JP3344438B2 - 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. More specifically, the present invention determines and changes control parameters suitable for road surface conditions in response to changes in vehicle speed. The present invention relates to a cab attitude control device that can provide a comfortable ride.

[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, optimal control is performed based on road surface input conditions at that time. By recalculating the 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-mentioned problems, an object of the present invention is to calculate a control parameter suitable for a road surface condition when an average vehicle speed exceeds a vehicle speed range up to now, and to automatically determine an optimal control parameter. An object of the present invention is to provide a cabin attitude control device that changes to control parameters.

[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 relative displacement amount calculating means for calculating a displacement amount of each mode of roll, pitch, and bounce with respect to a road surface from a change amount of the vehicle height detected by the vehicle height sensor; From the power spectrum density of the displacement of each mode, a control parameter calculating means for calculating the power spectrum density of the displacement of each mode of the road surface input, and the frequency characteristic diagram of the vibration received by the cab is divided by a predetermined frequency, Control parameter calculating means for calculating the area ratio of the region; and a control force for suppressing displacement of each mode of the cab from the control parameter calculating means. Yaw control amount calculation means, an oil amount control valve for generating the control force in each mode to each of the hydraulic actuators, a vehicle speed sensor, and when the vehicle speed detected by the vehicle speed sensor exceeds a conventional vehicle speed region, And a parameter change command determination calculating means for obtaining and changing the control parameter.

[0006]

According to the present invention, the driver travels at a high speed on a flat road such as a highway, runs at a medium speed on a slightly rough road, and runs at a low speed on a rough road. Utilizing the close relationship between vehicle speed and road surface conditions,
The average vehicle speed is determined every predetermined time from the vehicle speed detected from time to time, and when the average vehicle speed deviates from the current vehicle speed region,
A control parameter suitable for the road surface condition is calculated and automatically changed to an optimal control parameter.

That is, when the average vehicle speed deviates from the vehicle speed range up to now, the displacement of each mode of the cab with respect to the road surface is obtained from the change in the vehicle height of the cab detected by the vehicle height sensor by the relative displacement calculating means. From the power spectrum density of the relative displacement amount of each mode of the cab by the control parameter calculating means, the power spectrum density of the displacement amount of each mode of the road surface input is obtained, and the frequency characteristic diagram obtained by dividing the frequency characteristic diagram by a predetermined frequency And the control parameter is determined from each area ratio. The control amount calculating means obtains a control force for suppressing the displacement of each mode of the cab using the control parameter, and generates the control force to each hydraulic actuator.

[0008]

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 pressurized 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 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 cabinet 3 and 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 cabinet 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 controls the oil amount of each hydraulic actuator 19 in a feedback manner 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
5, the relative displacement xFL to xRR, and the relative displacement xcF of the cab 3.
L to xcRR are represented by the following equations.

.Times..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, kcθ1, kcx1: Constants determined by vehicle specifications kcφ2, kcθ2, kcx2: Constants determined by vehicle specifications Act on each axle 30 Assuming that the roll displacement of road input 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 as follows. It can be represented by.

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] −k2d [φ] dt−k7Σ [φ] dt−F22 = −k3 [θ] −k4d [θ] dt−k8− [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.

In 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 regardless of the road surface condition and the vehicle speed. The transfer function from the roll displacement φ of the road surface input to the roll displacement [φ] of the cab relative to the road surface is Hφ, and the transfer from the pitch displacement θ of the road surface input to the pitch displacement [θ] of the cab to the road surface. Assuming that the function is Hθ and the transfer function from the bounce displacement x of the road input to the bounce displacement [x] of the cab to the road is Hx,
Transfer functions Hφ, Hθ, H for each mode of pitch bounce
x is represented by the following equation.

[0020] ^{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 : Cap inertia moment of the cab IY: Pitch inertia moment of the cab Mc: Capacity of the g g: Acceleration of gravity hr: Height difference between the center of gravity of the cab and the center of the roll hp: Height difference between the center of gravity of the cab 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 at each frequency, and the relative displacement [φ],
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 the 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
The control map is set experimentally in advance and set as a control map in a ROM of a micro computer as an electronic control device, and is automatically selected in response to a change in vehicle speed. The power spectrum density Sφ of the displacement amount of each mode of road surface input,
The control parameters k1 to k9 can be changed more finely if the division of the frequency of Sθ and Sx is narrowed.

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-mentioned 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 + KV6 F32 VcV = + KV3F12 + KV3 F12 VcV = + KV3V12 + KV3V12 + KV3F12 + KV3V12 + KV3V12 + KV3F12 + KV3F12 + KV3F32 + cV8 + V8F8 + V8F8 + V8F8 + V8F8 + V8F32 + KV6F32 + KV6F32Vc6F32 + KV6F32 + cV6. ＶVcRR and the feedback voltage VsFL VsRR of the oil pressure sensor 17 drives each oil amount control valve 16 to control the hydraulic actuator 19,
The attitude of the cab 3 can be kept 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 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 change command determining means 3
3 to determine whether or not the vehicle speed exceeds the conventional vehicle speed region. If the vehicle speed exceeds the conventional vehicle speed region, the control parameter calculating means 34 determines the relative displacement amount of each mode of the cab with respect to the road surface. Power spectral density SΔφ, SΔ
From θ and SΔx, power spectrum densities Sφ, Sθ, and Sx of the displacement amount of each mode of the road surface input are obtained, and the frequency characteristic diagram is divided by a predetermined frequency fi (i = 1 to n), and each frequency region Area A of ~ f1, f1 ~ f2, ... fn-1 ~ fn
The area ratios γφi, γθi, γxi between φi, Aθi, Axi and the areas Aφ1, Aθ1, Ax1 are obtained, and the area ratio γφ of each frequency region is obtained.
From i, γθi, γxi, the control parameters k1 to k9 of each mode of roll, pitch and bounce are determined and changed.

Next, the relative amount of 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 cabinet 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 cab 3, and the control voltage VcFL
To VcRR and the feedback voltage FsFL of the oil pressure sensor 17
ＦFsRR to drive each oil amount control valve 16 to adjust 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 ~ p24, p41 ~ p46, p101 ~
p116, 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-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. If the control parameter needs to be changed, turn on the control parameter change flag. At p19, it is determined whether or not the control parameter change flag is ON. If the control parameter change flag is OFF, the process proceeds to p21. If the control parameter change flag is ON, the process proceeds to the control parameter calculation routine shown in FIG. 9 at p20. Calculate the optimal control parameters for the average vehicle speed.

At p21, based on 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], 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 p22, 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 p23, 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 p24.

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 determination routine starts at p101, reads the vehicle speed v2 at p102, and determines at p103 whether the number of additions N1 is greater than a predetermined number T. If the number of additions N1 is larger than the predetermined number of times T, the average vehicle speed va is obtained at p104, the added value vt1 of the vehicle speed up to the previous time is set to 0 at p105, the number of additions N1 is set to 0, and the routine proceeds to p110.

If the number of additions N1 is smaller than the predetermined number T in p103, the current (current) vehicle speed v2 is added to the previous vehicle speed addition value vt1 in p106, and the vehicle speed addition value vt up to this time is added.
Ask for 2. Next, the added value of the vehicle speed up to the previous time is
Replace vt1 with the added value of vehicle speed up to this time vt2, p108
Then, 1 is added to the number of additions N1 up to the previous time to obtain the number of additions N2 up to this time. In p109, the number of additions N1 up to the previous time is replaced with the number of additions N2 up to this time.

At p110, it is determined whether or not the average vehicle speed va is higher than the control parameter change boundary vehicle speed vc. Average vehicle speed va
Is greater than the control parameter change boundary vehicle speed vc,
At p111, the current situation determination parameter A2 is set to 1 and p113
Proceed to. If the average vehicle speed va is lower than the control parameter change boundary vehicle speed vc, the current situation determination parameter is determined at p112.
A2 is set to 0.

At p113, it is determined whether or not the current situation determination parameter A2 is equal to the previous situation determination parameter A1.
If the current status determination parameter A2 is equal to the previous status determination parameter A1, proceed to p115. If the current status determination parameter A2 is not equal to the previous status determination parameter A1, set the control parameter change flag to ON in p114. ,
At p115, the previous situation determination parameter A1 is replaced with the current situation determination parameter A2, and the program returns to the program at p116.

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 k1 is calculated from the area ratios γφi, γθi, γxi.
To k9, the parameter change flag is turned off at p56, and the program returns to p57 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.

In the above-described embodiment, the control range based on the vehicle speed is set in two stages, but may be set in three or more stages.

[0047]

As described above, the present invention utilizes the fact that the vehicle speed and the road surface condition are closely related to each other to obtain and change control parameters when the vehicle speed exceeds the conventional vehicle speed range. Therefore, the load on the electronic control unit is reduced, and the control parameters are automatically changed in accordance with changes in the road surface input (road surface conditions). Ride comfort can be 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 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: Cab 16: Oil control valve 19: Hydraulic actuator 25: Vehicle frame 28, 31: Vehicle height sensor 32: Vehicle speed sensor 33: Control parameter change command determination means 3
4: control parameter calculation means 35: relative displacement amount calculation means 37: control amount calculation 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 33/06 B62D 24/02 B60G 17/015

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. The relative displacement calculating means for calculating the displacement of each mode of the roll, pitch, and bounce with respect to the road surface from the change in the vehicle height of the cab, and the power spectrum density of the displacement of each mode of the cab, Control parameter calculating means for obtaining a power spectrum density of a displacement amount, control parameter calculating means for dividing a frequency characteristic diagram of vibration received by the cab at a predetermined frequency, and obtaining an area ratio of each frequency region, and the control parameter calculating means A control amount calculating means for obtaining a control force for suppressing displacement of each mode of the cab from the control unit; An oil amount control valve to be generated in the cutter, a vehicle speed sensor, and a parameter change command determination calculating means for obtaining and changing the control parameter when the vehicle speed detected by the vehicle speed sensor exceeds a conventional vehicle speed region. An attitude control device for a cab.