JP3353797B2 - 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 an apparatus 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. A posture control system for a cabin, in which a comfortable ride is obtained by automatically changing or updating the control parameters only when the deviation from the currently set control parameters is larger than a predetermined value. It is about.

[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 a driver issues a command, an optimum road surface (input) condition at that time is used. By recalculating various 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 device for a cab, operation is complicated in places where the road surface condition changes frequently, which hinders the driver's driving operation, which is not preferable in terms of safety.

[0004]

SUMMARY OF THE INVENTION In view of the above problems, an object of the present invention is to automatically set a control parameter when a deviation between a current control parameter and a control parameter newly obtained from a road surface condition exceeds a predetermined value. An object of the present invention is to provide a cabin posture control device which can eliminate complicated operation by updating the information in a dynamic manner.

[0005]

In order to achieve the above-mentioned object, according to the present invention, the displacement of each mode of the cab is obtained from the amount of change in the vehicle height of the cab with respect to the road surface, and each mode of the cab is obtained by a control parameter calculating means. From the power spectrum density of the relative displacement amount, the power spectrum density of the displacement amount of each mode of the road surface input is obtained, the frequency characteristic diagram is divided by a predetermined frequency, the area ratio of each frequency region is obtained, and from each area ratio The obtained control parameters are obtained, the control amount calculating means obtains a control force for suppressing the displacement of each mode of the cab using the control parameters, and the control position of the cab posture control device for generating the control force to each hydraulic actuator is set at the current setting. Each of the set control parameters is compared with each control parameter obtained from the current road surface condition, and at least one set of control parameters is determined. If the difference over data exceeds a predetermined value, it is to change the value obtained for each control parameter from the current road conditions.

[0006]

According to the present invention, each of the currently set control parameters is compared with each of the optimum control parameters calculated from the current road surface condition, and when a difference between at least one set of control parameters exceeds a predetermined value. Then, each control parameter is automatically updated to a value calculated from the current road surface condition.

That is, the amount of displacement of each mode of the cab with respect to the road surface is determined from the amount of change in the height of the cab detected by the vehicle height sensor by the relative displacement amount calculating means, and the relative amount of displacement of each mode of the cab is determined by the control parameter calculating means. From the power spectrum density of, the power spectrum density of the displacement amount of each mode of the road surface input is obtained, the frequency characteristic diagram is divided by a predetermined frequency, the area ratio of each frequency region is obtained, and the control parameter is obtained from each area ratio. Ask.

The control parameters thus obtained are compared with the currently set control parameters, respectively. If the difference between at least one set of control parameters exceeds a predetermined value, the control amount calculation means calculates the control parameters. The control force that suppresses the displacement of each mode of the cab is determined using the control parameters
The control force is generated in each hydraulic actuator.

[0009]

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 respective hydraulic actuators 19 that support the front, rear, left and right portions of the cabinet 3 on the vehicle frame 25. 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 vehicle frame 25 supports an axle or suspension member 30 for supporting the wheels 20 by a known hydraulic shock absorber 29.
The hydraulic shock absorber 29 is formed by inserting a piston into a cylinder,
A cylinder is connected to the suspension member 30, and a rod projecting upward from the piston is connected to the 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. A vehicle height sensor 28 for detecting a relative displacement amount of the cap 3 with respect to the vehicle frame 25 and a vehicle height sensor 31 for detecting a relative displacement amount of the vehicle frame 25 with respect to the suspension member 30 are provided.

The pressure oil in the pipe 7 is supplied to a check valve 14, an oil amount control valve 1 comprising 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.

Each of the front and rear and left and right hydraulic actuators 19 of the cap 3 is independently provided with check valves 14 and 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 amount control valve 16 performs feedback control of the oil amount of each hydraulic actuator 19 in accordance with a control voltage from an electronic control unit comprising a micro computer. When the front, rear, left and right hydraulic actuators 19 are specified, subscripts of FL, FR, RL, and RR are added.

The relative vehicle height of the vehicle frame 25 with respect to each wheel 20 is hFL to hRR, and the front, rear, left and right portions of the
Assuming that the relative vehicle height to the vehicle 5 is hcFL to hcRR, the vehicle frame 2
The vehicle height change amounts xFL to xRR of 5 and the vehicle height change amount xcF of Cab 3
L to xcRR are represented by the following equations.

.Times..times..times..times..times..times..times..times..times. 1) However, hFL0 to hRR0: standard vehicle height of each wheel supporting portion of the vehicle frame hcFL0 to hcRR0: standard vehicle height of front, rear, left and right portions of the cab The relative roll displacement Δφ, pitch displacement Δθ to the road surface of the vehicle frame 25, The bounce displacement amount Δx, the roll displacement amount Δφc, the pitch displacement amount Δθc, and the bounce displacement amount Δxc of the cabinet 3 relative 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; Determined constants kφ2, kθ2, kx2: Constants determined by vehicle specifications kc φ1, kc θ1, kc x1: Constants determined by vehicle specifications kc φ2, kc θ2, kc x2: Constants determined by vehicle specifications Road surface acting on each axle Assuming that the input roll displacement is φ, the pitch displacement is θ, and the bounce displacement is x, the roll displacement φ2, pitch displacement θ2, and bounce displacement x2 of the cab 3 are given by the following equations. Succoth can.

