JPH08268024A - Suspension control device - Google Patents

Abstract

(57) [Abstract] [Purpose] A suspension control device capable of completing initialization at an early stage by preventing the control origin configuration of the control system, that is, the repeated start and stop of initialization due to a decrease in power supply voltage during initialization. provide. [Composition] At least when the power supply voltage E _{N of the} battery becomes equal to or higher than the initialization start voltage E _INT , the initialization process is started, and the power supply voltage E _N exceeds the monitoring voltage E _WAT lower than the initialization start voltage E _INT during this period. Is determined (step S32), E _N ≦ E
_When it becomes _WAT , the count value N of the monitoring counter is incremented (step S33), and when the count value N is less than the set value N _S , the initialization process is continued, and the count value N is waited until the initialization is completed. Becomes equal to or more than the set value N _S , the initialization stop flag STP is set to "1" (step S36), and the initialization process is stopped.

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 that uses a step motor to open-loop control suspension characteristics such as damping force.

[0002]

2. Description of the Related Art As a conventional suspension control device, there is, for example, one disclosed in Japanese Patent Laid-Open No. 3-42319. In this conventional example, by inputting a control signal,
A shock absorber capable of changing the expansion-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 openings by rotary actuators such as step motors, and a spring for measuring sprung speed. The upper speed measuring means, the relative speed measuring means for measuring the relative speed between the sprung part and the unsprung part, the sign judging means for judging whether or not the sign of the sprung speed and the sign of the relative speed are coincident, and both signs are When they are the same and the sign of the relative speed is positive, the extension side has a high damping force and the compression side has a low damping force.When both signs are the same and the sign of the relative speed is negative, the extension is high. Control signal output means for outputting a control signal for making the damping side low damping force and the compression side high damping force, and, on the other hand, when both signs do not match, outputting a control signal for making both the extension side and the compression side low damping force. It has a configuration including.

[0003]

However, in the above-mentioned conventional suspension control device, since the throttle opening is adjusted by the rotary actuator which is open-loop controlled to change the damping force, the suspension is controlled. It is highly likely that the control origin will be misaligned due to external disturbances, etc. If this is left unchecked, the control performance of the actuator will deteriorate. Therefore, it is necessary to calibrate the control origin of the rotary actuator, that is, initialize it.

When performing this initialization, normally, it is necessary to bring the engaging piece rotating integrally with the rotary actuator into contact with the stopper representing the control origin several times, and at the same time, the engaging piece vigorously comes into contact with the stopper. If this happens, the reaction will cause the engaging piece to separate from the stopper, and the accuracy of the control origin calibration will decrease, so the speed at which it abuts the stopper is decreased, so the execution time for initialization is relatively long. .

On the other hand, since the driving torque of the step motor is affected by the power supply voltage, the initialization is started when the power supply voltage is equal to or higher than the preset initialization start voltage, and the power supply voltage is less than the initialization start voltage after the initialization is started. When it becomes, it is judged that the initialization is incorrect, and the initialization is executed again.

Therefore, in the conventional example, when the initialization is started in the state where the battery voltage is lowered, the four-wheel actuators are simultaneously driven, so that the power supply voltage is highly likely to be less than the initialization start voltage. However, there is an unsolved problem that the initialization cannot be completed forever because the initialization is repeatedly started and stopped.

Therefore, the present invention has been made by paying attention to the unsolved problem of the above-mentioned conventional example, and determines whether or not the initialization state can be maintained even if the power supply voltage is lowered during the initialization. Thus, it is an object of the present invention to provide a suspension control device capable of preventing the repetition of the start and stop of the initialization and completing the initialization at an early stage.

[0008]

In order to achieve the above object, the suspension control device according to the invention of claim 1 is
As shown in the basic configuration diagram of FIG. 1, the suspension is controlled by controlling the rotation of the valve element by a step motor interposed between the vehicle body side member and the wheel side member and driven according to an input control signal. A suspension control device including an actuator whose characteristics can be individually controlled, and a control unit which detects a posture change of a vehicle body and outputs the control signal corresponding to the detected posture change value to the step motor to perform open loop control. In the power source voltage detecting means for detecting the power source voltage for supplying power to the step motor, the control means when the power source voltage detection value of the power source voltage detecting means reaches a preset voltage for initializing the control system. Initializing execution means for performing the initialization, and after starting the initialization by the initializing execution means, It is characterized in that the voltage detection value and a initializing stop means for stopping the initialization of the initialization execution means when the sum of time equal to or less than a lower monitored voltage than the set voltage is equal to or larger than a set value.

The suspension control device according to a second aspect of the present invention is the suspension control device according to the first aspect of the present invention, when the vehicle speed is equal to or higher than a set vehicle speed and the power supply voltage detection value is equal to or higher than a set voltage. It is characterized in that the control means is initialized. Further, in the suspension control device according to the invention of claim 3, in the invention of claim 1 or 2, the initialization stopping means has a counter for updating the count value while the power supply voltage detection value is equal to or less than the monitoring voltage, It is characterized in that the initialization is stopped when the count value of the counter reaches a set value.

[0010]

According to the first aspect of the invention, the initialization of the control system is started when the power supply voltage becomes equal to or higher than the set voltage by the initialization execution means, and during the initialization, the power supply voltage is lowered to the monitoring voltage lower than the set voltage. When it does, the decrease time is measured by the initialization canceling means, and when the sum of the decrease times is less than the preset value, the initialization by the initialization executing means is continued, and the sum of the decrease times becomes the set value or more. At this time, the initialization is judged to be defective for the first time, and the initialization of the initialization execution means is stopped.

Further, in the invention of claim 2, the stepping motor generated at the time of initialization is started by starting the initialization when the vehicle speed becomes equal to or higher than the set vehicle speed by the initialization execution means and the power supply voltage detection value is equal to or higher than the set voltage. It is possible to avoid making the occupant feel uncomfortable by driving off the driving sound and the noise generated when the engaging piece comes into contact with the stopper and the noise caused by vibration by road noise.

Further, in the invention of claim 3, the initialization stopping means updates the count value of the counter when the detected value of the power supply voltage becomes less than the monitoring voltage, so that the power supply voltage returns to the monitoring voltage or more. Sometimes the count value can be held and the sum of the times when the voltage is below the monitoring voltage can be easily detected.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 2 is a schematic configuration diagram showing an embodiment of the present invention, in which damping force variable shock absorbers 3FL to 3RR serving as actuators constituting suspension devices are arranged between the wheels 1FL to 1RR and the vehicle body 2. Step motors 41FL to 41RR that are provided and switch the damping forces of these damping force variable shock absorbers 3FL to 3RR are controlled by a control signal from a controller 4 described later.

