JP3304797B2 - Body speed estimation device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an anti-lock brake control device (ABS) for preventing wheels from locking during braking of a vehicle, and an acceleration slip control device for preventing driving wheels from idling when suddenly starting. The present invention relates to a vehicle speed estimating device for calculating a vehicle estimated speed used for (TCL) and the like, and more particularly to a vehicle speed estimating device for calculating a vehicle speed based on a slip angle, a longitudinal acceleration, and a lateral acceleration of a vehicle.

[0002]

2. Description of the Related Art For example, in antilock brake control,
Braking is performed while controlling the wheel speed to a slip ratio of about 20% with respect to the vehicle speed. However, it is necessary to estimate the vehicle speed during antilock brake control, and various estimation techniques have conventionally been employed. As such a conventional technique for estimating the vehicle speed, a technology for detecting the front and rear G of the wheels and estimating the vehicle speed from the vehicle speed at the start of braking and the integrated value of the front and rear G has been known (Japanese Patent Laid-Open No. 57-111149). No.). Further, as described in JP-A-2-306865, in antilock brake control, during deceleration by braking, a vehicle speed obtained by integrating a value obtained by adding a 0.3G offset to a vehicle deceleration detected by a G sensor is obtained. Also, a technique has been proposed in which acceleration = 1.0 G is integrated to obtain the vehicle speed while the braking force is weakened and the vehicle speed returns. Further, as described in Japanese Patent Application Laid-Open No. 3-54058, although the vehicle speed is estimated based on the wheel speed in principle, the estimated vehicle speed is determined by a predetermined acceleration upper limit (0.5 G) and a deceleration upper limit (0.5 G). There is also proposed a technique in which an upper limit and a lower limit guard are provided so as to be in the range of 1.0 G). Furthermore, as described in JP-A-6-107142,
There has also been proposed a technique of detecting accelerations in two axial directions in a horizontal plane, synthesizing them, obtaining a horizontal speed, and estimating a vehicle speed.

[0003]

Generally, the vehicle deceleration during turning of the vehicle body is a deceleration (Gox) in a tangential direction of a turning circle of the vehicle body during turning as shown in FIG. However, if the vehicle body deceleration is detected only by the acceleration (Gx) in the vehicle longitudinal direction, Gx becomes a small value with respect to Gox, so that the problem shown in FIG. 11 occurs.

For example, in FIG. 11A, the estimated vehicle speed used for the antilock brake control is calculated higher than the actual vehicle speed because the detected deceleration Gx is smaller than Gox. No deceleration can be obtained.
In FIG. 11B, the estimated vehicle speed used for traction control is calculated to be lower than the actual vehicle speed because the detected acceleration Gx is smaller than Gox, and a desired acceleration cannot be obtained. . In order to correct these, there is a method as disclosed in JP-A-6-107142,
In this method, when the slip angle β of the vehicle body is large (see FIG. 1).
0 (A)) or when the lateral acceleration Gy is small even when the slip angle β is small or zero (FIG. 10 (B)), the combined vector Gxy of the longitudinal acceleration Gx and the lateral acceleration Gy is substantially tangential. However, as shown in FIG. 10C, when the lateral acceleration Gy is large even when the slip angle is small or zero, the resultant vector Gxy becomes larger than the tangential acceleration, as shown in FIG. The problem shown in FIG. 12 occurs.

For example, in FIG. 12 (A), the estimated vehicle speed used for the antilock brake control is calculated to be considerably lower than the actual vehicle speed because the deceleration Gxy used for the estimation is larger than Gx. The desired performance cannot be obtained because the amount becomes large. In FIG. 12B, the estimated vehicle speed used for the traction control is calculated to be considerably higher than the actual vehicle speed because the acceleration Gxy used for the estimation is larger than Gx, and the slip amount increases. Therefore, desired performance cannot be obtained.

An object of the present invention is to provide a vehicle speed estimating apparatus capable of estimating a vehicle speed with high accuracy required for performing anti-lock brake control and acceleration slip control.

