CN101172482A

CN101172482A - Lane departure prevention apparatus

Info

Publication number: CN101172482A
Application number: CNA2007101808330A
Authority: CN
Inventors: 定野温; 尾崎真弘; 上村吉孝
Original assignee: Nissan Motor Co Ltd
Current assignee: Nissan Motor Co Ltd
Priority date: 2003-11-14
Filing date: 2004-11-12
Publication date: 2008-05-07
Anticipated expiration: 2024-11-12
Also published as: JP2005145243A; JP4380301B2; CN101172482B

Abstract

The present invention relates to a lane departure prevention apparatus, which is configured to conduct a course correction in a lane departure avoidance direction when the controller determines that there is a potential for a vehicle to depart from a driving lane. The lane departure prevention apparatus has a driving road detecting section and a lane departure avoidance control section. The driving road detecting section is configured to determine at least one of a road slope direction and a road curvature direction of a driving road upon which a host vehicle is traveling. The lane departure avoidance control section is configured to start lane departure avoidance control based on a driving direction of the host vehicle and at least one of a road slope direction and a road curvature direction detected by the driving road detecting section.

Description

Lane departure prevention apparatus

The application number that the application submits on November 12nd, 2004 for same applicant be that " 200410092991.7 ", denomination of invention are the dividing an application of Chinese invention patent application of " lane departure prevention apparatus ".

Technical field

The present invention relates to a kind of lane departure prevention apparatus.More particularly, the present invention relates to a kind of lane departure prevention apparatus, be used for preventing when as if approaching that when this departing from main vehicle from departing from the driving track.

Background technology

Traditional lane departure prevention apparatus comprises the equipment that is used for to main vehicle notice yawing moment, this by control to the braking force of wheel and prevent that main vehicle from departing from and drive the track and carry out.The lane departure prevention apparatus that these are traditional might depart under the situation of driving the track at main vehicle, also drives the track by providing this yawing moment to notify driver master's vehicle to depart from.For example, a kind of such lane departure prevention apparatus is open in Japanese Patent Laid-Open Publication No.2000-33860, its control brake is so that provide yawing moment to main vehicle, and prevents deviation, and also by this yawing moment warning driver (referring to page or leaf 3 and Fig. 6).The lane departure prevention apparatus that this is traditional, by any distance (side travel amount) of leaving the center, driving track of main vehicular drive position, reach the drive route of estimating and whether surpassed predetermined value separately, determine deviation with respect to the angle (yaw angle amount of movement) of driving track formation.

Disclose another kind of lane departure prevention apparatus (page or leaf 7 and Fig. 2) in Japanese Patent Laid-Open Publication No.2003-112540, it estimates the deviation of main vehicle to the driving track, and avoids deviation by combination driftage control with deceleration control.Specifically, driftage control brake activation to be to provide yawing moment to main vehicle, and wherein the braking force difference is applied to a left side and right wheel to avoid deviation, and the while, the deceleration control brake activation was with the main vehicle that slows down.The total braking force of driftage control and deceleration control, according to estimating that the amount of following vehicle from its deviation applies, this bias is based on the driving condition calculating of main vehicle.

Just with on, open be apparent that from this for those skilled in the art, need a kind of improved lane departure prevention apparatus.Promptly at this needs and other needs in the industry, these need will be tangible for those skilled in the art openly from this in the present invention.

Summary of the invention

Have been found that in Japanese Patent Laid-Open Publication No.2000-33860 a kind of side travel detector detects the side travel of vehicle steering position to driving reference position, track, and impose braking force based on its side travel that detects.This provides yawing moment to vehicle, thereby prevents that vehicle from departing from the driving track.Promptly the deviation of the Japanese Patent Laid-Open Publication No.2000-33860 of Ti Chuing has avoided only considering driving the position relation between track and the vehicle, and prevents that vehicle from departing from from it.Though yet realized according to the position relation of driving between track and the vehicle deviation prevents control, might the driver feel to have for what mistake.

Just with on, the present invention is design-calculated considering the problems referred to above.An object of the present invention is to provide a kind of lane departure prevention apparatus, can respond the structure of driving the track and realize that the deviation of optimizing prevents control.

In order to address certain of these issues, lane departure prevention apparatus of the present invention is equipped with driving road detecting section, and lane departure avoidance control section.Driving road detecting section is configured to, and determines that the sideways inclined direction of the driving road that main vehicle travels and road bending direction are one of at least thereon.Lane departure avoidance control section is configured to, and the sideways inclined direction that detects based on the driving direction of main vehicle and by driving road detecting section and road bending direction one of at least start deviation and avoid controlling.

Description of drawings

From disclose the detailed description of the preferred embodiment of the present invention below in conjunction with accompanying drawing, for those skilled in the art's these and other purposes of the present invention, mode and advantage will be apparent.

Referring now to forming this original disclosed accompanying drawing:

Fig. 1 is the schematic configuration diagram of outfit according to the vehicle of the lane departure prevention apparatus of first embodiment of the invention;

Fig. 2 is a diagram of circuit, the contents processing that expression is carried out according to the driving power control unit of an assembly of the lane departure prevention apparatus of first embodiment of the invention Fig. 1 by conduct;

Fig. 3 is a diagram of circuit, and expression prevents definite processing of drive environment that the driving power control unit in the control convenience is carried out according to the first embodiment of the present invention by the deviation at Fig. 2;

The diagram of Fig. 4 vehicle on three tracks of one-way road of representing to travel;

The diagram of Fig. 5 is represented when travelling on three tracks of main vehicle at one-way road, by the imaging picture of main vehicle in each lane position shooting;

Fig. 6 is a diagram of circuit, and expression is used for by determined the contents processing of deviation tendency by driving power control unit;

The diagram of Fig. 7 is used for describing to depart from the time T of prediction or estimation _Out

Fig. 8 is characteristic pattern or the map that expression is used to calculate the feature of the gain K1 of yawing moment Ms and K2;

Fig. 9 is characteristic pattern or the map that expression is used to calculate the feature of the conversion factor Kgv of target brake fluid pressure Pgf and Kgx;

Figure 10 is the diagram that is used to describe brake control method under second situation or the sight;

Figure 11 is the diagram that is used to describe brake control method under the 3rd situation or the sight;

Figure 12 is a pair of diagram, is used for the lane departure prevention apparatus of comparison first embodiment and traditional departure prevention apparatus;

Figure 13 is the vehicle structure scheme drawing that is equipped with according to the lane departure prevention apparatus of second embodiment of the invention;

Figure 14 is a diagram of circuit, the contents processing that expression is controlled for driving power when pursuit-type vehicle according to a second embodiment of the present invention;

Figure 15 is a diagram of circuit, represents the contents processing of the driving power control unit bend inner control of second embodiment;

Figure 16 is a characteristic map, and expression is used to calculate the characteristic of conversion factor Kgvc of the target brake fluid pressure Pgf of second embodiment;

Figure 17 is a characteristic map, and expression is used to calculate the characteristic of conversion factor Kgv β of the target brake fluid pressure Pgf of second embodiment;

The diagram of Figure 18 is used for describing the lane departure prevention apparatus of second embodiment;

Figure 19 is a diagram of circuit, represents a third embodiment in accordance with the invention contents processing for driving power control unit when pursuit-type vehicle;

Figure 20 is a diagram of circuit, and expression is used to change the contents processing of the deceleration of driving power control unit;

Figure 21 is a gain diagram that is used for changing the processing of deceleration;

Figure 22 is a pair of diagram, and the deviation that is used for following situation is described to be provided with deceleration is avoided control method (A) value less than the plane when main vehicle driving up is driven, or (B) when the vehicle descending greater than the value on plane;

Figure 23 is shown in to go up a slope and avoids departing from the vehicle that uses deceleration control;

Figure 24 is a diagram of circuit, and expression is according to fourth embodiment of the invention contents processing for driving power control unit when the pursuit-type vehicle;

Figure 25 is a pair of diagram, be used for describing when main vehicle downhill retardation preset time or predetermined distance and the target of the driving road that prevents to depart between the main vehicle descending that slows down;

Figure 26 is a diagram of circuit, and expression is according to fifth embodiment of the invention contents processing for driving power control unit when the pursuit-type vehicle; And

Figure 27 is a pair of diagram, the relation between expression vehicle coordinate XYZ of system and the road surface tilt angle theta z.

The specific embodiment

The embodiment of the invention now with reference to the description of drawings selection.Be apparent that for those skilled in the art openly that from this following description of the embodiment of the invention is not the present invention that will limit by claims and equivalent definition thereof just for example provides.

At first referring to Fig. 1, the structural representation that is equipped with according to the main vehicle of the lane departure prevention apparatus of first embodiment of the invention is shown.This embodiment is a kind of rear wheel drive vehicle that lane departure prevention apparatus of the present invention is housed.This rear wheel drive vehicle is equipped with automatic transmission with hydraulic torque converter and traditional differential gear, and brake system is housed, and it allows in preceding and trailing wheel and a left side and the independent control brake power of right wheel.

In the diagram of Fig. 1, main vehicle is equipped with 1, one blwr 2 of a brake pedal basically, master cylinders 3, a fuel tank 4, a pair of front-wheel 5FL and 5FR, pair of rear wheels 5RL and 5RR, wheel cylinder 6FL and 6FR before a pair of, pair of rear wheels cylinder 6RL and 6RR, 7, one controllers of a brake fluid pressure controlling unit or driving power control unit 8, a

combustion engine

9,11, one driving torque control units 12 of 10, one flow regulating valve of an automatic transmission with hydraulic torque converter, an

imaging unit

13,17, one accelerator tramplings of 15, one master cylinders pressure sensors of a homing advice or cutoff port jaw opening sensor 17, a

torque sensor

18,20, one bearing circle 21 of 19, one directional signal switchs of a steering angle sensor, a pair of front-wheel speed sensor 22FL is to 22FR, and pair of rear wheels speed sensor 22RL is to 22RR.This vehicle also is equipped with a warning device, and it preferably warns the sound output unit.This warning device origin is self-driven/drive of brak control unit 8.

Driving power control unit 8 preferably includes a microcomputer that has deviation to prevent control program, control wheel cylinder 6FL, and 6FR, 6RL and 6RR are so that apply yawing moment to main vehicle as discussed below.Driving power control unit 8 also can comprise the assembly that other are traditional, such as input interface circuit, and output interface circuit, and memory storage such as ROM (read-only memory (ROM)) device and RAM (random access memory) device.Memory circuitry stores processor result and control program are such as the program that is used for the control brake operation by the processor circuit operation.Driving power control unit 8 is operationally connected to the sensor in a conventional manner.The state and the various control data of the internal RAM storage operation sign of driving power control unit 8.The inside ROM storage of driving power control unit 8 is used for the program and the predetermined variable of various operations.Driving power control unit 8 can be on demand and/or is wished to control selectively the assembly of the main vehicle of any number.Be apparent that for those skilled in the art that from the disclosure precision architecture and the algorithm that are used for driving power control unit 8 can be that hardware and the software that will carry out function of the present invention makes up arbitrarily.In other words, reach any structure or hardware and/or algorithm or the software that " device the adds function " statement that uses in the claim should comprise the function that can be used for implementing " device adds function " statement in this manual.

Brake fluid pressure controlling unit 7 preferably includes a microcomputer, and it preferably disposes and arranges for example to implement anti-skidding control and traction control.Brake fluid pressure controlling unit 7 also disposes and arranges, so that control the brake fluid pressure of wheel cylinder 6FL to 6RR independently.Like this, brake fluid pressure controlling unit 7 also is configured to, when from driving power control unit 8 input brake hydraulic pressure bid values, according to brake fluid pressure bid value control brake hydraulic pressure (following description).

Driving torque control unit 12 preferably includes a microcomputer, its configuration and arrangement are so that by controlling the mode of operation of driving engine 9, the selected converter speed ratio of automatic transmission with hydraulic torque converter 10, with or the throttle valve opening of flow regulating valve 11, control to as the trailing wheel 5RL of drive wheel and the driving torque of 5RR.Driving torque control unit 12 is by controlling the throttling hole size simultaneously, control fuel injection amount and ignition timing, and the mode of operation of control driving engine 9.Use this driving torque control unit 12, the driving torque Tw value that is used to control outputs to driving power control unit 8.

Driving torque control unit 12 also is configured to the driving torque of independent control trailing wheel 5RL and 5RR.Like this, driving torque control unit 12 also is configured to, when from driving power control unit 8 input driving torque bid values, according to the torque of driving torque bid value controlling and driving wheel.

Imaging unit 13 has a kind of picture processing capacity, and preferably for example comprise a CCD (charge-coupled device) camera, and the phase machine controller, as the target recognition sensor, be used to detect the position of main vehicle in driving the track, so that estimate preventing of main vehicular drive deviation.Like this, imaging unit 13 is designed to detect the position of main vehicle in driving the track, so that detect the deviation trend of main vehicle.Imaging unit 13 is configured to for example use single-lens (simple lens) camera pickup image that is made of CCD (charge-coupled device) camera.Imaging unit 13 preferably is configured in the front of main vehicle.

The phase machine controller that becomes to resemble unit 13 preferably disposes like this and arranges, so that for example detect white line or other lane markings from the imaging picture of main vehicle front region.Like this, detect the driving track based on the lane markings that detects.In addition, imaging unit 13 calculates angle (yaw angle) φ that is formed by main vehicular drive track and main longitudinal direction of car axle, leaves the cross travel X that drives the center, track, drives track curvature β, lane width L or the like.The yaw angle φ that imaging unit 13 calculates to 8 outputs of driving power control unit, the cross travel X of calculating, the driving track curvature β of calculating, lane width L or the like.The function of imaging unit 13 is as the running state test section, is used to detect the running state of vehicle.Imaging unit 13 also can be regarded driving road detecting section as, is used to detect the state of driving road.

Homing advice 15 is configuration and arrangement so preferably, to detect yaw speed φ ' and transverse acceleration Xg and/or the longitudinal acceleration Yg that produces in main vehicle.The transverse acceleration Xg that homing advice 15 detects to 8 outputs of driving power control unit, and the longitudinal acceleration Yg that detects, and the yaw speed φ ' that detects.Homing advice 15 is also to driving power control unit 8 output road informations.Road information (promptly main vehicle drive environment) preferably includes the information about road type, is ordinary road or through street such as number of track-lines and road.The function of homing advice 15 is used to detect the running state of vehicle also as a running state test section.Homing advice 15 also can be regarded driving road detecting section as, is used to detect the state of driving road.

