Active noise and vibration cancellation system

An active control system, comprising:

• (a) a digital signal processor for calculating weights in an adaptation path;
• providing an output control signal to a feedforward circuit and
• (b) a separate waveform generator for
• i) implementing a feedforward path by supplying sinusoidal control signal outputs to said feedforward circuit, said feedforward circuit which separately processes an input signal to arrive at particular phases and frequencies of said sinusoidal control signal to produce an active vibration control signal, and
• ii) supplying timing signals to said digital signal processor which are synchronized to said input signal from an input source;
• whereby the digital signal processor is freed from having to manipulate any data associated with the feedforward path.

A process of cancelling one of a mechanical vibration and noise, comprising the steps of:

• (a) inputting said input signal into a first phase-locked loop input of a phase-locked loop;
• (b) outputting a multiplied square wave signal to an input of a frequency divider, to a first clock input of a first switched capacitor filter, to a second clock input of a second switched capacitor filter, and to a third clock input of a shift register;
• (c) dividing said multiplied square wave signal in said frequency divider thereby providing a frequency divided output including at least one divided output signal and sending one of said at least one divided output signal to a second phase-locked loop input of said phased lock loop, to a shift register input of said shift register, to a first switched capacitor filter input of said first switched capacitor filter, and to a digital signal processor;
• (d) receiving a shifted signal from said shift register into a second switched capacitor filter input of said second switched capacitor filter;
• (e) outputting a first analog wave from said first switched capacitor filter and a second analog wave from said second switched capacitor filter, said first analog wave being synchronized with said input signal and said second analog wave being phase shifted from said first analog wave;
• (f) receiving said first and said second analog waves at a feedforward circuit;
• (g) receiving at least one divided output from said frequency divider as a timing signal in said digital signal processor;
• and
• (h) calculating the weights for an adaptation path in said digital signal processor and supplying said weights to said feedforward circuit to supply a cancelling signal to a transducer.

A controller for a system which actively cancels vibrations by providing cancellation signals that are out-of-phase sine waves of appropriate frequency and magnitude from a plurality of transducers, said controller comprising:

• a) a digital signal processor (DSP) for calculating weights in an adaptation path determining a magnitude of cancellation signal needed;
• b) a separate feedforward signal processor for implementing a feedforward path by
• i) digitally calculating a frequency and phase of control signals needed for a feedforward circuit,
• ii) for supplying timing signals to said digital signal processor which are synchronized to an input source, and
• iii) digitally multiplying said weights calculated by said DSP by said control signal;
• c) a digital-to-analog converter to change said digital control signals into analog outputs which can be fed to said plurality of transducers;
• whereby all of said computations by said DSP and said feedforward processor are performed digitally.