Development and Testing of an Online Oil Condition Monitor for Diesel Driven Army Ground Vehicles

This paper describes the author's experiences in the design, validation and field-testing of a low cost, online oil condition monitor for diesel driven Army ground vehicles. This online oil condition monitor utilizes a multi-frequency approach to electrochemical impedance spectroscopy to interrogate and evaluate fluid health in near real time. A dual microcontroller processing architecture embedded in the sensor itself executes an oil-health evaluation algorithm and provides estimates of lubricant remaining useful life, as well as identification of the primary mode of degradation of the fluid. These data are transmitted off the sensor via J1939 compliant CAN messages. In this paper the unique application requirements, which formed the foundation of the development process, are discussed, and the technical and design challenges associated with producing a military grade smart-sensor at a sufficiently low price point for widespread adoption in the ground vehicle market are detailed. The methodology of determining oil health from signal data is discussed. Symbolic regression modeling was performed to evaluate the performance of the oil condition monitor. The oil condition monitor was also implemented on field-tests on commercial diesel trucks. The authors will provide specific quantitative data and results from these tests and a summary of lessons learned during the test and evaluation. The project resulted in an oil condition monitor that effectively integrates this new on-line oil sensing with embedded monitoring capability.