Abstract: A gyroscope unit having a horizontal spin axis hangs from a suspension band within a container. The container is rotatably supported about a vertical axis. A transducer generates a control signal representative of the angular displacement between the gyroscope unit and the container about the vertical axis from a reference position. The container is rotated about the vertical axis responsive to the control signal to reduce the angular displacement from the reference position. A torque about the vertical axis that opposes the angular displacement is directly applied to the gyroscope unit responsive to the control signal. The directly applied torque is a nonlinear function of the angular displacement, being zero below a threshold value of angular displacement and having a predetermined gradient above the threshold value.

Abstract: The instant system describes a heading and attitude reference system for an aircraft in which slaving of the directional gyro to the magnetic compass and roll erection of the vertical gyro is cut off during turns which exceed a predetermined rate. A unique feature of the system is the manner in which the turn rate cutoff rate signal is generated from the directional gyro without incorporating either rate gyros or rate generators. The turn rate cutoff signal is generated from the directional gyro heading signal by converting the heading signal electrically into a signal proportional to turn rate. In one embodiment, the heading signal from the directional gyro which is representative of the heading shaft angle (.theta.) is converted into a plurality of signals proportional to the sine and cosine of shaft angle .theta.. These signals are first differentiated and then vector summed to produce a signal directly proportional to the rate of shaft rotation (d.theta.

Abstract: Numerical control means for controlling the position of a machine tool or the like by means of a servomotor are described. A position command signal is compared to the signal indicative of the servomotor position, and the resultant error signal is added to a speed command signal to control the speed of operation of the motor. A follow-up signal is generated whenever the amplitude of the error signal exceeds a predetermined level, and the latter is added to a digital position signal coupled to the system. A constant digital signal generated by said follow up signal is added to said error signal instead of said speed signal.

Abstract: Apparatus for effecting relative positioning between two mechanical members in accordance with digital (or analog) commands includes a standing wave supporting, electrical wave propagating structure terminated other than by its iterative impedance. The wave structure is mechanically fixed to one mechanical member, and a probe is coupled to the wave structure and fixed for translation with the other mechanical member.A voltage controlled oscillator excites the wave structure developing a standing electrical wave therein -- the wave pattern node positioning being determined by the input digital command. Feedback servomechanism apparatus then responds to the potential induced in the probe (or, by superposition, that on the wave structure) for positioning the probe at the requisite standing wave null point.In accordance with one aspect of the present invention, the wave propagating structure is sealed, and the probe disposed external thereto, to preserve measuring accuracy.