JP4826758B2 - Suspension system - Google Patents

Description

  The present invention relates to a suspension system including four suspension devices each having an actuator that generates a force that causes a wheel and a vehicle body to approach and separate from each other.

A suspension apparatus having an actuator that generates a driving force by using electromagnetic action or fluid pressure can generate a force that causes the wheel and the vehicle body to approach or separate from each other. For this reason, for example, it is possible not only to passively generate a resistance force to the relative motion between the wheel and the vehicle body as in a conventional fluid resistance type shock absorber, but also to generate a driving force that promotes the relative motion. Yes, it is possible to actively perform control suitable for the situation. Such a suspension device having an actuator is called, for example, an active suspension device, and has been conventionally studied in order to realize so-called skyhook model control. Examples of the active suspension device are described in the following Patent Documents 1 and 2, respectively.
JP 2000-168331 A Japanese Examined Patent Publication No. 7-64174

  Further, in the techniques described in Patent Documents 1 and 2, each suspension device is based on the heave amount, pitch amount, roll amount, warp amount, etc. of the vehicle body acquired based on the relative displacement amount between each wheel and the vehicle body. The target value of the control force that should be generated by the actuator of is determined. However, no consideration has been given to whether or not the determined distribution of the control force of each suspension device is appropriate. Such a problem is an example of a problem that can hinder the practicality of a suspension system including a conventional active suspension device, and the suspension system has room for improvement from various viewpoints. That is, by improving the conventional suspension system, it is possible to improve the practicality, such as reducing the burden on the suspension device. The present invention has been made in view of such circumstances, and an object thereof is to obtain a more practical suspension system.

In order to solve the above problems, the suspension system of the present invention determines a control force target value for each of the four actuators of each of the four suspension devices and uses the four suspension devices based on the four control force target values. A control device for controlling, and the control device reduces the absolute value of the specific control force target value which is one specific target value satisfying the set condition among the four control force target values. A control force distribution changing unit is provided that changes the distribution of the four control force target values by adding a warp component to the four control force target values for correction .

  According to the suspension system of the present invention, the warp component that hardly affects the heave, roll, and pitch in the movement of the vehicle body is added to the four control force target values, and the distribution of the control force target values is changed. The specific control force target value can be reduced while suppressing the influence on the roll and pitch. That is, according to the aspect described in this section, a more practical suspension system can be obtained.

Aspects of the Invention

In the following, some aspects of the invention that can be claimed in the present application (hereinafter sometimes referred to as “claimable invention”) will be exemplified and described. As with the claims, each aspect is divided into sections, each section is numbered, and is described in a form that cites the numbers of other sections as necessary. This is for the purpose of facilitating the understanding of the claimable invention, and is not intended to limit the combinations of the constituent elements constituting the claimable invention to those described in the following sections. In other words, the claimable invention should be construed in consideration of the description accompanying each section, the description of the embodiments, etc., and as long as the interpretation is followed, another aspect is added to the form of each section. In addition, an aspect in which some constituent elements are deleted from the aspect of each item can be an aspect of the claimable invention. In each of the following paragraphs, (1) corresponds to claim 1, (3) corresponds to claim 2, (5) corresponds to claim 3, and (2) corresponds to claim 4. To do.

