Abstract: A resolver includes an excitation coil provided at the rotor or the stator and formed on a sheet-shaped substrate, and a detection coil provided at the rotor or the stator and formed on the sheet-shaped substrate. At least one of the excitation coil and the detection coil is a sine coil and a cosine coil. In the sine coil, sine coil patterns of a pair of comb-shaped closed coils are disposed on the identical layer of the substrate. In the cosine coil, cosine coil patterns of a pair of comb-shaped closed coils are disposed on the identical layer of the substrate. Each of the pair of comb-shaped closed coils includes a first comb-shaped closed coil including an inward first projection and a second comb-shaped closed coil including an outward second projection.

Abstract: The present invention relates to an electromagnetic machine comprising: rotation shaft; a stator comprising a multi-phase winding wire; a mover (rotor 1) comprising the multi-phase winding wire and spaced apart from the stator at a preset interval; and a controller for independently controlling a first magnetic field of the stator and a second magnetic field of the mover (rotor 1). The electromagnetic machine according to the present invention can resolve, by means of the mover (rotor 1) and the wound-type stator that can be independently and actively controlled, a torque issue at start-up or when needed and, thereby, has the effects of producing a maximum driving torque while having a minimum size, and of maximizing efficiency.

Abstract: A positioning device (101) for producing a position signal indicative of a rotational position of a resolver is presented. The positioning device comprises a signal interface (102) for receiving alternating signals (V_cos, V_sin) from the resolver and a processing system (103) for generating the position signal based on position-dependent amplitudes of the alternating signals and on polarity information indicative of a polarity of an excitation signal (V_exc) of the resolver. The processing system is configured to recognize a polarity indicator, such as a change of frequency or phase, on a waveform of one or both of the alternating signals and to determine the polarity information based on the recognized polarity indicator. Thus, the polarity information related to the excitation signal is included in the alternating signals and therefore there is no need for a separate signaling channel for transferring the polarity information to the positioning device.

Abstract: An apparatus and a method for detecting a phase delay of a resolver are provided. The apparatus includes a resolver configured to output a signal corresponding to a rotation angle of a motor, an excitation signal generator configured to generate an excitation signal using a square wave signal, and a controller configured to differentiate the signal to obtain a differential signal, detect a time when the differential signal meets a reference voltage as a peak time of the signal, and detect a phase delay time of the signal based on the peak time of the signal and an edge time of the square wave signal.

Abstract: According to one embodiment, a driving device includes a voltage controller, a parameter setter, and a phase adjuster. The voltage controller causes an electric power converter to apply a drive voltage to the electric motor, the electric power converter converting input electric power to A/C electric power having desired voltage and frequency and supplying the converted electric power to an electric motor. The parameter setter sets at least one of a rotation speed of the electric motor and a parameter related to the rotation speed as speed information. The phase adjuster adjusts a phase of the drive voltage in such a manner that an index calculated based on a current flowing in the electric motor and the speed information set in the parameter setter becomes smaller.

Abstract: A package lift assembly for a delivery vehicle includes a plurality of rods that define at least one shelf. The package lift assembly further includes upper and lower rails. An alteration assembly is operably coupled to the upper and lower rails. Vertical guides are operably coupled to the alteration assembly. A platform is operably coupled to the vertical guides and include a central receiving member. At least a portion of the plurality of rods are selectively disposed within the central receiving member. A motor assembly is operably coupled to the central receiving member and the vertical guides. The motor assembly and the alteration assembly cooperate to translate the platform along the vertical guides and translate the central receiving member between a retrieval position and a holding position.

Abstract: The electric motor control device includes a rotation angle correction amount calculation unit that, based on a rotation angle signal for an alternating current electric motor output from an angle sensor and a current detection signal for the alternating current electric motor output from a detector, calculates a rotation angle correction amount to correct a rotation angle error between the rotation angle signal and a magnetic pole position of the alternating current electric motor, wherein the rotation angle correction amount calculation unit, based on a current detection signal when a short circuit is caused between winding terminals of the alternating current electric motor, calculates at least either one rotation angle correction amount of a direct current component rotation angle correction amount and an alternating current component rotation angle correction amount.

