JP3173313B2 - Suspension control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a suspension control device for controlling suspension characteristics such as damping force using a step motor.

[0002]

2. Description of the Related Art A conventional suspension control device is disclosed in, for example, Japanese Patent Application Laid-Open No. 3-42319. In this conventional example, by inputting a control signal,
A shock absorber that can change the extension-side damping force and the compression-side damping force to at least a low damping force and a high damping force by adjusting the throttle opening with a rotary actuator such as a step motor, and a spring that measures the sprung speed. An upper speed measuring means, a relative speed measuring means for measuring a relative speed between sprung and unsprung, a sign judging means for judging whether or not the sign of the sprung speed and the sign of the relative speed are coincident; When they match and the sign of the relative speed is positive, the extension side is set to high damping force and the compression side is set to low damping force.When both signs match and the sign of the relative speed is negative, A control signal output means for outputting a control signal for making the damping force low on the pressure side and a high damping force for the pressure side, and outputting a control signal for making both the compression side and the compression side have a low damping force when both codes do not match. It has the structure provided with.

[0003]

In the above-mentioned conventional suspension control device, the rotational position of the actuator cannot be detected when the ignition switch is turned off. This is used. However, when a large input is applied to the vehicle body when the ignition switch is turned off and a large input is applied to the vehicle body due to loading or unloading of the load and a high pressure is generated in the shock absorber, the actuator may be rotated by this pressure. Since the rotational position of the actuator that is present deviates from the actual rotational position, and the actuator control performance deteriorates, it is necessary to perform control origin calibration (initialization) of the rotary actuator at the start of control.

When performing the control origin calibration, usually,
It is necessary to make the engaging piece that rotates integrally with the rotary actuator contact the stopper that represents the control origin several times, and the operation sound of the actuator, the contact sound between the engaging piece and the stopper, and the noise due to the vibration are generated. In other words, since this noise gives the occupant an unpleasant sensation, the control origin calibration is performed when the road noise becomes greater than the vehicle speed at which the road noise becomes large, thereby suppressing the occupant from being uncomfortable.

However, when the actuator needs to be replaced at a maintenance shop or the like due to a failure of the actuator, for example, the control position of the actuator before the replacement may be largely different from that of the actuator after the replacement. If the vehicle is passed to the car owner without giving an opportunity to configure the control origin of the actuator, the ignition switch will be turned on and the vehicle will run, and until the vehicle speed exceeds the set vehicle speed, the control origin will be out of order and the actuator control will continue Therefore, there is a problem that the owner of the vehicle may feel uncomfortable that the control performance of the suspension is deteriorated despite repair at the maintenance shop.

Accordingly, the present invention has been made in view of the above-mentioned unresolved problems of the prior art, and performs control origin calibration at an early stage when at least one of the actuator and the control means is replaced. It is another object of the present invention to provide a suspension control device capable of maintaining a good control performance of a suspension.

[0007]

In order to achieve the above object, a suspension control device according to the first aspect of the present invention comprises:
As shown in the basic configuration diagram of FIG. 1A, the rotation of a valve body is controlled by a step motor interposed between a vehicle body-side member and a wheel-side member and driven according to an input control signal. And an actuator capable of individually controlling the suspension characteristics, and control means for detecting a change in the attitude of the vehicle body and outputting the control signal corresponding to the detected value of the attitude change to the step motor to perform drive control. In the control device, a vehicle speed detecting means for detecting a vehicle speed; a control origin calibrating means for calibrating the control origin of the step motor by the control means when a vehicle speed detection value of the vehicle speed detecting means reaches a set vehicle speed; Is the device normal?
Calibration state detection means for detecting whether or not the control origin calibration has been performed by the control origin calibration means after performing a self-diagnosis of whether or not the control origin calibration means, and the control origin calibration means, At the start of the control, when the calibration state detecting means detects that it is before the control origin calibration, it is configured to perform the control origin calibration regardless of the vehicle speed detection value of the vehicle speed detection means. I have.

A suspension control device according to a second aspect of the present invention has a basic structure as shown in FIG.
An actuator capable of individually controlling suspension characteristics by controlling rotation of a valve body by a stepping motor interposed between a vehicle body-side member and a wheel-side member and driven in accordance with an input control signal; A vehicle speed detecting means for detecting a vehicle speed, comprising a control means for detecting a change in attitude of the vehicle and outputting the control signal corresponding to the detected value of the attitude change to the step motor and performing open loop control; Control origin calibration means for performing control origin calibration of the step motor by the control means when a vehicle speed detection value of the vehicle speed detection means reaches a set vehicle speed;
Control position storage means for storing and holding the control position of the step motor at the end of control by the control means; and control origin calibration by the control origin calibration means after performing self-diagnosis as to whether or not each control device is normal. Calibration state detection means for detecting whether or not to perform, and holding the result, the control origin calibration means, at the start of control by the control means,
When the control position is not stored in the control position storage means, and when the control position is stored and the calibration state detection means detects that the control origin is not yet calibrated, the vehicle speed detection value of the vehicle speed detection means is used. It is characterized in that control origin calibration is performed irrespective of this.

[0009]

According to the first aspect of the present invention, the calibration state detecting means detects whether or not the control origin has been calibrated after performing self-diagnosis of whether or not each control device is normal . Therefore, in the normal traveling state, the control origin calibration is performed when the set vehicle speed is reached by the control origin calibration means, so that the detection result of the calibration state detection means is the control origin calibration completed state,
Thereafter, when the control is started after the vehicle is stopped and the control is terminated, the control origin calibration is performed only when the set vehicle speed becomes abnormal. However, each control device is normal
If the control is completed without performing the control origin calibration by the control origin calibration means after performing the self-diagnosis of whether or not the calibration origin detection means is in the control origin calibration incomplete state, and the next time control is started The calibration of the control origin is performed immediately.

According to the second aspect of the invention, when the control of the actuator by the control means is completed, the control position at that time is stored and held in the control position storage means, and when the control is started next time, the control position storage means stores the control position. When the control position is not stored and held, the control origin is immediately calibrated by the control origin calibrating means. When the control position is stored and held, the same operation as in the first aspect is performed.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 2 is a schematic configuration diagram showing one embodiment of the present invention, in which variable damping force shock absorbers 3FL to 3RR as actuators constituting a suspension device are arranged between the wheels 1FL to 1RR and the vehicle body 2, respectively. The step motors 41FL to 41RR for switching the damping force of these variable damping force shock absorbers 3FL to 3RR are controlled by a control signal from a controller 4 described later.

