JP2009137515A - Vehicular attitude control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicular attitude control device for changing/controlling damping force of a shock absorber and roll rigidity of an active stabilizer while making them cooperate with each other. <P>SOLUTION: The absorber ECU inputs acceleration Gfl, Gfr, Grl, Grr at positions corresponding to the respective wheels in a step S11 and determines whether the left wheels and the right wheels has relatively widely displaced to the vertical direction or not in a step S12. In a step S13, the ECU cooperates with a stabilizer ECU to operate an active stabilizer device according to the displacement of the wheels by comfort control. In steps S14-S16, the ECU determines the left wheels or the right wheels which have widely displaced to the vertical direction, changes a shock absorber on the widely displacing side to small damping force, and changes a shock absorber on the other side to large damping force. By this, in a situation in which only wheels on one side are widely displaced, disorder of the attitude can be suppressed and excellent comfort can be secured. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention includes a damping force changing means for changing and controlling the damping force of a shock absorber disposed between a vehicle body and left and right front and rear wheels, and a roll rigidity changing means for changing and controlling the roll rigidity of a stabilizer that connects between the left and right wheels. The present invention relates to an attitude control device for a vehicle that includes the vehicle.

  As conventionally known, for example, in Patent Document 1 described below, by appropriately controlling both the stabilizer force of the torsional rigidity variable stabilizer device and the damping force of the shock absorber, deterioration of the riding comfort of the vehicle is prevented. A roll control device for a vehicle that suppresses the roll of the vehicle without inviting is shown. In this conventional vehicle roll control device, when the rate of change of the roll amount of the vehicle is large, the damping force of the shock absorber is changed to the high damping side, and effective suppression control of the roll is ensured by this changed damping force. In addition, the stabilizer force of the stabilizer device is changed to the low torsional rigidity side. On the other hand, when the rate of change of the roll amount is small, the stabilizer force of the stabilizer device is changed to the high torsional rigidity side to ensure effective suppression control of the roll by this changed stabilizer force and to reduce the damping force of the shock absorber. By changing to the low attenuation side, the ride comfort is secured well.

  Further, as conventionally known, for example, Patent Document 2 below discloses a vehicle attitude control device that improves the steering stability of a vehicle by controlling the damping force when the roll rigidity of the vehicle is reduced. It is shown. This conventional vehicle attitude control device, for example, by increasing the damping force on the extension side by a semi-active suspension with adjustable damping force when the roll stiffness is reduced due to a failure or the like in the active stabilizer device, Even when the roll rigidity is lowered, good steering stability is ensured.

  Further, as conventionally known, for example, Patent Document 3 below discloses a damping force variable shock absorber control device that improves the ride comfort by achieving both vibration suppression for vehicle vertical vibration and suppression of roll or pitch. It is shown. This conventional damping force variable shock absorber control device improves the riding comfort of the vehicle by changing the magnitude of the damping force for controlling the vibration of the vehicle body from the magnitude of the roll or pitch speed. It has become.

  As conventionally known, for example, Patent Document 4 shown below discloses a vehicle behavior control device that stabilizes the behavior of a vehicle without lowering the running feeling. In this conventional vehicle behavior control device, when the spin state amount is greater than or equal to the spin side roll stiffness threshold, the front wheel roll stiffness is controlled to increase or the rear wheel roll stiffness is decreased, and the drift state amount is set to the drift side roll stiffness threshold. In the above case, the behavior of the vehicle is stabilized by increasing the roll rigidity of the rear wheel or decreasing the roll rigidity of the front wheel.

  Further, as conventionally known, for example, Patent Document 5 below discloses a suspension that accurately suppresses shock and unnecessary vibration of a vehicle body and suppresses deterioration of riding comfort even when a large protrusion is overcome. Or a stabilizer control device is shown. This conventional suspension or stabilizer control device is designed to control damping force, spring constant, and torsional force based on the magnitude of acceleration in the vertical direction or the horizontal direction of the vehicle body, or the duration of the acceleration above a predetermined level. By changing either one, the shock and unnecessary vibration suppression of the vehicle body can be accurately suppressed to ensure a good ride comfort.

Furthermore, as is conventionally known, for example, Patent Document 6 below shows a highly practical stabilizer system. In this conventional stabilizer system, a motor operating mode is changed so that the presence or absence of resistance to the operation of the actuator by an external input can be changed, so that the ease of operation of the actuator varies depending on the operation direction. It is designed to improve the stability and ride comfort.
JP 2006-256368 A JP 2007-45315 A JP-A-6-92126 JP 2006-89005 A JP-A-3-74215 JP 2006-347360 A

  By the way, in the said conventional apparatus, the change of the damping force of a shock absorber or the change of the roll rigidity (stabilizer force) of an active stabilizer is each performed separately (or independently). For this reason, in particular, in the conventional device described in Patent Document 1, for example, when only one of the left and right wheels is displaced in the vertical direction of the vehicle when the vehicle is in a straight traveling state, the vertical displacement of the wheel is reduced. Accordingly, the roll stiffness (stabilizer force) is changed to generate an unnecessary anti-roll moment when the active stabilizer is traveling straight, while the damping force of the shock absorber may be changed to a low damping force characteristic. That is, since the change control of the damping force of the shock absorber and the change control of the roll stiffness of the active stabilizer are executed independently, there is a case where unnecessary behavior of the roll occurs when these change controls influence each other. is there. As a result, the posture of the vehicle may be disturbed.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a vehicle attitude control device that can change and control the damping force of a shock absorber and the roll stiffness of an active stabilizer in cooperation with each other. There is to do.

