Abstract: A system and a method for controlling torque of a motor are provided. The method includes modifying a phase advance angle based on an identified phase coil that has a faulted condition, a type of fault condition, and a polarity of a commanded torque to obtain a desired output torque from a motor.

Abstract: In an apparatus of controlling a motor in a battery vehicle, a current command generation section has a table, and generates an exciting command current and a torque command current by referring to the table based on a torque command. A converting section generates 3-phase command voltages from the exciting command current and the torque command current. A motor driving section drives a motor in response to the 3-phase command voltages.

Abstract: In a motor driving control device, a high-frequency alternating voltage or rotation voltage (having a frequency of ?h) is applied to a motor so that magnetic saturation occurs in the motor, thereby extracting, from a ?-axis current, a high-frequency second-harmonic component (a frequency component of 2×?h) that is obtained by attenuating at least a direct-current component of the ?-axis current. The polarity checker detects the polarity of the magnetic pole of the rotor based on the difference, caused by magnetic saturation, between the positive and negative amplitudes of the high-frequency second-harmonic component.

Abstract: The operation of an AC induction motor 24 is controlled in response to the actual slip exhibited by the motor during operation. The slip of the motor 24 may be determined by determining the actual running speed, n, of the motor shaft 25A, measuring the line frequency, ns, of the electricity supplied to the motor, and calculating the slip, S, of the motor using the relationship: S=((ns?n)/ns)*100. If the slip is too high when compared to a predetermined maximum acceptable slip, corrective action is taken to decrease the loading on the motor. If the slip is too low when compared to a predetermined minimum acceptable slip, corrective action is taken to increase the loading on the motor.

Abstract: In an electric vehicle drive apparatus having an electric motor and a motor drive device, the electric motor having a stator, a rotor and a moving mechanism capable of changing a relative distance between the stator and the rotor to vary an effective magnetic flux of the motor, the motor drive device compares a regenerative current with a target current during a regenerative control of the motor, and when it is found that the regenerative current is larger than the target current, the distance between the stator and the rotor is increased to reduce the effective magnetic flux.

Abstract: A controller of an electric motor for improving operation efficiency in performing electric conducting control of the electric motor of an axial air-gap type is provided.

Abstract: A controller performs processing for calculating a main torque control value, processing for outputting a final control torque value based on the main torque control value and a vibration-suppression torque control value for mitigating torque fluctuation that occurs when a rotating electric machine is operated at the main torque control value, and processing for calculating the vibration-suppression torque control value. The processing for calculating the vibration-suppression torque control value includes processing for calculating an original control value serving as a source of the vibration-suppression torque control value, processing for performing guard processing for restricting the original control value by using a vibration suppression guard value, and processing for smoothing an angular portion where rate of change is discontinuous, that is generated in the torque control value that has been subjected to the guard processing.

Abstract: A control unit controls a drive signal for determining a voltage to be supplied to the motor. A drive unit drives the motor by applying a current corresponding to the voltage determined based on the drive signal to the motor. The control unit includes a velocity detecting unit that detects a rotation velocity of the motor and an output unit that outputs the drive signal corresponding to a voltage with which a current lower than a predetermined current limit is applied to the motor, based on the rotation velocity of the motor detected by the velocity detecting unit.

Abstract: A microcomputer includes a calculating section calculating a d-axis electric current command value and a q-axis electric current command value and a signal generating section. The signal generating section generates a motor control signal through feedback control in a d-q coordinate system based on the d-axis electric current command value and the q-axis electric current command value. The microcomputer also has an anomaly determining section, which detects an anomaly if a failure of electric current flow has occurred in any one of phases of a motor. If the anomaly is detected, the microcomputer produces a motor control signal instructing to use, as electric current flowing phases, two phases other than the phase with the failed electric current flow.

Abstract: A submersible motor is provided for a submersible pump, the motor being configured as a single-phase asynchronous motor, which includes a main winding (6), an auxiliary winding (8), and a starting device (10, 14, 16, 18, 20, 22) for controlling the starting procedure of the submersible motor. The starting device for the control of the current feed of the auxiliary winding (8) includes at least one electronic switch (20) in the circuit of the auxiliary winding (8).

