A braking method includes: obtaining a first state information of the vehicle, which includes a vehicle mass and a deceleration required by braking; calculating a braking torque according to the first state information, and controlling the vehicle to output an electric braking torque according to the braking torque; obtaining a current vehicle speed and a mechanical braking application delay time; calculating an electric braking exit speed according to the braking torque required by the vehicle and the deceleration required by braking; calculating a mechanical braking application speed according to the mechanical braking application delay time, the deceleration required by braking, and the electric braking exit speed; and determining whether to control the vehicle to unload the electric braking torque, and whether to control the vehicle to apply a mechanical braking torque according to the current vehicle speed, the electric braking exit speed, and the mechanical braking application speed.

Method and apparatus are disclosed for traction control based on friction coefficient estimation. An example vehicle includes a plurality of sensors to measure qualities of a surface of a road and an anti-lock brake system module. The anti-lock brake system module (a) estimates confidence values for different road surface types based on the qualities of the surface of the road, (b) estimates a coefficient of friction between the road and tires of the vehicle based on the confidence values, and (c) adapt a traction control system by altering a target slip based on the coefficient of friction.

Systems and methods are provided for generating data indicative of a friction associated with a driving surface, and for using the friction data in association with one or more vehicles. In one example, a computing system can detect a stop associated with a vehicle and initiate a steering action of the vehicle during the stop. The steering action is associated with movement of at least one tire of the vehicle relative to a driving surface. The computing system can obtain operational data associated with the steering action during the stop of the vehicle. The computing system can determine a friction associated with the driving surface based at least in part on the operational data associated with the steering action. The computing system can generate data indicative of the friction associated with the driving surface.

A method for adaptive estimation of a road surface adhesion coefficient for a vehicle with complex excitation conditions taken into consideration comprises the following steps: 1) designing an estimator according to a single-wheel dynamics model of a vehicle, and estimating a longitudinal tire force and a road surface peak adhesion coefficient under longitudinal excitation; 2) designing an estimator according to a two-degree-of-freedom kinematic model of the vehicle, and estimating a tire aligning moment and a road surface peak adhesion coefficient under excitation of a lateral force; and 3) determining an excitation condition met by the vehicle according to a vehicle state parameter, performing fuzzy inference to obtain limits achievable by current longitudinal and lateral tire forces, and designing a fusion observer to fuse estimation results. The method achieves favorable robustness, improves real-time capability, and can be performed quickly and accurately.

A vehicle control apparatus to be applied to a vehicle includes a first traveling motor, a second traveling motor, and a control system. The control system estimates a first friction coefficient between a first wheel and a road surface and a second friction coefficient between a second wheel and a road surface. When the vehicle starts in a situation in which any of the first and second friction coefficients is less than a first threshold and a difference between the first and second friction coefficients is greater than a second threshold, the control system increases a power running torque of the first traveling motor after elapse of a first delay time after increasing a power running torque of the second traveling motor, if the first friction coefficient is smaller than the second friction coefficient. The first delay time is set on the basis of the first friction coefficient.

A system calibrates a function of a tire friction of a vehicle traveling on a road from motion data including a sequence of control inputs to the vehicle that moves the vehicle on the road and a corresponding sequence of measurements of the motion of the vehicle moved by the sequence of control inputs. The system updates iteratively the probability distribution of the tire friction function until a termination condition is met, wherein, for an iteration, the system samples the probability distribution of the tire friction function, determines a state trajectory of the vehicle to fit the sequence measurements according to the measurement model and the sequence of control inputs according to the motion model including the sample of the tire friction function, and updates the probability distribution of the tire friction function based on the state trajectory of the vehicle.

A braking control apparatus to be installed an electric vehicle includes an acceleration and deceleration operation member, a controller, and a recognizer. The acceleration and deceleration operation member receives an acceleration request in accordance with an operation amount in a first direction from a neutral position, and receive a deceleration request in accordance with an operation amount in a second direction from the neutral position. The controller controls an amount of power regenerated by a rotary electric machine driven by wheels in accordance with the operation amount in the second direction. The recognizer recognizes a preceding vehicle traveling ahead of the electric vehicle. Upon detection of the preceding vehicle at a relative distance from the electric vehicle that is equal to or less than a threshold, the controller performs braking suppression control to decrease the amount of power regenerated in accordance with the operation amount in the second direction.

Method, apparatus, and computer-readable medium for performing a braking operation of a vehicle when an object is detected in front of the vehicle. The method includes acquiring at least one image of an external environment of the vehicle, determining a road condition of a road of the external environment of the vehicle based on the acquired at least one image, obtaining, based on the determined road condition and from memory, a braking table of one or more braking tables including distances and corresponding vehicle speeds at which the braking operation is performed, acquiring a speed of the vehicle and a distance between a preceding object and the vehicle, comparing the acquired speed of the vehicle and the acquired distance between the preceding object and the vehicle to the braking table, and sending, based on the comparison, an instruction to perform the braking operation of the vehicle.

A method for controlling a vehicle brake system of a heavy duty vehicle, the brake system comprising a service brake system and an electrical machine brake system. The method includes determining a total brake torque request for braking a wheel of the vehicle, obtaining a brake torque capability of the electrical machine, determining if the total brake torque request exceeds the brake torque capability of the electrical machine, and if the total brake torque request exceeds the brake torque capability of the electrical machine but is below a threshold level, applying a baseline brake torque by the service brake system, wherein the baseline brake torque is configured to compensate for a difference between total brake torque request and brake torque capability of the electrical machine, and controlling wheel slip by the electrical machine brake system.

A method for estimating a friction between a road surface and a tire of a steered wheel of a vehicle. The steered wheel being fit with dynamic steering. The vehicle includes a steering wheel and a set of sensors comprising wheel end sensors and steering wheel sensors configured to measure signals corresponding to a set of parameters., The steering wheel parameters comprising at least a steering wheel torque and a steering wheel angle. The method comprising the following steps implemented by the electronic control unit collect the signals, corresponding to the set of parameters, measured by the sensors during a period of time; process, by the signal processing module, the signals collected to provide processed signal data provide the processed signal data as input to the wheel end friction estimation model, the wheel end friction estimation model being configured to output a friction estimation of the friction between the road surface and the tire of the wheel.