Abstract: Provided is a magnetic encoder device capable of detecting a rotating angle of an actuator having a cavity structure. The magnetic encoder device includes a ring-shaped rotating body 11, a ring-shaped permanent magnet 12 which is inscribed in and fixed to an inner circumferential side of the ring-shaped rotating body 11 and magnetized in a direction perpendicular to a center axis of the rotating body 11, and a fixed body 13 which is disposed on an inner circumferential side of the permanent magnet 12 through an air gap and has a circular circumference and a cavity, and a magnetic field detecting element 14 disposed on an outer circumferential side of the fixed body 13 through the permanent magnet 12 and the air gap.

Abstract: A drive system for a multi-phase brushless motor comprises a single current sensor drive circuit, including switch means, switchable between a plurality of states. A controller is arranged to provide pulse width modulated drive signals to control the switch means so as to control the time that the drive circuit switches between said states in each of a series of pulse width modulation periods, and to: determine a demanded voltage parameter set, identify PWM periods during which the demanded voltage parameter set is such that neither two nominal corresponding state times, nor a higher number of equivalent state times producing the same net voltage, in a single PWM period, would allow a predetermined minimum time to be spent in a predetermined number of active states sufficient for current sensing.

Abstract: Moderately accurate closed loop speed control of a universal motor is attained without the need for any type of speed sensor. Motor armature (across the brushes) voltage is sensed and supplied to a control circuit for processing along with sensed motor current and zero-crossing information. Integration of the motor armature voltage provides a value which is related to current motor speed. By adjusting the gating angle for triac actuation, the armature voltage integral can be maintained at a desired value associated with a desired motor speed. The sensed motor current is also integrated to provide a speed droop compensation value that is added to the desired value, and the gating angle for triac actuation is adjusted to move the armature voltage integral value to approach the summed value of the speed droop compensation value and desired value.

Abstract: A linear actuator comprising a spindle nut, where the spindle nut and the spindle between a first and a second point, indicating the length of stroke, can move axially in proportion to each other, depending on whether the spindle or the spindle nut is being driven around via the transmission, and where the position is determined with incremental position sensors, such as at least two Hall sensors or Reed-switches. For determining the position an initiating procedure, where the nut/spindle is moved from a first point on the spindle/nut to a second point on the spindle nut, is carried out, and that the number of pulses from the incremental position sensors appearing by it are registered as a measurement for the length of stroke, and the position is subsequently determined in relation to that. It is noted that the control is active before, during and after the operation of the motor.

Abstract: A motor control system uses an incremental encoder that provides a signal indicative of motor position. If an illegal state change is detected in the same sampling interval, an error event is recorded and an error counter is incremented. When the number of counts exceeds a pre-determined threshold, the motor is disabled so that appropriate corrective action can be taken.

Abstract: An integrated motor and position sensor achieves motion between a moving portion and a stationary portion by electrically energizing poles to interact with magnetics respectively on the moving and stationary portions. The position sensor includes a plurality of sensing coils placed to intercept the magnetic flux between a plurality of the poles and the magnetics. The outputs from these coils are fed to a microprocessor or DSP through an internal or external A/D converter. The microprocessor or DSP decodes the measured voltages using resolver strategies to produce a position, velocity or acceleration measurement.

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: Systems, methods, apparatus, computer readable mediums and propagated signals are provided for controlling the position, orientation, movement, configuration and/or operation of one or more window coverings, doors, vanes, filters or other apparatus. In one embodiment, a system is provided for controlling at least one of the position and orientation of a blind. The system includes a controller for operating a blind, at least one detector operably connected to the controller for simultaneously detecting position and orientation of at least one element of the blind, and at least one output device operably connected to the controller for controlling at least one of the orientation and position of the blind. The embodiments may also include or utilize at least one of a receiver program module, a device controller module, a timer program module and a system controller module which are utilized by a controller to control the operation of the blind.

Abstract: A motor control method includes the steps of: measuring a time period from an output of a drive detection signal to a next output of a drive detection signal; storing the measurement result at each time of output of a drive detection signal as a measured cycle; calculating a driven velocity of the driven object based on the stored measured cycle; calculating an operation amount of the motor such that the calculated driven velocity is equal to a predetermined target velocity. In the motor control method, it is determined, at each calculation timing, whether or not the driven object is in a low velocity state where an actual velocity is lower than the target velocity. When determined affirmative, calculation of the driven velocity of the driven object is performed based on a measured value being currently measured at the calculation timing in place of the stored measured cycle.

