Research Article

Optimal Inspection Scheduling Model for Monitoring Railway Track Grids

Table 4

Comparison of actual and optimized track inspection schedule.

ItemInspection schedule using the OISM-RTGActual inspection schedule prepared by the field engineers

Constraint systemTime constraints between activitiesSatisfactionSatisfaction
Fixed duration constraintSatisfactionViolation. For example, the rail detection trolley inspection is not scheduled for track segments between 757.2 and 762 km in the downward direction of the Lanxin railway.
Space constraints between activitiesSatisfactionViolation. For example, the track geometry trolley inspection and manual inspection are simultaneously scheduled for track segments between 747.2 and 758.8 km in the downward direction of the Lanxin railway.
Rate constraint of activitiesSatisfactionViolation. For example, on December 26th, the track geometry trolley inspection is scheduled for track segments between 741 and 760 km in the downward direction of the Lanxin railway. The inspection rate is 19 km per maintenance window and is nearly double the upper inspection rate limit (10.6 km per maintenance window).
Resource constraintSatisfactionSatisfaction
Continuity constraintSatisfactionSatisfaction

ObjectivesEquilibrium THR0.9800.800
Robust r0.1610
Weighted objective function0.5700.400

Visual presentation resultsA comparison of Figures 7 and 8 shows that the inspection schedule using the TGOISM-MRT model is superior to the actual inspection schedule prepared by the field engineers.