A trajectory planning system for a vehicle includes a sensor system for measuring an actual curvature on the basis of a respective current yaw rate, a memory containing a target trajectory with target curvatures, wherein the trajectory planning system determines target yaw rates from the target curvature, and a steering system that uses steering variables to obtain target curvatures in actual curvatures. The system determines a respective first actual derivative of the measured respective current actual yaw rate over time and a respective first target derivative of the respective current target yaw rate over time. A correlator determines a respective current delay on the basis of the respective first actual derivatives and the respective first target derivatives in a current yaw rate segment, and a parameter estimator recursively estimates the delay between the target yaw rate and the actual yaw rate on the basis of respective current delay inputs.

A control apparatus controls a steering reaction motor. The control apparatus includes an ideal axial force calculation circuit, an estimated axial force calculation circuit, an imaginary rack end axial force calculation circuit, an axial force allocation calculation circuit and a maximum value selection circuit. The calculation circuits calculate an ideal axial force based on a target pinion angle, an estimated axial force based on a current value of a steering operation motor, an imaginary rack end axial force for imaginarily limiting an operation range of a steering wheel, a mixed axial force obtained by allocating the ideal axial force and the estimated axial force at predetermined allocation ratios. The maximum value selection circuit selects the mixed axial force or the imaginary rack end axial force having a larger absolute value as an axial force to be reflected in the command value.

An input torque fundamental component computation circuit includes: a torque command value computation circuit that computes a torque command value corresponding to a target value for steering torque that is to be input by a driver for drive torque obtained by adding the steering torque to an input torque fundamental component; and a torque F/B control circuit that computes the input torque fundamental component through execution of torque feedback control for causing the steering torque to follow the torque command value. A target steering angle computation circuit computes a target steering angle on the basis of the input torque fundamental component. A steering-side control circuit computes target reaction force torque on the basis of execution of angle feedback control for causing a steering angle to follow a target steering angle. The torque command value computation circuit computes the torque command value in consideration of the grip state amount.

A road surface condition is determined appropriately. A road surface determining section (84) configured to determine a road surface condition with reference to a wheel speed signal indicative of wheel speeds includes a band-stop filter (841) which acts on the wheel speed signal and has a cutoff frequency band which is changed in accordance with the wheel speed signal.

Systems and methods for determining whether a vehicle is in an understeer or oversteer situation. The system includes a controller circuit coupled to an IMU and an EPS, and programmed to: calculate, for a steered first axle, an axle-based pneumatic trail for using IMU measurements and EPS signals and estimate a saturation level as a function of a distance between the axle-based pneumatic trail and zero. The system estimates, for an unsteered second axle, an axle lateral force curve with respect to a slip angle of the second axle, and a saturation level as a function of when the axle lateral force curve with respect to the slip angle transitions from positive values to negative values. The saturation level of the first axle and the second axle are integrated. The system determines that the vehicle is in an understeer or oversteer situation as a function of the integrated saturation levels.

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 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.

A vehicle includes a main body, a steerable wheel, a steering, a steering actuator, and an electronic controller. The main body includes a saddle. The steerable wheel is coupled to the main body via a suspension. The steering is turnably coupled to the main body to steer the steerable wheel. The steering actuator is configured to apply steering torque to the steerable wheel. The electronic controller is configured to control the steering torque using the steering actuator and configured to generate steering damper torque to the steerable wheel using the steering actuator upon determining a reduced contact of the steerable wheel with a traveling surface with respect to a first prescribed threshold.

A vehicle steering arrangement for a vehicle comprises a rack a position sensor, a steering column, a steering wheel, a torque sensor arranged to sense a torque applied onto the steering wheel and arranged to provide a torque signal representative thereof, an electronic control unit provided with a virtual steering model, a rack-mounted electromechanical actuator, and a force obtaining arrangement configured to obtain forces of steered wheels acting on the rack. The electronic control unit is configured to provide a virtual rack position based on the virtual steering model and at least a combination of the obtained forces and the torque signal, and is arranged to control the rack-mounted electromechanical actuator such that the current position of the rack is controlled towards the virtual rack position. The present disclosure also relates to an autonomous vehicle steering arrangement, a vehicle and a method of steering a vehicle.

A method, device, and computer readable medium for controlling drift of a vehicle. The drift of the vehicle is controlled by acquiring a slip rate level and steering information of the vehicle in a drift mode opening state; determining a target drift parameter according to the slip rate level, the steering information and a current vehicle velocity, the target drift parameter includes a target yaw rate; determining a steering compensation quantity according to a current actual yaw rate and the target yaw rate; determining front axle torque, rear axle torque and rear wheel brake torque according to the steering compensation quantity and the steering information; and controlling the vehicle to drift travelling according to the front axle torque, the rear axle torque and the rear wheel brake torque, and controlling a power-assisted steering motor to perform steering compensation according to the steering compensation quantity and the vehicle velocity.