferably, the lateral acceleration detecting means for detecting the lateral acceleration of the vehicle, the yaw rate detected by the detecting means, and the lateral acceleration detected by the lateral acceleration detecting means are used. It further comprises a calculating means for calculating a related reference value, and an inclination detecting means for detecting the inclination of the road surface of the vehicle from the reference value.

Further, preferably, the reference value is defined by a parameter applied to a first-order lag variable relating to lateral acceleration and yaw rate.

The parameters are calculated by identification.

A parameter relating to the yaw rate is a,
When the parameter relating to the lateral acceleration is b, the reference value is calculated by b / 1-a.

Also, preferably, the inclination detecting means is
If the reference value is approximately 1, it is determined as a flat road, if the reference value is approximately 0, it is determined as a bank road, and if the reference value is greater than 1, it is determined as a cant road.

Further, preferably, the correcting means further corrects the sideslip angle calculated by the sideslip angle calculating means in accordance with the turning state of the traveling road.

[0023]

As described above, according to the invention described in claim 1, by calculating the reference value related to the yaw rate and the lateral acceleration, and detecting the inclination of the road surface of the vehicle from the reference value. It is possible to accurately detect the inclination of the traveling road by suppressing the influence of the sudden behavior change of the vehicle and the road surface friction coefficient μ.

According to the second aspect of the invention, the reference value is defined by the parameter applied to the first-order lag variable relating to the lateral acceleration and the yaw rate.
The influence of the steering angle and the road friction coefficient μ can be suppressed and the inclination of the traveling road can be accurately detected.

According to the third aspect of the present invention, the parameter is calculated by identification, so that the inclination of the road can be accurately detected by a simple calculation.

According to the invention of claim 4, the reference value is calculated by b / 1-a, so that the inclination of the traveling road can be accurately detected by a simple calculation.

According to the fifth aspect of the present invention, if the reference value is approximately 1, it is determined to be a horizontal plane path, if the reference value is approximately 0, it is determined to be a bank road, and if the reference value is greater than 1, it is determined to be a cant path. Thus, the inclination of the traveling road can be easily detected from the calculation result of the reference value.

According to the sixth aspect of the invention, the sideslip angle of the vehicle can be estimated quickly and accurately by a simple calculation by correcting the sideslip angle according to the inclination state of the road. it can.

Further, according to the invention described in claim 7, by detecting the inclination of the road surface of the vehicle from the reference value,
It is possible to further improve the estimation accuracy of the sideslip angle of the vehicle.

According to the eighth aspect of the invention, the reference value is defined by the parameter applied to the first-order lag variable relating to the lateral acceleration and the yaw rate.
It is possible to accurately detect the inclination of the traveling path and further improve the estimation accuracy of the sideslip angle of the vehicle.

According to the ninth aspect of the present invention, the parameters are calculated by identification, so that the inclination of the road can be accurately detected by a simple calculation to improve the estimation accuracy of the sideslip angle of the vehicle. Can be increased.

According to the invention described in claim 10,
Since the reference value is calculated by b / 1-a, the inclination of the traveling road can be accurately detected by a simple calculation, and the estimation accuracy of the sideslip angle of the vehicle can be further improved.

According to the invention described in claim 11,
If the reference value is approximately 1, it is a plane road, if the reference value is approximately 0, it is a bank road, and if the reference value is greater than 1, it is a cant road. Can be detected, and the estimation accuracy of the sideslip angle of the vehicle can be further improved from the calculation result of the reference value.

According to the invention of claim 12,
By further correcting the sideslip angle according to the turning state of the traveling road, it is possible to further improve the estimation accuracy of the sideslip angle.

[0035]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. [First Embodiment] First, a method for detecting the inclination of a traveling road surface will be described as a first embodiment.

In the vehicle of this embodiment, as will be described later with reference to FIG. 9, the FR wheel speed sensor 11 and the FL wheel speed sensor 1 are used.
2. RR wheel speed sensor 13, RL wheel speed sensor 14, vehicle speed sensor 15, steering steering angle sensor 16, yaw rate sensor 17 for detecting yaw rate acting on the vehicle, lateral acceleration for detecting lateral acceleration acting in the vehicle width direction A sensor 18 and a longitudinal acceleration sensor 19 for detecting an acceleration acting in the longitudinal direction of the vehicle are provided. SCS / ECU
10 is a vehicle speed sensor 15 and a steering angle sensor 1
6, yaw rate sensor 17, lateral acceleration sensor 18,
The calculation described below is performed using each detection signal of the longitudinal acceleration sensor 19.

