Abstract: An A/D conversion apparatus performs motor current detection in an A/D conversion period corresponding to two phases out of three phases of a sinusoidal drive motor, using reduced register resources while minimizing the number of A/D converters. The A/D conversion apparatus includes: a selection unit selecting one of a plurality of input channels; an A/D converter converting an analog signal from the selected input channel to a digital signal; a start register holding a start channel number of sequential conversion; an end register holding an end channel number of the sequential conversion; a prohibition information holding unit holding prohibition information indicating an input channel to be excluded from the sequential conversion; and a control unit causing the selection unit to select, in channel number order, input channels corresponding to channel numbers from the start channel number to the end channel number except the input channel indicated by the prohibition information.

Abstract: Interface unit for voltage input signals comprising two or more input channels. The input signals of these two or more input channels are connected alternately by an analog multiplexer to an analog-to-digital converter. The A/D converter comprises an integrated sigma-delta modulator circuit which generates a digitized 1-bit signal representing the input signal voltage level for a control unit irrespective of whether the input channel signal is digital or analog. By means of the invention all input voltage channels are made similar such that the input channels of the interface unit can receive an analog or digital signal irrespective of each other.

Abstract: A band elimination filter 35 that eliminates or reduces a low frequency noise superposed on resolver signals S1 and S2 is provided between a synchronous detection circuit 34 that performs synchronous detection by referring to an excitation signal and a controller 36 that controls a digital angle output ? to make a deviation (sin(???)), which is the output of the synchronous detection circuit, zero.

Abstract: An aircraft cabin pressure control system and the method implement a technique that oversamples and filters a sensed cabin pressure signal, and then differentiates the oversampled and filtered pressure signal to generate cabin pressure rate-of-change. The oversampling and filtering technique removes circuit and sensor induced noise from the cabin pressure signal, and results in cabin pressure rate-of-change values with less noise than currently known systems and methods.

Abstract: A tracking loop type digital angle converter that operates so that a deviation between input and output angles always becomes zero by feeding back the output angle to the input angle, wherein in order to eliminate a case where a control deviation decreases an angle error between the input and output angles is in the vicinity of 180°, i.e., where response becomes low, there are provided a detected signal sign judging section (41) that judges signs of rotation detection signals to determine a quadrant where the input angle exists, and an output angle correcting section (42) for comparing an angle region of the output angle and the quadrant of the input angle to detect a state where the angle error is excessive, judging that the control response is low and carrying out a process for compensating the output angle.

Abstract: The invention provides an angular position detector that can be configured at low cost and that accurately detects the angular position of a rotor in a rotary electric device and permits reliable control thereof even when the rotary electric device runs at a high speed. The angular position detector includes a resolver that outputs a signal indicating the rotational angle of the rotor and a signal processing circuit that calculates the rotational angle of the rotor based on the signal output from the resolver. The signal processing circuit samples output signals from the resolver at predetermined intervals and converts the signal into a digital signal. By calculating the angular speed according to the digital signal output from the resolver, the computation process is simpler, and can be performed using a microcomputer with less processing power, which reduces the component costs for the angular position detector.

Abstract: A method for adjusting a phase of a sampling frequency of ADC is disclosed. The method includes converting an analog signal into a first digital signal according to a first phase of the sampling frequency during a first time interval; calculating a first value according to the first digital signal; converting the analog signal into a second digital signal according to a second phase of the sampling frequency during a second time interval; calculating a second value according to the second digital signal; and adjusting the phase of the sampling frequency according to the first value and the second value.

Abstract: A high speed quadrature counter for use with a displacement measuring device is disclosed. The counter provides high speed counting by partitioning the tracking counter into a small fast tracking counter portion for the LSBs and a larger slow tracking counter portion for the MSBs. The fast tracking counter portion outputs a smaller number of bits according to a fast clock rate, while the slow tracking counter portion outputs a larger number of bits to update the remainder of the position at a slower clock rate. In various embodiments, the counter provides a corrected position value that has an effective timing within a few fast clock cycles of the time of the latch trigger signal. A corrected latched position circuit corrects an error that may otherwise be produced by the partitioning and the different clock rates of the fast and slow tracking counter portions.

