Actively controlled automotive suspension system with mutually independent hydraulic systems having mutually different damping characteristics for improving response characteristics in active suspension control

Claim 2

An actively controlled suspension system for an automotive vehicle comprising: a suspension assembly interposed between a vehicle body and a suspension member rotatingly supporting a road wheel, said suspension assembly including a variable pressure chamber which is variable of pressure therein in response to vibration input to said suspension assembly; a first pressure adjusting means associated with the variable pressure chamber and responsive to vibration input from said suspension member, for adjusting pressure in said variable pressure chamber for absorbing vibration energy input to said suspension assembly; and a second pressure adjusting means associated with the variable pressure chamber and responsive to vibration input from said vehicle body, for adjusting pressure in said variable pressure chamber for suppressing change of vehicular attitude.

Claim 3

An actively controlled suspension system as set forth in claim 1, wherein said first pressure adjusting means includes a pressure accumulator connected to said variable pressure chamber and a first flow restricting means interposed between said variable pressure chamber and said pressure accumulator for liming flow of said fluid for absorbing said vibration energy.

Claim 4

An actively controlled suspension system as set forth in claim 2, wherein said second pressure adjusting means includes a pressurized fluid source, a circuit connecting said pressrized fluid source, a valve means for adjusting flow of pressuirzed fluid, and a controller detective of attitude change of the vehicle body for operating said pressure control value for adjusting fluid pressure in said variable pressure chamber for suppressing attitude change of the vehicle body.

Claim 5

An actively controlled suspension system as set forth in claim 3, wherein said second adjusting means incorporates a second flow restricting means for restricting fluid flow between said variable pressure chamber and said pressure control valve, daid second flow restricting means having variable flow restriction rate variable depending upon vibration frequency so that said flow restriction rate becomes greater that that of said first flow resticting means when the vibration frequency is higher than a given value.

Claim 6

An actively controller suspension system as set forth in claim 4, wherein said given value is set at a boarder frequency between a resonance frequency of the vehicle body and a resonance frequency of said suspension member as coupled with said road wheel.

Claim 7

An actively controlled suspensioon system as set forth in claim 5, wherein said controller is connected to a detector detecting change of attitude of the vehicle body to produce an attitude change indicative signal indicative of magnitude of change of attitude, and said controller derives a control value for controlling said pressue control valve and whereby controlling fluid pressure in said variable pressure chamber to produce a control signal for controlling said pressrue control valve.

Claim 8

An actively controlled suspension system as set forth in claim 6, wherein said detector comprises an acceleration sensor monitoring bounding and rebounding acceleration of the vehicle body for producing a bounding and rebounding acceleration indicative signal.

Claim 9

An activelly controlled suspension system as set forth in claim 7, wherein said controller integrates said bounding and rebounding acceleration indicative signal value for obtaining bounding and rebounding motion indicative value to derive said control signal value bases thereon.

Claim 10

An actively controlled suspension system for an automotive vehicle comprising: a suspension assembly interposed between a vehicle body and a suspension member rotatingly supporting a road wheel, said suspension assembly including a variable pressure chamber which is variable of fluid pressure therein in response to vibration input to said suspension assembly; a first pressure adjusting means connected to said variable pressure chamber via a first path provided with a predetermined first flow restriction value for limiting fluid flow therethrough and responsive to vibration input from said suspension member, for adjusting pressure in said variable pressure chamber for absorbing vibration energy input to said suspension assembly; and a second pressure adjusting means connected to the variable pressure chamber via a second path provided with a second flow restriction value limiting fluid flow therethrough and variable dependeing upon the frequency of input vibration in such a manner that said second flow restriction value is smaller than that of said first restriction value when said vibration frequency is lower than a given frequency threshold and becomes greater than or equal to said first restriction value when said vibration frequency increases across said frequency threshold, said second pressure adjusting means being responsive to vibration having frequency lower than said frequency threshold for adjusting pressure in said variable pressure chamber for suppressing change of vehicular attitude.

