A method for determining a movement of a rotor of an electric motor, comprises supplying a drive signal to a drive coil of the electric motor, sensing a coil current of the drive coil, detecting current ripples of the sensed coil current caused by the rotor of the electric motor crossing ripple generating positions, inferring the movement of the rotor from the detected ripples, braking the motor by reducing the drive signal supplied to the drive coil from an initial signal value to zero according to a braking curve specifying a non-zero fall time during which the drive signal is reduced from the initial signal value to zero. The braking curve is adapted so that the rotor does not cross a ripple generating position after the drive signal has been reduced to zero.

A method for determining a rotation variable of a rotatably mounted rotor of a mechanically commutated electric motor, having a motor current path formed between two brush elements of the electric motor, and leading via the commutator bars contacted by the brush elements, and via coil windings of the rotor electrically connected to said commutator bars, wherein an oscillating input signal is fed into the motor current path and the rotation variable is determined with the aid of a ripple of a resultant output signal, said ripple being due to the mechanical commutation of the motor current path.

Maintenance of a transportation device propelled by an electric motor, wherein an incremental encoder senses motion of a moving part of, or a part moved by, the electric motor, may include acquiring a pulses-per-rotation configuration value PPRconf, representing a quantity of pulses which should be provided by the incremental encoder per one rotation of the electric motor; deriving a pulses-per-rotation estimation value PPRest representing a quantity of pulses provided by the incremental encoder per one rotation of the electric motor; determining a pulses-per-rotation error value PPRerr representing a deviation of the pulses-per-rotation estimation value PPRest from the pulses-per-rotation configuration value PPRconf, based on a relation: PPRerr=PPRestPPRconf, PPRconfPPRest, PPRest/PPRconf, or PPRconf/PPRest; and utilizing the pulses-per-rotation error value PPRerr to generate an instance of maintenance information indicating that a maintenance operation should be performed on the transportation device.

A brushless motor control apparatus includes an inverter circuit that applies a drive voltage to a winding of each phase of a brushless motor, a rotor magnetic pole detector that outputs a magnetic pole detection signal corresponding to a rotor position of the brushless motor based on a change of a magnetic pole detected by a Hall sensor, a rotor position estimator that outputs, each time a level of the magnetic pole detection signal is switched, an estimated rotor position signal that indicates an estimated rotor position with an electrical angle and indicates a predetermined electrical angle corresponding to the level after switching, a current detector that detects a current supplied to the inverter circuit as a power source current value, and an electrical angle correction unit that corrects the estimated rotor position signal by determining an electrical angle offset based on fluctuation in the power source current value and adding the electrical angle offset to the electrical angle indicated by the estimated rotor position signal.

The invention provides a noise filtering method for a motor. The motor rotates according to an operating voltage. The noise filtering method includes: setting an inspection period and a minimum threshold. The noise filtering method further includes: generating a pulse signal according to the operating voltage, determining whether a time corresponding to each sub-pulse signal in the pulse signal meets the inspection period, and determining whether a pulse width corresponding to each sub-pulse signal is equal to or greater than the minimum threshold. A recording medium storing a program code corresponding to the method, and a motor control circuit for executing the program code are also provided.

The present invention relates to an inverter-controlling device. The inverter-controlling device include a main controller configured to generate a predetermined command current; a comparison module configured to calculate a difference between the command current and an output current of an inverting module; a current controller configured to perform a proportional-integral (PI) control based on the difference; and a frequency estimation module configured to estimate a rotation speed of a motor based on a current response to the command current while the command current is injected to the current controller, wherein the main controller is further configured: when a flying start operation of the inverting module begins, to set an output frequency of the inverting module based on the rotation speed of the motor estimated by the frequency estimation module.

A rotation angle detector includes a rotational angular velocity calculator that calculates a rotational angular velocity of a motor based on an inter-terminal voltage of the motor detected by a voltage detector and a current flowing through the motor and detected by a current detector; a ripple detector that detects a ripple component included in the current; and a failure detector that detects a failure of any one of the voltage detector, the current detector, and the ripple detector based on outputs from the detectors. The failure detector determines that the failure has occurred when a state, where the outputs from two of the voltage detector, the current detector, and the ripple detector indicate normal rotation and the output from the remaining one of the voltage detector, the current detector, and the ripple detector does not indicate normal rotation, continues for a predetermined period of time.

A permanent magnet synchronous machine (1) having a rotor (R) and a stator (S). Connection terminals (2) apply a feed alternating voltage with a feed frequency (f.sub.0). The permanent magnet synchronous machine (1) has a motor controller (10). The controller (10) has an assembly (11) to detect the terminal voltage on the connection terminals (2) and the current frequency (f.sub.a). Also, the controller has an analysis device (12). The analysis device (12) ascertains whether the current frequency (f.sub.a) contains a frequency component (f.sub.r) with a frequency that deviates from the feed frequency (f.sub.0).

A brushless motor control apparatus includes an inverter circuit that applies a drive voltage to a winding of each phase of a brushless motor, a rotor magnetic pole detector that outputs a magnetic pole detection signal corresponding to a rotor position of the brushless motor based on a change of a magnetic pole detected by a Hall sensor, a rotor position estimator that outputs, each time a level of the magnetic pole detection signal is switched, an estimated rotor position signal that indicates an estimated rotor position with an electrical angle and indicates a predetermined electrical angle corresponding to the level after switching, a current detector that detects a current supplied to the inverter circuit as a power source current value, and an electrical angle correction unit that corrects the estimated rotor position signal by determining an electrical angle offset based on fluctuation in the power source current value and adding the electrical angle offset to the electrical angle indicated by the estimated rotor position signal.

The invention concerns a drive unit for an adjustment system (1), in particular in a motor vehicle, with an adjustable element (2) moved by an electric motor, comprising: a drive motor (4) operated by an electromagnet, a magnetic field sensor (9) which is arranged on a pole pot (42) or a housing of the drive motor (4) in order to provide an electrical sensor signal dependent on the magnetic field, a control unit (7) which is configured to detect a magnetic field which varies on rotation of a rotor (44) of the drive motor (4), so that in particular a relative position change of the adjustable element (2) can be derived from the electrical sensor signal.