JP4239804B2 - Vehicle stabilization control device - Google Patents

Description

  The present invention relates to a device that controls a vehicle including an electromagnetic suspension device, and more particularly, to a device that performs control to stabilize the traveling state of the vehicle.

  The electromagnetic suspension is a suspension device provided with an electromagnetic actuator having an electromagnetic motor or the like instead of the hydraulic shock absorber or the like provided in the conventional suspension, and by the generated force (attenuating force or propulsive force) of the electromagnetic actuator, Demonstrates the ability to maintain the body posture in an appropriate state. A vehicle equipped with an electromagnetic suspension has the advantage that it is easy to stabilize the posture of the vehicle body by controlling the generated force, and therefore has great expectations in terms of stabilizing the running state of the vehicle. It is.

On the other hand, there are techniques as described in [Patent Documents 1 to 4] below as techniques for stabilizing the running state of the vehicle. The techniques described in [Patent Documents 1 and 2] feed back the actual posture of the vehicle body, and a plurality of electromagnetic actuators or hydraulic suspension mechanisms (electromagnetic actuators and electromagnetic actuators) so that the vehicle body posture becomes a target posture. (Patent Documents 3 and 4) are technologies related to so-called VSC (Viecle Stability Control), that is, the vehicle operation. This is a technique for stabilizing the turning state of the vehicle by controlling the yaw rate or the like to become the target yaw rate or the like.
Japanese Patent Laid-Open No. 2003-102425 JP-A-7-172130 JP-A-4-358955 Japanese Patent Laid-Open No. 10-273032

  It is also possible to apply the control described in the above [Patent Documents 1 to 4] to a vehicle equipped with an electromagnetic suspension. However, when an electromagnetic actuator provided in any one of the electromagnetic suspensions fails, specifically, when the function of the electromagnetic actuator fails, the control described in the above [Patent Documents 1 to 4] It is thought that the failure is not considered and is insufficient. Specifically, for example, when the electromagnetic actuator fails, the generated force cannot be generated sufficiently, so that it is difficult to sufficiently stabilize the posture of the vehicle body, and the turning state of the vehicle Is difficult to stabilize sufficiently. That is, even if the control described in the above [Patent Documents 1 to 4] is applied to a vehicle equipped with an electromagnetic suspension, it is not practical from the viewpoint of fail-safe. The present invention has been made in view of such circumstances, and an object of the present invention is to obtain a practical control device for stabilizing the traveling state of a vehicle.

In order to solve the above-described problems, a vehicle stabilization control device according to the present invention is a vehicle stabilization control that controls a vehicle equipped with a suspension device having an electromagnetic actuator for each wheel to stabilize the traveling state of the vehicle. A vehicle body attitude control unit that performs control for determining the force to be generated by the electromagnetic actuator for each electromagnetic actuator based on information on the attitude of the vehicle body and stabilizing the attitude of the vehicle body; When the electromagnetic actuator of any one of the suspension devices fails and the force that can be generated by the electromagnetic actuator decreases , the vehicle body posture control unit is commensurate with the decrease in force due to the failure of the electromagnetic actuator. By increasing the force to be generated by the electromagnetic actuator of the other suspension device, the vehicle Characterized in that a posture which is configured to perform control to stabilize.

  In a state where any one of the electromagnetic actuators is lost, it is difficult to effectively stabilize the traveling state of the vehicle because the generated force of the electromagnetic actuator is reduced. However, according to the vehicle stabilization control device of the present invention, even when any of the electromagnetic actuators has failed, it is possible to effectively stabilize the traveling state of the vehicle in consideration of the influence of the failure. And a practical control device is realized. Various aspects of the vehicle stabilization control device of the present invention, and their operations and effects will be described in detail in the section of [Aspect of the Invention] below.

Aspects of the Invention

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

In each of the following items, the combination of items (1) and (2) and further limitation corresponds to claim 1, and the specific embodiment of claim 1 relates to claim 2. The technical feature of (3) is added to claim 1 or claim 2, and the technical feature of (4) is added to any of claims 1 to 3 in claim 3. Corresponds to Claim 4 respectively.

(1) A vehicle stabilization control device that performs control for stabilizing a running state of a vehicle with a suspension device having an electromagnetic actuator for each wheel.
When the electromagnetic actuator which any one of the said suspension apparatuses has failed, control which presupposes the failure is performed, The vehicle stabilization control apparatus characterized by the above-mentioned.

  When each of the plurality of electromagnetic suspension devices provided in the vehicle is operating normally, the traveling state of the vehicle is stabilized. However, when an event occurs such as when the electromagnetic actuator is de-energized due to disconnection or the like, that is, when the electromagnetic actuator is in a failed state, for example, an appropriate generated force can be generated. Disappear. For this reason, in the state where any electromagnetic actuator has failed, the control based on the state where none of the electromagnetic actuator has failed is performed. For example, the vehicle running state, The influence of the failure of the electromagnetic actuator is directly reflected on the turning state of the vehicle, and it is difficult to stabilize the traveling state of the vehicle. Therefore, in the embodiment described in this section, the control on the assumption that one of the electromagnetic actuators has failed, that is, the control in consideration of the influence of the failure is performed, so that the running state of the vehicle is effectively reduced. It stabilizes. As will be described in detail later, the vehicle stabilization control device of the present invention that has failed can effectively stabilize the running state of the vehicle even if any electromagnetic actuator has failed. It becomes a practical control device.

  In the mode described in this section, the specific control mode at the time of failure is not limited. Specifically, for example, as will be described later, a form in which the generated force of the failed electromagnetic actuator is compensated by another electromagnetic actuator, a form in which the gain in the control is changed, a form in which the target value of the running state of the vehicle is changed, etc. Various control modes can be employed.

  In the suspension device employed in the aspect described in this section, the electromagnetic actuator includes, for example, an electromagnetic motor such as a rotary motor or a direct acting motor (hereinafter, simply referred to as “motor”). The motor can be a source of generated force. The electromagnetic actuator can generate a force (attenuating force) that damps the movement of the vehicle body and wheels approaching / separating by operating the motor as a generator, and the movement is attenuated by supplying power to the motor. Or a force for propelling the movement (propulsive force) can be generated. Depending on the type of force generated by the electromagnetic actuator, the suspension device can be of various modes. Specifically, for example, the suspension device is configured as an active suspension by generating a propulsive force in an electromagnetic actuator, a semi-active suspension by making the damping force variable, and a passive suspension by fixing the damping force. Is possible.