Variable damping force shock absorber 3FL to 3RR
As shown in FIGS. 3 to 7, the piston is configured as a twin-tube type gas-filled strut type having a cylinder tube 7 composed of an outer cylinder 5 and an inner cylinder 6, and the inside of the inner cylinder 6 is in sliding contact with the piston. 8 define upper and lower pressure chambers 9U and 9L. 4 to 7, the piston 8 includes a cylindrical lower half body 11 having a central opening 10 formed in the inner peripheral surface of a seal member 9 that is slidably contacted with the inner cylinder 6 on the outer peripheral surface. It is composed of an upper half body 12 fitted in the lower half body 11.

In the lower half body 11, an expansion side oil flow path 13 is formed so as to vertically penetrate therethrough, and a sealing member 9 is provided downward from the upper surface side.
Hole 14a having a diameter larger than that of the expansion-side oil passage 13 and extending from the outer peripheral surface of the cylindrical body 11 to the hole 14a.
The pressure side oil flow passage 14 formed by a hole portion 14b that is formed by communicating with the bottom portion of a, the annular grooves 15U and 15L formed at the upper and lower open ends of the central opening 10, and formed on the upper surface side. A long groove 16 that communicates with the annular groove 15U and the expansion-side oil passage 13 is formed, and a long groove 17 that is formed on the lower surface side and that communicates with the annular groove 15L is formed. The long groove 17 is closed by the expansion 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 fitted in the central opening 10 of the lower half body 11 and the shaft portion 2.
1 and a large diameter shaft portion 22 having a diameter smaller than the inner diameter of the inner cylinder 6 integrally formed at the upper end of the small diameter shaft portion 21 and the lower end surface of the small diameter shaft portion 21 at the center position. Hole 23a reaching from the side to the middle portion of the large-diameter shaft portion 22 and a hole portion 23b having a smaller diameter than the hole portion 23a communicating with the upper end side of the hole portion 23a.
And a through hole 23 composed of a hole portion 23c having a larger diameter than this and communicating with the upper end side of the hole portion 23b is formed. Pair of through holes 24 penetrating to the inner peripheral surface side in the direction
a, 24b and 25a, 25b, and an arc-shaped groove 2 communicating with the upper end side of the hole portion 23a of the large-diameter shaft portion 22.
6 is formed, and an L-shaped pressure-side oil passage 27 that connects the arc-shaped groove 26 and the lower end surface is formed.
Is blocked by.

The lower half body 11 and the upper half body 12 are located below the lower half body 11 of the small diameter shaft portion 21 with the small diameter shaft portion 21 fitted in the central opening 10 of the lower half body 11. The nut 29 is screwed into the lower end portion projecting to the end and tightened with the nut to be integrally connected. Further, a cylindrical valve body 31 having a closed upper end which constitutes a variable throttle is rotatably disposed in the hole 23a of the upper half body 12. As shown in FIG. 4, the valve body 31 has an upper half body 1
2 has a through hole 32 that reaches the inner peripheral surface in the radial direction at a position facing the arcuate groove 26 of the large-diameter shaft portion 22, and the small-diameter shaft of the upper half body 12 is formed as shown in FIGS. A communication groove 33 is formed on the outer peripheral surface of the portion 21 corresponding to the space between the through holes 24a and 24b. Further, as shown in FIG. 6, the through hole 25a of the small diameter shaft portion 21 of the upper half body 12 is formed.
And 25b, an elongated hole 34 extending in the axial direction is formed on the outer peripheral surface corresponding to between the inner peripheral surface 25b and the inner peripheral surface 25b.
The positional relationship among the through hole 32, the communication groove 33, and the elongated hole 34 is selected so that damping force characteristics with respect to the position of the valve body 31 shown in FIG. 8, that is, the step angle of step motors 41FL to 41RR described later can be obtained. There is.

That is, at the position A of FIG. 8 which is the maximum rotation angle position in the clockwise direction when viewed from the plane, as shown in FIG. 4, only the through hole 32 communicates with the arcuate groove 26, and therefore the piston 8 The pressure side indicated by the broken line in FIG. 2 goes from the lower pressure chamber 9L to the upper pressure chamber 9U through the orifice formed by the opening end of the lower pressure chamber 9L and the pressure side disc 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 passage 27, and the orifice formed by the open end and the pressure side disc valve 28. Pressure side flow path C2 shown by a broken line toward the upper pressure chamber 9U
For the extension side movement in which the piston 8 is formed and the piston 8 rises, the orifice formed by the open end and the extension side disc valve 18 through the upper pressure chamber 9U, the long groove 16 and the extension side flow path 13. Only the extension side flow path T1 shown by the broken line toward the lower pressure chamber 9L is formed, and a high damping force that rapidly increases in accordance with an increase in piston speed is generated on the extension side, and on the compression side. It produces a low damping force that slightly increases as the piston speed increases.

By rotating the valve body 31 from this position A counterclockwise when viewed from the plane, as shown in FIG. 5, the communication groove 33 of the valve body 31 and the through hole 2 of the small diameter shaft portion 21 are formed.
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. Therefore, for the extension side movement of the piston 8, as shown in FIG. 5 (a), the long groove 16, the annular groove 15U, the through hole 24a, the communication groove 33, the through hole 25a, The long groove 1 passes through the circular groove 15L and the long groove 17.
7 and the pressure side disc valve 18 pass through the orifice to form the flow path T2 toward the lower pressure chamber 9L, and the maximum damping force is as shown in FIG.
3 and the through-holes 24a and 25a of the small-diameter shaft portion 21 gradually decrease with an increase in the opening area, and as to the extension side movement, as shown in FIG. 5B, the flow paths C1 and C2 are In order to maintain the formed state, the minimum damping force state is maintained.

Further, when the valve body 31 is rotated counterclockwise when viewed from the plane to be in the vicinity of 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.
Will be in communication with each other. Therefore, the piston 8
6A, as shown in FIG. 6 (a), as shown in FIG. 6 (a), the channels T1 and T2 are arranged in parallel with each other through the elongated groove 16, the annular groove 15U, the through hole 25a, the elongated hole 34, and the hole portion 23a. Pressure chamber 9L
Since the flow path T3 toward the side is formed, the extension side damping force becomes the minimum damping force state, and for the pressure side movement of the piston 8, in addition to the flow paths C1 and C2, the hole portion 23a, the long hole 34, through hole 25a, and circular groove 15U
6, the flow path C3 reaching 6 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 is formed which reaches the long groove 16 through the through hole 24a and the annular groove 15U, but maintains the minimum damping force state as shown in FIG.

