METHOD AND SYSTEM SHIFT ASSIST ROADWAY FOR MOTOR VEHICLE

The present invention relates generally to motor vehicles equipped with semi-automatic, or automatic driving assistance, and specifically to systems shift assist driving lane for a motor vehicle.

Such systems change lane, known as CCA (initial English Saxon updates for a LANE de l'équipement), have the purpose of control, by acting on the control means of the vehicle direction or even the brake system, the path followed by a vehicle when it is necessary to change lanes of travel, for example in the case of exceeding another vehicle or after exceeding of a vehicle.

Such systems generally utilize information from a sensor mark for road, such as an onboard camera in front of the vehicle, to identify not only the lateral boundaries of the lane on which the vehicle runs, but also lanes adjacent to the current channel rolling. When the vehicle is in a situation where a lane change, from an initial driving lane roadway to a final, is possible, conventional systems typically calculate the central path of the roadway final, and determine from information from a location system of the vehicle, such as a navigation system, and information of velocity and/or acceleration of the vehicle, a course to be followed by the vehicle to reach the central path of the roadway final. Conventional systems then controls the vehicle to follow automatically this path until reaching the central path of the roadway final.

As an example, is shown in Figure 1 a driving situation on a road 1, for example a highway, comprising, within two limits extreme side 11 and 10, three possible roadways with li, l_ l3 2 and in the same direction of travel, each being defined by two lines of pavement marking, the marking line such 13. A motor vehicle 2 equipped with a system of an extruded parison is represented rolling on the roadway li are located here the rightmost road 1 in the flow direction. The motor vehicle 2 follows in the example a third vehicle 3 that it is about to exceed using the assistance system lane change. For simplicity, it is assumed that the system has already identified the roadway initial, here the path of Li, the roadway final, here the track l2, and that the lane change is actually feasible (pavement marker allowing the lane change, none vehicle party on the roadway final that would interfere with the exceeding, for example a vehicle third party located at the rear of the vehicle 2). In this case, a conventional system of an extruded parison will determine the central path L._C. the roadway final l2, and then determine the path P to be followed by the vehicle 2 in order to bring the vehicle to the central path.

The Heimlich lane change is usually initiated after the driver or the system has verified that a lane change was possible, and the driver has activated the direction indicator. The duration T is necessary to permit the motor vehicle 2 to join the central path U is fixed, typically of the order of 5 seconds.

Such systems do however not always with a sense of security for the driver. In particular, some drivers will find that calm nature the maneuver is too fast, while other conductors, to the driving more aggressive, will instead be considered that the maneuver is too slow relative to what they would have done themselves.

There are also known US 2012/0215415 a driver assistance system that utilizes a determination of at least one characteristic parameter of the driving axle of a motor vehicle driver. The system is then able to control the speed of the vehicle based on the parameter. The change procedures channel are however not supported by the system.

The aim of the invention to overcome the disadvantages and limitations of known systems by providing a system for a vehicle which tends to approximate the natural behavior of a motorist and correspondingly increasing its sense of security.

For this purpose, the invention concerns a method for assisting the lane change for a motor vehicle from a driving lane initial to a final driving lane, the method comprising a step of detecting the final driving lane, and a step for checking the motor vehicle when it joins the roadway final in a time of predetermined lane change, characterized in that it further comprises a step of determining at least one characteristic parameter of the driving behavior of a driver of said motor vehicle, and in that said duration of lane change is predetermined and fixed in respect to said at least one parameter.

The characteristic parameter of the driving style of a driver can for example be bound to accelerations/decelerations made by a driver.

Alternatively or in combination, can also determine the driving style from other measures, for example through tracking of steering wheel angle (steering angle) when the driver performs a lane change manually.

Further, some known systems alert the driver, or even prevent the automatic lane change maneuver, when traffic conditions cannot be achieved. Figure 2 illustrates the monitoring areas near the motor vehicle 2 that allow such systems offer this functionality. For simplicity, only the monitoring areas located on the left path with respect to the roadway of the motor vehicle 2 have been shown, but it is understood easily that similar areas are provided on the right of the motor vehicle 2. a first monitoring region shown in Figure 2, at the height of the motor vehicle 2, forms a region said was security zone which prevents any automatic change of path since a third vehicle is detected as present in this area. The length of the zone AIs, taken in the direction of the curl, is predetermined with respect to the front and rear of the vehicle 2 and therefore also takes into account the vehicle length 2. in the example illustrated, this area AIs extends over 12 meters relative to the front of the vehicle 2, and 3 meters relative to the rear of the vehicle 2. the width of the area ai is further defined as being at least the width of the roadway final (typically on the order of 3.5 meters for a highway in France), preferably increased by a safety margin, for example of the order of 0.5 meter, impinging on the roadway of the motor vehicle 2, advantageously to take account of two-wheeled vehicles of rolling between the two paths.