  In order to achieve the above object, the present invention is characterized in that damping force changing means for changing and controlling the damping force of a shock absorber disposed between a vehicle body and left and right front and rear wheels, and roll rigidity of a stabilizer connecting the left and right wheels. In the vehicle attitude control device comprising a roll stiffness changing means for changing and controlling the physical quantity detecting means for detecting the physical quantity relating to the displacement of the left and right wheels of the vehicle in the vehicle vertical direction, and the detection Determination means for determining whether or not a difference value between the physical quantity of the left wheel and the detected physical quantity of the right wheel is larger than a predetermined value, and the difference value is larger than the predetermined value When the determination is made, the torsion bar forming the stabilizer rotates in accordance with the vertical displacement without hindering the vertical displacement of the connected wheel. And comparing the detected physical quantity of the left wheel with the detected physical quantity of the right wheel, and comparing the detected physical quantity of the left wheel with the roll stiffness control means for controlling the roll stiffness changing means. The discriminating means for discriminating the wheel with the larger displacement in the vertical direction of the vehicle, and the damping force of the shock absorber disposed on the side of the wheel with the large displacement in the vertical direction of the vehicle are changed to a small damping force. And a damping force control means for controlling the damping force changing means in order to change the damping force of the shock absorber disposed on the small wheel side to a large damping force.

  In this case, the physical quantity detection means may be provided, for example, at a position corresponding to the left and right front and rear wheels, and detect acceleration in the vehicle vertical direction at the same position as the physical quantity. The physical quantity detection means may detect, for example, a stroke amount of the shock absorber as the physical quantity.

  According to these, between the physical quantity of the left wheel and the physical quantity of the right wheel, using physical quantities related to the displacement of the front and rear wheels of the vehicle in the vertical direction of the vehicle (for example, acceleration, shock absorber stroke amount, etc.) In a situation where a difference value larger than a predetermined value set in advance, that is, a situation where a relatively large displacement occurs between the left and right wheels, more specifically, in a situation where only one wheel is greatly displaced in the vertical direction of the vehicle, roll rigidity It can change so that the roll rigidity of the stabilizer (active stabilizer) which has a change means may become smaller. As a result, the left and right torsion bars constituting the stabilizer do not disturb the displacement of the connection destination wheel in the vertical direction of the vehicle, in other words, the torsion bar is rotationally displaced following the displacement of the connection destination wheel. Does not give great resistance. Therefore, for example, in a situation where only one wheel is greatly displaced in the vehicle vertical direction in a situation where the vehicle is traveling straight, the stabilizer is less likely to generate an anti-roll moment. Thereby, for example, the wheel on the side where the external force is input from the road surface can be easily displaced in the vertical direction of the vehicle, and the external force is input from the road surface to the wheel on the side where the external force is not input from the road surface. The influence of the displacement of the wheel on the side can be made difficult to be transmitted via the stabilizer.

  In addition, the damping force of the shock absorber disposed on the wheel side that is largely displaced in the vertical direction of the vehicle is changed to a small damping force in accordance with the change in the roll rigidity of the stabilizer, and is disposed on the other wheel side. The damping force of the shock absorber can be changed to a large damping force. Therefore, for example, a shock absorber disposed on the side where external force is input from the road surface can displace the wheel in the vertical direction of the vehicle very easily, and a shock absorber disposed on the side where external force is not input from the road surface. Can satisfactorily suppress the roll of the vehicle body due to the large displacement of the wheel on the side where the external force is input from the road surface.

  In this way, by coordinating the change control of the damping force of the shock absorber and the change control of the roll rigidity of the stabilizer, even if the vehicle wheel is displaced greatly in the vertical direction of the vehicle, The change can be suppressed satisfactorily. Furthermore, since the wheel can be displaced very easily, a good riding comfort can be ensured.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 schematically shows the configuration of an attitude control device C that controls the attitude of a vehicle when traveling in common with each embodiment of the present invention. The attitude control device C includes a damping force control device 10 that attenuates input to the left and right front and rear wheels of the vehicle, and an active stabilizer device 20 that adjusts a roll generated in the vehicle.

  As shown in FIG. 1, the damping force control device 10 includes shock absorbers 11, 12, 13, and 14 that connect the vehicle body and the left and right front and rear wheels of the vehicle, respectively. Each of the shock absorbers 11, 12, 13, and 14 includes, for example, rotary valves 11a, 12a, 13a, and 14a as damping force changing means for changing the flow path of the working fluid (oil, high-pressure gas, etc.) steplessly. ing. In addition, although detailed description is abbreviate | omitted, each rotary valve 11a, 12a, 13a, 14a is comprised including the electric drive means (for example, an electric motor, a solenoid, etc.) which is not shown in figure. And each rotary valve 11a, 12a, 13a, 14a changes the flow path diameter of a working fluid by being electrically controlled by the electric control apparatus 30 mentioned later, As a result, each shock absorber 11, 12, 13 is changed. , 14 are changed steplessly.

