Abstract: A control and drive assembly for a transport vehicle door, and which includes a main control unit; a main motor to drive the door leaves and which is controlled by the main control unit to displace the leaves; an auxiliary control module; an auxiliary motor operable to: control the auxiliary motor so as to displace the leaves in at least one direction to a closed position, control a locking of the leaves in the closed position; and a connection device arranged between the main control unit and the auxiliary motor to facilitate transmission of a reference signal by the main control unit to the auxiliary control module, the reference signal being representative of a proper operating state of the main motor and the main control unit. The auxiliary control module is operable to actuate the auxiliary motor when the auxiliary control module does not receive the reference signal.

Abstract: A vehicle driving apparatus includes: an engine; a fluid transmission device; first and second rotary electric machines; an output shaft for receiving a power transmitted through a first power transmission path and outputting the power to one of a pair of front wheels and a pair of rear wheels; and a control device for controlling an engine operation point by adjusting an electrical path amount between the first and second rotary electric machines. The second rotary electric machine outputs the power to the other of the pair of front wheels and the pair of rear wheels, through a second power transmission path. The control device obtains a target electrical path amount enabling the engine operation point to become a target operation point, and causes a speed change device provided in the second power transmission path to establish a gear ratio enabling the target electrical path amount to be attainable.

Abstract: Robotic drummers include voice coil actuators that are coupled to linear-to-rotary motion convertors to produce drumstick rotations so as to strike a drum head. Such rotations can be triggered via a microprocessor using stored performance data, by a user with a mouse, trackpad, joystick, or other user input device. Performances are enhanced by driving the VCA with drive signals have random variations associated with strike timing, amplitude, location, and speed. Multiple strikes are provided by reducing, eliminating, or reversing drumstick rotation with a corresponding drive signal upon detection of drumstick contact with the drum head.

Abstract: An apparatus is provided for controlling environmental conditions using a fan and a light in connection with a building having a space including a partition, such as a wall. The apparatus may include a control adapted for being mounted to the partition and for coordinating the control of the fan and the light based on a sensed condition, such as temperature or occupancy. Groups of like devices for controlling environmental conditions may be similarly controlled, such as using control. Control may also provide an indication of an operational state of the device(s) controlled by it, or provide for control based on a preference of one or more people upon detecting their presence. Related methods are also described.

Abstract: An active vibration noise control system is applied to a vehicle provided with an EPS motor to change behavior of the vehicle. The active vibration noise control system includes an ANC processor configured to receive acoustic information at a predetermined position in a vehicle compartment as an error signal and control a vibration noise based on a reference signal correlate with the vibration noise and the error signal that is received and an inverse electromotive force information receiving section receiving information on an inverse electromotive force induced on the EPS motor by behavior change of the vehicle. The ANC processor utilizes as a reference signal the information on the inverse electromotive force received by the inverse electromotive force information receiving section. The active vibration noise control system actively controls the vibration noise generated in the vehicle.

Abstract: Method and apparatus are disclosed for accelerometer-based windshield wiper monitoring. A vehicle includes an accelerometer affixed to a vehicle window, a windshield wiper to actuate across the vehicle window, and a processor. The processor is configured to determine an acoustic profile corresponding to the windshield wiper based on structure-borne audio data received from the accelerometer, determine whether a bandlimited decibel level of the acoustic profile exceeds a threshold, and responsively provide an alert via a vehicle display.

Abstract: The disclosure relates to a centrifuge with a balancing mechanism and method of balancing such a centrifuge. The centrifuge includes a vertical shaft driven in rotation by a motor, and a mechanism for balancing the parts integral with said vertical shaft. The mechanism includes a plate integral with the vertical shaft, at least one compensating mass freely displacing on the plate, the mass being designed to limit the imbalance of parts integral with the vertical shaft, and a mechanism for blocking the compensating mass, the blocking mechanism being designed to immobilize the compensating mass on the plate when the rotation speed exceeds a determined value.

Abstract: An information handling system includes a pressure transducer and a fan controller. The pressure transducer produces a pressure reading in response to airflow through the information handling system. The fan controller is configured to communicate with the pressure transducer, the fan controller to operate a fan of an information handling system at a first duty cycle, to receive a first pressure reading from the pressure transducer, to determine a first airflow amount for the first duty cycle based on the first pressure reading, to create a first updated airflow-duty cycle table based on the first airflow amount at the first duty cycle, and to update a temperature control algorithm based on the first updated airflow-duty cycle table.

