JP2003154830A - Vehicular stabilizer device and lateral acceleration detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately control a vehicle by a vehicular stabilizer device in accordance with a turn of the vehicle, and provide a lateral acceleration detector that is suitable for the stabilizer device. SOLUTION: One end of each of two stabilizers for front wheels and rear wheels is switched to a free state and a lock state. A stability factor Kh varies with lateral acceleration Gy in accordance with every combination of states of both stabilizers. In accordance with a turning state of the vehicle (early period or end period) and the lateral acceleration Gy, the combination of states of both stabilizers is switched to control the stability factor Kh to a small value at the early period of the turn and to a large value at the end period of the turn and to improve a vehicle turning characteristic. The lateral acceleration Gy of the vehicle is arithmetically estimated according to the combination state of both stabilizers, a vehicle speed and a steering angle.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stabilizer device for a vehicle that changes a stability factor according to turning and a lateral acceleration detecting device applied to the vehicle.

[0002]

2. Description of the Related Art Conventionally, as a stabilizer device of this type, as shown in, for example, Japanese Patent Laid-Open No. 9-183306, the torsion bar portions of front and rear wheel stabilizers are each divided into two parts at the center. Then, one of these divided parts is connected to each housing side of the pair of hydraulic rotary actuators, and the other is connected to each rotor side of the same pair of hydraulic rotary actuators. It is known that the supply and discharge of hydraulic oil of both hydraulic rotor actuators are controlled according to the lateral acceleration so that the roll rigidity of both stabilizers becomes high when the vehicle turns.

Further, in this device, an orifice is provided in the hydraulic oil supply / discharge passage of the hydraulic rotary actuator for the front wheels to delay the supply / discharge of the hydraulic oil so that the rear wheel is used at the start of turning of the vehicle. The stabilizer's roll rigidity becomes higher than that of the front stabilizer to make the vehicle over-steering, and at the end of turning, the front stabilizer stabilizes the rear stabilizer. The vehicle has a tendency to understeer by being made higher than the roll rigidity of the vehicle to improve both turning performance and running stability of the vehicle.

[0004]

However, in the above-mentioned conventional stabilizer device for a vehicle, the stabilizer for the front wheels and the rear wheels is used at the start and end of turning of the vehicle by utilizing the delay of the hydraulic oil by the orifice. Since the difference between the roll rigidity forces of the above is realized, the oversteering tendency and the understeering tendency of the vehicle depending on the difference between the roll rigidity forces, that is, the steering characteristic of the vehicle is
It will largely depend on the characteristics of the orifice. Therefore, there is a problem that fine control of the steering characteristics depending on the turning state of the vehicle is impossible and the variations in the steering characteristics are likely to occur.

[0005]

SUMMARY OF THE INVENTION The present invention has been made to address the above-mentioned problems, and its purpose is to control steering characteristics with high accuracy and with little variation, and to perform accurate control according to the turning of a vehicle. It is to provide a stabilizer device for a vehicle that enables the above. Another object of the present invention is to provide a lateral acceleration detecting device for a vehicle, which is applied to this type of vehicle and can detect the lateral acceleration of the vehicle with high accuracy.

In order to achieve the above object, the features of the present invention are: a first roll rigidity force varying means capable of changing the roll rigidity force of the front wheel side stabilizer; and a first roll rigidity force changing means of the rear wheel side stabilizer. In a stabilizer device for a vehicle equipped with a roll stiffness force varying means of No. 2, a lateral acceleration detecting means for detecting a lateral acceleration of the vehicle, a turning state detecting means for detecting a turning state of the vehicle, and the detected lateral acceleration and Roll rigidity for controlling the first and second roll rigidity force varying means in accordance with the turning state and setting the roll rigidity forces of the front wheel side stabilizer and the rear wheel side stabilizer in accordance with the detected lateral acceleration and turning state. And a force control means.

In this case, the first roll rigidity force varying means is constituted by switching the magnitude of the roll rigidity force of the front wheel side stabilizer, and the second roll rigidity force varying means is constituted by the roll rigidity of the rear wheel side stabilizer. The roll rigidity force control means may be configured to switch the combination relationship of the roll rigidity forces of the front wheel side stabilizer and the rear wheel side stabilizer.

In the present invention constructed as described above,
If the roll stiffness force control means simply controls the first and second roll stiffness force varying means, respectively, according to the detected lateral acceleration and turning state, the roll stiffness forces of the front wheel side and rear wheel side stabilizers will be the same. It is set according to the detected lateral acceleration and turning state. Therefore, the steering characteristics of the vehicle are always set and controlled with high accuracy without depending on the characteristics of the orifice as in the above-mentioned conventional technique.
It becomes possible to control accurately according to the turning of the vehicle. As a result, the turning performance of the vehicle is improved.

Another feature of the present invention is that, in addition to the above structure, the first and second roll rigidity force varying means are controlled respectively when the vehicle is traveling at a low speed or on a rough road, and a front wheel side stabilizer and a stabilizer are provided. This is because there is provided roll rigidity force suppression control means for suppressing both the roll rigidity forces of the rear wheel side stabilizers.

According to this, when the vehicle is traveling at a low speed or traveling on a rough road, both the roll rigidity forces of the front wheel side stabilizer and the rear wheel side stabilizer are kept small. Therefore, when the vehicle is traveling at a low speed or traveling on a rough road, the ride comfort of the vehicle is kept good by avoiding the inappropriate control of the roll rigidity force due to the lateral acceleration and the turning state.

Further, another feature of the present invention is that, in addition to the above construction, a tire air pressure detecting means for detecting the air pressure of the tires of the front wheels and the rear wheels, and a roll rigidity force controlling means according to the detected air pressure of the tires. The first and second
The control mode changing means for changing and controlling the control mode of the roll stiffness force varying means of No. 1 is provided.

According to this, even if the tire air pressure changes and the stability factor of the vehicle is changed, the changed amount can be corrected by the control mode changing means. As a result, even if the tire air pressure changes, the steering characteristics and turning performance of the vehicle can always be kept good.

