FR2795852A1 - ON-BOARD ASSISTANCE DEVICE FOR CONTROLLING THE MOVEMENTS OF A MOTOR VEHICLE WITH A VIEW TO A CHANGE OF TRACK - Google Patents

Abstract

The invention provides an on-board device for assisting the movement of a first motor vehicle (10), characterized in that the computer calculates a time interval between the second vehicle (20) and the first vehicle (10), performing the quotient of the distance (D) separating the two vehicles by the relative speed of the second vehicle (20) then in that, as a function of the calculated time interval, the computer determines a level of danger of the change maneuver lane and in that the interface means indicate this level of danger to the driver.

Description

B497 "On-board assistance device for controlling the movements of a

  motor vehicle for a lane change maneuver "The invention relates to a device for assisting the movement control of a motor vehicle. The invention relates more particularly to a device for assisting the movement control of a motor vehicle, in particular for a lane change operation, of the type comprising sensors capable of informing a computer of the presence and the speed of a second vehicle, as well as of the distance which separates the first vehicle from the second vehicle, the second vehicle being driven at a speed relative to the first vehicle, of the type comprising interface means for assisting the driver of the first vehicle, during a change of maneuver

  channel, using data from the computer.

  The driver of the first vehicle who wishes to change lane to go to an adjacent lane, left or right of the first vehicle, is likely to cause an accident if he initiates the lane change maneuver when a second vehicle is close to it on the adjacent lane, or else when a second vehicle quickly approaches the first vehicle on the adjacent lane. Several documents propose a lane change assistance system among which are systems for monitoring the blind spot area of the driver's field of vision. In these systems, an audible signal is heard when a vehicle is detected in the blind spot area. In

  in addition to the sound signal, a light signal warns the driver.

  This signal is placed either in a rear view mirror or on the dashboard of the vehicle. Depending on the case, the audible signal is activated B497 when the driver puts on his flashing light, or when the steering wheel

  indicates to the system that a lane change will be made.

  These documents include a system which, in the event of danger, returns the control lever for changing the state of the direction indicator light to the neutral position, even though the driver had activated it to change lanes. There are also documents relating to the passing assistance dealing with systems which, in addition to monitoring the blind spot area, monitor a rear area distant from the

  vehicle, or even an area at the front of the vehicle.

  In all cases, the information provided to the driver of the vehicle does not appear to be sufficiently relevant. In fact, there

  never has progressive information processing.

  1 5 For example, document CA-A-2.120.638 provides for warning the driver when a vehicle is behind him in the adjacent lane. The driver then knows that a vehicle is near him, but he is never informed of the distance and the speed of this vehicle. It is up to him to assess the risk run by a possible change maneuver

of track.

  The object of the invention is to propose a device which makes it possible to solve this problem by indicating to the driver a danger level of the lane change maneuver.

circulation.

  For this purpose, the invention proposes a device of the type described above, characterized in that the computer calculates a time interval between the second vehicle and the first vehicle, by taking the quotient of the distance separating the two vehicles by the relative speed of the second vehicle then in that, as a function of the calculated time interval, the computer determines a danger level of the lane change maneuver and in that the means

  indicate this level of danger to the driver.

  B497 According to other characteristics of the invention - to determine the danger level, the computer compares the calculated time interval to values representing predetermined danger thresholds for a lane change maneuver; - the computer compares the calculated time interval to a critical value and to a safety value as follows: a) if the calculated time interval is greater than or equal to the safety value, the danger level is a minimum level of danger indicating that the lane change maneuver presents a minimum risk; b) if the calculated time interval is less than the safety value and greater than the critical value, the danger level is an intermediate danger level signaling that the lane change maneuver presents an intermediate risk; c) if the calculated time interval is less than or equal to the critical value, the danger level is a maximum danger level signaling that the lane change maneuver presents a maximum risk; - To indicate the level of danger, the interface means include a multi-color display device and / or an audible signaling device; - the display device displays a different color for each danger level and the sound signaling device emits a signal when the computer detects that the driver intends to change lanes while the maximum danger level is displayed; - The interface means comprise a first part placed near the left rear view mirror of the first vehicle which indicates the level of danger for the left side of the first vehicle, and a second part placed near the right rear view mirror B497 which displays the level of danger for the right side of the first vehicle; - The first part of the interface means is placed on the left mirror of the first vehicle, and the second part of the interface means is placed on the right mirror of the first vehicle; - It comprises, on one side of the first vehicle, a first area sensor which monitors an extended area comprising the blind spot area of the driver's field of vision as well as a more distant rear area and comprises, on the other side of the first vehicle, a second area sensor which monitors a reduced area consisting of the blind spot area of the driver's field of vision; the second zone sensor informs the computer only of the presence of the second vehicle and, if such a presence has been detected, the computer directly determines the maximum danger level that the interface means indicate to the driver; - the area sensor is a camera or a radar or a

