Method and apparatus for predicting a fault condition using non-linear curve fitting techniques

A method for predicting a fault condition for a machine, the machine having a plurality of parameters being dependent upon machine performance, the method comprising the steps of:

• sensing one of the parameters dependent upon machine performance and responsively producing an electrical signal;
• determining a non-linear data trend of the parameter in response to the electrical signal where determining a non-linear data trend further comprises the steps of attempting to fit an exponential function to the trend, and if the exponential function does not fit the trend within a predetermined tolerance limit, attempting to fit a polynomial function to the trend;
• and
• predicting the fault condition as a function of the trend and a threshold value indicative of the fault condition.

A method of predicting a fault condition comprising the steps of:

• sensing with a sensor at least one of a plurality of parameters of a machine where said parameters are dependent upon machine performance and responsively producing trend data;
• determining a polynomial function representative of the trend data, where the step of determining includes determining an order of the polynomial by iteratively incrementing an estimated order and computing a derivative until the resultant slope is constant, and then computing the parameters of the polynomial of the determined order;
• and
• predicting the fault condition as a function of the polynomial function and a threshold value indicative of the fault condition.