[0007]

Means for Solving the Problems In order to achieve the above object, the present invention is configured as follows. The invention according to claim 1 is a longitudinal G detecting means for detecting a longitudinal acceleration of the vehicle, a lateral G detecting means for detecting a lateral acceleration of the vehicle, a yaw rate detecting means for detecting a yaw rate of the vehicle, and the longitudinal direction. A vehicle body slip angle calculating means for calculating a slip angle of the vehicle body based on the acceleration, the lateral acceleration, and the yaw rate; and a vehicle turning angle based on the output of the vehicle body slip angle calculating means, the longitudinal G detecting means and the lateral G detecting means. A tangential acceleration calculating means for calculating a tangential acceleration of a turning circle of the vehicle, and a vehicle speed calculating means for calculating a vehicle speed based on an output value of the tangential acceleration calculating means are provided.

According to a second aspect of the present invention, in the vehicle speed estimating apparatus according to the first aspect, the vehicle body slip angle calculating means and the tangential acceleration calculating means are configured to repeatedly execute each calculation, and Angle calculation means, the preceding and following G detection means, the yaw rate detection means, the previous calculation result of the vehicle body slip angle calculation means,
A vehicle body slip angular velocity calculating means for calculating a vehicle body slip angular velocity from a previous calculation result of the vehicle speed calculating means,
The vehicle body slip angle is calculated based on the output of the vehicle body slip angular velocity calculating means.

According to a third aspect of the present invention, in the vehicle speed estimating apparatus according to the first or second aspect, a reference vehicle speed output for outputting a speed in a direction in which the vehicle is facing based on an output of the vehicle body slip angle calculating means. Means are provided. According to a fourth aspect of the present invention, in the vehicle body speed estimating apparatus according to any one of the first to third aspects, a steering angle detecting means for detecting a turning angle of a tire and a wheel rotational speed difference in a front-rear direction during turning are calculated. Front and rear wheel speed difference calculating means, inner and outer wheel speed difference calculating means for calculating a wheel rotation speed difference between an inner wheel and an outer wheel during turning, an output of the vehicle body speed calculating means, and an output of the vehicle body slip angle calculating means. And a reference wheel speed output means for outputting a speed corresponding to each wheel.

Next, such an invention will be described in detail with reference to FIG. FIG. 1A is a diagram illustrating the operation of the present invention, and FIG.
Is a block diagram of the element. In FIG. 1A, G
x is a longitudinal acceleration, which is obtained from a longitudinal acceleration sensor. Here, the longitudinal acceleration Gx may be calculated from the output of the wheel speed detecting means. Gy is a lateral acceleration, which is obtained from a lateral acceleration sensor. YAW is a yaw rate (angular velocity), which is obtained from a yaw rate sensor. For the vehicle body speed V and the vehicle body slip angle β, the immediately preceding values (the values obtained by the immediately preceding calculation) are used. Initially, the initial values V = Vweel and β = 0 are used for the vehicle speed V and the vehicle slip angle β. The arithmetic expression of the slip angular velocity β is derived from the relationship of the following expressions 1), 2) and 3) in FIG. ω is the revolution speed of the vehicle body, and β ₁ is the differential value of β.

[0011] _{YAW = β 1 + ω ...... 1} ) Goy = V · ω β 1 = YAW-ω β 1 = YAW- (Goy / V) Goy = -Gx · sinβ + Gy · cosβ β 1 = YAW - {(- Gx · sinβ + Gy · cosβ) / V} ...... 2) β = ∫β 1 · dt ...... 3)

Goy = −Gx · sinβ + Gy · cosβ Gox = Gy · sinβ + Gx · cosβ... 4) V = V ₀ + ∫t ₀ Gox · dt... 5) Goy: Acceleration (deceleration) in the centripetal direction Gox: Tangent line Direction acceleration (deceleration) V: estimated vehicle speed V ₀ : initial vehicle speed (vehicle speed at the start of estimation, for example, actual wheel speed)

FIG. 1B is an element block diagram showing the above operation in a block diagram. The longitudinal acceleration sensor 5, the lateral acceleration sensor 6, and the yaw rate sensor 9 determine Gx, Gy,
YAW, and the vehicle speed V and the vehicle slip angle β
Can be obtained from the immediately preceding values (the values obtained in the immediately preceding calculation), respectively (the initial values V = Vweel and β = 0 are used for the vehicle speed V and the vehicle body slip angle β at the beginning). the known data from the 2) the vehicle body slip angular velocity beta ₁ further vehicle body slip angular velocity beta ₁ the 3) it is possible to determine the vehicle body slip angle beta by the integration can be as shown in equation from the equation.

