Abstract: The technology described in this document can be embodied in a method that includes receiving an input signal representing audio captured by one or more sensors of an active noise reduction (ANR) headphone, and generating, based on the input signal, a first signal by a compensator disposed in an ANR signal flow path. The method also includes determining one or more characteristics of the first signal, and selecting, based on the one or more characteristics of the first signal, a plurality of filter coefficients for a digital filter disposed in series with the compensator in the ANR signal flow path. The filter coefficients are selected in accordance with a target frequency response of the digital filter. The method further includes generating, by processing the input signal using the plurality of filter coefficients of the digital filter, a feedback control signal for an electroacoustic transducer of the ANR headphone.

Abstract: In an aspect, in general, a system and method compensate for a misalignment characteristic of one or more acceleration sensors fixed to a sprung mass of a vehicle, each acceleration sensor having a location on the vehicle and a desired orientation relative to the vehicle.

Abstract: In an aspect, in general, a system and method compensate for a misalignment characteristic of one or more acceleration sensors fixed to a sprung mass of a vehicle, each acceleration sensor having a location on the vehicle and a desired orientation relative to the vehicle.

Abstract: A method and system for a noise cancellation comprises an amplifier in communication with the three or more speakers disposed in an area. A system controller produces a driver signal for each of the speakers in response to a signal from at least one microphone detecting sound in the area and communicates the driver signals to the amplifier. The amplifier drives each speaker with the driver signal produced for that speaker. In response to the driver signals, the speakers emit sound that combined produces a substantially uniform sound pressure field for a particular zone within the area. The substantially uniform sound pressure field produced by the speakers has a magnitude and phase adapted to attenuate a noise field in the area corresponding to the sound detected by the at least one microphone.

Abstract: A method and system for attenuating noise comprises identifying a location in an area at which sound emitted from one or more speakers has acoustic characteristics that are substantially similar in measure to corresponding acoustic characteristics of the emitted sound at a location approximated to be near an ear of an occupant of the area. A microphone, which may be a virtual microphone, is disposed at the identified location. The microphone detects sound at the identified location. In response to the sound detected by the microphone, the one or more speakers emit a noise-canceling audio signal adapted to attenuate one or more frequencies in the sound detected by the microphone.

Abstract: A vehicle suspension and wheel damper using anti-causal filtering. Information from in front of a wheel or information about an operating condition of a vehicle is used to anti-causally determine a response of an active suspension associated with the wheel.

Abstract: A vehicle suspension and wheel damper using anti-causal filtering. Information from in front of a wheel or information about an operating condition of a vehicle is used to anti-causally determine a response of an active suspension associated with the wheel.

Abstract: In an aspect, in general, a system and method compensate for a misalignment characteristic of one or more acceleration sensors fixed to a sprung mass of a vehicle, each acceleration sensor having a location on the vehicle and a desired orientation relative to the vehicle.

Abstract: In an aspect, in general, a system and method compensate for a misalignment characteristic of one or more acceleration sensors fixed to a sprung mass of a vehicle, each acceleration sensor having a location on the vehicle and a desired orientation relative to the vehicle.

Abstract: A vehicle suspension and wheel damper using anti-causal filtering. Information from in front of a wheel or information about an operating condition of a vehicle is used to anti-causally determine a response of an active suspension associated with the wheel.

Abstract: An active wheel damper. An active suspension damps vertical displacement of an unsprung mass in a frequency range and reduces vertical displacement of a sprung mass in another frequency range.

Abstract: In an aspect, in general, a system and method compensate for a misalignment characteristic of one or more acceleration sensors fixed to a sprung mass of a vehicle, each acceleration sensor having a location on the vehicle and a desired orientation relative to the vehicle.

Abstract: An active wheel damper. An active suspension damps vertical displacement of an unsprung mass in a frequency range and reduces vertical displacement of a sprung mass in another frequency range.

Abstract: A vehicle suspension and wheel damper using anti-causal filtering. Information from in front of a wheel or information about an operating condition of a vehicle is used to anti-causally determine a response of an active suspension associated with the wheel.

