TECHNICAL AREA

The invention relates to a method to assess the risk of change of traffic lane during the driving of a vehicle on a roadway with at least two neighbouring traffic lanes according to the introduction to claim 1 . The invention relates also to a system to assess the risk of change of traffic lane during the driving of a leading vehicle on a roadway with at least two neighbouring traffic lanes. The invention relates also to a motor vehicle. The invention relates also to a computer program and a computer program product.

BACKGROUND When driving a vehicle on a roadway with at least two neighbouring traffic lanes, a change of traffic lane involves a risk in the case in which a vehicle behind is approaching in the neighbouring traffic lane to which a change is to take place. From the point of view of traffic safety, thus, there is a need to assess the risk of change of traffic lane in the presence of a vehicle that is approaching the leading vehicle from behind.

What is known as a "blind-spot warning system" is, according to one variant, used for this purpose. Such a system warns or takes action in another manner when the driver's own vehicle is in the process of progressing into a neighbouring traffic lane in which an object such as another vehicle is present. This is normally achieved by means of a rearwards-directed radar that detects objects or vehicles in neighbouring traffic lanes, where it is assumed that the vehicle is being driven essentially straight ahead along the direction of travel. The assumption that the vehicle will drive straight forwards may lead to erroneous or omitted warnings.

On roads with several traffic lanes the degree of curvature of the roadway may lead to such a blind-spot warning system taking measures unnecessarily when vehicles with trailers such as a lorry with a drawing vehicle and a trailer are driven, as is illustrated in Figure 1 .

A warning system such as what is known as a "blind-spot warning system" assumes in this case that a vehicle detected in the detection region and determined to be present in a zone extending directly backwards and at a distance that corresponds to the distance from the vehicle or the drawing vehicle of the vehicle to the neighbouring traffic lane constitutes a threat, whereby a warning is activated during a change of traffic lane since the trailer, which is located in the traffic lane in which the vehicle is present, constitutes a threat due to the degree of curvature of the roadway, whereby the blind-spot warning system takes measures when the vehicle intends to carry out a change of traffic lane and consequently gives an unnecessary warning. Figure 1 illustrates this problem.

US2003025597 reveals a system to provide assistance during change of traffic lane where the position of the line markings at the traffic lanes are memorised, whereby the history of the traffic lane position is determined in order to determine the position of the vehicle.

PURPOSE OF THE INVENTION

One purpose of the present invention is to achieve a method and a system to assess the risk of change of traffic lane during the driving of a vehicle on a roadway with at least two neighbouring traffic lanes that minimises the risk of erroneous warnings when a risk during change of traffic lane is not present. SUMMARY OF THE INVENTION

These and other purposes, which are made clear by the description below, are achieved by means of a method, a system, a motor vehicle, a computer program and a computer program product of the type described in the introduction, and that furthermore demonstrate the distinctive features specified in the characterising part of the attached independent patent claims. Preferred embodiments of the method and the system are defined in the attached non-independent claims.

According to the invention, these purposes are achieved with a method to assess the risk of change of traffic lane during the driving of a vehicle on a roadway with at least two neighbouring traffic lanes, comprising the step: to detect the presence of objects in traffic lanes neighbouring to the traffic lane in which the said vehicle is being driven, comprising the steps: to determine, based on specifications concerning the extent of a specified traffic lane in which the vehicle is being driven, the extent of at least one neighbouring traffic lane based on continuously determined reference positions at the vehicle relative to the said neighbouring traffic lane in order to determine an action zone extending a specified extent in the said neighbouring traffic lane alongside the said vehicle, and, in the event of the presence of objects in the said action zone, to take measures in association with a change of traffic lane. By determining relevant risk zones in this way, the risk of erroneous warnings when there is no risk of change of traffic lanes is minimised. Consequently, in this way, the risk of erroneous warning when a vehicle with a trailer, such as an articulated lorry, is driven around a curve is eliminated in that the action zone determined in this way will not be sensitive to the driver's own trailer.

