JP2009208688A - Device and method for controlling damping force variable damper - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device for controlling a damping force variable damper can enhance the steering stability and the ride quality. <P>SOLUTION: When the roll damping force base value Drb is set in Step S15, a roll control unit 58 calculates the front wheel side mean value Gzfa by averaging the vertical accelerations Gzfr, Gzfl on the right and left front wheels side in Step S16. Next, the roll control unit 58 retrieves/sets the vehicle speed gain Gv from a map (not shown) based on the vehicle speed v in Step S17, and then, the front wheel side damping force correction value Dcf is calculated by multiplying the front wheel side mean value Gzfa with the vehicle speed gain Gv and the predetermined compensation gain in Step S18. Then, the roll control unit 58 calculates the front wheel side roll target damping force Drtf by subtracting the front wheel side damping force correction value Dcf from the roll damping force base value Drb in Step S19. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a control device and a control method for a damping force variable damper, and more particularly, to a technique for improving steering stability and ride comfort.

In recent years, various types of cylindrical dampers used in automobile suspensions have been developed that can variably control the damping force stepwise or steplessly in order to improve ride comfort and steering stability. In a vehicle equipped with a variable damping force damper (hereinafter simply referred to as a damper), steering stability and ride comfort are improved by variably controlling the damping force of the damper according to the running state of the vehicle. For example, when the vehicle is turning, the vehicle body rolls left and right due to the inertial force (lateral acceleration) that accompanies the lateral movement. In order to suppress excessive roll of the vehicle body at this time, depending on the differential value of the lateral acceleration, The target damping force is increased. In addition, when the vehicle is accelerating or decelerating, the vehicle body pitches due to the inertial force (longitudinal acceleration) that accompanies the longitudinal motion. In order to suppress the excessive pitch motion of the vehicle body at this time, the target of the damper is determined according to the differential value of the longitudinal acceleration. The damping force is increased. Furthermore, when traveling on rough roads with continuous small irregularities, the wheels move up and down in a short cycle, but in order to suppress transmission of the vertical movement of the wheels to the vehicle body (i.e., pushing up through the suspension). In other words, the target damping force of the damper is lowered according to the stroke speed of the damper (see Patent Document 1).
JP 2006-69527 A

  However, in the damping force control method of Patent Document 1, when the differential value of the lateral acceleration or the longitudinal acceleration is large (that is, the target damping force is high) during turning or acceleration / deceleration, there is unevenness on the road surface. However, the dampers are difficult to telescopically move, and there is a problem that ride comfort is deteriorated because most of the above mentioned things are not performed. Therefore, the present inventors have installed a vertical G sensor for detecting vertical acceleration in the vicinity of each wheel of the vehicle body (for example, a wheel house) in order to surely carry out thrusting when the target damping force is high. A method for reducing the damping force of each damper according to the detection results of these upper and lower G sensors was examined.

  However, even when this method is adopted, the damping force control device cannot determine whether the vertical acceleration of the vehicle body is due to road surface unevenness or the roll motion or pitch motion of the vehicle body. The problem described in the above occurred. For example, when the target damping force (roll target damping force or pitch target damping force) for suppressing roll motion or pitch motion is high, the amount of reduction of the target damping force due to boring (hereinafter referred to as boring load) Therefore, even if the vertical acceleration of the vehicle body due to the roll motion or the pitch motion is mistaken for the unevenness of the road surface, the posture does not change so much. However, when the roll target damping force and the pitch target damping force are low, the inertia load becomes relatively large. Therefore, if the vertical acceleration of the vehicle body due to the roll motion or pitch motion is mistaken as being due to road surface unevenness, the vehicle body rolls. During the movement or pitch movement, the target damping force suddenly decreases, and the roll speed or pitch speed increases and the driver may feel uncomfortable.

  The present invention has been made in view of such a background, and an object of the present invention is to provide a control device for a damping force variable damper that realizes improvement in handling stability and riding comfort.

  A first aspect of the present invention is a control device mounted on a vehicle having a damping force variable damper interposed between a vehicle body and a wheel, and used for damping force control of the damping force variable damper. Damping force base value setting means for setting a target damping force base value based on the state, vertical momentum detection means for detecting the vertical momentum of each wheel part, and damping force correction value based on the detection result of the vertical momentum detection means A correction value setting means for setting the target damping force by correcting the target damping force base value using the damping force correction value, and the correction value setting means When the vehicle body is rotating around a horizontal rotation axis, the damping force correction value is set based on the vertical momentum of the vehicle body at intermediate positions of the wheels positioned at both ends when viewed from the direction of the rotation axis. That features To.