Another feature of the present invention is that the first roll rigidity changing means for changing the roll rigidity of the front wheel stabilizer and the second roll for changing the roll rigidity of the rear wheel stabilizer. Rigid force varying means, first and second
It is applied to a vehicle equipped with a vehicle stabilizer device including roll rigidity force control means for controlling the front wheel side stabilizer and the rear wheel side stabilizer to control the front wheel side stabilizer and the rear wheel side stabilizer in desired states, and detects the vehicle speed. In addition to the vehicle speed detection means, the steering angle detection means for detecting the front wheel steering angle, the detected vehicle speed and the front wheel steering angle, depending on the setting state of the front wheel side stabilizer and the rear wheel side stabilizer by the roll rigidity force control means And a calculation means for calculating the lateral acceleration of the vehicle.

In this case, the coefficient used in the arithmetic expression for calculating the lateral acceleration of the vehicle using the vehicle speed and the front wheel steering angle is determined according to the setting states of the front wheel side and rear wheel side stabilizers, and the calculating means is calculated. May calculate the lateral acceleration of the vehicle using the determined coefficient, vehicle speed and front wheel steering angle.

According to this, the lateral acceleration of the vehicle, which changes according to the setting states of the front wheel side and rear wheel side stabilizers,
It will be detected with high accuracy.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 schematically shows in common a suspension device for front wheels and rear wheels of a vehicle to which the present invention is applied. FIG. 2 shows the stabilizer 16 in the front wheel and rear wheel suspension devices,
17 shows an electrical controller for controlling 16 roll stiffness forces.

This suspension system comprises suspension arms 11a and 11b and damper cylinders 12a and 12a.
b and coil springs 13a and 13b, and left and right wheels 14a and 14b are suspended from the vehicle body 15. In addition, this suspension device includes a stabilizer 16. The torsion bar portion 16a at the center of the stabilizer 16 is a bearing 1 fixed to the vehicle body 15 with bolts or the like.
It is rotatably supported around the axis by 7a and 17b. One end 16b of the stabilizer 16 is connected to the unsprung portion of the damper cylinder 12a via a link rod 18. A cylinder unit 20 is interposed between the other end 16c of the stabilizer 16 and the damper cylinder 12b.

The cylinder unit 20 is a hydraulic cylinder 2.
1. A piston 22 that divides the cylinder 21 into upper and lower oil chambers
And piston rod 2 whose upper end is fixed to the piston 22
It consists of three. The upper end of the hydraulic cylinder 21 is connected to the unsprung portion of the damper cylinder 12a. The lower end of the piston rod 23 is connected to the other end 16c of the stabilizer 16.

The cylinder unit 20 corresponds to each of the front wheel cylinder unit 20A and the rear wheel cylinder unit 20B shown in FIG. The front wheel cylinder unit 20A includes a hydraulic cylinder 21a, a piston 22a and a piston rod 23a corresponding to the hydraulic cylinder 21, the piston 22 and the piston rod 23, respectively. Rear wheel cylinder unit 20B
Is a hydraulic cylinder 21b corresponding to the hydraulic cylinder 21, the piston 22 and the piston rod 23,
It includes a piston 22b and a piston rod 23b.

The front wheel cylinder unit 20A also includes an electromagnetic switching valve 24a and an accumulator 25a. The electromagnetic switching valve 24a is kept in the illustrated state in the non-energized state, and the hydraulic cylinder 2 is checked by the check valve.
Communication between the upper and lower oil chambers of 1a is prohibited. In this state, the piston 22a cannot slide in the hydraulic cylinder 21a, so the stabilizer 16 (however, the stabilizer for the front wheels)
The other end portion 16c is fixed via the piston rod 23a, and the roll rigidity is maintained at a large value. on the other hand,
The electromagnetic switching valve 24a is switched from the illustrated state to the hydraulic cylinder 2 through the orifice when energized.
Allow the upper and lower oil chambers 1a to communicate with each other. In this state, the piston 22a can slide in the hydraulic cylinder 21a,
The other end 16c of the stabilizer 16 (however, the stabilizer for the front wheels) is freely displaced via the piston rod 23a, and the roll rigidity is kept at a small value. In addition,
The orifice exerts a damper action on the displacement of the piston 22a and the piston rod 23a, but since it is not directly related to the present invention, a detailed description thereof will be omitted. The accumulator 25a is connected to the common connection portion of the check valve and the orifice.

The rear wheel cylinder unit 20B also includes the electromagnetic switching valve 24a and the accumulator 25 described above.
It includes an electromagnetic switching valve 24b and an accumulator 25b having the same function as a. As a result, the electromagnetic switching valve 24b is kept in the illustrated state in the non-energized state, and the stabilizer 16 (however, the stabilizer for the rear wheel) is used.
Controls the roll stiffness force of to a large value. Further, the electromagnetic switching valve 24b is switched from the illustrated state in the energized state to control the roll rigidity force of the stabilizer 16 (however, the rear wheel stabilizer) to a small value.

Next, an electric control device for controlling the roll rigidity of the stabilizers for the front wheels and the rear wheels will be described. The electric control device includes electromagnetic switching valves 24a, 24.
The microcomputer 30 is provided with a microcomputer 30 connected to b, and a vehicle speed sensor 31 and a steering angle sensor 32 connected to the microcomputer 30.

The microcomputer 30 includes a CPU and an R
The electromagnetic switching valves 24a, 24b are composed of an OM, a RAM, etc., and are executed by executing the programs of FIGS.
Controls energization and de-energization of. The vehicle speed sensor 31 detects the vehicle speed V based on the rotation of the output shaft of the transmission or the rotation of the wheels.
Is detected and supplied to the microcomputer 30. The steering angle sensor 32 detects the steering wheel rotation angle θ based on the rotation angle of the steering wheel and supplies it to the microcomputer 30. The steering wheel rotation angle θ is represented by positive and negative values in the left and right directions with the neutral position of the front wheels set to “0”. In the present embodiment, the steering wheel rotation angle is used as the front wheel steering angle, but the present invention is not limited to this, and for example, the steering angle of the wheel may be directly detected and used as the front wheel steering angle. The steering angle of the wheels may be indirectly calculated from the displacement amount of the steering shaft to be used as the front wheel steering angle.

Next, the operation of the embodiment configured as described above will be described. When the ignition switch (not shown) is turned on, the microcomputer 30 starts executing the program in step 100 of FIG.
Note that the processing of steps 160 and 162 shown by the broken line in FIG. 3 is related to a modified example described later and is processing that is not related to the present embodiment.