(1) Four suspension devices each having an actuator for connecting a corresponding one of the four wheels and the vehicle body, and generating a force for approaching and separating the one wheel and the vehicle body,
A control force target value determining unit that determines a control force target value that is a target value of a vehicle body motion control force that is a force that controls the motion of the vehicle body for each of the four actuators of each of the four suspension devices; A suspension system comprising a control device for controlling the four suspension devices based on the four control force target values,
The control device adds a warp component to the four control force target values to change the distribution of the four control force target values to the four actuators, thereby setting the four control force target values. A suspension system comprising: a control force distribution changing unit that decreases an absolute value of a specific control force target value that is a specific target value that satisfies a specific condition.
The suspension system described in this section generates, for example, a vehicle body heave (vertical motion), a roll by generating a vehicle body motion control force having a magnitude corresponding to a control force target value by an actuator included in each of the four suspension devices. It is possible to suppress (rotational motion in which the left and right sides of the vehicle body are moved up and down in reverse), suppress pitch (rotational motion in which the front and rear surfaces of the vehicle body move up and down in reverse), suppress vibrations of the vehicle body, and the like. In the suspension system of this section, the control force distribution changing unit can change the distribution of the control force target value, which is the target value of the vehicle body movement control force, and reduce the absolute value of the specific control force target value. The specific control force target value will be described in detail later. For example, a suspension device that has a maximum absolute value among the four control force target values or that cannot exhibit a sufficient vehicle body motion control force due to an abnormality. Target value.
The control force distribution changing unit in this section changes the distribution of the four control force target values by adding a warp component to the four control force target values. The warp is, for example, a motion in which the front and rear of the vehicle body are twisted in the opposite direction, and among the four parts of the vehicle body, one diagonal part (for example, two parts of the right front and left rear) rises, The other diagonal part (for example, two parts of the left front part and the right rear part) moves downward. And a warp component is a component which acts on the direction which warps a vehicle body among the forces input into a vehicle body from a suspension apparatus. However, in general, the vehicle body has rigidity capable of withstanding the input of the warp component, and even when the warp component acts on the vehicle body, the warp amount of the vehicle body is often relatively small. Therefore, even if the distribution of the four control force target values is changed to increase the warp component, the influence on the vehicle body is often relatively small.
Further, the warp component hardly affects the heave, roll, and pitch in the movement of the vehicle body. Therefore, when the four suspension devices are controlled based on the four control force target values (hereinafter, sometimes referred to as “pre-change target values”) before the warp component is added, and when the warp component is added. In the case where the four suspension devices are controlled based on the subsequent four control force target values (hereinafter sometimes referred to as “target values after change”), even if the warp amount of the vehicle body slightly changes, Heave, roll, and pitch are almost unchanged. Therefore, according to the aspect described in this section, by changing the distribution of the control force target value by adding the warp component, the specific control force target value can be reduced while suppressing the influence on the heave, roll, and pitch. Can do. That is, according to the aspect described in this section, a more practical suspension system can be obtained.
The actuator described in this section can be operated by, for example, electromagnetic force, fluid pressure, or the like. Specifically, for example, it includes a rotational driving force source such as an electromagnetic motor or a hydraulic motor and a motion conversion device that converts the rotational motion into a linear motion, a linear electromagnetic motor, a hydraulic cylinder, etc. It is possible to have a direct-acting driving force source.
<Determination of control force target value based on body displacement>
(2) the control force target value determination unit, vehicle body displacement state determining said four control force target value based on the displacement state of the vertical direction in the absolute coordinate system of the four parts of the vehicle body corresponding to the four wheels The suspension system according to item (1), including a dependency target value determination unit.
In the aspect described in this section, for example, based on the detection value of the vertical acceleration sensor or the like, the displacement state such as the vertical acceleration, the vertical displacement speed, and the vertical displacement amount of the four parts of the vehicle body is acquired, and the displacement state is The four control force target values are determined. In other words, the control force target value is determined based on the relative displacement (relative displacement amount, relative displacement speed, etc.) between the vehicle body and the wheel as in the prior art (hereinafter referred to as “control based on relative displacement”). In contrast, the control force target value is determined on the basis of the vertical displacement of the vehicle body that is acquired regardless of the distance between the vehicle body and the wheel. Therefore, for example, when overcoming a relatively large ridge, it becomes easier to reduce the vibration of the vehicle body as compared with “control based on relative displacement”.
In the prior art described above, a heave amount, a roll amount, a pitch amount, a warp amount, and the like are calculated based on the relative displacement amount between each of the four wheels and the vehicle body, and the gain is multiplied by a gain to control force target. The value has been retrieved. However, in the control based on the relative displacement, even if the front and rear of the vehicle body is not actually twisted in the opposite direction, the amount of warp detected by the wheels moving up and down mainly due to the unevenness of the road surface becomes large. Riding comfort is worsened by generating a reduced control force. Therefore, in the prior art, the gain multiplied by the warp amount is set to a negative gain, for example, so that the warp component input to the vehicle body is canceled out. On the other hand, in the aspect described in this section, the control force target value is determined based on the displacement of the vehicle body, not the relative displacement of the wheel and the vehicle body, and thus the above-described problem does not occur. That is, in the aspect of this section, the necessity of canceling the warp component as in the control based on the relative displacement is small.
Note that the displacement state in the vertical direction in the absolute coordinate system is, for example, the displacement acceleration and displacement speed of the vehicle body, the displacement amount from the height position of the vehicle body (reference height position) as a reference when the vehicle travels, etc. be able to. The reference height position is, for example, the height position of the vehicle body acquired based on the detection value of a vertical acceleration sensor, a vehicle body-wheel separation distance, or a vehicle height detection device that detects a separation distance between the vehicle body and the road surface. Thus, it can be set to an average height position within the set time, or to a height position in a stopped state of the vehicle or a straight traveling state at a constant speed.
<Average of control force target value>
(3) The control force distribution changing unit sets the absolute value maximum target value having the maximum absolute value among the four control force target values as the specific control force target value, and decreases the absolute value thereof A target absolute value averaging unit that averages the absolute values of the four control force target values (1)
The suspension system according to item or (2).
According to the aspect described in this section, by reducing the absolute maximum target value, for example, a state where one actuator generates a large control force can be avoided, and the burden on the actuator can be reduced. .
“Averaging” in this section literally reduces the absolute value of the absolute maximum target value until the maximum of the four control force target values after changing the control force distribution becomes 2 or more. And the difference between the four control force target values is reduced to the limit possible by adding the warp component, but is not limited to them, and the absolute value of the absolute maximum target value compared to before the distribution change If it is changed so as to approach the absolute values of the other three control target values, it should be understood that they have been averaged.
The aspect described in this section is particularly effective when the absolute value of any one of the control force target values is larger than the others. Specifically, for example, when acceleration / deceleration (pitch), turning (roll), and vertical movement (heave) of the vehicle body overlap, the load is often concentrated on any of the actuators, which is effective in reducing the load. Moreover, when an actuator has an electromagnetic motor, the temperature rise of an electromagnetic motor can be suppressed.
(4) The target absolute value averaging unit
The absolute value of the warp component to be added to the four control force target values is expressed as the difference between the absolute value maximum target value and the control force target value for each of the two suspension devices adjacent to the corresponding suspension device. And the sum of the absolute value maximum target value and the control force target value for the suspension device located diagonally of the suspension device to which the absolute value maximum target value corresponds, The suspension system according to item (3), which averages the control force target value.
Adding a warp component to the four control force target values to reduce the absolute value of the absolute maximum target value increases the absolute value of one or more of the three control force target values other than the absolute maximum target value. To do. Then, after adding the warp component, if the absolute value after the increase of one or more other than the absolute maximum target value exceeds the absolute value of the absolute maximum target value after the decrease, the absolute value of the added warp component The value is considered too large. On the other hand, according to the aspect described in this section, the absolute value of the warp component added to the four control force target values is set to be “less than half of the minimum of each difference and the sum”. When the four control force target values are averaged, it is possible to prevent the warp component from being excessively added. Further, when the absolute value of the warp component to be added is set to “half of the minimum of each difference and the sum”, the absolute value of the maximum of the four control force target values is the absolute value. It can be made as small as possible. The specific processing of averaging will be described in detail in the examples.
<Reduced target value of suspension system with insufficient control force>
(5) The control force distribution changing unit
When any one of the four suspension devices is in a control force shortage state in which a vehicle body motion control force that can be generated is insufficient, the control force target value for the suspension device in the control force shortage state is specified. The suspension system according to any one of items (1) to (4), including a control force shortage target value absolute value decrease unit that decreases the absolute value of the control force target value.
According to the aspect described in this section, when one of the suspension devices is in a state where the control force is insufficient, the insufficient control force can be compensated by changing the distribution of the four control force target values. Disturbance of posture can be suppressed. For example, if electromagnetic actuators cannot generate sufficient control force due to poor contact or disconnection of electrical wiring, and hydraulic actuators due to hydraulic fluid leakage, etc. (no control force is generated at all) In other words, this mode is effective in such a case.
(6) The control force shortage target value absolute value reduction unit determines the absolute value of the warp component to be added to the four control force target values based on the shortage of the vehicle body motion control force. The suspension system according to item (5) including a part.
The magnitude of the warp component added to the four control force target values can be, for example, less than the shortage of the vehicle body motion control force. Specifically, for example, the size of the warp component can be made equal to the shortage amount, or smaller (for example, about half the shortage amount). Note that the deficiency can be acquired, for example, by subtracting “a possible vehicle motion control force” from the control force target value. This mode includes a mode in which when the actuator cannot generate any control force, the deficient amount is calculated by setting “the vehicle body motion control force that can be generated” to zero.
<Decrease in specific control force target value due to increase in warp component>
(7) The control force distribution changing unit decreases the absolute value of the specific control force target value by increasing the warp component included in the four control force target values. The suspension system according to any one of the items.
As described above, if the rigidity of the vehicle body is appropriate, even if the warp component increases, the amount of warp can be kept small. Therefore, the warp component can be added without worrying about the increase in the warp component included in the four control force target values. In the aspect described in this section, when the specific control force target value is decreased by adding the warp component, the warp components included in the four control force target values after the change are increased.
<Spring>
(8) The suspension device is
The suspension system according to any one of (1) to (7), further comprising a spring that is provided in parallel with the actuator and generates a force that separates the one wheel from the vehicle body.
Since the aspect described in this section includes the spring that supports the vehicle body, the four control force target values can be made relatively small, and the energy consumption of the actuator can be reduced. The spring of this term can be configured to include an elastic body such as a spring member or gas, for example.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. It should be noted that the present invention is by no means limited to the following examples, and in addition to the following examples, there are various types based on the knowledge of those skilled in the art including the aspects described in the above [Aspect of the Invention] section. It can implement in the various aspect which gave the change and improvement of these.

