An Event Based Simulation Algorithm for Train Scheduling

1. An Event Based Simulation Algorithm for Train Scheduling Presented by Rakesh A. Ambre (04319401) Under the Guidance of Prof. Narayan Rangaraj

2. Introduction • Preamble • Problem Definition • To increase section capacity for given blocks and station configuration, timetable and priority of scheduled trains, operating and safety policies, various types of trains (loco-wagon combination) and signaling regime, crew scheduling. • Scope of Thesis • Contribution of Thesis An Event Based Simulation Algorithm for Train Scheduling

3. Operating Scenario • Concept of Railway Network Capacity • Capacity Estimation • Scott’s Formula • Train Charting • Class of Traffic • Factors affecting Capacity An Event Based Simulation Algorithm for Train Scheduling

4. Simulation Approach • Systems of Working: • Absolute Block System • Automatic Block System • Scheduling Rules An Event Based Simulation Algorithm for Train Scheduling

5. Literature Survey • Literature Survey • Complexity of Problem • No-Wait Flow Shop Scheduling Problem (Naik, 2002) • Knapsack Problem (Cai and Goh, 1994) • Simulation Models • Route Seeking Models • Optimization Models • Computer Assisted Dispatching Models • Event Based Simulation Models An Event Based Simulation Algorithm for Train Scheduling

6. IIT Bombay IRISET Simulator • Input Module • Scheduler module • Output Module • Scheduling Strategy and Algorithm • Limitations of IIT Bombay IRISET Simulator An Event Based Simulation Algorithm for Train Scheduling

7. Priority Based Algorithm • Step 1: All trains (scheduled and unscheduled) are sorted in ascending order of their priorities. • Step 2: The train with the highest priority is scheduled first till it traverses through the entire section. Once a train is scheduled its timetable is fixed and it is not altered later. • Step 3: We then schedule the next train from the sorted list and so on, till all trains are scheduled. An Event Based Simulation Algorithm for Train Scheduling

8. Scheduling Algorithm An Event Based Simulation Algorithm for Train Scheduling

9. RAILS (Railway Analysis and Interactive Simulator) • Features • TPC • TDS • Scheduling Logic An Event Based Simulation Algorithm for Train Scheduling

10. Event Based Simulation • Deadlock-Free Routing • Methods to resolve deadlock • Restore the system • Preemption of the resources • Design Routing that avoids Deadlock (Dijkstra’s Bankers Algorithm) An Event Based Simulation Algorithm for Train Scheduling

11. Simple Deadlock Free Algorithm (Quan et al., 2004) • Example: • 10 trains arriving at 0,1,2,….,9 hrs, Headway-1hr then • In Efficient way, last train arrives after 19hrs • Using above algorithm, last train arrives after 100 hrs. An Event Based Simulation Algorithm for Train Scheduling

12. Proposed Simulation Algorithm • Final Velocity • Transit-Time • Look-Ahead • Main Routine (Algorithm) An Event Based Simulation Algorithm for Train Scheduling

13. Final-Velocity An Event Based Simulation Algorithm for Train Scheduling

14. Transit-Time 1) If Train is Accelerating/Decelerating 2) If Train is Accelerating/Decelerating and then moving with constant speed An Event Based Simulation Algorithm for Train Scheduling

15. Look-Ahead An Event Based Simulation Algorithm for Train Scheduling

16. Conflict at Block An Event Based Simulation Algorithm for Train Scheduling

17. An Event Based Simulation Algorithm for Train Scheduling

18. Main Routine • Algorithm: • Prepare Event List (ascending order of time) • Consider first event • Using Look-Ahead find out new event (either halt at current station or move to next station) • Insert new event at appropriate position • Check whether event list is empty • Generate Reports. An Event Based Simulation Algorithm for Train Scheduling

19. Proposed Algorithm An Event Based Simulation Algorithm for Train Scheduling

20. Java Simulator • Java 1.5 • Input through text files • Main Menu:- An Event Based Simulation Algorithm for Train Scheduling

