JP3039209B2 - Air suspension control 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 air suspension for a vehicle such as an automobile, and more particularly to an air suspension control device.

[0002]

2. Description of the Related Art Generally, an air suspension of a vehicle such as an automobile has an air spring provided for each wheel, and the volume of the air chamber of each air spring decreases and increases when the wheel bounces and rebounds. The spring force is increased / decreased by increasing / decreasing the pressure in the air chamber, and as one of such air suspension control devices, for example, as described in Japanese Utility Model Laid-Open No. 60-8112, A target pressure in the air chamber is set according to a traveling state of the vehicle, and an actual pressure in the air chamber is detected, and a control valve for air supply and a control valve for exhaust are set according to a deviation between the actual pressure and the target pressure. The air suspension control device is configured to feedback-control the pressure in the air chamber to control the pressure in the air chamber to a target pressure. There has been conventionally known.

According to such an air suspension control device, the attitude change of the vehicle body during acceleration / deceleration or turning of the vehicle can be reduced as compared with a normal air suspension in which the pressure in the air chamber is not actively controlled. Thus, the driving stability of the vehicle can be improved.

[0004]

However, in the conventional air suspension control device as described above, the wheels bounce and rebound due to the unevenness of the road surface accompanying the running of the vehicle, and the actual pressure in the air chamber is thereby reduced. As the supply and exhaust control valves are controlled to open and close accordingly, the supply and exhaust of air to and from the air chamber are performed repeatedly and frequently, so that energy consumption is likely to increase, and durability and responsiveness are reduced. There is a problem that an excellent control valve or the like is required and the cost is high.

In view of the above-mentioned problems in the conventional air suspension control device, the present invention keeps the air chamber in a closed space unless the control valve is opened and closed, and the mass of gas in the closed space is reduced. Focusing on the fact that it is constant irrespective of fluctuations in volume , pressure and temperature of the air spring, unnecessary control of the air spring is prevented from being performed repeatedly and frequently, reducing energy consumption and improving the durability of the air suspension. It is an object of the present invention to provide an improved air suspension control device capable of improving the cost and reducing the cost.

Further, the present invention not only reduces the energy consumption and cost and improves the durability of the air suspension, but also improves the riding comfort of the vehicle as compared with the prior art. It is intended to provide a suspension control device.

[0007]

Above-mentioned object, according order to achieve the above, according to the present invention, as represented in FIGS. 1 and 2, (1)
An air suspension control device that controls the posture of the vehicle body by controlling the supply and exhaust of working gas to and from an air chamber of an air spring (10) provided corresponding to each wheel to detect the running state of the vehicle. State detection means (12), target gas mass calculation means (14) for calculating a target gas mass Mo in the air chamber based on the detected running state of the vehicle, and calculation of an actual gas mass M in the air chamber Actual gas mass calculating means (16), and supply / discharge control means for controlling the supply / discharge of the working gas to / from the air chamber based on the difference Mc between the actual gas mass M and the target gas mass Mo. (18) and a said
The actual gas mass calculating means detects the volume of the air chamber.
Volume detection means (20), and pressure in the air chamber
Pressure detecting means (22) for detecting pressure, and the air chamber
Temperature detecting means (24) for detecting the temperature of the working gas in the chamber
And the volume detection means, the pressure detection means, and the temperature
Volume, pressure and temperature respectively detected by the detection means
As shown the air suspension control system, and in Figure 2 based and a calculating means for calculating an actual gas mass M, the (2) above At a air suspension control system, the actual gas mass calculation means (16) has a smooth processing means for smoothing processing (26) a signal indicative of the temperature of the operating gas detected by the previous SL temperature detecting means, said calculating means volumes and respectively detected by the volume detecting means and pressure detecting means It is achieved by an air suspension control system according to claim and Turkey to calculating the actual gas mass M on the basis of the temperature and which is smoothed by the pressure and the smoothing processing means.

[0008]

According to the above configuration (1) , the target gas mass Mo in the air chamber is calculated by the target gas mass calculating means (14) based on the running state of the vehicle detected by the running state detecting means (12). And the actual gas mass calculating means (16)
The actual gas mass M in the air chamber is calculated, and the supply / discharge of the working gas to / from the air chamber is controlled by the supply / discharge control means based on the deviation between the actual gas mass M and the target gas mass Mo so that the deviation decreases. Actual gas mass M is air chamber
Volume and pressure in the air chamber and operation in the air chamber
Based on the temperature of the gas Ru is calculated.

Therefore, even if the wheels bounce or rebound due to the unevenness of the road surface, the target gas mass Mo is not changed and the deviation Mc does not change, so that the supply and discharge of the working gas to and from the air chamber are repeatedly and frequently performed. without thereby improves the durability of the air suspension with energy consumption and cost are reduced compared with the case where the pressure in the air chamber is feedback controlled by the conventional control device, also of the actual gas mass M is the air chamber Volume and air chisel
The pressure in the chamber and the temperature of the working gas in the air chamber
Since the calculation is based on the actual gas mass M,
Compared to the case where the calculation is based only on the
Gas mass M is Ru is accurately calculated.

In the air suspension control device, the pressure in the air chamber of the air spring, the volume of the air chamber, the temperature of the gas in the air chamber, and the mass of the gas in the air chamber are P, V, T, and M, respectively. The pressure in the air chamber when the wheel is in the neutral position, the volume of the air chamber, the temperature of the gas in the air chamber, and the mass of the gas in the air chamber (target gas mass) are P ₁ and V, respectively. ₁ , T ₁ , M ₁ , the pressure in the air chamber, the volume of the air chamber, the temperature of the gas in the air chamber, the mass of the gas in the air chamber after the wheel is subjected to an external force such as over a bump on the road surface To P ₂ ,
V ₂ , T ₂ , and M ₂ , the gas is regarded as a perfect gas, and R is defined as the gas constant of the gas, and the mass M of the gas calculated in the air suspension controller is defined as the following equation 1.

## EQU1 ## M = (PV) / (RT)

Assuming now that the vehicle is traveling straight, and assuming that the mass of gas in the air chamber is constant,
The target mass M ₁ calculated by the air suspension control device is represented by the following equation (2).

## EQU2 ## M ₁ = (P ₁ · V ₁ ) / (R · T ₁ )

Assuming that the state change occurring in the air spring is a polytropic change and that the system of the air chamber is closed, n is a polytropic index and the following equation B
Holds.

## EQU3 ## P ₁ · V ₁ ⁿ = P ₂ · V ₂ ⁿ

From Equation 3, the pressure P ₂ in the air chamber after the air suspension receives an external force is expressed by Equation 4 below.

## EQU4 ## P ₂ = (V ₁ / V ₂ ) ⁿ · P ₁

The volume V ₂ in the air chamber after the external force is applied to the air suspension is represented by S as the suspension stroke (positive displacement in the bound direction from the standard position) and A as the cross-sectional area of the piston of the air suspension. Is represented by the following Expression 5.

## EQU5 ## V ₂ = V ₁ -AS

The pressure P ₂ and the volume V ₂ represented by Equations 4 and 5 are values detected by the pressure detecting means and the volume detecting means, respectively. Is represented by Equation 6 below.

