Abstract: The present invention relates to an apparatus for driving a stepping motor, including a plurality of push-pull circuits each of which is capable of controlling a push state in which a current is supplied to a terminal and a pull state in which a current is drawn through the terminal and which are connected to coils to operate the stepping motor utilizing the bipolar driving. In the apparatus of the present invention, at least one of the push-pull circuits is connected to a common terminal having one ends of the coils of different phases connected thereto, thereby reducing the number of circuits and driving lines.

Abstract: A failure monitor designed to monitor a failure in operation of a motor drive control system. The system works to drive a motor-driven member through an output shaft and an electric motor and includes an output shaft angular position sensor for determining an angular position of the output shaft and an encoder for determining an angular position of the motor for use in controlling the motor. The system works to discriminate among failures in operation of the output shaft angular position sensor and the encoder and another type of a failure using outputs of the sensors.

Abstract: A method for implementing control signal linearization for an electric motor is disclosed. In an exemplary embodiment, the method includes receiving a desired voltage command to be applied to the motor and determining whether the magnitude of the desired voltage command falls between a first value and a second value. If the magnitude of the desired voltage command falls between the first value and the second value, then modulating a voltage command between the first and the second value over a determined sample period, thereby resulting in the application of a modulated voltage command to the motor.

Abstract: The invention is a suspension element having an outer edge and an inner edge. The suspension element, such as a spider or surround, varies in shape along at least a portion of the suspension element to help relieve both the radial and tangential stress placed on the suspension element when it is stretched. The shape employed in the suspension element allows the suspension element to stretch more easily, creating a higher performance speaker of the same size by increasing the diaphragm excursion and voice coil movement.

Abstract: An object of the present invention is to provide a motor control apparatus having excellent harmonic current control performance, that can simplify circuit configuration and circuit processing while, at the same time, achieving improved control accuracy. To achieve this object, detected motor currents are converted by coordinate converters 19 and 20 into an nth-order dq-axis signal and an mth-order dq-axis signal, and their DC components are extracted by low-pass filters 22 and 23; then, the differences of the DC components relative to respective command values are converted back into three-phase AC signals to control the motor currents.

Abstract: The invention relates to an electric motor drive for operating an alternating-current motor. The electric motor drive comprises a frequency converter for controlling the motor, which frequency converter comprises a rectifier and an inverter implemented using semiconductor switches arranged in a bridge, and an intermediate circuit placed between the rectifier and the inverter and comprising a capacitor.

Abstract: On end of a reactor (L1) is connected to a positive electrode of a battery (B1) and the other end is connected to a power line via a transistor (Q1) and to the ground via a transistor (Q2). By PWM control of the transistors (Q1, Q2), an arbitrary increased voltage is obtained in the power line. It is possible to obtain an optimal inverter input voltage (power line voltage) according to the motor drive state, thereby increasing efficiency. Thus, it is possible to optimize the inverter input voltage according to the motor drive condition.

Abstract: A method for controlling a voltage mode controlled electric machine comprising: receiving a torque value representative of a desired torque; obtaining a speed value indicative of a rotational velocity of the electric machine; acquiring a phase advance value indicative of a desired phase advance angle; generating a voltage command responsive to the torque value, the position value; the generating is responsive to the torque value, the speed value, and the phase advance value.

Abstract: The frequency of the pulse width modulator within a step motor control circuit is increased above a base frequency under defined conditions to enable more accurate construction of the phase current waveform for preventing mid-range resonance. The PWM frequency is stepped between frequencies by a fixed amount above the base frequency, to prevent the excitation of system harmonics and prevent step motor operational instability.

Abstract: A controller includes a power source unit, a drive circuit, and a state control circuit. The drive circuit is coupled to the power source unit, and includes a drive coil and a switching transistor unit. The switching transistor unit is operable in one of a circuit-making state for making an electrical circuit between the drive coil and the power source unit so as to enable the drive coil to drive rotation of a rotor of a brushless direct current motor, and a circuit-breaking state for breaking the electrical circuit between the drive coil and the power source unit. The state control circuit is coupled to the power source unit, and includes a pulse width modulator, a sensing coil, and a control transistor coupled electrically in series. The state control circuit controls operation of the switching transistor unit according to magnetic position of the rotor relative to the sensing coil.

Abstract: Steering apparatus includes at least one motor for generating a steering assisting force in a direction to steer a steerable wheel, two drive circuits having respective switching elements for PWM-controlling the motor, and a controller for differentiating, between the drive circuits, a control frequency at which the switching element is switched on and off. The differentiated PWM switching timing can effectively reduce switching noise and magnetostrictive sound of the motor.

Abstract: A method and apparatus for controlling a permanent magnet synchronous motor by accurately detecting 3-phase motor currents from a DC input current in a full voltage range are provided. In the motor control apparatus for detecting the 3-phase motor currents on the basis of the value of the current detected at a DC side of a PWM inverter, when a difference width between PWM pulse signals of two of three phases of the 3-phase PWM inverter which cannot detect the motor currents is not larger than a predetermined value or when the output voltage of the 3-phase PWM inverter is low, the apparatus automatically reduce the carrier frequency of the PWM inverter.