Abstract: A load tap changer (LTC) having a plurality of windings is coupled to one of the primary and secondary windings of a power transformer in order to regulate the output voltage of the power transformer. The LTC includes a plurality of taps physically and electrically connected to the LTC windings and the transformer's output voltage is increased/decreased by moving along the taps a contacting element whose movement is controlled by a rotating shaft driven by a motor. The tap being contacted is determined by sensing the direction and number of shaft rotations and by checking the number of shaft rotations specified to go from a tap to the next tap being contacted. The time for a full rotation of the shaft is also measured. Also, the temperature of the tanks containing the LTC taps and the power transformer is measured for each tap position.

Abstract: The electric supercharger includes a vehicle connector, an impulse signal generator empowered by a power source, and a signal amplifier. The vehicle connector has a positive terminal and a negative terminal for electrically connecting to an electrical source of said vehicle. The impulse signal generator, which is electrically linked to the vehicle connector for receiving an impulse signal from the electrical source of the vehicle, includes a signal integral circuit stably generating a rectangular impulse signal. The signal amplifier electrically connects to the impulse signal generator to amplify the rectangular impulse signal and to send the amplified rectangular impulse signal back to sparkplugs and injectors of the vehicle through the vehicle connector for enhancing a combustion-efficiency of an engine of the vehicle.

Abstract: Some embodiments of the present invention provide an anti-collision device used for a sample-loading system. This device may include a code plate, an optical coupler, a location signal-detecting unit, a drive pulse counting unit and a drive pulse-sending unit. The optical coupler detects the code plate during the relative movement between the optical coupler and the code plate and outputs detection signals. The location signal detecting unit determines whether to output location signals to the drive pulse counting unit. The drive pulse counting unit judges whether collisions occur to the sample-loading system. Some embodiments of the present invention provide an anti-collision method and a sample-loading system comprising the anti-collision device.

Abstract: In a transport belt drive control device, a first detection unit has a first resolution and indirectly detects a feed amount of a transport belt, a control unit controls drive of the transport belt based on an output of the first detection unit, and a second detection unit has a second, lower resolution and directly detects the feed amount of the transport belt. The control unit is configured to switch, when an output of the second detection unit is determined as not allowing detection of a stop position of the transport belt, the direct detection of the belt feed amount by the second detection unit to the indirect detection of the belt feed amount by the first detection unit, so that the drive of the transport belt is controlled based on the output of the first detection unit.

Abstract: A motor encoder is mounted on a motor shaft of a geared motor 1, and the origin position is detected by using a Z-phase signal. An absolute value encoder with a precision that allows the number of motor rotations to be determined is mounted on an output shaft 4 of a reduction gear, and the absolute rotational position thereof is detected. When the first Z-phase signal generated in conjunction with the rotation of the motor shaft 2a is obtained at startup and at other times, the mechanical starting point at which the motor shaft and output shaft are both positioned at the origin can be calculated based on the absolute rotational position of the reduction-gear output shaft obtained from the output-side absolute value encoder. Since the mechanical starting point is obtained by rotating the motor shaft a single rotation at most, the time required to calculate the mechanical starting point is short in comparison with conventional examples, and extraneous rotational movements can be avoided.

Abstract: A motor control method and device. The motor control device includes a programmable integrated circuit (IC) receiving a phase signal, the phase of which is consistent with the rotation phase of a coil of the motor. The programmable IC generates a duty-cycle signal in accordance with the period of the phase signal. The duty-cycle signal comprises a rising segment and a falling segment and when the phase signal changes phase, the duty cycle represented by the duty-cycle signal is a first duty cycle, allowing the input power of the motor remain at a minimum. The duty-cycle signal is input to the coil, controlling the coil on and off and, thereby rotating the motor.

