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Title:
METHOD AND SYSTEM FOR SPACING ADJUSTMENT IN A MOVING VEHICLE TRAIN
Document Type and Number:
WIPO Patent Application WO/2013/147684
Kind Code:
A1
Abstract:
The present invention relates to a method for safe and fuel-efficient spacing adjustment in a moving vehicle train formed of at least two vehicles, comprising the steps of continuously maintaining (S1 ) communication between the train's vehicles, continuously determining (S2) parameters which characterise the train's journey, and using parameters thus determined (S3) as a basis for determining suitable mutual spacing for the train's vehicles, which step of determining (S3) said suitable mutual spacing of the train's vehicles comprises the step of using identified risk factors with a probability indication for each risk factor as a basis for evaluating (S3) the risk generated by said risk factors and adjusting said spacing accordingly. The present invention relates also to a system (I) for safe and fuel-efficient spacing adjustment in a moving vehicle train. The present invention relates also to a motor vehicle. The present invention relates also to a computer programme and a computer programme product.

Inventors:
AL ALAM ASSAD (SE)
PETTERSSON HENRIK (SE)
LYBERGER RICKARD (SE)
JOHANSSON ANDERS (SE)
Application Number:
PCT/SE2013/050317
Publication Date:
October 03, 2013
Filing Date:
March 21, 2013
Export Citation:
Click for automatic bibliography generation   Help
Assignee:
SCANIA CV AB (SE)
International Classes:
B60W30/16; B60W30/18; B61L23/34; G01S5/00; G05D1/02; G08G1/095; G08G1/16
Domestic Patent References:
WO2011151274A12011-12-08
Foreign References:
US5777451A1998-07-07
US5781119A1998-07-14
US20100256835A12010-10-07
EP2276012A22011-01-19
US6032097A2000-02-29
US6324465B12001-11-27
Other References:
See also references of EP 2830921A4
Attorney, Agent or Firm:
FRENDH, Eva (Södertälje, SE)
Download PDF:
Claims:
CLAIMS

1. A method for safe and fuel-efficient spacing adjustment in a moving vehicle train formed of at least two vehicles, comprising the steps of continuously maintaining (S1 ) communication between the train's vehicles, continuously determining (S2) parameters which characterise the train's journey, and using parameters thus determined (S3) as a basis for determining suitable mutual spacing for the train's vehicles, characterised in that the step of determining (S3) said suitable mutual spacing of the train's vehicles comprises the step of using identified risk factors with a probability indication for each risk factor as a basis for evaluating (S3) the risk generated by said risk factors and adjusting said spacing accordingly.

2. A method according to claim 1 , in which the step of using identified risk factors and probability indications as a basis for evaluating the risk generated by said risk factors includes taking account of local factors in relation to the vehicle train's journey.

3. A method according to claim 2, in which said local factors comprise prevailing and/or expected traffic situations in relation to the vehicle's journey.

4. A method according to claim 2, in which said local factors comprise topographical factors in relation to the vehicle's journey.

5. A method according to claim 2, in which said local factors comprise road characteristics in relation to the vehicle's journey, which characteristics comprise road status, number of traffic lanes, presence of bends, presence of entry and exit slips. 6. A method according to any one of claims 1-5, comprising the step of continuously determining the vehicles' mutual spacing by radar means.

7. A method according to any one of claims 1-6, in which the step of adjusting said mutual spacing of the train's vehicles is effected automatically by control of the speed of the respective vehicles.

8. A system (I) for safe and fuel-efficient spacing adjustment in a moving vehicle train formed of at least two vehicles, comprising means (110) for continuously maintaining communication between the train's vehicles, means for continuously determining parameters which characterise the train's journey, and means (100, 170) for using parameters thus determined as a basis for determining suitable mutual spacing of the train's vehicles, characterised in that said means (100, 110, 120, 130, 140, 150, 170) for determining said suitable mutual spacing of the train's vehicles comprise means (100, 110, 120, 130, 140, 150, 170) for using identified risk factors with a probability indication for each risk factor as a basis for evaluating the risk generated by said risk factors, and means for adjusting said spacing accordingly.