M = (P ₂ · V ₂ ) / (R · T ₂ ) = {(P ₁ · V ₁ ) / (R · T ₂ )} · {V ₁ / (V ₁ −A · S) ｝ ^N-1

Here, the temperature T of the gas in the air chamber detected by the temperature detecting means is smoothed so that the change in the temperature T is sufficiently slower than the change in the volume of the air chamber, and the polytropic index of the temperature change is substantially reduced. , The following equation 7 holds.

## EQU7 ## T ₂ = T ₁

Therefore, Equation 6 is expressed as Equation 8 below.

M = {(P ₁ · V ₁ ) / (RT ₁ )} · {V ₁ / (V ₁ − (V ₁ AS)} ⁿ⁻¹

Now, the feedback control amount E in the air suspension control device is defined as in the following equation (9).
In the following equation 9, K is a feedback gain.
E <0 corresponds to exhaust for discharging gas from the air chamber, and E> 0 corresponds to air supply for supplying gas to the air chamber.

E = K · (M ₁ −M)

By substituting Equations 2 and 8 into Equation 9, Equation 9 is expressed as Equation 10 below.

E = K · {(P ₁ · V ₁ ) / (R · T ₁ )} · [1- {V ₁ / (V ₁ − (V ₁ AS)} ^n-1 ]

Assuming that the wheel makes a stroke in the bounding direction by S as it passes through a convex portion of the road surface, V ₁ -A
· S because it is <V _1, the number 11 below is satisfied.

V ₁ / (V ₁ -AS)> 1

When the wheel bounces, the pressure P in the air chamber increases (ie, it is not a constant pressure change), so that the polytropic index n is 1 or more, and
Holds.

1− {V ₁ / (V ₁ −A · S)} ⁿ⁻¹ <0

When Equation 10 is examined based on Equation 12, the following Equation 13 is established.

E <0

Equation 13 means exhaust as described above, and means that when a wheel receives an input in the bounding direction from the road surface, gas is exhausted from the air chamber to reduce the spring force of the air spring.

If the wheel travels in the rebound direction by S as the wheel passes through the concave portion of the road surface,
_{Since 1−} A · S> V ₁ , the following Expression 14 is established.

V ₁ / (V ₁ −A · S) <1

When the wheel rebounds, the pressure P in the air chamber decreases (ie, it is not a constant pressure change).
The polytropic index n is greater than or equal to 1 and therefore:
5 holds.

1− {V ₁ / (V ₁ −A · S)} ⁿ⁻¹ > 0

When Equation 10 is examined based on Equation 15, the following Equation 16 is established.

E> 0

Equation (16) means air supply as described above, and means that when the wheel receives an input in the rebound direction, gas is supplied to the air chamber to increase the spring force of the air spring.

According to the above configuration (2) , the temperature detecting means
Working gas in the air chamber detected by step (24)
Temperature is smoothed by the smoothing processing means (26), the volume of the air chamber detected by the volume detecting means (20), and the air chamber pressure detected by the pressure detecting means (22), the flat smooth processing means ( The actual gas mass M is calculated by the calculating means (28) based on the temperature of the working gas in the air chamber smoothed by the process (26), so that the wheel passes through the convex portion of the road surface as described above. When the wheel receives a force in the bounding direction as in the case of the vehicle, the spring force of the air spring is reduced. It is increased, thereby power of the vehicle in comparison with the case of the control by the control device of the configuration of the normally supply and discharge of working gas is not performed to the air chamber air suspension or the above (1) Comfort is improved.

[0029]

According to one detailed feature of the present invention, the actual gas mass calculating means has an outside air temperature detecting means for detecting an outside air temperature . Performance
Calculation means configured to Let 's you calculating volume detecting means, volume respectively detected by the pressure detection means and outside air temperature detection means, the actual gas mass M on the basis of the pressure and outside air temperature. When the cutoff frequency is set to a very low frequency and the temperature of the working gas in the air chamber is low-pass filtered, the temperature after the low-pass filter processing becomes substantially equal to the outside air temperature. Therefore, according to this configuration, the supply and discharge of the working gas to and from the air chamber are controlled in the same manner as in the configuration of the second aspect, and the number of means for detecting the temperature is reduced to one.

According to another detailed feature of the present invention (the structure of claim 4), the air suspension control device includes a vehicle vertical movement detecting means for detecting the vertical movement of the vehicle, Target gas mass correction means for reducing and correcting the target gas mass Mo when moving and increasing and correcting the target gas mass Mo when moving below the vehicle body. According to this configuration, the vertical displacement of the vehicle body when the air spring receives a disturbance input from the vehicle body is reduced, so that the riding comfort of the vehicle is further improved.

According to another detailed feature of the present invention (the structure of claim 5), the air suspension control device includes a vehicle vertical speed detecting means for detecting a vertical movement speed of the vehicle, The supply of the working gas to the air chamber is prohibited when moving upward at a speed higher than the speed, and the working gas is discharged from the air chamber when the vehicle body moves downward at a speed higher than a predetermined speed. And supply / discharge prohibition means for prohibiting the operation. According to this configuration, the vertical displacement of the vehicle body when the air spring receives a disturbance input from the vehicle body is suppressed, thereby further improving the riding comfort of the vehicle.

Further, according to another detailed feature of the present invention (the structure of claim 6 or 7), the volume detecting means includes a vehicle height detecting means for detecting a vehicle height of a portion corresponding to each wheel, It is configured to have a volume calculating means for calculating the volume of the air chamber from the relationship between the set vehicle height and the volume of the air chamber. According to such a configuration, the actual gas mass M accompanying the change in the vehicle height is determined by the setting mode of the relationship between the vehicle height and the volume.
Can be calculated to be the same as the change in the actual gas mass in the air chamber, or can be calculated to be different from the change in the actual gas mass in the air chamber. It is possible to increase the degree of freedom of supply / discharge control.

For example, in a case where an air spring configured to have a substantially constant pressure receiving area even when the vehicle height changes is used, if the above relationship is set to a substantially nonlinear characteristic, (Structure of Claim 8) For example, by making the mass of the working gas supplied to and discharged from the air chamber larger than the mass of the gas corresponding to the actual volume change of the air chamber, the vertical movement of the vehicle body is effectively suppressed. Thus, the riding comfort of the vehicle is further improved.

In the case where an air spring configured to change the pressure receiving area with a change in vehicle height is used, the above-described relationship is related to the actual volume change of the air chamber with the change in vehicle height. If they are set substantially correspondingly (claim 9
), For example, by reducing the pressure receiving area of the air spring as the vehicle height decreases, the vertical movement of the vehicle body can be effectively suppressed, and the actual gas mass M is reduced by the actual volume change of the air chamber. Since the corresponding calculation is performed, the supply and discharge of the working gas to and from the air chamber can be controlled substantially only for the amount corresponding to the change in the polytropic index of the working gas, thereby ensuring a good ride comfort of the vehicle. In this way, it is possible to further reduce the consumption of the working gas.

