WO2014204381A1

WO2014204381A1 - System and method for support for change of lane

Info

Publication number: WO2014204381A1
Application number: PCT/SE2014/050711
Authority: WO
Inventors: Tony Sandberg
Original assignee: Scania Cv Ab
Priority date: 2013-06-20
Filing date: 2014-06-12
Publication date: 2014-12-24
Also published as: SE538365C2; SE1350753A1

Abstract

A method and a system that implements the method for a first vehicle in order to support change of lane from one lane A to a neighbouring lane B with the same direction of travel. The method comprises receiving data related to a second vehicle behind the first vehicle and recognising that the second vehicle desires to overtake the first vehicle based on the data that has been received. Data is received that indicates the presence of vehicles in lane B and to determine at least one parameter X that specifies a space U₁for the first vehicle in lane B based on the data. The parameter X is compared with a limiting value k₁that includes a length of the first vehicle, and, if the parameter X is greater than the limiting value, a parameter Y is determined that indicates when the second vehicle has overtaken the first vehicle based on the condition that the first vehicle changes lane to the space U₁ in lane B and maintains its speed v₁. It is subsequently determined whether the first vehicle can maintain its speed v₁ in the space U₁ until the second vehicle has overtaken the first vehicle, based on the parameter Y, and, if this is possible, to generate a lane-change signal s_f that indicates the space U₁.

Description

System and method for support for change of lane Technical area

The present invention relates to a system and a method for a vehicle for support for a change of lane according to the introductions to the independent claims, and in particular in cases in which a rearward vehicle desires to overtake.

Background to the invention

Traffic is becoming evermore dense on our roads, which has a negative influence on the flow of traffic and more traffic queues arise. In order to solve the problem, ever greater numbers of motorways are being built, with ever increasing numbers of lanes. These are not, however, used to their full capacity since drivers tend to avoid the lane that is farthest to the right (when traffic drives on the right side of the road), and dense traffic instead builds up in the lane to the left, which is to be the lane for fastest travel, which makes it also the most dangerous.

Changing lanes places high demands on the driver of a vehicle. The driver must maintain an overview backwards and to the side, while at the same time continuing to maintain an overview forwards. This requires more energy than simply continuing to drive straight on. Each driver appears to make choices based on what is most comfortable for the driver himself or herself. In addition, many drivers experience a large loss of prestige in manoeuvring to allow someone else to overtake, in particular if this involves the risk that the driver himself or herself becomes trapped in the slower right lane. It is difficult for drivers to make the correct decisions. It is necessary to estimate one's speed relative to the slower vehicles in the right lane, and it is necessary to estimate the relative speed of the vehicle that is approaching from the rear in the lane in which the driver is driving. Finally, it is necessary to decide whether to change lane and whether the rearward vehicle will have the time required to overtake before one's own vehicle has caught up with the vehicle in the right lane. The result may be that one remains in the fast lane, since one is not able to assess the situation sufficiently well, even though a change of lane would have facilitated the flow of traffic while at the same time no loss of time or adoption of a lower speed would have been necessary for the driver's own vehicle.

Several different known systems are available to help a driver drive a vehicle in a safe manner, such as warning systems for deviation from a lane, intelligent speed support, etc. For example, a system is known from DE-102007033887-A1 to help the driver change lane from the left to the right lane. The system detects whether a vehicle is approaching from behind at high speed, or whether the distance to the vehicle behind is short, which may indicate that the vehicle behind wants to overtake. The system determines when it is appropriate to change lane to the right lane, taking into consideration the safety distance to the vehicles in the right lane, and it suggests this to the driver in order to avoid a dangerous situation arising with the vehicle behind. The system, however, considers only the safety distance to the vehicles in the right lane, and does not consider whether the vehicle that is to change lanes will be disadvantaged by changing lanes.

The purpose of the invention, therefore, is to provide support to the driver of a vehicle for change of lane, which support is primarily based on the consequences of a change of lane for the driver's own vehicle.

