A sensorless induction motor system and a control method thereof includes a motor including a stator including windings forming a plurality of phases and a rotor including a permanent magnet, and a controller configured to control operation of the motor by controlling a voltage applied to each phase of the stator, to set a stop waiting time predicted to be necessary for the rotor to stop when the motor is controlled to stop, to apply a pulse voltage to each phase of the stator a plurality of times after the stop waiting time, and to conclude that the rotor has stopped when a minimum deviation value of an induced current is equal to or greater than a reference value.

A contact-and-separation system includes a first roller, a second roller, and a contact-and-separation device. The first roller contacts a belt. The second roller is opposed to the first roller. The contact-and-separation device contacts or separates the belt to or from the second roller via a sheet conveyed. The contact-and-separation device includes an eccentric cam, a motor, and a circuitry. The eccentric cam is mounted on an end of a rotation shaft of the first roller. The motor rotates the eccentric cam. The circuitry controls the motor to rotate the eccentric cam to contact or separate the belt to or from the second roller via the sheet conveyed. The circuitry controls the motor to decelerate a rotation speed of the motor on contact or separation of the belt to or from the second roller between the first roller and the second roller.

As first aspect provides, in an electronic control circuit, a method of controlling an electromotor of an actuator for controlling a position of an actuatable object of a vehicle. The method comprises receiving an instruction to hold position of the actuatable object, obtaining an initial hold voltage pattern for the electromotor and applying the initial hold voltage pattern to the electromotor. The method further comprises determining movement data on movement of the actuatable object, determining an adjusted hold voltage pattern based on the movement data and applying the adjusted hold voltage pattern to the electromotor. By applying a particular voltage to the electromotorstator, rotor or both, depending on the type, a magnetic force between rotor and stator may be created to counteract any external force. The voltage applied for holding the stator is determined on detection of any movement of the rotor.

Disclosed is a powered transport cargo system, and a method of retrofitting a powered transport cargo system that includes braking rollers. The method includes replacing a power drive unit (PDU) of the powered transport cargo system with a PDU including a permanent magnet motor (PMM), and removing a braking roller from the powered transport cargo system.

A controller for a permanent magnet synchronous motor having a rotor using a permanent magnet is provided. The rotor rotates by a rotating magnetic field caused by a current flowing through an armature. The controller starts a deceleration control of reducing a rotational speed of the rotor when a stop command is inputted in a state where the rotor rotates at a predetermined rotational speed; and performs a fixed excitation control when the rotational speed is reduced to a set speed. The fixed excitation control includes setting a current for causing a magnetic field vector for stopping the rotor at a target position in accordance with an amount of rotation of the rotor since the deceleration control has started and passing the current through the armature.

According to an aspect of the present disclosure, a motor drive control device driving a motor using position information detected by one sensor includes: a current detection unit detecting a magnitude of a coil current flowing through a coil of the motor; a rotation position detection unit detecting a rotation position of the motor based on the position information; and a hunting determination unit determining, based on the magnitude of the coil current, the rotation position of the motor, and a driving command for driving the motor, whether or not the motor is in a hunting condition.

In one embodiment, a magnetic orientation detent includes a motor coupled to a motor shaft, the motor mechanically coupled to a motor mount. The magnetic orientation detent may also include a flywheel mechanically coupled to a distal end of the motor shaft. The magnetic orientation detent may further include a first plurality of magnets coupled to the motor mount and a second plurality of magnets coupled to the flywheel. The second plurality of magnets couple magnetically to the first plurality of magnets.

A motor control device for a machine tool having a plurality of axes includes a plurality of motor control units that control motors; an abnormality detection unit provided for at least one of the motor control units and configured to output an abnormality detection signal upon detecting an abnormality with respect to the axis driven by the motor controlled by the motor control unit provided with the abnormality detection unit; a safety operation control unit provided for a motor control unit that is not the motor control unit provided with the abnormality detection unit, the safety operation control unit configured to control the motor upon receiving the abnormality detection signal in such a way that the tool comes out of contact with the workpiece; and a communication unit that transmits the abnormality detection signal outputted by the abnormality detection unit to the safety operation control unit.

A motor control device includes: an electric-current detection unit configured to detect an electric current that flows through a motor at a time when the motor is not to be driven; a voltage-polarity determining unit configured to determine polarity of a voltage corresponding to the detected electric current; and an operating-state management unit configured to perform control of stopping the motor depending on the polarity of the voltage.

A vibrato assembly for a keyboard percussion instrument comprises a motor and a vibrato fan or disc assembly. A motor (510) is responsive to a controller (1000), a run/stop switch (1035), and a potentiometer (1020). Pulleys (100A, 100B, 515) and a timing belt (520) couple rotation of the motor to an assembly of resonator or vibrato fans (720) via one or more magnets (120) or magnetically susceptible members to isolate vibrations. A sensor is activated by one of the magnets to sense the rotational position of a pulley when the fans are oriented vertically. When a run/stop switch 1035 is in a stop condition, sensor 525 signals controller 1000 to stop the motor, thereby leaving the fans vertical so that resonant tubes (725) are in an open condition when the vibrato function is stopped.