Master cylinders pressure sensor 17 is configuration and arrangement so preferably, so that detect the delivery pressure of master cylinders 3, i.e. master cylinders hydraulic pressure Pmf and Pmr.Like this, the function of master cylinders pressure sensor 17 is as brake operating amount test section, is used to detect the delivery pressure of master cylinders 3.Accelerator trampling or cutoff port jaw opening sensor 18 be configuration and arrangement so preferably, so that the downward power on the detection accelerator pedal 1 or the size of cutoff port aperture, so that the signal Acc of output indication cutoff port aperture size.Steering angle sensor 19 is configuration and arrangement so preferably, so that detect the steering angle δ of bearing circle 21.Directional signal switch 20 is configuration and arrangement so preferably, so that detect the signal for turn operation of signal for turn indicating device.Vehicle-wheel speed sensor 22FL preferably disposes like this and arranges to 22RR, so that detect the rotating speed of wheel 5FL to 5RR, promptly so-called wheel velocity Vwi (i=fl, fr, rr).

When in the driving condition of the main vehicle that is detecting or the status data left side or right directional being arranged, both direction is set, make left to being positive dirction.In other words, when turnon left, yaw speed φ ', longitudinal acceleration Yg, and yaw angle φ be on the occasion of, when from driving the center, track when being moved to the left, cross travel X be on the occasion of.And, period of acceleration longitudinal acceleration Yg be on the occasion of, be negative value between deceleration period.

Following now being illustrated as with reference to Fig. 2 avoided deviation, by the calculation processes of driving power control unit 8 execution.This computing uses timer to interrupt at each specific predetermined sampling time interval Δ T, such as per 10 milliseconds of execution.Communication process is not included in the processing shown in Figure 2, but the information that obtains by computing is updated in random access memory and stores, and reads required information from random access memory when needing.

At first in step S1, read various data from the sensor by driving power control unit 8.More particularly, read the data of following type: by the transverse acceleration Xg that homing advice 15 obtains, longitudinal acceleration Yg, yaw speed φ ', and road information; Wheel velocity Vwi; Steering angle δ, accelerator trampling amount or cutoff port aperture size Acc; Master cylinders hydraulic pressure Pmf and Pmr; Turning on-off signal WS from directional signal switch 20; The signal of dangerous switch 31; Drive torque Tw from drive torque control unit 12; And the yaw angle φ that comes selfimaging unit 13, cross travel X, and drive track curvature β.

Calculate main car speed V at step S2.More particularly, use equation (1) shown below to calculate main car speed V based on the wheel velocity Vwi that reads at above-mentioned steps S1.

Then, handle to move to step S2, based on the calculation of mean value master car speed V of the wheel velocity of non-driving wheel.In an illustrated embodiment, main vehicle is by back-wheel drive, and main like this car speed V is based on the speed Vw of a preceding left side and right wheel 5FL and 5FR _FLAnd Vw _FRCalculate.In any case, use one of equation (1) as follows, calculate main car speed V based on the wheel velocity Vwi of the non-driving wheel that reads at above-mentioned steps S1.

V=(Vwrl+Vwrr)/2 is for f-w-d, and

V=(Vwfl+Vwfr)/2 is for back-wheel drive (1)

In the equation (1), a Vwfl and Vwfr are a left side and each wheel velocity of off front wheel, and Vwfl and Vwfr are a left side and each wheel velocity of off hind wheel.In other words, in equation (1), as the calculation of mean value master car speed V of drive wheel wheel speed.In the present embodiment, main vehicle is by back-wheel drive, thereby promptly calculates main car speed based on the wheel velocity of front-wheel 5FL and 5FR from back one equation.

And the main car speed V of Ji Suaning preferably uses in normal driving like this.In other words, when control waits work, use the estimation body speed of vehicle of in ABS control, estimating at ABS (locking the moving system of customization) as above-mentioned car speed V.The value of using for the navigation information in homing advice 15 also is used as above-mentioned car speed V.

Determine main vehicle drive environment at step S3 then.More particularly, detect the road type and the main vehicular drive track of main vehicle ' as driving environment.From the definite direction of the result who detects based on safe class.This determines to be based on selfimaging unit 13 video informations, and carry out based on the road information from homing advice 15.In other words, determine that it is that the road type information of ordinary road or through street is carried out with the indication road that driving environment is based on number of track-lines.Fig. 3 illustrates the particular process that is used for determining driving environment.

At first,, obtain the current road type that travels (ordinary road or through street) from the road information that provides by homing advice 15 at step S21.And then, obtain the number of track-lines of the current road that travels from the road information that provides by homing advice 15 at step S22.

At following step S23, extract white line part (track cut-off rule part) from the imaging picture of taking by imaging unit 13.Example described herein is along the situation of three lanes of one-way road for main vehicle as shown in Figure 4.From left-hand side by first to Sibai line L1, L2, the road that L3 and L4 divide is configured to one-way road three tracks, as shown in Figure 4.When main vehicle during along such road driving, the imaging picture that each track is obtained is different.And then the picture that is made of the white line that extracts from picture is the difference by driving the track also.

In other words, when main vehicle 100A travels in the travel direction left hand carriageway, mainly comprise the first, the second and the 3rd white line LI1 by the imaging picture P of imaging unit 13 picked-up of main vehicle 100A, unique picture of LI2 and LI3 is shown in the picture (A) of Fig. 5.And, when main vehicle 100B travels at center lane, be mainly to comprise first, second, third and Sibai line LI1 by the imaging picture P of imaging unit 13 picked-up of main vehicle 100B, LI2, unique picture of LI3 and LI4 is shown in the picture (B) of Fig. 5.When main vehicle 100C travels in the travel direction right hand carriageway, mainly comprise the second, the third and fourth white line LI2 by the imaging picture P of imaging unit 13 picked-up of main vehicle 100C, unique picture of LI3 and LI4 is shown in the picture (C) of Fig. 5.Like this, the configuration of white line is different according to driving the track in the picture.

Determine main vehicular drive track at next step S24.More particularly, determine main vehicular drive track based on the information that in step S22 and S23, obtains.In other words, by number of lanes in the road of main vehicle ', and determine main vehicular drive track based on current by the imaging picture (picture that the white line of extraction is arranged) of imaging unit 13 picked-up.For example, picture according to number of lanes and the acquisition of driving track is stored as picture data in advance, cut-and-dried picture data with compare by the number of lanes in the road of main vehicle current driving and by the current imaging picture (picture that the white line of extraction is arranged) of imaging unit 13 picked-up, and determine main vehicular drive track.

In follow-up step S25, determine from the level of security in a lateral direction of the track observation of main vehicular drive.More particularly, when main vehicle during from deviation, the low direction of level of security is as information storage.Thereby when the track observation from main vehicle ', when the direction level of security was low leftward, this direction was as the low direction S of level of security _Out(hereinafter referred to as " direction that comprises obstacle ") is stored (S _Out=left side).Observe when the track from main vehicle ', when the right-hand lay level of security was low, this direction was as the direction S that comprises obstacle _OutBe stored (S _Out=the right side).For example this is following definite.

For example in Fig. 4, when main vehicle 100A travels leftward the track, main vehicle during from the left hand deviation in driction in left hand track level of security be lower than at the level of security of main vehicle when the right-hand lay in left hand track departs from.This be because curb from the left-hand in left hand track to, and high possibility curb is arranged is a wall, guardrail, obstacle, or similarly thing such as steep cliff will be arranged on curb.In other words, left the time, when curb, there are higher possibility master's vehicle 100A and these obstacles will come in contact etc. from left-lane in other words when deviation.Thereby, when main vehicle 100A travels leftward the track, determine that left-hand is to being the direction S that comprises obstacle _Out(S _Out=left side).

When center lane that main vehicle 100B travels, identical with respect to current driving track level of security with right both direction on a left side, if because depart from either direction, main vehicle 100B will be still on road.

When main vehicle 100C travelled in right hand track, main vehicle was at the level of security of right-hand lay during to reverse deviation, than direction is lower to the level of security that adjacent lane departs from leftward with main vehicle.Thereby under this situation, when main vehicle 100C travels in right hand track, determine that right-hand lay is the direction S that obstacle is arranged _Out(S _Out=the right side).

Compare with the through street, ordinary road has narrower shoulder width, and many obstacles are arranged on curb, and also has the pedestrian.Therefore, for departing to curb on ordinary road, it is lower to depart from level of security to curb than main vehicle on the through street.

Number of lanes relatively, when left-hand is single way when wherein right-hand lay is reverse track to the side for curb and road, level of security is lower.Under this situation, determine that a left side and right all are the direction S that obstacle is arranged _Out(S _Out=both).

For example, band in the middle of the two-way road in great majority two tracks does not have, guardrail or other partages, for in the country of road left handle drive when the imaging picture of main vehicle ' during at the two-way road in two tracks, it is picture one of shown in Fig. 5 picture (A), and, then be the picture as shown in Fig. 5 picture (C) for country in the road right hand drive.In other words, for country,, be identical imaging picture by imaging unit 13 picked-ups of the main vehicle 100A that travels in road left hand track, three tracks (unidirectional) when the imaging picture of main vehicle ' during at the two-way road in two tracks in the road left handle drive.Thereby, suppose not only to travel in ordinary road but also on the through street, then can not only use the imaging picture to define the direction S of obstacle _OutBased on this fact, number of lanes from the road of the main vehicle current driving of homing advice 15 acquisitions, and be two-way road in two tracks or three track one-way roads by the road of determining current driving, can determine when travel be the two-way road in two tracks the time, also low at the level of security of right-hand lay.

Use above-mentioned treating process shown in Figure 3 to carry out the estimation of the driving environment shown in Fig. 2 step S3.

Determine the trend of deviation then at step S4.This treating process of determining specifically is shown in Fig. 6.

At first, calculate the time T of estimating that departs from step S31 _OutMore particularly, be the variable quantity (variable quantity of unit time) of cross travel X by specifying dx, appointment L is a lane width, and uses cross travel X (for X, the value of dx and L is referring to Fig. 7), uses equation shown below (2) to calculate the time T that departs from of estimation _Out

T _out＝(L/2-X)/dx (2)

User's formula (2) can be calculated the time T that departs from of estimation _Out, up to the main vehicle 100 that equals cross travel amount X from center, track (X=0) cross travel, arriving in to equal from track centre distance is the outside locating area (for example curb) that the amount of L/2 is separated.Obtain lane width L from the imaging picture of handling by imaging unit 13.Also can obtain the position of main vehicle from homing advice 15, and can obtain lane width L from the map data that is stored in homing advice 15.

At subsequent step S32 deviation is set and determines sign.More particularly, estimation departs from time T _OutWith predetermined first depart from and determine that threshold value Ts relatively.Here, when main vehicle when the center, track is left, and when the time T of estimating that departs from _OutDepart from definite threshold value Ts (T less than first _Out＜Ts) time, determine sign F by the processing deviation of step S32 _OutSwitch to connection (F _Out=ON).In other words, determined that deviation will take place by (having deviation trend), and deviation sign F has been set _OutFor connecting (F _Out=ON).When main vehicle is in F _OutThe state of=ON and when returning the central side in track, that at this moment estimates departs from time T _OutBe equal to or greater than first and depart from definite threshold value Ts (T _Out＞Ts), and deviation is determined sign F _OutSwitch to disconnection (F _Out=OFF).In other words, when the time T of estimating that departs from _OutBe equal to or greater than first and depart from definite threshold value Ts (T _Out＞Ts) time, determine to depart from and will (departing from trend does not exist) can not take place.When there being deviation trend, and if for example when avoiding deviation to carry out control of braking (following description), if or driver itself when taking to evade action, then deviation is determined sign F _OutSwitch to disconnection from connection.

First departs from and determines that threshold value Ts is variable.In other words, for example can also be provided with first and depart from definite threshold value Ts based on the level of security that obtains at step S3.

Determine deviation direction D at step S33 based on cross travel X then _OutMore particularly, when main vehicle when direction is from track central cross displacement leftward, then this direction is set to deviation direction D _Out(D _Out=left side).When main vehicle at right-hand lay during from the central cross displacement in track, then this direction is set to deviation direction D _Out(D _Out=the right side).

In step S4 definite deviation trend as discussed above.

Determine the intention of driver's lane change at subsequent step S5.More particularly, as the following intention of determining driver's lane change based on the steering angle δ that obtains at step S1 and/or turning on-off signal.

When by turning on-off signal indicated direction (the flash light side of lighting) and the offset direction D that obtains by step S4 _OutWhen indicated direction is identical, determine that the driver has a mind to lane change, and deviation is determined sign F _OutBecome disconnection (F _Out=disconnect).In other words, determine that the result becomes indication and do not depart from generation.

When by turning on-off signal indicated direction (the flash light side of lighting) and the deviation direction D that obtains by step S4 _OutWhen indicated direction is identical, determine driver's lane change just intentionally, and deviation is determined sign F _OutBecome disconnection (F _Out=disconnect).In other words, determine that the result changes, indication departs from and will not take place or not depart from generation.

When by turning on-off signal indicated direction (the flash light side of lighting) with by the deviation direction D that obtains at step S4 _OutIndicated direction not simultaneously, deviation is determined sign F _OutRemain unchanged, and deviation is determined sign F _OutBe left connection (F _Out=connect).In other words, determine that the result remains unchanged, indication departs from generation or arrives.

When directional signal switch 20 is not operated, determine the intention of driver's lane change based on steering angle δ.In other words, the driver as steering angle δ and bump steer amount Δ δ (time per unit variable quantity) when being equal to or greater than the value of setting, determine the intentional lane change of driver, and deviation is determined sign F under the situation of deviation directional steering _OutBecome disconnection (F _Out=disconnect).

Be identified for avoiding the control method that departs from follow-up step S6.In other words, determine brake control method, whether the warning of departing from is arranged, or realize being used to avoiding the control of braking that departs from when the glancing impact avoided of control deviation.More particularly, to whether sending lane departur warning and/or departing from and avoid control of braking to determine.When carrying out deviation when avoiding control of braking, select brake control method.

