WO2018193685A1

WO2018193685A1 - Suspension control device

Info

Publication number: WO2018193685A1
Application number: PCT/JP2018/003142
Authority: WO
Inventors: 朋之工藤; 友夫窪田
Original assignee: Ｋｙｂ株式会社
Priority date: 2017-04-19
Filing date: 2018-01-31
Publication date: 2018-10-25
Also published as: JP2018177117A; JP6924062B2

Abstract

This suspension control device (C) is provided with a controller (3) for controlling an actuator (A) interposed, along with a suspension spring (S), between an unsprung member (W) and a sprung member (B) of a vehicle V. The controller (3) obtains, on the basis of vibration information for the unsprung member (W) and vibration information for the sprung member (B), a control command for cancelling out transmission force transmitted from the unsprung member (W) to the sprung member (B).

Description

Suspension control device

The present invention relates to a suspension control device.

When the unsprung member gets over the road surface unevenness while the vehicle is running, the suspension spring expands and contracts, and the support force of the suspension spring to support the sprung member fluctuates, so the sprung member vibrates. In order to suppress the vibration of the sprung member, an actuator interposed between the unsprung member and the sprung member in the vehicle is interposed, and the thrust exerted by the actuator is controlled to There are suspension control devices that suppress vibrations.

In such a suspension control device, for example, as disclosed in JPH05-319054A, the unsprung speed of the front wheel is detected, and the vibration generated in the sprung member when the rear wheel passes the same road surface as the front wheel. Some perform predictive control to predict the above. In such predictive control, the rear wheel is displaced by the unevenness of the road surface, and control is performed to cancel the transmission force transmitted from the rear wheel to the sprung member through the suspension spring. Vibration is suppressed.

In such a suspension control device, a hydraulic cylinder is used as an actuator, and in order to cope with a change in response characteristics due to a change in the oil temperature of the hydraulic cylinder, the oil temperature is detected and the predictive control force by the predictive control is corrected.

However, it is difficult to accurately understand the response characteristics of the actuator simply by detecting changes in the oil temperature, and the spring constant also changes when adjusting the vehicle height in vehicles that employ an air spring as the suspension spring. Insufficient response to changes in actuator and suspension spring parameters.

Therefore, in the conventional suspension control device, there is a case where the vibration transmitted from the unsprung member to the sprung member cannot be canceled well, and an improvement in the vibration suppression effect is required.

Therefore, an object of the present invention is to provide a suspension control device that can improve the vibration suppression effect of the sprung member even if the parameters of the actuator and the suspension spring change.

Therefore, the suspension control device of the present invention obtains a control command for canceling the transmission force transmitted from the unsprung member to the sprung member based on the vibration information of the unsprung member and the vibration information of the sprung member. As described above, according to the suspension control device, it is possible to correct the control command so as to correspond to the change in parameters such as the response of the actuator and the spring constant of the suspension spring.

FIG. 1 is a model diagram of a vehicle to which a suspension control device according to an embodiment is applied. FIG. 2 is a control block diagram of a controller in the suspension control apparatus according to the embodiment. FIG. 3A shows the spring force of the suspension spring, the force of the actuator, and the spring top when the actuator force is small relative to the spring force of the suspension spring and the phase of the actuator force is delayed from the phase that can cancel the transmission force. It is the graph which showed the relationship of the acceleration of a member. FIG. 3B shows the acceleration of the sprung member, the speed of the unsprung member, and the case where the actuator force is smaller than the spring force of the suspension spring and the phase of the actuator force is delayed from the phase that can cancel the transmission force. It is the graph which showed the multiplication value of the acceleration of the sprung member, and the speed of the unsprung member. FIG. 3 (c) shows the acceleration of the sprung member, the displacement of the unsprung member, and the displacement of the unsprung member when the actuator force is smaller than the suspension spring and the phase of the actuator force is delayed from the phase that can cancel the transmission force. It is the graph which showed the multiplication value of the acceleration of the sprung member, and the displacement of the unsprung member. FIG. 4A shows the spring force of the suspension spring, the force of the actuator, and the spring top when the actuator force is smaller than the spring force of the suspension spring and the phase of the actuator force advances from the phase that can cancel the transmission force. It is the graph which showed the relationship of the acceleration of a member. FIG. 4B shows the acceleration of the sprung member, the speed of the unsprung member, and the spring when the actuator force is smaller than the spring force of the suspension spring and the phase of the actuator force advances from the phase that can cancel the transmission force. It is the graph which showed the multiplication value of the acceleration of the upper member, and the speed of the unsprung member. FIG. 4C shows the acceleration of the sprung member, the displacement of the unsprung member, and the spring when the actuator force is smaller than the spring force of the suspension spring and the phase of the actuator force advances from the phase that can cancel the transmission force. It is the graph which showed the multiplication value of the acceleration of the upper member, and the displacement of the unsprung member. FIG. 5 shows the relationship between the spring force of the suspension spring and the force of the actuator when the spring force of the suspension spring is equal to the force of the actuator and the phase of the actuator force coincides with the phase that can cancel the transmission force. It is a graph. FIG. 6 is a control block diagram of the controller of the suspension control device according to the first modification of the embodiment. FIG. 7 is a control block diagram of a controller of a suspension control device according to a second modification of the embodiment. FIG. 8 is a control block diagram of a controller of a suspension control device according to a third modification of the embodiment.

Hereinafter, the present invention will be described based on the embodiments shown in the drawings. As shown in FIG. 1, a suspension control device C according to an embodiment includes an actuator A that is interposed together with a suspension spring S between a wheel W that is an unsprung member of a vehicle V and a vehicle body B that is a sprung member. Is controlled to suppress the vibration of the vehicle body B.

Hereinafter, each part will be described in detail. As shown in FIG. 1, a vehicle V as a system includes a wheel W having a tire Ti on its outer periphery, a vehicle body B, and a suspension spring S that is interposed between the wheel W and the vehicle body B and elastically supports the vehicle body B. It consists of and.

Vehicle V, the tire Ti and spring of spring constant K _t, the wheel W and the mass of the mass M _2, the suspension spring S and a spring of spring constant K _S, two mass two to the vehicle body B and the mass of the mass M ₁ This is a spring mass system having a degree of freedom, and can be expressed by a model of the spring mass system shown in FIG. Further, the road surface displacement is X ₀ , the vertical displacement of the vehicle body B is X ₁ , the vertical displacement of the wheel W is X _2, and the upward direction in FIG. 1 is positive.

The suspension control device C includes a first sensor 1 for detecting vibration information of the wheel W as an unsprung member, a second sensor 2 for detecting vibration information of the vehicle body B as a sprung member, and an actuator A. And a controller 3 for obtaining a final control command F to be provided.

In this example, the suspension control device C detects the displacement X _{2 in} the vertical direction of the wheel W and the speed dX ₂ / dt as vibration information of the wheel W that is an unsprung member. It is said that. The first sensor 1 detects the acceleration d ² X ₂ / dt ² in the vertical direction of the wheel W and inputs it to the controller 3. In addition, in this example, the suspension control device C detects the acceleration d ² X ₁ / dt ² in the vertical direction of the vehicle body B as vibration information of the vehicle body B that is a sprung member. It is considered as a sensor. The second sensor 2 detects the acceleration d ² X ₁ / dt ² in the vertical direction of the vehicle body B and inputs it to the controller 3.