1. Suspension system Fig. 1 schematically shows an outline of a suspension system according to an embodiment of the claimable invention. In the present embodiment, the suspension system is provided with four suspension devices 10, so that each of the four wheels 12 and each of the four parts of the vehicle body 14 can be approached and separated by the four suspension devices 10. It is connected. The suspension device 10 includes a compression coil spring 16 (hereinafter abbreviated as “spring”) for elastically supporting the vehicle body 14 as a sprung member, and the vehicle body 14 and the wheel 12 by electromagnetic driving force. And an electromagnetic actuator 20 that generates a force for approaching and separating.

  As shown in FIG. 2, the electromagnetic actuator 20 includes a cylinder 22 that can be expanded and contracted, and an electromagnetic motor 24 (hereinafter, abbreviated as “motor”) that is an electromagnetic driving force source that generates a force for expanding and contracting the cylinder 22. There is). A lower end portion of the cylinder 22 is connected to a suspension arm 26 that supports the wheel 12 so as to be able to approach and separate from the vehicle body 14, and an upper end portion is attached to the vehicle body 14. The cylinder 22 includes an outer tube 30 whose lower end is open, and an inner tube 32 that is inserted into the outer tube 30 from below. A set clearance is secured between the outer tube 30 and the inner tube 32, and the cylinder 22 can be expanded and contracted by enabling the relative movement of the outer tube 30 and the inner tube 32 smoothly. A mounted member 40 on which the vehicle body 14 is mounted is attached to the upper portion of the outer tube 30. A motor 24 is fixed to the top of the mounted member 40. The motor shaft 42 of the motor 24 extends downward and is held by a mounted member 40 via a bearing 46 above and below the large-diameter portion 44 so as not to move in the axial direction.

  A portion below the large-diameter portion 44 of the motor shaft 42 is a screw shaft 50 in which a screw groove 48 into which a bearing ball is fitted is formed on the outer peripheral portion. The screw shaft 50 has a length that extends through the outer tube 30 to the inside of the inner tube 32. On the other hand, a nut 52 for holding a bearing ball is fixed to the inner periphery of the upper end portion of the inner tube 32, and the nut 52 and the screw shaft 50 are screwed together via the bearing ball. That is, when a rotational driving force is applied to the screw shaft 50 by the motor 24, a force for moving the nut 52 in the axial direction is generated. In this embodiment, a ball screw, which is a kind of motion conversion device, is configured including the screw shaft 50 and the nut 52.

  A lower holding member 56 that supports the lower end of the spring 16 is attached to the outer periphery of the inner tube 32. The spring 16 is sandwiched between a flange 58 and a lower holding member 56 provided on the mounted member 40 to elastically support the vehicle body 14. A lower end portion of the inner tube 32 is connected to a suspension arm 26 (see FIG. 1) that supports a member that holds the wheel 12, and the inner tube 32 moves up and down with respect to the vehicle body 14 together with the wheel 12. Yes. With the above-described configuration, the vehicle body 14 and each wheel 12 are elastically coupled, and a force for causing the vehicle body 14 and each wheel 12 to approach and separate from each other is generated by the driving force of each motor 24. ing.

  An acceleration sensor 60 that detects the vertical acceleration of the vehicle body 14 is disposed on the mounted member 40. Based on the detection value of the sensor 60, the vertical displacement speed of each part of the vehicle body 14 is acquired.

2. Control Device As shown in FIG. 3, the electromagnetic actuator 20 of the suspension device 10 is controlled by an electronic control unit 100 (ECU, hereinafter simply referred to as “ECU 100”) provided therein. The ECU 100 is mainly configured by a computer including a CPU, a ROM, a RAM, and the like. In addition to the acceleration sensor 60, the ECU 100 is connected to various detection devices such as a lateral acceleration sensor 110 that detects the lateral acceleration of the vehicle body, a vehicle speed detection device 112, and an ammeter 114 that measures the current supplied to the motor 24. ing. Although not shown, the various detection devices are connected as necessary via a filter such as a low-pass filter so that high-frequency components such as noise are removed. Further, an inverter 130 is connected to the ECU 100, and drive power from the inverter 130 to the motor 24 of the electromagnetic actuator 20 is controlled based on various control commands transmitted from the ECU 100 to the inverter 130. Note that power is supplied from the battery 132 to the inverter 130.

  In this embodiment, the electromagnetic motor 24 is a three-phase DC brushless motor and is energized and controlled by the inverter 130. The inverter 130 is a general one as shown in the circuit diagram of FIG. 4, and corresponds to each of the high potential side and the low potential side, and to each of the three phases (U, V, W) of the motor. Corresponding six switching elements UHC, ULC, VHC, VLC, WHC, WLC are provided. The controller CNT determines the motor rotation phase (electrical angle) from the detection signals of the three Hall elements H provided in the motor 24, turns on / off each switching element based on the motor rotation phase, and energizes each coil.・ Generate rotational torque by switching between de-energization. The energization pattern is switched according to the direction of the rotational torque of the motor 24. In addition, the inverter 130 changes the current supplied to the motor 24 by the controller CNT changing the duty ratio (on / off time ratio of the energization pulse) by PWM (pulse width modulation) control, and the rotation torque Change the size. For example, when the duty ratio is increased, the amount of energization current is increased, and the rotational torque generated by the motor 24 is increased. Note that a command signal including information on the rotation direction of the motor 24 and the magnitude of the torque is transmitted from the ECU 100 to the inverter 130. Each switching element of the inverter 130 is provided with a reflux diode in parallel.

