JP2009166631A - Suspension system for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a practical suspension system for vehicles. <P>SOLUTION: In this suspension system, a suspension spring and an approaching and separating force generating device for controllably generating approaching and separating force are arranged parallel to each other. (a) a first pair unsprung component vibration controls S22, S23 which generate the approaching and separating force as a damping force against the vibration of a spring lower part and (b) a second pair unsprung component vibration control S24 which does not generate the approaching and separating force as a damping force against the vibration of the spring lower part are selectively performed. When a side slip of a vehicle exceeding an allowable limit occurs S17, the first pair unsprung component vibration control is performed. With this system, the lowering of the grounding performance of wheels can be suppressed since a damping effect on the vibration of the unsprung components can be increased when the side slip of the vehicle exceeding the allowable limit occurs. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a vehicle suspension system in which a device for moving an upper spring portion and an lower spring portion close to and away from each other by the force of an electromagnetic motor is provided for each wheel.

A device that controllably generates a force in a direction in which the upper and lower springs are moved toward and away from each other by the force of the electromagnetic motor (hereinafter also referred to as “close-and-separation force”), that is, an approach and separation force generator is provided for each wheel. In recent years, the vehicle suspension system deployed in has been rapidly developed because there is a high possibility that the behavior of the vehicle body such as the posture and vibration of the vehicle body can be appropriately controlled. As such a vehicle suspension system, for example, a system as shown in the following patent document has been studied.
JP 2002-218778 A JP 2002-211224 A JP 2006-82751 A

  The approaching / separating force generator included in the vehicle suspension system described in the above-mentioned patent document is controlled to suppress the roll of the vehicle body, for example, and plays a role in stabilizing the vehicle body posture. However, a system equipped with such an approaching / separating force generator is still under development, leaving much room for improvement. Therefore, it is considered that the practicality of the system is improved by making various improvements. This invention is made | formed in view of such a situation, and makes it a subject to provide a highly practical vehicle suspension system.

  In order to solve the above-mentioned problems, a vehicle suspension system according to the present invention is a system in which a suspension spring and an approaching / separating force generating device that generates an approaching / separating force in a controllable manner are arranged in parallel to each other. (A) First unsprung vibration control for generating approaching / separating force as damping force against vibration of the unsprung part, and (b) Approaching / separating force is generated in the first unsprung vibration control. The second anti-spring vibration control that is generated as a damping force that is smaller than the damping force or that is not generated as a damping force is configured to be selectively executed. It is comprised so that 1 pair unsprung vibration control may be performed.

  The approaching / separating force generating device can effectively control the vibration of the unsprung portion by the force generated by the electromagnetic motor. In the vehicle suspension system of the present invention equipped with the approaching / separating force generator, the first pair of unsprung vibration control, which is a relatively high damping effect for the unsprung vibration, and the damping effect for the unsprung vibration are provided. The second pair of unsprung vibration control, which is a relatively low control, can be selectively executed. If a side slip of the vehicle exceeding the allowable limit occurs, the first pair of unsprung vibration control is performed. The Therefore, according to the system of the present invention, it is possible to suppress, for example, a decrease in the grounding performance of the wheels when the skid of the vehicle exceeding the allowable limit occurs, and to improve the running stability of the vehicle. Is possible.

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 merely for the purpose of facilitating the understanding of the claimable inventions, and is not intended to limit the combinations of the constituent elements constituting those inventions 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 constituent elements are deleted from the aspect of each item can be an aspect of the claimable invention.

  Note that the following items (1) to (4) are related to the embodiment showing the structure that is the premise of the claimable invention, and any of the items listed in the following paragraphs is included in any of the above embodiments. An aspect to which the technical features described above are added becomes an aspect of the claimable invention. By the way, the item (5) that cites the item (1) corresponds to the item (1), and the technical feature described in the item (6) is added to the item (1). The technical feature described in (7) is added to Item 2 and the technical feature described in (8) is added to any one of Claims 1 to 3 in Claim 3. Is obtained by adding the technical feature described in (9) to claim 4, claim 5, or any one of claims 1 to 5, according to claim (12). A technical feature added to claim 6, a technical feature added to claim 6 (13) added to claim 7, and any one of claims 1 to 5. What added the technical feature described in the item (14) is claimed in claim 8, and what added the technical feature described in the item (15) in claim 8 is claimed. 9, obtained by adding the technical features described in any one (16) and (17) section of claim 1 to claim 9 to claim 10, corresponding respectively.

(1) a suspension spring disposed between the sprung portion and the unsprung portion;
An electromagnetic motor is provided in parallel with the suspension spring, and an approaching / separating force that is a force in a direction of approaching / separating the upper and lower parts of the spring is generated based on the force generated by the electromagnetic motor. An approach and separation force generator;
A vehicle suspension system comprising: a control device that controls an approaching / separating force generated by the approaching / separating force generating device by controlling an operation of the electromagnetic motor;
The control device is
(a) first unsprung vibration control for generating the approaching / separating force as a damping force having a magnitude according to a predetermined rule for the unsprung vibration; and (b) the approaching / separating force for the unsprung vibration. The unsprung vibration that selectively generates the second unsprung vibration control that is generated as a damping force smaller than the damping force generated in the first unsprung vibration control or not generated as the damping force. A vehicle suspension system having a control execution unit.

  The mode described in this section is a mode that forms the premise of the claimable invention, and is a mode in which the approaching / separating force generating device is used as a vibration damping device for damping the vibration of the vehicle. The “approaching / separating force generator” described in this section can effectively attenuate the vibration of the unsprung portion by the force generated by the electromagnetic motor. In the embodiment described in this section, It is possible to selectively execute the first pair of unsprung vibration control, which is a control with a relatively high damping effect, and the second pair unsprung vibration control, which is a control with a relatively low damping effect for the unsprung vibration. .

  A typical vehicle is provided with a vibration damping device, for example, a hydraulic shock absorber, provided between the sprung portion and the unsprung portion to attenuate the vibration of the vehicle, and the damping generated by the device. The value of the damping coefficient, which is a reference for the magnitude of the force, affects the grounding property of the wheel, the transmission of vibration to the spring top, and the like. Since the grounding performance of the wheel affects the operability of the vehicle and it is not desirable to reduce the grounding performance of the wheel, the damping force against the vibration of the unsprung portion is large in order to suppress the degradation of the grounding performance of the wheel. Is preferable. In other words, it is desirable to increase the damping coefficient for the vibration of the unsprung part and to increase the damping effect for the vibration of the unsprung part. On the other hand, when considering the transmission of vibration to the spring top, vibration in a relatively high frequency range is more easily transmitted to the spring top as the value of the damping coefficient is larger. For this reason, when considering the transmission of vibrations in a relatively high frequency range to the upper part of the spring, it is desirable to reduce the damping coefficient for the vibration of the unsprung part and reduce the damping effect for the vibration of the unsprung part. Therefore, when the damping effect against unsprung vibration is increased, the grounding property of the wheel is improved. On the other hand, when the damping effect against unsprung vibration is lowered, vibration in a relatively high frequency range is transmitted to the upper part of the spring. It becomes difficult.

  Further, the lower the damping effect on the unsprung vibration, that is, the smaller the damping force on the unsprung vibration, the more the power consumption by the electromagnetic motor is reduced and the burden on the electromagnetic motor is reduced. As described above, each control has different characteristics, and according to the aspect described in this section, by selectively executing each control, for example, the characteristics of each control are utilized. Is possible. For example, basically, in consideration of the transmission of vibrations in the high frequency range to the upper part of the spring and the reduction of the power consumption of the electromagnetic motor, etc., the second anti-spring vibration control should be executed to improve the wheel grounding property. In this case, the first unsprung vibration control can be executed.

  The configuration of the “approaching / separating force generator” described in this section is not particularly limited. For example, as will be described later, an elastic body connected to one of the spring upper part and the spring lower part and the elastic body thereof The actuator may be configured such that the force generated by the actuator is applied to the elastic body and the force is generated as an approaching / separating force. That is, the approaching / separating force generating device can be a constituent element of a so-called left and right independent stabilizer device. In addition, as will be described later, there is a sprung unit connected to the sprung portion and a sprung unit connected to the sprung portion. The unit can be expanded and contracted by relative movement, and a force in the direction of relative movement of the two units is generated based on the force generated by the electromagnetic motor, and the force acts as an approaching / separating force. There may be. That is, a so-called electromagnetic shock absorber may be employed as the approaching / separating force generator.

  (2) The vehicle suspension system according to (1), wherein the damping force having a magnitude according to the determined rule is a damping force having a magnitude corresponding to the unsprung absolute speed.

  The mode described in this section is a mode in which the control law of anti-sprung vibration control is limited. The approaching / separating force generator can generate a damping force that does not depend on the relative speed between the sprung portion and the unsprung portion due to the force generated by the electromagnetic motor. It is possible to execute control based on the so-called ground hook damper theory. Therefore, according to the aspect described in this section, the vibration of the unsprung portion can be effectively damped.

  (3) The vehicle suspension system according to (1) or (2), wherein the second unsprung vibration control is control that does not generate the approaching / separating force as a damping force with respect to the vibration of the unsprung portion.

  (4) The second unsprung vibration control is a control for generating the approaching / separating force as a damping force smaller than the damping force generated in the first unsprung vibration control with respect to the vibration of the unsprung portion ( The vehicle suspension system according to item 1) or (2).

  The modes described in the above two terms are modes in which the second unsprung vibration control is limited. According to the modes described in the respective terms, for example, the transmission of the high-frequency vibration to the upper part of the spring is reduced. In addition, it is possible to reduce the power consumption of the electromagnetic motor. Moreover, according to the aspect of the former term, it is possible to further reduce the transmission of vibrations in a high frequency region and further reduce the power consumption of the electromagnetic motor. However, in the case described in the former section, the unsprung spring is different from the approaching / separating force generating device because there is a possibility that the grounding property of the wheel may be considerably deteriorated when the vibration of the unsprung portion is not dealt with at all. It is desirable to provide a device capable of dampening vibration, more specifically, a hydraulic shock absorber.

  (5) Items (1) to (1), wherein the anti-sprung vibration control execution unit executes the first anti-sprung vibration control when a side skid of a vehicle exceeding an allowable limit occurs. 4. The vehicle suspension system according to any one of items 4).

