JP2010125959A - Vehicular stabilizer system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicular stabilizer system capable of preventing or reducing adverse effects due to the operation of an actuator with road-surface input when roll suppressing control is not executed. <P>SOLUTION: The vehicular stabilizer system includes a stabilizer, the actuator for changing the torsion amount of the stabilizer by its operation, and a control device for controlling the actuator to execute roll suppressing control. In the case that the operation amount of the actuator with road-surface input exceeds a set operation amount (S14) when the roll suppressing control (S8) is not executed, the control device executes operation amount reducing control (S15) to reduce the operation amount. This prevents or reduces adverse effects on the ride comfort of a vehicle resulting from the shift of the operation position of the actuator from a neutral operation position. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a vehicle stabilizer system for suppressing a roll of a vehicle body.

In recent years, development of a system that actively suppresses the roll of a vehicle body using an actuator has progressed, and some vehicles have already been installed. In such a vehicle stabilizer system, a condition for controlling the operation of the actuator is defined, and when the condition is satisfied, it is also considered to suppress the roll of the vehicle body by controlling the actuator. In the system described in the literature, the actuator is controlled when the steering angle becomes equal to or larger than a predetermined value.
JP-A-6-270638

  When the above conditions are not satisfied, active control for suppressing the roll of the vehicle body is not performed, but the actuator may be operated by the vertical movement of the wheel due to road surface undulation, that is, by road surface input. . In that case, the operation of the actuator may adversely affect the riding comfort of the vehicle. This invention is made | formed in view of such a situation, and makes it a subject to provide the stabilizer system for vehicles which can prevent or reduce the bad influence by operating an actuator in the state which is not controlled.

  In order to solve the above-described problems, a vehicle stabilizer system according to the present invention performs a roll suppression control by controlling a stabilizer bar, an actuator that changes the amount of twist of the stabilizer bar by its own operation, and the actuator. A vehicle stabilizer system comprising a control device, and when the control device does not perform roll suppression control, the operation amount when the operation amount of the actuator by road surface input exceeds the set operation amount It is characterized in that operation amount reduction control is performed to reduce the amount of motion.

  As will be described in detail later, when the actuator is operated by road input in a state where the roll suppression control is not executed, there is a possibility that the operating position of the actuator will deviate from the neutral operating position. In other words, the operating position of the actuator may shift from the neutral operating position. This shift is an unintended shift, and if the amount of the shift increases to some extent, the ride comfort of the vehicle will be adversely affected. According to the vehicle stabilizer system of the present invention, when the shift amount of the operation position is increased to some extent, the shift amount is reduced, so that the adverse effect on the riding comfort of the vehicle equipped with the system is prevented or reduced. It becomes possible to do.

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 some constituent elements are deleted from the aspect of each item can be an aspect of the claimable invention.

  In addition, the following (1) term is a term which shows the aspect used as the premise of claimable invention, and the term below the (2) term which cites (1) term becomes a term which shows the aspect of claimable invention. Incidentally, the combination of the items (1), (4), and (5) corresponds to claim 1, and the limitation to the technical features of the item (3) is added to claim 1. Claim 2 to which Claim 1 or Claim 2 is further limited by the technical features of (6) is based on Claim 3, or any one of Claims 1 to 3 (7) Claim 4 is limited by the technical feature of claim 5. Claim 4 is limited by technical feature of (16) to any one of claims 1 to 4. Further, Claim 5 plus limitations due to the technical features of (18) corresponds to Claim 6 respectively.

(1) A stabilizer bar that is twisted by a roll of the vehicle body and acts on the vehicle body as a roll restraining force with a torsional reaction force having a magnitude corresponding to the twist amount;
An actuator having an electromagnetic motor as a drive source, and changing the amount of twist of the stabilizer bar by its own operation;
A vehicle stabilizer system comprising a control device for controlling the actuator,
The control device is
When the setting condition is satisfied, roll restraint control is performed to control the actuator so that the torsional reaction force of the stabilizer bar has a magnitude corresponding to the roll moment received by the vehicle body due to vehicle turning. Vehicle stabilizer system.

  The vehicle stabilizer system described in this section is a precondition of the claimable invention as described above, and is a section listing basic components that the vehicle stabilizer system of the claimable invention should have. is there. Incidentally, the system described in this section is a system that can actively change the rigidity of the stabilizer bar, in other words, the roll rigidity of the vehicle body, and is a so-called active stabilizer system.

  The specific configuration of the vehicle stabilizer system of this section is not limited. In particular, when the “stabilizer device” includes the “stabilizer bar” and the “actuator”, the specific configuration of the stabilizer device is not limited. For example, as will be described later, the stabilizer bar is configured such that the existing stabilizer bar is divided into two at the intermediate portion and is composed of a pair of stabilizer bar members, and the actuator is provided with the pair of stabilizer bars. It can be set as the structure which changes the twist amount of the stabilizer bar by rotating a member relatively. Further, for example, an actuator is disposed between one end of the stabilizer bar and a wheel holding member that holds one of the left and right wheels, and the interval between the one end and the wheel holding member is changed. Thus, a configuration in which the amount of twist of the stabilizer bar is changed can also be adopted.

  “Roll suppression control” is control that is the basis of the stabilizer system, and can be considered as control for changing the stiffness of a so-called stabilizer bar, more specifically, the apparent stiffness, in order to change the roll stiffness. For example, if the roll moment received by the vehicle body due to turning of the vehicle (hereinafter, the term “roll moment” means the roll moment unless otherwise specified) Control can be performed to realize a state where the rigidity of the stabilizer bar is increased.

  The roll suppression control may be control that targets the magnitude of the torsional reaction force of the stabilizer bar, for example, control that directly targets the actuator force that is the force generated by the actuator. Control that targets the torsion amount of the actuator, for example, control that directly targets the operation amount of the actuator may be used. That is, the roll suppression control performed by the control device. Control for force may be used, or control for motion position may be used. In addition, when performing the control for the actuator force, as an aspect of the control, for the sake of convenience, the control may be the motor force that is the force generated by the electromagnetic motor that is the drive source. In the case of the control for the operation amount of the actuator, as an aspect of the control, for the sake of convenience, the control may be performed on the operation amount of the electromagnetic motor. In the case of control for the amount of movement of the actuator, the amount of movement is based on the movement position of the actuator (hereinafter sometimes referred to as “neutral movement position”) when the vehicle is stationary on a flat and horizontal road. The amount of movement can be adopted. Incidentally, in this specification, the “operation amount” of an actuator or an electromagnetic motor means an operation amount based on this neutral operation position unless otherwise specified.

  The “setting condition” regarding the roll suppression control can be considered as a condition for starting the roll suppression control. When roll suppression control is performed depending on some parameter, the roll suppression control should not be executed until the value of the parameter (hereinafter sometimes referred to as “dependence parameter”) reaches a certain limit. There are things to do. That is, in the roll suppression control, a so-called control dead zone may be provided. The above setting condition can be considered as a condition indicating that the situation where the vehicle is placed has escaped from this control dead zone. Specifically, for example, when the vehicle is traveling straight, it is not necessary to perform control for suppressing rolls caused by turning of the vehicle. In such a case, as a condition for preventing roll suppression control from being executed. The above setting conditions can be set. Furthermore, the setting conditions need not be limited to special ones. For example, as described later, when the roll moment is a dependency parameter, the roll moment exceeds the set level. This can be set as a setting condition.

(2) The control device
The actuator is controlled based on a roll moment index indicating a roll moment received by the vehicle body due to vehicle turning so that the torsional reaction force of the stabilizer bar has a magnitude corresponding to the value of the roll moment index. The vehicle stabilizer system according to (1), configured to execute the roll suppression control.

  The aspect in this section is an aspect in which the dependence parameter in the roll suppression control is limited to the “roll moment index”. The roll moment index is not particularly limited as long as it indicates the roll moment received by the vehicle body due to vehicle turning. For example, various parameters such as a lateral acceleration, a steering operation amount of a steering operation member, a steering amount such as a wheel turning amount, a yaw rate, a cornering force, and a lateral force can be employed.

