JPH07232530A - Suspension control device - Google Patents

Abstract

PURPOSE:To provide a suspension control device capable of acquiring favourable riding comfortability regardless of a road surface status. CONSTITUTION:This device is furnished with a large amplitude frequency computing part 45 having an amplitude threshold against an acceleration signal from an acceleration sensor 5 and finding frequency that two acceleration signals coming at about the same time change from large to small and small to large in comparison with the amplitude threshold, a judgment part 46 to judge a road surface status in accordance with a detection result of the large amplitude frequency computing part 45 and a parameter regulating part 47 to regulate a control gain K of a control target value computing part 43 as well as a dead zone A of a corrected value computing part 42 in accordance with a judgement result of the judgement part 46. The control gain K is set large in case of a good road and is set small in case of a bad road in accordance with the judgement result of the road surface status, and it is possible to set the dead zone A small in the case of the good road and to set it large in the case of the bad road. Consequently, it is possible to improve riding comfortability as influence of frequent vertical oscillation due to bad road traveling is reduced even in the case of bad road traveling.

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.

[0002]

2. Description of the Related Art As an example of a conventional suspension control device, there is a suspension control device disclosed in JP-A-5-330325. This suspension control device detects a shock absorber with a variable damping coefficient interposed between a sprung part and an unsprung part of a vehicle, an actuator that adjusts and sets a damping coefficient of the shock absorber with a variable damping coefficient, and a vertical acceleration of a vehicle body. An acceleration sensor; an integrating means for integrating an acceleration signal of the acceleration sensor to obtain a vertical absolute speed; a control target value calculating means for multiplying the vertical absolute speed by a control gain to obtain a control target value; Control signal generation for generating a corresponding control signal by pre-storing information indicating the correspondence between the control target value and the control signal based on the characteristics of the shock absorber and inputting the control target value from the control target value calculation means Means to obtain a damping coefficient according to the absolute velocity in the vertical direction to improve ride comfort and drivability.

[0003]

By the way, in order to suppress the vertical vibration of the vehicle body, it is theoretically desirable to adjust the damping force according to the absolute velocity of the vehicle body in the vertical direction, but the shock absorber directly adjusts the damping force. Since it is not possible (the damping force is a function of the piston speed having the damping coefficient as a coefficient), the damping coefficient is actually adjusted according to the absolute velocity in the vertical direction as in the above-described conventional technique.

Therefore, in the above-mentioned prior art, the control gain / dead zone is assumed on the assumption of an average piston speed generated when traveling on an ordinary paved road surface (relatively small vibration and small amplitude). Etc. were set and vibration was controlled.

However, when the vehicle travels on a rough road surface (there are many vibrations and the amplitude is large), the piston speed becomes a speed far from the average piston speed, and a large damping force is required as compared with the required damping force. Force is generated,
As a result, the riding comfort may be deteriorated.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a suspension control device which can obtain a good riding comfort regardless of road surface conditions.

[0007]

In order to achieve the above object, the invention of claim 1 is a damping coefficient variable type shock absorber interposed between a sprung part and an unsprung part of a vehicle, and the damping coefficient variable type shock absorber. An actuator that adjusts and sets the damping coefficient of the shock absorber based on a control signal, a vertical absolute speed detection unit that detects a vertical absolute speed of the vehicle body, and a vertical absolute speed signal from the vertical absolute speed detection unit according to a running state. A control unit for changing the control target signal, a control signal transmitting unit for generating a control signal from the control target signal from the control unit to the actuator, and a unit for generating a signal representing the roughness of the road surface on which the vehicle travels. A control unit adjusting means for adjusting a characteristic of changing the vertical absolute speed signal in the control unit according to a signal representing the roughness. It is characterized in.

According to a second aspect of the present invention, in order to achieve the above object, a damping coefficient variable type shock absorber interposed between a sprung part and an unsprung part of a vehicle and a damping coefficient of the damping coefficient variable type shock absorber are provided. An actuator that is adjusted and set based on a control signal, a vertical absolute speed detection unit that detects the vertical absolute speed of the vehicle body, a control target calculation unit that multiplies the vertical absolute speed by a control gain to obtain a control target signal, and the control target Control signal transmitting means for transmitting a control signal for the actuator from the signal, road surface condition determining means for determining whether or not the road surface condition on which the vehicle is traveling is a bad road, and the control when the road surface condition determining means determines a bad road And a control gain adjusting means for adjusting the gain to a small value.

In order to achieve the above object, a third aspect of the present invention is to provide a variable damping coefficient type shock absorber interposed between a sprung portion and an unsprung portion of a vehicle and a damping coefficient of the variable damping coefficient type shock absorber. An actuator that is adjusted and set based on a control signal, a vertical absolute speed detection unit that detects a vertical absolute speed of a vehicle body, and a correction value obtained by removing a vertical absolute speed that is smaller than a predetermined value as a dead zone. A correction value calculating means, a control target calculating means for obtaining a control target signal by multiplying the correction value by a control gain, a control signal transmitting means for transmitting a control signal of an actuator from the control target signal, and a road surface condition on which the vehicle travels. Is a rough road, and a predetermined value of the dead zone is adjusted to a large value when the road is judged to be a bad road by the road condition judging means. Characterized by comprising a sensitive zone adjusting unit.

According to a fourth aspect of the present invention, in order to achieve the above object, the suspension control device according to the first or second aspect is provided with a vertical acceleration sensor for detecting a vertical acceleration of the vehicle body, and the road surface condition determining means. Is a large-amplitude-count calculation unit that obtains a large-amplitude count in which the amplitude of the vertical-acceleration signal of the vertical-acceleration sensor exceeds a preset amplitude threshold within a predetermined time; and the large-amplitude count exceeds a predetermined count reference value. It is characterized in that it comprises a judging section for judging a rough road.

According to a fifth aspect of the present invention, in order to achieve the above object, in the suspension control device according to the second or third aspect, the road surface condition determining means is a vertical absolute velocity signal of the vertical absolute velocity detecting means. From the large-amplitude-number calculating unit that obtains a large-amplitude number that exceeds a preset amplitude threshold within a predetermined time, and a determining unit that determines a bad road when the large-amplitude number exceeds a predetermined number-of-times reference value. It is characterized by

According to a sixth aspect of the present invention, in order to achieve the above object, in the suspension control device according to the second or third aspect, a vehicle height sensor for detecting the vehicle height of the vehicle body is provided, and the road surface condition determining means is provided. Is a large-amplitude-number calculating unit that obtains a large-amplitude number in which the amplitude of the vehicle-height signal of the vehicle-height sensor exceeds a preset amplitude threshold within a predetermined time, and the large-amplitude number exceeds a predetermined number-of-times reference value. It is characterized in that it comprises a judging section for judging a rough road.

According to a seventh aspect of the present invention, in order to achieve the above object, in the suspension control device according to any one of the fourth to sixth aspects, a vehicle speed detecting means for detecting a vehicle speed of the vehicle is provided, and the determination section includes: It is characterized in that the rough road is determined by increasing the number-of-times reference value according to the vehicle speed detected by the vehicle speed detecting means.

