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. 28, 2003
Filed:
Jan. 22, 2002
Masaki Matsushita, Tokyo, JP;
Masahiro Kimata, Tokyo, JP;
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
An electric power steering control system is arranged so as to control a drive current of a brushless motor that generates a steering assist force on the basis of a steering torque acting on a steering shaft and a vehicle speed. The system comprises a d-q axis voltage command section for computing a d- and q-axis voltage command value in response to a deviation of current between a d- and q-axis current command value and a d- and q-axis detection current value, a d-q coordinate inverse transformation section for performing the d-q coordinate inverse transformation on the basis of the d- and q-axis voltage command value and an electrical angle signal, eventually thereby computing a three-phase voltage command value, a three-phase voltage command compensation section for performing compensation with respect to the three-phase voltage command value according to a computing expression for improving the efficiency of utilizing a preset voltage, thereby computing a three-phase voltage command compensation value, and a PWM output section for generating a PWM waveform for PWM drive of the brushless motor in response to the three-phase voltage command compensation value.