  ultrasonic sensor or any other means of detection.

  Other characteristics and advantages of the invention

  will appear on reading the detailed description which follows for

  the understanding of which reference will be made to the appended drawings in which: - Figure 1 is a schematic representation of an on-board assistance device produced in accordance with the invention; - Figure 2 is a schematic top view of a vehicle equipped with an on-board assistance device according to the invention; - Figure 3 is a schematic front view of the left rear view mirror of a motor vehicle equipped with the on-board assistance device according to the invention B497 - Figure 4 is a schematic front view of the right rear view mirror of a motor vehicle equipped with the on-board assistance device according to the invention; FIG. 5 is a diagram representing the distance separating the two vehicles as a function of the relative speed

  of the second vehicle relative to the first vehicle.

  There is shown diagrammatically in FIG. 1 an on-board assistance device for a motor vehicle

  produced in accordance with the invention.

  10 The on-board assistance device includes sensors 11, 12, 13 which transmit data to a computer 14. The computer 14 analyzes the data and determines a danger level ND which is indicated in the

  conductor by interface means 15, 16, 17.

  Sensors include a left area sensor

  11, a straight area sensor 12 and a speed sensor 13.

  FIG. 2 shows a first vehicle 10 equipped with an on-board assistance device according to the invention

and a second vehicle 20.

  We have schematized three traffic lanes in the same

  sense, the first vehicle 10 being located in the middle lane.

  The second vehicle 20 is located in an area monitored by an area sensor. For example, the second vehicle 20 has been placed in the lane to the left of the middle lane in which the first vehicle 10 travels, in the zone monitored by the left zone sensor 11, but the second vehicle 20 may, as a variant , as well be in the right lane of

that of the first vehicle 10.

  There are, on the first vehicle 10, a left rear view mirror 18, a right rear view mirror 19 as well as the left zone 11 and right zone sensors 12. For the sake of clarity, the other elements of the on-board device have not been shown. assistance. B497 The first vehicle 10 has a first gear

  V1. The second vehicle 20 is driven by a second speed V2.

  The two vehicles are separated by a distance D. The speed sensor 13 measures the speed V1 of the vehicle 10. The left zone sensors 11 and right 12 monitor zones located on the rear sides, respectively left

and right, of the first vehicle 10.

  The left zone sensor 11 is capable of detecting the presence of a second vehicle 20, of measuring its speed V2 and

  measure the distance D between the two vehicles.

  As shown in Figure 2, the left area sensor 11il monitors an extended area Ze which includes the blind spot area of the driver's field of vision on the left side of the

  first vehicle 10 as well as a more remote area.

  The extended zone Ze scans the adjacent traffic lane located to the left of the first vehicle 10 so as to be able to detect any vehicle present on this lane on a

  length for example equal to ninety meters.

  In the preferred embodiment of the invention, the right-hand zone sensor 12 monitors a reduced zone Zr constituted by the blind spot zone of the driver's field of vision on the right side of the first vehicle 10. The right-hand zone sensor 12 can only detect the presence of a

vehicle.

  The blind spot zones of the driver's field of vision correspond to zones situated towards the rear of the first vehicle 10, on the right and left sides, which the driver cannot observe either in his central interior mirror or in a rear-view mirror. lateral exterior of the conventional type. We will now explain the operation of the device

  assistance vehicle on the left side of the first vehicle 10.

