Microprocessor Based Data Acquisition for Analysis of Engine Performance

A computer system for data acquisition and analysis has been assembled and tested as an engineering development tool for advanced diagnostic techniques. This system includes custom hardware and software to facilitate high-speed acquisition of data, both digital and analog. The digital data is acquired via a time-stamping procedure, whereas the analog signals are sampled with a multiplexed A/D converter. By simultaneously monitoring both types of signals available to the engine control module, the performance parameters of an engine can be analyzed as functions of either time or engine position. Examples of misfire detection are given which illustrate the need for accurate digital data. Other examples include high-resolution velocity profiles of a defective engine, and samples of signals obtained from a normal engine.