According to one embodiment of the method, reference positions are continuously determined at predetermined intervals. Efficient and predictable determination of the action zone is in this way made possible. According to one embodiment of the method, the intervals are intervals of extent along the direction of travel of the vehicle. Efficient and predictable determination of the action zone is in this way made possible, independently of the speed of the vehicle. According to one embodiment of the method, the intervals are intervals of time. Efficient and predictable determination of the action zone that is simple to achieve is in this way made possible.

According to one embodiment, the method comprises the step to determine the extent at the said neighbouring traffic lanes based on parameters with respect to the travel of the vehicle, which parameters include the rate of change of yaw angle and speed of the vehicle. An efficient manner to accurately and precisely determine action zones is in this way made possible where the course of the vehicle around the curve, and thus consequently the extent and curvature of the neighbouring traffic lanes, are efficiently recreated at the action zone.

According to one embodiment of the method, the said determination of extent of the said neighbouring traffic lanes includes the determination of distance relative to the vehicle. An efficient manner to determine the width of the action zone is in this way made possible. According to one embodiment of the method, whereby the extent by which the said action zone extends in the said neighbouring traffic lanes alongside the said vehicle is set to an extent corresponding to the length of the vehicle or somewhat greater than this. It is in this way ensured that measures such as giving a warning, in the event that such a detected vehicle is located in the action zone, are taken as soon as the vehicle is detected.

The embodiments of the system demonstrate corresponding advantages as corresponding embodiments of the method described above. DESCRIPTION OF DRAWINGS

The present invention will be better understood with reference to the following detailed description read together with the attached drawings, where the same reference numbers refer to the same parts throughout the several views, and where:

Figure 1 illustrates schematically the driving of a leading vehicle on a roadway with at least two neighbouring traffic lanes, where a vehicle that is approaching the vehicle from behind is detected according to prior art technology; Figure 2 illustrates schematically a motor vehicle according to one embodiment of the present invention;

Figure 3 illustrates schematically a block diagram of a system to assess the risk of change of traffic lane during the driving of a vehicle on a roadway with at least two neighbouring traffic lanes according to the present invention; Figure 4 illustrates schematically the driving of a leading vehicle on a roadway with at least two neighbouring traffic lanes, where reference positions relative to traffic lanes that are neighbouring to the vehicle have been determined;

Figure 5 illustrates schematically the driving of a leading vehicle on a roadway with at least two neighbouring traffic lanes, where a vehicle that is approaching the vehicle from behind is detected according to one embodiment of the present invention;

Figure 6 illustrates schematically a block diagram of a method to assess the risk of change of traffic lane during the driving of a vehicle on a roadway with at least two neighbouring traffic lanes according to the present invention; and

Figure 7 illustrates schematically a computer according to one embodiment of the present invention. THE PRIOR ART

Figure 1 illustrates schematically the driving of a vehicle 1 with a drawing vehicle 2 and a trailer 4 travelling in the direction of the arrow P1 on a roadway R2 with two neighbouring traffic lanes L1 , L2, according to the prior art.

A radar means with a certain range is arranged to achieve a detection region A1 that is directed from the right side of the vehicle and essentially directly backwards relative to its direction of travel. What is known as a "blind-spot warning system" will in this case assume that a vehicle detected in the detection region and determined to be present in a zone ZA1 extending directly backwards and at a distance that corresponds to the distance from the vehicle 1 to the neighbouring traffic lane L2 constitutes a threat, whereby a warning is activated during change of traffic lane. The degree of curvature of the roadway in this case means that the trailer of the vehicle that is located in the traffic lane L1 of the vehicle itself constitutes a threat whereby the blind-spot warning system takes measures when the vehicle 1 intends to carry out a change of traffic lane, and consequently gives an unnecessary warning.

DESCRIPTION OF EMBODIMENTS

In this document, the term "link" refers to a communication link that may be a physical line, such as an opto-electronic communication line, or a non- physical line, such as a wireless connection, for example a radio link or microwave link.

