A method for phase-voltage based motor period measurement includes generating a commanded phase voltage and applying the commanded phase voltage to a first phase voltage input of an electric motor, a second phase voltage input of the electric motor, and a third phase voltage input of the electric motor, measuring a first period of a phase voltage associated with the first phase voltage input and the second phase voltage input and comparing the measured first period to a frequency of the commanded phase voltage, and, in response to a determination that the measured first period of the phase voltage associated with the first phase voltage input and the second phase voltage input is outside of a range of the frequency associated with the commanded phase voltage, identifying a fault associated with the first integrated circuit or signal path.

A method for synchronizing an MDPS motor and a motor position sensor may include: sequentially aligning, by a controller, a rotor of the MDPS motor by sequentially applying preset three-phase current pulses to the MDPS motor, the three-phase current pulses corresponding to one electrical-angle cycle of the rotor of the MDPS motor, and detecting an actual rotational position of the aligned rotor through the motor position sensor; determining a zero point rotational position of the rotor based on the actual rotational position; determining a reference rotational position of the rotor based on the actual rotational position and the number of pole pairs in the MDPS motor, and determining an offset rotational position of the rotor based on the actual rotational position and the reference rotational position; and correcting the zero point rotational position by adding the offset rotational position to the zero point rotational position.

An advance angle correction method of a motor device includes: acquiring first advance angle correction information indicating a correspondence relationship between an advance angle correction amount and a rotation speed difference of a rotor of the motor calculated in advance based on a rotation speed change rate; measuring the rotation speed difference of the rotor; calculating a first advance angle correction amount for each rotation direction of the rotor as a first forward rotation advance angle correction amount and a first reverse rotation advance angle correction amount so that a rotation speed difference of an output shaft becomes smaller based on the first advance angle correction information and the rotation speed difference of the rotor; and storing the calculated first forward rotation advance angle correction amount and the first reverse rotation advance angle correction amount as advance angle correction information for each motor device.

A method and position sensor system for detecting an error of a position sensor system are provided. The method and position sensor system implementing the steps of: determining the period length of three previous signal periods of the position signal, comparing the period lengths of the three previous signal periods of the position signal to detect a constant velocity position signal, a constant accelerating or decelerating position signal or position signal with a constant jerk, predicting the period length of the next signal period of the position signal, transferring the predicted period length of the next signal period to a predicted position signal for the next signal period, and comparing the predicted position signal with the actual position signal to detect errors in the position signal of the next signal period.

A motor controller integrated circuit (IC) includes a storage device containing software, and a processor core. The processor core has an output adapted to be coupled to a motor. The processor core is configured to execute the software to operate the motor in an open-loop control, calculate first and second orthogonal components of a back electromotive force (BEMF), calculate a total BEMF value, and determine that the first orthogonal component is within a threshold of the total BEMF value. The processor core is further configured to, responsive to the first orthogonal component being within the threshold of the total BEMF value, operate the motor in a closed-loop control.

A method for determining a position of a rotor of a brushless direct current (BLDC) motor at standstill. The method includes providing a plurality of current pulses to a plurality of windings of the BLDC motor while the rotor of the BLDC motor is at a standstill position. The method further includes measuring a plurality of times that it takes for the plurality of current pulses to reach a threshold for respective ones of the plurality of windings. A first position corresponding to a shortest time of the plurality of times is determined. A position detection value is determined based on the shortest time and based on times corresponding to positions that are adjacent to the first position. A position of the rotor at the standstill position is determined based on the position detection value and an interpolation function.

An external force estimation device is configured to estimate an external force acting on a motor. The external force estimation device includes a processor. The processor is configured to: calculate an output torque of the motor by using a value of a current supplied to the motor; estimate an inertia torque of the motor by using rotational position information of the motor; estimate a first friction torque of the motor by using the rotational position information of the motor; perform temperature-based correction for the first friction torque by using temperature information of the motor; and estimate the external force by subtracting the inertia torque and the first friction torque after the temperature-based correction from the output torque.

A method (100) for calibrating an offset angle (PhiO) for field-oriented control of an electric machine (210) between an angle signal (W) of a position encoder (220) and the direction of the rotor flux (RF), having the steps of: periodically varying (120) a current vector (Is) along a line of constant torque; ascertaining (130) a speed signal (n_t) of the position encoder (220) of the electric machine (210); calibrating (140) the offset angle (PhiO) on the basis of the ascertained speed signal (n_t).

A control device includes: a current detector that detects rotating electrical machine currents flowing to the rotating electrical machine; a position estimator that estimates a rotor position of the rotating electrical machine based on the rotating electrical machine currents; a controller that calculates drive voltage commands based on the rotating electrical machine currents and information on the rotor position, adds position estimation voltage commands and the drive voltage commands to obtain rotating electrical machine voltage commands. The position estimator extracts position estimation currents included in the rotating electrical machine currents, the position estimation currents being changed according to the position estimation voltage commands, and estimates the rotor position of the rotating electrical machine using a DC component of amplitudes of the position estimation currents extracted, the DC component being not changed according to the rotor position.

A method for maintaining a detected absolute position of an electric motor operating as an actuator during a critical operation involves the electric motor (2) being controlled by a controller (1) which is supplied with energy from an energy source. In the method, with which an absolute value sensor can be omitted, the absolute position of the electric motor (2) is measured during the operation thereof, wherein rotations of the electric motor (2) are detected. The rotations are counted, and a count value is output to a microprocessor (3) of the controller (1) in order to actuate the electric motor (2), and in the event of a critical operation, the currently detected count value is maintained by means of an independent voltage supply (7).