JP2018177117A - Suspension control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a suspension control device that can improve vibration suppression effect of a spring upper member even when parameters of an actuator and a suspension spring vary.SOLUTION: A suspension control device C includes a controller 3 for controlling an actuator A interposed together with a suspension spring S between an unsprung member W and a spring upper member B of a vehicle V. The controller 3 obtains a control command fthat negates transmission force transmitted to the spring upper member B from the unsprung member W based on vibration information of the unsprung member W and vibration information of the spring upper member B.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a suspension control device.

  When the unsprung member climbs over the irregularities of the road surface while the vehicle is traveling, the suspension spring expands and contracts, and the suspension force changes the supporting force for supporting the sprung member, so that 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 prevent the sprung member from There is a suspension control device that suppresses vibration.

  Among such suspension control devices, there is one that performs preview control that detects the unsprung speed of the front wheel and predicts the vibration generated on the sprung member when the rear wheel passes the same road surface as the front wheel (for example, Patent Document 1). In such preview control, the rear wheel is displaced due to the unevenness of the road surface, control is executed to cancel the transmission force transmitted from the rear wheel to the sprung member through the suspension spring, and further, skyhook control is used in combination Vibration is suppressed.

Unexamined-Japanese-Patent No. 5-319054

  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 oil temperature of the hydraulic cylinder, the oil temperature is detected to correct a preview control force by preview control.

  However, it is difficult to accurately grasp the response characteristics of the actuator only by detecting the oil temperature change, and in a vehicle adopting an air spring as the suspension spring, the spring constant also changes at the time of height adjustment etc. And can not sufficiently cope with changes in actuator and suspension spring parameters.

  Therefore, in the conventional suspension control device, the vibration transmitted from the unsprung member to the sprung member may not be canceled out in some cases, and an improvement of 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 spring top member even if the parameters of the actuator and the suspension spring change.

  In order to achieve the above object, the suspension control device of the present invention is a control command to cancel 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. Ask for As described above, according to the suspension control device, it is possible to correct the control command so as to be appropriate in response to changes in parameters such as the responsiveness of the actuator and the spring constant of the suspension spring.

  Further, the suspension control device corrects the vibration information of the unsprung member based on the vibration information of the sprung member to obtain the post-correction unsprung vibration information, and obtains the control command based on the post-correction unsprung vibration information. Good. According to the suspension control device configured in this way, the riding comfort in the vehicle can be improved according to the variation of the parameters of the actuator and the suspension spring without depending on the factors of the variation of parameters, and the number of sensors can be reduced. It can be reduced.

  Furthermore, the suspension control device may correct the vibration information of the unsprung member based on the product of the vibration information of the unsprung member and the vibration information of the sprung member. According to the suspension control device configured as described above, when the phase and magnitude of the force of the actuator do not match the phase and magnitude that can cancel the transmission force, the vibration information of the unsprung member is corrected to match them. It is possible to automatically correct the control command properly even if parameters such as the responsiveness of the actuator and the spring constant of the suspension spring change.

  Further, the suspension control device may integrate the multiplication values sequentially obtained to obtain an integral value, and correct the vibration information of the unsprung member based on the integral value. According to the suspension control device configured as described above, when parameters such as the responsiveness of the actuator and the spring constant of the suspension spring change, the control command is automatically learned and the control command is appropriately corrected, and the phase and magnitude of the force of the actuator If the transmission power is canceled and the phase and magnitude match, the learning can be terminated and the control command can be maintained in an appropriate state.

  Then, the suspension control device obtains a skyhook control command for suppressing the vibration of the sprung member based on the skyhook control, and a final control command given to the actuator based on the control command for canceling the transmission force and the skyhook control command. It may be configured to request. According to the suspension control device configured as described above, the vibration of the sprung member can be more effectively suppressed and the riding comfort in the vehicle can be improved by the combination of the control for canceling the transmission force and the skyhook control.

  According to the suspension control device of the present invention, the vibration suppression effect of the sprung member can be improved even if the parameters of the actuator and the suspension spring change.

1 is a model diagram of a vehicle to which a suspension control apparatus according to an embodiment is applied. It is a control block diagram of a controller in a suspension control device of one embodiment. In (a), the spring force of the suspension spring, the force of the actuator, and the sprung member in the case where the force of the actuator is small with respect to the spring force of the suspension spring and the phase of the force of the actuator lags the phase that can cancel the transmission force. It is the graph which showed the relation of acceleration. (B) is the acceleration of the sprung member, the velocity of the unsprung member, and the sprung member, when the force of the actuator is small relative to the spring force of the suspension spring and the phase of the force of the actuator lags the phase that can cancel the transmission force. It is the graph which showed the multiplication value of the acceleration of the member and the velocity of the unsprung member. (C) is the acceleration of the sprung member, the displacement of the unsprung member, and the sprung, in the case where the force of the actuator is small with respect to the spring force of the suspension spring and the phase of the force of the actuator lags the phase that can cancel the transmission force. It is the graph which showed the product of the acceleration of the member and the displacement of the unsprung member. In (a), when the force of the actuator is smaller than the spring force of the suspension spring and the phase of the force of the actuator is more than the phase that can cancel the transmission force, the spring force of the suspension spring, the force of the actuator and the sprung member It is the graph which showed the relation of acceleration. In (b), the acceleration of the sprung member, the speed of the unsprung member, and the sprung member when the force of the actuator is smaller than the spring force of the suspension spring and the phase of the force of the actuator advances beyond the phase that can cancel the transmission force. Of the acceleration of the spring and the speed of the unsprung member. In (c), the acceleration of the sprung member, the displacement of the unsprung member, and the sprung member when the force of the actuator is small relative to the spring force of the suspension spring and the phase of the force of the actuator advances beyond the phase that can cancel the transmission force. Of the displacement of the unsprung member and the acceleration of the unsprung member. It is the graph which showed the relationship between the spring force of a suspension spring, and the force of an actuator in, when the spring force of a suspension spring and the force of an actuator are equal, and the phase of the force of an actuator corresponds to the phase which can cancel transmission force. It is a control block diagram of a controller of a suspension control device of one modification in one embodiment. It is a control block diagram of a controller of a suspension control device of another modification in one embodiment. It is a control block diagram of a controller of a suspension control device of still another modification in one 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 one embodiment includes an actuator A interposed together with a suspension spring S between a wheel W which is an unsprung member of a vehicle V and a vehicle body B which is a sprung member. To control the vibration of the vehicle body B.