As shown in FIG. 2, the controller 3 integrates the acceleration d ² X ₂ / dt ² input from the first sensor 1 to obtain a speed dX ₂ / dt in the vertical direction of the wheel W; Based on the displacement calculation unit 32 that integrates the speed dX ₂ / dt obtained by the speed calculation unit 31 to obtain the vertical displacement X ₂ of the wheel W and the vertical acceleration d ² X ₁ / dt ² of the vehicle body B. A speed correction unit 33 that corrects the speed dX ₂ / dt, a displacement correction unit 34 that corrects the displacement X ₂ based on the vertical acceleration d ² X ₁ / dt ² of the vehicle body B, and a corrected speed dX _2. A speed-corresponding control command calculating unit 35 for determining a speed-corresponding control command f _V based on / dt, a displacement-corresponding control command calculating unit 36 for determining a displacement-corresponding control command f _X based on the corrected displacement X ₂ , and the vehicle body B the vertical direction of the vehicle body B vertical to integrating the acceleration d ^² X ₁ / dt ² of An integration unit 37 for determining the degree dX ₁ / dt, the skyhook control command calculating section 38 for determining the skyhook control command f _SKY by multiplying a skyhook gain in the vertical direction of the velocity dX ₁ / dt of the vehicle body B, rate response control A final control command calculation unit 39 that generates a final control command F by adding the command f _V , the displacement corresponding control command f _X, and the skyhook control command f _SKY and inputs it to the actuator A is provided. The controller 3 obtains a speed-corresponding control command f _V and a displacement-corresponding control command f _{X in} order to cancel the transmission force transmitted from the wheel W to the vehicle body B, and suppresses this vibration when the vehicle body B vibrates. In order to perform the skyhook control, the skyhook control command f _SKY is obtained. That is, the control command f _{W # ref} obtained by adding the speed corresponding control command f _V and the displacement corresponding control command f _X is a control command for causing the actuator A to exert a force to cancel the transmission force. The skyhook control command f _SKY is a control command for causing the actuator A to exert a control force based on the skyhook control.

In this way, the controller 3 determines the vertical displacement X ₂ and speed dX ₂ / dt of the wheel W as vibration information of the unsprung member and the vertical acceleration d ² of the vehicle body B as vibration information of the sprung member. A final control command F to be given to the actuator A is generated based on X ₁ / dt ² and given to the actuator A. The final control command F is a command for instructing the actuator A the direction of expansion and contraction and the magnitude of the thrust.

The actuator A is arranged in parallel with the suspension spring S and is interposed between the vehicle body B and the wheel W. For example, the actuator A is a telescopic cylinder or an electric linear actuator using hydraulic pressure or pneumatic pressure. It has a power source such as a pump driven by. Then, the actuator A expands and contracts in response to the input of the final control command F by exerting a thrust in the direction and size as in the control command, and vibrates the vehicle body B and the wheels W in the vertical direction.

First, the reason why the control command f _{W # ref} is obtained by adding the speed corresponding control command f _V and the displacement corresponding control command f _{X in} the control for canceling the transmission force transmitted from the wheel W to the vehicle body B will be described.

As shown in FIG. 1, the road surface displacement is X ₀ , the vertical displacement of the wheel W is X ₂ , the vertical displacement of the vehicle body B is X _1, and the thrust that is the output of the actuator A is f _W , When the upward direction is considered as positive, the equation of motion of the vehicle body B can be expressed as the following equation (1) from the balance in the vertical direction of the vehicle body B that is a sprung member.

Also, the equation of motion of the wheel W can be shown as the following equation (2) from the balance in the vertical direction of the wheel W which is an unsprung member.

Further, if the actuator A is a first-order lag system and the time constant in the response delay from the control command f _{W # ref of} the actuator A to the thrust f _{W as an} output is T, the differential equation related to the response of the actuator A is given by It can be shown as (3).

When the equation (1) is decomposed, the following equation (4) is obtained.

Here, the wheel W vibrates due to the fluctuation (disturbance) of the road surface displacement X ₀ , but if the transmission force transmitted to the vehicle body B is canceled by the vibration of the wheel W, the transmission of the vibration of the wheel W to the vehicle body B is canceled. Can be insulated. Both words, the displacement X ₁ of the vehicle body B which is moved by the fluctuation of the road surface displacement X ₀ (the disturbance), the actuator A is of the vehicle body B to be moved by exerting a force f _W displacement X ₁ is completely reversed if the magnitude Is offset. Transmitting force acting on the vehicle body B by a displacement X ₂ of the wheel W, since the suspension spring S and the suspension spring S is stretching the displacement X ₂ of the wheel W is a spring force that exerts a force f _W of the actuator A the wheel It only needs to be equal to a value obtained by inverting the sign of the spring force K _s X ₂ exerted by the suspension spring S due to the displacement of W.

It should be noted that the expression (1) indicates that the acceleration is not generated in the vehicle body B if the values of K _S (X ₂ −X ₁ ) and the force f _W have different signs and the numerical values are equal. I think. In other words, it seems that the force f _W = −K _S (X ₂ −X ₁ ) may be used. However, (X ₂ −X ₁ ) is a relative displacement between the vehicle body B and the wheel W, and the change in the relative displacement is caused by a change in the posture of the vehicle body B due to turning, braking, or acceleration, and a change in the load on the vehicle body B. Whether it is caused by road surface displacement cannot be determined. For example, when the front of the vehicle body B sinks due to pitching and the suspension spring S is contracted, if the actuator A exerts a force as f _W = −K _S (X ₂ −X ₁ ), the vehicle body B is submerged. Demonstrate power in the direction. When the vehicle body B is lifted, the lift is promoted. As described above, in the control that feeds back the relative displacement between the vehicle body B and the wheel W, there is a mode in which the posture of the vehicle body B is not stable and the vibration of the vehicle body B oscillates. Therefore, the force f _W of the actuator A can be obtained so that the force F _{W of the} actuator A can be canceled by using the spring force K _S · X ₂ exerted by the suspension spring S due to the displacement X _{2 of the} wheel W as a transmission force. That's fine. Considering the above, the following equation (5) may be established.

On the other hand, when the Laplace operator is s, and the relationship between the control command in equation (3) and the thrust of actuator A is expressed by a transfer function, the transfer function is expressed by the following equation (6).

When this equation (6) is substituted into equation (5), equation (7) is obtained. In Expression (7), k is a gain. This equation (7) is an equation that takes into account the response delay from the input of the control command f _{W # ref} of the actuator A to the output of the force f _W.

Since the variable multiplied by the Laplace operator s is differentiated, the following equation (8) is obtained by expanding and organizing equation (7).