Variable damping force shock absorber 3FL-3RR
Is a twin-tube gas-filled strut type having a cylinder tube 7 composed of an outer cylinder 5 and an inner cylinder 6 as shown in FIGS. 8 define upper and lower pressure chambers 9U and 9L. 4 to 7, the piston 8 has a cylindrical lower half 11 having a sealing member 9 molded on the outer peripheral surface thereof in sliding contact with the inner cylinder 6 and having a center opening 10 on the inner peripheral surface. The lower half 11 has an upper half 12 fitted therein.

The lower half body 11 has an extension oil passage 13 penetrating vertically and a sealing member 9 extending downward from the upper surface side.
The hole 14 a having a diameter larger than that of the extension-side oil flow path 13 and extending from the outer peripheral surface of the cylindrical body 11 to the hole 14.
a, a pressure-side oil flow path 14 formed of a hole 14b drilled in communication with the bottom of the hole a, annular grooves 15U, 15L formed at the upper and lower open ends of the central hole 10, and formed on the upper surface side. A long groove 16 communicating with the annular groove 15U and the expansion-side oil flow path 13 and a long groove 17 formed on the lower surface side and communicating with the annular groove 15L are formed. The long groove 17 is closed by the extension-side disk valve 18, and the upper end side of the compression-side oil flow path 14 is closed by the compression-side disk valve 19.

The upper half 12 has a small-diameter shaft portion 21 inserted into the center opening 10 of the lower half body 11 and the shaft portion 2.
The lower end face of the small-diameter shaft portion 21 is formed at the center of the small-diameter shaft portion 21 and the large-diameter shaft portion 22. 23a extending from the side to the middle part of the large-diameter shaft portion 22, and a hole 23b communicating with the upper end side of the hole 23a and having a smaller diameter than this.
And a hole 23c having a larger diameter than the hole 23c communicating with the upper end side of the hole 23b is formed. Pair of through holes 24 penetrating in the direction toward the inner peripheral surface side
a, 24b and 25a, 25b are drilled, and the upper end side of the hole 23a of the large-diameter shaft portion 22 is connected to the arc-shaped groove 2 communicating therewith.
6 is formed, and an L-shaped pressure-side oil flow path 27 that communicates the arc-shaped groove 26 with the lower end face is formed.
Is blocked by

The lower half 11 and the upper half 12 are positioned below the lower half 11 of the small diameter shaft 21 with the small diameter shaft 21 inserted into the central opening 10 of the lower half 11. The nut 29 is screwed into the lower end protruding from the nut, and the nut 29 is tightened to be integrally connected. Further, a cylindrical valve body 31 whose upper end is closed in a hole 23a of the upper half body 12 and constitutes a variable throttle is rotatably disposed. As shown in FIG. 4, the valve body 31 has an upper half 1
2, a through-hole 32 is formed at a position facing the arc-shaped groove 26 of the large-diameter shaft portion 22 so as to reach the inner peripheral surface in the radial direction, and as shown in FIGS. A communication groove 33 is formed in the outer peripheral surface corresponding to the portion between the through holes 24a and 24b of the portion 21 to communicate them with each other. Further, as shown in FIG.
And 25b, an elongated hole 34 extending in the axial direction is formed on the outer peripheral surface corresponding to the inner peripheral surface side.
Then, the positional relationship between the through hole 32, the communication groove 33 and the long hole 34 is selected so as to obtain the damping force characteristic with respect to the position of the valve element 31 shown in FIG. 8, that is, the step angles of the step motors 41FL to 41RR described later. I have.

That is, at a position A in FIG. 8, which is a clockwise maximum rotation angle position when viewed from a plane, only the through hole 32 communicates with the arcuate groove 26 as shown in FIG. Moves downward from the lower pressure chamber 9L through the pressure-side oil flow path 14 to the upper pressure chamber 9U through an orifice formed by the open end and the pressure-side disk valve 19. Channel C
1 through the inner peripheral surface of the valve body 31 from the lower pressure chamber 9L, through the through hole 32, the arc-shaped groove 26, the pressure side oil flow path 27, and through the orifice formed by the opening end and the pressure side disc valve 28. Pressure side flow path C2 shown by a broken line toward the upper pressure chamber 9U.
Is formed and the piston 8 moves upward on the extension side, the orifice formed by the open end and the extension side disc valve 18 from the upper pressure chamber 9U through the elongated groove 16 and the extension side flow path 13. Only the extension side flow path T1 shown by a broken line toward the lower pressure chamber 9L is formed, and a high damping force that rapidly increases in accordance with an increase in the piston speed is generated on the extension side, and is increased on the compression side. Generates a low damping force that increases slightly as the piston speed increases.

As shown in FIG. 5, the valve body 31 is rotated counterclockwise from the position A so that the communication groove 33 of the valve body 31 and the through hole 2 of the small-diameter shaft portion 21 are rotated.
4a and 25a are in communication with each other, and the opening area between the communication groove 33 and the through holes 24a and 25a gradually increases as the rotation angle increases. For this reason, as shown in FIG. 5 (a), the elongated groove 16, the annular groove 15U, the through hole 24a, the communication groove 33, the through hole 25a, Passing through the annular groove 15L and the long groove 17, the long groove 1
A flow path T2 is formed toward the lower pressure chamber 9L through an orifice formed by the pressure valve 7 and the pressure-side disk valve 18, and the maximum value of the damping force is increased as shown in FIG.
3 and the through-holes 24a, 25a of the small-diameter shaft portion 21 gradually decrease as the opening area increases, and as shown in FIG. To maintain the formed state, the minimum damping force state is maintained.

Further, when the valve body 31 is rotated counterclockwise as viewed from a plane and near the position B, as shown in FIG. 6, a long hole 34 is formed between the through holes 25a and 25b of the valve body 31.
The communication is established. Therefore, the piston 8
As shown in FIG. 6 (a), the lower side passes through the long groove 16, the annular groove 15U, the through hole 25a, the long hole 34, and the hole 23a in parallel with the flow paths T1 and T2. 9L pressure chamber
Is formed, the extension-side damping force becomes the minimum damping force state, and the hole 23a and the long hole are provided for the movement of the piston 8 on the compression side in addition to the channels C1 and C2. 34, the through-hole 25a, the long groove 1 through the annular groove 15U.
6, the flow path C3 and the hole 23a, the long hole 34, the through hole 25b, the annular groove 15L, the through hole 24b, the communication groove 33,
A flow path C4 that reaches the long groove 16 through the through hole 24a and the annular groove 15U is formed, but maintains the minimum damping force state as shown in FIG.