Abstract: Provided is a vector control apparatus for an induction motor which is capable of obtaining stable rotation in a short period of time for adjustment even at the time of low-speed operation by increasing the SN ratio of an output voltage to suppress the arithmetic error in the primary angular frequency arithmetic value based on a magnetic flux command value calculated from a circuit constant and an actual measurement of the induction motor even in the case where the rotation velocity of the induction motor is lower.

Abstract: A device for determining a constant of a rotating machine includes: a test number selector outputting a test number n, selected from 1 to N (N?2), and outputting a phase signal q determined by a predetermined condition that is previously set based on the test number n; a tester for supplying an alternating voltage to the rotating machine induction machine based on the test number n and the phase signal q and outputing a reference phase gain and a 90-degree-delay phase gain based on values of the phase signal q corresponding to 1 to N of the test number n; and a rotating machine constant calculator receiving the reference phase gain and the 90-degree-delay phase gain and then calculating a constant of the rotating machine using the reference phase gain and the 90-degree-delay phase gain.

Abstract: A motor control device is used to control a motor to rotate. The motor control device includes a phase-wave signal sampling module, a first waveform modulating module, a second waveform modulating module and a control signal integrating module. The phase-wave signal sampling module outputs a first phase-wave signal and a second phase-wave signal in accordance with the rotation of the motor. The first waveform modulating module generates a first control signal in accordance with the first phase-wave signal. The second waveform modulating module generates a second control signal in accordance with the second phase-wave signal. The control signal integrating module generates a rotation rate control signal in accordance with the first control signal and the second control signal, and inputs the rotation rate control signal to a drive module to control a rotation rate of the motor.

Abstract: The invention relates to a method for determining the angular position (theta) of a rotor (2) pertaining to an electric motor (1) and comprising a number of pairs of poles. Said method consists of the following steps: a pulse pattern (PM1, PM2, PM3) with a pulse duration (T) flows through at least one stator coil (7) of the electric motor (1), such that the rotor (2) does not rotate by more than 90 DEG, divided between the number of pairs of poles, during the pulse duration (T); the angular acceleration (alpha) of the rotor (2), caused by the pulse pattern flowing through the at least one stator coil, (7) is detected; and the angular position (theta) of the rotor (2) is determined by means of the correlation between the flow through the stator coil (7) and the angular acceleration (alpha) of the rotor (2).

Abstract: Systems and methods for controlling a rotating electromagnetic machine. The rotating machine, such as a permanent magnet motor or hybrid switched reluctance motor, includes a stator having a plurality of phase windings and a rotor that rotates relative to the stator. A drive is connected to the phase windings for energizing the windings. A controller outputs a control signal to the drive in response to an input demand such as a demanded speed or torque. Control methods (which can be implemented separately or in combination) include varying the gain of an estimator as a function of a demanded or estimated speed to position control system poles at desired locations, de-coupling control system currents to achieve a constant torque with motor speed, compensating flux estimates of the estimator for saturation operation of the stator, estimating rotor position using averages of sample values of energization feedback, and calculating a trim adjusted speed error from a plurality of speed estimates.

Abstract: In a system for controlling rotation of a rotor of a multiphase rotary electric machine in relation to a stator thereof, a superimposing unit superimposes a first frequency signal on the input signal to the multiphase rotary electric machine. The first frequency signal has a first phase and a first period, and the first period is different from a period of rotation of the rotor. An amplitude detector detects an amplitude of a second frequency signal. The second frequency signal is actually propagated in the multiphase rotary electric machine with a second phase based on the superimposed first frequency signal. A rotation angle determiner determines a rotation angle of the rotor so as to eliminate a difference between the detected amplitude of the second frequency signal and a predetermined target amplitude thereof.

Abstract: In an electric rotary excavator (construction machine) 1, when earth pressure acts on a rotary body 4 in an opposite direction to an instructed direction of a lever, a control-system changing means 150 of a rotation control device 100 increases a torque output of an electric motor 5 that drives the rotary body 4. Accordingly, the torque output can properly react against the acting earth pressure, thereby preventing the rotary body from continuing to be rotated in the opposite direction. Therefore, even when the earth pressure becomes large, the work will not be affected. In addition, when the rotary body is rotated on a slope, the rotary body can be prevented from being rotated back greatly due to the weights of the boom and the arm.