Abstract: An encoder signal processing device comprising an A/D converter converting a periodic analog signal, a memory storing position detection error information and a computing unit including a position data calculator which calculates position data from the digital data and an error correcting section which corrects the position data based on the position detection error information. The memory includes a first memory encoding position error data which is included in the position data by the use of the computing unit and storing a correction coefficient. A second memory decoding the position error data on the basis of the correction coefficient by the use of the computing unit and storing correction data for correcting the position data and error-containing position data generated on the basis of the encoded position error data.

Abstract: A device for converting position data to Hall code data includes a data input for providing the position data, a data output for providing the Hall code data, a first adder circuit operative to provide a sum of a first predetermined number and a value provided by the data input, and a memory circuit for storing a plurality of data. A most significant bit of the data input is provided to a first storage location of the memory circuit, and a most significant bit of the first adder circuit's sum is provided to a second storage location of the memory circuit. An output of the memory circuit is operatively coupled to the data output.

Abstract: A resolver includes an excitation signal generator which generates a sine wave and a cosine wave as an excitation signal, a rotor which receives the excitation signal, and a rotary transformer which detects an output signal of the rotor, the resolver being arranged to detect angle information of the rotor. The resolver further includes a controller which outputs angle information at a zero cross point of the output signal detected by the rotary transformer. The resolver can provide high detection accuracy and be low in cost.

Abstract: A small-sized and low-cost phase detection circuit which has improved noise immunity. The phase detection circuit comprises a multiplier for multiplying an input signal by a reference signal and outputting a first signal, an integration circuit for integrating the first signal and outputting a second signal, a phase estimation circuit for estimating phase information based on the second signal, and a reference signal generation circuit for generating the reference signal based on the estimated phase information. Since the phase is detected based on information representing an entire waveform, the influence of local noise can be diluted and noise immunity can be improved.

Abstract: A signal conditioning circuit time share multiplexes anti-aliasing filters and an A/D converter. A plurality of first tier multiplexers each time share multiplex one of a plurality of antialiasing filters between a plurality of AC or baseband input signals from a plurality of sensors. A second tier multiplexer selects its inputs from the outputs of the first tier multiplexers. The output of the second tier multiplexer feeds a high speed A/D converter. Thus, the A/D converter is time share multiplexed by the second tier multiplexer. In this manner, a plurality of sensors can share a single A/D converter. After allowing a settling time for the multiplexers and antialiasing filters, a plurality of samples of the input signals are taken, such as for one period. The samples of each AC input signal are multiplied by a sine vector and a cosine vector. The product vectors are then each averaged and the root mean square of the two averages yields the magnitude of the input signal.

Abstract: A tracking loop type digital angle converter that operates so that a deviation between input and output angles always becomes zero by feeding back the output angle to the input angle, wherein in order to eliminate a case where a control deviation decreases an angle error between the input and output angles is in the vicinity of 180°, i.e., where response becomes low, there are provided a detected signal sign judging section (41) that judges signs of rotation detection signals to determine a quadrant where the input angle exists, and an output angle correcting section (42) for comparing an angle region of the output angle and the quadrant of the input angle to detect a state where the angle error is excessive, judging that the control response is low and carrying out a process for compensating the output angle.

Abstract: A method for providing a correlation between a periodic analog/digital conversion and an angle-synchronous signal, in which the periodic analog/digital conversion is provided with a timing mark, which correlates with the angle-synchronous signal, and is assigned to an angular position of a device via this timing mark.

Abstract: Since an abnormality is judged by executing a square calculating process with respect to sin ? and cos ? for detecting an abnormality in an angular resolver, a processing time is elongated, and a burden to a CPU is great. Since the invention prepares a map which can judge whether the combination of sin ? and cos ? is normal or abnormal, and judges by mapping the combination of the detected sin ? and cos ?, a process can be easily executed, a processing speed is high, and a burden to the CPU can be reduced. Further, an assist can be maintained by controlling a motor by a rectangular wave current by detecting a rotation angle signal at low resolution level, such as Hall sensors arranged around the motor.

Abstract: An interpolation apparatus in an encoder includes an analog-to-digital converter for digitizing a sine wave signal and a cosine wave signal, respectively. An amplitude level detecting circuit detects each amplitude level of the digitized sine wave signal and cosine wave signal. A computing circuit multiplies the amplitude level of one of the signal by an interpolation position parameter according to a tangent value at an interpolation position. A comparing circuit compares an output from the computing circuit to an output from the amplitude level detecting circuit. The comparison is made at every the interpolation position. A region detecting circuit identifies a region sectionalized by the interpolation positions adjacent to each other based on an output from the comparing circuit corresponding to each the interpolation position. The phase angle of the sine wave signal and the cosine wave signal exists in the region.

