US 5,710,714 AGranted

Electronic controller for an adaptively tuned vibration absorber

AssigneeApplied Power Inc.

InventorsMathieu Mercadal, Kelvin B. Scribner, Andreas H. von Flotow

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Abstract

An apparatus for absorbing vibrations in a structural member has a mass suspended between two mounting plates by a separate springs. The mass has two sections and a mechanism for adjusting the spacing between the sections to alter the spring stiffness. Two sensors produce first and second signals representing the vibration of the structural member and the mass. The mechanism is operated by a controller that includes separate filters for the first and second signals in which each filter has a center frequency that is tuned by a clock signal. The phase comparator produces a phase output signal indicating a phase relationship between signals from the two filters and the control signal for the mechanism is produce in response to the phase output signal. A phase locked loop produces the clock signal for tuning the filters in response to a comparison between one of the first and second signals and a signal from one of the filters.

Claims22

Dependent claims

A vibration absorber comprising:

a mechanical resonator having a member for attachment to a body in which a vibrational disturbance occurs, a mass, and a spring connected between the member and the mass, said resonator further having a mechanism which adjusts stiffness of said spring in response to a control signal;
a first sensor which produces a first signal indicating the vibrational disturbance;
a second sensor which produces a second signal indicating movement of the mass;
and
a control circuit comprising:
(a) a first filter circuit which receives the first signal and produces a first filtered signal, said first filter circuit has a filter frequency that is tuned by a clock signal;
(b) a second filter circuit which receives the second signal and produces a second filtered signal, said second filter circuit has a filter frequency that is tuned by the clock signal;
(c) a first phase comparator which produces a phase output signal indicating a phase comparison of the first and second filtered signals;
(d) a mechanism control circuit which produces the control signal for the mechanism in response to the phase output signal from said first phase comparator;
and
(e) a clock signal generator which responds to one of the first and second signals and one of the first and second filtered signals by producing the clock signal.

8 more elements

A vibration absorber comprising:

mass-spring assembly having first and second members for attachment to a body in which a vibrational disturbance occurs, a mass formed by first and second blocks, a first spring connected between the first member and the first block, a second spring connected between the second member and the second block, said spring-mass assembly further having a mechanism which responds to a control signal by varying a distance between the first and second blocks to thereby alter stiffness of the first and second springs;
a first sensor which produces a first signal indicating the vibrational disturbance;
a second sensor which produces a second signal indicating movement of the mass;
and a control circuit comprising:
(a) a first filter circuit which receives the first signal and produces a first filtered signal, said first filter circuit has a center frequency that is tuned by a clock signal;
(b) a second filter circuit which receives the second signal and produces a second filtered signal, said second filter circuit has a center frequency that is tuned by the clock signal;
(c) a first phase comparator which produces a phase output signal indicating a phase comparison of the first and second filtered signals;
(d) a mechanism control circuit which produces the control signal for the mechanism in response to the phase output signal from said first phase comparator;
and
(e) a clock signal generator which responds to one of the first and second signals and one of the first and second filtered signals by producing the clock signal.

7 more elements

Dependencies are inferred from the claim text.