Abstract: The present invention provides long life optics for a modular, high repetition rate, ultraviolet gas discharge laser systems producing a high repetition rate high power output beam. The invention includes solutions to a surface damage problem discovered by Applicants on CaF2 optics located in high pulse intensity sections of the output beam of prototype laser systems. Embodiments include an enclosed and purged beam path with beam pointing control for beam delivery of billions of output laser pulses. Optical components and modules described herein are capable of controlling ultraviolet laser output pulses with wavelength less than 200 nm with average output pulse intensities greater than 1.75×106 Watts/cm2 and with peak intensity or greater 3.5×106 Watts/cm2 for many billions of pulses as compared to prior art components and modules which failed after only a few minutes in these pulse intensities.

Abstract: A motion control system for reducing vibration in moving components. The system includes a position control drive and a vibration control drive. At least one position sensor is used to provide feedback signals which are in turn used to provide control signals for both the position control drive and the vibration control drive. In a preferred embodiment the motion control system is applied to a stage of an integrated circuit lithography step and scan machine. The position control drives are linear magnetic actuators and the vibration control drives are electroceramic actuators. A laser interferometer position monitoring system is used to measure the position, speed, and acceleration of the stage system. Actuators apply controlled forces (based on measurements from the position monitoring system) to each stage to control the motion of the stage. Signals from the interferometer position system are also used to control vibration.

Abstract: The present invention provides a modular high repetition rate ultraviolet gas discharge laser light source for a production line machine. The system includes an enclosed and purged beam path with beam pointing control for delivery the laser beam to a desired location such as the entrance port of the production line machine. In preferred embodiments, the production line machine is a lithography machine and two separate discharge chambers are provided, one of which is a part of a master oscillator producing a very narrow band seed beam which is amplified in the second discharge chamber. This MOPA system is capable of output pulse energies approximately double the comparable single chamber laser system with greatly improved beam quality. A pulse stretcher more than doubles the output pulse length resulting in a reduction in pulse power (mJ/ns) as compared to prior art laser systems.

Abstract: The present invention provides long life optics for a modular, high repetition rate, ultraviolet gas discharge laser systems producing a high repetition rate high power output beam. The invention includes solutions to a surface damage problem discovered by Applicants on CaF2 optics located in high pulse intensity sections of the output beam of prototype laser systems. Embodiments include an enclosed and purged beam path with beam pointing control for beam delivery of billions of output laser pulses. Optical components and modules described herein are capable of controlling ultraviolet laser output pulses with wavelength less than 200 nm with average output pulse intensities greater than 1.75×106 Watts/cm2 and with peak intensity or greater 3.5×106 Watts/cm2 for many billions of pulses as compared to prior art components and modules which failed after only a few minutes in these pulse intensities.

Abstract: A system that provides a base stabilization system for controlling motion of a controlled structure. The system includes a ground structure such as the floor of a fabrication facility and the controlled structure includes a base on which equipment is mounted. The system also includes at least three air mounts and a plurality of actuators all attached to the ground structure and to the base to isolate the base from the ground structure and to stabilize the base. The system includes a plurality of position and acceleration sensors each of which are co-located with a corresponding actuator. The system also includes a multi-input, multi output feedback control system comprising a computer processor programmed with a feedback control algorithm for controlling each of the actuators based on feedback signals from each of the sensors. The co-location of the sensors with the actuators avoids serious problems resulting from higher order vibration modes.

Abstract: A system that provides a base stabilization system for controlling motion of a controlled structure. The system includes a ground structure such as the floor of a fabrication facility and the controlled structure includes a base on which equipment is mounted. The system also includes at least three air mounts and a plurality of actuators all attached to the ground structure and to the base to isolate the base from the ground structure and to stabilize the base. The system includes a plurality of position and acceleration sensors each of which are co-located with a corresponding actuator. The system also includes a multi-input, multi output feedback control system comprising a computer processor programmed with a feedback control algorithm for controlling each of the actuators based on feedback signals from each of the sensors. The co-location of the sensors with the actuators avoids serious problems resulting from higher order vibration modes.