Vibration removing apparatus and method thereof
AssigneeCanon Kabushiki Kaisha
InventorShinji Wakui
Life of this patent
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Abstract
An active vibration removing apparatus having an air-spring as an actuator, includes: a vibration removing table, a supporting air-spring for supporting the vibration removing table, a servo-valve for adjusting the pressure of the air-spring, and a feedback system for controlling the servo-valve. A pseudo-differentiator pseudo-differentiates a speed adjustment signal of a device placed on the vibration removing table. A pulse selector for selects an arbitrary numbers of pulse waveforms from a series of pulse waveforms outputted from the pseudo-differentiator. The output of the pulse selector is feedforwarded in the feedback system.
Claims34
A vibration removing apparatus which utilizes an air-spring comprising:
- control means for controlling the air-spring with a feedback control system utilizing a signal based on a displacement of a vibration removing table;
- producing means for producing a pulse signal corresponding to a selected edge of a driving signal of a device placed on said vibration removing table;
- and
- input means for inputting the pulse signal produced by said producing means as a feedforward signal in said feedback control system.
A vibration removing apparatus which utilizes an air-spring, comprising:
- control means for controlling the air-spring with a feedback control system utilizing a signal based on a displacement of a vibration removing table;
- generation means for generating a prediction signal corresponding to a driving signal of a device placed on said vibration removing table prior to generation of said driving signal;
- producing means for producing a pulse signal based on said prediction signal;
- and
- input means for inputting the pulse signal produced by said producing means as a feedforward signal in said feedback control system.
A vibration removing method for removing vibrations of a vibration removing table, utilizing an air-spring controlled by a feedback control system which utilizes a signal based on a displacement of the vibration removing table, comprising the steps of:
- producing a pulse signal corresponding to a selected edge of a driving signal of a device place on the vibration removing table;
- and
- inputting the pulse signal produced by said producing step as a feedforward signal in the feedback control system.
A vibration removing method for removing vibrations of a vibration removing table, utilizing an air-spring controlled by a feedback control system which utilizes a signal based on a displacement of the vibration removing table, comprising the steps of:
- generating a prediction signal corresponding to a driving signal of a device placed on the vibration removing table prior to generation of the driving signal;
- producing a pulse signal based on the prediction signal;
- and
- inputting the pulse signal produced in said producing step as a feedforward signal in the feedback control system.
Dependencies are inferred from the claim text.