Abstract:
In order to provide a track-guided transport system, and in particular a suspended monorail system, comprising a track network incorporating at least one node at which at least two track sections of the track network adjoin one another and also comprising a plurality of vehicles travelling along the track network and each of which comprises a control unit wherein the control of the movements of these vehicles can be effected in a simple and reliable manner even when there are a large number of vehicles, it is proposed that at least one successor or the information that the vehicle does not have a successor and/or at least one forerunner or the information that the vehicle does not have a forerunner be associated with each vehicle, wherein the information relating to the successor or the forerunner is stored in the control unit of the vehicle and is updated when the vehicle passes a node of the track network.

Description:
[0001]     This application is a continuation application of PCT/EP2003/011243 filed Oct. 10, 2003, the entire specification of which is incorporated herein by reference. 
     
    
     FIELD OF THE DISCLOSURE  
       [0002]     The present invention relates to a track-guided transport system, and in particular a suspended monorail system, which comprises a track network incorporating at least one node at which at least two track sections of the track network adjoin one another and also comprises a plurality of vehicles travelling along the track network and which each comprise a control unit.  
         [0003]     Furthermore, the present invention relates to a method of controlling the vehicles in such a track-guided transport system.  
       BACKGROUND  
       [0004]     Such a track-guided transport system is known from DE 195 12 107 A1 for example.  
         [0005]     If the track-guided transport system comprises a large number of vehicles which are travelling through the track network at the same time, then a system for controlling all these vehicles by means of a central control unit for the transport system necessitates a large amount of computing power in the central control unit and a very extensive exchange of data between the vehicles and the central control unit.  
       SUMMARY OF THE INVENTION  
       [0006]     Consequently, the object of the present invention is to provide a track-guided transport system of the type mentioned hereinabove which will enable the control of the movements of these vehicles to be effected in a simple and reliable manner even when there are a large number of vehicles.  
         [0007]     In accordance with the invention, this object is achieved in the case of a track-guided transport system comprising the features mentioned in the first part of Claim  1  in that at least one successor or the information that the vehicle does not have a successor, and/or at least one forerunner or the information that the vehicle does not have a forerunner is associated with each vehicle, wherein the information relating to the successor or the forerunner is stored in the control unit of the vehicle and is updated when the vehicle passes a node of the track network.  
         [0008]     Herein, a “successor” is to be understood as being another vehicle whose current position—as seen in the direction of travel of the vehicle concerned—is located behind the vehicle concerned. This successor could also be located on a track section other than that of the vehicle concerned.  
         [0009]     In corresponding manner, a “forerunner” is to be understood as being another vehicle whose current position—as seen in the direction of travel of the vehicle concerned—is located in front of the vehicle concerned. Such a forerunner could also be located on a track section other than that of the vehicle concerned.  
         [0010]     Since, in accordance with the solution according to the invention and at any arbitrary time point, each of the vehicles knows its successor and its forerunner (or knows that it does not have a successor or a forerunner to whom it would have to pay attention), the data traffic which is needed for controlling the movement of the vehicles and which is exchanged between the vehicles on the one hand and a central control unit of the track-guided transport system on the other can be significantly reduced. It is even possible for the movement of the vehicles to be controlled exclusively by a process of communication between the vehicles themselves without there being any need at all for a central control unit for performing this task.  
         [0011]     Thus, in particular, the regulation of the mutual spacing between vehicles travelling along a section of track one behind the other can be accomplished without the intermediary of a central control unit, for example, in that each vehicle continually passes its current position on to its successor, the successor continually determines the distance between the two vehicles from the position of the forerunner and its own position and, if necessary, takes the appropriate steps (decelerating or accelerating) that are required for regulating their mutual spacing to a given desired value.  
         [0012]     Since the track network of the track-guided transport system also contains nodal points whereat the successor and forerunner relationships between the vehicles may change, the information relating to the successor or the forerunner of each vehicle is updated when the vehicle passes a node of the track network.  
         [0013]     Such a node of the track network can, for example, be in the form of a branching point at which one track branches out into a plurality of onwardly extending tracks.  
         [0014]     Furthermore, such a node of the track network can be in the form of a junction point at which a plurality of tracks combine into one onwardly extending track.  
         [0015]     In a special embodiment of the transport system in accordance with the invention provision is made for the information relating to the successor or the forerunner of a vehicle to be updated by a process of communication with at least one other vehicle of the transport system.  
         [0016]     Alternatively or in addition thereto, provision may be made for the information relating to the successor or the forerunner of a vehicle to be updated by a process of communication with a node administration unit arranged outside the vehicle.  
         [0017]     In particular, such a node administration unit may comprise a programmable computer and the appertaining node administration software.  
         [0018]     Provision may also be made for the node administration unit to comprise a plurality of node administration software modules which run on different computers. These computers could also be spatially separate from one another. In particular, at least one of these computers can be fixed. As an alternative or in addition thereto, provision may also be made for at least one of these computers to be arranged in one of the vehicles in the transport system.  
         [0019]     In a preferred embodiment of the transport system, provision is made for at least one node administration unit to be fixed.  
         [0020]     As an alternative or in addition thereto, provision may also be made for at least one node administration unit to be arranged in a central control unit of the transport system.  
         [0021]     In order to reduce the number of node administration units required, provision may also be made for at least one node administration unit to administer a plurality of nodes of the track network.  
         [0022]     As an alternative thereto, provision may also be made for a separate node administration unit to be associated with each node of the track network.  
         [0023]     The updating of the information relating to the successor or the forerunner can, for example, be achieved in that, after passing a brake point which is associated with a node, a vehicle sends a message which is effective to update the information relating to a successor and/or a forerunner of the vehicle concerned.  
         [0024]     Herein, a  “ brake point” is to be understood as being a point of a track section that is at a predetermined distance from the node which may be a junction point or a branching point, said distance being determined—in dependence on the speed of the vehicle concerned—in such a way that the vehicle can still be brought to a stop in good time before reaching the node in order to prevent a collision with another vehicle passing through the node.  
         [0025]     The message sent by the vehicle when passing the brake point can be addressed to another vehicle or to a node administration unit of the transport system.  
         [0026]     Furthermore, after passing a brake point which is associated with a node, provision may be made for a vehicle to send a message which is effective to update the information relating to a successor and/or a forerunner of at least one other vehicle.  
         [0027]     A particularly high level of operational reliability is obtained if, after passing a brake point which is associated with a node, provision is made for a vehicle to send a message which is effective to update the information relating to a successor and/or a forerunner of at least one vehicle, and subsequently to receive an acknowledging message which was triggered directly or indirectly by the sending of said first-mentioned message. In this way, the vehicle which triggered the updating process receives a confirmation of the fact that its message for enabling the updating process has reached the receiver and that the updating process has been successfully concluded.  
