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Title:
METHOD AND CONTROL UNIT FOR ADJUSTING AN INTER VEHICULAR DISTANCE BETWEEN VEHICLES IN A VEHICLE PLATOON
Document Type and Number:
WIPO Patent Application WO/2018/111177
Kind Code:
A1
Abstract:
Method (400) and control unit (210) for adjusting an inter vehicular distance (130) between vehicles (100a, 100b, 100c) in a platoon (110). The control unit (210) is configured to: obtain a geographical position for a vehicle (100a, 100b, 100c) in the platoon (110); determine a zone (200a) wherein the obtained geographical position is situated; determine an inter vehicular minimum distance limit, associated with the determined zone (200a); and adjust the inter vehicular distance (130) between the vehicles (100a, 100b, 100c) in the platoon (110) into the determined inter vehicular minimum distance limit by sending a control signal to the vehicle (100a, 100b, 100c) in the platoon (110).

Inventors:
ALAM, Assad (Götalandsvägen 243, Älvsjö, 125 45, SE)
BERGSTRAND, Christian (Lorensbergsgatan 5B lgh 1103, Stockholm, 117 33, SE)
Application Number:
SE2017/051249
Publication Date:
June 21, 2018
Filing Date:
December 12, 2017
Export Citation:
Click for automatic bibliography generation   Help
Assignee:
SCANIA CV AB (151 87 Södertälje, 151 87, SE)
International Classes:
G08G1/00; B60W30/165; G01C21/00; G01C22/00; G05D1/02
Domestic Patent References:
WO2016134770A12016-09-01
WO2016134770A12016-09-01
Foreign References:
US20160362048A12016-12-15
US20140316671A12014-10-23
US20070152804A12007-07-05
US20160362048A12016-12-15
US20140316671A12014-10-23
US20070152804A12007-07-05
Attorney, Agent or Firm:
YOUSSEF, Maikel (Scania CV AB, Södertälje, 151 87, SE)
Download PDF:
Claims:
PATENT CLAIMS

1 . A control unit (210) for adjusting an inter vehicular distance (130) between vehicles (100a, 100b, 100c) in a platoon (1 10), which control unit (210) is configured to:

obtain a geographical position for a vehicle (100a, 100b, 100c) in the platoon (1 10); determine a zone (200a) wherein the obtained geographical position is situated; determine an inter vehicular minimum distance limit, associated with the determined zone (200a); and

adjust the inter vehicular distance (130) between the vehicles (100a, 100b, 100c) in the platoon (1 10) into the determined inter vehicular minimum distance limit by sending a control signal to the vehicle (100a, 100b, 100c) in the platoon (1 10).

2. The control unit (210) according to claim 1 , wherein the inter vehicular minimum distance limit is a legal restriction associated with the zone (200a). 3. The control unit (210) according to any of claim 1 or claim 2, configured to:

obtain information concerning road conditions; and

adjust the inter vehicular minimum distance limit, based on the obtained information.

4. The control unit (210) according to claim 3, wherein the obtained information con- cerning road conditions comprises temperature, precipitation, icy road surface, road work, traffic congestion, accident, object on the road.

5. The control unit (210) according to any of claims 1 -4, configured to:

predict when the vehicles (100a, 100b, 100c) in the platoon (1 10) are going to exit the zone (200a) and enter an adjacent zone (200b); and wherein the inter vehicular distance (130) is adjusted into an inter vehicular minimum distance limit associated with the adjacent zone (200b), when entering the adjacent zone (200b).

6. A method (400) for adjusting an inter vehicular distance (130) between vehicles (100a, 100b, 100c) in a platoon (1 10), wherein the method (400) comprises:

obtaining (401 ) a geographical position for one of the vehicles (100a, 100b, 100c) in the platoon (1 10);

determining (402) a zone (200a) wherein the obtained (401 ) geographical position is situated;

determining (405) an inter vehicular minimum distance limit, associated with the determined (402) zone (200a); and adjusting (407) the inter vehicular distance (130) between the vehicles (100a, 100b, 100c) in the platoon (1 10) into the determined (403) inter vehicular minimum distance limit by sending a control signal to the vehicle (100a, 100b, 100c) in the platoon (1 10). 7. The method (400) according to claim 6, wherein the inter vehicular minimum distance limit is a legal restriction associated with the zone (200a).

8. The method (400) according to any of claim 6 or claim 7, comprising:

obtaining (403) information concerning road conditions; and

adjusting (404) the inter vehicular minimum distance limit, based on the obtained

(403) information.

9. The method (400) according to claim 8, wherein the obtained (403) information concerning road conditions comprises temperature, precipitation, icy road surface, road work, traffic congestion, accident, object on the road.

10. The method (400) according to any of claims 6-9, comprising:

predicting (406) when the vehicles (100a, 100b, 100c) in the platoon (1 10) are going to exit the zone (200a) and enter an adjacent zone (200b); and wherein the inter vehicular distance (130) is adjusted (407) into an inter vehicular minimum distance limit associated with the adjacent zone (200b), when entering the adjacent zone (200b).