Claim 11

An actively controlled suspension system for an automotive vehicle comprising: a suspension assembly interposed between a vehicle body and a suspension member rotatingly supporting a road wheel, said suspension assembly including a variable pressure chamber which is variable of fluid pressure therein in response to vibration input to said suspension assembly; a first pressure adjusting means connected to said variable pressure chamber via a first path provided with a predetermined first flow restriction value for limiting fluid flow therethrough and responsive to vibration input from said suspension member, for adjusting pressure in said variable pressure chamber for absorbing vibration energy input to said suspension assembly; and a second pressure adjusting means connected to the variable pressure chamber via a second path provided with a second flow restriction value limiting fluid flow therethrough and variable dependeing upon the frequency of input vibration in such a manner that said second flow restriction value is smaller than that of said first restriction value when said vibration frequency is lower than a given frequency threshold and becomes greater than or equal to said first restriction value when said vibration frequency increases across said frequency threshold, said second pressure adjusting means being responsive to vibration having frequency lower than said frequency threshold for adjusting pressure in said variable pressure chamber for suppressing change of vehicular attitude.

Claim 12

An actively controlled suspension system as set forth in claim 9, wherein said first pressure adjusting means includes a pressure accumulator connected to said variable pressure chamber and a first flow restricting means interposed between said variable pressure chamber and said pressure accumulator for liming flow of said fluid for absorbing said vibration energy.

Claim 13

An actively controlled suspension system as set forth in claim 10, wherein said second pressure adjusting means includes a pressurized fluid source, a circuit connecting said pressrized fluid source, a valve means for adjusting flow of pressuirzed fluid, and a controller detective of attitude change of the vehicle body for operating said pressure control value for adjusting fluid pressure in said variable pressure chamber for suppressing attitude change of the vehicle body.

Claim 14

An actively controlled suspension system as set forth inclaim 11, wherein said second adjusting means incorporates a second flow restricting means for restricting fluid flow between said variable pressure chamber and said pressure control valve, daid second flow restricting means having variable flow restriction rate variable depending upon vibration frequency so that said flow restriction rate becomes greater than that of said first flow resticting means when the vibration frequency is higher than a given value.

Claim 15

An actively controller suspension system as set forth in claim 12, wherein said given value is set at a boarder frequency between a resonance frequency of the vehicle body and a resonance frequency of said suspension member as coupled with said road wheel.

Claim 16

An actively controlled suspensioon system as set forth in claim 13, wherein said controller is connected to a detector detecting change of attitude of the vehicle body to produce an attitude change indicative signal indicative of magnitude of change of attitude, and said controller derives a control value for controlling said pressure control valve and whereby controlling fluid pressure in said variable pressure chamber to produce a control signal for controlling said pressrue control valve.

Claim 17

An actively controlled suspension system as set forth in claim 14, wherein said detector comprises an acceleration sensor monitoring bounding and rebounding acceleration of the vehicle body for producing a bounding and rebounding acceleration indicative signal.

Claim 18

An activelly controlled suspension system as set forth in claim 15, wherein said controller integrates said bounding and rebounding acceleration indicative signal value for obtaining bounding and rebounding motion indicative value to derive said control signal value based thereon.

Claim 19

An actively controlled suspension system for an automotive vehicle comprising: a suspension assembly interposed between a vehicle body and a suspension member rotatingly supporting a road wheel, said suspension assembly including a variable pressure chamber which is variable of fluid pressure therein in response to vibration input to said suspension assembly; a first pressure adjusting means connected to said variable pressure chamber via a first path provided with a predetermined first flow restriction value for limiting fluid flow therethrough and responsive to vibration input from said suspension member, for adjusting pressure in said variable pressure chamber for absorbing vibration energy input to said suspension assembly; and a second pressure adjusting means connected to the variable pressure chamber via a second path provided with a second flow restriction value limiting fluid flow therethrough and variable dependeing upon the frequency of input vibration in such a manner that said second flow restriction value is smaller that that of said first restriction value when said vibration frequency is lower than a given frequency threshold and becomes greater than or equal to said first restriction value when said vibration frequency increases across said frequency threshold, said second pressure adjusting means including an actuator operable for adjusting said fluid pressure in said variable pressure chamber; a sensor means for detecting change of vehicular attitude and producing a sensor signal indicative of vehicular attitude change magnitude; and a controller receiving said sensor signal for deriving a control value to adjust said fluid pressure in said variable pressure chamber to produce a control signal for operating said second pressure adjusting means for adjusting pressure in said variable pressure chamber for suppressing vehicular attitude change.