         [0028]     The acknowledging message can be sent by the receiver of the message for enabling the updating process or by another transmitter which was included in the updating process by the receiver of the message for enabling the updating process.  
         [0029]     Furthermore, in a preferred embodiment of the invention, provision is made for a vehicle to send a message after passing a collision point which is associated with a node, which message is effective to update the information relating to a successor and/or a forerunner of the vehicle concerned.  
         [0030]     Herein, a “collision point” is to be understood as being a point of a track section which is at such a distance from the appertaining node that a vehicle, which is on the side of the collision point remote from the node, is at a distance from the node which is such as to exclude the possibility of a collision with another vehicle that is passing through the same node on other track sections.  
         [0031]     If the node is a junction point, then the collision point lies in front of the node in the direction of travel.  
         [0032]     If the node is a branching point, then the collision point lies beyond the node as seen in the direction of travel.  
         [0033]     The determination of a collision point is usually effected—other than is the case for the determination of the brake point—independently of the actual speed of the vehicle.  
         [0034]     The message triggering the updating process can be sent to another vehicle or to a node administration unit.  
         [0035]     Furthermore, provision may be made for a vehicle to send a message after passing a collision point that is associated with a node, which message is effective to update the information relating to a successor and/or a forerunner of at least one other vehicle.  
         [0036]     The operational reliability of the transport system in accordance with the invention is increased still further if provision is made for a vehicle to send a message after passing a collision point that is associated with a node, which message is effective to update the information relating to a successor and/or a forerunner of at least one vehicle, and subsequently to receive an acknowledging message which was triggered directly or indirectly by the sending of said first-mentioned, message. In this way, the vehicle which triggered the updating process receives a confirmation of the fact that its message for enabling the updating process has reached the receiver and that the entire updating process has been successfully concluded.  
         [0037]     In the case where the acknowledging message is missing, suitable measures can be adopted, for example, emergency stoppage of the vehicles.  
         [0038]     A further object of the invention is to provide a method of controlling the vehicles of a track-guided transport system of the type mentioned hereinabove which is such as to enable the process of controlling the movement of the vehicles to be effected in a simple and reliable manner even when there are a large number of vehicles.  
         [0039]     In accordance with the invention, this object is achieved in the case of a method comprising the features mentioned in the first part of Claim  16  in that at least one successor or the information that the vehicle does not have a successor, and/or at least one forerunner or the information that the vehicle does not have a forerunner is associated with each vehicle, wherein the information relating to the successor or the forerunner is stored in the control unit of the vehicle and is updated when the vehicle passes a node of the track network.  
         [0040]     Special embodiments of the method in accordance with the invention form the subject matter of the dependent Claims  17  to  30 , their advantages having already been explained in connection with the special embodiments of the transport system in accordance with the invention.  
         [0041]     Further features and advantages of the invention form the subject matter of the following description and the graphic illustration of exemplary embodiments. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0042]      FIG. 1 a  schematic cross section through a running rail of a suspended monorail system including a schematic illustration of the supporting and guide rollers as well as an energy transmission unit and a data transmission unit of a vehicle of the suspended monorail system;  
         [0043]      FIG. 2 a  schematic side view of the running rail depicted in  FIG. 1  in the case where a vehicle of the suspended monorail system is present;  
         [0044]     FIGS.  3  to  5  a schematic illustration of a process of communication between a vehicle and its successor in the case of a deceleration process of the forerunner;  
         [0045]      FIGS. 6 and 7  a schematic illustration of the communication process between a vehicle and other vehicles when passing a junction point;  
         [0046]      FIGS. 8 and 9  a schematic illustration of the communication process between a vehicle and other vehicles when passing a branching point;  
         [0047]      FIGS. 10 and 11  a schematic illustration of the communication process between a vehicle and a node administration unit when passing a junction point;  
         [0048]      FIGS. 12 and 13  a schematic illustration of the communication process between vehicles and a node administration unit and between themselves when passing a brake point and a collision point which are associated with a junction point;  
         [0049]      FIGS. 14 and 15  a schematic illustration of the communication process between vehicles and a node administration unit and between themselves when passing a collision point and a brake point which are associated with a junction point;  
         [0050]      FIG. 16 a  schematic illustration of the communication process between vehicles and a node administration unit and between themselves in a situation that is modified with respect to the situation shown in  FIG. 15 ;  
         [0051]      FIGS. 17 and 18  a schematic illustration of the communication process between a vehicle and a node administration unit when passing a brake point and a collision point relating to a branching point;  
         [0052]      FIG. 19 a  schematic illustration of the intercommunication process between vehicles and the communication process with a node administration unit when passing a collision point relating to a branching point; and  
         [0053]     FIGS.  20  to  26  a schematic illustration of the communication process between vehicles and a node administration unit and between themselves, wherein a plurality of vehicles are passing the brake points and the collision points of a branching point one behind the other.  
     
    
       [0054]     The same or functionally equivalent elements are designated by the same reference symbols in each of the Figures.  
       DETAILED DESCRIPTION OF THE INVENTION  
       [0055]     A transport system in the form of a suspended monorail system in the exemplary embodiment and bearing the general reference  100  comprises a running rail  102  which is illustrated in the form of a cross section in  FIG. 1  and as a side view in  FIG. 2  and comprises an upper flange  104  having an upper, essentially flat bearing surface  106  and two lateral guidance surfaces  108  and  110  as well as a lower flange  112  having a lower flat bearing surface  114  and two lateral guidance surfaces  116  and  118 .  
         [0056]     At the sides thereof opposite the bearing surfaces, the two flanges are connected by a vertical web  120  whose walls are flat and extend in parallel with the longitudinal direction  121  of the rail.  
         [0057]     A current supply line carrier  122  formed from an electrically insulating material projects out from a side wall of the web  120  between the two flanges  104  and  112  and supports a current supply line  124  on the end thereof remote from the web  120 .  
         [0058]     A supporting roller  126  of a vehicle  128  of the suspended monorail system  100  rolls on the upper bearing surface  106  of the running rail  102 .  
         [0059]     Apart from the supporting roller  126 , only the lateral guide rollers  132 ,  134 ,  136  and  138  which roll on the respective lateral guidance surfaces  108 ,  110 ,  116  and  118  and an energy transmission unit  140  and a data transmission unit  146  of this vehicle  128  are illustrated in the Figures.  
         [0060]     The energy transmission unit  140  comprises, for example, a current collector  142  which is in the form of a U-shaped ferrite core and has arranged thereon a coiled conductor  144  which is connected to a (not illustrated) current collecting electronic circuit for converting an alternating current that is induced in the coiled conductor into a DC voltage.  
         [0061]     The current supply line  124  dips into the U-shaped current collector  142  of the energy transmission unit  140  but does not touch it.  