Next, the calculated slip angle β, Gx,
Based on Gy, the acceleration Gox in the tangential direction of the turning circle of the turning vehicle can be obtained from the above equation (4). Further, the output value Gox of the tangential acceleration calculating means and the initial vehicle speed V ₀ are known, and the estimated vehicle speed V during the turning of the vehicle is accurately estimated by calculating the estimated vehicle speed V based on the above equation (5). Can be done.

Therefore, according to the present invention, the front and rear G (Gx) detecting means 5, the lateral G (Gy) detecting means 6, the yaw rate (YA)
W) Detecting means 9, vehicle body slip angle calculating means 20 for calculating vehicle body slip angle β based on Gx, Gy, YAW
And the tangential acceleration Gox from the tangential acceleration calculation means 25 for obtaining the tangential acceleration of the turning circle of the turning vehicle based on the Gx, Gy, β, and the wheel speed Vweel from the wheel speed detection means 26. The object of the present invention is achieved by providing the vehicle speed calculating means 27 for calculating the vehicle speed based on the vehicle speed.
Further, the vehicle body slip angle calculation means 20 and the tangential acceleration calculation means 25 are configured to repeatedly execute each calculation, and the vehicle body slip angle calculation means 20 includes a vehicle body slip angular velocity β ₁ calculation means 21 and the β _And a calculating means 22 for calculating the vehicle body slip angle β based on ₁ .

According to the third aspect of the present invention, in particular, A
When the slip angle β exists at the time of the BS control or the TCL control, the reference vehicle speed, which is the speed in the direction in which the vehicle is facing, is calculated as V · cos using the estimated vehicle speed V and the slip angle β.
By using β for the ABS and TCL controls, slip control can be performed based on the direction in which the vehicle is facing.

[0017] The invention of claim 4, wherein obtains a steering angle theta ₀ tire from the detection output theta of the steering wheel angle detecting means 28, and obtains the wheel speed difference between the front and rear wheels when the wheel speed difference and the turning of the turning inner and outer By providing the calculating means 29, a reference wheel speed which is a speed in consideration of a speed difference due to a different turning radius at each wheel position and a traveling direction of each wheel is output for each wheel, and the ABS control, Since the slip control is used for the TCL control, the slip control can be performed with higher accuracy.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be illustratively described in detail below with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention unless otherwise specified, and are merely illustrative examples. Only. First, FIG. 2 to FIG. 10 show an embodiment of a vehicle speed estimation apparatus according to an embodiment of the present invention, FIG. 2 is a system configuration diagram showing a vehicle control system according to the present invention, and FIG. 4 to 6 are flowcharts showing detailed control contents of FIG. 3, FIG. 7 is a diagram showing deceleration used in ABS control, FIG. 8 is an estimated vehicle speed in ABS control, and actual vehicle speed. FIG. 9 shows the relationship between the speed and the wheel speed.
FIG. 7 is a diagram showing a relationship among an estimated vehicle speed, an actual vehicle speed, and wheel speeds.

As shown in FIG. 2, a vehicle control system according to an embodiment of the present invention includes an engine control device 1 for controlling engine output and the like for controlling vehicle traction and the like as a system control device, and a hydraulic brake. A while controlling the hydraulic pressure of the
The hydraulic control unit 3 for performing the BS control and the engine control device 1 and the hydraulic control unit 3 each include a central control device 4 for inputting a control signal based on the operation state of the vehicle. Front-rear G detection sensor 5 for detecting front-rear direction acceleration, lateral G sensor 6 for detecting lateral acceleration of vehicle body, wheel speed detection sensor 7 for detecting wheel speed, and detecting steering angle of steering wheel for determining the traveling direction of vehicle body A steering wheel angle sensor 8 and a yaw rate detection sensor 9 for detecting a yaw rate (angular velocity) of the vehicle are provided.

