KR101128836B1 - Optimum Path Setup Method of Synchronization based City-Wide PRT - Google Patents

Abstract

The present invention relates to a method for setting an optimal route of a synchronization-based City-Wide PRT, comprising: (a) searching for all candidate paths between a starting point and a destination; (b) calculating a distance cost TR _r of the candidate path r for all the candidate paths searched in step (a); (c) calculating a vehicle-injectable time point TD _r of the candidate path r with respect to all candidate paths found in step (a); And (d) selecting an optimal path such that the sum of the distance cost TR _r calculated in the steps (b) and (c) and the vehicle insertion time point TD _r are minimized. It provides an optimal path setting method of synchronization-based City-Wide PRT, characterized in that it comprises a.
According to the present invention, the optimum route from the starting point to the destination is calculated in consideration of the distance and the time when the vehicle can be inserted in the shortest time to solve the inconvenience caused by the inefficiency of the operation of the vehicle and the increase of the waiting time of the passenger. Can play a role.

Description

Optimal Path Setup Method of Synchronization based City-Wide PRT}

The present invention relates to a method for setting an optimal route for synchronization-based City-Wide PRT. More particularly, the present invention relates to calculating a shortest time path in a complex City-Wide PRT system. The present invention relates to an optimal path setting method of synchronization-based City-Wide PRT, which can increase the operational efficiency of the PRT system by calculating the.

Personal Rapid Transit (PRT) systems include small vehicles that operate at the request of individual passengers. It is the same as a PRT system that runs a transportation network consisting of history and tracks. The PRT system can be constructed with a simpler structure and a lighter structure than a conventional transportation system such as urban railways and trams. Therefore, the construction cost of the PRT system is lower than that of the existing alternative means of transportation. The PRT system is environmentally friendly because it has less visual impact on the urban landscape, is low noise and can reduce air pollution. The history of the PRT system can also be installed in existing buildings already built. Because the driving distance and safety distance between vehicles can be kept short, the traffic capacity of the PRT system can maintain a traffic capacity similar to that of a conventional bus or tram.

However, in the existing PRT network system, when the target vehicle is inserted, the vehicle is injected by searching for the shortest route because the interference of other vehicles is insignificant. However, in the City-Wide based PRT system, the path is complicated and many other vehicles have interference. The presence of the target vehicle due to the presence is greatly affected.

Therefore, in the conventional method, the shortest path in terms of the distance or the time of the injection, the other candidate path becomes the shortest time path, and unnecessary waiting time is required for passengers and vehicles, resulting in inefficiency in operation.

The present invention has been made in view of the above-mentioned circumstances in the prior art, and is intended to calculate the shortest time path in a complex city-wide PRT system. It is an object of the present invention to provide an optimal path setting method of synchronization-based City-Wide PRT that can increase the operational efficiency of the PRT system.

In accordance with an aspect of the present invention, there is provided a method for setting an optimal route of a synchronization-based City-Wide PRT, comprising: (a) searching for all candidate routes between a starting point and a destination; (b) calculating a distance cost TR _r of the candidate path r for all the candidate paths searched in step (a); (c) calculating a vehicle-injectable time point TD _r of the candidate path r with respect to all candidate paths found in step (a); And (d) selecting an optimal path such that the sum of the distance cost TR _r calculated in the steps (b) and (c) and the vehicle insertion time point TD _r are minimized. Characterized in that it comprises a.

Also, in the optimal path setting method of the city-wide PRT, (a) when the network is complex and a plurality of candidate paths are possible, the candidate path is searched by considering only k shortest paths using the K-shortest path method. calculating a distance cost (TR) of k candidate paths; (b) calculating a vehicle-injectable time point TD _r of the candidate path r with respect to all candidate paths found in step (a); And (c) selecting an optimal path such that the sum of the distance cost TR of the candidate path calculated in steps (a) and (b) and the possible vehicle input time (TD _r ) of the candidate path r are minimum. ; Characterized in that it comprises a.

Further, for all candidate paths in step (b), the distance cost TR _r of the candidate path r is

TR _r = sum {C_N _rj N _{r (j + 1)} }, j: 1,... , (R _r My nodes -1)

It is characterized by that.

In addition, the step of calculating the vehicle input time (TD _r ) of the candidate path r may include (e) a virtual candidate including a virtual sector path before the starting point in order to estimate a time point when the other vehicles affecting the candidate path affect the candidate path. Creating a route; (f) selecting a vehicle to be joined when the at least one sector shared by the path of the other vehicle among the sectors from the start point to the destination of the candidate path affects the virtual candidate path; (g) projecting the merged vehicle onto a virtual candidate path; And (h) calculating a vehicle ready time point TD _r of the candidate path r; .