1 1 . A system (500) for adjusting an inter vehicular distance (130) between vehicles (100a, 100b, 100c) in a platoon (1 10), comprising:

a control unit (210) according to any of claims 1 -5; and

a database (220) configured to store information concerning a zone (200a, 200b) and an associated inter vehicular minimum distance limit.

12. The system (500), further comprising:

a road side unit (230a, 230b, 230c, 230d) configured to determine information concerning road conditions and provide the determined information to the control unit (210).

13. A computer program comprising program code for performing a method (400) according to any of claims 6-10, when the computer program is executed in a computer.

Description:
Method and control unit for adjusting an inter vehicular distance between vehicles in a vehicle platoon

TECHNICAL FIELD

This document discloses a control unit, a method in a control unit and a system. More par- ticularly, a method, a control unit and a system is provided, for adjusting an inter vehicular distance between vehicles in a platoon.

BACKGROUND

Grouping vehicles into platoons is an emerging technology, leading to reduced fuel con- sumption and increased capacity of the roads. A number of vehicles, e.g. 2-25 or more, may be organised in a platoon or vehicle convoy, wherein the vehicles are driving in coordination after each other with only a small distance between the vehicles, such as some decimetres or some meters, e.g. up to 50-100 meters. Thereby air resistance is reduced, which is important for reducing energy consumption, in particular for heavy duty vehicles such as trucks, busses and goods vehicles or other vehicles having a large frontal area. In principle, it may be said that the shorter the distance is between the vehicles, the lower the air resistance becomes, which reduces energy consumption for the vehicle platoon. Also, the occupied road area is thereby reduced, leading to increased road capacity. Platooning may be made by manually driven vehicles, or autonomously driven vehicles. Communication and coordination between the vehicles engaged in the platoon may be made over a wireless communication interface such as e.g. Vehicle-to-Vehicle (V2V) communication. However, legislation is lagging behind current technical developments within the area of platooning and coordination/ communication between vehicles. Further, legislation is currently not coordinated between different nations. There is no common legislation regarding shortest distance between vehicles in a platoon. For example, according to German legislation, a minimum distance of 50 meter has to be kept between vehicles in a platoon, while Denmark has a legislation defining a minimum distance of 30 meters. Further, the shortest distance may be defined in meters/ length units in some legislations and in seconds/ time units in other legislations, which further adds confusion.

As vehicles in a platoon typically comprises long haulage vehicles, driving long international routes, the involved drivers have to keep an updated record of allowed minimum distances in different nations along the route. Alternatively, the longest minimum distance between the vehicles of any nation along the route has to be set and kept during the route to the end destination. However, then the air resistance/ energy consumption is not optimised.

Further, the minimum legal distances between vehicles in a platoon may vary also within the same nation. Driving in a platoon formation may be allowed on certain roads but not on others, etc., depending on e.g. reduced visibility or that the state of the road is poor. Detailed and continuously updated knowledge about local legislation and regulations is thereby required in order to optimise advantages related to platooning.

Documents US20140156176 and US2014372561 discusses adaptation of vehicles rhythm based on environmental traffic conditions. This is done by the vehicles get information about traffic conditions and traffic. In document US20140156176, it is also shown that this data is used for adjustment of the distance between vehicles. However, none of the documents discusses the problem of different legislations concerning allowed minimum distance in different nations.

Documents US2016054735 and WO2016065055 discusses methods for controlling the distance between vehicles in platoons. The regulation of the distance takes into account both vehicle-related parameters such as vehicle weight, and external parameters such as weather conditions. Again, the specific problem of different legislations concerning allowed minimum distance in different nations is not addressed neither in these documents.

Document US2014278027 discloses a method for organising and coordinating vehicles having a common destination, e.g. by communicating a restaurant where a stop for lunch may be made. Again, the specific problem of different legislations concerning allowed minimum distance in different nations is not addressed in this document.

Furthermore, in a conventional vehicle platoon all vehicles always have a driver present in each vehicle. In the described group of coordinated vehicles, there may not be any driver at all in at least some of the vehicles in the platoon.

It appears that further development is required for reaching practical implementation of vehicle groups.

SUMMARY

It is therefore an object of this invention to solve at least some of the above problems and improve inter vehicular distance adjustments between vehicles in a platoon. According to a first aspect of the invention, this objective is achieved by a control unit for adjusting an inter vehicular distance between vehicles in a platoon. The control unit is configured to obtain a geographical position for a vehicle in the platoon. The control unit is further configured to determine a zone wherein the obtained geographical position is situated. In addition is also configured to determine an inter vehicular minimum distance limit, associated with the determined zone. Also, the control unit is configured to adjust the inter vehicular distance between the vehicles in the platoon into the determined inter vehicular minimum distance limit by sending a control signal to the vehicle in the platoon. According to a second aspect of the invention, this objective is achieved by a method in a control unit for adjusting an inter vehicular distance between vehicles in a platoon. The method comprises obtaining a geographical position for one of the vehicles in the platoon. Also, the method furthermore comprises determining a zone wherein the obtained geographical position is situated. The method additionally comprises determining an inter vehicular minimum distance limit, associated with the determined zone. Furthermore, the method also comprises adjusting the inter vehicular distance between the vehicles in the platoon into the determined inter vehicular minimum distance limit by sending a control signal to the vehicle in the platoon. According to a third aspect of the invention, this objective is achieved by a system for adjusting an inter vehicular distance between vehicles in a platoon. The system comprises a control unit according to the first aspect. Further, the system also comprises a database configured to store information concerning a zone and an associated inter vehicular minimum distance limit.

