SE1550389A1

SE1550389A1 - A method and a control unit for determining a set of velocity profiles for a platoon of grouped vehicles

Info

Publication number: SE1550389A1
Application number: SE1550389A
Authority: SE
Inventors: Johansson Björn; Flärdh Oscar
Original assignee: Scania Cv Ab
Priority date: 2015-03-31
Filing date: 2015-03-31
Publication date: 2016-10-01
Also published as: SE538817C2; DE102016003252A1

Abstract

38 SUMMARY Method (400) and control unit (310) for determining a set of velocity profiles for a platoon(110), comprising a grouped set of vehicles (100-1, 100-2, 100-3), for use at an upcomingroad section (220-2). The method (400) comprises extracting (402) vehicle related informa-tion, relevant for the vehicle performance in the upcoming road section (220-2) with regardto topology of the upcoming road section (220-2); computing (403) a set of candidate ve-locity profiles, based on the extracted (402) information in order to reduce a weighted sumof energy consumption and travel time; transmitting (404) the set of candidate velocity pro-files; receiving (405) information related to the transmitted (404) set of candidate velocityprofiles, from the other vehicle (100-1, 100-2, 100-3); iterating (406) steps 403-405,wherein the iterated computation (405) is made based also on the received (405) informa-tion; determining (407) the set of velocity profiles when an interruption condition for inter-rupting the iteration (406) is fulfilled; and instructing (407) each vehicle (100-1, 100-2, 100- 3) to start using a velocity profile upon arrival at the upcoming road section (220-2). (Publ. Fig. 3)

Description

VELOCITY PROFILE DETERMINATION TECHNICAL FIELD This document discloses methods, a control unit and a computing unit. More particularly, acontrol unit, a computing unit and methods therein are described, for determining a set of velocity profiles for a platoon, comprising a grouped set of vehicles.

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 coor-dination after each other with only a small distance between the vehicles, such as somedecimetres or some meters such as e.g. 20 meters or there about. Thereby air resistanceis reduced, which is important for reducing energy consumption, in particular for trucks,busses and goods vehicles or other vehicles having a large frontal area. ln principle it maybe said that the shorter the distance is between the vehicles, the lower the air resistance becomes, which reduces energy consumption for the vehicle platoon.

The distance between the vehicles in the platoon may be reduced as the vehicles are en-abled to communicate wirelessly with each other and thereby coordinate their velocity bye.g. accelerating or braking simultaneously. Thereby the reacting distance needed for hu- man reaction during normal driving is eliminated.

Platooning brings a multitude of advantages, such as improved fuel economy due to re-duced air resistance, and also reduced traffic congestion leading to increased capacity ofthe roads and enhanced traffic flow. On long distance routes vehicles could be mostly unat-tended whilst in following mode, giving the driver an opportunity to rest and be well restedwhen leaving the platoon for the final destination, which potentially leads to less traffic inci-dents. Further, it may not be required to stop the vehicle in order for the driver to rest, lead-ing to a reduced transportation time (this may require modified law regulation concerning driving times, breaks and rest periods for drivers of vehicles in a platoon).

However, the vehicles in the platoon may not share the same characteristics. They may forexample have different weight, different Power-to-weight ratio, different rolling resistance,their engines may require gear shift at different speed, the time for making the gear shift (leaving the vehicle in a temporal state without torque) may be different etc.

Thereby, the optimal method of driving, perhaps in particular when driving in hilly terrain, may be different for different vehicles. ln case the first vehicle in the platoon is an unloaded vehicle, it may hardly be affected atall by the uphill, while a heavily loaded following vehicle may not be able to maintain the desired speed.

Another and perhaps even bigger problem in particular for platoons comprising a largenumber of vehicles driving in hilly terrain is that the vehicles are in different states of incli- nation in all times, except when the road is horizontal.

For example, in case of uphill driving followed by a downhill, a single vehicle is normallyreleasing the accelerator when approaching the hill peak in order to roll over the peak anddownhill without any driving torque in the powertrain of the vehicle. Thereby fuel is saved.However, when a platoon is driving in the same hilly environment (uphill followed by down-hill) and the first vehicle of the platoon is approaching the hill peak, the following vehiclesare still driving uphill and need to accelerate in order to overcome the hill. ln case the firstvehicle of the platoon release the accelerator when approaching the hill peak, the followingvehicles will have to brake away energy in order to keep the distance to the fonNard vehi-cle. A following vehicle in the platoon which may be in the beginning of the uphill, may afterthe brake be required to change gears, leading to further lost velocity during the time of thegear change. The vehicle then has to speed up for reducing the gap to the fonNard vehicle,causing also the behind vehicle to speed up etc. Such inconsequent braking and accelera- tion will increase the fuel consumption of the vehicles in the platoon substantially.

The reversed problem may appear in the opposite situation when the first vehicle in theplatoon starts driving downhill and increase speed due to gravity while the following vehiclemay be driving on plain ground, or uphill and thus the following vehicle has to accelerate in order to keep the time gap, just for start braking some seconds later.

Thereby energy is unnecessarily wasted. Also, the brakes are excessively used, whichmay lead to early replacement due to wear, i.e. increased maintenance costs. lt also pre-sents a potential security problem, if a vehicle should run out of brake capacity when driv- ing in a platoon.

Thus, previously known look-ahead control strategies for a single vehicle in order to reduce fuel consumption are not necessarily suitable for platoons.

There are studies indicating that platoon driving is more fuel consuming in hilly terrain thannormal driving. The above described problems are true for any kind of vehicles, but theeffects will increase with vehicle weight, as more energy is required for accelerating a heavy vehicle like a truck or bus in comparison with a car.

As these described scenarios, and similar variants of them, will lead to increased fuel con-sumption, it is desirable to find a solution in order to achieve the advantages of platoon driving.

SUMMARY lt is therefore an object of this invention to solve at least some of the above problems and improve platooning.

According to a first aspect of the invention, this objective is achieved by a method in a co-ordinating vehicle in a platoon, for determining a set of velocity profiles for the platoon. Theplatoon comprises a grouped set of vehicles, for use at an upcoming road section situatedahead of the platoon in the driving direction. The method comprises extracting vehicle re-lated information, relevant for the vehicle performance in the upcoming road section withregard to topology of the upcoming road section. Further the method comprises computinga set of candidate velocity profiles to be used by the platoon at the upcoming road section,based on the extracted vehicle related information in order to reduce a weighted sum ofenergy consumption and travel time of the coordinating vehicle with regard to topology ofthe upcoming road section. Also, the method comprises transmitting the computed set ofcandidate velocity profiles to be received by at least one other vehicle in the platoon. Themethod furthermore comprises receiving information related to the transmitted set of can-didate velocity profiles, which information has been computed by the at least one othervehicle, in order to reduce a weighted sum of energy consumption and travel time of saidvehicle at the upcoming road section. ln some embodiments, the method also comprisesiterating the computation, the transmission and the reception of information and whereinthe iterated computation is made based also on the received information. ln further addi-tion, the method also comprises determining the set of velocity profiles to be used by theplatoon at the upcoming road section, when an interruption condition for interrupting theiteration is fulfilled. The method comprises instructing each vehicle in the platoon to startusing a velocity profile in the determined set of velocity profiles upon arrival at the upcom- ing road section.

According to a second aspect of the invention, this objective is achieved by a control unit ina control unit in a coordinating vehicle in a platoon configured for determining a set of ve-locity profiles for the platoon, comprising a grouped set of vehicles, for use at an upcomingroad section situated ahead of the platoon in the driving direction. The control unit is con-figured for extracting vehicle related information, relevant for the vehicle performance in thedefined upcoming road section with regard to topology of the upcoming road section. Addi-tionally, the control unit is configured for computing a set of candidate velocity profiles to beused by the platoon at the upcoming road section, based on the extracted vehicle relatedinformation in order to reduce a weighted sum of energy consumption and travel time withregard to topology of the upcoming road section. Furthermore the control unit is configuredfor transmitting the computed set of candidate velocity profiles to be received by at leastone other vehicle in the platoon. The control unit is further configured for receiving informa-tion related to the transmitted set of candidate velocity profiles, which information has beencomputed by the at least one other vehicle, in order to reduce a weighted sum of energyconsumption and travel time of said vehicle when driving at the upcoming road section.The control unit is also configured for iterating the computation of the set of candidate ve-locity profiles, the transmission of the computed set of candidate velocity profiles, and thereception of information. Furthermore, the control unit is also configured for determining theset of velocity profiles to be used by the platoon at the upcoming road section, when aninterruption condition for interrupting the iteration is fulfilled. The control unit is also config-ured for instructing each vehicle in the platoon to start using a velocity profile in the deter- mined set of velocity profiles upon arrival at the upcoming road section.

According to a third aspect of the invention, this objective is achieved by a method in avehicle in a platoon, for assisting a coordinating vehicle in the platoon in determining a setof velocity profiles for the platoon to use at an upcoming road section situated ahead of theplatoon in the driving direction. The method comprises receiving a set of candidate velocityprofiles to be used by the platoon at the upcoming road section, from the coordinating ve-hicle, or from another vehicle, and a request for information related to the upcoming roadsection. Further, the method also comprises extracting vehicle related information, relevantfor the vehicle performance at the upcoming road section, based on topography of the up-coming road section. The method in addition comprises computing information related tothe received set of candidate velocity profiles, in order to reduce a weighted sum of energyconsumption and travel time when driving at the upcoming road section with regard to to-pology of the upcoming road section. The method also comprises transmitting the com-puted information. Additionally the method further comprises iterating the reception, extrac- tion, computation and transmission as long as any set of candidate velocity profiles is re- ceived. Also the method comprises receiving an instruction to start using a velocity profile in a determined set of velocity profiles upon arrival at the upcoming road section.