Here based on what obtain obstacle direction S arranged at step S3 _Out, at the deviation direction D of step S4 acquisition _Out, and at the definite F that indicates of the deviation of step S5 acquisition _Out, determine to depart from the control content of avoiding.For example, as the definite sign of deviation F _OutBe left connection (T _Out＜Ts) time, send and depart from warning.For example, warning can be sound or demonstration.In addition, as the definite sign of deviation F _OutBe left connection (T _Out＜Ts) time, based on the direction S that obstacle is arranged _OutWith deviation direction D _Out, be identified for departing from the brake control method of avoiding.This will be in explanation after a while.

For example, when determining to carry out steering operation etc. when preventing deviation by the driver, if deviation is determined sign F _OutFor connecting (T _Out＜Ts), then activate deviation alarm or warning.In other words, for example determine sign F according to the deviation that obtains at step S5 _OutThe state that is switched on or switched off, from alarm device 31 sound that gives a warning.Alarm or warning show to wait and carry out by sound.If deviation is determined sign F _OutFor connecting (T _Out＜Ts), then based on longitudinal acceleration Yg, first has obstacle direction S _Out, and deviation direction D _Out, decision is used to avoid the control method that departs from.This goes through following.

As described here, there is such situation, wherein deviation is determined sign F _OutFor connecting (T _Out＜Ts), but can not determine that deviation can carry out steering operation etc. by the driver and prevent.For example, those situations comprise that wherein driver itself recognizes the trend that main vehicle lane departs from, and take to evade action then, but deviation is determined sign F _OutItself is still for connecting (T _Out＜Ts).

Determine sign F at deviation _OutFor connecting (T _OutUnder＜Ts) the situation, also obstacle direction S arranged based on what obtain at step S3 _Out, and the deviation direction D that obtains among the step S4 _Out, select brake control method.Below describe this process in detail.Step S2 to the processing of S6 corresponding to lane departure avoidance control section.

Calculate the target yaw moment that produces in the main vehicle at subsequent step S7.This target yaw moment is to be applied to main vehicle to be used to depart from the yawing moment of avoiding.More particularly, calculate target yaw moment Ms based on variable quantity dx that obtains at step S1 and cross travel X user formula (3).

Ms＝K1·X+K2·dx (3)

In equation (3), a K1 and K2 are the gains that changes or fluctuate according to main car speed V.For example, gain K1 and K2 have lower value at low speed among Fig. 8, when main car speed V reaches certain value, according to increasing with the cooresponding relation of main car speed V, and remain unchanged after reaching certain car speed V.

Calculate deviation at subsequent step S8 and avoid deceleration/decel.In other words, so that being target, main car retardation calculates the braking force that is applied to a left side and right wheel.Here, this braking force is to calculate as target brake fluid pressure Pgf that is applied to a left side and right wheel and Pgr.Use following equation (4) to calculate the target brake fluid pressure Pgf that is used for front-wheel.

Pgf＝Kgv·V+Kgx·dx (4)

In equation (4), a Kgv and Kgx are the conversion factors that is used for braking force is converted to brake fluid pressure.Based on main car speed V and variable quantity dx conversion factor Kgv and Kgx are set respectively.For example, conversion factor K gv and Kgx have higher value at low speed among Fig. 9, by reducing with the cooresponding relation of main car speed V, and remain unchanged after reaching certain car speed V when main car speed V reaches certain value.

Before consideration and in the braking distribution of back, calculate the target brake fluid pressure Pgr that is used for rear wheel based on the target brake fluid pressure Pgf that is used for front-wheel.

Obtain to be used to depart from the deceleration/decel of avoiding (more particularly, being target brake fluid pressure Pgf and Pgr) by this way at step S8.

Determined whether deviation trend at subsequent step S9.In other words, deviation is determined sign F _OutDetermined whether deviation trend.When deviation is determined sign F _OutBe left when connecting, handle and enter step S10, as the trend of main vehicle from deviation, and as the definite sign of deviation F _OutBe left when disconnecting, handle entering step S12, as main vehicle not from the trend of deviation.

Determine that at subsequent step S10 the track of main vehicle ' is straight turning road or crooked track.More particularly, determine that in driving track curvature β and crooked track that step S1 reads threshold value beta cur relatively, is straight turning road or crooked track with the track of determining main vehicle current driving.When driving track curvature β determined threshold value beta cur (β＞β cur) greater than the crooked track here, current driving track was defined as crooked track, and processing enters step S11.For this situation, crooked track is inner determines that sign Fcurin is for connecting (Fcurin=connection).Also obtain information about crooked track bending direction.Otherwise when driving track curvature β and be equal to or less than crooked track and determine threshold value beta cur (β＜=β cur), current driving track is defined as the straight turning road and processing enters step S13.

Determine at step S11 whether the deviation direction tends to crooked track internal direction.More particularly, at step S11 based on the deviation direction D that obtains at step S4 _OutAnd the direction of crooked track bending, determine whether the deviation direction tends to the internal direction in crooked track.In this point, if step S11 is definite, as deviation direction D _OutWhen being equidirectional with the direction of crooked track bending, the deviation direction is the internal direction in crooked track, then handles entering step S14.If step S11 determines, as deviation direction D _OutWhen opposite with the direction of crooked track bending, the deviation direction tends to the outside direction in crooked track, then handles entering step S13.

Calculate the target brake fluid pressure of each wheel at step S12 and S13.In other words, calculate final brake fluid pressure based on departing from the existence of avoiding control of braking.More particularly, calculate in the following manner.

At first at step S12, if deviation is determined sign F _OutFor disconnecting (F _Out=OFF), promptly when determining to depart from can not take place the time, then (rl rr) is set to master cylinders hydraulic pressure Pmf or Pmr, shown in following equation (5) and (6) for I=fl, fr for the target brake fluid pressure Psi of each wheel.

Psfl＝Psfr＝Pmf (5)

Psrl＝Psrr＝Pmr (6)

In equation (5) and (6), a Pmf is the master cylinders hydraulic pressure for front-wheel, and a Pmr is the master cylinders hydraulic pressure for trailing wheel.The master cylinders liquid Pmr of trailing wheel is before consideration and back braking is calculated based on the master cylinders hydraulic pressure Pmf for front-wheel when distributing.

At step S13, when deviation is determined sign F _OutFor connecting (F _Out=ON), promptly when definite deviation will take place, at first based target yawing moment Ms calculated front-wheel target braking liquid pressure reduction Δ Psf and trailing wheel target braking liquid pressure reduction Δ Psr.More particularly, use following equation (7) to (10) to calculate target braking liquid pressure reduction Δ Psf and Δ Psr.

When Ms＜Msl, then

ΔPsf＝0 (7)

ΔPsr＝2·Kbr·Ms/T (8)

When Ms 〉=Msl, then

ΔPsf＝2·Kbf·(Ms-Msl)/T (9)

ΔPsr＝2·Kbr·Msl/T (10)

In (10), a Msl is the threshold value that is used to the usefulness that is provided with at equation (7), and a T is a wheelspan.For simplicity, wheelspan T is identical value.Kbf and Kbr are for preceding and conversion factor trailing wheel, and according to brake parameters or standard setting when braking force is converted to brake fluid pressure.

Be applied to of the value distribution of the braking force of wheel like this according to target yaw moment Ms.In other words, as target yaw moment Ms during less than the threshold value Msl of the usefulness that is used to be provided with, front-wheel target braking liquid pressure reduction Δ Psf is set to 0, specifies a predetermined value to trailing wheel target braking liquid pressure reduction Δ Psr, and poor on a left side and off hind wheel generation braking force.As target yaw moment Ms during more than or equal to the threshold value Msl of the usefulness that is used to be provided with, specify a predetermined value to target braking liquid pressure reduction Δ Psf and Δ Psr, and poor on a preceding and back left side and the right generation braking force of taking turns.

When deviation is determined sign F _OutFor connecting (F _Out=ON), use as target braking liquid pressure reduction Δ Psf and Δ Psr and the target brake fluid pressure Pgf and the Pgr of above calculating, calculate ultimate aim brake fluid pressure Psi to each wheel (i=fl, fr, rl, rr).More particularly, (rl rr) is based on that the brake control method selected among the step S6 calculates for i=fl, fr to the ultimate aim brake fluid pressure Psi of each wheel.

In step S6, when deviation is determined sign F _OutDuring for connection, based on the direction S that obstacle is arranged _OutWith deviation direction D _OutSelect brake control method.At first, below for the direction S that obstacle is arranged _OutWith deviation direction D _OutBetween various relations, will describe when deviation and determine sign F _OutDuring for connection, based on the direction S that obstacle is arranged _OutWith deviation direction D _OutThe brake control method of selecting (first to the 3rd situation or sight).

First sight

In first sight or situation, as the direction S of obstacle _OutWith deviation direction D _OutWhen not matching, carry out control of braking (hereinafter referred to as " departing from avoid driftage control "), make yawing moment be added to main vehicle and depart from avoiding, determine sign F up to deviation _OutFor disconnecting.

Here, being added to main vehicle is target yaw moment Ms with the value of the yawing moment avoiding departing from.This yawing moment is applied to main vehicle by generate a difference in the braking force that is applied to a left side and right wheel.More particularly, as target yaw moment Ms during less than the threshold value Ms1 of the usefulness of setting, braking force of generation is poor in a left side and off hind wheel, so that target yaw moment Ms is added to main vehicle.When target yaw moment Ms was equal to or greater than the threshold value Ms1 of usefulness of setting, as mentioned above, it was poor to produce a braking force in a preceding and back left side and right wheel, so that target yaw moment Ms is added to main vehicle.

Depart from and to avoid control of braking, or driver itself has taked to evade under the situation of action when deviation trend, deviation is determined sign F _OutSwitch to disconnection from connection.

Second sight

Under second sight or situation, as the direction S of obstacle _OutWith deviation direction D _OutBetween coupling, and when the road type R that step S3 obtains is ordinary road, carry out the driftage control that deviation is avoided, determine sign F up to deviation _OutFor disconnecting.

In addition, definition second departs from determines threshold value Tr, and this value departs from less than first determines threshold value Ts (Ts＞Tr＞0).When the time T of estimating that departs from _OutBecome less than second and depart from definite threshold value Tr (T _Out＜Tr) time, apply deviation and avoid driftage control, and the main vehicle braked control (hereinafter referred to as " depart from and avoid deceleration control ") that is used to slow down.Deviation avoids deceleration control to be performed such, so that provide the braking force that equates basically with right wheel left.

Here, estimation departs from time T _OutBe a kind of indicating device of the value of deviation trend, then less than second depart from the estimation of determining threshold value Tr depart from the time corresponding to deviation trend greater than second threshold value.

The 3rd sight

Under the 3rd sight or situation, as the direction S of obstacle _OutWith deviation direction D _OutBetween when mating, and the road type R that obtains in step S3 carries out the driftage control that deviation is avoided when being the through street, determines sign F up to deviation _OutFor disconnecting.

In addition, under this 3rd situation, when the time T of estimating that departs from _OutReached at 0 o'clock, applied the driftage control that deviation is avoided, the moving traffic lane of going forward side by side departs from the deceleration control of avoiding.

Under the 3rd situation, as in second situation, when the time T of estimating that departs from _OutBecome less than second and departed from when determining threshold value Tr, also can carry out the deceleration control that deviation is avoided.Under this situation, for example when the time T of estimating that departs from _OutBecome at 0 o'clock, the deceleration of main vehicle increases by departing from the deceleration control of avoiding.Thereby the deceleration control that deviation is avoided disposes like this, makes when the time T of estimating that departs from _OutBecome to depart from and determined threshold value Tr less than second, and when the time T of estimating that departs from _OutBecome at 0 o'clock, can be activated.That estimates under this situation departs from time T _OutBecome at 0 o'clock, the deceleration of main vehicle further increases.

The direction S that obstacle is arranged in step S6 basis _OutWith deviation direction D _OutSelect brake control method like this.In other words, according to the direction S that obstacle is arranged _OutWith deviation direction D _Out, and/or according to the time T that departs from of main car speed V and estimation _Out, only avoid driftage control by departing from, or the combination of avoiding deceleration control of the driftage control of avoiding by deviation and deviation, selection is used to depart from the brake control method of avoiding.

At the brake control method of step S13 according to each type, calculate target brake fluid pressure Psi for each wheel (i=fl, fr, rl, rr).

In the driftage control of for example avoiding for the deviation of first to the 3rd situation, uses following equation (11) calculating for the target brake fluid pressure Psi of each wheel (i=fl, fr, rl, rr).

Psfl＝Pmf

Psfr＝Pmf+ΔPsf

Psrl＝Pmr

Psrr＝Pmr+ΔPsr (11)

Under the second and the 3rd situation, carry out the deceleration control that driftage control that deviation avoids and deviation are avoided, but under this situation, use following equation (12) calculating for the target brake fluid pressure Psi of each wheel (i=fl, fr, rl, rr).

Psfl＝Pmf+Pgf/2

Psfr＝Pmf+ΔPsf+Pgf/2

Psrl＝Pmr+Pgr/2

Psrr＝Pmr+ΔPsr+Pgr/2 (12)

And, with reference to the deceleration action of taking by the driver, calculate target brake fluid pressure Psi for each wheel (i=fl, fr, rl, rr).In other words, shown in equation (11) and (12), apply master cylinders hydraulic pressure Pmf and Pmr.

Processing for step S13 has more than been described.Like this, determine sign F at step S12 or above step S13 based on deviation _OutState, calculate target brake fluid pressure Psi for each wheel (i=fl, fr, rl, rr).When deviation is determined sign F _OutDuring for connection, according to the brake control method of selecting at step S6, response first has the direction S of obstacle _OutWith deviation direction D _OutValue between relation, calculate target brake fluid pressure Psi for each wheel (i=fl, fr, rl, rr).

In the above description, calculating is handled by driving power control unit 8.Driving power control unit 8 is to brake fluid pressure controlling unit 7, and (rl is rr) as the brake fluid pressure bid value for i=fl, fr at the target brake fluid pressure Psi for each wheel of step S12 or S13 calculating in output.