Abstract: In a method for machining a workpiece using a tool, the tool engages with the workpiece and between the two a cutting motion is induced. Furthermore, a relative first vibration motion between workpiece and tool, which is superimposed on the cutting motion, is induced in such a way that one or more characteristic values of the first vibration motion and one or more characteristic values of the cutting motion are adjusted in relation to one another. The superimposed vibration motion can also be induced in such a way that distinctive surface zones of the workpiece are generated.

Abstract: A gas treatment machine includes a main gas treatment circuit, connected to a gas compression chamber, a gas compressor, mounted in the compression chamber, a rotating electrical machine, for driving the gas compressor, including at least one coil for the flow of electric current for generating a magnetic flux, and a secondary cooling circuit, transporting gas from the compression chamber to the rotating electrical machine, for cooling this rotating electrical machine. The coil includes at least one toroidal core formed from a rolling of a plurality of turns (20) each consisting of at least one conductor (22) insulated over the length thereof by a primary insulator (24), the rolling which forms the toroidal core in turn being covered with a secondary insulator (26), the primary insulator (24) and the secondary insulator (26) including PolyEtherEtherKetone.

Abstract: A powertrain system includes an engine coupled to a multi-mode transmission configured to transfer tractive torque to an output member coupled to a ground wheel. A method for operating the powertrain system includes identifying an undesirable operating region for the multi-mode transmission associated with driveline growl including an input torque range and an output torque range. In response to a command to traverse the undesirable operating region from a first operating region to a second operating region, a fast engine torque transition is executed including controlling the engine as a fast-adjusting torque actuator to control input torque from the engine to the multi-mode transmission and correspondingly controlling motor torque from a torque machine to the multi-mode transmission to maintain output torque from the multi-mode transmission responsive to an output torque request while traversing the undesirable operating region from the first operating region to the second operating region.

Abstract: A method for suppression of vibration includes: adjusting a center frequency of a band-pass filter, and subjecting a to-be-detected signal to processing by the band-pass filter to result in a bandpass-filtered signal; performing signal processing upon the bandpass-filtered signal to obtain a converted result; determining whether a scanning process is completed, and repeating the previous two steps when a result is negative to obtain plural converted results; determining a maximum value among the converted results, and determining the corresponding center frequency to serve as an interference frequency; and setting the interference frequency as an operating frequency of a notch filter.

Abstract: Provided is an apparatus for controlling speed in induction motor in which tension command and friction loss compensation are used to calculate a torque limit relative to an output of a speed controller, which is then used to limit the speed of the induction motor, whereby a tension sensor and a position sensor are not used in the continuous processing line to improve performance of the vector control type induction motor.

Abstract: A fan array vibration control system may include a fan array having a plurality of fans, and a control unit operatively connected to the fans. The control unit is configured to operate the plurality of fans and detect a phase relationship among the plurality of fans. The control unit is configured to reduce the phase relationship among the plurality of fans in order to reduce vibrations within the fan array.

Abstract: A method for operating an electrical machine having a stator 1 with a coil from electrical conductors, which has two coil ends 2 lying opposite each other. The method includes simultaneously recording vibration measurements by means of which the elliptic vibration modes of the two coil ends 2 can be determined as a factor of time; determining the ellipse inclinations and the phase positions of elliptic vibration modes of the two coil ends 2; determining critical operating states of the electrical machine, in which the elliptic inclinations and the phase positions of the elliptic vibration modes of the two coil ends are substantially identical; and operating the electrical machine in such a manner that the critical operating states can be avoided by varying the idle power of the electrical machine.

Abstract: A linear actuator driving device is provided. The linear actuator driving device includes an electromagnetic driving unit which makes a moving element reciprocate in response to a driving command and an offset correcting unit which corrects the driving command to carry out offset energization to make the center of reciprocation of the moving element be moved in the direction in which deviation between the center of reciprocation of the moving element and the center of the movement possible range is eliminated. The offset correcting unit is configured such that the amplitude information is acquired and, with respect to the amplitude value corresponding to the acquired amplitude information, if the movable amplitude is in a movable area insufficient condition, correction of the driving command is performed and, on the other hand, if the movable amplitude is not in the movable area insufficient condition, correction of the driving command is released.