According to an eighth aspect of the present invention, in order to achieve the above object, in the suspension control device according to any one of the fourth to sixth aspects, a vehicle speed detecting means for detecting a vehicle speed of the vehicle is provided, and the determination section is A rough road is determined by increasing the amplitude threshold value according to the vehicle speed detected by the vehicle speed detecting means.

In order to achieve the above object, a ninth aspect of the present invention is to provide a variable damping coefficient type shock absorber interposed between a sprung part and an unsprung part of a vehicle and a damping coefficient of the variable damping coefficient type shock absorber. An actuator that is adjusted and set based on a control signal, a vertical absolute speed detection unit that detects the vertical absolute speed of the vehicle body, a control target calculation unit that multiplies the vertical absolute speed by a control gain to obtain a control target signal, and the control target Control signal transmitting means for transmitting a control signal for the actuator from the signal, vertical relative speed detecting means for detecting the vertical relative speeds of the sprung and unsprung of the vehicle, and the mean square of the vertical relative speeds within the latest predetermined time. And a control gain adjusting means for adjusting the control gain to a small value according to the magnitude of the mean square.

In order to achieve the above-mentioned object, a tenth aspect of the present invention is to provide a damping coefficient variable type shock absorber interposed between a sprung part and an unsprung part of a vehicle, and a damping coefficient of the variable damping coefficient type shock absorber. An actuator that is adjusted and set based on a control signal, a vertical absolute speed detection unit that detects a vertical absolute speed of a vehicle body, and a correction value obtained by removing a vertical absolute speed that is smaller than a predetermined value as a dead zone. A correction value calculating means, a control target calculating means for obtaining a control target signal by multiplying the correction value by a control gain, a control signal transmitting means for transmitting an actuator control signal from the control target signal, a sprung mass and a spring of a vehicle. A vertical relative velocity detecting means for detecting a lower vertical relative velocity, a mean square calculating means for obtaining a mean square of the vertical relative velocity within a latest predetermined time, and a square root Characterized by comprising a dead band adjustment means for adjusting to a higher value the predetermined value of the dead zone in accordance with the size.

[0017]

According to the first aspect of the invention, the control unit adjusting means adjusts the characteristic of changing the vertical absolute speed signal in the control unit according to the roughness of the road surface on which the vehicle travels.

According to the second aspect of the present invention, when the road surface is a bad road, the control gain is adjusted to a smaller value by the control gain control means, so that the damping coefficient is smaller than that on a good road. Even if the speed increases, the damping force is prevented from becoming too large.

According to the structure of claim 3, the predetermined value of the dead zone is adjusted to a larger value by the dead zone adjusting means when the road surface condition is a bad road. Therefore, in the area where the dead zone is expanded, the dead zone becomes a good road. Since the damping coefficient is smaller than that of the comparative example, the damping force is prevented from becoming too large even if the piston speed becomes fast.

According to the fourth aspect of the present invention, the number of large amplitudes in which the amplitude of the vertical acceleration of the vehicle body within the predetermined time exceeds the amplitude threshold value is calculated, and when the number of large amplitudes exceeds the reference value, it can be determined as a bad road. .

According to the fifth aspect of the invention, the number of large amplitudes in which the amplitude of the vertical absolute velocity of the vehicle body within the predetermined time exceeds the amplitude threshold value is obtained, and when the large amplitude number exceeds the reference value, it is determined as a bad road. it can.

According to the structure of claim 6, the number of times that the amplitude of the vehicle height of the vehicle body exceeds the amplitude threshold within a predetermined time is obtained, and when the number exceeds the reference value, it can be determined that the road is rough.

Further, when the amplitude threshold value is constant, the number of large amplitudes within a predetermined time increases even when the vehicle speed is high even on the same road surface. However, with the configuration of claim 7, the vehicle speed is high. When this occurs, the reference value for the number of times of large amplitude becomes large, so that the rough road can be accurately determined even if the vehicle speed becomes fast.

According to the structure of claim 8, when the vehicle speed becomes faster, the amplitude threshold value for judging the rough road is increased, so that the rough road can be accurately judged even if the vehicle speed becomes faster. .

According to the structure of claim 9, since the root mean square of the vertical relative speed increases as the road surface condition becomes bad, the control gain is set to a small value according to the root mean square of the vertical relative speed. As a result, the damping coefficient becomes a small value when traveling on a rough road, so that the damping force is prevented from becoming too large even if the piston speed becomes fast.

According to the structure of claim 10, since the root mean square of the vertical relative speed increases as the road surface condition becomes bad, the dead zone is adjusted to a predetermined value in accordance with the root mean square of the vertical relative speed. Since the damping coefficient is adjusted to a larger value and the damping coefficient is smaller than that on a good road, it is possible to prevent the damping force from becoming too large even if the piston speed becomes fast.

[0027]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A suspension controller according to a first embodiment of the present invention will be described below with reference to FIGS. In FIG. 1, between a vehicle body 1 (sprung) and four wheels (only one is shown in the figure) 2 (unsprung) constituting a vehicle,
A spring 3 and an expansion / contraction inversion type variable damping coefficient type shock absorber 4 are interposed in parallel, and support the vehicle body 1. An acceleration sensor 5 for detecting the vertical acceleration of the vehicle body 1 is mounted on the vehicle body 1. The acceleration signal of the acceleration sensor 5 is supplied to the controller 6. It should be noted that the damping coefficient variable type shock absorber 4 and the spring 3 are respectively provided in four pieces corresponding to the four wheels 2, but only one of them is shown for convenience.

The variable damping coefficient type shock absorber 4 is
As shown in FIG. 2, a free piston 12 is slidably housed in a cylinder 11, and the free piston 12 allows the gas chamber 13
And oil chamber 14 are defined. The gas chamber 13 is filled with high-pressure gas, and the oil chamber 14 is filled with oil liquid. A piston 15 is slidably accommodated in the oil chamber 14. The oil chamber 14 is defined by a piston 15 into a lower chamber R1 and an upper chamber R2. A piston rod 16 is connected to the piston 15. Piston rod 16 passes through upper chamber R2
11 extends out.

The piston 15 is formed with first and second communication passages 17 and 18 which communicate the lower chamber R1 and the upper chamber R2, respectively. A normally closed first damping valve 19 is attached to the upper portion of the piston 15. The first damping valve 19 is a piston rod
When the pressure in the lower chamber R1 increases and the pressure difference between the lower chamber R1 and the upper chamber R2 reaches a predetermined value when shortening 16, it opens so that the lower chamber R1 and the upper chamber R2 communicate with each other via the first communication passage 17. I am trying to make it. A normally closed second damping valve 20 is attached to the lower portion of the piston 15. The second damping valve 20 is a piston rod
When expanding 16, the pressure in the upper chamber R2 increases and the lower chamber R1 and the upper chamber R2
When the pressure difference between the upper chamber R2 and the lower chamber R2 reaches a predetermined value, the lower chamber R1 and the upper chamber R2 can communicate with each other via the second communication passage 18. The piston 15 is formed with third and fourth communication passages 21 and 22 that face each other with the axis of the piston rod 16 in between. The third and fourth communication passages 21 and 22 are respectively in the upper chamber R
2, communicating with lower chamber R1.