First, the parameters are identified based on the primary model shown in the following equation 1 regarding the yaw rate r and the lateral acceleration y, and the inclination of the traveling road surface is detected based on the gain calculated from these parameters.

[0038]

[Equation 1]

Here, k represents a sample number, and (a
yr, byr) are the identified parameters. A specific method of obtaining the parameters a and b is calculated by using the recursive least square method. The identification method is not limited to the least square method.

Based on these parameters, the yaw rate r
To the lateral acceleration y is calculated. The gain Gry is expressed by the following equation 2.

[0041]

[Equation 2]

The gain Gry can also be expressed by the following equations 3 to 4 where S is the Laplace operator and v is the vehicle speed.

[0043]

[Equation 3]

Then, by observing the response gain Gry from the yaw rate to the lateral acceleration, it is determined whether the traveling road surface of the vehicle is horizontal or the inclined road surface such as a cant or a bank.

That is, if the road surface of the vehicle is horizontal, the gain Gry will be a value close to 1, and if there is a cant, the yaw rate will remain 0 and the lateral acceleration output will be present, so it will be a value greater than 1 and there will be a bank. If so, the lateral acceleration remains 0 and the output appears at the yaw rate, so it is smaller than 1 and 0.
It is a value close to.

As described above, according to the first embodiment,
It is possible to accurately detect the inclination of the traveling road by suppressing the abrupt behavior change of the vehicle and the influence of the road surface friction coefficient μ. Second Embodiment Next, as a second embodiment, a method of estimating the friction coefficient μ of the road surface will be described.

This method estimates the friction coefficient μ of the traveling road surface based on the gain Gry calculated by the above equation 4.

In estimating the road surface friction coefficient μ, the above equation 4 is used.
In addition to the gain Gry from the yaw rate r to the lateral acceleration y calculated in step 1, the gain Gδr from the steering steering angle δ to the yaw rate r and the gain Gδy from the steering steering angle δ to the lateral acceleration y are used. These gains Gδ
r and Gδy are identified from the parameters based on the first-order models shown in the following equations 5 and 6, and are calculated from these parameters.

[0049]

[Equation 4]

Here, k represents a sample number, and (a
r, br) and (ay, by) are the identified parameters. A specific method of obtaining the parameters a and b is calculated by using the recursive least square method.

Based on these parameters, the gain Gδ
r and Gδy are calculated. The gains Gδr and Gδy are expressed by the following equations 7 and 8.

[0052]

[Equation 5]

FIG. 1 is a flow chart for explaining the method of estimating the friction coefficient μ of the road surface of the second embodiment. Figure 2
[Fig. 4] is a map showing the relationship between the gain Gδr from the steering steering angle δ to the lateral acceleration y and the road surface friction coefficient µ.
FIG. 3 is a map showing the relationship between the road friction coefficient μ and the gain Gδy from the steering steering angle δ to the lateral acceleration y or the gain Gδr from the steering steering angle δ to the yaw rate r. FIG. 4 shows the steering angle δ to the yaw rate r.
3 is a map showing the relationship between the gain Gδr and the road surface friction coefficient μ.

As shown in FIG. 1, in step S2, the output values of the yaw rate sensor, the lateral acceleration sensor, and the steering angle sensor are read. In step S4,
The gains Gδr, Gδy, and Gry are calculated from the above equations 2, 7, and 8.

In step S6, depending on whether or not the gain Gry is equal to or greater than the predetermined value a and equal to or less than the predetermined value b, the gain Gr is determined.
It is determined whether y is a value close to 1.

If the gain Gry is not less than the predetermined value a and not more than the predetermined value b in step S6 (YE in step S6).
S), the road surface μ is estimated using the map B shown in FIG. 3 in step S8. In step S8, since the gain Gry is close to 1 and the traveling road surface is considered to be horizontal, the road surface μ is estimated based on the yaw rate r with respect to the steering angle δ or the gain Gδr or Gδy for the lateral acceleration y.

