Multivariable adaptive vibration canceller

Claim 1

A multivariable adaptive vibration canceller for minimizing vibratory disturbances periodically induced in a structure comprising: a plurality of actuators operatively coupled to the structure for producing a counteracting vibration therein in response to a complex input signal for each actuator, the structure having a dynamic system characteristic in the form of a matrix of complex system responses to known vibrational inputs at selected harmonics of interest; a plurality of sensors, at least equal in number to the number of actuators, said sensors being coupled to the structure for sensing vibrations induced therein by the actuators and the disturbances, each sensor for producing a complex output representative of the algebraic sum of such vibrations sensed thereby for each harmonic; and multivariable adaptive vibration cancellation processor means responsive to complex outputs of the sensors for producing the complex inputs to the actuators, said vibration cancellation processor means having processing characteristic in the form of a complex conjugate transpose matrix of the dynamic system characteristic matrix.

Claim 10

A method for adaptively cancelling the vibration caused by external forces acting on a dynamic structure, comprising the steps of: measuring the external force acting on said body at a first point on said body; applying counteractive forces to said body at a plurality of points to counteract the external forces acting on said body; generating a time base signal related to dynamic system characteristics of said structure; generating sets of time base sinusoidal signals from at least one harmonic frequency of the time base signal; determining the algebraic sum of the magnitude of the external forces and the counteractive forces at each of said points and generating corresponding error signals therefrom in accordance with a dynamic system characteristic in the form of a matrix; generating sets of Fourier coefficient signals from the error signals and said sets of time base sinusoidal signals; generating sets of adaptive weighting coefficients in accordance with a predetermined adaptation algorithm employing a complex conjugate transposition matrix of the dynamic system characteristic in response to said error signals; multiplying said sets of time base sinusoidal signals by the set of respective weighting coefficients of said set of Fourier coefficient signals for producing weighted force component signals; combining said weighted force component signals and generating a composite counteractive force therefrom; and applying said counteractive force to said body in response to said reaction force signal.

Claim 11

A method for adaptively cancelling the vibration caused by external forces acting on a dynamic structure, comprising the steps of: measuring the external force acting on said body at a first point on said body; applying counteractive forces to said body at a plurality of points to counteract the external forces acting on said body; generating a time base signal related to dynamic system characteristics of said structure; generating sets of time base sinusoidal signals from at least one harmonic frequency of the time base signal; determining the algebraic sum of the magnitude of the external forces and the counteractive forces at each of said points and generating corresponding error signals therefrom in accordance with a dynamic system characteristic in the form of a matrix; generating sets of Fourier coefficient signals from the error signals and said sets of time base sinusoidal signals; generating sets of adaptive weighting coefficients in accordance with a predetermined adaptation algorithm employing a complex conjugate transposition matrix of the dynamic system characteristic in response to said error signals; multiplying said sets of time base sinusoidal signals by the set of respective weighting coefficients of said set of Fourier coefficient signals for producing weighted force component signals; combining said weighted force component signals and generating a composite counteractive force therefrom; and applying said counteractive force to said body in response to said reaction force signal.