Abstract: A method and an apparatus for estimating the position of a moving part of a linear actuator are provided. The method comprises the following steps. Move the moving part towards a target position. Receive magnetic signals generated by the magneto-resistive sensor of the linear actuator, which include a sine signal and a cosine signal. Then, generate a first square wave, a second square wave, and a regional square wave based on the sine signal and the cosine signal. Generate a saw-tooth wave based on the sine signal, the cosine signal, the second square wave, and the regional square wave. Next, calculate the number of regions which the moving part is across from the origin point based on the first square wave, the second square wave, and the regional square wave. Finally, estimate the current position of the moving part based on the saw-tooth wave and the number of regions.

Abstract: A pulse generator and method thereof. The pulse generator may include a first switching unit receiving a plurality of receiving a plurality of time interval indicators and a first selection signal. The first switching unit may select one of the plurality of time interval indicators in accordance with the first selection signal and may output the selected time interval indicator. The pulse generator may further include a second switching unit receiving a plurality of pulse states and a second selection signal. The second switching unit may select one of the plurality of pulse states in accordance with the second selection signal and may output the selected pulse state for a first time interval, where the first time interval may be determined by the selected time interval indicator.

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.

Abstract: Two standard waves from a standard waveform generation circuit are output via an output gate while being interchanged by a direction selector. The switching operation of the direction selector is controlled by a direction control signal M/I. 200 cycles of the standard waveforms are counted by a 200-cycle counter. A drive counter is downcounted every 200 cycles, while the drive counter is upcounted in accordance with the number of drive pulses DRIVE. When the count value of the drive counter becomes zero, output from the output gate is thereby stopped.

Abstract: Two standard waves from a standard waveform generation circuit are output via an output gate while being interchanged by a direction selector. The switching operation of the direction selector is controlled by a direction control signal M/I. 200 cycles of the standard waveforms are counted up by a 200-cycle counter. A drive counter is downcounted every 200 cycles, while the drive counter is upcounted in accordance with the number of drive pulses DRIVE. When the count value of the drive counter becomes zero, output from the output gate is thereby stopped. At the time of startup, outputs from the 200-cycle counter are counted so as to output a drive wave in a predetermined number in a predetermined direction.

Abstract: In rotating systems with angular references, angular- and/or time-based pulses must be generated which can be described in a generic manner to meet various requirements. The parameters for definition of the pulse are assigned as a value pair to permit more flexibility on definition of a pulse for generation, one value of which defines the type of the parameter, in other words, whether an angle, a time, or some other parameter is being defined. A calculation device can correctly assign the size value of the parameter using the additional value, interpret and carry out suitable subroutines to calculate the control values for controlling the relevant pulse generation circuits.

Abstract: A conveyance control apparatus controls an amount of movement of a carrier. A first encoder detects an amount of movement of the carrier and outputting a first signal. A second encoder detects an amount of movement of a drive member driving the carrier. A control part acquires an amount of movement of the carrier by complementing an amount of movement of the carrier acquired from the first signal by an amount of movement of the drive member acquired from the second signal. The control part corrects a value representing a corresponding relationship between the first signal and the second signal based on the complemented amount of movement so as to control the amount of movement of the carrier using the corrected value.

Abstract: A system and method of restarting a switched reluctance motor after a cycling of power provided to the motor is provided that includes receiving at the motor a power-off signal followed by a power-on signal, determining a rotational speed of a rotor, and energizing a stator only when the rotational speed of the rotor is determined to be less than a threshold speed.

Abstract: The invention aims to suppress or prevent the vibration that can occur due to the intervention of a low-rigidity part between detector and rotating body. An angular acceleration sensor for detecting the rotational angular acceleration of a rotating body is provided, and an angle/angular speed command value is compensated in accordance with the value of the angular acceleration.

Abstract: A method of generating pulses includes setting a cycle based on a frequency of reference clock, determining a total number of the pulses to be generated during the cycle, calculating the number of one or more first reference clocks used to determine a width of one or more first pulses, the number of one or more second reference clocks used to determine a width of one or more second pulses, a first pulse number for the first pulses and a second pulse number for the second pulses on the basis of the cycle and the total number of the pulses, and generating the first pulse number of the first pulse and the second pulse number of the second pulses during the cycle. A motor control system employs the above pulse generating method and a pulse generator using the method to improve accuracy of controllability of a motor by generating the total number of the pulses during a cycle, and decrease a manufacturing cost.