As can be understood from the equation (8), the control command f _{W # ref} that can compensate for the response delay of the actuator A is obtained using the speed at which the phase advances with respect to the displacement X ₂ . In this equation (8), it is sufficient to measure the time constant T and the gain k in advance in the actual machine for the response delay from the input of the control command f _{W # ref} of the actuator A to the output of the force f _W. The displacement X ₂ and the speed dX ₂ / dt are obtained from the acceleration d ² X ₂ / dt ² detected by the first sensor 1. Therefore, the control command calculation unit 23 can obtain the control command f _{W # ref} by calculating equation (8). When the control command f _{W # ref} is obtained and input to the actuator A in this way, the actuator A can exert the force f _W and cancel the transmission force from the wheel W, so that the vibration of the vehicle body B due to disturbance input from the road surface can be avoided. By canceling out, the vibration of the vehicle body B can be suppressed.

Therefore, the controller 3 integrates the acceleration d ² X ₂ / dt ² to calculate the speed dX ₂ / dt in the vertical direction of the wheel W, and the acceleration d in order to perform control to cancel the transmission force. ² X ₂ / dt ² is second-order integrated to obtain the displacement calculation unit 32 for obtaining the vertical displacement X ₂ of the wheel W, and the speed correspondence control for obtaining the speed correspondence control command f _V based on the corrected speed dX ₂ / dt. A command calculation unit 35 and a displacement response control command calculation unit 36 for obtaining a displacement response control command f _X based on the corrected displacement X ₂ are provided.

As shown in FIG. 2, the speed calculation unit 31 integrates the acceleration d ² X ₂ / dt ² to obtain the vertical speed dX ₂ / dt of the wheel W, and the obtained speed dX ₂ / dt. The filter unit 31b removes noise and drift components by extracting only the components in the unsprung resonance frequency band. Although not shown in detail, the filter unit 31b includes a two-stage high-pass filter and a two-stage low-pass filter, and the processed speed dX ₂ / dt is shifted to the actual gain and phase in the unsprung resonance frequency band. It is processed so as not to occur.

The displacement calculation unit 32 integrates the speed dX ₂ / dt obtained by the speed calculation unit 31 to obtain the vertical displacement X ₂ of the wheel W, and the unsprung resonance frequency band from the obtained displacement X ₂ . A filter unit 32b that extracts only components and removes noise and drift components is provided. Although not shown in detail, the filter unit 32b is composed of a two-stage high-pass filter and a two-stage low-pass filter, and the processed displacement X ₂ causes a shift in actual gain and phase in the unsprung resonance frequency band. Process so that there is no. The displacement calculation unit 32 does not receive the input of the speed dX ₂ / dt obtained by the speed calculation unit 31, but receives the input of the acceleration d ² X ₂ / dt ² from the first sensor 1 and the integration unit 32a. The acceleration d ² X ₂ / dt ² may be second-order integrated to determine the vertical displacement X ₂ of the wheel W.

The unsprung resonance frequency varies depending on the vehicle, but is generally in the range of 10 Hz to 17 Hz. The cutoff frequency of the high-pass filter in the

filter units

31b and 32b is set to 0.5 Hz, and the cutoff frequency of the low-pass filter is set to 150 Hz. It is. With this setting, the speed dX ₂ / dt and the displacement X ₂ after processing have little difference in gain and phase with respect to the actual speed and displacement, and the speed and displacement of the wheel W can be detected with high accuracy. Moreover, both the

filter parts

31b and 32b may be comprised with a band pass filter instead of being comprised with a low-pass filter and a high-pass filter.

The speed corresponding control command calculation unit 35 sets the spring constant of the suspension spring S as K _S , the time constant in the response of the actuator A as T, the gain as k, and the speed dX ₂ / dt as the speed gain − (K _S · T) / is multiplied by k determine the speed corresponding control command f _V. This speed-corresponding control command f _V corresponds to the first term on the right side of the equation (8), and is a force component that depends on the speed dX ₂ / dt of the force that cancels the transmission force.

Displacement corresponding control command calculating section 36, the spring constant K _S of the suspension spring S, the gain as k, it is multiplied by -K _S / k as a displacement gain to the displacement X ₂ Request displacement corresponding control instruction f _X. The displacement corresponding control instruction f _X is equivalent to the second term of the right side of the equation (8), a force component that depends on the displacement X ₂ of the force counteracting the transmission force.

Accordingly, the speed corresponding control command calculation unit 35 multiplies the speed dX ₂ / dt obtained by the speed calculation unit 31 by the speed gain to obtain the speed corresponding control command f _V , and the displacement corresponding control command calculation unit 36 determines the displacement calculation unit 32. obtains the displacement corresponding control command f _X by multiplying the displacement gain to the displacement X ₂ obtained by, if added to the speed corresponding control command f _V the displacement corresponding control command f _X, to exert a force for canceling the transmission force to the actuator a It is a trap to get

However, when the responsiveness changes due to a temperature change of the working fluid in the actuator A or the internal pressure is changed due to the suspension spring S being an air spring or the internal pressure changes due to a temperature change, the time constant of the actuator A Parameters for obtaining a force that cancels the transmission force, such as T and the spring constant K _{S of the} suspension spring, change. When these parameters change, an error occurs between the force for canceling the transmission force obtained by the arithmetic processing and the actual transmission force, and the transmission force cannot be canceled by the force exerted by the actuator A.

Therefore, in the controller 3 of this example, even if the time constant T of the actuator A and the spring constant K _S of the suspension spring S change, the speed dX ₂ / dt is corrected so as to automatically cope with the change. A speed correction unit 33 and a displacement correction unit 34 that corrects the displacement X ₂ are provided. Then, the corrected speed dX ₂ / dt as the corrected unsprung vibration information is input to the speed corresponding control command calculating unit 35, and the corrected corresponding control command calculating unit 36 is used as the corrected unsprung vibration information. The corrected displacement X ₂ is input to obtain the speed corresponding control command f _V and the displacement corresponding control command f _X. Therefore, even if the time constant T of the actuator A and the spring constant K _{S of the} suspension spring change, the actuator A exerts a force commensurate with the actual transmission force, and the vibration input from the wheel W to the vehicle body B is insulated. it can.

Hereinafter, the speed correction unit 33 and the displacement correction unit 34 will be described in detail. The speed correction unit 33 processes the vertical acceleration d ² X ₁ / dt ² of the vehicle body B by filtering, and the speed dX ₂ / dt obtained by the speed calculation unit 31 and the phase compensation unit 33 a. Multiplication unit 33b that multiplies the acceleration d ² X ₁ / dt ² , a gain multiplication unit 33c that multiplies the value obtained by the multiplication unit 33b by the correction gain k _V , and an integration that sequentially integrates the values obtained by the gain multiplication unit 33c. A value calculating unit 33d, a correction value calculating unit 33e that obtains a speed correction value C _V by multiplying the integral value I _V obtained by the integral value calculating unit 33d by the speed dX ₂ / dt obtained by the speed calculating unit 31, and a speed adding for obtaining the velocity dX ₂ / dt corrected by correcting the speed dX ₂ / dt determined by the speed calculator 31 adds the speed correction value C _V to the speed dX ₂ / dt determined by the arithmetic unit 31 Part 33f and .