9. A system (I) according to claim 8, in which said means (100, 110, 120, 130, 140, 150, 170) for using identified risk factors and probability indications as a basis for evaluating the risk generated by said risk factors include taking account of local factors in relation to the vehicle train's journey. 10. A system (I) according to claim 9, in which said means (120) for taking account of local factors comprises means (124) for determining prevailing and/or expected traffic situations in relation to the vehicle's journey.

11. A system (I) according to claim 9, in which said means (120) for taking account of local factors comprise means (122) for determining topographical factors in relation to the vehicle's journey.

12. A system (I) according to claim 9, in which said means (120) for taking account of local factors comprise means (126) for determining road characteristics in relation to the vehicle's journey, which characteristics comprise road status, number of traffic lanes, presence of bends, presence of entry and exit slips.

13. A system (I) according to any one of claims 8-12, comprising radar means (130) for continuously determining the vehicles' mutual spacing. 14. A system (I) according to any one of claims 8-13, in which said means for adjusting said mutual spacing of the train's vehicles comprises means (170) for automatic control of the speed of the respective vehicles.

15. A vehicle adapted to forming part of a vehicle train provided with a system (I) according to claims 8-14. 16. A computer programme (P) for safe and fuel-efficient spacing adjustment in a moving vehicle train, which programme (P) comprises programme code which, when run by an electronic control unit (100) or another computer (500) connected to the electronic control unit (100), enables the electronic control unit (100) to perform steps according to claims 1-7. 17. A computer programme product comprising a digital storage medium which stores the computer programme (P) according to claim 16.

Description:
METHOD AND SYSTEM FOR SPACING ADJUSTMENT IN A

MOVING VEHICLE TRAIN

TECHNICAL FIELD The invention relates to a method for spacing adjustment in a moving vehicle train according to the preamble of claim 1. It relates also to a system for spacing adjustment in a moving vehicle train according to the preamble of claim 8. It relates also to a motor vehicle. It relates also to a computer programme and a computer programme product. BACKGROUND

Driving at a short distance from a vehicle in front may in many traffic situations improve both traffic flow and fuel efficiency because the air resistance is reduced and the vehicle density on the road is increased. Achieving these gains and ensuring the maintenance of traffic safety when driving in this way does however require adaptive speed control and spacing adjustment based on information about other road users.

In this context the distance from other vehicles is important in that more distance gives the system more time to react to an event, e.g. for braking. More distance does however reduce the actual gain arising from using the system.

US2010256836 refers to a system for spacing adjustment in a moving vehicle train in which the distance is varied on the basis of parameters which comprise reaction times combined with allowing for stability in communication, leading to appropriate spacing adjustment. OBJECTS OF THE INVENTION

One object of the present invention is to propose a method for spacing adjustment in a moving vehicle train which makes it possible to optimise fuel consumption without affecting safety. One object of the present invention is to propose a system for spacing adjustment in a moving vehicle train which makes it possible to optimise fuel consumption without affecting safety.

SUMMARY OF THE INVENTION These and other objects indicated by the description set out below are achieved by means of a system and a method for safe and fuel-efficient spacing adjustment in a moving vehicle train, a motor vehicle, a computer programme and a computer programme product of the kind indicated in the introduction which further present the features indicated in the characterising parts of the attached independent claims 1 , 8, 15, 16 and 17.

Preferred embodiments of the method and the system are defined in the attached dependent claims 2-7 and 9-14.

The invention achieves the objects with a method for safe and fuel-efficient spacing adjustment in a moving vehicle train formed of at least two vehicles, comprising the steps of continuously maintaining communication between the train's vehicles, continuously determining parameters which characterise the train's journey, and using parameters thus determined as a basis for determining suitable mutual spacing for the vehicles, which step of determining said suitable mutual spacing of the vehicles comprises the step of using identified risk factors with a probability indication for each risk factor as a basis for evaluating the risk generated by said risk factors and adjusting said spacing accordingly.

