JP3346434B2 - Cab attitude 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 a device for controlling the attitude of a cab in a cab-suspended vehicle in which the cab is supported on a vehicle frame by a hydraulic actuator. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cab attitude control device that is gradually changed.

[0002]

2. Description of the Related Art In a cabin attitude control device proposed in Japanese Patent Application No. 5-103498 filed by the present applicant, when an occupant issues a command, an optimum road surface (input) condition at that time is used. By recalculating the control parameters and changing the control parameters, the comfort and riding comfort of the occupant can be improved.

[0003] However, in the above-described attitude control apparatus for a cab, since the control parameter is changed during one control cycle (one cycle of the control program), the control parameter is changed when the change amount of the control parameter is large. There is a problem that the behavior of the cab immediately after is greatly changed, and the riding comfort is significantly impaired.

[0004]

SUMMARY OF THE INVENTION In view of the above-mentioned problems, an object of the present invention is to change a control parameter gradually and prevent a sudden change in the behavior of the cap immediately after the change of the control parameter. Is to provide.

[0005]

In order to achieve the above object, the present invention is directed to a hydraulic actuator for supporting four points on the vehicle frame, that is, left, right, front and rear, respectively, a wheel supporting portion of the vehicle frame and a cap supporting portion of the vehicle frame. A vehicle height sensor, a relative displacement amount calculating means for obtaining a displacement amount in each mode of roll, pitch, and bounce from the vehicle height change amount with respect to the road surface detected by the vehicle height sensor, and a control parameter. Change command means, a control parameter change means for dividing a frequency characteristic diagram of vibration received by the cab at a predetermined frequency by a command from the control parameter change command means, and calculating an area ratio of each frequency region; Control parameter gradual change means for dividing the change amount of the control parameter into a plurality of parts and gradually changing each control parameter in the plurality of control cycles; A control amount calculating means for obtaining a control force for suppressing the displacement of each mode of the cab from the gradual change means; and an electromagnetic oil amount control valve for generating the control force of each mode to each of the hydraulic actuators. And

[0006]

According to the present invention, when a change command is issued from an occupant,
In each case, a control parameter suitable for the road surface condition is calculated, and the attitude control of the cab is performed using the control parameter.

In other words, the relative displacement amount in each mode of roll, pitch, and bounce with respect to the road surface is obtained from the vehicle height change amount by the relative displacement amount calculating means.

At predetermined time intervals, the control parameter calculating means obtains the power spectral density of the displacement of each mode of the road surface from the power spectral density of the relative displacement of each mode of the cab, and plots the frequency characteristic diagram thereof in a predetermined manner. An area ratio of each frequency region divided by frequency is obtained, and a control parameter is obtained from each area ratio.

The difference between each control parameter newly obtained by the control parameter gradual change means and each control parameter up to now, that is, the amount of change is divided into a plurality of parts, and each control parameter is gradually changed in a plurality of control cycles. A control amount (force) for suppressing displacement of each mode of the cab is obtained by using each control parameter that gradually changes by the calculating means, and the control amount is applied to each hydraulic actuator.

[0010]

FIG. 1 is a hydraulic circuit diagram of a cabinet attitude control apparatus according to the present invention. Hydraulic pump 4 driven by engine
Sucks oil from the oil tank 2 and supplies the oil from the pipe 5 to the pressure accumulator 8 of the pipe 7 via the check valve 6. In order to keep the oil pressure to the pipe 7 at a predetermined value, oil pressure holding means A is provided. That is, tube 5
When the detection value of the oil pressure sensor 9 that detects the oil pressure of the oil tank exceeds a predetermined value, the oil pressure control valve 12 is switched, and a part of the oil pressure of the pipe 5 passes through the pipe 10, the oil pressure control valve 12, the pipe 13, and the filter 27. It is returned to the oil tank 2. When the oil pressure at the discharge port of the hydraulic pump 4 becomes abnormally high, a part of the pressure oil in the pipe 5 is returned to the oil tank 2 via the known relief valve 26, the pipe 13, and the filter 27.

The pressure oil in the pipe 7 is supplied to hydraulic actuators 19 that support the front, rear, left and right portions of the cabinet 3 on the vehicle frame 25, respectively. The hydraulic actuator 19 is a cylinder 23
A piston 24 is fitted to the housing 3 and a rod 24 projecting upward from the piston 22 is connected to the cabin 3 by a ball joint or the like, while a cylinder 23 is connected to the vehicle frame 25 by a spherical bearing or the like. Cylinder 2 partitioned by piston 22
The upper and lower chambers 3 are communicated by a throttle passage provided in the piston 22.

