Abstract: An example apparatus includes: current driver circuitry configured to supply power to a stepper motor; and controller circuitry coupled to the current driver circuitry, the controller circuitry configured to: determine a first duty cycle of power transferred to the stepper motor by the current driver circuitry during a first operation of the stepper motor, the first operation to supply power using currents of a target magnitude; determine an previous duty cycle of power transferred to the stepper motor by the current driver circuitry during a second operation of the stepper motor, the second operation of the stepper motor to supply power using currents of the target magnitude; and determine changes in a mechanical load applied to the stepper motor responsive to a comparison of the first duty cycle to the previous duty cycle.

Abstract: For example, the switching drive device 100 includes a driver 30 configured to drive an N-type semiconductor switch element, a current limiter 50 configured to limit a current fed to a boot capacitor BC1 included in a bootstrap circuit BTC, and a current controller 60 configured to control the operation of the current limiter 50. The current controller 60 is configured to drive the current limiter 50 to limit the current fed to the boot capacitor BC1 when the charge voltage across the boot capacitor BC1 is higher than a threshold value.

Abstract: A power storage system has a battery, a three-phase motor in which coils of three phases are connected at a neutral point, an inverter connected on an electric power transmission path between the battery and the three-phase motor, and a DC power supply circuit connected to a connection portion positioned on an electric power transmission path between the inverter and the battery. The battery includes two power storages and a switch unit that switches between a first voltage state where the two power storages are connected in series and chargeable at a first voltage, and a second voltage state where the two power storages are connected in parallel and chargeable at a second voltage. The DC power supply circuit has a branch circuit connected to a coil of any one phase among the coils of three phases at a positive electrode side of the DC power supply circuit.

Abstract: A sliding-door drive unit for a vehicle is capable of transferring or blocking drive power required to pull or push a cable to open or close a sliding door. The sliding-door drive unit includes a worm wheel rotatable by a drive motor, a stationary disc coupled to an output shaft, and a movable disc rotatably installed between the worm wheel and the stationary disc along an axial direction of the output shaft. The movable disc is engaged with the worm wheel and is selectively engaged with the stationary disc.

Abstract: A synchronous-motor control device includes a torque-command-value conversion unit for converting a torque command value for a synchronous motor into a second-torque command value which gradually increases in a region including a peak of a torque of the synchronous motor, a voltage-phase control unit for controlling a voltage phase angle such that the torque of the synchronous motor matches the second-torque command value, and a power conversion unit for converting DC power into AC power based on the voltage phase angle and a rotational angle of the synchronous motor, and for outputting the AC power resulted from the conversion to the synchronous motor.

Abstract: A first circuit has a predetermined function with an output that has a small dependence on a certain operation condition. A second circuit has the same function as that of the first circuit with an output that has a large dependence on the certain operation condition. When the first circuit is operating normally, the main circuit operates according to the output of the first circuit. The main circuit is capable of generating a detection signal that indicates the certain operation condition based on a relative relation between the output of the first circuit and the output of the second circuit.

Abstract: A hand-held electrically powered cut-off tool (100) for cutting concrete and stone by a rotatable cutting disc (105), the cut-off tool (100) comprising an electric motor (130) arranged to be controlled by a control unit (110) via a motor control interface (120), wherein the control unit (110) is arranged to obtain data indicative of an angular velocity of the cutting disc (105), and to detect a kickback condition based on a decrease in angular velocity, wherein the control unit (110) is arranged to determine an angular acceleration associated with the electric motor (130), and to detect the kickback condition based on a comparison between the determined angular acceleration and a detection threshold, wherein the detection threshold is configured at an angular acceleration between 5000 rad/s2 and 35000 rad/s2, and preferably between 10000 rad/s2 and 30000 rad/s2, and more preferably between 20000 rad/s2 and 30000 rad/s2.

Abstract: Methods, systems, and devices for electric machine torque adjustment based on waveform multiples are disclosed herein. One electric machine controller, arranged to direct pulsed operation of an electric machine, utilizes a pulse controller that calculates a first average measured torque from sensed torque values over a first time period and a second average measured torque from sensed torque values over a second time period, wherein the first and second time periods are different time periods.

Abstract: A motor rotational speed control system and method having a duty cycle variable modulation mechanism is provided. The motor rotational speed control system is performed by the motor rotational speed control system including a motor rotational speed detector and a motor driver. When a rotational speed of a motor detected by the motor rotational speed detector is larger than or equal to a set rotational speed, the motor driver modulates duty cycles of a plurality of waveforms of an on-time signal, and modulates a duty cycle difference between the duty cycle of each of the plurality of waveforms and the duty cycle of a previous one or every other one of the plurality of waveforms in the on-time signal. The motor driver, according to the on-time signal, drives the motor such that the rotational speed of the motor is limited to be smaller than the set rotational speed.

Abstract: A vibratory actuator includes a vibration body, a contact body, a base, a holding member, and a flexible substrate. The vibration body includes an elastic body and an electro-mechanical energy conversion element. The contact body is in contact with the elastic body and relatively moves with the vibration body due to vibration of the vibration body. One end of the flexible substrate is arranged along a first surface of the holding member and is folded back with respect to an end portion of the holding member toward a second surface of the holding member on a back side of the first surface, and an other end of the flexible substrate is supported by a portion of the base. The flexible substrate separates from the second surface to form a U-turn portion so that the one end and the other end of the flexible substrate are electrically connected.