Thanks to the described aspects, by defining geographical zones, each associated with a predetermined minimum inter-vehicular distance, obtaining the geographical position of the vehicles in the platoon and determining which defined zone the platoon vehicles are situated in, the inter vehicular distance of the vehicles may be adjusted to the predetermined mini- mum inter-vehicular minimum distance limit of the current zone. Thereby, the distances between vehicles driving in the platoon may be continuously adjusted to local regulations concerning minimum distances between vehicles driving in a platoon.

Thereby, it is assured that the shortest allowed minimum inter vehicular distances are kept during platoon driving, which may be made over various nations with different legislation in this aspect. By adjusting the distance to the shortest allowed distance, air resistance is reduced, leading to reduced energy consumption. In addition, road capacity is increased. It is also assured that the vehicles in the platoon are not violating any local traffic regulation.

Other advantages and additional novel features will become apparent from the subsequent detailed description.

FIGURES

Embodiments of the invention will now be described in further detail with reference to the accompanying figures, in which:

Figure 1 illustrates an embodiment of a platoon comprising coordinated vehicles; Figure 2A illustrates a platoon and system according to an embodiment;

Figure 2B illustrates a platoon and system according to an embodiment;

Figure 3 illustrates a vehicle interior according to an embodiment;

Figure 4 is a flow chart illustrating an embodiment of the method;

Figure 5 is an illustration depicting a system according to an embodiment.

DETAILED DESCRIPTION

Embodiments of the invention described herein are defined as a control unit, a method in a control unit and a system, which may be put into practice in the embodiments described below. These embodiments may, however, be exemplified and realised in many different forms and are not to be limited to the examples set forth herein; rather, these illustrative examples of embodiments are provided so that this disclosure will be thorough and complete.

Still other objects and features may become apparent from the following detailed description, considered in conjunction with the accompanying drawings. It is to be understood, however, that the drawings are designed solely for purposes of illustration and not as a definition of the limits of the herein disclosed embodiments, for which reference is to be made to the appended claims. Further, the drawings are not necessarily drawn to scale and, unless otherwise indicated, they are merely intended to conceptually illustrate the structures and procedures described herein.

Figure 1 illustrates a scenario wherein a number of vehicles 100a, 100b, 100c, driving in a driving direction 105, in a platoon 110, on a route 120, with an inter-vehicular distance 130. The vehicles 100a, 100b, 100c are coordinated and organised in the platoon 1 10 of coordinated vehicles 100a, 100b, 100c. The platoon 1 10 may be described as a chain of coordinated, inter-communicating vehicles 100a, 100b, 100c travelling at given inter-vehicular distances 130 and velocity. The inter- vehicular distances 130 may be the same between all vehicles 100a, 100b, 100c in some embodiments. In other embodiments, the inter-vehicular distances 130 may be different for different vehicles 100a, 100b, 100c. Further, the inter-vehicular distances 130 may be adjustable. Thus, the distances 130 may be e.g. some centimetres, some decimetres, some meters or some tenths of meters in some embodiments. Alternatively, each vehicle 100a, 100b, 100c in the platoon 1 10 may have a different distance 130 to the vehicle following, or leading, vehicle 100a, 100b, 100c, than other vehicles 100a, 100b, 100c in the platoon 1 10.

The vehicles 100a, 100b, 100c may comprise e.g. a means for transportation in broad sense such as e.g. a truck, a car, a motorcycle, a trailer, a bus, a bike, an aircraft, a watercraft, a drone, a spacecraft, or other similar manned or unmanned means of conveyance running e.g. on wheels, air, water or similar media.

The vehicles 100a, 100b, 100c in the platoon 1 10 may comprise vehicles of the same, or different types in different embodiments.

Any, some or all of the vehicles 100a, 100b, 100c may be driver controlled or driverless, autonomously controlled, vehicles in different embodiments. However, for enhanced clarity, the vehicles 100a, 100b, 100c are subsequently described as having a driver, at least in the leading vehicle 100a.

The vehicles 100a, 100b, 100c in the platoon 1 10 are coordinated via wireless signal. Such wireless signal may comprise, or at least be inspired by wireless communication technology such as Wi-Fi, Wireless Local Area Network (WLAN), Ultra Mobile Broadband (UMB), Bluetooth (BT), Near Field Communication (NFC), Radio-Frequency Identification (RFID), optical communication such as Infrared Data Association (IrDA) or infrared transmission to name but a few possible examples of wireless communications in some embodiments.