A second zone a2, forming a back monitor, is also observed by the appropriate components of the system (cameras, radar...). This area a2, which starts immediately at the rear of the security zone AIs, may have a width identical to the KI-security area, and a predetermined length, fixed in the example to 67 meters. The observation of this area back monitor gives a permission of lane change under certain conditions only. The principle is as follows: the lane change is authorized by the system if neither vehicle third party were not detected as present in that zone₂ . If on the other hand, as shown in Figure 2, a third vehicle is detected on the final driving lane, as occurring rearward of the vehicle 2, the system will estimate, from determination of positions and relative speeds of the vehicle is detected and the vehicle 2 thirds, a duration Tcc (initial English Saxon Time updates to head crash) corresponding to the time that would occur to collision between the motor vehicle and the other car 2 detected in the event that the system ascertained the overshoot. A first threshold TTCth Re, for example attached to 5 seconds, to serve as a comparison value with the duration Tcc estimated to authorize or not the lane change. More specifically, a lane change will be allowed if the duration Tcc estimated is greater than the first threshold TTCth Re/and prohibited in the opposite case.

Some more advanced systems are similarly for monitoring traffic in a third area a3, forming a monitoring area before. This area a3, which starts immediately at the front of the security zone AIs, may have a width identical to the KI-security area, and a predetermined length, fixed in the example to 58 meters. Similarly to what has been described for the surveillance area rear a2, for any vehicle third party detected in this area a3, estimating a duration Tcc which is compared to a second threshold TTCth-epond/P-attached^{reverse speed} example to 7 seconds. The automatic handling of lane change will be allowed if the duration Tcc estimated is larger than the second threshold TTCth-epond/and prohibited in the opposite case.

To correspond with such systems, and in other aspects of possible method:

- the method may further include a step of monitoring a safety zone located on the roadway final, on a side of the motor vehicle, in order to prevent any lane change upon detection of the presence of a third party vehicle safety in this area;

- said safety zone extends a predetermined length depending on the length of the motor vehicle, a safe distance specified forward from the front of the motor vehicle, and a safe distance predetermined back from the rear of the motor vehicle;

- advantageously, said safe distance front and/or said rear safety distance also varies as a function of said at least one parameter characteristic of the driving performance of a driver of said motor vehicle;

the method preferably includes the further step of monitoring at least one monitoring area located on the final product and use, to the front or to the rear of said security zone, comprising a sousétape previously receiving detection information of a vehicle third party present in said at least one monitoring area, for determining the position and the relative speed of said motor vehicle and the vehicle third party detected, Tcc of estimating a time period corresponding to a time that would occur to collision between said motor vehicle and the other car detected, and for comparing the time Tcc estimated to a threshold value, and the lane change is prohibited if the duration Tcc estimate is lower than said threshold value;

- again, said threshold value can be advantageously varied as a function of said at least one parameter characteristic of the driving performance of a driver of said motor vehicle;

- said at least one monitoring area is e.g. an area

back monitor associated with a threshold value rear TTQ, . May be MC-re a^{the R}

also forecast area front monitoring, associated with a threshold value before ^ ^ Tcc. A complete system will combine advantageously the monitoring areas front and back;

- said determining step includes a substep of classifying a conductor in one of a plurality of categories representing driving behaviors based on said at least one parameter, and the duration T of lane change is set to a value within a range between a minimum period T._min. and a maximum time duration T_am the X, the minimum duration of T_{the m} Y_{the n} and the maximum time duration T_max. depending on the category.

The invention also relates to a shift-assisting device for a motor vehicle lane roadway from an initial to a final driving lane, the system comprising means for detecting final of the roadway, and means for monitoring the motor vehicle when it joins said roadway final in a time of predetermined lane change, characterized in that it further comprises means for determining at least one characteristic parameter of the driving behavior of a driver of said motor vehicle, and in that said control means are adapted to secure said duration of lane change as a function of said at least one parameter.

The invention and the various advantages that it provides will be better understood in view of the following description, made with reference to the drawings appended hereto, in which:

figure 1 -, already described above, describes an exemplary driving situation involving a lane change performed with a known system of an extruded parison;

figure 2 -, already described above, illustrates different monitoring areas likely to be examined in the authorization of lane change;

figure 3 - represents, in the form of simplified synoptic, a general architecture can be an aid for lane change capable of implementing the method according to the invention;

figure 4 - schematically shows steps of a method of an extruded parison.