(3) The controller is
When the roll moment index indicating the roll moment received by the vehicle body due to turning of the vehicle exceeds the value indicating the roll moment of the set magnitude, the roll suppression control is performed assuming that the setting condition is satisfied. The vehicle stabilizer system according to (1) or (2), which is configured to be executed.

  The mode of this section is a mode in which a limitation is imposed on the conditions for starting the roll suppression control, in other words, the conditions under which the vehicle is placed out of the control dead zone. Since the “low moment index” has been described in the previous section, a description thereof is omitted here. The aspect of this section becomes a more effective aspect by combining with the above aspect in which the roll moment index is a dependency parameter.

  (4) The vehicle stabilizer system according to any one of (1) to (3), wherein the actuator is configured to be operated by a road surface input that is a force acting on a wheel from the road surface.

  When the actuator is operated by road surface input in a state where the roll suppression control is not performed (hereinafter sometimes referred to as “non-control state”), there is a risk of adversely affecting the ride comfort of the vehicle, as will be described in detail later. There is. Therefore, in the aspect of this section, if the adverse effect is mitigated or eliminated, a highly practical vehicle stabilizer system can be constructed.

(5) When the operation position of the actuator in a state where the stabilizer bar is not twisted is defined as a neutral operation position,
The control device is
When the roll suppression control is not executed, the operation amount of the actuator is reduced when the operation amount of the actuator from the neutral operation position in the operation of the actuator by road surface input exceeds a set operation amount. The vehicle stabilizer system according to (4), which is configured to execute an operation amount reduction control for controlling the actuator.

  When the actuator is operated by road surface input in an uncontrolled state, the actuator generates some resistance force. For example, when the electromagnetic motor is operated by the operation, the electromagnetic motor has an operation resistance having a magnitude corresponding to the generated current based on the electromotive force, and the resistance force of the actuator is equal to the operation resistance. Will depend. The operating resistance of the electromagnetic motor that relies on the electromotive force is relatively large when the actuator, that is, the electromagnetic motor is operated relatively fast, and is relatively small when the actuator is operated slowly. Therefore, when the wheels move up and down relatively slowly due to road surface input, the actuator can be operated relatively easily. Conversely, when the wheels move up and down relatively quickly, the actuator operates relatively slowly. It is difficult to be let down.

  Here, consider a case where there is a road surface input that twists the stabilizer bar in a certain direction, and the vertical movement of the wheel at that time is relatively slow. In this case, the actuator shifts its operating position from the neutral operating position. That is, the actuator is moved in that direction by a certain amount of movement. For this reason, the stabilizer bar is not substantially twisted and hardly generates a torsional reaction force. From this state, there is road input that twists the stabilizer bar in the opposite direction, and when the wheel vertical movement at that time is relatively fast, the actuator can not be operated in a state where it is operated by a certain amount of operation, The torsional reaction force of the stabilizer bar becomes larger by an amount corresponding to the amount of operation than when the operation position of the actuator is the neutral operation position. This contributes to worsening the ride comfort of the vehicle. In other words, in the non-control state, the road surface input in the reverse direction when the operating position of the actuator is shifted to some extent from the neutral operating position adversely affects the riding comfort of the vehicle.

  From another point of view, there is the following problem regardless of the operating resistance of the actuator. As described above, when the above setting condition is satisfied, that is, when the situation where the vehicle is placed has deviated from the control dead zone described above, the actuator is controlled from the uncontrolled state (hereinafter referred to as “control state”). ”). In general, since the actuator is controlled with reference to the state where the actuator operating position is located at the neutral operating position (hereinafter sometimes referred to as “neutral state”), the actuator operating position is shifted from the neutral operating position. If the state is shifted from the non-control state to the control state, the transition may not be performed smoothly. That is, there is a possibility that the operation of the actuator becomes abrupt at the transition to the control state. Such a step-like operation (step-like operation) of the actuator contributes to deterioration of the riding comfort of the vehicle. In other words, in the non-control state, the start of control in a state where the operation position of the actuator is shifted to some extent from the neutral operation position adversely affects the riding comfort of the vehicle.

  In view of the above situation, in the system of the aspect of this section, when the operation position is shifted to some extent from the neutral operation position in the uncontrolled state, that is, when the operation amount of the actuator exceeds the set operation amount, The actuator is controlled so as to reduce the operation amount. Therefore, in the system according to the aspect of this section, the operation amount reduction control is executed, so that the operation position of the actuator does not greatly shift from the neutral operation position in the non-control state, and is based on the reverse road surface input described above. The adverse effect on the ride comfort of the vehicle and the adverse effect on the ride comfort of the vehicle at the time of transition from the non-control state to the control state are alleviated or eliminated.

(6) The control device
When the operation amount reduction control is being executed, if the operation amount of the actuator falls below the second set operation amount set smaller than the set operation amount, the execution of the operation amount reduction control is stopped. The vehicle stabilizer system according to item (5) configured as described above.

  When the actuator operation amount exceeds the set operation amount, the operation amount decrease control is executed. When the operation amount decrease control is immediately stopped when the actuator operation amount falls below the set operation amount, immediately after When the set operation amount is exceeded, the operation amount reduction control is executed again without any delay. That is, the execution / non-execution of the operation amount reduction control may be repeated in a very short time, and in some cases, control hunting may occur. In this aspect, the operation amount reduction control is performed when the operation amount reduction control is less than the second set operation amount that is set to be smaller than the set operation amount so that the start threshold value and the stop threshold value are different. The execution is stopped. This avoids a situation in which the execution / non-execution of the operation amount reduction control is repeated in a very short time.

(7) The control device
The roll suppression is performed by determining a target operation amount of the actuator according to a roll moment received by the vehicle body due to turning of the vehicle, and controlling the actuator so that the operation amount of the actuator becomes the target operation amount. The vehicle stabilizer system according to (5) or (6), which is configured to execute control.

  According to the aspect of this section, the roll suppression control as described above for the operation position of the actuator is performed. In such roll suppression control, the actuator is controlled based on the neutral operation position. Therefore, in the event described above, that is, in the state where the operation position of the actuator has shifted from the neutral operation position beyond a certain level. The stepwise operation of the actuator that occurs when shifting from the non-control state to the control state is likely to occur. Therefore, in the system according to the aspect of this section, the operation amount reduction control is particularly effective for alleviating or eliminating an adverse effect on the riding comfort of the vehicle.

  (8) The vehicle according to any one of (4) to (7), wherein when the actuator is operated by a road surface input, the electromagnetic motor is operated in accordance with the operation. Stabilizer system.

  According to the aspect of this section, when the electromagnetic motor is operated, the electromagnetic motor has an operating resistance of a magnitude corresponding to the generated current depending on the electromotive force. As described above, an actuator that generates a resistance force based on such an operating resistance has the above-described problem, that is, the problem of adversely affecting the ride quality of the vehicle in an uncontrolled state. Therefore, in the system of this aspect provided with such an actuator, the operation amount reduction control described above is an effective means for maintaining a good riding comfort of the vehicle.

(9) The control device
When the roll suppression control is not executed, the operation mode of the electromagnetic motor depends on the electromotive force generated in the electromagnetic motor when the speed of operation of the actuator by road surface input exceeds a set speed. The vehicle stabilizer system according to item (8), configured to execute motor operation mode switching control for switching from a small operating resistance mode having a relatively small resistance to a large operating resistance mode having a relatively large operating resistance.

  When the electromagnetic motor is operated by the road surface input, as described above, the electromagnetic motor has an operating resistance that depends on the electromotive force. In a state where this operating resistance is small, the resistance force of the actuator to the road surface input is relatively small. In the uncontrolled state, in principle, the ride comfort of the vehicle is better when the operating resistance of the electromagnetic motor is smaller than when it is larger. This is because the torsional reaction force of the stabilizer bar becomes small, so that the vertical movement of the wheel is difficult to be transmitted as the roll operation of the vehicle body. Therefore, from this point of view, it is desirable that the operating resistance of the electromagnetic motor be as small as possible.