Check valves 23 and 24 are provided in the third and fourth communication passages 21 and 22, respectively. The check valve 23 allows only the flow of oil liquid from the lower chamber R1 to the upper chamber R2, and the check valve 24 allows only the flow of oil liquid from the upper chamber R2 to the lower chamber R1. A disk-shaped movable plate 25 is rotatably held inside the piston 15 about the axis of the piston rod 16.
The plate surface of the movable plate 25 crosses the third and fourth communication passages 21 and 22, respectively. As shown in FIG. 3, the movable plate 25 is formed with a pair of elongated holes 26, 27 extending in an arc shape along the circumferential direction. The long holes 26 and 27 are formed concentrically with the center of the movable plate 25 so as to face each other. The opening area of the long hole 26 becomes smaller as it goes in the direction of the arrow R in FIG.
The opening area increases in the direction.

When the movable plate 25 is rotated in the direction of arrow R or L, the portions of the elongated holes 26, 27 facing the third and fourth communication passages 21, 22 are continuously changed, and the third and fourth portions are changed. The opening areas of the communication passages 21 and 22 gradually increase or decrease, whereby the variable damping coefficient shock absorber 4 can obtain the damping characteristics shown by the solid line in FIG. In addition, in order to change the damping coefficient smoothly, the center position of the long holes 26, 27
It is also possible to use damping coefficient characteristics that smoothly change around b2 and b1 as shown by the broken line.

In FIG. 2, 28 is a piston rod.
The lower end of the movable plate 25
Is an operation rod connected to. Further, 29 is an actuator such as a stepping motor which is connected to the upper end of the operating rod 28 and rotates the movable plate 25 in the arrow R direction or the arrow L direction via the operating rod 28. The actuator 29 rotates the operating rod 28 based on the control signal θ transmitted from the control signal transmission unit 44 of the controller 6.

Next, the third and fourth communication passages of the long holes 26 and 27.
The relationship between the parts facing 21 and 22 (a2 to b2 to c2, a1 to b1 to c1) and the damping coefficient will be described. Here, the positions of the elongated holes 26, 27 facing the third and fourth communication passages 21, 22 are represented by the rotation angle θ of the movable plate 25. When the positions b2 and b1 which are the centers of the long holes 26 and 27 face the third and fourth communication passages 21 and 22, this position is set as the reference position (θ = 0) of the movable plate 25.

(1) When the movable plate 25 is rotated in the arrow R direction from the reference position, that is, when the movable plate 25 is rotated in the positive direction (θ> 0), the position a2 of the slot 26 is the third communication passage. 21 and the position a1 of the long hole 27 faces the fourth communication passage 22. As a result, the oil liquid easily flows from the lower chamber R1 to the upper chamber R2, and it becomes difficult for the oil liquid to flow from the upper chamber R2 to the lower chamber R1, so that the expansion-side damping coefficient is large and the contraction-side damping coefficient is small.

(2) When the movable plate 25 is rotated in the direction of the arrow L from the reference position, that is, when the movable plate 25 is rotated in the negative direction (θ <0), the position c2 of the slot 26 is the third communication passage. 21 and the position c1 of the long hole 27 faces the fourth communication passage 22. As a result, the oil liquid does not easily flow from the lower chamber R1 to the upper chamber R2, the oil liquid easily flows from the upper chamber R2 to the lower chamber R1, and the expansion-side damping coefficient is small and the contraction-side damping coefficient is large.

The controller 6 includes an integration processing section 41, a correction value calculation section 42, a control target value calculation section 43, and a control signal transmission section.
44, a large-amplitude number calculation unit 45, a determination unit 46, and a parameter adjustment unit 47. The integration processing unit 41 is
An absolute vertical velocity S is formed by forming an absolute vertical velocity detecting means together with the acceleration sensor 5 and integrating the acceleration signal α of the acceleration sensor 5.
The correction value calculation unit 42 as a correction value calculation means
Output to. The correction value calculation unit 42 removes a portion of the vertical absolute velocity S from which the absolute value is smaller than a predetermined value A (hereinafter referred to as dead zone A) and data proportional to this data (hereinafter referred to as corrected vertical absolute velocity). .) S '(corresponding to S') (for convenience, a graph showing this information is shown in the block showing the correction value calculating unit 42 in FIG. 5) is stored, and the vertical absolute speed S is input. Then, the corresponding corrected vertical absolute velocity S'is obtained and this value is output to the control target value calculation unit 43 as the control target calculation means.

The correction value calculation unit 42 may store information as shown in FIG. 9 and obtain the corrected vertical absolute velocity S'based on the stored information. Here, FIG.
In the above example, as shown by the broken line, only the area of the dead zone A is changed without changing the correspondence between the vertical absolute speed S and the corrected vertical absolute speed S '.
In the case of FIG. 9, the area of the dead zone A is changed by shifting the correspondence relationship in the left-right direction as shown by the broken line. So in this case,
When the predetermined value A is increased, the dead zone A increases and the value of the corrected vertical absolute speed S'decreases with respect to the input of the vertical absolute speed S. Therefore, when using the one in FIG.
Even if the control gain K is not changed only by changing the dead zone A, substantially the same effect can be obtained as when both the control gain K and the dead zone A in FIG. 5 are changed.

The control target value calculator 43 multiplies the corrected vertical absolute speed S'by the control gain K to obtain the control target value C, and outputs this value to the control signal transmitter 44 as the control signal transmitter. The control signal transmitter 44 transmits a control signal θ corresponding to the rotation angle θ of the movable plate 25 based on the control target value C, and outputs this control signal θ to the actuator 29. In this case, the control signal transmission unit 44 sends information indicating the control target value C set on the basis of the characteristic of the variable damping coefficient type shock absorber 4 and the control signal θ proportional thereto (for convenience, the control signal transmission of FIG. 5 is performed). A graph showing this information is stored in the block showing the section 44. By inputting the control target value C, the corresponding control signal θ is generated.

The actuator 29 receives the control signal .theta. To rotate the movable plate 25 so that the variable damping coefficient shock absorber 4 can obtain desired extension side and contraction side damping coefficients. The control method in this case is disclosed in JP-A-5-33.
Similar to the principle disclosed in Japanese Patent No. 0325, for example, when the absolute velocity of the vehicle body 1 increases in the positive direction (upward direction of the vehicle body 1) and the target value of the damping coefficient increases in the positive direction,
As shown in the block indicating the control signal transmitting section 44, the control signal θ for increasing the rotation angle θ of the movable plate 25 in the positive direction is output to the actuator 29, and as a result, the expansion is performed as described in (1) above. The damping coefficient on the side is increased and the damping coefficient on the contraction side is decreased. On the other hand, when the absolute vertical speed S of the vehicle body 1 is increased in the negative direction (downward direction of the vehicle body 1) and the target value of the damping coefficient is increased in the negative direction, the rotation angle θ of the movable plate 25 is changed to the negative direction. Actuator for increasing control signal θ
29, which reduces the expansion-side damping coefficient and increases the contraction-side damping coefficient, as described in (2) above.

In the graph in the block showing the control signal transmitting unit 44 in FIG. 5, θ is constant in the region where the absolute value of the target value is large because the movable plate 25 rotates by a predetermined amount or more. This is because the third and fourth communication passages 21 and 22 are closed and the oil liquid does not flow through the third and fourth communication passages 21 and 22.