Further, if the above relationship is set so that the volume of the air chamber is substantially constant near the standard vehicle height (the structure of claim 10), the vehicle may be damaged due to slight irregularities on the road surface. Even if the height increases or decreases near the standard vehicle height, the actual gas mass M
Does not increase or decrease, and the supply and discharge of the working gas to and from the air chamber are not performed, so that the consumption of the working gas can be further reduced.

[0036]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of an embodiment of the present invention. First Embodiment FIG. 3 is a schematic configuration diagram showing a first embodiment of an air suspension control device according to the present invention. In FIG. 3, * is a symbol corresponding to each wheel, and the members indicated by * are the right front wheel (* = fr), the left front wheel (* = fl), and the right rear wheel. (* = Rr), which indicates that they are provided corresponding to each of the left rear wheels (* = rl).

In FIG. 3, reference numeral 30 * denotes a shock absorber disposed between a sprung portion and an unsprung portion not shown in the drawing, and 32 * denotes an integral part of the shock absorber 30 *. FIG. The air spring 32 * has an air chamber 34 * whose volume decreases and increases as the wheel bounces and rebounds, which are not shown, as is well known.

One end of an air supply conduit 36 * is connected to the air chamber 34 *, and the other end of the conduit is connected to a high-pressure tank 38 for storing high-pressure air therein. An air supply control valve 40 *, which is a solenoid-type normally closed on-off valve, is provided in the middle of the air supply conduit 36 *. Air supply conduit 36
One end of an exhaust conduit 42 * is connected to a portion between the * air spring 30 * and the air supply control valve 40 *, and the other end of the conduit is connected to a low-pressure tank 4 for storing low-pressure air therein.
4 are connected. An exhaust control valve 46 *, which is a solenoid-type normally-closed open / close valve, is provided in the exhaust conduit 42 * in the same manner as the control valve 40 *.

As shown in FIG. 3, in the illustrated embodiment, the control valves 40 * and 46 * include a steering angular speed sensor 48 for detecting the steering angular speed θd, a vehicle speed sensor 50 for detecting the vehicle speed V, and a vehicle body. A lateral acceleration sensor 52 for detecting the lateral acceleration Gy of the vehicle, a longitudinal acceleration sensor 54 for detecting the longitudinal acceleration Gx of the vehicle body, a vehicle height sensor 56 * for detecting the vehicle height H * of a portion corresponding to each wheel, and air of each air spring. Chamber 34
Based on signals from a pressure sensor 58 * for detecting the internal pressure P * and a temperature sensor 60 * for detecting the temperature T * of the air in each air chamber, the electronic control unit 62 controls the opening and closing as described later. Has become.

The electronic control unit 62 has a microcomputer 64 as shown in FIG. The microcomputer 64 may have a general configuration as shown in FIG. 4, and includes a central processing unit (CPU) 6.
6, a read only memory (ROM) 68, a random access memory (RAM) 70, and an input port device 72
And an output port device 74, which are connected to each other by a bidirectional common bus 76.

The input port device 72 has a signal indicating the steering angular velocity θd detected by the steering angular velocity sensor 48, a signal indicating the vehicle speed V detected by the vehicle speed sensor 50, and the lateral acceleration Gy of the vehicle body detected by the lateral acceleration sensor 52. And a signal indicating the longitudinal acceleration Gx of the vehicle body detected by the longitudinal acceleration sensor 54, and a vehicle height sensor provided corresponding to each wheel not shown in the figure. 56 *, pressure sensor 58 *, temperature sensor 6
From 0 *, a signal indicating the vehicle height H * of the portion corresponding to each wheel, the pressure P * in each air chamber, and the temperature T * of the air in each air chamber is input.

The input port device 72 appropriately processes the signal input thereto, and in accordance with the instruction of the CPU 66 based on the program stored in the ROM 68, the CPU and the RAM.
70, and outputs the processed signal. R
The OM 38 stores the control programs shown in FIGS. 5 to 7 and maps corresponding to the graphs shown in FIGS. The CPU 66 performs various calculations and signal processing based on the control programs shown in FIGS. 5 to 7 as described later. The output port device 74 is a CPU 6
In accordance with the instruction of 6, a control signal is output to the air supply control valve 40 corresponding to each air spring via the drive circuit 78 *, and the drive circuit 80 * is controlled to the exhaust control valve 46 * corresponding to each air spring. It is designed to output a signal.

Next, control of the air suspension in the illustrated embodiment will be described with reference to the flowchart shown in FIG. The routine shown in FIG. 5 is started by closing an ignition switch (not shown). In the flowchart shown in FIG.
Is a symbol corresponding to each wheel. The control by the routine shown in FIG.
l), right rear wheel (* = rr) and left rear wheel (* = rl) in this order.

In the first step 100, the target air mass Mo * in the air chamber is calculated in accordance with the flowchart shown in FIG.
At 0, the actual air mass M * in each air chamber is calculated according to the flowchart shown in FIG.
In step 300, the deviation Mc * (= Mo * -M *) of the mass calculated in steps 100 and 200 is calculated.

In step 400, it is determined whether or not the deviation Mc * is greater than or equal to -α and less than or equal to α using α (a positive constant) as a control threshold value. When it is determined that α is satisfied, the flow returns to step 100 after the air supply control valve 40 * and the exhaust control valve 46 * are closed in step 800, and -α ≦ Mc * ≦ α is not satisfied. When the determination is made, the process proceeds to step 500.

In step 500, it is determined whether or not the deviation Mc * is equal to or more than α. When it is determined that α ≦ Mc *, in step 600, the air supply control valve is determined. After the valve 40 * is opened and the exhaust control valve 46 * is closed, the process returns to step 100, and when it is determined that α ≦ Mc * is not satisfied, at step 700, the air supply control valve 40 * Is closed and the exhaust control valve 46 *
Is returned to step 100 after the valve is opened.

Next, the routine for calculating the target air mass Mo * performed in step 100 of the flowchart shown in FIG. 5 will be described with reference to the flowchart shown in FIG.

First, in step 105, the steering angular velocity θ
d, vehicle speed V, lateral acceleration Gy of vehicle body, longitudinal acceleration G of vehicle body
x, the temperature T * of the air in the air chamber 34 * of each wheel is read, and in step 110, the steering angular velocity θd is read.
A delay compensation value Gyo of the lateral acceleration of the vehicle body is calculated based on a map corresponding to the graph shown in FIG. When the steering angular velocity θd is a negative value, the delay compensation value Gyo is calculated as a negative value.

In step 115, the lateral acceleration G of the vehicle body
estimated lateral acceleration G of the vehicle body based on y and its delay compensation value Gyo
ym (= Gy + Gyo) is calculated. In step 120, the target roll amount Rm of the vehicle body is calculated based on the estimated lateral acceleration Gym of the vehicle and on the basis of a map corresponding to the graph shown in FIG. Similarly, in step 125, the target pitch amount Pm of the vehicle body is calculated based on the longitudinal acceleration Gx of the vehicle body and on the map corresponding to the graph shown in FIG.

