Justification of the N eed for Locomotive Diagnostic Systems
In the world and domestic practices of technical maintenance and repair (TMR) of locomotives there exists a tendency for the expanded use of technical diagnostics systems, the transition to predictive repair to reduce the costs of their life cycle. Modern hardware and software tools make it possible to create automated technical diagnostics systems (ATDS) for all types of locomotive equipment but equipping service repair locomotive depots with them requires significant capital costs with an unacceptably long payback period. The objective of the work is to develop a method and a corresponding simulation modelling software program to determine technical and economic feasibility of using certain means of technical diagnostics. Diagnostic systems reduce waiting time for repairs, the volume and cost of scheduled and unscheduled TMR, which makes it possible to reduce the operating fleet of locomotives. In modern economic calculations, to assess the success of an investment project, the indicator «Net present value (NPV)» of the project is used. Based on this principle, in relation to ATDS, a method for determining feasibility of introducing various types of ATDS and the corresponding methodology and software made with the algorithmic language VBA (Visual BASIC for Applications) in the MS Excel environment has been developed. The work carried out simulation modelling for Russian conditions of the payback of main types of diagnostic systems comprising on-board based microprocessor control systems, rheostat testing stations for diesel locomotives, diagnostics of traction motors, etc. The economic feasibility of introducing these systems has been proved. Also, economically inexpedient diagnostic systems have been identified, f o r example, automatic measurement of the profile of a wheel set tire.