  If the vehicle slips beyond the allowable limit, in other words, if the vehicle skids due to the wheels slipping beyond the grip limit, the vehicle will run off the planned travel line. Become. For this reason, in such a case, it is desirable to improve the grounding property of the wheel. In addition, the vibration of the unsprung part and the grounding property of the wheel are related to each other, and the damping effect on the vibration of the unsprung part is enhanced, that is, the grounding property of the wheel is enhanced by increasing the damping coefficient for the unsprung vibration. It is possible. Therefore, according to the aspect described in this section, it is possible to increase the damping effect against the unsprung vibration when the vehicle slips exceeding the allowable limit, for example, to improve the grounding property of the wheel. Thus, it becomes possible to improve the running stability of the vehicle.

  (6) In the item (5), the anti-sprung vibration control execution unit is configured to execute the second anti-sprung vibration control when the vehicle does not slip beyond the allowable limit. The vehicle suspension system described.

  In consideration of the transmission of vibration to the upper part of the spring, reduction of power consumption of the electromagnetic motor, etc., it is desirable to execute the second unsprung vibration control. Therefore, according to the aspect of this section, for example, when it is desired to improve the grounding property of the wheel, the first unsprung vibration control is executed, and in other cases, the transmission of vibration to the sprung portion is lowered. It becomes possible to reduce the power consumption of the electromagnetic motor.

(7) Side slip suppression in which the vehicle suspension system controls the side slip of the vehicle by controlling at least one of a braking force and a propulsive force against the vehicle when a side slip of the vehicle exceeding the allowable limit occurs. Provided in a vehicle equipped with a vehicle skid control system capable of performing control,
The unsprung vibration control execution unit is configured to execute the first unsprung vibration control based on a command from the vehicle skid restraint system. Vehicle suspension system.

  When the vehicle is traveling at a high speed, during an emergency avoidance operation, or traveling on a road surface with a low frictional resistance, a vehicle skidding exceeding the allowable limit may occur. In such a case, a so-called VSC (Vehicle Stability Control) system has already been put into practical use, which controls the side slip of the vehicle by controlling at least one of the braking force and the propulsive force on the vehicle. The mode described in this section is a mode in which the first unsprung vibration control is executed in conjunction with the vehicle side slip suppression system. In the case where the side skid of the vehicle is suppressed in the vehicle side slip restraining system, if the ground contact property of the wheel is lowered, the side skid restraining effect of this system may be lowered. Therefore, according to the aspect described in this section, for example, it is possible to improve the ground contact property of the wheel when the side-slip suppression control is executed, and the side-slip of the wheel can be effectively suppressed by the side-slip suppression control. That is, the performance of the vehicle skid restraint system can be improved by executing the first anti-sprung vibration control in conjunction with the vehicle skid restraint system.

  (8) The anti-sprung vibration control execution unit is configured to execute the first anti-sprung vibration control on condition that the vibration intensity of the unsprung resonance frequency exceeds a set value. The vehicle suspension system according to any one of (5) to (7).

  The mode described in this section is a mode in which the condition for executing the first unsprung vibration control is further limited. In other words, the “first unsprung vibration control” described in this section is executed on the condition that side slip of the vehicle exceeding the allowable limit occurs and vibration in the unsprung resonance frequency region having a certain level of strength occurs. It is done. The grounding property of a wheel in a vibration in a relatively high frequency range, specifically, in a vibration in an unsprung resonance frequency range, for example, is considerably lower than the grounding property of a wheel in a vibration in a low frequency range. There is. Therefore, according to the aspect described in this section, it is possible to execute the first unsprung vibration control when, for example, a decrease in the grounding property of the wheel is particularly assumed.

  Whether or not it is in the “situation where the intensity of vibration of the unsprung resonance frequency exceeds a set value” described in this section is determined not only based on the vibration of the unsprung resonance frequency, but also, for example, The determination may be made on the basis of vibrations in the resonance frequency range, specifically, vibrations of 3 Hz before and after the unsprung resonance frequency. When determining based on the vibration in the unsprung resonance frequency range, for example, it may be determined whether the average value of the vibration intensity in the unsprung resonance frequency range exceeds a certain value. It may be determined whether or not the maximum value of the vibration intensity exceeds a certain value. The “vibration intensity” described in this section indicates a vibration component, and for example, vibration amplitude, acceleration, and the like can be employed.

  (9) When the anti-sprung vibration control execution unit is in a situation where the vibration intensity of the unsprung resonance frequency is equal to or less than the set value, a side slip of the vehicle exceeding the allowable limit occurs. Even so, the vehicle suspension system according to the item (8) configured to execute the second pair of unsprung vibration control without performing the first pair of unsprung vibration control.

  According to the aspect of this section, for example, the first pair of unsprung vibration controls is executed only when the ground contact property of the wheel is particularly assumed, and in the other cases, the second pair unsprung vibration control is performed. As a result, it is possible to reduce the transmission of vibration to the upper part of the spring and reduce the power consumption of the electromagnetic motor.

  (10) Anti-sprung vibration control execution in which the control device executes anti-sprung vibration control for generating the approaching / separating force as a damping force having a magnitude corresponding to the absolute sprung speed with respect to the vibration of the sprung portion. The vehicle suspension system according to any one of (1) to (9), further including a section.

  (11) The control device uses the approach / separation force as at least one of a roll restraining force for restraining a roll of the vehicle body caused by turning of the vehicle and a pitch restraining force for restraining the pitch of the vehicle body caused by acceleration / deceleration of the vehicle. The vehicle suspension system according to any one of (1) to (10), further including an attitude change suppression control execution unit that executes the attitude change suppression control to be generated.

  The modes described in the above two terms are modes in which limitations on other functions of the approaching / separating force generator are added. The mode described in the former section is a mode that realizes the main function of the absorber, and is a mode that can execute control based on the so-called skyhook damper theory. The aspect described in the latter section is an aspect in which at least one of roll suppression control and pitch suppression control can be performed by causing the approaching / separating force to act as a posture change suppression force that suppresses the posture change of the vehicle body. It is an aspect which implement | achieves the function as a stabilizer apparatus. When one of the two anti-spring vibration controls and the anti-spring vibration control and the posture change suppression control are executed simultaneously, in addition to the approaching / separating force as a damping force against the vibration of the unsprung portion, The approaching / separating force generating device generates the approaching / separating force as the damping force against the vibration of the upper part and the posture change suppressing force.

(12) The approaching / separating force generator is
An elastic body having one end connected to one of the spring top and the spring bottom;
The elastic body is disposed between the other end of the elastic body and the other of the sprung part and the unsprung part and connects the other and the elastic body, and the electromagnetic motor is a component of the electromagnetic body. By applying the force generated by itself to the elastic body depending on the generated force, the deformation amount of the elastic body is changed according to the amount of movement of the elastic body, and the force approaches the elastic body through the elastic body. The vehicle suspension system according to any one of (1) to (11), further comprising: an electromagnetic actuator that acts on the spring upper portion and the spring lower portion as a separation force.

  The mode described in this section is a mode in which the structure of the approaching / separating force generator is limited to one type. The “approaching / separating force generating device” described in this section is configured to apply a force generated by the actuator to the elastic body and to change the deformation amount of the elastic body according to the operation amount of the actuator. The elastic body is not particularly limited as long as it exhibits some elastic force in accordance with the amount of deformation. For example, it is possible to employ elastic bodies having various structures such as a coil spring and a torsion spring. As the “approaching / separating force generating device” described in this section, for example, a so-called left and right independent type stabilizer device can be employed.

(13) A shaft portion in which the elastic body is rotatably held at the upper portion of the spring, and an arm portion extending from one end portion of the shaft portion so as to intersect the shaft portion and having a tip portion connected to the lower portion of the spring. Have
The vehicle suspension system according to item (12), wherein the actuator is fixed to a vehicle body and rotates the shaft portion around an axis thereof by a force generated by the actuator.

  The mode described in this section is a mode in which the structure of the approaching / separating force generator is more specifically limited. As for the “elastic body” in the aspect of this section, it is sufficient that at least one of the shaft portion and the arm portion has a function as an elastic body. For example, the shaft portion may be twisted so that it has a function as a spring, and the arm portion may be bent so that it has a function as a spring. Note that the elastic body may be a member in which the shaft portion and the arm portion are separate members, and may be formed by integrating them.

(14) The approaching / separating force generating device includes:
A sprung unit connected to the sprung part and a sprung unit connected to the sprung part, and as the sprung part and the sprung part approach and separate from each other, Is configured to be stretchable by relative movement, and
Based on the force generated by the electromagnetic motor, a force in the direction of relative movement between the unsprung unit and the unsprung unit is generated, and the force acts on the unsprung portion and unsprung portion as an approaching / separating force. The vehicle suspension system according to any one of (1) to (11) configured to be configured to be

  The mode described in this section is a mode in which the structure of the approaching / separating force generating device is limited to a type different from the above type. As the “approach and separation force generator” described in this section, for example, an electromagnetic wave that can generate not only a resistance force to the relative motion between the sprung portion and the unsprung portion but also a propulsive force to the relative motion between the sprung portion and the unsprung portion. It is possible to adopt a type of shock absorber.

(15) The approaching / separating force generating device includes:
A screw rod provided on one of the unsprung side unit and the unsprung side unit and formed with a male screw, and screwed with the screw rod to the other of the unsprung side unit and the unsprung side unit. A nut mechanism provided with a screw mechanism that is structured such that one of the screw rod and the nut rotates in accordance with the relative movement of the sprung unit and the unsprung unit;
Depending on the force generated by the electromagnetic motor, a rotational force is applied to one of the screw rod and the nut so as to generate a force in a direction in which the unsprung unit and the unsprung unit are relatively moved. The vehicle suspension system as set forth in (14), which is configured as follows.

  The mode described in this section is a mode limited to the approaching / separating force generator that employs a screw mechanism. When a rotary motor is used as the electromagnetic motor, the rotational force of the motor is expressed by the spring upper unit and the spring lower unit. It becomes possible to easily convert the force into relative movement with the side unit. In addition, in the aspect of this term, it is arbitrary which of the sprung side unit and the unsprung side unit is provided with the screw rod, and which is provided with the nut. Further, the screw rod may be configured to be non-rotatable and the nut may be configured to rotate. Conversely, the nut may be configured to be non-rotatable and the screw rod may be configured to be rotatable.