In this document, the term "neighbouring traffic lane" refers to neighbouring traffic lanes for vehicles travelling in the same direction, i.e. traffic lanes in the form of neighbouring lanes in which vehicles travel in the same direction, commonly found on larger roads such as motorways, and to neighbouring traffic lanes for travel in opposing directions, i.e. neighbouring traffic lanes in which oncoming traffic is present in the neighbouring traffic lane and in which overtaking manoeuvres can take place. Thus, in this document, the term "roadway with at least two neighbouring traffic lanes" refers to any appropriate roadway with neighbouring traffic lanes according to the definition above. Thus, the term "roadway with at least two neighbouring traffic lanes" can consequently include a larger road such as a motorway with two or more neighbouring traffic lanes in the form of neighbouring lanes for travel in the same direction, a roadway with two neighbouring traffic lanes for travel in opposing directions, i.e. neighbouring traffic lanes in which oncoming traffic is present in the neighbouring traffic lane and in which overtaking manoeuvres can take place.

Figure 2 illustrates schematically a motor vehicle 1 according to one embodiment of the present invention. The vehicle 1 taken as an example is constituted by a heavy vehicle in the form of a truck with a drawing vehicle 2 and a trailer 4. Alternatively, the vehicle may be a bus or a car. The vehicle comprises a system I to assess the risk of change of traffic lane during the driving of a vehicle on a roadway with at least two neighbouring traffic lanes according to the present invention.

Figure 3 illustrates schematically a block diagram of a system I to assess the risk of change of traffic lane during the driving of a vehicle on a roadway with at least two neighbouring traffic lanes according to one embodiment of the present invention. The system I comprises an electronic control unit 100.

The system I comprises means 1 10 to detect the presence of objects in traffic lanes neighbouring to the traffic lane in which a vehicle is being driven. The means 1 10 to detect the presence of objects in traffic lanes neighbouring to the traffic lane in which a vehicle is being driven may include any appropriate sensor means.

The means 1 10 to detect the presence of objects in traffic lanes neighbouring to the traffic lane in which a vehicle is being driven comprises, according to one variant, radar means. The means 1 10 to detect the presence of objects in traffic lanes neighbouring to the traffic lane in which a vehicle is being driven comprises, according to one variant, camera means. The means 1 10 to detect the presence of objects in traffic lanes neighbouring to the traffic lane in which a vehicle is being driven comprises, according to one variant, lidar means. The means 1 10 to detect the presence of objects in traffic lanes neighbouring to the traffic lane in which a vehicle is being driven comprises, according to one variant, laser scanning means.

The means 1 10 to detect the presence of objects in traffic lanes neighbouring to the traffic lane in which a vehicle is being driven includes sensor means for the detection on the relevant side of the vehicle in order to facilitate the detection of the presence of vehicles that are approaching the vehicle from behind in traffic lanes to the right of the vehicle and in traffic lanes to the left of the vehicle. The vehicle comprises the means 1 10 to detect the presence of objects in traffic lanes neighbouring to the traffic lane in which a vehicle is being driven.

The system I comprises means 200a to determine, based on specifications concerning the extent of a defined traffic lane in which the vehicle is being driven, the extent of at least one neighbouring traffic lane based on continuously determined reference positions at the vehicle relative to the said neighbouring traffic lane in order to determine an action zone extending a specified extent in the said neighbouring traffic lane alongside the vehicle.

Thus the system I comprises means 200 to determine an action zone extending a specified extent in the said neighbouring traffic lanes alongside the vehicle. The means 200 to determine an action zone comprises the means 200a to determine the extent at the said neighbouring traffic lanes.

The means to determine the extent 200a at the said neighbouring traffic lanes comprises means 210 to determine continuously reference positions at the vehicle relative to the neighbouring traffic lane to the traffic lane of the vehicle.