Further, when the valve element 31 is rotated counterclockwise as viewed from a plane, the elongated hole 34 and the through holes 24b and 25b
And the opening area between the hole 34 and the long hole 34 at the rotation angle θ _B2 is reduced.
7, the opening area between the through hole 32 and the arc-shaped groove 26 gradually decreases from the rotation angle θ _B2 . Therefore, between the rotation angle θ _B2 and the maximum counterclockwise rotation angle θ _C ,
For the movement of the piston 8 on the extension side, the flow path T1 and the flow path T2 coexist, so that the minimum damping force state is maintained. As the opening area between them gradually decreases, the maximum damping force gradually increases, and when the valve body 31 reaches the position C, as shown in FIG. By being in the cutoff state, the flow path from the lower pressure chamber 9L to the upper pressure chamber 9U is only the flow path C1 with respect to the pressure side movement of the piston, and the pressure side is in a high damping force state.

On the other hand, a cylindrical piston rod 35 is fitted into the hole 23c of the upper half body 12, and the upper end of the piston rod 35 projects upward from the cylinder tube 7, as shown in FIG. The upper end side is the vehicle body side member 36.
Is fixed to a bracket 37 attached to the bracket 37 via nuts 39 via rubber bushes 38U and 38L.
The rotating shaft 41a and the above-described valve body 31 are connected by a connecting rod 42 loosely inserted into the piston rod 35. 43 is a bumper rubber. The lower end of the cylinder tube 7 is connected to a wheel-side member (not shown).

As shown in FIG. 9, a projecting body 44 in the form of a rectangular parallelepiped protrudes from the upper end of the valve body 31 to rotate the valve body 31 by the rotating shaft 41a of the step motors 41FL to 41RR. It rotates synchronously with the movement. And the upper half 1
A stopper plate 45 is provided in the inner hole of the second receiving body 44, and the pressing body 44 and the stopper plate 45 constitute a stopper mechanism.

Two abutting projections 45a and 45b are provided in the inner hole of the stopper plate 45, and the abutting body 44 is rotated by the rotation shaft 41a of the step motor 41 or the valve body 31. When the valve body 31 rotates to the position A or the position C described above, the two restricting end faces 44a or 44b of the abutment body 44 are brought into contact with the abutment projection 4.
5a or 45b, the valve body 31 is prevented from rotating any further, and the position P of the valve body 31 is shifted to the positive maximum position _PMAX or the negative maximum pressure position (-).
P _MAX ) is used to correct the positional deviation between the rotation angle of the step motor 41 and the position of the valve element 31 by a control origin configuration process, that is, a so-called initialization process, which will be described later.

The controller 4 has, on its input side,
As shown in the figure, according to the vertical acceleration provided on the vehicle body side corresponding to each wheel position, the vertical acceleration detection values X _2FL ″ -X composed of analog voltages that are positive in the upward direction and negative in the downward direction
Vertical acceleration sensors 51FL to 51RR as vertical acceleration detecting means for outputting _2RR "are connected, and a vehicle speed sensor 52 for detecting the vehicle speed is connected. The damping force of each damping force variable shock absorber 3FL to 3RR is connected to the output side. Are connected.

The controller 4 includes a microcomputer 56 having at least an input interface circuit 56a, an output interface circuit 56b, an arithmetic processing device 56c, and a storage device 56d;
An A / D converter 57FL~57RR supplied to the input interface circuit 56a FL～51RR the vertical acceleration detection value X _2FL "~X _2RR" is converted into a digital value, the vehicle speed sensor 5
2, an A / D converter 58 that converts the detected vehicle speed value V into a digital value and supplies the digital value to the input interface 56a, and a step control signal for each of the step motors 41FL to 41RR output from the output interface circuit 56b. Are converted to step pulses to drive the step motors 41FL to 41RR.
With RR.

Here, the operation of the microcomputer 56
The processing device 56c calculates the vertical acceleration detection value X_2FL″ ~
X_2RR”Based on piston speed V_PEstimate this pis
Ton speed V _PIs the preset speed threshold V_PTLess than
The vehicle vertical acceleration detection value X_{2F L}"~ X_2RR″
Vertical speed X_2FL'~ X_2RR′
The extension side and compression side position P based on the vehicle vertical speed_TPassing
And P_CIs calculated, and these and the current position P_PDifference value from
Is calculated, and the step control amount corresponding to this is
Perform damping force control processing to output to circuits 59FL to 59RR
Is the vehicle speed detection value V is equal to the preset vehicle speed V_SThat is all
Running on a flat road surface with little road input and body swing
At some point, the butting body 44 is moved to the current position P._PFrom anti-time
Rotate in the measuring direction to abut against each abutting projection 45a, 45b
To return to the origin and perform control origin calibration.
Perform the initialization process.

The storage device 56d stores the arithmetic processing unit 5
A program necessary for the arithmetic processing of FIG. 6c is stored in advance, and values and operation results required in the arithmetic processing are sequentially stored. The output interface circuit 56b includes:
A diagnostic connector 60 is provided.
0 by connecting the diagnostic tester 61 to the self-diagnosis, the detection value of each sensor and the step motor 41FL.
It is possible to monitor the step amount and the like of ~ 41RR.

Next, the operation of the above embodiment will be described with reference to FIGS. 11 to 13 showing an example of the processing procedure of the arithmetic processing unit 56c of the microcomputer 56. That is, FIG.
Is executed as a main program when an ignition switch (not shown) is turned on,
First, in step S1, the initialization permission flag INT, the initialization completion flag END, and the control position holding state flag FH are set to "0" while the calibration state flag FS and the control position data CD that have been backed up in advance remain unchanged.
To reset the counter CNT to “0” and perform other necessary initialization.

Then, the process proceeds to step S2 to determine whether or not the control position data CD is held. If the control position data CD is held, the process proceeds to step S3 to set the control position holding state flag FH to "1". Then, the process proceeds to step S4. In this step S4, it is determined whether or not the calibration state flag FS has been set to "1". This determination is made after the self-diagnosis is performed after replacing any of the damping force variable shock absorbers 3FL to 3RR as the actuator, and it is determined whether or not the initialization process has been performed before the end of the previous control. If FS = 0, it is determined that the initialization process has been performed after the self-diagnosis, and the process proceeds to step S
Then, the process proceeds to 5 to start the normal control process shown in FIG.