After the execution of the program is started, the microcomputer 30 energizes both the electromagnetic switching valves 24a and 24b in step 102. This allows
The upper and lower chambers of the front and rear hydraulic cylinders 21a and 21b are in communication with each other, and the other end portions 16c and 16c of the front and rear stabilizers 16 and 16 are both kept in a free state. The roll rigidity forces of the stabilizers 16 and 16 are both set to small values. Step 10
After the processing of 2, the microcomputer 30 executes the step 1
At 04, the state value ST is set to "3".

Here, the state value ST will be described with reference to FIG. The state value ST being “1” means that the upper and lower chambers of the front wheel hydraulic cylinder 21a are communicated with each other and the upper and lower chambers of the rear wheel hydraulic cylinder 21b are released so that the other end of the stabilizer 16 for the front wheel is released. This means that the roll rigidity is set to a small value while keeping the portion 16c in a free state, and the roll rigidity is set to a large value while keeping the other end 16c of the stabilizer 16 for the rear wheels in a locked state. To do. The state value ST being “2” means that
Both the upper and lower chambers of the front and rear hydraulic cylinders 21a and 21b are released from each other to keep the other end portions 16c and 16c of the front and rear stabilizers 16 and 16 locked. It means that both roll rigidity forces are set to large values.

The state value ST of "3" means that the upper and lower chambers of both the front and rear wheel hydraulic cylinders 21a and 21b are communicated with each other, and the front and rear stabilizers 16 and 16 of the front and rear wheels are communicated with each other. This means that the other ends 16c and 16c are both kept in a free state and their roll rigidity forces are both set to a small value. The state value ST being “4” means that
The upper and lower chambers of the hydraulic cylinder 21a for the front wheels are released from each other and the upper and lower chambers of the hydraulic cylinder 21b for the rear wheels are communicated with each other, and the other end portion 16c of the stabilizer 16 for the front wheels is kept in a locked state and its roll rigidity is increased. Is set to a large value, and the other end 16c of the stabilizer 16 for the rear wheels is kept in a free state to set the roll rigidity force to a small value.

In FIG. 5, the state value ST is "1",
It shows the relationship between the lateral acceleration Gy of the vehicle and the stability factor Kh in each case of "2", "3", and "4". The stability factor Kh is an index indicating that the stability of the vehicle increases (the roll angle of the vehicle body decreases) as the value increases.
On the contrary, when the value is small, it means that the turning performance of the vehicle is improved. Further, the free states of both the other end portions 16c, 16c of the front wheel stabilizers 16 and the rear wheel stabilizers 16, 16 tend to improve the ride comfort of the vehicle.

After the processing of step 104, the microcomputer 30 executes a lateral acceleration estimation routine at step 106. Execution of this lateral acceleration estimation routine proceeds to step 200, as detailed in FIG.
Started at. Then, the microcomputer 30
In step 202, referring to the lateral acceleration calculation coefficient table, depending on the state value ST, that is, the combination of the free and locked states of the other end portions 16c, 16c of the stabilizers 16, 16 for the front wheels and the rear wheels, A coefficient k ₁ used for the calculation of the following formula 1 for estimating and calculating the lateral acceleration Gy,
Determine k ₂ .

[0030]

[Equation 1] Gy = k ₁ · θ · V + k ₂ · (dθ / dt) · V

The lateral acceleration calculation coefficient table is built in the microcomputer 30 and stores the coefficients k ₁ and k ₂ for each state value ST. For example, it is set to the values shown in Table 1 below. There is. Note that θ is the steering wheel rotation angle, and V is the vehicle speed.

[0032]

【table 1】

After the processing in step 202, the microcomputer 30 determines in step 204 the vehicle speed sensor 31.
The vehicle speed V is input from and the steering wheel rotation angle θ is input from the steering angle sensor 32. Then, in Step 206, the lateral acceleration Gy is calculated by substituting the determined coefficients k ₁ , k ₂ , the vehicle speed V, and the steering wheel rotation angle θ into the above-mentioned equation ₁ .
At step 208, the execution of this lateral acceleration estimation routine is completed. As a result, the lateral acceleration Gy of the vehicle can be estimated without using an extremely expensive and highly accurate lateral acceleration sensor. The lateral acceleration Gy is positive in the left direction and negative in the right direction.

It is also possible to calculate the lateral acceleration Gy of the vehicle by executing the following Expression 2 in which the third term k ₃ · V for advancing the phase of the lateral acceleration Gy is added to the above Equation 1. is there. Note that the coefficient k of the third term k ₃ · V in this equation 2
_A different value may be used for ₃ , depending on the state value ST, but a predetermined constant may be used.

[0035]

[Equation 2] Gy = k ₁ · θ · V + k ₂ · (dθ / dt) · V + k ₃ · V

Returning again to the description of the main program in FIG. 3, the lateral acceleration G calculated in step 108 is executed after the lateral acceleration estimating routine in step 106 is executed.
It is determined whether or not the absolute value | Gy | of y is greater than or equal to a predetermined small predetermined value Gy1. If the vehicle is stopped or is traveling straight ahead and the absolute value | Gy | of the lateral acceleration Gy is less than the predetermined value Gy1, it is determined as "No" in step 108 and the process returns to step 102. Therefore, as long as the vehicle is stopped or traveling straight ahead, step 102
The circulation process consisting of 108 is continuously executed, and the roll rigidity forces of the front wheel stabilizers 16 and the rear wheel stabilizers 16 are both set to be small (the state value ST is continuously set to "3"). As a result, the ride comfort of the vehicle is emphasized when the vehicle is traveling almost straight.

On the other hand, when the steering wheel is turned while the vehicle is running substantially straight and the vehicle starts to turn, the absolute value | Gy | of the lateral acceleration Gy calculated by the process of step 106 becomes large. Then, when the absolute value | Gy | of the lateral acceleration Gy becomes equal to or larger than the predetermined value Gy1, it is determined as "YES" in step 108, and the process proceeds to step 110. In step 110, the absolute value of lateral acceleration Gy | Gy |
Is less than a predetermined value Gy2 that is larger than the predetermined value Gy1 and is determined in advance.

If the vehicle is in the initial stage of turning and the absolute value | Gy | of the lateral acceleration Gy is less than the predetermined value Gy2, it is determined "Yes" at step 110 and the routine proceeds to step 112. In step 112, the differential value d | θ | / dt of the absolute value | θ | of the input steering wheel rotation angle θ is calculated, and whether or not this differential value d | θ | / dt is larger than "0" is determined. To determine. The differential value d | θ | / d
In the calculation of t, the steering wheel rotation angle θ input in the processing of step 106 this time and the steering wheel rotation angle θ input in the processing of the previous step 106 and stored in the microcomputer 30 are used.