Abstract: A drive system for a grid blower of a vehicle is provided. The system includes: an electrical bus, a grid of resistive elements connected to the electrical bus, the grid of resistive elements configured to thermally dissipate electrical power generated from braking of the vehicle, the electrical power being transmitted on the electrical bus to the grid of resistive elements, an electrical power modulation device configured to modify electrical power received from at least one of the electrical bus and the grid of resistive elements, and a grid blower motor coupled to an output of the electrical power modulation device, wherein a speed of the grid blower motor varies based on the electrical power that has been modified by the electrical power modulation device.

Abstract: Vibration protection in a compressor system with a variable speed compressor may include operating a variable speed compressor of a compressor system at a first frequency, measuring a vibration of the compressor system at the first frequency, determining whether the vibration exceeds a maximum vibration value, and operating the variable speed compressor at an average frequency equivalent to the first frequency, when the vibration exceeds the maximum vibration value, by identifying an allowed upper frequency and an allowed lower frequency, calculating an upper operating time and a lower operating time, and operating the variable speed compressor at the allowed upper frequency for the upper operating time and the allowed lower frequency for the lower operating time.

Abstract: A with a converter controlled drive includes a rotor, a drive having a variable rotational frequency a working machine and a frequency converter. The drive and the working machine are connected to one another such that a torque is transmitted. The frequency converter is electrically connected to the drive and converts input frequencies to output frequencies. The output frequencies are grouped into a plurality of concentration ranges based upon a rotational speed of the machine. Each concentration range defines a blocking range. The machine has an operating rotational speed range which lies outside the blocking ranges.

Abstract: Systems and methods for estimating an inertia and a friction coefficient for a controlled mechanical system are provided. In one or more embodiments, an inertia estimator can generate a torque command signal that varies continuously over time during a testing sequence. The velocity of a motion system in response to the time-varying torque command signal is measured and recorded during the testing sequence. The inertia estimator then estimates the inertia and/or the friction coefficient of the motion system based on the torque command data sent to the motion system and the measured velocity data. In some embodiments, the inertia estimator estimates the inertia and the friction coefficient based on integrals of the torque command data and the velocity data.

Abstract: A fan array vibration control system may include a fan array having a plurality of fans, and a control unit operatively connected to the fans. The control unit is configured to operate the plurality of fans and detect a phase relationship among the plurality of fans. The control unit is configured to reduce the phase relationship among the plurality of fans in order to reduce vibrations within the fan array.

Abstract: A motor-drive circuit includes: a filter circuit to attenuate a frequency band including a resonance frequency of an actuator in a target-current signal, the target-current signal corresponding to a digital signal indicative of a target value of a driving current; a digital-analog converter to convert an output signal of the filter circuit into an analog signal, to be outputted as a current-control signal; and a driving circuit to supply the driving current to the voice-coil motor in accordance with the current-control signal, the filter circuit including: a digital notch filter; and a digital low-pass filter, wherein either one of the digital notch filter and the digital low-pass filter configured to be inputted with the target-current signal, the other one of the digital notch filter and the digital low-pass filter configured to be inputted with an output signal of the one of the digital notch filter or the digital low-pass filter.

Abstract: When failure of an inverter or a coil set of one system of a motor drive apparatus having two systems, is detected, a power supply relay of the failing system is interrupted. At the same time, a control circuit sets a same maximum current limitation value as set before detection of failure. When an IG switch is in an ON-state and a steering toque detection value exceeds a predetermined threshold value thereafter, a vibration component, which has a predetermined amplitude and frequency, is added to a current command value so that a steering wheel is vibrated in a direction of rotation so that a driver is cautioned to notice the failure surely.

Abstract: In a method and module for controlling rotation of a motorized spindle driven by a driving unit, a sensing unit senses vibration of the spindle and generates a voltage signal corresponding to the vibration of the spindle. A processing unit receives the voltage signal from the sensing unit, generates an adjusting ratio equal to a reference voltage corresponding to a predetermined vibration level of the spindle by the voltage signal upon detecting that the voltage signal is greater than the reference voltage and is less than a predetermined threshold voltage that is greater than the reference voltage, and outputs a control signal corresponding to the adjusting ratio to the driving unit such that the driving unit reduces a rotation speed of the spindle by the adjusting ratio in response to the control signal from the processing unit.