Forbid controlling at step S14 as the driftage of avoiding that departs from that realizes at step S13.In other words, response deviation trend only realizes the deceleration control avoided for departing from.At this moment, the warning voice output is so that notify the driver to forbid the intention of the driftage control that deviation is avoided.

Above-mentioned lane departure prevention apparatus is according to following general introduction operation.

At first, from sensor, controller and control unit read various kind data (step S1).Then, calculate vehicle velocity V (step S2).

Calculate driving environment then, and the minimum relatively direction of definite level of security (first has the direction S of obstacle _Out) (step S3, Fig. 3).For example, the left-lane in Fig. 4 if main vehicle 100A travels then has the direction S of obstacle _OutBe used as left-hand to.

At step S4, deviation is determined sign F _OutBased on the time T of estimating that departs from _OutBe provided with, and determine deviation direction D based on cross travel X _Out(referring to Fig. 7).

And then, based on the deviation direction D of such acquisition _OutAnd/or determine the intention (step S5) of driver's lane change by directional signal switch 20 indicated directions (the flash light side of lighting).

For example, when by turning on-off signal indicated direction (the flash light side of lighting) with by deviation direction D _OutWhen indicated direction is identical, determine that the driver has a mind to lane change.Under this situation, deviation is determined sign F _OutBecome disconnection.

When by turning on-off signal indicated direction (the flash light side of lighting) with by deviation direction D _OutIndicated direction not simultaneously, deviation is determined sign F _OutThe situation that remains on its connection is constant.Reason is, when by turning on-off signal indicated direction (the flash light side of lighting) with by deviation direction D _OutIndicated direction not simultaneously, the deviation behavior of main vehicle may since be not driver's lane change etc. intention factor institute extremely, so deviation is determined sign F _OutState remain on this and be masked as when connecting constant.

In addition, calculate target yaw moment Ms (step S7), and also calculate and depart from the deceleration/decel of avoiding (step S8) based on cross travel X and variable quantity dx.

Determine sign F based on deviation _Out, first has obstacle direction S _Out, and deviation direction D _Out, calculate and be applied to target brake fluid pressure Psi (i=fl, the fr that each wheel is used to carry out brake control method, rl, rr), and then to the target brake fluid pressure Psi (i=fl of brake fluid pressure controlling unit 7 outputs as the brake fluid pressure bid value, fr, rl rr) (arrives step S13 referring to step S9).

More particularly, as the definite sign of deviation F _OutDuring for disconnection, the target brake fluid pressure Psi that is applied to each wheel is set, and (rl rr) is master cylinders hydraulic pressure Pmf and Pmr (step S12) for i=fl, fr.In addition, as the definite sign of deviation F _OutBe to connect, and drive the track when being the straight turning road, or determine sign F when deviation _OutBe to connect, and when to drive the track be crooked track, and also have when the deviation direction tends to crooked track lateral direction, based on first obstacle direction S is arranged _OutAnd deviation direction D _Out, calculate and be applied to target brake fluid pressure Psi (i=fl, fr, rl, rr) (step S10, step S11 and the step S13) that each wheel is used to carry out brake control method.

(rl rr) outputs to brake fluid pressure controlling unit 7 (step S12 or S13) as the brake fluid pressure bid value to target brake fluid pressure Psi for i=fl, fr.In brake fluid pressure controlling unit 7, distinguish control brake hydraulic pressure to 6RR based on the brake fluid pressure bid value for wheel cylinder 6FL.Thereby configuration is such, makes to show predetermined vehicle behavior according to driving environment when deviation trend.

Here, for first to the 3rd sight or the situation, the mode of master's vehicle behavior when carrying out control of braking is described with reference to Figure 10 (second situation) and 11 (the first and the 3rd situation).

The wheel of black is the wheel that wherein produces hydraulic pressure and provide braking force among Figure 10 and 11.In other words, when a left side and right wheel one of any during black, exist hydraulic pressure or braking force poor in the left and right wheel.This situation represents to be added to the yawing moment of main vehicle.And, when left and right wheel black, in its hydraulic pressure value, still having difference, main vehicle is controlled deceleration under this situation, and yawing moment is added to main vehicle simultaneously.

Second situation as previously discussed is that obstacle direction S is being arranged _OutWith deviation direction D _OutBetween have the situation of coupling, and wherein road type R is an ordinary road.In other words, when main vehicle 100 travels at the two-way road in two tracks, wherein curb A in the left side and oppositely track (center lane LI5 side) when the right side, such situation is arranged, wherein main vehicle 100 (the main vehicle 100 in the uppermost position of Figure 10) may tend to deviation in driction leftward, and wherein main vehicle (the main vehicle 100 in Figure 10 center) may tend to depart from right-hand lay, as shown in figure 10.

Under this situation, carry out the driftage control that deviation is avoided.In addition, when the time T of estimating that departs from _OutBecome less than second and depart from when determining threshold value Tr, apply the driftage control that deviation is avoided, and carry out the deceleration control that deviation is avoided.Thereby avoid main vehicle to depart from.The driver may feel as laterally quickening or avoiding action as the deviation that slows down at travel direction, and know that main vehicle has the trend that departs from.

Aforesaid the 3rd situation is wherein first obstacle direction S to be arranged _OutWith deviation direction D _OutBetween have coupling, and wherein road type R is the situation of through street.In other words, this is that the main vehicle 100A (at the main vehicle 100A of Figure 11 uppermost position) that wherein travels in the left hand track of three track one-way roads has the situation of the trend of deviation in driction leftward, as shown in figure 11.Another situation is the situation that the main vehicle 100C (the main vehicle 100C of Figure 11 center) that wherein travels in the right hand track of three track one-way roads has the trend that departs from right-hand lay, as shown in figure 11.

Under this situation, carry out and depart from the driftage control of avoiding.Thereby main vehicle can be avoided departing from.In addition, when the time T of estimating that departs from _OutReach at 0 o'clock, in other words when definite main vehicle when driving deviation, apply the driftage control that deviation is avoided, and carry out the deceleration control that deviation is avoided.

Aforesaid first situation is that obstacle direction S is wherein arranged _OutWith deviation direction D _OutBetween have the situation of coupling.In other words, such situation is arranged, the main vehicle 100A (the main vehicle 100A in Figure 11 center) that wherein travels in the left hand track of three track one-way roads has the trend that departs from right-hand lay, as shown in figure 11.Also have such situation, the main vehicle 100C (the main vehicle 100C of Figure 11 bottom position) that wherein travels in the right hand track of three track one-way roads has the trend of deviation in driction leftward, as shown in figure 11.And then also have such situation, wherein travel in the trend that main vehicle 100B has leftward or right-hand lay departs from of center lane.Carry out the driftage control that deviation is avoided in this case.Thereby main vehicle can be avoided departing from.

Together use sound or demonstration to give a warning together with this class being departed from the control of braking of avoiding.For example, in the identical time that control of braking begins, or before control of braking predetermined timing, warning beginning.

Even drive the track is crooked track, and when the lateral direction of the track of deviation direction trend bending, because the driftage that deviation is avoided control institute extremely, the vehicle behavior will be shown in Figure 12 figure (B).Therefore, can avoid main vehicle to tend to departing from of the crooked outside, track.

More than using Figure 10 to the declarative description of Figure 12, is that straight turning road or crooked track and deviation direction are when tending to crooked track lateral direction, for avoiding departing from the vehicle behavior of the control of braking of being realized in the driving track.In contrast, be crooked track and deviation direction when tending to the interior side direction in crooked track when driving the track, response deviation trend only is embodied as avoids the deceleration control that departs from.And then the sound that at this moment gives a warning is forbidden the intention (step S14) of the driftage control that deviation is avoided so that notify the driver.

For example as mentioned above, be straight turning road or crooked track and deviation direction when tending to crooked track lateral direction when driving the track, will realize the driftage control that deviation is avoided in predetermined timing.For example, when the deviation direction tends to crooked track lateral direction, response deviation trend only realizes being used to depart from the deceleration control of avoiding, though use deceleration control, rather than the driftage control of avoiding at the deviation that this type that is used for the driftage control that deviation avoids begins regularly to be realized for avoiding departing from.In addition, in the deviation direction tends to crooked track during side direction, response deviation trend only realizes being used to avoiding the deceleration control that departs from, be not used to depart from the deceleration control avoided and regularly also realize the driftage control that deviation is avoided though do not carry out at main unit, rather than the driftage control of avoiding at the deviation that the beginning that is used for the driftage control that deviation avoids regularly realizes.And then at this moment, output warning sound is forbidden the intention of the driftage control that deviation is avoided so that notify the driver.Therefore, even in the deviation direction tends to crooked track, deviation trend is arranged during side direction, but there is not the figure (effect of the driftage control that the deviation shown in the A is avoided as Figure 12.

Below effect of the present invention will be described.

As mentioned above, when main vehicle has the trend of the inboard deviation in driction in the crooked track of trend, do not realize the driftage control that deviation is avoided.

When main vehicle was driven on crooked track, the driver tended to drive along the interior side direction in crooked track.For this situation, if deviation trend is arranged and realized the driftage control that deviation is avoided, the driver will feel that what mistake is arranged.And then, when realizing that this class departs from the driftage control of avoiding, might at this moment main vehicle can tend to crooked track lateral direction and travel.This is that main vehicle tends to departing from of crooked track lateral direction.

Therefore, when the trend of the inboard deviation in driction in the oriented crooked track of main vehicle, by means of the driftage control that does not realize that deviation is avoided, even realize the driftage control that deviation is avoided, prevented that also the driver from feeling to make mistakes, and prevented main vehicle departing to crooked track lateral direction.

In contrast, when the trend that departs from the outside, the oriented crooked track of main vehicle, by means of the driftage control of not forbidding that deviation is avoided, and realize the driftage control that deviation is avoided with normal mode where necessary, prevented that main vehicle from departing to crooked track lateral direction.

In addition, as mentioned above, when not realizing the driftage control that deviation is avoided in the trend of the inboard deviation in driction in the oriented crooked track of main vehicle, output one warning sound is so that notify the driver to forbid the intention of the driftage control that deviation is avoided.This makes the driver to know, is not embodied as the driftage control that the deviation avoiding departing from is avoided, thereby makes the driver to take such as adequate measures such as drive behaviors.

Second embodiment

Referring now to Figure 13 and 18, explanation has been equipped with vehicle according to the lane departure prevention apparatus of second embodiment of the invention.The configuration (Figure 13) of the vehicle among this second embodiment is similar with the configuration (referring to Fig. 1) of the vehicle of first embodiment, institute's difference is, added back monitoring camera 23, its installing is to be equipped with according to the vehicle of lane departure prevention apparatus of the present invention vehicle behind for supervision.With regard to the similarity between first and second embodiment,, the label identical with first embodiment will be given to parts or the step of second embodiment identical with the parts of first embodiment or step.In addition, for the sake of brevity, can omit the parts of second embodiment identical or the description of step with the parts of first embodiment or step.In other words, except as otherwise noted, the remainder of the configuration of vehicle is identical with the configuration of first embodiment among second embodiment.

The monotubular camera that back monitoring camera 23 is made up of CCD (charge coupling device) camera, and be installed in the rear portion of vehicle.

To the calculation processes of being carried out by driving power control unit 8 be described based on this second embodiment now.This calculation processes almost with the calculation processes identical (Fig. 2) of first embodiment, and different parts will only be described.

In other words, to S8, read each categorical data, calculate the speed of a motor vehicle, determine driving environment, determine deviation trend, determine that the driver is intended to, determine control method, calculate target yaw moment, and calculate and be used to avoid the deceleration/decel that departs from step S1.

Use deviation to determine sign F at step S9 _OutDetermined whether deviation trend.When deviation is determined sign F _OutDuring for connection, deviation trend is arranged, and processing enters step S10.When deviation is determined sign F _OutDuring for disconnection, do not have deviation trend, and processing enters step S12.Determine that at step S10 the track of main vehicle ' is straight turning road or crooked track.In other words, when the curvature β that drives the track determines threshold value beta cur (β＞β cur) greater than crooked track, processing enters step S11, and when the curvature β that drives the track is equal to or less than crooked track and determines threshold value beta cur (β=＜β cur), handles entering step S13.Determine at step S11 whether the deviation direction tends to the interior side direction in crooked track.In other words, as deviation direction D _OutWhen identical, handle entering newly-generated step S11a with the track bending direction of bending, and as deviation direction D _OutWhen opposite, handle entering step S13 with the track bending direction of bending.

Determine whether to have in the back contiguous vehicle at step S11a.More particularly, whether based on back monitoring camera 23 output results, determining has vehicle at main vehicle back (vehicle that is close to later) in the deviation direction in this step.The back of main vehicle is defined as the deviation direction D that obtains at step S5 in the deviation direction _OutDriving track (contiguous track), and be the direction backward that main vehicle is seen on this driving track side (be actually oblique rear to).Lin Jin vehicle is in the back, on the direction that departs from main vehicle equidirectional or direction master's vehicle much at one, and the vehicle of driving in main vehicle back.When contiguous vehicle is arranged in the back, handle entering step S40, and when not having contiguous vehicle in the back, handle entering step S14.

Control in step S40 carries out crooked track.Figure 15 illustrates for the contents processing in crooked track inner control.

At first, carry out the processing identical at step S41 with step S13.In other words, based on obstacle direction S is arranged _OutWith deviation direction D _OutDetermine brake control method, and corresponding to determined brake control method calculate each wheel target brake fluid pressure Psi (I=fl, fr, rl, rr).Then, driving power control unit 8 is to target brake fluid pressure Psi (I=fl, fr, rl, rr) (the step S41) of brake fluid pressure controlling unit 7 outputs as the calculating of each wheel of brake fluid pressure bid value.This has realized the driftage control (step S42) that deviation is avoided.

Next, whether finish in the driftage that whether processing has been finished or deviation the is avoided control (step S42) of step S63 determining step S41.Control (step S42) when finishing when the driftage that processing has been finished or deviation is avoided of step S41, realize deceleration control.

Here the deceleration control setting of Shi Xianing as below be applied to a left side and the target brake fluid pressure Pgf and the Pgr of right wheel.Use equation (13) calculating shown below target brake fluid pressure Pgf for front-wheel.

