Motor vehicles – Compensating devices
Patent
1985-10-23
1989-01-31
Mitchell, David M.
Motor vehicles
Compensating devices
180142, 3644241, B62D 504
Patent
active
048009741
ABSTRACT:
An electronic control system for a steering assembly having an electric motor coupled to the steering assembly for providing power assist. The electric power assist motor is drivably connected to a steering member for assisting movement thereof in response to applied input torque to the vehicle steering wheel. The electronic control unit monitors an output signal from a torsion sensor which measures the amount of applied input torque. The electronic control unit generates a pulse width modulated signal having a duty cycle proportional to the measured amount of applied input torque. Solid state switches provide connection between the vehicle battery and the motor, the connection time being controlled by the duty cycle of the pulse width modulated signal. A speed decoder determines which of a plurality of speed ranges the vehicle is moving. A plurality of look-up tables are provided, each table includes a value of power assist for a given amount of applied input torque. A look-up table is selected depending upon the decoded vehicle speed. Soft start circuitry is provided to control the maximum amount of assist that is permitted upon initial application of power to the electronic control unit. The amount to assist permitted increases from a minimum to a maximum within a predetermined amount of time. Temperature foldback circuitry is also provided to limit the amount of current through the electric power assist motor dependent upon sensed temperature of the solid state switches. The amount of current permitted through the motor is also limited to an absolute maximum. A connection cable is provided to reduce radiated electromagnetic emissions and voltage transients.
REFERENCES:
patent: 491109 (1893-02-01), Holman
patent: 1625125 (1962-11-01), Latour
patent: 3201675 (1970-08-01), Curran et al.
patent: 3525029 (1975-02-01), Joslyn et al.
patent: 3536975 (1981-03-01), Hough
patent: 3868554 (1983-11-01), Konrad
patent: 4259626 (1984-10-01), Normura et al.
patent: 4415054 (1984-06-01), Drutchas
patent: 4437532 (1984-06-01), Nakamura et al.
patent: 4454573 (1984-09-01), Petcsch et al.
patent: 4456087 (1985-09-01), Lang et al.
patent: 4471280 (1984-09-01), Stack
patent: 4476529 (1984-10-01), Nakamura et al.
patent: 4513835 (1985-04-01), Fukino et al.
patent: 4538698 (1985-09-01), Hashimoto et al.
Motorola TDA 1285A.
Gaubis Philip A.
Guest, Jr. Philip Q.
Wand Thomas J.
McGiehan Donn
Mitchell David M.
TRW Inc.
LandOfFree
Electric steering gear does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Electric steering gear, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Electric steering gear will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-173607