Further, when the valve body 31 is rotated counterclockwise when viewed from the plane, the elongated hole 34 and the through holes 24b and 25b.
Open area between is reduced, the long hole 34 in the rotation angle theta _B2
7, the open area between the through hole 32 and the arcuate groove 26 is gradually reduced from the rotation angle θ _B2 . Therefore, between the rotation angle θ _B2 and the maximum counterclockwise rotation angle θ _C ,
With respect to the expansion side movement of the piston 8, the minimum damping force state is maintained because the flow paths T1 and T2 coexist, and conversely, with respect to the compression side movement of the piston 8, the through hole 32 and the arcuate groove 26 are formed. By gradually decreasing the opening area between them, the maximum damping force gradually increases, and when the valve body 31 reaches the position C, as shown in FIG. 7, there is a gap between the through hole 32 and the arc-shaped groove 26. Due to the cutoff state, only the flow path C1 reaches the upper pressure chamber 9U from the lower pressure chamber 9L with respect to the pressure side movement of the piston, and the pressure side high damping force state is achieved.

On the other hand, a cylindrical piston rod 35 is fitted in the hole portion 23c of the upper half body 12, and the upper end of the piston rod 35 is projected above the cylinder tube 7 as shown in FIG. , Its upper end side is the vehicle body side member 36
Is fixed to the bracket 37 attached to the bracket 37 by a nut 39 via rubber bushes 38U and 38L, and the step motors 41FL to 41RR are mounted on the upper end of the piston rod 35 via a bracket 40 so that the rotary shafts 41a to 41RR of the step motors 41FL to 41RR are rotated.
Is fixed in a downwardly projecting relationship, and the rotary shaft 41a and the valve element 31 described above are connected by a connecting rod 42 that is loosely inserted in the piston rod 35. In addition, 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 rectangular parallelepiped butting body 44 is provided at the upper end of the valve body 31 to rotate the valve body 31 by the rotary shafts 41a of the step motors 41FL to 41RR. It rotates synchronously with the movement. And the upper half 1
A stopper plate 45 is internally provided in the inner hole portion of the second body accommodating the abutting body 44, and the abutting body 44 and the stopper plate 45 constitute a stopper mechanism.

Two stopper projections 45a and 45b are provided in the inner hole of the stopper plate 45, and the stopper 44 is rotated by the rotation shaft 41a of the step motor 41 or the valve body 31. When the valve body 31 is rotated, when the valve body 31 is rotated to the position A or the position C described above, the two restraining end faces 44a or 44b of the butting body 44 are brought into contact with the butting projection 4
5a or 45b to prevent the valve body 31 from rotating any more, and to the position P of the valve body 31, the positive maximum position P _MAX on the extension side or the negative maximum position on the pressure side (-
P _MAX ) is exerted as a so-called limiter action, and it is also used when correcting the positional deviation between the rotation angle of the step motor 41 and the position of the valve body 31 by a control origin configuration process, that is, a so-called initialization process described later.

The input side of the controller 4 is shown in FIG.
As shown in, the vertical acceleration detection values X _2FL ″ to X 2 which are analog voltages that are positive in the upward direction and negative in the downward direction according to the vertical acceleration provided on the vehicle body side corresponding to each wheel position.
Vertical acceleration sensors 51FL to 51RR as vertical acceleration detecting means for outputting _2RR ″ are connected, a vehicle speed sensor 52 for detecting a vehicle speed is connected, and damping forces of the respective damping force variable shock absorbers 3FL to 3RR are connected to the output side. Step motors 41FL to 41RR for controlling the motors are connected.

Then, the controller 4 uses the battery 5
A stabilized power supply circuit 54 which is supplied with DC power from 3 and converts it to a control power supply, and an input interface circuit 5
5a, output interface circuit 55b, arithmetic processing unit 5
5c and a storage device 55d at least, an A / D converter 56 for converting the power supply voltage of the battery 53 into a digital value and inputting it to the input interface circuit 55a, and vertical acceleration sensors 51FL to 51FL-5.
The A / D converters 57FL to 57RR for converting the vertical acceleration detection values X _2FL ″ to X _2RR ″ of 1RR into digital values and inputting the digital values to the input interface circuit 55 a, and the vehicle speed detection value V of the vehicle speed sensor 52 are converted to digital values. A / D converter 58 which is supplied to the input interface 55a and each step motor 41 output from the output interface circuit 55b.
A step control signal for FL to 41RR is input, and this is converted into a step pulse to convert each step motor 41FL to
Motor drive circuits 59FL to 59RR for driving 41RR are provided.

Here, the arithmetic processing unit 55c of the microcomputer 55 uses the vehicle body vertical acceleration detection values X _2FL ″ to X 2.
_2RR ″ is integrated to calculate the vehicle body vertical speeds X _2FL ′ to X _2RR ′, the _expansion side and _compression side positions P _T and P _C are calculated based on the vehicle body vertical speeds, and these and the current position P
_The damping force control process of calculating the difference value from _P and outputting the corresponding step control amount to the motor drive circuits 59FL to 59RR is performed, but when the ignition switch is turned on and the vehicle speed detection value V is The abutment body 44 is rotated counterclockwise from the current position P _P while the vehicle is traveling on a flat road surface with a preset vehicle speed V _S or more and less road surface input and less vehicle swing. Each butt projection 4
Initialization processing is performed in which the control origin is calibrated by contacting 5a and 45b and then returning to the origin.

The storage device 55d is used as the arithmetic processing device 5.
A program required for the arithmetic processing of 5c is stored in advance, and necessary values and arithmetic results in the arithmetic processing process are sequentially stored. Next, the operation of the above embodiment will be described with reference to FIGS. 11 to 14 showing an example of the multitask processing procedure in the arithmetic processing unit 55c of the microcomputer 55.

That is, the process of FIG. 11 is a start determination process for determining the initialization start condition, and when the ignition switch (not shown) is turned on, a timer interrupt is performed every predetermined time (for example, 50 msec). First, in step S1, it is determined whether or not the initialization completion flag END is set to "1". When it is set to "1", it is determined that the initialization processing is completed. Then, the timer interrupt processing is finished as it is, and the processing shifts to another task processing, and when the initialization completion flag end is reset to "0", the processing shifts to step S2.