  Each part will be described in detail below. As shown in FIG. 1, a vehicle V, which is a system, includes a wheel W having tires Ti on its outer periphery, a vehicle body B, and a suspension spring S interposed between the wheel W and the vehicle body B to elastically support the vehicle body B. And consists of.

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 It is a spring mass system with a degree of freedom, which can be expressed by the model of the spring mass system shown in FIG. Further, the road surface displacement and X _0, the vertical displacement of the vehicle body B and X _1, the vertical displacement of the wheel W and X _2, are upward and positive in FIG.

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

Suspension control device C, in this example, in order to detect the vertical displacement X ₂ and velocity dX 2 _/ dt of the wheel W as the vibration information of the wheel W is unsprung member, the first sensor 1, an acceleration sensor It is assumed. The first sensor 1 detects an acceleration d ² X ₂ / dt ² in the vertical direction of the wheel W, and inputs it to the controller 3. Further, in the present embodiment, the second sensor 2 is an acceleration for detecting 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 which is a spring upper member. It is considered as a sensor. The second sensor 2 detects an acceleration d ² X ₁ / dt ² in the vertical direction of the vehicle body B, and inputs the detected acceleration d ² X ₁ / dt ² 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 the velocity dX ₂ / dt in the vertical direction of the wheel W, and a displacement calculating unit 32 for obtaining the vertical displacement _{X 2} of the wheel W by integrating the velocity _dX 2 / dt of the speed calculating part 31 is determined, based on the acceleration ^{d 2} _X 1 / dt 2 in the vertical direction of the vehicle body B Correction unit 33 that corrects the vehicle speed dX ₂ / dt, a displacement correction unit 34 that corrects the displacement X ₂ based on the acceleration d ² X ₁ / dt ² in the vertical direction of the vehicle body B, and the corrected speed dX ₂ / a speed corresponding control command calculating section 35 for determining the speed corresponding control command f _V based on dt, a displacement corresponding control command calculating section 36 for determining the displacement corresponding control command f _X based on the displacement X ₂ of the corrected body B acceleration ^d 2 of the vertical _X 1 / dt ² Integrating the integrator 37 for obtaining the vertical velocity dX 1 _/ dt of the vehicle body B, the skyhook control to determine 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 A final control instruction calculation unit 39 which generates a final control instruction F and adds it to the actuator A by adding together the instruction calculation unit 38, the velocity response control instruction f _V , the displacement response control instruction f _X and the skyhook control instruction f _SKY Is equipped. In order to cancel the transmission force transmitted from the wheel W to the vehicle body B, the controller 3 obtains the speed-responsive control command f _V and the displacement-responsive control command f _X, and additionally suppresses this vibration when the vehicle B vibrates. In order to perform the skyhook control, the skyhook control instruction _fSKY is obtained. That is, the control command f _{W_ref} obtained by adding a speed corresponding control command f _V and displacement corresponding control command f _X is a control command for exhibiting a force for canceling the transmission force to the actuator A. In addition, the skyhook control command _fSKY is a control command for causing the actuator A to exert a control force based on the skyhook control.

Thus, the controller 3, acceleration d ² of the vertical vehicle body B as vibration information in the vertical direction of the displacement X ₂ and velocity dX 2 _/ dt and sprung wheels W as vibration information unsprung 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 that instructs the actuator A on the direction of expansion and contraction and the magnitude of the thrust.

  The actuator A is disposed in parallel with the suspension spring S and interposed between the vehicle body B and the wheel W. For example, a telescopic cylinder or an electric linear actuator using oil pressure or air pressure is used. Power source such as a pump driven by the Then, when the final control command F is input, the actuator A exerts a thrust in the direction and magnitude according to the control command to expand and contract, and vibrates the vehicle body B and the wheel W in the vertical direction.

First, the reason why the control command f _{W — ref} is _added to the speed-corresponding control command f _V and the displacement-corresponding control command f _X in control for canceling the transfer 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 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 which is the sprung member.

また、ばね下部材である車輪Ｗの上下方向の釣り合いから車輪Ｗの運動方程式は、以下の式（２）のように示せる。

Further, the equation of motion of the wheel W from the vertical balance of the wheel W which is the unsprung member can be expressed as the following equation (2).

さらに、アクチュエータＡを一次遅れ系とし、アクチュエータＡの制御指令ｆ_{Ｗ＿ｒｅｆ}から出力である推力ｆ_Ｗまでの応答遅れにおける時定数をＴとすると、アクチュエータＡの応答に関する微分方程式は、以下の式（３）のように示せる。

Further, _assuming that 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 that is an output is T, the differential equation for the response of the actuator A is It can be shown as).

式（１）を分解すると以下の式（４）となる。

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

ここで、路面変位Ｘ_０の変動（外乱）によって車輪Ｗが振動するが、車輪Ｗの振動によって車体Ｂへ伝達される伝達力を打ち消せば、車体Ｂへ車輪Ｗの振動の伝達をキャンセルして絶縁できる。つまり、路面変位Ｘ_０の変動（外乱）によって動かされる車体Ｂの変位Ｘ_１と、アクチュエータＡが力ｆ_Ｗを発揮して動かされる車体Ｂの変位Ｘ_１が全く逆の大きさになれば両者が相殺される。車輪Ｗの変位Ｘ_２によって車体Ｂに作用する伝達力は、車輪Ｗの変位Ｘ_２によって懸架ばねＳが伸縮して懸架ばねＳが発揮するばね力となるから、アクチュエータＡの力ｆ_Ｗが車輪Ｗの変位によって懸架ばねＳが発揮するばね力Ｋ_ｓＸ_２の符号を反転した値に等しくなればよい。

Here, although the wheel W vibrates due to the fluctuation (disturbance) of the road surface displacement X ₀ , the transmission of the vibration of the wheel W to the vehicle body B is canceled if the transmission force transmitted to the vehicle body B is canceled by the vibration of the wheel W Can be isolated. 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 The displacement of W should be equal to the value obtained by inverting the sign of the spring force K _s X ₂ exerted by the suspension spring S.