In some embodiments, the communication between vehicles 100a, 100b, 100c in the platoon 1 10 may be performed via vehicle-to-vehicle (V2V) communication, e.g. based on Dedicated Short-Range Communications (DSRC) devices. DSRC works in 5.9 GHz band with bandwidth of 75 MHz and approximate range of 1000 m in some embodiments.

The wireless communication may be made according to any IEEE standard for wireless vehicular communication like e.g. a special mode of operation of IEEE 802.1 1 for vehicular networks called Wireless Access in Vehicular Environments (WAVE). IEEE 802.1 1 p is an extension to 802.1 1 Wireless LAN medium access layer (MAC) and physical layer (PHY) specification. In some embodiments, when the vehicles 100a, 100b, 100c in the platoon 1 10 are coordinated and are communicating, the driver of the first vehicle 100a drive the own vehicle 100a and the other vehicles 100b, 100c in the platoon 1 10 are merely following the driving commands of the first vehicle 100a. According to some embodiments, geo-fencing is applied on certain zones or areas along the route of the platoon 1 10, i.e. these zones are defined, e.g. on a map. The geographical position of the platoon 1 10, or at least one of the vehicles 100a, 100b, 100c in the platoon 1 10 is determined and a comparison is continuously made with the geo-fencing zones. It may then be determined when the platoon 1 10 enters/ leaves a defined zone.

Each defined zone may be associated with information concerning a minimum allowed distance, or inter vehicular minimum distance limit. This information may then be extracted and provided to the vehicles 100a, 100b, 100c in the platoon 1 10 for adjustment of the inter vehicular distances 130. Thereby, the vehicles 100a, 100b, 100c in the platoon 1 10 may apply the best control strategy legally possible for that specific nation/ road/ zone. This embodiment is illustrated in Figure 2A and further discussed in the corresponding text segment.

Similarly, according to some embodiments, the geo-fencing and the division of the route into zones, may be applied along with road side units that use vehicle-to-infrastructure (V2I) com- munication, as illustrated in Figure 2B. Thereby, the inter vehicular distance 130 may be adjusted, i.e. increased or reduced, based on the local road conditions or traffic conditions. For example, if the traffic is dense (traffic jam situation), a smaller inter-vehicle spacing 130 can be allowed for in the platoon to increase the road capacity. If the road is wet (detected e.g. by road side sensors) a larger inter vehicular spacing 130 may be enforced. This can also be suitable when it comes to increasing the spacing 130 between the vehicles 100a, 100b, 100c over bridges, since a bridge can only carry a limited amount of weight (heavy vehicles) at the same time. Also, factors such as maximum allowed vehicle velocity or road topography may influence the inter vehicular distance 130 between the vehicles 100a, 100b, 100c.

Furthermore, in some embodiments, platoon driving may be forbidden in some zones due to local restrictions, legislations, road conditions, etc., e.g. in city traffic, on highly congested roads and/ or roads having a 2+1 lane structure.

Other non-exhaustive examples when platooning may be prohibited or inappropriate may be when a road accident has occurred, when obstacles/ animals/ people have been detected on a highway, in a road segment under reconstruction, during extreme weather conditions involving e.g. blizzard, icy roads, tornadoes, etc., when it may be inappropriate with platoon driving in an automatic mode due to safety reasons.

In case traffic congestion/ traffic jam is detected, the control unit 210 may determine to dis- solve the platoon 1 10, as there is no/ very little point in platoon driving in very low velocity. Also, legal restrictions concerning minimum inter-vehicular distance 130 are not applicable in such situations, why said distance may be reduced to almost zero in order to avoid that the vehicles 100a, 100b, 100c are divided by other vehicles in between. Thereby, both safety and fuel-efficiency is improved, within the local legal framework, wherein adaptation also may be made according to local road conditions and/ or traffic conditions.

Figure 2A illustrates an example of a platoon 1 10 driving along a route 120 towards a des- tination. The vehicle is driving in a zone 200a, and is approaching an adjacent zone 200b. The zone 200a may be e.g. on a German side of the border while the adjacent zone 200b is the Danish side of the border.

Each of the zones 200a, 200b may be associated with a respective minimum inter vehicular distance 130 between vehicles 100a, 100b, 100c in the platoon 1 10. This information may be stored in a database 220, accessible by a control unit 210.

The control unit 210 may be situated in a vehicle external structure. The vehicles 100a, 100b, 100c in the platoon 1 10 may communicate over a wireless interface via a transceiver com- municating with the control unit 210 in the vehicle external structure via another communication device of the vehicle external structure.