Abstract: A method of actuating a system comprising a movable component and an actuator configured to move the movable component comprises providing a control signal representative of a desired motion of the movable component. The control signal is supplied to one or more resonators. Each of the one or more resonators has a mode of oscillation representative of at least one elastic mode of oscillation of the system. The control signal is modified by subtracting from the control signal a signal representative of a response of the one or more resonators to the control signal. The actuator is operated in accordance with the modified control signal. Thus, undesirable elastic oscillations of the system which might occur if the system were operated with the original control system can be reduced.

Abstract: A control system of a milling machine is disclosed. The milling machine has an overarm, a spindle connected to a cutter, a spindle motor, and an X-axis motor, a Y-axis motor and a Z-axis motor. The control system includes a vibration sensor for detecting a vibration level of the spindle. The control system also includes a central control unit configured to adjust a rotation speed of at least one of the X-axis motor, the Y-axis motor, and the Z-axis motor to bring a load current of at least one of the motors to be within a corresponding current range, and configured to adjust a rotation speed of the spindle motor to bring the vibration level to be within a vibration range.

Abstract: An electric machine including a housing, a stator mounted within the housing, a rotor rotatably mounted within the housing relative to the stator, and a vibration sensor arranged within the housing. The vibration sensor includes a sensing member configured and disposed to detect vibrations of the electric machine.

Abstract: An assembly is provided for receiving characteristic data of a mill including a rotating mill sleeve having rotor coils and a stator having stator coils, wherein oscillations of the mill sleeve are transmitted to stator coils and/or measurement coils on the stator. The assembly may include stator coil(s) configured to tap power supply induction voltages to detect oscillations of the mill sleeve, wherein the stator coil(s) and/or measurement coil(s) designed to tap induction voltages are positioned in a sector of the mill sleeve in which large oscillations are expected based on the scale of the mill sleeve. Further, a method includes determining the induction voltage induced on stator coil(s) and/or measurement coil(s) by tapping at least one stator coil power supply and/or by tapping at least one measurement coil, and deriving status variable(s) of a milling method that reflect the fill level status in the sector of the respective coil.

Abstract: A touch control arrangement is arranged for a container having a foldable cover being folded between an opened position and a closed position via an actuation unit. The touch control arrangement includes a power source and a touch actuator electrically linked to the power source, wherein the touch actuator is located out of the storage cavity of the container body and is arranged in such a manner that when the touch actuator is activated by a presence of a touch, the actuation unit is actuated to move the foldable cover from the closed position to the opened position.

Abstract: An electrically driven mooring winch is provided. The mooring winch includes a winding drum, an AC motor configured to drive the winding drum, a frequency conversion unit connected to the AC motor, and a control unit configured to control the frequency conversion unit on the basis of an indicator for tension of the mooring rope. The control unit is configured to set a reference value of rotational speed of the AC motor to a predetermined value, drive the AC motor in one direction for a predetermined time interval, define a first value of a torque of the AC motor, drive the AC motor in an opposite direction for the predetermined interval, define a second value of the torque of the AC motor, and compute a torque estimate using the first and second values of the torque.

Abstract: Automated shade systems comprise motorized window coverings, sensors, and controllers that use algorithms to control operation of the automated shade control system. These algorithms may include information such as: 3-D models of a building and surrounding structures, shadow information, reflectance information, lighting and radiation information, ASHRAE clear sky algorithms, log information related to manual overrides, occupant preference information, motion information, real-time sky conditions, solar radiation on a building, a total foot-candle load on a structure, brightness overrides, actual and/or calculated BTU load, time-of-year information, and microclimate analysis.

Abstract: A method is disclosed to increase a rotation speed of a spindle motor, which comprises: setting a predetermined rotation speed; increasing the rotation speed of the spindle motor to the predetermined rotation speed; recording a critical rotation speed of the spindle motor; decreasing the rotation speed of the spindle motor to the critical rotation speed and remaining at the critical rotation speed for a predetermined time; and increasing the rotation speed of the spindle motor to the working rotation speed for eliminating vibration noise.

Abstract: The described embodiments relate generally to control of rotational components in a computer system. In one embodiment, the rotational component includes a cooling fan, the cooling fan being controlled in accordance with data tailored to reduce the acoustic noise produced by the cooling fan. In one embodiment, the cooling fan is operated with non-uniform pulse width modulated signals. The non-uniform pulse width modulated signals can be a function of desired rotation speed and can include fundamental and harmonic components.