  According to a second aspect of the invention, in the control device for a damping force variable damper according to the first aspect of the invention, the wheel part is a vehicle body or a wheel near the wheel.

  According to a third aspect of the present invention, in the damping force variable damper control device according to the first or second aspect of the invention, the correction value setting means includes a left and right wheel portion of the vertical movement amount detected by the vertical movement amount detection means. The average value on the side or the average value on the front and rear wheel parts side is calculated, the damping force correction value is set based on the average value, and the target damping force setting means is used for calculating the average value. On the side, the target damping force base value is corrected using the damping force correction value.

  The fourth invention is a control method of a damping force variable damper provided for suspension of a vehicle, wherein a process for setting a target damping force base value based on a motion state of the vehicle body, and a vertical movement of each wheel part A process for detecting momentum, a process for determining whether or not the vehicle is in a turning state, and when the vehicle body is rotating around a horizontal rotation axis, both ends are viewed from the direction of the rotation axis. The target damping force is set by correcting the target damping force base value using the damping force correction value and the processing for setting the damping force correction value based on the vertical momentum of the vehicle body at the intermediate position of the wheel located. And a process to perform.

  According to the first invention, for example, when the vehicle body is rotating around a horizontal rotation axis passing through the center of gravity, the average of the vertical momentum at the wheel portions located at both ends is zero, so that the target damping force is unnecessary. Sudden changes in posture due to excessive reduction are less likely to occur. According to the second invention, the vertical momentum of the vehicle body in the vicinity of the wheel can be detected by a vertical acceleration sensor or the like that is easy to install. On the other hand, when the vertical momentum of the wheel is used, control responsiveness can be improved. It becomes. According to the third invention, for example, when the vehicle body is rotated around the roll axis or the pitch axis by roll motion or pitch motion, the average of the vertical acceleration at the left and right wheel portions or the front and rear wheel portions is 0. Therefore, changes in roll speed and pitch speed due to unnecessary reduction of the target damping force are less likely to occur. According to the fourth aspect of the invention, for example, when the vehicle body is rotated around a horizontal rotation axis passing through the center of gravity, the average of the vertical momentum at the wheel portions located at both ends is 0, so the target damping force Sudden changes in posture due to unnecessary reduction of the height are less likely to occur.

  Hereinafter, two embodiments in which the present invention is applied to a four-wheeled vehicle will be described in detail with reference to the drawings.

[First Embodiment]
FIG. 1 is a schematic configuration diagram of a four-wheel vehicle according to the first embodiment, FIG. 2 is a longitudinal sectional view of a damper according to the first embodiment, and FIG. 3 is a diagram of the damping force control device according to the first embodiment. FIG. 4 is a block diagram illustrating a schematic configuration, and FIG. 4 is a block diagram illustrating a schematic configuration of a roll control unit according to the first embodiment.

<< Configuration of First Embodiment >>
<Schematic configuration of automobile>
First, a schematic configuration of an automobile according to an embodiment will be described with reference to FIG. In the description, for the four wheels and members arranged for them, that is, tires, suspensions, and the like, suffixes indicating front, rear, left, and right are attached to the reference numerals, for example, wheel 3fl (front left), wheel 3fr (front right), wheel 3rl (rear left), wheel 3rr (rear right) and collectively referred to as wheel 3, for example.

  As shown in FIG. 1, an automobile (vehicle) V includes four wheels 3 on which tires 2 are mounted. Each wheel 3 includes a suspension arm, a spring, an MRF variable damping force variable damper (hereinafter simply referred to as a damper). It is suspended on the vehicle body 1 by a suspension 5 consisting of 4 etc. The vehicle V is provided with an ECU (Electronic Control Unit) 7 and an EPS (Electric Power Steering) 8 which are the control body of the suspension system. Further, the vehicle V includes a vehicle speed sensor 9 for detecting the vehicle speed, a lateral G sensor 10 for detecting lateral acceleration, a longitudinal G sensor 11 for detecting longitudinal acceleration, a yaw rate sensor 12 for detecting yaw rate, and the like installed at appropriate positions on the vehicle body 1. In addition, a stroke sensor 13 for detecting the displacement of the damper 4 and a vertical G sensor (vertical momentum detecting means) 14 for detecting vertical acceleration in the vicinity of the wheel house in the vehicle body 1 are installed for each wheel 3.

