Kabushiki Kaisha Toshiba

Toshiaki Ohgushi

Takeichiro Nishikawa

Takashi Usui

Takashi Endo

Daiki Kiribuchi

Takehiro Hara

Takehiko Tsuboi

Kunihiro Shimada

According to an embodiment of the present invention, a storage management apparatus to manage a plurality of storage combinations which are combinations of storages included in a storage group, includes a combination failure probability calculator and an allocation ratio calculator. The combination failure probability calculator calculates a failure probability of the storage combination based on a failure probability of each of the storages. The allocation ratio calculator calculates an allocation ratio of received data with respect to the storage combination based on the failure probability of the storage combination.

Storage management apparatus, storage system, and storage management method

According to one embodiment, physical position information on errors on a recording medium is acquired, physical position relationship between the errors on the recording medium is calculated based on the position information, and a failure mode related to the errors is determined based on the position relationship.

Information memory device, failure predicting device and failure predicting method

According to one embodiment, there is provided a quality controlling device including: a predictor, a frequency calculator, and an implementing signal creator. The predictor employs a prediction model that associates an inspection result value of a first inspection with a predicted value being a value relating to a possibility of pass or failure in a second inspection and calculates the predicted value from an inspection result value that is obtained for an inspection target in the first inspection. The frequency calculator calculates, for the inspection target, an implementation frequency to implement the second inspection in accordance with the predicted value calculated by the predictor. The implementing signal creator creates a signal that indicates, for the inspection target, necessity of implementing the second inspection in accordance with the implementation frequency.

Quality controlling device and control method thereof

According to one embodiment, a failure prognosis device includes circuitry configured to determine whether a sign of failure exists in a head, based on a signal quality value and a floating quantity of the head, the signal quality value being based on an error between a reproducing signal acquired from the head when reading data stored on a storage surface of a disk and a predetermined target signal, and output a determination result.

Failure prognosis device, method, and storage system

The motor driving circuit includes a first converting circuit that outputs an analog voltage proportional to a rotational speed of a motor, a differential voltage calculating circuit that calculates a differential voltage between the analog voltage and a rotation instruction voltage that prescribes the rotational speed of the motor and outputs a differential voltage signal including information on the differential voltage, a duty controlling circuit that outputs, based on the differential voltage signal, a duty controlling signal including information on a control duty that controls a duty of a PWM signal so as to bring the differential voltage between the rotation instruction voltage and the analog voltage close to zero, and a motor driving waveform controlling circuit that generates the PWM signal in response to a signal based on the duty controlling signal and that outputs the PWM signal.

Motor driving circuit and motor driving system

The characteristic is defined by a characteristic line that connects a lowest point at which the duty of the PWM signal is a minimum value and the rotation command signal is a minimum rotation command signal, and a highest point at which the duty of the PWM signal is a maximum value and the rotation command signal is a maximum rotation command signal. The duty calculating circuit updates the characteristic so that the characteristic line passes through a first control point at which the duty of the PWM signal is a value set based on the first setting signal and the rotation command signal is a first rotation command signal between the minimum rotation command signal and the maximum rotation command signal.

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.

Growing community of inventors

Kanagawa, Japan

Toshiaki Ohgushi