  The active stabilizer device 20 includes a front wheel side active stabilizer 21 provided between the left and right front wheels and a rear wheel side active stabilizer 22 provided between the left and right rear wheels. The front wheel side active stabilizer 21 and the rear wheel side active stabilizer 22 are respectively a pair of torsion bar portions 21a, 21b and torsion bar portions 22a, 22b extending along the lateral direction of the vehicle, and these torsion bar portions 21a, 21b. And a pair of arm portions 21c, 21d and arm portions 22c, 22d continuous to the torsion bar portions 22a, 22b. Here, the torsion bar portions 21a and 21b and the torsion bar portions 22a and 22b are supported with respect to the vehicle body so as to be rotatable around the axis thereof, and the arm portions 21c and 21d and the arm portions 22c and 22d are bent at the front ends thereof. Thus, the suspension is connected to a suspension (not shown).

  Further, between the pair of torsion bar portions 21a and 21b in the front wheel side active stabilizer 21 and between the pair of torsion bar portions 22a and 22b in the rear wheel side active stabilizer 22, respectively, an electric actuator 21e as a roll stiffness changing means and an electric motor are provided. An actuator 22e is provided. The electric actuator 21e is driven and controlled by an electric control device 30, which will be described later. When the left and right front wheels bounce and rebound in opposite phases, the torsion bar portions 21a and 21b are controlled based on the magnitude of the lateral acceleration generated in the vehicle body. The torsional force (that is, torque) is generated by rotating them in opposite directions, and the force for suppressing the bounce and rebound of the front wheels is adjusted. The electric actuator 22e is also driven and controlled by the electric control device 30, and when the left and right rear wheels bounce and rebound in opposite phases, the torsion bar portions 22a and 22b are rotationally driven in opposite directions as necessary to twist. Force (that is, torque) is generated, and the force that suppresses the bounce and rebound of the rear wheel is adjusted.

  As described above, the electric actuator 21e in the front wheel side active stabilizer 21 and the electric actuator 22e in the rear wheel side active stabilizer 22 are driven to increase or decrease the anti-roll moment applied to the vehicle body at the position where the left and right front and rear wheels are respectively positioned. The roll rigidity of the vehicle body on the front wheel side and the rear wheel side is variably controlled. Therefore, for example, with respect to the roll moment that acts when the vehicle turns, the electric actuators 21e and 22e rotate the torsion bar portions 21a, 21b, 22a, and 22b by a necessary amount to counteract this roll moment. A roll moment can be generated, and as a result, the roll moment acting on the vehicle can be reduced.

  Next, the electric control device 30 that controls the operation of the rotary valves 11a, 12a, 13a, and 14a of the damping force control device 10 and the electric actuators 21e and 22e of the active stabilizer device 20 will be described in detail. As shown in FIG. 2, the electric control device 30 includes an absorber electronic control unit 31 (hereinafter simply referred to as an absorber ECU 31) that controls the operation of the rotary valves 11a, 12a, 13a, and 14a of the damping force control device 10, and an active control device. A stabilizer electronic control unit 32 (hereinafter simply referred to as a stabilizer ECU 32) for controlling the operation of the electric actuators 21e and 22e of the stabilizer device 20 is provided. Here, the absorber ECU 31 and the stabilizer ECU 32 are connected to each other via the communication line A.

  The absorber ECU 31 is a microcomputer whose main components are a CPU, a ROM, a RAM, and the like. The absorber ECU 31 controls the operation of the rotary valves 11a, 12a, 13a, and 14a by executing various programs including an attitude control program to be described later, and changes and controls the damping force of the shock absorbers 11, 12, 13, and 14. To do. The stabilizer ECU 32 is also a microcomputer whose main components are a CPU, a ROM, a RAM, and the like. The stabilizer ECU 32 controls the operation of the electric actuators 21e and 22e by executing various programs (not shown), and changes and controls the magnitude of the anti-roll moment by the front wheel side active stabilizer 21 and the rear wheel side active stabilizer 22. Is.

  And, on the input side of the absorber ECU 31, vertical acceleration sensors 33a, 33b, 33c and 33d are connected as physical quantity detecting means for detecting acceleration as a predetermined physical quantity generated in the vehicle. Further, on the input side of the stabilizer ECU 32, a torque sensor 34a and a torque sensor 34b that detect torque generated in the front wheel side active stabilizer 21 and the rear wheel side active stabilizer 22, and a lateral acceleration sensor that detects lateral acceleration generated in the vehicle body. 35 is connected.

  As shown in FIG. 1, the vertical acceleration sensors 33 a to 33 d are assembled at the left and right and front and rear wheel positions, respectively, detect acceleration in the vehicle vertical direction generated at the same assembly position, and accelerate the detected acceleration. Gfl, Gfr, Grl, and Grr are output to the absorber ECU 31. As shown in FIG. 1, the torque sensor 34 a is assembled to the torsion bar 21 a or the torsion bar 21 b of the front wheel side active stabilizer 21, detects the torque generated in the front wheel side active stabilizer 21, and stabilizes it as torque Tf. It outputs to ECU32. Further, as shown in FIG. 1, the torque sensor 34 b is assembled to the torsion bar portion 22 a or the torsion bar portion 22 b of the rear wheel side active stabilizer 22 and detects the torque generated in the rear wheel side active stabilizer 22. The torque Tr is output to the stabilizer ECU 32. As shown in FIG. 1, the lateral acceleration sensor 35 is assembled on the vehicle body side and outputs the lateral acceleration generated in the vehicle body to the stabilizer ECU 32 as the lateral acceleration Gs.

  Further, driving circuits 36a, 36b, 36c, and 36d for controlling the operations of the rotary valves 11a, 12a, 13a, and 14a are connected to the output side of the absorber ECU 31, respectively. Further, drive circuits 37a and 37b for controlling the operation of the electric actuators 21e and 22e, respectively, are connected to the output side of the stabilizer ECU 32.

