Force and position control for active front steering
First Claim
1. A steering system comprising:
- an input shaft;
a torsion bar moved by the input shaft and providing torque feedback to the input shaft;
a differential operatively connected to the torsion bar;
a rack and pinion operatively connected to the differential;
a primary actuator operatively connected to the rack and pinion for moving the rack; and
, a secondary actuator operatively connected to the differential.
9 Assignments
0 Petitions
Accused Products
Abstract
A steering system with reduced coupling between a position overlay unit and a torque overlay unit may include a remote valve assembly for controlling a hydraulic assist force or an electric motor for providing torque overlay and electric assist to a rack of a rack and pinion steering system. In one embodiment, the position overlay unit may provide the assist force and the torque overlay unit may provide a motor command signal to the motor of a differential positioned on a steering shaft. In another embodiment, the position overlay unit may provide the motor command signal and the torque overlay unit may provide the assist force. In either embodiment, the position overlay unit may include variable ratio gain that uses a position signal to output a variable ratio command.
56 Citations
30 Claims
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1. A steering system comprising:
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an input shaft;
a torsion bar moved by the input shaft and providing torque feedback to the input shaft;
a differential operatively connected to the torsion bar;
a rack and pinion operatively connected to the differential;
a primary actuator operatively connected to the rack and pinion for moving the rack; and
,a secondary actuator operatively connected to the differential. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17)
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18. A steering system comprising:
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a position overlay unit for applying one of an assist force to a rack and a motor command to a motor;
a torque overlay unit for applying the other of the assist force to a rack or the motor command to a motor; and
,one of an electric power mechanism and a hydraulic power mechanism for providing the assist force to the rack. - View Dependent Claims (19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30)
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Specification