  (2) The vehicle stabilization control device determines a generated force, which is a force to be generated in the electromagnetic actuator, based on information on the posture of the vehicle body for each of the electromagnetic actuators, and controls to stabilize the vehicle body posture. A vehicle body posture control unit that performs the other vehicle body posture control unit to compensate for a decrease in generated force due to the failure of the electromagnetic actuator when any of the electromagnetic actuators has failed. The vehicle stabilization control device according to item (1), wherein control is performed by determining the generation force of the vehicle.

  The mode described in this section is a mode aimed at stabilizing the posture of the vehicle body, which is a kind of traveling state of the vehicle. Since the failure of the electromagnetic actuator directly affects the posture of the vehicle body, according to the aspect described in this section, it is possible to effectively prevent or suppress the vehicle body posture from becoming unstable due to the influence.

  The vehicle body posture control unit in the aspect described in this section performs control for stabilizing the vehicle body posture based on “information on the vehicle body posture”. The information includes, for example, vehicle heave information, roll Information such as information and pitch information is included. The heave information is information on the heave amount / speed, etc. (vertical displacement amount / displacement speed, etc. of the entire vehicle), and the roll information is information on the roll amount / speed, etc. The pitch information is information such as pitch amount and speed (inclination amount in the longitudinal direction of the vehicle body, inclining speed, etc.). The vehicle body attitude control unit may perform control based on at least one of those pieces of information. Specifically, for example, when the control is performed based on the pitch amount that is information on the posture of the vehicle body, the generated force of the electromagnetic actuator is individually determined so that the pitch amount becomes a target value (for example, 0). Control.

  When one of the electromagnetic actuators has failed, the control of the vehicle body attitude control unit described above is in a state where the generated force of the electromagnetic actuator is reduced, for example, a state where almost no generated force is obtained, or an insufficient generated force. Control that presupposes a condition that cannot be obtained, etc., and control that determines the generation force of other electromagnetic actuators so that the posture of the vehicle body can be stabilized effectively in that state Can do. Specifically, for example, the control is such that the generation force of the other electromagnetic actuator is increased by an amount commensurate with the decrease in the generation force of the failed electromagnetic actuator. In other words, the control is such that the generation force of the electromagnetic actuator is determined so that the other generation of the decrease in the generation force is borne by another electromagnetic actuator.

  The stabilization control device described in this section may be one in which control by the vehicle body attitude control unit is executed when all the electromagnetic actuators are normal, and other control is executed. It may be a thing. For example, when all the electromagnetic actuators are normal, control such as using the electromagnetic actuator as a shock absorber with a fixed damping force, that is, passive control may be performed.

  (3) The vehicle stabilization control device is based on information on the displacement of each part of the vehicle body equipped with each of the suspension devices separately from the first vehicle body posture control unit which is the vehicle body posture control unit. Each of the suspension devices has a second vehicle body attitude control unit that individually controls the generated force of the electromagnetic actuator and stabilizes the attitude of the vehicle body, and none of the electromagnetic actuators have failed. In this case, the control by the second vehicle body attitude control unit is executed, and when any of the electromagnetic actuators fails, the control by the first vehicle body attitude control unit is executed (2). The vehicle stabilization control device according to item.

  The aspect of this section is an example of an aspect in which control other than control based on information on the attitude of the vehicle body is performed when all the electromagnetic actuators are normal with respect to the control for stabilizing the attitude of the vehicle body. The control by the second vehicle body posture control unit in the aspect described in this section stabilizes the posture of the vehicle body based not on information on the vehicle body itself but on information on each part of the vehicle where the wheels are suspended. Control. Since the vehicle body is shared and supported by a plurality of suspension devices, it is also possible to determine the generation force of the electromagnetic actuator of the suspension device based on the information of the portion of the vehicle body equipped with one suspension device. The posture can be stabilized. That is, the posture of the vehicle body can be stabilized based on a control theory different from that of the vehicle body posture control described above, that is, the case of the first vehicle body posture control unit in this section. However, in such control, when one of the electromagnetic actuators fails, the generated force of the other electromagnetic actuator cannot be determined to an appropriate value. Therefore, in the aspect described in this section, when the electromagnetic actuator fails, the control of the vehicle body posture is controlled by switching to the control by the first vehicle body posture control unit. Note that the “information on the displacement of the vehicle body portion” referred to in this section includes, for example, information on the vertical displacement amount of the vehicle body portion where each suspension device is provided, the displacement speed of the portion, and the suspension devices. It is possible to adopt information such as the relative displacement amount between the vehicle body portion provided with the wheel and the wheel, the relative displacement speed between the portion and the wheel, and the like.

  (4) The vehicle stabilization control device is applied to any wheel based on a deviation between the target turning state of the vehicle determined based on at least the steering angle and the actual turning state of the vehicle. A turning state control unit that controls to stabilize the turning state of the vehicle by determining at least one of a braking force and a driving force to be applied, and the turning state control unit has failed in any of the electromagnetic actuators. In this case, control is performed by setting a gain for determining at least one of the braking force and the driving force to be larger than when none of the electromagnetic actuators have failed. 3. The vehicle stabilization control device according to any one of items 3).

  To put it flatly, the aspect described in this section is an aspect related to VSC control related to a vehicle equipped with an electromagnetic suspension device, that is, control for stabilizing the turning state of the vehicle. In the case of a vehicle equipped with an electromagnetic suspension, if any electromagnetic actuator fails, for example, the vehicle is appropriately set according to the steering angle or the like because the roll amount of the vehicle body becomes larger than normal. There is a case where a smooth turning state is not indicated (for example, oversteer, understeer, etc.). In such a case, if the same VSC control as when all the electromagnetic actuators are normal is performed, the deviation from the actual turning state from the target turning state (hereinafter, simply referred to as “turning state deviation”) is: In many cases, it is difficult to make sufficient corrections. The mode described in this section is premised on the failure of the electromagnetic actuator, and is a particularly effective mode in such a case. . According to the aspect described in this section, by increasing the gain in the control, it is possible to stabilize the turning state of the vehicle even when the electromagnetic actuator fails. Note that the control by the turning state control unit in the case where one of the electromagnetic actuators fails is effective even when going straight, but the effect of stabilizing the vehicle is particularly great when turning.