The determination process of step 112 is a process for distinguishing between the initial turning and the ending of turning of the vehicle, that is, the turning state of the vehicle. in this case,
As described above, since the vehicle is in the initial turning state, the absolute value | θ | of the steering wheel rotation angle θ tends to increase. Therefore, the differential value d | θ | / dt is positive, and step 11
In the case of 2, it is determined that “Yes”, that is, the differential value d | θ | / dt is “0” or more, and the routine proceeds to step 114.

In step 114, the microcomputer 30 controls energization of the electromagnetic switching valve 24a and deenergizes the electromagnetic switching valve 24b. As a result, the upper and lower chambers of the hydraulic cylinder 21a for the front wheels communicate with each other, and the other end portion 16c of the stabilizer 16 for the front wheels is connected.
Is maintained in a free state, and the roll rigidity of the stabilizer 16 is set to a small value. On the other hand, the communication between the upper and lower chambers of the hydraulic cylinder 21b for the rear wheels is released, the other end 16c of the stabilizer 16 for the rear wheels is kept in the locked state, and the roll rigidity of the stabilizer 16 is set to a large value. . After the processing of step 114, the state value ST is set to "1" in step 116.

After the processing of step 116, step 1
Returning to 06, the processing after step 106 is executed. Also at this time, the vehicle is in the initial turning state, the absolute value | Gy | of the lateral acceleration Gy is not less than the predetermined value Gy1 and less than the predetermined value Gy2, and the absolute value of the steering wheel rotation angle θ is |
If the differential value d | θ | / dt of θ | is positive, step 10
It is determined as “Yes” in all of 8, 110, and 112, and the microcomputer 30 performs steps 106 to 11.
The cyclic process consisting of 6 is repeatedly executed. During this circulation processing, the roll rigidity of the stabilizer 16 for the front wheels continues to be set low, and the stabilizer 16 for the rear wheels 16
The roll rigidity force of is continuously set to be large (the state value ST is continuously set to "1"). Therefore, in this state, as can be understood from FIG. 5, the stability factor Kh is maintained at a small value, and the turning performance of the vehicle at the initial turning stage becomes good.

On the other hand, the vehicle enters a turning motion and the lateral acceleration G
When the absolute value | Gy | of y becomes equal to or larger than the predetermined value Gy2, it is determined to be "No" in step 110, and the process proceeds to step 118. In step 118, it is determined whether the absolute value | Gy | is less than a predetermined value Gy3 that is larger than the predetermined value Gy2. In addition, this predetermined value Gy3
Is set to a value corresponding to a large lateral acceleration that rarely occurs during normal vehicle turning. Therefore, when the vehicle is making a normal turn, it is determined in step 118 that "Yes", that is, the absolute value | Gy | is less than the predetermined value Gy3, and the process proceeds to step 120.

In step 120, it is determined whether the extra flag EXF is "0". The extra flag EXF indicates that a lateral acceleration Gy having an absolute value equal to or greater than a predetermined value Gy3 has occurred in the vehicle during turning of the vehicle by "1" and indicates other states by "0". It is initially set to "0". Therefore, in this case, the extra flag EXF is "0".
Therefore, the microcomputer 30 determines “Yes” in step 120,
Proceed to 2,124. In step 122, the electromagnetic switching valves 24a and 24b are both de-energized. As a result, both the front and rear hydraulic cylinders 21
Communication between the upper and lower chambers a and 21b is released, and both roll rigidity forces of the front and rear stabilizers 16 and 16 are set to large values. After the processing of step 122, the microcomputer 30 executes step 124.
The state value ST is set to "2".

After the processing of step 124, step 1
Returning to 06, the processing after step 106 is executed. Also at this time, the vehicle is in a normal turn, and the absolute value | Gy | of the lateral acceleration Gy is equal to or greater than the predetermined value Gy2 and the predetermined value Gy.
If it is less than y3 and the extra flag EXF is "0", steps 108, 110, 118, 1
20, "Yes", "No", "Ye" respectively
When it is determined to be “s” or “Yes”, the microcomputer 30 continues to repeatedly execute the circulation process including steps 106 to 110 and 118 to 124. During this circulation processing, both the roll rigidity forces of the front wheel stabilizers 16 and the rear wheel stabilizers 16 continue to be set large (state value ST is "2").
Continue to be set). Therefore, in this state, as shown in FIG.
As can be understood from the above, the stability factor Kh is maintained at a medium value, and the roll angle is reduced for the traveling stability of the vehicle without significantly impairing the turning performance of the vehicle.

On the other hand, when the absolute value | Gy | of the lateral acceleration Gy becomes less than the predetermined value Gy2 when the vehicle exits the curve and goes straight ahead, that is, at the turning end time, the absolute value | Gy | On the condition that it is Gy1 or more, it is determined to be “Yes” in step 110, and the determination process of step 112 described above is executed. In this case, when the vehicle is at the turning end time, the absolute value of the steering wheel rotation angle θ | θ |
Is on the decline. Therefore, the above-mentioned step 11
The differential value d | θ | / dt calculated in 2 becomes negative, and it is determined as “No” in the same step 112, and step 126
Proceed to.

At step 126, the microcomputer 30 controls the electromagnetic switching valve 24a to be de-energized and the electromagnetic switching valve 24b to be energized. As a result, the communication between the upper and lower chambers of the front wheel hydraulic cylinder 21a is released, and the roll rigidity of the front wheel stabilizer 16 is set to a large value. On the other hand, the upper and lower chambers of the hydraulic cylinder 21b for the rear wheels communicate with each other, and the roll rigidity of the stabilizer 16 for the rear wheels is set to a small value. After the processing of step 126, the state value S
T is set to "4" and the extra flag EXF is set to "0" in step 130. In addition, this step 1
The process of 30 is effective when the extra flag EXF is set to "1" by the process described later,
This process has no substantial effect on the operation.