On the other hand, if the result of the determination in step S2 is that the control position data CD is not held, the flow proceeds to step S6, where the control position holding state flag FH is set to "0", and then to step S7. Similarly, when the result of the determination in step S4 indicates that the calibration state flag FS is set to "1", the process is terminated without performing the initialization process after the self-diagnosis is performed at the end of the previous control. Then, the process proceeds to step S7.

In step S7, a starting initialization process for performing control origin calibration at the time of starting is executed. The initializing process at the time of starting is performed at the final position of the valve element 31 (the position immediately before the initializing process is executed).
Assuming that P is in the position as shown in FIG. 14, the step motor 41FL-41RR is rotated counterclockwise and outputs a gradually decreasing step amount S as a control signal at predetermined time intervals. The valve body 31 and the abutment body 44 rotate in the counterclockwise direction while gradually reducing the rotation angle, and eventually rotate to the maximum pressure side position (−P _MAX ), and the abutment body 44 is moved to the stopper plate 45. Abuts against each of the abutting projections 45a, 45b, and no longer rotates. In this state, by outputting _a predetermined step amount Sa to the step motors 41FL-41RR, the step motors 41FL-41RR are rotated clockwise by the rotation angle a so that the abutment body 44, that is, the position P of the valve body 31 is rotated. To the position value “0”.

In this embodiment, the stepping motor 41
When FL-41RR is rotated counterclockwise and stepwise by a predetermined rotation angle, a predetermined time is maintained for each rotation position, and for a predetermined time, the supply voltage is turned off and the driving force is set to “0”. To That is, during the initialization, the driving force of the step motors 41FL to 41RR is interrupted. Further, as shown in FIG. 14, for example, an angle from the end position P to the extension side maximum position P _MAX and gamma, the speculative maximum overshoot position P _N to the compression side maximum position (-P _MAX) which is reached by and initialization processing Is set to be larger than the angle γ so that the final position P always reaches the maximum pressure side position (−P _MAX ) regardless of where the final position P is in the damping force control range. I have.

When the initialization processing at the time of starting is completed, the process proceeds to step S8, and the calibration state flag FS is set.
Is reset to "0" indicating that the control origin has been calibrated, and the process proceeds to step S5. On the other hand, the normal control process started in step S5 is executed as a timer interrupt process for a predetermined time, for example, every 10 msec, and as shown in FIG.
First, in step S11, has a self-diagnosis process started to perform a self-diagnosis as to whether the vehicle speed sensor 52, the vertical acceleration sensors 51FL to 51RR, the variable damping force shock absorbers 3FL to 3RR, etc. required for damping force control are normal. If the self-diagnosis process has not been started, the process proceeds to step S12, where the damping force control process shown in FIG. 13 is executed, the timer interrupt process is terminated, and the process returns to the predetermined main program. If the self-diagnosis process has been started, the flow shifts to step S13 to set the calibration state flag FS to "1", and then shifts to step S14.

In step S14, it is determined whether a predetermined self-diagnosis canceling condition is satisfied. As the self-diagnosis canceling condition, for example, the vehicle speed detection value V is equal to the set vehicle speed V
₁ (for example, 30 km / h) or more, or when the diagnostic tester 61 is connected to the diagnostic connector 60 of the controller 4 and the diagnostic tester 61 executes a diagnostic data monitoring process. When the self-diagnosis cancellation condition is not satisfied, the process proceeds to step S12, and when the self-diagnosis cancellation condition is satisfied, the process proceeds to step S15.

In this step S15, it is determined whether or not the control position data is not held and the control position holding state flag FH is reset to "0".
In step S16, the process proceeds to step S16 and
First, an initialization process for performing a control origin calibration process similar to the startup initialization process of step S7 in step S7 is performed, and then the process proceeds to step S17, where the calibration state flag FS is reset to "0", and then the process proceeds to step S12.
Move to

On the other hand, the result of the determination in step S15 is that the control position data is held and the control position holding state flag F
If H is set to "1", step S1
8 to determine whether or not the initialization completion flag END is set to "1". When the flag is set to "1", it is determined that the initialization processing has been completed, and the process proceeds to step S12. When the initialization completion flag END is reset to "0", it is determined that the initialization process has not been completed, and the process shifts to step S19.

In step S19, the vehicle speed sensor 52
The vehicle speed detection value V is higher than the vehicle speed V _S (for example, higher than the vehicle speed V ₁ of the self-diagnosis canceling condition described above, in which noise generated by the initialization processing or noise due to vibration is lost due to a preset road noise and the occupant cannot sense. 35
miles / h) determined at whether above, when a V <V _S, the process proceeds to step S20 noise initialization process determines that there is a risk of being perceived in the passenger,
After clearing the counter CNT to "0", the process proceeds to step S12, and if V ≧ V _S , the process proceeds to step S12.
Move to 21.

In this step S21, it is determined whether or not the initialization permission flag INT is set to "1". When the initialization permission flag INT is reset to "0", it is determined that the initialization processing is not permitted. And the process moves to step S22. In this step S22, each vertical acceleration sensor 51
It is determined whether or not the absolute value of the vertical acceleration detection value X _2i ″ of i (i = FL, FR, RL, RR) is less than a preset vertical acceleration X ₂₀ ″ with a predetermined road vibration input and a small vertical movement of the vehicle body. I do. This determination is performed to determine whether or not the fluid force passing through the orifice due to the influence of the piston speed of the shock absorber at the time of performing the initialization process can perform the accurate initialization process without affecting the driving force of the step motor 41i. If | X _2i ″ | ≧ X ₂₀ ″, it is determined that accurate initialization processing cannot be executed, and the routine goes to step S 20, where | X _2i ″
If | <X ₂₀ ″, it is determined that accurate initialization processing can be executed, and the flow shifts to step S23.

In step S23, the counter CNT
The "1" transition from incremented by the step S24, the count value of the counter CNT is equal to or a set value CNT ₀ or a preset, CNT <CN
Proceeds directly to step S12, when it is T _0, when a CNT ≧ CNT ₀ and proceeds to step S25, the initialization permission flag INT is set to "1", then the process proceeds to step S26, the counter CNT After clearing to "0", the process proceeds to step S12.