  The ECU 7 includes a microcomputer, ROM, RAM, peripheral circuit, input / output interface, various drivers, and the like, and the damper 4 of each wheel 3 via a communication line (CAN (Controller Area Network in this embodiment)). And each sensor 9-14.

<Damper structure>
As shown in FIG. 2, the damper 4 of the present embodiment is a monotube type (de carvone type), and a cylindrical cylinder tube 21 filled with MRF and an axial direction with respect to the cylinder tube 21. A piston rod 22 that slides, a piston 26 that is attached to the tip of the piston rod 22 and divides the inside of the cylinder tube 21 into an upper oil chamber 24 and a lower oil chamber 25, and a high-pressure gas chamber 27 under the cylinder tube 21. The main components are a defined free piston 28, a cover 29 for preventing dust from adhering to the piston rod 22 and the like, and a bump stop 30 for buffering at the time of full bound.

  The cylinder tube 21 is connected to the upper surface of the trailing arm 35 that is a wheel side member via a bolt 31 that is fitted into the eyepiece 21a at the lower end. The piston rod 22 has a pair of upper and lower bushes 36 and a nut 37, and a stud 22a at the upper end thereof is connected to a damper base (upper part of the wheel house) 38 which is a vehicle body side member.

  As shown in FIG. 3, the piston 26 is provided with an annular communication passage 39 that communicates the upper oil chamber 24 and the lower oil chamber 25, and an MLV coil 40 that is disposed inside the annular communication passage 39. Yes. When an electric current is supplied from the ECU 7 to the MLV coil 40, a magnetic field is applied to the MRF flowing through the annular communication path 39, and the ferromagnetic fine particles form a chain cluster, and the appearance of the MRF passing through the annular communication path 39. The upper viscosity increases.

<Damping force control device>
The ECU 7 includes a damping force control device 50 whose schematic configuration is shown in FIG. The damping force control device 50 is a damping force setting for setting the target damping force of each damper 4 based on the input interface 51 to which the above-described sensors 9 to 14 and the like are connected and the detection signals input from the sensors 9 to 12 and 14 etc. Unit 52, a drive current generation unit 53 that generates a drive current to each damper 4 (MLV coil 40) according to the target damping force and the detection result of the stroke sensor 13, and a drive current generated by the drive current generation unit 53 Is output to each damper 4. The damping force setting unit 52 accommodates a skyhook control unit 57 used for skyhook control, a roll control unit 58 used for roll control, and a pitch control unit 59 used for pitch control. .

<Roll control unit>
As shown in FIG. 4, the roll controller 58 includes a front wheel side target damping force setting unit 60f and a rear wheel side target damping force setting unit 60r. Both the target damping force setting units 60f and 60r have the same configuration. When describing the front wheel side target damping force setting unit 60f, the vehicle speed v input from the vehicle speed sensor 9 and the lateral acceleration Gy input from the lateral G sensor 10 are described. And a roll control base value setting unit 61 that sets a front wheel side roll control base value Drbf based on the yaw rate γ input from the yaw rate sensor 12, and vertical accelerations Gzfl and Gzfr input from the vertical G sensors 14fl and 14fr on the left and right front wheels. A phase compensation unit 62 that compensates the phase of the vehicle, a left-right average unit 63 that calculates an average value of the vertical accelerations Gzfl and Gzfr (front wheel side average value Gzfa), and a vehicle speed gain setting that sets the vehicle speed gain Gv based on the vehicle speed v. Part 64, correction value setting for setting front wheel side damping force correction value Dcf based on front wheel side average value Gzfa and vehicle speed gain Gv 65, and a target damping force setting unit 66 for setting the front-wheel-side roll target damping force Drtf by correcting the front-wheel-side roll control base value Drbf front wheel side damping force correction value Dcf.