Taking the incidence of the various risk factors into account makes it more possible to assess the consequences of being able to maintain a shorter spacing distance and thus be able to optimise fuel consumption without endangering safety. This entails assessing the current situation but also different scenarios for the situation some time ahead in order thereby to assess the consequences of a shorter spacing distance and thus as far as possible be able to maintain close spacing in the vehicle train for the sake of low fuel consumption without endangering safety.

In one embodiment of the method, the step of using identified risk factors and probability indications as a basis for evaluating the risk generated by each factor comprises taking account of local factors relating to the vehicle train's journey. The potential for optimising and consequently, where appropriate, shortening the spacing distance in the train without endangering safety is thus improved.

In one embodiment of the method, said local factors comprise prevailing and/or expected traffic situations in relation to the vehicle's journey. This makes it possible for the spacing distance in the vehicle train to be kept shorter where the traffic situation so allows, thereby improving the optimisation of spacing and the consequent potential for shortening the spacing distance in the train without endangering safety. In one embodiment of the method, said local factors comprise topographical factors in relation to the vehicle's journey. This makes it possible for the spacing distance to be kept shorter where the topography so allows, e.g. where the carriageway along the vehicle's itinerary is relatively level, thereby enhancing the potential for shortening the spacing distance without endangering safety.

In one embodiment of the method, said local factors comprise road characteristics in relation to the vehicle's journey, e.g. road status, number of traffic lanes, presence of bends, presence of entry and exit slips. Taking account of road characteristics such as road status, number of traffic lanes on the carriageway along the vehicle's itinerary, presence of bends and/or presence of entry and exit slips makes it possible to optimise the spacing distance in the vehicle train so that it may be shortened without endangering safety where there is little presence of such road characteristics. In one embodiment, the method comprises the step of continuously determining the vehicles' mutual spacing by radar means. Redundancy is thus achieved so that if communication between vehicles in the train is temporarily interrupted the spacing distance can be maintained on the basis of information about it via the radar means.

In one embodiment of the method, the step of adjusting said mutual spacing of the train's vehicles is conducted automatically by control of the speed of each vehicle, resulting in efficient travel and effective spacing adjustment between the vehicles in the train. The invention also achieves the objects with a system for safe and fuel- efficient spacing adjustment in a moving vehicle train formed of at least two vehicles, comprising means for continuously maintaining communication between the train's vehicles, means for continuously determining parameters which characterise the train's journey, and means for using parameters thus determined as a basis for determining suitable mutual spacing for the vehicles, which means for determining said suitable mutual spacing of the vehicles comprises means for using identified risk factors with a probability indication for each risk factor as a basis for evaluating the risk generated by said risk factors and means for adjusting said spacing accordingly. Taking the incidence of the various risk factors into account makes it more possible to assess the consequences of being able to maintain a shorter distance and thus be able to optimise fuel consumption without endangering safety. This entails assessing the current situation but also different scenarios for the situation some time ahead in order thereby to assess the consequences of a shorter spacing distance and thus as far as possible be able to maintain close spacing in the vehicle train for the sake of low fuel consumption without endangering safety.

In one embodiment of the system, said means for using identified risk factors and probability indications as a basis for evaluating the risk generated by said risk factors comprises means for taking account of local factors relating to the vehicle train's journey. The potential for optimising and consequently, where appropriate, shortening the spacing distance in the train without endangering safety is thus improved.

In one embodiment of the system, said means for taking account of local factors comprises means for determining prevailing and/or expected traffic situations in relation to the vehicle's journey. This makes it possible for the spacing distance in the vehicle train to be kept shorter where the traffic situation so allows, thereby improving optimisation of the spacing and the consequent potential for shortening it in the vehicle train without endangering safety.

In one embodiment of the system, said means for taking account of local factors comprises means for determining topographical factors in relation to the vehicle's journey. This makes it possible for the spacing distance to be kept shorter where the topography so allows, e.g. where the carriageway along the vehicle's itinerary is relatively level, thereby enhancing the potential for shortening the spacing distance without endangering safety.

