System for vehicle body roll control performing suspension hardness control

Claim 2

For a vehicle comprising a body and a plurality of wheels upon which it runs, a vehicle roll control system of vehicle height adjustment type, comprising: a plurality of means one provided corresponding to each one of said vehicle wheels for resiliently suspending said one of said vehicle wheels from the vehicle body and being controllable to vary the hardness/softness characteristic of said suspension of said vehicle wheel between at least two different hardness/softness characteristic levels including a harder characteristic level and a softer characteristic level, each said suspension means comprising an actuator assembly which has a pressure chamber and is adapted to increase or decrease the suspension height of its corresponding vehicle wheel as respective results of supplying or discharging of working fluid to or from its said pressure chamber; a plurality of working fluid supplying and discharging means which are provided corresponding to said actuator assemblies and which serve to supply working fluid to said working fluid chambers and to discharge working fluid from said working fluid chambers; a vehicle speed detecting means for sensing the road speed of the vehicle; a steering angle detecting means for sensing the steering angle of the vehicle; a means for sensing the actual roll angle Ø t of said vehicle body; and: a means for computing and control, which computes a steady state roll angle Ø ∞ of the vehicle body from the vehicle speed sensed by said vehicle speed detecting means and the steering angle sensed by said steering angle detecting means, advances the phase of a signal indicative of said steady state roll angle Ø ∞ to thereby compute a compensating value Φ ∞ of roll angle, and then computes a difference value φ̂ as based upon a desired roll angle Ø a of the vehicle body, said compensating value of roll angle, and said actual vehicle body roll angler. according to the equation: where kl and k2 are positive constants; said computing and control means being adapted to control said working fluid supplying and discharging means based upon said difference value φ̂ when the absolute value of said difference valuer is larger than a first determinate valuer, and to control the hardness/softness characteristics of said vehicle wheels suspension means according to the absolute value of said difference value φ̂ when the absolute value of said difference value φ̂ is smaller than said first determinate valuer.

Claim 3

For a vehicle comprising a body and a plurality of wheels upon which it runs, a vehicle roll control system of vehicle height adjustment type, comprising: a plurality of means one provided corresponding to each one of said vehicle wheels for resiliently suspending said one of said vehicle wheels from the vehicle body and being controllable to vary the hardness/softness characteristic of said suspension of said vehicle wheel between at least two different hardness/softness characteristic levels including a harder characteristic level and a softer characteristic level, each said suspension means comprising an actuator assembly which has a pressure chamber and is adapted to increase or decrease the suspension height of its corresponding vehicle wheel as respective results of supplying or discharging of working fluid to or from its said pressure chamber; a plurality of working fluid supplying and discharging means which are provided corresponding to said actuator assemblies and which serve to supply working fluid to said working fluid chambers and to discharge working fluid from said working fluid chambers; a plurality of vehicle height detection means which are provided corresponding to said vehicle wheels and which serve for sensing parameters representative of the suspended heights Hi of the vehicle body over said vehicle wheels; a vehicle speed detecting means for sensing the road speed of the vehicle; a steering angle detecting means for sensing the steering angle of the vehicle; a means for sensing the actual roll angle Pi of said vehicle body; and: a means for computing and control, which computes the differences ΔHi between said vehicle heights Hi as sensed by said vehicle height detection means and reference vehicle heights, computes a steady state roll angle Ø ∞ of the vehicle body from the vehicle speed sensed by said vehicle speed detecting means and the steering angle sensed by said steering angle detecting means, advances the phase of a signal indicative of said steady state roll angle Ø ∞ to thereby compute a compensating value Φ ∞ of roll angle, and then computes a difference valuer as based upon a desired roll angle Ø a of the vehicle body, said compensating value Φ ∞ of roll angle, and said actual vehicle body roll angle Ø t , according to the equation: where kl and k2 are positive constants; said computing and control means being adapted, when the absolute value of said difference value is larger than a first determinate valuer, to control said working fluid supplying and discharging means based upon said difference value φ̂, and to control said working fluid supplying and discharging means according to said vehicle height differences Hi so as to thereby adjust the absolute values of said vehicle height differences to be not more than a determinate valueAHo, and to control the hardness/softness characteristics of said vehicle wheels suspension means according to the absolute value of said difference valuer , when the absolute value of said difference value φ̂ is smaller than said first determinate valuer.

