CN102951147A - Method for carrying out velocity warning for motor vehicle and device thereof - Google Patents

Abstract

The present inventio relates to a method for carrying out velocity warning for motor vehicle. The method involves computing predetermined road ahead curvature (X Kurve) of the track by a control unit (5) on the basis of map data (2). A maximum cornering velocity is calculated as a recommendation output. The maximum turning velocity and expected steering error of the driver in the form of a likely faulty curvature (X Fehl) are calculation and added to the track curve when calculation of the maximum rate (Vmax) of turn by the driver is influenced. An independent claim is included for device for carrying out velocity warning for motor vehicle.

Description

Be used for the speed early warning, in particular for the method and apparatus of the bend early warning of self-propelled vehicle

Technical field

The present invention relates to the method and apparatus for the speed early warning of carrying out self-propelled vehicle, wherein control unit calculates the curvature in this highway section based on the map datum of the highway section part that is positioned at the place ahead that can provide in advance, and calculate thus and export maximum speed as recommendation, wherein the calculating of maximum speed can be affected by chaufeur.

Background technology

A kind of method of this class for example, is disclosed in DE102006028277A1.

Know the speed precaution device according to prior art, especially the bend precaution device.The bend precaution device calculate in advance vehicle should with what maximum speed cross be the bend in the place ahead and to the chaufeur Output rusults as recommendation, the telltale by optics especially.Speed actual travel or wheeled depends on physically feasible speed usually in bend, depend on equally environmental factor, such as street situation, the visbility of street trend and the drive manner of chaufeur, wherein this physically feasible speed determine such as curvature and street width by the geometric configuration in street.Referring to for example DE4205979A1, the calculating of this bend critical speed usually take the critical speed that physically limits as foundation, is calculated this critical speed according to transverse acceleration a and turning radius R:

Wherein a is mainly drawn by the friction valve of tire.

Scientific research is such as " the Geschwindigkeiten bei that is delivered by K.H.Schimmelpfennig, N.Hebing on the 5th 97-99 page or leaf of traffic accident (Der Verkehrsunfall) May nineteen eighty-two

Kurvenfahrt

-und Sicherheitsgrenze " show, in fact can't cross bend with physically feasible critical speed.Environmental factor and individual's drive manner obviously plays a role in the driving behavior of reality in a kind of mode that is difficult to explain.In mentioned paper research and analysis very many travelling.The result has derived the formula of the type:

V＝c+b·ln?R，

Wherein R represents that turning radius, c and b represent respectively regression constant.

Yet this known model only has limited cogency.What it can not be interpreted as can reach the higher bend speed that allows than this formula on express highway.Be not provided as any speed only with the explanation of logarithmic growth.Shortcoming by the described model of this formula also especially obviously is, for the straight line highway section, may increase to infinite by logarithmic rate.This known model can not be described binding of maximum bend speed so far.Regression constant is always only effective for concrete sight, that is to say the illumination that depends on separately, street width, weather and a lot of other parameters, and therefore must be for each sight study.Because do not provide the basis of those parameters, so the parameter of the sight of prediction the unknown is impossible.Shortcoming is that also this formula has a very wide uncertain region.At last, which factor can change regression parameter neither be very clear.Generally speaking, this very fuzzy conclusion is very weak to the support of the programming of bend precaution device.

Summary of the invention

Given this background, proposed described according to independent claims, according to method and apparatus of the present invention, by drawing other design plan of the present invention in dependent claims and the specification sheets.

According to being designed with in the method for the present invention, when calculating the first maximum speed, consider the deviation that turns to of the described chaufeur that may occur with the form of the possible deviation curvature that adds to described highway section curvature.

The present invention is based on design believable, model that have cogency and that be easy to the bend driving behavior of expanding by the aspect of considering other, this model contains free parameter seldom and is suitable for realizing simply in self-propelled vehicle bend precaution device.So draw this model, namely vehicle does not travel at desirable route, but swings with additional deviation curvature around desirable route.Thus so that become possibility for the study of the sight of the unknown and forecast maximum speed or bend speed.This bend speed precaution device or speed precaution device needn't always relearn whole sight.The method can be applicable to infinitely-great turning radius equally, namely is applied to the straight way situation.Herein, by considering that the true deviation curvature that occurs obtains binding of maximum speed in this case, so that the bend early warning provides significant speed to recommend on straight highway section equally.