  In FIG. 3, various functional units of the ECU 100 are illustrated. Although the configuration of the ECU 100 is not clearly divided as shown in the figure, such a diagram is used in order to facilitate understanding of the function of the ECU 100. The ECU 100 includes a “storage unit 140” configured to include a ROM, a RAM, and the like, and various programs such as a vehicle body motion control program described later and various types of data are recorded in the storage unit 140. (Details will be described later). The ECU 100 also includes a “control force target value determination unit 150” that determines a target value of the control force generated by the electromagnetic actuator 20 of each of the four suspension devices 10. The control force target value determining unit 150 includes a “damping force target value determining unit 152” that determines a target value Fd of a vibration damping force that attenuates the vertical vibration of the vehicle body 14, and a roll that suppresses the roll of the vehicle body 14 during turning. A “roll suppression force target value determination unit 154 (abbreviated as a roll suppression force determination unit in the drawing)” that determines the target value Fr of the suppression force, and a target of the pitch suppression force that suppresses the pitch of the vehicle body 14 during acceleration / deceleration. “Pitch suppression force target value determination unit 156 (abbreviated as pitch suppression force determination unit in the drawing)” for determining the value Fp. The ECU 100 also includes a “control force distribution changing unit 160” that adds a warp component to the four control force target values determined by the control force target value determination unit 150 and changes their distribution. The control force distribution change unit 160 decreases the absolute value of the control force target value for the failed suspension device 10 and the “control force target value averaging unit 162” that averages the absolute value of the control force target value. A “failure target value reduction unit 164”. Further, the ECU 100 includes a “suspension failure detection unit 170” that detects the failure of the suspension device 10. The details of the above functional units will be described together with the description of the control of the electromagnetic actuator 20 below.

3. Control of electromagnetic actuator
3.1. Vehicle Body Motion Control Program Control of the electromagnetic actuator 20 by the ECU 100 will be described. For ease of understanding, it is assumed that the center of gravity of the vehicle body is located at the center position of the four suspension devices 10 and the loads at which the four suspension devices 10 support the vehicle body are equal to each other. In the present embodiment, the ECU 100 generates a “body motion control force” having an appropriate magnitude by the electromagnetic actuator 20, and suppresses vertical vibration of the vehicle body 14 and disturbance in posture change. FIG. 5 shows a flowchart of the “body motion control program”. This program is repeatedly executed every extremely short time by the computer of the ECU 100. In step 11 (hereinafter, step 11 is abbreviated as “S11” and the same applies to other steps), the “vehicle speed” based on the detected value of the vehicle speed detecting device 112 and the vehicle body based on the detected value of the lateral acceleration sensor 110 are detected. “Lateral acceleration”, “vertical acceleration” based on the detection values of the four acceleration sensors 60, “vertical displacement speed” which is a value obtained by integrating each of these vertical accelerations, and supply to each motor 24 based on the detection value of the ammeter 114 The obtained “current value” or the like is acquired. In S <b> 12, the control force target value determination unit 150 determines a “control force target value” that is a target value of the vehicle body motion control force for each suspension device 10. Details of S12 will be described later.

After the control force target value is determined, in S13, the suspension failure detection unit 170 determines whether or not the four suspension devices 10 are operating normally. Specifically, the current value supplied to the motor 24 is monitored. For example, in the case where no current is supplied to the motor 24 even though a command is transmitted to the inverter 130, a disconnection or an inverter It is determined that the electromagnetic actuator 20 has failed due to the failure of 130. If the four suspension devices 10 are normal, the control force averaging unit 162 performs a process of averaging the control force target values in S14.
On the other hand, if any one of the electromagnetic actuators 20 of the four suspension devices 10 is broken due to, for example, disconnection or the like, the control force cannot be generated at all. In that case, in S15, the target value reduction unit 164 at the time of failure performs a process of reducing the control force target value for the suspension device 10 having the failed electromagnetic actuator 20. Details of S14 and S15 will be described later. In S16, a control command is issued to each inverter 130 based on the control force target value after the distribution is changed by the process of S14 or S15. Each inverter 130 supplies electric power so that the electromagnetic actuator 20 generates a vehicle body motion control force according to the control force target value. As a result, the vertical vibration of the vehicle body is suppressed, and the roll and pitch are suppressed.

3.2. Determination of Control Force Target Value The determination of the control force target value in S12 will be described in detail. FIG. 6 shows a vibration model in which a part of the vehicle body 14 is regarded as the sprung member 200. In this figure, one set of sprung member 200 and unsprung member 202 correspond to one wheel 12, and the vehicle has four sprung members 200 and four springs corresponding to four wheels 12. The lower member 202 is included. The vehicle body 14 is configured to include four sprung members 200. Further, the unsprung member 202 includes the wheel 12, the axle, the axle carrier, and the like. In the present embodiment, the spring 16 and the electromagnetic actuator 20 are disposed in parallel between the sprung member 200 and the unsprung member 202. Then, the elastic force of the spring 16 and the approach / separation force of the electromagnetic actuator 20 act on the sprung member 200 and the unsprung member 202.

  In such a model, in addition to the elastic force that supports the vehicle body 14 generated by the spring 16, vibration damping force, roll suppression force, and pitch suppression force are generated by the control of the electromagnetic actuator 20. The sum of these vibration damping force, roll restraining force and pitch restraining force is the vehicle body motion control force. The roll during the turning of the vehicle body and the pitch during acceleration / deceleration are regulated to some extent by the elastic force of the spring 16, but in addition, the vertical vibration, roll and pitch of the vehicle body 14 are controlled by the vehicle body motion control force generated by the electromagnetic actuator 20. Is suppressed even better.

FIG. 7 shows a flowchart of the control force target value determination process in S12, which will be described in detail. This control force target value determination process functions as a subroutine of the vehicle body motion control program. In S21, the damping force target value determining unit 152 determines the damping force target value Fd for each of the four suspension devices 10. Specifically, by multiplying each of the vertical displacement speeds Xvs1 to Xvs4 acquired in S11 by gains Cs1 to Cs4 (Equation 1), a damping force target for the suspension device 10 corresponding to each of the four parts of the vehicle body. Values Fd1-Fd4 are determined. The gains Cs1 to Cs4 are used by reading values stored in the storage unit 140 in advance. The vibration damping force is determined as a positive value for the upward direction and a negative value for the downward direction. The same applies to the following roll restraining force and pitch restraining force.
[Formula 1] Fd = Cs · Xvs

  In S <b> 22, the “roll suppression force target value Fr” is determined by the roll suppression force target value determination unit 154. Since the roll moment that rolls the vehicle body at the time of turning is approximately in accordance with the lateral acceleration, the target value Fr of the roll suppression force for canceling the roll moment is set in accordance with the lateral acceleration of the vehicle body 14. The storage unit 140 of the ECU 100 stores a map indicating the relationship between the lateral acceleration detected by the lateral acceleration sensor 110 and the roll suppression force, and reads the value of the roll suppression force according to the current lateral acceleration. Thus, the roll suppression force target value is determined. The roll restraining force of the present embodiment is a force that raises one of the left and right sides of the vehicle body 14 and a force that lowers the other, and the sign of the roll restraining force target value Fr is opposite to that of the left and right suspension devices 10. become.