Φ2 = φ + Δφ + Δφc θ2 = θ + Δθ + Δθcx2 = x + Δx + Δxc (3) Therefore, in order to keep the cab 3 flat (parallel to the road surface), the roll control force -F12, pitch which should be applied to the cab 3 by each hydraulic actuator 19 The control force-F22 and the bounce control force-F32 can be expressed by the following equations.

−F12 = −k1 [φ] −k2 d [φ] dt−k7Σ [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 condition. 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.

[0021] ^{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 (representing only the power spectrum density Sφ). 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, the area ratio γφi = Aφi / Aφ1 The area Aθ1, Aθ2,... Aθn, the area ratio γθi = Sφ
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 given by the frequency regions fi−1 to the areas 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 forces 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 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 + KV3F12 VcV = + KV3F12 + KV3V12 + KV3V12 + KV3V12 + KV3F12 + KV3V12 + KV3F12 + KV3F12 + KV3F12 + KV3F32 + CV8 + 32VK8 + 32VK8 + 32VK8F32 + KV6F32 + KV6F32 + KV3F32 + 32Vc6F32 + KV6F32 + KV6F32Vc6F32Vc6F32 + cV6F32 + kV6F32 + 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 based on 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 cap 3 are obtained, and the relative roll displacement Δφ, pitch displacement Δθ, and bounce displacement of the vehicle frame 25 with respect to the road surface are obtained. Δx, the relative roll displacement Δφc of the cab 3 with respect to the vehicle frame 25, the pitch displacement Δθc
, And the amount of bounce displacement Δxc.

Next, the control parameter calculating means 34 calculates the power spectral densities Sφ, S of the displacement amounts of the respective modes of the road surface input from the power spectral densities SΔφ, SΔθ, SΔx of the relative displacement amounts of the respective modes of the cab with respect to the road surface.
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
Ｆf2,... Fn-1 to fn, the area ratios γφi, γθi, γxi of 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, The optimum control parameters k1b to k9b for each of the pitch and bounce modes are obtained.

Each of the control parameters k1 to k9 currently set by the control parameter change command determining means 36,
Each optimal control parameter k1b obtained from the current road surface condition
and k9b. If the deviation of at least one set of control parameters exceeds a predetermined value k1c to k9c, it is determined that each control parameter needs to be changed or updated, and the control parameters are updated to control parameters k1b to k9b.

Next, the relative roll displacement Δφ, pitch displacement Δθ, bounce displacement Δx of the vehicle frame 25 with respect to the road surface, the relative roll displacement Δφc of the cab 3 with respect to the vehicle frame 25, Pitch displacement Δθ
The roll control force F12, pitch control force F22, and bounce control force F32 of the cab 3 are obtained from c and the bounce displacement amount Δxc.

Finally, the control voltages VcFL to VcRR of each oil amount control valve 16 are obtained from the roll control force F12, pitch control force F22, and bounce control force F32 of the cabin 3, and the control voltage VcFL
To VcRR and the feedback voltage F from the oil pressure sensor 17
Each oil amount control valve 16 is driven by sFL to FsRR to increase or decrease the oil amount of each hydraulic actuator 19.

FIGS. 5 to 10 are flow charts of a control program for performing the above-mentioned control by an electronic control unit composed of a microcomputer. This control program is repeatedly executed at predetermined time intervals. p11-p25, p41-p46, p101-
p113, p51 to p57, and p61 to p67 represent each step of the control program. Start the control program at p11
Then, the process proceeds to the hydraulic pressure holding routine shown in FIG. 7 at p13, the hydraulic control valve 12 is driven, and the output hydraulic pressure pm is maintained at the predetermined value pc.

At p14, the vehicle height hFL to hRR of the vehicle frame 25 is 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 of each mode of the vehicle frame 25, that is, the roll displacement Δφ, the pitch displacement Δθ, and the bounce displacement Δx are obtained from the vehicle height change amounts xFL to xRR of the vehicle frame 25. From the variations xcFL to xcRR, the relative displacement of each mode of the cab 3, that is, the roll displacement Δφc,
The pitch displacement Δθc and the bounce displacement Δxc are obtained.
The relative displacement of each mode of the cab 3 with respect to the road surface at p17,
That is, the roll displacement [φ], the pitch displacement [θ], and the bounce displacement [x] are sequentially stored in the RAM.