In Equation (1), it is shown that no acceleration is generated on 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. It seems. In other words, it seems that the force f _W = −K _S (X ₂ −X ₁ ) may be sufficient. However, (X ₂ −X ₁ ) is the relative displacement of the vehicle B and the wheel W, and the change in relative displacement is also due to the change in the posture of the vehicle B due to turning, braking or acceleration or the change in the load on the vehicle B It can not be determined whether it is attributable to road surface displacement. For example, when the front of the vehicle body B sinks by 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 promotes the sinking. It exerts power in the direction. When the vehicle body B is lifted, the lifting is promoted. As described above, in the control in which the relative displacement between the vehicle body B and the wheel W is fed back, 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. Accordingly, the spring force K _S · X ₂ a force f _W of the actuator A is the suspension spring S is exerted by the displacement X ₂ of the wheel W as transmission force, so as to cancel the transmission power, and determine the force f _W of the actuator A Just do it. Based on the above, the following equation (5) may be established.

他方、ラプラス演算子をｓとして、式（３）の制御指令とアクチュエータＡの推力の関係を伝達関数で表現すると、伝達関数は、以下の式（６）で表現される。

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

この式（６）を式（５）に代入すると、式（７）となる。なお、式（７）中で、ｋはゲインである。この式（７）は、アクチュエータＡの制御指令ｆ_{Ｗ＿ｒｅｆ}の入力から力ｆ_Ｗを出力するまでの応答遅れが勘案された式となる。

Substituting this equation (6) into the equation (5) gives the equation (7). In equation (7), k is a gain. The equation (7) is an equation in which 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 is taken into consideration.

ラプラス演算子ｓが乗算される変数は微分されるので、式（７）を展開して整理すると、以下の式（８）が得られる。

Since the variable to which the Laplace operator s is multiplied is differentiated, the equation (7) is expanded and rearranged to obtain the following equation (8).

式（８）から理解できるように、変位Ｘ_２に対して位相が進む速度を利用してアクチュエータＡの応答遅れを補償できる制御指令ｆ_{Ｗ＿ｒｅｆ}を求める。この式（８）において、アクチュエータＡの制御指令ｆ_{Ｗ＿ｒｅｆ}の入力から力ｆ_Ｗを出力するまでの応答遅れについて、予め、実機において時定数Ｔとゲインｋを計測すれば足り、車輪Ｗの変位Ｘ_２と速度ｄＸ_２／ｄｔを第一センサ１で検知する加速度ｄ^２Ｘ_２／ｄｔ^２から得られる。よって、制御指令演算部２３は、式（８）を演算すれば制御指令ｆ_{Ｗ＿ｒｅｆ}を求め得る。このように制御指令ｆ_{Ｗ＿ｒｅｆ}を求めてアクチュエータＡへ入力するとアクチュエータＡは、力ｆ_Ｗを発揮して車輪Ｗからの伝達力を打ち消せるので、路面からの外乱入力による車体Ｂの振動を相殺して、車体Ｂの振動を抑制できる。

As can be understood from the equation (8), a control command f _{W — ref} capable of compensating for the response delay of the actuator A using the speed at which the phase advances with respect to the displacement X ₂ is obtained. In this equation (8), it is sufficient to measure the time constant T and the gain k in advance on 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. 2} and the acceleration d ² X ₂ / dt ² detected by the first sensor 1 at a velocity dX ₂ / dt. Therefore, control instruction operation unit 23 can obtain control instruction f _{W — ref} by _operating equation (8). As described above, when the control command f _{W — ref} is obtained and input to the actuator A, the actuator A exerts the force f _W and can cancel the transmission force from the wheel W, thereby canceling the vibration of the vehicle body B due to the disturbance input from the road surface. Vibration of the vehicle body B can be suppressed.

Therefore, the controller 3 integrates the acceleration d ² X ₂ / dt ² to perform control to cancel the transmission force, and calculates the velocity dX ₂ / dt of the wheel W in the vertical direction, and the acceleration d Speed-based control for obtaining the speed-corresponding control command f _V based on the displacement calculation unit 32 for obtaining the displacement X ₂ in the vertical direction of the wheel W by second-order integration of ² X ₂ / dt ² and the corrected speed dX ₂ / dt a calculation unit 35, and a displacement corresponding control command calculating section 36 for determining the displacement corresponding control command f _X based on the displacement X ₂ of the corrected.

As shown in FIG. 2, the speed calculation unit 31 integrates the acceleration d ² X ₂ / dt ² to obtain the speed dX ₂ / dt in the vertical direction of the wheel W, and the calculated speed dX ₂ / dt And a filter unit 31b that extracts only the component of the unsprung resonance frequency band from the signal component and removes noise and drift components. Although not shown in detail, the filter unit 31 b is composed of a two-stage high pass filter and a two-stage low pass filter, and the processed speed dX ₂ / dt deviates to the actual gain and phase in the unsprung resonance frequency band. To prevent the occurrence of

Displacement calculation unit 32, an integrating unit 32a for obtaining the vertical displacement X ₂ of the wheel W by integrating the velocity dX 2 _/ dt of the speed calculating part 31 is determined, the determined displacement X ₂ to the spring under resonance frequency band A filter unit 32b is provided to extract only the components and remove noise and drift components. Filter unit 32b, although not illustrated in detail, is composed of two stages of the high-pass filter and a two-stage low-pass filter, a deviation of the actual gain and phase treated with the displacement X ₂ spring under resonance frequency band occurs Do not process. The displacement calculating unit 32 receives the input of the acceleration d ² X ₂ / dt ² from the first sensor 1 and does not receive the input of the velocity dX ₂ / dt obtained by the speed calculating unit 31. The acceleration d ² X ₂ / dt ² may be integrated in a second order to determine the displacement X ₂ in the vertical direction of the wheel W.

Although the unsprung resonance frequency varies depending on the vehicle, it is in the range of approximately 10 Hz to 17 Hz, the cutoff frequency of the high pass filter in the filter sections 31 b and 32 b is 0.5 Hz, and the cutoff frequency of the low pass filter is 150 Hz. It is With this setting, the velocity dX ₂ / dt and displacement X ₂ after processing are less in gain and phase shift with respect to the actual velocity and displacement, and the velocity and displacement of the wheel W can be detected accurately. Further, both the filter units 31 b and 32 b may be configured by band pass filters instead of being configured by low pass filters and high pass filters.