The suspension mechanism of the vehicle frame includes an axle or suspension member 30 for supporting the wheels 20 on the vehicle frame 25 and a known hydraulic shock absorber 29.
Supported by The hydraulic shock absorber 29 is formed by inserting a piston into a cylinder. The cylinder is connected to a suspension member 30, and a rod projecting upward from the piston is connected to a vehicle frame 25. The coil spring 21 is interposed between the cylinder and the vehicle frame 25. Instead of the coil spring 21, the suspension member 30 may be supported on the vehicle frame 25 by a known leaf spring. Cab 3
Height sensor 2 for detecting the relative displacement of the vehicle with respect to the vehicle frame 25
8 and a vehicle height sensor 31 for detecting the relative displacement of the vehicle frame 25 with respect to the suspension member 30 are provided.

The pressure oil in the pipe 7 is supplied to an oil quantity control valve 1 comprising a check valve 14, a general neutral position closed type electromagnetic proportional pressure control valve.
6. The air is supplied to the air spring or the pressure accumulator 18 through the throttle 18a, and further supplied to the lower end chamber of the cylinder 23 of the hydraulic actuator 19. The oil pressure supplied to the lower end chamber of the cylinder 23 is detected by the oil pressure sensor 17. When the oil amount control valve 16 is switched, the oil in the lower end chamber of the cylinder 23 is returned to the oil tank 2 via the oil amount control valve 16, the check valve 15, the pipe 13, and the filter 27.

The hydraulic actuators 19 on the front, rear, left and right sides of the cabinet 3 are independently provided with check valves 14, 15, an oil amount control valve 16,
An aperture 18a, an accumulator 18, a hydraulic pressure sensor 17, and a vehicle height sensor 28 are provided. Although not shown, a vehicle height sensor 31 is also provided in each suspension mechanism of the front, rear, left, and right vehicle frames.

Each oil quantity control valve 16 controls the oil quantity of each hydraulic actuator 19 in a feedback manner in accordance with a control voltage from an electronic control unit composed of a micro computer. When the front, rear, left and right hydraulic actuators 19 are specified, subscripts of FL, FR, RL, and RR are added.

Assuming that the relative vehicle height of the vehicle frame 25 with respect to each axle or wheel 20 is hFL-hRR, and the relative vehicle height of each of the front, rear, left and right portions of the cap 3 with respect to the vehicle frame 25 is hcFL-hcRR, the vehicle height change amount of the vehicle frame 25 is assumed. xFL to xRR and the vehicle height change amounts xcFL to xcRR of the cab 3 are expressed by the following equations.

XFL = hFL-hFL0, xFR = hFR-hFR0 xRL = hRL-hRL0, xRR = hRR-hRR0 xcFL = hcFL-hcFL0, xcFR = hcFR-hcFR0 xcRL = hcRL-hcRL0, xcRR ... cRR 1) However, hFL0 to hRR0: standard vehicle height of each wheel support of the vehicle frame hcFL0 to hcRR0: standard vehicle height of front, rear, left and right portions of the cab Relative displacement Δφ, Δ of each mode with respect to the road surface of the vehicle frame 25
θ, Δx, and relative displacement amounts Δφc, Δθc, Δxc of the mode of the cab 3 with respect to the vehicle frame 25 are expressed by the following equations, respectively.

Δφ = kφ1 (xFL−xFR) + kφ2 (xRL−xRR) Δθ = kθ1 (xFL + xFR) −kθ2 (xRL + xRR) Δx = kx1 (xFL + xFR) + kx2 (xRL + xRR) Δφc = kc φ1 (xcFL−xcFR) + kφ xcRL-xcRR) [Delta] [theta] c = kc [theta] 1 (xcFL + xcFR) -kc [theta] 2 (xcRL + xcRR) [Delta] xc = kcx1 (xcFL + xcFR) + kcx2 (xcRL + xcRR) ... [1], k1; Constants determined by kφ2, kθ2, kx2: Constants determined by vehicle specifications kc φ1, kcθ1, kcx1: Constants determined by vehicle specifications kc φ2, kcθ2, kcx2: Constants determined by vehicle specifications Each axle or wheel 20 Assuming that the displacement amounts of the respective modes of the road surface input to act are φ, θ, x, the relative displacement amounts φ2, θ2, x2 of the respective modes of the cab 3 can be expressed by the following equations.