According to an improvement project of the present invention, derive possible deviation curvature according to the deviation that turns to of the reality of chaufeur, wherein determine to turn to deviation by means of steering angle sensor.Can be correspondingly with the mode of less cost determine deviation curvature that this is possible and for after sight learn this possible deviation curvature.

Be introduced into the bend early warning by the long-term planning that for example draws according to visual bend zone with chaufeur, can advantageously replenish above-mentioned improvement project.For this reason, improvement project of the present invention proposes, determine the second maximum speed according to this improvement project by visual bend zone with for the merchant who prepares the typical time of chaufeur that turns to behavior afterwards, and next determine and export the minimum value of the first and second maximum speeies.

As replenishing aforesaid improvement project, in another particularly advantageous improvement project, revise and be applied on the straight highway section by also considering turning to of short-term, determine the 3rd maximum speed by the zone, track that still can be used for turning to correction motion with for the merchant in the typical reaction time of chaufeur that turns to correction motion needs, and next definite and export the minimum value of determined a plurality of maximum speeies.

Description of drawings

Below will further set forth the present invention according to embodiment.In the accompanying drawing:

Fig. 1 shows the sketch of where deriving the embodiment in visual bend zone for several be used to illustrating;

Fig. 2 shows be used to illustrating for several conditions that where derive, although in order to the sketch that turns to correction motion also self-propelled vehicle to be remained in the embodiment in the track is arranged;

Fig. 3 shows the scheme drawing be used to the diagram of block of the embodiment that illustrates foundation method of the present invention;

Fig. 4 shows be used to the figure that illustrates according to the contrast of prior art and the maximum bend speed calculated according to the present invention; And

Fig. 5 shows the scheme drawing according to device of the present invention.

The specific embodiment

Turning radius will be for the derivation of following geometry.Curvature X is defined as the inverse of turning radius R, i.e. R=1/X.

For turning to behavior, consider that curvature is simpler, because directly addition of curvature value (rotation of bearing circle will cause at the track of vehicle extra curvature).This can describe by adding simply a curvature X.

The known document that is used for calculating maximum bend speed of quoting when beginning calculates according to the curvature that draws by map datum (in case of necessity also by bend cutting (Kurvenschneiden)) all the time.In contrast, also will consider the deviation curvature that turns to behavior to draw by inclusive according to the present invention.Because in the time will adding to the turning radius that data according to the map draws with the possible deviation curvature that turns to deviation to conform to of the chaufeur that may occur, current car speed must still be lower than the maximum speed that physics allows.Can be for example determine the deviation curvature that may occur by means of steering angle sensor, and the aviation value that obtains of subsequently study.Particularly, can record some observed readings of steering angle sensor, next turn to the assessment (whether should be relevant according to predetermined this assessment of standard) of behavior to form aviation value according to the observed reading that records according to single in case of necessity, at last according to the definite deviation curvature that may occur of this aviation value.

At first, as be known in the art such, according to determining maximum speed about the lateral stiffness of maximum transverse force a.Thus, draw physically maximum bend speed according to following formula:

$V=\sqrt{\frac{a}{\mathrm{\χ}}}.$

Now add on actual (namely in fact to be travelled) highway section curvature and revise this known formula by coming from the deviation curvature that turns to deviation that may occur, that is:

$V=\sqrt{\frac{a}{{\mathrm{\χ}}_{\mathrm{Kurve}}+{\mathrm{\χ}}_{\mathrm{Fehl}}}}.$

Can be to the speed of experienced chaufeur recommendation than unfamiliar chaufeur Geng Gao according to this foundation model of the present invention, because in the situation that is experienced chaufeur, deviation curvature will be less.Only this deviation curvature being added known formula can be so that maximum bend speed can not be increased to infinite.