In step S2, each step motor 41i (i = F) is stored in the control position storage area at the end of the previous control.
It is determined whether or not the final control position P _{Pi of} L, FR, RL, RR) is stored. This determination is to determine whether or not the current position of each step motor 41i is secured and control accuracy can be maintained at the time of starting control by turning on the ignition switch, and the final control position P
_{When PFL to} P _PRR are stored, it is determined that the control accuracy can be maintained, and the process proceeds to step S3.

In this step S3, the vehicle speed detection value V of the vehicle speed sensor 52 is set in advance by the road noise, and the noise generated by the initialization process and the noise caused by the vibrations are mixed and the passenger cannot sense the vehicle speed. than V ₁ higher set speed V _S (e.g. 35k
m / h) or more, and when V <V _S, it is determined that the noise of the initialization process may be sensed by the occupant, the process proceeds to step S4, and the counter CNT is set to "0". After clearing to "", the timer interrupt process is terminated and the process shifts to another task process. When V≥V _S , the process shifts to step S5.

In this step S5, it is determined whether or not the initialization permission flag INT is set to "1", and when the initialization permission flag INT is reset to "0", the initialization processing is not permitted. Then, the process proceeds to step S6. In this step S6, the absolute value of the vertical acceleration detected value X _2i ″ in each vertical acceleration sensor 51 _i is the preset vertical acceleration X ₂₀ ″ with less road surface vibration input and vehicle body vertical movement set in advance
It is determined whether it is less than. This determination determines whether or not the fluid force passing through the orifice due to the influence of the piston speed of the shock absorber when the initialization process is performed does not affect the driving force of the step motor 41i and the accurate initialization process can be performed. When | X _2i ″ | ≧ X ₂₀ ″, it is determined that accurate initialization cannot be executed, and the process proceeds to step S4. When | X _2i ″ | <X ₂₀ ″, it is determined that it is correct. If it is determined that the initializing process can be executed, the process proceeds to step S7.

In this step S7, the counter CNT is incremented by "1" and then the process proceeds to step S8 to judge whether or not the count value of the counter CNT is equal to or more than a preset set value CNT ₀ , and CNT < CNT ₀
If CNT ≧ CNT0, the timer interrupt process is terminated and the process proceeds to another task. If CNT ≧ CNT ₀ , the process proceeds to step S9 and the initialization permission flag I
NT is set to "1", then the process proceeds to step S10, the counter CNT is cleared to "0", the timer interrupt process is terminated, and the process proceeds to another task process.

On the other hand, when the final control position P _Pi is not stored in the process of step S2 and when the result of the determination in step S5 is that the initialization permission flag INT is set to "1", the process proceeds to step S11. . In this step S11, the A / D converter 56
Read the current power supply voltage E _N of the battery 53, and then move to step S12 to read the read power supply voltage E _N.
Is equal to or higher than the initialization start voltage E _INT capable of compensating the preset drive torque of the step motor 41i, and when E <E _INT , the power supply voltage is too low to secure the reliability of the initialization process. If it is determined that the initialization is not possible, the timer interrupt processing is terminated without starting the initialization processing, and the processing shifts to another task processing. When E _N ≧ E _INT, it is determined that the reliability of the initialization processing can be secured. Then, the process proceeds to step S13 to clear the count value N of the monitoring counter in the power supply voltage monitoring process described later to "0", and then proceeds to step S14 to start the initialization execution process shown in FIG. Terminate the interrupt process.

The initialization execution process is set to have a higher priority than the other task processes. As shown in FIG. 12, first, the process proceeds to step S21 to execute the initialization process. In this initialization processing, assuming that the final position P of the valve body 31 (the position immediately before the initialization processing is performed) is in the position as shown in FIG. 15, the step motors 41FL to 41RR are rotated counterclockwise. The step amount S that is moved and becomes gradually smaller is output as a control signal at predetermined time intervals, whereby the valve body 3
1 Thus the body 44 butting rotates while reducing the stepwise the rotation angle in the counterclockwise direction, each the body 44 of the stopper plate 45 butting rotated eventually to the compression side maximum position (-P _MAX) The abutting abutting portions 45a and 45b are brought into contact with each other, and no more rotation occurs. From this state, step motor 41
By outputting a predetermined step amount S _a relative FL～41RR, step motor 41FL~41RR the rotation angle a only position the position P of the body 44 i.e. the valve element 31 butting is rotated clockwise value "0 ", And the initialization completion flag END is set to" 1 "in this state.

Next, in step S22, it is determined whether the initialization completion flag END is set to "1". Initialization completion flag END
Is reset to "0", step S23
And the initialization stop flag STP is "1".
If the initialization stop flag STP is reset to "0", the process proceeds to step S24, waits for a predetermined time, and then returns to step S21 to reset the initialization stop flag STP.
When TP is set to "1", step S
25, the initialization stop flag STP is reset to "0", the initialization execution process is terminated, and the process proceeds to another task process.

If the result of determination in step S22 is that the initialization completion flag END is set to "1", it is determined that the initialization processing has been completed, the initialization execution processing is terminated, and other task processing is executed. Move to. In the present embodiment, when the step motors 41FL to 41RR are rotated counterclockwise and stepwise by a predetermined rotation angle, each rotation position is held for a predetermined time, and the supply voltage is kept for a predetermined time. The driving force is set to "0" in the off state. That is, the driving force of the step motors 41FL to 41RR is interrupted during the initialization. Further, as shown in FIG. 15, for example, the angle from the final position P to the maximum expansion side position P _MAX is set to γ, and from the assumed maximum overshoot position P _N reached by the initialization processing to the compression side maximum position (−P _MAX ). Is δ, the angle δ is set to be larger than the angle γ so that the final position P always reaches the pressure side maximum position (-P _MAX ) regardless of the damping force control range. There is.

When the initialization execution process of FIG. 12 is started, at the same time as the initialization execution process is performed, a predetermined time (for example, 3.33 msec) is applied to the initialization execution process of FIG.
The battery voltage monitoring process shown in 3 is executed as a timer interrupt process. This battery voltage monitoring process is as follows:
In step S31, it reads the power supply voltage E _N of the battery 53, and then proceeds to step S32, the power supply voltage E _N
Is the preset initialization start voltage E _INT
It is determined whether or not the monitoring voltage E _WAT (<E _INT ) that can generate the minimum drive torque with the lower step motor 41i is exceeded, and if E _N ≦ E _WAT , the process _proceeds to step S33. transfers from incremented by the count value N "1" of the monitoring counter to step S34, as step S when a E _N> E _WAT
Move to 34.

