A method for controlling movement of an autonomous vehicle includes: estimating a set of tire force margins with respect to each wheel of the vehicle and a set of dynamic chassis margins associated with a chassis module of the vehicle; based on the margins, determining whether the vehicle is capable of moving in accordance with a decision command; when the determination is negative, outputting a request for update of the decision command; and when an updated decision command has not been received, calculating a set of marginal actuating signals based on the decision command, the margins, required slip angles respectively for the wheels and a center of percussion of the vehicle so as to make the autonomous vehicle move accordingly.

A yaw motion control method for a four-wheel distributed vehicle includes: calculating the steering response of the vehicle in a steady state using a nonlinear vehicle model in reference with an understeering degree while constraining by the limit value of the road surface adhesion condition according to the sideslip angle response and the vertical load change in the steady state, calculating the lateral force response and the self-aligning moment response of the tires in the steady state by a magic tire formula, calculating the required additional yaw moment by using the yaw motion balance equation, reasonably distributing the generalized control force to the four drive motors through the optimization algorithm in combination with the current driving conditions; finally, off-line storing and retrieving the calculation results of the off-line distribution of different vehicle parameters required by different upper layers to distribute the torques to the four drive wheels.

A yaw motion control method for a four-wheel distributed vehicle includes: calculating the steering response of the vehicle in a steady state using a nonlinear vehicle model in reference with an understeering degree while constraining by the limit value of the road surface adhesion condition according to the sideslip angle response and the vertical load change in the steady state, calculating the lateral force response and the self-aligning moment response of the tires in the steady state by a magic tire formula, calculating the required additional yaw moment by using the yaw motion balance equation, reasonably distributing the generalized control force to the four drive motors through the optimization algorithm in combination with the current driving conditions; finally, off-line storing and retrieving the calculation results of the off-line distribution of different vehicle parameters required by different upper layers to distribute the torques to the four drive wheels.

A device for estimating a friction coefficient between a road surface and an automotive tire through determination of a steering torque during a steering maneuver of a slow-rolling or stationary vehicle includes a computer configured for constructing a brush model for a description of the steering torque across a contact patch between the tire and road surface. The steering torque is a torque acting on a steering axis required to overcome resistance to tire twisting on the road surface at a wheel velocity and a steering rate. The steering torque depends on a tire brush vertical load distribution and relative motion of tire brushes and the road surface. The device further includes sensors for measuring the wheel velocity and the steering rate and mechanism for measurements or estimation of the steering torque. The friction coefficient is estimated based on the measurements or estimation of the steering torque and the brush model.

A device for estimating a friction coefficient between a road surface and an automotive tire through determination of a steering torque during a steering maneuver of a slow-rolling or stationary vehicle includes a computer configured for constructing a brush model for a description of the steering torque across a contact patch between the tire and road surface. The steering torque is a torque acting on a steering axis required to overcome resistance to tire twisting on the road surface at a wheel velocity and a steering rate. The steering torque depends on a tire brush vertical load distribution and relative motion of tire brushes and the road surface. The device further includes sensors for measuring the wheel velocity and the steering rate and mechanism for measurements or estimation of the steering torque. The friction coefficient is estimated based on the measurements or estimation of the steering torque and the brush model.

The disclosure relates to a method to control torque distribution among a plurality of electric machines connected to at least one front wheel and at least one rear wheel of a vehicle during operation, comprising: acquiring the total torque requested; obtaining the most energy efficient torque distribution mode by using a loss model or loss map; evaluating the actual driving situation; determining if a mode switch is allowed depending on the actual driving situation; switching the torque distribution mode, if allowed; and preventing a mode switch, if not allowed.

The disclosure relates to a method to control torque distribution among a plurality of electric machines connected to at least one front wheel and at least one rear wheel of a vehicle during operation, comprising: acquiring the total torque requested; obtaining the most energy efficient torque distribution mode by using a loss model or loss map; evaluating the actual driving situation; determining if a mode switch is allowed depending on the actual driving situation; switching the torque distribution mode, if allowed; and preventing a mode switch, if not allowed.

A method and system for controlling a wheel slip of a vehicle without using a reference speed is provided. The system includes a speed detector that detects a speed of a driving device for operating the vehicle and a controller that determines a torque calibration command based on a torque command of the driving device, and a current speed and a past speed of the driving device detected by the speed detector. The torque command of the driving device is calibrated using the determined torque calibration command, and a driving device is operated based on the calibrated torque command.

A method and system for controlling a wheel slip of a vehicle without using a reference speed is provided. The system includes a speed detector that detects a speed of a driving device for operating the vehicle and a controller that determines a torque calibration command based on a torque command of the driving device, and a current speed and a past speed of the driving device detected by the speed detector. The torque command of the driving device is calibrated using the determined torque calibration command, and a driving device is operated based on the calibrated torque command.

A vehicle including a Global Positioning System (GPS) sensor, an Inertial Measurement Unit (IMU), and an Advanced Driver Assistance System (ADAS) is described. Operating the vehicle includes determining, via the GPS sensor, first parameters associated with a velocity, a position, and a course, and determining, via the IMU, second parameters associated with acceleration and angular velocity. Roll and pitch parameters are determined based upon the first and second parameters. A first vehicle velocity vector is determined based upon the roll and pitch parameters, the first parameters, and the second parameters; and a second vehicle velocity vector is determined based upon the roll and pitch parameters, road surface friction coefficient, angular velocity, road wheel angles and the first vehicle velocity vector. A final vehicle velocity vector is determined based upon fusion of the first and second vehicle velocity vectors. The vehicle is controlled based upon the final vehicle velocity vector.