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

The displacement corresponding control command calculation unit 36 obtains a displacement corresponding control command f _X by multiplying the displacement X ₂ by −K _S / k as a displacement gain, with the suspension spring S as a spring constant K _S and a gain as k. The displacement corresponding control command f _X corresponds to the second term of the right side of the equation (8), and is a force component depending on the displacement X ₂ among the forces for canceling the transmission force.

Therefore, 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-related control command calculation unit 36 calculates the displacement calculation unit 32. The displacement corresponding control command f _X is obtained by multiplying the displacement X ₂ calculated by the displacement gain by the displacement gain to obtain the displacement corresponding control command f _V and the displacement corresponding control command f _X to cause the actuator A to exert the force to cancel the transmission force. You should get it.

However, when the response change due to the temperature change of the working fluid in the actuator A, etc., or when the suspension spring S is an air spring to change the internal pressure or the internal pressure changes due to the 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. If 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 can not 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 change, the speed for correcting the speed dX ₂ / dt so as to automatically cope with the change. It includes a correction unit 33, and a displacement correcting unit 34 that corrects the displacement X _2. The corrected speed dX ₂ / dt is input as the corrected unsprung vibration information to the speed corresponding control command calculating section 35, and the corrected speed uncorrected vibration information is input to the displacement corresponding control command calculating section 36. A velocity-corresponding control command f _V and a displacement-corresponding control command f _X are obtained by inputting the corrected displacement X ₂ . Therefore, even if the time constant T of the actuator A and the spring constant K _{S of the} suspension spring change, the force corresponding to the actual transmission force is exerted on the actuator A, and the vibration input from the wheel W to the vehicle body B is isolated. 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 phase compensation unit 33 a that filters the acceleration d ² X ₁ / dt ² in the vertical direction of the vehicle body B, and the speed dX ₂ / dt obtained by the speed calculation unit 31 and the phase compensation unit 33 a The multiplication unit 33b that multiplies the calculated acceleration d ² X ₁ / dt ² , the gain multiplication unit 33c that multiplies the correction gain k _V by the value obtained by the multiplication unit 33b, and integration that sequentially integrates the values obtained by the gain multiplication unit 33c A correction value calculation unit 33e for obtaining a speed correction value _CV by multiplying the value calculation unit 33d, the integral value _IV calculated by the integration value calculation unit 33d by the speed dX ₂ / dt obtained by the speed calculation unit 31; 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 And a 33f.

The acceleration d ² X ₁ / dt ^{2 in} the vertical direction of the vehicle body B is theoretically 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 does not become zero means that the force exerted by the actuator A can not completely cancel the transmission force. Moreover, the riding comfort in the vehicle is ideally a situation where the acceleration d ² X ₁ / dt ² of the vehicle body B is zero.

The operation result of the multiplication portion 33b is integrated is multiplied by the correction gain k _V as described above, the integrated value I _V is multiplied by the speed dX 2 _/ dt is the speed correction value C _V is determined. The speed correction value _CV is added to the speed dX ₂ / dt obtained by the speed calculation unit 31, and the added value becomes the speed dX ₂ / dt after correction. 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 33 b outputs a non-zero value, so the value of the integral value _IV is always updated Ru. Therefore, as long as the acceleration d ² X ₁ / dt ^{2 of} the vehicle body B does not become 0, the value of the integral value I _V continues to be 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 value of the gain, the acceleration d ² X ₁ / dt ² of the vehicle body B which is the sprung member is obtained by the speed correction unit 33. The velocity dX ₂ / dt is corrected in the direction of convergence toward zero. Then, when the acceleration d ² X ₁ / dt ^{2 of} the vehicle body B converges to 0, the output of the multiplication unit 33 b also becomes 0, so the value of the integral value I _V is not updated any more. The speed correction value _{CV is obtained} with a constant gain.

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

The phase compensation unit 33a is a low-pass filter for filtering the acceleration d ² X ₁ / dt ² in the vertical direction of the vehicle body B and extracting only the component in the unsprung resonance frequency band from the acceleration d ² X ₁ / dt ² And a high pass filter. If the acceleration d ² X ₁ / dt ² is processed by the phase compensation unit 33 a, only the component of the unsprung resonance frequency band due to the vibration transmitted from the wheel W side can be extracted from the acceleration d ² X ₁ / dt ² . The low frequency component in which the phase shift between the removal and the speed dX ₂ / dt of the wheel W becomes large is removed. As described above, when the phase shift described above is eliminated, the increase or decrease of the integral value _IV shifts in the direction to effectively cancel the transmission force, so that the value of the integral value _IV converges quickly. 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 by a band pass filter.

The displacement correction unit 34 filters the acceleration d ² X ₁ / dt ² of the vehicle body B in the vertical direction, the phase compensation unit 34 a, the displacement X ₂ obtained by the displacement calculation unit 32 and the acceleration processed by the phase compensation unit 33 a A multiplication unit 34b for multiplying d ² X ₁ / dt ² , a gain multiplication unit 34c for multiplying the value obtained by the multiplication unit 34b by the correction gain k _X , and an integral value calculation for sequentially integrating the values obtained by the gain multiplication unit 34c The unit 34d, a correction value calculator 34e for obtaining a displacement correction value _CX by multiplying the integral value I _X calculated by the integral value calculator 34d by the displacement X ₂ calculated by the displacement calculator 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.

Displacement correcting unit 34, like the speed correction unit 33 integrates multiplied by the correction gain k _X to the result of the multiplication unit 34b, obtains the displacement correction value C _X by multiplying the integrated value I _X to the displacement X _2. Displacement correction value C _X is added to the displacement X ₂ obtained by the displacement calculation unit 32, the added value becomes the displacement X ₂ of the corrected. Therefore, when the acceleration d ² X ₁ / dt ^{2 of} the vehicle body B is not zero, the calculation result of the multiplication unit 34 b outputs a non-zero value, so the value of the integral value I _X is necessarily updated. Therefore, as long as the acceleration d ² X ₁ / dt ^{2 of} the vehicle body B does not become 0, the value of the integral value I _X continues to be updated for each 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 the sprung member is obtained by the displacement correction unit 34. The displacement X ₂ is corrected in the direction of convergence toward zero. Then, when the acceleration d ² X ₁ / dt ^{2 of} the vehicle body B converges to 0, the output of the multiplication unit 34 b also becomes 0, so the value of the integral value I _X is no longer updated, 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 and the spring constant of the suspension spring S change, the displacement correction unit 34 updates the value of the integral value I _X 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 _X is held to correct the displacement X ₂ .