The system I in this case comprises means 210 to determine continuously reference positions at the vehicle relative to the neighbouring traffic lanes to the traffic lane of the vehicle. The means 210 to determine continuously reference positions at the vehicle relative to the neighbouring traffic lanes comprises means 212 to determine continuously the reference positions at predetermined intervals.

According to one embodiment, the predetermined intervals are constituted by intervals of extent. The means 210 to determine continuously reference positions at the vehicle relative to the neighbouring traffic lanes consequently comprises, according to this embodiment, means 212a to determine continuously the reference positions at predetermined intervals of extent. The intervals of extent are constituted by, according to one variant, predetermined distances/extents through which the vehicle has travelled, where the relevant distance/extent is the same. The means 21 0 to determine reference position is in this case arranged to determine continuously a reference position after each such distance/each such extent.

According to one embodiment, the predetermined intervals are constituted by intervals of time. The means 210 to determine continuously reference positions at the vehicle relative to the neighbouring traffic lanes consequently comprises, according to this embodiment, means 212b to determine continuously the reference positions at predetermined intervals of time. The intervals of time are constituted by predetermined intervals of time during which the vehicle has travelled, where each interval of time is the same. The means 210 to determine reference position is in this case arranged to determine continuously a reference position after each such interval of time.

The means 210 to determine continuously reference positions at the vehicle relative to the neighbouring traffic lanes comprises means 214 to determine parameters with respect to the travel of the vehicle. Parameters with respect to the travel of the vehicle include the rate of change of yaw angle and the speed of the vehicle.

The means 210 to determine extent at the said neighbouring traffic lanes consequently comprises means 214 to determine parameters with respect to the travel of the vehicle, which parameters include the rate of change of yaw angle and speed of the vehicle.

The system I thus comprises means 200a to determine extent at the said neighbouring traffic lanes based on parameters with respect to the travel of the vehicle, which parameters include the rate of change of yaw angle and speed of the vehicle.

The rate of change of yaw angle is in this case used as a basis to determine whether, and the extent to which, the traffic lane in which the vehicle is being driven curves, whereby the assumption is made that neighbouring traffic lanes have corresponding curvatures. The means 214 to determine parameters with respect to the travel of the vehicle comprises means 214a to determine the rate of change of yaw angle of the vehicle. The means 214a to determine the rate of change of yaw angle includes at least one gyroscope.

The means 214 to determine parameters with respect to the travel of the vehicle comprises means 214a to determine the speed of the vehicle. The means 214b to determine the speed of the vehicle comprises a speed gauge at the vehicle. The means 210 to determine continuously reference positions at the vehicle relative to neighbouring traffic lanes comprises, according to one variant, navigation means 214c that includes positional data of the current position of the vehicle, and map data that comprises information about the degree of curvature of the relevant route. The means 214 to determine parameters with respect to the travel of the vehicle comprises the said navigation means 214c.

The navigation means 214c may be used as a supplement to the means 214a to determine the rate of change of yaw angle, to achieve redundancy. The determination of the rate of change of yaw angle in order to determine whether the traffic lane curves may be influenced by lurching of the vehicle, where information from the navigation means 214c concerning the degree of curvature of the traffic lane can be used to avoid erroneous assessments on the basis of such lurching. The navigation means 214c may be used also as an alternative to the means 214a to determine the rate of change of yaw angle.

The means 210a to determine extent of the said neighbouring traffic lanes consequently comprises, according to one variant, navigation means 214c that includes positional data of the current position of the vehicle, and map data that comprises information about the degree of curvature of the relevant route.

The system I comprises means 214a to determine the rate of change of yaw angle of the vehicle.

The system I comprises means 214b to determine the speed of the vehicle. The system I comprises the said navigation means 214c.

The means 210 to determine continuously reference positions at the vehicle relative to neighbouring traffic lanes comprises means 216 to determine distance relative to the vehicle. The means 216 to determine distance relative to the vehicle comprises means 216a to determine line markings of neighbouring traffic lanes. The means 216a to determine line markings of neighbouring traffic lanes includes sensor means such as camera means. The means 216 to determine distance relative to the vehicle includes, according to one variant, sensor means. The said sensor means include, according to one variant, camera means.