Summary of the invention

According to a first aspect, the purpose is achieved with a method for a first vehicle in order to support change of lane from one lane A to a neighbouring lane B with the same direction of travel, whereby the method comprises:

- to receive data related to a second vehicle behind the first vehicle,

- to recognise that the second vehicle desires to overtake the first vehicle, based on the data that has been received, whereby the first vehicle has a speed of v-_\ and is located in lane A,

- to receive data that indicates that vehicles are present in file B, - to determine at least one parameter X related to a space Ui for the first vehicle in lane B based on the data that indicates the presence of vehicles in lane B,

- to compare the parameter X with a limiting value ^ that includes a length of the first vehicle, and, if the parameter X is greater than the limiting value:

- to determine a parameter Y that indicates when the second vehicle has overtaken the first vehicle based on the condition that the first vehicle changes lane to the space Ui in lane B and maintains its speed vi ,

- to determine whether the first vehicle can maintain its speed vi in the space Ui until the second vehicle has overtaken the first vehicle, based on the parameter Y, and, if this is possible,

- to generate a lane-change signal s_f that indicates the space Ui.

The driver of the first vehicle can, through the method, obtain support in the decision whether to change lane such that a rearward vehicle can overtake. The driver can, through the method, determine whether it is possible to change lane and to allow the rearward vehicle to overtake, without having to reduce the speed of his or her own vehicle before it is possible to return to the previous lane.

According to one embodiment, also the first vehicle may also be instructed to carry out the change of lane automatically.

The driver of the first vehicle may, thus, be encouraged to carry out the change of lane since the driver knows that he or she will not lose anything by carrying out the change. The rearward vehicle may thus continue in its lane without reducing speed, and the formation of traffic queues in this lane can be avoided. The first vehicle can maintain its speed also in the second lane, and the formation of queues can be avoided also there. A higher flow of traffic can be achieved, and the various lanes along the road are exploited more efficiently. The vehicles can to a large extent maintain their speeds unchanged, which gives more even speeds, which reduces fuel consumption. Since the rearward vehicle can continue onwards, a possibly dangerous situation that may arise when the rearward vehicle approaches too close to the first vehicle is avoided. According to a second aspect, the purpose is achieved with a system for a first vehicle in order to support change of lane from one lane A to a neighbouring lane B with the same direction of travel. The system comprises a first control unit and a memory unit that is configured to store instructions in order to cause the first control unit:

- to receive data related to a second vehicle behind the first vehicle,

- to receive data that indicates that vehicles are present in file B,

- to determine at least one parameter X related to a space Ui for the first vehicle in lane B based on the data that indicates the presence of vehicles in lane B,

- to compare the parameter X with a limiting value ki that includes a length of the first vehicle, and, if the parameter X is greater than the limiting value:

- to determine whether the first vehicle can maintain its speed in the space Ui until the second vehicle has overtaken the first vehicle, based on the parameter Y, and, if this is possible,

- to generate a lane-change signal s_f that indicates the space Ui.

According to one embodiment, two or more of the vehicles that are here described are equipped for vehicle-to-vehicle (V2V) communication, and are thus able to transfer signals between them in a wireless manner. According to another embodiment, one or several of the vehicles that are here described are equipped for vehicle-to/from-infrastructure (V2I) communication, and it is thus possible to transfer signals in a wireless manner between such a vehicle and infrastructure in the form of, for example, a roadside unit.

Preferred embodiments are described in the non-independent claims and in the detailed description. Brief description of the attached drawings

The invention will be described below with reference to the attached drawings, of which:

Figure 1 shows a system according to one embodiment of the present invention. Figure 2 shows a method according to one embodiment of the invention.

Figures 3A-3D show different situations for the change of lane.

Detailed description of preferred embodiments of the invention

Figure 1 shows a system 6 for a first vehicle 1 to support change of lane. The system 6 will now be described with reference to this drawing. Term "lane" is here used to denote a lane along a roadway. The later drawings 3A-3D show examples of a road with two lanes, one lane A and a neighbouring lane B with the same direction of travel, on which road the system 6 can be used to support change of lane. The system 6 may be entirely located inside the first vehicle 1 , or it may be partially located in a roadside unit or in another computer unit located at a distance from the first vehicle 1 , and partially inside the first vehicle 1 . The vehicle 1 may be, for example, a car. The units in the system 6 may, for example, communicate with each other through a local network in the vehicle, for example over a CAN bus (Computer Area Network) or a LIN bus (Local Interconnect Network).