  However, when the operating resistance of the electromagnetic motor is small, the actuator is easily operated at high speed by road surface input, and the operating sound of the actuator becomes loud during the high speed operation. The operation sound is often annoying to the occupant, and in such a case, the riding comfort of the vehicle is deteriorated in another sense. From the viewpoint of such operation noise, it is desirable to slow down the operation when the actuator is operated at a certain speed.

  According to the aspect of this section, when the operation of the actuator becomes high to some extent in the non-control state, the operation mode of the electromagnetic motor is switched from the mode with the small operation resistance to the mode with the large operation resistance. Therefore, when the operation of the actuator is fast, the operation is decelerated, and it is possible to reduce or prevent annoying operation sound. According to the aspect of this section, in this way, adverse effects on the riding comfort of the vehicle are reduced or eliminated.

  (10) The small operating resistance mode is a mode in which the generated current generated by operating the electromagnetic motor is relatively small, and the large operating resistance mode is a mode in which the generated current is relatively large. The vehicle stabilizer system described in 1.

  The operating resistance of the electromagnetic motor that relies on the electromotive force depends on the amount of generated current flowing through the electromagnetic motor, and is small when the amount of generated current is small and large when it is large. The aspect of this section uses such a principle so that the amount of generated current is reduced in the mode with low operating resistance, and the amount of generated current is increased in the mode with high operating resistance. Is done.

  (11) The control device realizes the small operation resistance mode by opening a plurality of energization terminals of the electromagnetic motor, and makes the large operation resistance mode by conducting the plurality of energization terminals mutually. The vehicle stabilizer system according to (9) or (10) configured to be realized.

  If the energization terminal of the electromagnetic motor is opened, the generated current based on the electromotive force does not flow, the operating resistance of the electromagnetic motor is small, and the electromagnetic motor can be operated relatively freely. Conversely, if the energization terminals of the electromagnetic motor are connected to each other, the coil of the electromagnetic motor becomes a closed loop, so that a relatively large amount of generated current flows and the operating resistance of the electromagnetic motor becomes relatively large. Incidentally, the operating resistance of the electromagnetic motor becomes the largest when the conduction terminals of the electromagnetic motor are made to conduct each other so as to be short-circuited. The former is an operation mode called a so-called free mode, and the latter is an operation mode called a so-called brake mode.

(12) The vehicle stabilizer system includes a battery serving as a power source of the electromagnetic motor, and a drive circuit disposed between the battery and the electromagnetic motor for driving the electromagnetic motor.
The vehicle stabilizer system according to any one of (9) to (11), wherein the control device controls the actuator via the drive circuit.

(13) The drive circuit includes:
A plurality of high-potential side switching elements provided between the plurality of energization terminals and the high-potential side terminal of the battery corresponding to the plurality of energization terminals of the electromagnetic motor;
The vehicle stabilizer system according to (12), further comprising a plurality of low-potential side switching elements provided between the plurality of energization terminals and the low-potential side terminal of the battery corresponding to the plurality of energization terminals. .

  (14) The drive circuit includes a plurality of free-wheeling diodes provided in parallel with the plurality of high-potential side switching elements and the plurality of low-potential side switching elements in correspondence with the plurality of high-potential side switching elements. Vehicle stabilizer system.

  The above three terms are embodiments in which electromagnetic motor control means are specifically limited. A so-called inverter can be employed as a drive circuit including the switching element. In addition, by providing the switching diode in parallel with the switching element, the electric energy generated by the electromagnetic motor can be regenerated in the battery.

  (15) The control device realizes the small operating resistance mode by opening all of the plurality of high potential side switching elements and all of the plurality of low potential side switching elements of the drive circuit. In addition, the large operating resistance mode is realized by opening all of one of the plurality of high potential side switching elements and the plurality of low potential side switching elements and closing all of the other ones. The vehicle stabilizer system according to (13) or (14), configured as described above.

  According to the aspect of this section, since the operation mode of the electromagnetic motor is switched by the drive circuit, no device is required for the switching, so that a simple system can be constructed.

(16) The stabilizer bar is
Provided corresponding to the left and right wheels, each of which extends in the vehicle width direction, and extends continuously across the torsion bar portion and intersects with the torsion bar portion. Including a pair of stabilizer bar members having an arm portion connected to a wheel holding portion for holding one of the wheels corresponding to itself,
The actuator is
The vehicle stabilizer system according to any one of (1) to (15), wherein the torsion bar portions of the pair of stabilizer bar members are relatively rotated.

(17) The actuator includes a speed reducer that reduces the rotation of the electromagnetic motor, and a housing that holds the electromagnetic motor and the speed reducer.
(16) The one torsion bar portion of the pair of stabilizer bar members is connected to the housing in a relatively non-rotatable manner, and the other torsion bar portion is connected to the output portion of the speed reducer in a relatively non-rotatable state. The vehicle stabilizer system described in 1.

  The above two terms relate to an aspect in which a limitation on the configuration of the stabilizer device is added. According to the modes described in the above two sections, it is possible to easily construct a so-called active stabilizer system.

  (18) The vehicle stabilizer system according to (17), wherein a reduction ratio of the reduction gear is 1/100 or less.

  The reduction ratio of the speed reducer can be expressed as the ratio of the operating speed (rotational speed) of the actuator to the rotational speed of the electromagnetic motor. As a general concept, when the value is small, “the reduction ratio is large When the value is large, it is said that the reduction ratio is small. In the following description, the magnitude of the reduction ratio will be shown according to its general concept. Incidentally, the speed reducer in the aspect of this section is a speed reducer having a considerably large speed reduction ratio.

  If the reduction gear ratio of the reduction gear is large, the actuator can generate a relatively large force even if the electromagnetic motor is relatively small, which has the advantage that the stabilizer device can be downsized. Therefore, in order to enjoy the advantages, it is desirable to increase the reduction ratio. In this case, the specific mechanism of the speed reducer is not particularly limited. For example, a harmonic gear mechanism (sometimes referred to as “harmonic drive (registered trademark) mechanism”, “strain wave gearing mechanism”, etc.) It is possible to employ a speed reducer having various mechanisms such as a hypocycloid speed reducing mechanism.

  On the other hand, when a reduction gear with a large reduction ratio is used, the forward / reverse efficiency ratio of the actuator becomes large. Here, the “normal / reverse efficiency ratio” is the ratio of the positive efficiency to the reverse efficiency of the actuator, and the “normal efficiency” is, for example, in the state where an external force is acting on the actuator. It can be defined as the minimum electromagnetic motor force required for the actuator to operate against it, and “reverse efficiency” is also determined by the external force acting on the actuator. It can be defined as the minimum electromagnetic motor force necessary for the actuator not to operate. Therefore, when the forward / reverse efficiency ratio of the actuator is large, the rotational speed of the electromagnetic motor increases with respect to the actuator operating speed as well as the operating resistance caused by friction. The current increases and the operating resistance based on the electromotive force increases. As a result, it becomes difficult for the actuator to be operated even by road surface input.

  As described above, the road surface input in the reverse direction in a state where the operation position of the actuator is shifted to some extent from the neutral operation position in the non-control state contributes to deterioration of the riding comfort of the vehicle. This is particularly noticeable when a reduction gear with a large reduction ratio is used. Therefore, in the stabilizer system according to the aspect of this section, the operation amount reduction control described above is particularly effective control.

  Further, according to the aspect of this section, since the operating resistance depending on the electromotive force is relatively large, the difference between the operating resistance and the degree in the small operating resistance mode and the operating resistance in the large operating resistance mode is compared. Become bigger. Therefore, in the system according to the aspect of this section, the effect of lowering the operation speed of the actuator is increased in the operation mode having a large operation resistance. Therefore, the effect of executing the motor operation mode switching control described above is effective. It will be higher.

