According to one or more embodiments, a method includes computing, by a steering system, a model rack force value based on a vehicle speed, steering angle, and a road-friction coefficient value. The method further includes determining, by the steering system, a difference between the model rack force value and a load rack force value. The method further includes updating, by the steering system, the road-friction coefficient value using the difference that is determined.

An arithmetic apparatus includes: a sensor acquisition unit that collects sensor information about the surroundings of a vehicle; a feature point extraction unit that extracts a feature point of an object; a target point detection unit that expresses the position of the feature point with spatial coordinates and detects it as a target point; a road edge presumption unit that presumes a segment between the target points, which are continuously aligned, as a road edge; and a blockade judgment unit that judges whether or not to cancel the road edge, on the basis of information about an area behind the presumed road edge, which is obtained from the sensor information, where the area behind the road edge is an area opposite the sensor at the other side of the presumed road edge.

A control device for a steer-by-wire type vehicle calculates a target turn angle being represented as a function of a steering angle of a steering wheel, and controls a turning device such that a turn angle of a wheel becomes the target turn angle. A variation range of the steering angle includes: an effective steering range in which the steering angle is an effective maximum steering angle or smaller; and an adjustment steering range in which the steering angle is between the effective maximum steering angle and a predetermined maximum steering angle. The target turn angle calculated according to the effective maximum steering angle is an effective maximum turn angle. The control device variably sets the function according to a road surface condition such that the effective maximum turn angle in a case of a low- condition is smaller than that in a case of a high- condition.

An object is to provide an attitude control system that can suppress an understeering characteristic when a vehicle such as an automobile travels in a medium-speed or low-speed range. A vehicle drives front wheels, and controls steering angles of the front wheels and steering angles of rear wheels. In an attitude control system to be mounted on the vehicle, a control amount detecting unit detects an operation amount of an accelerator pedal operated by a driver of the vehicle. A driving force estimating unit estimates a driving force generated on the front wheels based on the operation amount of the accelerator pedal. A rear-wheel steering angle determining unit determines a rear-wheel steering angle instruction value for controlling steering angles of the rear wheels based on an estimated front-wheel driving force that is the driving force estimated by the driving force estimating unit.

Provided is a steering control device (10) for a vehicle (12), including a front wheel steering device (14) and a rear wheel steering device (42). When a magnitude of a steering angle (MA) is large in a state in which rear wheels are steered by the rear wheel steering device in the same phase with respect to front wheels, the steering control device carries out calculation so as to increase a rear wheel target correction steering angle bt for a correction steering for the rear wheels (18RL and 18RR) toward an opposite phase direction with respect to the front wheels (18FL and 18FR) compared with when the magnitude of the steering angle is small, and controls the rear wheel steering device based on the target correction steering angle bt, thereby increasing a slip angle toward the inside of a turn of the vehicle.

A vehicle is provided. The vehicle may include an engine that is configured to auto-stop and auto-start. The system may also include a controller programmed to power an electrical actuator coupled to a steering mechanism to synchronize a drive angle of the vehicle and a steering wheel angle of the vehicle, in response to a parameter indicative of a likelihood of a wheel slip event exceeding a threshold and the steering-wheel angle being greater than a predetermined threshold.

The disclosure relates to assessing and responding to wheel slippage and estimating road friction for a road surface. For instance, a vehicle may be controlled in an autonomous driving mode in order to follow a trajectory. A wheel of the vehicle may be determined to be slipping such that the vehicle has limited steering control. In response to determining that the wheel is slipping, steering of one or more wheels may be controlled in order to orient the one or more wheels towards the trajectory in order to allow the vehicle to proceed towards the trajectory when the wheel is no longer slipping. In addition, the road friction may be estimated based on the determination that the wheel is slipping. The vehicle may be controlled in the autonomous driving mode based on the estimated road friction.

An electric power steering system includes a control for providing a calculated torque assist demand in the event of failure of a steering wheel torque sensor. The control is responsive to one or more of a vehicle speed, a steering column position, a steering column velocity, a gear lever position, a vehicle yaw rate and a vehicle lateral acceleration for generating the calculated torque assist demand. The control is operable to modify the torque assist demand by providing one or more of (a) friction and inertial compensation, (b) vehicle oversteer compensation, (c) reverse motion compensation, (d) damping compensation and (e) self steer prevention.

A second target steered angle setter includes: a first multiplier configured to, when the vehicle is making a right turn, reduce a base target steered angle correction amount so as to set the reduced base target steered angle correction amount to be a left target steered angle correction amount, and configured to, in other states, set the base target steered angle correction amount to be the left target steered angle correction amount on an as-is basis; and a second multiplier configured to, when the vehicle is making a left turn, reduce the base target steered angle correction amount so as to set the reduced base target steered angle correction amount to be a right target steered angle correction amount, and configured to, in other states, set the base target steered angle correction amount to be the right target steered angle correction amount on an as-is basis.

A method includes identifying at least a portion of a surface that has a coefficient of friction that is less than a coefficient of friction threshold. The method also incudes determining whether a vehicle speed is greater than a vehicle speed threshold, and determining whether an operator of the vehicle is engaging a handwheel of the vehicle. The method also includes, generating a first alert signal, selectively adjusting at least one steering characteristic of a steering system of the vehicle from a first value to a second value, and, in response to at least one of a reduction in the vehicle speed and a distance between the vehicle and the portion of the surface having the coefficient of friction being less than a distance threshold, selectively adjusting the at least one steering characteristic from the second value to the first value.