As is shown in Figure 1 , the system comprises a first control unit 7 and a memory unit 8. The control unit 7 may be, for example, an ECU (Electronic Control Unit). The control unit 7 comprises some form of processor, such as a CPU (Central Processing Unit). The memory unit 8 includes, for example, a non-transient computer memory such as a flash memory. The memory unit 8 is configured to store instructions in order to cause the control unit 7 to carry out a number of steps. The memory unit 8 stores, according to one embodiment, a computer program P, where the computer program P comprises program code in order to cause the control unit 7 to carry out any one of the steps that will be described below. The control unit 7 and the memory unit 8 may be separate units that are connected to each other, or the memory unit 8 may be incorporated into the control unit 7.

The control unit 7 is configured to received data from one or several units 1 1 , 12. According to one embodiment, the system 6 comprises a receiver unit 12 that is configured to receive wireless signals s_w from at least one of vehicles and roadside units, and to generate data s_t for the first control unit 7. Either a wireless signal or data s_t, or both a wireless signal and data, may, for example, contain information about the position p_x of the vehicle, its speed v_x, and its identity id_x, or it may contain a message from one or several vehicles. It may contain such information about the vehicle (position, speed, identity) and a message from one or several vehicles. The system 6 may also or instead comprise one or several detector units 1 1 that are configured to detect one or several vehicles in the surroundings of the first vehicle, and to generate data s_d that indicates one or several characteristics of the vehicle or vehicles. A characteristic may be, for example, a relative position Δρ or a relative speed Δν.

The first control unit 7 may obtain information about the position p-_\ of the first vehicle through a positioning unit 13 that uses, for example, GPS, the Global Positioning System. The speed v-_\ of the first vehicle 1 can be obtained through, for example, the network of the vehicle 1 .

Thus, the memory unit 8 is configured to store instructions in order to cause the first control unit 7 to receive data s_t, s_d related to a second vehicle 2 behind the first vehicle 1 , and further to recognise that the second vehicle 2 desires to overtake the first vehicle 1 based on the data that has been received. The first control unit 7 is configured to recognise that the rearward second vehicle 2 desires to overtake by analysing the data that has been received. For example, a distance between the first vehicle 1 and the second vehicle 2 can be determined, and in the case in which the distance is less than a limiting value k₂, it is recognised that the second vehicle 2 desires to overtake. Another alternative is to determine that the second vehicle 2 is approaching the first vehicle 1 . This can be carried out by determining a relative difference in speed between the first vehicle 1 and the second vehicle 2, and in the case in which the difference in speed is greater that a limiting value k₃, it is recognised that the second vehicle 2 desires to overtake. The limiting values k₂ and k₃ are adapted, according to one

embodiment, to the speed of the vehicle 1 . A further alternative is to compare the cruise-control speeds of the vehicles 1 , 2, and to determine whether the second vehicle 2 has a higher cruise-control speed than the first vehicle 1 . In the case in which the second vehicle 2 has a higher cruise-control speed than that of the first vehicle, it is recognised that the second vehicle desires to overtake. A further alternative is to receive a message from the second vehicle 2 that it desires to overtake. This message and the cruise-control speed of the second vehicle 2 can be received through, for example, V2V or V2I communication. The alternatives that have been described may, of course, be combined in order to recognise with greater reliability that the second, rearward, vehicle desires to overtake the first vehicle 1 .

The memory unit 8 is further configured to store instructions in order to cause the first control unit 7 to receive data s_t, s_d from at least one of the reception unit 12 and the detector unit 1 1 that indicates the presence of vehicles in lane B, and to determine at least one parameter X related to a space Ui for the first vehicle 1 in lane B based on the data that indicates the presence of vehicles in lane B.

According to one embodiment, the first control unit 7 is configured to identify a positional parameter p₃, p₄ for each one of at least two consecutive vehicles 3, 4 in lane B based on the data that indicates the presence of vehicles in lane B. The parameter X can then be calculated as the distance between the positional parameters p₃, p₄ that indicates also the space Ui between the two vehicles 3, 4.