After the processing of step 130, step 1
Returning to 06, the processing after step 106 is executed. Also at this time, the absolute value | Gy | of the lateral acceleration Gy is greater than or equal to the predetermined value Gy1 and less than the predetermined value Gy2 at the time when the vehicle turns, and the absolute value of the steering wheel rotation angle θ is |
If the differential value d | θ | / dt of θ | is negative, step 10
8, 110 and 112, respectively, "Yes" and "Y
When it is determined to be “es” or “No”, the microcomputer 30 continues to repeatedly execute the circulation process including steps 106 to 112 and 126 to 130. During this circulation process, the roll rigidity of the stabilizer 16 for the front wheels continues to be set high, and the roll rigidity of the stabilizer 16 for the rear wheels continues to be set small (state value ST continues to be set to "4"). Therefore, in this state, as can be understood from FIG. 5, the stability factor Kh is maintained at a large value, and the convergence at the end of turning of the vehicle becomes good.

After that, when the vehicle enters a substantially straight traveling state and the absolute value | Gy | of the lateral acceleration Gy becomes less than the predetermined value Gy1,
In step 108, it is determined as "No",
Return to step 102. Then, as long as the vehicle is traveling substantially straight and the absolute value | Gy | of the lateral acceleration Gy is less than the predetermined value Gy1, the determination of "No" is continued in step 108, and the circulation of steps 102 to 108 described above is continued. Continue executing the process repeatedly.

As a result of such control, when the vehicle that has been traveling straight ahead starts to turn, the chain line X in FIG.
As shown by, stability factor Kh
Becomes smaller, the initial turning property increases, and when the vehicle enters a turning state, the stability factor Kh is set to a medium level and the rolling of the vehicle body is suppressed. When the vehicle finishes turning and goes straight ahead, the stability factor Kh increases at the end of turning to increase the stability and the convergence of the vehicle, as indicated by the alternate long and short dash line Y in FIG. The stability factor Kh is set to an intermediate level when the vehicle travels straight again and the riding comfort of the vehicle is improved. As a result, the riding comfort of the vehicle is ensured when the vehicle travels straight ahead, and the turning performance of the vehicle is improved.

Next, a case where the absolute value | Gy | of the lateral acceleration Gy becomes extremely large and becomes equal to or larger than the predetermined value Gy3 during turning of the vehicle will be described. In this case, the microcomputer 30 determines “No” in step 118, and proceeds to step 132. In step 132, as in the process of step 126, the electromagnetic switching valve 24
a is de-energized and the electromagnetic switching valve 24
b is energized and controlled. As a result, the roll rigidity of the front wheel stabilizer 16 is set to a large value, and
The roll rigidity of the stabilizer 16 for the rear wheels is set to a small value. After the processing of step 132, step 1
At step 34, the state value ST is set to "4", and step 1
At 36, the extra flag EXF is set to "1".

After the processing of step 136, step 1
Returning to 06, the processing after step 106 is executed. Then, the absolute value | Gy | of the lateral acceleration Gy is the predetermined value G.
As long as it is y3 or more, it is determined to be “Yes”, “No”, and “No” in steps 108, 110, and 118, respectively, and the microcomputer 30 determines in steps 106 to.
The circulation process consisting of 110, 118, and 132 to 136 is repeatedly executed. During this circulation process, the roll rigidity of the stabilizer 16 for the front wheels continues to be set high, and the roll rigidity of the stabilizer 16 for the rear wheels continues to be set small (state value ST continues to be set to "4"). Therefore, in this state, as can be understood from FIG. 5, the stability factor Kh is kept at a large value, the understeering characteristic of the vehicle is strengthened, and the running stability of the vehicle is kept good.

On the other hand, the absolute value of such lateral acceleration Gy |
When Gy | changes from the state of being equal to or more than the predetermined value Gy3 to the state of being less than the predetermined value Gy3, the microcomputer 30 executes the step 1
When it is determined to be “Yes” at 18, the process proceeds to step 120. In this case, since the extra flag EXF is set to "1", it is determined to be "No" in step 120, and the process returns to step 106. And the lateral acceleration G
As long as the absolute value | Gy | of y is greater than or equal to the predetermined value Gy2 and less than the predetermined value Gy3, in steps 108, 110 and 118,
Since it is determined to be “Yes”, “No”, and “Yes”, respectively, the circulation process including steps 106 to 110, 118, and 120 is repeatedly executed. Therefore, in this case, the electromagnetic switching valves 24a and 24b are maintained in the set state by the processing of step 132 described above, the roll rigidity of the stabilizer 16 for the front wheels continues to be set large, and the stabilizer for the rear wheels is also set. The roll rigidity force of 16 continues to be set small (state value ST continues to be set to "4").

On the other hand, also in this case, when the absolute value | Gy | of the lateral acceleration Gy becomes less than the predetermined value Gy2 when the vehicle goes out of the curve and goes straight, that is, at the turning end time, the same absolute value | Gy. On the condition that | is equal to or greater than the predetermined value Gy1, it is determined as “Yes” in step 110,
The determination process of step 112 described above is executed. In this case, the absolute value | θ | of the steering wheel rotation angle θ tends to decrease at the turning end time of the vehicle. Therefore, the differential value d | θ | / dt calculated in step 112 described above becomes negative, a negative determination is made in step 112, and the processes of steps 126 to 130 described above are executed.

In this case, the roll rigidity of the stabilizer 16 for the front wheels is set to a large value and the roll rigidity of the stabilizer 16 for the rear wheels is set to a small value by the processing of steps 132 and 134, and Since the value ST remains set to "4", the above step 12 is performed.
The processing of 6,128 is virtually meaningless. On the other hand, in step 130, the extra flag EXF set to "1" is changed to "0". As a result, when the next vehicle turns, it is determined to be “Yes” in step 120, and the above-described steps 122 and 1 are executed.
24 processes will be performed.

After that, when the vehicle enters a substantially straight traveling state and the absolute value | Gy | of the lateral acceleration Gy becomes less than the predetermined value Gy1,
The microcomputer 30, as in the case described above,
In step 108, the determination is “No”, and the above-described circulation processing of steps 102 to 108 is repeatedly executed.
As a result, the absolute value of the lateral acceleration Gy | Gy |
When the vehicle returns to the straight running after the value becomes equal to or more than the predetermined value Gy3, the stability factor Kh is kept large until the turning end time, as indicated by the one-dot chain line Z in FIG. As a result, if the absolute value | Gy | of the lateral acceleration Gy once becomes extremely large, the vehicle becomes unstable when the absolute value | Gy | becomes large even if the absolute value | Gy | starts to decrease. In order to reliably eliminate the problem, the stability factor Kh is kept large and the traveling stability of the vehicle is ensured.

