This linear motor apparatus includes: a first linear motor and a second linear motor, movable bodies of which move in the same direction in a linked manner; a first control portion that causes the first linear motor to produce thrust to apply a load to a pressurizing target via the movable bodies; and a second control portion that causes the second linear motor to produce thrust and controls the thrust, wherein, if the first control portion is causing a load to be applied to the pressurizing target, then the second control portion causes the second linear motor to produce thrust that cancels an external force produced to the movable bodies.

This linear motor apparatus includes: a first linear motor and a second linear motor, movable bodies of which move in the same direction in a linked manner; a first control portion that causes the first linear motor to produce thrust to apply a load to a pressurizing target via the movable bodies; and a second control portion that causes the second linear motor to produce thrust and controls the thrust, wherein, if the first control portion is causing a load to be applied to the pressurizing target, then the second control portion causes the second linear motor to produce thrust that cancels an external force produced to the movable bodies.

A camera module actuator includes, a magnet, a coil, a driver, and a position estimating processor. The coil is disposed to face the magnet. The driver is configured to move the magnet by applying a driving signal to the coil. The position estimating processor is configured to estimate a position of the magnet from an oscillating signal. A frequency of the oscillating signal varies according to a movement of the magnet.

A camera module actuator includes, a magnet, a coil, a driver, and a position estimating processor. The coil is disposed to face the magnet. The driver is configured to move the magnet by applying a driving signal to the coil. The position estimating processor is configured to estimate a position of the magnet from an oscillating signal. A frequency of the oscillating signal varies according to a movement of the magnet.

An electric motor control device includes a drive waveform generating unit configured to generate a drive waveform (a sine wave or a pseudo-trapezoidal wave) to an electric motor. A plurality of photo interrupters detect a rotational phase of an electric motor, and a information of rotational speed is detected by an encoder circuit based on a detected signal of the rotational phase of the electric motor. The control unit controls the drive waveform generating unit on the basis of detection information of the rotational phase of the electric motor and performs control so that a phase relationship between the rotational phase of the electric motor and the phase of the drive waveform is kept constant. Furthermore, the control unit sets an amplitude value of the drive waveform generated by the drive waveform generating unit in accordance with a difference between a target speed and the detected information of rotational speed and performs speed control so that a speed of the electric motor is kept constant. The control unit calculates an amplitude setting value with which correction for suppressing non-linearity is performed in a region in which an amplitude setting value of the drive waveform and actual work given to the electric motor is non-linear and controls the speed.

An electric motor control device includes a drive waveform generating unit configured to generate a drive waveform (a sine wave or a pseudo-trapezoidal wave) to an electric motor. A plurality of photo interrupters detect a rotational phase of an electric motor, and a information of rotational speed is detected by an encoder circuit based on a detected signal of the rotational phase of the electric motor. The control unit controls the drive waveform generating unit on the basis of detection information of the rotational phase of the electric motor and performs control so that a phase relationship between the rotational phase of the electric motor and the phase of the drive waveform is kept constant. Furthermore, the control unit sets an amplitude value of the drive waveform generated by the drive waveform generating unit in accordance with a difference between a target speed and the detected information of rotational speed and performs speed control so that a speed of the electric motor is kept constant. The control unit calculates an amplitude setting value with which correction for suppressing non-linearity is performed in a region in which an amplitude setting value of the drive waveform and actual work given to the electric motor is non-linear and controls the speed.

A position sensor mounted in an actuator includes a magnetic detecting element for detecting the position of a shaft, and a temperature detecting element for detecting intra-sensor temperature which is used for correction of the temperature characteristics of the magnetic detecting element, the magnetic detecting element and the temperature detecting element being built therein. A control device for the actuator acquires both the temperature-corrected position of the shaft and the intra-sensor temperature from the position sensor, and uses them for control of the actuator.

In a method for actuating a parking brake in a vehicle, a clamping force is generated by an electromechanical braking device comprising a brake motor. The motor voltage of the brake motor is determined on the basis of the control-unit input voltage of a closed-loop or open-loop control unit.

This linear motor apparatus includes: a first linear motor and a second linear motor, movable bodies of which move in the same direction in a linked manner; a first control portion that causes the first linear motor to produce thrust to apply a load to a pressurizing target via the movable bodies; and a second control portion that causes the second linear motor to produce thrust and controls the thrust, wherein, if the first control portion is causing a load to be applied to the pressurizing target, then the second control portion causes the second linear motor to produce thrust that cancels an external force produced to the movable bodies.

This linear motor apparatus includes: a first linear motor and a second linear motor, movable bodies of which move in the same direction in a linked manner; a first control portion that causes the first linear motor to produce thrust to apply a load to a pressurizing target via the movable bodies; and a second control portion that causes the second linear motor to produce thrust and controls the thrust, wherein, if the first control portion is causing a load to be applied to the pressurizing target, then the second control portion causes the second linear motor to produce thrust that cancels an external force produced to the movable bodies.