The phase compensation unit 34 a filters the acceleration d ² X ₁ / dt ² in the vertical direction of the vehicle body B in the same manner as the phase compensation unit 33 a and performs acceleration d ² X ₁ / dt ^{2 to the} unsprung resonance frequency band. It consists of a low pass filter and a high pass filter to extract only the component. Therefore, when the phase compensation unit 34a is provided in the displacement correction unit 34, only the component of the unsprung resonance frequency band due to the vibration transmitted from the wheel W side can be extracted from the acceleration d ² X ₁ / dt ² And the low frequency component where the phase shift between the speed of the wheel W and the speed dX ₂ / dt of the wheel W becomes large. As described above, when the phase shift described above is eliminated, the increase or decrease of the integral value I _X shifts in the direction to effectively cancel the transmission force, so that the value of the integral value I _X converges quickly. 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 by a band pass filter.

Further, in this example, the phase compensation units 33a and 34a that perform the filtering process of the acceleration d ² X ₁ / dt ² to optimize the velocity correction unit 33 and the displacement correction unit 34 respectively are provided. The part 33 and the displacement correction part 34 may share one phase compensation part.

Furthermore, 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 according to the correction of the velocity dX ₂ / dt of the wheel W and the displacement X _2. The vibration information of the sprung member necessary for correction may be taken as the velocity dX ₁ / dt because it is only necessary to know how much vibration is occurring. In that case, the acceleration d ² X ₁ / dt ² detected by the second sensor 2 may be integrated into the velocity correction unit 33 and the displacement correction unit to obtain and input the velocity dX ₁ / dt.

Thus, the speed correction unit 33 and the displacement correction unit 34 update the integrals I _V and I _X as gains so that the acceleration d ² X ₁ / dt ² of the vehicle body B converges to 0, and Correct the corresponding velocity dX ₂ / dt and displacement X ₂ . Therefore, both the speed-corresponding control command f _V and the displacement-corresponding control command f _X determined by the controller 3 are optimized according to the response of the actuator A and the change of the spring constant of the suspension spring S. Even if parameters such as the response of the vehicle and the spring constant of the suspension spring S change, the vibration of the vehicle body B can be effectively suppressed.

Here, when the velocity dX ₂ / dt and the displacement X ₂ are corrected using the calculation results of the multiplication units 33b and 34b, the velocity corresponding control command f _V and the displacement corresponding control command f _X are made efficient according to the fluctuation of the parameters. The points that can be optimized well will be described in detail. The graph in FIG. 3A shows that 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, and 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 (dotted line in the figure) and the acceleration d ² X ₁ / dt ² (dotted line in the figure) of the sprung member oscillate It shows the state. The spring force of the suspension spring S is a transmission force transmitted from the wheel W to the vehicle body B. Therefore, in the graph of FIG. 3A, the phase of the force exerted by the actuator A with respect to the phase that can cancel the transmission force is Running late. In the context of FIG. 3 (a), FIG. 3 as shown in the graph of (b), the rate of acceleration ^{d 2} _X 1 / dt 2 and the wheel W shown by the broken line of the vehicle body B shown by a chain line _dX 2 / The multiplication value shown by the solid line in the figure obtained by multiplying dt and d is approximately 0 or more, though 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 shown by the solid line in the figure obtained by multiplying ₂ and 3, although it is oscillatory, takes a value of approximately 0 or more. As can be understood from the graph of FIG. 3A, when the phase of the force exerted by the actuator A is delayed with respect to the phase capable of canceling the transmission force (the spring force of the suspension spring S), the force exerted by the actuator A The transmission power can be canceled by advancing the phase of. The transmission force is the expansion and contraction of the suspension spring S, that is, the force generated by displacement of the wheel W, and the phase of the force exerted by the actuator A advances if the gain of the speed dX ₂ / dt advancing in phase is increased. . Therefore, correction may be made to increase the speed dX ₂ / dt by increasing the integral value _IV that can be regarded as a gain for the speed dX ₂ / dt of the wheel W. Also, 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 corrected so as to increase the displacement X ₂ . Here, looking at FIG. 3B and FIG. 3C, since both of the multiplication values are approximately 0 or more, the integrated values I _V and I _X are increased. As described above, if the multiplication result of the multiplication units 33 b and 34 b is used, the transfer force can be canceled by the force of the actuator A if the phase of the force exerted by the actuator A lags behind the phase that can cancel the transfer force. The velocity dX ₂ / dt and the displacement X ₂ can be corrected.

On the other hand, the case where the force exerted by the actuator A with respect to the spring force of the suspension spring S is small and the phase advances more than the phase which can cancel the transmission force will be described. In the graph of FIG. 4A, the force exerted by the actuator A is smaller than the force exerted by the actuator A with respect to the spring force of the suspension spring S, and the force exerted by the actuator A in the case where its phase is advanced than the phase capable of canceling the transmission force A state in which 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 (dotted line in the figure) of the sprung member change in a vibrating manner. In the context of FIG. 4 (a), 4 as shown in the graph of (b), the rate of acceleration ^{d 2} _X 1 / dt 2 and the wheel W shown by the broken line of the vehicle body B shown by a chain line _dX 2 / The multiplication value shown by the solid line in the figure obtained by multiplying dt and d is approximately 0 or less, though it is oscillatory. Further, 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 shown by the solid line in the figure obtained by multiplying ₂ and 3, although it is oscillatory, takes a value of approximately 0 or more. As can be understood from the graph of FIG. 4A, 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 force exerted by the actuator A Delaying the phase of can cancel transmission power. The transmission force is the expansion and contraction of the suspension spring S, that is, the force generated by displacement of the wheel W, and the phase of the force exerted by the actuator A is delayed if the gain of the speed dX ₂ / dt whose phase is advancing is lowered. . Therefore, the integral value _IV which can be regarded as a gain with respect to the velocity dX ₂ / dt of the wheel W may be corrected to be a negative value so as to reduce the velocity 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 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 corrected so as to increase the displacement X ₂ . Here, looking at FIG. 4B and FIG. 4C, the multiplication value of the velocity dX ₂ / dt and the acceleration d ² X ₁ / dt ² is approximately 0 or less, and the integral value I _V is decreased. Since the product of the displacement X ₂ and the acceleration d ² X ₁ / dt ² is approximately 0 or more, the integrated value I _X is increased. As described above, by using the multiplication result of the multiplication units 33b and 34b, even if the phase of the force exerted by the actuator A advances with respect to the phase that can cancel the transmission force, the force of the actuator A can cancel the transmission force. The velocity 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) and the magnitudes match, that is, the actuator A In the case where the force of (1) coincides with the phase that can cancel the transmission force and the magnitudes of the two are equal, the transmission force is canceled and the acceleration d ² X ₁ / dt ² of the spring top member becomes zero. In such a situation, the product of the velocity 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 phase is opposite to the phase of the force (solid line in the figure) exerted by the actuator A with respect to the spring force of the suspension spring S (broken line in the figure), the integral value _IV can be regarded as gain , I _X no longer fluctuate. As described above, if the multiplication result of the multiplication units 33 b and 34 b is used, if the phase and the magnitude of the force exerted by the actuator A become equal to the phase and the magnitude that can cancel the transmission force, the velocity dX ₂ / dt displacement correction value C _X for correcting the speed correction value C _V and the displacement X ₂ to correct the both now take a constant value, the phase and magnitude of the force of the actuator a is transmitted force Uchikeseru phase and magnitude It can maintain the matching state.