The means 216 to determine distance relative to the vehicle comprises, according to one variant, means 216b to determine virtual line markings of neighbouring traffic lanes. The means 216b to determine virtual line markings of neighbouring traffic lanes includes means to determine the width of traffic lanes in which the leading vehicle is travelling and/or neighbouring traffic lanes.

The means to determine the width of traffic lanes comprises, according to one variant, navigation means that includes map data with information about the width of traffic lanes at the relevant route, type of route, and information about the current position of the vehicle. The navigation means may be constituted by the navigation means 214c.

The means to determine the width of traffic lanes comprises, according to one variant, sensor means to determine the width of the traffic lane in which the vehicle is travelling, where, according to one variant, the width of the traffic lane at the neighbouring traffic lane is assumed to be the same as the width of the traffic lane in which the vehicle is travelling. The means to determine the width of traffic lanes comprises, according to one variant, predetermined stored information concerning the width of traffic lanes, which information may be stored in the electronic control unit 100.

The system I comprises means 100, 120 to take measures in association with a change of traffic lane, in the event of the presence of objects in the said action zone. The system I comprises means 120 to carry out measures in the event of the determination of the presence of a vehicle that is approaching the vehicle from behind in the said action zone.

The means 120 for taking measures comprises, according to one embodiment, means 122 to warn against a change of traffic lane in the event that such presence is determined. The means 122 of warning against change of traffic lane may be constituted by any suitable warning means at all, such as visual warning means, audible warning means and/or tactile warning means. The visual warning means includes, according to one variant, a display unit and/or a blinking unit or equivalent. The audible warning means includes warning in the form of a voice message and/or warning in the form of a sound alarm. The tactile warning means includes an influence on the steering wheel of the vehicle in the form of vibration/motion and/or influence on the seat of the vehicle in the form of vibration and/or influence on a pedal such as the accelerator pedal or brake pedal.

The means 120 to take measures comprises, according to one embodiment, means 124 to prevent the vehicle from changing traffic lanes or to make it more difficult for the vehicle to change traffic lanes in the event that such a presence has been determined. The means 124 to prevent or make it more difficult to change traffic lanes includes an influence on the control of the vehicle such as a change of steering wheel position in the direction towards the neighbouring traffic lane in which the risk is present. The means 120 for taking measures comprises, according to one variant, the electronic control unit 100. The electronic control unit 100 is connected such that it exchanges signals over a link 1 1 with the means 1 10 to detect the presence of objects in traffic lanes neighbouring to the traffic lane in which a vehicle is being driven. The electronic control unit 100 is arranged such that it receives through the link 1 1 a signal from the means 1 10 that represents vehicle data about the presence of vehicles that are approaching the vehicle from behind. The electronic control unit 100 is connected such that it exchanges signals over a link 20 with the means 200 to determine an action zone extending in neighbouring traffic lanes a specified extent backwards from the vehicle. The electronic control unit 100 is arranged to receive a signal over the link 20 from the means 200 representing action zone data for the action zone that has been determined extending backwards alongside the vehicle in neighbouring traffic lanes.

The electronic control unit 100 is connected such that it exchanges signals over a link 20a with the means 200a to determine the extent of the said neighbouring traffic lanes. The electronic control unit 100 is arranged to receive a signal over the link 20a from the means 200a representing extent data for the extent of neighbouring traffic lanes for the determination of the action zone backwards from the vehicle.

The electronic control unit 100 is connected such that it exchanges signals over a link 21 with the means 210 to determine continuously reference positions at the vehicle relative to traffic lanes neighbouring the traffic lane of the vehicle. The electronic control unit 100 is arranged to receive a signal over the link 21 from the means 210 representing reference position data for the reference positions to determine the extent of neighbouring traffic lanes for the determination of the action zone backwards from the vehicle.