Pgf＝Kgvc*V+Kgcβ*β- (13)

In this equation, Kgvc and Kgc β are used to change the conversion factor that braking force is a brake fluid pressure, and are provided with based on vehicle velocity V and driving track curvature β respectively.Figure 16 and Figure 17 illustrate such example.As shown in figure 16, conversion factor Kgvc is little in low-tach value, and when it became the vehicle velocity V value, it increased along with vehicle velocity V, and remains unchanged after reaching certain vehicle velocity V.In addition, as shown in figure 17, drive track curvature β among a small circle internal conversion factor Kgc β increase with driving track curvature β, and after reaching certain driving track curvature β, remain unchanged.

Control in step S40 realizes aforesaid crooked track.

According to above-mentioned processing, be straight turning road or crooked track even drive the track, when the deviation direction tends to crooked track lateral direction, realize the driftage control (step S10, S11, S11a, and S14) that deviation is avoided by the identical mode of first embodiment.

When the driving track was crooked track, the deviation direction tended to side direction in the crooked track, and when when deviation direction master vehicle back has vehicle, realizes the control (step S10, S11, S11a, and S40) in the crooked track.

Control period in crooked track is realized the driftage control (step S42) that deviation is avoided, and departing from after the driftage control of avoiding finishes, realizes deceleration control (step S43 and S44).Vehicle behavior when Figure 18 illustrates this control in being implemented in crooked track.As shown in figure 18,, realize the driftage control that deviation is avoided, the main vehicle in crooked track is slowed down to the change of crooked track lateral direction with main vehicle when when the direction that departs from crooked track has contiguous vehicle 101 in the back.

Below, will the effect of second embodiment be described.

As mentioned above, the deviation trend of side direction in the crooked track of trend, and when the direction that departs from crooked track has contiguous vehicle 101 in the back, realize the driftage control that deviation is avoided, after the driftage control that deviation is avoided, slow down main vehicle to avoid deviation.

So, the deviation trend of side direction in oriented crooked track, and at this moment when the direction that departs from crooked track has the vehicle 101 that is close to later, realize that the driftage control that deviation is avoided makes it possible to prevent that main vehicle from departing to adjacent lane, and the driver of harassing and wrecking back adjacent vehicle 101, and prevent that main vehicle from departing to adjacent lane and cause and the contacting of back adjacent vehicle 101.

If when the deviation trend of side direction in the oriented crooked track, realize the driftage control that deviation is avoided, might can travel to crooked track lateral direction by main vehicle.Therefore, avoided after the deviation of crooked track lateral direction, realizing deceleration control, will prevent that main vehicle from departing to crooked track lateral direction in the driftage control that deviation is avoided.For example, realize deceleration control like this, make the driver can use up to vehicle processing time of deviation in driction laterally.In addition, when not having driver's deceleration action during deceleration control, deceleration control can be released.

Below described embodiments of the invention, but the invention is not restricted to realization by above embodiment.In other words, describing combination control of braking (departing from the driftage control of avoiding) in above embodiment in detail makes the yawing moment of avoiding departing from be added to vehicle, with the method that is used to slow down with the deceleration control (departing from the deceleration control of avoiding) avoiding departing from, the operating process of these methods, and controlling quantity (value of yawing moment and the value of deceleration), but self-evident is to the invention is not restricted to these descriptions.

In addition, in above embodiment, described, when the inboard direction lane in oriented crooked track departs from trend, the embodiment that yawing moment does not act on main vehicle.Yet, the invention is not restricted to this.In other words, when the trend of the inboard deviation in driction in oriented crooked track, but yawing moment can act on main vehicle or the yawing moment effect Be Controlled to main vehicle.

In addition, the brake structure of describing among the above embodiment is a structure of wherein using hydraulic pressure.Yet, the invention is not restricted to this.For example can also use electronic friction braking, friction material be pressed to the rotor of wheel-side member, perhaps cause the regenerative brake or the dynamic brake of brake action in the mode of electricity by means of an electric autuator.Other selections comprise Jake brake, and this is to provide control of braking by the valve timing that changes driving engine etc., the gear braking, its as Jake brake by changing the transmitting ratio operation, or air brake.

And, in above embodiment, calculate the time T of estimating that departs from based on cross travel X and change amount dx wherein _Out(referring to above equation (2)), but estimate depart from time T _OutCan obtain by some other method.For example,, drive track curvature β based on yaw angle φ, yaw speed φ ', or steering angle δ can obtain to estimate depart from time T _Out

And, in above embodiment the intentional lane change of driver be intended that (referring to the step S5) that determines based on steering angle δ and change amount Δ δ thereof, but can determine the intention of driver's lane change by some other method.For example, can determine the intention of driver's lane change based on the turning torque.

And, in above embodiment, calculate target yaw moment Ms (referring to above equation (3)), but also can obtain target yaw moment Ms by additive method based on cross travel X and change amount dx.For example, can be based on yaw angle φ, cross travel X, or drive track curvature β acquisition target yaw moment Ms, shown in following equation (14).

Ms＝K3·φ+K4·X+K5·β (14)

Here, K3, K4 and K5 are the gains with the vehicle velocity V fluctuation.

And, in above embodiment, use the target brake fluid pressure Pgf (referring to equation 4) of specific equation description, but the invention is not restricted to this for front-wheel.For example, also can be from the target brake fluid pressure Pgf of following equation (15) calculating for front-wheel.

Pgf＝Kgv·V+Kgφ·φ+Kgβ·β (15)

Here, a Kg φ and Kg β are the conversion factors that is used for braking force is converted to brake fluid pressure, and are provided with based on yaw angle φ and driving track curvature β respectively.

In order to realize departing from the driftage control of avoiding, calculate in the above-described embodiments for preceding and target hydraulic difference Δ Psf and Δ Psr (referring to equation (7) and (8)) trailing wheel.Yet, the invention is not restricted to this.For example, can only use front-wheel target hydraulic difference Δ Psf to realize the driftage control that deviation is avoided.For this situation, use following equation (16) to calculate front-wheel target hydraulic difference Δ Psf.

ΔPsf＝2·Kbf·Ms/T (16)

Step S9 realizes by a kind of process or method to the processing of S11 in the foregoing description driving power control unit 8, and when the trend of the inboard deviation in driction in oriented crooked track, this method makes yawing moment to the not effect of main vehicle.

The 3rd embodiment

Referring now to Figure 19 to 23,, the vehicle that is equipped with according to the lane departure prevention apparatus of the 3rd embodiment is described.The configuration of vehicle and vehicle identical (referring to Fig. 1) among first embodiment among this 3rd embodiment.With regard to the similarity between the first and the 3rd embodiment, will give the label identical with step to parts or the step of the 3rd embodiment identical with the first embodiment parts or step with the first embodiment parts.In addition, for the sake of brevity, can omit the parts of three embodiment identical or the description of step with the first embodiment parts or step.In other words, except as otherwise noted, the remainder of the configuration of vehicle is identical with the configuration of first embodiment among the 3rd embodiment.

Figure 19 illustrates the calculation processes that the driving power control unit 8 by this 3rd embodiment carries out.This calculation processes is identical with calculation processes among first embodiment basically, and will only describe concrete those different parts.

Specifically, to S8, read Various types of data, calculate the speed of a motor vehicle by the mode identical with first embodiment at step S1, the assessment driving environment is estimated deviation trend, determines driver's intention, select control method, calculate target yaw moment, and calculate the deceleration/decel that deviation is avoided.

At the step S8 of present embodiment, be used to depart from the deceleration/decel of avoiding to calculate with the slightly different mode of first embodiment.At first, use above illustrated equation (4) to calculate target brake fluid pressure Pg.Calculate the target brake fluid pressure Pgf that is used for front-wheel from this target brake fluid pressure Pg by the gain of the deceleration/decel shown in the following equation (17) Kgg then.

Pgf＝Pg*Kgg (17)

Deceleration/decel gain Kgg is generally 1, though it changes when main vehicle is driven in the ramp as described below.

Calculate target brake fluid pressure Pgr based on the target brake fluid pressure Pgf of front-wheel for trailing wheel, before considering simultaneously and the back braking distribute.Like this, obtain to be used for the deceleration/decel (more particularly, being target brake fluid pressure Pgf and Pgr) that deviation is avoided by this way at step S8.

Determine at step S15 whether main vehicle travels in the ramp then.In this step, if main vehicle or up-hill journey or descent run will determine that then main vehicle travels on the ramp.This determines by always to determine based on information of vehicles (for example acceleration/accel) whether main vehicle carries out in flat travels down from navigating device 15 or from the road information of various sensors.When this result who determines is a main vehicle ' on the ramp time, handle entering step S16.When this result who determines is a main vehicle when not travelling (when main vehicle ' is on flat road), handle entering step S17 on the ramp.

The processing that is used to change deceleration/decel is carried out at step S16.Figure 20 is a diagram of circuit, and expression is used to change the treating process of deceleration/decel.

At first, determine the ramp at step S51.More particularly, determine to go up a slope or descending.

Proceed to step S52, detect the sideways inclined value of descending or upward slope road based on definite result of step S51.For example, based on information acquisition sideways inclined value from homing advice 15.

At step S53, obtain deceleration/decel gain Kgg then based on the sideways inclined value that obtains at step S52.More particularly, at step S53 at first with reference to gain map figure.

Figure 21 illustrates the example of gain map figure.Shown in this gain map figure, when road be when going up a slope the sideways inclined value be on the occasion of, and the sideways inclined value is a negative value when road is descending.For this gain map figure, deceleration/decel gain Kgg will be 1 when the road tilting value is 0, and if the sideways inclined value increase (become and go up a slope) from 0, then deceleration/decel gain Kgg will respond this increase and from 1 reduction.And then if reach certain sideways inclined value, deceleration/decel gain Kgg will be a stationary value (goes up a slope and tilt more to make progress) after reaching this sideways inclined value.Otherwise if the sideways inclined value is from 0 reduction (becoming descending), then deceleration/decel gain Kgg will respond this reduction increases from 1.And then if reach certain sideways inclined value, deceleration/decel gain Kgg will be a stationary value (descending tilts more downward) after reaching this sideways inclined value.

At step S53,, and obtain deceleration gain Kgg based on the result of reference corresponding to the sideways inclined value at subsequent step S54 by this way with reference to gain map figure.

Deceleration/decel after step S55 calculate to change then.More particularly, use the deceleration/decel gain Kgg that utilizes equation (17) to obtain at step S54, calculate target brake fluid pressure Pgf for front-wheel.Then, based on the trailing wheel of distribution consider preceding and to(for) this target brake fluid pressure Pgf of front-wheel, calculate target brake fluid pressure Pgr for trailing wheel.Therefore, be changed, and the sideways inclined of deceleration/decel response as a result of value is changed for preceding and target brake fluid pressure Pgf and Pgr trailing wheel.

More particularly, if road is to go up a slope, it is big more that the sideways inclined value becomes, and then deceleration value will become more little, and if road be descending, the sideways inclined value big more then deceleration value will become big more (when the sideways inclined value becomes greater than negative) that becomes.

Be changed like this and handle at step S16 deceleration/decel and enter step S17.

The processing of step S17 is still in the processing during at level line prior to step S15 master vehicle '.Calculate the target brake fluid pressure of two wheels at step S17.In other words, whether exist based on the control of braking that is used to avoid depart from and calculate final brake fluid pressure.More particularly, be calculated as follows.

(1) as the definite sign of deviation F _OutFor disconnecting (F _Out=OFF) promptly when the result who determines when not departing from, (rl rr) is set to master cylinders hydraulic pressure Pmf and Pmr, shown in above equation (5) and (6) for i=fl, fr to be applied to the target brake fluid pressure Psi of each wheel.

(2) as the definite sign of deviation F _OutFor connecting (F _Out=ON) promptly when determining when departing from, at first based target yawing moment Ms calculating front-wheel target braking liquid pressure reduction Δ Psf and trailing wheel target braking liquid pressure reduction Δ Psr.More particularly, use above equation (7) to calculate target braking liquid pressure reduction Δ Psf and Δ Psr to (10).

Be applied to of the value distribution of the braking force of wheel like this according to target yaw moment Ms.In other words, when target yaw moment Ms less than for the threshold value Msl of the usefulness of settings the time, the target braking liquid pressure reduction Δ Psf of front-wheel is set to 0, Psr specifies a predetermined value to trailing wheel target braking liquid pressure reduction Δ, and poor on a left side and off hind wheel generation braking force.When target yaw moment Ms is equal to or greater than threshold value Msl for the usefulness of settings, specify a predetermined value to target braking fluid power difference Δ Psf and Δ Psr, and take turns the generation braking force on a preceding and back left side and the right side poor.

When deviation is determined sign F _OutFor connecting (F _Out=ON) time, use the target braking liquid pressure reduction Δ Psf and Δ Psr and target brake fluid pressure Pgf and the Pgr that calculate as mentioned above, calculate each wheel final objective brake fluid pressure Psi (i=fl, fr, rl, rr).More particularly, based on the brake control method of selecting at step S6 calculate each wheel final objective brake fluid pressure Psi (i=fl, fr, rl, rr).

At step S6, when deviation is determined sign F _OutDuring for connection, based on the direction S that obstacle is arranged _OutWith deviation direction D _OutSelect brake control method.At first following, for the direction S that obstacle is arranged _OutWith deviation direction D _OutBetween various relations, will describe when deviation and determine sign F _OutDuring for connection, based on the direction S that obstacle is arranged _OutWith deviation direction D _OutThe brake control method of selecting (as above first to the 3rd situation or the sight of in first embodiment, being discussed).

The direction S that obstacle is arranged with the identical mode basis of first embodiment at step S6 like this, _OutWith deviation direction D _OutSelect brake control method.In other words, according to the direction S that obstacle is arranged _OutWith deviation direction D _Out, and/or according to the time T that departs from of main car speed V and estimation _Out, only avoid driftage control by departing from, or the combination of the deceleration control avoided of the driftage control of avoiding by deviation and deviation, selection is used to depart from the brake control method of avoiding.

At the brake control method of step S17 according to each type, calculate target brake fluid pressure Psi for each wheel (i=fl, fr, rl, rr).