Later on in the specification, and unless it does not add to otherwise disposed, the elements common to all of the drawings bear the same references.

Figure 3 illustrates simplified manner a system 4 for on-board system for a vehicle for a motor vehicle from a driving lane initial to a final product and use. In the nonlimiting example shown in this fig., the system 4 interacts with other components on the vehicle, in particular, with a detector 5 lines of road marking, for example a camera located at the front of the motor vehicle, a system 6 for locating the motor vehicle, for example a navigation receiver such as a GPS device, and various sensors 7 for determining the current velocity and/or acceleration of the motor vehicle. The system 4 also cooperates with a control system 8 of the steering column of the vehicle, or even with a braking system (not shown). It should be noted that the sensor 5 could also be integrated into the system without departing from the frame 4 of the present invention. The system includes, in a preferred embodiment, a set of sensors 9 (cameras, radar, lidar...) for monitoring various areas in the surrounding environment of the vehicle 2, such as the security zone AIs, the monitoring areas and rear or front a2 a3 described above, for the detection of presence of one or more third party vehicles.

The reference 40 of Figure 2 represents detection means rolling paths possible in front of the vehicle, and in particular the roadway initial and final of the roadway. These means 10, for example in the form of a module dedicated processing, receive the information from the detector 5, herein the images captured by the camera, and extract these data the road marking lines of the different paths located at the front of the vehicle, of which the roadway final for the lane change delimited laterally by two marking lines. Different processing algorithms exist for enabling detection of possible driving lane, and do not require to be referred to in detail before because without impacting the method according to the invention.

The system 4 also has conventionally means 41 for determining a central path the relative to the roadway final that was detected and means 42 control the motor vehicle when it joins the central path the. The central path the is for example determined from the detection of two road marking lines delimiting laterally the roadway final detected.

The means 42 control are especially adapted to determine a trajectory to be tracked by the motor vehicle 2 to get the roadway initial to final the roadway when joining the central path the (path P on Figure 1), and then to act on the system 8 control the steering column of said motor vehicle, or even on the braking system, to guide the car automatically upon actuation of lane change.

In the following, the following variables are defined:

- Xj is the initial position of the motor vehicle 2;

Xf is the final position of the vehicle 2;

Vj is the initial speed of the motor vehicle 2;

- Vf is the final speed of the motor vehicle 2;

- Aj is the initial acceleration of the motor vehicle 2;

- AF is the final acceleration of the motor vehicle 2;

- T represents the time required to effect the lane change maneuver.

The path to be performed by the motor vehicle is predefined and obeys the polynomial function of order 5 following:

The X (T-) = aF- + + aF-AF- + aF- + has, f + a₀

wherein the duration T is the input data and with:

has₀ THE X=_{the I}

has₂ =0, 5A_{the I}

^D. 3=vr)(10 (Χ, - Χ,)) + ^) (4 + 6 + ^ ^ L-Ο ΐ (3 β, -0, Α 5,)

^has 4=VJ(( V_F. - has,) - Τ (Α_F. 14 + 1,5 has,) - 1, 5a, T ))

^has e=' the I^WITHsrj VBE1CTAFs-to-3vf + 3a₃ V + 4a₂ T + 3a_{the L}

As has been indicated in the introduction, the prior systems use a fixed duration T, of the order of 5 seconds.

Differently, the present invention provides for determining beforehand at least one characteristic parameter of the driving performance of a driver of the motor vehicle 2, and varying at least the duration T of lane change as a function of this parameter.

The determination of the characteristic parameter of the behavior of the driver can be made according to the teachings of the US 2012/0215415, by observing the accelerations/decelerations made by the driver. Thereby using for example the comparison thresholds and speeds or accelerations of the vehicle 2 for categorizing driver behavior in several, e.g. three categories, a first category corresponding to a driver "calm", a second category corresponding to a driver "regular", and a third class corresponding to a conductor "aggressive".

Other methods can be used in addition or alternatively to characterize a specific driver behavior lane change:

- measuring one or more of the following parameters: steering angle, lateral speed, lateral acceleration, yaw rate and/or torque flywheel during multiple manual lane changes. The measurements are then compared with curves or values pattern corresponding to the desired behaviors (quiet, home, abrupt...);

- time measurement path exchange means in manual.