The large-amplitude number calculation unit 45 has an amplitude threshold value (FIG. 8) for the acceleration signal α from the acceleration sensor 5,
Two acceleration signals α that are temporally before and after in 0 ms
The number of times that the value of changes from small (within threshold) to large (outside of threshold) and from large to small in comparison with the amplitude threshold is obtained, and the large amplitude number signal F is output to the determination unit 46. The determination unit 46 stores in advance information indicating the road surface condition corresponding to the large amplitude frequency obtained by the large amplitude frequency calculation unit 45, and inputs the large amplitude frequency signal F from the large amplitude frequency calculation unit 45 to input the corresponding road surface condition. The road surface condition is determined by obtaining information, and the determination result is output to the parameter adjusting unit 47 as the control gain adjusting unit and the dead zone adjusting unit. The parameter adjustment unit 47 determines the control gain K and the dead zone A (predetermined value A) according to the determination result of the determination unit 46.
Adjust. The parameter adjustment unit 47 may be configured to adjust at least one of the control gain K and the dead zone A according to the determination result of the determination unit 46.

As shown in FIG. 6, when the controller 6 having the above-mentioned structure receives power supply from the vehicle engine start or the like (step S31), it first performs initialization (step S32) to determine whether the control cycle has been reached. Is determined (step S
33). In step S33, it is repeatedly determined whether the control cycle has been reached until it is determined that the control cycle has been reached.

When it is determined in step S33 that the control cycle has been reached, the actuator 29 is driven (step S34).
Subsequently, in step S35, a signal is output to a mechanism other than the actuator 29 for control. Next, the acceleration signal α is read from the acceleration sensor 5 (step S36). Then, the road surface condition is determined (step S37). The control target value C is obtained based on the determination result of step S37, and the actuator 29 is driven by the control signal θ corresponding thereto to obtain the desired damping coefficient.

The road surface determination subroutine in step S37 will be described with reference to FIG. First step S42
Or, in step S47, the frequency of the acceleration signal α for the latest 500 ms is calculated. That is, a predetermined absolute value threshold (amplitude threshold) is set for the acceleration signal α, and the front acceleration signal α
The absolute value of the value of _F is smaller than the threshold and the current acceleration signal α _P
When the absolute value of the value of is larger than the threshold value (step S42, step S45), the counter is incremented by "1" (step S46), and similarly, the absolute value of the value of the front acceleration signal α _F is larger than the threshold value and the current acceleration signal When the absolute value of the value of α _P is smaller than the threshold value (step S42, step S43), the counter is incremented by "1" (step S44),
Calculates the number of times (large number of amplitudes) that the absolute values of two acceleration signals α (α _F , α _P ) that move back and forth in time over 500 ms change from small to large and from large to small compared to the amplitude threshold value. (Step S47). It should be noted that here, both the number of changes from small to large and the change from large to small are obtained, but either one of the number of changes from small to large or from large to small may be obtained.

Subsequent to step S47, it is determined whether or not the large amplitude frequency signal F is greater than or equal to a preset frequency reference value FTH (step S48). If the large amplitude frequency signal F is equal to or greater than the frequency reference value FTH, it is determined that the road surface is a bad road (step S49), and if the large amplitude frequency signal F does not reach the frequency reference value FTH, the road surface is determined. Is determined to be a good road (step S50).

Subsequently, the current acceleration signal α _{P is changed} to the front acceleration signal α
_When it is determined to be a good road in the next step S52, if YES is determined, the control target value calculation unit 43 or the correction value calculation unit 42 is processed. On the other hand, the control gain K / dead zone A for a good road is set (step S53), and if NO is determined, the control gain K / dead zone A for a bad road is set (step S54).
). In this case, the control gain K / dead zone A for rough road is
Control gain K for good road / Control gain K compared to dead zone A
Is small and the dead zone A is large. Step S53
Alternatively, when the process of step S54 ends, the subroutine process of step S37 ends (step S55), and the process proceeds to step S38 of the main routine.

In step S38, the acceleration sensor 5 is operated while the control gain K / dead zone A for the good road or the bad road is set in the control target value calculation unit 43 or the correction value calculation unit 42 as described above. A desired control signal θ is generated by inputting the acceleration signal α. That is, when the acceleration signal α is input from the acceleration sensor 5, the integration processing unit 41 integrates the acceleration signal α to obtain the vertical absolute velocity S and outputs this value to the correction value calculation unit 42.

The correction value calculation unit 42 removes the vertical absolute speed S when it is included in the dead zone A set as described above, and removes the vertical absolute speed S when it exceeds the dead zone A. Proportional data, that is, corrected vertical absolute velocity S '
And outputs this value to the control target value calculation unit 43. The control target value calculation unit 43 multiplies the corrected vertical absolute speed S ′ by the control gain K set as described above to obtain the control target value C, and outputs this value to the control signal transmission unit 44. Control signal transmitter
Based on the control target value C, 44 generates a control signal θ corresponding to the rotation angle θ of the movable plate 25 and outputs this control signal θ to the actuator 29.

Then, the actuator 29 receives the control signal θ and rotates the movable plate 25, so that the third and fourth communication paths are connected.
The opening area of 21, 22 will be adjusted. As a result, the variable damping coefficient shock absorber 4 can obtain a desired damping coefficient on the extension side or the contraction side according to the road surface condition.

As described above, the dead zone A is set to be small for a good road and large for a bad road.
When driving on a rough road, the control does not become excessive due to a larger damping force than required, and the frequent vertical vibrations associated with running on a rough road can be controlled appropriately as when driving on a good road. It is possible to prevent deterioration of comfort. Further, as described above, the control gain K is set to a large value on a good road and a small value on a bad road. Therefore, when driving on a bad road, a larger damping force than required is generated. As a result, frequent vertical vibrations due to traveling on a bad road can be appropriately controlled as in the case of traveling on a good road, and deterioration of riding comfort can be prevented.

In the above embodiment, the large amplitude frequency calculation unit
Although the case where 45 is connected to the output side of the acceleration sensor 5 is taken as an example, instead of this, as shown in FIG.
May be provided on the output side of the integration processing unit 41. In this case, the large-amplitude frequency calculation unit 45 has an amplitude threshold value for the vertical absolute velocity signal from the integration processing unit 41, and the values of two vertical velocity signals that are temporally preceding and succeeding in 500 ms are compared with the amplitude threshold value. Then, the number of times of change from small to large and / or large to small is obtained, and this large amplitude number signal F is output to the determination unit 46.

Next, a suspension controller according to a second embodiment of the present invention will be described with reference to FIGS. 11 to 14. In this suspension control device, the high-pass filter 51 is interposed between the acceleration sensor 5 and the large-amplitude number calculation unit 45, which is directly connected to the output side of the acceleration sensor 5 in the first embodiment.
In contrast to the controller 6 of the first embodiment performing arithmetic processing on the front acceleration signal α _F and the current acceleration signal α _P obtained directly from the acceleration sensor 5, the controller 6 of the second embodiment has a high-pass filter 51. The difference is that arithmetic processing is performed on the front acceleration signal α _FH and the current acceleration signal α _PH after passing. The other parts are the same as in the first embodiment, and the description of the same parts is omitted.