The electronic control unit 100 is connected such that it exchanges signals over a link 22 with the means 212 means to determine continuously the reference positions at predetermined intervals. The electronic control unit 100 is arranged to receive a signal over the link 22 from the means 21 2 representing reference position data in order to determine continuously the reference positions at predetermined intervals, where the interval may be an interval of extent determined by means of the means 212a or an interval of time determined by means of the means 212b. In this case, reference position data for intervals of extent or intervals of time are received over the link 22. According to variant that is not shown here, it would be possible for the electronic control unit 100 to receive reference position data for intervals of extent from the means 212a over one link, and reference position data for intervals of time from the means 212b over a second link.

The electronic control unit 100 is connected such that it exchanges signals over a link 24a with the means 214a to determine the rate of change of yaw angle of the vehicle. The electronic control unit 100 is arranged to receive a signal over the link 24a from the means 214a representing rate of change of yaw angle data for the determination of any curvature of the traffic lane in which the vehicle is travelling. The electronic control unit 100 is connected such that it exchanges signals over a link 24b with the means 214b to determine the speed of the vehicle. The electronic control unit 100 is arranged to receive over the link 24b a signal from the means 214b that represents speed data for the speed of the vehicle. The electronic control unit 100 is connected such that it exchanges signals over a link 24c with the navigation means 214c. The electronic control unit 100 is arranged to receive a signal over the link 24c from the navigation means 214c representing map data for the width of the traffic lane in which the vehicle is travelling, including any curvature of the traffic lane that may be present.

The electronic control unit 100 is connected such that it exchanges signals over a link 26a with the means 216a to determine line markings of neighbouring traffic lanes. The electronic control unit 100 is arranged to receive a signal over the link 26a from the means 216a representing distance data for the distance to line markings of neighbouring traffic lanes.

The electronic control unit 100 is connected such that it exchanges signals over a link 26b with the means 216b to determine virtual line markings of neighbouring traffic lanes. The electronic control unit 100 is arranged to receive a signal over the link 26b from the means 216b representing distance data for the distance to virtual line markings of neighbouring traffic lanes.

The electronic control unit 100 is connected such that it exchanges signals over a link 12 with the means 120 to carry out measures in the event of the determination of the presence of a vehicle that is approaching the vehicle from behind in the said action zone. The electronic control unit 100 is arranged to transmit over the link 1 2 a signal to the means 120 representing action data, including warning data about the warning against change of traffic lane for the vehicle and/or impediment data in order to prevent or make more difficult change of traffic lane at the vehicle.

The electronic control unit 100 is arranged to process the said reference position data, rate of change of yaw angle data, speed data, and, where relevant, map data, distance data for line markings or virtual line markings in order to determine action zone data for action zones extending in neighbouring traffic lanes backwards from the vehicle, and to compare the action zone data with the said vehicle data for the presence of vehicles that are approaching the vehicle from behind in order to determine whether the vehicle that is approaching the vehicle from behind vehicle is present in the said action zone. If the vehicle that is approaching the vehicle from behind is present in the said action zone, the control unit is arranged to transmit to the means 120 action data, including warning data for the warning against change of traffic lane for the vehicle and/or impediment data in order to prevent or make more difficult change of traffic lane at the vehicle.

The reference positions are determined by means of the means 210 to determine continuously reference positions. The means 210 to determine reference positions continuously is determined, according to one embodiment, by means of the following equations:

D _x (t) = D _x (t-t _s ) - cos (t _s *u))*ts*v (1 )

Dy(t) = D _y (t-t _s ) - sin (t _s *u))*ts*v (2) where the x-axis concerns positive values forwards in the direction of the leading vehicle, and the y-axis concerns positive values to the right in the direction of the leading vehicle.

The following definitions apply for Equations (1 ) and (2) above: D denotes the distance [m] to line marking from a reference point at the leading vehicle 1 , where such a reference point at the leading vehicle may be constituted by, for example, the central point of the rear axle, the central point of the front axle, the central point of the front of the vehicle or equivalent, v denotes the speed of the leading vehicle [m/s], ω denotes the rate of change of yaw angle of the leading vehicle (rad/s), and t _s denotes the sampling time for updating of reference positions.