In addition, the vehicle input point (TD _r ) of the candidate path r in the step (h) is occupied state (RO _rd ) of the vehicle. = Smallest distance (d) satisfying 0

for d = TR _r to ∞

if RO _rd = 0 then TD _r = d exit for

next d

It characterized by using.

According to the optimal route setting method of the synchronization-based City-Wide PRT according to the present invention, the optimum route from the starting point to the destination in the shortest time is calculated in consideration of the distance and the time when the vehicle can be inserted. It can play a role of eco-friendly public transportation by eliminating inconvenience caused by increased waiting time.

1 is a flow chart of the optimal path calculation of the present invention.
2 is an exemplary view of projecting a merged vehicle of the present invention onto a candidate path.
3 is an exemplary view of repeatedly projecting the merging vehicles of the present invention to a candidate path.
4 is TR _r of the present invention. State diagram after advancing by value.

Hereinafter, with reference to the accompanying drawings will be described in detail a preferred embodiment according to the present invention.

Basic operation of the optimal path setting method of synchronization-based City-Wide PRT of the present invention is as follows.

1) Vehicles in the route are not stopped or delayed.

2) The vehicle's moving speed is the same and the distance is proportional to time.

3) Every moving vehicle (including tolerances) has a destination.

4) All moving vehicles are not changed after the route to their destination is confirmed.

5) Once the departure is confirmed, the route to the destination will be confirmed and will not be changed later.

6) You can always enter / stop the station at the destination.

The abbreviation of the algorithm used in the present invention is as follows.

N: Node set such as inverse, branch / confluence point, A: Arc set between all neighboring nodes

ST: virtual occlusion sector set constituting the arc,

R: set of candidate paths between specific departure / destination,

C _ij : Arc cost between nodes, TR _r : Distance cost of candidate path r

N _rj : j th node included in candidate path r,

TD _r : Possible vehicle input of candidate path r,

GST _r : sector set of candidate path r, GST _v : Sector set of other vehicle path v

RST _ri : Vehicle-based i-th sector of the input vehicle route

VST _vj : jth sector of the vehicle reference of the other vehicle route

RO _rd : Vehicle occupancy of sector with destination reference distance d in candidate path r

FIG. 1 is a flowchart illustrating an optimal path calculation of the present invention, and FIG. 2 is an exemplary view of projecting the merged vehicle of the present invention onto the candidate path, and FIG. 3 is an exemplary view of repeatedly projecting the merged vehicles of the present invention onto the candidate path. 4 is TR _r of the present invention. State diagram after advancing by value.

Referring to FIG. 1, in the present invention, the optimal path calculation includes searching for candidate paths between origin / destination (step 1), calculating TR _{r for each} candidate path (step 2), and calculating TD _{r for each} candidate path (step 3). In total, four steps are taken: optimal path selection (step 4), min (TD _r + TR _r ).

The first step is to search for a candidate path between the starting point / destination after inputting the starting point / destination (S10). The number of routes from the starting point to the destination is limited due to the limited nodes (directions) and the directional arcs (route), but there may be a large number of candidate routes in the case of a city-wide or lattice structure PRT line.

Candidate paths: R1, R2,... , Rr, where Rr = {N _rj }, j: The number of nodes in Rr.

After checking whether the network is complex (S11), if the simple network structure does not have many cases, it is necessary to search all candidate paths by simple enumeration method (S12). In consideration of the time constraint, it is also possible to consider only the k k shortest paths such as the K-shortest path.

The second step is to calculate TR _r for each candidate path. If the K-shortest path method is used because it is a complex network in the first step, skip this step and proceed to the next step. Otherwise, to calculate the TR value, the following calculation is performed for every candidate path. (S14)

TR _r = sum {C_N _rj N _{r (j + 1)} }, j: 1, ..., (number of nodes in R _r- 1)

The third step is to calculate the TD _r for each candidate path. Initially, the initialization is performed with r = 1 (S15) In step 3-1, the actual distance from the starting point is TR _r, but the virtual sector path before the starting point is estimated to estimate when the interfering vehicle affects the candidate path. Create a candidate path including (S16).

In step 3-2, when the vehicle that affects the virtual candidate path is selected as the expected to-be-joined vehicle when one or more sectors shared by the path of the other vehicle among the sectors from the starting point to the destination of the candidate path (input vehicle) are selected. For this purpose, the sector set GST _r = {RST _ri } of the candidate path and the sector set GST _v of the other vehicle path. Determine by comparing = {VST _vj }.

if GST _r ∋ VST _vj then GST _v Affecting other vehicle paths

else GST _v does not affect other vehicle paths

In step 3-3, the merged vehicle is projected onto the candidate path (S17). FIG. 2 illustrates the projected merged vehicle on the virtual candidate path.

