Abstract: An angle data computation apparatus, which comprises arithmetic means (4) for computing the angle data by considering the encoder signals in different phases as triangular-wave signals; correction data storage means (5) for storing correction data for correcting angle errors between the encoder signals and triangular-wave signals based on arithmetic data from the arithmetic means (4) serving as addresses; adder-subtracter means (6) for adding up the arithmetic data from the arithmetic means (4) and the correction data from the correction data storage means (5); and converter means (7) for converting the angle corresponding to the quadrant for the encoder signals.

Abstract: An apparatus and method for generating digital electrical signals which are representative of the angular position and rotational velocity of a rotatable shaft component in a servomechanism includes a resolver which is connected to the rotatable component. The resolver generates analog electrical output signals which are representative of an excitation signal modulated by both the sine and cosine of the electrical angular or position of the motor. The output signals from the resolver are fed to a digital signal processing circuit which employs software algorithm techniques to define a plurality of tasks which are implemented sequentially to obtain the desired angular position and velocity signals. First, the sine and cosine signals are read from the resolver through respective analog-to-digital converters. The sine and cosine signals are demodulated by multiplication with the excitation signal, and the undesired higher frequency components are deleted by filtering.

Abstract: An analog-to-digital converter comprises the following elements. A reference voltage generation circuit is provided for dividing a reference voltage into a plurality of divided reference voltages having voltage levels different from each other. A plurality of comparators are provided, each of which has a first input terminal connected to an analog input line for fetching analog signals and a second input terminal connected to the reference voltage generation circuit for fetching a corresponding one of the divided reference voltages so as to compare the analog signals with the divided reference voltage. Each of the comparators has an output terminal through which an output digital signal is outputted.

Abstract: Two A.C. output signals amplitude-modulated in accordance with two function values (sine and cosine) differing from each other in correspondence to a position-to-be-detected are received from a position sensor such as a resolver. By performing an addition or subtraction between a signal derived by shifting the electric phase of one of the received A.C. output signals by a predetermined angle, and the other received signal, two electric A.C. signals (sin(.omega.t .+-.d.+-..theta.), sin(.omega.t.+-.d-.theta.)) are electrically synthesized which have electric phase angles (.theta.) corresponding to the position-to-be-detected and are phase-shifted in opposite directions. ".+-.d" here represents phase variation error caused by factors, other than the position-to-be-detected, such as temperature change. In the synthesized two signals, the phase variation errors (.+-.d) appear in the same direction, while the phase differences (.theta.

Abstract: A software-based resolver-to-digital converter (RDC) (80) for computing an angle of rotation .THETA. of gimbal-mounted instrumentation (16) in a gimbal system. The RDC (80) computes the angle of rotation of the instrumentation using parameter signals received from a resolver (32) in the system. The parameter signals, along with a resolver reference signal are input into a multiplexor (60) and are multiplexed. The signals are then fed to an analog to digital converter (38) and converted to digital form. The digital signals are then input into a processor (36) associated with the system. This processor, in addition to performing numerous system computations, is programmed through appropriate software to filter the digital signals received, compute the value for the angle of rotation .THETA. and output the computed value to system circuitry (31) for processing to enhance system operation.

Abstract: An absolute position detection apparatus which comprises sine and cosine wave generators for generating one or more sets of sine and cosine waves within a cycle, analog-to-digital converters for converting the incoming sine and cosine waves generated by the sine and cosine wave generators into digital values. An arithmetic unit is used for calculating a compensation for errors including offset, amplitude and phase errors on the basis of the digital values from the analog-to-digital converters. In the apparatus, the arithmetic unit operates on a phase angle from phase angles found by the arithmetic performed prior to or during said error compensations and the digital values from the analog-to-digital converters, whereby a low-priced, highly reliable absolute position detection apparatus can be achieved without the addition of compensation circuits to the hardware.