During the continuous determination of the reference positions with predetermined intervals of extent, a new reference position is created regularly after a predetermined extent. During the continuous determination of the reference positions with predetermined time intervals, a new reference position is created regularly after a predetermined time.

Figure 4 illustrates schematically the driving of a leading vehicle 1 with a drawing vehicle 2 and a trailer 4 on a roadway R1 with two neighbouring traffic lanes L1 , L2, where reference positions relative to traffic lanes that are neighbouring to the vehicle have been determined. In this case, the presence of objects in traffic lanes neighbouring to the traffic lane in which a vehicle 1 is being driven is intended to be detected according to one embodiment of the present invention. Figure 4 illustrates in this case a list of reference positions D _L AI , D _L BI ; D _L A2, DI_B2; D|_A3, D|_B3; D|_A4, D|_B4 determined by means of Equations (1 ) and (2) above. The reference positions D _L AI , D _L BI ; DLA2, D _L B2! D _L A3, D _L B3; D _L A4, D _L B4 according to Figure 4 have been determined by means of a system I according to the present invention. An appropriate number N of reference positions D _L AI , D _L BI ; D _L A2, D _L B2! D _L A3, DLBS; D _L A4, D _L B4 in the form of reference points D _LA i, DLBI ! D _LA 2, D _LB 2; D _LA 3, DLB3! D _L A4, D _L B4 is in this case determined. The distances to the line markings M1 , M2 are here determined for the line marking M1 immediately to the right of the vehicle 1 and the next line marking M2 to the right, i.e. the line markings M1 , M2 defining the traffic lane L2 that is neighbour to the traffic lane L1 in which the vehicle 1 is travelling. This takes place continuously, whereby the oldest reference positions are overwritten when the desired number N of reference positions has been determined. The reference positions D _L AI , D _L A2, D _L A3, D _L A4, D _L B4 represent continuously determined distances to the line markings M1 immediately to the right of the leading vehicle 1 , and the reference positions D _L BI , D _L B2, D _L B3, D _L B4 the line markings M2 to the right of the line markings M1 . An action zone is in this case continuously determined by means of the reference positions D _L AI , DLBI ; D _L A2, D _L B2; DLAS, DLBS; D _L A4, D _L B4 as is made clear by Figure 5.

Figure 5 illustrates schematically the driving of a vehicle 1 with a drawing vehicle 2 and a trailer 4 travelling in the direction of the arrow P1 on a roadway R2 with two neighbouring traffic lanes L1 , L2, according to the present invention. The roadway R2 and the scenario correspond to that illustrated in Figure 1 .

An action zone Z2 is here determined based on continuously determined reference positions according to the present invention. By means of the system I according to the present invention, it is determined that the trailer 4 of the vehicle 1 is not located in the action zone Z2 that has been determined whereby no measures are taken during change of traffic lane, in contrast to the prior art technology according to Figure 1 in which unnecessary warning takes place during change of traffic lane.

Figure 6 illustrates schematically a block diagram of a method to assess the risk of change of traffic lane during the driving of a vehicle on a roadway with at least two neighbouring traffic lanes according to one embodiment of the present invention.

According to one embodiment, the method to assess the risk of change of traffic lane during the driving of a vehicle on a roadway with at least two neighbouring traffic lanes comprises a first step S1 . The presence of objects in traffic lanes neighbouring to the traffic lane in which the said vehicle is being driven is detected in this step.

According to one embodiment [missing text "the method"] to assess the risk of change of traffic lane during the driving of a vehicle on a roadway with at least two neighbouring traffic lanes, comprises a second step S2. The extent of at least one neighbouring traffic lane is determined in this step based on specifications concerning the extent of a defined traffic lane in which the vehicle is being driven, based on continuously determined reference positions at the vehicle relative to the said neighbouring traffic lane in order to determine an action zone extending a specified extent in the said neighbouring traffic lanes alongside the said vehicle [something strange in the source texte here!].

