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:
Apr. 15, 2008
Filed:
Jan. 24, 2005
Mimpei Morishita, Fuchu, JP;
Mimpei Morishita, Fuchu, JP;
Toshiba Elevator Kabushiki Kaisha, Tokyo, JP;
Abstract
Torque ripple of a motor due to a rotation detection device is reduced. A periodicity gain multipliermultiplies the rotation angle θ of a detection target by a ripple periodic number m per rotation of the detection target. An adderadds a phase adjusting value 'ψ' from a phase adjustorto the value 'mθ'. The value “sin(mθ+ψ)”, which is calculated by a sine calculator, is multiplied by a predetermined gain G by an amplitude adjustorand by the angular velocity ω of the detection target by a multiplier. A subtractorsubtracts the output of the multiplierfrom the value “ω” and outputs “ω(1−G sin(mθ+ψ))”. The output of the subtractorand the output “mθ+ψ” of the adderare input to the phase adjustorand amplitude adjustor. The phase adjustorcalculates the phase adjusting value “ψ” based on the summation of the derivative values of the outputs from the subtractorsampled for each “π/2” of the output from the adder. The amplitude adjustorcalculates the gain G based on the summation of the differences between averages of the sampled values at “0” and “π” of the output of the adderand averages of the time integration value at the integral interval of “0” to “π”.