According to one embodiment, all spaces Ui_..k between all k+1 vehicles that may be present in lane B along a predetermined distance, for example 2 km forwards along the road seen from the first vehicle 1 , are determined. The sizes and positions of the spaces Ui_..k are determined. This can be determined by receiving data about several k+1 vehicle positions, and subsequently calculating the distances, and thus also the sizes of the spaces Ui_..k, between the vehicles based on data about the vehicle positions. The data may contain also information about, for example, the lengths of the vehicles. The lengths of the vehicles can then be subtracted from the calculated distances in order to obtain a more exact calculation of the sizes of the spaces L._k. Alternatively, a standard value can be subtracted from the distances. The positions of the spaces Ui_..k can subsequently be determined as the start and end of the relevant space Ui_..k. The starts and ends of the spaces may be constituted by the positions of the vehicles that limit the spaces, or the positions of the vehicles adjusted for the lengths of the vehicles. A GPS receiver in the form of, for example, a positioning unit 13 is normally positioned in the forward part of the vehicle and thus this specifies the position of the forward part of the vehicle. The position of the rear part of the vehicle can then be determined using data about the length of the vehicle. The system 6 can in this way maintain an overview of all spaces along the stretch and can determine where it is possible for the first vehicle 1 to carry out change of lane according to the invention. The memory unit 8 may contain map data that describes the road, and the positions of the vehicles can then be related to the road. In cases in which no vehicles are present on the predetermined distance of road, X can be specified as the size of the predetermined distance. The spaces Ui_..k can instead be determined as they pass through the process of evaluation. In the case in which a space most closely adjacent to the first vehicle 1 is assessed to be too small, the next space forward in the direction of travel can be evaluated, etc. In cases in which the first vehicle 1 is located in lane A parallel to the space Ui in lane B, the parameter X is determined as the distance from the first vehicle 1 to the forward part of the vehicles that limit the space Ui . The system 6 in this way can take into consideration the location of the first vehicle 1 relative to the space Ui .

The control unit 7 is further configured to compare the parameter X with a limiting value ki that includes a length of the first vehicle 1 . The limiting value ki includes, according to one embodiment, also a safety distance to the vehicle or vehicles 3, 4 in lane B. The limiting value ki can be of a predetermined magnitude, or it may be adapted depending on the speed and length of the vehicles. If the parameter X is greater that the limiting value ki , the first vehicle 1 will fit into the space Ui , and in this case a number of further steps according to the method are carried out. A parameter Y is determined that indicates when the second vehicle 2 has overtaken the first vehicle 1 based on the condition that the first vehicle 1 changes lane to the space Ui in lane B and maintains its speed vi . It is possible in this way to know at least one of the time t₂ and the position p₂ of the second vehicle 2 when the second vehicle 2 has overtaken the first vehicle 1 , and the parameter Y can indicate this. Alternatively, the parameter Y may comprise a period of time At₂ or a distance s₂ that the second vehicle 2 has travelled until it has overtaken the first vehicle 1 .

According to one embodiment, the first control unit 7 is configured to determine a target speed v_a for the second vehicle 2. The parameter Y can then be determined based on at least the target speed v_a and the speed vi of the first vehicle 1 , which is to be maintained. The target speed v_a may be, for example, the speed v₂ of the second vehicle 2, or an upper speed limit that is permitted on the road. The control unit 7 may also be configured to determine a speed ramp for the speed v₂ of the second vehicle. It is possible that it has been necessary for the second vehicle 2 to adapt its speed to the speed of the first vehicle 1 , and that it will increase its speed when it is to overtake the first vehicle 1 . By including in this case a gradual increase of the speed of the second vehicle up to the target speed v_a, a more correct determination of at least one of the time and position at which the second vehicle 2 has overtaken the first vehicle 1 can be made, alternatively a more correct determination of At₂ or the distance s₂ that the second vehicle has travelled until it has overtaken the first vehicle 1 from the condition at which the second vehicle can start the overtaking manoeuvre can.

The first control unit 7 is furthermore configured to determine whether the first vehicle 1 can maintain its speed v-_\ in the space Ui until the second vehicle 2 has overtaken the first vehicle 1 , based on the parameter Y, and, if this is possible, to generate a lane-change signal s_f that indicates the space Ui . The lane-change signal s_f may contain information about the position and size of the space.