  Specifically, the “turning state” to be controlled by the turning state control unit is a concept including the yaw rate of the vehicle, the slip angle of the vehicle, the lateral G of the vehicle, and the like. For example, when the yaw rate is the target, the target yaw rate is determined as the “target turning state”, and the braking force and the driving force are determined so that the actual yaw rate in the “actual turning state” approaches the target yaw rate. Is possible. In this case, the target yaw rate can be determined based on, for example, only the steering angle (concept including the operation angle of the steering operation member, the turning angle of the steered wheel, etc.). It can also be determined based on a vehicle state quantity or the like (for example, vehicle body speed or the like). The “gain” in the aspect described in this section can be considered as a coefficient for determining the braking force or the like by multiplying the deviation between the target turning state and the actual turning state, for example. At the time of failure of the electromagnetic actuator, it is possible to set a value obtained by multiplying the gain when there is no failure by a set value. In this case, the set value may be, for example, a predetermined constant (for example, 1.3), a value that changes according to the steering angle, the vehicle body speed, the roll amount, the roll speed, or the like. Various values, such as a value that should be generated by a fallen electromagnetic actuator and changing according to the generated force, can be used. Moreover, the set value may be set uniformly with respect to all the wheels, for example, or may be set on the basis of individual rules for each wheel. When discriminating the setting value for each wheel, for example, the setting value for the wheel suspended on the suspension device having the failed electromagnetic actuator is different from the setting value for the other wheel. Can do.

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

1. Outline of the vehicle equipped with the vehicle stabilizer.
FIG. 1 schematically shows a portion deeply related to stabilization of a running state of a vehicle, including a vehicle equipped with a vehicle stabilization device 10 according to an embodiment of the present invention. In this figure, the vehicle includes four wheels 12 and a suspension device 14 that suspends the wheels 12. Of the four wheels 12, two front wheels (FR, FL) are steered wheels, and two rear wheels (RR, RL) are drive wheels. Each of the wheels 12 is provided with a wheel cylinder 16, and braking force is applied to the wheels 12 by transmitting the hydraulic pressure of the brake fluid to the wheel cylinders 16.

  The vehicle is provided with a steering wheel 30 and a steering angle sensor 32 that detects the rotational position of the steering wheel 30 in order to acquire the steering angle. The turning angle of the front wheels (FR, FL) is changed according to the operation performed on the steering wheel 30. The vehicle also has a brake pedal 34, a master cylinder 36 that pumps brake fluid in response to a depression operation of the brake pedal 34, and a brake fluid pressure fed from the master cylinder 36 via a hydraulic pressure transmission pipe 38. A brake fluid pressure control device 50 that distributes to each wheel cylinder 16 is provided. Further, the master cylinder 36 is provided with a pedaling force sensor 52 that detects a pedaling force in the depression operation of the brake pedal 34. Note that the steering angle and the pedal effort acquired by the steering angle sensor 32 and the pedal effort sensor 52 are transmitted to the vehicle stabilization control device 10 via signal lines that are not shown.

  The brake fluid pressure control device 50 includes various solenoid valves, a pump, a pump motor that drives the pump, and a drive circuit that drives them, and is based on the fluid pressure from the master cylinder 36 described above. Instead, the brake fluid can be pumped to each wheel cylinder 16. The brake fluid pressure control device 50 is used for a general ABS (anti-lock brake system) or the like. Briefly, the brake fluid pressure control device 50 is connected to the vehicle stabilization control device 10 and a signal line. In accordance with a command from the vehicle stabilization control device 10, the hydraulic pressure of the brake fluid to be pumped to each wheel cylinder 16 is adjusted by driving a solenoid valve, a pump motor, and the like by a drive circuit. That is, the brake fluid pressure control device 50 increases the fluid pressure of the brake fluid by driving the pump by a pump motor, and opens and closes necessary ones of a plurality of electromagnetic valves that open and close the passage of the brake fluid disposed therein. By switching the above, the hydraulic pressure of the brake fluid supplied to each wheel cylinder 16 is increased, reduced and held.

  The vehicle body 56 is provided with an actuator drive circuit 62 that supplies drive power to an electromagnetic actuator 60 (hereinafter abbreviated as “actuator 60”) (see FIGS. 3 and 4) of the suspension device 14. The actuator drive circuit 62 is connected to the vehicle stabilization control device 10 via a signal line, and supplies drive power to each actuator 60 in accordance with a command from the vehicle stabilization control device 10. When the driving power is supplied from the actuator driving circuit 62 to each actuator 60, a generating force that is a force for moving the vehicle body 56 and the wheel 12 toward and away from each other is generated in the suspension device 14. When the generated force is generated in a direction against the movement in which the vehicle body 56 and the wheel 12 approach or separate from each other, the generated force acts as a damping force. On the other hand, when the generated force is generated in the direction of propelling the motion, the generated force acts as a propulsive force. The vehicle stabilization control device 10 determines the generated force to be generated by each actuator 60, and supplies the drive power corresponding to the determined generated force from the actuator drive circuit 62 to each actuator 60, whereby each suspension device. 14 generates an appropriate generated force to stabilize the posture of the vehicle body 56. The actuator drive circuit 62 includes an actuator failure detection unit 64 (hereinafter abbreviated as “failure detection unit 64”), and detects the failure of the actuator 60. And when the actuator 60 fails, the signal to that effect is transmitted to the vehicle stabilization control apparatus 10 (refer FIG. 2).