According to a fourth aspect of the invention, this objective is achieved by a computing unitin a vehicle in a platoon, configured for assisting a coordinating vehicle in the platoon indetermining a set of velocity profiles for the platoon to use at an upcoming road sectionsituated ahead of the present road section in the driving direction. The computing unit isconfigured for receiving a set of candidate velocity profiles to be used by the platoon at theupcoming road section, from the coordinating vehicle, or from another vehicle, and a re-quest for information related to the upcoming road section. Furthermore the computing unitis configured for extracting vehicle related information, relevant for the vehicle performancein the upcoming road section based on topography of the upcoming road section. Thecomputing unit in addition is configured for computing information related to the receivedset of candidate velocity profiles, in order to reduce a weighted sum of energy consumptionand travel time when driving at the upcoming road section with regard to topology of theupcoming road section. The computing unit is also configured for transmitting the com-puted information. ln addition the computing unit is configured for iterating reception, ex-traction, computation and transmission as long as any set of candidate velocity profiles isreceived. The computing unit is further configured for receiving an instruction to start usinga velocity profile in a determined set of velocity profiles upon arrival at the upcoming road section.

Thanks to the described aspects, platooning may be made in an energy saving way also inhilly terrain, as unnecessary braking and acceleration respectively is avoided. Thereby en-ergy consumption of the platoon as a whole is reduced, while maintaining a safe distancebetween the vehicles in the platoon, thereby avoiding accidents. By letting one vehicle se-lect a candidate set of velocity profiles and then allowing other vehicles in the platoon toinfluence the candidate set by returning a gradient step, any vehicle in the platoon mayinfluence the determination of the candidate set without revealing any possibly sensitiveinformation concerning the own vehicle. Further, it is possible to divide the road in seg-ments of any length, also brief and possibly overlapping road segments, enabling moreprecisely selected velocity profiles for the vehicles in the platoon. Furthermore, the de-scribed aspects are robust and easily understandable, thereby presenting an easily imple- mented solution to energy saving platooning. Thereby, platooning is improved.

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 a vehicle organised in a platoon according to an embodiment ofthe invention; Figure 2A illustrates a vehicle according to an embodiment of the invention; Figure 2B illustrates a platoon according to an embodiment of the invention; Figure 2C illustrates a first vehicle in a platoon according to an embodiment of the in-venﬁon; Figure 2D illustrates a first vehicle in a platoon according to an embodiment of the in-venﬁon; Figure 3 illustrates a vehicle in a platoon according to an embodiment of the inven-tion; Figure 4 is a flow chart illustrating an embodiment of the method; Figure 5 is an illustration depicting a system according to an embodiment.

Figure 6 is a flow chart illustrating an embodiment of the method in a vehicle; Figure 7 is an illustration depicting a system according to an embodiment.

DETAILED DESCRIPTION Embodiments of the invention described herein are defined as methods and control units,which may be put into practice in the embodiments described below. These embodimentsmay, however, be exemplified and realised in many different forms and are not to be lim-ited 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 descrip-tion, considered in conjunction with the accompanying drawings. lt is to be understood,however, that the drawings are designed solely for purposes of illustration and not as adefinition of the limits of the herein disclosed embodiments, for which reference is to bemade to the appended claims. Further, the drawings are not necessarily drawn to scaleand, unless othenNise indicated, they are merely intended to conceptually illustrate the structures and procedures described herein.

Figure 1 illustrates a scenario with a multitude of vehicles 100-1, 100-2, 100-3, driving in adriving direction 105, with an inter-vehicular distance t1, t2, organised in a platoon 110, driving on a road 120.

The vehicle platoon may be described as a chain of coordinated, inter-communicating ve- hicles 100-1, 100-2, 100-3 travelling at a given inter-vehicular distance t1, t2 and velocity.

One of the vehicles 100-1, 100-2, 100-3 in the platoon 110 may be a coordinating vehicle100-1, such as e.g. the first vehicle in the platoon 110. This is however only a non-limiting example.

The inter-vehicular distances t1, t2 may be fixed or variable in different embodiments. Fur-ther, the inter-vehicular distances t1, t2 may comprise a time gap, or a length distance indifferent embodiments. Also, the inter-vehicular distances t1, t2 may be identical betweensome or all of the vehicles 100-1, 100-2, 100-3 in the platoon 110 in some embodiments.Alternatively however, the inter-vehicular distances t1, t2 between each of the vehicles100-1, 100-2, 100-3 in the platoon 110 may be distinct. Further, the inter-vehicular dis-tances t1, t2 in length between any vehicles 100-1, 100-2, 100-3 in the platoon 110 mayvary with the speed of the vehicles 100-1, 100-2, 100-3, as the time gaps t1, t2 will createlength distances of different length in different vehicle speeds (except when driving at verylow speed, approaching a stationary condition, where a certain minimum distance in lengthmay be desired). Thus the distances t1, t2 may be e.g. some centimetres, some decime-tres, some meters or some tenths of meters in some embodiments, such as e.g. 20-40meters. ln other embodiments, the distances t1, t2 may be e.g. some fractions of a secondsuch as e.g. some tenths of a second. The inter-vehicular distances t1, t2 may be the samebetween at least some of the vehicles 100-1, 100-2, 100-3 in the platoon 110 in some em-bodiments. Alternatively, each vehicle 100-1, 100-2, 100-3 in the platoon 110 may have adifferent distance t1, t2 to the vehicle following or leading vehicle 100-1, 100-2, 100-3, thanall other vehicles 100-1, 100-2, 100-3 in the platoon 110.

The low inter-vehicular distances t1, t2 in the platoon 110, in comparison with the normaldistance kept between non-coordinated vehicles, leads to reduced air drag for the vehicles 100-1, 100-2, 100-3 in the platoon 110, leading to reduced energy consumption.

The distance to the preceding vehicle 100-1, 100-2, 100-3 may be measured by a e.g. ra-dar unit or lidar unit in some embodiments, configured for emitting radio waves and receiv- ing reflexions of the emitted radio waves, reflected by the preceding vehicle 100-1, 100-2, 100-3. By continuously or at certain time intervals measuring the distance to the precedingvehicle 100-1, 100-2, 100-3 and also continuously or at certain time intervals determine thespeed of the vehicle 100-1, 100-2, 100-3, e.g. from the speedometer of the vehicle 100-1,100-2, 100-3, or from a Global Positioning System (GPS) receiver in the vehicle 100-1,100-2, 100-3. Thereby, the time gap t may be calculated by dividing the measured distance in length with the determined speed.

According to some alternative embodiments, another on-board rangefinder sensor may beused instead of the radar unit, such as e.g. a laser rangefinder, an ultrasonic sensor emit-ting an ultrasonic wave and detecting and analysing the reflections, or other similar de- vices. ln order to keep the respective time gap t1, t2 signals may be generated for increasing thespeed of the vehicle 100-1, 100-2, 100-3, or braking the vehicle 100-1, 100-2, 100-3, re-spectively. Thereby a safe distance is upheld to the preceding vehicle 100-1, 100-2, 100-3.

The vehicles 100-1, 100-2, 100-3 in the platoon 110 may comprise e.g. a truck, a bus, acar, a motorcycle or any similar vehicle or other means of conveyance. The vehicles 100-1, 100-2, 100-3 may comprise vehicles of the same, or different types.

The vehicles 100-1, 100-2, 100-3 may be driver controlled or driverless autonomously con-trolled vehicles in different embodiments. However, for enhanced clarity, the vehicles 100- 1, 100-2, 100-3 are subsequently described as having a driver.

According to some embodiments, a common set of velocity profiles is selected for all vehi-cles 100-1, 100-2, 100-3 in the platoon 110, to be used at an upcoming road section aheadof the platoon 110. The selection is made by distributed optimisation, where vehicles 100-1, 100-2, 100-3 may optimise the velocity profile with regard to the topography of the up-coming road section ahead of the platoon 110. Each vehicle 100-1, 100-2, 100-3 may haveits own utility function and the distributed problem may be to find the common set of veloc- ity profiles that maximises the sum of the utility functions. ln some embodiments, one of the vehicles 100-1, 100-2, 100-3 in the platoon 110, such ase.g. the first vehicle 100-1 in the platoon 110, may prepare a candidate set of velocity pro-files which is then distributed to another vehicle 100-1, 100-2, 100-3 in the platoon 110.The other, receiving vehicle 100-1, 100-2, 100-3 may improve the received set of velocity profiles by taking a gradient step, using the own local utility function. The improved set of velocity profiles may then be sent to yet another vehicle 100-1, 100-2, 100-3 in the platoon110 etc., around a plurality, or all, of the vehicles 100-1, 100-2, 100-3 in the platoon 110.Thus all the involved vehicles 100-1, 100-2, 100-3 may influence the computation and se-lection of the set of velocity profiles, without having to expose any sensitive information.Depending on the utility function, different properties of the resulting driving profile may beachieved. Another advantage with this embodiments is that little or no coordination is re- quired. ln some alternative embodiments, one of the vehicles 100-1, 100-2, 100-3 in the platoon110, such as e.g. the first vehicle 100-1 in the platoon 110, may prepare a candidate set ofvelocity profiles which is then distributed to all other vehicles 100-1, 100-2, 100-3 in theplatoon 110. Each receiving vehicles 100-1, 100-2, 100-3 in the platoon 110 may computea gradient step, using the own local utility function, and return the computed gradient stepto the first vehicle 100-1. The first vehicle 100-1 may then collect gradient steps from allother vehicles 100-1, 100-2, 100-3 and prepare yet a candidate set of velocity profiles,based on the collected gradient steps, which again may be distributed to the other vehicles100-1, 100-2, 100-3 in the platoon 110, etc.

With this embodiment, standard methods of optimisation may be used as gradient stepsare collected from all other vehicles 100-1, 100-2, 100-3. The individual values of utilityfunctions may also be collected so that the first vehicle 100-1 may keep track of how theaggregated utility is developed. This embodiment may require some coordination but mayprovide a faster convergence to the optimal set of velocity profiles. The selection of compu- tation algorithms may be made based on simulations.

The communication of candidate set of velocity profiles and gradient steps may be made wirelessly, e.g. by making a wireless broadcast.