Abstract: Two-phase sinusoidal signals QA, QB output from an encoder are interpolated by sample-and-hold (S/H) circuits and A/D conversion (ADC) circuits, and data D is output in accordance with a data request signal RQ from exterior. For this interpolation of encoder output, a direction discrimination up/down counter is arranged near a two-phase square-wave uniform pulse generating circuit, and the data D is latched and output using a signal which is obtained by delaying the data request signal RQ. This can reduce synchronization errors between the data request signal RQ from exterior and the interpolated data, with an improvement in dynamic precision.

Abstract: An absolute encoder employs multiple sub-encoders of different resolutions and a linking algorithm for combining the sub-encoder outputs to form an accurate, high-resolution position estimate. The sub-encoders can utilize edge modulation of a main grating track, sloped patterns of successively higher periods, and other types of scale patterns. The sub-encoders can also use a variety of detector types suitable for the patterns being used. In one linking approach, pairs of tracks are linked together successively by applying a phase shift to the coarser track and then combining it with the finer track such that the transitions of the coarse track estimates become aligned with those of the finer track, whereupon the values can be combined to form a linked position estimate. In another approach, beat tracks are calculated from physical tracks of similar period, and the beat tracks are used as the coarser tracks in the linking process.

Abstract: An absolute encoder employs multiple sub-encoders of different resolutions and a linking algorithm for combining the sub-encoder outputs to form an accurate, high-resolution position estimate. The sub-encoders can utilize edge modulation of a main grating track, sloped patterns of successively higher periods, and other types of scale patterns. The sub-encoders can also use a variety of detector types suitable for the patterns being used. In one linking approach, pairs of tracks are linked together successively by applying a phase shift to the coarser track and then combining it with the finer track such that the transitions of the coarse track estimates become aligned with those of the finer track, whereupon the values can be combined to form a linked position estimate. In another approach, beat tracks are calculated from physical tracks of similar period, and the beat tracks are used as the coarser tracks in the linking process.

Abstract: An apparatus and method for determining an angular position of a shaft are disclosed, which comprise resolving an excitation signal at an excitation frequency into at least two orthogonal signals, converting the orthogonal signals to a digital estimate, for each of the orthogonal signals, and evaluating an amplitude and a polarity of the orthogonal signals to determine the angular position. The process of converting the orthogonal signals comprises comparing the orthogonal signal to an analog feedback signal to generate a comparison result and incrementally adjusting the digital estimate in response to sampling the comparison result at an estimation frequency. The converting process also includes converting the digital estimate to the analog feedback signal, collecting a digital estimate history at a sample frequency that is a binary multiple of the excitation frequency, and analyzing the digital estimate history to determine the amplitude and the polarity substantially near the excitation frequency.

Abstract: An electrostatic encoder comprises a movable element having electrodes and a stator having induction electrodes and potential detection electrodes. The electrostatic encoder further comprises a voltage driving circuit configured to apply a voltage to the induction electrodes of the stator, and generate alternate potential distribution in the electrodes of the movable element by electrostatic induction, a vector generation circuit configured to generate a vector consisting of two signal components, from outputs of the potential detection electrodes of the stator which detect the alternate potential distribution, and a phase splitter circuit configured to measure the relative displacement of the movable element to the stator, from a rotation angle of the vector consisting of the two signal components outputted from the vector generation circuit.

Abstract: A resolver arrangement that is inexpensive and yet offers high resolution and high noise rejection includes a carrier signal generator and two processing channels each of which has an analog input connected a different one of the stator coils and a channel output. Each of the processing channels includes a sigma-delta modulator with an output that supplies a bit-stream representative of an analog input signal received from a respective stator coil. Each channel also includes a first digital filter that receives the bit-stream from the sigma-delta modulator and converts the bit-stream to intermediate digital data-words. In addition, each channel has a digital synchronous demodulator that demodulates the intermediate digital data-words in synchronism with the carrier signal providing demodulated data-words.

Abstract: A technique for detecting and correcting inaccuracies in curve-fitted models. Humps and dips in a curve-fitted model are identified. An analysis is performed on the humps and dips to determine if they are large enough to warrant correction. If so, then the source of the simulation and/or empirical data is modified to taking corrective action to improve the curve fit between the edge point and the next actual simulation and/or empirical data point.