<Pitch control unit>
As shown in FIG. 5, the pitch control unit 59 includes a left wheel side target damping force setting unit 70l and a right wheel side target damping force setting unit 70r. Both the target damping force setting units 70l and 70r have the same configuration. When the left wheel side target damping force setting unit 70l is described, the vehicle speed v input from the vehicle speed sensor 9 and the longitudinal acceleration Gx input from the longitudinal G sensor 11 are described. The pitch control base value setting unit 71 that sets the left wheel side pitch control base value Dpbl based on the above and the phase compensation unit 72 that compensates the phases of the vertical accelerations Gzfl and Gzrl input from the front and rear left wheel side vertical G sensors 14fl and 14rl. A left / right average unit 73 that calculates an average value (left wheel side average value Gzla) of both vertical accelerations Gzfl and Gzrl, a vehicle speed gain setting unit 74 that sets a vehicle speed gain Gv based on the vehicle speed v, and a left wheel side average value Gzla And a correction value setting unit 75 for setting a left wheel side damping force correction value Dcl based on the vehicle speed gain Gv, and a left wheel side pitch control base value Dpbl And a target damping force setting unit 76 for setting the left-wheel-side pitch target damping force Dptl by correcting the left-wheel-side damping force correction value Dcl.

<< Operation of First Embodiment >>
<Damping force control>
When the automobile starts running, the damping force control device 50 executes damping force control whose procedure is shown in the flowchart of FIG. 6 at a predetermined processing interval (for example, 2 ms). When the damping force control is started, the damping force control device 50 detects each acceleration of the vehicle body 1 obtained from the lateral G sensor 10, the longitudinal G sensor 11, and the vertical G sensor 14 in step S1 of FIG. The motion state of the vehicle V is determined based on the vehicle speed input from the vehicle, the steering speed input from the steering angle sensor (not shown), and the like. Next, the damping force control device 50 calculates the skyhook target damping force Dst of each damper 4 in step S2 based on the motion state of the vehicle V, and calculates the roll target damping force Drt of each damper 4 in step S3. In step S4, the pitch target damping force Dpt of each damper 4 is calculated.

  Next, the damping force control device 50 determines whether or not the stroke speed Ss of each damper 4 is a positive value in step S5, and if this determination is Yes (that is, the damper 4 is on the extension side). In the case of operation), the largest one of the three target damping forces Dst, Drt, Dpt is selected as the target damping force Dtgt in step S6. In addition, when the determination in step S5 is No (that is, when the damper 4 is operating on the contraction side), the damping force control device 50 determines that among the three target damping forces Dst, Drt, and Dpt in step S7. The smallest value is selected as the target damping force Dtgt.

  When the target damping force Dtgt is determined in step S6 or step S7, the damping force control device 50 searches / sets the target current Itgt corresponding to the target damping force Dtgt and the stroke speed Ss from the target current map of FIG. 7 in step S8. Thereafter, a drive current is output to the MLV coil 40 of each damper 4 in step S9.

<Roll target damping force setting process>
In parallel with the damping force control described above, the roll control unit 58 in the damping force control apparatus 50 repeatedly executes a roll target damping force setting process whose procedure is shown in the flowchart of FIG. 8 at a predetermined processing interval. Hereinafter, although the procedure for setting the roll target damping force on the left and right front wheels will be described, the roll target damping force on the left and right rear wheels is set in the same procedure.

  When the roll target damping force setting process is started, the roll control unit 58 calculates a differential value (hereinafter referred to as a lateral acceleration differential value) Gy ′ of the lateral acceleration Gy input from the lateral G sensor 10 in step S11 of FIG. In step S12, the first roll reference value Drf1 is retrieved / set using the lateral acceleration-damping force map of FIG.

  Next, the roll control unit 58 calculates the yaw rate second-order differential value γ ″ (lateral acceleration of the axle position) by second-order differentiation of the yaw rate γ input from the yaw rate sensor 12 in step S13, and then in step S14. The second roll reference value Drf2 is retrieved / set from the yaw rate-damping force map of Fig. 10. Next, in step S15, the roll control unit 58 multiplies the second roll reference value Drf2 by a predetermined yaw rate gain to obtain the first value. The roll damping force base value Drb is set by adding to the roll reference value Drf1 and further multiplying the vehicle speed gain retrieved / set from a map (not shown) based on the vehicle speed v.

  When the roll damping force base value Drb is set in step S15, the roll control unit 58 calculates the front wheel side average value Gzfa by averaging the vertical accelerations Gzfl and Gzfr on the left and right front wheels side in step S16. Next, after searching / setting the vehicle speed gain Gv from a map (not shown) based on the vehicle speed v in step S17, the roll control unit 58 sets the vehicle speed gain Gv and a predetermined compensation gain to the front wheel side average value Gzfa in step S18. By multiplying, the front wheel side damping force correction value Dcf is calculated. Next, the roll control unit 58 calculates the front wheel side roll target damping force Drtf by subtracting the front wheel side damping force correction value Dcf from the roll damping force base value Drb in step S19.