The evaluation may result in a rating or ranking of the received candidate velocity profiles.ln some embodiments, a veto may be applied by a vehicle 100-1, 100-2, 100-3 for a candi-date velocity profile that would result in an accident (or that a minimum distance t1, t2 be-tween the vehicles 100-1, 100-2, 100-3 is exceeded), or that would be impossible to followby the vehicle 100-1, 100-2, 100-3 due to constraints of the vehicle 100-1, 100-2, 100-3.

Thereby, an appropriate set of velocity profiles for the upcoming road section is selectedand determined, enabling a reduced and/ or low energy consumption for the platoon 110 as a whole. Thereby energy efficient driving may be made by the platoon 110 in all kind of landscapes, including hilly terrain. Another advantage of the described method is that aparticular velocity profile, which is very disadvantageous for a particular vehicle 100-1, 100-2, 100-3 may be disregarded, providing improved fairness between the vehicles 100-1,100-2, 100-3 in the platoon 110.

Reducing the energy consumption, when the vehicles 100-1, 100-2, 100-3 are using fossilfuel, leads to not only cheaper transport, but also reduced emissions of harmful exhaust gas.

A further advantage of the described method is that it is robust and easy to understand, making it easier to implement compared to other alternative, more complex methods.

Yet an advantage is the flexibility of the method, which may be implemented in a distrib-uted manner, enabling all vehicles 100-1, 100-2, 100-3 in the platoon 110 to participate inthe decision concerning the velocity profile selection for the platoon 110, but may also be centralised to one vehicle 100-1, 100-2, 100-3, or possibly to a vehicle external node.

Figure 2A illustrates an example of a scenario where a single vehicle 100 is driving on the road 120 in the driving direction 105 and has arrived to a hilly region.

The vehicle 100 has been driving uphill, and has reached the hill peak. When the vehicle100 was approaching the hill peak at a first position 210-1, the driver may release the ac-celerator and roll over the hill peak, firstly with descending velocity, but after having passedthe hill peak, the vehicle 100 gain velocity in the downhill slope. At a second point 210-2,the driver may again start pressing down the accelerator in order to gain velocity and mo- mentum for overcoming an ahead uphill slope (out of Figure 2A).

This method, which may be optimal from a fuel consumption perspective concerning a sin-gle vehicle 100 is however not appropriate during platooning, as will be further exemplified in Figure 2B.

Figure 2B illustrates the same, or a similar hill as illustrated in Figure 2A, but with a pla-toon 110 comprising various vehicles 100-1, 100-2, 100-3 with a respective distance t1, t2in between them, driving in a driving direction 105; i.e. from the right to the left in the Fig- UFG. 11 When the first vehicle 100-1 in the platoon 110 is approaching the hill peak, and from asingle vehicle optimisation point of view would benefit from releasing the accelerator inorder to roll over the top and roll downhill, thereby saving energy. However, the other fol-lowing vehicles 100-2, 100-3 are still driving uphill and releasing the accelerator is inappro-priate for these vehicles 100-2, 100-3, as they then may not have enough momentum for overcoming the hill.

Another problem is that the different vehicles 100-1, 100-2, 100-3 in the platoon 110 mayhave different weight and/ or different weight/ power ratio. Thereby, different vehicles 100-1, 100-2, 100-3 may be affected differently both in downhill and uphill. ln hilly terrain, perhaps in particular for heavy vehicles such as e.g. trucks when travellingalong an incline, the gravitational force has a strong influence. ln contrast with a passengervehicle, heavy vehicles is typically not able to produce a sufficient driving torque to main-tain the velocity when travelling along an uphill with a slope greater than approximately3.5% at 90 km/h, mentioned merely as a non-limiting example. Similarly, when facing adownhill heavy vehicles will typically experience a speed increase if the slope is less thanapproximately -1.4% in another non-limiting example. These values will vary considerablybetween different vehicles 100-1, 100-2, 100-3 depending on vehicle configuration, engine,vehicle weight, air resistance, roll resistance etc. Hence, the induced gravitational force can act as a positive or negative longitudinal force depending on the incline of the road 120.

Different vehicles 100-1, 100-2, 100-3 in the platoon 110 may have different weight and/ ordifferent weight/ power ratio. Thus, in order for the vehicles 100-1, 100-2, 100-3 in the pla-toon 110 to pass the hill in a grouped manner and still earning the advantages with theplatoon formation, a set of velocity profiles for the vehicles 100-1, 100-2, 100-3 in the pla-toon 110 has to be determined, that minimises or at least reduces a weighted sum of en- ergy consumption and travel time of the vehicles 100-1, 100-2, 100-3.

Thus some kind of compromise has to be calculated, that minimises or at least reduces theenergy consumption of the platoon 110 as a whole. The set of velocity profiles for the vehi-cles 100-1, 100-2, 100-3 may comprise one single velocity profile shared by all the vehicles100-1, 100-2, 100-3 in the platoon 110; or one distinct velocity profile for each vehicle 100-1, 100-2, 100-3 in the platoon 110, and everything in between, i.e. that some vehicles 100-1, 100-2, 100-3 in the platoon 110 share a common velocity profile. The bigger distancest1, t2 there is between the vehicles 100-1, 100-2, 100-3, the bigger differences there may be between the velocity profiles within the set of velocity profiles. Thus there may be a rela- 12 tion between the distances t1, t2 between the vehicles 100-1, 100-2, 100-3, and the veloc- ity of the vehicles 100-1, 100-2, 100-3 in some embodiments.

Figure 2C illustrates how the selection of the set of velocity profiles for the vehicles 100-1,100-2, 100-3 in the platoon 110 may be made when driving on the road 120 on a currentroad section 220-1, for determining the set of velocity profiles to be used in a upcomingroad section 220-2. Thereby, the computation and selection of the velocity profiles may be made in tranquillity.

The road slope may be determined at different geographical positions of the road 120ahead of the platoon 110 in the driving direction 105, such as e.g. at the current road sec-tion 220-1 and the upcoming road section 220-2, and/ or within the upcoming road section220-2.

The upcoming road section 220-2 may be defined by one of the vehicles 100-1, 100-2, 100-3 in the platoon 110, or they may have been previously agreed upon. ln the illustrated embodiment, the upcoming road section 220-2 starts where the currentroad section 220-1 ends, i.e. the road sections 220-1, 220-2 are not overlapping eachother. However, in other embodiments, as illustrated in Figure 2D, the road sections 220-1, 220-2 may be overlapping each other, partly or entirely. ln embodiments where the road sections 220-1, 220-2 are overlapping each other, the setof vehicle profiles determined for the upcoming road section 220-2 takes precedence over the determined set of vehicle profiles used at the current road section 220-1.

Figure 3 illustrates an example of how any of the previously scenario in Figure 1 and/ orFigures 2B- 2D may be perceived by the driver of a vehicle 100-1, 100-2, 100-3 in the pla-toon 110. Although the second vehicle 100-2 in the platoon 110 is illustrated, this is merelya non-limiting example. Any other vehicle 100-1, 100-2, 100-3 in the platoon 110, or some or all of them may be equally or similarly equipped.

The vehicle 100-2 thus follow the preceding vehicle 100-1 at a distance t1. The vehicle100-2 comprises a control unit 310 configured for determining a set of velocity profiles forthe platoon 110. ln some embodiments, the control unit 310 may comprise, or be part of anAdaptive Cruise Control (ACC). 13 ACC is an optional cruise control system for vehicles 100-1, 100-2, 100-3 that automati-cally adjusts the vehicle speed to maintain a safe distance from vehicles 100-1, 100-2, 100-3 ahead. The ACC may utilise e.g. on-board sensors such as a radar or a laser sensor formaintaining the distance t1, t2 to the vehicle 100-1, 100-2, 100-3 in front, or behind, and/ orsatellites, roadside beacons or mobile infrastructures as reflectors or transmitters on theback of other vehicles 100-1, 100-2, 100-3 ahead, in different embodiments. ln some embodiments, an optional display 370 may be comprised in the vehicle 100-2,connected to the control unit 310. Thereby, information associated with the velocity profilesand/ or the platoon 110 such as e.g. current size of the distance/ time gap t1, t2, currentroad slope ahead of the vehicle 100-1, 100-2, 100-3, etc.

The vehicle 100-2 also comprises a vehicle mounted distance measuring device 320, suchas e.g. radar unit, a rangefinder sensor, a stereo camera, an ultrasonic sensor emitting anultrasonic wave and detecting and analysing the reflections or similar device based on ra-dar, infra-red light or micro waves for detecting the vehicle 100-1 in front, and determine the distance t1.

Further, the vehicle 100-2 comprises a positioning unit 330. The positioning unit 330 maybe based on a satellite navigation system such as the Navigation Signal Timing and Rang-ing (Navstar) Global Positioning System (GPS), Differential GPS (DGPS), Galileo, GLON- ASS, or the like. Thus the positioning unit 330 may comprise a GPS receiver.

The geographical position of the vehicle 100-2 may be determined continuously or at cer- tain predetermined or configurable time intervals according to various embodiments.

Positioning by satellite navigation is based on distance measurement using triangulationfrom a number of satellites 340-1, 340-2, 340-3, 340-4. The satellites 340-1, 340-2, 340-3,340-4 continuously transmit information about time and date (for example, in coded form),identity (which satellite 340-1, 340-2, 340-3, 340-4 which broadcasts), status, and wherethe satellite 340-1, 340-2, 340-3, 340-4 are situated at any given time. GPS satellites 340-1, 340-2, 340-3, 340-4 sends information encoded with different codes, for example, butnot necessarily based on Code Division Multiple Access (CDMA). This allows informationfrom an individual satellite 340-1, 340-2, 340-3, 340-4 distinguished from the others' infor-mation, based on a unique code for each respective satellite 340-1, 340-2, 340-3, 340-4.This information can then be transmitted to be received by the appropriately adapted posi- tioning unit 330 in the vehicle 100-2. 14 Distance measurement can according to some embodiments comprise measuring the dif-ference in the time it takes for each respective satellite signal transmitted by the respectivesatellites 340-1, 340-2, 340-3, 340-4, to reach the positioning unit 330. As the radio signalstravel at the speed of light, the distance to the respective satellite 340-1, 340-2, 340-3, 340- 4 may be computed by measuring the signal propagation time.