Claim 20

An actively controlled suspension system for an automotive vehicle comprising: a suspension assembly interposed between a vehicle body and a suspension member rotatingly supporting a road wheel, said suspension assembly including a variable pressure chamber which is variable of fluid pressure therein in response to vibration input to said suspension assembly; a first pressure adjusting means connected to said variable pressure chamber via a first path provided with a predetermined first flow restriction value for limiting fluid flow therethrough and responsive to vibration input from said suspension member, for adjusting pressure in said variable pressure chamber for absorbing vibration energy input to said suspension assembly; and a second pressure adjusting means connected to the variable pressure chamber via a second path provided with a second flow restriction value limiting fluid flow therethrough and variable dependeing upon the frequency of input vibration in such a manner that said second flow restriction value is smaller that that of said first restriction value when said vibration frequency is lower than a given frequency threshold and becomes greater than or equal to said first restriction value when said vibration frequency increases across said frequency threshold, said second pressure adjusting means including an actuator operable for adjusting said fluid pressure in said variable pressure chamber; a sensor means for detecting change of vehicular attitude and producing a sensor signal indicative of vehicular attitude change magnitude; and a controller receiving said sensor signal for deriving a control value to adjust said fluid pressure in said variable pressure chamber to produce a control signal for operating said second pressure adjusting means for adjusting pressure in said variable pressure chamber for suppressing vehicular attitude change.

Claim 21

An actively controlled suspension system as set forth in claim 17, wherein said first pressure adjusting means includes a pressure accumulator connected to said variable pressure chamber and a first flow restricting means interposed between said variable pressure chamber and said pressure accumulator for liming flow of said fluid for absorbing said vibration energy.

Claim 22

An actively controlled suspension system as set forth in claim 18, wherein said second pressure adjusting means includes a pressurized fluid source, a circuit connecting said pressrized fluid source, a valve means for adjusting flow of pressuirzed fluid, and said controller detective of attitude change of the vehicle body for operating said pressure control value for adjusting fluid pressure in said variable pressure chamber for suppressing attitude change of the vehicle body.

Claim 23

An actively controlled suspension system as set forth in claim 19, wherein said second adjusting means incorporates a second flow restricting means for restricting fluid flow between said variable pressure chamber and said pressure control valve, daid second flow restricting means having variable flow restriction rate variable depending upon vibration frequency so that said flow restriction rate become greater than that of said first flow resticting means when the vibration frequency is higher than a given value.

Claim 24

An actively controller suspension system as set forth in claim 20, wherein said given value is set at a boarder frequency between a resonance frequency of the vehicle body and resonance frequency of said suspension member as coupled with said road wheel.

Claim 25

An actively controlled suspension system as set forth in claim 21, wherein said controller is connected to a detector detecting change of attitude of the vehicle body to produce an attitude change indicative signal indicative of magnitude of change of attitude, and said controller derives a control value for controlling said pressure control valve and whereby controlling fluid pressure in said variable pressure chamber to produce a control signal for con­trolling said pressure control valve.

Claim 26

An actively controlled suspension system as set forth in claim 22, wherein said detector comprises an acceleration sensor monitoring bounding and reboun­ding acceleration of the vehicle body for producing a bounding and rebounding acceleration indicative signal.

Claim 27

An actively controlled suspension system as set forth in claim 23, wherein said controller integrates said bounding and rebounding acceleration indicative signal value for obtaining bounding and rebounding motion indicative value to derive said control signal value based thereon.