Claim 4

For a vehicle comprising a body and a plurality of wheels upon which it runs, a vehicle roll control system of vehicle height adjustment type, comprising: a plurality of means one provided corresponding to each one of said vehicle wheels for resiliently suspending said one of said vehicle wheels from the vehicle body and being controllable to vary the hardness/softness characteristic of said suspension of said vehicle wheel between at least two different hardness/softness characteristic levels including a harder characteristic level and a softer characteristic level, each said suspension means comprising an actuator assembly which has a pressure chamber and is adapted to increase or decrease the suspension height of its corresponding vehicle wheel as respective results of supplying or discharging of working fluid to or from its said pressure chamber; a plurality of working fluid supplying and discharging means which are provided corresponding to said actuator assemblies and which serve to supply working fluid to said working fluid chambers and to discharge working fluid from said working fluid chambers; a plurality of vehicle height detection means which are provided corresponding to said vehicle wheels and which serve for sensing parameters representative of the suspended heights Hi of the vehicle body over said vehicle wheels; a vehicle speed detecting means for sensing the road speed of the vehicle; a steering angle detecting means for sensing the steering angle of the vehicle; a means for sensing the actual roll angle Pi of said vehicle body; and: a means for computing and control, which computes the differences ΔHi between said vehicle heights Hi as sensed by said vehicle height detection means and reference vehicle heights, computes a steady state roll angle Ø ∞ of the vehicle body from the vehicle speed sensed by said vehicle speed detecting means and the steering angle sensed by said steering angle detecting means, advances the phase of a signal indicative of said steady state roll angle Ø ∞ to thereby compute a compensating value Φ ∞ of roll angle, and then computes a difference valuer as based upon a desired roll angle Ø a of the vehicle body, said compensating value Φ ∞ of roll angle, and said actual vehicle body roll angle Ø t , according to the equation: where kl and k2 are positive constants; said computing and control means being adapted, when the absolute value of said difference value is larger than a first determinate valuer, to control said working fluid supplying and discharging means based upon said difference value φ̂, and to control said working fluid supplying and discharging means according to said vehicle height differences Hi so as to thereby adjust the absolute values of said vehicle height differences to be not more than a determinate valueAHo, and to control the hardness/softness characteristics of said vehicle wheels suspension means according to the absolute value of said difference valuer , when the absolute value of said difference value φ̂ is smaller than said first determinate valuer.

Claim 5

A system for vehicle roll control according to claim 1, wherein said computing and control means, when the absolute value of said difference value φ̂ is larger than said first determinate value φ̂ 1 , controls said working fluid supplying and discharging means according to said difference valuer.

Claim 6

A system for vehicle roll control according to claim 3, wherein said computing and control means is adapted to control the hardness/softness characteristics of said vehicle wheels suspension means to said harder characteristic level when the absolute value of said difference φ̂ is not larger than said first predetermined valued and is larger than a second predetermined value Ø 2 which is smaller than said first predetermined value Ø 1 , and to control the hardness/softness characteristics of said vehicle wheels suspension means to said softer characteristic level when the absolute value of said difference φ̂ is smaller than said second predetermined value Ø 2 .

Claim 7

A system for vehicle roll control according to claim 3 or 4, wherein said desired roll angle Ø a is zero.

Claim 8

A system for vehicle roll control according to claim 3 or 4, wherein said computing control means comprises a memory means, and said memory means stores a relationship between vehicle speeds, steering angles, and steady state roll angles.

Claim 9

A system for vehicle roll control according to claim 3 or 4, wherein said means for sensing the actual roll angle of said vehicle body is a plurality of vehicle height detecting means for sensing the vehicle height at locations corresponding to the vehicle wheels, and said computing control means is adapted to compute both a roll angle Ø f of said vehicle body with respect to the front vehicle wheels and also a roll angle Ø r of said vehicle body with respect to the rear vehicle wheels from vehicle height differences between the left and the right sides of said vehicle body based upon the vehicle heights sensed by said vehicle height detecting means and the distances between the left and the right vehicle wheels, and to compute as an actual roll angle Ø t the average of said two roll angles s b f and

Claim 10

A system for vehicle roll control according to claim 3 or 4, wherein said means for sensing the actual roll angle of said vehicle body is a plurality of vehicle height detecting means for sensing the vehicle height at locations corresponding to the vehicle wheels, and said computing control means is adapted to compute both a roll angle Ø tf of said vehicle body with respect to the front vehicle wheels and also a roll angle Ø tf of said vehicle body with respect to the rear vehicle wheels from vehicle height differences between the left and the right sides of said vehicle body based upon the vehicle heights sensed by said vehicle height detecting means and the distances between the left and the right vehicle wheels, and to perform the computing of said roll angle difference, the controlling of said working fluid supplying and discharging means, and the controlling of the hardness/softness characteristics of said suspension means individually as far as the front vehicle wheels are concerned and as far as the rear vehicle wheels are concerned, based upon said two roll angles Ø tf and0tr.