The positions of the satellites 340-1, 340-2, 340-3, 340-4 are known, as they continuouslyare monitored by approximately 15-30 ground stations located mainly along and near theearth's equator. Thereby the geographical position, i.e. latitude and longitude, of the vehicle100-2 may be calculated by determining the distance to at least three satellites 340-1, 340-2, 340-3, 340-4 through triangulation. For determination of altitude, signals from four satel- lites 340-1, 340-2, 340-3, 340-4 may be used according to some embodiments.

Having determined the geographical position of the vehicle 100-2, and also determined thedriving direction 105 of the vehicle 100-2 and the platoon 110, the control unit 310 mayextract a road slope at a geographical position of the road 120 ahead of the vehicle 100-2 in the determined driving direction 105, such as e.g. on the upcoming road section 220-2.

The topography i.e. road slope of the upcoming road section 220-2 ahead of the vehicle100-2 may be extracted from a database 350. The database 350 may be situated withinthe vehicle 100-2 in some embodiments, or alternatively external to the vehicle 100-2, and accessible via a wireless interface. ln the database 350, different geographical positions are stored associated with a respec-tive road slope values, which may be extracted by using a geographical position and a di- rection as input values.

The topography of the upcoming road section 220-2 is important when determining thevelocity profile for the vehicles 100-1, 100-2, 100-3 in the platoon 110. For example, whenarriving at a long and steep downhill, any, some or all of the vehicles 100-1, 100-2, 100-3may like to modify a mode or state of the vehicle 100-1, 100-2, 100-3, such as e.g. velocityand/ or the charge level of the battery etc., in order to upload the battery when rolling downthe hill.

The vehicles 100-1, 100-2, 100-3 in the platoon 110 may communicate with each otherover a wireless interface. Thus the first vehicle 100-1 may comprise a first transceiver 360- 1 and the second vehicle 100-2 a second transceiver 360-2.

The wireless communication may be e.g. a Vehicle-to-Vehicle (V2V) signal, or any otherwireless signal based on, or at least inspired by wireless communication technology suchas Wi-Fi, Wireless Local Area Network (WLAN), Ultra Mobile Broadband (UMB), Bluetooth(BT), the communication protocol IEEE 802.11p, Wireless Access in Vehicular Environ-ments (WAVE) or infrared transmission to name but a few possible examples of wireless communications.

Figure 4 illustrates an example of a method 400 in a coordinating vehicle 100-1 in a pla-toon 110, according to an embodiment. The flow chart in Figure 4 shows the method 400for determining a set of velocity profiles for the platoon 110, for use at an upcoming roadsection 220-2 situated ahead of the platoon 110 in the driving direction 105. The platoon 110 comprises a grouped set of vehicles 100-1, 100-2, 100-3.

The driving direction 105 of the vehicle 100 may be determined based on the location ofthe destination of the journey, or by extrapolating the driving direction based on previouslydetermined geographical positions and possibly knowledge of the road direction, e.g. from stored map data.

The vehicles 100-1, 100-2, 100-3 may be any arbitrary kind of means for conveyance, suchas a truck, a bus or a car. The number of vehicles 100-1, 100-2, 100-3 in the platoon 110 may be any number exceeding one, such as e.g. 2, 3, °<>.

The coordinating vehicle 100-1 may be the first vehicle in the platoon 110. However, anyvehicle 100-1, 100-2, 100-3 at any position in the platoon 110 may be the coordinating ve- hicle in different embodiments.

The vehicles 100-1, 100-2, 100-3 may communicate with other vehicles 100-1, 100-2, 100-3 in the platoon 110, and possibly also with other vehicles or entities, via wireless commu-nication signalling, based on e.g. Vehicle-to-Vehicle (V2V) communication or any otherwireless communication technology such as Wi-Fi, Wireless Local Area Network (WLAN),Ultra Mobile Broadband (UMB), Bluetooth (BT), or infrared transmission to name but a few possible examples of wireless communications. 16 The vehicles 100-1, 100-2, 100-3 are driving in the platoon 110 with a respective distancet1, t2 between each vehicle 100-1, 100-2, 100-3 in the platoon 110. The inter-vehiculardistances t1, t2 may be the same between some or all vehicles 100-1, 100-2, 100-3 insome embodiments. Alternatively, different vehicles 100-1, 100-2, 100-3 may keep a differ-ent distance t1, t2 to the vehicle 100-1, 100-2, 100-3 in front. The inter-vehicular distancest1, t2 may also vary within an interval in some embodiments. The inter-vehicular distancest1, t2 may be measured in time, then often referred to as a time gap, e.g. of 0.1 second, 1second etc. However, the inter-vehicular distances t1, t2 may alternatively be measured inlength distance, e.g. some centimetres, some decimetres, some meters, some tenths of meters, etc. ln some embodiments, the distances t1, t2 between the vehicles 100-1, 100-2, 100-3 in theplatoon 110 may be extended when an altitude difference between the highest and lowestpoint of the upcoming road section 220-2 exceeds a threshold value. Thus the platoon 110according to those embodiments may be dissolved in hilly terrain. ln some embodiments,the inter-vehicular distances t1, t2 may be extended by multiplication with a factor > 1, such as e.g. 2, 3, °<>. ln some embodiments, the distances t1, t2 may be variable based on the road slope of theupcoming road section 220-2 by increasing the distances t1, t2 when the road slope isnegative, indicating downhill, and/ or increasing the variable time gap t1, t2 when the road slope is positive, indicating uphill, in some alternative embodiments.

The set of velocity profiles may comprise one distinct velocity profile for each vehicle 100-1, 100-2, 100-3 in the platoon 110 in some embodiments. However in some embodiments,the set of velocity profiles may comprise one velocity profile for the whole platoon 110 to share, or at least for some vehicles 100-1, 100-2, 100-3 in the platoon 110 to share.

The set of velocity profiles may comprise one distinct velocity profile for each vehicle 100- 1, 100-2, 100-3 in the platoon 110 in some embodiments. ln order to correctly be able to determine the set of velocity profiles, the method 400 maycomprise a number of steps 401-408. However, some of these steps 401-408 may be per-formed solely in some alternative embodiments, like e.g. step 401. Further, the describedsteps 401-408 may be performed in a somewhat different chronological order than thenumbering suggests. ln some embodiments, steps 403-405 may be iterated in some em- bodiments. ln some embodiments, steps 403-405 may be iterated until an interruption con- 17 dition for interrupting the iteration is fulfilled, where after steps 406-408 are performed. The method 400 may comprise the subsequent steps: Step 401 which may be performed only in some embodiments, may comprise distributing geographical information defining the upcoming road section 220-2.

The upcoming road section 220-2 may however be predefined in some embodiments. lnother embodiments, any of the vehicles 100-1, 100-2, 100-3 in the platoon 110 may deter- mine and define the upcoming road section 220-2.

The topography i.e. road s|ope of the upcoming road section 220-2 may be stored in a da-tabase 350, associated with geographical positions at the upcoming road section 220-2.

The road sections 220-1, 220-2 may be overlapping in some embodiments.

Step 402 comprises extracting vehicle related information, relevant for the vehicle per-formance in the upcoming road section 220-2 with regard to topology of the upcoming road section 220-2, from the own, coordinating vehicle 100-1.

The extracted vehicle related information may comprise e.g. modes or states of the coordi-nating vehicle 100-1, gear ratios in the gearbox of the coordinating vehicle 100-1, minimumand maximum speed of the coordinating vehicle 100-1, air drag, speed and load-dependent losses, cooling/ heating requirements, maximum torque curve, information con-cerning the relation between torque, engine speed and energy consumption, gear-shifttiming, gear shift time, charging level of batteries, pressure level of pneumatic reservoir,exhaust after treatment system temperature, emissions and similar information relevant for vehicle performance on the upcoming road section 220-2.

Step 403 comprises computing a set of candidate velocity profiles to be used by the pla-toon 110 at the upcoming road section 220-2, based on the extracted 402 vehicle relatedinformation in order to reduce a weighted sum of energy consumption and travel time of thecoordinating vehicle 100-1 (in the first iteration), with regard to topology of the upcoming road section 220-2.

Thus the set of candidate velocity profiles for the platoon 110 with the smallest weightedsum of energy consumption and travel time may be determined, e.g. the set of profiles hav-ing the lowest possible energy consumption while passing the upcoming road section 220- 2 within a velocity interval, such as e.g. between 70-80 km/h (in a non-limiting example), 18 based on the extracted vehicle related information from the own coordinating vehicle 100-1. Typically the lowest velocity in the velocity interval may be kept while driving uphill and the highest velocity in the velocity interval in the downhill. ln some embodiments, a minimum velocity may be predetermined which has to be kept byall vehicles 100-1, 100-2, 100-3 in the platoon 110 may be determined. Also, correspond-ingly, a maximum velocity may be predetermined (by legal reasons), such as e.g. 80 km/h, or 90 km/h depending on vehicle type and legislation.

The evaluation may be based on the topography or road inclination of the upcoming roadsection 220-2. The road inclination will typically vary with the geographical position whendriving through the upcoming road section 220-2, e.g. when driving in a hilly region. Theroad inclination of the upcoming road section 220-2 may be extracted from a database,which may be situated on board the vehicle 100-1, 100-2, 100-3, or in a database externalto the vehicle 100-1, 100-2, 100-3, accessible via the previously discussed wireless inter- face.

The different road inclination at different geographical positions may influence differentvehicles 100-1, 100-2, 100-3 in the platoon 110 differently, e.g. depending on differentweight, weight/ power ratio and other parameters that may be different and unique to eachvehicle 100-1, 100-2, 100-3 in the platoon 110.

The weight/ power ratio, or power loading, may be a calculation commonly applied to vehi-cles in general, to enable the comparison of one vehicle's performance to another. lt isused as a measurement of performance of a vehicle 100-1, 100-2, 100-3 as a whole, withthe weight (or mass) of the vehicle 100-1, 100-2, 100-3 divided by the engine's power out- put, to give a metric that is independent of the vehicle's size.