In step 130, based on the target roll amount Rm and target pitch amount Pm calculated in steps 120 and 125, respectively, Kp and Kr are positive constants, and the stroke amount of each wheel is calculated according to the following equation (17). S * is calculated. When the vehicle height is controlled according to the vehicle speed V or the like, the heave amount h corresponding to the vehicle speed V or the like may be added in each of the following equations (17).

Sfl = -Kp-Pm-Kr-Rm Sfl = -Kp-Pm-Kr-Rm Srl = -Kp-Pm + Kr-Rm

In step 135, SV * is set as the reference volume of the air chamber 34 * of the air spring 32 * of each wheel (the volume when the corresponding wheel is at the neutral position).
The target air chamber volume Vo * of each air spring is calculated according to the following equation (18). In Equation (18), A ₁ and A ₂ are the cross-sectional areas of the cylinders of the shock absorber 30 for the left and right front wheels and the left and right rear wheels, respectively.

[Equation 18] Vofr = SVfr + A ₁ · Sfr Vofl = SVfl + A ₁ · Sfl Vorr = SVrr + A ₂ · Srr Voll = SVrl + A ₂ · Srl

In step 140, based on the estimated lateral acceleration Gym of the vehicle body calculated in step 115, Df and Dr are defined as positive constants for the front and rear wheels, respectively, according to the following equation (19). Internal pressure increment Py *
Is calculated.

[Equation 19] Pyfr = Df · Gym Pyfl = −Pyfr Pyrr = Df · Gym Pyrl = −Pyrr

In step 145, based on the longitudinal acceleration Gx of the vehicle body read in step 105, the increment Px * of the pressure in each air chamber is calculated in accordance with the following equation 20 with Dp as a positive constant.

[Equation 20] Pxfr = Dp · Gx Pxfl = Pxfr Pxrr = −Dp · Gx Pxrl = Pxrr

In step 150, SP * is set as the reference pressure of the pressure in each air chamber (the pressure when the vehicle is stationary and the corresponding wheel is at the neutral position) according to the following equation (21). The pressure Po * is calculated.

## EQU21 ## Pofr = SPfr + Pyfr + Pxfr Pofl = SPfl + Pyfl + Pxfl Porr = SPrr + Pyrr + Pxrr Porl = SPrl + Pyrl + Pxfl

In step 155, the air temperature T * in each air chamber read in step 105, and the target air chamber volume Vo calculated in step 135
*, Based on the target air chamber pressure Po * calculated in step 150, where R is a gas constant and
, The target air mass Mo * in each air chamber is calculated.

## EQU22 ## Mo * = (Po * Vo *) / (RT *)

Next, a routine for calculating the actual air mass M * performed in step 200 of the flowchart shown in FIG. 5 will be described with reference to the flowchart shown in FIG.

First, at step 210, the vehicle height H * at the portion corresponding to each wheel, and the pressure P in the air chamber of each wheel.
* The temperature T * in the air chamber of each wheel is read. In step 220, the cutoff frequency is set to, for example, 0.01 Hz, and the signal indicating the temperature T * is low-pass filtered to perform low-pass filtering. The temperature Tlp * after the filter processing is calculated.

In step 230, step 210
Based on the vehicle height H * of the portion corresponding to each wheel that is read At a, K ₁ and the coefficient of K ₂ About each of the left and right front wheels and left and right rear wheels volume (positive constant) as an air chamber of each wheel V * Is calculated according to the following equation (23).

[Number 23] _{Vfr = SVfr + K 1 · Hfr} Vfl = SVfl + K 1 · Hfl Vrr = SVrr + K 2 · Hrr Vrl = SVrl + K 2 · Hrl

In step 240, the pressure P * in the air chamber of each wheel read in step 210, the temperature Tlp * in each air chamber after the low-pass filter processing calculated in step 220, step 230 The actual air mass M * in each air chamber is calculated in accordance with the following equation 24 using R as a gas constant on the basis of each air chamber volume V * calculated in the above.

## EQU24 ## M * = (P * .V *) / (R.Tlp *)

Thus, according to the first embodiment, in step 100, that is, in steps 105 to 155, the target air mass Mo * in each air chamber is calculated according to the running state of the vehicle, that is, turning or acceleration / deceleration. In step 200, that is, in steps 210 to 240, the actual air mass M * in each air chamber is calculated, and in step 300, the deviation Mc * between the target air mass Mo * and the actual air mass M * is calculated. ,
In steps 400 to 800, the mass of the air in each air chamber is feedback-controlled so that the deviation Mc * is equal to or more than -α and equal to or less than α.

Accordingly, when the vehicle is not substantially turned or accelerated or decelerated, as in the case of a vehicle traveling at a constant speed, the target air mass Mo is obtained even if the wheels bounce or rebound due to unevenness of the road surface.
* Does not change and the deviation Mc * does not change.
* And 46 * are reliably prevented from being repeatedly opened and closed.

At the time of turning or acceleration / deceleration of the vehicle, a target air mass Mo * is calculated so as to suppress a change in the posture of the vehicle due to a lateral acceleration or a longitudinal acceleration of the vehicle. The deviation Mc * from * is -α or more and α
The control valves 40 * and 46 * are opened and closed as follows, and air is supplied to and exhausted from each air chamber, so that a roll, nose dive, squat, etc. A large posture change is effectively prevented.

Further, according to the first embodiment, the signal indicating the temperature T * of the air in each air chamber is low-pass filtered to smooth the signal indicating the temperature T *. The actual air mass M * in each air chamber is calculated based on Tlp *. Therefore, as described above along Formulas 1 to 16, when the wheel receives a force in the bounding direction, the air spring is used. When the wheel receives a force in the rebound direction, the spring force of the air spring increases, and based on the detected temperature T *, the actual air mass M * in each air chamber is reduced. The ride comfort of the vehicle is improved as compared with the case where the calculation is performed.

In the first embodiment, the temperature Tlp * after the smoothing process is calculated by subjecting a signal indicating the temperature T * of the air in each air chamber to low-pass filtering. However, the smoothing process on the signal indicating the temperature T * may not be performed by digital operation as in the illustrated embodiment, but may be performed in an analog manner by a low-pass filter incorporated in the electronic control unit.
Also, it may be executed by calculation of a weighted average or the like.

FIG. 8 is a flowchart similar to FIG. 7 showing a routine for calculating the actual air mass M * when the weighted average is calculated for the signal indicating the temperature T *. In this modified example, in step 220, Tlpf * is used as the weighted average value calculated in step 220 one cycle before, and the weighted average is calculated in accordance with the following equation (25). The temperature Tlp * is calculated,
In step 250, the temperature Tlp * after the smoothing process calculated in step 220 is rewritten to Tlpf *.

Tlp * = (T * + 99 · Tlpf *) / 100

Therefore, also in the first modification, the actual air mass M * in each air chamber is equal to the temperature Tlp * after the smoothing process.
, The actual air mass M * in each air chamber is equal to the detected temperature T *, as in the case of the first embodiment described above.
The ride comfort of the vehicle is improved as compared with the case where the calculation is performed based on

In the first embodiment, step 220 of the flowchart shown in FIG. 7 is omitted, and in step 240, the actual air mass M * is not the detected temperature Tlp * but the detected temperature T *. It may be modified to be calculated based on *. According to the second modification, the amount of air supply and exhaust to and from the air chamber can be reduced as compared with the case of the first embodiment, thereby reducing the amount of air consumption.