  As shown in FIG. 11A, when the vehicle V starts a roll motion around the roll axis Ar by turning, the vertical acceleration Gzfl on the left front wheel 3fl side and the vertical acceleration Gzfr on the right front wheel 3fr side are large in magnitude. Since the values are the same and have different signs, the front wheel side average value Gzfa (that is, the front wheel side damping force correction value Dcf) is zero. In this case, when the roll target damping force Drt is selected as the target damping force Dtgt in the damping force control, the front wheel side roll target damping force Drtf is not reduced. Can be suppressed.

  On the other hand, as shown in FIG. 11B, when only one wheel (left front wheel 3fl in the figure) rides on the step 81 during turning, the vertical acceleration Gzfl acts on the left front wheel 3fl side, but the right front wheel 3fr The vertical acceleration does not act on the side, and the front wheel side average value Gzfa is ½ of the vertical acceleration Gzfl on the left front wheel 3fl side. In this case, when the roll target damping force Drt is selected as the target damping force Dtgt in the damping force control, the front wheel-side roll target damping force Drtf is reduced to some extent, so that the impact when riding on the step 81 is mitigated. This makes it possible to achieve both a reduction in roll motion and a ride comfort.

  On the other hand, as shown in FIG. 11C, when the left and right front wheels 3fl and 3fr ride on the step 81 at the same time during turning, the vertical accelerations Gzfl and Gzfr of the same magnitude act on the left and right front wheels 3fl and 3fr. The side average value Gzfa is the same value as the vertical accelerations Gzfl and Gzfr. In this case, when the roll target damping force Drt is selected as the target damping force Dtgt in the damping force control, the front wheel side roll target damping force Drtf is greatly reduced, so that the impact when riding on the step 81 is effective. By being relaxed, good ride comfort is ensured.

<Pitch target damping force setting process>
In parallel with the damping force control described above, the pitch control unit 59 in the damping force control device 50 repeatedly executes a pitch target damping force setting process whose procedure is shown in the flowchart of FIG. 12 at a predetermined processing interval. Hereinafter, although the procedure for setting the pitch target damping force on the left front and rear wheels side will be described, the pitch target damping force on the right front and rear wheels side is set in the same procedure.

  When the pitch target damping force setting process is started, the pitch control unit 59 calculates a differential value (hereinafter referred to as a longitudinal acceleration differential value) Gx ′ of the longitudinal acceleration Gx input from the longitudinal G sensor 11 in step S21 of FIG. In step S22, the pitch reference value Dpf is retrieved / set using the longitudinal acceleration-damping force map of FIG.

  Next, in step S23, the pitch controller 59 sets the pitch damping force base value Dpb by multiplying the pitch reference value Dpf by the vehicle speed gain set based on the vehicle speed v.

  When the pitch damping force base value Dpb is set in step S23, the pitch control unit 59 calculates the left wheel side average value Gzla by averaging the vertical accelerations Gzfl and Gzrl on the left front and rear wheels side in step S24. Next, after searching / setting the vehicle speed gain Gv from a map (not shown) based on the vehicle speed v in step S25, the pitch control unit 59 sets the vehicle speed gain Gv and a predetermined compensation gain to the left wheel side average value Gzla in step S26. By multiplying, the left wheel side damping force correction value Dcl is calculated. Next, the pitch control unit 59 calculates the left wheel side pitch target damping force Dptl by subtracting the left wheel side damping force correction value Dcl from the pitch damping force base value Dpb in step S27.

  As shown in FIG. 14 (a), when the vehicle V starts to decelerate and pitches forward about the pitch axis Ap, the vertical acceleration Gzfl on the left front wheel 3fl side and the vertical acceleration Gzrl on the left rear wheel 3rl side are magnitudes. Are the same and the signs are different from each other, the left wheel side average value Gzla (that is, the left wheel side damping force correction value Dcl) is zero. In this case, when the pitch target damping force Dpt is selected as the target damping force Dtgt in the damping force control, the left wheel side pitch target damping force Dptl is not reduced. Can be suppressed.

  On the other hand, as shown in FIG. 14B, when only one wheel (left front wheel 3fl in the figure) falls on the step 81 during deceleration, the vertical acceleration Gzfl acts on the left front wheel 3fl side, but the left rear wheel 3rl. The vertical acceleration does not act on the side, and the left wheel side average value Gzla is a value half that of the vertical acceleration Gzfl on the left front wheel 3fl side. In this case, when the pitch target damping force Dpt is selected as the target damping force Dtgt in the damping force control, the left wheel side pitch target damping force Dptl is reduced to some extent, so that the impact when falling into the step 81 is mitigated. This makes it possible to control both pitch movement and ride comfort.