The central control unit 4 has a ROM, R
The microcomputer includes a microcomputer including an AM, an I / O, a CPU (MPU), a power supply circuit, a backup power supply circuit, and the like. The front / rear G detection sensor 5, the lateral G sensor 6, the wheel speed detection sensor 7, and the steering wheel angle sensor 8 , Is inputted to the central control unit 4 via the I / O. The control of the central control unit 4 will be described in detail with reference to FIG. 3. First, in step S1, the power of the drive circuit is turned on by turning on a key switch (not shown).
Then, the process proceeds to step S2 to initialize the set values (counters, various flags, etc.) used for various controls, and further proceeds to step S3, where the sensors 5 and 5 are used.
The sensor signal processing of various signals output by 6, 7, and 8 is performed. When the sensor signal processing is completed, the vehicle body slip angle calculation processing is performed in step S4, the vehicle body deceleration calculation processing is performed in step S5, and the vehicle speed estimation calculation processing corresponding to the present invention is performed in step S6. When the brake is depressed, the anti-lock brake control (AB) is performed in step S7 using the estimated vehicle speed estimated in step S6.
S control). Next, proceeding to step S8, it is determined whether or not the elapsed time t of the free running timer is equal to or longer than the control cycle time TL. If the elapsed time t is shorter than the control cycle time TL, it is estimated in step S6 until the elapsed time t becomes equal to or longer than the control cycle time TL. When the elapsed time t of the free running timer becomes equal to or longer than the control cycle time TL, the control returns to step S3, and the control of steps S3 to S7 is repeated to perform the next estimation. A vehicle speed estimation process is performed.

Hereinafter, the contents of each process will be described in detail. (Vehicle Body Slip Angle Calculation Processing) The vehicle body slip angle calculation processing in step 4 will be described in detail with reference to FIG. 4. First, in step S10, the vehicle body slip angle is calculated based on the output of the steering wheel angle sensor 8 or the output of the yaw rate detection sensor 9. It is determined whether the turning direction is the same as the turning direction before the determination. If the turning directions are the same, the process proceeds to step S11. If the turning directions are different, the process proceeds to step S20 to reset the slip angle β to the initial value 0, and proceeds to step 5 (vehicle deceleration calculation) of the next process. In step S11, it is determined whether or not the vehicle speed V is V> A. When V ≦ A, it is determined that the vehicle speed is such that no slip can occur except when the wheel speed is higher than the vehicle body speed, and the process proceeds to step S20, where the vehicle body slip angle β is set to β = 0, and the next process is performed in step 5 (vehicle reduction). (Speed calculation).

If the vehicle speed V is greater than A in step S11, it is determined that slip is likely to occur, and step S1 is executed.
Proceed to 2 and β (n-1) at the previous vehicle body slip angle β (n-1)
It is determined whether ≧ 0, and the slip angular velocity β ₁ is calculated separately for acceleration / deceleration turning motion (when there is slip) and constant speed turning motion (when there is no slip). Step S12
When the previous slip angle β (n-1) is determined to be acceleration / deceleration turning motion, the process proceeds to step S13, where the yaw rate Y
AW, longitudinal Gx, lateral Gy, obtaining the vehicle body slip angular velocity beta ₁ from the vehicle speed V. In this case, the slip angular velocity β ₁ is obtained by the calculation of the equation 2) β ₁ = YAW − {(− Gx · sinβ + Gy · cosβ) / V} (2) Here, Gx, Gy, and YAW are values input from the G sensors 5, 6 and the yaw rate detection sensor 9, and β is basically a value obtained by the immediately preceding calculation (at the start of control). Uses an initial value of 0 for β).