On the other hand, if the gain Gry is not less than the predetermined value a and not less than the predetermined value b in step S6 (NO in step S6), the process proceeds to step S10.

In step S10, it is determined whether or not the gain Gry is smaller than 1 and close to 0 depending on whether the gain Gry is 0 or more and less than the predetermined value a.

If the gain Gry is 0 or more and less than the predetermined value a in step S10 (YE in step S10).
S), the road surface μ is estimated using the map A shown in FIG. 2 in step S12. In this step S12, the gain Gr
Since y is smaller than 1 and close to 0, it is possible that the vehicle is traveling on a bank road. In that case, the lateral acceleration may remain 0, and the yaw rate may contain a certain error component. The road surface μ is estimated based on the gain Gδy from the steering angle δ to the lateral acceleration y.

Further, in step S10, the gain Gry is 0.
If the above is not less than the predetermined value a (N in step S10)
O), and proceeds to step S14.

In step S14, it is determined whether or not the gain Gry is greater than 1 depending on whether the gain Gry is greater than the predetermined value b and less than the predetermined value c.

In step S14, the gain Gry is the predetermined value b
If it is larger and smaller than the predetermined value c (step S14)
YES), the road surface μ is estimated using the map C shown in FIG. 4 in step S16. In this step S16, the gain Gry is larger than 1, so there is a possibility that the vehicle is traveling on a cant road. In that case, there is a possibility that the yaw rate remains 0 and a predetermined error component is included in the lateral acceleration. Therefore, the gain Gδr of the yaw rate r from the steering steering angle δ
The road surface μ is estimated based on.

If the gain Gry is larger than the predetermined value b and not smaller than the predetermined value c in step S14 (NO in step S14), the process proceeds to step S18.

In step S18, it is judged that the gain Gry is far from 1 and the accurate estimation of the road surface μ is impossible, and the road surface μ is held at the previous value.

Since the lateral acceleration sensor is generally mounted on a spring, the lateral acceleration sensor detects the tilt component of the vehicle body even while traveling on a horizontal plane. Therefore, the gain G
A value slightly larger than 1 when judging the size of ry,
For example, about 1.1 (determined based on the magnitude of the vehicle body roll angle with respect to the lateral acceleration of 0.5 G) may be used as a reference.
Further, this reference value may be changed according to the transient response of the vehicle.

Further, reference values for determining the magnitude of the gain Gry are set to a1, a2, b1 and b2 in FIG.
The values of the maps A and B may be interpolated between the reference values a1 and a2.

As described above, according to the second embodiment,
The road friction coefficient μ can be estimated quickly and with high accuracy. [Third Embodiment] Next, a method for estimating the sideslip angle β of a vehicle will be described as a third embodiment.

According to this method, as shown in FIG. 6, the differential value of the vehicle sideslip angle β0 calculated from the relational expression 9 of the yaw rate r, the lateral acceleration y, and the vehicle speed v is converted into the bank road or the cant as shown in the expression 10. Reference value βre of vehicle sideslip angle corrected by applying a correction value ω according to the road surface condition such as road and running condition such as spin
The vehicle sideslip angle β is estimated by calculating f and integrating the reference value βref.

[0069]

[Equation 6]

When integrating this reference value βref,
In order to adjust the sensor delay due to the yaw rate component when traveling on bank road and the lateral acceleration component when traveling on cant road,
The reference value βref from which the delay component is removed is integrated by the gain expressed by the relational expression 11 of the yaw rate r and the reference value βref and the relational expression 12 of the lateral acceleration y and the reference value βref.

[0071]

[Equation 7]

Here, the correction value ω is set as the sum of the correction value ω1 based on the inclination of the road surface and the correction value ω2 based on the traveling state of the vehicle, as shown in equation 13.

Ω = ω1 + ω2 (13) The correction value ω1 based on the inclination of the road surface is the gain Gry from the yaw rate r defined by the above equation 4 to the lateral acceleration.
It is set based on the value of.

FIG. 7 is a map showing the relationship between the correction value ω1 based on the inclination of the road surface and the gain Gry from the yaw rate r to the lateral acceleration.

