Patent ID: 6834247
Filing Date: 2004-12-21
Classification: G01C

Abstract:
A gyroscopic arrangement for measuring angular speed, the arrangement comprising:a gyroscope comprising: at least one mass supported on a support such that the mass can vibrate in a first mode around a first axis and a second mode around a second axis which is inclined relative to the first axis; an exciter adapted to excite vibrations in the first mode; and a detector adapted to generate an output comprising: at least one detection signal representative of the vibrations in the second mode, the vibration of the first mode being coupled to the second mode when said gyroscope is exposed to an angular motion about a third axis inclined relative to both the first and second axes, said at least one detection signal comprises information about the angular speed about the third axis, wherein said exciter is adapted to provide at least one electronic signal to said gyroscope, a varying device adapted to vary one or more of said at least one electronic signal; a simulation model of said gyroscope to obviate the effect of any errors in said gyroscope caused by at least one of undesired geometric properties of said gyroscope or undesired electric couplings, said simulation model, coupled to receive the one or more of said at least one electronic signal supplied to said gyroscope by said exciter, said simulation model being adapted to provide an output equivalent to the output of said gyroscope, the output of said simulation model being compared with the output of said gyroscope as one or more of said at least one electronic signal is varied to provide a difference signal; and an estimator being provided said difference signal, said estimator adapted to determine the presence of and size of errors within said gyroscope and in response to that determination to adjust said simulation model and to estimate a signal value corresponding to the angular speed about the third axis, wherein said estimator and said simulation model are adapted to perform an iterative process wherein said simulation model substantially simulates the instantaneous operation of said gyroscope so that the estimated signal value of the angular speed as estimated by said estimator is substantially the same as the actual angular speed about the third axis.