Abstract: A resolver system includes a rotatable primary winding, a secondary winding fixed relative to the rotatable primary winding, a tertiary winding fixed relative to the rotatable primary winding and positioned ?/2 radians out of phase with respect to the fixed secondary winding, an excitation module electrically connected to the rotatable primary winding and configured to provide an excitation signal to the rotatable primary winding where the excitation signal is an alternating current waveform having a fundamental frequency, and a controller electrically connected to the secondary winding and configured to sample a voltage across the secondary winding at 18 times the fundamental frequency, sample a voltage across the tertiary winding at 18 times the fundamental frequency, and determine an amplitude of the fundamental frequency based on the sampled voltages across the secondary and tertiary windings, where the alternating current waveform includes a third harmonic frequency.

Abstract: A control device capable of accurately detecting a rotor rotation angle is provided. The control device includes variable resistors R1 to R4 for converting the currents flowing in the four-phase coils of the current detection resolver into voltages, two differential amplifiers for a first phase signal of the voltage difference between the detection voltages of the variable resistors R1 and R3, and a second phase signal of the voltage difference between the detection voltages of the variable resistors R2 and R4 respectively, two phase shifters for shifting the phase of the first phase signal and the second phase signal respectively, a synthesizer for a phase modulation signal by synthesizing the phase shifted first phase signal and the phase shifted second phase signal, and an adjuster for adjusting the resistance values of the variable resistors R1 to R4 based on the width of the envelope of the phase modulation signal.

Abstract: A system for determining a phase angle of a sensor waveform relative to an excitation waveform includes a controller that provides an excitation signal having an excitation frequency and a sample signal having four times the excitation frequency. An exciter provides a sinusoidal excitation waveform at the excitation frequency to a primary winding, thereby inducing a sensor waveform in a secondary winding. An analog-to-digital converter (ADC) measures a first and second voltage of the sensor waveform separated in time by the period of the sample frequency, and a wrap-around ADC measures a first and second voltage of the sinusoidal excitation waveform. The first voltage measurements are made at the same time, and the second voltage measurements are made at the same time. The system calculates the phase angle based on the first voltage measurements and the second voltage measurements.

Abstract: According to an embodiment, a motor control apparatus includes a current detecting unit that detects a motor current, a rotation position detecting unit that detects a rotation position of a rotor, a phase difference calculating unit that calculates first phase difference information between the motor current and the rotation position when a rotation speed of a motor is equal to or lower than a predetermined rotation speed and second phase difference information when the rotation speed of the motor exceeds the predetermined rotation speed, a storage unit that stores phase correction information based on the first phase difference information, a correcting unit that outputs a corrected rotation position signal and a drive unit that generates a drive signal to be output to the motor.

Abstract: A rotation-detecting apparatus includes the following: a rotor coil provided on a rotor; detection coils provided on stators; a control circuit that detects the relative rotational angle between the rotor and the stators by processing detection signals induced in the detection coils as a result of the rotor coil being excited by an excitation signal; and a communicating means for performing data communication with an external device. The control circuit in the rotation-detecting apparatus has functionality whereby a switch signal that turns on and off at preset rotational angles is outputted on the basis of the aforementioned detection signals. Also, the control circuit is designed such that the set rotational angles for the aforementioned switch signal can be changed by the external device via the abovementioned communicating means.

Abstract: Described is a motion control system for drive motors in automated multiparameter luminaires that employs jerk (3rd derivative of position as a function of time) to offset the resonance characteristics of the motor as loaded by the components in the luminaire, so as to correct and mitigate movement caused by external vibration sources.

Abstract: A method and an angle sensor for contactless measurement of an angle between a first machine element and a second machine element rotatable with respect thereto. A plurality of coils are non-rotatably connected to the first machine element and include transmitter coils—distributed around the rotational axis. Each of the transmitter coils is arranged in a sector about the rotational axis. An iron-core element non-rotatably connected to the second machine element is disposed in a sector opposite the transmitter coils. Based on applying voltage pulses, a determination of the angle to be measured is effected starting from a ratio formation between the amplitude of a secondary voltage pulse associated with a selected transmitter coil and a peak amplitude.

Abstract: A vehicle includes one or more inverter-fed electric machines such as permanent magnet synchronous motors. In response to a torque request, a controller issues commands to an inverter calculated to cause the motor to produce the requested torque. A method of operating the inverter may determine the commands based on the ratio of rotor speed to inverter input voltage, reducing the approximation error associated with multi-dimensional lookup tables. When the speed and voltage vary while maintaining a constant ratio and constant torque request, the issued commands produce a winding current in the electrical machine with constant direct and quadrature components.

