Abstract: In an angle computation method and apparatus for a variable reluctance resolver, the maximum values Vsin(max) and Vcos(max) of sine and cosine output voltages in respective positive value ranges and the minimum values Vsin(min) and Vcos(min) of the sine and cosine output voltages in respective negative value ranges are extracted, and on the basis of these values, offset values, amplitude values, sin-cos voltage ratio, and a zero-point correction value are obtained in accordance with the following equations: VSINOFFSET=(Vsin(max)+Vsin(min))/2 VSINAMP=(Vsin(max)?Vsin(min))/2 ?SINPHASE=sin?1(VSINOFFSET/VSINAMP)?VSINOFFSET/VSINAMP VCOSOFFSET=(Vcos(max)+Vcos(min))/2 VCOSAMP=(Vcos(max)?Vcos(min))/2 K=VSINAMP/VCOSAMP On the basis of the thus-obtained values, an angle ? is obtained in accordance with the following equation: F(Vsin?VSINOFFSET, K(Vcos?VCOSOFFSET), ?SINPHASE)=?.

Abstract: An inverter control microcomputer 10 comprises AD converters 21–23, a selector control circuit 31, and a selector 32. The selector 32 selects three analog signals from among inputted seven analog signals in accordance with control from the selector control circuit 31. A control signal generation section, which comprises a CPU 11 and an inverter control signal generation circuit 17, generates a motor control signal Cntl based on three digital values obtained by the respective AD converters 21–23. By performing AD conversion concurrently for arbitrary three analog signals, it is possible to eliminate a phase shift between the detected analog signals and perform motor control with high precision. Thus, it is possible to detect an analog signal necessary for control of a motor, etc., at an appropriate timing without increasing the number of AD converters.

Abstract: A device for effectuating a digital estimate of a periodic electric signal is described. The device comprising a linear DAC having an output signal, a comparator that compares the output signal of the linear DAC with the periodic electric signal, and logic circuitry having in input the output signal of the comparator and a pulse clock signal. The logic circuitry provides a first digital signal in input to the linear DAC and a second digital signal representative of the estimate of the periodic electric signal.

Abstract: A servo system comprising an analog sigma delta modulator for generating a normalized digital error correction signal from first and second analog control signals. The sigma delta modulator comprises an analog low-pass filter, a quantizer delivering the digital error correction signal and a multiplying DA-converter in feedback arrangement between the output of the quantizer and the input of the low-pass filter for multiplying the feedback signals with the sum of the analog control signals.

Abstract: A linearity compensation circuit provides cancellation of harmonic distortion introduced by a non-linear system into an input signal by providing a separate harmonic correction component for each harmonic of a fundamental frequency of the input signal. The harmonic correction components are summed with a delayed version of the input signal to produce a corrected input signal for input to the non-linear system. The separate harmonic correction components are generated by respective harmonic correction units, each having a programmable input filter, a Hilbert Transformer filter and a plurality of phase shifters. The output of each programmable input filter is input to the Hilbert Transformer filter and a compensating delay.

Abstract: An A/D converter converts a sine and cosine wave output of a resolver to form a digital sine and cosine. A microcomputer uses an absolute value of digital sin ? as an address to retrieve ? from a memory containing angle values between 0° and 90°, if the absolute value of sin ? is between 0 and 0.707. Otherwise, if the absolute value of sin ? is between 0.707 and 1, cos ? is used as an address to retrieve ?. The polarities of sin ? and cos ? are used to determine a quadrant and an associated offset including 0°, 180°??, 180°+?, and 360°??, which is combined with ? such that the final angle of the rotor axis is obtained.

Abstract: A position measuring device including a detector unit that generates position-dependent scanning signals and a transmitting unit that transmits instantaneous values of the position-dependent scanning signals in a preset scanning clock pulse. A processing unit that establishes a resulting measured position value by filtering instantaneous values of several scanning clock pulses and an interface which, on the basis of a transmission clock pulse transmits the resulting measured position value to a sequential electronic unit via a serial data line.

Abstract: A heading and Omni-Bearing Selector (OBS) module for converting 3-phase analog heading signals input from a heading synchronic device and analog sine and cosine bearing signals input from an OBS resolver device.

Abstract: A correlation modulating apparatus that is adapted to modulate high frequency data into low frequency signals. In the apparatus, a register lists in parallel a data bit stream by at least two bit using a key clock having less frequency than a data clock. A converter converts the listed at least two bit data into an analog signal. A frequency of the analog signal is lowered into below at least ½ compared with that of the data bit stream.

Abstract: A digital to synchro converter converts digital values to an analog synchro signal. The values are mapped in a memory and sent to a digital to analog converter converting the digital values to analog values. Sample and hold circuitry is then used to create the analog synchro signal.

Abstract: An electronic encoder circuit and method for providing a set of quadrature waveforms whose frequency is related to the amplitude of an analog input signal. Broadly stated, the electronic encoder circuit comprises conversion circuitry that generates a digital signal from an analog signal that, in a typical application, will be representative of the speed or frequency of a master machine, process or assembly line. The conversion circuitry is connected to a microcontroller that processes the digital signal and produces a potentially modified digital signal as an output. The output digital signal from the microcontroller is received by additional conversion circuitry that generates an encoded analog signal whose frequency is related to the original input analog signal. Phase shifting circuitry generates quadrature waveforms through operation on the encoded analog signal. The quadrature waveforms can then be used to drive or control a slave device.