  In S <b> 23, the “pitch suppression force target value” is determined by the pitch suppression force target value determination unit 156. The pitch moment for pitching the vehicle body during acceleration / deceleration (acceleration / deceleration) is approximately the magnitude corresponding to the longitudinal acceleration. Therefore, the target value Fp of the pitch suppression force for canceling it is the vehicle speed detection device 112. Is determined according to the longitudinal acceleration of the vehicle acquired based on the change in the vehicle speed detected by the above. The storage unit 140 of the ECU 100 stores a map indicating the relationship between the longitudinal acceleration and the pitch suppression force, and the pitch suppression force target value is determined by reading the pitch suppression force value corresponding to the current longitudinal acceleration. Is done. Note that the pitch suppression force of the present embodiment is a force that raises one of the front and rear of the vehicle body 14 and a force that lowers the other, and the sign of the pitch suppression force target value Fp is opposite to that of the front and rear suspension devices 10. become.

In S24, the damping force target value Fd, the roll suppression force target value Fr, and the pitch suppression force target value Fp are added to determine the control force target values F1 to F4.
In this embodiment, the damping force target value determination unit 152 determines the damping force target value based on the displacement speed in the vertical direction of the vehicle body 14 rather than the relative displacement between the wheel 12 and the vehicle body 14. That is, the “vehicle body displacement state-based target value determination unit that determines four control force target values based on the vertical displacement state in the absolute coordinate system of the four portions of the vehicle body corresponding to the four wheels” is the damping force target. The value determining unit 152 is included.

3.3. Control force averaging process The control force averaging process of S14 described above changes the distribution of the four control force target values F1 to F4 to the four electromagnetic actuators 20 by adding a warp component, and maximizes the absolute value thereof. This is a process of decreasing the value to reduce the difference between the absolute values of the four control force target values, that is, a process of averaging the absolute values of the four control force target values. Here, before explaining the details of the control force averaging process, FIG. 8 schematically shows the vehicle, and the adjustment of the warp component is explained. In this figure, the control force target values F1 to F4 correspond to the right front (FR), left front (FL), right rear (RR), left rear (RL) electromagnetic actuators 20 (and thus the suspension device 10), respectively. ing. Symbols F1 ′ to F4 ′ represent control force target values after adding the warp component. The warp component is a component that rolls the front and rear portions of the vehicle body 14 in opposite directions. In other words, among the four parts of the vehicle body, one diagonal part (for example, two parts of FR and RL) is raised and the other diagonal part (for example, two parts of FL and RR). This is a component that lowers the portion. The adjustment of the warp component in this figure is shown below.
[Formula 2] F1 ′ = F1 + Wa
[Formula 3] F2 ′ = F2-Wa
[Formula 4] F3 ′ = F3-Wa
[Formula 5] F4 ′ = F4 + Wa
In the example of the figure, the warp component Wa is added to the control force target values F1 and F3 of one diagonal portion, and is subtracted from the control force target values F2 and F4 of the other diagonal portion. The absolute value of the warp component added to or subtracted from each of the four control force target values is equal.

  Here, an outline of determination of the warp component to be added to the four control force target values will be described. The absolute maximum target value (hereinafter, may be abbreviated as “maximum target value” in some cases) that is the control force target value with the maximum absolute value is Fmax, and the maximum target value Fmax is 2 adjacent to the corresponding suspension device 10. The adjacent target value that is the control force target value of each of the two is Fn, and the diagonal target value that is the control force target value for the suspension device 10 that is located diagonally of the suspension device 10 corresponding to the maximum target value Fmax is Fo. To do. When the warp component Wa is added to reduce the absolute value of the maximum target value Fmax, one or more of the two adjacent target values Fn and the diagonal target value Fo, which are the other three control force target values, are added. The absolute value of things increases. Therefore, the absolute value of the maximum target value Fmax cannot be reduced without limitation, and the absolute value of the warp component Wa is determined in consideration of the increase / decrease of the two adjacent target values Fn and the one diagonal target value Fo. The That is, the absolute value after subtracting the warp component Wa from each of the two adjacent target values Fn, and the maximum of the absolute values after adding the warp component Wa to the one diagonal target value Fo In the state where the absolute value after adding the warp component Wa to the maximum target value Fmax is equal, the maximum absolute value of the four control force target values can be made as small as possible. By obtaining the value of the warp component Wa in that state, the value of the warp component Wa that makes the four control force target values most averaged by reducing the absolute value of the maximum target value Fmax as much as possible. The most averaged warp value Wa1 (hereinafter may be abbreviated as “maximum averaged value Wa1”) can be obtained.

When one of the two absolute values after subtracting the warp component Wa from each of the two adjacent target values Fn is the maximum, the value obtained by adding the maximum average value Wa1 to the maximum target value Fmax and the adjacent value The value obtained by subtracting the maximum average value Wa1 from the target value Fn becomes equal (Formula 6), and the maximum average value Wa1 can be obtained (Formula 7). In this case, the maximum average value Wa1 is a value corresponding to the difference between the maximum target value Fmax and the adjacent target value Fn.
[Formula 6] Fmax + Wa1 = Fn−Wa1
[Formula 7] Wa1 = − (Fmax−Fn) / 2
Next, in the case where the absolute value after adding the warp component Wa to the one diagonal target value Fo is the maximum, the circumstances are slightly different from the above formulas 6 and 7. Since the warp component Wa having the opposite sign to the maximum target value Fmax is added to the adjacent target value Fn, the movement directions of the adjacent target value Fn and the maximum target value Fmax are opposite to each other on the number line. On the other hand, since the warp component Wa having the same sign as the maximum target value Fmax is added to the diagonal target value Fo, the movement directions of the diagonal target value Fo and the maximum target value Fmax are equal to each other on the number line. Become. Therefore, the absolute value of the diagonal target value Fo after addition of the warp component Wa is the maximum and equal to the absolute value of the maximum target value Fmax after addition of the warp component Wa is the diagonal target value after addition of the warp component Wa. This is a case where the sign of Fo and the sign of the maximum target value Fmax after addition of the warp component Wa are opposite to each other. Therefore, the value obtained by adding the maximum average value Wa1 to the maximum target value Fmax is equal to the value obtained by reversing the sign of the value obtained by adding the maximum average value Wa1 to the diagonal target value Fo (Equation 8). An averaged value Wa1 can be obtained (Formula 9). In this case, the maximum average value Wa1 is a value corresponding to the sum of the maximum target value Fmax and the diagonal target value Fo.
[Formula 8] Fmax + Wa1 = − (Fo + Wa1)
[Formula 9] Wa1 = − (Fmax + Fo) / 2

