A method for checking functionality of a motor vehicle braking system. The braking system has a main module, including: hydraulically actuatable wheel brakes, pairs being assigned to respective brake circuits; at least one electrically actuatable wheel valve per wheel brake sets wheel-specific brake pressures; a pressure provision device actively builds up pressure in the wheel brakes; a pressure-medium reservoir at atmospheric pressure, and an auxiliary module, which has for each of two wheel brakes: a pressure sensor for measuring pressure in a wheel brake line; an open when deenergized isolating valve in the wheel brake line; a pump. At least one variable is measured to assess functionality of the braking system. Using least one acceptance criterion, and checked whether the variable satisfies the acceptance criterion. Determining at least one variable representing the viscosity of the brake fluid, and the at least one acceptance criterion depends on a variable representing viscosity.

A pedal feel emulator comprises a housing extending along a center axis between a closed end and an opened end and defining a chamber extending therebetween. A first piston is slidably disposed in the chamber. The first piston defines a compartment in fluid communication with the chamber. A second piston is slidably disposed in the compartment. A spring seat extends radially outwardly from the second piston. A first elastic member is located in the chamber extending between the spring seat and the closed end. A second elastic member is located in the compartment and extending between the spring seat and the first piston. A third elastic member is located between the second piston and the first piston. A brake system including the pedal feel emulator is also disclosed herein.

A method of controlling a braking device includes receiving a braking torque instruction, on the basis of the received braking torque instruction, setting a first braking torque set point for a first brake and a second braking torque set point for a second brake, measuring a first value of a first parameter representative of the first braking torque and modifying the first braking torque set point as a function of the first value with the aid of a first servocontrol loop, and measuring a second value of a second parameter representative of the second braking torque and modifying the second braking torque set point as a function of the second value with the aid of a second servocontrol loop.

At least one embodiment of the present disclosure provides an electric booster brake apparatus including an electric booster unit, an electronic stability control (ESC) operating unit, and an electric-booster control unit. The electric booster unit has a motor, and a motor piston and a master cylinder and pressurizes the master cylinder by adjusting a displacement of the motor piston. The ESC operating unit includes a pressure sensor measuring pressure in the master cylinder and calculates a required braking pressure. The electric-booster control unit controls the position of the motor piston. The electric-booster control unit includes a feedforward control unit for converting the value of the required braking pressure into a motor piston displacement, and a feedback control unit for calculating a compensation displacement of the motor piston based on a difference between the value of the required braking pressure and the value of the pressure in the master cylinder.

A control method of a hydraulic brake apparatus for a vehicle including a first brake device and a second brake device configured to supply hydraulic pressure to wheel brakes, and a control unit including a first controller controlling the first brake device and a second controller controlling the second brake device, includes receiving information for determining a status of the first brake device by means of the control unit; determining whether the first brake device is normally operated using the information for determining a status of the first brake by means of the control unit; and controlling at least one of the first brake device and the second brake device to decrease a hydraulic pressure loss amount in the wheel brakes when the control unit determines that the first brake is not normally operated.

A brake pad state estimation device estimates a brake pad state including at least one of a wear volume and a temperature of a brake pad of a vehicle. The brake pad state estimation device acquires sensor detection information including a vehicle speed and a brake pressure, and calculates the brake pad state based on the sensor detection information during braking of the vehicle. The brake pad state estimation device variably sets a sampling period for acquiring the sensor detection information from a sensor according to a driving environment for the vehicle. The sampling period in a case where the wear volume or the temperature of the brake pad is expected to be lower is set to be longer than the sampling period in a case where the wear volume or the temperature of the brake pad is expected to be higher.

Systems and methods for providing opportunistic vehicle air brake system pressurization are disclosed. Vehicle air tanks used within an air brake system are pressurized during a time a battery charging status is satisfied. For example, such air tanks may be pressurized via an air compressor at a time during which the vehicle is electrically connected to a power source other than a battery of the vehicle. An example of such a power source may include an electrical charger, such as an electric vehicle charging station, or an electric generator during a regenerative braking event. The air tanks may also be pressurized by using a battery to energize the air compressor, based on the battery being charged above a predetermined threshold.

A vehicle includes: a brake pedal to produce vehicle brake pressure; a trailer brake valve to output a variable trailer brake pressure to a trailer brake of a trailer, the trailer brake valve configured to output the variable trailer brake pressure as a function of the vehicle brake pressure; and an electronic control unit operably coupled to the trailer brake valve and configured to: output a first valve signal to the trailer brake valve to output the trailer brake pressure according to a first vehicle brake pressure curve; and output a second valve signal to the trailer brake valve to output the trailer brake pressure according to a second vehicle brake pressure curve responsively to determining a curve adjustment condition exists. The first vehicle brake pressure curve and/or the second vehicle brake pressure curve is not a single straight line curve.

A brake system may include an actuating device, in particular a brake pedal; a first piston-cylinder unit having two pistons subjecting the brake circuits to a pressure medium via a valve device, wherein one of the pistons can be actuated by the actuation device; a second piston-cylinder unit having an electric motor drive, a transmission at least one piston to supply at least one of the brake circuits with a pressure medium via a valve device; and a motor pump unit with a valve device to supply the brake circuits with a pressure medium. The brake system may also include a hydraulic travel simulator with a pressure or working chamber which is connected to the first piston-cylinder unit.

A brake system for a vehicle is provided. The brake system is designed to selectively apply pressure to and release it from at least two pressure connectors for brake actuators, and each of the pressure connectors can be coupled to an associated brake actuator of a wheel of the vehicle. The brake system has a master brake module and an auxiliary brake module, wherein the master brake module and the auxiliary brake module each have at least one sensor for detecting a fluid pressure in the respective brake module, and with a control unit which is configured to monitor and compare a fluid pressure in the master brake module and in the auxiliary brake module by the measured values detected by the sensors, and, based on the pressure and/or pressure curve, to draw a conclusion about the functional capability of the auxiliary brake module. A method is furthermore provided for performing a functional test of the brake system.