When the acceleration signal α is input from the acceleration sensor 5, the high-pass filter 51 removes the low-frequency component and leaves the high-frequency component, and outputs this as the post-high-pass filter acceleration signal α _H to the large-amplitude frequency calculating section 45. . For example,
When the acceleration signal α as shown in FIG. 13 is input, the acceleration signal α _H after passing through the high-pass filter as shown in FIG.
The large amplitude number calculation unit 45 has an amplitude threshold for the acceleration signal α _H after passing through the high pass filter, and
The number of times the values of the acceleration signal α _H after passing through the two high-pass filters, which are temporally preceding and succeeding, changes from small to large and from large to small in comparison with the amplitude threshold value is obtained, and this large-amplitude number signal F is output to the determination unit 46. To do.

The controller 6 of the second embodiment is shown in FIG.
The road surface determination subroutine of FIG. 12 is executed instead of the road surface determination subroutine of step S37. Compared to that shown in FIG. 7, the road surface determination subroutine of FIG. 12 has a high-pass filter 51 instead of the front acceleration signal α _F and the current acceleration signal α _P.
Processing is performed on the front acceleration signal α _FH and the current acceleration signal α _PH after passing (steps S42, S43, S45, S51).
Etc.) and that the acceleration signal α is passed through the high-pass filter 51 to obtain the acceleration signal α _H after passing through the high-pass filter (step S41) prior to the process of step S42. The procedure is the same as that shown in FIG.

In the second embodiment, as in the first embodiment, the dead zone A is set to a small value on a good road and a large value on a bad road. A larger damping force than required does not occur and control is not excessive, and frequent vertical vibrations associated with traveling on a bad road can be appropriately controlled as in the case of traveling on a good road, and deterioration of riding comfort can be prevented. Further, as described above, the control gain K is set to a large value on a good road and a small value on a bad road. Therefore, when driving on a bad road, a larger damping force than required is generated. As a result, frequent vertical vibrations due to traveling on a bad road can be appropriately controlled as in the case of traveling on a good road, and deterioration of riding comfort can be prevented.

When frequent up-and-down vibration occurs due to traveling on a rough road, this vibration appears as a high-frequency component of the acceleration signal α, but in the second embodiment, the acceleration signal α is sent to the high-pass filter 51. Since it passes through, it is possible to remove the low-frequency component in which the high-frequency component is superposed, and by doing so, the high-frequency component of the acceleration signal α, that is, frequent vertical vibration can be detected with high accuracy, and a more comfortable riding comfort can be obtained. it can. In the embodiment of FIG. 10, a high pass filter may be interposed between the integration processing unit 41 and the large amplitude frequency calculation unit 45.

Next, a suspension controller according to the third embodiment of the present invention will be described with reference to FIG. In this suspension control device, a vehicle height sensor 52 is provided on the vehicle body 1 as compared with the large amplitude frequency calculation unit 45 connected to the output side of the acceleration sensor 5 in the first embodiment. Is connected to the output side of the large amplitude number calculation section 45, and the large amplitude number calculation section 45 of the first embodiment has an amplitude threshold value for the vertical acceleration signal α, The number of times the two vertical velocity signals are changed from small to large and / or large to small in comparison with the amplitude threshold value is calculated, and the large amplitude frequency signal F is output to the determination unit 46. The large-amplitude frequency calculation unit 45 of the third embodiment has an amplitude threshold value for the vehicle height signal H, and the values of two vehicle height signals H that are temporally preceding and succeeding in 500 ms are smaller than the amplitude threshold value. To large and /
Alternatively, the number of times of change from large to small is obtained and the large amplitude number signal F is output to the determination unit 46. The other parts are the same as those in the first embodiment.
The description is omitted. Further, in the first embodiment, the road surface condition determination process is performed for the acceleration signal α, whereas the third embodiment is different in that the road surface condition determination process is performed for the vehicle height signal H. The description of this flowchart is omitted.

In the third embodiment, as in the first embodiment, the dead zone A is set to be small for a good road and large for a bad road. A larger damping force than required does not occur and control is not excessive, and frequent vertical vibrations associated with traveling on a bad road can be appropriately controlled as in the case of traveling on a good road, and deterioration of riding comfort can be prevented. A high-pass filter may be provided between the vehicle height sensor 52 and the large-amplitude frequency calculation unit 45. Also, the vehicle height sensor
A differential processing unit is provided between 52 and the large amplitude number calculation unit 45,
The vehicle height signal H of the vehicle height sensor 52 is differentiated to obtain a vertical relative speed signal, and the number of times the value of this signal changes from small to large and / or large to small compared to the amplitude threshold value is calculated. The number of times signal F may be output to the determination unit 46 to determine whether the road is good or bad. In this case, the differentiated vertical relative velocity signal may be configured to pass through the high pass filter.

Next, a suspension controller according to a fourth embodiment of the present invention will be described with reference to FIG. In the fourth embodiment, the members and parts shown in FIGS. 1 to 4 of the first embodiment have the same structure, and the description of these members and parts is omitted. Further, in the figure, the same members and portions as those in the first embodiment are designated by the same reference numerals, and the description thereof will be appropriately omitted. In the fourth embodiment, the frequency increases when the vehicle speed is high even under the same road surface condition, and therefore the determination of the road surface condition is changed according to the vehicle speed.

In the figure, the vehicle body 1 is provided with a vehicle speed sensor 53, which detects the vehicle speed and outputs it to the judging section 46.

The determination unit 46 stores in advance information indicating the road surface condition (the content is shown in Table 1) corresponding to the large amplitude number obtained by the large amplitude number calculation unit 45, and the vehicle speed signal from the vehicle speed sensor 53 and The road surface condition is determined by inputting the large amplitude frequency signal F from the large amplitude frequency calculation unit 45 and selecting the corresponding road surface condition information, and the determination result is output to the parameter adjustment unit 47.

[0062]

In the first embodiment, the number of times of large-amplitude number of times is set to 1 to determine whether the road is good or bad. In the fourth embodiment, the number of times of reference value is set to 3, and the number of good roads is set to good. , Alley,
A determination result of a rough road or a rough road is obtained, and the control gain K / dead zone A having different values is set according to the four types of determination results. In this embodiment, the ride comfort can be improved by performing highly accurate control according to the road surface condition.

It should be noted that the large-amplitude frequency calculation unit 45 uses the vehicle speed sensor 53.
The amplitude threshold value may be changed as shown in Table 2 by inputting the vehicle speed signal V from. With this configuration, the sensitivity is increased when the vehicle speed is low, and the road surface can be determined more accurately.

[0065]

Next, a fifth embodiment of the present invention will be described with reference to FIGS. Compared to the fourth embodiment, the determination unit 46 in the fifth embodiment has a threshold value / change count table shown in Table 3 and a diagram.
21 and FIG. 22 are different in that the vehicle speed / road surface determination logic is stored, and the determination processing contents of the determination unit 46 are different due to the different stored data. The other parts are the same as in the fourth embodiment. The description of the same parts as those in the fourth embodiment will be omitted. The control contents of the controller 6 will be described with reference to the first embodiment.