  B497 The computer 14 analyzes the data supplied by the left-hand area sensor 11 and by the speed sensor 13. If the presence of a second vehicle 20 has been detected, it calculates the relative speed Vr of the second vehicle 20 relative to the first vehicle 10 by performing the quotient of the speed V2 of the second vehicle 20 by the speed V, of the first vehicle 10, or the difference between these two speeds. It then calculates a time interval ITcaj by performing the quotient of the distance D by the relative speed Vr, D being the distance which separates the io two vehicles and which is measured by the area sensor

left 11.

  The computer 14 has in memory time interval values, for example a critical value ITcrj and a safety value ITséc, representing danger thresholds t5 for a lane change maneuver. The computer 14 compares the calculated time interval ITcai with the critical value ITcrj and the safety value ITséc to determine the

  ND danger level of a lane change maneuver.

  If the calculated time interval ITcaJ is greater than or equal to the security value ITsec, the computer 14 then determines a minimum danger level NDmin which signals that the

  lane change maneuver presents minimal risk.

  That is to say that the second vehicle 20 is sufficiently distant or else has a speed V2 and / or a relative speed sufficiently low to allow the driver to change lanes safely, the risks being negligible. If the calculated time interval ITcai is less than the safety value ITsec and greater than the critical value ITcri, the computer 14 then determines an intermediate danger level NDint which signals that the lane change maneuver presents an intermediate risk. That is to say that the distance separating the two vehicles, or the speed of the second vehicle 20, is such that a maneuver of B497 lane change can be undertaken by the driver well

  that this maneuver presents significant risks.

  If the calculated time interval ITcal is less than or equal to the critical value ITcr, the computer 14 then determines a maximum danger level NDmax which signals that the lane change maneuver presents a maximum risk. That is to say that the second vehicle 20 is too close or else has a speed V2 too high to allow the driver to make a lane change without running very risky

io important.

  We will now explain the operation of the device

  assistance vehicle on the right side of the first vehicle 10.

  The computer 14 analyzes the data supplied by the right-hand area sensor 12 which monitors the reduced area Zr. As soon as a second vehicle 20 has been detected in this zone, the computer directly determines the maximum danger level NDmax. Indeed, the second vehicle 20 is located in the right blind spot area of the first vehicle 10. Undertake a lane change maneuver in this situation

  presents very significant risks.

  The danger level ND is then indicated to the driver by the interface means 15, 16, 17. These interface means are for example a left display device, a right display device 16 and a

audio signal 17.

  In the preferred embodiment of the invention, if a maximum danger level NDmax has been determined for one side of the first vehicle 10, and if the computer detects that the driver intends to change lanes on this side, by example if the driver has activated his flashing change of direction light, the audible signaling device 17 then emits an audible signal intended to warn the driver

  that he undertakes a dangerous maneuver.

  B497 The computer can use several methods at the same time to detect that the driver intends to change lanes. The computer can in particular detect an abrupt lateral movement from the angle of rotation of the steering wheel and / or from the position of the vehicle relative to a white line, which indicates that the driver intends to

to change of way.

  FIG. 3 shows an example of a left display device 15 mounted on the left mirror 18 of the

io first vehicle 10.

  The left display device 15 consists of three superimposed indicator lights, each being of a different color, for example red, orange and green. It indicates the level of danger ND for the left side of the first vehicle 10 with a different color for each of the three levels

of danger ND.

  To indicate that a minimum danger level NDmin has been detected, the left display device 15 thus causes

  the green indicator light comes on.

  To indicate that an intermediate danger level NDint has been detected, the left display device 15 thus causes

  the orange indicator light comes on.

  To indicate that a maximum danger level NDmax has been detected, the left display device 15 thus causes

  the red warning light comes on.

  FIG. 4 shows an example of a right display device 16 mounted on the right mirror 19 of the first

vehicle 10.

  The right display device 16 consists of a single indicator light, for example of red color. It indicates the maximum danger level NDmax for the right side of the first

  vehicle 10 by lighting up the red warning light.

  B497 The diagram in Figure 5 illustrates an example of time interval values representing thresholds of

  danger for a lane change maneuver.

  On the abscissa axis, the values of the relative speed Vr of the second vehicle 20 relative to the first are plotted.

  vehicle 10 in kilometers per hour.

  On the ordinate axis, the values of the distance D separating the first vehicle 10 from the second vehicle are reported.

in meters.

  o0 Every point on the diagram is characterized by a distance / relative speed D / V, couple. Any point in the diagram therefore represents a time interval value if we perform the quotient of its ordinate by its abscissa. A straight line in the diagram is characterized by its slope, i.e. by a value

l5 constant time interval.