Another creationary consideration for the driving behavior in the modelling bend practically is relevant with following knowledge, the driving behavior after namely chaufeur only can be planned in visual bend zone.Referring to Fig. 1, the regional S that this is visual _SichtbarCan measure by means of the environment acquisition system.For this reason, video system is most suitable.Alternatively, also this visual zone of data estimation according to the map.Referring to Fig. 1, when turning radius is R and lane width when being B, for the situation of the circular arc bend that illustrates, can calculates by means of simple how much and draw visual zone according to following formula:

$S_{\mathrm{sichtbar}}=2\·\sqrt{2\mathrm{RB}+B^2}.$

For driving behavior after planning or the preparation, after visual zone, chaufeur needs typical time T.S _SichtbarLess, so current bend more can hinder chaufeur to be seen to the visual field at a distance.Therefore, the maximum bend speed that is determined by long-term planning is v=S _Sichtbar/ T.If chaufeur is familiar with this running section, he needs shorter in fact time T so, comes behavior ready about.Therefore, on known highway section, can travel with higher bend speed.Why slower than what travel in open area on very narrow bend this equation has also been explained.

Also can be by calculating visual highway section S such as the environment acquisition system of video, radar or by map datum _SichtbarCan learn equally for setup time T the unknown and known area, because this typical intrinsic numeric that is chaufeur.This is so that forecast that for new running section maximum bend speed becomes possibility.

In addition, according to Fig. 1 can leading-out needle to the visual range of the situation of circular arc bend.Similarly certainly can leading-out needle to the visual range of the situation of the bend of convolution bend or any other form.

In nearer zone, can for example by means of the definite bend form of video acquisition, can gather by means of radar (by for example following the tracks of the vehicle that travels previously) for medium distance, and can employ the numerical map of storage for zone far away.

Current weather effect is also influential for visual range.Mist, dark, rain etc. can reduce visual range.Can determine environmental conditions according to diverse method, and when determining maximum bend speed discussed herein, consider this environmental conditions afterwards.Therefore, for controller, can whether open or recognize dark according to the time very simply according to illumination.For example, can whether start to identify rainy by means of rain sensor or rain brush.In addition, can whether start or according to traffic information identification mist by fog tail lamp.

In addition, visual range also can be subjected to building or the ozone deplation in roadside.These for example can be identified by analyzing camera image, perhaps as long as map comprises corresponding data, then also can extract from map.Also can derive typical visual range according to the street grade of current driving.So at express highway than having farther visual range at the state county road.Each street grade can read or derive by the typical feature of video by means of each street grade from the map of numeral, for example identifies by means of guideboard.Discernible traffic mark, for example " noting hairpin curve " also is hinting more by force restricted visual range certainly.

After chaufeur has been considered driving behavior long-term, afterwards, only need to carry out these.For this reason, chaufeur must be adjusted bearing circle again and again.Target is that vehicle is remained in the track of permission herein.Can for example measure still available lane width by means of the video sensing device.

In another embodiment of the present invention, the modeling of the part aspect of bend driving behavior being based on chaufeur makes and typically turns to deviation or turn to deviation to consider among its driving behavior this based on chaufeur.This will express as follows, namely also must add deviation curvature on the necessary highway section curvature of reality.Because this deviation curvature, vehicle may leave the track.This deviation curvature is corresponding to the deviation radius R _FehlWhen remaining lane width is B _VerbleibWhen (it deducts the automobile width for lane width), vehicle is crossing remaining residue length (zone, track)

$S_{\mathrm{verlassen}}=\sqrt{2\·R_{\mathrm{Fehl}}{b}_{\mathrm{verbleib}}+B_{\mathrm{verbleib}}^2}$

May leave this track afterwards, as where deriving by Fig. 2 is several.Within the reaction time, chaufeur must be revised, wherein this zone, track S _VerlassenCan supply the chaufeur dereaction.Therefore, " the maximum bend speed that is drawn by the short-term correction " is v=S _Verlassen/ T.