Abstract: A system and method for extracting estimated input voltage and input current values of an AC motor based on sensed power inverter output voltage and output current when the AC motor is connected to a front-end EMI filter and the EMI filter is connected to a power inverter. Where the system includes a current estimator portion, and a voltage estimator portion. The estimated input values are used by a feedback controller in the power inverter to control the motor. A second system and method for extracting estimated an input current of an AC motor based on the actual motor input voltage, and the output voltage of the power inverter.

Abstract: The invention relates to a method for power control of an electric motor, in particular a motor for driving the suction fan of a vacuum cleaner connected to an AC mains power supply. The power control is effected by varying the phase angle of the electric alternating quantity supplied to the motor by the use of semiconductor switches. AC power supplied to the motor is switched by using different delay times for the switching in each half-period of a full AC period to suppress odd harmonics, particularly the third harmonic of the mains power line frequency. Half-periods of a full period are mirrored in the next consecutive full period in order to suppress even harmonics, particularly the second harmonic of the mains power line frequency. A set of delay times t1 and t2 are defined and selected to be used in further avoiding critical delay time areas for harmonics and minimize the generation of vibrations.

Abstract: A system and method for controlling an inverter of a motor control unit includes a controller having a user interface configured to allow user selection of a waveform increment value or a waveform amplitude threshold. The controller also includes an integrator configured to receive the waveform increment value and generate a signal at least based on the waveform increment value. A logic circuit is configured to monitor the signal and reset the integrator when the signal reaches the waveform amplitude threshold to generate a waveform having a frequency-independent amplitude. A comparator compares the waveform to a modulating signal to trigger gating pulses delivered to an inverter to drive an associated motor.

Abstract: A motor control system for detecting motor run condition comprises power switches for connection to an AC line for controlling application of AC power to the motor. An input receives a motor start command. A controller is connected to the input and controls operation of the switches responsive to a motor start command. The controller includes a counter and a timer and is operable to disable the power switches if number of starts during a select interval exceeds a first threshold and to disable the power switches if motor run time after a motor start command exceeds a second threshold.

Abstract: A motor control unit including a rotational position detector detecting a rotational position of a brushless DC motor; a current detector detecting a current of the brushless DC motor; a coordinate transformer executing rotational coordinate transformation of the current by a control phase angle and obtaining a d-axis current and a q-axis current; a current controller generating a command d-axis voltage based on a d-axis current error, and generating a command q-axis voltage based on a q-axis current error; a coordinate transformer generating a three-phase command voltage by the control phase angle; a conductive signal generator; and a position controller that, when executing a positioning operation, maintains the command d-axis current at a constant value and the command q-axis current at zero, and that controls the control phase angle based on a difference between a target stop rotational position and a rotational position detected by the rotational position detector.

Abstract: A system and method for operating a motor drive unit. The motor drive unit is coupled to a motor driving a load and is configured to selectively control the motor according to a torque control mode and a speed control mode. The motor drive unit includes a circuit configured to generate an operational condition signal indicating an operational condition of the motor and a regulator configured to receive the operational condition signal and generate a motor control signal. The motor drive unit also includes a first controller configured to receive the motor control signal and a reference control signal and select either the motor control signal or the reference control signal to use as a control signal to drive the motor according to either torque control or speed control.

Abstract: A motor driving apparatus includes: a current instruction calculator, for calculating a current instruction value based on a deviation between a speed instruction value and an estimated speed value; a current controller, for controlling an output current based on the current instruction value; a frequency instruction calculator, for calculating a frequency instruction value based on an output voltage instruction value or an output voltage detection value, wherein, when an induction motor is to be activated, the current instruction value and the frequency instruction value are calculated directly using the speed instruction value, and an output current and an output frequency are controlled in accordance with the current instruction value and the frequency instruction value.

Abstract: A motor driving apparatus is provided which can minimize ripple current flowing through a DC link capacitor, and downsize the motor driving apparatus. It synchronizes the frequency of the inverter carrier signal for driving an inverter with the frequency of the DC/DC converter carrier signal for driving a DC/DC converter, and carries out control in such a manner that the center of a period during which the input current of the inverter is zero and the center of a period during which the output current of the DC/DC converter is zero are matched.

