Patent EP0659629A2 successfully refreshed from Google Patents.
EP0659629A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Electric power steering apparatus
Assignee: Koyo Seiko Co Ltd
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Filing: 1994-12-21
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Granted: —
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Expires: 2014-12-21
Abstract
Abstract The invention provides an electric power steering apparatus, in which one of a pair of switching elements (Q₁),(Q₂),(Q₃),(Q₄) that has been PWM controlled is turned off and the other switching element is PWM controlled instead when a steering wheel is returning to its neutral position, thereby allowing the steering wheel to return smoothly and preventing a control hunting.
Inventors
- 👤 Hirofumi C/O Koyo Seiko Co. Ltd. Matsuoka
- 👤 Mitsuhiko C/O Koyo Seiko Co. Ltd Nishimoto
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-31 18:36
CPC Classifications
B; B62; B62D; B62D5/00; B62D5/04; B62D5/0457; B62D5/046; B62D5/0466
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
145 words
An electric power steering apparatus for assisting a steering force by driving a motor (M) so as to decrease torque supplied to a steering wheel, comprising a bridge circuit including said motor (M) and two pairs of first and second switching elements (Q₁, Q₂, Q₃ and Q₄), said two pairs being provided for driving said motor in the clockwise direction and in the counterclockwise direction, respectively, characterized by including: decision means for deciding whether said steering wheel is being returned to its neutral position; and means (10) for performing PWM control on one of said first switching elements in accordance with the torque supplied to said steering wheel and turning off one of said second switching elements belonging to the same pair as said first switching element belongs to, when said decision means decides that said steering wheel is being returned to its neutral position.
Claim 2
Dependent Claim
156 words
An electric power steering apparatus according to claim 1, wherein said decision means includes: a resistance (R) connected in series with said motor at a bridging portion in said bridge circuit; a differential amplifier (1) for obtaining a difference between a motor driving current detected by said resistance and a target value of the motor driving current in accordance with the torque supplied to said steering wheel; means (11) for deciding whether polarities of said target value of the motor driving current and a differential output of said differential amplifier (1) are different; and means (10) for detecting change of the polarity of said differential output, and said decision means decides that said steering wheel is being returned to its neutral position when said means (11) for deciding whether the polarities are different decides that the polarities are different and said means (10) for detecting the change of the polarity decides that the polarity is changed.
Claim 3
Dependent Claim
43 words
An electric power steering apparatus according to claim 1, wherein said means (10) for performing PWM control usually performs PWM control on said second switching element in accordance with the torque supplied to said steering wheel and turns on said first switching element.
References Cited (Backward Citations)
No citation records indexed.
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