  On the other hand, as shown in FIG. 14C, when the left and right front wheels 3fl and 3fr simultaneously fall on the steps 81 and 82 during deceleration, vertical accelerations Gzfl and Gzrl of the same magnitude act on the left front and rear wheels 3fl and 3rl. The left wheel side average value Gzla is the same value as the vertical accelerations Gzfl and Gzrl. In this case, when the pitch target damping force Dpt is selected as the target damping force Dtgt in the damping force control, the left wheel side pitch target damping force Dptl is greatly reduced. A good ride comfort is ensured by effectively mitigating.

[Second Embodiment]
FIG. 15 is a block diagram illustrating a schematic configuration of the roll control unit according to the second embodiment, and FIG. 16 is a block diagram illustrating a schematic configuration of the pitch control unit according to the second embodiment. The second embodiment is different from the first embodiment described above because only the configuration of the roll control unit and the pitch control unit, the roll target damping force setting process, and the pitch target damping force setting process are different. Description is omitted.

<Roll control unit>
As shown in FIG. 15, the roll control unit 58 of the second embodiment also includes a front wheel side target damping force setting unit 60f and a rear wheel side target damping force setting unit 60r. Both the target damping force setting units 60f and 60r have the same configuration. When describing the front wheel side target damping force setting unit 60f, the vehicle speed v input from the vehicle speed sensor 9 and the lateral acceleration Gy input from the lateral G sensor 10 are described. And a roll control base value setting unit 61 for setting a left front wheel side roll control base value Drbfl and a right front wheel side roll control base value Drbfr based on the yaw rate γ input from the yaw rate sensor 12, and a vertical G sensor 14fl on the left and right front wheels side , 14fr based on the phase compensation unit 62 that compensates the phase of the vertical accelerations Gzfl, Gzfr, the left / right average unit 63 that calculates the average value (front wheel side average value Gzfa) of both the vertical accelerations Gzfl, Gzfr, and the vehicle speed v. Vehicle speed gain setting unit 64 for setting vehicle speed gain Gv, front wheel side average value Gzfa, vehicle speed gain Gv, and roll control A correction value setting unit 65 for setting a left front wheel side damping force correction value Dcfl and a right front wheel side damping force correction value Dcfr based on the code signal Sgn input from the base value setting unit 61, and a left and right front wheel side roll control base value Drbfl , Drbfr is corrected with left and right front wheel side damping force correction values Dcfl and Dcfr, respectively, and a target damping force setting unit 66 for setting left and right front wheel side roll target damping forces Drtfl and Drtfr is provided.

<Pitch control unit>
As shown in FIG. 16, the pitch control unit 59 of the second embodiment also includes a left wheel side target damping force setting unit 70l and a right wheel side target damping force setting unit 70r. Both the target damping force setting units 70l and 70r have the same configuration. When the left wheel side target damping force setting unit 70l is described, the vehicle speed v input from the vehicle speed sensor 9 and the longitudinal acceleration Gx input from the longitudinal G sensor 11 are described. And a vertical acceleration Gzfl input from the pitch control base value setting unit 71 for setting the left front wheel side pitch control base value Dpbfl and the left rear wheel side pitch control base value Dpbrl, and the vertical G sensors 14fl and 14rl on the front and rear left wheels. , Gzrl, a phase compensation unit 72 for compensating the phase, a left / right average unit 73 for calculating an average value (left wheel side average value Gzla) of both vertical accelerations Gzfl, Gzrl, and a vehicle speed for setting the vehicle speed gain Gv based on the vehicle speed v Based on the gain setting unit 74, the left wheel average value Gzla, and the vehicle speed gain Gv, the left front wheel damping force correction value Dcfl and the left rear wheel The left front / rear wheel side pitch target is obtained by correcting the left front / rear wheel side pitch control base values Dpbfl, Dpbrl with the left front / rear wheel side damping force correction values Dcfl, Dcrl, respectively, for setting the damping force correction value Dcrl. And a target damping force setting unit 76 for setting damping forces Dptfl and Dptrl.