  (16) The vehicle suspension system according to any one of (1) to (15), wherein the vehicle suspension system includes a hydraulic shock absorber disposed in parallel with the suspension spring. .

  (17) The vehicle suspension system according to (16), wherein the shock absorber has a damping coefficient set to 1000 to 2000 N · sec / m.

  The aspect described in the above two terms is an aspect in which the suspension spring, the hydraulic shock absorber, and the approach / separation force generator are provided in parallel. In the modes described in the above two items, even if the approaching / separating force is not generated as a damping force for the vibration of the lower part of the second pair of unsprung vibrations, the vibration of the lower part of the spring is attenuated by the hydraulic shock absorber. It is possible. Therefore, the modes described in the above two terms are preferable when the second pair of unsprung vibration control is a control that does not generate a damping force against the vibration of the unsprung portion. Moreover, in the aspect of the latter term, the damping coefficient of the shock absorber is set relatively low. According to the latter aspect, for example, a hydraulic shock absorber having a low damping coefficient is set without generating an approaching / separating force as a damping force for the vibration of the unsprung portion in the second unsprung vibration control. It is possible to attenuate the vibration of the unsprung part. That is, it is possible to considerably reduce the power consumption of the electromagnetic motor, reduce the transmission of vibrations in the high frequency range to the upper part of the spring, and attenuate the vibration of the lower part of the spring to some extent. Note that “1000 to 2000 N · sec / m” described in the latter section is not a value when the force generated by the absorber is applied to the stroke operation of the absorber, but an approach / separation operation between the vehicle body and the wheel. On the other hand, it is a value when it is assumed that the vehicle body and the wheel are directly operated in the vertical direction of the wheel.

  Several embodiments of the claimable invention will now be described in detail with reference to the drawings. In addition to the following examples, the claimable invention includes various aspects in which various modifications and improvements have been made based on the knowledge of those skilled in the art, including the aspects described in the above [Aspect of the Invention] section. Can be implemented.

(A) First embodiment <Configuration of vehicle suspension system>
FIG. 1 schematically shows a vehicle suspension system 10 according to an embodiment. The system 10 includes four suspension devices 20 provided corresponding to the front, rear, left and right four wheels 12 and a control device that controls the suspension devices 20. Since the front wheel suspension device 20 that is a steered wheel and the rear wheel suspension device 20 that is a non-steered wheel can be regarded as substantially the same configuration except for a mechanism that enables the wheel to steer, the simplification of the description is taken into consideration. The rear wheel suspension device 20 will be described as a representative.

  As shown in FIGS. 2 and 3, the suspension device 20 is an independent suspension type and is a multi-link type suspension device. The suspension device 20 includes a first upper arm 30, a second upper arm 32, a first lower arm 34, a second lower arm 36, and a toe control arm 38, each of which is a suspension arm as a wheel holding portion. One end of each of the five arms 30, 32, 34, 36, and 38 is rotatably connected to the vehicle body, and the other end is rotatable to an axle carrier 40 that rotatably holds the wheel 12. It is connected. With these five arms 30, 32, 34, 36, and 38, the axle carrier 40 can move up and down so as to draw a substantially constant locus with respect to the vehicle body.

  The suspension device 20 includes a coil spring 50 as a suspension spring and a hydraulic shock absorber (hereinafter sometimes abbreviated as “absorber”) 52, which are each a component part of the spring top. Between the mount part 54 provided in the tire housing and the second lower arm 36 which is one component part of the unsprung part, they are arranged in parallel to each other. The absorber 52 is of a hydraulic type and has a structure that attenuates the relative vibration between the spring top and the spring bottom. In other words, the suspension device 20 elastically supports the wheel 12 and the vehicle body, and generates a damping force against vibration associated with the approach and separation. Since the structure of the hydraulic absorber 52 is known, detailed description thereof is omitted.

  In addition, the suspension device 20 has a vehicle body wheel distance adjustment device (hereinafter also referred to as “adjustment device”) 60 that can adjust the distance between the vehicle body and the wheel (hereinafter also referred to as “vehicle body wheel distance”). Each of the adjusting devices 60 includes an L-shaped bar 62 that is generally L-shaped, and an actuator 66 that rotates the bar 62. As shown in FIGS. 2 and 3, the L-shaped bar 62 is divided into a shaft portion 70 that extends substantially in the vehicle width direction and an arm portion 72 that is continuous with the shaft portion 70 and that intersects the shaft portion 70 and extends substantially rearward of the vehicle. Can do. The shaft portion 70 of the L-shaped bar 62 is rotatably held at the lower portion of the vehicle body by a holder 74 fixed to the vehicle body at an axial intermediate portion thereof. The actuator 66 is fixed in the vicinity of the center in the vehicle width direction of the lower part of the vehicle body by a mounting member 76 provided at one end thereof, and the end portion of the shaft portion 70 (the end portion on the center side in the vehicle width direction) The actuator 66 is connected. On the other hand, the end portion of the arm portion 72 (the end portion opposite to the shaft portion 70) is connected to the second lower arm 36 via a link rod 77. Specifically, the second lower arm 36 is provided with a link rod connecting portion 78, one end of the link rod 77 is connected to the link rod connecting portion 78, and the other end is an end of the arm portion 72 of the L-shaped bar 62. Each part is connected so as to be able to swing.

  As shown in FIG. 4, the actuator 66 included in the adjusting device 60 includes an electromagnetic motor 80 as a drive source and a speed reducer 82 that transmits the rotation of the electromagnetic motor 80 at a reduced speed. The electromagnetic motor 80 and the speed reducer 82 are provided in a housing 84 that is an outer shell member of the actuator 66. The housing 84 is attached to the vehicle body by the mounting member 76 fixed to one end portion thereof. It is fixedly attached. The L-shaped bar 62 is arranged such that its shaft portion 70 extends from the other end of the housing 84. The shaft portion 70 of the L-shaped bar 62 is connected to a speed reducer 82 as will be described in detail later in a portion existing in the housing 84 thereof. Further, the shaft portion 70 is rotatably held by the housing 84 via a bush type bearing 86 at an intermediate portion in the axial direction thereof.

  The electromagnetic motor 80 includes a plurality of coils 88 that are fixedly arranged on one circumference along the inner surface of the peripheral wall of the housing 84, a hollow motor shaft 90 that is rotatably held by the housing 84, and a coil 88. And a permanent magnet 92 that is fixedly disposed on the outer periphery of the motor shaft 90 so as to face each other. The electromagnetic motor 80 is a motor in which the coil 88 functions as a stator and the permanent magnet 92 functions as a rotor, and is a three-phase DC brushless motor. A motor rotation angle sensor 94 for detecting the rotation angle of the motor shaft 90, that is, the rotation angle of the electromagnetic motor 80 is provided in the housing 84. The motor rotation angle sensor 94 mainly includes an encoder, and is used for controlling the actuator 66, that is, controlling the adjusting device 60.

  The reducer 82 includes a wave generator 96, a flexible gear (flex spline) 98, and a ring gear (circular spline) 100, and includes a harmonic gear mechanism ("harmonic drive (registered trademark) mechanism", "strain wave gearing mechanism). ”And so on). The wave generator 96 includes an elliptical cam and a ball bearing fitted on the outer periphery thereof, and is fixed to one end of the motor shaft 90. The flexible gear 98 has a cup shape in which the peripheral wall portion can be elastically deformed, and a plurality of teeth are formed on the outer periphery on the opening side of the peripheral wall portion. The flexible gear 98 is connected to and supported by the shaft portion 70 of the L-shaped bar 62 described above. Specifically, the shaft portion 70 of the L-shaped bar 62 passes through the motor shaft 90, and the outer peripheral surface of the portion extending from the motor shaft 90 is relative to the bottom portion by spline fitting while penetrating the bottom portion of the flexible gear 98. It is connected non-rotatably. The ring gear 100 is generally ring-shaped and has a plurality of teeth (two more teeth than the number of teeth of the flexible gear 98 in the speed reducer 82) on the inner periphery, and is fixed to the housing 84. Yes. The flexible gear 98 has a peripheral wall portion fitted on the wave generator 96 and is elastically deformed into an elliptical shape, and meshes with the ring gear 100 at two positions located in the major axis direction of the ellipse and does not mesh at other positions. It is said that. With this structure, when the wave generator 96 makes one rotation (360 degrees), that is, when the motor shaft 90 of the electromagnetic motor 80 makes one rotation, the flexible gear 98 and the ring gear 100 are relatively rotated by two teeth. .

  From the above configuration, when the electromagnetic motor 80 is driven, the L-shaped bar 62 is rotated by the motor force generated by the motor 80, and the shaft portion 70 of the L-shaped bar 62 is twisted. . The torsional reaction force generated by this torsion is transmitted to the second lower arm 36 via the arm portion 72, the link rod 77, and the link rod connecting portion 78, and the force that pushes down or pulls up the second lower arm 36 with respect to the vehicle body. In other words, it acts as an approaching / separating force that is a force in a direction in which the vehicle body and the wheel approach / separate vertically. That is, the actuator force that is the force generated by the actuator 66 acts as an approaching / separating force via the L-shaped bar 62 that functions as an elastic body. From this, it can be considered that the adjusting device 60 has a function as an approaching / separating force generating device that generates an approaching / separating force, and by adjusting the approaching / separating force, the distance between the vehicle body and the wheel. It is possible to adjust.

  The configuration of the suspension device 20 can be conceptually illustrated as shown in FIG. As can be seen from the drawing, the coil spring 50, the absorber 52, and the adjusting device 60 are disposed between a part of the vehicle body as the spring upper portion including the mount portion 54 and the spring lower portion including the second lower arm 36 and the like. Are arranged in parallel with each other. Further, the L-shaped bar 62 and the actuator 66 as elastic bodies constituting the adjusting device 60 are arranged in series between the spring top and the spring bottom. In other words, the L-shaped bar 62 is disposed in parallel with the coil spring 50 and the absorber 52, and an actuator 66 that connects them is disposed between the L-shaped bar 62 and a part 54 of the vehicle body. It is.

