US 7,581,616 B2Granted

Control system for a steer-by-wire vehicle

AssigneeToyota Jidosha Kobushiki Kaisha

InventorsTakeshi Goto, Ryuichi Kurosawa, Kenji Tozu, Daisuke Yamada

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Abstract

In a vehicle steering apparatus of a steer-by-wire system, front wheels are controlled to be turned by a computer program processing. A displacement/torque conversion section 51 converts a steering angle θ into a steering torque Td that is in relation of exponential function. A torque/lateral-acceleration conversion section 52 converts the steering torque Td into an anticipated lateral acceleration Gd (or anticipated yaw rate γd and anticipated turning curvature ρd) that is in relation of exponentiation function and that serves as a vehicle motion state quantity that can be perceived by a human. A turning angle conversion section 53 calculates a target turning angles δd necessary for the vehicle to move with the anticipated lateral acceleration Gd (or anticipated yaw rate γd and anticipated turning curvature ρd). A turning control section 60 controls the steered wheels to be turned into the target turning angle δd. A driver turns the handle, feeling the lateral acceleration, and hence, the driver can easily drive the vehicle.

Claims15

Dependent claims

A vehicle steering apparatus of a steer-by-wire system provided with a steering handle operated by a driver for steering a vehicle, a turning actuator for turning steered wheels and a turning control device that drives and controls the turning actuator according to the operation on the steering handle for turning the steered wheels, wherein the turning control device comprises:

operation input value detecting means that detects an operation input value by a driver to the steering handle;
motion state quantity calculating means that calculates an anticipated motion state quantity of the vehicle by using the detected operation input value, wherein the anticipated motion state quantity of the vehicle represents the vehicle motion state, that relates to a turn of the vehicle and can be sensed by a driver, and are in the predetermined relation of exponential function or in the predetermined relation of exponentiation function with the operation input value to the steering handle;
turning angle calculating means that calculates a turning angle of the steered wheels necessary for the vehicle to move with the calculated anticipated motion state quantity calculated by the motion state quantity calculating means by using the calculated anticipated motion state quantity;
and
turning control means that controls the turning actuator according to the calculated turning angle for turning the steered wheels into the calculated turning angle.

2 more elements

Dependencies are inferred from the claim text.