Abstract: The motor drive apparatus to perform vector control having excellent control performance on a motor includes an A/D converter which acquires currents flowing through a u-phase, a v-phase and a w-phase of the motor, a vector control unit which performs vector control on the motor based on d-axis motor current and q-axis motor current acquired by coordinate-converting the digitalized currents, a motor parameter and a desired angular speed of a motor rotor, a PWM generator which generates a PWM signal to drive the motor based on a motor voltage acquired by the vector control unit, and a parameter estimation unit which estimates a motor resistance, a d-axis motor inductance and a q-axis motor inductance in a direct current excitation state based on maximum peak values and minimum peak values of a d-axis motor voltage and a q-axis motor voltage and estimates a motor inductive voltage constant in a forced commutation control state.

Abstract: The motor drive apparatus to perform vector control having excellent control performance on a motor includes an A/D converter which acquires currents flowing through a u-phase, a v-phase and a w-phase of the motor, a vector control unit which performs vector control on the motor based on d-axis motor current and q-axis motor current acquired by coordinate-converting the digitalized currents, a motor parameter and a desired angular speed of a motor rotor, a PWM generator which generates a PWM signal to drive the motor based on a motor voltage acquired by the vector control unit, and a parameter estimation unit which estimates a motor resistance, a d-axis motor inductance and a q-axis motor inductance in a direct current excitation state based on maximum peak values and minimum peak values of a d-axis motor voltage and a q-axis motor voltage and estimates a motor inductive voltage constant in a forced commutation control state.

Abstract: In a laser-power control method, a power of laser light emitted from a laser-light emitting element and a driving current for driving the laser-light emitting element are detected. An approximate expression indicating a driving-current to light-power characteristic of the laser-light emitting element is updated on the basis of the detected light power and the detected driving current while sequentially increasing accuracy. A command driving current corresponding to a target light power is calculated by using the updated approximate expression. The laser-light emitting element is driven on the basis of the calculated command driving current so as to output the target light power.