In one embodiment of the system, said means for taking account of local factors comprises means for determining road characteristics in relation to the vehicle's journey, e.g. road status, number of traffic lanes, presence of bends, presence of entry and exit slips. Taking account of road characteristics such as road status, number of traffic lanes on the carriageway along the vehicle's itinerary, presence of bends and/or presence of entry and exit slips makes it possible to optimise the spacing distance in the vehicle train so that it may be shortened without endangering safety where there is little presence of such road characteristics.

In one embodiment, the system comprises radar means for continuously determining the vehicles' mutual spacing. Redundancy is thus achieved so that if communication between vehicles in the train is temporarily interrupted the spacing distance can be maintained on the basis of information about it via the radar means. In one embodiment of the system said means for adjusting said mutual spacing of the train's vehicles comprises means for automatic control of the speed of the respective vehicles, resulting in efficient travel and effective spacing adjustment for the vehicles in the train. DESCRIPTION OF DRAWINGS

The present invention will be better understood by reading the detailed description set out below in conjunction with the attached drawings, in which the same reference notations are used for similar items throughout the various views, and Fig. 1 schematically illustrates a motor vehicle according to an embodiment of the present invention.

Fig. 2 schematically illustrates a system and a method for safe and fuel- efficient spacing adjustment in a moving vehicle train according to an embodiment of the present invention, Fig. 3 schematically illustrates a vehicle train according to an embodiment of the present invention,

Fig. 4 is a schematic block diagram of a method according to the present invention, and

Fig. 5 schematically illustrates a computer according to an embodiment of the present invention.

DESCRIPTION OF EMBODIMENTS

The term "link" refers herein to a communication link which may be a physical connection such as an opto-electronic communication line, or a non-physical connection such as a wireless connection, e.g. a radio link or microwave link. Fig. 1 illustrates schematically a motor vehicle 1 intended to form part of a vehicle train according to an embodiment of the present invention. The vehicle exemplified is a heavy vehicle in the form of a truck with a cab 2. It may alternatively be any suitable vehicle, e.g. a bus or a car. The vehicle is provided with a system I according to the present invention.

Fig. 2 is a schematic block diagram of a system I for spacing adjustment in a moving vehicle train according to an embodiment of the present invention.

The system I comprises an electronic control unit 100 for said spacing adjustment.

The system comprises communication means 110 for continuously maintaining communication between the train's vehicles. It comprises in one variant so-called wireless LAN or WLAN for conveying information between the vehicles which is relevant for assessment of their mutual spacing.

The system comprises local factor incorporation means 120 for taking account of local factors in relation to the vehicle train's journey. Said local factor incorporation means comprise itinerary determination means 122. The system I is thus provided with itinerary determination means adapted to providing predetermined characteristics of the carriageway along the vehicle's itinerary and the vehicle's location along its itinerary.

Said itinerary determination means comprise in one variant a map information unit 122a containing map data comprising said characteristics of the carriageway along the vehicle train's itinerary, e.g. topography, any presence of bends and any presence of entry and exit slips, to make it easier to assess the consequences of being able to maintain a shorter distance between the vehicles in the train and thereby be able to optimise fuel consumption without endangering safety. Said itinerary determination means further comprise vehicle location determination means 122b in the form of a geographical position determination system, i.e. GPS, for identifying the vehicle's location at the time of the respective braking process. The itinerary determination means, i.e. the map information unit 122a and the vehicle location determination means 122b, thus make it possible to continuously identify each vehicle at the vehicle train's location and the characteristics of the carriageway to make it more possible to assess the consequences of being able to maintain a shorter distance between the vehicles in the train. Such characteristics of the carriageway may affect safety with regard to the spacing between the train's vehicles and might thus constitute a risk factor.

Said local factor incorporation means 120 for taking account of local factors in relation to the vehicle train's journey comprise traffic situation determination means 124 for determining prevailing and/or expected traffic situations in relation to the journey of the train's vehicles which might affect safety with regard to the spacing between the vehicles and might thus constitute a risk factor. The system I is therefore provided with said traffic situation determination means, which comprise communication means 124a provided with radio units and/or so-called wireless LAN or WLAN for determining prevailing and/or expected traffic situations. Said traffic situation determination means further comprise sensor means 24b situated on board vehicles in the train to monitor other vehicles in their vicinity and other objects such as other road users, e.g. cyclists or pedestrians or obstacles to, for example, the train's leading vehicle. Said sensor means may take the form of camera means, radar means and/or laser measuring means.

