The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 11, 2005
Filed:
Feb. 24, 2004
Kazuaki Tobari, Hitachiota, JP;
Tsunehiro Endo, Hitachiota, JP;
Hidefumi Shirahama, Hitachi, JP;
Yoshiyuki Taguchi, Funabashi, JP;
Tomofumi Okubo, Narashino, JP;
Kazuaki Tobari, Hitachiota, JP;
Tsunehiro Endo, Hitachiota, JP;
Hidefumi Shirahama, Hitachi, JP;
Yoshiyuki Taguchi, Funabashi, JP;
Tomofumi Okubo, Narashino, JP;
Hitachi, Ltd., Tokyo, JP;
Hitachi Industrial Equipment Systems Co., Ltd., Chiba, JP;
Abstract
The object of the invention is to inhibit the axial displacement caused by the insufficiency of a control response angular frequency of a frequency arithmetic unit of a synchronous motor and realize high-precision torque control also in acceleration/deceleration. To achieve the object, the axial displacement of the synchronous motor caused by the insufficiency of the control response angular frequency of the frequency arithmetic unit is estimated in consideration of the control response angular frequency and input Δθc(=Δθc+Δθc) including an estimated value Δθcin addition to an axial displacement operated value Δθcto the frequency arithmetic unit is acquired. Hereby, even if the frequency arithmetic unit has an insufficient control response angular frequency, the quantity of axial displacement which will be caused by the insufficiency is estimated as a second axial displacement signal Δθc, is added and input. Therefore, actual axial displacement Δθcof the synchronous motor is stable at a value substantially close to zero.