On the other hand, if the result of determination in step S21 is that the initialization permission flag INT has been set to "1", the flow proceeds to step S27.
After executing the normal initialization processing for performing the control origin calibration processing similar to the initialization processing of the above-described steps S7 and S16, the process proceeds to step S28,
The calibration state flag FS is reset to "0", and then the process proceeds to step S29 to initialize the completion flag EMD.
Is set to "1", and the routine goes to the step S12.

In the damping force control process in step S12, as shown in FIG. 13, first, in step S31, each vertical acceleration detection value X _2i ″ (i = FL, FR, RL, RR) is read. In step S32, the vehicle vertical acceleration X _2i ″ at each damping force variable shock absorber 3i position read in step S1 is integrated by performing a low-pass filter process to calculate the vehicle vertical speed X _2i ′. Then, the process proceeds to step S33 to determine whether or not the calculated vehicle body vertical speed X _2i ′ is positive including zero. This determination is to determine whether the piston rod 35 of the variable damping force shock absorber 3i is moving to the extension side or to the compression side. When X _2i ′ ≧ 0, the piston rod 35 is moved to the extension side. Is determined to be present, and step S3
4 proceeds to a vehicle body vertical velocity X _2i value X _2i divided by '/ X _2TM' 'to a preset true maximum value P _TLMAX become the vehicle body vertical velocity X _2TM when the extension phase position' is 1 It is determined whether or not _X2i '/ _X2TM '> 1, and if _X2i '/ _X2TM '> 1, the _routine goes to step S35, where _X2i '/ _X2TM '.
= 1 and then the process proceeds to step S36, where _X2i '/
If X _2TM ′ ≦ 1, step S36
Move to

In step S36, the vehicle vertical speed X_2i′
And X_2TM'And the maximum position P on the extension side_TMAXAnd based on
The following formula (2) is used to calculate the target extension side position P._TTo
After the calculation, the process moves to step S37. P_T= (X_2i'/ X_2TM') P_TMAX (2) In this step S37, the data stored in the storage device 56d is stored.
Current position P _PAnd target position P_T(Or later
P to describe_C) And calculate this as the step control amount.
Update and store in a predetermined storage area of the storage device 56d as S
With the target position P_TOr P_CThe current position
P_PIs updated and stored, and then to step S38.
The data is transferred to a predetermined storage area of the storage device 56d
Step control amount S is output to the motor drive circuit 59i.
Then, the process proceeds to step S39, where predetermined control ends.
Judge whether the condition is satisfied or not and satisfy the control end condition.
If not, end the timer interrupt processing and
Return to the main program and satisfy the control end condition.
Sometimes, the process proceeds to step S40 and the current position P
_PTo the ignition switch installed in the storage device 56d.
Backup power is supplied even if the switch is turned off.
Semiconductor memory or backup power
Electrically rewritable non-volatile memory that does not require a source
(E^Two(PROM) stored in the holding memory 56e
Then, the process proceeds to step S41, and the calibration state flag F
S is similarly stored in the holding memory 56e, and then the processing is terminated.
I do. Here, as the predetermined control end condition, for example,
A specified time after the ignition switch is turned off
Is set when the self-holding period has elapsed.

On the other hand, the result of the determination in step S33 is X _2i ′.
When <0, the damping force variable shock absorber 3
It is determined that the piston rod 35 of i is moving to the compression side, and the flow shifts to step S42 to change the vehicle vertical speed X _2i ′.
_Is the true maximum value P _CMAX of the preset pressure side position.
The value X _2i ′ divided by the vehicle body vertical speed X _2CM ′ when
It is determined whether or not X _2CM ′ exceeds 1, and X _2i ′ / X
_2CM 'when> is 1, the process proceeds to step S43, X _2i' step after setting the / X _2CM '= 1 S4
4 and when X _2i ′ / X _2CM ≦ 1, the process directly _proceeds to step S44.

In step S44, the vehicle body vertical speed X _2i '
And performing the following calculation formula (3) proceeds from the calculated target compression side position P _C to the step S37 on the basis of the on and the compression side maximum position P _CMAX X _2CM '. P _C = (X _2i ′ / X _2CM ′) P _CMAX (3) In the processing of FIGS.
The processing of S7, S15, S16, S18 to S27 corresponds to the control origin calibration means, and steps S8, S11, S13,
The processing of S17, S28, S41 corresponds to the calibration state detecting means, the processing of step S12 and the processing of FIG. 13 correspond to the control means, and the processing of step S40 and the holding memory 56
"e" corresponds to the control position holding means.

Therefore, when the ignition switch is turned on, the controller 4 is turned on, whereby the microcomputer 56 is turned on.
First, the processing of FIG. 11 is started by the arithmetic processing device 56c. Therefore, first, a predetermined initialization is performed (step S1), the then determines whether or not the control position data P _P at the control end of the previous to the holding memory 56e is stored, the control position to the holding memory 56e Data P _P
Is stored, when the calibration state flag FS held at the end of the previous control is "0", that is, when the self-diagnosis is not performed, or when the initialization process is performed after the self-diagnosis is performed, the process directly proceeds to step S5. The process proceeds to start the normal control process of FIG. In this case, since the initialization process for calibrating the control origin is not performed at the time of starting the vehicle, the occupant does not feel uncomfortable.

[0045] However, when the control position data P _P to the holding memory 56e represents the current position is not stored in a control position of the current damping force variable shock absorber 3i is undefined, the damping force control via the traveling anyway Is executed, accurate damping force control cannot be performed until the initialization processing at the set vehicle speed is executed. Therefore, the initialization processing at the start is executed immediately after resetting the control position holding state flag FH to “0”. I do. By this initializing process at the time of starting, the stepping motor 41i is rotated counterclockwise so as to reduce the amount of rotation stepwise as shown in FIG.
5a, is brought into contact 45b, then by a predetermined amount a is rotated in the clockwise direction, in this state, is set to "0" the current control position P _P.

When the initialization processing at the start is completed, the control origin is correctly calibrated, so that the calibration state flag FS is reset to "0" and the normal control processing of FIG. 12 is started. When the self-diagnosis process is executed after replacing any of the damping force variable shock absorbers 3i and the controller 4 during the previous control, the calibration state flag FS is set to "1". since the exchange of variable shock absorbers 3i and the controller 4 performs while the vehicle is stopped in garages or the like, self release condition that set vehicle speeds V _{1 to} above not established, the diagnostic connector 6
When the diagnostic tester 61 is connected to 0 and the diagnostic result is monitored, only the release condition is satisfied. However, the initialization process is not executed unless the vehicle is driven at the set vehicle speed V _S or higher thereafter. After the self-diagnosis is performed, the holding state of the holding memory 56 is kept while the calibration state flag FS for turning off the ignition switch is set to "1".
e.

