Lane-keep control system for vehicle

Claim 2

A lane-keep control system for a host-vehicle, comprising: a control unit configured, to detect a traveling condition of the host-vehicle, to determine that there is a tendency of a lane deviation that the host-vehicle is deviating from a traveling lane, on the basis of the traveling condition, to calculate a driving/braking force controlled variable of each wheel according to the traveling condition so as to generate a yawing moment directed toward a direction of preventing the lane deviation when there is the tendency of the lane deviation, to detect a steering state quantity indicative of a quantity of state of a steering wheel, to correct the driving/braking force controlled variable on the basis of the steering state quantity, and to control a driving/braking force of each wheel according to the driving/braking force controlled variable.

Claim 3

The lane-keep control system as claimed in claim 1 , wherein the control unit is configured to correct the driving/braking force controlled variable according to the steering state quantity so as to decrease the yawing moment directed toward the direction of preventing the host-vehicle from deviating from the traveling lane when the steering state quantity acts to suppress the lane deviation.

Claim 4

The lane-keep control system as claimed in claim 1 , wherein the control unit is configured to estimate a yawing moment due to a steering operation from the steering state quantity, and to correct the driving/braking force controlled variable according to the estimated yawing moment.

Claim 5

The lane-keep control system as claimed in claim 1 , wherein the control unit is configured to calculate a target yawing moment from a difference between a future lateral displacement of the host-vehicle relative to the traveling lane and a lateral displacement limit value, where the future lateral displacement is estimated from the steering state quantity, and to calculate the driving/braking force controlled variable on the basis of the target yawing moment.

Claim 6

The lane-keep control system as claimed in claim 4 , wherein the control unit is configured to estimate a yawing moment due to a steering operation from the steering state quantity, to obtain a corrected target yawing moment by subtracting the yawing moment due to the steering operation from the target yawing moment, and to correct the driving/braking force controlled variable on the basis of the corrected target yawing moment.

Claim 7

The lane-keep control system as claimed in claim 1 , wherein the control unit is capable of independently controlling braking forces of right and left wheels of the host-vehicle.

Claim 8

The lane-keep control system as claimed in claim 1 , wherein the control unit is configured to determine that there is the tendency of the lane deviation when a future lateral displacement of the host-vehicle relative to a traveling lane becomes greater than or equal to a lateral displacement limit value, where the future lateral displacement is estimated from the traveling condition.

Claim 9

The lane-keep control system as claimed in claim 1 , wherein the driving/braking force control variable includes a target yawing moment MS which is determined from the following expression: MS=Kdd×M S0 , where M S0 =−K 1 ×K 2 ×(XS−X C ), K 1 is a constant determined by vehicle specifications, K 2 is a coefficient which is decreased according to an increase of a vehicle speed, X C a value obtained by subtracting a half of a host-vehicle width L 0 from a half of a traveling-lane width L, and XS is a future lateral displacement expressed by the following expression, XS=Tt×V× (Φ+ Tt×V×β )+ X, where Tt is a vehicle head time for calculating a front remarking distance, and the front remarking distance is calculated by multiplying the vehicle head time Tt and vehicle speed V of the host-vehicle, Φ is a yaw angle of the host-vehicle relative to the traveling lane, X is a lateral displacement X of the host-vehicle relative to a center of the traveling lane, and β is a curvature of the traveling lane.

Claim 10

A lane-keep control system of a host-vehicle comprising: a traveling condition detecting device that detects a traveling condition of the host-vehicle, the traveling condition including a state of a steering wheel; a brake hydraulic pressure control circuit that independently controls a hydraulic pressure of each wheel cylinder of the host-vehicle to generate a desired braking force of the host-vehicle; a driving torque control unit that controls a driving torque applied to driving wheels of the host-vehicle; and a driving/braking force control unit coupled to the traveling condition detecting device, the brake hydraulic control circuit and the driving torque control unit, the driving/braking force control unit being arranged, to determine that there is a tendency of a lane deviation that the host-vehicle is deviating from a traveling lane, on the basis of the traveling condition, to calculate a target yawing moment reference value on the basis of the traveling condition when there is the tendency of the lane deviation, to calculate a target yawing moment by correcting the target yawing moment reference value according to a rate of change of the state of the steering wheel with respect to time, to calculate a target brake hydraulic pressure according to the traveling condition and the target yawing moment, to calculate a target driving force according to the traveling condition and the target brake hydraulic pressure, and to output a first drive signal indicative of the target brake hydraulic pressure to the brake hydraulic pressure control circuit and a second drive signal indicative of the target driving force to the driving force control unit.

Claim 11

A lane-keep control system of a host-vehicle comprising: a traveling condition detecting device that detects a traveling condition of the host-vehicle, the traveling condition including a state of a steering wheel; a brake hydraulic pressure control circuit that independently controls a hydraulic pressure of each wheel cylinder of the host-vehicle to generate a desired braking force of the host-vehicle; a driving torque control unit that controls a driving torque applied to driving wheels of the host-vehicle; and a driving/braking force control unit coupled to the traveling condition detecting device, the brake hydraulic control circuit and the driving torque control unit, the driving/braking force control unit being arranged, to determine that there is a tendency of a lane deviation that the host-vehicle is deviating from a traveling lane, on the basis of the traveling condition, to calculate a target yawing moment reference value on the basis of the traveling condition when there is the tendency of the lane deviation, to calculate a target yawing moment by correcting the target yawing moment reference value according to a rate of change of the state of the steering wheel with respect to time, to calculate a target brake hydraulic pressure according to the traveling condition and the target yawing moment, to calculate a target driving force according to the traveling condition and the target brake hydraulic pressure, and to output a first drive signal indicative of the target brake hydraulic pressure to the brake hydraulic pressure control circuit and a second drive signal indicative of the target driving force to the driving force control unit.

Claim 14

A lane-keep control system for a host-vehicle, comprising: traveling condition detecting means for detecting a traveling condition of the host-vehicle; deviation determining means for determining that there is a tendency of a lane deviation that the host-vehicle is deviating from a traveling lane, on the basis of the traveling condition; driving/braking force control quantity calculating means for calculating a driving/braking force controlled variable of each wheel according to the traveling condition so as to generate a yawing moment directed toward a direction of preventing the lane deviation when there is the tendency of the lane deviation; driving/braking force controlling means for controlling a driving/braking force of each wheel according to the driving/braking force controlled variable; and steering condition quantity detecting means for detecting a steering state quantity indicative of a quantity of state of a steering wheel; wherein the driving/braking control quantity calculating means comprises driving/braking force controlled-variable correcting means for correcting the driving/braking force controlled variable on the basis of the steering state quantity.

Claim 15

A lane-keep control system for a host-vehicle, comprising: traveling condition detecting means for detecting a traveling condition of the host-vehicle; deviation determining means for determining that there is a tendency of a lane deviation that the host-vehicle is deviating from a traveling lane, on the basis of the traveling condition; driving/braking force control quantity calculating means for calculating a driving/braking force controlled variable of each wheel according to the traveling condition so as to generate a yawing moment directed toward a direction of preventing the lane deviation when there is the tendency of the lane deviation; driving/braking force controlling means for controlling a driving/braking force of each wheel according to the driving/braking force controlled variable; and steering condition quantity detecting means for detecting a steering state quantity indicative of a quantity of state of a steering wheel; wherein the driving/braking control quantity calculating means comprises driving/braking force controlled-variable correcting means for correcting the driving/braking force controlled variable on the basis of the steering state quantity.