Position of at least one vehicle 100a, 100b, 100c in the platoon 1 10 may be determined e.g. by GPS or similar technology, as will be further discussed in the text segment corresponding to Figure 3. The determined geographical position may be reported to the control unit 210 over the wireless interface. The communication may be made e.g. over any of the previously discussed wireless communication technologies. The communication may alternatively be made over a wireless interface comprising, or at least being inspired by radio access technologies such as e.g. 3GPP LTE, LTE-Advanced, E-UTRAN, UMTS, GSM, GSM/ EDGE, WCDMA, Time Division Multiple Access (TDMA) net- works, Frequency Division Multiple Access (FDMA) networks, Orthogonal FDMA (OFDMA) networks, Single-Carrier FDMA (SC-FDMA) networks, Worldwide Interoperability for Microwave Access (WiMax), or Ultra Mobile Broadband (UMB), High Speed Packet Access (HSPA) Evolved Universal Terrestrial Radio Access (E-UTRA), Universal Terrestrial Radio Access (UTRA), GSM EDGE Radio Access Network (GERAN), 3GPP2 CDMA technologies, e.g., CDMA2000 1 x RTT and High Rate Packet Data (HRPD), or similar, just to mention some few options, via a wireless communication network.

When the control unit 210 receives geographical positions of vehicles 100a, 100b, 100c in the platoon 1 10, it may be determined which zone 200a, 200b the vehicles 100a, 100b, 100c are currently situated in. Further, a minimum inter vehicular distance 130 associated with the determined zone 200a is extracted from the database 220. This distance is then communicated to the vehicles 100a, 100b, 100c in the platoon 1 10. The control unit 210 may generate control signals for adapting the inter vehicular distance 130 between the vehicles 100a, 100b, 100c in the platoon 1 10 according to the associated minimum distance.

Figure 2B illustrates an example of a platoon 1 10 driving along a route 120 towards a destination, very similar to the scenario previously described in Figure 2A, but with one important difference: road side units 230a, 230b, 230c, 230d. The road side units 230a, 230b, 230c, 230d may determine information concerning local road conditions. Such information may be collected e.g. by one or more sensors at the road side unit 230a, 230b, 230c, 230d such as thermometer, rain sensor, wind meter, camera, stereo camera, infrared camera, video camera, radar, lidar, ultrasound device, time-of-flight camera, or similar device, in different embodiments. Thereby situations such as traffic con- gestion but also traffic accidents, objects on the road, animals/ people on the highway etc., may be detected by image recognition/ computer vision and object recognition.

Computer vision is a technical field comprising methods for acquiring, processing, analysing, and understanding images and, in general, high-dimensional data from the real world in order to produce numerical or symbolic information. A theme in the development of this field has been to duplicate the abilities of human vision by electronically perceiving and understanding an image. Understanding in this context means the transformation of visual images (the input of retina) into descriptions of world that can interface with other thought processes and elicit appropriate action. This image understanding can be seen as the disentangling of symbolic information from image data using models constructed with the aid of geometry, physics, statistics, and learning theory. Computer vision may also be described as the enterprise of 5 automating and integrating a wide range of processes and representations for vision perception.

However, information concerning local traffic conditions may also be entered manually by e.g. a traffic operator, police officer or similar person, either directly at the road side unit 10 230a, 230b, 230c, 230d, or remotely, from a traffic surveillance centre or similar central node for traffic regulation.

The local traffic conditions may comprise various things such as road work, accidents, etc., or other extraordinary situations that may influence the traffic flow and the suitability for pla- 15 toon driving. An example of the latter may be a close by robbery where the perpetrator has thrown caltrops on the road, or placed real or fake Improvised Explosive Device (IED); objects dropped on the road, animals on the road 120 and similar events, influencing the traffic conditions, which are difficult or impossible to predict.

20 In some embodiments, the road side unit 230a, 230b, 230c, 230d may receive information via wireless communication from vehicles 100 on the road 120, such as rain sensors, cameras, radars etc. Thereby, the road side unit 230a, 230b, 230c, 230d may also estimate the traffic intensity and follow/ predict traffic congestion.

25 In some embodiments, a vehicle having functional problems may emit an emergency signal, possibly automatically at dysfunction or accident, which may be perceived by the road side unit 230a, 230b, 230c, 230d. Thereby, a traffic accident/ vehicle on the roadside may be detected. The control unit 210 may in turn receive this information concerning the traffic accident/ road blocking vehicle, which may trigger the control unit 210 to prolong the inter ve-

30 hicular distance 130 between vehicles 100a, 100b, 100c and/ or dissolving the platoon 1 10.

Possibly also an alert may be provided to the drivers in the vehicles 100a, 100b, 100c of the platoon 1 10 (in case there are any drivers), to be alert and observant on the traffic situation.

Figure 3 illustrates an example of a scenario as it may be perceived by the driver of the 35 vehicle 100a, i.e. the first vehicle 100a in the platoon 1 10 of coordinated vehicles 100a, 100b, Communication may be made over a wireless interface, such as any of the previously discussed, with the other vehicles 100a, 100b, 100c in the platoon 1 10, and/ or with the control unit 210 by a transceiver 310. Thereby information may be interchanged and communicated within the platoon 1 10, and also with the control unit 210. In some particular embodiments, 5 information may also be transmitted or exchanged with the road side unit 230a, 230b, 230c, 230d.