Abstract: A control device is applied to a vehicle having a motor with a rotary shaft connected to a drive shaft of the vehicle, a rotational position detector to detect a rotational position of the rotary shaft of the motor, and a battery. The control device performs a procedure for obtaining an offset amount in response to a request for obtaining the offset amount, store the obtained offset amount, and keep the stored offset amount without relying on electric power supplied from the battery, which offset amount is a difference between a detected rotational position of the rotary shaft with the rotational position detector and an actual rotational position of the rotary shaft. The control device is configured to find an occurrence of the request for obtaining the offset amount when battery is dismounted from the vehicle.

Abstract: A circuit is provided for detecting peaks of a sinusoidal input signal includes circuitry for generating first and second sinusoidal output signals that are out of phase with one another and with the sinusoidal input signal. A comparator block compares the sinusoidal output signals to determine instances where the amplitudes of the first and second sinusoidal output signals cross over each other. The sinusoidal output signals may lead the sinusoidal input signal somewhat so that, after taking into account processing delay, the indicated crossover instances substantially coincide with peaks in the sinusoidal input signal such that a trigger signal generated by the circuit accurately indicates the timing of the peaks.

Abstract: Two excitation coils (excitation A coil, excitation B coil) and two detection coils (detection A coil, detection B coil) are provided. The excitation A coil and the excitation B coil are excited at frequencies that are different from each other. The number of turns of the detection A coil and the detection B coil are respectively set with two sine waves using the number ms1 and ms2 of pole pairs. The number ms1 and ms2 of pole pairs, the number mx1 and mx2 of pole pairs of the excitation A coil and the excitation B coil, and the number mr of pole pairs of a rotor are set to have a predetermined relationship. A resolver having redundancy can be realized with small number of coils.

Abstract: Provided is a system and method for calibrating an offset of a resolver in a motor of a vehicle. More specifically, a current is applied to the ?d-axis of the motor, the Vq, Vd, Iq, and Id of the motor is measured and a power input to the motor is calculated by a controller, and when the input power is not within a predetermined range, the controller adjusts the offset of the resolver to a positive or negative value accordingly.

Abstract: An apparatus for measuring an error in a resolver includes a first calculator that perform an inverse Park transform based on voltages Uq and Ud at an output of PI current regulators, and delivers voltage setpoint signals PWMA, PWMB, PWMC to a power stage via a line on which a DC voltage Ubus-dc is available. The power stage generates a three-phase system of voltages UA, UB, UC for energizing an electric machine. The apparatus also includes a signal processor that provides an angle measurement ?m. Based on currents MesIA, MesIB, MesIC of the three phases, and on a rotor angle ?r, a second calculator of the device delivers values MesId, MesIq used by the first calculator. A PI voltage regulator delivers an angle ?c for correcting the error by regulating a setpoint value for the voltage Ud.

Abstract: A motor control device determines a rotation angle and an angular speed of a motor, and has: a correcting unit including N number (N is an positive integer equal to or more than 2) of bit-shift circuits, which divide the angular speed by powers of 2 by bit shift, and a circuit, which subtracts output values of the second to Nth bit-shift circuits from an output value of the first bit-shift circuit to determine a correction amount for the rotation angle and correct the rotation angle by the correction amount; so as to determine two-phase direct voltages to obtain a target torque from the three-phase alternate currents passing through the motor according to the angular speed, and convert the two-phase direct voltages into the three-phase alternate voltages according to the sine, cosine of the corrected rotation angle.

Abstract: A motor speed determining circuit determining a rotation speed of a motor is provided and a processing of generating motor driving waveform is switched in accordance with the rotation speed of the motor. A resolver signal outputted from a resolver 2 is converted to a digital value by an R/D converter 3, and inputted to a computing circuit of resolver value correction 5 via an R/D conversion interface 4. A current value of a motor M is converted to a digital value by an A/D convertor 8. The computing circuit of resolver value correction 5 computes a resolver correction value of the inputted digital signal and calculates positional data from a corrected resolver value. The computing circuit of motor control computes a current instruction value from a motor current value subjected to digital conversion by the A/D converter 8 and a motor current instruction value etc.