         [0062]     The transfer of energy from the current supply line  124  to the energy transmission unit  140  is effected by an induction process. To this end, a medium frequency alternating current, which produces a corresponding time-varying magnetic flux in the current collector  142 , is fed into the current supply line  124  and the running rail  102  serving as a return conductor so that an alternating current can be induced in the coiled conductor  144  and be converted into a DC voltage in the vehicle  128  for operational and control purposes.  
         [0063]     The vehicle  128  is supported on the running rail  102  by means of a plurality of supporting rollers  126  and is guided on the lateral guidance surfaces of the running rail  102  by means of the guide rollers  132 ,  134 ,  136  and  138 .  
         [0064]     Furthermore, the vehicle  128  is adapted to be driven by a (not illustrated) drive unit which may be in the form of a friction wheel drive for example.  
         [0065]     The data transmission unit  146  of the vehicle  128  comprises a near field coupler  148  which is held on the vehicle  128  above the energy transmission unit  140  and is designed for bi-directional communication with a data transmission line  150  which extends along the running rail  102  and is held by means of mounting plates  152  (see  FIG. 2 ) on the side wall of the web  120  of the rail  102  facing the near field coupler  148 .  
         [0066]     The data transmission line  150  is in the form of a coaxial cable  155  having a central copper conductor  156  and a sheath  158  surrounding the same, whereby, on the side thereof facing the near field coupler  148  of the vehicle  128 , the sheath  158  incorporates an axial slot  159  which extends in the longitudinal direction of the coaxial cable  155  and through which high frequency waves can exit from the coaxial cable  155  or enter into the coaxial cable  155 .  
         [0067]     The coaxial cable  155  slit in the longitudinal direction thereof thus forms a leaky wave guide  154 .  
         [0068]     The leaky wave guide  154  is fed with high frequency signals by a (not illustrated) fixed central control unit of the transport system  100 , by fixed decentralized node administration computers and/or by other vehicles, said signals propagating along the leaky wave guide  154  and being received by the near field coupler  148  of the vehicle  128 . A (not illustrated) evaluating circuit in the vehicle  128  demodulates these high frequency signals and converts them into data that is usable by the control unit of the vehicle  128 .  
         [0069]     Conversely, data produced in the control unit of the vehicle  128  is modulated onto a high-frequency carrier signal by a modulating circuit and fed via the near field coupler  148  into the leaky wave guide  154  wherein these signals propagate to another vehicle or to fixed (centralized or decentralized) control stations of the transport system  100 .  
         [0070]     The information relating to at least one successor of the vehicle concerned is stored in the control unit of each vehicle  128  (which unit comprises a freely programmable processor and a memory). Herein, a  “ successor” is to be understood as being another vehicle whose current position—as seen in the direction of movement of the vehicle concerned—is located behind the vehicle concerned. The successor can be on a section of track other than that of the vehicle concerned. If, at a certain point in time, no successor is associated with the vehicle  128  concerned, then the information that the vehicle does not have a successor is stored in its control unit.  
         [0071]     Furthermore, the information relating to at least one forerunner of the vehicle concerned is stored in the control unit of each vehicle  128 . Herein, a  “ forerunner” is to be understood as being another vehicle whose current position—as seen in the direction of movement of the vehicle concerned—is located in front of the vehicle concerned. The forerunner can be on a section of track other than that of the vehicle concerned. If, at a certain point in time, no forerunner is associated with the vehicle concerned, then the information that the vehicle does not have a forerunner is stored in its control unit.  
         [0072]     The fact that, at any arbitrary time point, each of the vehicles  128  knows about its successor and its forerunner (or knows that it does not have a successor or a forerunner), makes it possible for the movement of the vehicles to be controlled exclusively by a process of communication between the vehicles themselves without the need to enlist a central control unit for this purpose.  
         [0073]     Thus, in particular, the regulation of the mutual spacing between vehicles travelling one behind the other on a section of track can be accomplished without the intervention of a central control unit. This will be explained in more detail hereinafter with reference to FIGS.  3  to  5 .  
         [0074]     Three vehicles which are designated by V 0 , V 1  and V 2  and which are travelling along a track section  160  in the same direction of movement  162  are illustrated in exemplary manner in  FIG. 3 .  
         [0075]     Here, the vehicle V 2  is the forerunner of the vehicle V 1  which, for its part, is the forerunner of the vehicle V 0 . The vehicle V 2  does not have a current forerunner.  
         [0076]     The vehicle V 0  is the successor of the vehicle V 1 , which, for its part, is the successor of the vehicle V 2 . The vehicle V 0  does not have a current successor.  
         [0077]     Each successor continuously computes the distance to its forerunner. This can, for example, be effected directly by means of a distance measuring instrument which is arranged in the vehicle (V 1  for example) and measures the distance to the vehicle travelling ahead of it (V 2  for example).  
         [0078]     As an alternative or in addition thereto, provision could also be made for the vehicle V 1  to continuously determine its own position in the track network, for it to be informed continuously of the current position of the vehicle V 2  by the vehicle V 2  and for it then to determine the spacing between the two vehicles V 2  and V 1  by forming the difference between the positions of these two vehicles.  
         [0079]     The determination of the position of a vehicle in the track network of the transport system  100  can, for example, be effected with the aid of position indicators which are arranged along the tracks of the transport system  100  and are detected by means of a detecting device in the vehicle concerned. The entire track network including all the position indicators is stored in the control unit of each vehicle  128  so that the vehicle concerned can set its current position equal to the position of the position indicator when travelling past a position indicator. The control unit of the vehicle can interpolate positions located between two position indicators succeeding one another along the track network by means of a path measuring system arranged in the vehicle which, for example, determines the distance travelled since the last position indicator on the basis of the number of revolutions of a supporting roller of the vehicle.  
         [0080]     At the time point illustrated in  FIG. 4 , the vehicle V 1  determines that its spacing from the forerunner V 2  has become too small. As a reaction thereto, the vehicle V 1  reduces its speed and conveys to its successor V 0  the information that the vehicle V 1  has reduced its speed.  
         [0081]     The transmission of this information is symbolized by the arrow  164  in  FIG. 4 .  
         [0082]     Due to this message from the forerunner V 1 , the successor V 0  is informed about the deceleration of the vehicle V 1  before it has determined this fact from its own measurement of the distance between the vehicles V 1  and V 0 . In consequence, the vehicle V 0  can immediately adapt its own speed to the reduced speed of the vehicle V 1  travelling ahead of it in good time.  
         [0083]     In this way, all the vehicles can be braked without jerking until they have settled into a state wherein they are at a sufficient distance from one another as at the time point illustrated in  FIG. 5  whereat the vehicle V 2  has reached the position P 2  and the vehicle V 1  has reached the position PI.  
         [0084]     Since the track network of the transport system  100  also incorporates junction points and branching points at which the successor and forerunner relationships between the vehicles change, the information relating to the respective successor and the respective forerunner that is stored in the vehicles must be updated when passing such a node of the track network.  