Next, a modified example will be described in which the roll rigidity of the front and rear stabilizers 16, 16 at the beginning of turning of the vehicle of the above embodiment is changed according to the tire pressure. This is because when the actual stability factor of the vehicle is reduced due to changes in the tire pressures of the front and rear wheels, the stability factor Kh is reduced by the processing of step 114 in FIG. 3 for improving the turning performance of the vehicle. As a result of the reduction, it is possible to prevent the traveling stability of the vehicle from being deteriorated.

In this modification, in addition to the electric control device of the above embodiment, as shown by the broken lines in FIG. 2, the tire pressures Pfl, Pfr, Prl, Prr of the left and right front wheels and the left and right rear wheels are shown.
Tire pressure sensors 33a to 33d for detecting the are connected to the microcomputer 30. These tire air pressure sensors 33a to 33d detect the tire air pressure of each wheel and detect the tire air pressures Pfl, Pfr,
The microcomputer 30 sends detection signals representing Prl and Prr.
Although it is transmitted wirelessly to a receiver connected to, the tire pressures Pfl, Pfr, Prl,
It is shown that the detection signal representing Prr is directly supplied to the microcomputer 30.

Further, the microcomputer 30 executes step 16 shown by a broken line in the above-mentioned main program of FIG.
0, 162 processing and steps 112 to 116 and 126 to 1 surrounded by broken lines of the main program.
The main program obtained by modifying the processing of 30 as shown in FIG. 6 is executed.

In this modified example, in the initial stage of turning of the vehicle, after the determination in step 112 is "Yes", the microcomputer 30 determines in step 140 whether or not the up flag UPF is "1". To do. In other words, at the beginning of turning of the vehicle, step 1
12, "Yes", that is, the absolute value of the lateral acceleration Gy | G
y | is greater than or equal to the predetermined value Gy1 and less than the predetermined value Gy2, and the differential value d | θ | / of the absolute value | θ | of the steering wheel rotation angle θ
When dt is “0” or more, the microcomputer 30
Determines in step 140 whether the up flag UPF is "1". In addition, this up flag UPF
Is a stabilizer 16, 16 for the front wheels and rear wheels for increasing the stability factor Kh by "1".
Represents a state in which the control state of the roll rigidity force of (1) is changed from the first state (a state in which the value of the state value ST is increased), and "0" represents the other states, and is initially set to "0". It is set.

If the up flag UPF is set to "0", it is determined to be "No" in step 140, and the same processes in steps 114 and 116 as those in the above-described embodiment are executed, so that the front wheel And a stabilizer 16 for the rear wheels,
The control state of the roll rigidity force of 16 is the first state (state value ST
Is "1").

After the processing of these steps 114 and 116, the microcomputer 30 refers to the stability factor table in step 142 and refers to the state value ST.
And the stability factor Kh depending on the lateral acceleration Gy
To calculate. The stability factor table is prepared in advance in the microcomputer 30, and as shown in FIG. 5, the stabilizers 1 for the front wheels and the rear wheels are provided.
The stability factor Kh that changes according to the lateral acceleration Gy is stored for each combination of roll rigidity forces of 6 and 16 (that is, each state value ST). In the calculation of the stability factor Kh, if the stability factor Kh corresponding to the lateral acceleration Gy is not in the table, the stability factor Kh is calculated by interpolation.
To calculate.

After the processing of step 142, the microcomputer 30 at step 144 detects the tire pressures Pfl and Pf from the tire pressure sensors 33a to 33d.
Enter r, Prl, and Prr. Then, in step 146, the average value of the tire pressures Pfl and Pfr of the left and right front wheels is determined as the front wheel tire pressure Pf (= (Pfl + Pfr) / 2), and the average value of the tire pressures Prl and Prr of the left and right rear wheels is set to the rear side. The tire pressure is determined as Pr (= (Prl + Prr) / 2).

Next, at step 148, referring to the air pressure correction coefficient table, the correction coefficient αf corresponding to the calculated front wheel tire pressure Pf and rear wheel tire pressure Pr,
Determine αr. Even in the determination of these correction coefficients αf and αr, if they are not in the table, the correction coefficients αf and αr are calculated by using interpolation calculation. This air pressure correction coefficient table is previously stored in the microcomputer 3
The correction coefficients αf, αr corresponding to the front wheel tire air pressure Pf and the rear wheel tire air pressure Pr are stored. As the correction coefficients αf and αr and the values, for example, the values shown in Table 2 below can be adopted.

[0064]

[Table 2]

Further, the correction factors αf and αr are changed according to the tire pressure by correcting the stability factor Kh calculated using the stability factor table according to the front tire pressure Pf and the rear tire pressure Pr. This is for calculating the corrected stability factor Kh '. In this case, the relationship between the stability factor Kh (stability factor table value), which is a value calculated by fixing the tire pressure to a predetermined value, and the corrected stability factor Kh 'is as follows according to a general vehicle motion theory. It is defined as Equation 3.

[0066]

[Equation 3] Kh ′ = Kh {(Wf / αf) − (Wr / αr)} · {1 / (Wf−Wr)}

In the above equation 3, Wf is the front wheel load applied to the front wheels, and Wr is the rear wheel load applied to the rear wheels. In this case, the front wheel load Wf and the rear wheel load Wr may be treated as constants determined in advance depending on the vehicle type and the like. Alternatively, load sensors may be provided on the front wheel side and the rear wheel side, respectively, and the front wheel load Wf and the rear wheel load Wr detected by the respective load sensors may be used.

After the processing of step 148, step 1
At 50, the corrected stability factor Kh ′ is calculated by executing the calculation of the above-mentioned Equation 3 using the calculated stability factor Kh and the correction coefficients αf and αr. Then, in step 152, it is determined whether or not the corrected stability factor Kh 'is less than or equal to a predetermined value Kho.
It should be noted that this predetermined value Kho is a predetermined small value that may affect the running stability of the vehicle.

If the corrected stability factor Kh 'is larger than the predetermined value Kho, step 152 returns "N".
It is determined to be “o” and the process returns to step 106. Therefore, in this case, the stabilizer 16,
It is the same as the roll rigidity control operation of 16.

On the other hand, if the corrected stability factor Kh 'is less than or equal to the predetermined value Kho, "Yes" in step 152.
Then, in step 154, “1” is added to the state value ST, and the process proceeds to step 156. In step 156, both front wheel and rear wheel stabilizers 16, 1 are
The roll rigidity force of No. 6 is controlled to the ST state corresponding to the state value ST.