Second Embodiment In the above-described first embodiment, when the cutoff frequency is set to a very low frequency and the signal indicating the temperature T * in each air chamber is low-pass filtered, the low-pass filter processing is performed. The subsequent temperature becomes substantially equal to the outside air temperature T. Assuming that the temperature in each air chamber is the same as the outside air temperature T, the target air mass Mo * and the actual air mass M * are represented by the following Expressions 26 and 27, respectively.

## EQU26 ## Mo * = (Po * .Vo *) / (RT)

[Mathematical formula-see original document] M * = (P * V *) / (RT)

Accordingly, the deviation Mc * is expressed by the following equation (28). From equation (28), the temperature T is considered as a control gain, and as long as the outside air temperature T does not significantly deviate from the actual temperature T * in each air chamber, Assume that the temperature inside the air chamber is the same as the outside air temperature T does not hinder the air supply / discharge control to the air chamber.

[Equation 28] Mc * = (1 / RT) (Po * .Vo * -P * .V *)

FIG. 12 is a schematic configuration diagram showing a second embodiment of the air suspension control device according to the present invention constructed in accordance with the above-described concept. FIG. 13 shows one embodiment of the electronic control device shown in FIG. It is a block diagram shown. In these figures, the same members as those shown in FIGS. 3 and 4 are denoted by the same reference numerals as those shown in FIGS. 3 and 4.

In the second embodiment, one outside air temperature sensor 60 for detecting the outside air temperature T is provided instead of the temperature sensor 60 * in the first embodiment. Correspondingly, steps 100 and 200 of the main routine are respectively shown in FIGS.
Is executed according to the flowchart shown in FIG.

In step 105 of the target air mass Mo * calculation routine shown in FIG. 14, the outside air temperature T detected by the outside air temperature sensor 60 is read instead of the temperature T * in each air chamber. In step 151, the cut-off frequency is set to, for example, 0.1 Hz, and the signal indicating the outside temperature T is subjected to low-pass filtering to calculate the outside temperature Tlp from which noise components have been removed. The target air mass Mo * is calculated according to the equation (29).

## EQU29 ## Mo * = (Po * .Vo *) / (R.Tlp)

In step 210 of the actual air mass M * calculation routine shown in FIG. 15, the outside air temperature T detected by the outside air temperature sensor 60 is read instead of the temperature T * in each air chamber. Step 15 at 220
Similarly to 1, the signal indicating the outside air temperature T is subjected to low-pass filtering to calculate the outside air temperature Tlp from which the noise component has been removed. In step 240, the actual air mass M * is calculated according to the following equation (30).

[Mathematical formula-see original document] M * = (P * .V *) / (R.Tlp)

Thus, according to the second embodiment, it is not necessary to provide a temperature sensor for each wheel, and only one temperature detection sensor is required. Can be simplified and the cost can be reduced, and substantially the same operation and effect as those of the first embodiment can be obtained.

In this embodiment, the noise component is removed from the actual air mass M * by performing weighted averaging on the signal indicating the outside air temperature T as shown in FIG. 16, for example. The calculation may be performed based on the subsequent outside air temperature Tlp. In this embodiment, if the outside air temperature of the area where the outside air temperature sensor 60 is provided is different from the outside air temperature of the area where the air spring is provided, for example, Ka and Kb are respectively corrected by a correction coefficient and a correction constant. The outside air temperature T detected by the outside air temperature sensor may be corrected according to the following Expression 31.

T = T · Ka + Kb

Third and Fourth Embodiments According to the control in the first and second embodiments, when the air spring receives an input from either a sprung (body) or unsprung (wheel) state, In addition, when the air spring is compressed, the air is discharged from the air chamber, and when the air spring is expanded, the air is supplied to the air chamber. Therefore, when the air spring receives an input from the road surface, the input can be suppressed from being transmitted to the vehicle body and the ride comfort of the vehicle can be improved. However, for example, the air spring occurs after the wheel passes over a step on the road surface. When the air spring receives an input from the vehicle body due to a tilt of the vehicle body, the air is discharged from the air chamber when the air spring is compressed, and the air is supplied to the air chamber when the air spring is extended. There is a disadvantage that the vertical movement of the vehicle body is promoted.

For example, as shown in FIG.
When the vehicle body 00 moves on a horizontal road surface after passing through the projection 102a of the road surface 102, the vehicle body 104 moves up and down as shown by an imaginary arrow in FIG.
06 and the shock absorber 108 receive a downward force from the vehicle body 104. As a result, the air in the air chamber is exhausted, which promotes the downward movement of the vehicle body.

Also, as shown in FIG.
When the vehicle 0 moves on a horizontal road surface after passing through the depression 102b of the road surface 102, the vehicle body 104 moves up and down as shown by the imaginary arrow in FIG.
6 and the shock absorber 108 receive an upward force from the vehicle body 104. As a result, air is supplied into the air chamber, which promotes the upward movement of the vehicle body.

Therefore, when the vehicle body moves downward, the amount of air discharged from the air chamber is reduced or is prevented, and when the vehicle body moves upward, the amount of air supplied to the air chamber is reduced. By preventing the supply of air, the vertical movement of the vehicle body can be reduced or suppressed, and the riding comfort of the vehicle can be further improved.

FIG. 17 is a schematic diagram showing the third and fourth embodiments of the air suspension control device according to the present invention constructed in accordance with the above concept. FIG. 18 is a schematic diagram showing one of the electronic control devices shown in FIG. It is a block diagram showing an example. In these figures, the same members as those shown in FIGS. 3 and 4 are denoted by the same reference numerals as those shown in FIGS. 3 and 4.

In the third and fourth embodiments, the vertical acceleration G of the vehicle body detected by the vertical acceleration sensor 82
A signal indicating z is also supplied to the electronic control unit 62. In particular, in the third embodiment, the supply and exhaust of air to and from the air chamber is performed in step 100 of the main routine.
In the fourth embodiment, the control of the target air mass Mo * is performed in the same manner as in the first embodiment except that the calculation of the target air mass Mo * is executed in accordance with the flowchart shown in FIG. Is controlled in the same manner as in the first embodiment except that the main routine is executed according to the flowchart shown in FIG.

In the third embodiment, as shown in FIG. 19, in step 105, the vertical acceleration sensor 82
A signal indicating the vertical acceleration Gz of the vehicle body detected by the above is also read. Also, in step 160, the vertical acceleration Dz of the vehicle body is calculated by integrating the vertical acceleration Gz of the vehicle body. In step 165, a signal indicating the vertical speed Dz of the vehicle body is set with a cutoff frequency of 0.5 Hz, for example. Step 1 is performed by performing high-pass filter processing.
The vertical speed Dzhp of the vehicle body after the drift component in the calculation by the integration at 60 has been removed is calculated.
In step 70, the corrected air mass Ma based on the vertical velocity of the vehicle body is calculated according to the following equation 32, using Kd as a positive constant. In step 175, the target air mass Mo calculated in step 155 is calculated. The correction is made by rewriting the sum of * and the correction air mass Ma calculated in step 170.