  FIG. 9 illustrates four control force target values by simple numerical values, and the adjustment of the warp component will be described. For example, when the control force target values F1 to F4 are 9, 1, 3, and -5, and the warp component Wa = -2 is added, F1 'to F4' become 7, 3, 5, and -7, respectively. It can be seen that the two control force target values (F1 ′ = 7 and F4 ′ = − 7) are averaged to a state where the absolute values are equal to each other at the maximum. That is, in the example of this figure, the value −2 of the warp component Wa is the maximum average warp value Wa1. On the other hand, when the warp components Wa = −1 and −3 are added, the state is averaged to some extent, and when the warp component Wa = 1 is added, the maximum target value Fmax is increased. Note that when the warp component Wa = -3 is added, the total absolute value of the control force target values becomes larger than when Wa = -1 is added. It is preferable to add Wa = −1. Thus, the four control force target values can be averaged by appropriately determining the magnitude of the warp component Wa to be added.

FIG. 10 shows a flowchart of the control force averaging process in S14. This control force averaging process functions as a subroutine of the vehicle body motion control program. The control force averaging process will be described below along the flowchart of FIG. 10 and the specific example of FIG.
In S31, the absolute value of each control force target value is acquired, and in S32, the target value having the maximum absolute value is set to “absolute value maximum target value Fmax”. Note that the absolute maximum target value (hereinafter may be abbreviated as “maximum target value”) is a “specific control force target value that satisfies the condition“ absolute value is maximum ”as an example of“ set condition ”. Is. In the specific example of FIG. 9, the maximum target value Fmax is “F1 = 9”. In S33, values “D1, D2” obtained by subtracting each of the two adjacent target values Fn1, Fn2 from the maximum target value Fmax are calculated (Formula 10). Further, the sum “S” of the absolute maximum target value Fmax and the “diagonal target value Fo” is calculated (Formula 11). Equations 10 and 11 calculate values in parentheses of Equations 7 and 9, respectively.
[Formula 10] D1 = Fmax−Fn1, D2 = Fmax−Fn2
[Formula 11] S = Fmax + Fo
In the example of FIG. 9, the adjacent target values Fn1 and Fn2 are F2 = 1 and F3 = 3, respectively, and the differences D1 = 9-1 = 8 and D2 = 9-3 = 6. The diagonal target value Fo is F4 = −5, and the sum S = 9 + (− 5) = 4.

In S34, the most averaged warp value Wa1 is obtained using the value having the smallest absolute value among "D1, D2, S". This is because if the averaged warp value Wa1 is obtained using a value whose absolute value is not the minimum, the warp component Wa to be added becomes excessive. For example, in the example of FIG. 9, when the warp component Wa = −3 is added, the warp component Wa to be added becomes excessive and corresponds to the control force target value other than the maximum target value Fmax (in this example, the diagonal target value Fo) Wa = −3 is added to F4 = −5, so that F4 ′ = − 8. As a result, the absolute value of F4 ′ is maximized. Therefore, the value having the smallest absolute value among “D1, D2, S” is substituted into the variable β. In addition, the inside of parentheses in either Equation 7 or Equation 9 is the variable β, and the maximum average value Wa1 is obtained.
[Formula 12] Wa1 = −β / 2
In the example of FIG. 9, since the minimum value is S = 4 as described above, 4 is substituted into the variable β, and the maximum average value Wa1 = −2.

In S35, it is determined whether or not the absolute value of the maximum average value Wa1 exceeds the set value. When the absolute value of the maximum average value Wa1 is equal to or less than the set value, for example, it is determined that the effect of averaging is small, and the process of S36 is skipped. In this case, the control force target value is not averaged, and the control command of S16 is made based on the control force target value determined by the process of S12. Note that the determination in S35 may be YES when, for example, the maximum average value Wa1 is a value other than zero. On the other hand, if the maximum average value Wa1 exceeds the set value, “u · Wa1” is added to the maximum target value Fmax and the diagonal target value Fo in S36, and each of the two adjacent target values Fn “ u · Wa1 ”is subtracted.
The “coefficient u” can be a positive number of 1 or less, and the degree of averaging can be changed by changing its value. For example, in the example of FIG. 9, if the coefficient u is 1, u · Wa1 = 1 × (−2) = − 2 and the warp component Wa = −2 is added. Therefore, when Wa = −2 is added to the maximum target value F1 = 9, F1 ′ = 7 is obtained. For the calculation of the control force target value other than the maximum target value, in the example of FIG. 9, Wa = −2 is added to F4 = −5, which is the diagonal target value, so that F4 ′ = − 7. Wa = −2 is subtracted from each of F2 = 1 and F3 = 3, and F2 ′ = 3 and F3 ′ = 5. If the coefficient u is 0.5, the warp component Wa = −1 is added in the example of FIG. 9, and the four control force target values are averaged to a considerable extent.

  By controlling the electromagnetic actuator based on the control force target values F1 'to F4' averaged by the above processing, it is possible to reduce the concentration of the output to the specific suspension device 10. Moreover, the temperature rise of the motor 24 can be suppressed by decreasing the maximum target value.

