Abstract: A display system can include a head-mounted display configured to project light to an eye of a user to display virtual image content at different amounts of divergence and collimation. The display system can include an inward-facing imaging system images the user's eye and processing electronics that are in communication with the inward-facing imaging system and that are configured to obtain an estimate of a center of rotation of the user's eye. The display system may render virtual image content with a render camera positioned at the determined position of the center of rotation of said eye.

Abstract: An adaptive control unit is described for receiving an analog input signal containing at least an indication of a parameter to be controlled to generate an analog output signal for control of the parameter. The analog input signal contains a fed back component resulting from the analog output signal. The adaptive control unit comprises an analog filter having an adjustable gain, a gain adjuster for adjusting the gain of the analog filter using a feedforward adjustment method, and a filter for compensating for the fed back component in the analog input signal.

Abstract: An adaptive control unit is described for receiving an analog input signal containing at least an indication of a parameter to be controlled to generate an analog output signal for control of the parameter. The analog input signal contains a fed back component resulting from the analog output signal. The adaptive control unit comprises an analog filter having an adjustable gain, a gain adjuster for adjusting the gain of the analog filter using a feedforward adjustment method, and a filter for compensating for the fed back component in the analog input signal.

Abstract: An adaptive control unit is described for receiving an analog input signal containing at least an indication of a parameter to be controlled to generate an analog output signal for control of the parameter. The analog input signal contains a fed back component resulting from the analog output signal. The adaptive control unit comprises an analog filter having an adjustable gain, a gain adjuster for adjusting the gain of the analog filter using a feedforward adjustment method, and a filter for compensating for the fed back component in the analog input signal.

Abstract: An active vibration absorber is provided for absorbing vibrations in a member. An inertial mass is mounted on the member with a stiffness between the member and the mass. A force actuator arrangement applies a force between the inertial mass and the member. A damping arrangement provides for damping of a resonance of the active vibration absorber. A first sensor arrangement provides at least one first signal indicative of at least one movement and/or stress related parameter for the member and a second sensor arrangement provides for at least one second signal indicative of a reaction of the inertial mass. A control arrangement is provided for controlling the force actuator arrangement using the at least one first signal and the at least one second signal.

Abstract: An adaptive control unit is described for receiving an analog input signal containing at least an indication of a parameter to be controlled to generate an analog output signal for control of the parameter. The analog input signal contains a fed back component resulting from the analog output signal. The adaptive control unit comprises an analog filter having an adjustable gain, a gain adjuster for adjusting the gain of the analog filter using a feedforward adjustment method, and a filter for compensating for the fed back component in the analog input signal.

Abstract: An active vibration absorber is provided for absorbing vibrations in a member. An inertial mass is mounted on the member with a stiffness between the member and the mass. A force actuator arrangement applies a force between the inertial mass and the member. A damping arrangement provides for damping of a resonance of the active vibration absorber. A first sensor arrangement provides at least one first signal indicative of at least one movement and/or stress related parameter for the member and a second sensor arrangement provides for at least one second signal indicative of a reaction of the inertial mass. A control arrangement is provided for controlling the force actuator arrangement using the at least one first signal and the at least one second signal.

Abstract: A system for attenuating noise in a cabin of a vehicle is provided in which the vehicle has an interior wall defining the cabin and an exterior wall defining a cavity between the interior wall and the exterior wall. A plurality of actuators are arranged within the cavity, on the interior wall or on the exterior wall for providing a physical actuation resulting in an acoustic disturbance. A plurality of sensors are arranged in the cavity on the interior wall, or on the exterior wall to provide indications of acoustic disturbances. A control system uses the indications from the sensors to generate control signals for the actuators. In one arrangement the sensors are arranged in an array interspersed between the actuators which are also arranged in an array. A drive signal for each actuator is then generated using the signals from sensors adjacent to the actuators.