Abstract: A digital phase to digital sine and cosine amplitude translator generates sine and cosine outputs from an input angle word, which is decomposed into the most significant bits (MSBs) and the least significant bits (LSBs), and the octant number of the angle is identified by the octant identifier bits. Radix-4 multiplier/adder circuits improve the efficiency of multiplication/addition computations. An incrementor and a decrementor are used for sine and cosine MSB computations, respectively, to further save the computer memory and logic. In a preferred embodiment, the MSBs of the sine and cosine outputs for all octants are generated based upon the octant number of the input angle, and the LSBs of the outputs are generated by trigonometric approximations and octant selection, thereby resulting in a savings in computer memory and logic.

Abstract: A data processing system (10) is disclosed which comprises a microprocessor host (12) coupled to a decoding system (14). A host interface block (18) receives a bit stream and passes bit stream on to a system decoder block (20). The system decoder block (20) extracts the appropriate data from the bit stream and loads an input buffer (24) or an optional external buffer (26). An audio decoder block (28) retrieves the data from the input buffer (24) and generates scale factor indices, bit per code word values and subband samples which are stored in an arithmetic unit buffer (30). A hardware filter arithmetic unit block (32) retrieves the information from the arithmetic unit buffer (30) and dequantizes, transforms and filters the data to generate PCM output data which is loaded into a PCM buffer (34). The data within the PCM buffer (34) is output by a PCM output block (36) to a digital-to-analog converter (16).

Abstract: A multiphase converter circuit generates a plurality of sinusoidal outputs of displaced phase and given speed value from the output of an angular resolver system attachable to a motor excited by these multi-phase outputs, the resolver system having a lower speed value than that of the motor. The angular resolver system provides in parallel format sequential digital numbers indicative of the amount of rotation of the shaft of an angular position sensor associated with the angular resolver system. These numbers are used to excite simultaneously identical addresses of a plurality of addressable memory systems, each memory system having stored therein at sequential addresses sequential values of a sinusoidal wavetrain of a given number of sinusoids. The stored wavetrain values represent sinusoids displaced from each other in phase according to the number of output phases desired.

Abstract: A system provides I and Q baseband analog modulation signals for use in GMSK modulation responsive to serial bits of digital data. The I baseband modulation signal is represented by I(t)=cos [2.pi.f.sub.m .intg.g(t)dt] and the Q baseband modulation signal is represented by Q(t)=sin [2.pi.f.sub.m .intg.g(t)dt], wherein f.sub.m is the modulating frequency and g(t) is a filtered version of the serial bits of digital data. The system includes an input for receiving the serial bits of digital data, a memory including addressable memory locations for storing data representing the waveform amplitudes of the I and Q modulation baseband analog signals, and an address generator for addressing selected ones of the memory locations responsive to the serial bits of digital data. The system further includes digital to analog converters coupled to the memory for receiving the data stored at the memory locations addressed by the address generator and for converting the data to the I and Q modulation baseband analog signals.

Abstract: The invention herein disclosed is a digital circuit which emulates a synchro signal in a synchro-resolver follower system for precise control of shaft position and rotation at very low rotational rates. The subject invention replaces the synchro and drive motor in a synchro-resolver follower system with a digital and analog synchro emulation circuit for generating the resolver control signal. The synchro emulation circuit includes amplitude modulation means to provide relatively high frequency resolver excitation signals for accurate resolver response even with very low shaft rotation rates.

Abstract: A circuit for converting a phase signal to an amplitude signal comprises a signal separating circuit which receives a phase signal and provides in accordance therewith a phase conversion signal and a sign signal, and a conversion unit including a conversion table in which a predetermined signal wave in a reference phase angle range is stored. A phase angle of a phase signal is converted into a converted phase angle, when the phase angle is outside a reference phase angle range. An amplitude signal is obtained by reading an amplitude based on the phase angle or the phase converted angle from the conversion unit.

Abstract: A signal generator generates a temporal signal with a periodic configuration defined by an arrangement of seed patterns resulting from a branching construction iteratively using laws for composing several patterns and consisting in defining the periodic configuration of the signal as a component "a.sub.n " of the nth term Un with several components (a.sub.n, b.sub.n) of a recurrent sequence defined at the level of each of its components by a specific recurrent composition law, the initial term U0 having for its components the seed patterns (a.sub.0, b.sub.0). The temporal signals known as "fractal" signals result from a branching construction of this kind. The generator comprises a microprocessor (10) associated with a keyboard-display system (11), a read-only memory (12) for programs, a random access memory (13) and an output digital-to-analog converter (14).

Abstract: Apparatus for generating synchro/resolver stimulus signals is disclosed wherein the stimulus signals are generated in an arbitrary time sequence of synchro/resolver shaft angles under control of an external computer. Data from the computer is applied to random access memory (RAM) banks and is read out from sequential RAM address locations at a predetermined rate to two independent digital to synchro/resolver converters. The converter outputs correspond to synchro/resolver shaft angle information in a three or four wire AC output format.

Abstract: A linear, analog, synchro control differential transmitter for implementing he common synchro CDX function whereby a scaled linear analog voltage is used as input instead of a mechanical shaft angular displacement. Alternate synchro functions of CT and CX that the invention implements are also disclosed.

Abstract: An instrument with cross-coil type movable magnet which performs desired indication by A-D converting in accordance with the state of an object under measurement and applying to the crossed coils the current corresponding to a digital value after A-D conversion, comprising an A-D converter to which an input signal corresponding to the state of the object under measurement is sent after overlapping with a dithering ripple, thereby enabling improvement in the resolution of pointer indication.

Abstract: A software-based resolver-to-digital converter (RDC) (80) for computing an angle of rotation &THgr; 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 &THgr; and output the computed value to system circuitry (31) for processing to enhance system operation.