Abstract: A method for controlling the release of a brush motor which has applied a load includes several steps. One step includes applying a release current to the brush motor to rotate the brush motor in a direction toward releasing the applied load of the brush motor. Another step includes sensing the commutator bar ripple current of the brush motor. Another step includes determining when to remove the release current using at least the sensed commutator bar ripple current.

Abstract: A motor control method is provided in which a cycle between at least one of leading edges and trailing edges of a pulse signal is measured. The pulse signal is outputted from a pulse signal generator which generates a pulse signal every time a driven target is driven for a specified distance by a motor. A driving velocity of the driven target is calculated from the measured edge cycle. A manipulated variable of the motor is calculated such that the calculated driving velocity corresponds to a specified target velocity, and the motor is driven and controlled based on the manipulated variable. The driving velocity is replaced with a specified set velocity that is lower than the target velocity, when no output of edges from the pulse signal generator continues for and over a specified replacement determination time while the motor is driven and controlled.

Abstract: A correction value calculating method includes: preparing a printer including a motor, a PID control system for controlling the motor, and a memory for storing a correction value, the printer being configured to calculate a value of a current flowing through the motor based on the correction value and an output value of an integral element of the PID control system; obtaining in advance a relationship, for when a property of a motor fluctuates, between a correction value and a sum of an output value of the integral element when a motor is driven at a first velocity and an output value of the integral element when the motor is driven at a second velocity; driving the motor of the printer at the first velocity and measuring an output value of the integral element at that velocity; driving the motor of the printer at the second velocity and measuring an output value of the integral element at that velocity; and determining the correction value to be stored in the memory based on the relationship and a sum of the

Abstract: A resonant scanning mirror driver configured to drive a micro-electro-mechanical system (MEMS) mirror to a desired deflection utilizes a PWM pattern selected from patterns having a preset number of bits. The patterns reflect the first positive quarters of the PWM pattern and the remaining quarters are generated utilizing the symmetry of the sine wave that is generated. Patterns having a harmonic distortion less than a preselected maximum are sorted into amplitude bins and ranked to generate a subset of patterns having a linearly varying deflection amplitude.

Abstract: A print control system according to the present invention comprises: a paper rear edge holding/driving control part for driving and controlling a paper feed motor so that the rear edge of a paper, which is fed by the paper feed motor, is held in a predetermined holding region; a usual paper feed control part for controlling the paper feed motor so as to carry out a usual paper feed operation; and a control selecting part for selecting one of the paper rear edge holding/driving control part and the usual paper feed control part on the basis of the kind and feed amount of the paper and the presence of detection of the rear edge of the paper.

Abstract: A carrier signal generation section is provided for each of U, V, and W phases, and each of the carrier signal generation sections has an up-down counter for counting clock signals output from a clock generator. An initial value is set for each of the up-down counters. When the up-down counters are simultaneously started by method of a count start signal output from a CPU, the respective up-down counters start counting operations from the respective initial values, perform cumulative subtraction until the count value reaches an upper limit, and perform cumulative addition until the count value reaches a lower limit. As a result, triangular wave carrier signals Cu, Cv and Cw of respective phases having a predetermined phase difference can be readily generated with high accuracy.

Abstract: An interrupt signal is generated at each of rising timings of PWM signals which are produced on the basis of phase-shifted triangular wave carrier signals for phases, and voltage command values for the phases. At timings of the interrupt signals, A/D conversion of motor currents of the phases detected by a shunt is started. Interrupt signals are also produced at timings of valleys of the triangular wave carrier signals. Additionally, peak interrupt signals and valley interrupt signals are respectively produced at timings of peaks and valleys of triangular wave carrier signals for phases. Based on each of the peak interrupt signals, normality/abnormality of a switching element of an upper side of the phase corresponding to the interrupt signal is checked, and, based on each of the valley interrupt signals, normality/abnormality of a switching element of a lower side of the phase corresponding to the interrupt signal is checked.

Abstract: A pulse count accumulator includes a plurality of counters and a communication port. The plurality of counters are each coupled to a different one of a plurality of actuators and a value of each of the counters corresponds to a position of a corresponding one of the plurality of actuators. The communication port is in communication with the plurality of counters and provides the value of each of the plurality of counters to an external device through the communication port.