Therefore, also in this case, when the process of FIG. 11 is executed with the ignition switch turned on, the process proceeds from step S4 to step S7, the initialization process at the start is executed, and the control origin calibration is performed. Will be. Here, when performing the self-diagnosis, by performing a specific process when turning on the ignition switch or by connecting the diagnostic tester 61 to the diagnostic connector 60, if the self-diagnosis start condition is satisfied,
When the self-diagnosis process is executed and the process of FIG. 12 is executed, the calibration state flag FS is set to "1" (step S13).

Thereafter, when the vehicle speed V reaches the set vehicle speed V ₁ or when the self-diagnosis canceling condition is satisfied by setting the data monitoring state by the diagnostic tester 61, step S is executed.
Moves to 15, when the control position data P _P at startup as described above has not been held, the control position holding state flag FH is set to "0", immediately when the self-diagnosis condition has cleared In step S16, the initialization processing is executed, and the control origin calibration is executed again.

When the execution of the normal control process of FIG. 12 is started, it is determined in step S11 whether or not the self-diagnosis is started. In the normal state, the self-diagnosis process is not executed. Then, the process proceeds to step S12 to execute the damping force control process shown in FIG. At this time, since the vehicle is in a stopped state, assuming that there is no occupant getting on / off or loading / unloading of the load, the vehicle body does not swing and the vertical acceleration detection output from the vertical acceleration sensors 51FL to 51RR is detected. Since the values X _2FL ″ to X _2RR ″ become substantially zero and the vehicle body vertical speeds X _2FL ′ to X _2RR ′ are also substantially zero accordingly, the _{process proceeds} from step S33 to step S36 via step S34, and _proceeds to step S36. position P _T also body vertical velocity X _2i 'is next to zero for a zero, is driven to the step motor 41FL~41RR matches the extension side target position P _T. For this reason, the valve elements 31 of the damping force variable shock absorbers 3FL to 3RR are set to the position B shown in FIG. 6, whereby the extension side and the compression side damping force of the piston 8 are set to the minimum soft state.

When the vehicle is started slowly from this stopped state and runs straight on a flat good road, the vehicle body hardly moves up and down again in this case.
Vertical acceleration detection value X _2FL ″ output from 1RR
X _2RR ″ becomes substantially zero, and the valve element 31 of the variable damping force shock absorbers 3FL to 3RR maintains the position B shown in FIG. 6, whereby the soft state in which the extension side and compression side damping forces of the piston 8 are in the minimum state. Therefore, even if vibrations due to fine irregularities on the road surface are input to the wheels, the vibrations are absorbed by the variable damping force shock absorbers 3FL to 3RR and are not transmitted to the vehicle body, so that a good ride comfort can be secured. .

When the vehicle does not move up or down due to the passage of a temporary step such as a step rising forward in this good road traveling state, the vehicle vertical speed X
_{Since 2FL} 'to _X2RR ' are maintained at zero, to maintain the minimum damping force state, it is possible to absorb the thrust force when the wheel rides on the step, but ride on a relatively large step, If you can't absorb that thrust,
Body also would be displaced upward, thus resulting in the vehicle body vertical velocity X _2FL '~X _2RR' is increased in the positive direction. As described above, when the vehicle body vertical speeds X _2FL ′ to X _2RR ′ increase in the positive direction, the _{process proceeds} to step S3 through step S34.
6 goes to, so the extension side position P _T of the target maximum position P _TMAX side of the extension side position P _T1 in FIG. 8 is calculated, the valve body 31 of the damping force variable shock absorber 3FL~3RR shown in FIG. 5 The switching is controlled as follows. As a result, when the displacement speed X _1i ′ on the wheel side is higher than the displacement speed X _2i ′ on the vehicle body side due to the stepping over and the piston 8 moves to the compression side, the compression-side minimum damping force is maintained.
The vibration input to the wheel side can be absorbed, and when the climbing speed on the wheel side becomes lower than the climbing speed on the vehicle body side by overcoming the step from this state, the piston 8 moves to the extension side. At this time, since the damping force has a large value, the damping force exerts a damping effect of suppressing the rise of the vehicle body, and when the vehicle body stops rising thereafter, the vehicle body vertical speed _X2FL'- X
_{When 2RR} 'becomes zero, the step motors 41FL to 41RR are rotated counterclockwise and returned to the position B as described above, whereby both the compression side and the extension side are controlled to the minimum damping force, and then the vehicle body is When you start descending,
By the vehicle body vertical velocity X _2FL '~X _2RR' is increased in the negative direction in response to this, step S from step S33
42 and proceeds to step S44 through, by calculating the compression side target position P _C, the valve element 31 is rotated to further counterclockwise, is rotated in the rotated position shown in FIG. Therefore, when the vehicle body is lowered and the piston 8 moves to the pressure side, the damping force is increased, so that a large damping effect is exhibited.

Conversely, when the wheels pass through the step of descending forward, the relative speeds X _DFL 'to X _DRR ' increase in the forward direction due to the rebound of the wheels, but the vehicle does not move up and down at this time. Body vertical speed X _2FL '~ X
_{Since 2RR} 'is zero, the damping coefficients of the damping force variable shock absorbers 3FL to 3RR maintain the minimum damping force, allow the wheels to descend, and then the vehicle body starts to descend, and the vehicle vertical speed _X2FL ' When to X _2RR 'is increased in the negative direction, and the compression side target position P _C becomes a large value, since the valve body 31 is rotated to the position shown in FIG. 7, a large damping force against the movement of the compression side of the piston 8 To exert a large vibration damping effect, and thereafter, the vehicle vertical speed X _{2F L} ′ to X _2RR ′
Depending on the compression side target position P _C is smaller becomes small, the valve body 31 is returned to position B side is rotated clockwise, the vehicle body vertical velocity X _2FL '~X _{2R R'} is zero, the valve The body 31 becomes the position B and returns to the minimum damping force state. Then, when you start to rise by the vehicle body unwag, since the vehicle body vertical velocity X _2FL '~X _2RR' is increased in the positive direction increases the extension phase target position P _T, the valve element 31 is rotated clockwise As a result, a large damping force can be applied to the movement of the piston 8 on the extension side to exert the vibration damping effect.

