A system and a method of improving a braking performance during a failure of a brake-by-wire (BBW) device, includes BBW devices including electro-mechanical brakes provided for respective wheels of a vehicle and independently performing braking, and the BBW devices including controllers electrically connected to the electro-mechanical brakes, and the system includes a steer-by-wire controller configured for controlling front wheels through an electronic signal and a rear wheel steering (RWS) controller configured for controlling steering of rear wheels such that a rear wheel steering angle is to be controlled in the same or an antiphase of a front wheel steering angle, wherein when one of the controllers fails, at least one of the steer-by-wire controller and the RWS controller is configured to control steering based on whether a driver's required braking force exceeds a maximum braking force which may be generated by any one of the front and rear wheels.

An apparatus for estimating a friction coefficient of a road surface is provided. The apparatus includes a current sensor configured to measure a control current value of a rear wheel steering (RWS) motor, a stroke sensor configured to measure a stroke value indicating a movement amount of a rear wheel steering link, and a controller configured to estimate the friction coefficient of the road surface based on the control current value measured by the current sensor and the stroke value measured by the stroke sensor.

An assembly for plausibility checking and/or reinitializing a rear wheel steering system of a vehicle having a rear wheel steering unit, which includes at least one rear wheel actuator for adjusting a rear-wheel steering angle and a sensor for detecting the set position of the rear wheel actuator, with at least one reference sensor for detecting a reference signal and with an electronic control unit for carrying out the plausibility check and/or reinitialization of the sensor. The reference sensor is part of a vehicle unit different from the rear wheel steering unit and is designed to detect a vehicle-status-dependent reference signal. Furthermore, the control unit includes at least one mathematical model which, based on the vehicle-status-dependent reference signal, can determine a reference value and/or a reference vehicle status, with which the plausibility check and/or reinitialization can be carried out by the control unit.

Disclosed herein is an apparatus for controlling standalone-type rear wheel steering (RWS), which includes a vehicle speed detection unit for detecting a vehicle speed by communicating with a sensor installed in a vehicle or an Electronic Control Unit (ECU); a steering angle and steering angular velocity detection unit for detecting steering angles and steering angular velocities of front and rear wheels by communicating with a sensor installed in the vehicle or the ECU; a master cylinder pressure detection unit for detecting a master cylinder pressure by communicating with a sensor installed in the vehicle or the ECU; and a controller for determining braking or turning of the vehicle using the information detected using the sensors or received from the ECU, calculating the amount of toe-in when the vehicle is braking or calculating a rear wheel steering angle when the vehicle is turning, and controlling the RWS based thereon.

A steering control device is configured to control a steering of a vehicle having at least one piloted actuator associated with a system for steering a wheel of the vehicle and a piloted actuator associated with a decoupled braking system at a wheel of the vehicle. The steering control device includes at least one control unit. The control unit is configured to recover at least one value characteristic of the travel of the vehicle and to issue a control instruction to the at least one piloted actuator according to the recovered value(s). The control unit includes a calculation module in which a model of a lateral dynamic behavior of the vehicle frame is implemented. At least one specific physical quantity of the lateral dynamic behavior is expressed according to the specific drifts of each set of front wheels and rear wheels of the vehicle.

A four wheel steering vehicle (1), in which front wheels (2f) and rear wheels (2r) can be steered in response to a steering input from a steering wheel (11), includes a rear wheel steering control unit (50) that variably controls a rear wheel steering device such that the rear wheels are steered in a prescribed relation to a steered angle of the front wheels. When the steering input is determined while the front wheel brake and the rear wheel brake are engaged, the rear wheel steering control unit disengages the rear wheel brake and steers the rear wheels. When the fore and aft inclination angle detected by an inclination sensor (40) provided on the vehicle is greater than a threshold value, the rear wheel steering control unit prohibits a steering of the rear wheels and keeps the rear wheel brake engaged even if the steering input is determined.

An integrated control system for a vehicle is provided. The system includes a friction coefficient calculation unit that calculates friction coefficients of left side and right side road surfaces, respectively, based on vehicle wheel state information and a predetermined setting information collected during ABS operation. A feedforward braking pressure calculation unit calculates a feedforward braking pressure of each vehicle wheel using the friction coefficients. An ABS braking pressure calculation unit calculates an ABS braking pressure of the each vehicle wheel based on the feedforward braking pressure and slip rate information. A rear wheel steering control amount calculation unit calculates a rear wheel steering control amount for yaw compensation using the ABS braking pressure of each vehicle wheel and a rear wheel steering controller executes a rear wheel steering control according to the rear wheel steering control amount.

A vehicle control system with a control device includes an additional deceleration calculation unit, an additional braking force calculation unit that calculates an additional braking force to be generated by a braking force generator according to the additional deceleration, and a control permission determination unit that selectively permits an additional deceleration control that commands the braking force generator to generate the additional braking force at least according to the steering angle, the steering angular velocity, and the lateral acceleration, the control permission determination unit permitting the additional deceleration control when a product of the steering angle and the steering velocity is a positive value, wherein even when the product of the steering angle and the steering velocity is a not positive value, the control permission determination unit permits the additional deceleration control when a product of the steering angle and a differential value of the lateral acceleration is not negative.

A method generates a setpoint for controlling a steering system and a differential braking system of a motor vehicle. The method includes: acquiring a value relating to a total yawing moment to be applied to the motor vehicle such that it follows a required path, and the speed of the motor vehicle, calculating, as a function of the speed, at least one threshold relating to the maximum proportion of the total yawing moment that the steering system or that the differential braking system can provide, determining, as a function of the threshold, a distribution rate relating to the proportion of the total yawing moment that the steering system or that the differential braking system must provide, and generating a setpoint for controlling the steering system and the differential braking system as a function of the distribution rate and of the value relating to the total yawing moment.

A method for estimating a friction coefficient of a roadway by a transportation vehicle, wherein a control device of the transportation vehicle receives a first estimated value of a maximum horizontal force from a traction control system that is transmitted to the roadway by a wheel of the transportation vehicle. A control device receives a second estimated value of a wheel contact-patch force of the wheel from a damper controller and calculates the friction coefficient as a vehicle-independent friction coefficient based on the estimated values from the wheel contact-patch force and the horizontal force.