This formula shows, and rule of thumb is correct: the bend that travels is narrower, Vehicle Driving Cycle slower.In addition, along with the growth of vehicle driver's experience has less deviation curvature, and therefore higher bend speed can be arranged.

In this case, environmental conditions is also to divertical motion, and the deviation curvature that namely must take in the process of moving has tremendous influence.For vehicle is remained in the track, extremely violent beam wind will cause the huge correction that turns to.Learn the bend speed that turns to behavior and correspondingly automatically reduce subsequently to recommend this enhancing, short-term.Similarly, also should cross with lower bend speed the relatively poor street with a lot of pits, because the there also needs very large readjusting, i.e. R _FehlBe a very little value, it has caused lower bend speed.

Can measure street width by means of environment collection (for example video).Can estimate street situation (pit) by means of the environment collection equally.

Can determine to turn to deviation by steering angle sensor, i.e. the steering safety of chaufeur.This sensor measurement divertical motion and provide thus the conclusion that turns to deviation and steering safety about chaufeur.Therefore, can directly measure value required in the above-mentioned formula, or also can learn to turn to deviation as the representative value of chaufeur.

Referring to Fig. 2, the formula of this short-term correction is derived by the width in track for simplicity.In fact can't take full advantage of whole track.On the contrary, chaufeur always remains on vehicle for each chaufeur in the typical wobble area.When chaufeur for example travelled on a broad square, he still can remain in this zone.In the width of this wobble area, vehicle is as moving in a pipeline, and certainly, the width of this wobble area depends on environmental conditions separately, the drive safety of this chaufeur and speed separately.For example measure and learn now the width of this wobble area by means of the video sensing device.

Once learning the width of this wobble area, use so it to replace street width (the perhaps minimum value between street width and the wobble area).Be clear that thus can not move in extremely broad street because of vehicle, maximum bend speed just rises to infinitely.Restriction from wobble area is effective all the time.

The block diagram of Fig. 3 shows piece 11, according to above-mentioned first embodiment, realizes determining the first maximum speed or bend speed in this piece, namely adds according to highway section curvature to turn to deviation to determine.Wherein use according to the data of the numerical map of piece 14 with according to the steering angle sensor data of piece 15 and determine highway section curvature.Setup time T based on visual range and chaufeur in piece 10 determines the second maximum bend speed, wherein such as in the above more properly as described in according to piece 13 environment for use data and study to the setup time T that turns to behavior.In addition, in piece 12, determine the 3rd maximum bend speed, as in the above in more detail as described in, this is based on: turn to the correction motion chaufeur will vehicle to remain in the track or in its unique wobble area although have.Wherein will reuse environmental data and according to the steering angle sensor data of piece 15.In ensuing 16, determine the minimum value of three above-mentioned maximum bend speed, use it for subsequently the bend early warning to chaufeur according to piece 17.

In the diagram of Fig. 4, illustrated according to the maximum bend speed that depends on radius of the known logarithmic relationship of prior art with according to the contrast of embodiments of the invention described above with the minimum value in three the determined maximum bend speed.As seen according to method of the present invention on the result to known similar to counting method.Yet, can explain that why this bend speed is so and for this bend speed of extremely large radius also to be believable according to method of the present invention.Explained that in addition why older people (long reaction time) and driving beginner (larger deviation curvature is arranged in the control) drive slowlyer than youth with experienced vehicle driver.By using the environment acquisition system of vehicle, the bend speed of recommending will optimally be matched to street and light environment separately.In addition, also consider the following fact according to method of the present invention, namely when visual range is wide, travel very fast and on narrower street the time, traffic is slower, and why this bend speed has the effect that binds.