According to one embodiment, the first control unit 7 is configured to determine a parameter Z that indicates how long the first vehicle 1 can be driven at speed v-_\ without needing to reduce its speed when it has changed lane to the space Ui in lane B. Z can be determined is several different ways. The first control unit 7, for example, may be configured to determine how the size of the space Ui changes with time, based on the speeds v₃ and v₄ of the vehicles 3, 4 in lane B, and the distance between them. The position p-_\ of the first vehicle 1 relative to the space Ui can be determined with time, and in this way the duration of a period Ati during which the first vehicle can travel in the space Ui without colliding with the vehicle that constitutes the forward limit of the space Ui in the direction of travel of the vehicle. The parameter Z can thus be determined to be Ati . The parameter Z can instead be determined to be a time t_s or position p_s for the first vehicle 1 at which the first vehicle 1 after the time t_s or at the position p_s can no longer be driven while retaining its speed in lane B.

The first control unit 7 is subsequently configured to compare the parameter Y with the parameter Z, and to generate a lane-change signal s_f that indicates the space Ui , depending on the result of the comparison. It is here a necessary condition that the parameters Y and Z are of the same dimension, such as time. In the case in which, for example, Y is At₂ and Z is ΔΤι , and, when At₂ is compared with ΔΤι it becomes apparent that ΔΤ^ Δί₂, the first vehicle 1 can travel in the space Ui while retaining its speed v-_\ until the second vehicle 2 has overtaken the first vehicle 1 , and the first vehicle 1 can then return to lane A. A lane-change signal s_f is then generated that indicates the space Ui .

Alternatively, the control unit 7 may be configured to determine whether it is possible for the first vehicle 1 to travel to Z, in the case in which Z is a position p₂ or a time t₂, without needing to reduce its speed in order to avoid a collision. If this is possible, a lane-change signal Sf is generated that indicates the space Ui . According to one embodiment, the system 6 comprises an indicator unit 9 that is configured to receive a lane-change signal s_f and to indicate the space Ui to the driver of the first vehicle 1 . The indication may comprise the location of the space Ui in the form of at least one of positions of the space Ui and a relative distance between the first vehicle 1 and the space Ui. The indication may comprise also the time or position at which the first vehicle 1 can drive into the space Ui . This may be an advantage in the case in which the space Ui is located a certain distance in front of the first vehicle 1 .

According to another embodiment, or as a supplement to the indication that has been described above, the first control unit 7 is configured to transmit the lane- change signal s_f to a second control unit 10 in the first vehicle 1 , whereby the second control unit 10 at least partially automatically controls the first vehicle 1 to carry out the change of lane from lane A to the space Ui in lane B. The second control unit 10 is in this case configured to generate control signals for, for example, a cruise-control system and a control system in the first vehicle 1 .

The memory unit 8 may comprise also map data, and the first control unit 7 may be configured to retain information about the locations of the vehicles 1 , 2, 3, 4, 5, etc. relative to each other along the road, and the lanes in which they are driving.