According to one embodiment, the method to assess the risk of change of traffic lane during the driving of a vehicle on a roadway with at least two neighbouring traffic lanes comprises a third step S3. In this step, measures are taken in association with the change of traffic lane [and again!], in the event of the presence of objects in the said action zone.

With reference to Figure 7, there is shown a drawing of a design of an arrangement 500. The control unit 100 that has been described with reference to Figure 3 can comprise in one execution the arrangement 500. The arrangement 500 comprises a non-transient memory 520, a data processing unit 510 and a read/write memory 550. The non-transient memory 520 has a first section of memory 530 in which a computer program, such as an operating system, is stored in order to control the function of the arrangement 500. Furthermore, the arrangement 500 comprises a bus controller, a serial communication port, I/O means, an A D converter, a unit for the input and transfer of time and date, an event counter and an interrupt controller (not shown in the drawing). The non-transient memory 520 has also a second section of memory 540.

There is provided a computer program P that comprises routines to assess the risk of change of traffic lane during the driving of a vehicle on a roadway with at least two neighbouring traffic lanes. The program P comprises routines to detect the presence of objects in traffic lanes neighbouring to the traffic lane in which the said vehicle is being driven [and again!]. The program P comprises routines to determine, based on specifications concerning the extent of a defined traffic lane in which the vehicle is being driven, the extent of at least one neighbouring traffic lane based on continuously determined reference positions at the vehicle relative to the said neighbouring traffic lane in order to determine an action zone extending a specified extent in the said neighbouring traffic lane alongside the said vehicle. The program P comprises routines to take measures in association with a change of traffic lane, in the event of the presence of an object in the said action zone [and again!]. The program P may be stored in an executable form or in a compressed form in a memory 560 and/or a read/write memory 550.

When it is described that the data processing unit 510 carries out a certain function, it is to be understood that the data processing unit 510 carries out a certain part of the program that is stored in the memory 560, or a certain part of the program that is stored in the read/write memory 550. The data processing arrangement 510 can communicate with a data port 599 through a data bus 515. The non-transient memory 520 is intended for communication with the data processing unit 510 through a data bus 512. The separate memory 560 is intended to communicate with the data processing unit 510 through a data bus 51 1 . The read/write memory 550 is arranged to communicate with the data processing unit 510 through a data bus 514. Links associated with the control units 200; 300, for example, may be connected to the data port 599.

When data is received at the data port 599 it is temporarily stored in the second section of memory 540. When the data that has been received has been temporarily stored, the data processing unit 510 is prepared for the execution of code in a manner that has been described above. The signals that have been received at the data port 599 can be used by the arrangement 500 to detect the presence of objects in traffic lanes neighbouring to the traffic lane in which the said vehicle is being driven . The signals that have been received at the data port 599 can be used by the arrangement 500 to determine, based on specifications concerning the extent of a specified traffic lane in which the vehicle is being driven, the extent of at least one neighbouring traffic lane based on continuously determined reference positions at the vehicle relative to the said neighbouring traffic lane in order to determine an action zone extending a specified extent in the said neighbouring traffic lane alongside the said vehicle. The signals that have been received at the data port 599 can be used by the arrangement 500, in the event of the presence of objects in the said action zone, to take measures in association with a change of traffic lane. Parts of the methods described here may be carried out by the arrangement 500 with the aid of the data processing unit 510, which runs the program stored in the memory 560 or in the read/write memory 550. When the arrangement 500 runs the program, the method described here is executed.

The description above of the preferred embodiments of the present invention has been given for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the variants that have been described. Many modifications and variations will be obvious for one skilled in the arts. The embodiments have been selected and described in order to best describe the principles of the invention and its practical applications, and thus to make it possible for one skilled in the arts to understand the invention for various embodiments and with the various modifications that are appropriate for the intended use.