  Hereinafter, embodiments of the claimable invention will be described in detail with reference to the drawings. In addition to the following examples, the claimable invention is implemented in various modes including various modifications and improvements based on the knowledge of those skilled in the art, including the mode described in the above [Mode of Invention]. can do.

≪Configuration of vehicle suspension system≫
(A) Overall Configuration of Suspension System FIG. 1 schematically shows a vehicle suspension system according to this embodiment. The suspension system includes two stabilizer devices 14 disposed on the front wheel side and the rear wheel side of the vehicle. Each of the stabilizer devices 14 includes a stabilizer bar 20 connected to a suspension arm (see FIGS. 2 and 3) as a wheel holding member that holds the left and right wheels 16 at both ends. The stabilizer bar 20 is configured to include a pair of stabilizer bar members 22 into which the stabilizer bar 20 is divided. The pair of stabilizer bar members 22 are connected by an actuator 26 so as to be relatively rotatable.

(B) Configuration of Suspension Device A vehicle equipped with this system is provided with four independent suspension type suspension devices corresponding to the respective wheels 16. The suspension device for the front wheel that is the steered wheel and the suspension device for the rear wheel that is the non-steered wheel can be regarded as substantially the same configuration except for the mechanism that enables the wheel to steer, The wheel suspension device will be described as a representative.

  As shown in FIGS. 2 and 3, the suspension device 30 is a multi-link suspension device. The suspension device 30 includes a first upper arm 32, a second upper arm 34, a first lower arm 36, a second lower arm 38, and a toe control arm 40, each of which is a suspension arm. One end of each of the five arms 32, 34, 36, 38, 40 is rotatably connected to the vehicle body, and the other end is rotatable to an axle carrier 42 that rotatably holds the wheel 16. It is connected. With these five arms 32, 34, 36, 38, and 40, the axle carrier 42 can move up and down so as to draw a substantially constant locus with respect to the vehicle body. In addition, the suspension device 30 includes a coil spring 44 and a hydraulic shock absorber 46, which respectively include a mount portion 48 provided on a tire housing, which is a component of the spring upper portion, and a spring lower portion. They are arranged in parallel with each other between the second lower arm 38 which is one component. That is, the suspension device 30 elastically supports the sprung portion and the unsprung portion together, and generates a damping force against vibration associated with the approach and separation.

(C) Configuration of Stabilizer Device As shown in FIGS. 2 and 3, each stabilizer bar member 22 of the stabilizer device 14 has a torsion bar portion 50 that extends generally in the vehicle width direction, and a torsion bar portion 50 that is integrated therewith. It can be divided into an arm portion 52 that intersects and extends approximately in front of the vehicle. The torsion bar portion 50 of each stabilizer bar member 22 is rotatably held by a holder 54 fixedly provided on the vehicle body at a location close to the arm portion 52 and is coaxially arranged. The end portions of the torsion bar portions 50 (end portions opposite to the arm portion 52 side) are connected to the actuators 26 as will be described in detail later. On the other hand, the end of each arm 52 (the end opposite to the torsion bar 50) is connected to the second lower arm 38 via a link rod 56. The second lower arm 38 is provided with a link rod connecting portion 57. One end of the link rod 56 is connected to the link rod connecting portion 57, and the other end is connected to the end of the arm portion 52 of the stabilizer bar member 22. It is linked so that it can move.

  As shown in FIG. 4, the actuator 26 included in the stabilizer device 14 includes an electromagnetic motor 60 as a drive source, and a speed reducer 62 that reduces and transmits the rotation of the electromagnetic motor 60. The electromagnetic motor 60 and the speed reducer 62 are provided in a housing 64 that is an outer shell member of the actuator 26. One end of the housing 64 is fixedly connected to the end of one torsion bar portion 50 of the pair of stabilizer bar members 22, while the other of the pair of stabilizer bar members 22 is connected to the housing 64. It is arranged in a state of extending from the other end portion of the motor to the inside thereof, and is connected to the speed reducer 62 as will be described in detail later. Further, the other of the pair of stabilizer bar members 22 is rotatably held by the housing 64 via the bush type bearing 70 at the axial intermediate portion thereof.

  The electromagnetic motor 60 includes a plurality of coils 72 fixed on a circumference along the inner surface of the peripheral wall of the housing 64, a hollow motor shaft 74 rotatably held in the housing 64, and the coil 72. And a permanent magnet 76 which is fixedly disposed on the outer periphery of the motor shaft 74. The electromagnetic motor 60 is a motor in which the coil 72 functions as a stator and the permanent magnet 76 functions as a rotor, and is a three-phase DC brushless motor. A motor rotation angle sensor 78 for detecting the rotation angle of the motor shaft 74, that is, the rotation angle of the electromagnetic motor 60 is provided in the housing 64. The motor rotation angle sensor 78 mainly includes an encoder and is used for controlling the actuator 26, that is, controlling the stabilizer device 14.

  The speed reducer 62 includes a wave generator 80, a flexible gear (flex spline) 82, and a ring gear (circular spline) 84. ”And so on). The wave generator 80 is configured to include an elliptical cam and a ball bearing fitted on the outer periphery thereof, and is fixed to one end of the motor shaft 74. The flexible gear 82 has a cup shape in which the peripheral wall portion can be elastically deformed, and a plurality of teeth (400 teeth in the speed reducer 62) are formed on the outer periphery on the opening side of the peripheral wall portion. The flexible gear 82 is connected to and supported by the end of the other torsion bar portion 50 of the pair of stabilizer bar members 22 described above. More specifically, the torsion bar portion 50 of the stabilizer bar member 22 passes through the motor shaft 74, and penetrates the bottom portion of the flexible gear 82 as the output portion of the speed reducer 62 on the outer peripheral surface of the portion extending from the motor shaft 74. In this state, it is connected to the bottom of the base plate by spline fitting so that relative rotation is impossible. The ring gear 84 is generally ring-shaped and has a plurality of teeth (402 teeth in the present speed reducer 62) formed on the inner periphery, and is fixed to the housing 64. The flexible gear 82 is fitted into the ring gear 84 at two locations located in the major axis direction of the ellipse, and is not meshed at other locations, with its peripheral wall portion being fitted on the wave generator 80 and elastically deformed into an elliptical shape. It is said that. With such a structure, when the wave generator 80 rotates once (360 degrees), that is, when the motor shaft 74 of the electromagnetic motor 60 rotates once, the flexible gear 82 and the ring gear 84 are relatively rotated by two teeth. . That is, the reduction ratio of the reduction gear 62 is 1/200.

  With the above configuration, a force that relatively changes the distance between one of the left and right wheels 16 and the vehicle body and the distance between the other of the left and right wheels 16 and the vehicle body, that is, a roll moment, acts on the vehicle body by turning the vehicle or the like. In this case, a force that relatively rotates the left and right stabilizer bar members 22, that is, an external force acting on the actuator 26 acts. In that case, the actuator 26 causes the external force to be generated by a motor force that is generated by the electromagnetic motor 60 (which may be referred to as rotational torque because the electromagnetic motor 60 is a rotational motor and may be considered rotational torque). When the force which opposes is generated, one stabilizer bar 20 constituted by these two stabilizer bar members 22 is twisted. The torsional reaction force generated by this twisting is a force that opposes the roll moment. That is, the stabilizer device 14 is configured such that the stabilizer bar 20 constituting the stabilizer device 14 is twisted by the roll of the vehicle body, and a torsional reaction force having a magnitude corresponding to the amount of twist is applied to the vehicle body as a roll suppression force. It is. If the relative rotation amount of the left and right stabilizer bar members 22 is changed by changing the rotation amount (operation amount) of the actuator 26 by the motor force, the torsion amount of the stabilizer bar 20 changes, thereby Roll suppression force changes. That is, it is possible to actively suppress the roll of the vehicle body by changing the rotation amount of the actuator.