Said local factor incorporation means 120 for taking account of local factors in relation to the vehicle train's journey further comprise road state characteristics determination means 126 for determining road state characteristics. The system I is therefore provided with road state characteristics determination means. Road state characteristics comprise running surfaces such as wet road surfaces, gravel roads and the like which might affect safety with regard to the spacing between the train's vehicles and might thus constitute a risk factor. Said road state characteristics determination means may comprise any suitable means for road surface determination, e.g. friction sensor means, temperature means for determining ambient and/or road temperatures, and the like.

The system I further comprises spacing distance determination means 130 for continuously determining spacing between a vehicle in the train and a vehicle in front and/or behind in the train. Said spacing distance determination means comprises in one variant radar means and/or laser measuring means. In this case the spacing distance determination means in for example the form of radar means serves as redundancy so that if communication between vehicles in the train is temporarily broken the spacing can be maintained on the basis of information about it via the radar means.

The system I further comprises driving conditions determination means 140 for determination of conditions in which vehicles in the train are driven. Said conditions comprise the time of day with a view to assessing whether it is dark during the train's journey, the weather, e.g. any precipitation and its type, and outdoor temperature, vehicle load, vehicle speed, type of road, e.g. motorway or national highway, number of traffic lanes on the road, whether the respective stretch of road is affected by accidents, etc.

Said driving conditions determination means comprise in one variant time determination means 142 for determining the time when the vehicle train travels.

Said driving conditions determination means in one variant further comprises weather determination means 144 for determining weather along the vehicle train's itinerary at the time when the train travels. Said weather determination means may comprise rain sensor means, weather information receiving means for receiving weather information via radio or equivalent.

Said driving conditions determination means in one variant further comprise speed determination means 146 for continuously determining the running speed of the train's vehicles. Said speed determination means in one variant comprises speedometer means.

Said driving conditions determination means in one variant further comprise road type determination means 148 for determining the types of road on which the train's vehicles travel, which in one variant is provided via said map data from the map information unit 122a of the itinerary determination means 122.

The system in one variant further comprises vehicle identification means 150 for identifying vehicles which belong to the vehicle train and any which do not, e.g. vehicles which cut into the train. In one variant said vehicle identification means comprises camera means.

The system in one variant further comprises warning means 160 to warn the driver of prevailing or potential dangers/risk factors arising from prevailing spacing between the train's vehicles. This serves as redundancy to automatic spacing adjustment based on risk assessment and probability assessment taking account of the aforesaid parameters. Said warning means may comprise warning devices in the form of flashing or continuous lights, warning texts, warning images, auditory warning devices such as acoustic alarm devices, tactile warning devices or equivalent. The system is provided with a spacing distance regulating unit 170 to regulate the spacing between the train's vehicles.

The system I is further provided with brake regulating means 172 to regulate braking of vehicles in the train in order to regulate the spacing between them. Said brake regulating means comprise service brakes, auxiliary brakes and engine brakes.

The system I further comprises speed regulating means 174 to regulate the speed of vehicles in the train in order to regulate the spacing between them. Said speed regulating means may comprise engine means of the vehicle, brake means of the vehicle, gearchange means of the vehicle, acceleration regulating means such as accelerator pedal means of vehicles.

The system I further comprises control regulating means 176 to regulate the operation of brake means and/or engine means in order to regulate the speed of vehicles in the train for spacing adjustment. Said control regulating means may comprise regulating units for regulation of torque of engine means, gear position of gearchange means, braking of braking means.

The electronic control unit 100 is signal-connected to said communication means 1 0 via a link 10a, enabling it to receive from said means a signal which represents communication data from vehicles in the train for determination of suitable spacing in the train.

The electronic control unit 100 is signal-connected to said local factor incorporation means 120 via a link 20, enabling it to receive from said means a signal which represents local factors data for determination of suitable spacing in the vehicle train.