As shown in FIG. 7, if the gain Gry is close to 1, it is considered that the vehicle is traveling on a horizontal road surface, and if the gain Gry is close to 0 or larger than 1, the vehicle is running. Is considered to be traveling on the bank road or the cant road, the correction value ω1 is changed in the increasing direction as the gain Gry approaches 1.

Further, the correction value ω2 based on the running state of the vehicle
Is a gain Gry from the yaw rate r to the lateral acceleration y defined by the above equations 4, 7, and 8, a steering steering angle δ and a gain Gδr to the yaw rate, and a gain from the steering steering angle δ to the lateral acceleration y. It is set based on the gain Gδry calculated by the relational expression 13 regarding each value of Gδy.

[0077]

[Equation 8]

FIG. 8 shows the correction value ω based on the running state of the vehicle.
3 is a map showing the relationship between 2 and the gain Gδry.

As shown in FIG. 8, if the gain Gδry is close to 1, it is considered that the vehicle is normally running, and if the gain Gδry is close to 0 or larger than 1, the vehicle spins. Since it is considered that the vehicle is traveling or drifting out, the correction value ω2 is changed in the increasing direction as the gain Gδry is further away from 1.

As described above, according to the third embodiment,
The sideslip angle of the vehicle can be estimated quickly and highly accurately by a simple calculation. [Vehicle Attitude Control] Next, the vehicle attitude control commonly applied to the above-described embodiments will be described.

FIG. 9 is a diagram showing the overall structure of a control block of the vehicle attitude control system of this embodiment.

As shown in FIG. 9, the vehicle attitude control system according to the present embodiment, for example, when the traveling state of the vehicle is cornering, when an emergency obstacle is avoided, or when the road surface condition changes suddenly,
In order to prevent skidding and spin of a running vehicle,
The braking force on each of the left and right wheels is controlled. Each wheel has an FR (right front wheel) brake 31, FL (left front wheel) brake 32, RR (right rear wheel) such as a hydraulic disc brake.
A brake 33 and an RL (left rear wheel) brake 34 are provided. These FR, FL, RR, RL brakes 31-
34 are connected to the hydraulic control unit 30, respectively. The hydraulic control unit 30 is connected to each wheel cylinder (not shown) of the FR, FL, RR, and RL brakes 31 to 34, and applies a braking force to each wheel by introducing hydraulic pressure into the wheel cylinder of each brake 31 to 34. To do. The hydraulic control unit 30 is connected to the pressurizing unit 36 and the master cylinder 37. The master cylinder 37 generates a primary hydraulic pressure according to the pedal effort pressure of the brake pedal 38.
This primary hydraulic pressure is introduced into the pressurizing unit 36, and is pressurized to the secondary hydraulic pressure by the pressurizing unit 36, so that the hydraulic control unit 3
Introduced to zero. The hydraulic control unit 30 is SCSEC
It is electrically connected to U10, and FR, FL, RR, and RL brakes 31 to 3 according to a braking control signal from the ECU 10.
The hydraulic pressure to 4 is distributed and controlled to control the braking force to each wheel.

SCS (STABILITY CONTROLLED SYSTEM)
The ECU (ELECTRONIC CONTROLLED UNIT) 10 controls braking of front and rear wheels and left and right wheels as an attitude control device of the present embodiment, and also has conventionally known ABS (antilock brake system) control and traction control system control (hereinafter , Traction control). The SCS / ECU 10 includes an FR wheel speed sensor 11, an FL wheel speed sensor 12, and an RR wheel speed sensor 1.
3, RL wheel speed sensor 14, vehicle speed sensor 15, steering angle sensor 16, yaw rate sensor 17 for detecting a yaw rate acting on the vehicle, lateral acceleration sensor 18 for detecting a lateral acceleration acting in the width direction of the vehicle, front and rear of the vehicle The longitudinal acceleration sensor 19, which detects the acceleration acting in the direction, the brake pedal force pressure sensor 35, the EGI ECU 20, and the traction off switch 40 are connected.