  The amount of rotation of the actuator 26 here refers to a state where the vehicle is stationary on a flat road as a reference state, and a rotation position (operation position) of the actuator 26 in the reference state is a neutral position (neutral operation position). In this case, the rotation amount (motion amount) from the neutral position is meant. In the control of the stabilizer device 14, the rotation amount of the actuator 26 and the rotation angle of the electromagnetic motor 60 (the rotation angle when the rotation position of the actuator 26 is in the neutral position is 0) have a correspondence relationship. Therefore, in actuality, instead of the rotation amount of the actuator 26, control is performed on the motor rotation angle acquired by the motor rotation angle sensor 78.

(D) Configuration of Control System In this system, as shown in FIG. 1, an electronic control unit (ECU) 90 is provided. The ECU 90 is a control unit for controlling the operation of each stabilizer device 14, specifically, each actuator 26, and includes two inverters 92 as a drive circuit corresponding to the electromagnetic motor 60 included in each actuator 26, CPU, ROM , And a controller 96 as a control device mainly composed of a computer having a RAM or the like (see FIG. 10). Each of the inverters 92 is connected to the battery 100 via the converter 98 and is connected to the electromagnetic motor 60 of the corresponding stabilizer device 14. The electromagnetic motor 60 is driven at a constant voltage, and the power supplied to the electromagnetic motor 60 is changed by changing the amount of supplied current. The supply current amount is changed by the inverter 92 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 78, the controller 96 includes a steering sensor 102 for detecting an operation angle of the steering wheel, which is an operation amount of the steering operation member as a steering amount, and a lateral acceleration actually generated in the vehicle body. A lateral acceleration sensor 104 that detects a certain actual lateral acceleration is connected. The controller 96 is further connected to a brake electronic control unit (hereinafter also referred to as “brake ECU”) 108 which is a control device of the brake system. The brake ECU 108 is connected to a wheel speed sensor 110 that is provided for each of the four wheels and detects the rotational speed of each of the four wheels. Has a function of estimating the traveling speed of the vehicle (hereinafter sometimes referred to as “vehicle speed”). The controller 96 acquires the vehicle speed from the brake ECU 108 as necessary. Further, the controller 96 is also connected to each inverter 92 and controls them to control the electromagnetic motor 60 of each stabilizer device 14. Note that a ROM included in the computer of the controller 96 stores a program related to control of the stabilizer device 14 to be described later, various data, and the like. The vehicle interior is provided with a mode selection switch 112 that is operated by the driver to select an operation mode of the electromagnetic motor 60 in a non-control state, which will be described later. It is connected to the.

≪Operation mode of electromagnetic motor≫
(A) Configuration of Inverter As shown in FIG. 5, the electromagnetic motor 60 is a three-phase DC brushless motor that is Δ-connected, and each of the energization terminals 122 u and 122 v corresponds to each phase (U, V, W). , 122w (hereinafter may be collectively referred to as “energization terminal 122”). The inverter 92 includes two switching elements on the high (positive) side and the low (negative) side corresponding to each energization terminal, that is, each phase (U, V, W). That is, three high-potential side switching elements (hereinafter, each of the three switching elements may be referred to as “UHC”, “VHC”, and “WHC”) 124 and three low-potential side switching elements (hereinafter, “3HC”). Each of the two switching elements is provided with 126 (which may be referred to as “ULC”, “VLC”, or “WLC”). Further, inverter 92 includes six free-wheeling diodes 128 arranged in parallel with each of switching elements 124 and 126, and an electromotive force generated in electromagnetic motor 60 generates an output voltage of converter 98. In such a case, the generated current based on the electromotive force is allowed to flow to the converter 98 via the return diode 128. The switching element switching circuit also detects a rotation angle (specifically, an electrical angle) based on detection signals from three hall elements H _A , H _B , H _C (denoted as H in the figure) provided in the electromagnetic motor 60. And the ON / OFF switching of each of the six switching elements is performed based on the rotation angle. The inverter 92 is connected to a high potential side terminal 130 h and a low potential side terminal 130 l of the battery 100 via a converter 98.

  In this system, the electromagnetic motor 60 can be operated in three operation modes, and is operated in one operation mode selected based on conditions set from the three operation modes. The operation mode is determined by the operation state of the inverter 92, in other words, the switching mode of the switching elements 124 and 126. Specifically, the operation mode is switched by changing the ON / OFF switching mode of the switching elements 124 and 126 of the inverter 92.

  The operation mode can be roughly divided into two modes. One of them is a control energization mode, in which ON / OFF control according to the duty ratio, that is, duty control is performed, and an operation mode in which power can be supplied from the battery 100 to the electromagnetic motor 60. is there. The other is an operation mode in which power supply from the battery 100 to the electromagnetic motor 60 is not performed. In this system, two modes of a brake mode and a free mode are prepared. Hereinafter, each operation mode will be described.

(B) Control energization mode Referring to FIG. 6, in the control energization mode, each switching element UHC, ULC, VHC, VLC, WHC, WLC is turned on by a so-called 120 ° energization rectangular wave drive. / OFF is switched according to the rotation angle of the electromagnetic motor 60. Specifically, one switching element among the high potential side switching elements UHC, VHC, WHC and one switching element among the low potential side switching elements ULC, VLC, WLC are turned on (closed state). At the same time, all of the remaining switching elements are turned off (open state), and the two switching elements that are turned on (closed state) correspond to the detection signals of the three hall elements H _A , H _B , and H _C. Be changed. That is, under this operation mode, energization from the high potential side terminal 130h of the battery 100 to one energization terminal 122 of the electromagnetic motor 60 is permitted, and another energization terminal other than the one energization terminal of the electromagnetic motor 60 is allowed. Energization from the energization terminal 122 to the low potential side terminal 130l of the battery 100 is allowed.

  Further, only the low potential side switching elements ULC, VLC, WLC execute the duty control, and the amount of current supplied to the electromagnetic motor 60 is changed by changing the duty ratio. ing. “1 *” in FIG. 6 indicates this. By the way, the switching mode of each switching element differs depending on the direction in which the motor force is generated. For convenience, the directions will be referred to as the right direction (CW direction) and the left direction (CCW direction).

  As described above, the control energization mode is a mode in which the direction in which the electromagnetic motor 60 generates a motor force (hereinafter sometimes referred to as “motor force generation direction”) and the amount of power supplied to the electromagnetic motor 60 can be controlled. In this control energization mode, the electromagnetic motor 60 can generate a motor force having a magnitude corresponding to the supplied current amount in an arbitrary direction. Therefore, by controlling the amount of current supplied to the electromagnetic motor 60, the roll restraining force generated by the stabilizer device 14 can be controlled to a desired magnitude.

(C) Brake mode In the brake mode, the energization terminals of the electromagnetic motor 60 are electrically connected to each other. That is, all of the switching elements arranged on one of the high side and the low side are kept in a closed state, and all those arranged on the other of the high side and the low side are kept in an open state. Specifically, in this system, as shown in FIG. 6, all of the high potential side switching elements UHC, VHC, WHC are turned on (closed state), and the low potential side switching elements ULC, VLC, All of the WLCs are in an OFF state (open state). By the high potential side switching elements UHC, VHC, WHC which are in the ON state, the three energization terminals of the electromagnetic motor 60 are in a state of being short-circuited to each other. In such a state, when the electromagnetic motor 60 is rotated by an external input, a relatively large generated current flows, so that a so-called short-circuit braking effect is obtained for the electromagnetic motor 60. Therefore, when the actuator 26 is forced to operate by road surface input or the like, even if power is not supplied from the battery 100 to the electromagnetic motor 60, the electromagnetic motor 60 has a relatively large operating resistance. A relatively large resistance force is generated against the operation. As a result, a torsional reaction force of the stabilizer bar 20 is obtained, and the stabilizer device 14 generates a resistance force against the relative vertical movement of the left and right wheels. From the above, this brake mode is an operation mode in which the operation resistance of the electromagnetic motor 60 is relatively large, that is, a large operation resistance mode.