  Next, the operation of the vehicle attitude control device C configured as described above will be described in detail.

  In general, for example, when a vehicle turns, it is preferable that an appropriate roll behavior is generated. For this reason, when the vehicle is in a turning state, the vehicle attitude control device C prevents excessive roll behavior and stabilizes the generated roll behavior. That is, the damping force control device 10 changes the damping force of the shock absorbers 11, 12, 13, and 14, and the active stabilizer device 20 changes the roll rigidity of the front wheel side active stabilizer 21 and the rear wheel side active stabilizer 22. This stabilizes the behavior of the roll generated in the vehicle.

  Specifically, the absorber ECU 31 drives and controls the drive circuits 36a, 36b, 36c, and 36d so that a predetermined correlation is established between the actual roll angle generated in the vehicle body and the actual pitch angle. 11a, 12a, 13a, and 14a are made to change the flow path diameter of a working fluid suitably, and the damping force of the shock absorbers 11, 12, 13, and 14 is increased / decreased. The stabilizer ECU 32 controls the drive circuits 37a and 37b so that a predetermined correlation is established between the actual roll angle and the actual pitch angle generated in the vehicle body, and controls the electric actuators 21e and 22e with a torsion bar unit. The torque between 21a and 21b and the torque between the torsion bar portions 22a and 22b are appropriately changed to increase or decrease the roll rigidity (anti-roll moment) generated by the front wheel side active stabilizer 21 and the rear wheel side active stabilizer 22. Let Thereby, for example, the behavior of an excessive roll when the vehicle is turning can be appropriately reduced, and as a result, the steering stability can be ensured satisfactorily.

  By the way, for example, when the vehicle is traveling straight, there is a situation where only the left wheel or the right wheel strokes in the vertical direction by the input of external force from the road surface. In such a situation, the absorber ECU 31 and the stabilizer ECU 32 independently perform the damping force change control of the shock absorbers 11, 12, 13, and 14 and the roll stiffness change control of the front wheel side active stabilizer 21 and the rear wheel side active stabilizer 22. If done, useless roll behavior may occur.

  Specifically, the front wheel side will be described as an example. Assume that a large upward stroke is generated only in the left front wheel when passing through a convex portion existing on the road surface. In this case, since the vehicle is in a straight traveling state, the stabilizer ECU 32 does not drive the electric actuator 21e in the locked state, so the front wheel side active stabilizer 21 apparently functions as one stabilizer. For this reason, the torsion bar portion 21a connected to the left front wheel is twisted in accordance with the upward stroke of the wheel, and an anti-roll moment is generated even though the vehicle is not turning.

  On the other hand, the right front wheel does not stroke in the vertical direction because it passes on a flat road surface. However, since the torsion bar portion 21b connected to the right front wheel is fixed by the same wheel that does not stroke, the torsion bar portion 21b acts upward with respect to the right wheel under the influence of the torque associated with the torsion of the torsion bar portion 21a. Torque is applied. Therefore, the rightward wheel to which no external force from the road surface is input has its downward stroke inhibited by the torque of the torsion bar portion 21b.

  Further, the absorber ECU 31 increases the damping force of the shock absorber 11 because a large low-frequency force is input when the left front wheel passes over the convex portion on the road surface. Therefore, in this case, the upward stroke when the left front wheel gets over the convex portion on the road surface is limited by the damping force generated by the shock absorber 11 and the torque generated by the torsion bar portion 21a. The downward stroke of the right front wheel is limited by the torque generated by the portion 21b.

  As a result, when only the left front wheel passes through the convex portion on the road surface, the vehicle body rolls in the right direction with respect to the traveling direction. As described above, when the vehicle is in a straight traveling state and an external force is input to only one of the left wheel and the right wheel, the absorber ECU 31 and the stabilizer ECU 32 each perform control independently. There is a possibility that (unintentional) roll behavior may occur, which may cause a disturbance in the posture of the vehicle or impair the riding comfort.

  In order to prevent such disturbance of posture and deterioration of riding comfort, the absorber ECU 31 cooperates with the stabilizer ECU 32 to repeatedly execute the posture control program shown in FIG. 3 at a predetermined short time interval. Hereinafter, this attitude control program will be described in detail.

  The execution of the attitude control program is started in step S10 after execution of the predetermined initialization program. In step S11, the absorber ECU 31 receives accelerations Gfl, Grl (in the following description, these accelerations) from the vertical acceleration sensors 33a, 33c assembled to the left wheel and the vertical acceleration sensors 33b, 33d assembled to the right wheel. Are collectively referred to as acceleration Gl) and accelerations Gfr and Grr (in the following description, these accelerations are collectively referred to as acceleration Gr). The acceleration Gl and the acceleration Gr can be implemented, for example, by employing an average value of the accelerations Gfl and Grl and an average value of the accelerations Gfr and Grr.

  Subsequently, the absorber ECU 31 determines in step S12 whether or not a large vertical acceleration has occurred on either the left wheel or the right wheel of the vehicle. Specifically, the absorber ECU 31 determines whether or not the absolute value of the difference value between the absolute value of the acceleration Gl and the absolute value of the acceleration Gr input in step S11 is greater than a predetermined value α. judge. That is, if the absolute value of the difference value is equal to or less than the predetermined value α, the absorber ECU 31 receives an input from the left wheel or right wheel of the vehicle passing through, for example, a convex portion or a concave portion existing on the road surface. Therefore, it is determined as “No”, and the acceleration Gl and the acceleration Gr are input again in the step S11.