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 Resolver/Digital (R/D) converter includes an encoder output divider having a DSP generating 14-bit encoded signals A2 and B2 from a timing analysis performed during the first period of 12-bit encoded signal A1. The DSP generates a selection signal output to a multiplexer to select encoded signals A1 and BE1 or encoded signals A2 and B2 depending on the rotational speed of the rotor of a resolver. Based on the selection signal, the multiplexer outputs 12-bit encoded signals A1 and B1 when the rotational speed is less than 400 rpm or greater than 1200 rpm, and outputs 14-bit encoded signals A2 and B2 when rotational speed is between 400 rpm and 1200 rpm.

Abstract: Methods and systems for simply and inexpensive converting the signals of solid-state sensors for use by analog systems and indicators. An embodiment of the system receives a DC voltage value from at least one sensor, converts the DC voltage value into one or more analog signals based on a reference AC voltage signal, and performs at least one of outputting or storing the generated analog signals. The conversion is performed digitally then converted to analog or is performed using an analog trigonometric converter.

Abstract: A resolver detected position compensation system for a resolver is provided that can enhance a position detection precision by performing a further compensation on a compensated position that was obtained from a static error compensation. The position detection circuit outputs a compensated detected position signal in which a static error has been compensated. The differential circuit differentiates the compensated detected position signal to obtain a rotational speed of the resolver. Based on a signal representing the rotational speed output from the differential circuit, the phase data memory device and the peak value memory device send the variation in phase and the amplitude peak value, respectively, of the dynamic error signal to the multiplication device. The multiplication device calculates an estimated dynamic error and the subtraction circuit removes the estimated dynamic error from the compensated detected position signal.

Abstract: A rotary type encoder is provided with a signal generating portion 2 for generating a sine wave signal of N periods for each revolution in accordance with the rotation of the shaft 4 of a motor; a calculation means for obtaining the rotation angle of the shaft 4 based on the sine wave signal; an EEPROM 37 being arranged in a manner that the error value of the rotation angle for one revolution of the shaft 4 thus measured is divided in relation with the N periods to set a plurality of first angle regions i, the angle region almost at the center of the angle region i is divided into plural regions to set second angle regions j, and an error value corresponding to the angle at almost the center of each of the angle regions j is stored therein in correspondence with the rotation angle; and a correction means for reading the error value stored in the EEPROM 37 in correspondence with the rotation angle to correct the rotation angle.

Abstract: An R/D converter allows high precision detection of a rotation angle of a rotor axis of a resolver having high rates of rotation. An A/D converter is built into a digital signal processor and converts a sine wave and cosine wave output from the resolver. An axis angle calculator calculates tan ?=A((sin ?t)(sin ?))/A((sin ?t)(cos ?)) from A(sin ?t)(sin ?) and A(sin ?t)(cos ?) and further calculates ?=tan?1 ?. The angle space is divided into quadrants and an offset value is set for each quadrant and by adding or subtracting the calculated ? to or from the offset value to form the final angle of the rotor axis of the resolver.

Abstract: In a control apparatus, a “characteristic value calculation” block calculates a characteristic value (such as amplitude value, offset value, or waveform distortion for each phase of two-phase sinusoidal signals optically input from an encoder, or phase difference between the two phase signals) for each of the two-phase sinusoidal signals, and an “alarm detection” block checks the presence or absence of an excursion outside a predetermined allowable range and, if such an excursion is detected, produces an alarm indication or the like. Each time the “present characteristic value” is input, a “characteristic value comparison” block compares it with “previous characteristic values”, and analyzes the result of the comparison. That is, the difference between the present value and each previous data is calculated, and the largest amount of variation (with plus or minus sign) is obtained; if this amount is larger than a predetermined value, a signal indicating an “imminent failure” is output.

Abstract: This invention provides an electrically-powered steering apparatus capable of assisting a steering torque appropriately using a resolver. A reference signal is applied to a resolver arithmetic processing I/F circuit 34 and a resolver arithmetic processing I/F circuit 36 through a reference signal input means 38 and a microcomputer 30 obtains a differential in amplification factor from outputs of the resolver arithmetic processing I/F circuit 34 and the resolver arithmetic processing I/F circuit 36 when the reference signal is supplied. A correction value for computing a position from the outputs of the resolver arithmetic processing I/F circuit 34 and the resolver arithmetic processing I/F circuit 36 is computed from the obtained differential.