Φ2 = φ + Δφ + Δφc θ2 = θ + Δθ + Δθc x2 = x + Δx + Δxc (3) Therefore, in order to keep the cab 3 flat (parallel to the road surface), the control amount (force) of each mode to be added to the cab 3 by each hydraulic actuator 19 ) -F12, -F22, -F32 can be represented by the following equations.

−F12 = −k1 [φ] −k2 d [φ] dt−k77 [φ] dt−F22 = −k3 [θ] −k4d [θ] dt−k8Σ [θ] dt−F32 = −k5 [x] −k6 d [x] dt−k9 Σ [x] dt (4) where [φ] is the roll displacement of the cab relative to the road surface (Δφ + Δφc) [θ] is the pitch displacement of the cab relative to the road surface (Δθ + Δ
θc) [x]: The amount of bounce displacement of the cab relative to the road surface (Δx +
Δxc) k1 to k9: control parameters Σ: Integral symbol (▲ ◆ ▼) for convenience.

According to the present invention, the control parameters k1 to k9 of the above equation (4) can be changed so that a comfortable ride can be obtained on any road surface. The transfer function from the road input roll displacement φ to the road roll displacement [φ] with respect to the road surface is Hφ, and the pitch input displacement θ of the cabin with respect to the road surface from the road input pitch displacement θ.
Is defined as Hθ, and the transfer function from the bounce displacement x of the road surface input to the bounce displacement [x] of the cab with respect to the road surface is defined as Hx.
The transfer functions Hφ, Hθ, and Hx of each bounce mode are represented by the following equations.

[0022] ^{Hφ = - (IX s 3 -Mc} ghr s) / (IX s 3 + k2 s 2 + k1 s-Mc ghr s + k7) = (Δφ + Δφc) / φ Hθ = - (IY s 3 -Mc ghp s) / ( ^{IY s 3 + k4 s 2 +} k3 s-Mc ghp s + k8) = where (Δθ + Δθc) / θ Hx = -Mc s 3 / (Mc s 3 + k6 s 2 + k5 s + k9) = (Δx + Δxc) / x ...... (5), IX : Cabinet's pitch inertia moment IY: Cab's pitch inertia moment Mc: Cab's mass g: Acceleration of gravity hr: Height difference between the center of gravity of the cap and the roll center hp: Height difference between the center of gravity of the cap and the center of the pitch s: Operator and , And the power spectral densities of the displacement amounts φ, θ, x of the roll, pitch, and bounce modes of the road surface input are Sφ, S
Assuming that the power spectrum densities of θ, Sx, and the relative displacement of each mode of the roll roll pitch bounce with respect to the road surface are SΔφ, SΔθ, SΔx, the following relationship exists between the two power spectrum densities for each frequency. is there.

Sφ = SΔφ / [Hφ] ² Sθ = SΔθ / [Hθ] ² Sx = SΔx / [Hx] ² (6) Now, the transfer functions Hφ, Hθ, Hx can be calculated for each frequency,
The relative displacement [φ] of each mode of the cab to the road surface,
Since [θ] and [x] are always detected, the power spectral densities SΔφ, SΔθ, and SΔx of the relative displacement of each mode of the cab with respect to the road surface are also obtained. Therefore, the power spectrum densities Sφ, Sθ, and Sx of the displacement amount of each mode of the road surface input, that is, the road surface condition can be known from the above equation (6).

Next, the obtained power spectrum densities Sφ, Sθ, and Sx of the displacement amounts of the respective modes of the road surface input are determined in advance by a frequency characteristic diagram shown in FIG. 3 (only the power spectrum density Sφ is shown). The set frequency fi (i = 1 to
n), and the respective frequency regions 0 to f1, f1 to f2,.
The area Aφ1, of the areas Aφi, Aθi, Axi of fn-1 to fn
The area ratios γφi, γθi, γxi to Aθ1, Ax1 are determined.

Aφ1, Aφ2,... Aφn surrounded by Sφ, area ratio γφi = Aφi / Aφ1 Area Aθ1, Aθ2,... Aθn surrounded by Sθ, area ratio γθi =
Aθi / Aθ1 Areas Ax1, Ax2,... Axn surrounded by Sx, area ratio γxi =
Axi / Ax1 The roll ratio is calculated from the area ratio γφi, γθi, γxi of each frequency domain.
Control parameters k1 to k for each mode of pitch and bounce
Determine 9 Specifically, the control parameters k1 to k9 suitable for many road surface conditions are determined by changing the area ratios γφi, γθi, γxi
Is experimentally obtained in advance as a function of, and set as a control map in a ROM of a micro computer as an electronic control device, and is automatically selected. The control parameters k1 to k9 can be calculated more minutely by narrowing the division of the displacement amount of each mode of the road surface input by the frequency of the power spectral densities Sφ, Sθ, and Sx.