The ABS control and the traction control will be briefly described. The ABS control means that when a wheel is suddenly braked and the wheels are likely to lock on the road surface, the braking force to the wheels is automatically adjusted. It is a system that controls and stops while suppressing the locking of the wheels, and traction control suppresses the phenomenon that the wheels slip on the road surface while the vehicle is traveling by controlling the driving force or braking force to each wheel. It is a system to drive while running.

The FR wheel speed sensor 11 outputs a detection signal v1 of the wheel speed of the right front wheel to the SCS • ECU 10. The FL wheel speed sensor 12 sends the detection signal v2 of the wheel speed of the left front wheel to the SC
Output to the S-ECU 10. The RR wheel speed sensor 13 outputs a detection signal v3 of the wheel speed of the right rear wheel to the SCS / ECU 10. The RL wheel speed sensor 14 outputs a detection signal v4 of the wheel speed of the left rear wheel to the SCS / ECU 10. The vehicle speed sensor 15 outputs the detection signal V of the traveling speed of the vehicle to the SCS / ECU 1
Output to 0. The steering angle sensor 16 outputs a steering rotation angle detection signal δ to the SCS / ECU 10. The yaw rate sensor 17 outputs a detection signal r of the yaw rate actually generated in the vehicle body to the SCS • ECU 10.
The lateral acceleration sensor 18 outputs a detection signal y of the lateral acceleration actually generated in the vehicle body to the SCS / ECU 10.
The longitudinal acceleration sensor 19 outputs a detection signal Z of the longitudinal acceleration actually generated in the vehicle body to the SCS / ECU 10. The brake pedal force pressure sensor 35 is provided in the pressurizing unit 36, and outputs the detection signal PB of the pedal effort pressure of the brake pedal 38 to S.
Output to CS / ECU 10. The traction off switch 40 is a switch for forcibly stopping the spin control (traction control) of the wheels, which will be described later, and outputs the switch operation signal S to the SCS / ECU 10. EGI
The (ELECTRONIC GASOLINE INJECTION) ECU 20 is connected to an engine 21, an AT (AUTOMATIC TRANSMISSION) 22, and a throttle valve 23, and controls output control of the engine 21, shift control of the AT 22, and opening / closing control of the throttle valve 23.

SCS · ECU 10 and EGI · ECU 2
Reference numeral 0 includes a CPU, a ROM, and a RAM, and executes an attitude control program and an engine control program stored in advance based on the input detection signals. <Outline of Attitude Control> In the attitude control of the present embodiment, braking control of each wheel is applied to apply a turning moment and a deceleration force to the vehicle body to suppress skidding of the front wheels or the rear wheels. For example, when the rear wheels are likely to skid while the vehicle is turning (spin), a brake is mainly applied to the front outer wheels to apply an outward moment to suppress the rolling-in behavior. Also, when the front wheels are likely to skid to the side of turning (drift out), an appropriate amount of brake is applied to each wheel to apply an inward moment, and the engine output is suppressed to add deceleration force to turn radius. Suppress the increase of.

Although the details of the attitude control will be described later, in general, the SCS / ECU 10 includes the vehicle speed sensor 15, the yaw rate sensor 17, and the lateral acceleration sensor 18 described above.
Various calculations described in the first to third embodiments are performed based on the detection signals V, r, and y, and the actual sideslip angle (hereinafter, referred to as the actual sideslip angle) βact occurring in the vehicle (the third embodiment described above). Corresponding to β0) and the actual yaw rate (hereinafter referred to as the actual yaw rate) ract, and the actual sideslip angle βa
Estimated sideslip angle βco actually used for ct to SCS control
The reference value βref referred to in the calculation of nt is calculated.
Further, the SCS-ECU 10 calculates a target sideslip angle βTR and a target yaw rate rTR as a posture to be a target of the vehicle from a detection signal from a steering angle sensor or the like, and calculates a difference between the estimated sideslip angle βcont and the target sideslip angle βTR or an actual yaw rate.
The attitude control is started when the difference between r0 and the target yaw rate rTR exceeds the predetermined threshold values β0 and r0, and the estimated actual sideslip angle βcont or the actual yaw rate ract is controlled to converge to the target sideslip angle βTR or the target yaw rate rTR.

The present invention can be applied to a modified or modified version of the above embodiment without departing from the spirit of the present invention.