In one implementation of the invention, is used for the duration T of the automatic handling of lane change, a value of around 6.5 seconds for the conductors "normal", whereas this value T will be lower (typically of the order of 4.5 seconds) for drivers "aggressive" which would naturally tend to operate more quickly a lane change, and that this value T will be greater (typically of the order of 7 seconds) for drivers "quiet" which would naturally tend to operate more slowly a lane change.

In one implementation more complex of the invention, in which the assistance system would include means capable of monitoring areas on the side, the front and/or rear of the vehicle 2 (typically cameras, radars and/or laser radars on-board the vehicle 2, generally represented by the reference 9 in Figure 3, also considered that the characteristic parameter of the driving performance of a driver of the motor vehicle 2 will advantageously be used to modify the conditions for authorizing a lane change or not, in the case of presence detections of vehicle third party in one of the monitoring zones AIs, a2 or a3 described above with reference to Figure 2.

In the case of the security zone AIs, the principle is to increase safety distances front and/or rear "quiet" for the conductors, and reduce these same safety distances front and/or rear "aggressive" for the conductors. In other words, the more the driver is calm, the greater the security zone ai is long.

In the case of the surveillance zone or area rear a2 front monitoring a3, the principle is to increase the value of the threshold rear Tcc_mC __reset , respectively avantTTC ^ __rF for the conductors "quiet", and for lowering the same threshold value rear Tcc ^, ^ ^ avantTTC respectively for the conductors "aggressive". In other words, the rider is more aggressive, more threshold values back Tcc ^ __reset , respectively avantTTC_{the th RF} , are low, reflecting a much improved behavior of such conductors.

In a preferred embodiment, is defined as, for

each category of conductors, two limit values T and T for the ^³ figure 12

duration T required for a lane change maneuver.

The table 1 below gives an example of the different values that can be adopted in a system of system for a vehicle according to the present invention, depending on the category of the conductor.

Table 1

For each category of conductors, the way to determine the time T required for lane change preferentially obeys the following rules (assuming of course that none vehicle third party were not detected in the security zone ai, in rules in which case any lane change maneuver), to have a proper period to traffic conditions:

- If at least one duration Tcc estimated for a vehicle third party detected in any one of monitoring areas front or rear a2 a3 is substantially equal to the threshold value corresponding to the monitored zone considered (Tcc_{the thrE} for the surveillance zone a2 Tcc and_mC __F. for the surveillance zone a3), then one can be found in a situation in which the lane change maneuver needs to last for the least long as possible.

In this case, the duration T is set equal to the minimum duration of T_{the m} Y_{the n} .

- If on the contrary, all times estimated Tcc are greater than the threshold value of the surveillance area in question, increased by a safety margin, then one can be found in a situation in which the lane change maneuver can last longer. In this case, the duration T is set equal to the maximum duration of T_max. . The safety margin is for example given by the difference between T_max. and T_{the m} Y_{the n} .

- In all other cases which are intermediate, it is to say if all times estimated Tcc are between the threshold value of the surveillance area in question, and this threshold value plus the safety margin, the duration T is to be set at a value of between said minimum Tmin and Tmax represents the maximum duration, defined for example according to the following relationship:

The T=mins (Tcc_F. TCC -,, + T-. ; - TCC TCC, + T-. ; T-)^V. rF MC-epond minutes' ER MC-re a minutes' max.^J wherein Tcc_rF is an estimated duration for a vehicle third party detected in the front region a3, Tcc and_reset is an estimated duration for a third vehicle rear a2 detected in the area.

Figure 4 summarizes the steps of a method of an extruded parison for a motor vehicle from a driving lane initial to a final product and use according to the present invention, in its most elaborate form:

The method starts with a step 100 detecting final of the roadway, for example by treatment of images captured by a camera 2 for extracting the road marking lines on the front of the vehicle.

The process is continued by a step 110 of determining at least one characteristic parameter of the driving performance of a driver of the motor vehicle 2, for classification of the conductor in one of a plurality.

The step 120 corresponds to monitoring of the security zone AIs. The procedure is ended without change lane change lane upon detection of a third vehicle AIs security in this area. As seen previously, the length of the surveillance area is preferably adapted to the type of driver.

The step 130 corresponds to monitoring of the monitored zone and/or front rear a2 a3. The procedure is ended without change lane change lane upon detection of a third vehicle in one of these zones, for which the duration is estimated Tcc below the threshold value of the surveillance area in question. As seen previously, the threshold values are also preferably adapted to the type of driver.

The last step 140 depicted corresponds to the step of checking the motor vehicle 2 for it joins the roadway final l2 in a duration T lane change, defined, according to the invention, to the type of driver.