  On the other hand, if the absolute value of the difference value is larger than the predetermined value α, the absorber ECU 31 determines “Yes” because the left wheel or the right wheel of the vehicle has received a large input, and proceeds to step S13. That is, in this case, the left wheel or the right wheel of the vehicle strokes greatly in the vertical direction in order to pass through the convex part and the concave part existing on the road surface.

  In step S13, the absorber ECU 31 does not obstruct the stroke on the left wheel side or the right wheel side of the vehicle with respect to the stabilizer ECU 32 by the magnitude of the roll rigidity generated by the front wheel side active stabilizer 21 and the rear wheel side active stabilizer 22. It is instructed to control to a certain level (hereinafter, control by the stabilizer ECU 32 is referred to as ride comfort control). Hereinafter, the ride comfort control by the stabilizer ECU 32 will be specifically described.

  Based on the lateral acceleration Gs output from the lateral acceleration sensor 35, the stabilizer ECU 32 calculates a target generated torque corresponding to the roll rigidity (anti-roll moment) that should be generated by the front wheel side active stabilizer 21 and the rear wheel side active stabilizer 22. To do. Then, the electric actuator 21e and the electric actuator 22e are driven and controlled via the drive circuits 37a and 37b so that the torque Tf and the torque Tr detected by the torque sensor 34a and the torque sensor 34b become the target generated torque, respectively. However, as described above, for example, in a situation where the vehicle is traveling straight and only the left wheel or the right wheel strokes in the vertical direction by the input from the road surface, the lateral acceleration Gs is not generated in the vehicle body, and the target is generated. The torque is “0”, that is, the electric actuator 21e and the electric actuator 22e are in a locked state and are not driven. For this reason, as shown in FIG. 4, the actual torque detected by the torque sensor 34a and the torque sensor 34b by twisting the torsion bar portions 21a, 22a or the torsion bar portions 21b, 22b by the stroke of the left wheel or the right wheel. The absolute value of Tf and the absolute value of actual torque Tr increase.

  In such a situation, when the stabilizer ECU 32 receives an instruction to perform ride comfort control from the absorber ECU 31, the absolute value of the detected actual torque Tf and the detected absolute value of the actual torque Tr are preset as shown in FIG. The electric actuator 21e and the electric actuator 22e are driven so as to be smaller than the small torque Ta. That is, the stabilizer ECU 32 rotates the torsion bar portions 21a, 22a or the torsion bar portions 21b, 22b in accordance with the stroke direction of the left wheel or the right wheel, in other words, the torsion bar portions 21a, 22a or the torsion bar portion 21b. , 22b is driven and controlled so that the electric actuator 21e and the electric actuator 22e rotate following the stroke of the left wheel or the right wheel.

  Thereby, the front wheel side active stabilizer 21 and the rear wheel side active stabilizer 22 do not impede the vertical stroke of the left wheel or right wheel, in other words, do not give a large resistance to the stroke of the left wheel or right wheel. Become. Therefore, the external force input from the road surface as the vehicle travels is attenuated by the damping force of the shock absorbers 11, 12, 13, and 14, and the riding comfort can be improved. Thus, when the stabilizer ECU 32 completes the transition to the control by the ride comfort control of the front wheel side active stabilizer 21 and the rear wheel side active stabilizer 22, the absorber ECU 31 sends a transition signal indicating the control transition via the communication line A. Output. Then, in the absorber ECU 31, when the transition signal is acquired from the stabilizer ECU 32, the process proceeds to step S14.

  In step S14, the absorber ECU 31 determines which of the left wheel and the right wheel has a large acceleration. That is, the absorber ECU 31 compares the absolute value of the acceleration Gl input in step S11 with the absolute value of the acceleration Gr. If the absolute value of the acceleration Gl is larger than the absolute value of the acceleration Gr, a large acceleration is applied to the left wheel. Since it has occurred, “Yes” is determined, and the process proceeds to step S15.

  In step S15, the absorber ECU 31 straightens the damping force of the shock absorbers 11 and 13 in order to easily make the left wheel to make a large stroke and to suppress the behavior of the vehicle body rolling in the right direction accompanying the stroke of the left wheel. The damping force is changed to be smaller than the damping force set during traveling, and the damping force of the shock absorbers 12 and 14 is changed to be larger than the damping force set during straight running. That is, the absorber ECU 31 changes the flow diameter of the working fluid in the shock absorbers 11 and 13 by driving and controlling the rotary valves 11a and 13a via the drive circuits 36a and 36c. On the other hand, the absorber ECU 31 changes the flow diameter of the working fluid in the shock absorbers 12 and 14 by driving and controlling the rotary valves 12a and 14a via the drive circuits 36b and 36d.

  As a result, the left wheel can easily make a large stroke, and for example, can easily pass through the unevenness present on the road surface. Further, since the stroke of the right wheel is regulated by a large damping force, the behavior of rolling rightward or leftward of the vehicle body can be satisfactorily suppressed.