The weight/ power ratio of the vehicle 100-1, 100-2, 100-3 may be measured by a weightsensor on the vehicle 100-1, 100-2, 100-3, or estimated based on the load in some em- bodiments, and a stored power value.

However, the road inclination may also influence the vehicles 100-1, 100-2, 100-3 basedon modes or states of the vehicle 100-1, 100-2, 100-3, gear ratios in the gearbox of thevehicle 100-1, 100-2, 100-3, minimum and maximum speed of the vehicle 100-1, 100-2,100-3, speed and load-dependent losses, cooling/ heating requirements, maximum torque curve, information concerning the relation between torque, engine speed and energy con- 19 sumption, gear-shift timing, gear shift time, charging level of batteries, pressure level ofpneumatic reservoir, exhaust after treatment system temperature, emissions and similarinformation relevant for vehicle performance on the upcoming road section 220-2, whichmay be different for different vehicles 100-1, 100-2, 100-3 in the platoon 110.

Any candidate velocity profile that results in that minimum distances t1, t2 between anyvehicles 100-1, 100-2, 100-3 in the platoon 110 cannot be kept may be disregarded fromthe determined set of velocity profiles. The minimum distances t1, t2 may be set for secu-rity reasons in order to avoid a collision and may be pre-set to e.g. some centimetres, some decimetres, some meters, etc.

Step 404 comprises transmitting the computed 403 set of candidate velocity profiles to be received by at least one other vehicle 100-1, 100-2, 100-3 in the platoon 110.

The set of candidate velocity profiles may be communicated via the above described wire-less communication signalling, for example broadcasted so that any vehicle 100-1, 100-2,100-3 in the platoon 110 is able to receive it in some embodiments. ln other embodiments,the set of candidate velocity profiles is sent to a dedicated other single vehicle 100-1, 100- 2, 100-3 in the platoon 110, for further computations.

Step 405 comprises receiving information related to the transmitted 404 set of candidatevelocity profiles, which information has been computed by the at least one other vehicle100-1, 100-2, 100-3 in the platoon 110, in order to reduce a weighted sum of energy con-sumption and travel time of said vehicle 100-1, 100-2, 100-3 at the upcoming road section220-2.

The information may comprise a gradient step, i.e. a modification of the transmitted 404 setof candidate velocity profiles in some embodiments. This may be referred to as gradient information.

The information related to the transmitted 404 set of velocity profiles may in some em-bodiments comprise a modified set of velocity profiles, wherein a plurality of vehicles 100-1, 100-2, 100-3 in the platoon 110 subsequently receives the modified set of velocity pro-files, and modify it in order to reduce a weighted sum of energy consumption and traveltime of said vehicle 100-1, 100-2, 100-3 When driving at the upcoming road section 220-2and transmit the modified set of velocity profiles to be received by yet another vehicle 100-1, 100-2, 100-3 in the platoon 110. ln some embodiments, the information related to the transmitted 404 set of velocity profilesmay comprise a modification of the received set of velocity profiles. A plurality of vehicles100-1, 100-2, 100-3 in the platoon 110 may receive the transmitted 404 set of velocity pro-files, and may modify the set of velocity profiles in order to reduce a weighted sum of en-ergy consumption and travel time for the own vehicle 100-1, 100-2, 100-3 when driving onthe upcoming road section 220-2, and send the modification to one particular vehicle 100-1, 100-2, 100-3, which compile the respective modifications and prepare yet a set of veloc- ity profiles, based on the received modifications.

The information related to the transmitted 404 set of velocity profiles is computed in re-spective vehicle 100-1, 100-2, 100-3 in order to minimise the energy consumption andtravel time for said vehicle 100-1, 100-2, 100-3 when driving on the upcoming road section220-2 with regard to topology of the upcoming road section 220-2, based on modes orstates of the vehicle 100-1, 100-2, 100-3, gear ratios in the gearbox of the vehicle 100-1,100-2, 100-3, minimum and maximum speed of the vehicle 100-1, 100-2, 100-3, speed andload-dependent losses, cooling/ heating requirements, maximum torque curve, informationconcerning the relation between torque, engine speed and energy consumption, gear-shifttiming, gear shift time, charging level of batteries, pressure level of pneumatic reservoir,exhaust after treatment system temperature, emissions and similar information relevant for the vehicle performance on the upcoming road section 220-2.

Step 406 comprises iterating the above described steps 403-405, wherein the iterated computation 405 is made based in addition also on the received 405 information.

The iteration may be performed until an interruption condition is fulfilled. Such interruptioncondition for interrupting the iteration 406 may comprise: the difference between each itera-tively computed 403 set of candidate velocity profiles is smaller than a threshold value; thenorm of the gradient information is smaller than a threshold value; a predetermined limit ofnumbers of iterations is reached such as e.g. 5-10 times; a time limit is reached such ase.g. 30 seconds or five minutes; or the platoon 110 arrives at the upcoming road section 220-2, in different embodiments.

Step 407 comprises determining the set of velocity profiles to be used by the platoon 110at the upcoming road section 220-2, based on the received 405 information, when an inter- ruption condition for interrupting the iteration 406 is fulfilled. 21 The set of velocity profiles may be determined so that minimum distances t1, t2 betweenthe vehicles 100-1, 100-2, 100-3 in the platoon 110 are maintained when driving at the up- coming road section 220-2, in some embodiments.

The set of velocity profiles may in some embodiments be determined so that all vehicles100-1, 100-2, 100-3 in the platoon 110 are able to follow the set of velocity profiles andmaintain maximum distances t1, t2 to the vehicle 100-1, 100-2, 100-3 in front when driving at the upcoming road section 220-2.

Step 408 comprises instructing each vehicle 100-1, 100-2, 100-3 comprised in the platoon110 to start using a velocity profile in the determined 407 set of velocity profiles upon arri- val at the upcoming road section 220-2.

Thus the vehicles 100-1, 100-2, 100-3 in the platoon 110 may start using the determinedvelocity profiles simultaneously when arriving at the upcoming road section 220-2, e.g.when the first vehicle 100-1 of the platoon 110 arrives at the upcoming road section 220-2;or when any vehicle 100-1, 100-2, 100-3 in the platoon 110 arrives at the upcoming roadsection 220-2. ln some embodiments, vehicles 100-1, 100-2, 100-3 in the platoon 110 maystart using the determined respective velocity profiles as they pass a geographical positionand enter the upcoming road section 220-2. ln such embodiments, the vehicles 100-1, 100- 2, 100-3 consecutively may start using the respective velocity profile. ln some embodiments, when at least some of the steps in the method 400 has been iter-ated, step 408 may be performed when the platoon 110, or the first vehicle 100-1 of the platoon 110 arrives at the upcoming road section 220-2.

Figure 5 illustrates an embodiment of a system 500 in a vehicle platoon 110. The system500 comprises a control unit 310, in a coordinating vehicle 100-1 of the platoon 110, fordetermining a set of velocity profiles to be used by the platoon 110 at an upcoming roadsection 220-2, situated ahead of the platoon 110 in the driving direction 105. The platoon110 comprises a grouped set of vehicles 100-1, 100-2, 100-3, wherein the coordinating vehicle 100-1 is one vehicle, e.g. the first vehicle in the platoon 110.

The control unit 310 of the coordinating vehicle 100-1 may thus perform at least some ofthe previously described steps 401-408 according to the method 400 described above andillustrated in Figure 4. 22 The coordinating vehicle 100-1 may be one of the vehicles 100-1, 100-2, 100-3 in the pla-toon 110, such as e.g. the first vehicle 100-1 in the platoon 110, or any other vehicle 100-1, 100-2, 100-3 at any arbitrary position in the platoon 110.

Thus the control unit 310 in the vehicles 100-1, 100-2, 100-3 is configured for extractingvehicle related information, relevant for the vehicle performance in the defined upcomingroad section 220-2 with regard to topology of the upcoming road section 220-2. Further-more the control unit 310 is also configured for computing a set of candidate velocity pro-files to be used by the platoon 110 at the upcoming road section 220-2, based on the ex-tracted vehicle related information in order to reduce a weighted sum of energy consump-tion and travel time with regard to topology of the upcoming road section 220-2. ln addition,the control unit 310 is also configured for transmitting the computed set of candidate veloc-ity profiles to be received by at least one other vehicle 100-1, 100-2, 100-3 in the platoon110.

Also the control unit 310 is configured for receiving information related to the transmittedset of candidate velocity profiles, which information has been computed by the at least oneother vehicle 100-1, 100-2, 100-3 in the platoon 110, in order to reduce a weighted sum ofenergy consumption and travel time of said vehicle 100-1, 100-2, 100-3 when driving at theupcoming road section 220-2. The received information may comprise either gradient in- formation or a modified set of candidate velocity profiles in different embodiments.

Also the control unit 310 is configured for iterating the computation of the set of candidatevelocity profiles, the transmission of the computed set of candidate velocity profiles, andthe reception of information. The control unit 310 is further configured for determining theset of velocity profiles to be used by the platoon 110 at the upcoming road section 220-2,when an interruption condition for interrupting the iteration is fulfilled. Such interruptioncondition may comprise e.g. the difference between each iteratively computed 403 set ofcandidate velocity profiles is smaller than a threshold value; the norm of the gradient infor-mation is smaller than a threshold value; a predetermined limit of numbers of iterations isreached; a time limit is reached; or the platoon 110 arrives at the upcoming road section220-2.

Also, the control unit 310 is configured for determining the set of velocity profiles to be usedby the platoon 110 at the upcoming road section 220-2, based on the received information. ln addition, the control unit 310 is further configured for instructing each vehicle 100-1, 100- 23 2, 100-3 comprised in the platoon 110 to start using a velocity profile in the determined set of velocity profiles upon arrival at the upcoming road section 220-2.

The control unit 310 may thus be configured for iterating at least some of the steps 403- 405 of the method 400 for a predetermined, or undetermined amount of times. ln some embodiments, the control unit 310 may further be configured for processing infor-mation related to the transmitted set of candidate velocity profiles, which information com- prises a modified set of velocity profiles, or a gradient step.