[0067]

The controller 6 performs the process of step S37A instead of step S37 of FIG. 6 (first embodiment). In step S37A, road surface determination is performed based on the acceleration signal α of the acceleration sensor 5 and the vehicle speed signal V of the vehicle speed sensor 53. The contents of this step S37A will be explained based on FIG. 18 to FIG. First, in step S61, the first threshold value is passed to the change count subroutine in step S62. Step S6
The subroutine of step S62 subsequent to 1 will be described with reference to FIG. In this subroutine, the first, second, and third thresholds whose absolute values are small, medium, and large are sequentially processed for comparison.

First, the process is performed by using the first threshold value delivered in the process of step S61 as a comparison target. That is,
When the absolute value of the value of the front acceleration signal α _F is smaller than the first threshold value and the absolute value of the value of the current acceleration signal α _P is larger than the first threshold value (steps S81, S84), the counter is incremented by “1” ( Similarly, when the absolute value of the value of the front acceleration signal α _F is larger than the first threshold value and the absolute value of the value of the current acceleration signal α _P is smaller than the first threshold value (step S85), the counter is turned on. Incremented by "1" (step S83), the number of times the values of two acceleration signals α, which are temporally preceding and following, change from small to large and from large to small in comparison to the first threshold value within 500 ms (acceleration signal (corresponding to the frequency of α)) and returns to step S63 of the main routine. In step S63, the order of the thresholds delivered from step S61 is the number of thresholds NMAX.
(3 in this embodiment) is determined.

At the stage when the first threshold value is delivered as described above, NO is determined in step S63, and the process is performed in step S6.
Set back to 1. Then, in step S61, the second threshold is
Hand over to S62. Second in the subroutine of step S62
The number of large amplitudes is calculated for the threshold value. Similarly, the number of large amplitudes will be obtained for the third threshold.
When the large amplitude frequency for the third threshold value is obtained, YES is determined in step S63 and the process proceeds to step S64.

In step S64, data corresponding to the first, second and third threshold values and the number of times of large amplitude (for example, 3A, 2B, 1C).
Etc.) from Table 3. Then, a road surface determination subroutine is executed (step S65). In this case, the determination unit 46 is 0
_{~V 1, ~V 2, ~V 3} , ~V 4 ... (0 <V 1 <V
₂ <V ₃ <V ₄ <...) (Km / h) for each of the first, second,
Third, fourth, ... Nth logic L1, L2, L3, L4 ,.
Stores Ln. 1st, 2nd, 3rd, 4th, ...
The n-th logic L1, L2, L3, L4, ... Ln includes determination information indicating the road surface condition based on the combination of the data in Table 3. For example, the first logic includes the determination information of Table 4.

[0072]

The vehicle speed is 0 to V ₁ , to V ₂ , and V
₃ , to V ₄ , ... (Km / h), it is determined which region is included (step S91, step S93, etc.), and the first, second, third, fourth, ... A corresponding logic is selected from the nth logic (steps S92, S94, etc.). For example, the vehicle speed is 0 to V ₁
If it is (Km / h), the first logic is selected (step S92), and if the vehicle speed is ˜V ₂ (Km / h), the second logic is selected (step S94). Selected 1st, 2nd, 3rd, 4th, ... nth logic L1, L
The road surface condition is judged based on 2, L3, L4, ... Ln (step S95), and the road surface judgment subroutine is ended (step S96). Road surface determination subroutine (step S6
After 5), the current acceleration signal α _P is replaced with the front acceleration signal α _F to perform the updating process (step S66).

Hereinafter, the control gain K / dead zone A is set according to the determination result in step S95. That is,
If it is determined to be a good road, YES is determined in step S67 and the control gain K / dead zone A for the good road is set (step S68). If it is determined to be a parallel road, the control for parallel road is performed. Set gain K / dead zone A (step S69, step S7
0), when it is determined that the road is a swell, the control gain K / dead zone A for the swell is set (step S71, step S71).
S72), if it is determined that the road is bad, the control gain K / dead zone A for bad road is set (step S73).

When the processing of steps S68, S70, S72 and S73 is completed, the processing of the subroutine of step S37 is completed (step S74), and the process proceeds to step S38 of the main routine. In step S38, the acceleration sensor is set in the control target value calculation unit 43 and the correction value calculation unit 42 with the control gain K / dead zone A for the good road, the parallel road, the swell road, or the bad road set as described above. By inputting the acceleration signal α from 5, a desired control signal θ is generated. That is, when the acceleration signal α is input from the acceleration sensor 5, the integration processing unit 41
The acceleration signal α is integrated to obtain the vertical absolute velocity S, and this value is output to the correction value calculation unit 42.

The correction value calculation unit 42 excludes the vertical absolute velocity S when it is included in the dead zone A set as described above among the dead zones A for good roads, parallel roads, swells or bad roads. On the other hand, when the dead zone A is exceeded, data proportional to the vertical absolute velocity S, that is, the corrected vertical absolute velocity S ', is obtained and this value is output to the control target value calculation unit 43. The control target value calculation unit 43 multiplies the corrected vertical absolute speed S ′ by the control gain K set as described above among the control gains K for the good road, the parallel road, the swell road, or the bad road to obtain the control target value C. And outputs this value to the control signal transmission unit 44.

The control signal transmission unit 44 generates a control signal θ corresponding to the rotation angle θ of the movable plate 25 based on the control target value C and outputs this control signal θ to the actuator 29. Then, the actuator 29 receives the control signal θ and rotates the movable plate 25 to adjust the opening areas of the third and fourth communication passages 21 and 22. As a result, the variable damping coefficient shock absorber 4 can obtain a desired damping coefficient on the extension side or the contraction side according to the road surface condition.

In the first embodiment, the good road and the bad road are determined, but in the fifth embodiment, the good road, the parallel road, the ridge (swell road) and the bad road are obtained. Since the control gain K / dead zone A having different values can be set according to the four types of determination results, more accurate control can be performed according to the road surface condition, and the riding comfort can be improved.

In the fourth and fifth embodiments, the case where the large-amplitude frequency calculating unit 45 inputs the acceleration signal α from the acceleration sensor 5 is taken as an example, but instead of this, as shown in FIG. The vertical absolute velocity signal obtained by integrating the vertical acceleration signal, and Fig. 24
As shown in, the vehicle height signal H from the vehicle height sensor 52 or the vertical relative speed signal obtained by differentiating the vehicle height signal H may be input.

Next, a sixth embodiment of the present invention will be described with reference to FIGS. In the sixth embodiment, the members and parts shown in FIGS. 1 to 4 of the first embodiment have the same structure, and the description of these members and parts is omitted. Also in the figure,
The same members and portions as those in the first embodiment are designated by the same reference numerals and the description thereof will be appropriately omitted. In the figure, the vehicle body 1 is provided with a vehicle height sensor 52, which detects the vehicle height and outputs the vehicle height to the vertical relative speed calculation unit 48 of the controller 6. The vehicle height sensor 52 and the vertical relative speed calculation unit 48 constitute vertical relative speed detecting means. For example, Fig. 27 when driving on a rough road surface, Fig. 28 when driving on a slightly rough road surface, and Fig. 28 when driving on a rough road surface.
The vehicle height signal H shown in 29 is output.

