US5835872A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electric power steering apparatus
Assignee: Koyo Seiko Co Ltd
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Filing: 1996-09-04
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Granted: 1998-11-10
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Expires: 2016-09-04
Abstract
Abstract An electric power steering apparatus comprising a broken-line function circuit for outputting a predetermined analog broken-line function signal on the basis of a torque detection signal, a gain circuit for giving a predetermined gain to the broken-line function signal, a polarity inverting circuit for inverting the polarity of the broken-line function signal, a first attenuating means for attenuating the torque detection signal at a predetermined rate, a second attenuating means for attenuating an output signal of said polarity inverting circuit at a predetermined rate, an addition circuit for adding a signal from the first attenuating, a signal from the second attenuating means and an output signal of the gain circuit, and outputting the addition value as a target value of a motor current, and a differential amplifying circuit for calculating a difference between the target value and the motor current detected by a detecting circuit for the purpose of feedback control, wherein a steering force assisting motor is driven on the basis of an output signal from the differential amplifying circuit.
Inventors
- 👤 Hirofumi Matsuoka
- 👤 Yasuji Noritou
- 👤 Ken Fukuda
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 09:42
CPC Classifications
B; B62; B62D; B62D5/00; B62D5/04; B62D5/0457; B62D5/0481; B62D5/0487; B62D5/046; B62D5/0463
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
200 words
An electric power steering apparatus, comprising: a steering force assisting motor; a motor driving circuit for driving said motor; a detecting circuit for detecting a motor current in said motor driving circuit; a torque sensor for detecting a steering torque and outputting a torque detection signal; a broken-line function circuit for outputting a predetermined analog broken-line function signal on the basis of said torque detection signal; a gain circuit for providing a gain to said broken-line function signal; a polarity inverting circuit for inverting the polarity of said broken-line function signal; a first attenuating means for attenuating said torque detection signal at a predetermined rate; a second attenuating means for attenuating an output signal of said polarity inverting circuit at a predetermined rate; an addition circuit for adding a signal from said first attenuating means, a signal from said second attenuating means and an output signal of said gain circuit, and outputting the addition value as a target value of said motor current; and a differential amplifying circuit for calculating a difference between said target value and the motor current detected by said detecting circuit and supplying the difference to said motor driving circuit for the purpose of feedback control.
Claim 2
Dependent Claim
200 words
An electric power steering apparatus, comprising: a steering force assisting motor; a motor driving circuit for driving said motor; a detecting circuit for detecting a motor current in said motor driving circuit; a torque sensor for detecting a steering torque and outputting a torque detection signal; a broken-line function circuit for outputting a predetermined analog broken-line function signal on the basis of said torque detection signal; a gain circuit for providing a gain to said broken-line function signal; a polarity inverting circuit for inverting the polarity of said broken-line function signal; a first attenuating means for attenuating said torque detection signal at a predetermined rate; a second attenuating means for attenuating an output signal of said polarity inverting circuit at a predetermined rate; an addition circuit for adding a signal from said first attenuating means, a signal from said second attenuating means and an output signal of said gain circuit, and outputting the addition value as a target value of said motor current; and a differential amplifying circuit for calculating a difference between said target value and the motor current detected by said detecting circuit and supplying the difference to said motor driving circuit for the purpose of feedback control.
Claim 3
Dependent Claim
30 words
An electric power steering apparatus according to claim 1, further comprising a differential circuit for differentiating said torque detection signal and outputting the differentiated signal to said polarity inverting circuit.
Claim 4
Dependent Claim
46 words
An electric power steering apparatus according to claim 1, further comprising a gain determining means for determining said gain on the basis of running conditions of a vehicle, wherein said gain circuit provides said gain determined by said gain determining means to said broken-line function signal.
Claim 5
Dependent Claim
46 words
An electric power steering apparatus according to claim 2, further comprising a gain determining means for determining said gain on the basis of running conditions of a vehicle, wherein said gain circuit provides said gain determined by said gain determining means to said broken-line function signal.
Claim 6
Dependent Claim
49 words
An electric power steering apparatus according to claim 1, further comprising: an upper/lower limit value determining means for determining upper/lower limit values of said target value on the basis of running conditions of a vehicle; and a limiter circuit for limiting said target value by said upper/lower limit values.
Claim 7
Dependent Claim
49 words
An electric power steering apparatus according to claim 2, further comprising: an upper/lower limit value determining means for determining upper/lower limit values of said target value on the basis of running conditions of a vehicle; and a limiter circuit for limiting said target value by said upper/lower limit values.
Claim 8
Dependent Claim
49 words
An electric power steering apparatus according to claim 3, further comprising: an upper/lower limit value determining means for determining upper/lower limit values of said target value on the basis of running conditions of the vehicle; and a limiter circuit for limiting said target value by said upper/lower limit values.
Claim 9
Dependent Claim
49 words
An electric power steering apparatus according to claim 4, further comprising: an upper/lower limit value determining means for determining upper/lower limit values of said target value on the basis of running conditions of the vehicle; and a limiter circuit for limiting said target value by said upper/lower limit values.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2001-11-09 | 2002-05-11 | 2002-11-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-11-09 | 2006-05-11 | 2006-11-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-11-09 | 2010-05-11 | 2010-11-10 | $7700.00 | Window Closed / Lapsed |