  Two divergent curves were drawn from the same point of origin PO. The upper curve Csec represents the safety value ITs3é of the time intervals. The lower curve Ccri represents the critical value ITcri of the intervals

of time.

  The upper curve Cscé consists of a line segment between the point of origin Po and an upper point Psec, and a half-line whose origin is the upper point Psec. The slope of the half-line is greater than the slope of the line segment. Therefore the security value ITséc of the half-line is greater than the security value ITs, é

of the line segment.

  The point of origin Po, in the example proposed, has the ordinate value five meters and the abscissa value zero, that is to say that at this point the two vehicles are traveling at the

  same speed and are separated by a distance D of five meters.

  This is an example of the safety distance that both vehicles must keep when traveling at the same speed. B497 II The lower curve Cc has a general shape similar to the upper curve Cso. The lower curve Ccri comprises a line segment between the point of origin Po and a lower point Pcrj, and a half-line which originates from the lower point Pcri. The two curves Cséc and Crj delimit three zones of the diagram. A first upper zone Zmin comprises the upper curve Csec and all the points of the diagram situated above the upper curve Csec. The upper zone Zmin represents the time interval values allowing a safe lane change maneuver. This

  zone therefore corresponds to the minimum danger level NDmin.

  A second intermediate zone Zint includes all the is points of the diagram located between the upper curve Cséc and the lower curve Ccri. The intermediate zone Ziot represents the time interval values for which a maneuver of

  changing lanes presents significant risks.

  This zone therefore corresponds to the intermediate danger level

NDint.

  A third lower zone Zmax includes all the points of the diagram located below the lower curve Ccri. The lower zone Zmax represents the time interval values for which a lane change maneuver presents very significant risks. This zone

  therefore corresponds to the maximum danger level NDmax.

  When the computer 14 has calculated a time interval value ITcai, it determines in which zone of the diagram is this value to define the danger level ND of a

lane change maneuver.

  The configuration of the upper curve Csec and the lower curve Ccrî in two parts of different slopes allows to have two separate critical values ITcri and two separate safety values ITséc, for example for B497 to differentiate between situations or vehicles are separated by a distance D less than or more than ten meters. In variants of this embodiment, it is possible to set up curves comprising a single part or more than two parts. There are then as many distinct ITcri critical values and distinct ITsec safety values as there are parts on each curve. The curves can also not

  not be straight lines but for example parables.

  We have described above the operation of an on-board assistance device in which we are able to indicate

  up to three ND danger levels.

  It is conceivable to provide only two danger levels ND, for example a maximum danger level NDmax and a minimum danger level NDmin. It is also possible to predict more than three ND danger levels. It is then necessary to define other values of time intervals to represent the new danger thresholds and it is necessary to provide means

adapted interface.

  According to the preferred embodiment of the invention, the on-board assistance device operates differently on the left side and on the right side. This characteristic is explained by the fact that the driving rules impose on vehicles

  automobiles drive on one side of the roadway.

  In the majority of countries, motor vehicles are required to drive on the right side of the road and make overtaking on the left side of vehicles. Consequently, in the majority of cases, the vehicles coming from the rear pass through the left of the first vehicle 10. This is why it is firstly important to monitor an extended zone Ze on the left side of the first vehicle 10 and , on the other hand, it is sufficient to monitor a reduced area Zr on the side

first vehicle right 10.

  B497 Of course, if the first vehicle 10 is intended to circulate in a country in which the vehicles drive on the left side of the road, it is then advisable to reverse the on-board assistance device so as to monitor an extended zone Ze on the side right of the first vehicle 10. The fact of differentiating the operating principle of the left and right interface means allows the driver to realize that the dimensions of the detected area and the information provided on the left are different from those detected. to the right. The purpose of this differentiation is to make him understand intuitively that, on the right side, the system only covers the blind spot and does not ensure detection

"distant".

  In a variant of the on-board assistance device according to the invention, an extended zone Ze can be monitored on each side of the first vehicle 10. In this case, the structure of the left 15 and right 16 display devices is similar to

  to indicate one of the three possible ND danger levels.