(D) Free mode In the free mode, energization from the high-potential side terminal 130h of the battery 100 to the three energization terminals 122 of the electromagnetic motor 60 is prohibited, and from the three energization terminals 122 of the electromagnetic motor 60, Energization of the low potential side terminal 130l is prohibited. Specifically, as shown in FIG. 6, all of the switching elements UHC, ULC, VHC, VLC, WHC, and WLC are turned off (open state). Simply put, it will be in a state where the energization terminals for each phase of the electromagnetic motor 60 are opened. Therefore, in this mode, in principle, the generated current does not flow through the electromagnetic motor 60, and the electromagnetic motor 60 has almost no operating resistance. Therefore, even if the road surface input is operated as an actuator, the operation resistance of the electromagnetic motor 60 is small, and the actuator 60 is in a state in which almost no resistance force is generated with respect to its own operation. As a result, the stabilizer device 14 is in a state in which almost no resistance force is generated with respect to the relative movement in the vertical direction of the left and right wheels due to road surface input. In other words, relatively free relative rotation of the pair of stabilizer bar members 22 is allowed, and the stabilizer bar 20 is in a state in which almost no torsional reaction force is generated. From the above, this brake mode is an operation mode in which the operation resistance of the electromagnetic motor 60 is relatively small, that is, a small operation resistance mode.

  Since each switching element UHC, ULC, VHC, VLC, WHC, WLC is provided with a free-wheeling diode 128, the electromotive force of the electromagnetic motor 60 causes the output voltage of the converter 98 to change even in the free mode. In such a case, a part of the generated electric energy is regenerated in the battery 100. In that case, even in the free mode, the stabilizer device 14 generates a certain amount of resistance.

≪Control of vehicle stabilizer system≫
Hereinafter, the control of the stabilizer system for a vehicle will be described. In the system, both the two stabilizer devices 14 are controlled in the same manner. Therefore, the description from here is one unless otherwise specified. Only the control of the stabilizer device 14, that is, the control of the actuator 26 included in one of the stabilizer devices 14 is performed.

(A) Roll suppression control In the vehicle stabilizer system of the present embodiment, roll suppression control, which is control for suppressing the roll of the vehicle body caused by turning of the vehicle, is executed. In the roll suppression control, the actuator 26 is controlled so that the torsional reaction force of the stabilizer bar 20 has a magnitude corresponding to the roll moment received by the vehicle body due to the vehicle turning. Specifically, in order to generate a roll restraining force corresponding to the roll moment received by the vehicle body due to the turning of the vehicle, the control target of the electromagnetic motor 60 is determined based on the roll moment index indicating the roll moment received by the vehicle body. The target motor rotation angle θ ^* that is the motor rotation angle is determined, and the actual motor rotation angle θ that is the actual motor rotation angle of the electromagnetic motor 60 is controlled to be the target motor rotation angle θ ^* .

Specifically, it is the lateral acceleration used for control based on the estimated lateral acceleration Gyc estimated based on the steering angle δ of the steering wheel and the vehicle traveling speed v, and the actual lateral acceleration Gyr actually measured. Control lateral acceleration Gy ^* is determined according to the following equation. That is, in this roll suppression control, this control lateral acceleration Gy ^* is adopted as a roll moment index.
Gy ^* = K _A · Gyc + K _B · Gyr
Here, K _A, K _B is a gain, based on the thus determined control-use lateral acceleration Gy ^*, target motor angle theta ^* is determined. The controller 96 stores map data of the target motor angle θ ^{* using} the control lateral acceleration Gy ^* as a parameter, and the target motor angle θ ^* is determined with reference to the map data.

Then, the electromagnetic motor 60 is controlled so that the actual motor rotation angle θ becomes the target motor rotation angle θ ^* . In the control of the electromagnetic motor 60, the electric power supplied to the electromagnetic motor 60 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 ^* . The 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 certified based on the detection value of the motor rotation angle sensor 78 included in the electromagnetic motor 60, and then using that 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 ^* indicates the motor force generation direction of the electromagnetic motor 60 by its sign, and the drive of the electromagnetic motor 60 is controlled based on the target supply current i ^*. The duty ratio for driving 60 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 92, and the inverter 92 controls the drive of the electromagnetic motor 60 based on the command under the control operation mode.

(B) Control dead zone The said roll suppression control is performed when setting conditions are satisfied. More specifically, it is started when a specific start condition is satisfied. This setting condition is “the control lateral acceleration Gy ^*, which is a roll moment index, exceeds the set threshold acceleration Gy ₀ ”. When the control lateral acceleration Gy ^* exceeds the set threshold acceleration Gy ₀ , the roll suppression control is performed. Executed. That is, this roll suppression control is not executed when the control lateral acceleration Gy ^* is equal to or less than the set threshold acceleration Gy ₀ , and therefore, a control dead zone is provided.

The significance of providing the control dead zone is to appropriately suppress the roll of the vehicle body caused by the turning of the vehicle, for example, to prohibit the execution of the roll suppression control that is not necessary when the vehicle is traveling straight. In this roll restraining control, when the control lateral acceleration Gy ^* is equal to or less than the set threshold lateral acceleration Gy ₀ , the situation where the vehicle is placed, that is, the roll moment index indicating the roll moment acting on the vehicle body is within the control dead zone. In that case, the actuator 26 is placed in a state where no control is performed, that is, an uncontrolled state.

(C) Operation mode of electromagnetic motor in non-control state In the non-control state in which the actuator 26 is not controlled, in other words, in the state in which the roll suppression control is not executed, in this vehicle stabilizer system, the operation mode of the electromagnetic motor 60 is described above. Either the free mode or the brake mode is set. Which of the two modes is selected is determined according to whether the free mode is selected or the brake mode is selected by the mode selection switch 112 in principle.

  The free mode is a mode that can be referred to as a small operating resistance mode. In this mode, as described above, the electromagnetic motor 60 has almost no operating resistance. Therefore, even if the actuator is operated by the road surface input, the operation resistance of the electromagnetic motor 60 is small, and the actuator 60 is in a state in which almost no resistance force is generated with respect to its own operation. That is, from the viewpoint of the rolling of the vehicle body described above, the ride comfort of the vehicle is good. Generally, when such characteristics are desired, the free mode is selected by the driver.

  On the other hand, the brake mode is a mode that can be referred to as a large operating resistance mode. In this mode, the electromagnetic motor 60 is compared even if power is not supplied from the battery 100 to the electromagnetic motor 60 as described above. A state having a large operating resistance. Therefore, when the operation is forced by the road surface input or the like, the actuator 26 generates a relatively large resistance force to the operation, and as a result, the torsional reaction force of the stabilizer bar 20 is obtained. That is, it is excellent in terms of stability of the vehicle body posture, and generally, when such characteristics are desired, the brake mode is selected by the driver.

(D) Motor operation mode switching control As described above, when the operation mode of the electromagnetic motor 60 is set to the free mode in the non-control state, the operation resistance of the electromagnetic motor 60 is considerably small. Therefore, when the wheel moves up and down at high speed by road surface input, the actuator 26 is highly likely to be operated at high speed. The operating sound of the actuator 26 when it is operated at a high speed is loud, and the operating sound is annoying to the occupant. Therefore, from the viewpoint of quietness of the vehicle, such an operation sound deteriorates the riding comfort of the vehicle.

  In view of the above situation, in the present system, even if the free mode is set in the non-control state, when the actuator 26 is operated at a high speed, the operation mode of the electromagnetic motor 60 is changed from the free mode to the brake mode. Can be switched. By switching the operation mode, that is, by executing the motor operation mode switching control, the operation of the actuator 26 is decelerated, and the operation noise can be reduced or prevented.

Specifically, based on the change in motor rotation angle are calculated motor rotation speed S.theta the rotational speed of the electromagnetic motor 60, when the motor rotational speed S.theta exceeds the set threshold speed S.theta _0, actuator Assuming that the operation speed of 26 exceeds the set speed, the operation mode is switched from the free mode to the brake mode. Incidentally, a mode selection switch 112, when the free mode is selected, when the motor rotational speed S.theta becomes set threshold speed S.theta ₀ or less, and is returned from the brake mode to the free mode.

