Information Technology Reference
In-Depth Information
- Delay and conflict detection Within a dispatching plan arising
disturbances (e.g. a high train density) and conflicts (e.g. overlapping
blocking times) have to be detected. The conflict time detection uses
reduction functions to simulate the uncertainty of future operation situ-
ations, conflicts beyond a time horizon can be ignored.
- Rescheduling If conflicts are detected within a dispatching plan
dp
i
,
a new conflict free plan
dp
i
+1
is produces by conflict solving components.
The primary goal of a microscopic dispatching system is the elimination of
blocking time overlaps. If equivalent solutions exist, additional weighting
criteria are applied, e.g. weighted sum of new delays, kept train links etc.
Several algorithms and approaches for conflict solving algorithms exists,
a good overview and evaluation is given e.g. in [3].
- Dispatching plan propagation Decisions made by dispatching sys-
tems must be propagated and submitted to interlocking stations and/or
train drivers. Depending on the technical, organizational and legal envi-
ronment different integration levels are possible. The propagation process
can be a safety relevant task of such systems.
With this rough introduction of computer based dispatching systems and
there integration within the operational environment the next chapter analy-
ses the functional components of such systems more detailed and introduces
interactions and data flows.
2
System Architecture
Following the rough overview of computer based dispatching systems and
their tasks, a generic system architecture can be set up. The architecture
must contain components covering the required functionalities:
- Basic infrastructure and timetable data must be provided when the sys-
tem is initialized. The initialization must provide microscopic infrastruc-
ture data for routing algorithms of the dispatching system and for detailed
run time and occupation computation as well as timetable data contain-
ing the planed trajectories, allocated travel times, departure and arrival
times for delay evaluation and stopping policies to evaluate valid routes.
- Communication channels provide dispatching systems with required real
time information. As evaluated e.g. by the
-project [4] two kinds
of system messages are seriously evaluable by computer based dispatching
systems: messages associated to a specific train and messages containing
interlocking data.
Train related messages are e.g. messages about train positions, delay re-
ports or notifications about the change of train characteristics and proper-
ties. Interlocking messages reflect information about routes currently set
or released by interlocking stations or block occupations. These messages
are finally evaluated and the derived information is integrated within the
current timetable, possibly leading to modified train trajectories.
DisKon
