US 6,188,316 B1 · Vehicle dynamic control system

Abstract

Recognizing curve geometry, judgement accuracy of an over speed condition is improved with minimal increase of calculation load, even when the road to an objective curve is not a straight line. The standard deceleration calculator calculates a standard deceleration from the road surface friction coefficient and road slope. The permissible access speed calculator calculates a permissible access speed from the permissible lateral acceleration based on road geometry and the road surface friction coefficient. The equivalent linear distance calculator calculates an equivalent linear distance, converting a winding part of a road to the objective curve into an equivalent straight line. The passing judgement device compares a required deceleration, which is determined based on the present vehicle speed, the permissible access speed and the equivalent linear distance, with a warning deceleration level and a forced deceleration level, which are calculated from the standard deceleration. According to the comparison result, the warning deceleration controller carries out a warning control through the display and a loudspeaker and forced deceleration control by the engine control unit, the transmission control unit and the brake control unit.

Claims9

Dependent claims

A vehicle dynamic control system comprising:

a running condition detecting means for detecting running conditions of a vehicle;
a road data detecting means for detecting road data relating to a road in front of the vehicle;
a worth judging distance calculating means for calculating a worth judging distance from a point of operation to a curve on the road in front of the vehicle based on said road data, said worth judging distance being corrected and reduced according to a curvature of a winding part of the road between said point of operation and the curve, wherein said worth judging distance calculating means includes equivalent linear distance calculating means responsive to a coefficient signal relating to road friction characteristics, said road data, and a warning deceleration threshold level, said equivalent linear distance calculating means for deriving a linear distance equivalent to a shortened distance of the curve and for generating a linear distance signal which is provided to the passing judgement means;
a passing judgement means for judging a possibility of the vehicle passing through the curve based on said worth judging distance calculated by said worth judging distance calculating means;
and
a warning and deceleration control means for activating at least one of a warning means and a decelerating means based on a judgement of said passing judgement means.

3 more elements

A dynamic control system of a vehicle, comprising:

road surface friction coefficient estimating means responsive to a vehicle speed signal, a steering signal, and a yaw rate signal for calculating a road surface friction coefficient by comparing a cornering power of each vehicle wheel and for generating a coefficient signal;
road inclination calculating means responsive to said vehicle speed signal and a longitudinal acceleration signal for calculating a degree of road slope using a predetermined equation and for generating a slope signal;
warning deceleration value calculating means responsive to said slope signal and said coefficient signal for determining a permissible deceleration value by deriving a reference deceleration value from said road slope and said road surface friction coefficient and for producing a warning deceleration signal;
forced deceleration value calculating means for calculating a forced deceleration value from the reference deceleration value, the forced deceleration value relating to an amount of deceleration required for safely passing the curve and for generating a forced deceleration value signal;
acceptable curve-entering speed calculating means responsive to said coefficient signal and a road information signal providing information relating to characteristics of the road, said acceptable curve-entering speed calculating means for calculating a permissible speed in order to enter a curve by referring to a permissible acceleration value for said road information and for outputting a permissible entering speed signal;
equivalent linear distance calculating means responsive to said coefficient signal, said road information signal, and said warning deceleration signal for deriving a linear distance equivalent to a shortened distance of the curve and for generating a linear distance signal;
required deceleration value calculating means responsive to said warning deceleration signal, permissible entering speed signal, said vehicle speed signal, and said linear distance signal for calculating a required deceleration value from a predetermined equation relating to said road information and said vehicle speed and for outputting a required deceleration signal;
passing possibility judgement means responsive to said required deceleration signal, said warning deceleration signal, and said forced deceleration value signal for judging a possibility of passing through the curve in accordance with said required deceleration value and for generating a possibility signal;
and
warning control means connected to an engine of the vehicle, transmission control means, and a brake control system, responsive to said possibility signal, said required deceleration signal, said warning deceleration signal, and said forced deceleration value signal for warning a driver of the vehicle of an over speed condition or reducing vehicle speed to a speed that enables the vehicle to safely pass the curve even if a portion of the road before entering the curve is curved.

7 more elements

Dependencies are inferred from the claim text.

Vehicle dynamic control system

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Vehicle dynamic control system

Life of this patent

Abstract

Claims9