The acceleration d ² X ₁ / dt ^{2 in} the vertical direction of the vehicle body B theoretically becomes zero if the actuator A exerts a force that cancels the transmission force cleanly. The fact that the acceleration d ² X ₁ / dt ^{2 of the} vehicle body B is not zero means that the force exerted by the actuator A cannot completely cancel the transmission force. Also, the ride comfort in the vehicle is ideal when the acceleration d ² X ₁ / dt ² of the vehicle body B is zero.

As described above, the calculation result of the multiplication unit 33b is multiplied and integrated by the correction gain k _V , and the speed dX ₂ / dt is multiplied by the integral value I _V to obtain the speed correction value C _V. The speed correction value C _V is added to the speed dX ₂ / dt obtained by the speed calculation unit 31, and the added value becomes the corrected speed dX ₂ / dt. As described above, when the acceleration d ² X ₁ / dt ^{2 of} the vehicle body B is not 0, the calculation result of the multiplication unit 33b outputs a non-zero value, so that the integral value I _V is always updated. The Therefore, unless the acceleration d ² X ₁ / dt ^{2 of} the vehicle body B becomes 0, the value of the integral value I _V is continuously updated every control cycle. The integral value I _V can be regarded as a gain for obtaining the speed correction value C _V, and by updating the gain value, the acceleration d ² X ₁ / dt ² of the vehicle body B, which is the sprung member, is updated by the speed correction unit 33. The velocity dX ₂ / dt is corrected in the direction of convergence toward 0. When the acceleration d ² X ₁ / dt ^{2 of} the vehicle body B converges to 0, the output of the multiplication unit 33b also becomes 0, so that the value of the integral value I _V is not updated any more, and the speed correction unit 33 The speed correction value C _{V is obtained} with a constant gain.

That is, when the response of the actuator A or the spring constant of the suspension spring S changes, the speed correction unit 33 updates the integrated value I _V until the acceleration d ² X ₁ / dt ² of the vehicle body B converges to zero. When it converges to 0, the value of the integral value I _V is held to correct the speed dX ₂ / dt.

The phase compensation unit 33a filters the acceleration d ² X ₁ / dt ² in the vertical direction of the vehicle body B and extracts only the component of the unsprung resonance frequency band from the acceleration d ² X ₁ / dt ^2. And a high-pass filter. When the acceleration d ² X ₁ / dt ² is processed by the phase compensator 33 a, only the component of the unsprung resonance frequency band caused by the vibration transmitted from the wheel W side can be extracted from the acceleration d ² X ₁ / dt ² . The low frequency component that causes a large phase shift between the removal and the speed dX ₂ / dt of the wheel W is removed. When the phase shift is eliminated in this way, the increase / decrease in the integral value I _V shifts in a direction that effectively cancels the transmission force, so that the value of the integral value I _V converges quickly, and the response of the actuator A When the spring constant of the suspension spring S changes, the transmission force can be canceled with good responsiveness. The phase compensation unit 33a may be configured with a bandpass filter.

The displacement correction unit 34 filters the vertical acceleration d ² X ₁ / dt ² of the vehicle body B, the displacement X ₂ obtained by the displacement calculation unit 32, and the acceleration processed by the phase compensation unit 33a. a multiplication unit 34b for multiplying d ² X ₁ / dt ² , a gain multiplication unit 34c for multiplying a value obtained by the multiplication unit 34b by a correction gain k _X , and an integral value calculation for sequentially integrating the values obtained by the gain multiplication unit 34c 34d, a correction value calculation unit 34e for obtaining a displacement correction value C _X by multiplying the integral value I _X obtained by the integral value calculation unit 34d by the displacement X ₂ obtained by the displacement calculation unit 32, and the displacement calculation unit 32 a displacement X ₂ obtained by the displacement calculation unit 32 adds the displacement correction value C _X to the displacement X ₂ obtained by correcting and an adding unit 34f for obtaining the displacement X ₂ of the corrected.

Similar to the speed correction unit 33, the displacement correction unit 34 multiplies the calculation result of the multiplication unit 34 b by the correction gain k _X and integrates, and multiplies the integration value I _X by the displacement X ₂ to obtain the displacement correction value C _X. The displacement correction value C _X is added to the displacement X ₂ obtained by the displacement calculator 32, and the added value becomes the corrected displacement X ₂ . Therefore, when the acceleration d ² X ₁ / dt ^{2 of} the vehicle body B is not 0, the calculation result of the multiplication unit 34b outputs a non-zero value, so that the value of the integral value I _X is always updated. Therefore, unless the acceleration d ² X ₁ / dt ^{2 of} the vehicle body B becomes 0, the value of the integral value I _X is continuously updated every control cycle. The integral value I _X can be regarded as a gain for obtaining the displacement correction value C _X, and by updating the gain value, the acceleration d ² X ₁ / dt ² of the vehicle body B, which is a sprung member, is updated by the displacement correction unit 34. The displacement X ₂ is corrected in the direction of convergence toward 0. When the acceleration d ² X ₁ / dt ^{2 of} the vehicle body B converges to 0, the output of the multiplication unit 34b also becomes 0, so that the value of the integral value I _X is not updated any more, and the displacement correction unit 34 The displacement correction value C _{X is obtained} with a constant gain.

That is, when the response of the actuator A or the spring constant of the suspension spring S changes, the displacement correction unit 34 updates the integrated value I _X until the acceleration d ² X ₁ / dt ² of the vehicle body B converges to zero. When the value converges to 0, the integrated value I _X is held and the displacement X ₂ is corrected.

Similarly to the phase compensation unit 33a, the phase compensation unit 34a filters the acceleration d ² X ₁ / dt ² in the vertical direction of the vehicle body B to obtain the unsprung resonance frequency band from the acceleration d ² X ₁ / dt ² . In order to extract only the component, it is composed of a low-pass filter and a high-pass filter. Therefore, when the phase compensation unit 34a is provided in the displacement correction unit 34, only the component of the unsprung resonance frequency band caused by the vibration transmitted from the wheel W side can be extracted from the acceleration d ² X ₁ / dt ² , and noise can be removed. And a low frequency component that causes a large phase shift between the wheel W and the speed dX ₂ / dt of the wheel W can be removed. When the phase shift is eliminated in this way, the increase / decrease in the integral value I _X shifts in a direction that effectively cancels the transmission force, so that the value of the integral value I _X converges quickly, and the response of the actuator A When the spring constant of the suspension spring S changes, the transmission force can be canceled with good responsiveness. The phase compensation unit 34a may be configured with a band pass filter.

Further, in this example, the

phase compensation units

33a and 34a that perform the filter processing of the acceleration d ² X ₁ / dt ² are provided for optimization by the speed correction unit 33 and the displacement correction unit 34, respectively. The unit 33 and the displacement correction unit 34 may share one phase compensation unit.

Further, in the above description, the acceleration d ² X ₁ / dt ² of the vehicle body B is used as the vibration information of the sprung member in the correction of the speed dX ₂ / dt and the displacement X ₂ of the wheel W. Since it is sufficient to know how much vibration is present, the vibration information of the sprung member necessary for correction may be the speed dX ₁ / dt. In that case, the speed dX ₁ / dt may be obtained by integrating the acceleration d ² X ₁ / dt ² detected by the second sensor 2 into the speed correction unit 33 and the displacement correction unit 34.