In some embodiments, wherein at least one of the vehicles 100a, 100b, 100c in the platoon 1 10 comprises a driver, the vehicle 100a may comprise a visual presentational device 320, 10 such as e.g. a display on the dashboard, a head up display, intelligent glasses of the driver etc. Alternatively, the distance limitations 130 may be presented by an audio signal outputted by a loudspeaker 330.

The geographical position of the vehicle 100a (and thereby also the platoon 1 10) may be 15 determined by the positioning unit 350 in the vehicle 100a, which may be based on a satellite navigation system such as the Navigation Signal Timing and Ranging (Navstar) Global Positioning System (GPS), Differential GPS (DGPS), Galileo, GLONASS, or the like.

The geographical position of the positioning unit 350 may be made continuously with a cer- 20 tain predetermined or configurable time intervals according to various embodiments.

Positioning by satellite navigation is based on distance measurement using triangulation from a number of satellites 340a, 340b, 340c, 340d. In this example, four satellites 340a, 340b, 340c, 340d are depicted, but this is merely an example. More than four satellites 340a,

25 340b, 340c, 340d may be used for enhancing the precision, or for creating redundancy. The satellites 340a, 340b, 340c, 340d continuously transmit information about time and date (for example, in coded form), identity (which satellite 340a, 340b, 340c, 340d that broadcasts), status, and where the satellite 340a, 340b, 340c, 340d are situated at any given time. The GPS satellites 340a, 340b, 340c, 340d sends information encoded with different codes, for

30 example, but not necessarily based on Code Division Multiple Access (CDMA). This allows information from an individual satellite 340a, 340b, 340c, 340d distinguished from the others' information, based on a unique code for each respective satellite 340a, 340b, 340c, 340d. This information can then be transmitted to be received by the appropriately adapted positioning device comprised in the vehicle 100a.

35

Distance measurement can according to some embodiments comprise measuring the difference in the time it takes for each respective satellite signal transmitted by the respective satellites 340a, 340b, 340c, 340d to reach the positioning unit 350. As the radio signals travel at the speed of light, the distance to the respective satellite 340a, 340b, 340c, 340d may be computed by measuring the signal propagation time.

5 The positions of the satellites 340a, 340b, 340c, 340d are known, as they continuously are monitored by approximately 15-30 ground stations located mainly along and near the earth's equator. Thereby the geographical position, i.e. latitude and longitude, of the vehicle 100a may be calculated by determining the distance to at least three satellites 340a, 340b, 340c, 340d through triangulation. For determination of altitude, signals from four satellites 340a, 10 340b, 340c, 340d may be used according to some embodiments.

Having determined the geographical position of the positioning unit 350 (or in another way), it may be presented on a map, a screen or a display device where the position of the vehicle 100a may be marked, in some alternative embodiments.

15

Figure 4 illustrates an example of a method 400 according to an embodiment. The flow chart in Figure 4 shows the method 400 in a control unit 210 for adjusting an inter vehicular distance 130 between vehicles 100a, 100b, 100c in a platoon 1 10. The inter vehicular minimum distance limit may be a legal restriction associated with the zone 200a.

20

The control unit 210 may be vehicle external, i.e. situated in a vehicle external structure. Alternatively, the control unit 210 may be comprised in one of the vehicles 100a, 100b, 100c in the platoon 1 10.

25 The vehicles 100a, 100b, 100c in the platoon 1 10 may be any arbitrary kind of means for conveyance. However, in some particular embodiments, the vehicles 100a, 100b, 100c may be vehicles for long haulage transportation, transportation of passengers etc.

In order to correctly be able to adjust the inter vehicular distance 130, the method 400 may 30 comprise a number of steps 401-407. Further, the described steps 401 -407 may be performed in a somewhat different chronological order than the numbering suggests. Some of the presented method steps such as e.g. steps 403-404 and step 406 may be performed only in some particular embodiments. The method 400 may comprise the subsequent steps:

35 Step 401 comprises obtaining a geographical position for at least one of the vehicles 100a, 100b, 100c in the platoon 1 10. The geographical position of the vehicle 100a may be determined by the positioning unit in the vehicle 100a, which may be based on a satellite navigation system such as the Navigation Signal Timing and Ranging (Navstar) Global Positioning System (GPS), Differential GPS (DGPS), Galileo, GLONASS, or the like.

The geographical position of the positioning device 350, (and thereby also of the vehicle 100a and the platoon 1 10), as well as time, vehicle speed, heading, etc., may be determined continuously, or at a certain predetermined or configurable time interval according to various embodiments.

The geographical position of the vehicle 100a may alternatively be determined, e.g. by having transponders positioned at known positions around the route and a dedicated sensor in the vehicle 100a, for recognising the transponders and thereby determining the position; by detecting and recognising WiFi networks (WiFi networks along the route may be mapped with certain respective geographical positions in a database); by receiving a Bluetooth beaconing signal, associated with a geographical position, or other signal signatures of wireless signals such as e.g. by triangulation of signals emitted by a plurality of fixed base stations or road side units 230a, 230b, 230c, 230d with known geographical positions. The position may alternatively be entered manually by the driver.

