Apparatus for controlling damping coefficient of vehicular shock absorber
First Claim
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1. An apparatus comprising:
- a) a plurality of shock absorbers, each of said shock absorbers being interposed between a portion of a vehicle body and corresponding road wheel and each having a piston member defining a fluid upper chamber and a fluid lower chamber and damping coefficient varying means associated with the piston member, said damping coefficient varying means operatively varying the damping coefficient in either stroke direction of the piston member to a target damping coefficient;
a plurality of acceleration sensors, each associated with a shock absorber, each disposed on said vehicle body at a location proximate the associated shock absorber, and each arranged to produce an output signal indicative of a vertical acceleration;
circuit means operatively connected with each of said plurality of acceleration sensors for receiving said output signals from said acceleration sensors, said circuit means including;
sprung mass speed detecting means for filtering a sprung mass speed signal from each of said output signals;
pitching rate detecting means for filtering a pitching rate component of the vehicle body from each of said sprung mass speed signals;
rolling rate detecting means for filtering a rolling rate component of the vehicle body from each of said sprung mass speed signals; and
controlling means for deriving a control signal for each of said damping coefficient varying means on the basis of at least one of the sprung mass speed signals, pitching rate components, and rolling rate components and outputting said control signal to the respective damping coefficient varying means of the corresponding shock absorbers.
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Abstract
An apparatus for controlling the damping coefficient of shock absorbers which are associated with the road wheels of the vehicle, produces control signals using one or more of a bouncing rate, a pitching rate and a rolling rate value which is filtered out of a plurality of outputs provided by a plurality of acceleration sensors which are each located in proximity of a shock absorber. The control signal can be modified using the outputs of weight sensors which are used to derive the relative velocities of the road wheels with respect to the vehicle body.
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Citations
43 Claims
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1. An apparatus comprising:
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a) a plurality of shock absorbers, each of said shock absorbers being interposed between a portion of a vehicle body and corresponding road wheel and each having a piston member defining a fluid upper chamber and a fluid lower chamber and damping coefficient varying means associated with the piston member, said damping coefficient varying means operatively varying the damping coefficient in either stroke direction of the piston member to a target damping coefficient; a plurality of acceleration sensors, each associated with a shock absorber, each disposed on said vehicle body at a location proximate the associated shock absorber, and each arranged to produce an output signal indicative of a vertical acceleration; circuit means operatively connected with each of said plurality of acceleration sensors for receiving said output signals from said acceleration sensors, said circuit means including; sprung mass speed detecting means for filtering a sprung mass speed signal from each of said output signals; pitching rate detecting means for filtering a pitching rate component of the vehicle body from each of said sprung mass speed signals; rolling rate detecting means for filtering a rolling rate component of the vehicle body from each of said sprung mass speed signals; and controlling means for deriving a control signal for each of said damping coefficient varying means on the basis of at least one of the sprung mass speed signals, pitching rate components, and rolling rate components and outputting said control signal to the respective damping coefficient varying means of the corresponding shock absorbers. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22)
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23. An apparatus for controlling each damping coefficient for vehicular shock absorbers comprising:
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a) a plurality of shock absorbers, each interposed between a portion of a vehicular body and corresponding tire wheel and each having a piston member defining a fluid upper chamber and a fluid lower chamber and damping coefficient varying means associated with the piston member, said damping coefficient varying means operatively varying its position in response to a control signal so that the damping coefficient at either stroke side of the chambers defined by the piston member is set to a target damping coefficient; b) vertical sprung mass speed detecting means for detecting a vertical sprung mass speed of an adjacent position of the vehicular body on which each shock absorber is placed; c) pitching rate detecting means for detecting a pitching rate of the vehicle body; d) rolling rate detecting means for detecting a rolling rate of the vehicle body; and e) controlling means for deriving the control signal for each shock absorber on the basis of at least any one of the vertical sprung mass speed, pitching rate, and rolling rate determined according to a position of each shock absorber located at a corresponding tire wheel and outputting the control signal to each damping coefficient varying means of the corresponding shock absorbers so to provide the target damping coefficient therein; wherein said pitching rate detecting means detects the pitching rate of the vehicle body from a difference between the vertical sprung mass speeds of a forward vehicle body and rearward vehicle body with a weight center of the vehicle body as a center on the basis of the detected vertical sprung mass speeds of the vertical sprung mass speed detecting means and said rolling rate detecting means detects the rolling rate of the vehicle body from a difference between the vertical sprung mass speeds of rightward vehicle body and leftward vehicle body with the weight center of the vehicle body as the center on the basis of the detected vertical sprung mass speeds of the vertical sprung mass speed detecting means; wherein said vertical sprung mass speed detecting means includes a plurality of vertical G sensors, each located on the vehicle body adjacent to the corresponding shock absorber; wherein said vertical sprung mass speed detecting means includes a first band pass filter for each vertical G sensor which passes a signal component whose frequency falls in a first predetermined frequency range including a sprung mass resonance frequency at one of the front and rear tire wheels, said pitching rate detecting means includes a second band pass filter for each vertical G sensor which passes a signal component whose frequency falls in a second predetermined frequency range including a pitch resonance frequency of the vehicle body, and said rolling rate detecting means includes a third band pass filter for each vertical G sensor which passes a signal component whose frequency falls in a third predetermined frequency range including a rolling resonant frequency range; wherein said controlling means derives the control signal V as follows; For one of the shock absorbers located at a front, right tire wheel;