The controller 6 includes an integration processing section 41, a correction value calculation section 42, a control target value calculation section 43, and a control signal transmission section.
44, a vertical relative velocity calculation unit 48, a root mean square calculation unit 49,
The parameter adjusting unit 47 is generally configured. The vertical relative speed calculation unit 48 differentiates the vehicle height signal H from the vehicle height sensor 52 to differentiate the vertical relative speed v ₀ (FIG. 27, FIG. 28, FIG.
29) and obtains the vertical relative speed signal and calculates the mean square calculator 49
Output to. The root mean square calculation unit 49 obtains a square value v _h2 of the relative speed based on the vertical relative speed signal,
s ~10s) stores, further outputs it to obtain a mean square v _h2a of the latest relative speed within a predetermined time stored on the basis of the square value v _h2 to the parameter adjuster 47. The sensitivity can be changed by the length of this predetermined time.
As is clear from comparison between FIGS. 27, 28 and 29, the _root mean square value v _{h2a of the} relative speed increases as the road surface becomes rough.

The parameter adjusting unit 47 adjusts the control gain K / dead zone A based on the above-described relationship between the _root mean square value v _h2a of the relative speed and the road surface condition. The parameter adjustment unit 47 stores a table of the control gain K and the dead zone A. An example of that is shown in Table 5 as a control gain table,
Table 6 shows a dead zone table.

[0083]

[0084]

The control gain K and the dead zone A are selected by the table pointer TBLP, and as will be described later, the control gain K is in order when the road surface is not rough, slightly rough, or rough (in case of bad road). Is small, dead zone A
The control gain K / dead zone A is set to be large.

The controller 6 sets the control gain K / dead zone A in step S37 of FIG. 6 (first embodiment).
Instead of step S37B and step S37C processing (FIG. 26)
I do. In step S37B, the mean square value v of the relative speed
_h2a is obtained, and in step S37C, the mean square value v of the relative speed
_Judgment of road conditions (setting of control parameters) is performed based on _h2a . The subroutine of step S37C will be described with reference to FIG. First, the _root mean square value v _h2a of the vertical relative velocity v ₀ obtained in step S37B is calculated (step S10).
1). A table pointer TBLP is created from the _root mean square value v _h2a of the vertical relative speed v ₀ (step S102). Mean square value v _h2a of vertical relative velocity v ₀ and table pointer TB
The relationship with LP is shown in FIG. That is, the _root mean square value v _h2a
The table pointer TBLP also increases with increasing. Then, the control gain K / dead zone A corresponding to the table pointer TBLP is selected from the stored information (step S103), the processing of this subroutine is terminated (step S104), and the process proceeds to step S38 (FIG. 26) of the main routine. Return.

In the sixth embodiment, the control gain K / dead zone A having different values is set according to the road surface condition. Therefore, it is possible to suppress the vertical vibration according to the road surface condition and improve the riding comfort. In the first embodiment, the good road and the bad road can be determined and these two types of control can be performed, but in the sixth embodiment, it is possible to perform a multi-step setting, and it is possible to perform higher precision control, which is excellent. You can get a comfortable ride.

In the sixth embodiment, the case where the process of step S37C is performed after the mean square value of the vertical relative velocity v ₀ is calculated in step S38B is taken as an example, but as shown in FIG. 32, step S3
7C and step S38 instead of step S38A and step S3
It may be configured to perform 8B processing.

In step S38A, the target damping coefficient before correction is temporarily calculated based on the vertical relative velocity v ₀ . Step S3
In 8B, using the _root mean square value v _h2a of the vertical relative velocity v ₀ obtained in step S37B for the target damping coefficient before correction, the following equation (1) is calculated to obtain the corrected target damping coefficient C. obtain.
By performing the calculation of the following equation (1), the correction can be performed when the road surface is rough and the unsprung energy on the wheel side is large (the _root mean square value v _h2a is large at this time).

Target damping coefficient C = (target damping coefficient before correction)
/ (Root mean square value of relative speed) ... (1)

In the above embodiment, the large-amplitude frequency calculating section 45, the judging section 46, the vertical relative velocity calculating section 48, and the mean square calculating section 49 constitute means for generating a signal representing the roughness of the road surface. Further, the parameter adjusting unit 47 and step S38 of FIG.
A and S38B constitute the control unit adjusting means. Further, as the damping coefficient adjusting type shock absorber, the one using the disk-shaped movable plate 25 shown in FIG. 3 was used, but the present invention is not limited to this, and a cylindrical shutter type, a spool type using a proportional solenoid, etc. May be used.

[0092]

Since the present invention is the suspension control device configured as described above, when the road surface condition is determined to be a bad road, or when it is determined, the control gain has a small value. Or, because the predetermined value of the dead zone becomes a large value, the damping force does not become too large even if the piston speed increases while driving on a rough road, thereby suppressing transmission of vibration to the vehicle body, It is possible to prevent deterioration of riding comfort.

[Brief description of drawings]

FIG. 1 is a diagram schematically showing a suspension control device according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a variable damping coefficient type shock absorber used in the suspension control device.

FIG. 3 is a plan view showing a movable plate assembled to the variable damping coefficient type shock absorber.

FIG. 4 is a diagram showing a relationship between a rotation angle of the movable plate and a damping coefficient.

FIG. 5 is a block diagram showing a controller of the suspension control device.

FIG. 6 is a flowchart showing control contents of the controller.

FIG. 7 is a flowchart showing a road surface determination subroutine of the same flowchart.

FIG. 8 is a diagram showing a correspondence relationship between a detection signal of the acceleration sensor and a threshold value.

FIG. 9 is a diagram schematically showing another example of information stored in the correction value calculation unit.

FIG. 10 is a diagram showing another example of the controller.

FIG. 11 is a diagram schematically showing a suspension control device according to a second embodiment of the present invention.

FIG. 12 is a flowchart showing a road surface determination subroutine of the suspension control device.

FIG. 13 is a diagram showing a correspondence relationship between acceleration signals and threshold values of the suspension control device.

FIG. 14 is a diagram showing a correspondence relationship between a signal from an acceleration sensor through a high pass filter and a threshold value.

FIG. 15 is a diagram schematically showing a controller according to a third embodiment of the present invention.

FIG. 16 is a diagram schematically showing a controller according to a fourth embodiment of the present invention.

FIG. 17 is a flowchart showing the control contents of the controller of the fifth embodiment of the present invention.

FIG. 18 is a flowchart showing a road surface determination subroutine of the flowchart.

FIG. 19 is a flowchart showing a change count counting subroutine of the flowchart.

20 is a flowchart showing a road surface determination subroutine of FIG.

FIG. 21 is a diagram schematically showing stored information in the determination unit of FIG.

FIG. 22 is a diagram schematically showing a part of the stored information.

23 is a diagram showing a relationship between an acceleration signal output from the acceleration sensor of FIG. 16 and first, second, and third threshold values.

FIG. 24 is a diagram showing an example of another controller that replaces the controller of FIG. 16;

FIG. 25 is a block diagram showing a controller according to a sixth embodiment of the present invention.