Abstract: This resolver/digital converter has a resolver, a resolver/digital converting portion and an exciting signal generator. The exciting signal generated from the exciting signal generator is supplied to the resolver, and the resolver signals produced from the resolver are supplied to the resolver/digital converter. This resolver/digital converter further has a conversion trigger generator that generates a conversion trigger signal on the basis of the exciting signal generated from the exciting signal generator, an A/D converter that converts the resolver signals produced from the resolver to digital values in response to the conversion trigger signal generated from the conversion trigger generator, and computing means that detects the failure status on the basis of the digital values produced from the A/D converter.

Abstract: This resolver/digital converter has a resolver, a resolver/digital converting portion and an exciting signal generator. The exciting signal generated from the exciting signal generator is supplied to the resolver, and the resolver signals produced from the resolver are supplied to the resolver/digital converter. This resolver/digital converter further has a conversion trigger generator that generates a conversion trigger signal on the basis of the exciting signal generated from the exciting signal generator, an A/D converter that converts the resolver signals produced from the resolver to digital values in response to the conversion trigger signal generated from the conversion trigger generator, and computing means that detects the failure status on the basis of the digital values produced from the A/D converter.

Abstract: There is provided a frequency-digital signal conversion circuit for automatically converting a clock frequency into a digital signal. The frequency-digital signal conversion circuit includes: a frequency detecting unit for detecting a frequency of an input clock signal; a latch unit for sampling and latching an output of the frequency detecting unit; and a digital signal generating unit for receiving an output of the latch unit and generating a digital signal of a predetermined bits with respect to the frequency of the input clock signal.

Abstract: A programmable limit switch includes output channels for receiving position data, each position value of the position data representing an incremental advance of a workpiece through a production field, and for producing actuation signals. The channels are connectable to respective output devices responsive to the respective actuation signals and located in the field. Each output channel has an output controller, which is individually programmable to change the state of respective actuation signals in response to reaching selected position values. Preferably, the PLS includes input connectors coupled to a respective channel and connectable to respective input devices located within the production field. Each channel operates its own inputs and outputs according to a variety of programmed functions depending upon system conditions seen by the output controller.

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 circuit for processing the outputs of an array of photoconductive detectors, includes amplifiers (101) for amplifying the detector outputs and analogue-to-digital converters (109) for digitizing the amplified outputs. The A to D converters oversample the detector signals. A digital processor (110) then applies a linearity correction to the digitized signals. The circuit is particularly suitable for processing the signals from an array of photoconductive detectors in an FT-IR microscope.

Abstract: A method for providing a digital current signal from an analog armature current signal of a motor. The method includes subjecting the analog current signal to an analog-to-digital conversion to produce a first digital current signal having current ripples for each current ripple of the analog current signal. During start-up and run-down motor operation phases, the analog current signal is sampled at a sampling rate which is greater than an expected rate of the current ripples of the analog current signal to produce a second digital current signal having current ripples for each current ripple of the analog current signal during the start-up and run-down motor operation phases. The current ripples of the first and second digital current signals are then compared. The current ripples of the second digital current signal which are in non-conformance with the current ripples of the first digital current signal are evaluated.

Abstract: An R/D converter allows high precision detection of a rotation angle of a rotor axis of a resolver having high rates of rotation. An A/D converter is built into a digital signal processor and converts a sine wave and cosine wave output from the resolver. An axis angle calculator calculates tan &thgr;=A((sin &ohgr;t)(sin &thgr;))/A((sin &ohgr;t)(cos &thgr;)) from A(sin &ohgr;t)(sin &thgr;) and A(sin &ohgr;t)(cos &thgr;) and further calculates &thgr;=tan−1 &thgr;. The angle space is divided into quadrants and an offset value is set for each quadrant and by adding or subtracting the calculated &thgr; to or from the offset value to form the final angle of the rotor axis of the resolver.

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 &thgr; as an address to retrieve &thgr; from a memory containing angle values between 0° and 90°, if the absolute value of sin &thgr; is between 0 and 0.707. Otherwise, if the absolute value of sin &thgr; is between 0.707 and 1, cos &thgr; is used as an address to retrieve &thgr;. The polarities of sin &thgr; and cos &thgr; are used to determine a quadrant and an associated offset including 0°, 180°−&thgr;, 180°+&thgr;, and 360°−&thgr;, which is combined with &thgr; such that the final angle of the rotor axis is obtained.