In this way, the speed correction unit 33 and the displacement correction unit 34 update the integral values I _V and I _X that are gains so that the acceleration d ² X ₁ / dt ² of the vehicle body B converges to 0, respectively. Corresponding speed dX ₂ / dt and displacement X ₂ are corrected. Therefore, the speed corresponding control command f _V and the displacement corresponding control command f _X obtained by the controller 3 are both optimized in response to the response of the actuator A and the change in the spring constant of the suspension spring S. The vibration of the vehicle body B can be effectively suppressed even if parameters such as the response of the motor and the spring constant of the suspension spring S change.

Here, when the speed dX ₂ / dt and the displacement X ₂ are corrected using the calculation results of the

multipliers

33b and 34b, the speed corresponding control command f _V and the displacement corresponding control command f _X are efficiently used in accordance with the variation of the parameters. The points that can be optimized well will be described in detail. In the graph of FIG. 3A, when the force exerted by the actuator A is small with respect to the spring force exerted by the suspension spring S due to expansion and contraction, the phase of the force of the actuator A lags behind the phase that can cancel the transmission force. The force exerted by the actuator A (solid line in the figure), the spring force of the suspension spring S (broken line in the figure), and the acceleration d ² X ₁ / dt ² (dashed line in the figure) of the sprung member are oscillating. Indicates the state. Since the spring force of the suspension spring S is a transmission force transmitted from the wheel W to the vehicle body B, in the graph of FIG. 3A, the phase of the force exerted by the actuator A with respect to the phase at which the transmission force can be canceled out. Running late. In the situation of FIG. 3A, as shown in the graph of FIG. 3B, the acceleration d ² X ₁ / dt ^{2 of} the vehicle body B indicated by the alternate long and short dash line and the speed dX ₂ / wheel of the wheel W indicated by the broken line. The multiplication value indicated by the solid line in the figure obtained by multiplying by dt takes a value of approximately 0 or more although it is oscillatory. Further, in the situation of FIG. 3A, as shown in the graph of FIG. 3C, the acceleration d ² X ₁ / dt ^{2 of} the vehicle body B indicated by the alternate long and short dash line and the displacement X of the wheel W indicated by the broken line _The multiplication value indicated by the solid line in the figure obtained by multiplying by ₂ is a vibrational value, but generally takes a value of 0 or more. As can be understood from the graph of FIG. 3A, the force exerted by the actuator A when the phase of the force exerted by the actuator A is delayed with respect to the phase capable of canceling the transmission force (spring force of the suspension spring S). If the phase is advanced, the transmission force can be canceled. The transmission force is expansion / contraction of the suspension spring S, that is, a force generated by the displacement of the wheel W. If the gain of the speed dX ₂ / dt at which the phase is advanced is increased, the phase of the force exerted by the actuator A is advanced. . Therefore, the integral value I _V that can be regarded as a gain for the speed dX ₂ / dt of the wheel W is increased to correct the speed dX ₂ / dt. Further, since the force exerted by the actuator A is smaller than the transmission force, the transmission force can be canceled by increasing this force. As described above, transmission power, expansion and contraction of the suspension spring S, that is, since the force the wheel W is generated by displacement, by raising the gain with respect to the displacement X _2, can be increased force actuator A exerts. Therefore, the integral value I _X that can be regarded as a gain with respect to the displacement X ₂ of the wheel W may be increased to correct the displacement X ₂ . Here, when looking at FIG. 3 (b) and FIG. 3 (c), both the multiplication values are approximately 0 or more, so that the integral values I _V and I _X are changed. Thus, by using the multiplication results of the

multipliers

33b and 34b, when the phase of the force exerted by the actuator A is delayed with respect to the phase that can cancel the transmission force, the transmission force can be canceled by the force of the actuator A. In addition, the velocity dX ₂ / dt and the displacement X ₂ can be corrected.

In contrast, a case will be described in which the force exerted by the actuator A with respect to the spring force of the suspension spring S is small and the phase advances beyond the phase that can cancel the transmission force. The graph of FIG. 4A shows the force exerted by the actuator A when the force exerted by the actuator A is small with respect to the spring force of the suspension spring S and the phase advances from the phase that can cancel the transmission force (in the figure). The solid line), the spring force of the suspension spring S (broken line in the figure), and the acceleration d ² X ₁ / dt ^{2 of the} sprung member (dashed line in the figure) are in a state of oscillating. In the situation of FIG. 4A, as shown in the graph of FIG. 4B, the acceleration d ² X ₁ / dt ^{2 of} the vehicle body B indicated by the alternate long and short dash line and the speed dX ₂ / wheel of the wheel W indicated by the broken line. The multiplication value indicated by the solid line in the figure obtained by multiplying by dt takes a value of approximately 0 or less although it is oscillatory. Also, in the situation of FIG. 4A, as shown in the graph of FIG. 4C, the acceleration d ² X ₁ / dt ^{2 of} the vehicle body B indicated by the alternate long and short dash line and the displacement X of the wheel W indicated by the broken line _The multiplication value indicated by the solid line in the figure obtained by multiplying by ₂ is a vibrational value, but generally takes a value of 0 or more. As can be understood from the graph of FIG. 4A, the force exerted by the actuator A when the phase of the force exerted by the actuator A is advanced with respect to the phase capable of canceling the transmission force (spring force of the suspension spring S). The transmission force can be canceled by delaying the phase. The transmission force is expansion / contraction of the suspension spring S, that is, a force generated by the displacement of the wheel W. If the gain of the speed dX ₂ / dt at which the phase is advanced is lowered, the phase of the force exerted by the actuator A is delayed. . Therefore, correction may be made so that the speed dX ₂ / dt is reduced by setting the integral value I _V regarded as a gain with respect to the speed dX2 / dt of the wheel W as a negative value. Further, since the force exerted by the actuator A is smaller than the transmission force, the transmission force can be canceled out by increasing the force. As described above, transmission power, expansion and contraction of the suspension spring S, that is, since the force the wheel W is generated by displacement, by raising the gain with respect to the displacement X _2, can be increased force actuator A exerts. Therefore, the integral value I _X that can be regarded as a gain with respect to the displacement X ₂ of the wheel W may be increased to correct the displacement X ₂ . Here, looking at FIG. 4B and FIG. 4C, the multiplication value of the speed dX ₂ / dt and the acceleration d ² X ₁ / dt ² is approximately 0 or less, and the integral value I _V decreases. Since the multiplication value of the displacement X ₂ and the acceleration d ² X ₁ / dt ² is substantially equal to or greater than 0, the integral value I _X is increased. As described above, by using the multiplication results of the

multipliers

33b and 34b, the transmission force can be canceled by the force of the actuator A even when the phase of the force exerted by the actuator A advances with respect to the phase where the transmission force can be canceled. The speed dX ₂ / dt and the displacement X ₂ can be corrected.