Claim 11

A system for vehicle roll control according to claim 2, wherein said computing and control means, when the absolute value of said difference value φ̂ is larger than said first determinate valued, controls said working fluid supplying and discharging means according to said difference value φ̂.

Claim 12

A system for vehicle roll control according to claim 9, wherein said computing and control means is adapted to control the hardness/softness characteristics of said vehicle wheels suspension means to said harder characteristic level when the absolute value of said difference φ̂ is not larger than said first predetermined value Ø 1 and is larger than a second predetermined value Ø 2 which is smaller than said first predetermined valuer, and to control the hardness/softness characteristics of said vehicle wheels suspension means to said softer characteristic level when the absolute value of said difference φ̂ is smaller than said second predetermined valuer.

Claim 13

A system for vehicle roll control according to claim 9 or 10, wherein said desired roll angle Ø a is zero.

Claim 14

A system for vehicle roll control according to claim 9 or 10, wherein said computing control means comprises a memory means, and said memory means stores a relationship between vehicle speeds, steering angles, and steady state roll angles.

Claim 15

A system for vehicle roll control according to claim 9 or 10, wherein said means for sensing the actual roll angle of said vehicle body is a plurality of vehicle height detecting means for sensing the vehicle height at locations corresponding to the vehicle wheels, and said computing control means is adapted to compute both a roll angle/ f of said vehicle body with respect to the front vehicle wheels and also a roll angle#r of said vehicle body with respect to the rear vehicle wheels from vehicle height differences between the left and the right sides of said vehicle body based upon the vehicle heights sensed by said vehicle height detecting means and the distances between the left and the right vehicle wheels, and to compute as an actual roll angle Ø t the average of said two roll angles Ø f and Ø r .

Claim 16

A system for vehicle roll control according to claim 9 or 10, wherein said means for sensing the actual roll angle of said vehicle body is a plurality of vehicle height detecting means for sensing the vehicle height at locations corresponding to the vehicle wheels, and said computing control means is adapted to compute both a roll angle Ø tf of said vehicle body with respect to the front vehicle wheels and also a roll angle Ø tr of said vehicle body with respect to the rear vehicle wheels from vehicle height differences between the left and the right sides of said vehicle body based upon the vehicle heights sensed by said vehicle height detecting means and the distances between the left and the right vehicle wheels, and to perform the computing of said roll angle difference, the controlling of said working fluid supplying and discharging means, and the controlling of the hardness/softness characteristics of said suspension means individually as far as the front vehicle wheels are concerned and as far as the rear vehicle wheels are concerned, based upon said two roll angles Ø tf and Ø tr .

Claim 17

A system for vehicle roll control according to claim 9 or 10, wherein said determinate value ΔHo for said vehicle height difference ΔHi is not substantially larger than the absolute value of said vehicle height difference ΔHi at the time when the absolute value of said roll angle difference φ̂ is substantially equal to said first determinate valuer.

Claim 18

A system for vehicle roll control according to claim 1, wherein said computing and control means, when the absolute value of said difference valuer is larger than said first determinate valuer, calculates a modified value φ̂ s of said difference value φ̂ according to the equations: where k3 and k4 are positive coefficients, and controls said working fluid supplying and discharging means according to said modified valuer.

Claim 19

A system for vehicle roll control according to claim 16, wherein said computing and control means is adapted to control the hardness/softness characteristics of said vehicle wheels suspension means to said harder characteristic level when the absolute value of said difference φ̂ is not larger than said first predetermined valuer and is larger than a second predetermined value Ø 2 which is smaller than said first predetermined value Ø 1 , and to control the hardness/softness characteristics of said vehicle wheels suspension means to said softer characteristic level when the absolute value of said difference φ̂ is smaller than said second predetermined valuer.

Claim 20

A system for vehicle roll control according to claim 16 or 17, wherein said desired roll angle Ø a is zero.

Claim 21

A system for vehicle roll control according to claim 16 or 17, wherein said computing control means comprises a memory means, and said memory means stores a relationship between vehicle speeds, steering angles, and steady state roll angles.