Abstract: The present invention relates to synchronized vibration devices that can provide haptic feedback to a user. A wide variety of actuator types may be employed to provide synchronized vibration, including linear actuators, rotary actuators, rotating eccentric mass actuators, and rocking mass actuators. A controller may send signals to one or more driver circuits for directing operation of the actuators. The controller may provide direction and amplitude control, vibration control, and frequency control to direct the haptic experience. Parameters such as frequency, phase, amplitude, duration, and direction can be programmed or input as different patterns suitable for use in gaming, virtual reality and real-world situations.

Abstract: The present invention relates to synchronized vibration devices that can provide haptic feedback to a user. A wide variety of actuator types may be employed to provide synchronized vibration, including linear actuators, rotary actuators, rotating eccentric mass actuators, and rocking mass actuators. A controller may send signals to one or more driver circuits for directing operation of the actuators. The controller may provide direction and amplitude control, vibration control, and frequency control to direct the haptic experience. Parameters such as frequency, phase, amplitude, duration, and direction can be programmed or input as different patterns suitable for use in gaming, virtual reality and real-world situations.

Abstract: Disclosed are methods and devices for controlling the state of a fan of an electronic device during audio output based in whole or in part on loudness data of a digital audio file. An audio data file is sampled so that loudness data is determined from the sample audio data. The loudness data may indicate at least one portion of the audio data file that has a predetermined loudness level. For example, when the loudness data indicates that the audio output is low, the fan can be deactivated or slowed. In this way the noise of the fan does not impair the user's audio experience. Alternatively, when the loudness data indicates that the audio output is high, the fan can be activated or its speed may be increased. The predetermined loudness level of the audio output may have a value that is sufficiently high to mask fan noise.

Abstract: Disclosed is a system and method for reducing vibrations caused by a motor during braking of a vehicle, More specifically, the disclosed technique detects an actual rotational speed of a drive motor, calculates a target rotational speed of the drive motor by filtering the actual rotational speed, calculates a speed difference between the actual rotational speed and the target rotational speed, calculate an offset value by filtering the speed difference, calculate a speed vibration by deducting the offset value from the speed difference, and reduce the speed vibration of the motor by applying a compensated torque in an opposite direction of the speed vibration based on the calculated speed vibration.

Abstract: A method for operating an electric motor is provided, wherein a motor actuating signal is generated and transmitted to the motor. In order to reduce the noise generated by operating the motor, a suitable additional signal is generated and overlaid on the motor actuating signal when the motor actuating signal is transmitted to the motor.

Abstract: A control system of a milling machine is disclosed. The milling machine has an overarm, a spindle connected to a cutter, a spindle motor, and an X-axis motor, a Y-axis motor and a Z-axis motor. The control system includes a vibration sensor for detecting a vibration level of the spindle. The control system also includes a central control unit configured to adjust a rotation speed of at least one of the X-axis motor, the Y-axis motor, and the Z-axis motor to bring a load current of at least one of the motors to be within a corresponding current range, and configured to adjust a rotation speed of the spindle motor to bring the vibration level to be within a vibration range.

Abstract: Disclosed herein is a method of controlling a motor in an image reading apparatus. It may be possible to optimize the drive current of the motor for driving the movement of the scanning module by using information associated with, for example, the time it takes for the scanning module to return to a home or rest position after the scanning module is moved from the home position to a predetermined position. Such optimized drive current can result in improvements in the reading performance of an image by the image reading apparatus and reduction of power consumption.

Abstract: The disclosure relates to General Synchronized Vibration devices that provide haptic feedback to a user and improve the performance of existing vibratory devices. Different actuator types may be employed to provide synchronized vibration, including linear rotary actuators, rotating eccentric mass actuators including interleaved rotating mass actuators, and rocking mass actuators. A controller sends signals to one or more driver circuits to provide adjustment of vibration magnitude, frequency, and direction of the actuators. The system may apply forces onto an object, and a sensor measures a feature(s) of the object. This information is provided to a vibration device controller, which can then modify the vibration waveform to improve overall system performance. Fourier synthesis can be used to approximate arbitrarily shaped waveforms by controlling the phase and frequency of vibration actuators.