(E) Operation amount reduction control In the non-control state, when the actuator 26 is operated by road surface input, the rotational position of the actuator 26 is shifted from the neutral position. That is, the motor rotation angle of the electromagnetic motor 60 is not zero. Consider the case where the roll suppression control is started from such a state. In this case, the roll suppression control is executed based on the state in which the actuator 26 is located at the neutral position. Therefore, depending on the direction in which the rotational position of the actuator 26 is shifted, for example, There is a risk of sudden movement. Such an abrupt operation, that is, a step-like operation deteriorates the riding comfort of the vehicle.

  Further, when the brake mode is set in the non-control state, when the actuator 26 is operated relatively slowly, the rotational position of the actuator 26 is relatively easily shifted from the neutral position. On the other hand, when there is a road surface input that causes the actuator 26 to operate relatively quickly, the operating resistance of the electromagnetic motor 60 becomes relatively large, so the actuator 26 cannot be operated to follow the road surface input. The stabilizer bar 20 generates a torsional reaction force. Therefore, when there is a road surface input that causes the actuator 26 to move relatively fast in the opposite direction from a state in which the rotational position of the actuator 26 is shifted in a certain direction by a relatively slow motion, In comparison, the torsional reaction force of the stabilizer bar 20 increases as the rotational position is shifted. The generation of such a large torsional reaction force also contributes to the deterioration of the riding comfort of the vehicle.

In order to reduce or prevent the above-described deterioration in riding comfort, in this stabilizer system, when the rotation amount of the actuator 26 exceeds a set rotation amount that is a set operation amount in an uncontrolled state, the rotation The actuator 26 is controlled so as to reduce the amount. This control is an operation amount reduction control. Specifically, in this control, when the actual motor rotation angle θ of the electromagnetic motor 60 exceeds the first set threshold rotation angle θ ₁ , the actual motor rotation angle θ. The electromagnetic motor 60 is operated in the direction in which becomes zero. More specifically, the target supply current i ^* is determined according to the following equation based on the motor rotation angle deviation Δθ (= θ ^* −θ), where the target motor rotation angle θ ^* is 0.
i ^* = K _P · Δθ (K _P is proportional gain)
Next, based on this target supply current i ^* , the duty ratio for driving the electromagnetic motor 60 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 92, and the inverter 92 controls the drive of the electromagnetic motor 60 based on the command under the control operation mode.

Note that when the actual motor rotation angle θ falls below the second set threshold rotation angle θ ₂ set to a value smaller than the first set threshold rotation angle θ ₁ by the operation amount reduction control, the rotation of the actuator 26 is performed. It is considered that the amount has fallen below the second set rotation amount, and the execution of the operation amount reduction control is stopped. In stopping this execution, the duty ratio is set to 0, and a command for the duty ratio is issued to the inverter 92. Incidentally, the reason for stopping the execution of the operation amount reduction control based on the second set threshold rotation angle θ ₂ is to avoid a situation in which the execution and stop of the operation amount reduction control are repeated in a very short time. This is to prevent so-called control hunting.

≪Control program and control flow≫
In the stabilizer system, the stabilizer device 14 is controlled by the controller 96 executing a stabilizer control program whose flowchart is shown in FIG. This program is repeatedly executed with a short time interval (for example, several milliseconds) while the ignition switch is in the ON state. The control flow will be briefly described below with reference to the flowchart shown in the figure.

In the process according to this control program, first, in step 1 (hereinafter abbreviated as “S1”, the same applies to other steps), the steering wheel operating angle δ is acquired based on the detected value of the steering sensor 102. Subsequently, in S2, the vehicle speed v is acquired from the brake ECU 108. Next, in S3, the estimated lateral acceleration Gyc is calculated based on the obtained steering wheel operation angle δ and the vehicle speed v. Next, in S4, the actual lateral acceleration Gyr is acquired based on the detected value of the lateral acceleration sensor 104, and in S5, control is performed according to the above formula based on the acquired estimated lateral acceleration Gyc and actual lateral acceleration Gyr. Lateral acceleration Gy ^* is calculated.

Then, in S6, the calculated control-use lateral acceleration Gy ^* is in S5 whether exceeds the set閾横acceleration Gy ₀ is determined. If the control-use lateral acceleration Gy ^* exceeds the set閾横acceleration Gy ₀ is certified and control lateral acceleration is a roll-moment index Gy ^* has emerged a control dead zone operation amount described in S7, after The decrease control execution flag Fr is set to “OFF”, and subsequently, roll suppression control is executed in S8.

The roll suppression control is performed by executing a roll suppression control subroutine whose flowchart is shown in FIG. In the processing according to this subroutine, first, in S21, the target motor rotation angle θ ^* is determined based on the control lateral acceleration Gy ^* calculated in S5. Next, in S22, the target motor rotation angle θ ^* and the rotation are determined. Based on the actual motor rotation angle θ acquired from the detection value of the angle sensor 78, the motor rotation angle deviation Δθ is certified, and in the subsequent S23, based on the motor rotation angle deviation Δθ, to the electromagnetic motor 60 according to the above formula. The target supply current i ^* to be supplied is determined. In S24, based on the target supply current i ^* , the duty ratio and motor force generation direction necessary for drive control of the electromagnetic motor 60 by the inverter 92 are determined. In S25, based on the duty ratio and motor force generation direction. A command is issued to the inverter 92. After the process of S25 is finished, the process according to this subroutine is finished, and a series of processes according to the stabilizer control program is finished.

In the previous S6, if the control-use lateral acceleration Gy ^* is determined not to exceed the set閾横acceleration Gy ₀ is the control-use lateral acceleration Gy ^* is recognized as not emerged control dead zone, S9 following uncontrolled Processing in the state is executed.

  In the process in the non-control state, first, in S9, it is determined whether or not the operation amount decrease control execution flag Fr is “ON”. Incidentally, when this flag Fr is “ON”, the operation amount reduction control described later is being executed, and when it is “OFF”, the operation amount reduction control is not executed. . When the flag Fr is “ON”, S10 to S14 are skipped and the execution of the operation amount reduction control in S15 is continued.

If it is determined in S9 that the operation amount reduction control execution flag Fr is not “ON”, it is determined in S10 whether or not the free mode is selected as the operation mode of the electromagnetic motor 60 by the mode selection switch 112. The When the free mode is selected, in S11, the change in the actual motor rotation angle θ acquired from the detection value of the rotation angle sensor 78, specifically, from the actual motor rotation angle θ at the previous execution time of the program. motor speed S.theta obtained based on the change, whether exceeds the set threshold speed S.theta ₀ is determined. If the motor rotation speed Sθ does not exceed the set threshold rotation speed Sθ ₀ , the operation mode of the electromagnetic motor 60 is determined to be the free mode in S 12, and that fact is issued to the inverter 92.

If it is determined in S10 that the free mode is not selected, it is determined that the brake mode is selected. In S13, the operation mode of the electromagnetic motor 60 is determined to be the brake mode, and this is indicated by the inverter 92. Will be announced. Incidentally, when the motor rotational speed S.theta is determined to exceed the set threshold speed S.theta ₀ in S11, even when the free mode is selected by the processing of S13 is executed, The operation mode is set to the brake mode. By executing the process of S13 based on the determination of S11, the motor operation mode switching control described above is executed.

After the operation mode of the electromagnetic motor 60 is determined to be either the free mode or the brake mode, it is determined in S14 whether or not the actual motor rotation angle θ exceeds the first set threshold rotation angle θ ₁ . When the actual motor rotation angle θ does not exceed the first set threshold rotation angle θ ₁ , the process of S15 is skipped and a series of processes according to the stabilizer control program ends. On the other hand, when the actual motor rotation angle θ exceeds the first set threshold rotation angle θ ₁ , the operation amount reduction control is executed in S15.