  The adjusting device 60 can generate an approaching / separating force that is a force in a direction for approaching / separating the spring upper portion and the spring lower portion, and can change the magnitude of the approaching / separating force. More specifically, the actuator 66 deforms the L-shaped bar 62 as an elastic body by an actuator force that depends on the motor force, that is, while twisting the shaft portion 70 of the L-shaped bar 62, Through the character-shaped bar 62, the spring upper part and the spring lower part are made to act as an approaching / separating force. The deformation amount of the L-shaped bar 62, that is, the torsional deformation amount of the shaft portion 70 corresponds to the operation amount of the actuator 66, and also corresponds to the actuator force. Since the approaching / separating force corresponds to an elastic force due to the deformation of the L-shaped bar 62, the approaching / separating force corresponds to the operation amount of the actuator 66 and corresponds to the actuator force. Therefore, the approaching / separating force can be changed by changing either the operation amount of the actuator 66 or the actuator force. In the suspension system 10, the approaching / separating force is controlled by executing a control in which the operation amount of the actuator 66 is directly controlled.

  In the control of the system 10, the operation amount of the actuator 66 is treated as an operation amount with reference to a predetermined neutral position. This neutral position exhibits the actuator force in a reference state in which, for example, a roll moment, a pitch moment, etc. are not substantially applied to the vehicle body, and it can be regarded that no vibration is generated in the vehicle body and the wheels 12. It is set as the operating position of the actuator 66 when it is not. In the control of the system 10, since the operation amount of the actuator 66 and the rotation angle of the electromagnetic motor 80 are in a corresponding relationship, in actuality, they are obtained by a motor rotation angle sensor instead of the operation amount of the actuator 66. Control for the motor rotation angle is performed.

  As shown in FIG. 1, the system 10 includes an adjustment device electronic control unit (adjustment device ECU) 110 that is a control device that controls the operation of each adjustment device 60, more specifically, each actuator 66. The adjustment device ECU 110 controls the operation of each actuator 66, and a controller mainly composed of a computer including four inverters 112 as a drive circuit corresponding to the electromagnetic motor 80 included in each actuator 66, a CPU, a ROM, a RAM, and the like. 114. (See FIG. 9). Each inverter 112 is connected to a battery 118 via a converter 116, and each inverter 112 is connected to an electromagnetic motor 80 of each adjustment device 60.

  Since the electromagnetic motor 80 is driven at a constant voltage, the amount of power supplied to the electromagnetic motor 80 is changed by changing the amount of supplied current, and the electromagnetic motor 80 exhibits a force corresponding to the amount of supplied current. It becomes. Incidentally, the supply current amount is changed by each inverter 112 changing the ratio (duty ratio) between the pulse on time and the pulse off time by PWM (Pulse Width Modulation).

  In addition to the motor rotation angle sensor 94, the controller 114 includes a steering sensor 120 for detecting an operation angle of a steering wheel, which is an operation amount of a steering operation member as a steering amount, a vehicle traveling speed (hereinafter abbreviated as “vehicle speed”). Vehicle acceleration sensor 124 for detecting lateral acceleration generated in the vehicle body, longitudinal acceleration sensor 124 for detecting longitudinal acceleration generated in the vehicle body, and vehicle body mounting portion 54. An unsprung longitudinal acceleration sensor 126 for detecting the unsprung longitudinal acceleration generated on the vehicle body and an unsprung longitudinal acceleration sensor 128 for detecting unsprung longitudinal acceleration occurring on the vehicle body are connected. Further, the controller 114 is also connected to the inverter 112 and controls the adjustment device 60 by controlling it. Note that a ROM included in the computer of the controller 114 stores a program related to control of the adjusting device 60 described later, various data, and the like.

<Configuration and control of vehicle skid control system>
Further, in a vehicle equipped with the present suspension system 10, a vehicle side slip suppression system 130 is employed as a system that suppresses a side slip of the vehicle exceeding an allowable limit. As shown in FIG. 1, the vehicle skid control system 130 includes a brake actuator 132 that can independently control the braking force of each wheel 12, a throttle actuator 136 that controls the opening of an accelerator throttle that adjusts the engine output, The vehicle side slip suppression system electronic control unit (vehicle side slip suppression ECU) 138 that controls the operation of the brake actuator 132 and the throttle actuator 136 is configured.

  The vehicle skid control ECU 138 includes a drive circuit 140 that controls the operation of the brake actuator 132, a drive circuit 142 that controls the operation of the throttle actuator 136, and a controller 144 mainly composed of a computer having a CPU, a ROM, a RAM, and the like. I have. (See FIG. 9). Each drive circuit 140, 142 is connected to the battery 118 via the converter 116, the drive circuit 140 is connected to the brake actuator 132, and the drive circuit 142 is connected to the throttle actuator 136. A yaw rate sensor 146 for detecting the yaw rate of the vehicle is connected to the controller 144 together with the steering sensor 120 and the vehicle speed sensor 121. Further, the controller 144 is also connected to the drive circuits 140 and 142, and controls the braking force and engine output of each wheel 12 by controlling them. Note that a ROM included in the computer of the controller 144 stores a program for suppressing a side slip of the vehicle, which will be described later, various data, and the like. Incidentally, the controller 144 of the vehicle skid restraining ECU 138 and the controller 114 of the adjusting device ECU 110 are connected to each other so as to be able to communicate with each other, and information, commands, etc. relating to control of each system are communicated as necessary.

  In this vehicle skid control system 130, when the skid of the vehicle exceeding the allowable limit occurs, the engine output as the driving force for the vehicle is reduced and the braking force of some of the wheels 12 is increased. By doing so, it is possible to execute side-slip suppression control that suppresses such side-slip of the vehicle. Specifically, when the vehicle slips beyond the allowable limit due to the side wheels sliding sideways relative to the rear wheels (hereinafter referred to as “when vehicle side slip occurs due to front wheel side slip”). By decreasing the engine output and increasing the braking force of the rear wheel of the turning inner wheel, the side slip of the front wheel is suppressed and the side slip of the vehicle is suppressed. On the other hand, when the side slip of the vehicle exceeding the allowable limit occurs due to the side slip of the rear wheel relative to the front wheel (hereinafter sometimes referred to as “the vehicle side slip occurs due to the side slip of the rear wheel”), By reducing the engine output and increasing the braking force of the front wheel of the turning outer wheel, the side slip of the rear wheel is suppressed and the side slip of the vehicle is suppressed. In this way, when a side skid of the vehicle exceeding the allowable limit occurs, such a side skidding of the vehicle is suppressed by controlling the braking force of each wheel 12 and the engine output.

The occurrence of side slip of the vehicle exceeding the allowable limit is determined based on the estimated yaw rate ωc estimated based on the steering angle δ of the steering wheel and the vehicle traveling speed v, and the actually measured actual yaw rate ωr. Specifically, the estimated yaw rate ωc and the actual yaw rate ωr are compared, and if the actual yaw rate ωr is greater than the estimated yaw rate ωc and the absolute value of the difference between them is greater than the set threshold value Δω ₁ , the vehicle turns The state is in an excessive oversteer tendency, and it is determined that the vehicle skids due to the skidding of the rear wheels. On the other hand, when the actual yaw rate ωr is smaller than the estimated yaw rate ωc and the absolute value of the difference between them is larger than the set threshold value Δω ₁ , the turning state of the vehicle tends to be excessive understeer, and the vehicle skids due to the skidding of the front wheels. Determined to occur.

<Control of vehicle suspension system>
i) Basic control In the present suspension system 10, control for damping the sprung vibration corresponding to each of the four wheels 12 by independently controlling the approaching / separating force generated by each adjusting device 60 (hereinafter, referred to as “control”). “Sprung vibration damping control” (sometimes referred to as “sprung vibration damping control”), vehicle body roll control resulting from turning of the vehicle (hereinafter also referred to as “roll suppression control”), vehicle body pitch resulting from vehicle acceleration / deceleration Control for suppression (hereinafter, sometimes referred to as “pitch suppression control”) is executable. In this system, usually, control in which these three controls are integrated is executed. In this control, the motor rotation angle of the electromagnetic motor 80 is controlled in each adjusting device 60 so as to exert an appropriate approaching / separating force based on the sprung speed, the roll moment received by the vehicle body, the pitch moment, and the like. Specifically, based on the sprung speed, the roll moment received by the vehicle body, the pitch moment, etc., the target motor rotation angle as the control target value, which is the target motor rotation angle, is determined, and the actual motor rotation angle is the target motor rotation angle. The electromagnetic motor 80 is controlled so as to have a motor rotation angle. Note that the roll suppression control and the pitch suppression control are controls for suppressing the posture change of each vehicle body such as the roll and pitch of the vehicle body, and therefore can be considered as a kind of posture change suppression control.

In the present system 10, the target motor rotation angle as the control target value described above is the sum of the target motor rotation angle components, which are control target value components for each control of sprung vibration damping control, roll suppression control, and pitch suppression control. To be determined. The components for each control are
Sprung vibration damping target motor rotation angle component (sprung vibration damping component) θ ^* _U
Roll suppression target motor rotation angle component (roll suppression component) θ ^* _R
Pitch suppression target motor rotation angle component (pitch suppression component) θ ^* _P
It is. In the following, each of the sprung vibration damping control, roll suppression control, and pitch suppression control will be described in detail with a focus on the method for determining the respective target motor rotation angle components, and to the electric motor 80 based on the target motor rotation angle. The determination of the supplied power will be described in detail.

a) On-spring vibration damping control In the on-spring vibration damping control, the approaching / separating force is generated as a damping force having a magnitude corresponding to the vertical movement speed of the vehicle body, the so-called absolute speed on the spring. Control based on the damper theory is executed. Specifically, based on the sprung vertical acceleration Gu detected by the sprung vertical acceleration sensor 126 provided on the mount portion 54 of the vehicle body in order to generate the approaching / separating force having a magnitude corresponding to the sprung absolute speed, the spring The upper absolute speed Vu is calculated, and the sprung vibration damping component θ ^* _U is calculated according to the following equation.
θ ^* _U = K ₁ · C _S · Vu
Here, K ₁ is a gain for converting the damping force for the sprung vibration into the sprung vibration component θ ^* _U , and C _S is a damping coefficient based on the skyhook damper theory.

