Precision vibration-isolation system with floor feedforward assistance
AssigneeTechnical Manufacturing Corporation
InventorsIgor Kordunsky, Jeffrey L. Worthey, Antonio Lopes
Life of this patent
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Abstract
Apparatus and methods to reduce unwanted motion in precision instruments are described. An active vibration-isolation system may include a feedback loop that senses motion of an intermediate mass. In noisy environments, where the feedback loop would otherwise fail or provide inadequate isolation, feedforward control can be implemented to sense floor vibrations and reduce motion of the intermediate mass that would otherwise be induced by the floor vibrations. The feedforward control can reduce motion of the intermediate mass to a level that allows the feedback loop to operate satisfactorily.
Claims24
A vibration-isolation system comprising:
- an intermediate mass;
- a feedback motion sensor arranged to sense motion of the intermediate mass;
- a feedforward motion sensor to sense motion of a base;
- an actuator configured to drive the intermediate mass relative to the base, wherein the base is configured to support at least the actuator and the intermediate mass;
- and
- a control system configured to process a first signal from the feedback motion sensor and a second signal from the feedforward motion sensor and output a drive signal to drive the actuator to reduce vibrational motion of the intermediate mass, wherein without application of the second signal from the feedforward motion sensor to the control system, vibrational levels of the intermediate mass during operation of the vibration-isolation system saturate the feedback motion sensor.
A vibration-isolation system comprising:
- a first isolation assembly to support a first portion of a payload or a payload support;
- the first isolation assembly including:
- a first intermediate mass;
- a first feedback motion sensor arranged to sense motion of the first intermediate mass;
- a feedforward motion sensor to sense motion of a base;
- a first actuator configured to drive the first intermediate mass relative to the base, wherein the base is configured to support at least the first actuator and the first intermediate mass;
- and
- a first control system configured to process a first signal from the first feedback motion sensor and a feedforward signal from the feedforward motion sensor and output a first drive signal to drive the first actuator to reduce vibrational motion of the first intermediate mass, wherein without application of the feedforward signal from the feedforward motion sensor to the first control system, vibrational levels of the intermediate mass during operation of the vibration-isolation system saturate the feedback motion sensor.
A vibration-isolation control system comprising:
- a feedback motion sensor to sense motion of an intermediate mass that is configured to isolate vibrations of a base from a payload or payload support;
- a feedforward motion sensor to sense motion of the base;
- a first signal path to receive and process a first signal from the feedback motion sensor;
- a first signal filter in the first signal path to filter the first signal;
- a first phase adjuster in the first signal path to change a phase of the first signal;
- a first amplifier in the first signal path to amplify the first signal;
- a second signal path to receive and process a second signal from the feedforward motion sensor;
- a second signal filter in the second signal path to filter the second signal;
- a second phase adjuster in the second signal path to change a phase of the second signal;
- a second amplifier in the second signal path to amplify the second signal;
- and
- a summer to sum a first processed signal from the first signal path and a second processed signal from the second signal path to produce a drive signal for an actuator that is configured to drive the intermediate mass.
Dependencies are inferred from the claim text.