For example, in the driftage avoided for the deviation of the first and the 3rd situation control, use above equation (11) calculate each wheel target brake fluid pressure Psi (i=fl, fr, rl, rr).

Carry out the deceleration control that driftage control that deviation avoids and deviation are avoided in the second and the 3rd situation, but under this situation, use above equation (12) calculate each wheel target brake fluid pressure Psi (i=fl, fr, rl, rr).

And, with reference to the deceleration action of taking by the driver calculate each wheel target brake fluid pressure Psi (i=fl, fr, rl, rr).In other words, apply master cylinders hydraulic pressure Pmf and Pmr shown in equation (11) and (12).

When main vehicle driving up travels, target brake fluid pressure Pgf and Pgr become less than when main vehicle when level line travels target brake fluid pressure Pgf and the value of Pgr.When main vehicle during at descent run, target brake fluid pressure Pgf and Pgr become greater than when main vehicle when level line travels target brake fluid pressure Pgf and the value of Pgr.

The processing of step S11 has more than been described.Like this, determine sign F at this step S11 based on deviation _OutEach wheel of state computation target brake fluid pressure Psi (i=fl, fr, rl, rr).When deviation is determined sign F _OutDuring for connection, response first has the direction S of obstacle _OutWith deviation direction D _OutValue between relation, according to the brake control method of selecting at step S6, calculate each wheel target brake fluid pressure Psi (i=fl, fr, rl, rr).

In the above description, calculating is handled by driving power control unit 8.Driving power control unit 8 is to brake fluid pressure controlling unit 7, output as the target brake fluid pressure Psi of each wheel that calculates at step S11 of brake fluid pressure bid value (i=fl, fr, rl, rr).

Lane departure prevention apparatus described above is according to following general introduction work.

At first, from sensor, controller and control unit read Various types of data (step S1).Calculate vehicle velocity V (step S2) then.

Assess driving environment then and determine that (first has the direction S of obstacle to the minimum relatively direction of level of security _Out) (Fig. 3, step S3).For example, if main vehicle 100A travels at the left-lane of Fig. 4, the direction S of obstacle is arranged then _OutBe used as left-hand to.

At step S4, based on the time T of estimating that departs from _OutDeviation is set determines sign F _Out, and determine deviation direction D based on cross travel X _Out(referring to Fig. 7).

In addition, based on the deviation direction D of such acquisition _OutAnd/or, determine the intention (step S5) of driver's lane change by directional signal switch 20 indicated directions (the flash light side of lighting).

For example, when by turning on-off signal indicated direction (the flash light side of lighting) with by deviation direction D _OutWhen indicated direction is identical, determine driver's lane change just intentionally.Under this situation, deviation is determined sign F _OutBecome disconnection.

When by turning on-off signal indicated direction (the flash light side of lighting) with by deviation direction D _OutIndicated direction not simultaneously, deviation is determined sign F _OutIt is constant to remain on its connection situation.Its reason is, when by turning on-off signal indicated direction (the flash light side of lighting) with by deviation direction D _OutIndicated direction not simultaneously, the deviate behavior of main vehicle may since non-driver have a mind to the factor of lane change etc. and cause, so deviation is determined sign F _OutConstant when remaining on this sign connection.

In addition, this method is determined: whether come into existence for the warning that is used to avoid departing from, whether the control of braking that is used to avoid departing from exists, and works as based on determining sign F _Out, the direction S of obstacle is arranged _OutWith deviation direction D _OutRealization is used to avoid the control of braking (step S6) that departs from.

And then, calculate target yaw moment Ms (step S7) based on cross travel X and variable quantity dx, and also calculate and depart from the deceleration/decel of avoiding (step S8).

Calculating is applied to the target brake fluid pressure Psi of each wheel, and (rl rr), is used for carrying out based on deviation and determines sign F for i=fl, fr _Out, the direction S of obstacle is arranged _OutWith deviation direction D _OutThe brake control method of determining (step S17).

When main vehicle ' is on level line, calculate the target brake fluid pressure Psi (i=fl, fr, rl, rr) deceleration/decel that calculates for step S8 that are applied to each wheel.When main vehicle driving up travelled, the deceleration/decel that calculates in step 8 became little value.For this situation, deceleration/decel will become less when the sideways inclined value becomes big.In addition, calculate the target brake fluid pressure Psi be applied to each wheel (i=fl, fr, rl, rr) deceleration/decel after for a change.When main vehicle descent run, the deceleration/decel that calculates at step S8 becomes higher value.For this situation, deceleration/decel will become bigger when the sideways inclined value becomes big (becoming bigger negative in the sideways inclined value).And then, calculate the target brake fluid pressure Psi be applied to each wheel (i=fl, fr, rl, rr) deceleration/decel after for a change.

(rl rr) outputs to brake fluid pressure controlling unit 7 (step S17) as brake fluid pressure control command value to target brake fluid pressure Psi for i=fl, fr.In brake fluid pressure controlling unit 7, respectively for wheel cylinder 6FL to 6RR based on the indivedual control brake hydraulic pressure of brake fluid pressure control command value.Thereby configuration is such, when lane shift trend, shows predetermined vehicle behavior according to driving environment.

Fig. 1 and Figure 19 will be used to be described in during the control of braking vehicle behavior from first situation to the, three situations then.Here, suppose that main vehicle ' is on level line.In other words, deceleration/decel gain Kgg is 1.

As mentioned above, second situation is the direction S as obstacle _OutWith deviation direction D _OutWhen coupling and classification of road R are ordinary road.In other words, as shown in figure 10, when the oriented left avertence of main vehicle 100 (being positioned at the main vehicle 100 at Figure 10 top) from trend, or the oriented right avertence of main vehicle 100 (being positioned at the main vehicle 100 at Figure 10 center) from trend, simultaneously the left side is that curb A and main vehicle 100 travel on the single way one-way road, so that the right side is when being reverse track (center lane LI5 side).

In this case, carry out the driftage control that deviation is avoided.And then, when the time T of estimating that departs from _OutBecome less than second and depart from when determining threshold value Tr, apply the driftage control that deviation is avoided, and carry out the deceleration control that deviation is avoided.Thereby main vehicle is avoided departing from.The driver can feel that conduct is laterally quickened or conduct is avoided taking action at the deviation of travel direction deceleration, and knows that main vehicle has the trend that departs from.

Aforesaid the 3rd situation is the first direction S that obstacle arranged wherein _OutWith deviation direction D _OutBetween the situation of coupling, and wherein road type R is the through street.In other words, this is the main vehicle 100A (at the main vehicle 100A of Figure 11 uppermost position) in three track one-way roads left hand track of wherein travelling, and the trend of deviation in driction is leftward arranged, as shown in figure 11.Another situation is the main vehicle 100C (the main vehicle 100C in Figure 11 center) in three track one-way roads right hand track of wherein travelling, and the trend that departs from right-hand lay is arranged, as shown in figure 11.

Under this situation, carry out the driftage of avoiding departing from and control.Thereby main vehicle can be avoided departing from.And then, when the time T of estimating that departs from _OutReach at 0 o'clock, in other words when definite main vehicle when driving deviation, apply the driftage control that deviation is avoided, and carry out the deceleration control that deviation is avoided.

Among Figure 10 and Figure 11 the wheel of black be the wheel that wherein produces hydraulic pressure and provide braking force.In other words, when a left side and right wheel are one of any be during the wheel of black, at the hydraulic pressure or the braking force of left and right wheel difference is arranged.This situation represents to be added to the yawing moment of main vehicle.And, when left and right wheel black, in its hydraulic pressure value, difference may be arranged still, the deceleration that main in this case vehicle is controlled applies yawing moment to main vehicle simultaneously.

Aforesaid first situation is wherein the direction S of obstacle to be arranged _OutWith deviation direction D _OutBetween do not have the coupling situation.In other words, such situation is arranged, the main vehicle 100A (the vehicle 100A of the center of Figure 11) in the left hand track on one-way road three tracks of wherein travelling has the trend that departs from right-hand lay, shown in Fig. 1 l.Also have such situation, the main vehicle 100C (at the main vehicle 100C of Figure 11 extreme lower position) in the one-way road three tracks right hand track of wherein travelling has the trend of deviation in driction leftward, as shown in figure 11.Further situation is arranged, the main vehicle 100B that wherein travels at center lane leftward or right-hand lay the trend that departs from is arranged.Carry out the driftage control that deviation is avoided under this situation.Thereby main vehicle can be avoided departing from.

Use sound or demonstration to give a warning together with being used for the control of braking that departing from of this type avoid.For example, predetermined timing warning beginning when control of braking begins or before control of braking.

Otherwise the behavior of vehicle is as follows when main vehicle ' is carried out control of braking on the slope.Figure 22 (A) illustrates when main vehicle 100 up-hill journeys, and Figure 22 (B) illustrates when main vehicle 100 descent runs.When main vehicle travels when on the slope deviation trend being arranged like this, might be as shown in figure 23 avoid the deceleration control that departs from being implemented as.For this situation, if shown in Figure 22 (A) main vehicle 100 up-hill journeys, then owing to will be set to one less than the value when travelling on level line for the deceleration/decel of avoiding the deceleration control that departs from.Otherwise, if shown in Figure 22 (A) main vehicle 100 descent runs, then owing to will be set to one greater than the value when travelling on level line for the deceleration/decel of avoiding the deceleration control that departs from.

Below effect of the present invention will be described.

As mentioned above, when up-hill journey, be used to avoid the deceleration/decel of the deceleration control that departs to become little value.Therefore, when main vehicle 100 up-hill journeys, even be used to avoid the deceleration control that departs from, deceleration/decel can be not excessive yet.

And then as mentioned above, when descending travels, be used to avoid the deceleration/decel of the deceleration control that departs to become big value.Therefore, when main vehicle 100 descent runs, fully slowed down by the deceleration control vehicle that is used to avoid departing from, thereby make it prevent from reliably to depart from.

The 4th embodiment

Referring now to Figure 24 and 25, the vehicle that is equipped with according to the lane departure prevention apparatus of the 4th embodiment will be explained.The configuration of the vehicle among this 4th embodiment identical with the configuration of vehicle among first embodiment (referring to Fig. 1).With regard to the 4th and previous embodiment between similarity, will parts or the step of four embodiment identical with previous embodiment parts or step be given and the previous embodiment parts label identical with step.In addition, for the sake of brevity, can omit the parts of four embodiment identical or the description of step with previous embodiment parts or step.In other words, except as otherwise noted, the configuration remainder of vehicle is identical with the configuration of previous embodiment among the 4th embodiment.

In the 4th embodiment, when descending travels, be used to depart from the deceleration control of avoiding, and when avoiding departing from the descent run of vehicle continuation afterwards, carry out deceleration control.In order to realize this control, in the 4th embodiment, relatively make the contents processing of driving power control unit 8 different with the 3rd embodiment.

The calculation processes of being carried out by driving power control unit 8 is shown in Figure 24.This calculation processes almost calculation processes with first embodiment is identical.Obvious dissimilarity will be described.

In other words, read each class data to S8, calculate the speed of a motor vehicle, determine driving environment, determine deviation trend, determine driver's intention, determine control method, calculate target yaw moment, and calculate the deceleration/decel that is used to avoid deviation at step S1.

In addition, determine at step S15 whether main vehicle travels in the ramp.If main vehicle travels in the ramp, handle entering step S16.If main vehicle travels at level line, handle entering step S17.

Carry out deceleration/decel at step S16 and change processing (referring to Figure 20).Step S17 also calculate the target brake fluid pressure Psi that is applied to each wheel (i=fl, fr, rl, rr).

By and the similar mode of first embodiment, when main vehicle ' during at level line, calculate the target brake fluid pressure Psi that is applied to each wheel (i=fl, fr, rl, rr), with the deceleration/decel that obtains to calculate at step S8.When main vehicle driving up travels, the deceleration/decel that calculates at step S8 will become little value.For this situation, when the sideways inclined value became big, it is less that deceleration/decel will become.In addition, (rl rr) changes deceleration/decel afterwards for this for i=fl, fr to calculate the target brake fluid pressure Psi that is applied to each wheel.When main vehicle descent run, be used to depart from the deceleration/decel of avoiding and become big value what step S8 calculated.For this situation, when the sideways inclined value becomes big, deceleration/decel will become big (the sideways inclined value becomes bigger negative).And then, calculate the target brake fluid pressure Psi be applied to each wheel (i=fl, fr, rl, rr) deceleration/decel after for a change.

(rl rr) outputs to brake fluid pressure controlling unit 7 as the brake fluid pressure bid value to the target brake fluid pressure Psi of Ji Suaning for i=fl, fr like this.Do not control the brake fluid pressure of each wheel cylinder 6FL based on the brake fluid pressure bid value by 7 of brake fluid pressure controlling units to 6RR.

Determine at newly-generated step S18 deviation is avoided whether finishing and whether main vehicle continues descent run.Avoid finishing and main vehicle when continuing descent run when deviation here, handle entering step S19.Avoid not finishing and main vehicle when not continuing descent run when deviation here, the processing of Figure 24 finishes.

And then, carry out determining that deviation avoids finishing when supposing to be used to depart from the deceleration control of avoiding.In other words, when the driftage control of only avoiding by deviation had been finished deviation and avoided, even main vehicle continues descent run, but the processing of Figure 24 will finish.

Control when step S19 continues descending.More particularly, only the fixing cycle is carried out deceleration control.This deceleration control is applied to the target brake fluid pressure Psi of each wheel by setting, and (rl rr) carries out for hydraulic pressure Pgz for i=fl, fr.Fixing period definition is fixing distance or regular time.For example, when deceleration control begins to reduce this hydraulic pressure in time so that preset time later this hydraulic pressure become at 0 o'clock, be applied to the target brake fluid pressure Psi (i=fl of each wheel at a fixed time by means of handle, fr, rl rr) is set to hydraulic pressure Pgz and carries out deceleration control.

According to above-mentioned processing, the trend of deviation is arranged when at descending and during the deceleration control that is used to avoid depart from, will depart from the deceleration control of avoiding by the deceleration/decel bigger than typical values is set.And then, when by means of depart from the deceleration control of avoiding avoid departing from after main vehicle still during descent run, shown in Figure 25 (B), will only carry out deceleration control to a set time.