2. Vehicle stabilization control device.
FIG. 2 shows a functional block diagram of the vehicle stabilization control device 10. The vehicle stabilization control device 10 is a computer-based device, and its components are not clearly separated as shown in this figure, but it is easy to understand the functions of the vehicle stabilization control device 10. To make it like this, The vehicle stabilization control device 10 includes a vehicle body attitude control unit 100, a braking control unit 110, and a state quantity calculation unit 114. The vehicle body posture control unit 100 includes a first vehicle body posture control unit 120, a second vehicle body posture control unit 122, and a posture control change unit 124. The braking control unit 110 includes an ABS control unit 130, a TRC control unit 132, and a VSC control unit 134. The VSC control unit 134 has a gain determination unit 136 that determines a gain for determining the braking force in the VSC control. The state quantity calculation unit 114 calculates a vehicle state quantity that is a parameter related to a posture state, a turning state, and the like necessary for control based on detection values of various sensors. Details of the vehicle body posture control unit 100, the braking control unit 110, and the like will be described later.

  A steering angle sensor 32, a pedal force sensor 52, a wheel speed sensor 140, a yaw sensor 142, a G sensor 144, and the like are connected to the vehicle stabilization control device 10, and the vehicle stabilization control device 10 detects these sensors. Control is performed based on the vehicle state quantity acquired by the state quantity calculation unit 114 based on the value or the detected value. The state quantity calculation unit 114 simulates the maximum value among the detection values of the wheel speed sensor 140 provided for each wheel 12 as the vehicle body speed. As shown in FIG. 3, the G sensor 144 is a portion of the vehicle body 56 in which each of the suspension devices 14 is mounted, that is, the upper portion of the suspension device 14 in the vehicle body 56 is attached and supported by the suspension device 14. One part is disposed in the vicinity of the supported part 150 (only the front left (FL) is shown in FIG. 3) which is a part (right front, left front, right rear, left rear). The vertical acceleration, which is the acceleration in the vertical direction of the supported portion 150 at the front right, left front, right rear, and left rear of the vehicle body 56, is detected. The state quantity calculation unit 114 acquires the calculated heave information, roll information, and pitch information of the vehicle body 56 based on the detected vertical accelerations.

3. Suspension device.
FIG. 4 shows a portion deeply related to stabilization of the vehicle body posture in the suspension device 14. The suspension device 14 includes an electromagnetic actuator 60, an elastic force generation mechanism 156, and the like. The suspension device 14 supports the vehicle body 56 while buffering an impact from the road surface by the elastic force generated by the elastic force generation mechanism 156, and the actuator. The generated force generated by the motor 60 attenuates the impact and further functions to stabilize the posture of the vehicle body 56.

  The actuator 60 includes an electromagnetic motor 160 (hereinafter abbreviated as “motor 160”), a ball screw 162, a housing 164 for holding them, and the like. The drive shaft of the motor 160 fixed to the housing 164 and the ball screw 162 are connected to each other by a joint 166 so as to be coaxial and non-rotatable. The ball screw 162 is provided with a disk-shaped flange portion 172. The two screw bearings 174 hold the ball screw 162 so as to sandwich the flange portion 172 from both sides in the axial direction. It can rotate around and cannot move in the axial direction.

  The actuator 60 also includes an inner tube 180 and an outer tube 182. The inner tube 180 is fitted into an inner hole of the outer tube 182 so as to be relatively movable in the axial direction, and is fixed to a lower end portion of the housing 164 at a flange portion provided at an upper portion thereof. A ball nut 186 is fixed to the inner wall surface of the outer tube 182 so as not to rotate relative to the outer tube 182 and not to move in the axial direction. The ball nut 186 is screwed with the ball screw 162 via a bearing ball. Have been combined. With such a structure, the rotational motion of the ball screw 162 is converted into the linear motion of the ball nut 186 in the axial direction. Conversely, the linear motion of the ball nut 186 is also converted into the rotational motion of the ball screw 162. When the ball screw 162 is rotated and the ball nut 186 is moved in the axial direction, the outer tube 182 to which the ball nut 186 is fixed is moved in the axial direction. The inner tube 180 is fixed to the vehicle body via the housing 164, and the outer tube 182 is connected to a lower arm (not shown) so as to be rotatable and non-rotatable around the axis. Therefore, the inner tube 180 and the outer tube 182 cannot be rotated relative to each other.

  The elastic force generation mechanism 156 includes a coil spring 190 (hereinafter abbreviated as a spring 190) that is an elastic member, and an upper support member 192 and a lower support member 194 that support the spring 190 so as to sandwich the spring 190. The upper support member 192 is fixed to the housing 164 of the actuator 60 and is fixedly attached to the supported portion 150 in the vehicle body 56 described above. Further, the lower support member 194 is fixed to the upper portion of the outer tube 182. With such a structure, when the outer tube 182 and the inner tube 180 move relative to each other in the axial direction, the separation distance between the upper support member 192 and the lower support member 194 changes, and the spring 190 is expanded and contracted. The elastic force generation mechanism 156 generates an elastic force corresponding to the degree of expansion / contraction of the spring 190.

4. Switching between fault detection and vehicle stabilization control.
In the present embodiment, vehicle body posture control by the vehicle body posture control unit 100 and braking control by the brake control unit 110 are performed in order to stabilize the traveling state of the vehicle. When the actuators 60 included in all the suspension devices 14 function normally (hereinafter, simply referred to as “when the actuator is normal”), normal control is performed. The above-described failure detection unit 64 detects the current of each actuator 60, and when a current does not flow even though a voltage is applied to any actuator 60, the failure detection unit 64 detects the failure of the actuator 60. To detect. When a failure of any actuator 60 is detected, that is, when any actuator 60 has failed (hereinafter simply referred to as “actuator failure”), an actuator failure signal (hereinafter referred to as “actuator failure signal”). , Abbreviated as “failure signal”) is transmitted from the failure detection unit 64 to the vehicle stabilization control device 10. The failure signal includes arrangement information (information regarding which of FR, FL, RR, and RL has failed) of the actuator 60 that has failed. When the vehicle stabilization control device 10 receives the failure signal, each control by the attitude control unit 100 and the braking control unit 110 is performed on the assumption that all the actuators 60 are in a normal state. The control can be switched to the premise of a failure state. Note that the failure of the actuator 60 is notified to the driver by, for example, lighting an indicator lamp indicating a failure of the suspension device 14 provided on the instrument panel of the vehicle. In the present embodiment, it is assumed that the suspension device 14 including the failed actuator 60 cannot generate a damping force and a propulsive force.