Further, the control unit 310 may be configured for determining the set of velocity profilesso that minimum distances t1, t2 between the vehicles 100-1, 100-2, 100-3 in the platoon 110 are maintained when driving at the upcoming road section 220-2.

The control unit 310 may also be configured for determining the set of velocity profiles sothat all vehicles 100-1, 100-2, 100-3 in the platoon 110 are able to follow the set of velocityprofiles and maintain maximum distances t1, t2 to the vehicle 100-1, 100-2, 100-3 in front when driving at the upcoming road section 220-2. ln some embodiments, the control unit 310 may further be configured for distributing geo- graphical information defining the upcoming road section 220-2.

The control unit 310 may further be configured for extending the distances between thevehicles 100-1, 100-2, 100-3 in the platoon 110, when an altitude difference between the highest and lowest point of the upcoming road section 220-2 exceeds a threshold value.

Also, the control unit 310 may be configured for iterating steps 403-405 of the method 400,until the difference between each iteratively computed velocity profile is smaller than athreshold value, or until the platoon 110 arrives at the upcoming road section 220-2, when steps 407-408 are performed.

Further, the control unit 310 may be configured for processing one distinct velocity profile of the set of velocity profiles for each vehicle 100-1, 100-2, 100-3 in the platoon 110.

The control unit 310 may further, in some embodiments be configured for instructing eachvehicle 100-1, 100-2, 100-3 comprised in the platoon 110 to start using a velocity profile in the determined set of velocity profiles upon arrival at the upcoming road section 220-2. 24 Also, in some embodiments, the control unit 310 may be further configured for disregardingany candidate velocity profiles that result in that minimum distances t1, t2 between anyvehicles 100-1, 100-2, 100-3 in the platoon 110 cannot be kept, from the determined set of velocity profiles.

Further, the control unit 310 may be configured for distributing geographical informationdefining the upcoming road section. Such geographical information may comprise coordi- nates or other similar means of determining geographical position.

The control unit 310 may in some embodiments be additionally configured for extendingthe distances t1, t2 between the vehicles 100-1, 100-2, 100-3 in the platoon 110, when analtitude difference between the highest and lowest point of the upcoming road section 220- 2 exceeds a threshold value.

The control unit 310 may comprise a receiving circuit 510 configured for receiving wirelessand/ or wired signals from e.g. a distance measuring device 320 and a positioning device330.

The control unit 310 may also comprise a processor 520 configured for performing at leastsome of the calculating or computing of the control unit 310. Thus the processor 520 maybe configured for determining a set of velocity profiles for a platoon 110, comprising agrouped set of vehicles 100-1, 100-2, 100-3, for use at an upcoming road section 220-2 situated ahead of the platoon 110 in the driving direction 105.

The processor 520 may thus be further configured for extracting vehicle related informa-tion, relevant for the vehicle performance in the defined upcoming road section 220-2 withregard to topology of the upcoming road section 220-2. Further, the processor 520 may beadditionally configured for computing a set of candidate velocity profiles to be used by theplatoon 110 at the upcoming road section 220-2, based on the extracted vehicle relatedinformation in order to reduce a weighted sum of energy consumption and travel time withregard to topology of the upcoming road section 220-2. The processor 520 may also befurther configured for transmitting the computed set of candidate velocity profiles to be re-ceived by at least one other vehicle 100-1, 100-2, 100-3 in the platoon 110. ln addition, themethod may be configured for receiving information related to the transmitted set of candi-date velocity profiles, which information has been computed by the at least one other vehi- cle 100-1, 100-2, 100-3 in the platoon 110, in order to reduce a weighted sum of energy consumption and travel time of said vehicle 100-1, 100-2, 100-3 when driving at the up-coming road section 220-2. The processor 520 may additionally be configured for iteratingthe computation of the set of candidate velocity profiles, the transmission of the computedset of candidate velocity profiles, and the reception of information. The processor 520 isfurther configured for determining the set of velocity profiles to be used by the platoon 110at the upcoming road section 220-2, when an interruption condition for interrupting the it-eration is fu|fi||ed. Such interruption condition may comprise e.g. the difference betweeneach iteratively computed set of candidate velocity profiles is smaller than a thresholdvalue; the norm of the gradient information is smaller than a threshold value; a predeter-mined limit of numbers of iterations is reached; a time limit is reached; or the platoon 110 arrives at the upcoming road section 220-2.

The processor 520 may also be configured for instructing each vehicle 100-1, 100-2, 100-3comprised in the platoon 110 to start using a velocity profile in the determined set of veloc- ity profiles upon arrival at the upcoming road section 220-2.

Such processor 520 may comprise one or more instances of a processing circuit, i.e. aCentral Processing Unit (CPU), a processing unit, a processing circuit, a processor, anApplication Specific Integrated Circuit (ASIC), a microprocessor, or other processing logicthat may interpret and execute instructions. The herein utilised expression ”processor” maythus represent a processing circuitry comprising a plurality of processing circuits, such as, e.g., any, some or all of the ones enumerated above.

Furthermore, the control unit 310 may comprise a memory 525 in some embodiments. Theoptional 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-basedtransistors. The memory 525 may comprise e.g. a memory card, a flash memory, a USBmemory, a hard disc, or another similar volatile or non-volatile storage unit for storing datasuch as e.g. ROM (Read-Only Memory), PROM (Programmable Read-Only Memory),EPROM (Erasable PROM), EEPROM (Electrically Erasable PROM), etc. in different em- bodiments.

Further, the control unit 500 may comprise a signal transmitter 530. The signal transmitter530 may be configured for transmitting a control signal over a wired or wireless interface toa wireless transmitter 360 which in turn may signal or broadcast Wireless signals to vehi-cles 100-1, 100-2, 100-3 of the platoon 110. 26 The previously described steps 401-408 to be performed in the control unit 310 may beimplemented through the one or more processors 520 within the control unit 310, togetherwith computer program product for performing at least some of the functions of the steps401-408. Thus a computer program product, comprising instructions for performing thesteps 401-408 in the control unit 310 may perform the method 400 comprising at leastsome of the steps 401-408 for determining a set of velocity profiles for a platoon 110, com-prising a grouped set of vehicles 100-1, 100-2, 100-3, for use in a upcoming road section220-2, situated ahead of the platoon 110 in the driving direction 105, when the computer program is loaded into the one or more processors 520 of the control unit 310.

The computer program product mentioned above may be provided for instance in the formof a data carrier carrying computer program code for performing at least some of the step401-408 according to some embodiments when being loaded into the one or more proces-sors 520 of the control unit 310. 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 appro-priate 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 com-puter program code on a server and downloaded to the control unit 310 remotely, e.g., over an lnternet or an intranet connection.

Further, some embodiments may comprise a vehicle 100-1, 100-2, 100-3 comprising a control unit 310 as described above.

Additionally, some embodiments may comprise a stationary central node 380 comprising acontrol unit 310 as described above. The stationary central node 380 may comprise e.g. a server, or a cloud service in some embodiments.

Figure 6 illustrates an example of a method 600 in a vehicle 100-1, 100-2, 100-3 in a pla-toon 110, according to an embodiment. The flow chart in Figure 6 shows the method 600for assisting a coordinating vehicle 100-1 in the platoon 110 in determining a set of velocityprofiles for the platoon 110, for use at an upcoming road section 220-2 situated ahead of the platoon 110 in the driving direction 105. ln order to correctly be able to assist the other vehicle 100-1, 100-2, 100-3 in determiningthe set of velocity profiles, the method 600 may comprise a number of steps 601-607.

However, some of these steps 601-607 may be performed in alternative manners. Further, 27 the described steps 601-607 may be performed in a somewhat different chronological or- der than the numbering suggests. The method 600 may comprise the subsequent steps: Step 601 which is comprised only in some embodiments, comprises receiving geographi-cal information defining the upcoming road section 220-2, from the coordinating vehicle100-1.

The upcoming road section 220-2 may be predefined in some embodiments. ln other em-bodiments, the coordinating vehicle 100-1 may determine and define the upcoming roadsection 220-2.

Step 602 comprises receiving a set of candidate ve|ocity profiles to be used by the p|atoon110 at the upcoming road section 220-2, from the coordinating vehicle 100-1, or from anyother vehicle 100-1, 100-2, 100-3, and a request for information related to the upcoming road section 220-2.

The requested information related to the upcoming road section 220-2 comprises modes orstates of the vehicle 100-1, 100-2, 100-3, gear ratios in the gearbox of the vehicle 100-1,100-2, 100-3, minimum and maximum speed of the vehicle 100-1, 100-2, 100-3, speed andload-dependent losses, cooling/ heating requirements, maximum torque curve, informationconcerning the relation between torque, engine speed and energy consumption, gear-shifttiming, gear shift time, charging level of batteries, pressure level of pneumatic reservoir,exhaust after treatment system temperature, emissions and similar information relevant forvehicle performance on the upcoming road section 220-2. These are merely some exam- ples of some parameters that may be comprised in the requested information.

Step 603 comprises extracting vehicle related information, relevant for the vehicle per-formance at the upcoming road section 220-2, from the own vehicle 100-1, 100-2, 100-3, based on topography of the upcoming road section 220-2.

Some vehicle related information such as e.g. the weight of the vehicle 100-1, 100-2, 100-3may be measured by a weight sensor on the vehicle 100-1, 100-2, 100-3, or estimated based on the load, in some embodiments.

Step 604 comprises computing information related to the received 602 set of candidate ve|ocity profiles, in order to reduce a weighted sum of energy consumption and travel time 28 for the vehicle 100-1, 100-2, 100-3 When driving at the upcoming road section 220-2 with regard to topology of the upcoming road section 220-2.

Step 605 comprises transmitting the computed 604 information.

The information may be transmitted wirelessly, to be received by the coordinating vehicle100-1, or the vehicle 100-1, 100-2, 100-3 having transmitted the set of candidate velocity profiles in different embodiments.

Step 606 comprises iterating steps 602-605 for as long as any set of candidate velocity profiles is received 602.

Step 607 comprises receiving an instruction to start using a velocity profile in a determined set of velocity profiles upon arrival at the upcoming road section 220-2.

