A time series waveform of detected vibration of a tire during travel is multiplied by a window function of a prescribed time width and a time series waveform for each time window is extracted to calculate a feature vector from the time series waveform for each time window. Thereafter, when determining the state of the road surface during travel using the feature vector for each time window and road surface models, a plurality of the aforementioned road surface models is constructed depending on the magnitude of a braking/driving force, the braking/driving force acting on the aforementioned tire is estimated, and the state of the road surface is determined using the road surface models, which depend on the aforementioned feature vector and the magnitude of the estimated braking/driving force. The aforementioned road surface models are constructed with learning data comprising time series waveform data of tire vibration obtained by causing a vehicle mounted with a tire provided with an acceleration sensor to travel on road surfaces in multiple road surface states.

The present disclosure provides a system and a method for correcting a friction coefficient of a brake pad for a vehicle, which can estimate a brake factor including a friction coefficient of a brake pad, and ultimately correct the brake factor through the calculation and the update of a brake factor offset based on the estimated brake factor, thereby enhancing the braking linearity of an electric brake system.

A braking force control device includes a target acceleration calculation unit that calculates a first target acceleration based on an acquired operation amount of an accelerator pedal, a powertrain capability acquisition unit that acquires a braking force that is generable by a powertrain, and an instruction unit that instructs generation of braking forces in the powertrain and a brake. The instruction unit is configured to, when a first braking force for achieving the first target acceleration is equal to or less than the braking force that is generable by the powertrain, instruct a controller of the powertrain to generate the first braking force, and when the first braking force is larger than the braking force that is generable by the powertrain, instruct the controller of the powertrain to generate the braking force that is generable by the powertrain.

For rapid and precise actuation of a friction brake, the thermal expansion of the friction brake is determined using a thermal model of the friction brake and therefrom the temperature-dependent shift in the contact point is determined for the braking operation and the temperature-dependent shift in the contact point is taken into account when determining the actuation measure of the friction brake to be adjusted.

The disclosed invention makes use of slip related values to calculate friction related values and tire stiffness related values and feeds back an estimated tire stiffness relates value or a calculated friction related as a basis for further calculations. In particular, the disclosure relates to methods, apparatuses and computer program products to achieve the mentioned objective.

A method and a device for determining braking-related actual values of a train assembly including multiple carriages for carrying out a deceleration-controlled braking of the train assembly, in which the longitudinal deceleration and the longitudinal slope are considered to be actual values, from which an adjustment value balancing the control deviation is determined for a control element of the brake by a deceleration controller/deceleration force controller according to a predefined setpoint value of a desired braking deceleration.

In a braking performance evaluation method including the steps of acquiring a tire ground contact pressure distribution, acquiring a sliding friction coefficient table, and calculating a friction force of an entire tire using a brush model having a function representing the tire ground contact pressure distribution and the sliding friction coefficient table, the step of acquiring the tire ground contact pressure distribution includes the step of acquiring a first ground contact pressure distribution on a road surface on which no water film is present via actual measurement or calculation and the step of acquiring a second ground contact pressure distribution by applying reduction in a ground contact pressure due to a water film intruded between the tire and the road surface to the first ground contact pressure distribution and using the second ground contact pressure distribution as the tire ground contact pressure distribution used for the calculating.

An arithmetic model generation system includes a sensor information acquisition unit, a tire force calculator, and an arithmetic model update unit. The sensor information acquisition unit acquires acceleration of a tire. The tire force calculator includes an arithmetic model for calculating tire force F based on the acceleration, and calculates the tire force F by inputting the acceleration acquired by the sensor information acquisition unit. The arithmetic model update unit compares tire axial force measured by the tire and the tire force F calculated by the tire force calculator, and updates the arithmetic model.

A method and a device for estimating coefficients of friction of a wheel of a vehicle with respect to an underlying surface including decomposing a supplied trajectory into individual curve segments, estimating a lateral force and a slip angle for a front axle of the vehicle, assigning respectively estimated lateral forces and slip angles relating to the associated individual curve segments and storing these value pairs in a memory, estimating a tire characteristic curve for each of the curve segments based on the value pairs stored for the respective curve segment in the memory, estimating a coefficient of friction for each curve segment based on the respectively estimated tire characteristic curve, and storing the estimated coefficients of friction relating to the respectively associated curve segments in a coefficient of friction map.

An emergency braking system of a single-track vehicle configured to intervene in a braking process of the single-track vehicle is provided. The emergency braking system includes a plurality of sensors that determine various physical variables. From the physical variables an accident risk actual value is determined, compared with an accident risk target value using an emergency braking system control unit, and if the accident risk actual value exceeds the accident risk target value, the single-track vehicle's brake is actuated by the emergency braking system control unit.