         [0085]     This process of updating the information relating to the successor and the forerunner can, for example, be effected by a direct communication process between the respective three vehicles involved.  
         [0086]     Hereby, a first vehicle, which is approaching the junction point of two track sections, sends a message to its forerunner (second vehicle) claiming the right to pass the junction point. The second vehicle, which is on the section of track leading away from the junction point, has two successors: a respective successor on each of the track sections leading to the junction point. If this forerunner receives the message from one of its successors that this successor is claiming the right to pass the junction point, then it sends a message to the respective other successor (third vehicle) that the junction point is blocked by the first successor and simultaneously strikes the second successor from the list of its successors.  
         [0087]     The third vehicle, which has received the message regarding the blockage of the junction point by the first vehicle from the second vehicle, stores the first vehicle as its new forerunner and sends to the first vehicle, the one which triggered the updating process, an acknowledging message to the effect that the third vehicle is now a successor of the first vehicle.  
         [0088]     After receipt of this acknowledging message, the first vehicle stores the third vehicle as an additional successor and passes the junction point.  
         [0089]     After passing the junction point, the first vehicle sends a message to the third vehicle that the junction point is free again.  
         [0090]     This updating process which occurs when passing a junction point and which was described hereinabove will be explained in exemplary manner hereinafter with reference to  FIGS. 6 and 7 .  
         [0091]     As can be seen from  FIG. 6 , two track sections  166  and  168  leading towards a junction point  164  combine at the junction point  164  into a track section  170  leading away from the junction point  164 .  
         [0092]     The direction of movement in each of the track sections is indicated by a respective arrow designated by the reference  162 . The vehicles V 0 , V 1  and V 2  are moving towards the junction point  164  on the track section  166 . The vehicles V 3  and V 5  are moving away from the junction point  164  on the track section  170 . The vehicles V 4  and V 6  are moving towards the junction point  164  on the track section  168 .  
         [0093]     The vehicle V 1  is associated with the vehicle V 2  as a successor and the vehicle V 3  is associated therewith as a forerunner.  
         [0094]     The vehicles V 2  and V 4  are associated with the vehicle V 3  as successors and the vehicle V 5  is associated therewith as a forerunner.  
         [0095]     The vehicle V 6  is associated with the vehicle V 4  as a successor and the vehicle V 3  is associated therewith as a forerunner.  
         [0096]     At the time point illustrated in  FIG. 6 , the vehicle V 2  has (in dependence on the speed of the vehicle) reached a predetermined distance (brake point) from the junction point  164  and thereupon triggers an updating process by sending to its forerunner V 3  a message (arrow  172 ) that it is entering the region of the junction point  164  and is thus blocking the junction point  164 .  
         [0097]     The vehicle V 3  thereupon sends to its second successor, the vehicle V 4 , a message (arrow  174 ) that the junction point  164  is blocked and that the vehicle V 2  is the new forerunner of the vehicle V 4 . Furthermore, the vehicle V 3  deletes the vehicle V 4  from the list of its successors.  
         [0098]     The vehicle V 4  replaces the vehicle V 3  by the new forerunner V 2  in its list of forerunners and sends to the vehicle V 2  an acknowledging message (arrow  176  in  FIG. 6 ) from which the vehicle V 2  deduces that the updating process has been concluded and that the vehicle V 4  is its new successor. In consequence, the vehicle V 2  registers the vehicle V 4  as a further successor in its list of successors.  
         [0099]     The vehicle V 2  subsequently passes the junction point  164  and thus makes the junction point  164  available again so that the state illustrated in  FIG. 7  then ensues.  
         [0100]     Now either the vehicle V 1  or the vehicle V 4  can trigger a new updating process in dependence on which of these vehicles is the first to drop below a predetermined distance from the junction point  164 , this thereby triggering the previously described updating process.  
         [0101]     The updating process which is triggered when a vehicle approaches a branching point of the track network of the transport system  100  is described hereinafter.  
         [0102]     A first vehicle, which is on the section of track leading to the branching point, has two forerunners, namely, a respective forerunner on each of the sections of track leading away from the branching point.  
         [0103]     If, (in dependence on the speed of the vehicle), the first vehicle approaching the branching point drops below a given distance from the branching point, then it sends a message to that one of its forerunners which is on the track section into which the first vehicle will not be running, said message signifying that the first vehicle is logging-off as a successor to this second vehicle and, at the same time, it informs the second vehicle who the successor of the first vehicle is.  
         [0104]     The second vehicle thereupon strikes out the first vehicle from the list of its successors and adopts instead the thus communicated successor of the first vehicle as its new successor.  
         [0105]     Furthermore, the second vehicle sends a message to a third vehicle, namely, to the previous successor of the first vehicle and the new successor of the second vehicle, that the second vehicle is now a further forerunner of the third vehicle.  
         [0106]     Thereupon, the third vehicle, which is travelling behind the first vehicle on the section of track leading to the branching point, enters the second vehicle as an additional forerunner in its list of forerunners.  
         [0107]     Furthermore, the third vehicle sends an acknowledgement message to the first vehicle, from which the first vehicle deduces that the updating process has been concluded.  
         [0108]     The first vehicle then passes the branching point and a new updating process is started as soon as the third vehicle that was following it drops below the given distance from the branching point.  
         [0109]     This updating process is explained hereinafter with reference to  FIGS. 8 and 9 .  
         [0110]     In the situation illustrated in  FIG. 8 , the vehicles V 2 , V 1  and V 0  are travelling towards the branching point  178  on the track section  180  leading to the branching point  178  in the direction of movement  162 , whereas the vehicles V 3  and V 4  are travelling away from the branching point  178  on a first track section  182  that leads away from the branching point  178  and the vehicles V 5  and V 6  are travelling away from the branching point  178  on a second track section  184  that leads away from the branching point  178 .  
         [0111]     The vehicle V 0  is associated with the vehicle V 1  as a successor and the vehicle V 2  is associated therewith as a forerunner.  
         [0112]     The vehicle V 1  is associated with the vehicle V 2  as a successor and the vehicles V 3  and V 5  are associated therewith as forerunners.  
         [0113]     The vehicle V 2  is associated with the vehicle V 3  as a successor and the vehicle V 4  is associated therewith as a forerunner.  
         [0114]     The vehicle V 2  is associated with the vehicle V 5  as a successor and the vehicle V 6  is associated therewith as a forerunner.  
         [0115]     At the time point illustrated in  FIG. 8 , the vehicle V 2  drops below a minimum distance from the branching point  178  (in dependence on the speed of the vehicle), this thereby triggering an updating process.  
