Automatic steering apparatus for vehicle and control method of same
AssigneeToyota Jidosha Kabushiki Kaisha
InventorJun Sakugawa
Life of this patent
Estimating the term…
Abstract
A target relative rotation angle of automatic steering is calculated; a target current for assist steering during automatic steering is calculated based on the sum of a torque that inhibits a reaction force of the automatic steering from acting on a steering wheel, a torque that cancels out torque that acts resulting from self-aligning torque of the steered wheels, and a torque according to a steering angle; a target current for assist steering to reduce a steering load on a driver is calculated; a weight of the target current is calculated to increase as the target relative rotation angle increases; and an electric power steering unit is controlled, with a weight sum of the target currents as a final target current.
Claims14
A semi-steer-by-wire automatic steering apparatus for a vehicle, comprising:
- an assist steering unit, which is provided in a steering system between a steering wheel and steered wheels, and which assists with steering of, and automatically steering, the steered wheels relative to the steering wheel;
- an assist steering force generating unit, which is provided in the steering system, and which generates an assist steering force that assists with steering the steered wheels;
- a first detector that detects a torque of the steering system;
- and
- a controller which calculates a target assist steering amount of the assist steering unit;
- calculates a first target assist steering force to control a torque acting on the steering wheel to a target torque during non-automatic steering based on the torque detected by the first detector;
- calculates a second target assist steering force to control a torque acting on the steering wheel to a target torque during automatic steering based on the target assist steering amount and a running state of the vehicle;
- calculates a final target assist steering force as a weight sum of the first and second target assist steering forces;
- controls the assist steering unit based on the target assist steering amount;
- controls the assist steering force generating unit based on the final target assist steering force;
- and decreases the weight of the first target assist steering force and increases the weight of the second target assist steering force during automatic steering as compared to during non-automatic steering.
A control method for a semi-steer-by-wire automatic steering apparatus for a vehicle having an assist steering unit, which is provided in a steering system between a steering wheel and steered wheels, which assists with steering of, and automatically steering, the steered wheels relative to the steering wheel, and an assist steering force generating unit, which is provided in the steering system, which generats an assist steering force that assists with steering the steered wheels, the control method by comprising:
- calculating a target assist steering amount of the assist steering unit;
- detecting a torque of the steering system;
- calculating a first target assist steering force to control a torque acting on the steering wheel to a target torque during non-automatic steering based on the detected torque;
- calculating a second target assist steering force to control a torque acting on the steering wheel to a target torque during automatic steering based on the target assist steering amount and a running state of the vehicle;
- calculating a final target assist steering force as a weight sum of the first and second target assist steering forces;
- controlling the assist steering unit based on the target assist steering amount;
- controlling the assist steering force generating unit based on the final target assist steering force;
- and
- decreasing the weight of the first target assist steering force and increasing the weight of the second target assist steering force during automatic steering as compared to during non-automatic steering.
Dependencies are inferred from the claim text.