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 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 service and emergency braking control system for at least one railway vehicle, including a plurality of braking control modules is provided. Each braking control module is equipped for: if, when achieving a determined braking torque value from an applied braking torque, an instantaneous deceleration value is lower than the target deceleration value, increasing the applied braking torque until the instantaneous deceleration value reaches the target deceleration value, or until the maximum available adhesion from an axle controlled by said braking control module is indicated.

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 controlling a hydraulic brake system for a motor vehicle to carry out a braking operation by means of at least one wheel brake includes, in a first step, a pressure buildup in the wheel brake, wherein hydraulic fluid is passed to a wheel brake via a normally open inlet valve. In a second step, a pressure reduction takes place in the wheel brake, wherein hydraulic fluid is discharged from the wheel brake via an energized normally closed outlet valve. The pressure reduction at the wheel brake is accomplished by means of control of the outlet valve in a predefined manner.

Methods and apparatus to control braking of a vehicle during low deceleration operations are disclosed. A disclosed apparatus includes a controller configured to determine a deceleration of a vehicle, compare the deceleration to a threshold, and modulate, at a predetermined frequency, a brake pressure of the vehicle in response to the deceleration being below the threshold.

A method is described for operating a vehicle, including the following steps: determining a respective traction of the vehicle wheels; determining which of the respective tractions of the vehicle wheels per axle of the vehicle is the highest traction; determining which of the respective highest tractions per axle is the lowest traction; controlling a admission pressure-generating device as a function of the determined lowest traction of the respective highest tractions per axle such that the admission pressure-generating device regulates a brake pressure in a single-channel brake circuit for the vehicle wheels as a function of the determined lowest traction such that the vehicle is decelerated according to the regulated brake pressure. Also described are a corresponding device, a corresponding system, and a computer program product.

The invention relates to a method for improving the control behavior of an electronic motor vehicle braking system which comprises at least a slip control function. Wheel dynamic information which is evaluated as a criterion for initiating a control intervention is used individually for each wheel and is compared with control thresholds for a pressure reduction phase, a pressure maintenance phase, and a pressure buildup phase for generating corresponding braking torques by means of a vehicle braking system. According to the invention, the expected acceleration change of a vehicle wheel is calculated from a pressure change at said wheel, said pressure change being caused by a control intervention; the actual acceleration change at the vehicle wheel, said acceleration change being caused by the pressure change, is determined from measured wheel speeds as wheel dynamic information; and the control behavior of the slip control is adapted when the actual acceleration change deviates from the expected acceleration change by a defined degree such that the deviation is minimized.

A method for estimating a value representing the frictional behavior of a vehicle being driven on a road segment, including receiving operating parameters of a vehicle including at least, a driving wheel angular velocity, an angular velocity of a free wheel of the vehicle, and vehicle a dynamic characteristic; computing a first ratio between the driving wheel angular velocity and the angular velocity of a free wheel of the vehicle, which are acquired when the vehicle is moving substantially in a straight line at a velocity greater than or equal to a first preset threshold; determining, from the received operating parameters, a second ratio between the driving wheel radius and the free wheel radius; determining a slip rate from a product of the first and second determined ratios; and obtaining a value representing the vehicle's frictional behavior by normalizing the determined slip rate using at least the vehicle's dynamic characteristic.

Various antilock braking systems, devices, and methods using sensorized brake pads are disclosed. In some embodiments, the present disclosure provides a method for improving the performance of an antilock braking (ABS) and anti-slip regulation (ASR) system of a vehicle. The method can include detecting the actual value of the coefficient of friction (e.g., between a tire and the ground), updating the coefficient of friction during braking using the braking torque data derived from at least one braking pad of each wheel, and adjusting brake force. For example, the brake force can be adjusted as a function of and/or to be approximately equal to the value of the actual tire-road friction during braking.