As shown in FIG. 2, in addition to the above-described configuration, the controller 3 performs acceleration d ² X ₁ / dt ² of the vehicle body B in the vertical direction in order to perform skyhook control that suppresses vibration of the vehicle body B. an integration unit 37 that integrates, and a skyhook control command calculating section 38 for determining the skyhook control command f _SKY.

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

Final control command calculating section 39 adds up the speed corresponding control command f _V and displacement response control command f _X and the skyhook control command f _SKY to produce the final control command F, and outputs to the actuator A. As described above, the actuator A exerts a thrust in the direction and magnitude according to the control command according to the input of the final control command F, and expands and contracts, thereby vibrating the vehicle body B and the wheel W in the vertical direction.

As described above, the suspension control device C performs control to cancel the transmission force transmitted from the wheel W to the vehicle body B based on the vibration information of the wheel W as the unsprung member and the vibration information of the vehicle body B as the sprung member in the vehicle. The command f _{W_ref} is obtained. According to the suspension control device C configured in this way, 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. The vibration suppression effect can be improved to improve the ride quality of the vehicle. When the vehicle body B vibrates due to the excess or deficiency of the force emitted by the actuator A, the acceleration d ² X ₁ / dt ² of the sprung member immediately affects the acceleration of the sprung member 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 high responsiveness to changes in parameters, and the ride quality in the vehicle can be further improved. Since the vibration of the vehicle body B can also be monitored 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 assumed to be the velocity dX ₁ / dt, the acceleration d ² X ₁ / dt ² is out of phase and the direction of the correction is changed.

  Furthermore, in the suspension control device 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 the post-correction unsprung vibration information, and the post-correction spring Since the control command is determined based on the lower vibration information, it is not necessary to directly detect changes in parameters such as the responsiveness of the actuator A and the spring constant of the suspension spring S. For example, regarding the actuator A, in addition to the one caused by the temperature change of the working fluid, the response changes due to the friction of the sliding portion due to aging and the change of the pump efficiency, and the suspension spring S is also an air spring In such a case, the spring constant changes due to the temperature change of the gas in addition to the change of the internal pressure. Even if the suspension spring is a metal spring, the spring constant may change due to replacement. As described above, there are multiple factors of parameter variation of the actuator A and the suspension spring S, and it is difficult to detect parameter variation by sensing, and as many as possible, many sensors are required. On the other hand, in the suspension control device C of this embodiment, the fluctuation of the parameter is not directly detected, but the vibration of the vehicle body B as the spring upper member is detected as a result of the parameter fluctuation, and Since the vibration information is corrected, the installation of only one second sensor 2 is sufficient to cope with the parameter fluctuation. Thus, 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 variation of the parameters of the actuator A and the suspension spring S regardless of the variation of the parameters In addition to being able to do so, the number of sensors installed is also small, so the manufacturing cost can be reduced.

In this example, although the controller 3 corrects the vibration information of the unsprung member based on the vibration information of the sprung member, the speed corresponding control command calculation unit 35 and the displacement are calculated based on the vibration information of the sprung member. The velocity gain − (K _S · T) / k and the displacement gain −K _S / k which are multiplied by the corresponding control command calculation unit 36 may be corrected. Here, the multiplication result of the multiplication units 33 b and 34 b is an index for determining the direction of increase / decrease of the velocity X ₁ / dt of the sprung member and the acceleration d ² X ₁ / dt ² , and the integral value _IV and integral value The value I _X is a constant value when the transfer force transmitted from the wheel W to the vehicle body B can be canceled by the force exerted by the actuator A with the integral value of the multiplication results of the multiplication units 33 b and 34 b. Therefore, when correcting the velocity gain-(K _S · T) / k and the displacement gain -K _S / k in this way, for example, the integral value I _V and the integral value I _X are determined as in the present example, The value I _V and the integral value I _X may be used to correct the corresponding velocity gain − (K _S · T) / k and displacement gain −K _S / k.

Furthermore, 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 the product of the vibration information of the unsprung member and the vibration information of the sprung member. ing. According to the suspension control device C configured in this way, since the multiplication value is used, when the phase and magnitude of the force of the actuator A do not match the phase and magnitude that can cancel the transmission force, they are matched. Thus, the vibration information of the unsprung member can be corrected. Therefore, according to the suspension control device C of this example, even if parameters such as the responsiveness 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 matches the transmission force is also shortened.

Further, in the suspension control device C of this example, the integral value I _V , I _X is determined by integrating the multiplication value of the vibration information of the unsprung member and the vibration information of the sprung member, which are sequentially obtained by the controller 3 The vibration information of the unsprung member is corrected based on the integrals I _V and I _X. According to the suspension control device C configured in this way, since the integral values I _V and I _X are used, when the phase and magnitude of the force of the actuator A become equal to 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 device C of this example, when parameters such as the responsiveness of the actuator A and the spring constant of the suspension spring S change, it automatically learns and corrects the control command appropriately. When the phase and magnitude match the phase and magnitude that can cancel the transmission force, learning can be ended and the control command f _{W — ref} can be maintained in an appropriate state.