Fig. 5 shows the favourable design plan according to device 1 of the present invention.Wherein, device 1 comprises memory device 3, stores numerical map 2 in this memory device.This memory device 3 also can only so be connected with device 1, so that device can use the numerical map 2 of (for example reading) another equipment.Wherein, device itself or another equipment can be navigationsystem.The running section of the vehicle before this device 1 for example can be determined current location and be positioned at this equipment by means of GPS by means of registration device 4.In addition, this device 1 comprises control unit 5, and it can determine to be positioned at by means of the map datum of the position data of registration device 4 and numerical map 2 the street trend in the place ahead.In addition, this device 1 has indication and/or prior-warning device 7, can inform that by means of its this device the operator of this device or vehicle is about determined maximum bend speed and/or to its early warning.In addition, the data of the data of steering angle sensor 8 and environmental sensor 9 can offer control unit 5.The input value of learning can for example be stored in the input media 6 in particular for preparing the typical time of the chaufeur that turns to behavior afterwards.

Claims (12)

1. method of be used for carrying out the speed early warning of self-propelled vehicle, wherein control unit (5) calculates the curvature (χ in highway section based on the map datum (2) of the highway section part that is positioned at the place ahead that can provide in advance _Kurve), and calculate thus and export maximum speed as recommendation, the calculating of wherein said maximum speed can be affected by chaufeur, it is characterized in that, is calculating the first maximum speed (V _Max) time, to add to described highway section curvature (χ _Kurve) possible deviation curvature (χ _Fehl) form, the described chaufeur that consideration may occur turn to deviation.

2. method according to claim 1 is characterized in that, derives described possible deviation curvature (χ according to the drive manner of described chaufeur _Fehl).

3. method according to claim 2 is characterized in that, derives described possible deviation curvature (χ according to the deviation that turns to of reality _Fehl), wherein determine the described deviation that turns to by means of steering angle sensor (8).

4. each described method is characterized in that according to claim 1-3, by visual bend zone (S _Sichtbar) and be used for to prepare after the merchant of the typical time of chaufeur that turns to behavior determine the second maximum speed (V _Max), and determine and export described the first and second maximum speed (V _Max) minimum value.

5. method according to claim 4 is characterized in that, by means of environmental sensor (9), especially video system, and/or determines described visual bend zone (S according to described map datum (2) _Sichtbar).

6. according to claim 4 or 5 described methods, it is characterized in that, derive typical time of described chaufeur that turns to behavior after being used for preparing according to the described drive manner of described chaufeur, especially for very first time in known area with for second time in the area of the unknown.

7. each described method is characterized in that according to claim 4-6, in order to determine described visual bend zone (S _Sichtbar), environment for use information (9) also is especially about the environmental information (9) of current weather effect.

8. each described method is characterized in that according to claim 1-7, by zone, the track (S that still can be used for turning to correction motion _Verlassen) and turn to the merchant in the typical reaction time of chaufeur that correction motion needs to determine the 3rd maximum speed (V for described _Max), and determine (16) and output (17) determined a plurality of maximum speed (V _Max) minimum value.

9. method according to claim 8 is characterized in that, in order to determine described still available zone, track (S _Verlassen), determine described lane width (B) by means of environmental sensor (9), especially video system and/or according to described map datum (2), and determine the described correction motion (8) that turns to by means of steering angle sensor.

10. according to claim 8 or 9 described methods, it is characterized in that, according to the described relevant environmental information of correction motion (9) that turns to, especially about violent beam wind occurring or having the environmental information (9) of pit, obtain, learn the described correction motion that turns to, and when corresponding environmental conditions occurring, use the described correction motion that turns to.

11. each described method according to claim 8-10, it is characterized in that, substitute the lane width (B) of described reality and obtain, the typical wobble area of driving pupil, especially depend on the wobble area of environmental conditions separately, and use it for and calculate described the 3rd maximum speed (V _Max).

12. a device, it is configured to according to claim 1 the speed early warning of each described method execution self-propelled vehicle in-11, especially bend early warning, and it comprises be used to the highway section curvature (χ that determines to be positioned at the place ahead _Kurve) first determine device (2,4), be used for determining to stem from the possible deviation curvature (χ that turns to deviation of the chaufeur that may occur _Fehl) second determine device (6,8) and control unit (5), described control unit comprises and calculates the first maximum speed (V _Max) device.

Images