Ma = Kd · Dzhp

Therefore, according to the third embodiment, when the vehicle body moves downward, for example, when the wheels move on a horizontal road surface after passing through a protrusion on the road surface, step 16 is executed.
At 0 to 175, the target air mass Mo * is increased and corrected according to the downward moving speed of the vehicle body, so that the amount of air discharged from the air chamber is reduced or the air is discharged from the air chamber. Therefore, the downward movement of the vehicle body is reduced. Similarly, when the vehicle body moves upward, such as when the wheels move on a horizontal road surface after passing through a depression on the road surface, the target air mass Mo * is corrected to be reduced according to the upward moving speed of the vehicle body. Thus, the amount of air supplied to the air chamber is reduced or the supply of air to the air chamber is prevented, so that the upward movement of the vehicle body is reduced.

In the fourth embodiment, as shown in FIG. 20, a signal indicating the vertical acceleration Gz of the vehicle body detected by the vertical acceleration sensor 82 in step 410 is read, and The vertical acceleration Dz of the vehicle body is calculated by integrating the vertical acceleration Gz of the vehicle body, and in step 420, a high-pass filter process is performed on a signal indicating the vertical speed Dz of the vehicle body with, for example, 0.5 Hz as a cutoff frequency. As a result, the vertical velocity Dzhp of the vehicle body after the drift component in the calculation by the integration in step 410 has been removed is calculated.

If the determination in step 500 is YES, the vertical speed Dzhp of the vehicle body after the high-pass filter processing is changed to the reference value Du (positive constant) in step 510.
Is determined, that is, whether the vehicle body is moving upward. When it is determined that Dzhp> Du, the flow proceeds to step 800, where the supply of air to the air chamber is prohibited, and Dzhp> D.
When it is determined that it is not u, step 600
Proceed to.

Conversely, if a negative determination is made in step 500, a determination is made in step 520 as to whether the vertical speed Dzhp of the vehicle body after the high-pass filter processing is less than a reference value Dd (negative constant). That is, it is determined whether the vehicle body is moving downward. When it is determined that Dzhp <Du, the routine proceeds to step 800, where the discharge of air from the air chamber is prohibited, and Dzhp> Du.
If it is determined that it is not, the process proceeds to step 700.

Therefore, according to the fourth embodiment, the vertical speed Dzhp of the vehicle body is calculated in steps 410 and 420. If the vehicle body moves downward at a speed higher than the reference value Dd, the process proceeds to step 520. Judgment of Jesus is made at
By preventing the air from being exhausted from the air chamber, the downward movement of the vehicle body is suppressed. Similarly, when the vehicle body moves upward at a speed equal to or higher than the reference value Du, a determination of YES is made in step 510, and the supply of air to the air chamber is prevented, thereby moving the vehicle body upward. Is suppressed.

Thus, according to the third and fourth embodiments,
The vertical movement of the vehicle body, which occurs after the wheels pass through the bumps or dents on the road surface, can be reduced and suppressed, thereby further improving the ride comfort of the vehicle as compared with the first and second embodiments. Can be improved, and wasteful consumption of compressed air can be reduced.

By combining the third and fourth embodiments with each other, the ride comfort of the vehicle may be further improved as compared with the case where these embodiments are used alone. In that case, steps 410 and 420 are omitted. Further, the third or fourth embodiment may be combined with the second embodiment.

Fifth Embodiment In the first to fourth embodiments described above, the inner edge of the rolling diaphragm of the air spring 32 * is fixed to the substantially cylindrical cylinder of the shock absorber 30 *. cage, thus receiving area of the piston of the air spring is constant regardless suspension stroke, calculated in accordance with the volume V * is the number 23 of the air chamber 34 in the * correspondingly the coefficients K ₁ and K ₂ as a positive constant It is supposed to be. Therefore, in these embodiments, since the actual air mass M * is calculated according to the actual volume change of the air chamber, the supply and discharge of air to and from the air chamber is an amount corresponding to the change in the polytropic index of the air. , The consumption of compressed air can be reduced, and energy saving and cost reduction can be achieved.

However, since the air consumption may be increased, the displacement of the vehicle body due to road surface disturbance is to be effectively suppressed and the riding comfort of the vehicle is to be further improved. By controlling only the posture change of the vehicle body such as the roll and pitch of the vehicle body and using an air spring configured to change the pressure receiving area according to the suspension stroke, the displacement of the vehicle body due to road surface disturbance is It is not necessary to supply / discharge air to / from the air chamber. Even if the volume of the air chamber changes due to slight unevenness of the road surface, the air is not supplied / discharged to / from the air chamber. These requirements could not be met even when further reduction was desired.

FIG. 21 is a flow chart showing a routine for calculating the actual air mass in the fifth embodiment of the air suspension control device according to the present invention, which is configured to satisfy the above-mentioned requirements.

In the fifth embodiment, the air spring is not shown in the drawing, but is structured such that the pressure receiving area is constant irrespective of the suspension stroke as in the first to fourth embodiments. Have been. Also, in step 225 of the flowchart shown in FIG. 21, coefficients K ₁ and K ₂ are calculated based on the map corresponding to the graph shown in FIG.
3, the volume V * of the air chamber is calculated.

Therefore, according to the fifth embodiment, even in the case of an air spring having a constant pressure receiving area irrespective of the suspension stroke, when the vehicle height is in the range a to b, the volume of the air chamber is reduced. Is calculated so as to fluctuate more than the actual volume of the vehicle, whereby the fluctuation of the apparent actual air mass M * becomes large, and the displacement of the vehicle body due to the road surface disturbance is suppressed more effectively. The ride comfort of the vehicle can be further improved as compared with the case of the fourth embodiment.

Sixth Embodiment FIG. 23 is a schematic configuration diagram showing a sixth embodiment of the air suspension control device according to the present invention configured to satisfy the above-mentioned requirements, and FIG. 24 shows a sixth embodiment. 6 is a flowchart showing a calculation routine of an actual air mass in the present embodiment. FIG. 23
3, the same members as those shown in FIG. 3 are denoted by the same reference numerals as those shown in FIG.

In the sixth embodiment, as shown in FIG. 23, the inner edge of the rolling diaphragm 32a of the air spring 32 * is fixed to the cylinder of the shock absorber 30 * and is tapered downward. The pressure receiving area of the air spring increases as the vehicle height increases and decreases as the vehicle height decreases.

In this embodiment, coefficients K ₁ and K ₂ are calculated based on a map corresponding to the graph shown in FIG. 25 in step 225 of the flowchart shown in FIG. Based on the result, in step 230, the volume V * of the air chamber is calculated according to equation (23).

