Patent ID: 8136610

Claim:
A system for drilling a cavity in a medium, wherein the system comprises: a drill bit, wherein the drill bit is configured to: rotate in the medium; and remove at least a portion of the medium to at least partially define the cavity; a drillstring coupled with the drill bit, wherein the drillstring is configured to: receive a rotational motion; rotate the drill bit; and apply a force to the drill bit; a processor, wherein the processor is configured to: receive a first set of data representative of a variable rotational speed of the drill bit during a length of time in the medium; and determine, based at least in part on the first set of data, a first resonant frequency of the variable rotational speed of the drill bit; and a controller, wherein the controlled is configured to: receive a second set of data representative of the first resonant frequency of the variable rotational speed of the drill bit; and vary the force applied to the drill bit by the drillstring using a band-stop filter to remove the first resonant frequency from the variance of force applied to the drill bit by the drillstring.