In step S34, it is determined whether or not the count value N of the monitoring counter has reached a predetermined value N _S for judging that the reliability of the preset initialization process may be lowered, and N < If it is N _S , the process proceeds to step S35, the initialization stop flag STP indicating the stop of initialization is cleared to "0", the timer interrupt process is terminated, and the process is returned to the initialization execution process of FIG. _{When S} , step motor 4
When it is determined that the reliability of the initialization due to the decrease in the driving torque of 1i has deteriorated, the process proceeds to step S36, the initialization stop flag STP is set to "1", and then the process ends.

Further, in the microcomputer 55,
12 and 13 are not initialized.
In some cases, the damping force control process shown in FIG.
Executed as timer interrupt processing. This damping force control processing
As shown in FIG. 14, first, in step S41,
Vertical acceleration detection value X_2iRead ″ (i = FL, FR, RL, RR)
Then, the process proceeds to step S42, and step S41
At each damping force variable shock absorber 3i position read in
Vertical acceleration X in the vehicle_2i″ For low pass filter
The vertical velocity X of the vehicle body is integrated by performing processing._2i′ Is calculated
Out, then move to step S43, the calculated vehicle body
Vertical speed X_2iIt is determined whether ′ is positive including zero.
This judgment is made by the piston of the variable damping force shock absorber 3i.
Ton rod 35 is moving to the extension side or the compression side
X is to determine whether_2iWhen ′ ≧ 0
Decides that it is moving to the extension side, and determines in step S4
Move to 4, body speed V_2i′ Is set to a preset
True maximum value of side position P_TLMAXOn the car body when
Lower speed X_2TMValue X divided by_2i′ / X_2TM′ Exceeds 1
It is determined whether or not_2i′ / X_2TM′> 1
If so, move to step S45, where X_2i′ / X _2TM′
= 1 is set and then the process proceeds to step S46, where X_2i′ /
X_2TMIf ′ ≦ 1, step S46 is performed as it is.
Move to.

In step S46, the vehicle body vertical velocity X_2i′
And X_2TM′ And maximum position P on extension side_TMAXBased on
The target extension side position P is calculated by the following formula (2)._TTo
After the calculation, the process proceeds to step S47. P_T= (X_2i′ / X_2TM′) P_TMAX (2) In step S47, the data is stored in the storage device 55d.
Present position P _PAnd target position P_T(Or later
P to describe_C) And the step control amount
Update and store in a predetermined storage area of the storage device 55d as S
Together with the target position P_TOr P_CThe current position
Yon P_PIs updated and stored as, and then to step S48
After the migration, the data is stored in the predetermined storage area of the storage device 55d.
Outputs the step control amount S present to the motor drive circuit 59i
Then, the process proceeds to step S49 to end the predetermined control
It is judged whether the condition is satisfied, and if the control end condition is satisfied.
If not, the timer interrupt process is terminated and the specified
Returned to the main program and satisfied the control termination condition
Sometimes the process moves to step S50 and the current position P
_PThe ignition switch installed in the storage device 55d
Backup power is supplied even when the power is off.
A semiconductor memory or backup battery that holds the stored contents
Source rewritable non-volatile memory
(E²Stored in holding memory 55e composed of PROM)
Then, the process ends.

Here, the predetermined control end condition is set, for example, when a self-holding period of a predetermined time has elapsed since the ignition switch was turned off. On the other hand, when the determination result of step S43 is X _2i ′ <0, it is determined that the piston rod 35 of the damping force variable shock absorber 3i is moving to the compression side, and the process proceeds to step S51, and the vehicle body vertical speed X _2i It is determined whether or not a value X _2i ′ / X _2CM ′, which is _obtained by dividing ′ ′ by the vehicle body vertical velocity X _2CM ′ when the _preset maximum value P _CMAX of the pressure side position exceeds 1, exceeds X. _2i '/ X _2CM '> 1
If so, the process proceeds to step S52 and X _2i ′ /
After setting X _2CM ′ = 1, move to step S53,
When X _2i ′ / X _2CM ′ ≦ 1, the process directly _proceeds to step S53.

In step S53, the vehicle body vertical velocity X _2i '
, X _2CM ′ and the maximum pressure side position P _CMAX , the target pressure side position P _C is calculated by the following equation (3), and then the _{process proceeds} to step S47. P _C = (X _2i ′ / X _2CM ′) P _CMAX (3) Note that in the processing of FIGS. 11 to 14, FIG. 11 and FIG.
The processing of 2 corresponds to the initialization executing means, the processing of FIG. 13 corresponds to the initialization stopping means, and the processing of FIG. 14 corresponds to the control means.

Therefore, when the ignition switch is turned on, the controller 4 is powered on, and the microcomputer 55 is turned on.
The arithmetic processing unit 55c resets each flag to "0", executes a predetermined initialization process such as clearing the count values N and CNT to "0", and then starts the process of FIG.

At this time, since the initialization completion flag END is reset to "0" by the initialization,
Final control position P _{PFL to} P _PRR at the end of previous control
Is stored in the holding memory 55e (step S2), and in the normal state, the final control positions P _{PFL to} P _PRR are stored in the holding memory 55e by the damping force control process of step S14 at the end of the previous control. since it is, it is determined whether the vehicle speed V is set vehicle speed V _S or higher (step S3), and because the vehicle is stopped, the count value CNT of the time counter "0" timer interrupt processing is cleared to To finish. Therefore, the initialization execution process of FIG. 12 is not activated, and instead of this, the damping force control process of FIG. 14 is executed.

In this stopped state, the passengers get on and off and the load
If there is no loading / unloading, the car body will swing.
Output from the vertical acceleration sensors 51FL to 51RR without
Vertical acceleration detection value X_2FL″ 〜X_2RR″ Is almost zero
And the vehicle body vertical speed X_2FL’～ X_2RR′ Is also omitted
Since it is zero, it goes from step S43 to step S44.
Then, the process proceeds to step S46, and the extension side target position P_TAlso
Body vertical speed X_2iSince ′ is zero, it becomes zero, and the step
The motors 41FL to 41RR set the extension side target position P. _TMatches
Is driven to. Therefore, the damping force variable shock
The valve body 31 of the absorbers 3FL to 3RR is in the position shown in FIG.
B is set to the extension side of the piston 8.
And the damping force on the compression side is set to the minimum soft state.