Abstract: The position of a rotor of a motor is determined. The motor includes a stator having a plurality of coils. The rotor includes at least one rotating magnetic field device. When the rotor is moving below a threshold speed, the current in the coils is measured. A pre-programmed data structure is accessed. The data structure stores stator currents associated with predetermined rotor positions. A first absolute position of the rotor is determined from the data structure according to the measured current from each of the coils. When the rotor is moving above the threshold speed, one or more rising or falling edges of magnetic field strength associated with the at least one rotating magnetic field device are sensed. At least one timing aspect of the rising and falling edges of magnetic field strength are compared to determine a second absolute position of the rotor.

Abstract: There is provided a motor control system and motor control method which can shorten settling time by restraining vibration and deviation relative to an advancing direction during operation. Moreover, according to the present invention, it is possible to cause a motor to be operated with an ideal track and, since it is possible to always monitor a present position, it is made easy to cause a plurality of axes to be synchronously operated. The motor control system is provided with a unit generating command waveforms from a jerk data which has significant effects on the vibration relative to the advancing direction, and a unit performing a real time real position control of regenerating future command waveforms according to a deviation amount, while always performing jerk-limit, whereby the vibration and the deviation relative to the advancing direction when the motor operates at high speed are restrained.

Abstract: A method and an arrangement for determining the rotation speed of a motor fed by an inverter, the arrangement comprising means for determining the rotation speed of the motor in at least two alternative manners, whereby the means for determining the rotation speed of the motor comprise one of the at least two alternative manners of performance: means for measuring the frequency of the voltage fed to the motor by the inverter; and means for estimating the rotation speed of the motor on the basis of the measured frequency.

Abstract: An electric motor drive control apparatus includes a detection angle obtaining section that obtains the detection angle of the resolver; a correction information storage section that stores correction information for correcting the detection angle, in association with a modulation ratio that is a ratio of an effective value of a fundamental wave component of the AC voltage to the system voltage; and a detection angle correcting section that obtains the correction information from the correction information storage section, based on the modulation ratio at the time the detection angle obtaining section obtains the detection.

Abstract: A resolver includes a disc-shaped rotor provided with a detection coil pattern formed in flat shape and a stator formed in flat plate shape placed to concentrically fact the rotor in an axial direction and configured such that a planar first excitation coil pattern to which a cosine wave is supplied and a planar second excitation coil pattern to which a sine wave is supplied, the first and the second patterns being laminated. The first and second excitation coil patterns are placed to face the detection coil pattern. An insulation layer is formed with insulating coating material between the first and second excitation coil patterns.

Abstract: The rotation angle detection device detects the rotation angle of a rotary member by employing, at the least, either a sine wave signal or a cosine wave signal that is generated as the rotary member is rotated, and employs a change per unit time in the sine wave signal or cosine wave signal to determine whether an output abnormality has occurred in the rotation angle detection device. Further, this rotation angle device is employed to detect the motor angle of an electric power steering apparatus.

Abstract: A variable speed drive for an electric motor has an inverter for receiving pulse width modulation controls. The inverter communicates power signals to a poly-phase electrical motor. A resolver communicates signals from the poly-phase motor back to a motor control. The motor control includes a speed control, a field-oriented control, and a pulse width modulation drive for driving the inverter. The resolver is connected to the speed control and to the field-oriented control, and further communicates with a synchronous compensator. The synchronous compensator is configured to drive the harmonic content at a target frequency or frequencies in a selected signal towards zero over time.

Abstract: A control device for a travel motor mounted to a vehicle has a resolver which works as a rotation-angle sensor. The control device has a RDC which calculates a rotation-angle output value ? based on rotation detection signals Sa, Sb transferred from the resolver. The control device supplies electric power to the travel motor based on the rotation angle output value ?. The RDC calculates “sin(???)” as an error deviation ? based on the signals Sa and Sb and the rotation-angle output value ?. The RDC calculates an angular acceleration by multiplying the error deviation ? with a gain (=Ka·Kb), and integrates the angular acceleration two times in order to obtain a next rotation-angle output value. A gain control part of the RDC decreases the gain when the judgment means judges that the travel motor rotates at a constant rotation speed.

Abstract: Methods and apparatus are provided for deriving precision position and rate information for motors using relatively low precision analog sensors, and for implementing compensation techniques that overcome inherent sensor errors and rotor magnet flux tolerances.

