Abstract
M.Ing.
The principal reasons for the development of a prototype improved control system are
the high maintenance costs and unreliability of Spoomet's fleet of class 6E/6E1
resistor technology electric main line locomotives. These factors may largely be
attributed to two fundamental shortcomings of the existing locomotive control systems,
namely the lack of inherent feedback and application of inconsequent control practices
during acceleration from standstill. The improved control system features the application of a rule based fuzzy controller, implementing human skill and experience to control tractive effort of a resistor technology main line locomotive. The aim of the fuzzy controller is to accelerate the train from standstill to approximately 35 km/h, smoothly and safely.
The prototype fuzzy controller was implemented with a personal computer using an
advanced fuzzy logic development system. A simulation model was developed for the
locomotive and the load. This model was used to first test the structure of the
controller and the initial rule blocks. Following the verification of the fuzzy rules on the simulation model, a relay interface was developed to implement the operation of the control system in coupled mode with the existing control system on a locomotive. The interactive fine-tuning and evaluation of the fuzzy rules were performed during this phase of the development. The test results include the successful evaluation of the prototype fuzzy controller under a variety of typical and "worst case" operating conditions, as well as under conditions of wheel slip. The industrialisation and long term considerations for continued development of the fuzzy logic controller are described in the conclusion.