The occupied state is initialized to the non-occupied state (RO _rd = 0) for all sectors in the candidate path, and is recorded as the occupied state (RO _rd = 1) when projecting another vehicle. Based on the destination, the section immediately after the sector shared by the candidate path sector and the other vehicle path becomes the joining section of the other vehicle. That is, RST _ri = VST _vj VST _{v (j + 1)} becomes the confluence point when RST _{r (i + 1)} ≠ VST _{v (j + 1)} is satisfied simultaneously. Therefore, the other vehicle is projected to the position of (TR _r -i) + (j + 1) of the candidate path with respect to the destination. Since other vehicles projected before the vehicle can be inserted into the vehicle, the projected vehicle is advanced by TR _r and the sector j-i + i is occupied at the destination (RO _{r (j-i + 1)} = 1)

If the above process is repeatedly performed on the vehicle route selected in step 3-2, it is projected as shown in FIG. 3, and finally, as shown in FIG.

The TD for calculating _r of the candidate route from the step 3-4 (S18), and repeatedly performed until the r = rmax. (S19) the input vehicle TD _r point satisfying the RO from the RO _{rd rd} = 0 The smallest d value is TD _r . TD _r Each time the value is calculated, the for statement below is repeated.

for d = TR _r to ∞

if RO _rd = 0 then TD _r = d exit for

next d

In the fourth step, an optimal path of min (TD _r + TR _r ) is selected. (S20) The path r whose minimum sum of TR _r and TD _r calculated in the second and third steps is the best path. Also, the optimal path time for the target vehicle to reach the destination is min (TD _r + TR _r ).

According to the present invention, by calculating the optimum route in consideration of the input time of the target vehicle in a complex city-wide PRT system, the vehicle can be efficiently operated and the inconvenience caused by the increased waiting time of the passenger can be eliminated. .

The present invention is not limited to the above-described specific preferred embodiments, and various modifications can be made by any person having ordinary skill in the art without departing from the gist of the present invention claimed in the claims. Of course, it is obvious that such changes will fall within the scope of the claims.

Claims (5)

In the optimal path setting method of the city-wide PRT,
(a) searching for a limited number of candidate paths with limited nodes and directions between the origin and destination;
(b) calculating a distance cost TR _r of the candidate path r for all the candidate paths searched in step (a);
(c) calculating a vehicle-injectable time point TD _r of the candidate path r with respect to all candidate paths found in step (a); And
(d) selecting an optimal path such that the sum of the distance cost TR _r calculated in steps (b) and (c) and the vehicle ready time point TD _r are minimized; Optimal path setting method of synchronization-based City-Wide PRT, characterized in that it comprises a.
In the optimal path setting method of the city-wide PRT,
(a) If the network is not complicated, all candidate paths are searched, and if the network is complex and multiple candidate paths are possible, the candidate path is searched and only k considering the k highest shortest paths using the K-shortest path method. Calculating a distance cost (TR) of the dog candidate paths;
(b) calculating a vehicle-injectable time point TD _r of the candidate path r with respect to all candidate paths found in step (a); And
(c) selecting an optimal path in which the sum of the distance cost TR of the candidate path calculated in steps (a) and (b) and the possible vehicle input time (TD _r ) of the candidate path r are minimum; Optimal path setting method of synchronization-based City-Wide PRT, characterized in that it comprises a.
The method of claim 1,
For all candidate paths in step (b), the distance cost TR _r of the candidate path r is
TR _r = sum {C_N _rj N _{r (j + 1)} }, j: 1,... , (R _r My nodes -1)
Optimal path setting method of synchronization-based City-Wide PRT, characterized in that the.
3. The method according to claim 1 or 2,
Computing the vehicle input time (TD _r ) of the candidate path r is
(e) generating a virtual candidate path including a virtual sector path before the starting point to estimate a time when the interfering other vehicles affect the candidate path;
(f) When the vehicle screen affecting the virtual candidate path includes one or more sectors shared by the path of another vehicle among the sectors from the starting point to the destination of the candidate path, the sector set of the candidate path GST _r = {RST _ri } and the other. Judging by comparing the sector set GST _v = {VST _vj } of the vehicle path and selecting the vehicle to be joined;
(g) projecting the merged vehicle onto a virtual candidate path; And
(h) calculating a vehicle ready time point TD _r of the candidate path r; Optimal path setting method of synchronization-based City-Wide PRT, characterized in that consisting of.
The method of claim 4, wherein
The vehicle input point (TD _r ) of the candidate path r in the step (h) is occupied by the vehicle (RO _rd ). = Smallest distance (d) satisfying 0

for d = TR _r to ∞
if RO _rd = 0 then TD _r = d exit for
next d

Optimal path setting method of synchronization-based City-Wide PRT, characterized in that using the.

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