Here, the three components of the vehicle body motion control force included in the four control force target values and the force for controlling the posture of the vehicle body will be described. FIG. 11 shows a heave component (H) for controlling the heave motion, a roll component (R) for controlling the roll motion, and a pitch component (P) for controlling the pitch motion. In addition, a component that controls the posture of the vehicle body of the target value after the distribution change by adding the warp component is also shown. In the example of this figure, the four control force target values include 2 for the heave component (H), 4 for the roll component (R), and 3 for the pitch component (P). As shown in this figure, in the calculation, even if the warp component (Wa = −2) is added, the heave component (H), the roll component (R), and the pitch component, which are the three components that control the posture of the vehicle body. It can be seen that (P) does not change. In other words, even if the warp component is added to the control force target value, the control of the posture of the vehicle body is not affected or hardly exerted. In addition, each component is calculated | required by following Formula.
[Formula 13] H = (F1 + F2 + F3 + F4) / 4
[Formula 14] R = (F1-F2 + F3-F4) / 4
[Formula 15] P = (F1 + F2-F3-F4) / 4

  Furthermore, FIG. 12 shows a determinant (a) for calculating a heave component (H), a roll component (R), a pitch component (P), and a warp component (W) from four control force target values F1 to F4. A determinant (b) for calculating four control force target values F1 ′ to F4 ′ obtained by changing the distribution by adding the warp component Wa to the control force target values F1 to F4, and four control force target values F1 ′ after the distribution change. A determinant (c) for calculating each component H ′, R ′, P ′, W ′ after the change from .about.F4 ′ is shown. W represents a warp component included in the four control force target values, and Wa represents a warp component to be added to change the control force distribution. In the example of FIG. 11, the warp component (W) included in the four control force target values before the change is 0, and the warp component Wa added to change the control force distribution is −2. H ′, R ′, P ′, and W ′ are components of H, R, P, and W included in the four control force target values F1 ′ to F4 ′ after the control force distribution change. From the determinant (c), it can be seen that the three components H ′, R ′, and P ′ after the change of the control force distribution are the same as before the change. Further, the warp component W ′ after the change has a size obtained by adding the warp component Wa to the warp component W before the change. In the example of FIG. 10, the warp component (W ′) included after the control force distribution change is W + Wa = 0 + (− 2) = − 2.

  As described above, according to the control force averaging process performed by the control force averaging unit 162, the maximum target value is decreased by adding a warp component while suppressing the influence on the control of the posture of the vehicle body. The absolute values of the two control force target values can be averaged. That is, the “target absolute value averaging unit” includes the control force averaging unit 162. If only the maximum target value is simply decreased, the magnitudes of the three components (H, R, P) for controlling the posture change, which may adversely affect the posture control. .

  Further, when the warp component is adjusted to the control force target value, in many cases, the absolute value of the warp component included in the four control force target values increases. In FIG. 11, the absolute value of the warp component increases from 0 to 2. The increased warp component acts to roll the front and rear of the vehicle body 14 in opposite directions, but in this embodiment, the rigidity of the vehicle body 14 with respect to the front and rear torsion is sufficiently increased. That is, the warp amount can be kept sufficiently small. Further, heave, roll and pitch motions are allowed to some extent by the suspension device 10, whereas warp motion is strongly regulated by the rigidity of the vehicle body, so the warp amount is heave, roll and pitch motions. And generally very small.

3.4. Failure Load Reduction Processing FIG. 13 shows a flowchart of the failure load reduction processing in S15. In the failure load reduction process, when any of the electromagnetic actuators 20 of the four suspension devices 10 has failed, the suspension device 10 having the failed electromagnetic actuator 20 (hereinafter, “failed suspension device 10”). The control force target value for “the failure control force target value” (which is one aspect of the “specific control force target value”) is reduced. Accordingly, the warp component is added to the four control force target values. Whether or not the electromagnetic actuator 20 has failed is determined based on the current value supplied to each motor 24 from each inverter 130 detected by the ammeter 114 as described above. Specifically, for example, when the current value supplied to the motor 24 is 0 even though a control command is issued to the inverter 130 to generate a force corresponding to the determined control force target value. Is determined that the electromagnetic actuator 20 has failed due to disconnection of the motor 24, failure of the inverter 130, or the like. In this embodiment, the control force that can be generated by the failed electromagnetic actuator 20 is set to zero. The state where the control force is not generated due to the failure of the electromagnetic actuator 20 is an aspect of the “control force insufficient state”.

In S41, the control force target value for the lost suspension apparatus 10 is set as the control force target value γ at the time of failure, and the load reduction amount, that is, the magnitude Wa of the warp component to be added is calculated by the following equation based on this value. It is determined.
[Formula 16] Wa = −z · γ (0 <z ≦ 1)
The “coefficient z” can be a positive number of 1 or less, and the degree of load reduction can be changed by changing the value. FIG. 14 shows an example in which the distribution of the control force target value is changed by adding the warp components Wa = −9 and Wa = −4.5. In the example of FIG. 14, the control force target value γ at the time of failure is 9, and when the coefficient z is 1, Wa = −1 × 9 = −9. That is, when the coefficient z is 1, the warp component Wa is added so that the control force target value of the lost suspension apparatus 10 becomes 0. On the other hand, when the coefficient z is set to 0.5, the warp component Wa is added so that the control force target value of the suspended suspension apparatus 10 is halved.
When the electromagnetic actuator 20 can generate a certain amount of force, the coefficient z can be changed according to the force that the electromagnetic actuator 20 can generate. For example, when the electromagnetic actuator 20 can generate a force that is about half of that in a normal state, the coefficient z can be set to 0.5.

  In S42, the control force target value γ at the time of failure (F1 = 9) and the diagonal target value Fo that is the control force target value for the suspension device 10 that is located diagonally to the corresponding suspension device 10 that has failed. The warp component Wa (= -9) is added to each of (F4 = -5). Further, adjacent target values Fn1, Fn2 (F2 = 1, F3 =) that are control force target values for each of the two suspension devices 10 adjacent to the suspension device 10 that corresponds to the control force target value γ at the time of failure. Wa is subtracted from 3). Note that symbols and numerical values in the example of FIG. 14 are shown in parentheses. The value −9 of the warp component Wa is a value when the coefficient z is set to 1. By performing the above calculation, F1 '= 0, F2' = 10, F3 '= 12, and F4' =-14 are obtained.

  The lower half of FIG. 14 shows three components and warp components of the posture control force of the four control force target values before and after the change. It can be seen that even if the warp component Wa is added, the heave component (H), roll component (R), and pitch component (P) do not change in the calculation. That is, by adding the warp component to the four control force target values by the load reduction process at the time of the failure, the control force target value for the failed suspension device 10 is suppressed while suppressing the influence on the control of the posture of the vehicle body. Can be reduced.

  In this embodiment, when the electromagnetic actuator 20 fails, the control force cannot be generated, and the control force is insufficient, that is, the “control force insufficient state”. Then, the target value decrease unit 164 at the time of failure decreases the absolute value of the control force target value for the suspension device 10 in the insufficient control force state by adding the warp component Wa. In other words, in the present embodiment, the “target value absolute value decrease unit at the time of insufficient control force” includes the target value decrease unit 164 at the time of failure. Further, in the present embodiment, since the control force cannot be generated by the failed electromagnetic actuator 20, the control power deficiency becomes the control force target value γ−0 = γ at the time of failure. The absolute value of the warp component is determined based on the control force target value γ at the time of failure, which is an insufficient amount of control force. In other words, the “control force deficient amount dependency reducing unit” that determines the absolute value of the warp component based on the deficient amount of the vehicle body motion control force includes the failure target value reducing unit 164.