<Roll target damping force setting process>
In parallel with the damping force control described above, the roll control unit 58 in the damping force control apparatus 50 repeatedly executes a roll target damping force setting process whose procedure is shown in the flowchart of FIG. 17 at a predetermined processing interval. Hereinafter, although the procedure for setting the roll target damping force on the left and right front wheels will be described, the roll target damping force on the left and right rear wheels is set in the same procedure.

  When the roll target damping force setting process is started, the roll control unit 58 calculates a differential value (hereinafter referred to as a lateral acceleration differential value) Gy ′ of the lateral acceleration Gy input from the lateral G sensor 10 in step S31 of FIG. In step S32, the first roll base value Drb1 is retrieved / set using the lateral acceleration-damping force map of FIG.

  Next, the roll controller 58 calculates the yaw rate second-order differential value γ ″ (lateral acceleration of the axle position) by second-order differentiation of the yaw rate γ input from the yaw rate sensor 12 in step S33, and then in step S34. The second roll base value Drb2 is retrieved / set from the yaw rate-damping force map of Fig. 10. Next, in step S35, the roll control unit 58 multiplies the second roll base value Drb2 by a predetermined yaw rate gain to obtain the first value. It is added to the roll base value Drb1, multiplied by a vehicle speed gain retrieved / set from a map (not shown) based on the vehicle speed v, and the left front wheel-side roll control base value Drbfl and the right front wheel according to the sign of the lateral acceleration differential value Gy ′ A side roll control base value Drfr is set.

  When the left and right front wheel side roll damping force base values Drbfl and Drbfr are set in step S35, the roll control unit 58 calculates the front wheel side average value Gzfa by averaging the vertical accelerations Gzfl and Gzfr on the left and right front wheels in step S36. To do. Next, after searching / setting the vehicle speed gain Gv from a map (not shown) based on the vehicle speed v in step S37, the roll control unit 58 sets the vehicle speed gain Gv and a predetermined compensation gain to the front wheel side average value Gzfa in step S38. Further, the left and right front wheel damping force correction values Dcfl and Dcfr are calculated according to the sign Sgn of the lateral acceleration differential value Gy ′ input from the roll control base value setting unit 61. Next, in step S39, the roll control unit 58 calculates the left front wheel side roll target damping force Drtfl by subtracting the left front wheel side damping force correction value Dcfl from the left front wheel side roll control base value Drbfl, and the right front wheel side roll. The right front wheel side roll target damping force Drtfr is calculated by subtracting the right front wheel side damping force correction value Dcfr from the control base value Drbfr.

<Pitch target damping force setting process>
In parallel with the damping force control described above, the pitch control unit 59 in the damping force control device 50 repeatedly executes a pitch target damping force setting process whose procedure is shown in the flowchart of FIG. 18 at a predetermined processing interval. Hereinafter, although the procedure for setting the pitch target damping force on the left front and rear wheels side will be described, the pitch target damping force on the right front and rear wheels side is set in the same procedure.

  When the pitch target damping force setting process is started, the pitch control unit 59 calculates a differential value (hereinafter referred to as a longitudinal acceleration differential value) Gx ′ of the longitudinal acceleration Gx input from the longitudinal G sensor 11 in step S41 of FIG. In step S42, the pitch reference value Dpf is retrieved / set using the longitudinal acceleration-damping force map of FIG.

  Next, in step S43, the pitch control unit 59 multiplies the pitch reference value Dpf by the vehicle speed gain set based on the vehicle speed v, thereby obtaining the left front wheel side pitch damping force base value Dpbfl and the left rear wheel side pitch attenuation. Force base value Dpbrl is set.

  When the left front and rear wheel side pitch damping force base values Dpbfl and Dpbrl are set in step S24, the pitch control unit 59 averages the left front and rear wheel side vertical accelerations Gzfl and Gzrl in step S44, thereby obtaining the left wheel side average value Gzla. Is calculated. Next, after searching / setting the vehicle speed gain Gv from a map (not shown) based on the vehicle speed v in step S45, the pitch control unit 59 sets the vehicle speed gain Gv and a predetermined compensation gain to the left wheel side average value Gzla in step S46. By multiplying them, the left front and rear wheel side damping force correction values Dcfl and Dcrl are calculated. Next, in step S47, the pitch control unit 59 calculates the left front wheel side pitch target damping force Dptfl by subtracting the left front wheel side damping force correction value Dcfl from the left front wheel side pitch damping force base value Dpbfl, and the left rear wheel. The left rear wheel side pitch target damping force Dptrl is calculated by subtracting the left rear wheel side damping force correction value Dcrl from the side pitch damping force base value Dpbrl.