  In step S14, the absorber ECU 31 compares the absolute value of the acceleration Gl input in step S11 with the absolute value of the acceleration Gr, and if the absolute value of the acceleration Gr is larger than the absolute value of the acceleration Gl. Since a large acceleration is generated on the right wheel, the determination is “No” and the process proceeds to step S16. In step S16, the absorber ECU 31 straightens the damping force of the shock absorbers 12 and 14 in order to make the right wheel easily stroke a large amount and to suppress the behavior of the vehicle body rolling in the left direction accompanying the stroke of the right wheel. The damping force is changed to be smaller than the damping force set during traveling, and the damping force of the shock absorbers 11 and 13 is changed to be larger than the damping force set during straight running.

  In other words, the absorber ECU 31 changes the flow diameter of the working fluid in the shock absorbers 12 and 14 by driving and controlling the rotary valves 12a and 14a via the drive circuits 36b and 36d. On the other hand, the absorber ECU 31 changes the flow diameter of the working fluid in the shock absorbers 11 and 13 by controlling the driving of the rotary valves 11a and 13a via the drive circuits 36a and 36c. As a result, the right wheel can easily make a large stroke and, for example, can easily pass through the unevenness present on the road surface. Further, since the stroke of the left wheel is regulated by a large damping force, the behavior of rolling in the left direction or the right direction of the vehicle body can be satisfactorily suppressed.

  And if the absorber ECU31 performs the damping force change process in the said step S15 or step S16, it will progress to step S17 and will once complete | finish the execution of an attitude | position control program. Then, after the elapse of a predetermined short time, the absorber ECU 31 again starts executing the attitude control program in step S10 as described above.

  As can be understood from the above description, according to the first embodiment, the absorber ECU 31 detects accelerations Gfl, Gfr, Grl, which are detected as physical quantities related to the displacement in the vehicle vertical direction of the front and rear wheels of the vehicle. Using the magnitude of the absolute value of Grr, the difference value between the absolute value of the acceleration Gl of the left wheel and the absolute value of the acceleration Gr of the right wheel is larger than a predetermined value α, that is, between the left and right wheels. In a situation where a relatively large displacement occurs, more specifically, in a situation where only one of the wheels is greatly displaced in the vehicle vertical direction, the front wheels constituting the active stabilizer device 20 in cooperation with the stabilizer ECU 32 (cooperation). The torque corresponding to the roll rigidity of the side active stabilizer 21 and the rear wheel side active stabilizer 22 can be changed to be smaller. As a result, the left and right torsion bar portions 21a and 21b and the torsion bar portions 22a and 22b constituting the front wheel side active stabilizer 21 and the rear wheel side active stabilizer 22 do not hinder the displacement of the connected wheels in the vehicle vertical direction. In other words, a large resistance force is not applied following the displacement of the connected wheel.

  Therefore, for example, in a situation where only one wheel is greatly displaced in the vehicle vertical direction while the vehicle is traveling straight, the front wheel side active stabilizer 21 and the rear wheel side active stabilizer 22 are less likely to generate an anti-roll moment. Thereby, for example, the wheel on the side where the external force is input from the road surface can be easily displaced in the vertical direction of the vehicle, and the external force is input from the road surface to the wheel on the side where the external force is not input from the road surface. The influence of the displacement of the side wheel can be made difficult to be transmitted via the front wheel side active stabilizer 21 and the rear wheel side active stabilizer 22.

  Further, the absorber ECU 31 is a shock disposed on the wheel side that is largely displaced in the vehicle vertical direction in accordance with the situation in which the front wheel side active stabilizer 21 and the rear wheel side active stabilizer 22 generate a small roll rigidity under the control of the stabilizer ECU 32. The damping force of the absorbers 11 and 13 or the shock absorbers 12 and 14 is changed to a small damping force, and the damping force of the shock absorbers 12 and 14 or the shock absorbers 11 and 13 disposed on the other wheel side is changed to a large damping force. can do. Therefore, for example, the shock absorbers 11 and 13 or the shock absorbers 12 and 14 disposed on the side where the external force is input from the road surface can displace the wheel in the vertical direction of the vehicle very easily, and the external force is input from the road surface. The shock absorbers 12 and 14 or the shock absorbers 11 and 13 disposed on the side where the external force is not provided can satisfactorily suppress the roll of the vehicle body due to the large displacement of the wheel on the side where the external force is input from the road surface.

  Thus, the absorber ECU 31 and the stabilizer ECU 32 cooperate (cooperate) with each other to execute the change control of the damping force of the shock absorbers 11, 12, 13, and 14 and the change control of the roll stiffness of the active stabilizer device 20. Even in a situation where only one wheel of the vehicle is largely displaced in the vehicle vertical direction, the change in the posture of the vehicle can be suppressed satisfactorily. Furthermore, since the wheel can be displaced very easily, a good riding comfort can be ensured.

b. Second Embodiment In the first embodiment, the absorber ECU 31 executes acceleration control Gl, Gr (from the vertical acceleration sensors 33a to 33d assembled at the left and right front and rear wheel positions by executing the attitude control program. Specifically, based on the magnitude of the absolute value of acceleration Gfl, Gfr, Grl, Grr), in step S12, the stabilizer ECU 32 is instructed to execute ride comfort control, and in step S14, which of the left wheel or the right wheel is selected. It was carried out so as to determine whether or not the stroke was large. In contrast, the stroke amounts of the shock absorbers 11, 12, 13, and 14 are directly detected, and the posture control program is executed by using the stroke amounts of the shock absorbers 11, 12, 13, and 14. It is also possible. Hereinafter, although this 2nd Embodiment is described in detail, the same code | symbol is attached | subjected to the same part as the said 1st Embodiment, and the detailed description is abbreviate | omitted.