Figure 25 (A) illustrate when main vehicle just from finish depart from the deceleration control of avoiding (departing from) for preventing light the predetermined space descent run, and the situation of target when being level line.For this situation, deceleration control just departs from lighting of the deceleration control of avoiding (departing from for preventing) finishing, and the interim of main vehicle descent run carries out, and stops on target level line road or discharge deceleration control.

Avoid the deceleration control of (departing from for preventing) to finish from departing from when main vehicle and actually continue a descent run, and can confirm from departing from the deceleration control of avoiding to finish when a little being level line, this road will not thought the ramp and needn't carry out deceleration control.For example, when predetermined spacing distance in short-term, the processing of this class is an actv..

Effect of the present invention among the 4th embodiment below will be described.

As mentioned above, when main vehicle downhill retardation and the target that prevents the driving road that departs from when being descending, main vehicle will be during preset time or predetermined distance slow down.

Usually, by after avoiding departing from for the intervention that departs from the deceleration control of avoiding, stop or discharging departing from the deceleration control of avoiding.Yet, if when descent run by after avoiding departing from for the intervention that departs from the deceleration control of avoiding, stop or discharging departing from the deceleration control of avoiding, might main vehicle understand and quicken because of descent run.For this situation, the driver will experience the acceleration/accel bigger than actual acceleration, and feel to have certain mistake.In order to prevent this class situation, when main vehicle downhill retardation and the target that prevents to depart from the driving road of travelling thereon when being descending, main vehicle slows down at preset time or predetermined distance.

In above-described embodiment, use specific equation (cf. equation (4)) to describe target brake fluid pressure Pg.Yet, the invention is not restricted to this.For example can use above equation (15) to calculate target brake fluid pressure Pg.

In order to realize departing from the driftage control of avoiding, calculate in the above-described embodiments for preceding and target hydraulic difference Δ Psf and Δ Psr (referring to equation (8) and (9)) trailing wheel.Yet, the invention is not restricted to this.For example, can only use front-wheel target hydraulic difference Δ Psf to realize the driftage control that deviation is avoided.For this situation, use above equation (16) to calculate front-wheel target hydraulic difference Δ Psf.

In the description of the foregoing description, driving power control unit 8 has been equipped with and has departed from the control method of avoiding, this method is obliquely installed deceleration/decel based on the gradient of driving road, and makes main car retardation to the deceleration/decel that is provided with, and drives the track to prevent that main vehicle from departing from.In other words, step S16 shown in Figure 19 changes the processing (referring to Figure 20) of the deceleration/decel of driving power control unit 8, has realized that the gradient based on driving road is obliquely installed the processing of deceleration/decel.In addition, the step S6 of driving control unit 8 shown in Figure 19, S7, S8, S9, the processing of S15 and S16 has realized, makes main car retardation to the deceleration/decel that is provided with, and drives the track to prevent that main vehicle from departing from.

The 5th embodiment

Referring now to Figure 26 and 27, the vehicle that is equipped with according to the lane departure prevention apparatus of the 5th embodiment will be explained.The configuration of vehicle similar (referring to Fig. 1) among the configuration of the vehicle among this 5th embodiment and first embodiment, the different variations that are the following programming of pointing out.With regard to the 5th and previous embodiment between similarity, will parts or the step of five embodiment identical with previous embodiment parts or step be given and the previous identical label of embodiment parts.In addition, for the sake of brevity, can omit the parts of five embodiment identical or the description of step with previous embodiment parts or step.In other words, except as otherwise noted, the remainder of the configuration of vehicle is identical with the configuration of previous embodiment among the 5th embodiment.

The calculation processes of being carried out by driving power control unit 8 is shown in Figure 26.This calculation processes almost calculation processes with first embodiment is identical.Obvious dissimilarity will be described.

In other words, read each class data to S8, calculate the speed of a motor vehicle, determine the inclination of road, determine deviation trend, determine driver's intention, determine control method, calculate target yaw moment, and calculating is used to depart from the deceleration/decel of avoiding at step S1.Like this, step S1 is similar to step S8 and first embodiment, and the step S3 that institute is different to be first embodiment are by the step S3 ' replacement of definite sideways inclined.

More particularly, based on the longitudinal acceleration Yg that obtains at step S1, transverse acceleration Xg, upper and lower acceleration/accel Zg and yaw angle θ, and, detect road surface tilt angle theta z at the speed V that step S2 obtains.Figure 27 illustrates the relation between vehicle axis system XYZ and the road surface tilt angle theta z.Figure 27 (A) be from the view of vehicle 100, and Figure 27 (B) be from after the view of the vehicle 100 seen.

For example, if when having the road surface to tilt (θ z=0), certain yaw angle θ is not arranged, can obtain certain longitudinal acceleration Yg and transverse acceleration Xg.If certain yaw angle θ is arranged when the road surface tilts, then can obtain longitudinal acceleration Yg and transverse acceleration Xg, it is different from the value when not having the road surface to tilt.Can use the relation of this type to estimate road surface tilt angle theta z.

In addition, obtain longitudinal acceleration Yg, transverse acceleration Xg, up and down acceleration/accel Zg as map data in advance, and between the yaw angle θ, and the relation between speed V and the road surface tilt angle theta z, these map datas make it possible to during actual detected with reference to this map data, and the longitudinal acceleration Yg from obtaining by actual measurement, transverse acceleration Xg, up and down acceleration/accel Zg, yaw angle θ obtains road surface tilt angle theta z with speed V.

In the description of present embodiment, as road surface tilt angle theta z during greater than 0 (θ z＞0), this road surface tilts to make the left of seeing from vehicle to being in thrown wall.As road surface tilt angle theta z during less than 0 (θ z＜0), this road surface tilts to make that the right of seeing from vehicle is in thrown wall.When road surface tilt angle theta z is 0 (θ z=0), there is not the road surface to tilt.

Determine deviation trend at step S4 then.Specifically be shown in Fig. 6 for this process of determining processing, this figure and first embodiment are similar, and difference is the processing of step S33.

At step S33, determine deviation direction D _OutMore particularly, determine deviation direction D based on cross travel X _OutIn other words, when vehicle from the center, track at left during to horizontal displacement, this direction will be deviation direction D _Out(D _Out=left side), and when vehicle from the center, track during at the right cross travel, this direction will be deviation direction D _Out(D _Out=the right side).

Also can use transverse acceleration Xg to determine deviation direction D _OutFor example, as transverse acceleration Xg during greater than 0 (Xg＞0), transverse acceleration Xg will quicken left.As transverse acceleration Xg during less than 0 (Xg＜0), transverse acceleration Xg will quicken to the right.From this relation, because quicken during greater than 0 (Xg＞0) will be left as transverse acceleration Xg, this direction will be deviation direction D _Out(D _OutAnd because time acceleration will be to the right less than 0 (Xg＜0) as transverse acceleration Xg, this direction will be deviation direction D a=left side), _Out(D _Out=the right side).

Then, handle and enter subsequent step S5 to S8, they are identical with first embodiment discussed above.

Next, calculate the target brake fluid pressure of each wheel at step S17.In other words, based on whether existing and calculate final brake fluid pressure to departing from the control of braking of avoiding.More particularly, the calculating of step S17 uses above equation (5) to (10).

Therefore the braking force that is applied to wheel is that the value according to target yaw moment Ms distributes.In other words, as target yaw moment Ms during less than the threshold value Msl that is used to be provided with, front-wheel target braking liquid pressure reduction Δ Psf is set to 0, specifies a predetermined value to trailing wheel target braking liquid pressure reduction Δ Psr, and the generation braking force is poor in a left side and off hind wheel.When target yaw moment Ms is equal to or greater than the threshold value Msl that is used to be provided with, specify a predetermined value to target braking liquid pressure reduction Δ Psf and Δ Psr, and it is poor to produce braking force in a preceding and back left side and right wheel.

When deviation is determined sign F _OutFor connecting (F _Out=ON), use as target braking liquid pressure reduction Δ Psf and Δ Psr and the target brake fluid pressure Pgf and the Pgr of above-mentioned calculating, calculate ultimate aim brake fluid pressure Psi to each wheel (i=fl, fr, rl, rr).More particularly, (rl rr) is based on that the brake control method selected among the step S6 calculates for i=fl, fr for the ultimate aim brake fluid pressure Psi of each wheel.

Here will be described in the brake control method of determining among the step S6.

In step S6, when deviation is determined sign F _OutDuring for connection, based on road surface tilt angle theta z and deviation direction D _OutDetermine brake control method.

As mentioned above, can use transverse acceleration Xg to determine deviation direction D _OutIn other words, as transverse acceleration Xg during greater than 0 (Xg＞0), left is to being deviation direction D _Out(D _OutAnd as transverse acceleration Xg during less than 0 (Xg＜0), right will be deviation direction D a=left side), _Out(D _Out=the right side).According to this class relation, when road surface tilt angle theta z greater than 0 (θ z＞0) and transverse acceleration Xg during greater than 0 (Xg＞0), or when road surface tilt angle theta z less than 0 (θ z＜0) and transverse acceleration Xg during less than 0 (Xg＜0), deviation will be at road surface bevelled thrown wall.In addition, when road surface tilt angle theta z greater than 0 (θ z＞0) and transverse acceleration Xg during less than 0 (Xg＜0), or when road surface tilt angle theta z less than 0 (θ z＜0) and transverse acceleration Xg during greater than 0 (Xg＞0), deviation will be at road surface bevelled upthrow side.

Based on this class relation, by dividing road surface tilt angle theta z and deviation direction D _OutBrake control method (first situation to the, three situations) will be described.

Under first situation, when not having the road surface to tilt (θ z=0) and deviation trend arranged, to be that yawing moment is acted on the control of braking (hereinafter referred to as depart from the driftage control avoided) of vehicle to prevent to depart from, and make car retardation determine sign F up to deviation _OutCombination for open circuited control of braking (hereinafter referred to as being used to depart from the deceleration control of avoiding).Determine sign F when departing from _OutFor connecting (T _Out＜these controls prevent to depart from beginning Ts) time.

The driftage control that the deviation is here avoided is as target yaw moment Ms, acts on the yawing moment of vehicle to prevent to depart from.Yawing moment provides a difference to the effect of vehicle to the braking force that is applied to a left side and right wheel.More particularly, as mentioned above, when target yaw moment Ms when threshold value Ms1 is set, will be poor on a left side and off hind wheel generation braking force, Ms acts on vehicle target yaw moment.And then, when target yaw moment Ms is equal to or greater than when threshold value Ms1 is set, will be on a left side and right front and trailing wheel generation braking force is poor, Ms acts on vehicle target yaw moment.In addition, be used to depart from the deceleration control of avoiding identical braking strength is added on a left side and right wheel.

When deviation is determined sign F _OutBecome from connection and to disconnect and when deviation trend is arranged, execution is prevented the control of braking that departs from, or driver itself will attempt to take the action avoided.

Under second situation, when road surface tilt angle theta z greater than 0 (θ z＞0) and transverse acceleration Xg during greater than 0 (Xg＞0), or when road surface tilt angle theta z less than 0 (θ z＜0) and transverse acceleration Xg during less than 0 (Xg＜0), might deviation trend will be at road surface bevelled thrown wall.

For this situation, when the time T that departs from of expection _OutBecome when determining threshold value (Ts+dTkdown) less than deviation, wherein certain specified amount dTkdown adds first to be departed from and determines threshold value Ts (T _Out＜(Ts+dTkdown)), execution is departed from the deceleration control of avoiding.In addition, determine that second of threshold value Ts departs from and determine threshold value Tr (Ts＞Tr＞0) when definition departs from less than first, and expection depart from time T _OutBecome less than second and depart from definite threshold value Tr (T _Out＜Tr) time, then except departing from the deceleration control of avoiding, also carry out the driftage control that deviation is avoided.

For example, the amount dTkdown of regulation is for departing from the value of determining threshold value Ts (Ts＞dTkdown) less than first.

Therefore, when the time T that departs from of expecting _OutBecome less than deviation and determine threshold value (Ts+dTkdown) (T _Out＜(Ts+dTkdown)) time, begin to be used to depart from the deceleration control of avoiding, and when the time T that departs from of expecting _OutBecome less than second and depart from definite threshold value Tr (T _Out＜Tr) time, then except being used to depart from the deceleration control of avoiding, also will start the driftage control that deviation is avoided.At this moment, and do not have the road surface rake ratio, the startup that is used to depart from the deceleration control of avoiding regularly only as prescribed amount dTkdown partly be provided with early.

And then when road surface tilt angle theta z absolute value became greatly, specified amount dTkdown became bigger.So when road surface bevelled tilt quantity became greatly, the startup that is used to depart from the deceleration control of avoiding regularly became early.

Under the 3rd situation, when road surface tilt angle theta z greater than 0 (θ z＞0), transverse acceleration Xg is during less than 0 (Xg＜0), or when road surface tilt angle theta z less than 0 (θ z＜0) and transverse acceleration Xg during greater than 0 (Xg＞0), might deviation trend will be at road surface bevelled upthrow side.

For this situation, when the time T that departs from of expection _OutBecome when determining threshold value, wherein depart from and determine that threshold value Ts deducts certain specified amount dTkup (Ts-dTkdown) (T from first less than deviation _Out＜(Ts-dTkdown)), will carry out the driftage control that deviation is avoided.

Here, when certain specified amount dTkup greater than 0 the time, it will be to depart from the value (Ts＞dTkup＞0) of determining threshold value Ts less than first.Therefore when not having the road surface to tilt, the startup of the driftage control of avoiding for deviation regularly will become morning.

And then when road surface tilt angle theta z absolute value became greatly, specified amount dTkup became bigger.So, becoming when big in road surface bevelled tilt quantity, the startup of the driftage control of avoiding for deviation regularly becomes early.

Though in the description of above first situation to the, three situations, when definite deviation direction, use transverse acceleration Xg, in definite deviation direction, also can use deviation direction D _Out

In step S6, response road surface tilt angle theta z value and deviation direction D _OutOr transverse acceleration Xg, determine various brake control methods.In other words, response road surface tilt angle theta z value and deviation direction D _OutOr transverse acceleration Xg, being defined as for the brake control method that prevents to depart from is the driftage control that deviation is avoided, perhaps deviation driftage control of avoiding and the combination that is used to depart from the deceleration control of avoiding.