b) Roll suppression control In roll suppression control, when the vehicle is turning, the adjusting device 60 in the bounce direction is applied to the adjusting device 60 on the turning inner wheel side according to the roll moment resulting from the turning, and the adjusting device on the turning outer wheel side. In 60, an approaching / separating force in the rebound direction is generated as a roll restraining force. Specifically, first, as the lateral acceleration that indicates the roll moment received by the vehicle body, the estimated lateral acceleration Gyc estimated based on the steering angle δ of the steering wheel and the vehicle traveling speed v, and the actually measured actual lateral acceleration Gyr. Based on the above, the control lateral acceleration Gy ^* , which is the lateral acceleration used for the control, is determined according to the following equation.
Gy ^* = K ₂ · Gyc + K ₃ · Gyr (K ₂ , K ₃ : gain)
Then, the roll suppression component θ ^* _R is determined based on the determined control lateral acceleration Gy ^* . In the controller 114 of the adjusting device ECU 110, map data of the roll suppression component θ ^* _R having the control lateral acceleration Gy ^* as a parameter is stored, and the map data is referred to in determining the roll suppression component θ ^* _R. Is done.

c) Pitch suppression control In the pitch suppression control, the front wheel side adjusting device 60 has an approaching / separating force in the rebound direction according to the pitch moment that causes the nose dive to occur when braking the vehicle body. In the rear wheel side adjusting device 60, the approaching / separating force in the bounce direction is generated as the pitch restraining force. As a result, nose diving is suppressed. Further, with respect to the squat of the vehicle body generated during the acceleration of the vehicle body, the approaching / separating force in the rebound direction is applied to the adjustment device 60 on the rear wheel side according to the pitch moment that generates the squat, and the adjustment device 60 on the front wheel side is applied. Generates an approaching / separating force in the bounce direction as a pitch restraining force. In the pitch suppression control, nose dives and squats are suppressed by such approach and separation force. Specifically, the actual actual longitudinal acceleration Gzg is employed as the longitudinal acceleration that indicates the pitch moment received by the vehicle body, and the pitch suppression component θ ^* _P is determined according to the following equation based on the actual longitudinal acceleration Gzg. .
θ ^* _P = K ₄ · Gzg (K ₄ : gain)

d) Determination of target supply current As described above, when the sprung vibration damping component θ ^* _U , the roll suppression component θ ^* _R , and the pitch suppression component θ ^* _P are determined, the target motor rotation angle θ ^* Determined according to the formula.
θ ^* = θ ^* _U + θ ^* _R + θ ^* _P
Then, the electromagnetic motor 80 is controlled so that the actual motor rotation angle θ, which is the actual motor rotation angle, becomes the target motor rotation angle θ ^* . In the control of the electromagnetic motor 80, the electric power supplied to the electromagnetic motor 80 is determined based on a motor rotation angle deviation Δθ (= θ ^* −θ) that is a deviation of the actual motor rotation angle θ from the target motor rotation angle θ ^* . Is done. Specifically, it is determined according to a feedback control method based on the motor rotation angle deviation Δθ. Specifically, first, the motor rotation angle deviation Δθ is recognized based on the detection value of the motor rotation angle sensor 94 included in the electromagnetic motor 80, and then, using it as a parameter, the target supply current i ^* according to the following equation: Is determined.
i ^* = K _P · Δθ + K _I · Int (Δθ)
This equation follows the PI control law. The first term and the second term mean the proportional term and the integral term, respectively, and K _P and K _I mean the proportional gain and the integral gain, respectively. Int (Δθ) corresponds to an integral value of the motor rotation angle deviation Δθ.

Incidentally, the target supply current i ^* also indicates the direction of generation of the motor force of the electromagnetic motor 80 by its sign, and the drive control of the electromagnetic motor 80 is based on the target supply current i ^* . The duty ratio for driving the electromagnetic motor 80 and the motor force generation direction are determined. Then, a command regarding the duty ratio and the direction in which the motor force is generated is issued to the inverter 114, and the inverter 114 performs drive control of the electromagnetic motor 80 based on the command. In this way, each of the four adjusting devices 60 generates an approaching / separating force to be generated, suppresses rolls and pitches of the vehicle body, and attenuates sprung vibration.

  In the system 10, as described above, the control for the vibration of the sprung portion, that is, the sprung vibration damping control that is anti-sprung vibration control is executed. Is not running. Attenuating not only the unsprung vibration but also the unsprung vibration by the adjusting device 60 is due to concerns about power consumption by the electromagnetic motor 60, a burden on the electromagnetic motor 60, and the like. Therefore, in the present system 10, the vibration of the unsprung portion is dealt with by the absorber 52. In consideration of the transmission of the vibration of the unsprung portion to the sprung portion, regarding the vibration in a relatively high frequency range, the vibration of the unsprung portion is less likely to be transmitted to the sprung portion with a lower damping coefficient of the absorber. For this reason, the attenuation coefficient of the absorber 52 of the system 10 is set to a low value. More specifically, the damping coefficient of the absorber 52 is 1500 N · sec / m (a value that is assumed to be applied directly to the wheel with respect to the operation of the wheel), and the suspension that does not include the adjusting device 60. It is set to less than half of 3000 to 5000 N · sec / m, which is a value set for a shock absorber in the system, that is, a conventional shock absorber.

ii) Control of the adjusting device in consideration of the grounding property of the wheel The value of the damping coefficient of the absorber 52 not only affects the transmission of vibration from the unsprung portion to the unsprung portion but also affects the grounding property of the wheel. Specifically, as shown in FIG. 6, the ground load variation rate with respect to vibration of the unsprung resonance frequency is higher as the damping coefficient is smaller. The ground load variation rate and the wheel grounding property are in a relative relationship. The higher the ground load variation rate, the lower the wheel grounding property. Therefore, the smaller the damping coefficient, the smaller the grounding property against vibration at the unsprung resonance frequency. It is low. In the present system 10, the damping coefficient of the absorber 52 is set to be low as described above, and the grounding property of the wheel against the vibration of the unsprung resonance frequency is low.

  Further, the vehicle on which the present suspension system 10 is mounted employs the vehicle side-slip suppression system 130, and the side-slip suppression control is executed when a side-slip of the vehicle exceeding an allowable limit occurs. When the control for suppressing the side slip of the wheel is executed, if the ground contact property of the wheel is low, the effect of suppressing the side slip of the wheel by this control may be reduced. Therefore, in the present suspension system 10, when the side slip suppression control is executed when there is a possibility that the grounding property of the wheel is lowered, the vibration of the unsprung portion is attenuated to prevent the wheel grounding property from being lowered. Thus, the side slip of the wheel is effectively suppressed. In other words, in the case where vibration of the unsprung resonance frequency is generated and the side slip of the vehicle exceeding the allowable limit is generated, in addition to the above-described sprung vibration damping control, roll suppression control, and pitch suppression control, The unsprung vibration control, that is, the unsprung vibration damping control, which is the control for the lower vibration, is executed.

In the unsprung vibration damping control, the approaching / separating force generated by the adjusting device 60 is generated as a damping force having a magnitude corresponding to the vertical movement speed of the unsprung portion, that is, the so-called unsprung absolute speed. Control based on the ground hook damper theory is executed. Specifically, the unsprung absolute velocity Vs is calculated based on the unsprung longitudinal acceleration Gs detected by the unsprung longitudinal acceleration sensor 128 in order to generate an approaching / separating force having a magnitude corresponding to the unsprung absolute velocity. An unsprung vibration damping target motor rotation angle component (unsprung vibration damping component) θ ^* _S, which is a control target value component of unsprung vibration damping control, is calculated according to the following equation.
θ ^* _S = K ₅ · C _U · Vs
Here, K ₅ is a gain for converting the damping force against the unsprung vibrations in the unsprung vibration component θ ^* _S, C _U is a damping coefficient for unsprung vibration damping effect against vibration of the unsprung portion It is set to be relatively high in order to increase the ground contact performance of the wheel.

In addition, in order to determine the presence or absence of vibration of the unsprung resonance frequency, the vibration component of the frequency region is calculated from the vibration of the unsprung portion by filtering, and the magnitude of the vibration component of the frequency region is compared. . Specifically, first, the unsprung longitudinal acceleration Gs is detected by the unsprung longitudinal acceleration sensor 128, and based on the detected unsprung longitudinal acceleration Gs, a filter for vibrations in the region of 3 Hz before and after the unsprung resonance frequency. Execute the process. Then, the maximum amplitude α of the amplitude that is the intensity of vibration in the frequency region is calculated. When the calculated maximum amplitude α is greater than or equal to the set threshold value α ₁ , it is determined that vibration at the unsprung resonance frequency is occurring.

When vibration at an unsprung resonance frequency is occurring and a side slip of the vehicle exceeding the allowable limit is occurring, the unsprung vibration damping component θ ^* _S determined as described above and the above sprung Based on the vibration damping component θ ^* _U , the roll suppression component θ ^* _R , and the pitch suppression component θ ^* _P , the target motor rotation angle θ ^* is determined according to the following equation.
θ ^* = θ ^* _S + θ ^* _U + θ ^* _R + θ ^* _P
Based on the determined target motor rotation angle θ ^* , the target supply current i ^* is determined according to the above equation according to the PI control law, and the target supply current i ^* is supplied to the electromagnetic motor 80. In this way, by executing unsprung vibration damping control in addition to sprung vibration damping control, roll restraining control, and pitch restraining control, the vibration of the lower part of the spring is also attenuated by the approaching / separating force generated by the adjusting device 60. This effectively suppresses the skidding of the vehicle.

  As described above, in the present system 10, the control considering the grounding property of the wheel and the control considering the high frequency vibration transmission and the load on the electromagnetic motor are selectively executed. . In other words, in order to improve the grounding property of the wheel, the first anti-sprung vibration control, which is a control that causes the approaching / separating force to act as a damping force against the vibration of the unsprung part, and the transmission of the vibration in the high frequency range are reduced and the electromagnetic motor In order to reduce the power consumption, the second unsprung vibration control, which is a control that does not cause the approaching / separating force to act as a damping force against the vibration of the unsprung portion, is selectively executed.