Abstract: A drive system for a grid blower of a vehicle is provided. The system includes: an electrical bus, a grid of resistive elements connected to the electrical bus, the grid of resistive elements configured to thermally dissipate electrical power generated from braking of the vehicle, the electrical power being transmitted on the electrical bus to the grid of resistive elements, an electrical power modulation device configured to modify electrical power received from at least one of the electrical bus and the grid of resistive elements, and a grid blower motor coupled to an output of the electrical power modulation device, wherein a speed of the grid blower motor varies based on the electrical power that has been modified by the electrical power modulation device.

Abstract: An electric machine including a housing, a stator mounted within the housing, a rotor rotatably mounted within the housing relative to the stator, and a vibration sensor arranged within the housing. The vibration sensor includes a sensing member configured and disposed to detect vibrations of the electric machine.

Abstract: A brushless motor system which can suppress adverse influences of electromagnetic noise without increasing the size and enhancing the performance of a filter circuit. In a brushless motor system comprising a brushless motor, an inverter, and a direct current power source, a noise return line for returning a noise current is connected between the brushless motor and the inverter. The noise current is generated in the inverter and reaches the brushless motor. With the provision of the noise return line, a common mode current leaking from the brushless motor to a ground can be reduced.

Abstract: A drive system for a grid blower of a vehicle is provided. The system includes: an electrical bus, a grid of resistive elements connected to the electrical bus, the grid of resistive elements configured to thermally dissipate electrical power generated from braking of the vehicle, the electrical power being transmitted on the electrical bus to the grid of resistive elements, an electrical power modulation device configured to modify electrical power received from at least one of the electrical bus and the grid of resistive elements, and a grid blower motor coupled to an output of the electrical power modulation device, wherein a speed of the grid blower motor varies based on the electrical power that has been modified by the electrical power modulation device.

Abstract: A system includes two counter-rotating electric fans. A cooling controller is configured to run the fans at first and second operating points responsive to a measured value of a parameter. The first and second operating points correspond to first and second different required volumes per unit time of air flow. Rotational speeds of the fans at the first and second operating points define first and second different rotational speed offsets.

Abstract: In a closure panel control apparatus, an ECU controls a rotational speed of an electric motor, which provides a drive force to drive a closure panel in an opening movement and a closing movement thereof. The ECU obtains a vehicle speed measured with a vehicle speed sensor and receives a command signal from a switch, which is operable by an occupant of a vehicle to command the opening movement or the closing movement of the closure panel. The ECU controls the rotational speed of the electric motor based on the measured vehicle speed that is obtained at the time of receiving the command signal from the switch.

Abstract: In a method and module for controlling rotation of a motorized spindle driven by a driving unit, a sensing unit senses vibration of the spindle and generates a voltage signal corresponding to the vibration of the spindle. A processing unit receives the voltage signal from the sensing unit, generates an adjusting ratio equal to a reference voltage corresponding to a predetermined vibration level of the spindle by the voltage signal upon detecting that the voltage signal is greater than the reference voltage and is less than a predetermined threshold voltage that is greater than the reference voltage, and outputs a control signal corresponding to the adjusting ratio to the driving unit such that the driving unit reduces a rotation speed of the spindle by the adjusting ratio in response to the control signal from the processing unit.

Abstract: A compensating system for compensating a cogging torque of a motor includes a speed measuring apparatus, a moment of inertia measuring apparatus, a rotor position sensor, a processor, a plurality of band-pass filters, and a current control apparatus. The processor receives a speed, a moment of inertia, and a rotor position of the motor, to determine the cogging torque of the motor. Each band-pass filter is arranged with a different frequency to filter different frequencies of waveforms of the cogging torque. The processor determines a Fourier transformation of the cogging torque according to a number of Fourier coefficients from the band-pass filters, a cogging torque at a preset rotor position, and a cogging current according to the Fourier transformation of the cogging torque. The current control apparatus outputs a current opposite to the cogging current, to compensate the cogging torque of the motor.

Abstract: A motor controller that outputs a drive signal to a direct-current brush motor to drive the motor is provided. The motor controller includes a drive signal generating section that generates the drive signal. The drive signal generating section generates the drive signal by superimposing on a direct-current voltage a compensation voltage for generating a compensation torque that can cancel rotation torque fluctuations in a no-load rotation state of the motor.