Abstract: A portable altitude/azimuth telescope mount having an integral locator system with a magnetic encoder mechanism for facilitating location of astronomical objects and telescope positioning for observation thereof. A microprocessor receives signals from the encoder mechanism and translates such into position data for display. The locator system also includes a database of astronomical objects, including their locations and other relevant information. The mount is preferably provided with a drive mechanism adapted to allow for automatically or manually positioning the telescope to view astronomical objects and for automatically repositioning or steering the telescope in order to track the astronomical objects during extended viewing. When moved manually, components of the drive act as a clutch mechanism that effectively disengages the drive motor to avoid damage. An instance of the drive may be provided for each axis of movement.

Abstract: A control device measures time intervals T1 to T12 from the reference time until when each of the rotational angles ?bn1, ?bn2 output from each of resolvers becomes n×60 degrees (n=1 to 12, i.e., 60 degrees to 720 degrees). Then, the control device calculates a deviation angle ??n at each of the rotational angles at the intervals of 60 degrees by calculating T1/T12 to T11/T12 using the measured T1 to T12. By substituting the calculated deviation angle ??n into an equation, n×60°+??n (n=1 to 11), the control device corrects the rotational angles at the intervals of 60 degrees. The control device generates each of drive signals DRV1, DRV2 using each of the corrected rotational angles, and outputs each of the drive signals DRV1, DRV2 to each of inverters. The inverters drive each of AC motors (M1, M2) based on each of the drive signals DRV1, DRV2.

Abstract: The invention relates to a circuit arrangement and a method for operating an electric motor in a direct voltage source, in particular for operating a permanent-magnet-excited DC motor in the direct voltage network of a motor vehicle, having a rotary position transducer (32) for detecting the rotary position of the rotor (20), and having an electronic commutation controller (32) for switching over the current in the armature winding of the stator (12) as a function of the position of the rotor (20). It is proposed that the rotary position transducer (32) is positioned relative to the stator (12) for an early commutation, and that the actual commutation time can be set by means of a delay correction, ascertained by measurement separately for each motor (10), in the electronic commutation controller (30).

Abstract: A method of regulating an electric motor, regulation being implemented with a loop of gain less than unity as a function of a divergence between a setpoint signal for an operating parameter of the motor and a measured value of the same operating parameter of the electric motor, the divergence being taken into account only if said divergence is greater than a predetermined threshold whenever the measured value is greater than the setpoint signal.

Abstract: A Hard Disk Drive VCM positioning servo loop comprises an oversampling bitstream Digital to Analog converter. The oversampling DAC is a sigma-delta converter which yields higher resolution and lower noise than Nyquist-rate DACs. This allows driving the VCM with finer level of current control for higher track density. This approach can be implemented in the VCM driver chip (“combo chip”) or in the microprocessor device either in hardware or in software, reducing significantly the development and manufacturing cost. Furthermore this approach can be utilized in combination with a VCM actuation method known as “voltage mode drive” wherein the output of the sigma-delta converter represents the voltage to be applied directly to the VCM actuator. Furthermore this approach can be utilized for optical data storage motor positioning servo loops or any other motor positioning servo loops where high dynamic and resolution is needed.

Abstract: A strategy to control and diagnose the operation of an electric motor using a sensorless control system augmented by feedback from a position and speed sensor is disclosed. The strategy can improve the robustness of operation and diagnose potential faults in electric motors. The present invention includes a method for diagnosing operation of an electric motor and a method and system for controlling an electric motor. In the diagnostic method, a sensorless system and a sensor based system are checked against each other to determine if either of the systems is faulted. In the control method, the sensor based control system is used when the motor speed is below a predetermined threshold and the sensorless system is used when the motor speed is above the predetermined threshold. The position sensor can be a low resolution position sensor, an engine crankshaft sensor, an engine camshaft sensor, or a transmission sensor.

Abstract: When a signal level of a motor brush switching signal is low and thus dropouts or omission of the pulse signals converted by a waveform shaping part take place, so that an interval between a pulse signal to be currently counted and an immediately preceding pulse signal thereof becomes longer than a predetermined average interval, a pulse signal counter makes a correction of the number of counts by adding one pulse to the pulse to be counted. Therefore, even if the signal level of the motor brush switching signals generated from a vertical motion motor M2 is low for some reasons, accurate control can be exercised over the number of rotations of the vertical motion motor M2.