<Control program>
In the vehicle side-slip suppression system 130, the side-slip suppression control is performed by the controller 144 of the vehicle side-slip suppression ECU 138 executing the side-slip suppression control program shown in the flowchart of FIG. On the other hand, the approaching / separating force generated by the adjusting device 60 in the suspension system 10 is controlled by the controller 114 of the adjusting device ECU 110 executing the adjusting device control program shown in the flowchart of FIG. These two programs are repeatedly executed at short time intervals (for example, several milliseconds) while the ignition switch is in the ON state. Below, the flow of each control is demonstrated easily, referring the flowchart shown in a figure.

i) Side Slip Suppression Control Program In the processing according to this program, first, in step 1 (hereinafter simply referred to as “S1”, the same applies to other steps), the vehicle speed v is acquired based on the detection value of the vehicle speed sensor 121. Next, in S <b> 2, the operation angle δ of the steering wheel is acquired based on the detected value of the steering sensor 120. Subsequently, in S3, the estimated yaw rate ωc is estimated based on the acquired vehicle speed v and operation angle δ. The controller 144 stores map data regarding the estimated yaw rate ωc using the vehicle speed v and the operation angle δ as parameters, and the estimated yaw rate ωc is estimated by referring to the map data. In S4, the actual yaw rate ωr, which is the yaw rate actually generated in the vehicle body, is acquired based on the detection value of the yaw rate sensor 146.

Next, in S5, it is determined whether or not a side skid of the vehicle exceeding the allowable limit has occurred. Specifically, the actual yaw rate ωr and the estimated yaw rate ωc are compared, and it is determined whether or not the absolute value of the difference between them is larger than the set threshold value Δω ₁ . If it is determined that the absolute value of the difference between the actual yaw rate ωr and the estimated yaw rate ωc is greater than the set threshold value Δω _1, it is determined that a side slip of the vehicle exceeding the allowable limit has occurred, and in step S6, the side skid of the vehicle is determined. The flag value of the flag G is set to 1. When the flag value of the flag G is 1, it indicates that the vehicle has slipped beyond the allowable limit. When the flag value is 0, the vehicle has slipped beyond the allowable limit. It has not occurred.

Subsequently, in S7, it is determined whether the vehicle side slip occurs due to the front wheel side slip or the vehicle side slip occurs due to the rear wheel side slip. Specifically, it is determined whether or not the actual yaw rate ωr is greater than the estimated yaw rate ωc, and when it is determined that the actual yaw rate ωr is greater than the estimated yaw rate ωc, it is determined that a vehicle skid has occurred due to a side slip of the rear wheel. In S8, a control signal for decreasing the throttle opening is transmitted to the drive circuit 142 to reduce the engine output, and a control signal for increasing the braking force of the front wheels of the turning outer wheel is transmitted to the drive circuit. 140. If it is determined in S7 that the actual yaw rate ωr is smaller than the estimated yaw rate ωc, it is determined that a vehicle skid has occurred due to the skidding of the front wheels. In S9, the accelerator throttle opening is set to reduce the engine output. A control signal for lowering is transmitted to the drive circuit 142, and a control signal for increasing the braking force of the rear wheel of the turning inner wheel is transmitted to the drive circuit 140. Further, in the case where the absolute value of the difference between the actual yaw rate ωr and the estimated yaw rate ωc is determined to set the threshold value [Delta] [omega ₁ below S5, it is determined that skidding of the vehicle has exceeded the allowable limit has not occurred, in S10 The flag value of the vehicle skid flag G is set to zero.

ii) Adjustment device control program The adjustment device control program is executed for each actuator 66 for each actuator 66 of the four adjustment devices 60. In the following description, processing by this program for one actuator 66 will be described in consideration of simplification of description. In the processing according to this program, first, in S11, the sprung absolute speed Vu is calculated based on the sprung vertical acceleration Gu detected by the sprung vertical acceleration sensor 126, and in S12, the calculated sprung absolute speed Vu is calculated. Based on this, the sprung vibration damping component θ ^* _U for the sprung vibration damping control is determined. Next, in S13, a control lateral acceleration Gy ^* is calculated based on the actual lateral acceleration Gyr detected by the lateral acceleration sensor 122 and the estimated lateral acceleration Gyc, and in S14, based on the control lateral acceleration Gy ^*. The roll suppression component θ ^* _R for roll suppression control is determined. Subsequently, in S15, the longitudinal acceleration sensor 124 detects the longitudinal acceleration Gzg, and in S16, the pitch suppression component θ ^* _P for pitch suppression control is determined based on the detected longitudinal acceleration Gzg.

Next, in S17, it is determined whether or not a side skid of the vehicle exceeding the allowable limit has occurred. Specifically, it is determined whether or not the flag value of the vehicle skid flag G determined in the above-described skid control program is 1. Information on the flag G is transmitted from the controller 144 of the vehicle side-slip suppression ECU 138 to the controller 114 of the adjustment device ECU 110. That is, the side slip of the vehicle is determined based on the command from the vehicle side slip suppression system 130. When it is determined that the flag value of the vehicle skidding flag G is 1, that is, when it is determined that the vehicle skids exceeding the allowable limit, the vibration of the unsprung resonance frequency occurs. It is determined whether or not. Specifically, the unsprung longitudinal acceleration Gs is detected by the unsprung longitudinal acceleration sensor 128 in S18, and the filtering process for the unsprung resonance frequency region is executed in S19 based on the detected unsprung longitudinal acceleration Gs. Then, the maximum amplitude α of the amplitude of vibration in the unsprung resonance frequency region is calculated. Subsequently, in S20, whether the maximum amplitude alpha is set threshold alpha ₁ or more is determined.

If it is determined that the maximum amplitude α is greater than or equal to the set threshold value α _1, it is determined that vibration in the unsprung resonance frequency region has occurred, and in S21, the unsprung absolute velocity Vs is calculated based on the unsprung longitudinal acceleration Gs. In S22, an unsprung vibration damping component θ ^* _S for unsprung vibration damping control is determined based on the calculated unsprung absolute velocity Vs. In S23, the unsprung vibration damping component θ ^* _S , the unsprung vibration damping component θ ^* _U , the roll restraining component θ ^* _R, and the pitch restraining component θ ^* _P are summed, so that the target motor rotation angle θ ^{* is obtained.} Is determined.

Also, if the flag value of the vehicle side slip flag G is determined to be zero in S17, or if the maximum amplitude α is determined to set the threshold value α less than ₁ step S20, in S24, the sprung vibration The target motor rotation angle θ ^* is determined by adding the damping component θ ^* _U , the roll suppression component θ ^* _R, and the pitch suppression component θ ^* _P.

When the target motor rotation angle θ ^* is determined, the actual motor rotation angle θ is acquired based on the motor rotation angle sensor 94 in S25, and in S26, the deviation of the actual motor rotation angle θ from the target motor rotation angle θ ^* is obtained. A certain motor rotation angle deviation Δθ is determined. In S27, based on the target motor rotation angle θ ^* , the target supply current i ^* is determined according to the formula according to the above-described PI control law. In S28, the control signal based on the determined target supply current i ^* is transmitted to the inverter 112. After being transmitted to, one execution of this program ends.

<Functional configuration of controller>
The controller 144 of the vehicle side-slip suppression ECU 138 that executes the above-mentioned side-slip suppression control program can be considered to have a functional configuration as shown in FIG. 9 in view of the execution process. As can be seen from the figure, the controller 144 uses the vehicle side slip detection unit 150 as a function unit that executes the processes of S5 and S7, that is, a function unit that detects the occurrence of a side slip of the vehicle exceeding the allowable limit. A functional unit that executes the process of S9, that is, a side slip suppression control execution unit 152 is provided as a functional unit that executes the side slip suppression control by decreasing the engine output and increasing the braking force of a part of each wheel. ing.

  Further, the controller 114 of the adjustment device ECU 110 that executes the adjustment device control program can be considered to have a functional configuration as shown in FIG. 9 in view of the execution process. As will be understood from the figure, the controller 114 performs the anti-sprung vibration control execution unit 154 as the functional unit that executes the processes of S11 and S12, that is, the functional unit that executes anti-sprung vibration control. As the functional unit that executes the unsprung vibration control, the anti-sprung vibration control execution unit 156 performs the functional unit that executes the processes of S13 to S16, that is, the posture change suppression control. As a functional unit, the posture change suppression control executing unit 158 is used as a functional unit that executes the process of S17, that is, as a functional unit that determines whether or not a side skid of the vehicle that exceeds an allowable limit has occurred. 160 is used as a functional unit that executes the processes of S18 to S20, that is, a functional unit that determines whether vibration at an unsprung resonance frequency is occurring or not. The tough 162 comprises respectively. The anti-sprung vibration control execution unit 156 includes the first anti-sprung vibration control execution unit 164 as a functional unit that executes the processes of S21 to S23, that is, a functional unit that executes the first anti-sprung vibration control. , S24 has a second unsprung vibration control execution unit 166 as a function unit that executes the process of S24, that is, a function unit that executes the second unsprung vibration control.

(B) Second embodiment <Configuration of vehicle suspension system>
FIG. 10 schematically shows a vehicle suspension system 170 according to the second embodiment. The suspension system 10 of the previous embodiment includes the adjusting device 60 as an approaching / separating force generating device, whereas the present system 170 is an electromagnetic shock absorber (hereinafter referred to as “absorber”) as an approaching / separating force generating device. 172). Since the system 170 includes many components common to the system 10 of the previous embodiment, the same reference numerals are used for the components common to the system 10 in the description of the system 170, and those components are the same. The description will be omitted or simplified.

  The system 170 includes four suspension devices 174 provided corresponding to the four wheels 12 in the front, rear, left, and right directions. As shown in FIG. 11, the suspension device 174 is an independent suspension type and is a multi-link type suspension device, like the suspension device 20 provided in the suspension system 10 of the previous embodiment. The suspension device 174 includes a coil spring 176 as a suspension spring and an electromagnetic absorber 172, which are arranged in parallel with each other between the mount portion 54 and the second lower arm 36, respectively. Yes.

  As shown in FIG. 12, the electromagnetic absorber 172 includes a generally bottomed cylindrical lower tube 180 and an upper tube 182 that fits into the lower tube 180 and protrudes upward from the upper end of the lower tube 180. It consists of The lower tube 180 is connected to the second lower arm 36 via a mounting bush 184, while the upper tube 182 is fixedly connected to a motor case 188 that houses the electromagnetic motor 186 at the upper end thereof. The motor case 188 is connected to the mount portion 54 via a buffer rubber at the outer peripheral portion thereof.