Note that the area ratios γφi, γθi, γxi are obtained by dividing each frequency region fi-1 with respect to the area of all the frequency regions f1 to fn.
To fi.

K1 = k1 (γφ2, γφ3,... Γφn) k2 = k2 (γφ2, γφ3,... Γφn) k3 = k3 (γθ2, γθ3,... Γθn) k4 = k4 (γθ2, γθ3,... Γθn) k5 = k5 (Γx2, γx3, ... γxn) k6 = k6 (γx2, γx3, ... γxn) k7 = k7 (γφ2, γφ3, ... γφn) k8 = k8 (γθ2, γθ3, ... γθn) k9 = k9 (γx2, γx3, ... γxn) (7) As shown in FIG. 4, for example, a frequency characteristic diagram showing the power spectral density Sφ of the roll displacement amount of the road surface input is represented by 1
When divided by two frequencies, the control parameter k1 obtained from the area ratio γφ2 of the two frequency regions is preferably set in advance so that the control parameter k1 changes more gradually than the staircase in accordance with the area ratio γφ2.

From the control amounts F12, F22, and F32 of each mode of the cab using the above-described control parameters k1 to k9, the control voltages VcFL to VcR of the respective oil amount control valves 16 represented by the following equations are obtained.
Find R.

VcFL = -KV1 F12-KV2 F22 + KV5 F32 VcFR = + KV1 F12-KV2 F22 + KV5 F32 VcRL = -KV3 F12 + KV4 F22 + KV6 F32 VcRR = + KV3F12 + KV6 F32 VcV = + KV3F12 + KV3 F12 VcV = + KV3V12 + KV3V12 + KV3V12 + KV3V12 + KV3F12 + KV3F12 + KV3F32 + cV8 + V8V8 + V8F8 + V8F8 + V8F8 + F8 + F8V3F12 + KV4F22 + KV6F32Vc6F32 + KV6F32Vc6F32 + KV6F32 + cV6 + 32VcF = + KV3F12 + KV3F32 + cV6F32VcV = + KV3F12 + KV3F32 + cV6F32 + cV6. By driving each oil amount control valve 16 and controlling the hydraulic actuator 19 with the feedback control voltages VsFL to VsRR from the hydraulic pressure sensor 17, the attitude of the cab 3 can be maintained substantially flat (parallel to the road surface). .

As shown in FIG. 2, according to the present invention, the vehicle height sensor 31 detects the vehicle heights hFL to hRR of the vehicle frame 25 according to the above-described principle.
From the vehicle height sensor 28, the vehicle height hcFL to hcR of the cab 3.
R are respectively detected, and the vehicle heights hFL to hRR of the vehicle frame 25 and the vehicle heights hcFL to hcR of the cab 3 are calculated by the relative displacement amount calculating means 35.
From R, the vehicle height change amounts xFL to xRR of the vehicle frame 25 and the vehicle height change amounts xcFL to xcRR of the cab 3 are obtained, and the relative displacement amounts Δφ, Δθ, Δx of each mode of the vehicle frame 25 with respect to the road surface are obtained.
And the relative displacement amounts Δφc, Δθc, Δxc of each mode of the cabinet 3 with respect to the vehicle frame 25 are obtained.

When a change command is issued from the control parameter change command means 33, the control parameter nki is changed as follows.
Is newly calculated. The power parameter densities Sφ, SΔθ, SΔx of the relative displacement of each mode of the cab with respect to the road surface are calculated by the control parameter calculating means 34 from the power spectrum densities Sφ, S of the displacement of each mode of the road input.
θ and Sx are determined, and the frequency characteristic diagram thereof is converted to a predetermined frequency f
i (i = 1 to n), and each frequency domain 0 to f1, f1
F2,... Fn-1 to fn, the area ratios γφi, γθi, γxi between the areas Aφi, Aθi, Axi and the areas Aφ1, Aθ1, Ax1 are obtained, and from the area ratios γφi, γθi, γxi of each frequency domain, Is determined.

The difference between each control parameter nki newly obtained by the control parameter gradual change means 36 and each control parameter ki up to now, that is, the amount of change is divided into a plurality of parts, and each control parameter is gradually changed in a plurality of control cycles. .