Abstract: A method for controlling a calendering system having a first roll having a first roll speed controller and a second roll having a second roll speed controller is disclosed. An exemplary method comprises the steps of: (a) setting the first roll at a desired process speed with the first roll speed controller; (b) determining a target torque of the first roll; (c) contactingly engaging the first and second rolls; (d) determining an actual torque of the first roll; (e) comparing the target torque and the actual torque; and, (f) adjusting a speed of the second roll with the second roll speed controller to maintain the target torque of the first roll according to the comparison of the target torque and the actual torque.

Abstract: A motor drive unit includes a controller, a voltage inverter, and a speed estimator. The controller is operable to generate at least one command signal for controlling a motor associated with the motor drive unit. The voltage inverter is operable to generate motor drive signals to be applied to the motor based on the command signal. The speed estimator is operable to estimate a speed of the motor when the voltage inverter is not providing the motor drive signals. The speed estimator is further operable to receive two-axis voltage measurements associated with the motor, determine flux angles for the motor based on the two-axis voltage measurements, and estimate the speed based on the determined flux angles.

Abstract: A Motor driving apparatus adjusts activation start timing of high-side activation control signals UU, VU, WU and the low-side activation control signals UL, VL, and WL with a state determination signal SJ in an activation controller 40, in the period from starting to the time when rotor rotating speed reaches a predetermined value, sets the activation start timing earlier than in normal times to perform leading phase activation control, and in normal times when the rotor rotating speed is a predetermined value or more, controls activation start timing in efficient and optimum phase. Hence, the motor driving apparatus can carry out stable PWM sensorless starting without any starting failure such as oscillation, loss of synchronism and reverse rotation and shorten starting time.

Abstract: A control circuit of rotational speed of a fan is provided, wherein by a switching of a switch unit, a PWM (Pulse Wide Modulation) unit can output a sampling pulse whose period is changing. A voltage is also changing following the period after taking a sample to an AC voltage by the control unit. The voltage after sampling serves as a working voltage of a load unit, so as to enable a fan device and a lamp device of the load unit to achieve effects of adjusting speed and brightness.

Abstract: A position-sensorless motor control device has a superposer that superposes, on the drive current with which the motor is driven, a superposed current having a different frequency than the drive current, a superposed component extractor that extracts, from the motor current fed to the motor, the ?-axis and ?-axis components of the superposed current, and a controller that controls the motor so that the direct-current component of the arithmetic product of the extracted ?-axis and ?-axis components of the superposed current converges to zero.

Abstract: A motor starter system comprises solid state switches for connection between an AC line and motor terminals for controlling application of AC power to the motor. A voltage sensor senses AC line voltage and the motor terminal voltage. Current sensors sense motor current. A control circuit controls operation of the solid state switches. The control circuit limits switch current during a start mode and detects a stall condition responsive to sensed AC line voltage and motor terminal voltage and selectively boosts motor current during the start mode if a stall condition is detected.

Abstract: A method and system for controlling a power converter coupled to a polyphase power line. The method includes measuring at least two motor phase currents, obtaining a floating reference frame for the current Park vector, adjusting the reference frame based on an estimated rotor speed, and controlling the power converter via the floating reference frame to reinitiate power to a motor while a rotor is still moving.

Abstract: Included herein is a system and method for controlling a velocity vector of an overhead crane. A motor is attached to the crane and is positioned to move the overhead crane and has an output vector including a rotational direction and a rotational speed. A variable frequency drive is positioned to transfer voltage and current at a frequency to the motor. A processing unit converts the output vector to an amount of voltage and current at a given frequency and can instruct the variable frequency drive to send a frequency to the motor at a frequency substantially equal to the frequency at which the motor is presently rotating. This creates a speed match for the motor reducing spikes during operation of the motor and substantially eliminates open circuit decay. A hydraulic brake operates in connection with the processing unit and the variable frequency drive to slow the crane without driving the motor into the brake.

Abstract: An AC servo drive without current sensor includes a PI (proportional integration) controller, at least two first-order controllers (polar point and zero point), a decoupling compensator, a coordinate converter, a pulse width modulator, a counter and a speed estimator. The AC servo drive is connected with a servomotor to form an AC servo module. The servomotor comprises an encoder receiving a current command signal from the servo module to function as input current command signal or the d, q axes PI controller and the decoupling compensator. The voltage command signal generated by the d, q axes PI controller and the signal generated by the decoupling compensator form a control signal and input to the coordinate converter. The signal output from the coordinate converter is processed by PWM controller to control the servomotor. Therefore, the deterioration of servo motor control caused by temperature drift and cost can be solved.