  The electromagnetic motor 186 includes a plurality of coils 190 fixedly arranged on one circumference along the inner surface of the peripheral wall of the motor case 188, a motor shaft 192 rotatably supported by the motor case 188, and a coil 190. And a permanent magnet 194 that is fixedly disposed on the outer periphery of the motor shaft 192 so as to face each other. The electromagnetic motor 186 is a motor in which the coil 190 functions as a stator and the permanent magnet 194 functions as a rotor, and is a three-phase DC brushless motor.

  The absorber 172 includes a screw rod 200 having a male screw formed on the outer peripheral portion, and a nut 202 that holds a bearing ball and is screwed with the screw rod 200. The screw rod 200 and the nut 202 are a ball screw mechanism. Is configured. The nut 202 is fixedly supported on the upper end portion of a cylindrical nut support member 204 erected on the inner bottom portion of the lower tube 180 in a state of being screwed with the screw rod 200. On the other hand, the screw rod 200 is disposed in the upper tube 182 so as to extend in the vertical direction with its lower end inserted into the nut support member 204, and is fixed to the motor shaft 192 at the upper end. .

  The upper tube 182 is provided with a pair of guide grooves 210 extending in the vertical direction on the inner wall surface thereof, and each of the guide grooves 210 is attached to the upper end portion of the nut support member 204. Each of the pair of keys 212 is fitted, and the guide groove 210 and the key 212 allow the nut support member 204 and the upper tube 182, that is, the lower tube 180 and the upper tube 182 to be relatively unrotatable, and The relative movement in the vertical direction is possible.

  In addition, an annular lower retainer 216 is fixed to the outer periphery of the lower tube 180, and an annular upper retainer 218 is attached to the lower surface side of the mount portion 54 via a vibration isolating rubber. The coil spring 176 is supported by the lower retainer 216 and the upper retainer 218 while being sandwiched between them.

  Due to the structure as described above, the absorber 172 includes an upper tube 182, a motor case 188, and the like, which constitute a spring upper unit connected to the mount portion 54, and includes a lower tube 180, a nut support member 204, and the like. Thus, the unsprung unit connected to the second lower arm 36 is configured. The unsprung unit and the unsprung unit can be moved relative to each other with the approach and separation between the unsprung portion and the unsprung portion. With the relative movement between the unsprung unit and the unsprung unit, The absorber 172 is assumed to expand and contract.

  As the absorber 172 expands and contracts, the screw rod 200 and the nut 202 move relative to each other and the screw rod 200 rotates. Since the electromagnetic motor 186 provided in the absorber 172 can apply a rotational force to the screw rod 200, the absorber 172 depends on the rotational force, and therefore, the spring upper side unit and the spring lower side unit, It is possible to generate an approaching / separating force that is a force in a direction in which the upper and lower parts of the spring are moved closer to and away from each other. The approaching / separating force can act as a resistance force that prevents relative movement between the sprung portion and the unsprung portion. By using this resistance force as a damping force, the relative vibration between the sprung portion and the unsprung portion can be reduced. It is possible to attenuate. The absorber 172 is also capable of generating a propulsive force with respect to the relative motion between the spring upper part and the spring unsprung, and executes control based on the so-called skyhook damper theory or the like, and rolls the vehicle body during turning. It is possible to effectively suppress the pitch of the vehicle body during acceleration / deceleration, adjust the vehicle height, and the like.

  Further, in the present suspension system 170, as shown in FIG. 10, absorber electronic control units (absorber ECUs) 220 corresponding to the four absorbers 172 are provided. The absorber ECU 220 is a control device that controls the operation of each absorber 172, more specifically, each electromagnetic motor 186, and includes four inverters 222 as drive circuits corresponding to each electromagnetic motor 186, a CPU, a ROM, a RAM, and the like. And a controller 224 mainly composed of a computer. (See FIG. 14). Each inverter 222 is connected to the battery 118 via the converter 116, and each inverter 222 is connected to the electromagnetic motor 186 of each absorber 172. The controller 224 is also connected to the inverter 222 and controls the absorber 172 by controlling it.

  A vehicle equipped with the present suspension system 170 is also provided with a system 226 similar to the vehicle skid restraining system 130 provided in the vehicle equipped with the previous suspension system 10. The side-slip suppression control is executable.

<Control of vehicle suspension system>
i) Basic control In this suspension system 170, the approaching / separating force generated by each absorber 172 is independently controlled, and as in the previous system 10, sprung vibration damping control, roll suppression control, pitch Suppression control is being executed. Furthermore, in the present system 170, unlike the system 10, the hydraulic shock absorber is not provided in parallel with the coil spring 176. Therefore, in order to attenuate the vibration of the unsprung portion, the unsprung vibration damping control is also performed. Usually running. That is, in this system 170, the approaching / separating force is normally applied as a damping force for sprung vibration, a damping force for unsprung vibration, a roll restraining force, and a pitch restraining force. More specifically, the sprung vibration damping approach / separation force component (sprung vibration damping component) F _U that is the approaching / separating force for each control of sprung vibration damping control, unsprung vibration damping control, roll restraint control, and pitch restraint control. , unsprung vibration damping displacement force component (the unsprung-vibration damping component) F _S, roll restraining displacement force component (roll restraining component) F _R, pitch reduction displacement force component targets the sum of the (pitch restrain component) F _P The approaching / separating force F ^* is determined, and the absorber 172 is controlled so as to generate the target approaching / separating force F ^* . Since these four controls are substantially the same as the controls executed in the previous system 10, a method of determining the approaching / separating force component in each control will be briefly described below. The operation control of the electromagnetic motor 186 for controlling the approaching / separating force will also be described.

In the sprung vibration damping control, the sprung vibration damping component F _U is calculated according to the following equation in order to generate an approaching / separating force having a magnitude corresponding to the sprung absolute speed Vu in order to damp the vibration of the sprung part. .
F _U = C _S · Vu (C _S : damping coefficient based on skyhook damper theory)

In the unsprung vibration damping control, an unsprung vibration damping component F _S is calculated according to the following equation in order to generate an approaching / separating force having a magnitude corresponding to the unsprung absolute speed Vs in order to attenuate the vibration of the unsprung part. .
F _S = C _G · Vs (C _G : damping coefficient based on the ground hook damper theory)

In the roll suppression control, the control lateral acceleration Gy ^* , which is the lateral acceleration used for the control, is generated in the same manner as the previous system 10 in order to generate an approaching / separating force having a magnitude corresponding to the roll moment caused by the turning of the vehicle. Determined according to the following formula:
Gy ^* = K ₂ · Gyc + K ₃ · Gyr (K ₂ , K ₃ : gain)
Such based on the determined control-use lateral acceleration Gy ^*, the roll restrain component F _R is determined. The in the controller 224 are stored map data of the roll restrain component F _R to the the control-use lateral acceleration Gy ^* as a parameter is, by referring to the map data, the roll restrain component F _R is determined.

In pitch restrain control, so as to generate a magnitude displacement force of in accordance with due to pitch moment to acceleration and deceleration of the vehicle, on the basis of the actual longitudinal acceleration GZG, pitch restrain component F _P is determined according to the following equation.
F _P = K ₆ · Gzg (K ₆ : gain)

When the sprung vibration damping component F _U , the unsprung vibration damping component F _S , the roll restraining component F _R , and the pitch restraining component _FP are determined as described above, the sprung vibration damping control, the unsprung vibration damping control, the roll In order to unify the suppression control and the pitch suppression control, the target approach / separation force F ^* is determined according to the following equation.
F ^* = F _U + F _S + F _R + F _P
Then, the electromagnetic motor 186 is controlled to generate the determined target approach / separation force F ^* .

Operation control of the electromagnetic motor 186 for generating the target approach / separation force F ^* is performed by the inverter 222. More specifically, based on the determined target approaching / separating force F ^* , a command regarding the duty ratio corresponding to the direction in which the motor force is generated and the magnitude of the motor force is issued to the inverter 222 by the controller 224. Switches the switching element provided in itself based on the command to drive the electromagnetic motor 186, and the electromagnetic motor 186 has an approaching / separating force having a magnitude corresponding to the issued motor force direction and the duty ratio. It is generated.

ii) Absorber control considering the ground contact of the wheel When considering the transmission of the unsprung vibration to the unsprung part, the vibration of the unsprung part is lower when the damping coefficient of the absorber is lower in terms of relatively high frequency vibrations. Is difficult to be transmitted to the spring top. Therefore, in order to suppress the transmission to the vehicle body vibration of the high frequency range, the damping coefficient C _G used for ordinary unsprung-vibration damping control in the present system 170 is as relatively low. However, if the value of the damping coefficient is low, the grounding property against vibration of the unsprung resonance frequency tends to decrease as shown in FIG.

Further, even in a vehicle equipped with the suspension system 170, the above-mentioned side slip suppression control can be executed. If the ground contact property of the wheel is low at the time of executing the side slip suppression control, the vehicle side slip suppression effect by this control can be reduced. May decrease. Therefore, in this suspension system 170, when the side slip suppression control is executed when there is a possibility that the grounding property of the wheel may be lowered, the damping used for the unsprung vibration damping control is performed in order to increase the grounding property of the wheel. the coefficients are switched to the large damping coefficient C _B than the attenuation coefficient C _G used for ordinary unsprung-vibration damping control. More specifically, when vibration of an unsprung resonance frequency is generated and a side slip of the vehicle exceeding the allowable limit occurs, the unsprung vibration damping component F _S is calculated according to the following equation. And
F _S = C _B · Vs
Such and the unsprung-vibration damping component F _S which is determined, the sprung-vibration damping component F _U, the roll restrain component F _R, based on the pitch restrain component F _P, the target displacement force F ^* is determined.

  In the system 170, as described above, the first unsprung vibration control in which the damping effect is increased by increasing the damping coefficient with respect to the vibration of the unsprung portion in consideration of the grounding property of the wheel, and the vibration in the high frequency range. Therefore, the second unsprung vibration control in which the damping effect is reduced by reducing the damping coefficient with respect to the vibration of the unsprung portion is selectively executed. In the second unsprung vibration control, a damping force smaller than the damping force generated in the first unsprung vibration control is generated, so that the power consumption by the electromagnetic motor is reduced and the load on the electromagnetic motor is reduced. Mitigation etc. are planned.