Claim 22

A system for vehicle roll control according to claim 16 or 17, wherein said means for sensing the actual roll angle of said vehicle body is a plurality of vehicle height detecting means for sensing the vehicle height at locations corresponding to the vehicle wheels, and said computing control means is adapted to compute both a roll angle Ø f of said vehicle body with respect to the front vehicle wheels and also a roll angler of said vehicle body with respect to the rear vehicle wheels from vehicle height differences between the left and the right sides of said vehicle body based upon the vehicle heights sensed by said vehicle height detecting means and the distances between the left and the right vehicle wheels, and to compute as an actual roll angle Ø t the average of said two roll angles of and Ø t .

Claim 23

A system for vehicle roll control according to claim 16 or 17, wherein said means for sensing the actual roll angle of said vehicle body is a plurality of vehicle height detecting means for sensing the vehicle height at locations corresponding to the vehicle wheels, and said computing control means is adapted to compute both a roll angle o tf of said vehicle body with respect to the front vehicle wheels and also a roll angle Ø tr of said vehicle body with respect to the rear vehicle wheels from vehicle height differences between the left and the right sides of said vehicle body based upon the vehicle heights sensed by said vehicle height detecting means and the distances between the left and the right vehicle wheels, and to perform the computing of said roll angle difference, the controlling of said working fluid supplying and discharging means, and the controlling of the hardness/softness characteristics of said suspension means individually as far as the front vehicle wheels are concerned and as far as the rear vehicle wheels are concerned, based upon said two roll φ tf angles Ø tf and Ø tr .

Claim 24

A system for vehicle roll control according to claim 2, wherein said computing and control means, when the absolute value of said difference value φ̂ is larger than said first determinate value Ø 1 , calculates a modified value φ̂ s of said difference value according to the equations: where k3 and k4 are positive coefficients, and controls said working fluid supplying and discharging means according to said modified valuer.

Claim 25

A system for vehicle roll control according to claim 22, wherein said computing and control means is adapted to control the hardness/softness characteristics of said vehicle wheels suspension means to said harder characteristic level when the absolute value of said difference φ̂ is not larger than said first predetermined valued and is larger than a second predetermined value Ø 2 which is smaller than said first predetermined valuer, and to control the hardness/softness characteristics of said vehicle wheels suspension means to said softer characteristic level when the absolute value of said difference φ̂ is smaller than said second predetermined valuer.

Claim 26

A system for vehicle roll control according to claim 22 or 23, wherein said desired roll angle Ø a is zero.

Claim 27

A system for vehicle roll control according to claim 22 or 23, wherein said computing control means comprises a memory means, and said memory means stores a relationship between vehicle speeds, steering angles, and steady state roll angles.

Claim 28

A system for vehicle roll control according to claim 22 or 23, wherein said means for sensing the actual roll angle of said vehicle body is a plurality of vehicle height detecting means for sensing the vehicle height at locations corresponding to the vehicle wheels, and said computing control means is adapted to compute both a roll angle Ø f of said vehicle body with respect to the front vehicle wheels and also a roll angle Ø r of said vehicle body with respect to the rear vehicle wheels from vehicle height differences between the left and the right sides of said vehicle body based upon the vehicle heights sensed by said vehicle height detecting means and the distances between the left and the right vehicle wheels, and to compute as an actual roll angle Øt the average of said two roll angles Øf and Ør.

Claim 29

A system for vehicle roll control according to claim 22 or 23, wherein said means for sensing the actual roll angle of said vehicle body is a plurality of vehicle height detecting means for sensing the vehicle height at locations corresponding to the vehicle wheels, and said computing control means is adapted to compute both a roll angle Øtf of said vehicle body with respect to the front vehicle wheels and also a roll angle Ø tr of said vehicle body with respect to the rear vehicle wheels from vehicle height differences between the left and the right sides of said vehicle body based upon the vehicle heights sensed by said vehicle height detecting means and the distances between the left and the right vehicle wheels, and to perform the computing of said roll angle difference, the controlling of said working fluid supplying and discharging means, and the controlling of the hardness/softness characteristics of said suspension means individually as far as the front vehicle wheels are concerned and as far as the rear vehicle wheels are concerned, based upon said two roll angles Ø tf and Ø tr :

Claim 30

A system for vehicle roll control according to claim 22 or 23, wherein said determinate value ΔHo for said vehicle height difference ΔHi is not substantially larger than the absolute value of said vehicle height difference ΔHi at the time when the absolute value of said roll angle difference φ̂ is substantially equal to said first determinate value Ø 1 .