  In the second embodiment, as indicated by broken lines in FIGS. 1 and 2, instead of or in addition to the vertical acceleration sensors 33 a to 33 d of the first embodiment, the shock absorbers 11, 12, 13, and 14 Stroke sensors 38a, 38b, 38c, and 38d for detecting each stroke amount are provided. The stroke sensors 38a to 38d are assembled to the shock absorbers 11 to 14, detect the stroke amounts hfl, hfr, hrl, and hrr of the shock absorbers 11 to 14, and detect the stroke amounts hfl, hfr, hrl and hrr are output to the absorber ECU 31. The stroke sensors 38a to 38d detect the stroke amount from a reference stroke position set in advance in each shock absorber 11 to 14, for example, the stroke amount in the direction in which each shock absorber 11 to 14 contracts. Is detected as a positive value, and the stroke amount in the direction in which each shock absorber 11-14 extends is detected as a negative value.

  In the second embodiment, the absorber ECU 31 executes the attitude control program shown in FIG. The posture control program in the second embodiment is changed from step S11, step S12, and step S14 to step S20, step S21, and step S22, respectively, as compared to the posture control program of the first embodiment shown in FIG. Has been.

  That is, similarly to the first embodiment, the absorber ECU 31 starts execution of the attitude control program in step S10, and in step S20, the absorber ECU 31 is assembled to the stroke sensors 38a and 38c assembled to the left wheel and the right wheel. From the stroke sensors 38b and 38d, the stroke amounts hfl and hrl (in the following description, these stroke amounts are simply referred to as “stroke hl”) and the stroke amounts hfr and hrr (in the following description, these stroke amounts are simply referred to as “stroke”). Enter the stroke hr). Note that the stroke hl and the stroke hr can be implemented by adopting, for example, an average value of the stroke amounts hfl and hrl and an average value of the stroke amounts hfr and hrr.

  Subsequently, the absorber ECU 31 determines in step S21 whether or not a large stroke has occurred in either the left wheel or the right wheel of the vehicle. Specifically, the absorber ECU 31 determines whether or not the absolute value of the difference value between the absolute value of the stroke amount hl and the absolute value of the stroke amount hr input in step S20 is greater than a predetermined value β set in advance. Determine whether. That is, if the absolute value of the difference value is equal to or less than the predetermined value β, the absorber ECU 31 receives an input from the left wheel or the right wheel of the vehicle passing through, for example, a convex portion or a concave portion existing on the road surface. Therefore, it is determined as “No”, and the stroke amount hl and the stroke amount hr are input again in step S20.

  On the other hand, if the absolute value of the difference value is greater than the predetermined value β, the absorber ECU 31 determines that the result is “Yes” because the left wheel or the right wheel of the vehicle has received a large input, and the process proceeds to step S13. That is, in this case, the left wheel or the right wheel of the vehicle has a large stroke in the vertical direction in order to pass through the convex portion and the concave portion existing on the road surface. Then, the absorber ECU 31 instructs the stabilizer ECU 32 to execute the riding comfort control and acquires the transition signal, similarly to step S13 in the attitude control program of the first embodiment, the process proceeds to step S22.

  In step S22, the absorber ECU 31 determines which of the left wheel and the right wheel is making a large stroke. That is, the absorber ECU 31 compares the absolute value of the stroke hl input in step S20 with the absolute value of the stroke hr. If the absolute value of the stroke hl is larger than the absolute value of the stroke hr, the left wheel makes a large stroke. Therefore, “Yes” is determined. Then, the absorber ECU 31 proceeds to step S15 as in the first embodiment, changes the damping force of the shock absorbers 11 and 13 to be smaller than the damping force set during straight traveling, and the shock absorber 12 , 14 is changed so as to be larger than the damping force set during straight traveling.

  On the other hand, the absorber ECU 31 compares the absolute value of the stroke hl input in step S20 with the absolute value of the stroke hr. If the absolute value of the stroke hr is larger than the absolute value of the stroke hl, the right wheel makes a large stroke. Therefore, it is determined as “No”. Then, the absorber ECU 31 proceeds to step S16 as in the first embodiment, changes the damping force of the shock absorbers 12 and 14 to be smaller than the damping force set during straight traveling, and the shock absorber 11 , 13 is changed so as to be larger than the damping force set during straight traveling.

  As can be understood from the above description, also in the second embodiment, similarly to the first embodiment, the absorber ECU 31 and the stabilizer ECU 32 cooperate (cooperate) with each other, and the shock absorbers 11, 12, 13, By executing the control for changing the damping force 14 and the control for changing the roll rigidity of the active stabilizer device 20, the change in the posture of the vehicle is good even in a situation where only one wheel of the vehicle is greatly displaced in the vertical direction of the vehicle. Can be suppressed. Furthermore, since the wheel can be displaced very easily, a good riding comfort can be ensured.

  In carrying out the present invention, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the object of the present invention.

  For example, in the above embodiments, when the stabilizer ECU 32 controls the front wheel side active stabilizer 21 and the rear wheel side active stabilizer 22 to ride comfort, the actual torque Tf and the actual torque Tr detected by the torque sensor 34a and the torque sensor 34b are The electric actuator 21e and the electric actuator 22e were driven and controlled to be smaller than a preset small torque Ta. In this case, for example, the stabilizer ECU 32 may be configured to shut off the supply of electric power to the electric actuators 21e and 22e via the drive circuits 37a and 37b, that is, to enter an unlocked state.