<Control program>
In the vehicle side-slip suppression system 226, the side-slip suppression control similar to the side-slip suppression control executed in the previous vehicle side-slip suppression system 130 is executed by the controller 144 of the vehicle side-slip suppression ECU 138, as shown in the flowchart of FIG. It is done by being executed. On the other hand, in the suspension system 170, the approaching / separating force generated by the absorber 172 is controlled by the controller 224 of the absorber ECU 220 executing the absorber control program shown in the flowchart of FIG. These two programs are repeatedly executed at short time intervals (for example, several milliseconds) while the ignition switch is in the ON state. Since the flow of the skid control is described in the previous embodiment, the description of the flow of the skid control is omitted. Further, since the processing according to the absorber control program is substantially the same as the processing according to the adjustment device control program of the suspension system 10 described above, the control flow of the absorber 172 will be omitted or simplified.

In the process according to the absorber control program, similarly to the process substantially in accordance preceding regulator control program, in S31 to S36, according to the above formula, the sprung-vibration damping component F _U, the roll restrain component F _R, pitch restrain component F _P is It is determined. Then, in S39, it is determined whether or not the vehicle has slipped beyond the allowable limit. If it is determined that a vehicle skidding has occurred based on a command from the vehicle skidding suppression system 170, it is determined in S40 and S41 whether vibration at an unsprung resonance frequency has occurred. If it is determined that vibration of the unsprung resonance frequency is occurring, the unsprung vibration damping component F _S is determined in S42 according to the damping coefficient C _{B in} order to execute the first unsprung vibration control. . If it is determined in S39 that the vehicle has not skid, or if it is determined in S41 that no unsprung resonance frequency vibration has occurred, then in S43, the second unsprung vibration is detected. In order to execute the control, the unsprung vibration damping component F _S is determined according to the damping coefficient C _G. When the unsprung vibration damping component F _S is determined, in S44, the unsprung vibration damping component F _U , the roll restraining component F _R , the pitch restraining component _FP, and the unsprung vibration damping component F _S are summed up. The target approaching / separating force F ^* is determined, and a control signal based on the determined target approaching / separating force F ^* is issued to the inverter 152 in S45. After the series of processes described above, one execution of this program ends.

<Functional configuration of controller>
The controller 224 of the absorber ECU 220 that executes the absorber control program and the controller 144 of the vehicle side slip suppression ECU 138 that executes the side slip suppression control program have functional configurations as shown in FIG. Can be considered. Since the vehicle side-slip suppression system 226 includes the same vehicle side-slip suppression ECU 138 as that of the previous vehicle side-slip suppression system 130, description of the functional configuration of the controller 144 of the vehicle side-slip suppression ECU 138 will be omitted. Further, since the functional configuration of the controller 224 of the absorber ECU 220 is substantially the same as the functional configuration of the controller 114 of the adjusting device ECU 110 of the previous suspension system 10, the description of the functional configuration of the controller 224 of the absorber ECU 220 will be simplified. Assumed to be performed.

  The controller 224 includes an anti-sprung vibration control execution unit 230 as a functional unit that executes the processes of S31 and S32, and an anti-springless vibration control execution unit 232 as a functional unit that executes the processes of S37, S38, S42, and S43. Attitude change suppression control execution unit 234 as a functional unit for executing the processes of S33 to S36, vehicle skid determination unit 236 as a functional unit for executing the process of S39, and unsprung resonance as a functional unit for executing the processes of S40 and S41 A frequency vibration generation determination unit 238 is provided. The unsprung vibration control execution unit 232 executes the first unsprung vibration control execution unit 240 as a function unit that executes the process of S42, and executes the second unsprung vibration control execution unit as a function unit that executes the process of S43. Each has a portion 242.

1 is a schematic diagram showing an overall configuration of a vehicle suspension system according to a first embodiment of the claimable invention. It is a schematic diagram which shows the suspension apparatus with which the suspension system for vehicles of FIG. 1 is provided from the viewpoint from the vehicle rear. It is a schematic diagram which shows the suspension apparatus with which the suspension system for vehicles of FIG. 1 is provided from the viewpoint from the vehicle upper side. It is a schematic sectional drawing which shows the actuator which comprises the adjustment apparatus with which a suspension apparatus is provided. It is a figure which shows a suspension apparatus notionally. It is a graph which shows notionally the relationship between the ground load fluctuation rate with respect to the vibration of an unsprung resonance frequency, and a damping coefficient. It is a flowchart which shows a skid control program. It is a flowchart which shows an adjustment apparatus control program. It is a block diagram which shows the function of the control apparatus which manages control of a suspension system, and the control apparatus which controls control of a vehicle skid control system. It is a schematic diagram which shows the whole structure of the suspension system for vehicles which is 2nd Example of claimable invention. It is a schematic diagram which shows the suspension apparatus with which the suspension system for vehicles of FIG. 1 is provided from the viewpoint from the vehicle rear. It is a schematic sectional drawing which shows the electromagnetic shock absorber with which a suspension apparatus is provided. It is a flowchart which shows an absorber control program. It is a block diagram which shows the function of the control apparatus which manages control of a suspension system, and the control apparatus which controls control of a vehicle skid control system.

Explanation of symbols

  10: Vehicle suspension system 36: Second lower arm (lower spring) 50: Coil spring (suspension spring) 52: Hydraulic shock absorber 54: Mount part (upper spring) 60: Vehicle wheel distance adjustment device (approaching / separating force generation) (Device) 62: L-shaped bar (elastic body) 66: Actuator 70: Shaft portion 72: Arm portion 80: Electromagnetic motor 110: Adjustment device electronic control unit (control device) 130: Vehicle side slip suppression system 154: Anti-spring vibration control Execution unit 156: Anti-spring vibration control execution unit 158: Posture change suppression control execution unit 170: Vehicle suspension system 172: Electromagnetic shock absorber (approaching / separating force generator) 176: Coil spring (suspension spring) 180: Lower tube (unsprung unit) 182: Upper tube (unsprung unit) 186: Electromagnetic motor 188: Motor case (unsprung unit) 200: Screw rod (screw mechanism) 202: Nut (screw mechanism) 204: Nut support member (unsprung side unit) 220: Absorber electronic control unit (control device) 226: Vehicle side slip suppression system 230: Anti-sprung vibration control execution unit 232: Anti-sprung vibration control execution unit 234: Posture change suppression Control execution unit

Claims (10)

A suspension spring disposed between the spring top and the spring bottom;
An electromagnetic motor is provided in parallel with the suspension spring, and an approaching / separating force that is a force in a direction of approaching / separating the upper and lower parts of the spring is generated based on the force generated by the electromagnetic motor. An approach and separation force generator;
A vehicle suspension system comprising: a control device that controls an approaching / separating force generated by the approaching / separating force generating device by controlling an operation of the electromagnetic motor;
The control device is
(a) first unsprung vibration control for generating the approaching / separating force as a damping force having a magnitude according to a predetermined rule for the unsprung vibration; and (b) the approaching / separating force for the unsprung vibration. The unsprung vibration that selectively generates the second unsprung vibration control that is generated as a damping force smaller than the damping force generated in the first unsprung vibration control or not generated as the damping force. A vehicle suspension system having a control execution unit.   2. The vehicular vibration control apparatus according to claim 1, wherein the anti-spring vibration control execution unit is configured to execute the second anti-spring vibration control when the vehicle does not slip beyond the allowable limit. Suspension system. When the vehicle suspension system exceeds the allowable limit, the vehicle suspension system performs side slip suppression control that controls at least one of braking force and propulsive force on the vehicle to suppress the vehicle side slip. Provided in vehicles equipped with a possible vehicle skid control system,
3. The vehicle according to claim 1, wherein the anti-spring vibration control execution unit is configured to execute the first anti-spring vibration control based on a command from the vehicle skid suppression system. Suspension system.   The unsprung vibration control execution unit is configured to execute the first unsprung vibration control on condition that the vibration intensity of the unsprung resonance frequency exceeds a set value. The vehicle suspension system according to any one of claims 1 to 3.   In the situation where the unsprung vibration control execution unit has a vibration intensity of an unsprung resonance frequency equal to or lower than the set value, a side slip of the vehicle exceeding the allowable limit occurs. 5. The vehicle suspension system according to claim 4, wherein the second anti-spring vibration control is executed without executing the first anti-spring vibration control. The approaching / separating force generator is
An elastic body having one end connected to one of the spring top and the spring bottom;
The elastic body is disposed between the other end of the elastic body and the other of the sprung part and the unsprung part and connects the other and the elastic body, and the electromagnetic motor is a component of the electromagnetic body. By applying the force generated by itself to the elastic body depending on the generated force, the deformation amount of the elastic body is changed according to the amount of movement of the elastic body, and the force approaches the elastic body through the elastic body. The vehicle suspension system according to any one of claims 1 to 5, further comprising: an electromagnetic actuator that acts on the upper and lower portions of the spring as a separation force. The elastic body has a shaft portion rotatably held on the spring upper portion, and an arm portion extending from one end portion of the shaft portion so as to intersect the shaft portion and having a tip portion connected to the spring lower portion,
The vehicle suspension system according to claim 6, wherein the actuator is fixed to a vehicle body and rotates the shaft portion around an axis thereof by a force generated by the actuator. The approaching / separating force generator is
A sprung unit connected to the sprung part and a sprung unit connected to the sprung part, and as the sprung part and the sprung part approach and separate from each other, Is configured to be stretchable by relative movement, and
Based on the force generated by the electromagnetic motor, a force in the direction of relative movement between the unsprung unit and the unsprung unit is generated, and the force acts on the unsprung portion and unsprung portion as an approaching / separating force. The suspension system for a vehicle according to any one of claims 1 to 5, wherein the suspension system for a vehicle is configured to cause the vehicle to stop. The approaching / separating force generator is
A screw rod provided on one of the unsprung side unit and the unsprung side unit and formed with a male screw, and screwed with the screw rod to the other of the unsprung side unit and the unsprung side unit. A nut mechanism provided with a screw mechanism that is structured such that one of the screw rod and the nut rotates in accordance with the relative movement of the sprung unit and the unsprung unit;
Depending on the force generated by the electromagnetic motor, a rotational force is applied to one of the screw rod and the nut so as to generate a force in a direction in which the unsprung unit and the unsprung unit are relatively moved. The vehicle suspension system according to claim 8 configured as described above. The vehicle suspension system includes a hydraulic shock absorber disposed in parallel with the suspension spring,
10. The vehicle suspension system according to claim 1, wherein the shock absorber has a damping coefficient set to 1000 to 2000 N · sec / m.

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