Abstract: A Resolver/Digital (R/D) converter includes an encoder output divider having a DSP generating 14-bit encoded signals A2 and B2 from a timing analysis performed during the first period of 12-bit encoded signal A1. The DSP generates a selection signal output to a multiplexer to select encoded signals A1 and BE1 or encoded signals A2 and B2 depending on the rotational speed of the rotor of a resolver. Based on the selection signal, the multiplexer outputs 12-bit encoded signals A1 and B1 when the rotational speed is less than 400 rpm or greater than 1200 rpm, and outputs 14-bit encoded signals A2 and B2 when rotational speed is between 400 rpm and 1200 rpm.

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 motor controller (30) includes three analog Hall-effect sensors (42, 44, 46) for forming continuous-time signals proportional to the sine and cosine of the position of the rotor (24) of a motor (20). The sine and cosine signals are differentiated to obtain signals proportional to the rotor rate times the sine and cosine values. These integrated values are then multiplied by the cosine and inverse of the sine values, respectively, to obtain values equal to the rotor rate times the square of the cosine and the rotor rate times the square of the sine. These latter two values are summed to obtain an output signal proportional to the rotor rate based on the trigonometric identity sin2(x)+cos2(x)=1. Since the motor controller (30) derives a high-resolution value for the rotor rate, it may be used for fine resolution control of brushless motors and the like.

Abstract: In a calculation processing device of a resolver signal, a processing speed of the resolver signal is increased, and a noise-proof characteristic thereof and also reliability thereof are improved, while total system cost is reduced. The resolver signal calculation processing device is arranged such that a resolver signal output from a resolver is digitally converted by a resolver interface into a digital rotary angle signal; the digitally-converted rotary angle signal is processed by a central calculation processing unit; and the resolver interface is provided within the resolver signal calculation processing device.

Abstract: Systems and methods are provided for calibrating a sample delay time between a position request time from a host computer and a position encoder sample time. The position encoder includes a readhead with a transducer and transducer electronics, and encoder interface electronics which exchange data and commands with the readhead and with the host computer. The transducer electronics may lack a clock capable providing a sufficiently consistent sample delay time. To provide a consistent sample delay the interface electronics measures an inherent sample delay time based on signals from the readhead during a calibration mode. The difference between the inherent delay time and the desired delay time is saved and inserted by the interface electronics during position measurement such that the calibrated sample delay time is consistently the desired sample delay time.

Abstract: In an abnormality detecting device for a position detecting device which generates an amplitude-modulated or phase-modulated signal from a position sensor according to the rotational position of the rotor of a motor when a reference signal having a predetermined periodic waveform is supplied, there are provided a bias current applying unit made of a passage including a resistance of applying DC bias current to an output winding of the position sensor, positional abnormality detecting units for detecting a biased DC signal of an amplitude-modulated or phase-modulated signal applied to the output winding apart from a position detector circuit for detecting the rotational position of the rotor, and an abnormality detection judgment processing part for judging abnormality of the position detecting device from a DC signal detected by the positional abnormality detecting units.

Abstract: At least one exemplary embodiment of the present invention includes a method for compensating for delays in a circuit of a serial encoder. The method includes determining at least one delay associated with the circuit of the serial encoder. The method also includes adjusting an internal clock signal received by a data receiving memory associated with the serial encoder to account for the at least one determined delay.

Abstract: The present invention provides an automatic resolution changing method and circuit for use in a high-precision digital conversion of two-phase sinusoidal wave signals. The angular velocity (d&phgr;/dt) of the rotor obtained from the difference between these two-phase sinusoidal wave signals is integrated by a counter. Subsequently, digital conversion of the rotation angle (&thgr;) of the rotor with respect to the stator is performed, and a result of the digital conversion is outputted. At this time, in the case where the angular velocity (d&phgr;/dt) is equal to or higher than a first percentage of the follow-up speed at the current resolution of the counter, the resolution of the counter is reduced. Further, in the case where the angular velocity (d&phgr;/dt) is equal to or lower than a second percentage of the follow-up speed at the current resolution of the counter, the resolution of the counter is increased.