  Thus, in the situation where the supply of electric power to the electric actuators 21e, 22e is interrupted (unlocked state), the torsion bars 21a, 21b of the front wheel side active stabilizer 21 and the torsion bars of the rear wheel side active stabilizer 22 22a and 22b can be in a state in which they can relatively freely rotate and displace via electric actuators 21e and 22e, respectively. For this reason, the torsion bar portions 21a and 21b and the torsion bar portions 22a and 22b can be freely rotationally displaced without generating torque in accordance with the stroke of the left wheel or the right wheel, so that the input from the road surface is shocked. It can be attenuated by the absorbers 11-14. Therefore, also in this case, the same effects as those in the above embodiments can be obtained.

  Moreover, in each said embodiment, when the absorber ECU31 changes the damping force of the shock absorbers 11-14, you may make it change the flow path diameter of the working fluid by rotary valve 11a-14a continuously, You may make it change a flow path diameter in steps. Moreover, when changing continuously, the flow path diameter of a working fluid may be changed linearly and may be changed nonlinearly. In any case, it is possible to reduce the damping force of the shock absorbers 11 and 13 or the shock absorbers 12 and 14 on the side where a large acceleration is generated by the input from the road surface or on the side where the stroke is large. The damping force of the shock absorbers 12 and 14 or the shock absorbers 11 and 13 can be increased. Therefore, the same effects as those in the above embodiments can be obtained.

  In each of the above embodiments, the shock absorbers 11, 12, 13, and 14 are all configured to be able to change the damping force. However, for example, only the shock absorbers 11 and 12 provided on the front wheel side or only the shock absorbers 13 and 14 provided on the rear wheel side can be implemented as a configuration in which the damping force can be changed. Moreover, in each said embodiment, it implemented so that the active stabilizer apparatus 20 might be comprised from the front-wheel side active stabilizer 21 and the rear-wheel side active stabilizer 22. FIG. However, the active stabilizer device 20 may be implemented as a configuration including, for example, only the front wheel side active stabilizer 21 or only the rear wheel side active stabilizer 22.

  Further, in each of the embodiments described above, the stabilizer ECU 32 has been illustrated as an example in which the electric actuators 21e and 22e are driven and controlled using the actual torques Tf and Tr detected by the torque sensors 34a and 34b. However, the drive control of the electric actuators 21e and 22e is not limited to the drive control using the detected actual torques Tf and Tr, and the drive control of the electric actuators 21e and 22e is performed by other drive control methods. It goes without saying that it is possible.

1 is a schematic diagram illustrating a configuration of a vehicle attitude control device common to embodiments of the present invention. It is a block diagram for demonstrating the structure of the electric control apparatus of FIG. It is a flowchart of the attitude | position control program performed by the absorber ECU of FIG. 3 is a graph for explaining ride comfort control by the stabilizer ECU of FIG. 2. It is a flowchart of the attitude | position control program which concerns on 2nd Embodiment of this invention and is performed by absorber ECU of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Damping force control apparatus 11, 12, 13, 14 ... Shock absorber, 11a, 12a, 13a, 14a ... Rotary valve, 20 ... Active stabilizer apparatus, 21 ... Front wheel side active stabilizer, 21a, 21b ... Torsion bar part, 21e ... Electric actuator, 22 ... Rear wheel side active stabilizer, 22a, 22b ... Torsion bar, 22e ... Electric actuator, 30 ... Electric controller, 31 ... Absorber ECU, 32 ... Stabilizer ECU, 33a-33d ... Vertical acceleration sensor, 34a, 34b ... torque sensor, 38a-38d ... stroke sensor, C ... attitude control device

Claims (3)

A damping force changing means for changing and controlling the damping force of the shock absorber disposed between the vehicle body and the left and right front and rear wheels, and a roll rigidity changing means for changing and controlling the roll rigidity of the stabilizer connecting the left and right wheels. Vehicle attitude control device
Physical quantity detection means for detecting physical quantities relating to displacement in the vehicle vertical direction of the left wheel of the vehicle and the right wheel of the vehicle;
Determining means for determining whether or not a difference value between the detected physical quantity of the left wheel and the detected physical quantity of the right wheel is larger than a predetermined value;
When it is determined that the difference value is larger than the predetermined value, the torsion bar forming the stabilizer rotates in accordance with the vertical displacement without inhibiting the vertical displacement of the connected wheel. Roll stiffness control means for controlling the roll stiffness change means;
A discriminating means for comparing the detected physical quantity of the left wheel and the detected physical quantity of the right wheel, and discriminating a wheel on the side of the left and right wheels that has a large displacement in the vehicle vertical direction;
Change the damping force of the shock absorber arranged on the wheel side with a large displacement in the vehicle vertical direction to a small damping force, and change the damping force of the shock absorber arranged on the wheel side with a small displacement in the vehicle vertical direction to a large damping force. A vehicle attitude control device comprising: damping force control means for controlling the damping force changing means for changing to In the vehicle attitude control device according to claim 1,
The physical quantity detection means includes
An attitude control device for a vehicle, which is provided at a position corresponding to the left and right front and rear wheels and detects an acceleration in a vehicle vertical direction at the same position as the physical quantity. In the vehicle attitude control device according to claim 1,
The physical quantity detection means includes
A vehicle attitude control device that detects a stroke amount of the shock absorber as the physical quantity.

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