A motor drive system capable of suppressing heat generation during a low speed operation may include: an inverter including a plurality of switching elements to convert direct current power to alternating current power having a plurality of phases; a motor driven with the alternating current power converted in the inverter; and a controller determines an operating point of the motor on the basis of a torque command of the motor and generates a d-axis current command and a q-axis current command corresponding to the operating point. In particular, when each of the switching elements is overheated, the controller changes the d-axis current command and the q-axis current command by changing the operating point to a different operating point corresponding to a torque of the same magnitude as the torque command.

According to one embodiment, there is provided a motor control device including an acquisition unit, an AD conversion unit, a calculation unit and a drive control unit. The acquisition unit acquires an analog signal indicating a rotational position of a motor. The AD conversion unit AD-converts the analog signal to generate a digital value. The calculation unit estimates a slope of a waveform of the analog signal by using a plurality of the digital values and obtains an intersection timing at which a straight line corresponding to the estimated slope intersects with a threshold. The drive control unit controls driving of the motor according to a rotation cycle obtained from a plurality of the intersection timings.

According to one embodiment, there is provided a motor control device including an acquisition unit, an AD conversion unit, a calculation unit and a drive control unit. The acquisition unit acquires an analog signal indicating a rotational position of a motor. The AD conversion unit AD-converts the analog signal to generate a digital value. The calculation unit estimates a slope of a waveform of the analog signal by using a plurality of the digital values and obtains an intersection timing at which a straight line corresponding to the estimated slope intersects with a threshold. The drive control unit controls driving of the motor according to a rotation cycle obtained from a plurality of the intersection timings.

A motor drive system capable of suppressing heat generation during a low speed operation may include: an inverter including a plurality of switching elements to convert direct current power to alternating current power having a plurality of phases; a motor driven with the alternating current power converted in the inverter; and a controller determines an operating point of the motor on the basis of a torque command of the motor and generates a d-axis current command and a q-axis current command corresponding to the operating point. In particular, when each of the switching elements is overheated, the controller changes the d-axis current command and the q-axis current command by changing the operating point to a different operating point corresponding to a torque of the same magnitude as the torque command.

In an embodiment of a system for closed-loop control of a linear resonant actuator, a system processor coupled to a magnetic field sensor is configured to: receive a magnetic field sensor signal from a channel coupling a magnetic field sensor and the system processor; receive measurements of actuator current and actuator voltage from drive electronics; receive a temperature signal from a linear resonant actuator, the temperature signal indicating a temperature of the magnetic field sensor; calculate a first estimate of mass position using the magnetic field sensor signal, actuator current and a magnetic model; calculate an estimate of coil resistance based on the temperature signal, the actuator current, the actuator voltage and a thermal model; and calculate a second estimate of mass position and an estimate of mass velocity based on the first estimate of mass position, the actuator current, the actuator voltage and the estimated coil resistance.

In an embodiment of a system for closed-loop control of a linear resonant actuator, a system processor coupled to a magnetic field sensor is configured to: receive a magnetic field sensor signal from a channel coupling a magnetic field sensor and the system processor; receive measurements of actuator current and actuator voltage from drive electronics; receive a temperature signal from a linear resonant actuator, the temperature signal indicating a temperature of the magnetic field sensor; calculate a first estimate of mass position using the magnetic field sensor signal, actuator current and a magnetic model; calculate an estimate of coil resistance based on the temperature signal, the actuator current, the actuator voltage and a thermal model; and calculate a second estimate of mass position and an estimate of mass velocity based on the first estimate of mass position, the actuator current, the actuator voltage and the estimated coil resistance.

Upon determining that the absolute value of an electrical angular speed of a motor-generator is smaller than or equal to a threshold value, a control apparatus compensates a current detected by a U-phase current sensor based on a temperature detected by a U-phase temperature sensor and compensates a current detected by a V-phase current sensor based on an estimated temperature of a V-phase current sensor. On the other hand, upon determining that the absolute value of the electrical angular speed is larger than the threshold value, the control apparatus compensates the currents detected by the U-phase and V-phase current sensors based on temperature detected by the U-phase temperature sensor.

An energization control system includes a sensor unit including a magnetic detection portion detecting a magnetic flux density of a magnetic flux generated at a surrounding of a conductor in response to a current flowing in the conductor of an electrical apparatus, a temperature detection portion detecting a temperature level within a package in which the magnetic detection portion is disposed, a correction portion correcting a temperature characteristic of a detection result of the magnetic detection portion based on the detected temperature level, and an output portion outputting temperature information indicating the detected temperature level. The energization control system further includes a control unit including a control portion controlling a current flowing in a heating element of the electrical apparatus based on the temperature information.

The invention provides a position detection apparatus comprising: a base part, a moving part movable relatively with respect to the base part, a position detection part that detects a position of the moving part relative to the base part on the basis of a magnetic flux change to produce position data, a temperature detection part that detects an ambient temperature, a position correction part that calculates a correction value on the basis of a difference between the position data and a given reference value and the ambient temperature, and corrects the position data on the basis of the calculated correction value to produce a first corrected position data, and a linearity correction part that corrects the first corrected position data on the basis of the correction value for nonlinearity of the position detection part to produce a second corrected position data, wherein: the position detection part is capable of detecting position value as far as a position area where, within a position range of relative movement of the moving part to the base part, the magnetic flux change in association with a change in an amount of the relative movement is nonlinear.

An energization control system includes a sensor unit including a magnetic detection portion detecting a magnetic flux density of a magnetic flux generated at a surrounding of a conductor in response to a current flowing in the conductor of an electrical apparatus, a temperature detection portion detecting a temperature level within a package in which the magnetic detection portion is disposed, a correction portion correcting a temperature characteristic of a detection result of the magnetic detection portion based on the detected temperature level, and an output portion outputting temperature information indicating the detected temperature level. The energization control system further includes a control unit including a control portion controlling a current flowing in a heating element of the electrical apparatus based on the temperature information.