Figure 2 shows a flow diagram for a method for the first vehicle 1 , and Figures 3A- 3B show an example of a scenario in which the method can be used. The method will now be described with reference to these drawings. Two neighbouring lanes A and B with the same direction of travel along a road are shown in Figures 3A and 3B. Figure 3A shows the first vehicle 1 driving along lane A with a speed vi at position A second vehicle 2 that has speed v₂ at position p₂ approaches behind the first vehicle 1 . According to the flow diagram in Figure 2, data related to the second vehicle 2, which is behind the first vehicle 1 , is received (A1 ). Based on the data that has been received, it is recognised that the second vehicle 2 desires to overtake the first vehicle 1 (A2). As has previously been described, this can be carried out in various manners, for example, by receiving a message from the second vehicle 2 over wireless communication that the second vehicle 2 desires to overtake the first vehicle 1 . If it is recognised that the second vehicle 2 desires to overtake, data is received that indicates the presence of vehicles in lane B (A3). Figures 3A and 3B illustrate two vehicles 3, 4, and these are illustrated in Figure 3A with a space Ui between them. The data may, for example, indicate the positions p₃, p₄ of the vehicles 3, 4. The data may indicate also the speeds v₃, v₄, respectively, of the vehicles 3, 4. Also this data may be received through wireless communication. Based on the data that has been received that indicates the presence of vehicles in lane B, at least one parameter X related to the space U1 for the first vehicle 1 in lane B is determined (A4). This may be carried out by identifying a positional parameter p₃, p₄ for each of the, at least two, consecutive vehicles 3, 4 in lane B based on the data, and calculating the parameter X as the distance between the positional parameters p₃, p₄ that also indicate the space Ui between the two vehicles 3, 4. The distance between the positions p₃ and p₄ of the vehicles 3, 4 can thus be determined, and in this way also the space between the vehicles 3, 4 in the direction of travel of the vehicles, which is illustrated by an arrow in the drawings. The parameter X is after this compared with a limiting value k^ that includes a length of the first vehicle 1 (A5). The limiting value k^ may be, for example, a distance that comprises the length of the first vehicle 1 plus safety distance to the vehicles 3, 4 that limit the space Ui . If the parameter X is greater that the limiting value ki , the first vehicle 1 will fit into the space Ui . If the parameter X is less than or equal to the limiting value ki the space Ui is considered to be insufficiently large for it to be possible for the first vehicle 1 to drive into it. If X is greater than ki , and thus the first vehicle 1 will be able to fit into the space Ui , a parameter Y is determined that indicates when the second vehicle 2 has overtaken the first vehicle 1 based on the condition that the first vehicle 1 changes lane to the space Ui in lane B and maintains its speed vi (A6). Figure 3B illustrates the scenario in which the first vehicle 1 has driven into the space Ui in lane B and the second vehicle 2 has overtaken the first vehicle in lane A. Thus Y may be at least one of the position p₂ of the second vehicle 2 and the time t₂ at which it is calculated that the second vehicle 2 will have overtaken the vehicle 1 . According to one embodiment, also a safety distance between the first and the second vehicles 1 , 2 is added such that the first vehicle 1 will be able to drive out again safely into lane A without the risk of coming into a dangerous situation with the second vehicle 2. According to the flow diagram, it is now determined whether the first vehicle can maintain its speed vi in the space Ui until the second vehicle 2 has overtaken the first vehicle 1 , based on the parameter Y (A7), and, if this is possible, a lane-change signal s_f is generated that indicates the space Ui (A8). If it is not possible, the method returns to step A1 . The step A7 may comprise the determination of a parameter Z that indicates how long the first vehicle 1 can be driven with the speed vi without needing to reduce its speed when it has changed lane to the space Ui in lane B. This has previously been explained in association with the system 6 (Figure 1 ) and the reader is referred to this in order to obtain an example. The parameter Y may indicate, for example, a time ti or a position p₂ of the second vehicle 2.

According to this embodiment, the parameter Y is subsequently compared with the parameter Z, and a lane-change signal s_f that indicates the space Ui is generated, depending on the result of the comparison. In the case in which the comparison shows that the first vehicle 1 can maintain its speed in the space Ui until the second vehicle 2 has overtaken, a lane-change signal s_f that indicates the space Ui is generated.

According to one embodiment, the space Ui is indicated to the driver of the first vehicle 1 . The driver can then choose to carry out the change of lane. According to another or supplementary embodiment, the lane-change signal s_f is transmitted to a control unit 10 in the first vehicle 1 , whereby the control unit 10 at least partially automatically controls the first vehicle 1 to carry out the change of lane from lane A to the space Ui in lane B.

According to the flow diagram, it is now determined whether the first vehicle 1 can maintain its speed v-_\ in the space Ui until the second vehicle 2 has overtaken the first vehicle 1 based on the parameter Y (A7), and, if this is possible, a lane- change signal s_f is generated that indicates the space Ui (A8). If it is not possible, the method returns to step A1 .

Figure 3C shows an example in which the first vehicle 1 is not able to maintain its speed in the space Ui in lane B until the second vehicle 2 has overtaken the first vehicle 1 . The space Ui is sufficiently large to accommodate the first vehicle 1 , but it is too small for the second vehicle 2 to have sufficient time to overtake before the first vehicle 1 has caught up with the forward vehicle 3 that limits the space Ui . The speed v₃ of the forward vehicle 3 is also too low relative to speed that the first vehicle 1 desires to maintain. Thus step A7 can be determined based on the parameter X, the speed v₃ of the forward vehicle 3 and the speed v-_\ that the first vehicle 1 desires to maintain.