Step 402 comprises determining a zone 200a wherein the obtained 401 geographical position is situated.

The zone 200a may be predetermined and geographical coordinates defining the zone 200a may be stored in the database 220.

Step 403, which only may be performed in some particular embodiments, comprises obtaining information concerning road conditions. The obtained information concerning road conditions may comprise e.g. any of temperature, precipitation, icy road surface, road work, traffic congestion, accident, and/ or object on the road 120.

Step 404, which only may be performed in some particular embodiments wherein step 403 has been performed, comprises adjusting the inter vehicular minimum distance limit, based on the obtained 403 information. Step 405 comprises determining an inter vehicular minimum distance limit, associated with the determined 402 zone 200a.

The inter vehicular minimum distance limit may be a legal restriction associated with the zone 5 200a in some embodiments. The inter vehicular minimum distance limit may be predetermined for each zone 200a, 200b, and may be stored e.g. in the database 220.

In some embodiments, the inter vehicular minimum distance limit may be manually entered and associated with the zone 200a in some embodiments. Further, the inter vehicular mini- 10 mum distance limit may be updated, e.g. based on information concerning traffic situation received from the road side units 230a, 230b, 230c, 230d, from (sensors in the) vehicles on the road 120, etc.

Step 406, which only may be performed in some particular embodiments, comprises pre- 15 dieting when the vehicles 100a, 100b, 100c in the platoon 1 10 are going to exit the zone 200a and enter an adjacent zone 200b.

The prediction may be made e.g. on obtained information concerning destination of the platoon 1 10, obtained or estimated information concerning driving direction 105 of the platoon 20 1 10, etc.

Step 407 comprises adjusting the inter vehicular distance 130 between the vehicles 100a, 100b, 100c in the platoon 1 10 into the determined 403 inter vehicular minimum distance limit by sending a control signal to the vehicle 100a, 100b, 100c in the platoon 1 10.

25

The control signal sent to the vehicle 100a, 100b, 100c in the platoon 1 10 may upon reception trigger an automatic adjustment of the inter vehicular distance 130, without interaction required by the driver (if any), according to some embodiments.

30 In some embodiments, the control signal sent to the vehicle 100a, 100b, 100c in the platoon 1 10 may trigger an output of information concerning the inter vehicular minimum distance limit associated with the zone 200a wherein the vehicle 100a, 100b, 100c/ platoon 1 10 is situated. The information may be outputted to the respective driver via the visual presentational device 320, via the loudspeaker 330, and/ or via a portable communication device of

35 the driver. The driver is thereby advised to adjust the inter vehicular distance 130 into the inter vehicular minimum distance limit. In some embodiments, the inter vehicular distance 130 may be adjusted into an inter vehicular minimum distance limit associated with the adjacent zone 200b, when entering the adjacent zone 200b, or there about such as e.g. after entrance into the adjacent zone 200b. Figure 5 illustrates an embodiment of a system 500. The system 500 is configured for adjusting an inter vehicular distance 130 between vehicles 100a, 100b, 100c in a platoon 1 10.

The system 500 comprises a control unit 210 may be situated in a vehicle external structure in some embodiments. Alternatively, the control unit 210 may be situated in one of the vehi- cles 100a, 100b, 100c in the platoon 1 10. The control unit 210 is configured to perform at least some of the presented method steps 401 -407. Thus, the control unit 210 is configured to obtain a geographical position for a vehicle 100a, 100b, 100c in the platoon 1 10. Further, the control unit 210 is also configured to determine a zone 200a wherein the obtained geographical position is situated. The control unit 210 is furthermore configured to determine an inter vehicular minimum distance limit, associated with the determined zone 200a. In addition, the control unit 210 is configured to adjust the inter vehicular distance 130 between the vehicles 100a, 100b, 100c in the platoon 1 10 into the determined inter vehicular minimum distance limit by sending a control signal to the vehicle 100a, 100b, 100c in the platoon 1 10. In some embodiments, the inter vehicular minimum distance limit is a legal restriction associated with the zone 200a. Further, the control unit 210 may be configured to obtain information concerning road conditions. The obtained information concerning road conditions may comprise comprises temperature, precipitation, icy road surface, road work, traffic congestion, accident, object on the road 120. In addition, the control unit 210 may also be con- figured to adjust the inter vehicular minimum distance limit, based on the obtained information.

The control unit 210 may in addition be configured to predict when the vehicles 100a, 100b, 100c in the platoon 1 10 are going to exit the zone 200a and enter an adjacent zone 200b. Further, the control unit 210 may be configured to adjust the inter vehicular distance 130 into an inter vehicular minimum distance limit associated with the adjacent zone 200b, when entering the adjacent zone 200b.