Abstract: The present invention provides a motor drive apparatus capable of calculating an angular velocity and a rotation angle accurately in the entire rotation velocity range of a motor using a cheap Hall sensor having an inferior accuracy without using an expensive resolver having a high accuracy. The present invention includes a first angular velocity calculating means for calculating the angular velocity based on the back-EMF of the motor when it rotates at low speeds and a second angular velocity calculating means for calculating the angular velocity based on a signal from the Hall sensor when it rotates at high speeds. According to the present invention, the angular velocity and rotation angle can be calculated accurately in the entire rotation speed range using the Hall sensor under hybrid usage.

Abstract: An electronic drive for vector control of an induction motor controls slip and operating frequency in response to changes in stator voltage. The drive includes a torque control loop, a flux control loop and a frequency control loop. The control is based on a commanded stator current that is resolved into a torque-producing, or q-axis, current component and a flux-producing, or d-axis, current component that are in quadrature. The frequency control loop includes slip control in which a slip frequency command is produces based on a value for the leakage inductance of the motor. The leakage inductance value dynamically varies as a function of the q-axis current reference command.

Abstract: A vector-control system and method of a “sensorless” type for electric drives with a.c. motors is based upon generation of an oscillating magnetic field and upon measurement of the deviation, with respect to said oscillating field, of the flux generated thereby on account of anisotropy, whether natural or induced, of the magnetic structure of the machine.

Abstract: A rotation angle detecting apparatus having a reference signal-generating device that generated a reference signal; a rotation angle detecting section that generated an output signal in response to the reference signal; a feedback control section that determines a rotational angular speed based on the output signal and performs feedback control to calculate a rotation angle; and a free-running range change device that narrows a free-running range of the rotational angular speed at a time of starting settling of the rotation angle. In the rotation angle detecting apparatus, the free-running range of the rotational angular speed at the time of starting the settling of the rotation angle is narrowed, whereby the settling time can be shortened. Accordingly, the time that elapses before it becomes possible to detect a rotation angle can be shortened correspondingly.

Abstract: A variable speed drive is provided having a converter to convert an AC voltage to a DC voltage, a DC link to filter and store energy from the converter, and a plurality of inverters, wherein each inverter is configured to convert a DC voltage to an AC voltage to power a corresponding load connected to the inverter The converter is electrically connected to an AC power source, the DC link is electrically connected to the converter, and the plurality of inverters are electrically connected in parallel to the DC link. Each inverter of the plurality of inverters is configured to operate substantially independently of other inverters of the plurality of inverters.

Abstract: A non-highway vehicle including an engine, a DC power source driven by the engine and providing DC power via a DC bus, a traction motor, a circuit for connection to the DC bus for providing power to the traction motor, and a controller. The circuit includes at least two inverters which share the power supplied to the traction motor. A first inverter connects between the DC bus and the traction motor and a second inverter connects between the DC bus and the traction motor. The second inverter is in parallel connection with the first inverter. The controller coordinates operation of the first and second inverters.

Abstract: The invention provides an electrically movable vehicle drivable by a simplified mode of control and a control program for driving the vehicle. A normalized value Y? representing translation motion and a normalized value X? representing turning motion are fed from a command value input unit 110 to a velocity command value calculating unit 120. The calculating unit 120 determines a translation velocity command value Vg—trg based on the normalized value Y?. The calculating unit 120 determines a turn angular velocity command value ?f—trg that will always satisfy Expression (2–4) for preventing the vehicle from falling down. The translation velocity command value Vg—trg and the turn angular velocity command value ?f—trg determined by the unit 120 are fed to a control command value calculating unit 130, which calculates control command values for left and right drive wheels. The control command values are fed to a motor control unit 140 to control motors Mr, Ml and control the drive wheels.

Abstract: In a transport refrigeration system which is susceptible to having its drive motors connected to a power source in reverse phase relationship to thereby operate the drive motors in reverse, provision is made to measure the current flow to the motors during operation in each direction and for comparing those current flows to determine which is greater and therefore representative of operation in the proper direction. A backup method is also provided for sensing the ambient temperature of the air downstream of the condenser coil, both before and during motor operation to determine whether the temperature during motor operation is greater than that prior to operation to thereby indicate a proper connection.