  In known manner, the left zone sensors 11 and 2o right 12 are radars. But it is possible to replace radars with cameras. In this case, the images filmed by the cameras are analyzed in order to detect the presence of the second vehicle 20 and to determine its speed V2 as well as the distance separating the second vehicle 20

of the first vehicle 10.

  In variants of the invention, the left zone 11 and right zone 12 sensors are ultrasonic sensors or a

other known means of detection.

B497

Claims (10)

  1. On-board device for assisting the movement control of a first motor vehicle (10), in particular for a lane change maneuver, of the type comprising sensors (11, 12, 13) capable of informing a computer (14) on the presence and speed (V2) of a second vehicle (20), as well as on the distance (D) which separates the first vehicle (10) from the second vehicle (20), the io second vehicle (20 ) being driven by a relative speed (Vr) relative to the first vehicle (10), of the type comprising interface means (15, 16, 17) to assist the driver of the first vehicle (10), during a lane change maneuver, using data from the computer (14), i5 characterized in that the computer (14) calculates a time interval (It) between the second vehicle (20) and the first vehicle (10), by taking the quotient of the distance (D) separating the two vehicles by the relative speed (Vr) of the second vehicle (20) then in that, as a function of the calculated time interval (ITcal), the computer (14) determines a danger level (ND) of the lane change maneuver and in that the interface means (15, 16, 17) indicate this level danger (ND) to the driver.   2. Device according to the preceding claim, characterized in that, to determine the danger level (ND), the computer (14) compares the calculated time interval (lTcal) to values representing predetermined danger thresholds for an operation of change of track.   3. Device according to claim 2, characterized in that the computer (14) compares the calculated time interval (ITcai) to a critical value (lTcri) and to a safety value (ITsec) as follows B497 a) if the calculated time interval (ITal) is greater than or equal to the safety value (ITse), the danger level (ND) is a minimum danger level (NDmijn) signaling that the lane change maneuver poses a risk minimal; b) if the calculated time interval (ITca.) is less than the safety value (lTscé) and greater than the critical value (ITcjri), the danger level (ND) is an intermediate danger level (NDint) signaling that the lane change maneuver presents an intermediate risk; Io c) if the calculated time interval (ITcal) is less than or equal to the critical value (ITcri), the danger level (ND) is a maximum danger level (NDmax) signaling that the maneuver   lane change poses maximum risk.   4. Device according to any one of the claims   above, characterized in that, to indicate the level of danger (ND), the interface means (15, 16, 17) comprise a display device (15, 16) in several colors and / or a   audible signaling device (17).   5. Device according to the preceding claim taken in combination with claim 3, characterized in that the display device (15, 16) displays a different color for each level of danger (ND) and the sound signaling device (17) emits a signal when the computer detects that the driver intends to change lanes then   the maximum danger level (NDmax) is displayed.   6. Device according to any one of the claims   previous, characterized in that the interface means (15, 16, 17) comprise a first part (15) placed near the left mirror (18) of the first vehicle (10) which indicates the level of danger (ND) for the left side of the first vehicle (10), and a second part (16) placed near the right rear view mirror (19) which displays the danger level (ND) for the right side of the first vehicle (10).   B497 7. Device according to the preceding claim, characterized in that the first part (15) of the interface means is placed on the left rear-view mirror (18) of the first vehicle (10) and the second part (16) of the interface means is placed on the right mirror (19) of the first vehicle (10).   8. Device according to any one of the claims   previous, characterized in that it comprises, on one side of the first vehicle (10), a first area sensor (11) which monitors an extended area (Ze) comprising the area 1o dead angle of the field of vision of the driver as well as a more distant rear zone and comprises, on the other side of the first vehicle (10), a second zone sensor (12) which monitors a reduced zone (Zr) consisting of the blind spot zone of the field driver's vision.   1 5 9. Device according to the preceding claim, characterized in that the second zone sensor (12) informs the computer (14) on the mere presence of the second vehicle (20) and, if such a presence has been detected, the computer (14 ) directly determines the maximum danger level (NDmax) that the interface means (15, 16, 17) indicate to the driver.   10. Device according to any one of the claims   above, characterized in that the area sensor (11, 12) is a camera or a radar or an ultrasonic sensor or any other means of detection.