Abstract: A method and apparatus for use with a motor controller that receives a command velocity and that applies voltages to drive a motor at the command velocity, the apparatus comprising a dual inertia lost motion assembly including a motor and a load couplable to the motor, the lost motion assembly characterized by at least some lost motion between the motor and the load, the motor and load together characterized by a total assembly inertia, an acceleration error determiner for generating an acceleration error that is the difference between a derivative of the command velocity and a motor acceleration value and a low pass acceleration error filter filtering the acceleration error and having a gain set as a percentage of the total assembly inertia, the acceleration error filter providing the filtered signal to the controller, the controller using the filtered signal to adjust the applied voltages.

Abstract: Windings of each phase in a three-phase AC motor are independent of one another. A motor control unit gives, to windings of each phase (U, V and W-phase), currents (IU, IV, IW) obtained by adding, to a fundamental sine wave current, a current having a frequency which is three times as high as that of the fundamental sine wave current. That is, IU=I·sin ?t+Ia·sin 3?t: IV=I·sin(?t+2/3?)+Ia·sin 3?t: IW=I·sin(?t+4/3?)+Ia·sin 3?t Also, amplitude Ia of a current having a frequency which is three times as high as that of the fundamental sine wave current is set to a predetermined value smaller than amplitude I of the fundamental sine wave current.

Abstract: A method and apparatus for use with a controller that supplies voltages to an induction machine via supply lines, the voltages including a fundamental voltage component and an injected voltage component, the line voltages also including harmonic voltage components where the harmonic voltage components include at least a high frequency first harmonic component having a frequency substantially equal to the sum of the fundamental component frequency and the injected component frequencies, the method for identifying the high frequency first harmonic component and comprising the steps of sensing the line voltages, identifying a zero sequence voltage component of the line voltages, rectifying the zero sequence voltage component to generate a rectified signal and using the rectified signal to identify the high frequency first harmonic component.

Abstract: A controller for an electric machine. The controller includes a first voltage input that directly provides a first voltage to the electric machine, a second voltage input configured to receive a second voltage, and an inverter coupled to the second voltage input. The inverter is configured to be activated by the second voltage, to frequency-regulate the second voltage to generate a frequency-regulated voltage, and to provide the frequency-regulated voltage to the electric machine.

Abstract: A technique for reconstructing phase currents based on measurements of a DC bus current. Non-observable regions of DC bus current samples to reconstruct phase currents are reduced in size by using two phase space vector modulation. The non-observable regions can be further reduced by omitting deadtime insertions for switch actuations when output current is higher than a given threshold. Voltage command vectors in non-observable areas can be constructed by two time averaged vectors one of which is constructed to obtain an observable DC bus current reflecting motor phase current. The additive vectors have the same combined time average value as that of the voltage command vector in order to preserve volt-seconds. Current samples may also be averaged to provide a more accurate reconstruction of phase current. Current samples are time delayed to avoid transients for more accurate readings.

Abstract: A numerical controller which, after once stopping a slave axis during superposing control, can easily resume the superposing control. In the superposing control, a motion amount for a master axis and a motion amount for the slave axis are added to a workpiece coordinate value of the master axis and a workpiece coordinate value of the slave axis, respectively, to update their present position data (I2, II2). These motion amounts are supplied also to servo processing (I3, II3) for the master axis and the slave axis, where an amount obtained by superposing a motion amount ?zIm for the master axis ZIm on a motion amount ?zIIs for the slave axis ZIIs is supplied to the servo processing for the slave axis ZIIs. When a slave axis motion stop command is issued, the motion of the slave axis is stopped and a motion amount ?zIm for the master axis ZIm is subtracted from the workpiece coordinate value of the slave axis ZIIs.

Abstract: In an automatic transmission position control by a motor, it is determined whether the present instant belongs to a starting period, that is, the present instant is immediately after resetting of a control unit or application of power to it. If it is the starting period, an actual shift position that is detected from an output of an output shaft sensor for detecting a rotation position of a motor is set as an instructed shift position. With this measure, even if the control unit is reset for a certain reason while the vehicle is running, the instructed shift position is not changed in association with the resetting. This prevents trouble that the shift position is switched contrary to the intention of the driver, whereby the reliability of a position switching control can be increased.

Abstract: A power control apparatus includes an inverter giving a rectangular waveform drive signal to an induction motor, an inverter voltage controlling section controlling an output voltage of the inverter, a converter boosting a voltage supplied to the inverter, a converter voltage controlling section controlling an output voltage of the converter, and a control signal generating section that controls the inverter voltage controlling section in a low-rotational speed region and controls the converter voltage controlling section in a high-rotational speed region.