[0089]

[Brief description of drawings]

FIG. 1 is a flowchart illustrating a method of estimating a friction coefficient μ of a traveling road surface according to a second embodiment.

FIG. 2 is a map showing a relationship between a gain Gδr from a steering steering angle δ to a yaw rate r and a road surface friction coefficient μ.

FIG. 3 is a map showing a relationship between a road friction coefficient μ and a gain Gδy from a steering steering angle δ to a lateral acceleration y or a gain Gδr from a steering steering angle δ to a yaw rate r.

FIG. 4 is a map showing a relationship between a gain Gδr from a steering steering angle δ to a yaw rate r and a road surface friction coefficient μ.

FIG. 5 is a diagram illustrating another method for determining the magnitude of gain Gry.

FIG. 6 is a block diagram showing a logic for estimating a vehicle sideslip angle.

FIG. 7 is a correction value ω1 and yaw rate r based on the inclination of the road surface.
3 is a map showing a relationship between a horizontal direction acceleration and a gain Gry.

FIG. 8 is a correction value ω2 and a gain G based on the running state of the vehicle.
It is a map showing the relationship with δry.

FIG. 9 is a diagram showing an overall configuration of a control block of the vehicle attitude control device of the present embodiment.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor, Teru Iyoda             3-1, Shinchi, Fuchu-cho, Aki-gun, Hiroshima Prefecture Mazda             Within the corporation F term (reference) 3D045 BB40 GG00 GG25 GG26 GG27                       GG30                 3D046 BB25 BB26 HH00 HH08 HH22                       HH25 HH28

Claims (12)

[Claims] 1. A yaw rate detecting means for detecting a yaw rate of a vehicle, a lateral acceleration detecting means for detecting a lateral acceleration of the vehicle, and a yaw rate detected by the yaw rate detecting means.
It is provided with a calculating means for calculating a reference value related to the lateral acceleration detected by the lateral acceleration detecting means, and an inclination detecting means for detecting an inclination of a traveling road surface of the vehicle from the reference value. The vehicle running state detection device. 2. The vehicle running state detection device according to claim 1, wherein the reference value is defined by a parameter applied to a first-order lag variable relating to lateral acceleration and yaw rate. 3. The vehicle running state detection device according to claim 2, wherein the parameter is calculated by identification. 4. The vehicle according to claim 3, wherein the reference value is calculated by b / 1-a, where a is a parameter relating to the yaw rate and b is a parameter relating to lateral acceleration. State detection device. 5. The reference value of the inclination detecting means is approximately 1.
If the reference value is substantially 0, the road is a bank road, and if the reference value is greater than 1, it is a cant road. 6. A detection means for detecting at least a steering angle and a vehicle speed of a vehicle, a sideslip angle calculation means for estimating and calculating a sideslip angle of the vehicle from the steering angle and the vehicle speed detected by the detection means, and the sideslip. A running condition detection device for a vehicle, comprising: a correcting device that corrects the sideslip angle calculated by the angle calculating device according to a tilted state of a running road. 7. A reference relating to a lateral acceleration detecting means for detecting a lateral acceleration of a vehicle, a yaw rate detected by the detecting means, and a lateral acceleration detected by the lateral acceleration detecting means. The vehicle running state detection device further comprising: a calculating unit that calculates a value; and an inclination detecting unit that detects an inclination of a traveling road surface of the vehicle from the reference value. 8. The vehicle running state detection device according to claim 7, wherein the reference value is defined by a parameter applied to a first-order lag variable relating to lateral acceleration and yaw rate. 9. The vehicle running state detection device according to claim 8, wherein the parameter is calculated by identification. 10. The vehicle according to claim 8, wherein the reference value is calculated by b / 1−a, where a is a parameter relating to the yaw rate and b is a parameter relating to lateral acceleration. State detection device. 11. The inclination detecting means determines that the reference road is a flat road if the reference value is approximately 1, a bank road if the reference value is substantially 0, and a cant road if the reference value is greater than 1. The traveling state detection device for a vehicle according to claim 8 or 10. 12. The vehicle running state detecting apparatus according to claim 6, wherein the correcting unit further corrects the sideslip angle calculated by the sideslip angle calculating unit according to a turning state of a road. .