5. Car body attitude control.
The vehicle body posture control that is feedback control by the vehicle body posture control unit 100 will be described. In order to simplify the description, it is assumed that the center of gravity of the vehicle body 56 is equidistant from each wheel 12 and the front wheel tread and the rear wheel tread are equal. The attitude control changing unit 124 manages which of the first attitude control unit 120 and the second attitude control unit 122 is a control entity, and performs a function of changing the control entity as necessary. In this embodiment, when the actuator is normal, the second vehicle body attitude control unit 122 performs second vehicle body attitude control (hereinafter referred to as “normal second attitude control”) on the assumption that the actuator is normal. At the time of actuator failure, the vehicle body posture control performed by the vehicle body posture control unit 100 is changed from the normal second posture control to the first vehicle body posture control (hereinafter referred to as “the first vehicle body posture control unit 120”). This is referred to as “first attitude control at the time of failure”.

5.1. First posture control during normal operation.
The control by the first vehicle body attitude control unit 120 will be described. The first vehicle body attitude control unit 120 determines the generated force of the electromagnetic actuator 60 of each suspension device 14 such that the heave amount, pitch amount, and roll amount of the vehicle body 56 become set target values (for example, 0). . Actual posture state quantity (a kind of vehicle state quantity) such as the actual heave amount Xh, pitch amount Xp, roll amount Xr of the vehicle body 56, which is information (hereinafter sometimes abbreviated as "posture information") regarding the posture of the vehicle body 56. Is acquired by the state quantity calculation unit 114 based on the detection values of the four G sensors 144. The height position of each supported portion 150 of the vehicle body in a stationary state of the vehicle is set as a reference height position X0, and the vertical acceleration detected by each G sensor 144 is integrated to obtain the reference height position X0. The amount of vertical displacement that is the amount of displacement in the vertical direction is calculated. If the amount of vertical displacement from the reference height position of each supported portion 150 (FR, FL, RR, RL) of the vehicle body 56 is X _FR , X _FL , X _RR , X _RL (see FIG. 1), The above three quantities are calculated by the following equation. Lh and Lt represent a vehicle wheel base and a wheel tread, respectively.
[Heave amount] Xh = (X _FR + X _FL + X _RR + X _RL ) / 4 (1)
[Pitch _{amount] Xp = (X FR + X} FL -X RR -X RL) / (2Lh) ··· (2)
[Roll _{amount] Xr = (X FR -X FL} + X RR -X RL) / (2Lt) ··· (3)

In the first vehicle body posture control, posture control force (control force for each actuator) that is a generated force to be generated in each actuator 60 in order to set the posture of the vehicle body 56 to a target posture is determined. The control generated by each actuator 60 is performed. Prior to the determination of the actuator-specific control force, the first vehicle body attitude control unit 120 determines a reference control force that serves as a reference for determining the actuator-specific control force based on the attitude information. Desired. The reference control force includes a heave reference control force Fh, a pitch reference control force Fp, and a roll reference control force Fr, which are reference control force components for controlling the heave amount, the pitch amount, and the roll amount, respectively. This is obtained by calculation performed by the first vehicle body attitude control unit 120. At that time, as shown in the following equation, the determined gains Kh, Kp, Kr are the values of the posture state quantity target values Xh1, Xp1, Xr1 and the Xh, Xp, Xr, respectively. The posture state quantity deviations ΔXh, ΔXp, ΔXr, which are deviations, are multiplied.
[Heave control force] Fh = Kh · ΔXh (4)
[Pitch control force] Fp = Kp · ΔXp (5)
[Roll control force] Fr = Kr · ΔXr (6)

Next, based on the obtained reference control force, the actuator-specific control force A of each actuator 60 (for each wheel, a subscript is added as shown in FIG. 5 to A _FR , A _FL , A _RR. , _ARL ). The actuator-specific control force A is obtained by adding the actuator-specific heave control force Ah, the actuator-specific pitch control force Ap, and the actuator-specific roll control force Ar, which are control force components for controlling the heave amount and the pitch amount, respectively. First, they are determined. Note that the direction in which the actuator-specific pitch control force Ap and the actuator-specific roll control force Ar are generated differ depending on the positions of the suspension devices 14, and therefore, the direction in which Ap and Ar are generated is also determined. Specifically, Ap is oriented differently in the front wheel side suspension device 14 and the rear wheel side suspension device 14, and Ar is oriented in the left wheel side suspension device 14 and the right wheel side suspension device 14. Different. Note that the difference in orientation is indicated by different symbols. The control force component for each actuator when the actuator is normal is determined as shown in the following equations.
[Heave control force by actuator] Ah _FR = Ah _FL = Ah _RR = Ah _RL = -Fh (7)
[Pitch control force per actuator] Ap _FR = Ap _FL = −Fp, Ap _RR = Ap _RL = + Fp (8)
[Roll Control Force by Actuator] Ar _FR = Ar _RR = −Fr, Ar _FL = Ar _RL = + Fr (9)

As explained above, the control force for each actuator is
[Control force by actuator] A = Ah + Ap + Ar (10)
If the control force components Ah, Ap, Ar for each actuator 60 in the above formulas 7, 8, 9 are summed for each of the actuators 60, the control force for each actuator 60 of each actuator 60 when "actuator is normal" Is required.
[Control Force FR by Actuator] A _FR = Ah _FR + Ap _FR + Ar _FR = −Fh−Fp−Fr (11)
[Control force FL for each actuator] A _FL = Ah _FL + Ap _FL + Ar _FL = −Fh−Fp + Fr (12)
[Control force RR for each actuator] A _RR = Ah _RR + Ap _RR + Ar _RR = −Fh + Fp−Fr (13)
[Control Force RL for Each Actuator] A _RL = Ah _RL + Ap _RL + Ar _RL = −Fh + Fp + Fr (14)
The control for determining the generated force of the actuator 60 of each suspension device 14 as described above is “normal first posture control”.

5.2. First posture control during failure.
The first vehicle body attitude control unit 120 performs the calculations of Equations 1 to 6 in both cases of “actuator normal” and “actuator failure”. However, since “first attitude control at the time of failure” is performed at the time of “actuator failure”, the calculation methods after Expression 7 are different. As an example of the first posture control at the time of failure, a case where the actuator 60 of the suspension device 14 located on the right front wheel (FR) has failed will be described as an example.

