Abstract: A method of automatically isolating item faults is disclosed. Subtest results T[i] are obtained for a plurality of items, where T[] comprises a vector of m subtest results and T[i]=a value if subtest i fails and subtest i does not fail, T[i]=a negative value or 0. The subtest results T[i] are multiplied or ANDed with respective matrix values Y[i,j], where Y[] comprises a predetermined m×n matrix where Y[i,j]>0 if hardware module j causes subtest i to fail and Y[i,j]≦0 if item j does not cause subtest i to fail. The results are summed in order to obtain a number S[j] for each item that is reflective of the number of subtest failures that are explained by a failure of item j, wherein any item j is suspect if S[j]>0.

Abstract: A hybrid system for stabilizing the attitude of an instrument relative to a dynamic platform includes a plurality of (roll, pitch and yaw) inertial rate sensors, whose outputs are sampled at a rate sufficient to provide real time tracking of changes in orientation of the platform, and a global positioning system (GPS) receiver, whose precision platform attitude output is updated periodically, but at a rate less than the rate of change of attitude of the platform. The inertial rate sensors provide effectively continuous motion (e.g., angular rate) data signals representative of three-dimensional changes in attitude (position derivative signals) of the platform. The inertial rate output are integrated to provide output signals representative of the dynamic orientation of the platform. Sequential outputs of the integration-processing circuitry are also coupled to a sample buffer, which is controllably read-out in accordance with the periodic updates from the GPS receiver.

Abstract: A hybrid system for stabilizing the attitude of an instrument relative to a dynamic platform includes a plurality of (roll, pitch and yaw) inertial rate sensors, whose outputs are sampled at a rate sufficient to provide real time tracking of changes in orientation of the platform, and a global positioning system (GPS) receiver, whose precision platform attitude output is updated periodically, but at a rate less than the rate of change of attitude of the platform. The inertial rate sensors provide effectively continuous motion (e.g., angular rate) data signals representative of three-dimensional changes in attitude (position derivative signals) of the platform. The inertial rate output are integrated to provide output signals representative of the dynamic orientation of the platform. Sequential outputs of the integration-processing circuitry are also coupled to a sample buffer, which is controllably read-out in accordance with the periodic updates from the GPS receiver.

Abstract: A method of and an apparatus for analyzing multi-bit digital words to identify their source or content. The digital words are converted to multi-bit fields, with each field being a portion of the digital word or corresponding to one or more descriptive parameters of the source. Each multi-bit field is analyzed to generate an additional multi-bit field. The additional multi-bit fields are grouped into pairs, and each pair is analyzed to generate a further multi-bit field. The further multi-bit fields are grouped into pairs. If more than one pair exists, the analyzing and grouping into pairs continues until a single pair remains, and that pair is analyzed to identify the source or content. Preferably each of the additional and further fields has the same number of bits, and each of the means for analyzing the additional and further multi-bit fields has twice that number of input bits.

Abstract: An improved torque control for a brushless DC motor is disclosed. A torque command A of a time varying nature is applied to an excitation winding which is magnetically coupled through a resolver to produce output signals respectively on sensing windings of Acosine .theta. and of Asine .theta. wherein .theta. is the angular position of an armature and resolver of the motor. Armature windings respectively coupled to the sensing windings are driven by signals proportional to or equal to the signals sensed by the sensing windings to produce a torque equal to A.

Abstract: A mechanism for correcting for time-varying errors that affect the pointing accuracy of a shipboard mounted antenna employs a Kalman filter for realizing an optimal correction estimator through which inputs to the antenna aiming control hardware are adjusted. A series of coordinate system transformations, corrected by the Kalman filter error estimator, are carried out to provide a command input to an antenna pointing servo system. The servo control system produces a servo error signal representative of a deviation in the actual direction of the antenna pointing mechanism from the command input to the servo loop as defined by the corrected aiming signal. The actual direction in which the servo control system points the antenna is compared with a reference (the actual direction to the satellite). As a result of this comparison, a pointing deviation signal representative of any offset from the intended pointing direction is generated.