Abstract: A technique for synchronizing the servo control systems between two optical wireless links (OWLs) that are in communication with one another. This synchronization allows the alignment in time of the various tasks to be assigned in a desired time period. The synchronization is not intended to synchronize the two OWLs down to the processor clock level, but rather at the servo sampling level, preferably to within a few percent of the servo sampling time. This synchronization may be advantageous in improving processor efficiency and control loop performance, and or improving system calibrations.

Abstract: A method that allows a digital communications system to detect the presence of transmitted messages in noisy environments. The system includes an OFDM transmitter and an OFDM receiver. The OFDM transmitter converts a digital signal to be transmitted to a plurality of sub-signals, each corresponding to a respective sub-carrier frequency. The signal is a packet including a preamble field having a known data pattern. The transmitter pre-codes the preamble data pattern, maps the data to corresponding phase information, converts the sub-signals to the time domain, and converts the sub-signals to analog form for subsequent transmission. The OFDM receiver receives the transmitted sub-signals, converts the sub-signals to digital form, converts the sub-signals to the frequency domain, and subjects the sub-signals to preamble detection processing to detect the signals' presence.

Abstract: A system and method of varying the control loop gain of an optical wireless communication link between a transmitting station and a receiving station as an inverse function of distance between the transmitting station and the receiving station to allow the optical wireless communication link to be used reliably over a wide range of distances.

Abstract: A method of moving a MEM system mirror in a well defined trajectory that allows longer seeks to be used to reach a target position as compared with known methods that employ small step sizes due to lack of well defined seek trajectories. One method uses the same seek trajectory (scaled in amplitude for seek length) for both axes (x-axis and y-axis) associated with the MEM mirror. This forces both axes to take the same length of time and to use the same “shape” to perform the move, and results in a straight line path between two points. Multiple straight line moves can be employed to provide a more complex trajectory. Another method uses a different trajectory with the same length, but a different shape, for each axis to force the MEM mirror along substantially any desired path such as an arc and/or straight line, among others.

Abstract: A technique for synchronizing the servo control systems between two optical wireless links (OWLs) that are in communication with one another. This synchronization allows the alignment in time of the various tasks to be assigned in a desired time period. The synchronization is not intended to synchronize the two OWLs down to the processor clock level, but rather at the servo sampling level, preferably to within a few percent of the servo sampling time. This synchronization may be advantageous in improving processor efficiency and control loop performance, and or improving system calibrations.

Abstract: A method 400 of maximizing the field of view associated with an OWL by providing a value for an offset and a maximum radius to use during an acquisition scan to prevent collisions in a micro-electro-mechanical (MEM) mirror assembly associated with the OWL. The field of view is maximized by measuring the range of travel in the positive and negative directions along each axis, and using the midpoints to define a new origin to use as the center or the spiral scan. This new center will typically be offset from the original center as defined by the zero current location.

Abstract: A technique for integrating both local and remote feedback in an optical wireless communication link in a manner that simultaneously minimizes network overhead and maintains a high bandwidth loop sufficient to control the resonances of the mirror.

Abstract: A technique that eliminates or minimizes the effects of reflective surfaces to reduce or eliminate interference in the data stream and allow an optical wireless communication link to be used reliably. The most important reflective surface is the reflective surface in front of the data detector itself, as that is the one that will be reflected after the transmitting and receiving stations are properly aligned. The greatest reduction in reflected data associated with a remote detector is then achieved by angling the surface in front of the data detector itself, such that reflections from that surface will not fall within the field of view of the remote detector once the stations are properly aligned.

Abstract: A technique that reduces or eliminates the non-linearities associated with the internal feedback sensor used in a micro-electro-mechanical mirror assembly. Using the relatively linear response of the mirror positioning motor, associated driver electronics, and the mirror itself, a calibration is performed that compensates for the internal feedback sensor non-linearity. An expected position can then be calculated simply by multiplying the gain of the system by the output, due to the good inherent linearity in the system. The calibration will compare measured versus expected position criteria for a predefined set of constant outputs. The data will form a look-up table that will be used to correct for the sensor non-linearities.

Abstract: A method of adjusting a MEMS mirror control system is provided to calibrate a MEMS mirror control system to a particular MEMS mirror in a fashion that optimizes MEMS mirror control loop performance. This calibration is implemented by measuring the gain and resonant frequency of the particular MEMS mirror, and adjusting one or more of the parameters used in the implementation of a PID controller, a state estimator, and a feed forward component used to perform seeks.

Abstract: A method of adjusting a MEMS mirror control system is provided to calibrate a MEMS mirror control system to a particular MEMS mirror in a fashion that optimizes MEMS mirror control loop performance. This calibration is implemented by measuring the gain and resonant frequency of the particular MEMS mirror, and adjusting one or more of the parameters used in the implementation of a PID controller, a state estimator, and a feed forward component used to perform seeks.

Abstract: A technique that reduces or eliminates the non-linearities associated with the internal feedback sensor used in a micro-electro-mechanical mirror assembly. Using the relatively linear response of the mirror positioning motor, associated driver electronics, and the mirror itself, a calibration is performed that compensates for the internal feedback sensor non-linearity. An expected position can then be calculated simply by multiplying the gain of the system by the output, due to the good inherent linearity in the system. The calibration will compare measured versus expected position criteria for a predefined set of constant outputs. The data will form a look-up table that will be used to correct for the sensor non-linearities.

Abstract: A method of moving a MEM system mirror in a well defined trajectory that allows longer seeks to be used to reach a target position as compared with known methods that employ small step sizes due to lack of well defined seek trajectories. One method uses the same seek trajectory (scaled in amplitude for seek length) for both axes (x-axis and y-axis) associated with the MEM mirror. This forces both axes to take the same length of time and to use the same “shape” to perform the move, and results in a straight line path between two points. Multiple straight line moves can be employed to provide a more complex trajectory. Another method uses a different trajectory with the same length, but a different shape, for each axis to force the MEM mirror along substantially any desired path such as an arc and/or straight line, among others.

Abstract: A system and method of varying the control loop gain of an optical wireless communication link between a transmitting station and a receiving station as an inverse function of distance between the transmitting station and the receiving station to allow the optical wireless communication link to be used reliably over a wide range of distances.

Abstract: A disk drive and method of optimizing data access time by selecting a seek profile and/or settle criteria based on a queued or non-queued environment. The disk drive includes an actuator and a servo system, wherein the servo system is directed to move the actuator as a result of an input/output command received from a host by an interface processor. The disk drive may execute the input/output commands in a queued or non-queued environment. The servo system commands the actuator to perform a seek using a seek profile and defines settling criteria for the seek operation. The seek profile includes an acceleration profile and a deceleration profile. The method includes the step of providing a queued seek profile and a queued settling criteria for a seek used to position the actuator to execute a command in a queued environment.