At p18, the process proceeds to a control parameter change command determination routine shown in FIG. 8, and it is determined whether or not the control parameter needs to be changed. That is, the current control parameters k1 to
The difference between k9 and each of the optimum control parameters k1b to k9b is determined, and even one of the differences between these control parameters exceeds a predetermined value (control parameter change reference value set for each control parameter) k1c to k9c. If so, it is determined that the control parameter needs to be changed, and the control parameter change flag is turned ON. At p19, it is determined whether or not the control parameter change flag is ON. When the control parameter change flag is OFF, the process proceeds to p22. When the control parameter change flag is ON, the control parameter ki is updated to a new control parameter, that is, the optimal control parameter kib at p20, and the control parameter change flag is turned off at p21. To

At p22, based on the relative displacement of each mode of the cab 3 with respect to the road surface, ie, the roll displacement [φ], the pitch displacement [θ], and the bounce displacement [x], the control amount of the cab 3, ie, the roll control force. F12, pitch control force F22, and bounce control force F32 are determined. At p23, the control amount F12 of the cab 3
The control voltage VcFL of the oil amount control valve 16 corresponding to F22 and F32.
To VcRR. At p24, the operation proceeds to the hydraulic actuator driving routine shown in FIG. 10, the oil amount of each hydraulic actuator 19 is adjusted by each oil amount control valve 16, and the operation is terminated at p25.

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 change command judging routine is started at p101, and at p102, the routine proceeds to the control parameter calculating routine shown in FIG.
1b to k9b are obtained, the control parameter change flag is turned off, and it is determined at p103 whether the difference between the control parameter k1 and the optimal control parameter k1b is larger than a predetermined value k1c. If the difference between the control parameter k1 and the optimum control parameter k1b is larger than the predetermined value k1c, the control parameter change flag is turned on at p104, and the program proceeds to p110. The difference between the control parameter k1 and the optimal control parameter k1b is a predetermined value k1c
If it is smaller, the process proceeds to p105.

At p105, the control parameter k2 is determined in the same manner as in the case of p103, and similarly, at p106 to p112, the control parameters k3 to k9 are sequentially determined. Each control parameter k2 to k9 and optimal control parameter k2b to k
If the difference from 9b is larger than the predetermined values k2c to k9c, p104
If the difference between each of the control parameters k2 to k9 and the optimum control parameter k2b to k9b is smaller than the predetermined value k2c to k9c, the program returns to p113 at p113.

As shown in FIG. 9, the control parameter calculation routine starts at p51. At p52, the relative displacement of each mode of the cab 3 with respect to the road surface, that is, the roll displacement [φ], the pitch displacement [θ], the bounce From the displacement [x], the power spectral densities SΔφ, SΔθ, SΔx of the displacement of each mode of the cab 3 with respect to the road surface are obtained. At p53, the power spectrum densities Sφ, Sθ, Sx of the displacement amounts of the respective modes of the road surface input are determined from the power spectrum densities SΔφ, SΔθ, SΔx of the displacement amounts of the respective modes of the cab 3 with respect to the road surface.

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, the control parameter k1b is calculated from the area ratios γφi, γθi, γxi.
To k9b, and turn off the control parameter change flag with p56
And return to this program at p57.

As shown in FIG. 10, the hydraulic actuator driving routine starts at p61, and at p62 each hydraulic sensor 17
, The hydraulic pressures pFL-pRR of each hydraulic actuator 19 are read, and the hydraulic pressures pFL-pRR are converted into voltages VsFL-VsRR at p63. The control voltage VcFL to VcRR and the voltage V
From sFL to VsRR, the excitation voltage VeFL of each oil amount control valve 16 is calculated.
Find VeRR. The oil quantity Q to be supplied to or discharged from each hydraulic actuator 19 by exciting each oil quantity control valve 16 at p65
FL-QRR is adjusted, and each hydraulic actuator 1 is adjusted by p66.
9 is driven and the program returns to this program at p67.

As shown in FIG. 11, the amount of oil QFL to QRR applied to each hydraulic actuator 19 is adjusted by the excitation voltage VeFL to VeRR of each oil amount control valve 16.

[0046]

As described above, according to the present invention, each of the currently set control parameters is compared with each of the optimum control parameters calculated from the current road surface condition, and at least one is set.
When the difference between the set of control parameters exceeds a predetermined value,
Since each control parameter is automatically switched to a value calculated from the current road surface condition, the comfort and riding comfort of the occupant can be improved without hindering the driver's driving operation.

[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 flowchart of a control program of the attitude control device.

FIG. 11 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
4: control parameter calculation means 35: relative displacement amount calculation means 36: control parameter change command determination means 37: control amount calculation means

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-5-229329 (JP, A) JP-A-3-109113 (JP, A) JP-A-5-238435 (JP, A) 18374 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) B60G 17/015

Claims (1)

(57) [Claims] 1. The displacement of each mode of the cab is determined from the amount of change in the vehicle height of the cab with respect to the road surface, and the displacement of each mode of the road input is determined by the control parameter calculating means from the power spectrum density of the relative displacement of each mode of the cab. Amount of the power spectrum density, the frequency characteristic diagram thereof is divided by a predetermined frequency, the area ratio of each frequency region is obtained, the control parameter obtained from each area ratio is obtained, and the control parameter is used by the control amount calculating means. In the attitude control device of the cab for obtaining the control force for suppressing the displacement of each mode of the cab and generating the control force for each hydraulic actuator, the respective control parameters obtained from the currently set control parameters and the current road surface conditions are used. Each parameter is compared with at least one set of control parameters. And changes to the value obtained from the road surface condition of standing, posture control device for the cab.