Abstract: In an illustrative embodiment of the invention, an angular digital-to-resolver data converter apparatus is provided for converting a digital input signal representative of angular data into digital pseudo sine and cosine output signals representative of the angular data, which when converted into analog signals may be used to provide excitation to analog servo system resolvers. The digital or binary output signals which approximate the sine and cosine function of the digital angular data input signal are related such that the ratio of the digital output signal representative of the pseudo sine function to the digital output signal representative of the pseudo cosine function equals the true tangent of the actual angle.

Abstract: An absolute resolver digitizer for a numerical control system generating a digital number indicative of the absolute angular position of a resolver's rotor within a given revolution is disclosed herein. The resolver digitizer comprises a reference generator generating resolver excitation signals and a digital number indicative of the phase of the generated excitation signals and a resolver follower generating a digital number indicative of the sum of phase of the excitation signal generated by the reference generator and the angular position of the resolver's rotor. Subtraction of the digital number generated by the reference generator from the digital number generated by the resolver follower produces a digital number indicative of the resolver's absolute position within a given revolution. This subtraction may be performed by a separate circuit within the absolute resolver digitizer or may be performed by the computer associated with the numerical control system.

Abstract: A device is disclosed for damping the critical frequencies of a rotor suspended by a radial electromagnetic bearing which has means associated therewith for detecting the radial position of the rotor, comprising a servo-circuit for connection between the detecting means and windings of the electromagnetic bearing and including a circuit for controlling the current supply to the windings in response to signals from the detecting means to keep the rotor in a predetermined radial position. The servo-circuit is provided with means for the selective amplification of the phase advance gain of said circuit in a frequency equal to the speed of rotation of the rotor for damping said critical frequencies.

Abstract: A servo system, particularly well suited for use in a computerized numerical control system for a large machine tool, in which a plurality of axis controlling servo circuits are controlled by one computerized axis controller. As each controlled axis moves, an attached resolver's output is digitized to generate a digital position feedback signal which is compared to the desired position in the computer. The resultant error signal is converted to an analog voltage to control said axis motion. A digital clock and counter drives two digital to analog converters to create the two resolver inputs, and supplies timing signals to the computer, thus synchronizing the system.

Abstract: A device employing the inherent self-torquing properties of a torque repeater to position its rotor. In the present invention, the torque repeater or synchro may have three stator windings and an output rotor. It is contemplated that the electrical input to the device will be digital signals. However, the invention will perform equally well with time varying or analogue input signals. A plurality of electronic switching means are connected to the stator terminals of the synchro converter and they operate under the control of a programmable switch control to short-circuit predetermined stator windings to provide the desired positional output signals. A sectant detector connected to the stator windings detects signals on the stator windings and determines the present position of the rotor. From this information, the desired positioning of the rotor is attained from the signals from the sectant detector.

Abstract: This invention relates to an electronic apparatus for automatic positioning and distance measurement of mobile members. The apparatus according to the invention comprises a rotary electromagnetic transducer with two pairs of windings, in which the primary circuits receive electrical voltages representative of the controlled angular distance values and the secondary circuits deliver accordingly an electrical response voltage, whose shape and amplitude depend on the difference between said controlled distance and the mechanical angle between rotar and stator portions containing said secondary and, respectively, primary circuits. The electrical voltages representative of the controlled angular distance values are generated by electronic circuits comprising a first binary counter which translates the controlled distance into binary code, a second binary counter which generates a binary ramp, two adders, a combining network, four sequential networks and two analogue amplification and sign circuits.

Abstract: A digital to analog resolver converter uses a digital to analog converter to convert a part of the digital input to a corresponding analog angle value. This analog angle value is applied to sine and cosine function generators which use the equations of chords to approximate the value of the sine and cosine functions in one octant. Bits of the digital input are used to select slope values from the chord equations for approximating the sine and cosine of the analog angle value. The digital to analog resolver converter uses the minimum number of precision resistors to generate the sine and cosine slope and intercept values for the equations of a given number of approximating chords.

Abstract: A high accuracy digital to analog resolver converter uses a read only memory device (PROM) programmed to generate a digital signal proportional to the inherent systematic error of a digital to analog resolver converter. This signal is then converted to analog form by conventional means and combined with the primary signal in analog form thereby substantially increasing the accuracy of a digital to analog resolver converter.