In step S12, the previous slip angle β
When the determination of (n-1) is a constant velocity turning motion, step S14
To determine the vehicle body slip angular velocity β ₁ from the yaw rate YAW, the lateral acceleration Gx, and the vehicle body velocity V. The slip angular velocity β _{1 in} this case is obtained by the calculation of β ₁ = YAW − (− Gx) / V. Step S13 or Step 14
In obtains a slip angular beta ₁ then proceeds to step S15 after performed a calculation of the slip angle beta. The calculation of the slip angle β is obtained by β = ∫β ₁ · dt (3).

Specifically, first, in step S15, it is determined whether or not the current turning motion is a motion having a large slip angular speed, based on whether or not the slip angular speed β ₁ > B. If the slip angular velocity β ₁ > B, that is, if the slip angular velocity is large, the process proceeds to step S16, where the slip angular velocity β ₁ is multiplied by the control cycle time TL as shown in equation 3 ′),
It is added to the previous slip angle β (n-1). β (n) = β (n-1) + β ₁ · TL 3 ′) This is set as the current slip angle. Slip angular velocity β ₁ ≦
In the case of B, that is, when the value of the slip angular velocity is small and is a value that can be generated due to a sensor error or the like, the process proceeds to step S17, and it is determined whether the current turning motion is in a stable state. judge. If the determination in step S17 is that the slip angular velocity β ₁ ≧ B, it is determined that the current turning motion is not sufficiently stable, and the flow advances to step S21 with the slip angle β (n-1) as the current slip angular velocity. The value of the free running timer t (n) is reset to 0, and the process exits the vehicle body slip angle calculation processing flow and shifts to the next processing step.

In step S17, the slip angular velocity β
_{If 1} <C, it is determined that the current turning motion is stable, and the process proceeds to step S18. In order to measure the duration of the stable turning motion, the free running timer t (n) is set to t (n) = Set to t (n-1) + TL. Then, the process proceeds to the next step S20, where t>
Dt is determined. The determination in step S20 is t ≦ D
If t, the process proceeds to the next process. If t> Dt, the vehicle body slip angle β is reset to β = 0, and the process proceeds to step 5 of the next process.

(Calculation Processing of Vehicle Deceleration) Next, the calculation of the vehicle deceleration in step S5 will be described in detail with reference to FIG.
First, at step 25, it is determined whether or not the vehicle body slip angle β obtained by the flow of FIG. When β ≧ 0, that is, when the direction of the vehicle body is inward with respect to the tangential direction of the turning circle, the process proceeds to step 26, and the vehicle body deceleration is calculated by the calculation process of Gox = Gy · sinβ + Gx · cosβ. . Here, in equation (4), the calculation may be performed with cosβ = 1 in the second term on the right side. If β <0, the process proceeds to step 26 where the detection signal from the longitudinal acceleration sensor is taken as it is (Gox = G
x) Set the vehicle body deceleration.

(Vehicle Speed Estimation Process) The vehicle speed estimation process in step S6 will be described in detail with reference to FIG. In this estimation, first, at step S30, the wheel speed Vsel is calculated from the left and right VFL, VFR, VRL, VRR detected by the wheel speed sensor 7, and then at step S31, the deceleration Gsp (last deceleration), Gslp ( (Current deceleration). In this case, Vsel is obtained from the function of f (VFL, VFR, VRL, VRR). Here, one of the four wheels, for example, VFL may be selected. In the case of ABS, the decelerations Gsp and Gslp are Gsep = f1 (Gx) and Gsl, as shown in FIG.
It is determined from p = f2 (Gx). Deceleration G in step S31
After obtaining sp and Gslp, the process proceeds to step 32 and thereafter to start estimating the vehicle speed.