The electronic control unit 100 is signal-connected to said itinerary determination means 122 via a link 22, enabling it to receive from said means a signal which represents itinerary data comprising location data from the vehicle location determination means 122b and map data from the map information unit 122a, for determination of suitable spacing in the vehicle train.

The electronic control unit 100 is signal-connected to said traffic situation determination means 124 via a link 24, enabling it to receive from said means a signal which represents traffic situation data, for determination of suitable spacing in the vehicle train.

The electronic control unit 100 is signal-connected to said road state characteristics determination means 126 via a link 26, enabling it to receive from said means a signal which represents road state data for prevailing road surfaces, for determination of suitable spacing in the vehicle train. The electronic control unit 100 is signal-connected to said spacing distance determination means 130 via a link 30, enabling it to receive from said means a signal which represents spacing data for distances from vehicles in front and/or behind in the train. The electronic control unit 100 is signal-connected to said driving conditions determination means 140 via a link 40, enabling it to receive from said means a signal which represents conditions data for determination of conditions in which the vehicle travels.

The electronic control unit 100 is signal-connected to said time determination means 142 via a link 42, enabling it to receive from said means a signal which represents time data for the time of day at which vehicles in the train travel in order thereby to determine whether night driving conditions prevail and to assess probable traffic density.

The electronic control unit 100 is signal-connected to said weather determination means 144 via a link 44, enabling it to receive from said means a signal which represents weather data in order to determine prevailing weather conditions.

The electronic control unit 100 is signal-connected to said speed determination means 146 via a link 46, enabling it to receive from said means a signal which represents speed data in order to determine the speed at which vehicles in the train travel.

The electronic control unit 100 is signal-connected to said road type determination means 148 via a link 48, enabling it to receive from said means a signal which represents road type data for the type of road on which the train's vehicles travel.

The electronic control unit 100 is signal-connected to said identification means 50 via a link 50, enabling it to receive from said means a signal which represents identification data for identification of vehicles which belong to the train and any which do not. The electronic control unit is adapted to processing said communication data from the communication means 110, said local factors data from the local factor incorporation means 120 comprising itinerary data from the itinerary determination means 122 comprising map data including said characteristics of the carriageway along the vehicle train's itinerary, e.g. topography, any presence of bends, any presence of entry and exit slips, and/or traffic situation data for prevailing traffic situations from the traffic situation determination means 124 and/or road state data for prevailing road surfaces from said road state characteristics determination means 126, in order to determine suitable mutual spacing for the train's vehicles, which processing includes identification of risk factors on the basis of said communication data and local factors data, and using identified risk factors with a probability indicator for each of them as a basis for evaluating the risk generated by said risk factors.

In one variant, in addition to the aforesaid processing, the electronic control unit 100 is adapted to processing said conditions data from said driving conditions determination means 140 to determine the conditions in which the vehicles of the train travel, in conjunction with said communication data and local factors data, in order to determine suitable mutual spacing for the train's vehicles, which processing further comprises identification of risk factors on the basis of said conditons data and local factors data, and using identified risk factors with a probability indicator for each of them as a basis for evaluating the risk generated by said risk factors. Said conditions data comprise in one variant said time data, weather data, speed data and/or road type data.

In one variant, in addition to the aforesaid processing, the electronic control unit 100 is adapted to processing said identification data to identify vehicles in order to assess whether each belongs to the vehicle train or has for example cut into the vehicle train, representing a risk which in the light of other risk factors with probability indications for them might generate a risk which makes it necessary to increase the spacing distance. In one variant, in addition to the aforesaid processing, the electronic control unit 100 is adapted to processing said spacing data in order to determine distances from vehicles in front and/or behind in the train. In the event of temporary interruption of communication from the communication means, the information from the spacing distance determination means serves as redundancy.

The electronic control unit 100 is signal-connected to said communication means 110 via a link 10b, enabling it to send to said means a signal which represents communication data comprising said processed data for determination of suitable spacing in the vehicle train.