As shown in FIG. 5, when the phase of the force (solid line in the figure) exerted by the actuator A is opposite to the spring force of the suspension spring S (broken line in the figure), that is, the actuator A Is equal to the phase at which the transmission force can be canceled and the magnitudes of both are equal, the transmission force is canceled and the acceleration d ² X ₁ / dt ² of the sprung member becomes zero. In such a situation, the product of the speed dX ₂ / dt and the acceleration d ² X ₁ / dt ² and the product of the displacement X ₂ and the acceleration d ² X ₁ / dt ² are zero. Therefore, as long as the magnitude is the same as the phase of the force (solid line in the figure) opposite to the force exerted by the actuator A (solid line in the figure) with respect to the spring force of the suspension spring S (broken line in the figure), the integrated value I _V can be regarded as a gain. , I _X no longer fluctuates. In this way, if the multiplication results of the

multipliers

33b and 34b are used, if the phase and magnitude of the force exerted by the actuator A coincide with the phase and magnitude that can cancel the transmission force, the speed dX ₂ / dt Both the speed correction value C _V for correcting the displacement and the displacement correction value C _X for correcting the displacement X ₂ both take a constant value, and the phase and magnitude of the force of the actuator A become the phase and magnitude that can cancel the transmission force. You can maintain a consistent state.

As shown in FIG. 2, in addition to the above-described configuration, the controller 3 increases the vertical acceleration d ² X ₁ / dt ² of the vehicle body B in order to perform skyhook control that suppresses vibration of the vehicle body B. An integrating unit 37 for integrating and a skyhook control command calculating unit 38 for _{obtaining a} skyhook control command f _SKY are provided.

The integrating unit 37 integrates the vertical acceleration d ² X ₁ / dt ² of the vehicle body B to obtain the vertical velocity dX ₁ / dt of the vehicle body B. The integration unit 37 performs high-pass filter processing to remove low-frequency drift components. The skyhook control command calculation unit 38 obtains the skyhook control command f _SKY by multiplying the vertical speed dX ₁ / dt of the vehicle body B by the skyhook gain. The skyhook control command f _SKY is a control command for causing the actuator A to exert a control force based on the skyhook control.

The final control command calculation unit 39 adds the speed corresponding control command f _V , the displacement corresponding control command f _X and the skyhook control command f _SKY to generate a final control command F and outputs it to the actuator A. As described above, when the final control command F is input, the actuator A expands and contracts by exerting thrust in the direction and size as in the control command, and vibrates the vehicle body B and the wheels W in the vertical direction.

Thus, the suspension control device C controls to cancel the transmission force transmitted from the wheel W to the vehicle body B based on the vibration information of the wheel W that is an unsprung member in the vehicle and the vibration information of the vehicle body B that is a sprung member. The command f _{W # ref} is obtained. According to the suspension control device C configured as described above, the control command f _{W # ref} can be corrected to be appropriate in response to changes in parameters such as the response of the actuator A and the spring constant of the suspension spring S, and Riding comfort in the vehicle can be improved by improving the vibration suppressing effect of the member. When the vehicle body B vibrates due to excess or deficiency of the force generated by the actuator A, the acceleration d ² X ₁ / dt ² of the sprung member is immediately affected. Therefore, the acceleration of the sprung member is used as vibration information of the sprung member. When d ² X ₁ / dt ² is used, the vibration information of the unsprung member is corrected with good responsiveness to parameter changes, and the riding comfort in the vehicle can be further improved. Since the vibration of the vehicle body B can be monitored even at the speed dX ₁ / dt, the vibration information of the sprung member may be the speed dX ₁ / dt as described above. When the vibration information of the sprung member is the speed dX ₁ / dt, the phase is shifted from the acceleration d ² X ₁ / dt ² and the correction direction is changed.

Further, in the suspension control apparatus C of this example, the controller 3 corrects the vibration information of the unsprung member based on the vibration information of the sprung member to obtain corrected unsprung vibration information, and the corrected spring. Since the control command is obtained based on the lower vibration information, it is not necessary to directly detect fluctuations in parameters such as the response of the actuator A and the spring constant of the suspension spring S. For example, in regard to the actuator A, in addition to the change in the temperature of the working fluid, the responsiveness changes due to the friction of the sliding portion and the change in the pump efficiency due to deterioration over time, and the suspension spring S is also an air spring. In such a case, in addition to the change in the internal pressure, the spring constant changes due to the temperature change of the gas. Even if the suspension spring is a metal spring, the spring constant may be changed by replacement. As described above, there are a plurality of parameter fluctuation factors of the actuator A and the suspension spring S, and it is difficult to detect the parameter fluctuation by sensing, and even if possible, a large number of sensors are required. On the other hand, in the suspension control device C of this example, the variation of the parameter is not directly detected, but the vibration of the vehicle body B as the sprung member as a result of the parameter variation is detected to detect the unsprung member. Since the vibration information is corrected, it is sufficient to install only the second sensor 2 to cope with the parameter fluctuation. As described above, in the suspension control device C of this example, the installation of only the second sensor 2 improves the riding comfort in the vehicle corresponding to the fluctuations regardless of the parameter fluctuation factors of the actuator A and the suspension spring S. In addition, since the number of sensors installed is small, the manufacturing cost can be reduced.

In this example, the controller 3 corrects the vibration information of the unsprung member based on the vibration information of the sprung member. However, the speed corresponding control command calculating unit 35 and the displacement are corrected based on the vibration information of the sprung member. The speed gain − (K _S · T) / k and displacement gain −K _S / k multiplied by the corresponding control command calculation unit 36 may be corrected. Here, the multiplication results of the

multipliers

33b and 34b serve as indexes for determining the direction of increase / decrease of the speed X ₁ / dt and acceleration d ² X ₁ / dt ² of the sprung member, and the integral value I _V and the integral value I _X becomes a constant value when it becomes possible to cancel the transmission force transmitted from the wheel W to the vehicle body B by the force exerted by the actuator A by the integral value of the multiplication results of the

multiplication units

33b and 34b. Therefore, when correcting the speed gain − (K _S · T) / k and the displacement gain −K _S / k in this way, for example, as in the present example, the integral value I _V and the integral value I _X are obtained, and the integral Using the value I _V and the integral value I _X , the velocity gain − (K _S · T) / k and the displacement gain −K _S / k corresponding to each may be corrected.

Further, in the suspension control device C of this example, the controller 3 is configured to correct the vibration information of the unsprung member based on a multiplication value of the vibration information of the unsprung member and the vibration information of the sprung member. ing. According to the suspension control apparatus C configured in this way, since the multiplication value is used, if the phase and magnitude of the force of the actuator A do not match the phase and magnitude that can cancel the transmission force, these are matched. Thus, the vibration information of the unsprung member can be corrected. Therefore, according to the suspension control apparatus C of this example, even if parameters such as the response of the actuator A and the spring constant of the suspension spring S change, the control command f _{W # ref} can be automatically corrected appropriately. Further, since the multiplication value is used, the vibration information of the unsprung member is corrected according to the magnitude of the vibration of the sprung member, so that the time until the force exerted by the actuator A coincides with the transmission force is shortened.