As described above, when the vehicle travels on a temporary step while traveling on a good road, a good vibration damping effect can be exerted by the skyhook control. also, by a positive vehicle body vertical velocity X _2FL '~X _2RR' (or negative) by Shin-side target position P _T (or pressure side target position P _C) is calculated, the piston 8 body rises Gasing The damping force is controlled to the minimum damping force in the vibration direction in which the piston 8 moves to the compression side, and the piston 8 moves to the compression side when the body moves up and the piston 8 moves to the extension side. When it is in the vibration direction, the damping force is controlled to the optimum damping force according to the vertical speed X _2FL ′ to X _2RR ′,
Good ride comfort can be ensured.

Further, even when the vehicle is traveling on a rough road, similarly to the above-mentioned step passage, the vehicle body rises and the piston 8 moves to the extension side, and the vehicle body descends and the piston moves to the compression side. The damping force is controlled to the minimum damping force in the vibration direction. Conversely, vibration suppression is performed when the vehicle body rises and the piston 8 moves to the compression side, and when the vehicle body descends and the piston moves to the extension side. When the damping force is in the vertical direction X
Control is made to an optimum value according to _2FL 'to _X2RR ', and a good ride comfort can be secured.

On the other hand, when starting, the control position data _PP
Is held, and when the control position holding state flag FH is set to "1", the process proceeds from step S15 to step S18, and when the vehicle speed V becomes equal to or higher than the set vehicle speed V _S , the process proceeds to step S21. Step S2
2 and the vehicle is traveling on a flat good road, and the absolute value | X _2i ″ | of the vertical acceleration detection value of the vertical acceleration sensor 51i is less than the set acceleration X ₂₀ ″, the flow proceeds to step S23. counter CNT is incremented by "1", which is repeated, when the count value CNT reaches the set value CNT _0, initialization permission flag I
NT is set to "1" and the counter CNT is cleared to "0".

Therefore, when the processing of FIG. 12 is executed next, the process proceeds from step S21 to step S27, where the normal initialization processing is executed and the control origin calibration is performed. In this state, the vehicle is running at the set vehicle speed V _S or higher, and the noise and the noise generated by the initialization process due to the road noise are eliminated, and the occupant does not feel uncomfortable.

Thereafter, the vehicle is stopped from the running state,
When the ignition switch off, when the processing of FIG. 13 has been executed, the process proceeds from step S39 to step S40, holds the holding memory 56e the current control position P _P as control position data, calibration state The flag FS holds the holding memory 56e, and the control ends.

[0058] Thus, according to the above embodiment, there is no possible to perform the replacement of variable damping force shock absorber 3i, in the normal running state, at the control end, the current position P _P is held in the holding memory 56e , The calibration state flag FS reset to "0" is stored in the holding memory 56e.
Since the ignition switch is turned on next time, the control origin calibration by the initialization process is not executed at the time of starting, and the control origin calibration by the initialization process is executed at the set vehicle speed V _S or more. Therefore, it is possible to reliably prevent the occupant from feeling uncomfortable.

However, when the ignition switch is turned off while the self-diagnosis process is being performed after replacing the damping force variable shock absorber 3i, the current position P _P held in the holding memory 56e.
And the actual position of the variable damping force shock absorber 3i are in a disagreement state. In this case, the calibration state flag FS is kept set to "1" so that the initialization processing is immediately performed at the time of starting. By performing the control origin calibration, it is possible to reliably prevent the damping force control performance from deteriorating due to the deviation of the control origin.

Similarly, when the ignition switch is turned on and the control position data is not stored in the holding memory 56e, the control origin is disturbed. In this case, too, the control by the initialization process is performed immediately at the start. Origin calibration is performed, and accurate damping force control can be performed. In the above embodiment, the variable damping force shock absorbers 3FL to 3FL are used as actuators.
Although the description has been given of the case where the RR is applied, the present invention is not limited to this, and even if a roll rigidity variable stabilizer that can vary the roll rigidity or an air suspension that can vary the spring constant, the open loop The present invention can be applied when a controlled step motor is used.

In the above embodiment, the case where the replacement of the actuator and the control means is determined based on whether or not to execute the self-diagnosis processing has been described. However, the present invention is not limited to this. May be set by a switch or the like, and a predetermined flag may be set. Further, in the above embodiment, the case where the valve element 31 for controlling the damping force is formed in a rotary type is described. However, the present invention is not limited to this. Different flow paths may be formed. In this case, a pinion is connected to the rotating shaft 41a of the step motors 41FL to 41RR, and a rack meshing with the pinion is attached to the connecting rod 42 or an electromagnetic solenoid is applied. Then, the sliding position of the valve element 31 may be controlled.

Further, in the above embodiment, the case where the abutting body 44 is provided on the connecting rod 42 connected to the rotating shaft 41a of the step motors 41FL to 41RR and the stopper plate 45 is provided on the upper half body 12 has been described. The stopper plate 45 is connected to the connecting rod 42 in the reverse relationship,
4 may be provided on the upper half body 12. Further, instead of the stopper plate 45, a position detecting means such as a microswitch which engages with the abutting body 44 is provided. When the body 44 is detected, the driving of the step motors 41FL to 41RR may be stopped to perform the origin calibration more accurately.

Furthermore, in the above embodiment, the case where the vertical acceleration of the vehicle body is detected and the skyhook approximation control in which the damping force is controlled based on the detected vertical acceleration is performed is described. Instead, a stroke sensor for detecting the relative displacement between the vehicle body and the wheels is separately provided, and the relative speed X _Di 'obtained by differentiating the relative displacement detection value X _Di of the stroke sensor and the vehicle body vertical speed X _2i ' described above. Based on this, the following equation (3) is calculated to calculate a damping coefficient C, and based on the damping coefficient C, a target position is calculated with reference to, for example, a map corresponding to FIG. It may be performed.

C = C _{S ×} X _2i ′ / X _Di ′ (3) where C _S is a preset damper damping coefficient.
Further, in the above-described embodiment, the case where the posture change of the vehicle body due to the vibration input from the road surface is described, but the invention is not limited thereto, and the running state of the vehicle such as the roll state and the braking state is detected, and Control for suppressing a change in the posture of the vehicle body may be performed together.

In the above embodiment, the set vehicle speed V
_The case where the control origin calibration by the normal initialization process is performed when the vehicle is traveling on a flat road surface at _S or more has been described. However, the present invention is not limited to this. The case where the piston speed of the damping force variable shock absorber 3i is high is described. In some cases, step-out may occur due to a change in the step amount due to the driving force of the step motor 41i due to the influence of the fluid force passing through the orifice. After reaching a certain piston speed, the control origin calibration by the initialization process may be performed.

