Patent ID: 7849934

Claim:
A method, comprising: collecting sensor data at a sampling frequency by sampling at least one sensor disposed in a drill bit, wherein the at least one sensor is responsive to at least one physical parameter associated with a drill bit state; and analyzing the sensor data in the drill bit to develop a time encoded parameter stream of the sensor data, wherein the analyzing comprises: partitioning the sensor data into epochs, each epoch comprising consecutive samples between zero crossings; determining a duration parameter as a number of samples for each epoch; determining a shape parameter as a number of minima or a number of maxima for each epoch; converting the time encoded parameter stream to a symbol stream wherein each symbol in the symbol stream is based on a predetermined alphabet of symbols developed as a combination of possible duration parameters and possible shape parameters; converting the symbol stream to a histogram, each element of the histogram representing one of the alphabet symbols and comprising a number of symbols in the symbol stream matching that element symbol; developing a severity index from analyzing the histogram; comparing the severity index to at least one adaptive threshold; and modifying a data sampling mode responsive to the comparison.