First, at step S32, d / dt · Vsel
<Gsp is determined. In the case of ABS, if the wheels are locked, d / dt · Vsel <Gsp is established, in other words, the condition for starting the vehicle speed estimation for ABS control. Therefore, when d / dt · Vsel <Gsp, the process proceeds to step S33 to turn on the estimation flag indicating the state of the vehicle body speed estimation, and then proceeds to step 34 to determine whether the estimation flag is ON or OFF. d / dt · Vsel ≧ Gs
In the case of p, step 33 is jumped to step 34
To determine whether the estimation flag is ON. Step 3
4, when the estimation flag is ON, d / dt · Vsel ≧ Gs
Even if it is p, it indicates a state in which the vehicle speed estimation for the ABS control is being performed, and the process proceeds to step 35.

[0029] At step _{35, VB = V 0 + ∫t} 0 Gslp · dt V 0: the vehicle initial velocity of the vehicle body speed estimating the start point, to calculate the body speed VB, VB is the wheel speed Vsel that the arithmetic in the step 36 It is determined whether or not: If VB is larger than Vsel, VB is set to the vehicle speed, and the next process, for example, the ABS control shown in step 7 of FIG. 3 is performed. When Vsel ≧ VB in step 36, the estimation flag is set to O.
FF, the process proceeds to step S38, and VB = Vsel.
When the estimation flag is OFF in steps 37 and 34, the process proceeds to step 38, where VB = Vsel, and the process proceeds to the next step 7.

(ABS Control, TCL Control) In step 7, during the turning of the vehicle, in particular, in the ABS control or the TCL control in which the slip angle β exists, first, the estimated vehicle speed VB estimated by the vehicle speed estimation shown in FIG. By using the slip angle β and using the reference vehicle speed VB · cosβ for control, the direction in which the vehicle is facing, that is, the longitudinal acceleration G
Slip control is performed based on the x direction.

More specifically, taking into account the steering angle θ of the steering wheel angle sensor, the turning angle θ _{0 of the} tire, the wheel speed difference between the inner and outer wheels during turning and the wheel speed difference between the front and rear wheels during turning, the front outer wheel, the front outer wheel, Reference wheel speeds VBf ₀ , corresponding to the inner wheel, the rear outer wheel, and the rear inner wheel,
VBf _i, VBr _0, VBr _i, respectively set as follows. _{VBf 0 = VB · cos (β} + θ 0) + Vf 0 VBf i = VB · cos (β + θ 0) -Vf i VBr 0 = VB · cosβ + Vr 0 VBr i = VB · cosβ-Vr i

[0032] _{However, Vf 0, Vf i, Vr} 0, Vr i is a correction value wheelbase, tread, determined by center-of-gravity position and calculation based on the above slip angle beta.

According to this embodiment, for example, in FIG. 8, in the case of the anti-lock brake control, the actual vehicle speed indicated by the dotted line substantially matches the estimated vehicle speed indicated by the solid line, or the estimated vehicle speed is compared with the actual vehicle speed. It is possible to make it slightly smaller, so that accurate brake control can be performed. Also, in FIG. 9, in the case of the acceleration slip control, the actual vehicle speed shown by the dotted line and the estimated vehicle speed shown by the solid line are almost the same, or the estimated vehicle speed can be made slightly higher than the actual vehicle speed. Can be improved.

[0034]

As described above, according to the present invention, it is possible to estimate a highly accurate vehicle speed required for performing antilock brake control and acceleration slip control.

[Brief description of the drawings]

FIG. 1A is an explanatory diagram of the operation of the present invention, and FIG. 1B is an element block diagram thereof.

FIG. 2 is a system configuration diagram illustrating a vehicle control system according to the present invention.

FIG. 3 is a flowchart showing a main flow of the central control device.

FIG. 4 is a flowchart showing the content of a vehicle body slip angle calculation process of the central control device.

FIG. 5 is a flowchart showing the content of a calculation of a vehicle body deceleration by the central control device.

FIG. 6 is a flowchart showing the content of vehicle speed estimation by the central control device.

FIG. 7 is a diagram showing estimated deceleration used for ABS control.

FIG. 8 is a diagram illustrating a relationship among an estimated vehicle speed, an actual vehicle speed, and wheel speeds in ABS control.