When the vehicle is slowly started from this stopped state and straightly travels on a flat good road, the vertical movement of the vehicle body hardly occurs in this case as well, so that the vertical acceleration sensors 51FL to 51FL-5
Vertical acceleration detection value X _2FL ″ output from 1RR
X _2RR ″ becomes substantially zero, and the valve elements 31 of the variable damping force shock absorbers 3FL to 3RR maintain the position B shown in FIG. 6, whereby the damping force on the extension side and the compression side of the piston 8 is the minimum state. Therefore, even if the vibration due to the fine unevenness of the road surface is input to the wheels, the vibration is absorbed by the damping force variable shock absorbers 3FL to 3RR and is not transmitted to the vehicle body, so that a good riding comfort can be secured. .

In this running condition on a good road, when passing through a temporary step portion such as a step rising forward, when the vehicle body does not move up and down due to the passage of the step portion, the vehicle body vertical speed X
_{Since 2FL} ′ to X _2RR ′ maintain zero, the minimum damping force state is maintained, so the thrust force when the wheel rides on the step can be absorbed, but on the relatively large step, When you can not absorb the thrust force,
The vehicle body is also displaced upward, which causes the vehicle body vertical speeds X _2FL ′ to X _2RR ′ to increase 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 goes through step S44 and step S4.
6, the extension side position P _T on the side of the target maximum position P _TMAX is calculated from the extension side position P _{T1 of} FIG. 8, so the valve element 31 of the damping force variable shock absorbers 3FL to 3RR is shown in FIG. The switching control is performed as follows. As a result, the minimum damping force on the pressure side is maintained when the displacement speed X _1i ′ on the wheel side is faster than the displacement speed X _2i ′ on the vehicle body side and the piston 8 moves to the pressure side due to stepping on the step portion.
The vibration input to the wheel side can be absorbed, and if the ascending speed on the wheel side becomes smaller than the ascending speed on the vehicle body side by overcoming the step from this state, the piston 8 will move to the extending side. At this time, since the damping force has a large value, the damping effect of suppressing the rise of the vehicle body is exerted, and when the raising of the vehicle body stops thereafter, the vehicle body vertical speeds X _2FL ′ to X 2
_{As 2RR} ′ becomes zero, as described above, the step motors 41FL to 41RR are rotated counterclockwise and returned to the position B, 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,
Accordingly, the vehicle body vertical velocities X _2FL ′ to X _2RR ′ increase in the negative direction.
After 51, the process proceeds to step S53 to calculate the pressure side target position P _C , whereby the valve body 31 is further rotated counterclockwise and rotated to the rotation position shown in FIG. 7. Therefore, when the vehicle body descends and the piston 8 moves to the pressure side, the damping force becomes large, so that a large damping effect is exerted.

On the contrary, when the wheel passes through the step of descending to the front, the wheel rebounds first to increase the relative speeds X _DFL ′ to X _DRR ′ in the positive direction, but at this time, the vehicle body does not move up and down. Vertical speed of the vehicle X _2FL '~ X
_{Since 2RR} 'is zero, the damping coefficients of the variable damping force shock absorbers 3FL to 3RR maintain the minimum damping force and allow the wheels to descend, after which the vehicle body starts to descend, and the vehicle body vertical velocity X _2FL ' 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 damping effect, and then the vehicle body vertical speed X _{2F L} ′ to X _2RR ′.
When the pressure side target position P _C becomes smaller and the valve body 31 is rotated clockwise to return to the position B side and the vehicle body vertical speeds X _2FL ′ to X _{2R R} ′ become zero, the valve The body 31 comes to the position B and returns to the minimum damping force state. After that, when the vehicle body starts to rise by _swinging back, the vehicle body vertical velocities X _2FL ′ to X _2RR ′ increase in the positive direction, so that the extension side target position P _T increases and the valve body 31 is rotated clockwise. 5 to the position shown in FIG. 5, a large damping force can be given to the extension side movement of the piston 8 to exert a vibration damping effect.

As described above, when passing a temporary step while traveling on a good road, a good damping effect can be exhibited by skyhook control, and when traveling on a bad road. Also, the _expansion side target position P _T (or the _compression side target position P _C ) is calculated by the positive (or negative) of the vehicle body vertical speeds X _2FL ′ to X _2RR ′, so that the vehicle body rises and the piston 8 extends. The damping force is controlled to the minimum damping force when the vibration direction is moving to the side, and conversely, when the vehicle body rises and the piston 8 moves to the extension side, and when the vehicle body descends and the piston 8 becomes the compression side. When it is in the swing direction, it is controlled to the optimum damping force according to the vertical velocities X _2FL ′ to X _2RR ′,
A good ride comfort can be secured.

Even when the vehicle is traveling on a rough road, the vehicle body moves up and the piston 8 moves to the extension side, and the vehicle body moves down to move the piston to the pressure side, as in the case of passing the step. Damping force is controlled to the minimum damping force in the vibration direction, and conversely, damping 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. The damping force is vertical velocity X
It is possible to secure a good ride comfort by controlling to an optimum value according to _2FL 'to _X2RR '.

After that, the vehicle speed V is the set vehicle speed V._SReach
Then, when the processing of FIG. 11 is executed, step S5 is executed.
After that, the process proceeds to step S6 and is traveling on a flat and good road.
The absolute value of the vertical acceleration detection value of the vertical acceleration sensor 51i.
Value | X_2i″ | Is the set acceleration X₂₀When less than ″,
Go to step S7 and the counter CNT is only "1".
It is incremented and this is repeated until the count
Value CNT is set value CNT ₀When you reach
The permission flag INT is set to "1" and
Unta CNT is cleared to "0".

Therefore, when the processing of FIG. 11 is executed next, the process proceeds from step S5 to step S11,
The power supply voltage E _N of the battery 53 is read, then the process proceeds to step S12, and when the power supply voltage E _N is equal to or higher than the initialization start voltage E _INT , the process proceeds to step S13 and the initialization execution process of FIG. 12 is started. When this initialization execution process is activated, the priority of this process is high, so the damping force control process of FIG. 14 is suspended, and the initialization execution process is executed with priority.

By this initialization execution process, the step motor 41i is rotated counterclockwise as shown in FIG. 45a, 45
Then, the current control position P _P is set to "0" in this state.