At step S17 according to each class brake control method, calculate target brake fluid pressure Psi for each wheel (i=fl, fr, rl, rr).

For example in the driftage avoided for the deviation of the 3rd situation control, use above equation (11) calculate target brake fluid pressure Psi for each wheel (i=fl, fr, rl, rr).

Under first and second situations, carry out the deceleration control that driftage control that deviation avoids and deviation are avoided, but under this situation, use above equation (12) calculate target brake fluid pressure Psi for each wheel (i=fl, fr, rl, rr).

And, with reference to the deceleration action of taking by the driver calculate target brake fluid pressure Psi for each wheel (i=fl, fr, rl, rr).In other words, shown in equation (11) and (12), apply master cylinders hydraulic pressure Pmf and Pmr.

The processing of step S17 has more than been described.Like this, determine sign F based on deviation _OutState computation for the target brake fluid pressure Psi of each wheel (i=fl, fr, rl, rr).When deviation is determined sign F _OutDuring for connection, according to the brake control method response road surface tilt angle theta z value of selecting at step S6, transverse acceleration Xg and deviation direction D _OutBetween relation, calculate target brake fluid pressure Psi for each wheel (i=fl, fr, rl, rr).

In the above description, calculating is handled by driving power control unit 8.Driving power control unit 8 to brake fluid pressure controlling unit 7 output as the target brake fluid pressure Psi that calculates at step S17 of brake fluid pressure bid value for each wheel (i=fl, fr, rl, rr).

The schematic illustration of lane departure prevention apparatus operation as described below.

At first, from each sensor, controller and control unit read the data (step S1) of each type.Then, computation speed (step S2).

Then, detect road surface inclination (step S3).More particularly, as reference road surface tilt angle theta z and road surface tilt angle theta z during greater than 0 (θ z＞0), will the left of seeing from vehicle to thrown wall detect the road surface.As road surface tilt angle theta z during, will detect the road surface at the thrown wall of the right of seeing from vehicle less than 0 (θ z＜0).When road surface tilt angle theta z is 0 (θ z=0), will detect less than the road surface.

At step S4, based on the time T of estimating that departs from _OutDeviation is set determines sign F _Out(referring to Fig. 6), and determine deviation direction D based on cross travel X _Out

In addition, based on the deviation direction D of such acquisition _OutAnd/or determine the intention of driver's lane change by directional signal switch 20 indicated directions (the flash light side of lighting).

When by turning on-off signal indicated direction (the flash light side of lighting) with by deviation direction D _OutIndicated direction not simultaneously, deviation is determined sign F _OutThe situation that remains on its connection is constant.Reason is, when by turning on-off signal indicated direction (the flash light side of lighting) with by deviation direction D _OutIndicated direction not simultaneously, the deviation behavior of main vehicle may be since the intention of non-driver's lane change etc. with other factor institute extremely, thereby deviation is determined sign F _OutConstant when remaining on its connection.

This method is determined for following situation, is to depart from the warning of avoiding and whether exist, and whether exists for departing from the control of braking of avoiding, and when based on road surface tilt angle theta z, determines sign F _OutAnd deviation direction D _OutOr transverse acceleration Xg, when realizing being used to depart from the control of braking of avoiding (step S6).

And then, calculate target yaw moment Ms (step S7) based on transverse acceleration X and variable quantity dx, and also calculating is used to depart from the deceleration control of avoiding (step S8).

For realizing, determine sign F based on road surface tilt angle theta z _OutAnd deviation direction D _OutOr the brake control method determined of transverse acceleration Xg, calculate the target brake fluid pressure Psi that is applied to each wheel (i=fl, fr, rl, rr).(rl rr) outputs to brake fluid pressure controlling unit 7 (step S17) as the brake fluid pressure bid value to the target brake fluid pressure Psi that calculates for i=fl, fr.Do not control the brake fluid pressure of each wheel cylinder 6FL based on the brake fluid pressure bid value by 7 of brake fluid pressure controlling units to 6RR.Therefore, when deviation trend, the response road surface tilts to show following vehicle behavior.

When determining sign F _OutFor connection has the trend of deviation and does not have road surface inclination (T _Out＜Ts) time, combination is used to depart from the deceleration control avoided and departs from the driftage control of avoiding.And then this prevents that the control that departs from from will proceed to definite sign F _OutBe (first situation) till disconnecting.So, prevented that main vehicle from departing from.Otherwise the operation that the driver avoids owing to the deviation of vehicle in the driving direction is felt laterally to quicken or slow down, thereby makes the driver can know that main vehicle has the trend of deviation.

When road surface tilt angle theta z greater than 0 (θ z＞0) and transverse acceleration Xg during greater than 0 (Xg＞0), or when road surface tilt angle theta z less than 0 (θ z＜0) and transverse acceleration Xg during less than 0 (Xg＜0), promptly when deviation trend will be at road surface bevelled thrown wall, when the time T that departs from of expection _OutBecome (T when determining threshold value (Ts+dTkdown) less than deviation _Out＜(Ts+dTkdown)), carry out and depart from the deceleration control of avoiding.And then, when the time T that departs from of expection _OutBecome less than second and depart from definite threshold value Tr (T _Out＜Tr) time, then except being used to depart from the deceleration control of avoiding, also will carry out the driftage control that deviation is avoided.So, prevented that main vehicle from departing from.Otherwise because the deviation of vehicle is avoided operation, the driver feels in the driving direction deceleration is arranged, thereby makes the deviation of the trend driver can know to(for) main vehicle.Deviation is avoided the specified amount dTkdown that the operation of deceleration control will be when not having the road surface to tilt.

When road surface tilt angle theta z greater than 0 (θ z＞0) and transverse acceleration Xg during less than 0 (Xg＜0), or when road surface tilt angle theta z less than 0 (θ z＜0) and transverse acceleration Xg during greater than 0 (Xg＞0), promptly when deviation trend during at road surface bevelled upthrow side, when the time T that departs from of expection _OutBecome (T when determining threshold value (Ts-dTkup) less than deviation _Out＜(Ts-dTkup)), the driftage control that deviation is avoided carried out.So, prevented that main vehicle from departing from.Otherwise because the deviation of vehicle is avoided operation, the driver feels that deceleration is laterally being arranged, thereby the driver can be known for main vehicle deviation trend is arranged.The operation of the driftage control that deviation is avoided will be later than the situation when not having the road surface to tilt.

Below effect of the present invention will be described.

As mentioned above, when the time T that departs from of expecting _OutBecome (T when determining threshold value (Ts+dTkdown) less than deviation _Out＜(Ts+dTkdown)), and deviation trend will be carried out and depart from the deceleration control of avoiding when the bevelled thrown wall of road surface.The startup of this control regularly is set to the situation Zao specified amount dTkdown part relatively when not having the road surface to tilt.

So, when deviation trend, can lingeringly not start and be used to depart from the deceleration control of avoiding, make it possible to the optimal control track and avoid departing from.

In addition, as mentioned above, when the time T that departs from of expection _OutBecome (T when determining threshold value (Ts-dTkup) less than deviation _Out＜(Ts-dTkup)), promptly, will carry out the driftage control that deviation is avoided when deviation trend during at road surface bevelled upthrow side.The startup of this control regularly will postpone when not having the road surface to tilt more.

So, can do sth. in advance and start the driftage control that deviation avoids, this makes this control operation to carry out too early and can not bother the driver.

Embodiments of the invention have below been described.Yet, the invention is not restricted to this.In other words, in above embodiment, describe combination in detail and be applied for the control of braking (departing from the driftage control of avoiding) of avoiding the yawing moment that departs to vehicle, for avoiding departing from the method for the deceleration control (departing from the deceleration control of avoiding) of slowing down, the operating process of these methods, and their controlling quantity (value of yawing moment and deceleration value), the invention is not restricted to these descriptions but should need not explanation.

For example, as mentioned above,, will carry out as the control that prevents to depart from and depart from the deceleration control of avoiding when deviation trend during at road surface bevelled thrown wall.Yet,, will also carry out as the control that prevents to depart from and depart from the driftage control of avoiding when deviation trend during at road surface bevelled thrown wall.In addition, as mentioned above,, will carry out the driftage control that deviation is avoided as the control that prevents to depart from when deviation trend during at road surface bevelled upthrow side.Yet,, will also carry out as the control that prevents to depart from and depart from the deceleration control of avoiding when deviation trend during at road surface bevelled upthrow side.

And then the brake structure of describing among the above embodiment is a structure of wherein using hydraulic pressure.Yet, the invention is not restricted to this.For example, can also use by means of electric autuator and press the electric power friction braking of friction material, or cause the regenerative brake or the dynamic brake of braking maneuver in the mode of electricity to the wheel side rotor.Other selection comprises Jake brake, and its valve timing by changing driving engine etc. provides control of braking, the gear braking, and it operates perhaps air brake by changing transmitting ratio as Jake brake.

And, in above embodiment, calculate the time T of estimating that departs from based on cross travel X and change amount dx thereof _Out(referring to above equation (2)), but can be by the time T that departs from of some other method acquisition estimation _OutFor example, can drive track curvature β based on yaw angle φ, yaw speed φ ' or steering angle δ obtain the time T that departs from of estimation _Out

And, in above embodiment, determine the intention (referring to step S5) of driver's lane change, but can determine the intention of driver's lane change by some other method based on steering angle δ and variation delta δ thereof.For example, can determine the intention of driver's lane change based on the turning torque.

And, in above embodiment, calculate target yaw moment Ms (referring to above equation (3)), but can obtain target yaw moment Ms by additive method based on cross travel X and variable quantity dx.For example can be based on yaw angle φ, cross travel X, or drive track curvature β acquisition target yaw moment Ms, shown in above equation (14).And, in above embodiment, use specific equation (referring to equation 4) to describe the target brake fluid pressure Pgf of front-wheel, but the invention is not restricted to this.For example, also can calculate the target brake fluid pressure Pgf of front-wheel from above equation (15).

In embodiment described above,, calculate for preceding and target hydraulic difference Δ Psf and Δ Psr (referring to equation (7) and (8)) trailing wheel in order to realize departing from the driftage control of avoiding.Yet, the invention is not restricted to this.For example, can only use the target hydraulic difference Δ Psf of front-wheel to realize the driftage control that deviation is avoided.For this situation, use above equation (16) to calculate the target hydraulic difference Δ Psf of front-wheel.

In the description of the foregoing description, driving power control unit 8 has been equipped with and has departed from the control method of avoiding, this method is obliquely installed the beginning timing that is used to control for preventing to depart from based on the road surface, and have when driving the trend of deviation when main vehicle, use this timing start-up control to depart from preventing.In other words, in step S6 shown in Figure 2, deviation determines that the setting of threshold value tilts based on the road surface, has realized to prevent that the control setting that departs from from starting timer-operated processing at driving power control unit 8.Driving power control unit 8 is in the processing of step S6 shown in Figure 2 to S9, realized using this startup regularly to start and prevent the control that departs from, and prevents deviation when main vehicle has trend from the driving deviation.

As used herein, following direction term " forward, backward, more than, vertical downwards, level, below and oppositely " and any other similar direction term be meant those directions that have been equipped with vehicle of the present invention.So these terms should make an explanation with respect to being equipped with vehicle of the present invention when of the present invention being used for describing.

As being used for the element of tracing device here, the term " configuration " of part or parts comprises hardware and/or software, and it is configured and/or programmes to carry out required function.In addition, the term that is expressed as " device adds function " in the claims should comprise any structure of the function that can be used for carrying out part of the present invention.The term of degree used herein is such as " basically ", and " approximately " reaches " being similar to ", means the rational departure of modification item, makes net result not have marked change.For example, these terms may be interpreted as comprise modification item deviation at least ± 5%, if this deviation will can not negate the meaning of the word of its modification.

The application requires following Japanese patent application Nos.2003-385611,2003-385612, and each preceence of 2003-388208.Japanese patent application Nos.2003-385611,2003-385612, and the whole of 2003-388208 are disclosed in combination here as a means of contrast.

Though only selected selected embodiment is explained the present invention, openly be apparent that from this for those skilled in the art, not deviating under the scope of the present invention that limits as claims, can make various changes and modification at this.In addition, just providing for example according to the above description of the embodiment of the invention, is not to limit the present invention who is limited by claims and equivalent thereof.Like this, scope of the present invention is not limited to disclosed embodiment.

Claims

1. lane departure prevention apparatus comprises:

Driving road detecting section is configured to determine the road bending direction of driving road; And

Lane departure avoidance control section is configured to interior side direction or lateral direction according to the road bending direction of deviation direction trend driving road, and lane change departs from avoids controlling quantity.

2. according to the lane departure prevention apparatus of claim 1, wherein

Lane departure avoidance control section is configured to, and when main vehicle trend departs from when driving the track, applies to make main car retardation depart from the brake snub power of driving the track to prevent main vehicle, also applies yawing moment avoiding main vehicle to depart from the direction of driving the track.

3. according to the lane departure prevention apparatus of claim 1, wherein

Lane departure avoidance control section is configured to, and when main vehicle is tending towards to the road bending direction inboard of driving road deviation in driction, regulates the effect of the yawing moment that is added to main vehicle.

4. according to the lane departure prevention apparatus of claim 3, wherein

Lane departure avoidance control section is configured to, and when main vehicle is tending towards to the inboard deviation in driction of the road bending direction of driving road, forbids being added to the effect of the yawing moment of main vehicle.

5. according to the lane departure prevention apparatus of claim 4, wherein

Lane departure avoidance control section is configured to, when main vehicle is tending towards to the road bending direction inboard of driving road deviation in driction, and travel with the unidirectional adjacent vehicle of main vehicle the time after the main vehicle when not being positioned at, forbid being added to the effect of the yawing moment of main vehicle.

6. according to the lane departure prevention apparatus of claim 2, wherein

Lane departure avoidance control section is configured to, when main vehicle is tending towards to the road bending direction inboard of driving road deviation in driction, and when travelling after being positioned at main vehicle with the unidirectional adjacent vehicle of main vehicle, make yawing moment act on main vehicle and avoiding making main car retardation after main vehicle departs from by applying yawing moment.