A Rugged and Reliable System for Measuring Engine Crankshaft Speed Fluctuations

A measurement system and the associated signal processing algorithm for accurately determining engine crankshaft speed fluctuations are presented in this work. The main features of the system include ruggedness, simple sensor installation, and high accuracy and resolution. The ruggedness and simplicity of the system are characterized by the use of highly reliable Hall-Effect Transducers (HETs) mounted on the engine flywheel bell housing to sense the passing of flywheel gear teeth. A relatively significant noise component is introduced to the HET measurements by the nonuniform flywheel gear tooth spacings. The high measurement accuracy is achieved by a very computationally efficient signal processing algorithm based on two HET inputs. The advantages of the current system over the single HET systems commonly used in practice are clearly demonstrated through experiments on a Detroit Diesel Corporation 6V-92TA engine.