Motor vehicle steering system
First Claim
1. A motor vehicle steering system selectively operable in a steer-by-wire mode with rear steering, steer-by-wire mode without rear steering, electronic power assist steering (EPAS) mode with rear steering, electronic power steering (EPAS) without rear steering, mechanical backup manual mode with rear steering, and mechanical backup manual mode without rear steering, the steering system comprising:
- a front road wheel actuator system including a front road wheel actuator adapted for directing an at least one front road wheel in accordance with a front steering value;
a rear road wheel actuator system including an independent rear road wheel actuator adapted for directing an at least one rear road wheel in accordance with a rear steering value;
a driver interface system including a reaction torque generator, the driver interface system coupled to the front road wheel actuator system, the driver interface system adapted to determine the steering value, and further adapted to communicate the steering value to the front and rear road wheel actuator systems;
a clutch mechanism selectively coupling the driver interface system and the front road wheel actuator system; and
a controller adapted to determine one of the steer-by-wire mode with rear steering, steer-by-wire mode without rear steering, electronic power assist steering (EPAS) mode with rear steering, electronic power steering (EPAS) without rear steering, mechanical backup manual mode with rear steering, or mechanical backup manual mode without rear steering, the controller coupled to the front and rear road wheel actuator systems, the driver interface system, and the clutch mechanism,wherein in the steer-by-wire mode with rear steering the controller maintains the clutch mechanism in a disengaged state and the controller operates the driver interface system and the front and rear road wheel actuator system such that the motor vehicle is electronically steerable; and
in the steer-by-wire mode without rear steering the controller maintains the clutch mechanism in a disengaged state and the controller operates the driver interface system and the front road wheel actuator system such that the motor vehicle is electronically steerable; and
in the EPAS mode with rear steering the controller causes the clutch mechanism to engage and selectively causes one of the road wheel actuator system or the driver interface system to provide electronic power assist steering while controlling the rear steering; and
in the EPAS mode without rear steering the controller causes the clutch mechanism to engage and selectively causes one of the road wheel actuator system or the driver interface system to provide electronic power assist steering while deactivating the rear steering; and
in the backup mode with rear steering, the controller causes the clutch mechanism to engage such that the motor vehicle is mechanically steerable while controlling the rear steering; and
in the manual backup mode without rear steering, the controller causes the clutch mechanism to engage such that the motor vehicle is mechanically steerable while deactivating the rear steering.
13 Assignments
0 Petitions
Accused Products
Abstract
A steering system selectively operable in one of six modes: steer-by-wire with rear steering, steer-by-wire without rear steering, electronic power assist steering (EPAS) with rear steering, electronic power steering (EPAS) without rear steering, mechanical backup manual steering with rear steering, and mechanical backup manual steering without rear steering. The steer-by-wire system includes a driver interface system (DIS), a front road wheel actuator system (FRWAS), a rear road wheel actuator system (RRWAS), and a controller for monitoring and implementing the preferred control strategy. The steering system operates normally in a steer-by-wire mode. In each of the EPAS mode and manual mode, the controller causes a clutch mechanism to engage, thus creating a mechanical linkage between the steerable member and the rack and pinion system while maintaining rear wheel assisted steering. In the EPAS mode, one of the front road wheel actuator or the reaction torque generator is available to assist in the steering operation along with rear wheel steering. Alternatively, in the manual mode, both the DIS and the FRWAS are deactivated and the vehicle is steerable through mechanical device along with the rear wheel assisted steering.
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Citations
40 Claims
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1. A motor vehicle steering system selectively operable in a steer-by-wire mode with rear steering, steer-by-wire mode without rear steering, electronic power assist steering (EPAS) mode with rear steering, electronic power steering (EPAS) without rear steering, mechanical backup manual mode with rear steering, and mechanical backup manual mode without rear steering, the steering system comprising:
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a front road wheel actuator system including a front road wheel actuator adapted for directing an at least one front road wheel in accordance with a front steering value; a rear road wheel actuator system including an independent rear road wheel actuator adapted for directing an at least one rear road wheel in accordance with a rear steering value; a driver interface system including a reaction torque generator, the driver interface system coupled to the front road wheel actuator system, the driver interface system adapted to determine the steering value, and further adapted to communicate the steering value to the front and rear road wheel actuator systems; a clutch mechanism selectively coupling the driver interface system and the front road wheel actuator system; and a controller adapted to determine one of the steer-by-wire mode with rear steering, steer-by-wire mode without rear steering, electronic power assist steering (EPAS) mode with rear steering, electronic power steering (EPAS) without rear steering, mechanical backup manual mode with rear steering, or mechanical backup manual mode without rear steering, the controller coupled to the front and rear road wheel actuator systems, the driver interface system, and the clutch mechanism, wherein in the steer-by-wire mode with rear steering the controller maintains the clutch mechanism in a disengaged state and the controller operates the driver interface system and the front and rear road wheel actuator system such that the motor vehicle is electronically steerable; and
in the steer-by-wire mode without rear steering the controller maintains the clutch mechanism in a disengaged state and the controller operates the driver interface system and the front road wheel actuator system such that the motor vehicle is electronically steerable; and
in the EPAS mode with rear steering the controller causes the clutch mechanism to engage and selectively causes one of the road wheel actuator system or the driver interface system to provide electronic power assist steering while controlling the rear steering; and
in the EPAS mode without rear steering the controller causes the clutch mechanism to engage and selectively causes one of the road wheel actuator system or the driver interface system to provide electronic power assist steering while deactivating the rear steering; and
in the backup mode with rear steering, the controller causes the clutch mechanism to engage such that the motor vehicle is mechanically steerable while controlling the rear steering; and
in the manual backup mode without rear steering, the controller causes the clutch mechanism to engage such that the motor vehicle is mechanically steerable while deactivating the rear steering. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40)
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Specification