21. Selection Menu An Event Based Simulation Algorithm for Train Scheduling

22. Output An Event Based Simulation Algorithm for Train Scheduling

23. Difference between Priority Based Simulation and Event Based Simulation An Event Based Simulation Algorithm for Train Scheduling

24. Single Direction Traffic Test Case An Event Based Simulation Algorithm for Train Scheduling

25. Track Configuration and Input Data Railway Network: Input Data for Trains: An Event Based Simulation Algorithm for Train Scheduling

26. Results obtained using Proposed Algorithm Various Events: An Event Based Simulation Algorithm for Train Scheduling

27. Distance vs Time Plot An Event Based Simulation Algorithm for Train Scheduling

28. Graphical Output of IRISET Simulator IIT Bombay-IRISET Simulator An Event Based Simulation Algorithm for Train Scheduling

29. Both Direction Traffic Test Case An Event Based Simulation Algorithm for Train Scheduling

30. Train Data Input Train Data An Event Based Simulation Algorithm for Train Scheduling

31. Event List for Up Direction Traffic An Event Based Simulation Algorithm for Train Scheduling

32. Event List for Down Direction Traffic An Event Based Simulation Algorithm for Train Scheduling

33. Distance vs Time Plot An Event Based Simulation Algorithm for Train Scheduling

34. Effect of Block Length Test Case An Event Based Simulation Algorithm for Train Scheduling

35. Train Data Input Train Data An Event Based Simulation Algorithm for Train Scheduling

36. Event Lists For 4 Km:- For 6 Km:- For 9 Km:- For 12 Km:- An Event Based Simulation Algorithm for Train Scheduling

37. Distance vs Time Graph An Event Based Simulation Algorithm for Train Scheduling

38. Inferences from Test Cases 1) For first two test cases 2) For third test case An Event Based Simulation Algorithm for Train Scheduling

39. Deadlock Test Case An Event Based Simulation Algorithm for Train Scheduling

40. Track Configuration and Input Data Railway Network: Input Data for Trains: An Event Based Simulation Algorithm for Train Scheduling

41. Possibility of Deadlock An Event Based Simulation Algorithm for Train Scheduling

42. Output by Proposed Algorithm An Event Based Simulation Algorithm for Train Scheduling

43. Conclusions • Train Scheduling Problem is NP-Complete. • Simulation Techniques can be use to model Train Scheduling Problem. • Proposed Algorithm uses list of events and tries to mimic train handling in actual practice. • Algorithm may prove helpful in justifying slacks provided in passenger train timetable. • Test Cases shows algorithm gives feasible results in most of the cases. • Test case shows algorithm can handle some of deadlock situations. • Section Capacity depends on Track Configuration, traffic congestion, block length, Types of Trains. • Section Capacity also depends on Speed Restrictions, Topography, Station Configuration, Operating Policies, Failures. An Event Based Simulation Algorithm for Train Scheduling

44. Future Work • Testing algorithm for other input parameters such as topography, station configuration • Possible extensions to proposed simulator- Report Generator, Graphical Output. • Use of slacks in Passenger train timetables. An Event Based Simulation Algorithm for Train Scheduling

45. Thank You! ? An Event Based Simulation Algorithm for Train Scheduling

46. Bankers Algorithm • How much of each resource each process could possibly request • How much of each resource each process is currently holding • How much of each resource the system has available An Event Based Simulation Algorithm for Train Scheduling

47. Bankers Algorithm Example Available system resources: A B C D 3 1 1 2 Processes (maximum resources): A B C D P1 3 3 2 2 P2 1 2 3 4 P3 1 1 5 0 Processes (current resources): A B C D P1 1 2 2 1 P2 1 0 3 3 P3 1 1 1 0 P1 6 4 3 4 P2 7 6 6 8 Deadlock Free A B C D Free 3 1 0 2 P1 1 2 2 1 P2 1 0 3 3 P3 1 1 2 0 Possible Deadlock A B C D Free 3 0 1 2 P1 1 2 2 1 P2 11 3 3 P3 1 1 1 0 An Event Based Simulation Algorithm for Train Scheduling