Therefore, according to the sixth embodiment, the air spring has a structure in which the pressure receiving area decreases as the wheel bounces and increases as the wheel rebounds, and thus has an progressive spring characteristic. Since the volume of the air chamber is calculated corresponding to the actual volume change of the air chamber, the supply and discharge of air to and from the air chamber is controlled substantially only for an amount corresponding to the change in the polytropic index of the air, whereby The consumption of the compressed air can be reduced, and the displacement of the vehicle body due to the road surface disturbance can be effectively reduced by the progressive spring characteristic as compared with the first and second embodiments.

In the fifth and sixth embodiments, step 2
The maps used for calculating the coefficients K ₁ and K ₂ at 25 are modified to correspond to, for example, the graphs shown in FIGS. 26 and 27, so that the vehicle height H * becomes close to the standard vehicle height. The coefficients K ₁ and K ₂ may be modified so that they remain unchanged at 0 even if they increase or decrease.

According to this modified example, the actual air mass M * does not change even if the vehicle height H * increases or decreases near the standard vehicle height due to slight unevenness of the road surface, and the air flow to the air chamber does not change. Since supply and discharge are not performed, the air consumption can be further reduced as compared with the first and second embodiments described above, and the above-described requirements can be satisfied.

In the illustrated fifth and sixth embodiments,
Although the coefficient K ₁ and K ₂ are adapted to be computed from the common map corresponding to the graph shown in FIGS. 22 and 25, maps individually for coefficients K ₁ and K ₂ are set, the coefficient K ₁ is the front wheel vehicle height Hfr, is calculated based on Hfl, vehicle height Hrr of the coefficient K ₂ is the rear wheel side, it may be configured to be computed based on Hrl.

In the illustrated fifth and sixth embodiments, the coefficients K ₁ and K ₂ in step 230 of the calculation routine for the actual air mass M * are calculated from a preset map. , The volume V * of the air chamber is calculated according to the vehicle height. However, the volume V of the air chamber is directly calculated from a map set in the relationship between the vehicle height H * and the volume V *. May be configured.

The fifth and sixth embodiments or their modifications are the second modification of the first embodiment, any one of the second to fourth embodiments, and the third and fourth embodiments. The combination of the embodiments may be combined with the embodiment.

Although the present invention has been described in detail with reference to specific embodiments, the present invention is not limited to these embodiments, and various other embodiments may be included within the scope of the present invention. It will be clear to those skilled in the art that is possible.

[0105]

As is apparent from the above description, according to the present invention, even if the wheels bounce or rebound due to the unevenness of the road surface, the target gas mass Mo is not changed and the deviation Mc
Does not change, so that the supply and discharge of the working gas to and from the air chamber are not performed repeatedly and frequently, so that energy consumption and cost are reduced as compared with the case where the pressure in the air chamber is feedback-controlled by a conventional control device. The durability of the air suspension can be improved , and the actual gas mass M is, for example, the volume of the air chamber and
Compared to the case where the calculation is performed based only on the pressure, the actual gas mass M is
Since it is calculated accurately, regardless of the temperature of the working gas
Control the supply and exhaust of working gas to and from the air chamber
Rukoto is Ru can.

According to the second aspect of the present invention, when the wheel receives a force in the bounding direction such as when the wheel passes over a convex portion of the road surface, the spring force of the air spring is reduced, and conversely, when the wheel is mounted on the road surface, In the case of receiving a force in the rebound direction such as when passing through a concave portion, the spring force of the air spring is increased, so that a normal air suspension which does not supply / discharge working gas to / from the air chamber or the above-described first air suspension. The ride comfort of the vehicle can be improved as compared with the case of the configuration described above.

According to the third aspect of the present invention, there is no need to provide a temperature detecting means for detecting the temperature of the working gas in the air chamber corresponding to each air spring, and one outside air temperature detection for detecting the outside air temperature is not required. Since the means may be provided, the structure of the control device can be simplified and the cost can be reduced as compared with the case of the first aspect, and substantially the same operation and effect as the case of the second aspect can be achieved. Can be obtained.

According to a fourth aspect of the present invention, the target gas mass Mo is reduced and corrected when the vehicle body moves upward, and the target gas mass Mo is increased and corrected when the vehicle body moves downward. In the above, when the vehicle body is moving upward at a speed higher than a predetermined speed, supply of the working gas to the air chamber is prohibited, and when the vehicle body is moving downward at a speed higher than the predetermined speed, the air is not supplied. Since the discharge of the working gas from the chamber is prohibited, according to these configurations, the vertical displacement of the vehicle body when the air spring receives a disturbance input from the vehicle body is reduced or suppressed. The ride comfort of the vehicle can be further improved as compared with the case of the configuration.

According to the sixth and seventh aspects of the present invention, the volume of the air chamber is calculated from the relationship between the vehicle height and the volume of the air chamber set in advance. , The change of the actual gas mass M accompanying the change of the vehicle height is calculated to be the same as the change of the actual gas mass in the air chamber, or the actual gas mass in the air chamber is changed. The calculation can be performed so as to be different from the change in the mass, whereby the degree of freedom in controlling the supply and discharge of the working gas to and from the air chamber can be increased.

According to the configuration of claim 8, it is possible to calculate the actual gas mass such that the change in the actual gas mass M accompanying the change in the vehicle height is different from the change in the actual gas mass in the air chamber. Therefore, for example, by making the mass of the working gas supplied to and discharged from the air chamber larger than the mass of the gas corresponding to the actual change in the volume of the air chamber, the vertical movement of the vehicle body is effectively suppressed. Riding comfort can be further improved.

According to the ninth aspect of the present invention, the vertical movement of the vehicle body can be effectively suppressed by using, for example, an air spring configured to reduce the pressure receiving area as the vehicle height decreases. Moreover, since the actual gas mass M is calculated in accordance with the actual change in the volume of the air chamber, the supply and discharge of the working gas to and from the air chamber are controlled substantially only for the amount corresponding to the change in the polytropic index of the working gas. As a result, it is possible to further reduce the consumption of the working gas while securing good riding comfort of the vehicle.

According to the tenth aspect of the present invention, the actual gas mass does not increase or decrease even if the vehicle height increases or decreases near the standard vehicle height due to, for example, slight unevenness of the road surface. Is not supplied, the consumption of the working gas can be further reduced.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a configuration of an air suspension control device according to the present invention, corresponding to the description of claim 1 of the appended claims.

FIG. 2 is an explanatory diagram showing a configuration of an air suspension control device according to the present invention, corresponding to the description of claim 2 of the claims;

FIG. 3 is a schematic configuration diagram showing one embodiment of an air suspension control device according to the present invention.

FIG. 4 is a block diagram showing one embodiment of the electronic control device shown in FIG. 3;

FIG. 5 is a flowchart showing a main routine of control of an air suspension achieved by the electronic control device shown in FIGS. 3 and 4;

FIG. 6 is a step 10 of the flowchart shown in FIG. 5;
7 is a flowchart showing a target air mass calculation routine performed at 0.

FIG. 7: Step 20 of the flowchart shown in FIG.
7 is a flowchart showing a routine for calculating the actual air mass performed at 0.

FIG. 8 is a diagram illustrating an actual air mass M when a weighted average calculation is performed on a signal indicating the temperature T * of air in the air chamber;
FIG. 7 is a flowchart similar to FIG. 6 showing a calculation routine of *.