Abstract: Apparatus for generating a feedback signal for effecting rotation of a servo motor precisely in accordance with changes in the input signal and which includes a first annular coil and two angularly positioned coils inductively coupled with the first coil. An alternating current signal is fed to the first coil and the voltages induced into the angularly positioned coils are rectified and subtracted to produce the feedback signal. Variations in the feedback signal are effected by mechanically coupling the shaft of the servo motor with said coils to produce rotation of the first coil relative to said angularly positioned coils. An electronic network is provided to effect rectification and subtraction of the induced AC signals and a corrective network may be included for additional accuracy, if desired.

Abstract: An electromechanical transducer for converting mechanical analog angular information to electrical linear information, utilizing a primary winding and a first and second secondary winding, said secondary windings being arranged perpendicular to each other and rotatable in relationship to the primary winding. The primary winding is connected to the output of an amplifier. The amplifier is inductively fed back by means of the primary winding and one of the secondary windings. The input voltage of the amplifier is related to the voltage across the other secondary winding and privides a linear measure for the rotation of the secondary windings in relationship to the primary winding.

Abstract: A demodulator wherein the typical low-pass filter is replaced with a sample nd hold circuit. By sampling the peak information of the input a-c signal and storing until the next peak sample, an output of extremely low ripple is accomplished.

Abstract: A numerical control system having a digitized phase loop comprising a motor for moving an object being controlled, a servo amplifier for driving the motor, feedback means coupled to the motor for generating a first signal indicative of the actual position of the object, and means for converting the first signal to a digital signal indicative of a change in the actual position of the object. Further provided is means for comparing a command digital signal indicative of the desired change in position of the object with the digital signal indicative of the actual change in position of the object to generate an error digital signal and for converting the error signal to an analog signal for driving the servo amplifier.

Abstract: An absolute positioning servo for positioning a shaft in response to a digital command input which utilizes a resolver, for providing an analog position indication of the shaft, an analog to digital converter, which provides a digital indication of the shaft position, a comparator for comparing the digital command input signal with the digital indication signal and providing a differential digital error signal which is converted to an analog signal and fed back to position the shaft so that the differential digital error is 0. An analog fine control positioning means is provided which positions and maintains the shaft near the center point of the position represented by the digital command input signal when the digital differential error is 0. A signal representing the difference between the exact analog position of the shaft and the digital approximate position of the shaft is provided at the output of the translator.

Abstract: A circuit arrangement for the digitalization of the angle of rotation .phi. of a rotatable device which is operated at fa rotations per second, employing auxiliary voltages modulated with sin .phi. and cos .phi. of a fundamental frequency fo, which with the aid of further circuit elements are converted into a counter pulse train which indicates the angle of rotation, in which n pulses correspond to the angle of rotation of 360.degree.; wherein from two auxiliary voltages is formed a third auxiliary voltage which contains only one of the frequencies (fo+fa) or (fo-fa), which third auxiliary voltage and a comparison voltage of the frequency n.sup.. fo are conducted to a comparator circuit, comprising a D-flip-flop, with the comparison voltage being present at the D-input (preparation input) and the third auxiliary voltage being present at the clock-input, whereby the desired counter pulse train with n.sup.. fa is obtained at the output of the D-flip-flop.

Abstract: A resolver-to-digital converter where a signal of predetermined frequency is converted to a given waveform sequence by a logic circuit, band passed filtered, and phase splitted into orthogonal components. These components are fed to operational amplifiers and then into the input windings of a resolver. The outputs of the resolver are fed to a pair of zero crossing differential comparators and then to phase detectors, the outputs of which are summed. The sum of the signals is filtered and is used to regulate a voltage controlled oscillator that pulses a synchronous counter that is fed back to the phase detectors forming a phase-locked loop. The synchronous counter feeds a serial register that is strobed by the output of a zero crossing differential amplifier fed by the compensation windings of the resolver.

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: A manual control system including a powered feed for a numerically controlled machine tool. The system includes a manually operable differential resolver located in the position feedback loop of the servo control system for each slide and a variable speed motor for driving that differential resolver at a controlled rate so as to effect controlled feeding movement of the slides independent of the numerical control unit.