         [0116]     This updating process involves the vehicle V 2  initially sending a message (arrow  186 ) to the vehicle V 5  to the effect that the vehicle V 2  is logging-off as a successor to the vehicle V 5  whilst simultaneously informing it that the former successor of the vehicle V 2  is now the new successor of the vehicle V 5 .  
         [0117]     The vehicle V 5  thereupon replaces its former successor V 2  by the new successor V 1  in the list of its successors.  
         [0118]     Subsequently, the vehicle V 5  sends a message (arrow  188 ) to the vehicle V 1  for the purposes of informing it that the vehicle V 5  is a new, additional forerunner of the vehicle V 1 .  
         [0119]     The vehicle V 1  thereupon enters the vehicle V 5  as an additional forerunner in its list of forerunners.  
         [0120]     Furthermore, the vehicle V 1  sends an acknowledging message (arrow  190 ) to the vehicle V 2 , and the vehicle V 2  deduces therefrom that the updating process has been successfully concluded.  
         [0121]     The vehicle V 2  then passes the branching point  178  (see  FIG. 9 ) and a new updating process, which is triggered by the vehicle V 1 , begins as soon as the vehicle V 1  drops below the given minimum distance from the branching point  178 .  
         [0122]     In the previously described junction type and branching type processes, the successor and forerunner relationships between the vehicles were updated when passing the respective node exclusively by a process of communication between the vehicles themselves. As an alternative or in addition thereto, provision could also be made for the updating of the successor and forerunner relationships when passing a node to be effected with the help of a node administration unit assigned to the respective node.  
         [0123]     Such a node administration unit, which comprises a programmable computer and the appertaining node administration software, can be arranged outside the vehicles, and in particular, in a fixed node administration computer.  
         [0124]     However, as an alternative or in addition thereto, it is also possible for the node administration unit to be in the form of a component of the control unit of one of the vehicles.  
         [0125]     An updating process occurring when passing a junction point can be effected by drawing upon the node administration unit for the junction point as follows:  
         [0126]     When passing a so-called brake point which is spaced from the junction point by a given distance that is dependent on the speed of the vehicle, a vehicle moving towards this junction point sends a message to the node administration unit indicating that the vehicle is entering the region covered by the junction point. associated with the node administration unit.  
         [0127]     The node administration unit keeps a list of the vehicles which have previously entered the region covered by the junction point.  
         [0128]     If this list is empty, then the node administration unit only sends an acknowledging message to the approaching vehicle, and the forerunner and successor relationships of the vehicle remain unchanged.  
         [0129]     If, however, a vehicle is registered in this node administration unit&#39;s list, then the node administration unit sends a message to the vehicle registered in the list that this second vehicle should adopt the first vehicle as a so-called “next successor”.  
         [0130]     In this embodiment of the invention, two successors are associated with each vehicle, namely, a “current successor” and a “next successor”.  
         [0131]     In corresponding manner, two forerunners are also associated with each vehicle, namely, a “current forerunner” and a “next forerunner”.  
         [0132]     The second vehicle thus registers the first vehicle as its “next successor” and sends an acknowledgement message to the first vehicle, from which the first vehicle deduces that the second vehicle is now its “next forerunner”. In corresponding manner, the first vehicle registers the second vehicle as its “next forerunner”.  
         [0133]     The first updating process that was triggered by the first vehicle when passing the brake point is thereby concluded.  
         [0134]     A second updating process is triggered by the first vehicle when it reaches a so-called “collision point” located prior to the junction point. The distance of the collision point from the junction point is specified (independently of speed) in such a way that a vehicle located prior to the collision point cannot collide with another vehicle travelling on another track section towards the selfsame junction point.  
         [0135]     If the vehicle does not have a current successor when reaching the collision point, then the vehicle sends a message to the node administration unit, the node administration unit deducing therefrom that the vehicle concerned will be travelling via the junction point into the track section leading away from the junction point.  
         [0136]     Thereupon, the node administration unit sends an acknowledgement message to the vehicle concerned, the vehicle deducing from this message that the node administration unit has registered its passage through the junction point, said acknowledgement message also causing the vehicle to make its next successor, should there be one, into its current successor.  
         [0137]     If the vehicle does have a current successor when reaching the collision point, then this first vehicle sends a message to this current successor, i.e. a second vehicle, said message causing the second vehicle to strike out the first vehicle as its current forerunner and to make its “next forerunner” into its “current forerunner” instead.  
         [0138]     If, at this time point, there is no next forerunner associated with the second vehicle, then only the current forerunner is deleted.  
         [0139]     Furthermore, the second vehicle sends a message to the node administration unit by means of which the node administration unit is informed that the first vehicle is passing the junction point.  
         [0140]     The node administration unit thereupon sends an acknowledging message to the first vehicle, which thus leads to the first vehicle striking out its current successor and, should there be one, making its next successor into its new current successor.  
         [0141]     The second updating process that was triggered by the act of reaching the collision point is thereby concluded.  
         [0142]     The previously described procedure when passing a junction point will be explained hereinafter by means of examples taken with reference to FIGS.  10  to  16 .  
         [0143]     In  FIG. 10 , the vehicle V 1  is moving towards the junction point  164  on the track section  166 .  
         [0144]     No current successor is associated with the vehicle V 1 . The forerunner list in the node administration unit  192  assigned to the junction point  164  is empty.  
         [0145]     Upon reaching the brake point (BP), the vehicle V 1  sends a message (arrow  194 ) to the node administration unit  192  by means of which the vehicle V 1  announces its presence to the node administration unit  192 .  
         [0146]     The node administration unit  192  sends an acknowledging message (arrow  196 ) back to the vehicle V 1 .  
         [0147]     Upon reaching the collision point (CP), the vehicle V 1  sends a message (arrow  198 ) to the node administration unit  192  by means of which an indication is given to the node administration unit  192  of the passing of the junction point  164  by the vehicle V 1  ( FIG. 11 ).  
         [0148]     The node administration unit  192  sends an acknowledging message (arrow  200 ) to the vehicle V 1 .  
         [0149]     The vehicle V 1  subsequently changes from the track section  166  via the junction point  164  to the track section  170  leading away from the junction point  164 . A change of successor or forerunner relationships of the vehicle V 1  has not taken place.  
         [0150]     In the situation illustrated in  FIG. 12 , the vehicles V 1  and V 2  are moving towards the junction point  164  on the track section  168 . The vehicle V 3  is moving towards the junction point  164  on the track section  166 . The vehicle V 4  is moving away from the junction point  164  on the track section  170 .  
         [0151]     The vehicle V 1  is associated with the vehicle V 2  as the current successor. The vehicle V 2  does not possess a next successor.  
         [0152]     Neither a current forerunner nor a next forerunner are associated with the vehicle V 3 .  
         [0153]     The vehicle V 2  is associated with the vehicle V 1  as the current forerunner. The vehicle V 1  does not possess a next forerunner.  