Abstract: A fault-tolerant position feedback filter may be used in an actuation control system to limit the authority of a first position signal, should the first position signal become erroneous, and thereby prevent a postulated runaway condition of an acuator. The filter includes a difference function, a limited integrator, and a summer. The difference function supplies a first position error signal representative of a mathematical difference between a first position signal and a combined position signal. The limited integrator supplies an integrated position error signal that is limited in magnitude to a predetermined limit. The summer supplies the combined position error signal that is representative of a mathematical sum of the integrated position error signal and the second position signal.

Abstract: An apparatus, system, and method are provided for simulating outputs of a resolver. One apparatus includes an adjustable sine waveform generator for simulating first and second sine wave signals, and an adjustable cosine waveform generator for simulating first and cosine wave signals. The apparatus also includes an adjustable waveform generator and an adjustable gain circuit coupled to the sine waveform generator and cosine waveform generator. The system includes a device simulating a resolver coupled to a motor controller. The device includes an adjustable sine waveform generator and an adjustable cosine waveform generator coupled to an adjustable waveform generator and an adjustable gain circuit. One method includes transmitting a signal simulating at least one resolver fault condition to a motor controller to determine if the motor controller detects the fault condition(s).

Abstract: A motor controller includes a reference signal generator; an A/D converter performing A/D conversion of the cosine and the sine signals outputted from a resolver; a first amplitude calculator calculating cosine and sine signal amplitudes based on twice-A/D converted cosine and sine signals respectively; a second amplitude calculator calculating averages of the cosine and the sine signals, and that calculates the amplitude of the cosine signal from a difference between the cosine signal average and a latest A/D converted cosine signal, and that calculates the amplitude of the sine signal from a difference between the sine signal average and a latest A/D converted sine signal; a synthesizer synthesizing the cosine and sine signal amplitudes obtained by the first and the second amplitude calculators respectively; a rotational angle calculator calculating a rotational angle based on the synthesized cosine and sine signal amplitudes; and a PWM controller.

Abstract: Apparatus and methods are provided for diagnosing faults in multiple, associated motor-resolver systems. One apparatus includes a swapping circuit coupling a first resolver to a first or second decoder, and a swapping circuit coupling a second resolver to the first or second decoder. One method includes applying a signal from a resolver to a first decoder to determine that the first decoder is malfunctioning if the first decoder continues to generate a fault signal, and applying a signal from a different resolver to a second decoder to determine that a motor associated with the first decoder is malfunctioning if the second decoder generates a fault signal. Another method includes transmitting a signal from a resolver to first and second decoders, transmitting a signal from a different resolver to the first and second decoders, and determining if the first decoder, second decoder, a first motor, or a second motor is malfunctioning.

Abstract: A position-measuring device having integrated function testing includes a position-recording unit, a processing unit, and a control-word generator. In a positional-data request, a positional-data word is first generated in the position-recording unit and output to the processing unit. There, the position data word is processed into a position value. Subsequently, a control-data word is generated in the position-recording unit according to the specification of the control-word generator and output to the processing unit. The processing unit processes the control-data word into a control value which has a defined mathematical relationship to the position value.

Abstract: In an inspection procedure of a completed product of an automatic transmission main body at a unit factory, a control system transmits a control signal to an actuator to receive characteristic data (hardware performance information) output in response to operation of the automatic transmission main body according to the control signal. The hardware performance information of the automatic transmission main body is brought into correspondence with hardware identification information, and set in a database as learning value data. The learning value data of the automatic transmission main body is transferred to a vehicle factory to be aggregated in a database management system at the vehicle factory.

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: In accordance with an embodiment of the present invention, a resolver system has at least one resolver and at least one amplifier in electrical communication with each resolver. A reference circuit is in electrical communication with the amplifiers. The reference circuit provides reference signals to the amplifiers. A non-linearity calibration and compensation circuit in communication with each amplifier uses the amplified reference signals to provide scale factors, so as to enhance a precision of the resolver system.

Abstract: A motor controller includes a reference signal generator; an A/D converter performing A/D conversion of the cosine and the sine signals outputted from a resolver; a first amplitude calculator calculating cosine and sine signal amplitudes based on twice-A/D converted cosine and sine signals respectively; a second amplitude calculator calculating averages of the cosine and the sine signals, and that calculates the amplitude of the cosine signal from a difference between the cosine signal average and a latest A/D converted cosine signal, and that calculates the amplitude of the sine signal from a difference between the sine signal average and a latest A/D converted sine signal; a synthesizer synthesizing the cosine and sine signal amplitudes obtained by the first and the second amplitude calculators respectively; a rotational angle calculator calculating a rotational angle based on the synthesized cosine and sine signal amplitudes; and a PWM controller.