Specifically, since the state value ST is initially set to "1" by the process of step 116, the state value ST is "2" by the process of step 154.
Is set to. Therefore, in step 156, both of the electromagnetic switching valves 24a and 24b are de-energized in the same manner as the processing of step 122 of FIG. 3 described above.
By this non-energization control, the other ends 16c, 16c of the front and rear stabilizers 16, 16 are both set in the locked state (set in the second state), and the roll rigidity of the both stabilizers 16, 16 is set. Both forces are set to large values. As a result, as shown in FIG. 5, the stability factor Kh has a larger value than in the case of the first state.

After the processing of step 156, step 1
At 58, the up flag UPF is set to "1", and the process returns to step 142. Then, the above-mentioned steps 142 to
By the processing of 152, the ST state (in this case, the second state
(State), the correction value Kh 'of the stability factor Kh by the tire pressures Pf, Pr is calculated, and the correction value Kh' is calculated.
Is below a predetermined value Kho.

If the correction value Kh 'of the stability factor Kh is larger than the predetermined value Kho, step 152
It is determined to be “No” in step S106 and the process returns to step. In this case, if the absolute value | Gy | of the lateral acceleration Gy is greater than or equal to the predetermined value Gy1 and less than the predetermined value Gy2, the differential value d | θ | / dt of the absolute value | θ | of the steering wheel rotation angle θ is "0" or more. On the condition that the condition is “Yes” in steps 108, 110 and 112,
s ”, and the determination processing of step 140 is executed. In this case, since the up flag UPF is set to "1", it is determined to be "Yes" in step 140, and the process returns to step 106. As a result, in this case,
The circulation processing of steps 106 to 112 and 140 is repeatedly executed, and the roll rigidity of the stabilizers 16 and 16 is set to the second value.
The state, that is, both are maintained at a large value.

Then, in this state, the absolute value | Gy | of the lateral acceleration Gy becomes less than the predetermined value Gy1, and step 108
If it is determined to be "No" at step 160, the up flag UPF is returned to "0" at step 160 shown by the broken line in FIG.
Return to step 108. Also, the absolute value of lateral acceleration Gy |
If Gy | becomes equal to or larger than the predetermined value Gy2 and it is determined to be “No” in step 110, the up flag UPF is returned to “0” in step 162 shown by the broken line in FIG. 3, and the process proceeds to step 118. . As a result, thereafter, the operation is similar to that of the above embodiment.

On the other hand, if the correction value Kh 'by the tire air pressures Pf, Pr of the stability factor Kh in the changed ST state (in this case, the second state) is less than or equal to the predetermined value Kho, it is again checked in step 152. "Yes"
It is determined that the stability factors Kh are sequentially increased by the ranks of the states of the front wheel stabilizers 16 and 16 for the rear wheels by the processing of steps 154 and 156. If the stability factor Kh is increased, the process of step 140 maintains the increased stability factor Kh.
The roll rigidity of the front and rear stabilizers 16, 16 is maintained and controlled. If the absolute value | Gy | of the lateral acceleration Gy becomes less than the predetermined value Gy1 or becomes more than the predetermined value Gy2, the above-described steps 160 and 162 are performed.
Then, the up flag UPF is returned to "0", and the subsequent operation is the same as in the above embodiment.

In the modified example that operates as described above, in order to improve the turning performance of the vehicle at the initial stage of turning, the characteristics of the front and rear stabilizers 16, 16 are changed and controlled to change the stability factor Kh. Even when it is set low, this change control is corrected and the running stability of the vehicle is secured. That is, the tire pressures Pfl, Pfr of the left and right front wheels
If the tire pressures Prl and Prr of the left and right rear wheels are not appropriate and the actual stability factor of the vehicle (corrected stability factor Kh ') becomes small enough to impair the running stability of the vehicle, step 154 , 156, the stability factor is increased, so that the running stability of the vehicle is ensured.

In the modified example, the corrected stability factor Kh 'is calculated from the tire pressures Pfl, Pfr, Prl, Prr, and the stabilizers for the front wheels and the rear wheels are calculated using the corrected stability factor Kh'. By controlling the roll rigidity of 16 and 16, the running stability of the vehicle is ensured. However, the corrected stability factor Kh '
Without calculating tire pressure Pfl, Pfr, Prl, P
stabilizer 16 for the front and rear wheels based on rr,
The roll rigidity of 16 may be directly controlled to ensure the running stability of the vehicle. In this case, the stabilizers 16 and 1 for the front wheels and the rear wheels are arranged according to the extent to which the tire pressures Pfl, Pfr, Prl, Prr deviate from the proper values.
It suffices that the combination state of the roll rigidity forces of No. 6 is switched and controlled.

Next, in the above-described embodiment or modification, the roll rigidity of the front and rear stabilizers 16, 16 is forcibly kept small when the vehicle runs at low speed or on a rough road. A modified example will be described.

The vehicle according to this modification is provided with a stroke sensor 41 for detecting the vehicle height (height from the road surface of the vehicle body) as shown by the broken line in FIG. Also,
The microcomputer 30 executes a main program obtained by modifying a part of FIG. 3 as shown in FIG. 7. This Figure 7
In the modified program of step 1,
The determination process of steps 170 and 172 is inserted between 04 and step 106.

In step 170, the vehicle speed sensor 3
The vehicle speed V is input from 1 and it is determined whether the vehicle is traveling at a low speed by determining whether the vehicle speed V is equal to or lower than a predetermined vehicle speed Vo (for example, 20 km / h) indicating a low speed.
In step 172, the vehicle height detected by the stroke sensor 41 is input, and it is determined whether the vehicle is traveling on a rough road according to the change state of the vehicle height. As shown by the broken line in FIG. 2, a vertical acceleration sensor 42 for detecting the vertical acceleration of the vehicle body is provided, and it is determined whether the vehicle is traveling on a rough road according to the change state of the acceleration. You may

Further, in a four-wheel drive vehicle, etc., FIG.
As shown by the broken line, a range switch 43 for detecting the shift range of the transmission may be provided and the signal of the range switch 43 may be used to detect the traveling on the rough road of the vehicle. That is, some four-wheel drive vehicles are equipped with a range switching device that selects either the H range for normal traveling or the L range for traveling on rough roads. Therefore, in this case, it may be determined that the vehicle is traveling on a rough road when the L range is selected. Even if the H range is selected, it may be determined that the vehicle is traveling on a rough road when the low speed gear is selected.

