A steering system for a vehicle, including: a pair of wheel steering devices that respectively steer right and left wheels independently of each other; and a controller configured to control the pair of wheel steering devices, wherein the controller is configured to: determine a standard steering amount or each of the right and left wheels in accordance with a steering request; execute opposite-phase shift steering in which steering amounts of the respective right and left wheels are shifted in mutually opposite directions by respective shift amounts with respect to the standard steering amounts determined respectively for the right and left wheels; and estimate a friction coefficient of a road surface on which the vehicle is running based on steering forces respectively applied to the right and left wheels in the opposite-phase shift steering.

An automatic steering control apparatus includes a steering torque detector and a steering processor. The steering torque detector is configured to detect a steering torque amount applied to a steering shaft of a vehicle. The steering processor is configured to switch between an automatic steering and a manual steering. The steering processor is configured to calculate an integration value in which the steering torque amount detected by the steering torque detector is integrated for a predetermined period, and switch the automatic steering to the manual steering when the integration value exceeds an integration threshold.

A vehicle steering intervention system and method prevents a loss of vehicle control condition or a vehicle rollover condition. The system includes a driver input torque sensor for sensing torque applied by a driver to a steering wheel, a steering angle sensor for sensing a steering angle, and a speed determination device for determining a vehicle speed. An electronic power steering unit includes an electronic processor and a memory. The electronic power steering unit determines a vehicle steering intervention threshold based on the torque sensed, the steering angle, and the vehicle speed. The electronic power steering unit predicts whether the vehicle steering intervention threshold will be exceeded within a predetermined time based on a torque gradient and/or a steering angle gradient. When the vehicle steering intervention threshold is predicted to be exceeded, the electronic power steering unit reduces a power steering assist and/or provides a counter steer force.

A steering assistance control apparatus to be applied to a vehicle includes a detection unit and a correction unit. The detection unit is configured to detect a road surface cant of a road on which the vehicle is traveling. The correction unit is configured to correct a steering target steering-wheel angle in a steering control system, on the basis of a steering characteristic value for each of left steering and right steering and the road surface cant detected by the detection unit. The steering characteristic value indicates a steering characteristic for each combination of a traveling speed and the road surface cant.

An AV is described herein. The AV includes a lidar sensor system. The AV additionally includes a computing system that executes a road surface analysis component to determine, based upon lidar sensor data, whether a road surface feature is present on or in a roadway in a travel path of the AV. The AV can be configured to initiate a mitigation maneuver responsive to determining that the road surface feature is present. Performing the mitigation maneuver causes the AV to avoid the road surface feature or decelerate prior to reaching the road surface feature, thereby improving the apparent quality or comfort of the ride to a passenger of the AV.

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.

A data processing system including a data processing apparatus that can generate an accurate road surface displacement correlating value that is used for a preview damping control is provided. The system includes a cloud having a data processing section and a processing-data-base-section for temporally storing data. The data processing apparatus stores sensing data in the processing-data-base-section, wherein the sensing data is a chunk of sensor values from which a road surface displacement correlating value correlating with a vertical displacement of a road surface on which said vehicle is traveling can be calculated. The sensor values are sequentially and successively detected/obtained by various sensors of the vehicle. The data processing section performs specific offline data processing for a chunk of the sensing data stored in the processing-data-base-section so as to generate data of the road surface displacement correlating value from the sensing data.

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.

A travel control system for a vehicle includes: an external environment recognizing unit that recognizes an obstacle around the vehicle; a tire parameter estimation unit that estimates a tire parameter of a tire of the vehicle; and a travel plan unit that sets a travel route, an amount of acceleration and deceleration, and an amount of turning based on the obstacle and the tire parameter. The travel plan unit sets the travel route, the amount of acceleration and deceleration, and the amount of turning so as to suppress an excess amount of a slip ratio of the tire relative to an adhesion limit slip ratio while avoiding approach to the obstacle.

A surface characterization system includes an active suspension a system with a wheel controller to control a first and second wheel of a vehicle where the active suspension causes a difference in loading between the first and second wheel. The wheel controller may cause the first wheel to slow and receive a signal indicative of a change of state of the vehicle. The wheel controller may cause the second wheel to oppose the change of state caused by the first wheel. The surface characterization system may estimate tire-surface parameterization data associated with the first tire and a surface upon which the vehicle is located.