4. Modification In the process of S12 of the above embodiment, the vibration suppression of the unsprung member 202 is not considered when determining the control force target value. However, the control force is determined in consideration of the vibration suppression of the unsprung member 202. A target value can also be determined. For example, in FIG. 6, an acceleration sensor is provided in the unsprung member 202, and the displacement speed acquired based on the detected value is Xvg.
[Formula 17] Fdg = −Cg · Xvg
Cg is an “unsprung gain” set for each suspension device 10. The Fdg becomes an unsprung damping force that attenuates the vibration of the unsprung member 202. The unsprung damping force Fdg is added to the control force target value F determined in the above embodiment to obtain the final control force target value. When the timing of adding the unsprung damping force Fdg is before the control force target value is averaged, the control force target value obtained by combining the vehicle body motion control force and the unsprung damping force Fdg is averaged. Thus, the absolute maximum target value can be effectively reduced. On the other hand, when the unsprung damping force Fdg is added after the control force target value is averaged, it is possible to suppress the effect of damping the vibration of the unsprung member 202 from being reduced by changing the distribution of the control force target value. it can. However, when damping of the unsprung member 202 is taken into consideration, it is desirable to add the unsprung damping force Fdg after averaging the control force target value.
When performing the load reduction process at the time of failure, it is desirable that the control force target value at the time of failure does not include the unsprung damping force Fdg. This is because the failure load reduction process is a process for supplementing the vehicle body motion control force by the suspension device 10 that has not failed.

In the above embodiment, the force generated by the electromagnetic actuator 20 includes a vibration damping force component. However, in addition to the vibration damping force component, a force for suppressing vibration can be generated based on the amount of displacement. In that case, for example, a term obtained by multiplying the right side of [Formula 1] by the gain Ks set to the displacement amount Xs of the sprung member 200 can be added.
[Formula 18] Fdp = Cs · Xvs + Ks · Xs
The displacement amount Xs of the sprung member 200 is a displacement amount from the reference height position Xs0 of the vehicle body 14. The reference height position Xs0 is, for example, provided with a separation distance detection device (a kind of vehicle height detection device) that detects a separation distance between the vehicle body 14 and the wheel 12 in the suspension system, and a detection value of the separation distance detection device. The average value per set time of the height position of the vehicle body 14 obtained based on the above, or the value when the vehicle is stopped can be used.

  Furthermore, in the above embodiment, the center of gravity of the vehicle body 14 is positioned at the center of the four suspension devices 10. However, even in a suspension system where the center of gravity is not positioned at the center of the four suspension devices 10, the control force averaging is performed. Processing, failure load reduction processing can be applied. This is because even if the warp component is added, as long as the vehicle body 14 is considered as a rigid body, the three components H, R, and P that control the posture of the vehicle body are not affected regardless of the position of the center of gravity of the vehicle body 14.

It is a figure which shows typically the suspension system which is an Example of claimable invention. It is a figure which shows the suspension apparatus of the said suspension system. It is a figure which shows typically the electronic control unit (ECU) which controls the electromagnetic actuator of the said suspension apparatus. It is a schematic diagram which shows the inverter which supplies electric power to the said electromagnetic actuator. It is a schematic diagram which shows the flowchart of the program which controls the said electromagnetic actuator and controls the motion of a vehicle body. It is the schematic diagram which represented a part of vehicles provided with the said suspension apparatus with the model containing a sprung member and an unsprung member. It is a flowchart which shows the control force target value determination process of the said vehicle body movement control program. It is a figure which shows typically the vehicle provided with the said suspension system. It is a figure which shows the simple example of the control force target value F1-F4 about the said electromagnetic actuator, and the control force target value F1'-F4 'after the warp component Wa addition. It is a flowchart which shows the control force average process of the said vehicle body movement control program. It is a figure which shows the heave component before and after the averaging process of the said control force target value, a roll component, and a pitch component. It is a figure which shows the formula which calculates the heave component, roll component, and pitch component which are contained in the four control force target values before and after the addition of the warp component Wa. It is a flowchart which shows the load reduction process at the time of failure of the said vehicle body movement control program. It is a figure which shows four control-force target values before and after the said load reduction process at the time of failure, a heave component, a roll component, and a pitch component.

Explanation of symbols

10: Suspension device 12: Wheel 14: Vehicle body 16: Spring 20: Electromagnetic actuator (actuator) 22: Cylinder 24: Electromagnetic motor 60: On-spring acceleration sensor 100: Electronic control unit [ECU] (control device) 110: Lateral acceleration Sensor 112: Vehicle speed detection device 130: Inverter 132: Battery (power source) 140: Storage unit 150: Control force target value determination unit 152: Damping force target value determination unit 154: Roll suppression force target value determination unit 156: Pitch suppression force target Value determining unit 160: Control force distribution changing unit 162: Control force averaging unit 164: Failure target value decreasing unit 170: Suspension failure detecting unit 200: Sprung member 202: Unsprung member

Claims (4)

Four suspension devices each having an actuator for connecting a corresponding one of the four wheels and the vehicle body, and generating a force for moving the one wheel and the vehicle body toward and away from each other;
A suspension system comprising a control device for controlling these four suspension devices,
The control device is
A control force target value determining unit that determines a control force target value that is a target value for each of the four actuators of the vehicle body motion control force that is a force that controls the motion of the vehicle body;
The warp component is determined so as to decrease the absolute value of the specific control force target value which is a specific target value among the four control force target values determined by the control force target value determination unit, and the determination A control force distribution changing unit that changes the distribution of the vehicle body motion control force to the four actuators by adding the warp component to each of the four control force target values and correcting the four control force target values. A suspension system characterized by comprising: The control force distribution changing unit is
The absolute value maximum target value having the maximum absolute value among the four control force target values is set as the specific control force target value, and the absolute value is decreased, thereby reducing the four control force target values. The suspension system according to claim 1, further comprising a target absolute value averaging unit that averages the absolute values of the two. The control force distribution changing unit is
When any one of the four suspension devices is in a control force shortage state in which a vehicle body motion control force that can be generated is insufficient, the control force target value for the suspension device in the control force shortage state is specified. The suspension system according to claim 1, further comprising a target value absolute value reduction unit when the control force is insufficient to reduce the absolute value of the control force target value. The control force target value determination unit determines the four control force target values based on the vertical displacement states in the absolute coordinate system of the four portions of the vehicle body corresponding to the four wheels. The suspension system according to any one of claims 1 to 3 , further comprising a determination unit.

Images