Further, in the above embodiment, the case where the control is performed by applying the microcomputer 56 has been described. However, the present invention is not limited to this. The output of the vertical acceleration sensor 51i is integrated to calculate the vehicle vertical speed. An electronic circuit such as an integrator for calculating the target position and an arithmetic circuit for calculating the target position may be combined. Furthermore, in the above embodiment, the case where the vertical acceleration sensors 51FL to 51RR are provided at the positions of the wheels 1FL to 1RR of the vehicle body 2 has been described. However, one of the vertical acceleration sensors is omitted, and the position of the omitted position is omitted. The vertical acceleration may be estimated from the value of another vertical acceleration sensor.

Furthermore, the variable damping force shock absorber is not limited to the above-described configuration, and the present invention can be applied to other variable damping force shock absorbers in which the damping force can be switched in two or more steps by a stepping motor. I can do it.

[0068]

As described above, according to the first aspect of the present invention, the vehicle speed detecting means for detecting the vehicle speed, and the control means when the detected vehicle speed value of the vehicle speed detecting means reaches the set vehicle speed. Control origin calibration means for calibrating the control origin of the step motor, and calibration state detection means for detecting whether or not the control origin calibration has been performed by the control origin calibration means after exchanging the actuator and holding the detection result. Since the control origin calibration means is configured to perform control origin calibration even when the calibration state detection means detects that it is before control origin calibration at the start of control by the control means,
In the normal state where at least one of the actuator and the control means is not replaced, the control origin calibration is performed only in a situation where the noise caused by the control origin calibration means is not detected by the occupant due to road noise, thereby ensuring that the occupant is uncomfortable. If the control origin is misaligned due to replacement of the actuator and control means, etc., the control origin can be calibrated immediately at startup. It is not necessary to run the vehicle at a speed higher than the predetermined vehicle speed, and it is not necessary to provide a new switch for calibrating the control origin.

According to the second aspect of the present invention, in addition to the effect of the first aspect of the present invention, it is determined whether or not the control position at the end of the previous control is held at the time of starting.
The control origin calibration can be performed when the control position is not held and when the control origin is misaligned even when the control position is held, and an effect that better actuator control can be performed can be obtained. .

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing a basic configuration of the present invention.

FIG. 2 is a schematic configuration diagram showing one embodiment of the present invention.

FIG. 3 is a partially sectional front view showing an example of a variable damping force shock absorber.

FIG. 4 is an enlarged sectional view showing a damping force adjusting mechanism in a maximum damping force state when the vehicle body is lifted.

FIGS. 5A and 5B are enlarged sectional views showing a damping force adjusting mechanism in an intermediate damping force state when the vehicle body is lifted, wherein FIG. 5A shows a hydraulic oil path on the extension side and FIG.

FIGS. 6A and 6B are enlarged cross-sectional views illustrating a damping force adjustment mechanism when the vehicle body does not fluctuate. FIG.

FIGS. 7A and 7B are enlarged cross-sectional views illustrating a damping force adjusting mechanism in a state of a maximum damping force when the vehicle body descends, wherein FIG. 7A illustrates a hydraulic oil path on the extension side and FIG.

FIG. 8 is an explanatory diagram showing a damping force characteristic with respect to a position of a valve body of a variable damping force shock absorber.

FIG. 9 is an enlarged sectional view taken on line AA of FIG. 3;

FIG. 10 is a block diagram illustrating an example of a controller.

FIG. 11 is a flowchart illustrating an example of a processing procedure of a controller.

FIG. 12 is a flowchart illustrating an example of a normal control process in a controller.

FIG. 13 is a flowchart illustrating an example of a damping force control process in the process of FIG. 12;

14 is an explanatory diagram of the operation of the initialization (control origin calibration) processing in FIGS. 11 and 12. FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1FL-1RR Wheel 2 Body 3FL-3RR Variable damping force variable shock absorber 4 Controller 8 Piston 11 Lower half 12 Upper half 13 Extension oil flow path 14 Compression oil flow path 31 Valve element 35 Piston rod T1-T3 Extension side flow path C1-C4 Pressure side flow path 41FL-41RR Step motor 51FL-51RR Vertical acceleration sensor 52 Vehicle speed sensor 56 Microcomputer 59FL-59RR Motor drive circuit 60 Diagnostic connector 61 Diagnostic tester

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B60G 17/015 F16F 9/46 F16F 9/50

Claims (2)

(57) [Claims] 1. The suspension characteristics can be individually controlled by controlling the rotation of a valve body by a step motor interposed between a vehicle body-side member and a wheel-side member and driven according to an input control signal. And a control means for detecting a change in the posture of the vehicle body and outputting the control signal corresponding to the detected change in the posture to the stepping motor to perform drive control. Detection means, control origin calibration means for performing control origin calibration of the step motor by the control means when the vehicle speed detection value of the vehicle speed detection means reaches a set vehicle speed, and whether or not each control device is normal. A calibration state detecting means for detecting whether or not the control origin calibration has been performed by the control origin calibration means after performing the self-diagnosis, and holding a detection result thereof; The point calibration means is configured to perform control origin calibration regardless of the vehicle speed detection value of the vehicle speed detection means when the calibration state detection means detects that the control origin calibration has not yet been performed at the start of control by the control means. A suspension control device characterized by being configured. 2. The suspension characteristics can be individually controlled by controlling the rotation of a valve body by a step motor which is interposed between a vehicle body-side member and a wheel-side member and driven in accordance with an input control signal. And a control means for detecting a change in the attitude of the vehicle body and outputting the control signal corresponding to the detected value of the attitude change to the step motor to perform open-loop control. Vehicle speed detection means, control origin calibration means for calibrating the control origin of the step motor by the control means when a vehicle speed detection value of the vehicle speed detection means reaches a set vehicle speed, and the step at the end of control of the control means A control position storage means for storing and holding a control position of the motor; and a control source after performing self-diagnosis of whether or not each control device is normal. Calibration state detection means for detecting whether or not the control origin calibration has been performed by the point calibration means and holding the result, wherein the control origin calibration means is controlled by the control position storage means when control by the control means is started. When the position is not stored and when the control position is stored and the calibration state detection means detects that the control origin is not yet calibrated, the control origin calibration is performed regardless of the vehicle speed detection value of the vehicle speed detection means. And a suspension control device configured to perform the suspension control.