space="preserve" listing-type="equation">V.sub.1 =α
.sub.f /4 (v.sub.1 +v.sub.2 +v.sub.3 +v.sub.4)+β
.sub.f (v'"'"'.sub.1 -v'"'"'.sub.3)+τ
.sub.f (v".sub.1 -v".sub.2)For one of the other shock absorbers located at a front, left tire wheel;
space="preserve" listing-type="equation">V.sub.2 =α
.sub.f /4 (v.sub.1 +v.sub.2 +v.sub.3 +v.sub.4)+β
.sub.f (v'"'"'.sub.2 -v'"'"'.sub.4)+τ
.sub.f (v".sub.2 -v".sub.1)For one of the other shock absorbers located at a rear, right tire wheel;
space="preserve" listing-type="equation">V.sub.3 =α
.sub.r /4 (v.sub.1 +v.sub.2 +v.sub.3 +v.sub.4)+β
.sub.r (v'"'"'.sub.3 -v'"'"'.sub.1)+τ
.sub.r (v".sub.3 -v".sub.4)For one of the other shock absorbers located at a rear, left tire wheel;
space="preserve" listing-type="equation">V.sub.4 =α
.sub.r /4 (v.sub.1 +v.sub.2 +v.sub.3 +v.sub.4)+β
.sub.r (v'"'"'.sub.4 -v'"'"'.sub.2)+τ
.sub.r (v".sub.4 -v".sub.3)wherein α
f, β
f, and τ
f denote respective proportional constants on spring constants of the front tire wheels, on rolling rigidities thereof, and on pitching rigidities thereof, α
r, β
r, and τ
r denote the respective proportional constants on spring constants of the rear tire wheels, on pitching rigidities thereof, and on the rolling rigidities thereof, v1, v'"'"'1 and v"1 denote vertical sprung mass speed signal derived from the front, right tire wheel vertical G sensor, v2, v'"'"'2 and v"2 denote vertical sprung mass speed signal derived from the front, left tire wheel vertical G sensor, and v3, v'"'"'3 and v"3 denote vertical sprung mass speed signal derived from the rear, right tire wheel vertical G sensor, and v4, v'"'"'4 and v"4 denote vertical sprung mass speed signal derived from the rear, left tire wheel vertical G sensor. - View Dependent Claims (24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36)
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37. An apparatus comprising:
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a plurality of shock absorbers, each interposed between a portion of a vehicular body and a corresponding road wheel, each of said shock absorbers having a piston member and a damping coefficient varying means associated with the piston member, said damping coefficient varying means operatively varying the damping coefficient in either stroke direction of the piston member to a target damping coefficient; a plurality of acceleration sensors, each associated with a shock absorber, each disposed on said vehicle body at a location proximate the associated shock absorber, and each arranged to produce an output signal indicative of a vertical acceleration; circuit means operatively connected with each of said plurality of acceleration sensors for receiving the output signals from said acceleration sensors, said circuit means including; filter means for filtering a sprung mass speed from each of the output signals from said plurality of acceleration sensors and producing a plurality of sprung mass speed signals; bouncing component detecting means for deriving a bouncing component from each of said plurality of sprung mass speed signals; pitching component detecting means for deriving a pitching component from each of said plurality of sprung mass speed signals; rolling component detecting means for deriving a rolling component for each of said plurality of sprung mass speed signals; and e) controlling means for; deriving and outputting a control signal to each damping coefficient varying means of the shock absorbers associated with road wheels located at a forward end of said vehicle body at least on the basis of the derived bouncing components, and deriving and outputting a control signal to each damping coefficient varying means of the shock absorbers associated with road wheel located at a rear end of said vehicle body on the basis of at least one of the derived pitching component and rolling component outputting the control signals to the respective damping coefficient varying means.
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38. An apparatus for controlling a plurality of shock absorbers, each of said shock absorbers being interposed between a portion of a vehicular body and corresponding road wheel, comprising:
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a plurality of damping coefficient varying means, each of said damping coefficient means being associated with one of said shock absorbers and responsive to a control signal, for varying a damping coefficient of the shock absorber to a target damping coefficient; a plurality of acceleration sensors each disposed on said vehicular body at a location proximate a shock absorber, each of said acceleration sensors producing an output signal indicative of a sensed acceleration; circuit means associated said plurality of acceleration sensors, said circuit means including filtering means for filtering each of the output signals from said plurality of acceleration sensors and for deriving a bounce signal component, a pitch signal component, and a roll signal component for each of said output signals; and control means, responsive to said circuit means, for deriving and outputting a control signal to each of said damping coefficient varying means on the basis of at least one of said bounce signal component, pitch signal component, and roll signal component derived for each of said input signals.
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39. An apparatus comprising:
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a shock absorber, said shock absorber being operatively connected between a vehicle body and a vehicle road wheel; damping coefficient varying means incorporated into said shock absorber for controlling the damping coefficient of said shock absorber during both compression and contraction modes of said shock absorber; an acceleration sensor mounted on said vehicle body proximate location where said shock absorber is connected with said vehicle body; first filtering means for extracting a sprung mass speed signal from the output of said acceleration sensor; second filtering means for filtering said sprung mass speed signal so as to derive; a bounce rate component, a pitch rate component, and a rolling rate component; and control means for deriving a control signal on the basis of at least one of said bounce rate component, pitch rate component and rolling rate component. - View Dependent Claims (40, 41, 42, 43)
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Specification