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

In the sky hook control described above, 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 _fSKY is obtained. As described above, in the case of using the integral operation, it is necessary to perform high-pass filter processing to remove low frequency drift components. When the skyhook gain is increased, oscillation is easily generated with low frequency components. Therefore, a camera is installed on the vehicle body B, and the image captured by the camera is processed to obtain information on the attitude of the vehicle body B such as pitch, bounce, and roll, and the speed of the vehicle body B is obtained from the attitude information. It is conceivable to use for control. Since the posture information of the vehicle body B obtained in this manner is displacement information, in order to obtain the speed of the vehicle body B in the vertical direction, the posture information may be differentiated. For differentiation of attitude information, low-pass filter processing is required to remove high-frequency noise, but high-pass filter processing is not necessary, so the speed dX ₁ / dt of the vehicle B without phase change in the low frequency region can be obtained It will be. Thus, the acceleration to obtain velocity dX 1 _/ dt by differentiating the vertical displacement X ₁ of the low-frequency region of the vehicle body B obtained by processing the images obtained from the camera, in a high frequency region detected by the second sensor 2 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 obtained is used for skyhook control, there is no possibility of oscillation even if the skyhook gain is increased. In order to realize this, as in the modification of the suspension control device C shown in FIG. 6, the displacement obtained by processing the image taken by the camera 5a with respect to the controller 3 of FIG. A speed detection unit 5 having an operation unit 5b and a differentiation unit 5c for differentiating the displacement detected by the displacement operation unit 5b is provided in parallel in the integration unit 37, and the speed output by the integration unit 37 and the speed detection unit 5 are output. A speed calculation unit 6 may be provided to process the speed to obtain the speed of the vehicle body B. In this way, the skyhook gain can be increased, and the vibration of the vehicle body B can be effectively suppressed to further improve the riding comfort of the vehicle.

Subsequently, in the case where the actuator A has the second-order delay characteristic, control may be performed in consideration of the acceleration whose phase is further advanced in addition to the displacement and the speed as the vibration information of the unsprung member. That is, when the actuator A has the second-order lag characteristic, the acceleration-corresponding control instruction f _a may be added to the velocity-corresponding control instruction f _V and the displacement-corresponding control instruction f _X to obtain the control instruction f _{W_ref.} .

Here, assuming that the natural angular frequency is ω and the attenuation factor is 、, the gain is k, the transfer function from the control command f _{W — ref} to the force f _W is expressed by the following equation (9).

この式（９）を式（５）に代入すると、式（１０）となる。式（１０）は、アクチュエータＡの制御指令ｆ_{Ｗ＿ｒｅｆ}の入力から力ｆ_Ｗを出力するまでの二次の応答遅れが勘案された式となる。

When this equation (9) is substituted into the equation (5), the equation (10) is obtained. Expression (10) is an expression in which a second-order response delay from the input of the control command f _{W — ref} of the actuator A to the output of the force f _W is taken into consideration.

ラプラス演算子ｓが乗算される変数は微分され、ラプラス演算子ｓの二乗が乗算される変数は二階微分となるので、式（１０）を展開して整理すると、以下の式（１１）が得られる。

The variable to be multiplied by the Laplace operator s is differentiated, and the variable to be multiplied by the square of the Laplace operator s is a second derivative. Therefore, the equation (10) is expanded and rearranged to obtain the following equation (11) Be

式（１１）から理解できるように、アクチュエータＡが二次の応答遅れの特性を備えている場合、一次遅れのアクチュエータＡに比較して、変位Ｘ_２から位相が進んだ速度ｄＸ_２／ｄｔに加えて、更に位相が進んだ加速度ｄ^２Ｘ_２／ｄｔ^２を加味して、制御指令ｆ_{Ｗ＿ｒｅｆ}を求めればよい。つまり、二次遅れのアクチュエータＡの場合、制御指令ｆ_{Ｗ＿ｒｅｆ}を求めるために利用するばね下部材である車輪Ｗの振動情報は、変位Ｘ_２、速度ｄＸ_２／ｄｔおよび加速度ｄ^２Ｘ_２／ｄｔ^２となる。このようにすれば、アクチュエータＡの応答遅れを補償しつつ、路面からの外乱入力による車体Ｂの振動を相殺して、車体Ｂの振動を抑制できる。よって、アクチュエータＡが高次の応答遅れとなれば、車輪Ｗの変位Ｘ_２から位相が次数分進んだ情報を加味すれば、アクチュエータＡの応答遅れの特性に対応して車体Ｂの振動を抑制できる。よって、制御指令ｆ_{Ｗ＿ｒｅｆ}を得るためのばね下部材である車輪Ｗの振動情報は、アクチュエータＡの応答遅れの次数に応じて、前述のように決定すればよい。

As can be understood from the equation (11), when the actuator A has the second-order response delay characteristic, the velocity dX ₂ / dt from the displacement X ₂ to the phase advanced as compared with the actuator A of the first-order delay In addition, the control command f _{W — ref} may be obtained in consideration of the acceleration d ² X ₂ / dt ² whose phase is further advanced. That is, in the case of the actuator A of the second-order lag, the vibration information of the wheel W which is an unsprung member used to obtain the control command f _{W_ref} is displacement X ₂ , velocity dX ₂ / dt and acceleration d ² X ₂ / dt It becomes ² . In this way, it is possible to suppress the vibration of the vehicle body B by offseting the vibration of the vehicle body B due to the disturbance input from the road surface while compensating for the response delay of the actuator A. Therefore, if the actuator A is a higher order response delay, if considering the information phase advances a few minutes following the displacement X ₂ of the wheel W, suppressing the vibration of the vehicle body B so as to correspond to the characteristics of the response delay of the actuator A it can. Therefore, the vibration information of the wheel W which is the 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 the second-order response delay characteristic, the acceleration d ² X ₂ / dt ^{2 is applied} to the controller 3 of FIG. 2 as in the other modification of the suspension control device C shown in FIG. And an acceleration-corresponding control command calculation unit 41 for obtaining an acceleration-corresponding control command f _a from the corrected acceleration d ² X ₂ / dt ^2. displacement control command f _V corresponding control command f _X and acceleration corresponding control command by summing the f _a and the skyhook control command f _SKY may be obtained a final control command F. In this case, the control command f _{W — ref} is the _sum of the speed-based control command f _V , the displacement-based control command f _X, and the acceleration-based control command f _a .