Abstract: In a stabilizer apparatus for a vehicle, an electronic control unit calculates a target current of an electric motor from vehicle speed, steering angle, and lateral acceleration, and increases and decreases actual current such that the calculated target current flows through the motor. The control unit decreases the actual current by a predetermined amount when the difference between the target current and the actual current becomes smaller than a predetermined value during control of increasing the actual current. The predetermined amount is equal to the difference between the determined target current at the time of the detection of the difference and current which is necessary to obtain, during control of decreasing the actual current, an output torque equal to the output torque of the speed reduction mechanism obtained as a result of the target current flowing through the electric motor.

Abstract: An apparatus and method for controlling a brushless DC motor, which minimizes a torque ripple thereof, and includes a power converting unit to convert alternating current (AC) power to polyphase AC power and to supply the polyphase AC power to the brushless DC motor. A rotator position/speed detecting unit detects status information of a rotator. A terminal voltage detecting unit detects variations of terminal voltages of the polyphase AC power. A control unit detects phase commutation periods of the polyphase AC power using the status information provided from the rotator position/speed detecting unit and the terminal voltage variation information of the polyphase AC power provided from the terminal voltage detecting unit. The control unit controls the power converting unit to supply a compensation voltage used to constantly maintain a mean voltage of a non-commutation phase of the polyphase AC power during the detected phase commutation periods.

Abstract: To protect against overuse of a motor, such as may be used to control seat position in an automotive vehicle, an estimated temperature of the motor is determined based on an ambient temperature, a current applied to the motor, a period of time during which the current is applied to the motor, and at least one thermal property. A voltage applied to the motor is reduced, such as by a motor controller, when the estimated motor temperature is greater than a safe operating temperature of the motor.

Abstract: An electronic control unit (40) calculates the current flowing through a reactor (L) by dividing an output required BP* of a battery (32), obtained from converting the power required by a motor (22), by a terminal voltage Vb of the battery (32). A carrier frequency (optimum carrier frequency) is set for transistors (T7, T8) where the loss of a DC/DC converter (34) is minimized from the calculated current, and the DC/DC converter (34) is controlled at the set switching frequency.

Abstract: In a turbine apparatus comprising a runner rotatable to be rotationally driven by a water, a gain of a derivative calculation element generating a derivative component of a control signal for controlling a flow rate of the water which derivative component is to be applied to the derivative calculation element and the integration calculation element by performing differentiation on a difference between an actual rotational speed and a desired rotational speed of the runner with respect to a time proceeding has a value sufficiently increased to converge a value of the control signal toward a desired value in accordance with the time proceeding in S-characteristic portion.

Abstract: A method of providing ride-through capability in a chiller/refrigeration system employs a variable speed drive with an active converter stage, a DC link stage and an inverter stage for providing variable frequency and voltage to power at least one motor. An induction motor is coupled to the output of the inverter stage for driving a compressor in the chiller/refrigeration system. The ride-through method comprises operating the active converter to regulate the DC link voltage of the DC link stage to a predetermined voltage level until the current through the active converter equals a predetermined current limit, then transferring regulation of the DC link to the inverter upon reaching the current limit of the converter. The compressor is unloaded, and the power flow through the inverter is reversed to maintain the voltage level of the DC link stage.

Abstract: In a turbine apparatus comprising a runner rotatable to be rotationally driven by a water, a gain of a derivative calculation element generating a derivative component of a control signal for controlling a flow rate of the water which derivative component is to be applied to the derivative calculation element and the integration calculation element by performing differentiation on a difference between an actual rotational speed and a desired rotational speed of the runner with respect to a time proceeding has a value sufficiently increased to converge a value of the control signal toward a desired value in accordance with the time proceeding in S-characteristic portion.

Abstract: In a neutral range preset, there are set a zone for stopping and holding a rotating body only by a mechanical brake, a zone for holding the body only by performing position holding control, and a zone for simultaneously exerting both effects, i.e., the effect of the mechanical brake and the effect of the holding control. On-the-spot holding torque generated when the position holding control is performed is stored. The higher of the on-the-spot holding torque stored and accelerating torque according to an operation amount of the body at a rotation starting time is set as electric motor torque for acceleration. When performing a pressing work including pressing a bucket against an object for work, torque control is carried out according to the operation amount.