A method is described for determining interface conditions between a tire and the ground in a motor vehicle, particularly to determine an onset of an aquaplaning phenomena. The method includes: determining a reference longitudinal acceleration of the vehicle, measuring an actual longitudinal acceleration of the vehicle, calculating a difference between the reference longitudinal acceleration and the actual longitudinal acceleration, determining an additional drag at the interface between tire and ground on the basis of the difference, and a lift at the interface between tire and ground on the basis of the additional drag, and determining a threshold force at which a lifting of the tire from the ground occurs, comparing the lift with the threshold force and determining a degree of proximity of the interface conditions between tire and ground to an aquaplaning condition.

Methods and systems are provided for operating a driveline of a hybrid vehicle that includes an internal combustion engine, an electric machine, and a transmission are described. In one example, torque output from the engine and the electric machine is adjusted to provide controlled vehicle side slip during cornering by a vehicle.

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.

A vehicle and associated method for calculating tire saturation is provided. The method may include the stability control computer calculating slip ratio and longitudinal force for the tire, calculating tire longitudinal stiffness by dividing longitudinal force by slip ratio, calculating tire saturation from tire longitudinal stiffness, and the stability control computer altering dynamic control of the vehicle based on calculated tire saturation. The stability control computer may calculate tire saturation from a tire saturation membership function which includes a first tire longitudinal stiffness value representing an unsaturated tire, a second tire longitudinal stiffness value representing a saturated tire, and a function line connecting the first tire longitudinal stiffness value to the second tire longitudinal stiffness value.

A system for monitoring vehicle dynamics and detecting adverse events during operation is presented. Position sensors attached to a vehicle are configured to identify a vehicle orientation (heading) as well as the vehicle's direction of travel (trajectory). A system controller connected to these position sensors can detect the difference between these two measurements. When the difference between these two measurements exceeds a safety threshold, it can be an indication of a slip event. A slip event can be caused by compromised traction or stability and may lead to a loss of vehicle control. The system controller can be configured to monitor various vehicle dynamics to detect these slip events. The system controller may be configured to track geolocations of slip events to create a database of historical slip events for determining location-based risk factors and prevention of future events.

A travel control device includes: a risk level calculation unit configured to acquire a speed in a traveling direction of a vehicle, a speed of the vehicle in a horizontal direction perpendicular to the traveling direction, and an azimuth angular velocity of the vehicle and calculate a rollover risk level based on a lateral load transfer ratio (LTR) of the vehicle; a deceleration calculation unit configured to calculate deceleration indicating an extent to which to lower the speed in the traveling direction when an absolute value of the rollover risk level exceeds a threshold value; and a control unit configured to control a driving system of the vehicle using a value obtained by lowering a target speed of the vehicle on the basis of the deceleration as a new target speed.

A method for vehicle motion control includes receiving sensor data from a plurality of sensors of a vehicle and monitoring a vehicle response of the vehicle using the sensor data. The vehicle response is represented by a plurality of vehicle-response signals. The method further includes fusing the plurality of vehicle-response signals to obtain at least one fused signal. The method further includes determining whether to activate a vehicle stability control of the vehicle based on the at least one fused signal and commanding the vehicle to activate the vehicle stability control in response to determining to activate the vehicle stability control of the vehicle based on the at least one fused signal.

A coordinated control method for electric vehicles having independent four-wheel driving and steering, comprising the steps of: calculating to obtain a desired value of yaw velocity according to the steering angle and the current vehicle driving speed, and limiting the desired value of yaw velocity according to the current road adhesion condition; constructing an optimization problem according to the current vehicle motion state and the desired value of yaw velocity, and solving the optimization problem to obtain a desired active rear wheel steering angle control variable and a desired additional yaw moment control variable; calculating to obtain an additional torque of each wheel according to a desired additional yaw moment control variable, obtaining a desired active rear wheel steering angle, and sending the additional torque of each wheel and the desired active rear wheel steering angle to an executor of the vehicle for performing a coordinated control.

A system for lateral control in-path tracking of an autonomous vehicle includes a lateral controller. The lateral controller controls movement of the autonomous vehicle relative to a path and receives as an input a desired target. An outer control loop of the lateral controller includes a first controller generating an output based on the difference between the desired target and a current position of the autonomous vehicle. An inner control loop of the lateral controller includes a second controller receiving the generated output from the first controller. The inner control loop generates a sideslip angle and a yaw rate, wherein the sideslip angle and the yaw rate are returned to the second controller. The sideslip angle and the yaw rate are used to generate the relative yaw angle and lateral distance, which are returned to the first controller as the current position of the autonomous vehicle.

A set of driving scenarios are determined for different types of vehicles. Each driving scenario corresponds to a specific movement of a particular type of autonomous vehicles. For each of the driving scenarios of each type of autonomous vehicles, a set of driving statistics is obtained, including driving parameters used to control and drive the vehicle, a driving condition at the point in time, and a sideslip caused by the driving parameters and the driving condition under the driving scenario. A driving scenario/sideslip mapping table or database is constructed. The scenario/sideslip mapping table includes a number of mapping entries. Each mapping entry maps a particular driving scenario to a sideslip that is calculated based on the driving statistics. The scenario/sideslip mapping table is utilized subsequently to predict the sideslip under the similar driving environment, such that the driving planning and control can be compensated.