         [0154]     The vehicle V 2  is registered in the forerunner list of the node administration unit  192 , this vehicle being the last one to have indicated its presence to the node administration unit  192  when passing the brake point in the track section  168 .  
         [0155]     Upon reaching the brake point (BP) in the track section  166 , the vehicle V 3  sends a message (arrow  202 ) for the purposes of indicating the presence of the vehicle V 3  to the node administration unit  192  ( FIG. 12 ).  
         [0156]     The node administration unit  192  thereupon sends a message (arrow  204 ) to the vehicle V 2  for indicating thereto that the vehicle V 3  is now the next successor to the vehicle V 2 .  
         [0157]     The vehicle V 2  registers the vehicle V 3  as its next successor and sends an acknowledging message (arrow  206 ) to the vehicle V 3  which leads to the vehicle V 3  registering the vehicle V 2  as its next forerunner.  
         [0158]     The updating process that was triggered by the vehicle V 3  upon passing the brake point is thereby concluded.  
         [0159]     At the time point illustrated in  FIG. 13 , the vehicle V 2  reaches the collision point (CP) and in consequence sends a message (arrow  208 ) to its current successor, the vehicle V 1 , this message causing the vehicle V 1  to strike the vehicle V 2  as its current forerunner and replace it by the next forerunner. However, as there is no next forerunner associated with the vehicle V 1 , the vehicle V 1  does not receive a new current forerunner.  
         [0160]     Furthermore, the vehicle V 1  sends a message (arrow  210 ) to the node administration unit  192  for informing the node administration unit  192  that the vehicle V 2  is now changing to the track section  170 .  
         [0161]     The node administration unit  192  sends an acknowledging message (arrow  212 ) to the vehicle V 2  which thereupon strikes the vehicle V 1  as its current successor and registers the vehicle V 3  as its current successor rather than its next successor and strikes the vehicle V 3  as its next successor.  
         [0162]     The updating process that was triggered by the vehicle V 2  upon reaching the collision point is thereby concluded.  
         [0163]     In the situation illustrated in  FIG. 14 , the vehicle V 1  is moving towards the junction point  164  on the track section  168 . The vehicles V 3  and V 4  are moving towards the junction point  164  on the track section  166 . The vehicle V 2  is moving away from the junction point  164  on the track section  170 .  
         [0164]     The vehicle V 4  is associated with the vehicle V 3  as the current successor. A next successor is not associated with the vehicle V 3 . The vehicle V 2  is associated with the vehicle V 3  as the current forerunner. A next forerunner is not associated with the vehicle V 3 .  
         [0165]     The vehicle V 3  is associated with the vehicle V 4  as the current forerunner. A next forerunner is not associated with the vehicle V 4 .  
         [0166]     In the situation illustrated in  FIG. 14 , the vehicle V 3  reaches the collision point in the track section  166  and thereupon sends a message (arrow  214 ) to the vehicle V 4 , its current successor, which causes the vehicle V 4  to strike out the vehicle V 3  as its current forerunner. Since the vehicle V 4  does not have a next forerunner, it does not receive a new current forerunner.  
         [0167]     The vehicle V 4  sends a message (arrow  216 ) to the node administration unit  192  for indicating to the node administration unit  192  that the vehicle V 3  is now passing the junction point  164 .  
         [0168]     The node administration unit  192  sends an acknowledging message (arrow  218 ) to the vehicle V 3  which causes the vehicle V 3  to strike out the vehicle V 4  as its current successor. Since the vehicle V 3  does not have a next successor, it does not receive a new current successor.  
         [0169]     A short time later, as is illustrated in  FIG. 15 , the vehicle V 4  reaches the brake point (BP) and thereupon sends a message (arrow  220 ) to the node administration unit  192  for informing it that the vehicle V 4  intends to pass the junction point  164 .  
         [0170]     The vehicle V 3  is registered in the forerunner list of the node administration unit  192 .  
         [0171]     The node administration unit  192  therefore sends a message (arrow  222 ) to the vehicle V 3 , said message indicating that the vehicle V 4  is now a new next successor to the vehicle V 3 .  
         [0172]     The vehicle V 3  registers the vehicle V 4  as its new next successor and sends an acknowledging message to this effect (arrow  224 ) to the vehicle V 4  which thereupon registers the vehicle V 3  as its next forerunner.  
         [0173]     The updating process that was triggered by the vehicle V 4  upon reaching the brake point is thereby concluded.  
         [0174]     In the case of a variant of the situation shown in  FIG. 15  which is illustrated in  FIG. 16 , the vehicle V 4  reaches the brake point before the vehicle V 3  has reached the collision point.  
         [0175]     Consequently, in the situation illustrated in  FIG. 16 , the vehicle V 3  is registered as the current forerunner of the vehicle V 4  and the vehicle V 4  is registered as the current successor of the vehicle V 3 .  
         [0176]     Upon reaching the brake point, the vehicle V 4  sends a message (arrow  226 ) to the node administration unit  192  for informing it that the vehicle V 4  wishes to pass through the junction point  164 .  
         [0177]     The vehicle V 3  is registered in the forerunner list of the node administration unit  192  and, for this reason, the node administration unit  192  sends a message (arrow  228 ) to the vehicle V 3  by means of which the vehicle V 4  is indicated as being a new next successor to the vehicle V 3 .  
         [0178]     The vehicle V 3  registers the vehicle V 4  as its next successor and sends an acknowledging message (arrow  230 ) to the vehicle V 4  which causes the vehicle V 4  to register the vehicle V 3  as its new next forerunner.  
         [0179]     The updating process that was triggered by the vehicle V 4  upon reaching the brake point is thereby concluded.  
         [0180]     The updating processes involving the inclusion of a node administration unit when passing a branching point of the track network of the transport system  100  correspond to the updating processes that occur when passing a junction point but with the difference that, in the case of a branching point, the collision points (CP) are not located prior to the node in the direction of movement, but rather, are located beyond the node in the direction of movement, i.e. beyond the branching point, that the node administration unit maintains its own forerunner list for each of the track sections leading away from the branching point and that, when the vehicles are announcing their intention of passing the branching point  178  to the node administration unit  192 , they simultaneously indicate the particular track sections leading away from the branching point  178  upon which they want to travel.  
         [0181]     Thus, when a vehicle reaches the brake point prior to the branching point, it then sends a message to the administration unit assigned to the node for informing it that the vehicle intends to pass the branching point and for indicating that one of the onwardly extending track sections over which it intends to continue its journey.  
         [0182]     If there is no forerunner entered in the forerunner list of the node administration unit for the track section concerned, the node administration unit sends an acknowledgement message back to the vehicle concerned.  
         [0183]     If a vehicle is contained in the forerunner list of the node administration unit for the desired track section, then the node administration unit sends a message to this second vehicle which results in this second vehicle registering the first vehicle as its next successor and sending an acknowledgement message to the first vehicle for causing the first vehicle to register the second vehicle as its next forerunner.  