Thus the velocity profile in the set of velocity profiles for the platoon 110 with the smallestweighted sum of energy consumption and travel time may be used by the vehicle 100-1,100-2, 100-3, e.g. the velocity profile that gives the vehicle 100-1, 100-2, 100-3 the lowestpossible energy consumption while passing the upcoming road section 220-2 within a ve-locity interval, such as e.g. between 70-80 km/h in a non-limiting example. Typically thelowest velocity in the velocity interval may be kept while driving uphill or reached at the crest and the highest velocity in the velocity interval may be kept in the downhill.

The velocity profile may thereby be selected so that energy consumption is minimised orreduced, appropriate for the topography of the upcoming road section 220-2. For example,in a downhill, the vehicles 100-1, 100-2, 100-3 may change state, e.g. charge the batteries and/ or the pneumatic compressor tank.

Thus the vehicles 100-1, 100-2, 100-3 in the platoon 110 may start using the determinedset of velocity profiles simultaneously when arriving at the upcoming road section 220-2,e.g. when the first vehicle 100-1 of the platoon 110 arrives at the upcoming road section 220-2 in some embodiments. 29 Figure 7 illustrates an embodiment of a system 700 in a vehicle platoon 110. The system700 comprises a computing unit 390 in a vehicle 100-1, 100-2, 100-3 in the vehicle platoon110. The computing unit 390 is configured for assisting a coordinating vehicle 100-1 in de-termining a set of velocity profiles for a platoon 110 for use at an upcoming road section220-2 situated ahead of the present road section 220-2 in the driving direction 105 of theplatoon 110. The platoon 110 thus comprises a grouped set of vehicles 100-1, 100-2, 100-3.

The computing unit 390 may thus perform at least some of the previously described steps 601-606 according to the method 600 described above and illustrated in Figure 6.

The vehicle 100-1, 100-2, 100-3 may be one of the vehicles 100-1, 100-2, 100-3 in the pla-toon 110.

Thus the computing unit 390 is configured for receiving a set of candidate velocity profilesto be used by the platoon 110 at the upcoming road section 220-2, from the coordinatingvehicle 100-1, or any other vehicle 100-1, 100-2, 100-3, and a request for information re-lated to the upcoming road section 220-2. Further, the computing unit 390 is configured forextracting vehicle related information, relevant for the vehicle performance in the upcomingroad section 220-2 from the vehicle 100-1, 100-2, 100-3 based on topography of the up-coming road section 220-2. The computing unit 390 is in addition configured for computinginformation related to the received set of candidate velocity profiles, which information iscomputed in order to reduce a weighted sum of energy consumption and travel time of thevehicle 100-1, 100-2, 100-3 when driving at the upcoming road section 220-2 with regard totopology of the upcoming road section 220-2. Furthermore, the computing unit 390 is inaddition configured for iterating reception, extraction, computation and transmission as longas any set of candidate velocity profiles is received, and furthermore configured for receiv-ing an instruction to start using a velocity profile in a determined set of velocity profiles upon arrival at the upcoming road section 220-2.

Thereby, the selection of velocity profile in the set of velocity profiles to be used by the ve-hicle 100-1, 100-2, 100-3 in the platoon 110 may be based on the topography or road incli-nation of the upcoming road section 220-2. The road inclination will typically vary with thegeographical position when driving through the upcoming road section 220-2, e.g. when driving in a hilly region.

Also, in some embodiments, the computing unit 390 may be further configured for disre-garding any candidate velocity profiles that result in that minimum distances t1, t2 betweenany vehicles 100-1, 100-2, 100-3 in the platoon 110 cannot be kept, from the determinedset of velocity profiles. Thus any vehicle 100-1, 100-2, 100-3 in the platoon 110 may ex-clude a particular candidate velocity profiles from use by the platoon 110 in the set of ve-locity profiles in some embodiments. ln other embodiments, any vehicle 100-1, 100-2, 100-3 in the platoon 110 may exclude a particular candidate velocity profiles from use by thatvehicle 100-1, 100-2, 100-3.

The computing unit 390 may comprise a receiving circuit 710 configured for receiving wire-less and/ or Wired signals from e.g. a distance measuring device 320 and a positioningdevice 330.

The computing unit 390 may also comprise a processor 720 configured for performing atleast some of the calculating or computing of the computing unit 390. Thus the processor720 may be configured for assisting a coordinating vehicle 100-1 in determining a set ofvelocity profiles for the platoon 110, for use in a upcoming road section 220-2 situated ahead of the platoon 110 in the driving direction 105.

The processor 720 may thus be further configured for receiving a set of candidate velocityprofiles to be used by the platoon 110 at the upcoming road section 220-2, from the coor-dinating vehicle 100-1 or any other vehicle 100-1, 100-2, 100-3, and a request for informa-tion related to the upcoming road section 220-2. Further, the processor 720 may be config-ured for extracting vehicle related information, relevant for the vehicle performance in theupcoming road section 220-2 from the vehicle 100-1, 100-2, 100-3 based on topography ofthe upcoming road section 220-2. The processor 720 may in addition be configured forcomputing information related to the received set of candidate velocity profiles, which in-formation is computed in order to reduce a weighted sum of energy consumption and traveltime of the vehicle 100-1, 100-2, 100-3 when driving at the upcoming road section 220-2with regard to topology of the upcoming road section 220-2. The processor 720 may alsobe configured for iterating reception, extraction, computation and transmission as long asany set of candidate velocity profiles is received, and furthermore configured for receivingan instruction to start using a velocity profile in a determined set of velocity profiles upon arrival at the upcoming road section 220-2.

Such processor 720 may comprise one or more instances of a processing circuit, i.e. a Central Processing Unit (CPU), a processing unit, a processing circuit, a processor, an 31 Application Specific Integrated Circuit (ASIC), a microprocessor, or other processing logicthat may interpret and execute instructions. The herein utilised expression ”processor” maythus represent a processing circuitry comprising a plurality of processing circuits, such as, e.g., any, some or all of the ones enumerated above.

Furthermore, the computing unit 390 may comprise a memory 725 in some embodiments.The optional memory 725 may comprise a physical device utilised to store data or pro-grams, i.e., sequences of instructions, on a temporary or permanent basis. According tosome embodiments, the memory 725 may comprise integrated circuits comprising silicon-based transistors. The memory 725 may comprise e.g. a memory card, a flash memory, aUSB memory, a hard disc, or another similar volatile or non-volatile storage unit for storingdata such as e.g. ROM (Read-Only Memory), PROM (Programmable Read-Only Memory),EPROM (Erasable PROM), EEPROM (Electrically Erasable PROM), etc. in different em- bodiments.

Further, the computing unit 390 may comprise a signal transmitter 730. The signal trans-mitter 730 may be configured for transmitting a control signal over a Wired or wireless inter-face to a wireless transmitter 360 which in turn may signal or broadcast wireless signals tothe coordinating vehicle 100-1, or any other vehicles 100-1, 100-2, 100-3 of the platoon110 and/ or stationary central node 380.

The previously described steps 601-607 to be performed in the computing unit 390 may beimplemented through the one or more processors 720 Within the computing unit 390, to-gether with computer program product for performing at least some of the functions of thesteps 601-607 of the method 600. Thus a computer program product, comprising instruc-tions for performing the steps 601-607 in computing unit 390 may perform the method 600comprising at least some of the steps 601-607 for determining a set of velocity profiles for aplatoon 110, comprising a grouped set of vehicles 100-1, 100-2, 100-3, for use at an up-coming road section 220-2, situated ahead of the platoon 110 in the driving direction 105,when the computer program is loaded into the one or more processors 720 of the comput-ing unit 390.

The computer program product mentioned above may be provided for instance in the formof a data carrier carrying computer program code for performing at least some of the step601-607 according to some embodiments when being loaded into the one or more proces-sors 720 of the computing unit 390. 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 32 appropriate 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 com-puter program code on a server and downloaded to the computing unit 390 remotely, e.g., over an lnternet or an intranet connection.

Further, some embodiments may comprise a vehicle 100-1, 100-2, 100-3 comprising a computing unit 390 as described above.

The terminology used in the description of the embodiments as i||ustrated in the accompa-nying drawings is not intended to be |imiting of the described methods 400, 600; the controlunit 310; the computing unit 390; the systems 500, 700; the computer programs; or thevehicle 100-1, 100-2, 100-3. Various changes, substitutions 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 ofthe associated listed items. The term ”or” as used herein, is to be interpreted as a mathe-matical OR, i.e., as an inclusive disjunction; not as a mathematical exclusive OR (XOR),unless expressly stated otherwise. ln addition, the singular forms "a", "an" and "the" are tobe interpreted as “at least one", thus also possibly comprising a plurality of entities of thesame kind, unless expressly stated otherwise. lt will be further understood that the terms"includes", "comprises", "including" or "comprising", specifies the presence of stated feat-ures, actions, integers, steps, operations, elements, or components, but do not precludethe presence or addition of one or more other features, actions, integers, steps, operations,elements, components, or groups thereof. A single unit such as e.g. a processor may fulfilthe functions of several items recited in the claims. The mere fact that certain measuresare recited in mutually different dependent claims does not indicate that a combination ofthese measures cannot be used to advantage. A computer program may be stored/ distrib-uted on a suitable medium, such as an optical storage medium or a solid-state mediumsupplied together with or as part of other hardware, but may also be distributed in other forms such as via lnternet or other wired or wireless communication system.