Abstract: An apparatus and method for generating digital electrical signals which are representative of the angular position and rotational velocity of a rotatable shaft in a servomechanism includes a resolver which is connected to the rotatable component. The resolver generates analog electrical output signals which are representative of an excitation signal modulated by both the sine and cosine of the electrical angular position of the motor. The output signals from the resolver are fed to a digital signal processing circuit which employs software algorithm techniques to define a plurality of tasks which are implemented sequentially to obtain the desired angular position and velocity signals. First, the sine and cosine signals are read from the resolver through respective analog-to-digital converters. The sine and cosine signals are demodulated by multiplication with the excitation signal, and the undesired higher frequency components are deleted by filtering.

Abstract: A method and apparatus for determining the nature of an error in an amplitude encoded periodic signal and for compensating for such errors. The method includes receiving two such amplitude encoded periodic signals, each periodic signal having a sinusoidal amplitude component signal, the sinusoidal amplitude component signals being quadrature related. The method further includes squaring the two quadrature related sinusoidal amplitude component signals, summing the squared signals, and utilizing the sum signal to compensate at least one of the two sinusoidal amplitude component signals. The sum signal can be manually or automatically monitored. The sum signal can be displayed on an oscilloscope display device and at least one of the amplitude component signals compensated so as to reduce the error signal by providing a compensation signal to at least one amplitude component signal so as to obtain a substantially constant value display of the sum signal.

Abstract: A dual phase resolver to digital converter having two separate channels for generating rotor position data. The first channel generates an indication of rotor position based on a sinewave type reference signal applied to a first stator winding and the rotor signal while the second channel provides an indication of rotor position based on a cosinewave type reference signal applied to the second stator winding and the rotor signal. Logic circuitry associated with the data channels provide separate fault data indicative of when position data may be subject to error. The data from the two channels are selectively combined in the output of the converter. Data from one channel is used when the other channel is subject to fault. An average of the data is used when both channels are operating properly in order to provide greater accuracy.

Abstract: An apparatus, preferably in the form of a resolver to digital converter for converting the amplitude modulated, encoded signals into digital signals representative of the velocity and position is described. The apparatus is of the type that includes an electronic control transformer circuit for providing respective products of sine and cosine analog signals respectively times the cosine and sine of the digital position signals and for differencing the products so as to produce an analog AC error signal. The improvement comprises means for converting the analog AC error signal into a digital DC error signal and a digital accumulator for time integrating the DC error signal to generate the digital position signal. In a preferred embodiment the output of the accumulator is digitally modulated so as to provide the digital position signal as a bit-reduced feedback signal to the electronic control transformer.

Abstract: An magnetic encoder includes a multipolar magnetic body having a row of alternate North and South poles of equal widths, and a magnetoresistive element diposed in confrontation to the multipolar magnetic body. The magnetoresistive element includes at least one A phase magnetoresistive element member and at least one B phase magnetoresisitve element disposed in juxtaposition over ##EQU1## where n is an integer greater than or equal to 1, and .lambda. is a width of each individual pole of the multiplar magnetic body. Each of the A phase magnetoresistive element members and the B phase magnetoresistive element member has a group of series connected linear conductors arranged side-by-side into a comb-like shape.

Abstract: A DC to DC sine/cosine positioning servo system has an electro-mechanical DC to AC converter. The latter includes a DC torquer, having a rotor with respective windings for receiving two DC input signals proportional to the error signals detected. Mechanial movement of the rotor is proportional to the relative values of the two input signals. The rotor of a synchro control transmitter is mechanically coupled to the rotor of the DC torquer. A reference oscillator is provided which produces an AC output voltage at a predetermined frequency. The oscillator output is connected to the rotor of the control transmitter. The stator windings of the control transmitter are connected to the stator windings of a control transformer. The rotor of the control transformer produces an output voltage directly proportional to the relative angle between the rotor of the control transformer and the stator windings.

Abstract: A synchro-to-digital converter circuit is disclosed which includes memories that store digitized representations of the waveforms produced by the resolver. By matching these digitized waveforms to the specific resolver with which the circuit is to be employed, errors produced by the resolver are compensated.Two embodiments of the synchro-to-converter circuit are disclosed as well as a circuit for creating and storing the matched waveforms.