         [0184]     In the event that the second vehicle does not have a current successor, the first vehicle is registered as being the current successor of the second vehicle and struck out as the next successor of the second vehicle.  
         [0185]     In the event that the first vehicle does not have a current forerunner, the second vehicle is registered as the current forerunner of the first vehicle and struck out as the next forerunner of the first vehicle.  
         [0186]     The updating process that was triggered by the first vehicle upon reaching the brake point is thereby concluded.  
         [0187]     When the vehicle reaches the collision point (CP) on its new track section after passing the branching point, then this first vehicle sends a message to its current successor which causes this second vehicle to strike out the first vehicle as its current forerunner and, should there be one, to make its next forerunner its current forerunner.  
         [0188]     Furthermore, the second vehicle sends a message to the node administration unit by means of which the node administration unit is informed that the first vehicle has passed the branching point.  
         [0189]     The node administration unit thereupon sends an acknowledging message to the first vehicle which causes the first vehicle to strike out the second vehicle as its current successor and, should there be one, to make its next successor into its current successor.  
         [0190]     The updating process that was triggered by the first vehicle upon reaching the collision point is thereby concluded.  
         [0191]     If, upon reaching the collision point, no current successor is associated with the vehicle, then the vehicle concerned sends a message to the node administration unit by means of which the node administration unit is informed that the vehicle concerned has passed the branching point.  
         [0192]     The node administration unit sends an acknowledging message to the vehicle concerned which then causes this vehicle to make its next successor, should there be one, into its current successor.  
         [0193]     The updating process that was triggered by the vehicle upon reaching the collision point is thereby concluded.  
         [0194]     The updating processes occurring when passing a branching point  178  will be explained hereinafter with reference to FIGS.  17  to  26 .  
         [0195]     In the situation illustrated in  FIG. 17 , the vehicle V 6  is moving towards the branching point  178  on the track section  180 , whilst the vehicle V 7  is moving away from the branching point  178  on the track section  182 .  
         [0196]     At the time point illustrated in  FIG. 17 , the vehicle V 6  reaches the brake point (BP) in the track section  180  and thereupon sends a message (arrow  232 ) to the node administration unit  192  responsible for the branching point  178  by means of which the node administration unit  192  is informed that the vehicle V 6  would like to pass the branching point  178  and change onto the track section  184 .  
         [0197]     Since the vehicle V 7  is present on the other track section  182  and hence the forerunner list of the node administration unit  192  is empty for the track section  184 , the node administration unit  192  sends an acknowledging message (arrow  234 ) directly to the vehicle V 6 .  
         [0198]     At the time point illustrated in  FIG. 18 , the vehicle V 6  has passed the branching point  178 , has changed onto the track section  184  and has gone past the collision point (CP) there.  
         [0199]     Since, at this time point, the vehicle V 6  does not have a current successor, it sends a message (arrow  236 ) to the node administration unit  192  by means of which an indication is given to the node administration unit  192  that the vehicle V 6  has left the region of the branching point  178 .  
         [0200]     The node administration unit  192  sends an acknowledging message (arrow  238 ) to the vehicle V 6  which causes the vehicle V 6  to make its next successor, should there be one, the current successor.  
         [0201]     The updating process that was triggered by the vehicle V 6  upon passing the collision point is thereby concluded.  
         [0202]     In the situation illustrated in  FIG. 19 , the vehicle V 4  is moving towards the branching point  178  on the track section  180 , whilst the vehicle V 5  is moving away from the branching point  178  on the track section  184 .  
         [0203]     The vehicle V 5  is associated with the vehicle V 4  as the current forerunner. The vehicle V 4  is associated with the vehicle V 5  as the current successor.  
         [0204]     At the time point illustrated in  FIG. 19 , the vehicle V 5  has gone past the collision point (CP) in the track section  184  and therefore sends a message (arrow  240 ) to its current successor, the vehicle V 4 , which message causes the vehicle V 4  to strike out the vehicle V 5  as its current forerunner and to register its next forerunner as its current forerunner. However, as no next forerunner is associated with the vehicle V 4 , it does not receive a new current forerunner.  
         [0205]     The vehicle V 4  sends a message (arrow  242 ) to the node administration unit  192  by means of which the node administration unit  192  is informed that the vehicle V 5  has left the region of the branching point  178 .  
         [0206]     The node administration unit  192  sends an acknowledging message (arrow  244 ) to the vehicle V 5  which causes the vehicle V 5  to strike out the vehicle V 4  as its current successor and, should there be one, to register its next successor as its current successor. However, as no next successor is associated with the vehicle V 5 , the vehicle V 5  does not receive a new current successor.  
         [0207]     The updating process that was triggered by the vehicle V 5  upon passing the collision point is thereby concluded.  
         [0208]     In the situation illustrated in  FIG. 20 , the vehicle V 2  is moving towards the branching point  178  on the track section  180 , whilst the vehicle V 4  is moving away from the branching point  178  on the track section  182  and the vehicle V 3  is moving away from the branching point  178  on the track section  184 .  
         [0209]     The vehicle V 3  is associated with the vehicle V 2  as the current forerunner, but there is no vehicle associated therewith as the next forerunner. Furthermore, an (as yet not illustrated in  FIG. 20 ) vehicle V 1  is associated with the vehicle V 2  as the current successor thereof, although no vehicle is associated therewith as the next successor.  
         [0210]     The vehicle V 2  is associated with the vehicle V 3  as the current successor, although no vehicle is associated therewith as the next successor.  
         [0211]     Neither a current successor nor a next successor are associated with the vehicle V 4 .  
         [0212]     At the time point illustrated in  FIG. 20 , the vehicle V 2  reaches the brake point in the track section  180  and thereupon sends a message (arrow  246 ) to the node administration unit  192  for informing it that the vehicle V 2  intends to pass the branching point  178  and continue its journey on the track section  182 .  
         [0213]     Since the vehicle V 4  is registered in the forerunner list of the node administration unit  192  for the track section  182 , the node administration unit  192  sends a message (arrow  248 ) to the vehicle V 4  which causes the vehicle V 4  to register the vehicle V 2  as its next successor.  
         [0214]     Since the vehicle V 4  does not have a current successor, the vehicle V 2  is registered as the current successor of the vehicle V 4  and struck out as the next successor of the vehicle V 4 .  
         [0215]     The vehicle V 4  sends an acknowledging message (arrow  250 ) to the vehicle V 2  which causes the vehicle V 2  to register the vehicle V 4  as its next forerunner.  
         [0216]     The updating process that was triggered by the vehicle V 2  upon reaching the brake point is thereby concluded.  
         [0217]     At the time point illustrated in  FIG. 21 , the vehicle V 1  following the vehicle V 2  on the track section  180  reaches the brake point in the track section  180 .  