The control force component for each actuator is determined as shown in the following equations. At this time, with respect to the heave control force Ah, the other three actuators 60 are equally assigned the reduced amount of the lost actuator 60. In addition, with respect to the pitch control force Ap, the fall of the lost actuator 60 is shared by the actuator 60 of the suspension device 14 on the same side in the front-rear direction, and with respect to the roll control force Ar, the fall of the failed actuator 60 The portion is shared by the actuator 60 of the suspension device 14 on the same side in the left-right direction. The generated force (A _FR ) of the actuator 60 in which the suspension device 14 has failed is displayed as 0.
[Heave control force by actuator] (A _FR = 0), A _FL = A _RR = A _RL = −4 / 3Fh (7 ′)
[Pitch control force per actuator] (A _FR = 0), A _FL = -2Fp, A _RR = A _RL = + Fp (8 ')
[Roll control force by actuator] (A _FR = 0), A _RR = -2Fr, A _FL = A _RL = + Fr (9 ')

Next, as in the case of “first posture control during normal operation” (see Expression 10), the control force components Ah, Ap, Ar for each actuator in Expressions 7 ′, 8 ′, 9 ′ are summed for each of the actuators 60. , The generated force of each actuator 60 at the time of “actuator failure” is obtained.
[Control force FR by actuator] (A _FR = 0) (11 ')
[Control force by actuator FL] A _FL = −4 / 3Fh−2Fp + Fr (12 ′)
[Control force RR for each actuator] A _RR = −4 / 3Fh + Fp−2Fr (13 ′)
[Control force RL for each actuator] A _RL = −4 / 3Fh + Fp + Fr (14 ′)
The control for determining the generated force of the actuator 60 of each suspension device 14 as described above is the “first attitude control at the time of failure”. The above description is for the case where the actuator 60 of the suspension device 14 located on the right front wheel (FR) has failed. However, if the actuator 60 of the suspension device 14 for other wheels has failed, In accordance with the position where the suspension device 14 is disposed, the generated force of the actuator 60 that has not failed is determined so as to compensate for the decrease in the generated force of the actuator 60 that has failed. In order to avoid the specification becoming redundant, the description in that case is omitted.

5.3. Second posture control during normal operation.
“Normal second posture control” performed by the second vehicle body posture control unit 122 will be described. The normal second posture control is different from the control performed by the first vehicle body posture control unit 120, and the vertical displacement amount and the vertical displacement speed of each supported portion 150 of the vehicle body calculated by the state amount calculation unit 114. The vehicle body posture control is performed based on the vertical displacement speed (which is obtained by integrating the vertical acceleration detected by each G sensor 144). In the normal second posture control, the actuator-specific control force A that is the generated force of the actuator 60 of each suspension device 14 is the target value X1 _FR , X1 of the vertical displacement amount of each supported portion 150 for each actuator 60. Vertical displacement deviations ΔX _FR , ΔX _FL , ΔX _RR , ΔX _RL , and vertical displacements, which are deviations between _FL , X1 _RR , X1 _RL (for example, X0) and vertical displacements X _FR , X _FL , X _RR , X _RL Based on the speeds V _FR , V _FL , V _RR , V _RL , it is determined according to the following equation. Ka and Kb are gains to be multiplied by them.
[Control force FR for each actuator] A _FR = Ka · ΔX _FR + Kb · V _FR (15)
[Control force for each actuator FL] A _FL = Ka · ΔX _FL + Kb · V _FL (16)
[Control force RR for each actuator] A _RR = Ka · ΔX _RR + Kb · V _RR (17)
[Control force RL for each actuator] A _RL = Ka · ΔX _RL + Kb · V _RL (18)

  According to the normal second attitude control, the control force of each actuator 60 is determined so that the vertical displacement amount is individually reduced in each portion (FR, FL, RR, RL) of the vehicle body 56. Also in this control, the vertical displacement amount of each supported portion 150 of the vehicle body 56 is reduced. As a result, the heave amount, the pitch amount, and the roll amount are reduced as a whole, and the posture of the vehicle body 56 is stabilized. is there.

6. Braking control.
The braking control that is feedback control by the braking control unit 110 will be described. The braking control unit 110 is a kind of ABS control by the ABS control unit 130, TRC control by the TRC control unit 132, and VSC control by the VSC control unit 134 (a turning state control) in order to stabilize the traveling state of the vehicle. )I do. ABS control and TRC control control braking force so that the wheels do not slip during braking and acceleration, respectively, and are not described because they are general controls. Similarly, the VSC control is a general control for controlling the braking force of each wheel 12 so that the yaw rate of the vehicle approaches the target yaw rate to stabilize the turning state of the vehicle. However, since the posture of the vehicle body 56 is likely to be unstable and the turning state of the vehicle is likely to change when “actuator fails”, in this embodiment, VSC control is performed on the premise of “when the actuator fails”. .

“Normal VSC control”, which is VSC control based on the premise of “actuator normal”, will be briefly described. In this embodiment, the yaw rate is adopted as a parameter indicating the turning state, and the actual yaw rate γ that is the actual yaw rate of the vehicle is acquired by the VSC control unit 134 based on the detected value of the yaw sensor 142. On the other hand, the target yaw rate γt that is the target is determined based on the steering angle detected by the steering angle sensor 32 and the vehicle speed simulated by the state quantity acquisition unit 114, and the target yaw rate γt stored in the VSC control unit 134 is determined. Obtained from the map data. The yaw rate deviation Δγ is obtained by subtracting the target yaw rate γt from the actual yaw rate γ. The yaw rate deviation Δγ is multiplied by gains K _FR , K _FL , K _RR , and K _{RL set} for each wheel 12 to determine a braking force B that brakes each wheel 12 according to the following equation. The gains K _{FR and the} like are determined by the gain determination unit 136. Incidentally, the gain K _{FR and the} like used for the control when “the actuator is normal” is a value stored in advance.
[Braking force FR] B _FR = K _FR · Δγ (19)
[Braking force FL] B _FL = K _FL · Δγ (20)
[Braking force RR] B _RR = K _RR · Δγ (21)
[Braking force RL] B _RL = K _RL · Δγ (22)

When the braking force of each wheel 12 is determined, the braking force B is applied to only one of the left wheel 12 and the right wheel 12 according to the sign of Δγ. More specifically, when the counterclockwise yaw rate is a positive value and Δγ <0, the braking forces B _FL and B _RL are applied only to the left wheel 12 (FL, RL), and the right wheel 12 No braking force is applied to (FR, RR). Conversely, when Δγ> 0, the braking force B _FR , B _RR is applied only to the right wheel 12 (FR, RR), and the left side No braking force is applied to the wheels 12 (FL, RL). For example, in the left turn state as shown in FIG. 6, the actual yaw rate γ and the target yaw rate γt are compared, and if the actual yaw rate γ is larger than the target yaw rate γt, the sign of Δγ becomes negative, Therefore, braking force is applied to the right wheel 12 (FR, RR).