Next, the relative displacement amounts Δφ, Δθ, Δx of each mode of the vehicle frame 25 with respect to the road surface by the control amount calculating means 37.
And the relative Δφc of each mode of the cab 3 with respect to the vehicle frame 25.
, Δθc, Δxc, and the control parameters F12, F22, F32 of each mode of the cab 3 are obtained from the gradually changing control parameters.

Finally, the control amount F1 of each mode of the cab 3
Control voltage VcFL of each oil amount control valve 16 from 2, F22, F32
ＶVcRR, each of the oil quantity control valves 16 is driven by the control voltages VcFL VcRR and the feedback voltage FsFL FsRR from the hydraulic pressure sensor 17, and each hydraulic actuator 19
To adjust the amount of oil.

FIGS. 5 to 9 are flow charts of a control program for performing the above-mentioned control by the electronic control unit composed of a microcomputer. This control program is repeatedly executed at predetermined time intervals. p11-p28, p41-p46, p51-p5
6, p61 to p67 represent each step of the control program.
Start the control program at p11, initialize at p12,
In the hydraulic pressure holding routine shown in FIG.
To maintain the output hydraulic pressure pm at a predetermined value pc.

At p14, the vehicle heights hFL to hRR of the vehicle frame 25 are obtained from the vehicle height sensor 31 and the vehicle height hcF of the cab 3 is obtained from the vehicle height sensor 28.
Read L to hcRR respectively. At p15, the vehicle height change amounts xFL to xRR of the vehicle frame 25 are obtained from the vehicle heights hFL to hRR of the vehicle frame 25, and the vehicle height change amounts xcFL to xcRR of the cabinet 3 are obtained from the vehicle heights hcFL to hcRR of the cabinet 3, respectively.

At p16, the relative displacement amounts Δφ, Δθ, Δx of each mode of the vehicle frame 25 are obtained from the vehicle height change amounts xFL to xRR of the vehicle frame 25.
And the relative displacement amounts Δφc, Δθc, Δxc of each mode of the cab 3 from the vehicle height change amounts xcFL to xcRR of the cab 3.
Ask for. At p17, the relative displacement [φ], [θ], [x] of each mode of the cab 3 with respect to the road surface are sequentially stored in the RAM.

At p18, it is determined whether or not a control parameter change command has been received from the control parameter change command means 33. If there is no control parameter change command, the process proceeds to p22. If there is a control parameter change command, the process proceeds to a control parameter calculation routine shown in FIG. 8 at p19, where a new control parameter nki is obtained. The change amount dki in one control cycle is obtained from the difference between the control parameter nki and each control parameter ki so far, and the control parameter change is completed in N control cycles. For this reason,
At p21, the counter C is set to N, and at p22, it is determined whether or not the counter C is larger than zero.

If the counter C is 0, the process proceeds to p25. If the counter C is larger than 0, the counter C is reset to C−
1 and the control parameter is changed to ki = ki + d at p24.
The value of dki is added to the control parameter every control cycle until the counter C becomes 0, the addition is stopped in N control cycles at which the control parameter reaches the desired nki, and the program proceeds to p25.

At p25, control amounts F12, F22 and F32 of each mode of the cab 3 are obtained from relative displacement amounts [φ], [θ] and [x] of each mode of the cab 3 with respect to the road surface. At p26, control voltages VcFL to VcRR of the oil amount control valve 16 corresponding to the control amounts F12, F22, and F32 of the respective modes of the cab 3 are obtained. p27
Then, in the hydraulic actuator driving routine shown in FIG. 9, the amount of oil in each hydraulic actuator 19 is adjusted by each oil amount control valve 16, and the process ends at p28.

As shown in FIG. 7, the hydraulic pressure holding routine is p
Starting at 41, the output oil pressure pm of the hydraulic pump 4 is read by the oil pressure sensor 9 at p42, it is determined at p43 whether or not the output oil pressure pm is larger than a predetermined value pc, and when the output oil pressure pm is smaller than the predetermined value pc. Closes the hydraulic control valve 12 at p44 and proceeds to p46. If the output hydraulic pressure pm is larger than the predetermined value pc, the hydraulic control valve 12 is opened at p45 to lower the output hydraulic pressure pm, and the output hydraulic pressure pm is maintained at the predetermined value pc. To return to this program.