The electronic control unit 100 is signal-connected to said warning means 160 via a link 60, enabling it to send to said means a signal which represents warning data to warn of prevailing or potential dangers/risk factors arising from prevailing spacing between the train's vehicles. The electronic control unit 100 is signal-connected to said spacing distance regulating unit 170 via link 70, enabling it to send to said unit a signal which represents distance data for desired spacing based on assessed risks pertaining to prevailing situations and assessed risks in the near future.

The spacing distance regulating unit 170 is signal-connected to said brake regulating means 172 via a link 72, enabling it to send to said means a signal which represents braking data for braking to adjust the spacing between the train's vehicles.

The spacing distance regulating unit 170 is signal-connected to said speed regulating means 174 via a link 74, enabling it to send to said means a signal which represents speed data for speed increase to adjust the spacing between the train's vehicles.

The spacing distance regulating unit 170 is signal-connected to said control regulating means 176 via a link 76, enabling it to send to said means a signal which represents control data for control of brake means and/or engine means of vehicles in the train in order to adjust their speed and hence their spacing in the train.

The spacing distance regulating unit 170 is adapted to automatically regulating the spacing distance on the basis of spacing data from the electronic control unit 100 and to using said data as a basis for sending signals to the brake regulating means, the speed regulating means and/or the control regulating means.

Said communication means 110 is signal-connected via a link 10b to other corresponding systems of vehicles in the train and is adapted to sending signals via the link which represent communication data.

In one variant, said spacing distance regulating unit is integrated in the electronic control unit 100.

The electronic control unit 100 is adapted to processing said data as above by means of neural networks and/or by game theory. It is provided accordingly with a neural network to determine suitable mutual spacing of the train's vehicles, which involves using identified risk factors with a probability indication for each of them as a basis for evaluating the risk generated by said risk factors.

In one example, the train's vehicles travel on a motorway where the road type determination means 148 of said driving conditions determination means 140 determines that the type of road on which they are travelling is a motorway, and in one variant the information about road type is provided via said map data from the map information unit 122a of the itinerary determination means 122. According to traffic data information received from the traffic situation determination means, there are substantially no other vehicles in the vicinity. It is also registered that the communication means is not functioning satisfactorily, with the result that only sporadic or no communication data are received in the electronic control unit, so communication between the vehicles in the train is imperfect. The electronic control unit's processing, e.g. by means of neural networks, identifies that there are risks but that the probability that other forms of communication containing other data received in the electronic control unit are not functioning is slight, the probability of rapid changes of speed is slight and the risk that another vehicle might cut into the vehicle train is slight, leading to the conclusion that despite imperfect communication between the vehicles the shorter spacing distance may be maintained, whereupon the spacing distance regulating unit uses these identified risk factors with this probability indication as a basis for automatically ensuring that the spacing is maintained by using the brake regulating means and/or the speed regulating means.

In another example, the train's vehicles travel on a national highway where the road type determination means 148 of said driving conditions determination means 140 determines that the type of road on which they are travelling is a national highway, and in one variant the information about road type is provided via said map data from the map information unit 122a of the itinerary determination means 122, and there are bends and/or topographic differences, i.e. hills. According to traffic data information received from the traffic situation determination means, there are other vehicles in the vicinity, with risk of overtaking and consequent risk that vehicles might interpose between vehicles in the train. It is also registered that the communication means is not functioning satisfactorily, with the result that only sporadic or no communication data are received in the electronic control unit, so communication between the vehicles in the train is imperfect. The electronic control unit's processing, e.g. by means of neural networks, identifies that there are risks, that the probability that other forms of communication containing other data received in the electronic control unit are not functioning is slight, the probability of rapid changes of speed is slight leading to the conclusion that because of imperfect communication between the vehicles and other identified risk factors the shorter spacing distance needs to be increased, whereupon the spacing distance regulating unit uses these identified risk factors with this probability indication as a basis for automatically ensuring that the spacing is increased by means of the brake regulating means 172 and/or the speed regulating means 174 and/or the control regulating means 176.

