A novel design concept of cost-effective permanent rail-track monitoring system

Abstract

This paper presents a novel design concept of low-cost permanent monitoring system for rail-track problems. The introduced design is theoretically overcome the currant in-use designs in terms of providing permanent accurate observations for detecting rail-track irregularities for all railway network during service time using low-cost integrated sensors. The paper investigates the rail-track common irregularities by identifying the issues, presenting challenges, and highlighting the limitations of currently in-use rail-track monitoring techniques. Then, the potential of using cost-effective sensors and intelligent techniques for detecting the rail-track geometric parameters and rail irregularities is theoretically studied. This includes using low-cost GPS, MEMS-INS & high frequency single-point and multi-spot laser distance sensors for detecting rail surface cracks, fractures, cross-level, wrap, gauge and vertical & horizontal rail alignments. Different levels of GPS/MEMS-INS integration are covered, illustrating the advantages of each solution and the optimal utilization in the system. Vision-based monitoring using low-cost HD non-metric digital cameras is also investigated, showing the optimal specifications required for fulfill the system requirements. Data logging and GPS-time-based synchronization method is presented as a part of the design concept of the suggested system. The processing techniques and unit outputs are illustrated in details, showing how each unit works for detecting the rail-track irregularities, providing the geodetic positioning and the vision-based assessing. The main part of the system, which is Automatic Adjusted Wheeled Carrier Frame (AAWCF) is discussed in more details, showing simple and clear different views for all details and integrated sensors. It is recommended to carry out this idea, by building up and evaluating the performance of AAWCF in real railway environments, evaluating the design concept of each unit individually to know the weaknesses of each technique, and then evaluating the whole system in all expected railway cases to find out the advantages and limitations of this design concept.