公开(公告)号：US20210405118A1

公开(公告)日：2021-12-30

申请号：US17285700

申请日：2019-10-01

Applicant: Hitachi, Ltd.

Inventor： Akihiro NAKAMURA ,  Kenta DEGUCHI ,  Yoshitaka IWAJI

IPC: G01R31/34 ,  G01R23/02 ,  G06F30/20

Abstract: An object of the present invention is to provide a technique for monitoring the condition of a device or a target processing object.
A monitoring system according to one aspect of the present invention monitors a device powered by an AC motor and estimates a condition of at least one of the device or a target processing object of the device, and includes a time-series data acquisition unit configured to acquire voltage data relating to a drive voltage of an AC motor; a feature value computation unit configured to analyze a feature value of an abnormal voltage waveform in a time-series waveform of the voltage data; and a state estimation unit configured to estimate the condition based on the feature value of the abnormal voltage waveform.

公开(公告)号：US20230417809A1

公开(公告)日：2023-12-28

申请号：US18203870

申请日：2023-05-31

Applicant: Hitachi, Ltd.

Inventor： Akihiro NAKAMURA ,  Takahiro YAMADA ,  Daisuke YAMAZAKI

IPC: G01R23/16 ,  B65G23/00

CPC classification number: G01R23/16 ,  B65G23/00

Abstract: A stretch detection system of a power transmission mechanism is connectable to a conveyor system including a motor, a rotation mechanism driven by the motor, and the power transmission mechanism driven by rotation of the rotation mechanism. The stretch detection system converts a signal of a current of the motor into a frequency domain signal, and calculates an integral value by performing integration on the frequency domain signal obtained by the frequency domain signal conversion unit, by using, as an integration range, at least one of regions of a sideband wave having a frequency determined using a rotation frequency of the rotation mechanism. A stretch diagnosis unit diagnoses a state of stretch of the power transmission mechanism by using the integral value calculated by the integral value calculation unit. Further, an output unit outputs a diagnosis result of the stretch diagnosis unit.

公开(公告)号：US20230102125A1

公开(公告)日：2023-03-30

申请号：US17907846

申请日：2020-10-13

Applicant: Hitachi, Ltd.

Inventor： Akihiro NAKAMURA ,  Koichiro NAGATA

IPC: G01R31/34 ,  G01R19/00 ,  H02P21/14 ,  H02P23/14 ,  H02P27/06

Abstract: The purpose of the present invention is to provide a device monitoring technique having little restriction even on application to an already-existing device or facilitating monitoring even when a device to be monitored is in variable speed operation or under load variation. One of the representative device monitoring devices of the present invention monitors a device system using, as a power source, an AC electric motor driven by an inverter and is provided with a torque current estimation unit and a state estimation unit. The torque current estimation unit acquires information about AC currents of at least two phases and excitation current of the AC electric motor and calculates a torque current estimated value of the AC electric motor on the basis of the AC currents and the excitation current. The state estimation unit estimates the state of the device system from information including at least one of the feature amounts extracted from the torque current estimated value.

公开(公告)号：US20180292813A1

公开(公告)日：2018-10-11

申请号：US15920497

申请日：2018-03-14

Applicant: HITACHI, LTD.

Inventor： Koichiro NAGATA ,  Akihiro NAKAMURA ,  Shuji SOGA ,  Naohito IKEDA ,  Gen TSUCHIDA

IPC: G05B19/418

Abstract: A manufacturing system 10 is configured to include a driving device 4 configured to drive a manufacturing machine 5 in a step pertaining to product manufacture in a predetermined production management system, the driving device 4 driving the manufacturing machine 5 in the step in response to predetermined information obtained related to a state of the step.

公开(公告)号：US20230070822A1

公开(公告)日：2023-03-09

申请号：US17752420

申请日：2022-05-24

Applicant: Hitachi, Ltd.

Inventor： Akihiro NAKAMURA ,  Koichiro NAGATA ,  Takuma NISHIMURA

IPC: F16H61/12 ,  F16H59/70 ,  F16H59/14 ,  G01M13/028 ,  G01R19/00

Abstract: Provided is a transmission device monitoring system including: a diagnostic frequency estimation unit that extracts a plurality of diagnostic frequency candidate groups from a frequency region separated by a specific frequency or more using at least current information on a motor, a gear ratio of a transmission device, and the number of stages of the transmission device, and estimates a frequency satisfying a specific relationship from frequencies obtained in the plurality of diagnostic frequency candidate groups as a diagnostic frequency; and an abnormality diagnosis unit that diagnoses abnormality of the transmission device using at least the one diagnostic frequency estimated by the diagnostic frequency estimation unit.

公开(公告)号：US20140058688A1

公开(公告)日：2014-02-27

申请号：US13975826

申请日：2013-08-26

Applicant: Hitachi, Ltd.

Inventor： Tohru KOHNO ,  Akihiro NAKAMURA ,  Tomoharu NAKAMURA ,  Koki MORIKAWA

IPC: G01R31/02

CPC classification number: G01R31/02 ,  H02S50/10

Abstract: A low-cost failure diagnosis method, without addition of a measuring unit and a communication unit, provided for a solar battery system, of calculating a working temperature and the number of failed solar battery modules in a solar battery array, by calculating a solar radiation amount while updating a predetermined coefficient as a ratio between a short-circuit current and a working current in accordance with state of the solar battery array and using measured data having the working current and working voltage measured with a detection unit.

Abstract translation: 一种低成本故障诊断方法，通过计算太阳能辐射来计算太阳能电池阵列中的太阳能电池模块的工作温度和数量，而不添加用于太阳能电池系统的测量单元和通信单元 根据太阳能电池阵列的状态更新作为短路电流与工作电流之间的比例的预定系数，并使用利用检测单元测量的具有工作电流和工作电压的测量数据。