  As described above, the VSC control generates a force for rotating the vehicle in the yaw direction due to a difference in braking force between the left and right wheels 12. When a braking force is applied to the wheel 12, the braking force of any of the wheels 12 is increased by the previously determined braking force B. Further, since the slip of the wheel 12 is controlled by the ABS control, the braking force may be increased only in a range where the wheel 12 does not lose the grip. In such a case, processing is performed such that the braking force of the wheel 12 on the side opposite to the wheel whose braking force is to be increased is reduced by the braking force B.

The “VSC control at the time of failure” that is the control based on “at the time of actuator failure” will be described. The suspension device 14 in which the actuator 60 has failed cannot generate a force for suppressing the roll of the vehicle body 56 other than the spring 190, and the roll amount of the vehicle body 56 becomes larger than “when the actuator is normal”. For this reason, the “over-steer tendency” is often stronger when “actuator is failed” than when “actuator is normal”. In this case, if the “normal VSC control” is performed, the situation where the turning state is not sufficiently corrected or it takes a long time for the correction. Therefore, the gain determination unit 136 determines gains Kf _FR , Kf _FL , Kf _RR , and Kf _RL that are gains at the time of “actuator failure” in order to eliminate such a situation at “at the time of actuator failure”. To do. The determination of the gain Kf _{FR and the} like is performed by multiplying the gain K _{FR and the} like in “normal VSC control” by a set value C (for example, a value larger than 1 such as 1.3). By increasing the gain Kf _{FR and the} like, the value of the braking force B with respect to the yaw rate deviation Δγ is increased, and the turning state of the vehicle can be changed with a force larger than “when the actuator is normal”. Therefore, the phenomenon that the turning state becomes unstable due to the failure of the actuator 60 can be effectively suppressed or canceled. Specifically, the braking force B applied to each wheel 12 is obtained by the following equation.
[Braking force FR] B _FR = Kf _FR · Δγ, (Kf _FR = K _FR · C) (23)
[Braking force FL] B _FL = Kf _FL · Δγ, (Kf _FL = K _FL · C) (24)
[Braking force RR] B _RR = Kf _RR · Δγ, (Kf _RR = K _RR · C) (25)
[Braking force RL] B _RL = Kf _RL · Δγ, (Kf _RL = K _RL · C) (26)

7. Other aspects.
In the embodiment described above, the first vehicle body posture control unit 120 performs the first posture control when the actuator is normal or failed. The vertical displacement of the supported portion 150 of the vehicle body 56 in which the G sensor 144 described above is disposed. However, it is also possible to provide a stroke sensor for detecting the relative distance between the vehicle body 56 and each wheel 12 and based on the detected relative distance, the change speed of the relative distance, and the like. . In addition, the first posture control by the first vehicle body posture control unit 120 is performed based on the heave amount, the pitch amount, and the roll amount acquired based on the amount of displacement of the supported portion 150 in the vertical direction. It is also possible to control based on the change amount per set time of the amount, the pitch amount and the roll amount, that is, the heave speed, the pitch speed and the roll speed (these are also a kind of posture state quantity). The control force generated in the electromagnetic actuator 60 can be calculated by multiplying the gain set for each of the heave speed, pitch speed and roll speed. Further, in the first vehicle body posture control described so far, control based on a plurality of posture state quantities is performed. However, the first vehicle body based on one posture state quantity is controlled, for example, control is performed based only on the roll amount. Attitude control can also be performed. That is, the first vehicle body posture control can be a control based on at least one posture state quantity.

  In the first attitude control, the target values of the pitch amount and the roll amount are fixed. However, the target values of the pitch amount and the roll amount are adjusted to match the posture change of the vehicle body during braking and turning by calculation. May be changed. For example, if the vehicle is turning, an appropriate roll amount can be calculated from the detected steering angle, vehicle body speed, and the like according to discipline arbitrarily determined, and the roll amount can be set as a target value.

  Similarly, the control by the second vehicle body attitude control unit 122 can be performed based on the relative distance, the relative distance change speed, and the like acquired based on the detection value of the stroke sensor.

  In the above embodiment, the attitude control changing unit 124 changes the control so that the second vehicle body attitude control unit 122 performs the control when “the actuator is normal”. It is also possible to perform “first posture control when normal” when “actuator is normal” and perform the above first posture control when failure occurs when “actuator fails”.

  In the above embodiment, the failure of the actuator 60 is detected by the failure detection unit 64 based on whether or not current is flowing through the actuator 60. However, the actuator stabilization determination unit is provided in the vehicle stabilization control device 10. The failure of the actuator 60 can also be determined based on the vertical displacement amount, vertical displacement speed, vertical displacement acceleration, etc. of the supported portion 150 of the vehicle body 56. If the actuator 60 fails, the displacement of the relative distance between the vehicle body 56 and each wheel 12 cannot be suppressed. Especially in the suspension device 14 in which the actuator 60 has failed, In comparison, a phenomenon occurs in which the vertical displacement amount and the like are significantly different from the predicted vertical displacement amount. By detecting this phenomenon, the failure of the agony eater 60 is detected. In addition, a relative distance sensor between the vehicle body 56 and each wheel 12 is provided in the vehicle, and it is determined whether any of the actuators 60 has failed based on the relative distance, the relative distance change speed, the relative distance change acceleration, and the like. You can also.