The operation amount reduction control is performed by executing an operation amount reduction control subroutine shown in the flowchart of FIG. In accordance processing subroutine, first, in S31, whether the actual motor rotation angle theta is less than a second set threshold rotation angle theta ₂ is determined. If the actual motor rotation angle θ is not less than the second set threshold rotation angle θ ₂ , the operation amount decrease control execution flag Fr is set to “ON” in S32, and the processing of S33 to S37, that is, the operation amount is performed. Processing for reduction control is executed.

In the process for the operation amount reduction control, first, the target motor rotation angle θ ^* is determined to be 0 in S33, and then in S34, based on the target motor rotation angle θ ^* and the actual motor rotation angle θ, The motor rotation angle deviation Δθ is certified, and in the subsequent S35, the target supply current i ^* to be supplied to the electromagnetic motor 60 is determined according to the above formula based on the motor rotation angle deviation Δθ. In S36, based on the target supply current i ^* , the duty ratio and the motor force generation direction necessary for the drive control of the electromagnetic motor 60 by the inverter 92 are determined. In S37, the duty ratio and the motor force generation direction are determined. A command is issued to the inverter 92. After the process of S37 is finished, the process according to this subroutine is finished, and a series of processes according to the stabilizer control program is finished.

On the other hand, the actual motor rotational angle theta step S31 when it is determined that falls below the second set threshold rotation angle theta _2, in S38, the operation amount reduction control execution flag Fr is set to "OFF", then, S39 , The duty ratio is determined to be 0, and a command based on the duty ratio is issued to the inverter 92 in S37. The operation amount reduction control is ended by the processing of S38, S39, and S37. When the process of S37 ends, the process according to this subroutine ends, and a series of processes according to the stabilizer control program ends.

<Functional configuration of control device>
The controller 96 that executes the stabilizer control program functions as a control device in the present stabilizer system. In view of the execution process, the controller 96 can be considered to have a functional configuration as shown in a block diagram in FIG. As can be seen from the figure, the controller 96 has a roll suppression control unit 150 as a functional unit that executes the roll suppression control in S8 of the program in a state where the roll moment index is out of the control dead zone.

  Further, the controller 96 functions as a functional unit that controls the system in a state where the roll moment index does not escape the control dead zone, in other words, as a functional unit that controls the actuator 26 when the roll suppression control is not performed. A suppression control non-execution control unit 152 is provided. The roll suppression control non-execution control unit 152 is a functional unit that determines the operation mode of the electromagnetic motor 60 as either the free mode or the brake mode, that is, a function that executes the processing of S10 to S13 in the stabilizer control program. As a unit, a motor operation mode determination unit 154 is provided. Then, the motor operation mode determination unit 154 executes a process of S13 based on the determination of S11, that is, a functional unit that switches from the free mode to the brake mode when the operation speed of the actuator 26 exceeds the set speed. A motor operation mode switching control unit 156 is provided as a functional unit.

  Further, the roll suppression control non-execution control unit 152 is a functional unit that controls the actuator 26 so as to reduce the rotation amount of the actuator 26 when the rotation amount of the actuator 26 exceeds the set rotation amount, that is, stabilizer control. The operation amount reduction control unit 158 is provided as a functional unit that executes the operation amount reduction control of S15 in the program.

1 is a schematic diagram showing an overall configuration of a vehicle stabilizer system that is an embodiment of the claimable invention. It is a schematic diagram which shows the stabilizer apparatus and suspension apparatus with which the vehicle stabilizer system of FIG. 1 is provided from the viewpoint from the vehicle upper side. It is a schematic diagram which shows the stabilizer apparatus and suspension apparatus with which the stabilizer system for vehicles of FIG. 1 is provided from the viewpoint from the vehicle front. It is a schematic sectional drawing which shows the actuator with which a stabilizer apparatus is provided. FIG. 5 is a circuit diagram in a state where an inverter included in the vehicle stabilizer system of FIG. 1 and an electromagnetic motor included in the actuator of FIG. 4 are connected. It is a table | surface which shows the switching state of the switching element by the inverter of FIG. 5 in each operation mode of an electromagnetic motor. It is a flowchart which shows the stabilizer control program performed in the stabilizer system for vehicles of FIG. FIG. 8 is a flowchart showing each of a roll suppression control subroutine and an operation amount reduction control subroutine executed in the stabilizer control program of FIG. 7. It is a block diagram which shows the function of the control apparatus which manages control of the vehicle stabilizer system of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10: Stabilizer system for vehicles 14: Stabilizer apparatus 16: Wheel 20: Stabilizer bar 22: Stabilizer bar member 26: Actuator 30: Suspension apparatus 50: Torsion bar part 52: Arm part 60: Electromagnetic motor 62: Reduction gear 64: Housing 78 : Motor rotation angle sensor 90: Electronic control unit (ECU) 92: Inverter 96: Controller 98: Converter 100: Battery 112: Mode selection switch 122u, 122v, 122w: Energizing terminal 124: High potential side switching element 126: Low potential side Switching element 128: Freewheeling diode 130h: High potential side terminal 130l: Low potential side terminal 150: Roll suppression control unit 152: Roll suppression control non-execution control unit 154: Motor operation mode determination unit 156 Motor operation mode switching control unit 158: operation amount reduction control unit

Claims (6)

(A) A stabilizer bar that is twisted by the roll of the vehicle body and acts on the vehicle body as a roll suppression force with a torsional reaction force corresponding to the amount of torsion, and (B) an electromagnetic motor that serves as a drive source. An actuator that changes the amount of twist of the stabilizer bar by operation, and (C) a control device that controls the actuator,
When the control device satisfies the set conditions, roll suppression control is performed to control the actuator so that the torsional reaction force of the stabilizer bar has a magnitude corresponding to the roll moment received by the vehicle body due to vehicle turning. A vehicle stabilizer system configured to:
The actuator is structured to be operated by a road surface input that is a force acting on the wheel from the road surface,
In the case where the operating position of the actuator in a state where the stabilizer bar is not twisted is defined as a neutral operating position,
The control device is
When the roll suppression control is not executed, the operation amount of the actuator is reduced when the operation amount of the actuator from the neutral operation position in the operation of the actuator by road surface input exceeds a set operation amount. A vehicle stabilizer system configured to execute an operation amount reduction control for controlling the actuator. The control device is
When the roll moment index indicating the roll moment received by the vehicle body due to turning of the vehicle exceeds the value indicating the roll moment of the set magnitude, the roll suppression control is performed assuming that the setting condition is satisfied. The vehicle stabilizer system according to claim 1, wherein the vehicle stabilizer system is configured to be executed. The control device is
When the operation amount reduction control is being executed, if the operation amount of the actuator falls below a second set operation amount set smaller than the set operation amount, the execution of the operation amount reduction control is stopped. The vehicle stabilizer system according to claim 1 or 2, configured as described above. The control device is
The roll suppression is performed by determining a target operation amount of the actuator according to a roll moment received by the vehicle body due to turning of the vehicle, and controlling the actuator so that the operation amount of the actuator becomes the target operation amount. The vehicle stabilizer system according to any one of claims 1 to 3, wherein the vehicle stabilizer system is configured to execute control. The stabilizer bar is
Provided corresponding to the left and right wheels, each of which extends in the vehicle width direction, and extends continuously across the torsion bar portion and intersects with the torsion bar portion. Including a pair of stabilizer bar members having an arm portion connected to a wheel holding portion for holding one of the wheels corresponding to itself,
The actuator is
The vehicle stabilizer system according to any one of claims 1 to 4, wherein the torsion bar portion of the pair of stabilizer bar members is configured to relatively rotate. The actuator includes a speed reducer that decelerates rotation of the electromagnetic motor; and a housing that holds the electromagnetic motor and the speed reducer;
One torsion bar portion of the pair of stabilizer bar members is connected to the housing in a relatively non-rotatable manner; the other torsion bar portion is connected to the output portion of the speed reducer in a relatively non-rotatable manner; and
The vehicle stabilizer system according to claim 5, wherein a reduction ratio of the reduction gear is 1/100 or less.

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