  The operation / effect of the second embodiment is substantially the same as that of the first embodiment described above, but the left and right front wheel-side roll target damping forces Drtfl and Drtfr are set individually, so that the roll motion and pitch motion are suppressed and the ride comfort is reduced. Can be achieved at a higher level.

  Although description of specific embodiment is finished above, the aspect of the present invention is not limited to the above embodiment. For example, in the above-described embodiment, the present invention is applied to the roll target damping force setting process and the pitch target damping force setting process, but the damping force correction value is set based on the average value of the vertical accelerations of all wheel parts. You may do it. In addition, as long as it does not deviate from the gist of the present invention, the specific configuration of the automobile and the control device, the specific procedure of control, and the like can be appropriately changed.

1 is a schematic configuration diagram of a four-wheeled vehicle according to a first embodiment. It is a longitudinal section of the damper concerning a 1st embodiment. It is a block diagram which shows schematic structure of the damping-force control apparatus which concerns on 1st Embodiment. It is a block diagram which shows schematic structure of the roll control part which concerns on 1st Embodiment. It is a block diagram which shows schematic structure of the pitch control part which concerns on 1st Embodiment. It is a flowchart which shows the procedure of damping force control which concerns on 1st Embodiment. 3 is a target current map according to the first embodiment. It is a flowchart which shows the procedure of the roll target damping force setting process which concerns on 1st Embodiment. 3 is a lateral acceleration-damping force map according to the first embodiment. It is a yaw rate-damping force map concerning a 1st embodiment. It is explanatory drawing which shows the effect | action at the time of the roll exercise | movement which concerns on 1st Embodiment. It is a flowchart which shows the procedure of the pitch target damping force setting process which concerns on 1st Embodiment. It is a longitudinal acceleration-damping force map concerning a 1st embodiment. It is explanatory drawing which shows the effect | action at the time of the pitch exercise | movement which concerns on 1st Embodiment. It is a block diagram which shows schematic structure of the roll control part which concerns on 2nd Embodiment. It is a block diagram which shows schematic structure of the pitch control part which concerns on 2nd Embodiment. It is a flowchart which shows the procedure of the roll target damping force setting process which concerns on 2nd Embodiment. It is a flowchart which shows the procedure of the pitch target damping force setting process which concerns on 2nd Embodiment.

Explanation of symbols

1 Body 3 Wheel 4 Damper 7 ECU
10 lateral G sensor 11 longitudinal G sensor 12 yaw rate sensor 14 vertical G sensor (vertical momentum detection means)
50 Damping Force Control Device 58 Roll Control Unit 59 Pitch Control Unit V Automobile

Claims (4)

A control device mounted on a vehicle in which a damping force variable damper is interposed between a vehicle body and a wheel, and used for damping force control of the damping force variable damper,
Damping force base value setting means for setting a target damping force base value based on the motion state of the vehicle body;
Up and down momentum detecting means for detecting up and down momentum of each wheel part;
Correction value setting means for setting a damping force correction value based on the detection result of the vertical momentum detection means;
A target damping force setting means for setting a target damping force by correcting the target damping force base value using the damping force correction value;
When the vehicle body is rotated about a horizontal rotation axis, the correction value setting means is configured to reduce the damping based on the vertical momentum of the vehicle body at intermediate positions of wheels positioned at both ends when viewed from the direction of the rotation axis. A control device for a damping force variable damper, wherein a force correction value is set.   2. The damping force variable damper control device according to claim 1, wherein the wheel part is a vehicle body or a wheel in the vicinity of the wheel. The correction value setting means calculates an average value on the left and right wheel parts side or an average value on the front and rear wheel parts side among the vertical movement amounts detected by the vertical movement amount detection means, and the damping force correction based on the average value Set the value
The target damping force setting means corrects the target damping force base value using the damping force correction value for a wheel part side used for the calculation of the average value. The control device for a damping force variable damper according to claim 2. A control method of a damping force variable damper provided for suspension of a vehicle,
A process of setting a target damping force base value based on the motion state of the vehicle body;
Processing to detect the vertical momentum of each wheel part;
A process for determining whether or not the vehicle is turning.
A process of setting a damping force correction value based on the vertical momentum of the vehicle body at intermediate positions of wheels positioned at both ends when viewed from the direction of the rotation axis when the vehicle body is rotating about a horizontal rotation axis; ,
And a process for setting the target damping force by correcting the target damping force base value using the damping force correction value.

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