If the vehicle is traveling at a low speed or on a rough road, the result of step 170 or step 172 is "Yes".
s ”, steps 102, 104, 170
The cyclic process including (and step 160) or the cyclic process including steps 102, 104, 170, and 172 (and step 160) is repeatedly executed. As a result, the absolute value | Gy | of the lateral acceleration Gy described above is the predetermined value G.
Similar to the case where it is less than y1, the roll rigidity forces of the front and rear wheel stabilizers 16, 16 both continue to be set small (state value ST continues to be set to "3"). As a result, when the vehicle is traveling at a low speed or on a rough road, the control of the inappropriate roll rigidity force according to the lateral acceleration Gy and the turning state is avoided, and the riding comfort of the vehicle is always kept good. .

If the vehicle is not traveling at a low speed or traveling on a rough road, both "No" in steps 170 and 172.
Is determined, and the above-described processing from step 106 onward is executed. Therefore, in this case, as in the case of the above embodiment, according to the lateral acceleration Gy and the turning state,
The roll rigidity of the front and rear stabilizers 16, 16 is controlled.

Further, in the above-described embodiment and modification, the determination processing in step 112 determines whether the differential value d | θ | / dt of the absolute value | θ | of the steering wheel rotation angle θ is positive or negative.
Although the initial turning and the ending timing of the vehicle, that is, the turning state of the vehicle is detected, the turning state of the vehicle may be detected from the lateral acceleration Gy, the history of the yaw rate, and the like.

Further, in the above-described embodiment and modification, the lateral acceleration Gy is estimated and calculated by using the lateral acceleration estimation routine in step 106. However, the stabilizers 16 and 16 for the front wheels and the rear wheels
In the invention relating to roll rigidity force control, the lateral acceleration Gy detected by a method other than the lateral acceleration Gy by the estimation calculation can be used. For example, if the detection accuracy or cost is not a problem, various lateral acceleration sensors that directly detect lateral acceleration may be provided and the lateral acceleration Gy detected by the sensor may be used.

[Brief description of drawings]

FIG. 1 is a schematic view commonly showing a suspension device for front wheels and rear wheels of a vehicle according to an embodiment of the present invention.

FIG. 2 is a block diagram of an electric control device for controlling a roll rigidity force of a stabilizer in the front wheel and rear wheel suspension devices.

FIG. 3 is a flowchart showing a main program executed by the microcomputer of FIG.

FIG. 4 is a flowchart showing details of a lateral acceleration estimation routine of FIG.

FIG. 5 is a graph showing the relationship between lateral acceleration and stability factor.

FIG. 6 is a flowchart showing a part of a main program according to a modification in which a part of the main program of FIG. 3 is modified.

7 is a flowchart showing a part of a main program according to another modification in which a part of the main program of FIG. 3 is modified.

[Explanation of symbols]

11a, 11b ... Suspension arms, 12a, 12
b ... Damper cylinder, 13a, 13b ... Coil spring, 14a, 14b ... Wheel, 15 ... Car body, 16 ... Stabilizer, 20, 20A, 20B ... Cylinder unit, 2
1, 21a, 21b ... Hydraulic cylinders, 22, 22a, 2
2b ... Piston, 23, 23a, 23b ... Piston rod, 24a, 24b ... Electromagnetic switching valve, 30 ... Microcomputer, 31 ... Vehicle speed sensor, 32 ... Steering angle sensor, 33a-33d ... Air pressure sensor, 41 ... Stroke sensor, 42 ... Vertical acceleration sensor, 43 ... Range switch.

Claims (5)

[Claims] 1. A first roll rigidity force varying means capable of changing a roll rigidity force of a front wheel side stabilizer, and a second roll stiffness force varying means capable of changing a roll rigidity force of a rear wheel side stabilizer. In a stabilizer device for a vehicle, a lateral acceleration detecting means for detecting a lateral acceleration of the vehicle, a turning state detecting means for detecting a turning state of the vehicle, and the first and second depending on the detected lateral acceleration and the turning state. And a roll rigidity force control means for setting the roll rigidity forces of the front wheel side stabilizer and the rear wheel side stabilizer in accordance with the detected lateral acceleration and turning state. Characteristic vehicle stabilizer device. 2. The first roll rigidity force varying means switches between large and small roll rigidity forces of the front wheel side stabilizer, and the second roll rigidity force varying means means roll rigidity of the rear wheel side stabilizer. The stabilizer device for a vehicle according to claim 1, wherein the magnitude of force is switched, and the roll rigidity force control means switches a combination relationship of magnitude of roll rigidity forces of the front wheel side stabilizer and the rear wheel side stabilizer. . 3. The stabilizer device for a vehicle according to claim 1 or 2, further controlling the first and second roll rigidity force varying means, respectively, when the vehicle is traveling at a low speed or traveling on a rough road, A stabilizer device for a vehicle, comprising roll rigidity force suppression control means for suppressing both roll rigidity forces of the front wheel side stabilizer and the rear wheel side stabilizer to be small. 4. The stabilizer device for a vehicle according to claim 1, further comprising: a tire air pressure detecting means for detecting tire air pressures of front and rear wheels, and the detected tire. 2. A stabilizer device for a vehicle, comprising: a control mode changing unit for changing and controlling a control mode of the first and second roll rigidity force varying units by the roll rigidity force controlling unit according to air pressure. 5. A first roll rigidity force varying means capable of changing the roll rigidity force of the front wheel side stabilizer, a second roll stiffness force varying means capable of changing the roll rigidity force of the rear wheel side stabilizer, and the first roll rigidity force varying means. The present invention is applied to a vehicle provided with a stabilizer device for a vehicle, which comprises roll rigidity force control means for controlling the first and second roll rigidity force varying means respectively to set the front wheel stabilizer and the rear wheel stabilizer to desired states. A vehicle speed detection means for detecting a vehicle speed, a steering angle detection means for detecting a front wheel steering angle, a front wheel side stabilizer and a rear wheel side by the roll rigidity force control means in addition to the detected vehicle speed and front wheel steering angle A lateral acceleration detecting device for a vehicle, comprising: a calculating unit that calculates a lateral acceleration of the vehicle according to a setting state of a stabilizer.