DYNAMIC TESTING OF INTERNAL COMBUSTION ENGINES

Abstract

The automated testing of internal combustion engines is a field of considerable importance. This thesis describes a novel area in the form of dynamic testing. The investigation represents an original approach to the problem with which the author believes he has developed a new concept in engine testing. The resulting information, combined with an appreciation of the latest developments in automation equipment technology, has lead to a review of the requirements of a generalised engine test system together with an outline of the way in which it could be implemented. The automated engine test beds used during the work are described. The conventional methods of testing internal combustion engines are reviewed and a generalised approach to automating them proposed. This then leads to the suggestion of a new method using dynamic testing techniques specially evolved in the course of the work. On the basis of this the implementation of a dynamic full-load power curve as a replacement for its steady state equivalent was pursued. The second major use of dynamic techniques is for exhaust emission cycles. Both dynamic (USEPA Smoke Cycle) and steady-state (USEPA 13 Mode Cycle) cycles were performed. In the case of the former, outer digital loop techniques were used to improve control response. In performing the above work, use was made of both analog and digital simulation techniques for development purposes. This work was also extended by the development of a simulation of a material handling system to enable the control and optimisation of a production test facility to be studied. The testing methods associated with automated fault diagnosis are also analysed. On the basis of the above work an engine test system task analysis was generated and this new concept used to plan a microprocessor based engine test automation scheme.