As shown in FIG. 8, the control parameter calculation routine starts at p51. At p52, the relative displacement [φ], [θ], [x] of each mode of the cab 3 with respect to the road surface is calculated based on the cab 3 with respect to the road surface. The power spectrum densities SΔφ, SΔθ, and SΔx of the relative displacement amount of each mode are obtained. At p53, from the power spectrum densities SΔφ, SΔθ, SΔx of the relative displacement amounts of each mode of the cab 3 with respect to the road surface, the power spectrum densities Sφ, S of the displacement amounts of each mode of the road surface input are obtained.
Find θ and Sx.

In p54, each frequency range 0 to f1, f1 to f2,.
From fn-1 to fn, the area Aφi, Aθi, Axi and the area Aφ1,
The area ratios γφi, γθi, γxi with Aθ1, Ax1 are obtained, and p
At 55, a new control parameter nki is obtained from the area ratios γφi, γθi, γxi, and the program returns to p56 at p56.

As shown in FIG. 9, the hydraulic actuator driving routine starts at p61, reads the hydraulic pressures pFL-pRR of each hydraulic actuator 19 from each hydraulic pressure sensor 17 at p62, and converts the hydraulic pressures pFL-pRR to voltages VsFL-VsRR at p63. Convert to At p64, the above-described control voltages VcFL to VcRR and voltage VsF
From L to VsRR, the excitation voltages VeFL to V of each oil amount control valve 16 are obtained.
Find eRR. Exciting each oil amount control valve 16 at p65 and supplying or discharging the oil amount QFL to or from each hydraulic actuator 19
~ QRR is adjusted, and each hydraulic actuator 19
Is driven, and the program returns to p67 in p67.

As shown in FIG. 10, the oil amounts QFL to QRR to the respective hydraulic actuators 19 are adjusted by the excitation voltages VeFL to VeRR of the respective oil amount control valves 16.

The present invention can also be applied to a cabin attitude control device that automatically changes control parameters in response to changes in running conditions.

[0047]

As described above, according to the present invention, each control parameter is gradually changed in a plurality of control cycles.
A sudden change in the behavior of the cab immediately after the change of the control parameter is suppressed, and the riding comfort and the sense of security are improved.

[Brief description of the drawings]

FIG. 1 is a hydraulic circuit diagram of a cabinet attitude control device according to the present invention.

FIG. 2 is a block diagram of the attitude control device.

FIG. 3 is an explanatory diagram of control parameter calculation means in the attitude control device.

FIG. 4 is an explanatory diagram of control parameter calculation means in the attitude control device.

FIG. 5 is a flowchart of a control program of the attitude control device.

FIG. 6 is a flowchart of a control program of the attitude control device.

FIG. 7 is a flowchart of a control program of the attitude control device.

FIG. 8 is a flowchart of a control program of the attitude control device.

FIG. 9 is a flowchart of a control program of the attitude control device.

FIG. 10 is a diagram illustrating a relationship between an excitation voltage of an oil amount control valve and an oil amount.

[Explanation of symbols]

3: Cap 16: Oil control valve 17: Oil pressure sensor 1
9: Hydraulic actuator 20: Wheel 25: Vehicle frame 28, 31: Vehicle height sensor 3
3: Control parameter change instructing means 34: Control parameter calculating means 35: Relative displacement amount calculating means 36: Control parameter gradual changing means 37: Control amount calculating means

────────────────────────────────────────────────── ─── Continued on the front page (56) References JP-A-5-229329 (JP, A) JP-A-3-200485 (JP, A) JP-A-3-98189 (JP, U) (58) Investigation Field (Int.Cl. ⁷ , DB name) B62D 24/02 B60G 17/015 B62D 33/06

Claims (1)

(57) [Claims] 1. A hydraulic actuator for supporting four points, left, right and front and rear of a cab, respectively, a vehicle height sensor disposed on a wheel support portion of the vehicle frame and a cab support portion of the vehicle frame, and detection by the vehicle height sensor. Relative displacement calculating means for calculating the displacement of each mode of roll roll, pitch, and bounce from the change in the vehicle height with respect to the road surface, control parameter change command means, and a command from the control parameter change command means. Dividing the frequency characteristic diagram of the vibration received by the predetermined frequency, the control parameter calculating means for calculating the area ratio of each frequency region, and dividing the amount of change of each control parameter into a plurality, and controlling each control in the plurality of control cycles. A control parameter gradual change means for gradually changing a parameter; and a control force for suppressing displacement of each mode of the cab from the control parameter gradual change means. That the cab control amount calculating means, the attitude control system of the cab, characterized by comprising an electromagnetic oil control valve to control power of each mode is generated in the respective hydraulic actuators.