In this state, the vehicle is traveling at the set vehicle speed V _S or higher, and the noise generated by the initialization process due to the road noise and the noise due to the vibration are erased, which does not give an occupant an uncomfortable feeling. Absent. When this initialization execution process is started,
The power supply voltage monitoring process 3 is also executed as a timer interrupt process for the initialization process at the same time.

Therefore, the power supply voltage E _{N of the} battery 53 is
Is above the initialization start voltage E _INT , and when it is above the monitoring voltage E _WAT lower than this, it is judged that the initialization process can be normally performed, and the initialization execution process of FIG. 12 is continued. When the initialization process is completed and the initialization completion flag END is set to "1", the initialization execution process is terminated and the damping force control process is returned to.

By the way, when the power supply voltage E _N falls below the monitoring voltage E _WAT as shown in FIG. 16 while the initialization execution processing of FIG. 12 continues, the power supply voltage monitoring processing of FIG. 13 is executed. Each time, the count value N of the monitoring counter is incremented by "1". Until the count value N reaches the set value N _S , as shown in FIG. 15, the number of steps for contacting the abutting member 44 with the abutting protrusions 45a, 45b of the stopper plate 45 is the actual maximum number of steps. By setting a larger amount, accurate control origin calibration can be performed, so the initialization execution processing of FIG. 12 is continued. If the initialization processing is completed during this time, the initialization completion flag END Is set to "1" to end the initialization execution process.

However, the power supply voltage E _N is the monitoring voltage E _WAT.
When the count value N of the monitoring counter becomes equal to or greater than the set value N _S due to an increase in the time of falling below, the abutment body 44 causes the abutment body 44 of the stopper plate 45 due to insufficient drive torque of the step motors 41FL to 41RR in this state. 45a, 4
The initialization cancel flag STP is set to "1" (step S3), because it is determined that the initializing reliability may be lowered because it may not be in contact with 5b.
6).

For this reason, when the process of FIG. 12 is restarted, the process proceeds from step S23 to step S25, the initialization stop flag STP is reset to "0", and the initialization execution process is prepared again. To cancel the initialization execution process. After that, in the process of FIG. 11, when the initialization start condition is satisfied, the initialization execution process is started again, and when the initialization process is completed, the initialization completion flag END is set to "1".
11 is executed, the timer interrupt process is ended as it is from step S1, and this state is maintained until the ignition switch is turned off and the control is ended. Repeated.

After that, the vehicle is stopped from the running state,
When the ignition switch is turned off, when the process of FIG. 13 is executed, the process proceeds from step S49 to step S50, the current control position P _P is held in the holding memory 55e as the control position data, and the control ends. To do. On the other hand, when the ignition switch is turned on and the control position data P _P representing the current position is not stored in the holding memory 55e,
Since the current control position of the damping force variable shock absorber 3i is indefinite, accurate damping force control can be performed until the initialization processing at the set vehicle speed is performed when the damping force control is executed through running as it is. Disappear. Therefore, when the process of FIG. 11 is executed, the process proceeds from step S2 to step S11, and the power supply voltage _EN
12 becomes equal to or higher than the initialization start voltage E _INT, the initialization execution process of FIG. 12 is immediately activated, and the initialization process is executed at the time of startup.

As described above, according to the above-described embodiment, when the ignition switch is turned on, it is determined whether or not the current control position data P _P is stored, and when it is not stored, When the initialization process is immediately executed and the control position data P _P is stored, the initialization process is executed after a predetermined initialization start condition that does not give an occupant an unpleasant sensation is established, and during the execution of the initialization process,
Monitoring for a moment the power supply voltage due to the influence of noise, such as voltage E _WAT
Even if the following cases occur, if the count value N of the monitor counter that counts up when the voltage becomes the monitor voltage or less is less than the set value, the initialization process is continued, and if the initialization process is completed during this period, Since it can be determined that the initialization has been completed, and the initialization process is stopped only when the count value N becomes equal to or greater than the set value N _S , it is possible to instantaneously receive the influence of noise or the like as in the conventional example described above. It is possible to reliably avoid the chattering phenomenon in which the initialization process is repeatedly stopped and restarted due to a decrease in the power supply voltage.

In the above embodiment, the case where the damping force variable shock absorbers 3FL to 3RR are applied as the actuator has been described, but the present invention is not limited to this, and the roll rigidity variable which can change the roll rigidity is used. The present invention can be applied to a stabilizer, an air suspension capable of varying a spring constant, and the like when an open loop controlled step motor is used.

In the above embodiment, the valve body 31 for controlling the damping force is described as a rotary type. However, the invention is not limited to this, and the spool type is used to extend the compression side. Different flow paths may be formed on the side of the step motors.
A pinion may be connected to the rotating shaft 41a of 1RR and a rack meshing with the pinion may be attached to the connecting rod 42 or an electromagnetic solenoid may be applied to control the sliding position of the valve element 31.

Further, in the above embodiment, the case where the abutment body 44 is provided on the connecting rod 42 connected to the rotary 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 attached to the connecting rod 42 in the reverse relationship, and the abutting member 4
4 may be provided in the upper half body 12, and further, a position detecting means such as a micro switch which engages with the abutting body 44 instead of the stopper plate 45 is provided, and the abutting body is abutted by this position detecting means. When 44 is detected, the driving of the step motors 41FL to 41RR may be stopped to perform the origin calibration more accurately. In this case, since the vibration and noise caused by the contact between the butting body and the stopper plate are small, the holding process can be executed when the holding memory 55e is omitted and the ignition switch is turned on. Furthermore, even when the occurrence of vibration or noise can be ignored, the initialization process can be executed when the ignition switch is turned on.

Further, in the above embodiment, the case where the count value N of the monitor counter is incremented when the power supply voltage becomes equal to or lower than the monitor voltage has been described, but the present invention is not limited to this, and the power supply voltage is first monitored. When it becomes the following, the count value of the monitoring counter is preset to the set value N _S and then decremented sequentially, and when the count value N becomes zero, the initialization stop flag ST
You may make it set P to "1".

Furthermore, in the above-described 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 described, but the present invention is not limited to this. However, a stroke sensor for detecting the relative displacement between the vehicle body and the wheels is separately provided, and the relative velocity X _Di ′ obtained by differentiating the relative displacement detection value X _Di of the stroke sensor and the vehicle body vertical velocity X _2i ′ described above. The following equation (3) is used to calculate the damping coefficient C, and based on this damping coefficient C, the target position is calculated with reference to the 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 embodiment, the case where the posture change of the vehicle body due to the vibration input from the road surface is suppressed has been described.
However, the present invention is not limited to this, and it is also possible to detect the running state of the vehicle, such as the rolling state and the braking state, and perform the control for suppressing the change in the posture of the vehicle body.