Abstract: A control circuit and method for DC motors is disclosed in the present application. The control circuit may comprise a voltage monitoring unit for monitoring the output voltage of the DC power supply, a switching circuit for controlling the operation of the DC motor, and a PWM signal output unit to output PWM signal for controlling the switching circuit. The PWM signal output unit may be configured to regulate the duty cycle of the output PWM signal based on the results of the voltage monitoring unit. In this way, motors with different resistances may work continuously in a stabilized state. Also, it may detect when a load like motor is heavy loaded or overloaded, stop motor from starting, and avoid overtime working due to the drop of supply voltage damaging the load like motor.

Abstract: There is provided an electric traction system 1, comprising: a traction converter module 2 comprising: a positive input terminal 4 and a negative input terminal 6 for operatively coupling to a DC power supply, and a plurality of power inverters 11, each of which comprises positive and negative input nodes 3, 5 configured to receive DC power and output nodes 9 configured to supply AC power, wherein the positive and negative input nodes 3, 5 of the plurality of power inverters 11 are electrically connected in series between the positive input terminal 4 and the negative input terminal 6; and at least one electric motor 8 configured to be driven by the traction converter module 2, the at least one electric motor 8 comprising a multi-phase electric motor 81.

Abstract: An excitation waveform determination device (100) sets an initial candidate solution group (IS) and a new candidate solution group (US) as one or a plurality of candidate groups of an excitation waveform based on a harmonic superimposition condition (HC) being information that specifies a harmonic to be superimposed on a fundamental wave included in the excitation waveform, executes an electromagnetic field analysis to calculate respective electromagnetic forces generated in a stator (320) when making the candidate solutions included in the one or plurality of set candidate solution groups of the excitation waveform flow through a motor (M), and determines the excitation waveform based on a result of the execution of the electromagnetic field analysis.

Abstract: A safety device (10) for monitoring an electric motor (101) connected to a power supply line (100) and equipped with a drive shaft (102). The safety device (10) comprises a control unit (12) having detection means, adapted to detect at least two physical quantities related to and associated with the operation of the electric motor (101), signaling means configured to transmit a control signal (C) generated by a first processing unit (17), which is connected to the detection means and the signaling means and configured to transmit the control signal (C) by means of the signaling means. The processing unit (17) is configured to compare the at least two physical quantities with each other, in order to detect faults or anomalies and to generate the control signal (C) on the basis of the aforementioned comparison.

Abstract: A power converter includes a charger, a battery, a motor, an inrush current limiter, and processing circuitry. A first switching unit connects the charger to the battery. A second switching unit connects a positive conductor to the neutral point of the motor. A third switching unit connects the battery and the inverter. The inrush current limiter is connected in parallel to the third switching unit and includes a resistance element and a fourth switching unit. The controller pre-charges a second capacitor arranged between the battery and the inverter by turning off the third switching unit and turning on the fourth switching unit. The controller pre-charges a first capacitor arranged between the charger and the battery after pre-charging the second capacitor by performing a step-down operation with the inverter while turning on the second and third switching units and turning off the first and fourth switching units.

Abstract: To appropriately detect an abnormal state of a motor without monitoring air pressure. A motor drive control device includes a monitoring control unit for setting a physical quantity related to operation of a drive-target motor as a monitoring parameter, and monitoring an operation state of the drive-target motor based on measurement data of the monitoring parameter and a reference value of the monitoring parameter. The monitoring control unit determines whether the drive-target motor is in an abnormal state based on a comparison result between a deviation of the measured value from the reference value of the monitoring parameter in the drive-target motor and a deviation of the measured value from the reference value of the monitoring parameter in another motor acquired by a communication unit.

Abstract: An electric motor controller is equipped to mitigate drive line induced vehicle vibration. The motor speed is measured at the output of the motor, separately from any measurement of drive shaft or wheel speed. At least bandpass filtering is applied to the measured motor speed, at a pass band based on the natural frequency of the drive shaft. The filtering detects drive line induced oscillations of the motor speed. A controller uses the detected drive line induced oscillations to generate an oscillation control output, subject to limiting. An oscillation mitigation torque signal corresponding to the control output is added to a torque command for desired motor speed, to adjust for the oscillations. The adjusted torque command is used to control the motor, with a significant reduction in the oscillation of the motor's speed.

Abstract: A control system includes processing circuitry that calculates, based on a control target model that indicates a relationship between an operation of a control target and a friction acting on the control target, a continuous value for compensating for the friction as a feedforward compensation value, generates a command based on the feedforward compensation value, and outputs the command to cause the control target to operate.

Abstract: The releases of an electromechanical parking brake are controlled by measuring the change in the intensity (I) of the electrical current provided to the control motor, or a function derived from this intensity, and by extending the release of the brake only for a determined duration (?t) after stabilization of this intensity, in order not to unnecessarily increase the idle travel of the brake actuator nor to extend the duration of the control. The determined duration (?t) also depends on the temperature and on the hydraulic pressure in the brake.

Abstract: The disclosure discloses a nonlinear predicative position control method suitable for a biaxial permanent magnet servo system. In consideration of uncertainty disturbance of the biaxial permanent magnet synchronous motor driving system, a value function for the biaxial permanent magnet synchronous motor driving system and a constraint condition of the value function are constructed, and the value function is solved to obtain a voltage control quantity of the permanent magnet synchronous motor, and the voltage control quantity of the permanent magnet synchronous motor is input into the stator voltage input end of the permanent magnet synchronous motor, thereby realizing the adjustment control of the nonlinear prediction position of the biaxial permanent magnet synchronous motor driving system.