Fig. 3 schematically illustrates a vehicle train according to an embodiment of the present invention, comprising a first vehicle 1a, a second vehicle 1 b, a third vehicle c and a fourth vehicle 1d, travelling on a carriageway R and maintaining a mutual spacing distance d between them. The train may comprise any number of vehicles. It is provided with and uses system I according to Fig. 2 for safe and fuel-efficient spacing adjustment while in motion, such that communication takes place continuously between the vehicles on the basis of communication means 110 via links 10 whereby inter alia the front vehicle conveys information to the other vehicles and each vehicle is provided with an electronic control unit 100 and one or more from among said local factor incorporation means 120, driving conditions determination means 140, spacing distance determination means 130, vehicle identification means 150, warning means 160 and spacing regulating means 170.

Fig. 4 is a schematic block diagram of a method for safe and fuel-efficient spacing adjustment in a moving vehicle train which comprises at least two vehicles according to an embodiment of the present invention. At a first step S1 , communication is continuously maintained between the train's vehicles.

At a second step S2, parameters characterising the train's journey are determined.

At a third step S3, said parameters serve as a basis for determining suitable mutual spacing of the train's vehicles, including using identified risk factors with a probability indication for each of them as a basis for evaluating the risk generated by said risk factors and adjusting said spacing accordingly.

Figure 5 is a diagram of one version of a device 500. The control unit 100 described with reference to Figure 2 may in one version comprise the device 500. The device 500 comprises a non-volatile memory 520, a data processing unit 510 and a read/write memory 550. The non-volatile memory has a first memory element 530 in which a computer programme, e.g. an operating system, is stored for controlling the function of the device 500. The device 500 further comprises a bus controller, a serial communication port, I/O means, an A/D converter, a time and date input and transfer unit, an event counter and an interruption controller (not depicted). The non-volatile memory has also a second memory element 540.

A proposed computer programme P comprises routines for enabling safe and fuel-efficient spacing adjustment in a moving vehicle train formed of at least two vehicles according to the innovative method. The programme comprises routines for continuously maintaining communication between the train's vehicles. It comprises routines for continuously determining parameters which characterise the vehicle train's journey. It comprises routines for using said parameters as a basis for determining suitable mutual spacing for the train's vehicles, including using identified risk factors with a probability indication for each risk factor as a basis for evaluating the risk generated by said risk factors and adjusting said spacing accordingly. The programme P may be stored in an executable form or in compressed form in a memory 560 and/or in a read/write memory 550.

Where the data processing unit 510 is described as performing a certain function, it means that it conducts a certain part of the programme stored in the memory 560, or a certain part of the programme stored in the read/write memory 550.

The data processing device 510 can communicate with a data port 599 via a data bus 515. The non-volatile memory 520 is intended for communication with the data processing unit 510 via a data bus 512. The separate memory 560 is intended to communicate with the data processing unit via a data bus 511. The read/write memory 550 is adapted to communicating with the data processing unit via a data bus 514. The links associated with the control unit 100 may for example be connected to the data port.

When data are received on the data port 599, they are stored temporarily in the second memory element 540. When input data received have been temporarily stored, the data processing unit 510 is prepared to conduct code execution as described above. The signals received on the data port may be used by the device 500 to continuously maintain communication between the train's vehicles. The signals received on the data port may be used by the device 500 to continuously determine parameters which characterise the vehicle train's journey. The signals received on the data port may be used by the device 500 to determine on the basis of said parameters suitable mutual spacing of the train's vehicles, including using identified risk factors and a probability indication for each factor as a basis for evaluating the risk generated by said risk factors and adjusting said spacing accordingly. Parts of the methods herein described may be conducted by the device 500 by means of the data processing unit 510 which runs the programme stored in the memory 560 or the read/write memory 550. When the device 500 runs the programme, methods herein described are executed. The above description of the preferred embodiments of the present invention is provided for illustrative and descriptive purposes. It is not intended to be exhaustive nor to restrict the invention to the variants described. Many modifications and variations will obviously suggest themselves to one skilled in the art. The embodiments have been chosen and described in order best to explain the principles of the invention and their practical applications and thus make it possible for one skilled in the art to understand the invention for different embodiments and with the various modifications appropriate to the intended use.