The acceleration correction unit 40, like the velocity correction unit 33 and the displacement correction unit 34, includes a phase compensation unit 40a that filters the acceleration d ² X ₁ / dt ² in the vertical direction of the vehicle B, and the acceleration d ² X ₂ / dt ² and the multiplication unit 40b multiplying the acceleration ^d 2 _X 1 / dt ² treated with a phase compensator 40a, a gain multiplication unit 40c multiplying the correction gain _{k a} to a value determined by the multiplication unit 40b, a gain multiplication unit 40c is and integral value calculating unit 40d sequentially integrating the values obtained, the correction value calculation section 40e which is multiplied by the acceleration ^{d 2} _X 2 / dt 2 in the integral value _{I a} that is integral value calculating section 40d determined obtaining the acceleration correction value _{C a} 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.

An acceleration-related control command calculation unit 41 multiplies the acceleration d ² X ₂ / dt ² by the acceleration gain −K _S / ω ² as a suspension spring S with a spring constant K _S and a natural angular frequency ω, and generates an acceleration-related control command Find f _a The acceleration-related control command f _a corresponds to the first term of the right side of the equation (11), and is a force component depending on the acceleration d ² X ₂ / dt ² of the force that cancels the transmission force. In the speed corresponding control command calculating section 35, it may be determined speed corresponding control command _{f V} by multiplying the -2ζK _S / ω to the speed _dX 2 / dt after correction.

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

  Furthermore, the velocity correction unit 33 and the displacement correction unit 34 may correct the velocity and the displacement as follows. The speed correction unit 33 and the displacement correction unit 34 are both added to the configuration of the speed correction unit 33 and the displacement correction unit 34 of FIG. 2 as in the other modification of the suspension control device C shown in FIG. Low-pass filter 33h provided between code extracting units 33g and 34g provided between multiplying units 33b and 34b and gain multiplying units 33c and 34c, and integrated value calculating units 33d and 34d and correction value calculating units 33e and 34e , And 34h, and dead zone processors 33i and 34i provided between the phase compensators 33a and 34a and the multipliers 33b and 34b.

  The code extracting units 33g and 34g extract codes from the calculation results of the multiplying units 33b and 34b to which they correspond, respectively, and output 1, 0 or -1 from the code to the gain multiplying units 33c and 34c. That is, the code extracting units 33g and 34g respectively output 1 if the operation result of the multiplying units 33b and 34b to which they correspond are positive values, 0 if they are 0, and -1 if they are negative values. Do.

The gain multiplication units 33c and 34c respectively multiply the values outputted by the code extraction units 33g and 34g by the correction gains k _V and k _X and output the results to the integral value calculation units 33d and 34d. That is, in this example, when the calculation results of the gain multiplication units 33 c and 34 c are not 0, the integrals I _V and I _X increase or decrease by the correction gains k _V and k _X.

In the low-pass filters 33h and 34h, when the calculation results of the gain multiplication units 33c and 34c are not 0, the integrals I _V and I _X increase or decrease by the correction gains k _V and k _X , so changes in the integrals I _V and I _X Smooth out. As described above, when the low pass filters 33 h and 34 h are inserted, the sudden change of the force exerted by the actuator A is alleviated, and the riding comfort in the vehicle is improved. For the same purpose, a low pass filter may be provided downstream of the integral value calculators 33d and 34d of the controller 3 of FIG.

The dead zone 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 zone process. The dead zone processors 33i and 34i are configured to increase the acceleration d ^{2 of the} vehicle body B, which is a spring upper member, when the rate of change of the integrated values I _V and I _X output by the integrated value calculators 33 d and 34 d to which they correspond are large. The dead zone with respect to X ₁ / dt ² is reduced, and the dead zone is increased as the rate of change decreases. Specifically, the dead zone processing units 33i and 34i differentiate the integrals I _V and I _X and perform absolute value processing to obtain the rate of change of the integrals I _V and I _X , and the rate of change indicates the threshold value. When it exceeds, the value of the dead zone is decreased according to the increase of the change rate, and finally it is made zero. The dead zone processors 33i and 34i set the value of the dead zone to a predetermined value when the rate of change of the integrals I _V and I _X is less than the threshold. 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 more than the value of the dead zone, the acceleration d ² X ₁ / dt ² is output as it is and is input to the multiplication units 33 b and 34 b. In this manner, when the dead zone processing units 33i and 34i are provided, when the vibration of the vehicle body B converges and becomes extremely small, the values of the integrals I _V and I _X are not updated, and the transmission force can be canceled by the force of the actuator A. Can maintain In the case where the dead zone processors 33i and 34i are not provided, when the vehicle body B vibrates even a little, the values of the integrals I _V and I _X are updated. When the values of the integrals I _V and I _X are updated, the force of the actuator A may be shifted with respect to the phase that can cancel the transmission force, or the transmission force may be different from the magnitude, but the dead zone processing unit 33i, If 34i is provided, such a situation can be avoided.

As described above, even in the other modification of the suspension control device C, even if the response of the actuator A or the spring constant of the suspension spring S fluctuates, the integration is performed from the sign of the calculation result of the multiplication units 33b and 34b. The values of the values I _V and I _X can be _updated to generate the control command f _{W — ref} so as to be optimal for canceling the transmission force.

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

  While the preferred embodiments of the present invention have been described above in detail, modifications, variations and changes are possible without departing from the scope of the claims.

  3 ... controller, A ... actuator, B ... vehicle body (sprung member), C ... suspension control device, S ... suspension spring, W ... wheel (unsprung member)

Claims (5)

A controller for controlling an actuator interposed with a suspension spring between the unsprung member and the sprung member in the vehicle;
The controller determines 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. Suspension control device. The controller corrects vibration information of the unsprung member based on vibration information of the sprung member to obtain post-correction unsprung vibration information, and obtains the control command based on the post-correction unsprung vibration information. The suspension control device according to claim 1, characterized in that The controller
The suspension control device according to claim 2, wherein the vibration information of the unsprung member is corrected based on a product of the vibration information of the unsprung member and the vibration information of the sprung member. The controller
Integrating the product values sequentially obtained to obtain an integrated value;
The suspension control device according to claim 3, wherein the vibration information of the unsprung member is corrected based on the integral value. The controller
A skyhook control command for suppressing the vibration of the sprung member is obtained based on the skyhook control, and a final control command to be given to the actuator is obtained based on the control command for canceling the transmission force and the skyhook control command. The suspension control device according to any one of claims 1 to 4, characterized in that:

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