Figure 3D shows an example in which several vehicles 2, 5, 6 that desire to overtake the first vehicle 1 are present in lane A. In the case in which V2V or V2I communication is used, also the vehicles 5, 6 that are located behind the second vehicle 2 can be discovered. The step A6 can in this case be extended to determine when also these vehicles 5, 6 have overtaken the first vehicle 1. The vehicle 5 has a speed v₅ and a position p₅, and the vehicle 6 has a speed v₆ and a position p₆. In the case in which the space Ui is not sufficient, one or several new spaces U₂...U_k can determined that are subsequently evaluated by the method. Three vehicles 3, 4, 7 are shown in Figure 3D in addition to the first vehicle 1 . The vehicle 3 has a speed v₃ and a position p₃, the vehicle 4 has a speed v₄ and a position p₄, and the vehicle 7 has a speed v₇ and a position p₇. A further space U₂ between vehicles 3 and 7 can be determined and evaluated.

The invention relates also to a computer program product comprising program code stored on a medium that can be read by a computer in order to carry out any one of the method steps described above.

The present invention is not limited to the embodiments described above. Various alternatives, modifications and equivalents can be used. For this reason, the embodiments named above do not limit the scope of the invention, which is defined by the attached patent claims.

Claims

1 . A method for a first vehicle (1 ) in order to support change of lane from one lane A to a neighbouring lane B with the same direction of travel, whereby the method comprises:

(A1 )- to receive data related to a second vehicle (2) behind the first vehicle (1 ), (A2)- to recognise that the second vehicle (2) desires to overtake the first vehicle (1 ), based on the data that has been received, whereby the first vehicle (1 ) has a speed of v-_\ and is located in lane A,

(A3)- to receive data that indicates that vehicles are present in file B,

(A4)- to determine at least one parameter X related to a space Ui for the first vehicle (1 ) in lane B based on the data that indicates the presence of vehicles in lane B,

(A5)- to compare the parameter X with a limiting value ki that includes a length of the first vehicle (1 ), and, if the parameter X is greater than k^

(A6)- to determine a parameter Y that indicates when the second vehicle (2) has overtaken the first vehicle (1 ) based on the condition that the first vehicle (1 ) changes lane to the space Ui in lane B and maintains its speed vi ,

(A7)- to determine whether the first vehicle (1 ) can maintain its speed V in the space Ui until the second vehicle (2) has overtaken the first vehicle (1 ), based on the parameter Y, and, if this is possible:

(A8)- to generate a lane-change signal s_f that indicates the space U_{1 ;} and if the parameter X is less than or equal to the limiting value k_{1 :}

- start over from step (A3).

2. The method according to claim 1 , that comprises indicating the space

Ui to the driver of the first vehicle (1 ).

3. The method according to claim 1 or 2, that comprises transmitting the lane-change signal s_f to a control unit (10) in the first vehicle (1 ), whereby the control unit (10) at least partially automatically controls the first vehicle (1 ) to carry out the change of lane from lane A to the space Ui in lane B.

4. The method according to any one of the preceding claims, that comprises identifying the rearward second vehicle (2) that desires to overtake by analysing the data that has been received, and at least one of the following steps: to determine a distance between the first vehicle (1 ) and the second vehicle (2) that lies below a limiting value k₂, to determine that the second vehicle (2) is approaching the first vehicle (1 ), to receive a message from the second vehicle (2) that it desires to overtake, to determine that the second vehicle (2) has a higher cruise-control speed than the first vehicle (1 ).

5. The method according to any one of the preceding claims, that comprises:

- to identify a positional parameter for each one of at least two consecutive vehicles (3, 4) in lane B based on the data that indicates the presence of vehicles in lane B,

- to calculate the parameter X as the distance between the positional parameters that indicate also the space Ui between the two vehicles (3, 4).

6. The method according to any one of the preceding claims, that comprises to determine a target speed v_a for the second vehicle (2), and to determine a parameter Y based on at least the target speed v_a and the speed of the first vehicle (1 ).

7. The method according to any one of the preceding claims, whereby the parameter Y indicates a time t₂ or a position p₂ of the second vehicle (2).

8. The method according to any one of the preceding claims, that comprises to determine whether the first vehicle (1 ) can maintain its speed vi in the space Ui until the second vehicle (2) has overtaken the first vehicle (1 ) by:

- determining a parameter Z that indicates how long the first vehicle (1 ) can be driven with the speed v-_\ without needing to reduce its speed when it has changed lane to the space Ui in lane B,

- comparing the parameter Y with the parameter Z, - generating a lane-change signal s_f that indicates the space Ui , depending on the result of the comparison.