The system 500 further comprises a database 220. The database 220 is configured to store information concerning a zone 200a, 200b and an associated inter vehicular minimum distance limit. The database 120 may comprise a Database Management System (DBMS), i.e. a computer software application that interacts with the user, other applications, and the database 120 itself to capture and analyse data. A general-purpose DBMS is designed to allow the definition, creation, querying, update, and administration of databases. Some arbitrary examples of DBMSs may comprise e.g. MySQL, PostgreSQL, Microsoft SQL Server, Oracle, Sybase, SAP HANA, and/ or IBM DB2.

Furthermore, the system 500 may also comprise a road side unit 230a, 230b, 230c, 230d in some embodiments, configured to determine information concerning road conditions and provide the determined information to the control unit 210.

The control unit 210 comprises a receiver 510 configured to receive information from vehicles 100a, 100b, 100c in the platoon 1 10, from the database and/ or from the road side units 230a, 230b, 230c, 230d.

The control unit 210 further comprises a processor 520 configured for performing various calculations and computations in order to perform the method 400, according to the previously described steps 401 -407. Such processor 520 may comprise one or more instances of a processing circuit, i.e. a Central Processing Unit (CPU), a processing unit, an Application Specific Integrated Circuit (ASIC), a microprocessor, or other processing logic that may interpret and execute instructions. The herein utilised expression "processor" may thus represent a processing circuitry comprising a plurality of processing circuits, such as, e.g., any, some or all of the ones enu- merated above.

Furthermore, the control unit 210 may also comprise a memory 525 in some embodiments. The optional memory 525 may comprise a physical device utilised to store data or programs, i.e., sequences of instructions, on a temporary or permanent basis. According to some em- bodiments, the memory 525 may comprise integrated circuits comprising silicon-based transistors. The memory 525 may comprise e.g. a memory card, a flash memory, a USB memory, a hard disc, or another similar volatile or non-volatile storage unit for storing data such as e.g. ROM (Read-Only Memory), PROM (Programmable Read-Only Memory), EPROM (Erasable PROM), EEPROM (Electrically Erasable PROM), etc. in different embodiments.

Further, the control unit 210 also comprises a transmitter 530, configured to transmit information to the vehicles 100a, 100b, 100c in the platoon 1 10, to the database and/ or to the road side units 230a, 230b, 230c, 230d in some embodiments.

The previously described steps 401 -407 to be performed in the control unit 210 may be implemented through the one or more processors 520 within the control unit 210, together with computer program product for performing at least some of the functions of the steps 401 - 407. Thus, a computer program product, comprising instructions for performing the steps 401 -407 in the control unit 210 may perform the method 400 comprising at least some of the steps 401 -407 for adjusting an inter vehicular distance 130 between vehicles 100a, 100b, 100c in the platoon 1 10 when the computer program is loaded into the one or more proces- sors 520 of the control unit 210. The described steps 401 -407 thus may be performed by a computer algorithm, a machine executable code, a non-transitory computer-readable medium, or a software instructions programmed into a suitable programmable logic such as the processor 520 in the control unit 210. The computer program product mentioned above may be provided for instance in the form of a data carrier carrying computer program code for performing at least some of the step 401 -407 according to some embodiments when being loaded into the one or more processors 520 of the control unit 210. The data carrier may be, e.g., a hard disk, a CD ROM disc, a memory stick, an optical storage device, a magnetic storage device or any other appropri- ate medium such as a disk or tape that may hold machine readable data in a non-transitory manner. The computer program product may furthermore be provided as computer program code on a server and downloaded to the control unit 210 remotely, e.g., over an Internet or an intranet connection. Further, some embodiments may comprise a vehicle 100a, comprised in the platoon 1 10 of coordinated vehicles 100a, 100b, 100c, comprising the control unit 210, configured for adjusting an inter vehicular distance 130 between vehicles 100a, 100b, 100c in a platoon 1 10.

The terminology used in the description of the embodiments as illustrated in the accompa- nying drawings is not intended to be limiting of the described method 400, control unit 210; computer program, system 500, vehicle 100a and/ or vehicle external structure. Various changes, substitutions and/ or alterations may be made, without departing from invention embodiments as defined by the appended claims. As used herein, the term "and/ or" comprises any and all combinations of one or more of the associated listed items. The term "or" as used herein, is to be interpreted as a mathematical OR, i.e., as an inclusive disjunction; not as a mathematical exclusive OR (XOR), unless expressly stated otherwise. In addition, the singular forms "a", "an" and "the" are to be interpreted as "at least one", thus also possibly comprising a plurality of entities of the same kind, unless expressly stated otherwise. It will be further understood that the terms "includes", "comprises", "including" and/ or "comprising", specifies the presence of stated features, actions, integers, steps, operations, elements, and/ or components, but do not preclude the presence or addition of one or more other features, actions, integers, steps, operations, elements, components, and/ or groups thereof. A single unit such as e.g. a processor may fulfil the functions of several items recited in the claims. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. A computer program may be stored/ distributed on a suitable medium, such as an optical storage medium or a solid-state medium supplied together with or as part of other hardware, but may also be distributed in other forms such as via Internet or other wired or wireless communication system.