FIG. 26 is a flowchart showing control contents of the controller.

FIG. 27 is a diagram showing a signal waveform of each part when the road surface is not rough in the sixth embodiment.

FIG. 28 is a diagram showing a signal waveform of each part when the road surface is slightly rough in the sixth embodiment.

FIG. 29 is a diagram showing a signal waveform of each part when the road surface is rough in the sixth embodiment.

FIG. 30 is a flowchart showing a control parameter setting subroutine of FIG. 26.

FIG. 31 is a diagram showing a relationship between a root mean square value of vertical relative speeds and a table pointer.

32 is a flowchart showing control contents of another controller in place of the controller having the control contents of FIG. 26. FIG.

[Explanation of symbols]

 4 Damping coefficient variable shock absorber 5 Acceleration sensor 6 Controller 29 Actuator 41 Integral processing unit 42 Correction value calculation unit 43 Control target value calculation unit 44 Control signal transmission unit 45 Large amplitude frequency calculation unit 46 Judgment unit 47 Parameter adjustment unit

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Yoshiko Matsumura 1-6-3 Fujimi, Kawasaki-ku, Kawasaki-shi, Kanagawa Tokiko Co., Ltd. (72) Noriyuki Ichimaru 1-3-6 Fujimi, Kawasaki-ku, Kanagawa Prefecture Issue Tokiko Co., Ltd.

Claims (10)

[Claims] 1. A damping coefficient variable type shock absorber interposed between a sprung part and an unsprung part of a vehicle, an actuator for adjusting and setting a damping coefficient of the damping coefficient variable type shock absorber based on a control signal, and a vehicle body A vertical absolute speed detecting means for detecting the vertical absolute speed, a control unit for obtaining a control target signal by changing the vertical absolute speed signal from the vertical absolute speed detecting means according to a running state, and a control target signal from the control unit Signal generating means for generating a control signal from the actuator to the actuator, a means for generating a signal indicating the roughness of a road surface on which the vehicle travels, and the vertical absolute speed signal in the control unit according to the signal indicating the roughness. And a control unit adjusting means for adjusting a characteristic for changing the suspension. 2. A variable damping coefficient type shock absorber interposed between a sprung part and an unsprung part of a vehicle, an actuator for adjusting and setting a damping coefficient of the variable damping coefficient type shock absorber based on a control signal, and a vehicle body A vertical absolute speed detecting means for detecting a vertical absolute speed, a control target calculating means for multiplying the vertical absolute speed by a control gain to obtain a control target signal, and a control signal transmitting means for transmitting a control signal of an actuator from the control target signal. A road surface condition judging means for judging whether the road surface condition on which the vehicle is traveling is a bad road, and a control gain adjusting means for adjusting the control gain to a small value when the road surface condition judging means judges a bad road. A suspension control device characterized by being provided. 3. A variable damping coefficient type shock absorber interposed between a sprung part and an unsprung part of a vehicle, an actuator for adjusting and setting a damping coefficient of the variable damping coefficient type shock absorber based on a control signal, and a vehicle body A vertical absolute speed detecting means for detecting the vertical absolute speed, a correction value calculating means for correcting to a correction value obtained by removing one of the vertical absolute speeds whose absolute value is smaller than a predetermined value as a dead zone, and a control gain for the correction value. Control target calculation means for multiplying to obtain a control target signal, control signal transmission means for transmitting a control signal of an actuator from the control target signal, and road surface condition determination means for determining whether the road surface condition on which the vehicle is traveling is a bad road And a dead zone adjusting means for adjusting a predetermined value of the dead zone to a large value when the road surface condition determining means determines a bad road. Pension control device. 4. A vertical acceleration sensor for detecting vertical acceleration of a vehicle body is provided, and the road surface condition determining means has a large amplitude in which an amplitude of a vertical acceleration signal of the vertical acceleration sensor exceeds an amplitude threshold value set in advance within a predetermined time. 4. The suspension control according to claim 2 or 3, comprising a large-amplitude-number calculating section for obtaining the number of times and a judging section for judging a bad road when the large-amplitude number exceeds a predetermined number-of-times reference value. apparatus. 5. The large-amplitude-count calculating unit, wherein the road surface condition determining unit obtains a large-amplitude number at which the amplitude of the vertical-absolute-velocity signal of the vertical-absolute-velocity detecting unit exceeds a preset amplitude threshold within a predetermined time. The suspension control device according to claim 2 or 3, further comprising a determination unit that determines a bad road when the number of times of large amplitude exceeds a predetermined number of times reference value. 6. A vehicle height sensor for detecting a vehicle height of a vehicle body is provided, and the road surface condition determining means has a large amplitude in which an amplitude of a vehicle height signal of the vehicle height sensor exceeds an amplitude threshold value set in advance within a predetermined time. 4. The suspension control according to claim 2 or 3, comprising a large-amplitude-number calculating section for obtaining the number of times and a judging section for judging a bad road when the large-amplitude number exceeds a predetermined number-of-times reference value. apparatus. 7. A vehicle speed detecting means for detecting a vehicle speed of the vehicle is provided, and the judging section judges a bad road by increasing the number-of-times reference value in accordance with the vehicle speed detected by the vehicle speed detecting means. The suspension control device according to any one of claims 4 to 6, characterized in that: 8. A vehicle speed detecting means for detecting a vehicle speed of a vehicle is provided, and the judging section judges a bad road by increasing the amplitude threshold value according to the vehicle speed detected by the vehicle speed detecting means. The suspension control device according to any one of claims 4 to 6, characterized in that: 9. A variable damping coefficient type shock absorber interposed between a sprung part and an unsprung part of a vehicle, an actuator for adjusting and setting the damping coefficient of the variable damping coefficient type shock absorber based on a control signal, and a vehicle body A vertical absolute speed detecting means for detecting a vertical absolute speed, a control target calculating means for multiplying the vertical absolute speed by a control gain to obtain a control target signal, and a control signal transmitting means for transmitting a control signal of an actuator from the control target signal. An up-and-down relative speed detecting means for detecting the up-and-down relative speeds of the sprung and unsprung of the vehicle; a mean square calculating means for obtaining a mean square of the up and down relative speeds within a latest predetermined time; And a control gain adjusting means for adjusting the control gain to a small value in accordance with the size of the suspension control device. 10. A damping coefficient variable type shock absorber interposed between a sprung part and an unsprung part of a vehicle, an actuator for adjusting and setting a damping coefficient of the damping coefficient variable type shock absorber based on a control signal, and a vehicle body A vertical absolute speed detecting means for detecting the vertical absolute speed, a correction value calculating means for correcting to a correction value obtained by removing one of the vertical absolute speeds whose absolute value is smaller than a predetermined value as a dead zone, and a control gain for the correction value. Control target calculating means for multiplying to obtain a control target signal, control signal transmitting means for transmitting a control signal of an actuator from the control target signal, and vertical relative speed detecting means for detecting vertical relative speeds of sprung and unsprung of the vehicle. And the mean square of the vertical relative speed within the latest predetermined time 2
A suspension control device comprising: a mean value calculating means; and a dead zone adjusting means for adjusting a predetermined value of the dead zone to a large value according to the magnitude of the mean square.