Vehicular suspension control system with variable damping characteristics depending upon road condition and vehicle speed
First Claim
1. A suspension control system for an automotive vehicle comprising:
- a damper means interpositioned between a vehicle body and a road wheel for absorbing, at least in part, relative displacement between the vehicle body and the road wheel, said damper means having damper characteristics selectably variable between a first weaker damping characteristics mode and a second stronger damping characteristics mode;
a first sensor producing a first sensor signal, the amplitude and frequency of which correspond to the amplitude and frequency of vibrations of the vehicle body;
a second sensor adapted to produce a second sensor signal indicative of a vehicle speed;
a filter means receiving said first sensor signal and outputting a filter signal representative of the amplitude of a specific frequency range of said sensor signal;
a comparator means receiving said filter signal and comparing the amplitude thereof with a reference value, said comparator means producing a comparator signal when the filter signal value is greater than the reference value;
a reference signal generator for transmitting said reference signal to said comparator means, said reference signal generator being responsive to said second sensor signal to vary the value of said reference signal based thereon;
a controller associated with said damper means for normally operating the latter in said first softer damping characteristics mode, said controller being responsive to said comparator signal to operate said damper means in said second harder damping characteristics mode.
1 Assignment
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Accused Products
Abstract
A suspension control system for automotive vehicles automatically adjusts the damping strength of variable shock absorbers or other dampers in accordance with road surface conditions. The sensor signal reflects vertical displacement of the vehicle body from the road surface. The sensor signal is compared to a corresponding reference level which is variable depending upon a vehicle speed. The results of comparison give an indication of the degree and scale of irregularities in the road surface. The comparison information is sent to a suspension system controller which causes actuation of the shock or other dampers absorbers to a stiffer mode of operation when road surface roughness requiring harder suspension is recognized.
134 Citations
8 Claims
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1. A suspension control system for an automotive vehicle comprising:
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a damper means interpositioned between a vehicle body and a road wheel for absorbing, at least in part, relative displacement between the vehicle body and the road wheel, said damper means having damper characteristics selectably variable between a first weaker damping characteristics mode and a second stronger damping characteristics mode; a first sensor producing a first sensor signal, the amplitude and frequency of which correspond to the amplitude and frequency of vibrations of the vehicle body; a second sensor adapted to produce a second sensor signal indicative of a vehicle speed; a filter means receiving said first sensor signal and outputting a filter signal representative of the amplitude of a specific frequency range of said sensor signal; a comparator means receiving said filter signal and comparing the amplitude thereof with a reference value, said comparator means producing a comparator signal when the filter signal value is greater than the reference value; a reference signal generator for transmitting said reference signal to said comparator means, said reference signal generator being responsive to said second sensor signal to vary the value of said reference signal based thereon; a controller associated with said damper means for normally operating the latter in said first softer damping characteristics mode, said controller being responsive to said comparator signal to operate said damper means in said second harder damping characteristics mode. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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Specification