FIG. 9 is a graph showing a relationship between a vehicle speed V, a steering angular velocity θd, and a delay compensation value Gyo of a lateral acceleration of a vehicle body.

FIG. 10 is a graph showing a relationship between an estimated lateral acceleration Gym of the vehicle body and a target roll amount Rm of the vehicle body.

FIG. 11 is a graph showing a relationship between a longitudinal acceleration Gx of the vehicle body and a target pitch amount Pm of the vehicle body.

FIG. 12 is a schematic configuration diagram showing a second embodiment of the air suspension control device according to the present invention.

FIG. 13 is a block diagram showing one embodiment of the electronic control device shown in FIG. 12;

FIG. 14 is a flowchart showing a routine for calculating a target gas mass in the second embodiment.

FIG. 15 is a flowchart showing a routine for calculating the actual air mass in the second embodiment.

FIG. 16 is a flowchart showing another example of the routine for calculating the actual air mass in the second embodiment.

FIG. 17 is a schematic configuration diagram showing third and fourth embodiments of the air suspension control device according to the present invention.

18 is a block diagram showing one embodiment of the electronic control device shown in FIG.

FIG. 19 is a flowchart showing a routine for calculating a target gas mass in the third embodiment.

FIG. 20 is a flowchart showing a main routine in the fourth embodiment.

FIG. 21 is a flowchart showing a routine for calculating the actual air mass in the fifth embodiment of the air suspension control device according to the present invention.

FIG. 22 shows a vehicle height H * and a coefficient K ₁ in the fifth embodiment.
Is a graph showing the relationship between K _2.

FIG. 23 is a schematic configuration diagram showing a sixth embodiment of the air suspension control device according to the present invention.

FIG. 24 is a flowchart showing a routine for calculating the actual air mass in the sixth embodiment.

FIG. 25 shows a vehicle height H * and a coefficient K ₁ in the sixth embodiment.
Is a graph showing the relationship between K _2.

FIG. 26 is a graph showing a relationship between a vehicle height H * and coefficients K ₁ and K _{2 in} a modification of the fifth embodiment.

FIG. 27 is a graph showing a relationship between a vehicle height H * and coefficients K ₁ and K _{2 in} a modification of the sixth embodiment.

FIG. 28 is an explanatory diagram showing displacement of a vehicle body when a wheel moves on a horizontal road surface after passing a protrusion on the road surface.

FIG. 29 is an explanatory diagram showing displacement of a vehicle body when a wheel moves on a horizontal road after passing through a depression in the road.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Air spring 12 ... Running state detection means 14 ... Target gas mass calculation means 16 ... Actual gas mass calculation means 18 ... Supply / discharge control means 20 ... Volume detection means 22 ... Pressure detection means 24 ... Temperature detection means 26 ... Smoothing processing means 28 arithmetic means 30 * shock absorber 32 * air spring 34 * air chamber 40 * air supply control valve 46 * exhaust control valve 48 steering angle speed sensor 50 vehicle speed sensor 52 lateral acceleration sensor 54 Longitudinal acceleration sensor 56 * ... vehicle height sensor 58 * ... pressure sensor 60 * ... temperature sensor 60 ... outside air temperature sensor 62 ... electronic control device 82 ... vertical acceleration sensor

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B60G 17/015 B60G 17/052

Claims (10)

(57) [Claims] An air suspension control device for controlling the posture of a vehicle body by controlling the supply and discharge of working gas to and from an air chamber of an air spring provided for each wheel to detect a running state of the vehicle. Running state detecting means, target gas mass calculating means for calculating a target gas mass Mo in the air chamber based on the detected running state of the vehicle, and actual gas mass for calculating an actual gas mass M in the air chamber. a calculating means, and a supply and discharge control means for controlling the supply and discharge of working gas to said air chamber such that the deviation based on the deviation Mc between the actual gas mass M and the target gas mass Mo is reduced, the actual The gas mass calculating means is the
Volume detection means for detecting the volume of the chamber;
Pressure detecting means for detecting the pressure in the chamber;
Temperature detection means for detecting the temperature of the working gas in the chamber;
The volume detecting means, the pressure detecting means and the temperature detecting means
Based on the volume, pressure and temperature respectively detected by the step
An air suspension control device having an operation means for calculating an actual gas mass M. At a air suspension control apparatus of the claim 1, wherein the actual gas mass calculation means has a smoothing means for smoothing a signal indicating the temperature of the working gas which is detected by the previous SL temperature detecting means , the computing means is characterized by a Turkey to calculating the actual gas mass M based on the temperature that is smoothed by respectively detected the the volume and pressure the smoothing processing means by the volume detecting means and said pressure detecting means Air suspension control device. 3. The air suspension control device according to claim 1, wherein said actual gas mass calculating means has an outside air temperature detecting means for detecting an outside air temperature , said calculating means being said volume detecting means,
The actual gas mass M based on the volume, the pressure, and the outside air temperature detected by the pressure detection unit and the outside air temperature detection unit, respectively.
Air suspension control system according to claim and Turkey to calculating the. 4. An air suspension control system according to claim 2, wherein said vehicle body vertical movement detecting means detects vertical movement of said vehicle body, and reduces and corrects said target gas mass Mo when said vehicle body moves upward. And a target gas mass correction means for increasing and correcting the target gas mass Mo when the vehicle body moves downward. 5. An air suspension control device according to claim 2, wherein said vehicle body vertical speed detecting means detects a vertical movement speed of said vehicle body, and said vehicle body moves upward at a speed higher than a predetermined speed. Supply / discharge prohibition means for prohibiting the supply of the working gas to the air chamber when the vehicle is moving, and prohibiting the discharge of the working gas from the air chamber when the vehicle body is moving downward at a predetermined speed or more An air suspension control device comprising: At a air suspension control apparatus 6. The method of claim 1, prior Symbol volume detecting means and the vehicle height detecting means for detecting the vehicle height of the portion corresponding to each wheel, preset vehicle height and the air chamber And a volume calculating means for calculating the volume of the air chamber from the relationship with the volume of the air suspension. 7. The air suspension control device according to claim 2, wherein said volume detecting means detects a vehicle height of a portion corresponding to each wheel, and a predetermined vehicle height. An air suspension control device, comprising: a volume calculating means for calculating the volume of the air chamber from the relationship between the height and the volume of the air chamber. 8. The air suspension control device according to claim 6, wherein the air spring is configured such that the pressure receiving area is substantially constant even when the vehicle height changes, and the relationship is substantially the same. An air suspension control device, wherein the air suspension control device is set to have non-linear characteristics. 9. The air suspension control device according to claim 6, wherein said air spring is configured such that a pressure receiving area changes with a change in vehicle height, and said relationship is determined by a change in vehicle height. The air suspension control device is set substantially corresponding to an actual volume change of the air chamber. 10. The air suspension control device according to claim 6, wherein the relationship is set such that the volume of the air chamber is substantially constant near a standard vehicle height. An air suspension control device, characterized in that: