JPH05286331A - Vehicle vibration reduction device - Google Patents

Abstract

(57) [Abstract] [Purpose] To reduce the so-called fixed point as the transfer function of the vibration acceleration of the vehicle body against the road surface input at the vibration of the vehicle body, especially at the vibration frequency determined by the spring constant of the wheel and the unsprung mass. At the same time, the vehicle body vibration is reduced over a wide frequency band. [Arrangement] An auxiliary mass body 7 is arranged on the vehicle body 1 side (spring side) of a vehicle, and a vibrator 8 for exciting the auxiliary mass body 7 is provided. The relative displacement and sprung acceleration between the vehicle body 1 and the wheels 2FL are detected by the relative displacement sensor 15 and the vertical acceleration sensor 1.
6, and each of the detection signals is detected by the high-pass filters 30, 3
In step 2, only the high frequency component is filtered, and based on the filtered signal, the auxiliary mass body 7 is vibrated using the vibration exciter 8 so as to counter the vibration of the vehicle body. At the same time, the low-pass filters 29 and 31 filter only the low-frequency components of the detection signals of the sensors 15 and 16, and based on these signals, hydraulic fluid is supplied to and discharged from the fluid cylinder 3 of the suspension device to obtain suspension characteristics. To change.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a vehicle vibration reducing device.

[0002]

2. Description of the Related Art Conventionally, as a vehicle vibration reducing device,
A so-called active suspension device is known, for example, as disclosed in Japanese Patent Laid-Open No. 63-130418. This suspension device is provided with a fluid cylinder between a sprung portion and an unsprung portion of the vehicle, detects vertical acceleration and vehicle height applied to the vehicle, fluid pressure in the fluid cylinder, and the like, and based on these detection signals. By controlling the flow rate of the fluid supplied to and discharged from the fluid cylinder, each vibration of the bounce, pitching and roll of the vehicle is reduced regardless of the operating state of the vehicle.

Further, since the vibration of the vehicle body, especially the vibration associated with the unsprung resonance of the vehicle, is so-called bubbling and unpleasant vibration, conventionally, in order to reduce the unsprung vibration, the unsprung weight is reduced to reduce the unsprung resonance frequency. A method of optimizing by shifting to a high frequency side or adjusting a damping characteristic of a suspension device damper has been adopted.

[0004]

The active suspension device as described above, the semi-active suspension device in which only the damping force of the damper is variable by simplifying the structure, or the normal suspension device in which the suspension characteristic does not change is provided. Generally, a vehicle can be represented by a two-degree-of-freedom model including an unsprung mass m1 and an unsprung mass m2, as shown in FIG.

Now, in the two-degree-of-freedom model of FIG. 8, the tire spring constant is KT, the road surface displacement is X0, and the unsprung displacement is X1.
, The sprung displacement is X2, and the reaction force of the suspension device is F
Then, the equation of motion is expressed by the following equation.

[0006]

[Equation 1]

[Equation 2] Based on the above equation, the transfer characteristic of the vibration from the road surface to the vehicle body (d
² X2 / dt ² ) / X0 is the graph shown in FIG.

Next, when the above equations (1) and (2) are added to eliminate the reaction force F,

[Equation 3] Is obtained, and by subjecting this formula to the Laplace transform and substituting S = jω, the following formula (3) is obtained.

[Equation 4] Next, let H (S) be the vibration transmission characteristic of the vehicle body, and H (S) = X2
Putting (S) · S ² / X0 (S), in the above formula (3),
Frequency transfer function H when ωa = √ (KT / m1)
(Ωa) is

[Equation 5] Becomes In the above formula (4), KT, m2 and ωa ²
Is a constant, so as shown in FIG. 10, ωa = √ (K
The transfer function H (ωa) of the frequency near 10 Hz, which is T / m1), is uniquely determined to be a constant value regardless of the type of suspension device. However, the transfer function H (ωa) of the frequency at ωa = √ (KT / m1) can be improved to be small, no matter how properly the damper is adjusted, the damper is adjusted, or the spring constant in the active suspension device is controlled. As a result, there was a limit to the reduction of vehicle vibration. For the above circumstances, see, for example, page 78 of “6. Design method of active suspension” described on pages 73 to 82 of the teaching materials of the Japan Society of Mechanical Engineers (Experience and vibration control of '91 -7.18,19). Is also disclosed, and the transfer function H (ωa) of the frequency when ωa = √ (KT / m1) is referred to as a fixed point. In this description, the transfer function H (ω
a) is called a fixed point.

Therefore, for example, in order to improve the fixed point H (ωa) to be small, theoretically from the above formula (4), the spring constant KT of the tire is limited to a small value, the sprung mass m2 is increased, or the spring mass is increased. Countermeasures such as setting a dynamic damper below may be considered, but none of them is a drastic solution, and has a drawback that the running property and durability of the vehicle are deteriorated.

The present invention has been made in view of the above point, and particularly focused on the structure of a vibration damping device for suppressing vibration due to strong wind using an auxiliary mass body in a high-rise building or the like. This damping device is used, for example, as a training material for the Japan Society of Mechanical Engineers ('91 -7.18,1
9) Experience / vibration control), page 1 to page 20, “1.
As disclosed in "Guidelines for Active Vibration Control System Design", two high-rise buildings that are built upright in parallel are connected by a passage or the like, and the passage is vibrated as an auxiliary mass body so that two It suppresses the vibration of high-rise buildings.

Therefore, the present inventor has considered a case where an auxiliary mass body is separately provided in the vehicle and the vehicle is represented by a three-degree-of-freedom model including a sprung mass, an unsprung mass, and an auxiliary mass body. That is,
In the three-degree-of-freedom model of the vehicle shown in FIG. 11, m3 is the mass of the auxiliary mass body arranged on the spring, Ks is the spring constant of the suspension device, Cs is the damping coefficient of the suspension device, and U is the addition mass to be added to the auxiliary mass body. If it is a vibrating force, the following three expressions are established.

[Equation 6]

[Equation 7]

[Equation 8] Here, in the above formula (6),

[Equation 9] That is,

[Equation 10] If the excitation force U to the auxiliary mass m3 is controlled so that the sprung mass acceleration can always be maintained at zero value and the fixed point H (ωa) can be eliminated regardless of the road surface input. I understood.

Therefore, generally, K1 and K2 are defined as control gains, and

[Equation 11] It has been found that the gain K1 and K2 can be set equal to the spring constant Ks and the damping coefficient Cs of the suspension device or set to a predetermined value to reduce the sprung acceleration and reduce the fixed point H (ωa).

FIG. 12 shows the displacement amount of the auxiliary mass body when the control of the above equation (8) is carried out. As can be seen from the figure, the displacement amount of the auxiliary mass body sharply increases and becomes excessive in the low frequency component region below the frequency near 2 Hz. Therefore, it is practical to use the above control in the high frequency component region exceeding the low frequency component region of about 2 Hz or less.

From the above point of view, the object of the present invention is to employ a structure in which an auxiliary mass body is provided in a vehicle, and the auxiliary mass body is appropriately vibrated based on the above formula (8). As a configuration for reducing the vehicle body vibration in the high frequency component region exceeding 2 Hz, the fixed point can be reduced by using the active suspension device or the semi-active suspension device shown in the above conventional example in the low frequency component region of 2 Hz or less. It is to reduce the vibration of the vehicle in a wide frequency range while using the configuration.

In this case, since two vibration control systems are provided, common components are shared to simplify the configuration, and energy consumption is large due to the simultaneous operation of the two control systems. In consideration of the fact that desired control may not be performed, by giving priority to one of the vibration control systems that is required depending on the vehicle state, the vehicle state is ensured in good condition, It is also an object of the present invention to improve vehicle running performance such as riding comfort and turning performance.

[0015]

In order to achieve the above object, a concrete solving means of the invention according to claim 1 is arranged in a sprung portion or an unsprung portion of a vehicle as shown in FIG. The auxiliary mass body 7, a vibrating means 8 for vibrating the auxiliary mass body 7, and the vibrating means 8 based on a signal relating to vehicle body vibration.
With the first control system 50 including the control means 28a for controlling the vibration of the auxiliary mass body 7 by the above, and the characteristic changing means 11 for changing the suspension characteristic of the suspension device of the vehicle, the suspension characteristic is changed according to the state of the vehicle. And a second control system 51 for changing the vehicle body, and the first control system 50 is operated to reduce the vehicle body vibration in the high frequency component region of the vehicle body vibration, and the vehicle body vibration is reduced in the low frequency component region of the vehicle body vibration. The operation area setting means 53 for operating the second control system 51 is provided so as to operate.

According to the second aspect of the invention, the first control system 50 and the second control system 51 of the first aspect of the invention are described.
Thus, the oil pressure source and the sensor are shared.

Further, in the invention described in claim 3, in addition to the configuration of the invention described in claim 1, vehicle state detecting means for detecting the state of the vehicle and vehicle state detected by the vehicle state detecting means. Accordingly, a control gain ratio changing means for changing the control gain ratio between the first control system 50 and the second control system 51 is added.

In addition, in the invention described in claim 4, the vehicle state detecting means and the control gain ratio changing means of the invention described in claim 3 are specified, and the vehicle state detecting means detects the vehicle speed. However, the control gain ratio changing means is configured to largely change the control gain of the first control system when the vehicle speed is higher than the set value of the vehicle.

Further, in the invention described in claim 5, in place of the configuration of the invention described in claim 4, vehicle state detection means is provided.
The control gain ratio changing means is configured to detect the lateral acceleration of the vehicle, and to greatly change the control gain of the second control system when the lateral acceleration of the vehicle is larger than a set value.

Further, in the invention according to claim 6, the vehicle state detecting means is configured to detect the vertical acceleration of the vehicle, and the control gain ratio changing means is provided when the vertical acceleration of the vehicle is larger than a set value. The control gain of the second control system is largely changed.

In addition, according to the invention described in claim 7, the vehicle state detecting means is configured to detect the steering angle of the vehicle, and the control gain ratio changing means is used when the steering angle of the vehicle is a set value or more. When it is very large, the control gain of the second control system is largely changed.

[0022]

With the above construction, in the invention of claim 1,
The auxiliary mass body 7 of the first control system 50 is vibration-controlled by the control means 28a and vibrates in a range of a small displacement amount so as to counter the vibration of the vehicle body.
The vehicle body vibration is effectively reduced in the high frequency component region including the frequency of the fixed point near Hz. On the other hand, since the second control system 51 such as the active or semi-active suspension device changes the suspension characteristic in the low frequency component region of the vehicle body vibration, the vehicle body vibration in the low frequency component region of the vehicle body vibration is the same as the conventional one. Effectively reduced.

Further, according to the second aspect of the invention, since the hydraulic pressure source or the sensor is shared, the structure can be simplified accordingly.

Further, in the inventions according to claims 3 to 7, in the state of the vehicle, for example, in the state where the vehicle speed is higher than the set value, the control gain of the first control system 50 is largely changed, and the auxiliary mass body is changed. Since the vibration control of 7 has priority over the second control system 51, the vibration operation of the auxiliary mass body 7 is secured, and the vehicle body vibration of the high frequency component including the frequency near 10 Hz including the fixed point is effectively reduced, The riding comfort of the vehicle is improved. Further, for example, when the lateral acceleration or the steering angle of the vehicle is more than the set value in the turning state, the control gain of the second control system 51 is largely changed to secure the change of the suspension characteristic of the suspension device. Attitude control is reliably performed, and the vehicle turns in a good attitude with good stability. Further, for example, when the vehicle is running on a rough road where the vertical acceleration is equal to or greater than the set value, the control gain of the second control system 51 is greatly changed, and the attitude control of the vehicle is ensured by ensuring the change of the suspension characteristics. Since this is performed, the posture of the vehicle on a bad road or the like can be properly secured.

[0025]

As described above, according to the vehicle vibration reducing apparatus of the first aspect of the invention, the first control system for controlling the vibration of the auxiliary mass body is used for the vehicle body vibration in the high frequency component region of the vehicle body vibration. Since the second control system such as the active suspension device is operated to reduce the vehicle body vibration in the low frequency component region of the vehicle body vibration,
It is possible to effectively reduce the vehicle body vibration having a frequency near Hz while effectively reducing the vehicle body vibration in a wide frequency range from the low frequency component region to the high frequency component region of the vehicle body vibration.

According to the invention of claim 2, the first
Since the control system and the second control system share the hydraulic source and the sensor, the configuration can be simplified.

Further, according to the invention described in claims 3 to 7, the control gain ratio between the first control system and the second control system is changed according to the state of the vehicle. The vehicle vibration control or the vehicle attitude control can be focused on according to the state, the ride comfort of the vehicle can be improved, and the vehicle attitude can be appropriately secured when the vehicle is turning or traveling on a rough road. Produce an effect.

[0028]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to FIGS.

FIG. 2 shows a schematic structure of a vehicle vibration reducing apparatus according to the present invention. Although only the left side of the vehicle body is shown in the figure, the right side of the vehicle body is also similarly configured. In the figure, 1 is a vehicle body, 2FL is a left front wheel, 2FR is a left rear wheel, and a fluid cylinder 3 is provided between the vehicle body 1 and the left front wheel 2FL and between the vehicle body 1 and the right rear wheel 2FR. Is installed.

Further, an auxiliary mass body 7 is arranged at the center of the vehicle body 1, that is, the sprung portion of the vehicle in the front-rear direction, and
In the vicinity of the auxiliary mass body 7, a vibrator 8 as a vibrating means for vibrating the auxiliary mass body 7 is arranged. As shown in FIG. 3, the vibration exciter 8 has a structure in which a cylindrical auxiliary mass body 7 is slidably arranged in a vertical direction of a vehicle body in a casing 8a mounted and fixed to the vehicle body 1. The hydraulic chambers 8b and 8c are formed above and below the mass body 7, and two support springs 8d and 8d that elastically support the upper and lower sides of the auxiliary mass body 7 to the casing 8a are arranged above and below the auxiliary mass body 7. A stopper 8 for restricting the maximum displacement of the auxiliary mass body 7
e, 8e. The support springs 8d, 8
If the spring constant is Kd and the mass of the auxiliary mass body 7 is md, the support spring characteristic of d is, for example, 2 Hz of vehicle body vibration.
In order to reduce the above high frequency components, 2> 1 / 2π√
It is set to (Kd / md). Also, the casing 8
Supply and discharge ports 8f and 8f communicating with the hydraulic chambers 8b and 8c are formed above and below a, and oil pipes 8g and 8g are connected to the supply and discharge ports 8f and 8f, respectively. The pipes 8g and 8g are connected to a hydraulic pressure source 9 via a flow rate or pressure control valve 8h.
And the oil tank 8i are connected for communication, and the control valve 8
By the switching control of h, the upper hydraulic chamber 8b or the lower hydraulic chamber 8
The first control system 50 is configured such that hydraulic oil is alternately supplied to c to vibrate the auxiliary mass body 7 by vertically vibrating it.

On the other hand, in FIG. 2, the fluid cylinder 3 is
A hydraulic chamber 3c is formed below a piston 3b fitted in a cylinder body 3a so as to constitute an active suspension device, and the piston 3b includes a piston rod 3
The cylinder body 3 is connected to the vehicle body 1 via d.
a is connected to the front left wheel 2FL or the rear left wheel 2FR, respectively. A gas spring 4 is connected to each of the fluid cylinders 3. The gas spring 4 is divided into a hydraulic chamber 4a communicating with the hydraulic chamber 3c of the fluid cylinder 3 via a communication passage 5 and a gas chamber 4b in which gas is sealed. Further, the hydraulic pressure source 9 is connected to each of the fluid cylinders 3 through a communication passage 10, and the hydraulic pressure source 9 is used both for exciting the auxiliary mass body 7 and for operating the fluid cylinder 3.

Further, the communication passage 10 of each of the fluid cylinders 3 described above.
Is a proportional flow control valve 11 with a pressure compensation function as a characteristic changing means for controlling the amount of oil supplied to the fluid cylinder 3 to change the suspension characteristic of the suspension device.
A second control system 51 that controls the suspension characteristics by supplying and discharging hydraulic oil from the proportional flow rate control valves 11 to the fluid cylinders 3 ...

Further, the hydraulic pressure source 9 is provided with a discharge pressure gauge 12 for detecting the discharge pressure of oil, and a hydraulic pressure sensor 13 for detecting the hydraulic pressure of the hydraulic chamber 3c of each fluid cylinder 3.

In addition, in the vicinity of the fluid cylinders 3 and 3 of the left front wheel 2FL and the left rear wheel 2FR, between the vehicle body 1 and the left front wheel 2FL, and by detecting the cylinder stroke amount of the corresponding fluid cylinder 3, and Relative displacement sensors 15 and 15 for detecting the displacement between the vehicle body 1 and the left rear wheel 2FR, that is, the relative displacement between the sprung portion and the unsprung portion of the vehicle, respectively, are arranged. A vertical acceleration sensor 1 for detecting the vertical acceleration of the vehicle body 1 at a position above the cylinder 3.
6 are arranged.

Further, in the vicinity of the auxiliary mass body 7, a stroke sensor 17 for detecting a stroke amount between the vibrating auxiliary mass body 7 and the vehicle body 1 is arranged, and the vehicle body 1 is also provided.
A lateral acceleration sensor 18 for detecting a lateral acceleration acting on the vehicle body 1 is arranged at the center of gravity of the vehicle. Further, a vehicle speed sensor 19 for detecting a vehicle speed and a steering angle sensor 20 for detecting a steering steering angle are provided. The vehicle speed sensor 19,
The lateral acceleration sensor 18, the vertical acceleration sensor 16 and the steering angle sensor 20 constitute a vehicle state detecting means 21 for detecting the state of the vehicle.

The detection signals of the sensors 12 to 20 are input to a controller 25 having a CPU or the like inside, and the controller 25 controls the vibration of the auxiliary mass body 7 and obtains desired suspension characteristics. The proportional flow rate control valve 11 is controlled so as to achieve the above.

Next, the internal structure of the controller 25 will be described with reference to the block diagram of FIG. Since the configuration for each wheel is the same, the figure shows only one wheel. In the figure, 28 is a drive circuit,
A low-pass filter 29 for filtering only a low frequency band of, for example, 2 Hz or less of the relative displacement signal between the vehicle body 1 and the left front wheel 2FL is used as an input system of the detection signal of the relative displacement sensor 15 to the drive circuit 28, and 2 Hz on the contrary. A high-pass filter 30 that filters only a high-frequency band that exceeds 0 is arranged to separate the relative displacement signal into a low-frequency component and a high-frequency component at a boundary of 2 Hz.

Similarly, the input system of the detection signal of the vertical acceleration sensor 16 to the drive circuit 28 is also provided with the same low-pass filter 31 and high-pass filter 32 as described above.

Further, inside the drive circuit 28, the relative displacement signal and the vertical acceleration signal of only the high frequency components from the above two high pass filters 30 and 32 are input, and the auxiliary mass body 7 of the auxiliary mass body 7 is based on these signals. A vibration control unit 28a as a control means for performing vibration control based on the control flow of FIG. 5 described later.
And the relative displacement signals and sprung acceleration signals of only the low frequency components from the two low pass filters 29, 31 are input, and the suspension characteristics are supplied by supplying / discharging the flow rate to / from each fluid cylinder 3 based on these signals. A suspension characteristic changing unit 28b that appropriately changes is provided.

The suspension characteristic changing section 28b is
Vehicle height control, vehicle height displacement speed control, vertical vibration suppression control of the vehicle, vehicle body twist suppression control, and lateral vibration suppression control of the vehicle are performed. The vehicle height control calculates the bounce component of the vehicle, the pitching component, and the roll component of the vehicle from the relative displacement signals of the relative displacement sensors 15 ...
Based on these, the vehicle height and the roll amount are controlled to the target values and the pitching is suppressed. In the vehicle height displacement speed control, the relative displacement signal of each relative displacement sensor 15 is differentiated to calculate the relative displacement speed, and the pitch component and the roll component are calculated to perform the pitch control and the target roll amount. The speed is controlled toward. Further, the control for suppressing the vertical vibration of the vehicle is performed by each vertical acceleration sensor 16 ...
3 of the bounce, pitching and roll of the detection signal of
It is a control that calculates a component and suppresses vertical vibration based on these. In addition, the control for suppressing the twisting of the vehicle body is performed based on the deviation between the hydraulic pressure ratios of the left and right front wheel side fluid cylinders 3, 3 of the respective hydraulic pressure sensors 13 ... To control. Further, the control for suppressing the lateral vibration of the vehicle is a control for suppressing the lateral vibration based on the output signal of the lateral acceleration sensor 18.

Then, the above two high-pass filters 3
With 0 and 32, low frequency components of 2 Hz or less of the relative displacement signal between the vehicle body 1 and the wheels 2FL and the vertical acceleration signal of the vehicle body 1 are removed, and the vehicle body vibration is reduced in the high frequency component region of the vehicle body vibration exceeding 2 Hz. The first control system 50 is operated so as to vibrate the auxiliary mass body 7, and the two low-pass filters 29 and 31 cause the relative displacement signal between the vehicle body 1 and the wheels 2FL and the vertical acceleration signal of the vehicle body 1 to be generated. Of the fluid cylinders 3 so as to reduce the vehicle body vibration in the low frequency component region of the vehicle body vibration of 2 Hz or less by removing the above high frequency component.
The operating region setting means 52 is configured to operate the second control system 51 so as to change the suspension characteristics by controlling the supply / discharge of the hydraulic oil to / from.

Subsequently, the vibration control of the auxiliary mass body 7 by the controller 25 and the suspension characteristic change control by the supply / discharge control of the hydraulic oil to / from each fluid cylinder 3 will be described based on the control flow shown in FIG.

In the figure, start and step S1
Is used to determine the value of the vehicle speed V signal of the vehicle speed sensor 19, and
In step S2, the value of the lateral acceleration gs signal of the lateral acceleration sensor 18 is determined, and in steps S3 and S4, the value of the vertical acceleration ga signal of the vertical acceleration sensor 16 and the steering angle sensor 19 are determined.
The value of the steering steering angle θ signal is determined. When the vehicle speed V ≧ Vo is high, the control gain G1 of the first control system 50 for controlling the vibration of the auxiliary mass body 7 in step S5 is larger than the normal value “0.5” by “0.7”. Value, and the control gain G2 of the second control system 51 for changing and controlling the suspension characteristic is set to the normal value "0.
Set to a value of "0.3" which is smaller than the value of "5".

On the other hand, in step S2, the lateral acceleration gs of the vehicle
Is greater than gs ≧ go, it is determined that the vehicle is turning or the like, and in step S3, when the vertical acceleration ga of the vehicle is greater than ga ≧ g1, it is determined that the vehicle is traveling on a bad road, and step S4 is performed. And steering steering angle θ is θ ≧ θo
If it is larger, it is determined that the vehicle is turning, etc., and in step S6, the control gain G1 of the first control system 50 is set to "0.3" smaller than the normal value, contrary to the above. At the same time, the control gain G2 of the second control system 51 is set to "0.
7 ”value is set larger than the normal value.

On the other hand, when the determinations at steps S1 to S5 are all NO, at step S7 the control gain G1 of the first control system 50 and the control gain G2 of the second control system 51 are both set to normal. Set to the value "0.5".

After that, in step S8, after the signals from the respective sensors 12 to 20 which have filtered the low frequency component region or the high frequency component region are input, the suspension characteristic changing unit 28b controls the suspension characteristic changing.

Further, in step S10, the relative displacement sensor 1
The relative speed signal d between the vehicle body 1 and the left front wheel 2FL is differentiated by differentiating the detection signal X2-X1 obtained by filtering the low frequency component from
X2 / dt-dX1 / dt is calculated, and the relative speed between the vehicle body 1 and the left front wheel 2FL is dX2 / dt-d in step S11.
The control signal value I1 for the control valve 8h of the vibrator 8 based on the X1 / dt signal is calculated by the following formula.

[Equation 12] And the vehicle body 1 is calculated in step S12.
And the control signal value I2 for the vibrator 8 based on the relative displacement X2-X1 signal between the left front wheel 2FL and the following formula:

[Equation 13] Calculate based on. In the above equations, A1 and A2 are phase coefficients.

[0048] Thereafter, the control signal value I3 for the sprung acceleration d ² X2 / dt vibrator 8 based on ² signal from the vertical acceleration sensor 16 in step ^{S13, I3 = (d 2 X2} / dt 2) · while operation at G1, by integrating the sprung acceleration d _² X ² / dt ² signal from the vertical acceleration sensor 16 in step S14, after obtaining the sprung speed dX2 / dt signal, based on the sprung speed signal The control signal value I4 for the shaker 8 is calculated by I4 = (dX2 / dt) .G1.

Then, in step S14, the respective control signal values I1, I2, I3 and I4 are added to calculate the total control signal value I, and the signal value I is output to the vibration exciter 8 to return.

Therefore, in the control flow of FIG.
According to the vehicle speed V, the lateral acceleration gs of the vehicle, the vertical acceleration ga, and the steering angle θ detected by the vehicle state detecting means 21 in steps S1 to S7, the first control system 50 is used when the vehicle speed is V ≧ Vo. Of the control gain G1 of the second control system 51 is set to a value "0.7" which is larger than the normal value of "0.5", and the control gain G2 of the second control system 51 is set to a value "0.3" which is smaller than the normal value. On the other hand, when the vehicle lateral acceleration gs, vertical acceleration ga, and steering steering angle θ are gs ≧ go, ga ≧ g1, and θ ≧ θo, respectively,
The control gain G2 of the second control system 51 is set to a value "0.7" larger than the normal value, and the control gain G1 of the first control system 50 is set to a value "0.3" smaller than the normal value. Thus, the control gain ratio changing means 53 is configured to change the control gain ratio between the first control system 50 and the second control system 51.

[0051] Thus, the high frequency in the above in the embodiment, the vehicle body 1 and a left front wheel 2FL relative displacement X2 -X1 signal and the vehicle body 1 between the vertical acceleration d ² X2 / dt ² signals are each high-pass filter 30 and 32 After filtering only the components, the control signals I1 and I2 based on the relative displacement signal and the relative velocity dX2 / dt−dX1 / dt signal obtained by differentiating the relative displacement signal are calculated, and the vertical acceleration signal is calculated. When,
The control signals I3 and I4 based on the vertical speed dX2 / dt signal of the vehicle body 1 obtained by integrating the signals are calculated, and the control valve value 8h of the vibration exciter 8 is obtained with the control signal value I obtained by summing these signals.
Is controlled. Therefore, the excitation force U represented by the following equation acts on the auxiliary mass body 7,

[Equation 14] Since the high frequency component of the vibration of the vehicle body 1 is canceled, the high frequency component of the vibration of the vehicle body 1 is effectively reduced.

Simultaneously with the vibration control of the auxiliary mass body 7, a relative displacement X2 -X1 between the vehicle body 1 and the left front wheel 2FL is obtained.
After the low frequency components of the signal and the sprung acceleration d ² X 2 / dt ² signal are filtered by the low-pass filters 29 and 31, respectively, the fluid cylinders 3 based on the relative displacement X 2 -X 2 signal of only the low frequency component. Since the hydraulic oil is supplied to and discharged from the vehicle body, the vehicle height and the roll amount of the vehicle body 1 are controlled to the target values, and the low frequency component of the pitching of the vehicle body 1 is effectively suppressed. Further, at the same time, the hydraulic oil supply / discharge control to / from the fluid cylinders 3 is performed based on the sprung acceleration signal d ² X2 / dt ² from the vertical acceleration sensor 16 ... The low frequency components will be effectively suppressed.

As a result, as shown in FIG. 6, the vehicle body vibration in the high frequency region including the frequency of the fixed point in the vicinity of 10 Hz over 2 Hz is caused by the first control system 50 by the vibration control of the auxiliary mass body 7. In addition to being effectively reduced, vibrations in the low frequency region of 2 Hz or less are effectively reduced by the suspension characteristic change control (second control system 51) by the supply / discharge control of the hydraulic oil to / from the fluid cylinders 3 ... As a result, the vibration of the vehicle body can be effectively reduced while eliminating the fixed point.

Further, the hydraulic power source 9 serves as the active suspension control, and each fluid cylinder 3 of the second control system 51 ...
Of the hydraulic oil to the hydraulic chambers 8b and 8c of the vibrator 8 of the first control system 50 that vibrates the auxiliary mass body 7, and Relative displacement sensor 1
5 and the vertical acceleration signal 16 are transmitted to the first control system 50 and the second control system 50.
Since it is shared with the control system 51, the configuration can be simplified accordingly.

In addition, as described above, in response to the vibration of the vehicle body 1, the supply / discharge control of the hydraulic oil to / from each fluid cylinder 3 and the supply / discharge control of the hydraulic oil to / from the vibrator 8 of the auxiliary mass body 7 are simultaneously performed. Due to the operation performed, there is a concern that the amount of hydraulic oil from the hydraulic power source 9 may be insufficient. However, when the vehicle speed V is a high vehicle speed equal to or higher than the set value Vo, for example, when traveling on a highway or the like, it is a situation where it is desired to improve the riding comfort of the vehicle by removing high frequency components of vibration. While the control gain G1 of the control signal I for the control valve 8h of the container 8 is changed to a value of "0.7" which is larger than the normal value ("0.5" value), the control signal for each fluid cylinder 3 ... Control gain G2 of "0.
Since it is changed to a small value of "3", the excitation control of the auxiliary mass body 7 by the exciter 8 is performed intensively, and as a result, the vehicle body 1
The high-frequency component of the vibration is reliably reduced, and the riding comfort of the vehicle is improved. Also, when the lateral acceleration or steering angle that acts on the vehicle is large, the vehicle is turning, and when the vertical acceleration that acts on the vehicle is large, it is when the vehicle is running on a rough road. In the situation where the attitude control of the vehicle is more important than the reduction of the vibration of the vehicle, in this situation, the control gain G2 of the control signal for each fluid cylinder 3 ... Is more than the normal value (“0.5” value). Large value of "0.7"
Is changed to a value, and the control gain G1 of the control signal I for the control valve 8h of the shaker 8 is changed to a value "0.3" which is a smaller value than the normal value. The posture control is ensured, and the steering stability and safety are improved when the vehicle is turning or traveling on a rough road.

Although the auxiliary mass body 7 is arranged on the vehicle body 1 (on the spring) in the above embodiment, it may be arranged on the unsprung body.
In this case, as shown in FIG.
The auxiliary mass body 7 and the vibrator 8 may be built in the lower part of the damper 4. Explaining the configuration of the shaker 8'in this case, the shaker 8'is of an electric type, and a hollow auxiliary mass body 7'is supported in a cover 8a 'that is attached and fixed to the vehicle body 1. Two support springs 8d 'and 8d', which are loosely fitted to the shaft 8b 'and elastically support the upper and lower sides of the auxiliary mass body 7'on the cover 8a', and the inner circumference of the hollow portion of the auxiliary mass body 7 '. Placed and fixed hollow cylindrical magnet 8
e'and the magnet 8e 'extending from the bottom of the cover 8a'
Of the auxiliary mass body 7 ', which is arranged in the hollow portion of the coil 8f' for moving the magnet 8e 'by electromagnetic force, and the coil 8f' which is arranged on the upper surface and the bottom of the cover 8a ', respectively. And an elastic stopper 8g 'for controlling the magnet 8e according to the amplitude and phase of the alternating current to the coil 8f'.
′ And the auxiliary mass body 7 are configured to be vibrated vertically.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of an invention according to claim 1.

FIG. 2 is a diagram showing an overall schematic configuration.

FIG. 3 is a diagram showing a specific configuration of a vibration exciter.

FIG. 4 is a block configuration diagram inside a controller.

FIG. 5 is a flowchart showing vibration reduction control.

FIG. 6 is a diagram showing the degree of the effect of the invention according to claim 1;

FIG. 7 is a specific configuration diagram in the case where the shaker is arranged under the spring.

FIG. 8 is a diagram showing a two-degree-of-freedom model of a vehicle.

FIG. 9 is a diagram showing riding comfort characteristics of a conventional suspension device.

FIG. 10 is an explanatory diagram of a fixed point.

FIG. 11 is a diagram showing a three-degree-of-freedom model of a vehicle.

FIG. 12 is a diagram showing displacement amount characteristics of the auxiliary mass body with respect to the frequency of vehicle body vibration.

[Explanation of symbols]

1 vehicle body 2FL, 2FR wheel 7, 7'auxiliary mass body 8, 8'vibrator (vibrating means) 9 hydraulic power source 11 proportional flow rate control valve (characteristic changing means) 15 relative displacement sensor (vehicle state detecting means) 16 up and down Acceleration sensor (vehicle state detecting means) 18 Lateral acceleration sensor (vehicle state detecting means) 19 Vehicle speed sensor (vehicle state detecting means) 20 Steering angle sensor (vehicle state detecting means) 25 Controller 28 Drive circuit 28a Vibration control section 28b Suspension characteristics Change unit 50 First control system 51 Second control system 52 Operating region setting means 53 Control gain ratio changing means

Claims (7)

[Claims] 1. An auxiliary mass body arranged in a sprung portion or an unsprung portion of a vehicle, a vibrating means for vibrating the auxiliary mass body,
And a first control system having a control means for controlling the vibration of the auxiliary mass body by the vibration means on the basis of a detection signal relating to vehicle body vibration, and a characteristic changing means for changing the suspension characteristic of the suspension device of the vehicle. , A second control system for changing the suspension characteristic according to the state of the vehicle, and operating the first control system so as to reduce the vehicle body vibration in the high frequency component region of the vehicle body vibration. A vibration reduction device for a vehicle, comprising an operation region setting means for operating a second control system so as to reduce vehicle body vibration in a component region. 2. The first control system and the second control system share a hydraulic pressure source and a sensor.
The vehicle vibration reduction device described. 3. A vehicle state detecting means for detecting the state of the vehicle, and a control gain ratio between the first control system and the second control system according to the state of the vehicle detected by the vehicle state detecting means. The vibration reduction apparatus for a vehicle according to claim 1, further comprising: a control gain ratio changing unit that changes the control gain ratio. 4. The vehicle state detecting means detects the vehicle speed, and the control gain ratio changing means largely changes the control gain of the first control system when the vehicle speed is higher than a set value of the vehicle. The vibration reduction device for a vehicle according to claim 3, which is characterized in that. 5. The vehicle state detecting means detects the lateral acceleration of the vehicle, and the control gain ratio changing means largely changes the control gain of the second control system when the lateral acceleration of the vehicle is larger than a set value. The vehicle vibration reduction device according to claim 3, wherein the vibration reduction device is a vehicle vibration reduction device. 6. The vehicle state detecting means detects the vertical acceleration of the vehicle, and the control gain ratio changing means largely changes the control gain of the second control system when the vertical acceleration of the vehicle is larger than a set value. The vehicle vibration reduction device according to claim 3, wherein the vibration reduction device is a vehicle vibration reduction device. 7. The vehicle state detecting means detects a steering angle of the vehicle, and the control gain ratio changing means determines when the steering angle of the vehicle is larger than a set value.
The vibration reduction device for a vehicle according to claim 3, wherein the control gain of the control system is largely changed.