Abstract: The invention concerns a method of regulating the current in a direct current machine with which are associated an arrangement for generating a current target value signal, as well as a PWM generator (FIG.

Abstract: A resonant scanning mirror driver configured to drive a micro-electro-mechanical system (MEMS) mirror to a desired deflection utilizes a PWM pattern selected from patterns having 32, 40, 48, 56 or 64 bits. The patterns reflect the first positive and negative quarters of the PWM pattern and the remaining quarters are generated utilizing the symmetry of the sine wave that is generated.

Abstract: In a method for controlling a physical variable in an electronically commutated motor, current is supplied to the stator winding arrangement (102) of the motor in the form of current blocks. The interval (BW) between the switch-on command and switch-off command for controlling those current blocks, i.e. the length (BW) of the control signals, is influenced by a control apparatus, and the effective current value of those current blocks is influenced by setting a pulse duty factor (pwm). The length of the control signals is limited in both directions. If a control signal becomes shorter than a specified lower limit, the pulse duty factor (pwm) is decreased, so that the effective value of the current falls and the length (BW) of the current blocks is increased by the control system. If a control signal becomes longer than a specified upper limit, the pulse duty factor is increased, so that the effective value of the current rises and the length of the current blocks decreases in compensatory fashion.

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: A rotation angle detecting apparatus for a synchronous rotary electric machine includes an incremental encoder. The incremental encoder generates an index pulse each time electric power is supplied to said plurality of phase-coils and an auxiliary index pulse each time the rotor rotates 360 degrees.

Abstract: A non-invasive apparatus and method for measuring the speed of a rotating device that includes a sensor that measures a dynamic characteristic of the rotating device. A sample of the signal is transformed from the time domain into a frequency spectrum. The frequency spectrum is then analyzed to determine the motor speed. The resulting motor speed can be combined with other motor data by an order analysis to identify malfunctioning or improperly installed components.

Abstract: A motor control apparatus which can improve detection accuracy of control information and stabilize a control system includes a detector for detecting first pulse information which corresponds to the drive speed of a driven object and second pulse information out of phase with the first pulse information; edge detectors for detecting rising edges and falling edges of the detected first pulse information and second pulse information; edge interval measuring units for measuring edge-to-edge periods using the detected rising edges and falling edges; a calibrator for calibrating the measured edge-to-edge periods with a reference period for driving the driven object at constant speed; a corrector for correcting the first pulse information and second pulse information based on the calibration; and a controller for generating control commands to drive the driven object based on the corrected first pulse information and second pulse information.

Abstract: A CPU sets an SPM driver in SPM start-up mode when a SPM is started up. At this time, a voltage selector applies, to a driver circuit, a voltage (high voltage) boosted by a voltage booster. A starter control circuit controls, during the period of an SPM start-up mode, the driver circuit with the high voltage applied thereto, thereby starting up the SPM. After the SPM has been started up, the CPU sets the SPM driver in PWM mode. At this time, the voltage selector switches the voltage applied to the driver circuit, from the boosted voltage to the voltage (low voltage) of a power supply. During the period of the PWM mode, a PWM circuit controls the driver circuit with the low voltage applied thereto, so as to rotate the SPM at a rated speed.

Abstract: In controlling a motor in a device which drives a mechanism using the motor as a power source, pre-driving of giving a predetermined driving parameter to the motor and driving the mechanism is executed. During the pre-driving, movement of the mechanism is monitored, and a command value to the motor, which is necessary for starting the mechanism, is obtained. Driving of the motor is controlled using feedback using the command value as the initial value of the driving parameter. High-speed accurate position control can be achieved independently of the individual difference in an object to be controlled and the frictional force of the mechanical portion or the difference in use environment.

Abstract: A electric motor control device is provided for controlling an electric motor which actuates a movable member of a machine through a transmitting mechanism. When a torque command is given as motion command signal (9) to servo device (3), servo device (3) sends input torque signal (12) corresponding to motion command signal (9) to electric motor (5), which is energized. Movable member (7) is thus moved, producing vibrations. Servo device (3) outputs input torque signal (11) equivalent to input torque signal (12), and input torque signal (11) and rotational speed signal (10) are stored in memory device (2). Analyzing device (1) analyzes the frequencies of input torque signal (11) and rotational speed signal (10) according to an FFT, and outputs analytical result (14).