         [0218]     The vehicle V 2  is associated with the vehicle V 1  as the current forerunner.  
         [0219]     Upon reaching the brake point, the vehicle V 1  sends a message (arrow  252 ) to the node administration unit  192  for informing it that the vehicle V 1  intends to pass the branching point  178  and continue its journey on the track section  184 .  
         [0220]     Since the vehicle V 3  is registered in the forerunner list of the node administration unit  192  for the track section  184 , the node administration unit  192  sends a message (arrow  254 ) to the vehicle V 3  which causes the vehicle V 3  to register the vehicle V 1  as its next successor.  
         [0221]     Furthermore, the vehicle V 3  sends an acknowledging message (arrow  256 ) to the vehicle V 1  which causes the vehicle V 1  to register the vehicle V 3  as its next forerunner.  
         [0222]     The updating process that was triggered by the vehicle V 1  upon reaching the brake point is thereby concluded.  
         [0223]     At the time point illustrated in  FIG. 22 , the vehicle V 3  has gone past the collision point (CP) on the track section  184  and, for this reason, the vehicle V 3  sends a message (arrow  258 ) to its current successor, the vehicle V 2 , which causes the vehicle V 2  to strike out the vehicle V 3  as its current forerunner and to register its next forerunner, the vehicle V 4 , as its current forerunner, whereby the vehicle V 4  is simultaneously struck out as the next forerunner of the vehicle V 2 .  
         [0224]     Furthermore, the vehicle V 2  sends a message (arrow  260 ) to the node administration unit  192  which indicates to the node administration unit  192  that the vehicle V 3  has left the region of the branching point.  
         [0225]     The node administration unit  192  sends an acknowledging message (arrow  262 ) to the vehicle V 3  which causes the vehicle V 3  to strike out the vehicle V 2  as its current successor and to register its next successor, the vehicle V 1 , as its current successor, whereby the vehicle V 1  is simultaneously struck out as the next successor.  
         [0226]     The updating process that was triggered by the vehicle V 3  upon passing the collision point is thereby concluded.  
         [0227]     At the time point illustrated in  FIG. 23 , a further vehicle V 0 , which is moving behind the vehicle V 1  on the track section  180 , reaches the brake point on the track section  180 .  
         [0228]     The vehicle V 1  is associated with the vehicle V 0  as the current forerunner.  
         [0229]     Upon reaching the brake point, the vehicle V 0  sends a message (arrow  264 ) to the node administration unit  192  by means of which the vehicle V 0  announces its intention of passing the branching point  178  and continuing its journey on the track section  182 .  
         [0230]     Since the vehicle V 2  is registered in the forerunner list of the node administration unit  192  for the track section  182 , the node administration unit  192  sends a message (arrow  266 ) to the vehicle V 2  which causes the vehicle V 2  to register the vehicle V 0  as its next successor.  
         [0231]     Furthermore, the vehicle V 2  sends an acknowledging message (arrow  268 ) to the vehicle V 0  which causes the vehicle V 0  to register the vehicle V 2  as its next forerunner.  
         [0232]     The updating process that was triggered by the vehicle V 0  upon reaching the brake point is thereby concluded.  
         [0233]     At the time point illustrated in  FIG. 24 , the vehicle V 2  has passed the collision point (CP) on the track section  182 .  
         [0234]     Consequently, the vehicle V 2  sends a message (arrow  270 ) to its current successor, the vehicle V 1 , which causes the vehicle V 1  to strike out the vehicle V 2  as its current forerunner and to register its next forerunner, the vehicle V 3 , as its current forerunner, whereby the vehicle V 3  is simultaneously struck out as the next forerunner of the vehicle V 1 .  
         [0235]     Furthermore, the vehicle V 1  sends a message (arrow  272 ) to the node administration unit  192  by means of which the node administration unit  192  is informed that the vehicle V 2  has left the region of the branching point.  
         [0236]     The node administration unit  192  sends an acknowledging message (arrow  274 ) to the vehicle V 2  which causes the vehicle V 2  to strike out the vehicle V 1  as its current successor and to register instead, its next successor, the vehicle V 0 , as its current successor, whereby the vehicle V 0  is simultaneously struck out as the next successor of the vehicle V 2 .  
         [0237]     The updating process that was triggered by the vehicle V 2  after it had passed the collision point is thereby concluded.  
         [0238]     At the time point illustrated in  FIG. 25 , the vehicle V 1  has gone past the collision point (CP) on the track section  184 .  
         [0239]     Consequently, the vehicle V 1  sends a message (arrow  276 ) to its current successor, the vehicle V 0 , which causes the vehicle V 0  to strike out the vehicle V 1  as its current forerunner and to register instead, its next forerunner, the vehicle V 2 , as its current forerunner, whereby the vehicle V 2  is simultaneously struck out as the next forerunner of the vehicle V 0 .  
         [0240]     Furthermore, the vehicle V 0  sends a message (arrow  278 ) to the node administration unit  192  by means of which the node administration unit  192  is informed that the vehicle V 1  has left the region of the branching point.  
         [0241]     The node administration unit  192  sends an acknowledging message (arrow  280 ) to the vehicle V 1  which causes the vehicle V 1  to strike out the vehicle V 0  as its current successor and to register its next successor as the new current successor. However, as no next successor is associated with the vehicle V 1 , the vehicle V 1  does not receive a new current successor.  
         [0242]     The updating process that was triggered by the vehicle V 1  after it had passed the collision point is thereby concluded.  
         [0243]     At the time point illustrated in  FIG. 26 , the vehicle V 0  has gone past the collision point (CP) on the track section  182 .  
         [0244]     No current successor is associated with the vehicle V 0  and, for this reason, the vehicle V 0  sends a message (arrow  282 ) directly to the node administration unit  192  for informing the node administration unit  192  that the vehicle V 0  has left the region of the branching point.  
         [0245]     The node administration unit  192  sends an acknowledging message (arrow  284 ) to the vehicle V 0  which causes the vehicle V 0  to strike out its current successor and to register its next successor as a new current successor, whereby the next successor is simultaneously struck out.  
         [0246]     However, as neither a current successor nor a next successor are associated with the vehicle V 0 , the successor relationships of the vehicle V 0  remain unchanged.  
         [0247]     The updating process that was triggered by the vehicle V 0  after it had passed the collision point is thereby concluded.  
         [0248]     The junction points  164  and the branching points  178  of the track network of the transport system  100  are implemented by means of so-called “active points”, whereby an “active point” is to be understood as being a point having movable rail sections, in contrast to a  “ passive point” wherein all the rail sections are stationary and the rail section to be used by a vehicle is selected by operating a guidance device located in the vehicle. An active point for a suspended monorail system is known from DE 33 02 266 C2 for example.