Active noise and vibration control system

DETAILED DESCRIPTION It is, therefore, an object of the present invention to provide an improved system for controlling vibrational energy within a first frequency range within a vehicle or the like from a vibrational energy source connected to the vehicle.
It is another object of the present invention to provide a control system including a power dissipation reduction means including an inductance and providing substantially all current flow to the vibration control actuator to reduce energy loss and heat generation in an active vibration and/or noise control system.
It is a further object of the present invention to provide a pulse-width modulation control based active vibration and/or noise control system for control ling vibrational energy at a first lower frequency range with a pulse-width modulated signal operating at a higher second frequency above the frequency range of the vibrational energy to be controlled.
These and other objects are provided, according to the invention, by providing a pulse width modulated power amplifier electrically connected to an active vibration control actuator by an actuator power dissipation reduction circuit.
A sensor detects the vibrational energy signal to be controlled and provides an input signal to a controller circuit which generates a control signal to the power amplifier which in turn outputs a pulse width modulation driven signal to the actuator resulting in a force being produced by the actuator to control the vibrational energy in a vehicle which is affected by the vibrational energy.
In particular, a system for controlling vibrational energy within a first frequency range within a vehicle or the like from a vibrational energy source connected to the vehicle includes a pulse width modulated amplifier operating at switching frequencies in a high frequency range such as at least 50 kHz.
The output of the amplifier is passed through the actuator power dissipation reduction circuit to reduce the high frequency energy transients on the signal to reduce heat generating eddy currents from passing to the actuator