In the suspension control device C of this example, the controller 3 integrates the product of the vibration information of the unsprung member and the vibration information of the sprung member, which are sequentially obtained, to obtain integrated values I _V and I _X. The vibration information of the unsprung member is corrected based on the integral values I _V and I _X. According to the suspension control device C configured as described above, since the integral values I _V and I _X are used, the phase and magnitude of the force of the actuator A coincide with the phase and magnitude that can cancel the transmission force. The integral values I _V and I _X can be fixed. Therefore, according to the suspension control apparatus C of this example, when parameters such as the response of the actuator A and the spring constant of the suspension spring S change, the control command is appropriately corrected and the force of the actuator A is corrected. When the phase and magnitude match the phase and magnitude that can cancel the transmission force, the learning is terminated and the control command f _{W # ref} can be maintained in an appropriate state.

The suspension control device C of this example uses the skyhook control together with the control for canceling the transmission force, and the skyhook control is used for the low-frequency vibration of the vehicle body B that is difficult to suppress by the control for canceling the transmission force. The control force is exerted on the actuator A. Therefore, the suspension control apparatus C of the present example can more effectively suppress the vibration of the vehicle body B that is the sprung member and improve the riding comfort in the vehicle by using the control for canceling the transmission force and the skyhook control in combination.

As described above, in the skyhook control, the acceleration d ² X ₁ / dt ² of the vehicle body B is detected by the second sensor 2 and the acceleration d ² X ₁ / dt ² is integrated to obtain the speed dX ₁ / dt. The skyhook control command f _SKY was obtained. In the case of using the integral calculation as described above, it is necessary to perform a high-pass filter process in order to remove the low-frequency drift component, and if the skyhook gain is increased, the low-frequency component tends to oscillate. Therefore, a camera is installed on the vehicle body B, an image taken by the camera is processed to obtain information on the posture of the vehicle body B such as pitch, bounce, and roll, the speed of the vehicle body B is obtained from the posture information, and the skyhook is obtained. It can be used for control. Since the posture information of the vehicle body B obtained in this way is displacement information, the posture information may be differentiated to obtain the vertical speed of the vehicle body B. Differentiating the posture information requires low-pass filter processing to remove high-frequency noise, but does not require high-pass filter processing. Therefore, the speed dX ₁ / dt of the vehicle body B with no phase change can be obtained in the low-frequency region. It becomes like this. Therefore, in the low frequency region, the vertical displacement X ₁ of the vehicle body B obtained by processing the image obtained from the camera is differentiated to obtain the velocity dX ₁ / dt, and the acceleration detected by the second sensor 2 in the high frequency region. if you get the speed dX ₁ / dt by integrating d ^² X ₁ / dt ^2, it may determine the free velocity dX ₁ / dt of the phase shift in the actual speed. If the speed dX ₁ / dt thus determined is used for skyhook control, there is no fear of oscillation even if the skyhook gain is increased. In order to realize this, as in the first modification of the suspension control apparatus C shown in FIG. 6, the image taken by the camera 5a is processed for the controller 3 in FIG. A speed detection unit 5 having a displacement calculation unit 5b and a differentiation unit 5c for differentiating the displacement detected by the displacement calculation unit 5b is provided in parallel with the integration unit 37, and the speed output by the integration unit 37 and the speed detection unit 5 are output. What is necessary is just to provide the speed calculating part 6 which calculates the speed of the vehicle body B by processing the speed to perform. In this way, the skyhook gain can be increased, and the ride comfort in the vehicle can be further improved by effectively suppressing the vibration of the vehicle body B.

Subsequently, when the actuator A has a second-order lag characteristic, the vibration information of the unsprung member may be controlled by taking into account the acceleration with further advanced phase in addition to the displacement and speed. That is, when the actuator A has a second order delay characteristic, the control command f _{W # ref} can be obtained by adding the acceleration corresponding control command f _a in addition to the speed corresponding control command f _V and the displacement corresponding control command f _X. That's fine.

Here, when the natural angular frequency is ω, the attenuation rate is ζ, and the gain is k, the transfer function from the control command f _{W # ref} to the force f _W is expressed as in the following equation (9). .

When this equation (9) is substituted into equation (5), equation (10) is obtained. Expression (10) is an expression that takes into account a secondary response delay from the input of the control command f _{W # ref} of the actuator A to the output of the force f _W.

Since the variable multiplied by the Laplace operator s is differentiated and the variable multiplied by the square of the Laplace operator s is the second derivative, the following equation (11) is obtained by expanding and organizing the equation (10). It is done.

As can be understood from the equation (11), when the actuator A has a second-order response delay characteristic, the velocity dX ₂ / dt in which the phase has advanced from the displacement X ₂ compared to the first-order delay actuator A. In addition, the control command f _{W # ref} may be obtained in consideration of the acceleration d ² X ₂ / dt ² with further advanced phase. That is, in the case of the second-order lag actuator A, the vibration information of the wheel W, which is the unsprung member used to obtain the control command f _{W # ref} , is displacement X ₂ , speed dX ₂ / dt, and acceleration d ² X _2. / Dt ² . In this way, the vibration of the vehicle body B can be suppressed by compensating for the response delay of the actuator A and canceling the vibration of the vehicle body B due to disturbance input from the road surface. Therefore, if the actuator A has a high-order response delay, the vibration of the vehicle body B is suppressed corresponding to the response delay characteristic of the actuator A if the information whose phase is advanced by the order from the displacement X _{2 of the} wheel W is added. it can. Therefore, the vibration information of the wheel W that is an unsprung member for obtaining the control command f _{W # ref} may be determined as described above according to the order of the response delay of the actuator A.

From the above, when the actuator A has a second-order response delay characteristic, the acceleration d ² X ₂ / dt ^{2 is} transmitted to the controller 3 of FIG. 2 as in the second modification of the suspension control device C shown in FIG. the acceleration correction unit 40 for correcting, from the corrected acceleration d ^_² X ² / dt ² is provided an acceleration corresponding control command calculating section 41 for determining the acceleration corresponding control instruction f _a, the speed corresponding with final control command computation unit 39 The final control command F may be obtained by adding the control command f _V , the displacement control command f _X , the acceleration control command f _a, and the skyhook control command f _SKY . In this case, the control command f _{W # ref} is a sum of the speed corresponding control command f _V , the displacement corresponding control command f _X and the acceleration corresponding control command f _a .

Like the speed correction unit 33 and the displacement correction unit 34, the acceleration correction unit 40 filters the acceleration d ² X ₁ / dt ² in the vertical direction of the vehicle body B, and the acceleration d ² X ₂ / dt. ² and the acceleration d ² X ₁ / dt ² processed by the phase compensation unit 40a, _a gain multiplication unit 40c that multiplies the value obtained by the multiplication unit 40b by the correction gain ka, and a gain multiplication unit 40c. An integration value calculation unit 40d that sequentially integrates the obtained values, and a correction value calculation unit 40e that obtains an acceleration correction value C _a by multiplying the integration value I _a obtained by the integration value calculation unit 40d by the acceleration d ² X ₂ / dt ^2. When, an addition unit 40f for obtaining the acceleration d ^_² X ² / dt ² after correction by correcting the acceleration d ^_² X ² / dt ² by adding the acceleration correction value C _a of the acceleration d ^_² X ² / dt ² Prepare.