Further, in the above embodiment, the case where the control origin calibration by the normal initialization processing is performed when the vehicle is traveling on a flat road surface at the set vehicle speed V _S or more has been described, but the present invention is not limited to this. If the damping force variable shock absorber 3i has a high piston speed, the step amount due to the driving force of the step motor 41i may change due to the influence of the fluid force passing through the orifice. Alternatively, the piston velocity may be estimated and the control origin calibration by the initialization process may be performed after the piston velocity that may cause step-out is reached.

Furthermore, in the above embodiment, the case where the microcomputer 55 is applied to control is described, but the present invention is not limited to this, and the output of the vertical acceleration sensor 51i is integrated to determine the vehicle vertical speed. An electronic circuit such as an integrator for calculating and a calculation circuit for calculating the target position may be combined. Furthermore, in the above embodiment, each wheel 1FL to 1RR of the vehicle body 2 is
Although the vertical acceleration sensors 51FL to 51RR are provided at the positions, any one vertical acceleration sensor may be omitted and the vertical acceleration at the omitted position may be estimated from the values of other vertical acceleration sensors. Good.

Further, the variable damping force shock absorber is not limited to the above-mentioned constitution, and the present invention is applied to other variable damping force shock absorbers in which the damping force can be switched in two or more steps by the step motor. obtain.

[0071]

As described above, according to the first aspect of the present invention, the initialization of the control system is started when the power supply voltage becomes equal to or higher than the set voltage by the initialization execution means, and the power supply voltage is increased during the initialization. Is lower than the monitoring voltage lower than the set voltage, the initializing stopping means measures the lowering time, and when the sum of the lowering times is less than a preset set value, the initializing by the initializing executing means is continued to lower the voltage. When the time sum exceeds the set value, the initialization is judged to be defective for the first time and the initialization of the initialization execution means is stopped.Therefore, even if the power supply voltage drops below the monitor voltage, the sum of the drop times exceeds the set value. The initialization process can be continued during this period, and the initialization process can be completed during this period. Can, to prevent the chattering phenomenon to repeat initialization start and stop and the like in the conventional example described above, there is an advantage that it is possible to complete the early initialization process.

According to the second aspect of the present invention, when the vehicle speed becomes equal to or higher than the set vehicle speed by the initialization execution means and the power supply voltage detection value is equal to or higher than the set voltage, the initialization is started, so that the initialization occurs. It is possible to obtain an effect that it is possible to prevent the occupant from feeling uncomfortable by driving off the driving noise of the step motor or the noise generated when the engaging piece comes into contact with the stopper and the noise caused by vibration by road noise or the like.

Further, according to the invention of claim 3, the initialization stopping means updates the count value of the counter when the power supply voltage detection value becomes less than the monitoring voltage, so that the power supply voltage becomes equal to or higher than the monitoring voltage. It is possible to retain the count value when returning, and it is possible to easily detect the sum of the times when the voltage is equal to or lower than the monitoring voltage, that is, the cumulative time.

[Brief description of drawings]

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

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

FIG. 3 is a front view with a part in section showing an example of a damping force variable shock absorber.

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

FIG. 5 is an enlarged cross-sectional view showing a damping force adjusting mechanism in an intermediate damping force state when the vehicle body is raised, (a) showing an extension side and (b) showing a pressure side hydraulic fluid path, respectively.

FIG. 6 is an enlarged cross-sectional view showing a damping force adjusting mechanism when there is no change in the vehicle body.

FIG. 7 is an enlarged cross-sectional view showing a damping force adjusting mechanism in a maximum damping force state when the vehicle body is descending, (a) showing an extension side and (b) showing a pressure side hydraulic fluid path, respectively.

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

9 is an enlarged cross-sectional view taken along the line AA of FIG.

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

FIG. 11 is a flowchart illustrating an example of an initialization start determination processing procedure of the controller.

FIG. 12 is a flowchart showing an initialization execution process of the controller.

FIG. 13 is a flowchart showing a power supply voltage monitoring process executed during the initialization execution process of FIG.

FIG. 14 is a flowchart showing an example of a damping force control process of a controller.

15 is an explanatory diagram of the operation of the initialization (control origin calibration) processing of FIG.

FIG. 16 is an explanatory diagram showing a relationship between a power supply voltage variation at initialization and a count value of a monitoring counter.

[Explanation of symbols]

 1FL to 1RR Wheels 2 Vehicles 3FL to 3RR Damping force variable shock absorber 4 Controller 8 Piston 11 Lower half 12 Upper half 13 Expansion side oil flow path 14 Pressure side oil flow path 31 Valve body 35 Piston rods T1 to T3 Expansion side flow path C1 to C4 Pressure side flow path 41FL to 41RR Step motor 51FL to 51RR Vertical acceleration sensor 52 Vehicle speed sensor 53 Battery 55 Microcomputer 59FL to 59RR Motor drive circuit

Claims (3)

[Claims] 1. Suspension characteristics can be individually controlled by rotationally controlling a valve element by a step motor interposed between a vehicle body side member and a wheel side member and driven in response to an input control signal. A suspension control device including an actuator and a control unit that detects a posture change of a vehicle body and outputs the control signal corresponding to the detected posture change value to the step motor to perform open loop control. Power supply voltage detection means for detecting the power supply voltage to be supplied, and initialization for performing the initialization of the control means when the power supply voltage detection value of the power supply voltage detection means has reached a preset voltage for initializing the control system. Means and the power supply voltage detection value after the initialization is started by the initialization execution means. A suspension control device comprising: an initialization stop means for stopping the initialization of the initialization execution means when the sum of the times when the monitoring voltage is lower than the set voltage and becomes equal to or higher than a set value. 2. The suspension control device according to claim 1, wherein the initialization executing means initializes the control means when the vehicle speed is equal to or higher than a set vehicle speed and the power supply voltage detection value is equal to or higher than a set voltage. . 3. The initialization canceling means has a counter for updating the count value while the power supply voltage detection value is equal to or lower than the monitoring voltage, and cancels the initialization when the count value of the counter reaches a set value. The suspension control device according to claim 1 or 2, wherein the suspension control device is configured as follows.