Abstract: A method of arranging a resolver comprises the steps of: a, setting stator magnetic poles number of the resolver Ns as a number being in integral multiples (t) of a phase number q; b, figuring out rotor magnetic pole number Nr based on a formula; c, arranging the stator and the rotor based on the stator magnetic poles number of the resolver Ns and the rotor magnetic pole number Nr, and producing signals with phase differences.

Abstract: A method of designing a reluctance resolver, and the resolver comprises a stator and a rotor, and an exciting coil and two sets of outputting wires wind around the tooth portion of the stator. The designing method comprises the following steps: fixing relative position; calculating the turn ratio of the stator; winding the coil of the stator; and designing the resolver. And the resultant resolver can improve the precision of calculating the position of the motor rotor.

Abstract: The present invention relates to an apparatus and method for generating digital electrical signals which are representative of the angular position and rotational velocity of a rotatable shaft or similar movable mechanical component in a servomechanism. In particular, the present invention utilizes oversampling techniques to create an accurate, flexible and responsive method for determining shaft position on a high speed motor. The present invention also includes methods for overcoming deadtime losses and velocity lag.

Abstract: A motor control apparatus for controlling a motor based on an output from a sensor includes a storage unit storing a value according to an excitation power supply to excite the sensor, a PWM output unit outputting a PWM output signal having a pulse width modulated to have a duty ratio corresponding to a value stored to the storage unit, and a filter input with the PWM output signal from the PWM output unit. The sensor is supplied with the excitation power supply based on an output from the filter.

Abstract: This invention provides methods for electric vehicle motor control and rotor position detection and fault-tolerant processing. The rotor position signal sampled by the system is compared with the previous rotor position ?0. When there is a sudden change, the current position signal acquired is discarded. Instead, a fault-tolerant processing strategy for use during an error condition is employed where the previous sampled rotor position ?0 is used as a base to determine the corrected current rotor position angle ?1?. Then the correcting value is used to control the electric motor.

Abstract: In accordance with an embodiment of the present invention, a resolver system has at least one resolver and at least one amplifier in electrical communication with each resolver. A reference circuit is in electrical communication with the amplifiers. The reference circuit provides reference signals to the amplifiers. A non-linearity calibration and compensation circuit in communication with each amplifier uses the amplified reference signals to provide scale factors, so as to enhance a precision of the resolver system.

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 electric drive apparatus has an electric motor having a rotor and a stator; and a magnetic pole position detecting portion having a sensor rotor attached to the rotor, and a sensor stator that is adjacent to the stator, and that is fixed to a case, and that extends over a partial region of the sensor rotor extending in a circumferential direction. Because the sensor rotor of the magnetic pole position detecting portion is attached to the rotor and the sensor stator is adjacent to the stator and is fixed to the case, it is no longer necessary to use an all-round embracing type magnetic pole position detecting portion that embraces the entire shaft of an electric machine.

Abstract: A system for controlling an electric motor includes a controller and a position indicator that provides position information regarding at least one motor component to the controller. The controller utilizes phase relationships indicative of the position information to determine the actual position of the component of interest. The phase information in one example is derived from the output of a resolver that provides two output signals corresponding to sin (?) and cos (?), where ? is the angular position. Utilizing the phase relationship simplifies the task of determining accurate position information that is useful to modify motor control signals to compensate for latency when making position determinations, velocity calculations or both. The inventive system makes it possible to use less expensive electronics to arrive at more reliable results.

Abstract: Control over velocity of a model train may be determined based upon the speed of rotation of a control knob. A processor receives electronic pulses indicating rotation of the knob beyond a predetermined increment of angular distance. The processor calculates the amount of power ultimately conveyed to the model train based not only upon the number of pulses received, but also upon the elapsed time between these pulses. The shorter the elapsed time between pulses, the greater the change in power communicated to the train. Initially, a user can rapidly rotate the knob to attain coarse control over a wide range of velocities, and then rotate the knob more slowly to achieve fine-grained control over the coarse velocity. Utilizing the control scheme in accordance with embodiments of the present invention, in a compact and uninterrupted physical motion, a user can rapidly exercise both coarse and fine control over velocity of a model train.