The acceleration corresponding control command calculation unit 41 sets the suspension spring S as a spring constant K _S , the natural angular frequency as ω, and multiplies the acceleration d ² X ₂ / dt ² by −K _S / ω ² as an acceleration gain, thereby responding to the acceleration corresponding control command. Find f _a . The acceleration corresponding control command f _a corresponds to the first term on the right side of the equation (11), and is a force component depending on the acceleration d ² X ₂ / dt ² in the force for canceling the transmission force. The speed corresponding control command calculation unit 35 may obtain the speed corresponding control command f _V by multiplying the corrected speed dX ₂ / dt by −2ζK _S / ω.

When the vehicle body B as the sprung member vibrates, the vibration information of the wheel W as the unsprung member is corrected by multiplying the variable gain, and the variable gain may be increased as the vibration of the vehicle body B continues. .

Furthermore, the speed correction unit 33 and the displacement correction unit 34 may correct the speed and displacement as follows. The speed correction unit 33 and the displacement correction unit 34 are both a multiplication unit, in addition to the configuration of the speed correction unit 33 and the displacement correction unit 34 of FIG. 2, as in the third modification of the suspension control apparatus C shown in FIG. Low-

pass filters

33h and 34h provided between

code extraction units

33g and 34g provided between 33b and 34b and gain

multiplication units

33c and 34c, and integral

value calculation units

33d and 34d and correction

value calculation units

33e and 34e. And dead

zone processing units

33i and 34i provided between the

phase compensation units

33a and 34a and the

multiplication units

33b and 34b.

The

code extraction units

33g and 34g extract the code from the calculation results of the

corresponding multiplication units

33b and 34b, and

output

1, 0 or −1 from the code to the

gain multiplication units

33c and 34c. That is, each of the

code extraction units

33g and 34g outputs 1 if the calculation result of the

corresponding multiplication unit

33b or 34b is a positive value, 0 if the calculation result is 0, and -1 if the calculation result is a negative value. To do.

The

gain multiplication units

33c and 34c multiply the values output by the

code extraction units

33g and 34g by the correction gains k _V and k _X , respectively, and output the multiplication values to the integration

value calculation units

33d and 34d. That is, in this example, when the calculation results of the

gain multipliers

33c and 34c are not 0, the integral values I _V and I _X increase or decrease by the correction gains k _V and k _X.

Low pass filter

33h, 34h is, when the

gain multiplication unit

33c, 34c of the operation result is not zero, the integral value I _V, since I _X is increased or decreased by the correction gain k _V, k _X, variation of the integrated value I _V, I _X To smooth. Thus, when the low-

pass filters

33h and 34h are inserted, sudden changes in the force exerted by the actuator A are alleviated, so that the riding comfort in the vehicle is improved. For the same purpose, a low-pass filter may be provided at the subsequent stage of the integral

value calculation units

33d and 34d of the controller 3 in FIG.

The dead

band processing units

33i and 34i receive the input of the acceleration d ² X ₁ / dt ² of the vehicle body B, which is a sprung member, and perform the dead band processing. The dead

zone processing units

33i and 34i have an acceleration d ^{2 of the} vehicle body B that is a sprung member when the rate of change of the integral values I _V and I _X output by the corresponding integral

value calculation units

33d and 34d is large. The dead zone for X ₁ / dt ² is reduced, and the dead zone is increased when the rate of change is reduced. Specifically, the dead

zone processing units

33i and 34i differentiate the integral values I _V and I _X and perform absolute value processing to obtain the rate of change of the integral values I _V and I _X , respectively. If it exceeds, the value of the dead zone is decreased as the rate of change increases and finally set to zero. The dead

zone processing units

33i and 34i set the dead zone value as a predetermined value when the rate of change of the integrated values I _V and I _X is less than the threshold value, respectively. The dead

zone processing unit

33i, 34i is 0 if the absolute value is less than the dead band value of the acceleration d ^² X ₁ / dt ² of the vehicle body B, the absolute value of the acceleration d ^² X ₁ / dt ² of the vehicle body B If it is equal to or greater than the dead zone value, the acceleration d ² X ₁ / dt ² is output as it is and input to the

multipliers

33b and 34b. When the dead

zone processing units

33i and 34i are provided in this way, when the vibration of the vehicle body B converges and becomes very small, the integrated values I _V and I _X are not updated and the transmission force can be canceled by the force of the actuator A. Can be maintained. If the dead

zone processing units

33i and 34i are not provided, the integrated values I _V and I _X are updated when the vehicle body B vibrates even a little. When the values of the integral values I _V and I _X are updated, the force of the actuator A shifts from the phase where the transmission force can be canceled or the transmission force and the magnitude differ, but the dead zone processing unit 33i, Such a situation can be avoided by providing 34i.

As described above, even in the third modified example of the suspension control device C, even if the response of the actuator A and the spring constant of the suspension spring S vary, the integral value I is calculated from the sign of the calculation result of the

multipliers

33b and 34b. By updating the values of _V and I _X , the control command f _{W # ref} can be generated so as to be optimal for canceling the transmission force.

Although not shown, a dynamic damper that suppresses the vibration of the wheel W may be provided to suppress the vibration of the wheel W. If the natural frequency of the dynamic damper matches the natural frequency of the wheel W, the vibration of the wheel W can be suppressed. If the dynamic damper is used in addition to the control for canceling the transmission force in this way, even if the wheel W vibrates, this vibration can be reduced and the vibration of the vehicle body B can be effectively suppressed.

The preferred embodiments of the present invention have been described above in detail, but modifications, changes, and modifications can be made without departing from the scope of the claims.

This application claims priority based on Japanese Patent Application No. 2017-082846 filed with the Japan Patent Office on April 19, 2017, the entire contents of which are incorporated herein by reference.

Claims

A suspension control device,
A controller for controlling an actuator interposed with a suspension spring between an unsprung member and a sprung member in a vehicle;
The controller determines a control command for canceling a transmission force transmitted from the unsprung member to the sprung member based on vibration information of the unsprung member and vibration information of the sprung member.
The suspension control device according to claim 1,
The controller corrects the vibration information of the unsprung member based on the vibration information of the sprung member to obtain corrected unsprung vibration information, and obtains the control command based on the corrected unsprung vibration information. Control device.
The suspension control device according to claim 2,
The controller is
A suspension control device that corrects vibration information of the unsprung member based on a multiplication value of vibration information of the unsprung member and vibration information of the sprung member.
The suspension control device according to claim 3,
The controller is
Integrating the multiplication values obtained sequentially to obtain an integral value,
A suspension control device that corrects vibration information of the unsprung member based on the integral value.
The suspension control device according to claim 1,
The controller is
Suspension control for obtaining a skyhook control command for suppressing vibration of the sprung member based on skyhook control, and for obtaining a final control command to be applied to the actuator based on the control command for canceling the transmission force and the skyhook control command apparatus.