  In the above embodiment, the control at the time of failure has been described on the assumption that the failed actuator 60 cannot generate the generated force, but the actuator 60 generates some generated force even at the time of the failure. In addition, it is possible to perform control according to the amount of decrease in the generated force at the time of failure. In addition, for example, the propulsive force cannot be generated because the drive power cannot be supplied to any of the actuators 60, but the function of the actuator 60 as a generator is not lost and only the damping force can be generated. In some cases, the control can be performed on the assumption of the state.

In the VSC control of the above embodiment, the braking force of the left and right front and rear wheels 12 is increased to bring the actual yaw rate closer to the target yaw rate. However, depending on the state of the vehicle, the braking force is applied only to one of the front and rear wheels 12. It is also possible to perform control such as adding. For example, when the vehicle is turning, the control is such that the braking force of the front wheel on the outer turning wheel side is increased in order to correct the oversteer tendency. In the above embodiment, the VSC control employs the yaw rate as a parameter indicating the turning state of the vehicle and is performed based on the yaw rate. However, the turning state of the vehicle is determined based on other parameters, for example, the spin degree Sv. It may be determined whether or not it is appropriate, and if it is not appropriate, the turning state may be corrected. The degree of spin Sv is a value obtained by multiplying the vehicle slip angle β and the rate of change dβ / dt of the slip angle β by a constant. When the lateral acceleration Gy is detected by providing a lateral acceleration sensor in the vehicle and the spin rate Sv is obtained based on the detected value, it may be calculated according to the following equation. In the following formula, V is the vehicle speed.
dβ / dt = (Gy / V) −γ (27)
β = ∫ {(Gy / V) −γ} dt (28)
Sv = k1 · β + k2 · dβ / dt (29)

It is a figure which shows typically the structure of the vehicle provided with the vehicle stabilization control apparatus which is an Example of this invention. It is a block diagram which shows the function of the stabilization control apparatus for vehicles. It is a side view which shows typically the mutual positional relationship of a vehicle body, an electromagnetic suspension, and a wheel. It is sectional drawing which shows a part of electromagnetic suspension provided in the vehicle. It is a top view which shows typically arrangement | positioning of the electromagnetic suspension in a vehicle. It is a top view which shows typically the vehicle in turning.

Explanation of symbols

10: Vehicle stabilization device 12: Wheel 14: Suspension device 16: Wheel cylinder 30: Steering wheel 32: Steering angle sensor 34: Brake pedal 36: Master cylinder 38: Fluid pressure transmission pipe 50: Braking fluid pressure control device 52: Treading force sensor 56: vehicle body 60: electromagnetic actuator 62: actuator drive circuit 64: failure detection unit 100: vehicle body posture control unit 110: braking control unit 120: first vehicle body posture control unit 122: second vehicle body posture control unit 124: posture Control change unit 130: ABS control unit 132: TRC control unit 134: VSC control unit 136: Gain determination unit 140: Wheel speed sensor 142: Yaw sensor 144: G sensor 150: Supported portion 156: Elastic force generation mechanism 16 : Electromagnetic motor 162: Ball screw 164: Housing 166: Joint 172: flange portion 174: Bearing 180: inner tube 182: outer tube 186: ball nut 190: coil spring 192: upper support member 194: lower support member

Claims (4)

A vehicle stabilization control device that performs control to stabilize a running state of a vehicle with a suspension device having an electromagnetic actuator for each wheel,
A vehicle body posture control unit that performs control for determining the force to be generated by the electromagnetic actuator for each electromagnetic actuator based on information on the posture of the vehicle body and stabilizing the posture of the vehicle body;
If the electromagnetic actuator of any of the suspension devices fails and the force that can be generated by the electromagnetic actuator decreases , the vehicle body posture control unit reduces the force due to the failure of the electromagnetic actuator. A vehicle stabilization control device configured to perform control for stabilizing the posture of the vehicle body by increasing a force that should be generated by an electromagnetic actuator included in another suspension device by an appropriate amount . A vehicle to be controlled by the vehicle stabilization device includes four suspension devices corresponding to four wheels on the front, rear, left, and right.
The vehicle body attitude control unit
Based on the heave amount, roll amount and pitch amount as information on the posture of the vehicle body, the heave control force, roll control force and pitch control force of each electromagnetic actuator are determined as components of the force to be generated by each electromagnetic actuator. And is configured to be able to execute control to stabilize the posture of the vehicle body,
When the electromagnetic actuator of any one of the suspension devices fails and the force that can be generated by the electromagnetic actuator decreases, (A) the decrease in the heave control force of the failing electromagnetic actuator. Is equally shared by the electromagnetic actuators of the other three suspension devices, and (B) the decrease in the roll control force of the failed electromagnetic actuator is reduced by the electromagnetic force of the suspension device on the same side on the left and right. (C) The decrease in the pitch control force of the failing electromagnetic actuator is shared by the electromagnetic actuator of the suspension device on the same side in the front and rear to stabilize the posture of the vehicle body The vehicle stabilization control device according to claim 1, wherein the vehicle stabilization control device is configured to perform control to be activated. In addition to the first vehicle body posture control unit, which is the vehicle body posture control unit, the vehicle stabilization control device has its respective suspensions based on information about the displacements of the vehicle body parts on which the suspension devices are mounted. When there is a second vehicle body posture control unit that performs control to individually determine the force that the electromagnetic actuators of the device should generate and stabilize the posture of the vehicle body, and none of the electromagnetic actuators has failed , the control by the second vehicle body attitude control unit is executed, any one of when said electromagnetic actuator is defective, the control by the first vehicle body attitude control unit is to be executed according to claim 1 or The vehicle stabilization control device according to claim 2.   The vehicle stabilization control device is applied to any wheel based on a deviation between a target turning state of the vehicle determined based on at least a steering angle and an actual turning state that is an actual turning state of the vehicle. There is a turning state control unit that performs control to stabilize the turning state of the vehicle by determining at least one of power and driving force, and the turning state control unit has any one of the electromagnetic actuators failed. 4. The control is performed with a gain for determining at least one of the braking force and the driving force being set larger than that in the case where none of the electromagnetic actuators has failed. The vehicle stabilization control device described.

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