Claims

1. A method (400) in a coordinating vehicle (100-1) in a platoon (110), for determin-ing a set of velocity profiles for the platoon (110), comprising a grouped set of vehicles(100-1, 100-2, 100-3), for use at an upcoming road section (220-2) situated ahead of theplatoon (110) in the driving direction (105), wherein the method (400) comprises: extracting (402) vehicle related information, relevant for the vehicle performance inthe upcoming road section (220-2) with regard to topology of the upcoming road section(220-2); computing (403) a set of candidate velocity profiles to be used by the platoon(110) at the upcoming road section (220-2), based on the extracted (402) vehicle relatedinformation in order to reduce a weighted sum of energy consumption and travel time of thecoordinating vehicle (100-1) with regard to topology of the upcoming road section (220-2); transmitting (404) the computed (403) set of candidate velocity profiles to be re-ceived by at least one other vehicle (100-1, 100-2, 100-3) in the platoon (110); receiving (405) information related to the transmitted (404) set of candidate veloc-ity profiles, which information has been computed by the at least one other vehicle (100-1,100-2, 100-3), in order to reduce a weighted sum of energy consumption and travel time ofsaid vehicle (100-1, 100-2, 100-3) at the upcoming road section (220-2); iterating (406) steps 403-405, wherein the iterated computation (405) is madebased also on the received (405) information; determining (407) the set of velocity profiles to be used by the platoon (110) at theupcoming road section (220-2), when an interruption condition for interrupting the iteration(406) is fulfilled; instructing (408) each vehicle (100-1, 100-2, 100-3) in the platoon (110) to startusing a velocity profile in the determined (407) set of velocity profiles upon arrival at the upcoming road section (220-2).

2. The method (400) according to claim 1, wherein the received (405) information comprises either gradient information or a modified set of candidate velocity profiles.

3. The method (400) according to any of claim 1 or claim 2, wherein the received(405) information comprises a modified set of candidate velocity profiles, and wherein aplurality of vehicles (100-1, 100-2, 100-3) in the platoon (110) subsequently receives themodified set of candidate velocity profiles, modify it in order to reduce a weighted sum ofenergy consumption and travel time of said vehicle (100-1, 100-2, 100-3) when driving atthe upcoming road section (220-2) and transmit the modified set of candidate velocity pro-files to be received by yet another vehicle (100-1, 100-2, 100-3) in the platoon (110). 34

4. The method (400) according to any of claim 1 or claim 2, wherein the received(405) information comprises gradient information made based on the set of candidate ve-locity profiles, and wherein a plurality of vehicles (100-1, 100-2, 100-3) in the platoon (110)receives the transmitted (404) set of velocity profiles, and computes gradient informationthere upon, in order to reduce a weighted sum of energy consumption and travel time forthe own vehicle (100-1, 100-2, 100-3) when driving on the upcoming road section (220-2), and send the computed gradient information to the coordinating vehicle (100-1).

5. The method (400) according to any of claims 1-4, wherein the set of velocity pro-files is determined (407) so that minimum distances (t1, t2) between the vehicles (100-1,100-2, 100-3) in the platoon (110) are maintained when driving at the upcoming road sec-tion (220-2).

6. The method (400) according to any of claims 1-5, wherein the set of velocity pro-files is determined (407) so that all vehicles (100-1, 100-2, 100-3) in the platoon (110) areable to follow the set of velocity profiles and maintain maximum distances (t1, t2) to the vehicle (100-1, 100-2, 100-3) in front when driving at the upcoming road section (220-2).

7. The method (400) according to any of claims 1-6, wherein the information relatedto the transmitted (404) set of velocity profiles is computed in respective vehicle (100-1,100-2, 100-3) in order to minimise the energy consumption and travel time for said vehicle(100-1, 100-2, 100-3) when driving on the upcoming road section (220-2) with regard totopology of the upcoming road section (220-2), based on modes or states of the vehicle(100-1, 100-2, 100-3), gear ratios in the gearbox of the vehicle (100-1, 100-2, 100-3),minimum and maximum speed of the vehicle (100-1, 100-2, 100-3), speed and load-dependent losses, cooling/ heating requirements, maximum torque curve, information con-cerning the relation between torque, engine speed and energy consumption, gear-shifttiming, gear shift time, charging level of batteries, pressure level of pneumatic reservoir,exhaust after treatment system temperature, emissions and similar information relevant for the vehicle performance on the upcoming road section (220-2).

8. The method (400) according to any of claims 1-7, further comprising distributing (401) geographical information defining the upcoming road section (220-2).

9. The method (400) according to any of claims 1-8, further comprising extending thedistances (t1, t2) between the vehicles (100-1, 100-2, 100-3) in the platoon (110), when an altitude difference between the highest and lowest point of the upcoming road section (220- 2) exceeds a threshold value.

10. tion for interrupting the iteration (406) comprises: the difference between each iteratively The method (400) according to any of claims 1-9, wherein the interruption condi- computed (403) set of candidate velocity profiles is smaller than a threshold value; thenorm of the gradient information is smaller than a threshold value; a predetermined limit ofnumbers of iterations is reached; a time limit is reached; or the platoon (110) arrives at the upcoming road section (220-2).

11.files comprises one distinct velocity profile for each vehicle (100-1, 100-2, 100-3) in theplatoon (110). The method (400) according to any of claims 1-10, wherein the set of velocity pro-

12. for determining a set of velocity profiles for the platoon (110), comprising a grouped set of A control unit (310) in a coordinating vehicle (100-1) in a platoon (110) configured vehicles (100-1, 100-2, 100-3), for use at an upcoming road section (220-2) situated aheadof the platoon (110) in the driving direction (105), wherein the control unit (310) is config-ured for extracting vehicle related information, relevant for the vehicle performance in thedefined upcoming road section (220-2) with regard to topology of the upcoming road sec-tion (220-2); and additionally configured for computing a set of candidate velocity profiles tobe used by the platoon (110) at the upcoming road section (220-2), based on the extractedvehicle related information in order to reduce a weighted sum of energy consumption andtravel time with regard to topology of the upcoming road section (220-2); and furthermoreconfigured for transmitting the computed set of candidate velocity profiles to be received byat least one other vehicle (100-1, 100-2, 100-3) in the platoon (110); and also configuredfor receiving information related to the transmitted set of candidate velocity profiles, whichinformation has been computed by the at least one other vehicle (100-1, 100-2, 100-3), inorder to reduce a weighted sum of energy consumption and travel time of said vehicle(100-1, 100-2, 100-3) when driving at the upcoming road section (220-2); and further con-figured for iterating the computation of the set of candidate velocity profiles, the transmis-sion of the computed set of candidate velocity profiles, and the reception of information;and also configured for determining the set of velocity profiles to be used by the platoon(110) at the upcoming road section (220-2), when an interruption condition for interruptingthe iteration is fulfilled; and also configured for instructing each vehicle (100-1, 100-2, 100-3) in the platoon (110) to start using a velocity profile in the determined set of velocity pro- files upon arrival at the upcoming road section (220-2). 36

13. cording to any of claims 1-11 when the computer program is executed in the control unit A computer program comprising program code for performing a method (400) ac- (310), according to claim 12.

14. A vehicle (100-1, 100-2, 100-3) comprising a control unit (310) according to claim12.

15. A method (600) in a vehicle (100-1, 100-2, 100-3) in a platoon (110), for assistinga coordinating vehicle (100-1) in the platoon (110) in determining a set of velocity profiles for the platoon (110) to use at an upcoming road section (220-2) situated ahead of the pla-toon (110) in the driving direction (105), wherein the method (600) comprises: receiving (602) a set of candidate velocity profiles to be used by the platoon (110)at the upcoming road section (220-2), from the coordinating vehicle (100-1), or from an-other vehicle (100-1, 100-2, 100-3), and a request for information related to the upcomingroad section (220-2); extracting (603) vehicle related information, relevant for the vehicle performanceat the upcoming road section (220-2), based on topography of the upcoming road section(220-2); computing (604) information related to the received (602) set of candidate velocityprofiles, in order to reduce a weighted sum of energy consumption and travel time whendriving at the upcoming road section (220-2) with regard to topology of the upcoming roadsection (220-2); transmitting (605) the computed (604) information; iterating (606) steps 602-605 as long as any set of candidate velocity profiles isreceived (602); receiving (607) an instruction to start using a velocity profile in a determined set of velocity profiles upon arrival at the upcoming road section (220-2).

16. lated information comprises modes or states of the vehicle (100-1, 100-2, 100-3), gear ra- The method (600) according to claims 15, wherein the extracted (603) vehicle re- tios in the gearbox of the vehicle (100-1, 100-2, 100-3), minimum and maximum speed ofthe vehicle (100-1, 100-2, 100-3), air drag, speed and load-dependent losses, cooling/heating requirements, maximum torque curve, information concerning the relation betweentorque, engine speed and energy consumption, gear-shift timing, gear shift time, charging level of batteries, pressure level of pneumatic reservoir, exhaust after treatment system 37 temperature, emissions and similar information relevant for vehicle performance on the upcoming road section (220-2).

17. (601) geographical information defining the upcoming road section (220-2). The method (600) according to any of claims 15-16, further comprising receiving

18. A computing unit (390) in a vehicle (100-1, 100-2, 100-3) in a platoon (110), con-figured for assisting a coordinating vehicle (100-1) in the platoon (110) in determining a setof velocity profiles for the platoon (110) to use at an upcoming road section (220-2) situatedahead of the present road section (220-2) in the driving direction (105) of the platoon (110),wherein the control unit (310) is configured for receiving a set of candidate velocity profilesto be used by the platoon (110) at the upcoming road section (220-2), from the coordinat-ing vehicle (100-1), or from another vehicle (100-1, 100-2, 100-3), and a request for infor-mation related to the upcoming road section (220-2); and furthermore configured for ex-tracting vehicle related information, relevant for the vehicle performance in the upcomingroad section (220-2) based on topography of the upcoming road section (220-2); and inaddition configured for computing information related to the received set of candidate ve-locity profiles, in order to reduce a weighted sum of energy consumption and travel timewhen driving at the upcoming road section (220-2) With regard to topology of the upcomingroad section (220-2); and also configured for transmitting the computed information; andalso configured for iterating reception, extraction, computation and transmission as long asany set of candidate velocity profiles is received, and furthermore configured for receivingan instruction to start using a velocity profile in a determined set of velocity profiles upon arrival at the upcoming road section (220-2).

19. cording to any of claims 15-17 when the computer program is executed in the computing A computer program comprising program code for performing a method (600) ac- unit (390) according to claim 18.

20. claim 18. A vehicle (100-1, 100-2, 100-3) comprising the computing unit (390) according to