9. A system (6) for a first vehicle (1 ) to support change of lane from one lane A to a neighbouring lane B with the same direction of travel, whereby the system (6) comprises a first control unit (7) and a memory unit (8) that is configured to store instructions in order to cause the first control unit (7):

(A1 )- to receive data related to a second vehicle (2) behind the first vehicle (1 ),

(A2)- to recognise that the second vehicle (2) desires to overtake the first vehicle (1 ) based on the data that has been received, whereby the first vehicle (1 ) has a speed v-_\ and is located lane A; characterised in that the memory unit (8) is further configured to store instructions to cause the first control unit (7):

(A3)- to receive data that indicates that vehicles are present in file B, (A4)- to determine at least one parameter X related to a space Ui for the first vehicle (1 ) in lane B based on the data that indicates the presence of vehicles in lane B,

(A5)- to compare the parameter X with a limiting value that includes a length of the first vehicle (1 ), and, if the parameter X is greater than the limiting value:

(A7)- to determine whether the first vehicle (1 ) can maintain its speed Vi in the space Ui until the second vehicle (2) has overtaken the first vehicle (1 ), based on the parameter Y, and, if this is possible:

(A8)- to generate a lane-change signal s_f that indicates the space Ui_; and if the parameter X is less than or equal to the limiting value k_{1 :}

- start over from step (A3).

10. The system (6) according to claim 9, that comprises an indicator unit

(9) that is configured to receive the lane-change signal s_f and to indicate the space Ui to the driver of the first vehicle (1 ).

1 1 . The system (6) according to claim 9 or 10, that comprises transmitting the lane-change signal s_f to a second control unit (10) in the first vehicle (1 ), whereby the second control unit (10) at least partially automatically controls the first vehicle (1 ) to carry out the change of lane from lane A to the space Ui in lane B.

12. The system (6) according to any one of claims 9 to 1 1 , whereby the first control unit (7) is configured to identify the rearward second vehicle (2) that desires to overtake by analysing the data that has been received, and at least one of the following steps: to determine a distance between the first vehicle (1 ) and the second vehicle (2) that lies below a limiting value k₂, to determine that the second vehicle (2) is approaching the first vehicle (1 ), to receive a message from the second vehicle (2) that it desires to overtake, to determine that the second vehicle (2) has a higher cruise-control speed than the first vehicle (1 ).

13. The system (6) according to any one of claims 9 to 12, whereby the first control unit (7) is configured to identify a positional parameter for each of at least two consecutive vehicles (3, 4) in lane B based on the data that indicates the presence of vehicles in lane B and to calculate the parameter X based on the positional parameters that indicate the space Ui between the two vehicles (3, 4).

14. The system (6) according to any one of claims 9 to 13, whereby the first control unit (7) is configured to determine a target speed v_a for the second vehicle (2), and to determine a parameter Y based on at least the target speed v_a and the speed v-_\ of the first vehicle (1 ).

15. The system (6) according to any one of claims 9 to 14, whereby the parameter Y indicates a time t₂ or a position p₂ of the second vehicle (2).

16. The system (6) according to any one of claims 9 to 15, that comprises a reception unit (12) that is adapted to receive wireless signals from at least one of vehicles (1 , 2, 3, 4, 5, 6, 7) and roadside units, and to generate data s_t for the first control unit (7).

17. The system (6) according to any one of claims 9 to 16, that comprises one or several detector units (1 1 ) that are configured to detect one or several vehicles (2, 3, 4) in the surroundings of the first vehicle (1 ), and to generate data Sd that indicates one or several characteristics of the vehicle or vehicles (2, 3, 4).

18. The system (6) according to any one of claims 9 to 17, whereby the control unit (7) is configured to determine whether the first vehicle (1 ) can maintain its speed v-_\ in the space Ui until the second vehicle (2) has overtaken the first vehicle (1 ) by:

- comparing the parameter Y with the parameter Z,

- generating a lane-change signal s_f that indicates the space Ui , depending on the result of the comparison.

19. A computer program (P) at a system (6), where the said computer program (P) comprises program code to cause the control unit (7) to carry out any one of the steps according to claims 1 to 8.

20. A computer program product comprising program code stored on a medium that can be read by a computer in order to carry out the method steps according to any one of claims 1 to 8.