FIG. 9 is a diagram showing a relationship among an estimated vehicle speed, an actual vehicle speed, and wheel speeds in TCL control.

10A and 10B show a composite vector Gxy of a longitudinal acceleration Gx and a lateral acceleration Gy when the vehicle is turning, and FIG. 10A shows a lateral acceleration Gy in which the slip angle β of the vehicle body is large.
Is small, (b) shows a case where the slip angle β is small or zero and the lateral acceleration Gy is small, and (c) shows a case where the slip angle β is small or zero and the lateral acceleration Gy is large. .

FIG. 11 (A) shows the wheel speed when the estimated vehicle speed shown by the solid line is lower than the actual vehicle speed shown by the dotted line in the case of the antilock brake control, by a dashed line.
(B) shows the wheel speed when the estimated vehicle speed shown by the solid line becomes lower than the actual vehicle speed shown by the dotted line in the case of the acceleration slip control, by a dashed line.

FIG. 12A is a diagram showing a relationship among an estimated vehicle speed, an actual vehicle speed, and wheel speeds in the conventional ABS control.
(B) is a diagram showing a relationship between the estimated vehicle speed, the actual vehicle speed, and the wheel speed in the conventional TCL control.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Engine control device 2 Wheel 3 Hydraulic control unit 4 Central control device 5 Front and rear G detection sensor 6 Lateral G detection sensor 7 Wheel speed detection sensor 8 Handle angle sensor 9 Yaw rate detection sensor

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-8-268257 (JP, A) JP-A-6-107142 (JP, A) JP-A-2-306865 (JP, A) JP-A-7-107 215190 (JP, A) JP-A-8-310366 (JP, A) JP-A-62-125944 (JP, A) JP-A-5-208669 (JP, A) JP-A-61-291261 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) B60T 8/32-8/96

Claims (4)

(57) [Claims] 1. A front-rear G for detecting a longitudinal acceleration of a vehicle.
Detecting means; lateral G detecting means for detecting a lateral acceleration of the vehicle; yaw rate detecting means for detecting a yaw rate of the vehicle; and a vehicle body for calculating a slip angle of the vehicle body based on the longitudinal acceleration, the lateral acceleration, and the yaw rate A tangential acceleration calculating means for calculating a tangential acceleration of a turning circle of the turning vehicle based on outputs of the vehicle body slip angle calculating means, the longitudinal G detecting means and the lateral G detecting means; A vehicle speed calculating means for calculating a vehicle speed based on an output value of the tangential acceleration calculating means. 2. The vehicle body speed estimating device according to claim 1, wherein the vehicle body slip angle calculating means and the tangential acceleration calculating means are configured to repeatedly execute each calculation, and wherein the vehicle body slip angle calculating means includes: A front / rear G detecting means; a yaw rate detecting means; and a vehicle body slip angular velocity calculating means for calculating a vehicle body slip angular velocity from a previous calculation result of the vehicle body slip angle calculating means and a previous calculation result of the vehicle speed calculating means. A vehicle speed estimating device configured to calculate a vehicle body slip angle based on an output of the vehicle body slip angular speed calculating means. 3. The vehicle speed estimating device according to claim 1, wherein a speed in a direction in which the vehicle body is directed is output based on an output of the vehicle speed calculating unit and an output of the vehicle slip angle calculating unit. A vehicle speed estimating device comprising a reference vehicle speed output means. 4. A vehicle speed estimating device according to claim 1, wherein a steering angle detecting means for detecting a turning angle of a tire, and a front and rear wheel for calculating a front and rear wheel rotation speed difference at the time of turning. Speed difference calculating means, and inner and outer wheel speed difference calculating means for calculating a wheel rotation speed difference between the inner wheel and the outer wheel during turning, an output of the vehicle body speed calculating means, an output of the vehicle body slip angle calculating means, Reference wheel speed output means for outputting a speed corresponding to each wheel based on an output of a steering angle detection means, an output of the front and rear wheel speed difference calculation means, and an output of the inside and outside wheel speed difference calculation means. A vehicle speed estimating apparatus characterized by the above-mentioned.