The present invention relates to a method for avoiding excess pressures in a pressure medium circuit of an electronically slip-controllable braking system in the event of a decline of an intrinsic elasticity of the braking system and an electronically slip-controllable braking system. Electronic control units, ascertain a setpoint value for a delivery volume of the pressure generator of these braking systems and convert it into an activation signal for the drive of the pressure generator. In dependence on the prevailing elasticity of the pressure medium circuit, a pressure gradient is established, using which the pressure in the pressure medium circuit changes over time. The ascertainment of an activation signal for the drive of the pressure generator by the electronic control unit is based on the established pressure gradient.

An electronic parking brake (EPB) system having expanded functionality, such that after a Hydraulic Electronic Control Unit (HECU) (i.e., host) commands the parking brake units to release clamping force on the brake discs, a pressure differential is generated in the rear calipers. When the normally closed valves at the HECU are opened, fluid is transferred to a low-pressure accumulator, transferring the brake fluid from the housing of the caliper. A pump is then activated to further draw fluid from the accumulator and the caliper, transferring the fluid back to the master cylinder. The suction created by the activation of the pump moves the caliper piston towards the housing and the brake pad away from the brake disc, and achieving the desired air gap.

A method of identifying a fault in a friction brake actuated by hydraulic brake pressure and configured to decelerate a vehicle road wheel includes detecting, via a first sensor, a vibration at the road wheel and communicating data indicative of the detected vibration to a controller. The method additionally includes detecting, via a second sensor, upon application of the hydraulic brake pressure, a hydraulic brake pressure variation and communicating data indicative of the detected hydraulic brake pressure variation. The method additionally includes comparing, via the controller, the data indicative of the detected vibration with a threshold vibration value and the data indicative of the detected hydraulic brake pressure variation with a threshold hydraulic brake pressure value. Furthermore, the method includes generating a sensory signal indicative of the brake fault when magnitudes of the detected vibration and the detected hydraulic brake pressure variation are greater than their respective threshold values.

A diagnostic method, in particular to determine the leak tightness of at least one seal and/or one valve, for at least one component of a vehicle, wherein a piston cylinder unit, whose piston is driven by an electromotive drive, forms a pressure supply unit, wherein a control unit identifies the piston position and/or piston movement of the piston by means of at least one sensor and the pressure generated by the pressure supply unit or the motor current flowing through the drive by means of at least one sensor. During the diagnostic method, the control unit may be used to measure quantities relating to piston movement/position, pressure, and/or pressure variation.

The present disclosure provides systems and methods for communicating between control systems via hydraulic fluid. In one example embodiment, a computer-implemented method includes operating a first pressure regulating device associated with a first control system to regulate a fluid pressure of hydraulic fluid being supplied through a hydraulic line, the first pressure regulating device being in fluid communication with a hydraulically actuated component via the hydraulic line. The method includes controlling the operation of the first pressure regulating device to generate a fluid-pressure based signal within the hydraulic line, the signal providing an indication of an operational status of at least one of the first control system or the hydraulically actuated component. The method includes detecting pressure changes within the hydraulic line associated with the signal to allow a second control system to monitor the operational status of the first control system and/or the hydraulically actuated component.

A system comprises a plurality of handheld devices including a plurality of transceivers. A control unit may be coupled to a handheld device of the plurality of handheld devices. The system may further include a plurality of end-of-train air devices coupled to a plurality of air brakes. An air manifold may be coupled to the plurality of air brakes. The system may include a controller coupled to the control unit and to the air manifold. A processor may be coupled to the controller and the control unit, and a non-transitory computer readable medium may be coupled to the processor. The non-transitory computer readable medium may include instructions executable to receive information from the control unit corresponding to an air brake test performed on the plurality of end-of-train air devices, determine a status of the air brake test, generate an inspection form based on the received information and the determined status, and transmit the generated inspection form for printing.

A method of detecting a leak in an air trailer brake circuit of a trailer includes providing a controller, a base valve, a first sensor, a second sensor, a leak control valve having a solenoid, a pneumatic fluid supply, a first brake output, and a second brake output. The method further includes supplying a first pressure to an inlet of the base valve and outputting a second pressure from an outlet of the base valve. The first pressure is detected with the first sensor and the second pressure is detected with the second sensor. The method also includes communicating the detected first pressure and the second pressure to the controller, and comparing a difference between first pressure and the second pressure to a threshold. A leak is detected in the air trailer brake circuit if the difference satisfies the threshold.

A method for monitoring a hydraulic brake system for a motor vehicle, wherein a diagnostic valve is omitted and, instead, air volume and leakage are identified by a volume balance during generation of a dynamic pressure. An associated brake system is also disclosed.

A method of detecting a leak in a hydraulic trailer brake circuit of a trailer includes providing a controller, a base valve, a first sensor, a second sensor, a control valve having a solenoid, a reduction valve, a hydraulic fluid supply, a first brake output, and a second brake output. The method also includes supplying a first pressure to an inlet of the base valve and outputting a second pressure from an outlet of the base valve to the first brake output. The first pressure is detected by the first sensor and the second pressure is detected by the second sensor, and the detected first and second pressures are communicated to the controller. The difference between the first and second pressures are compared to a threshold, and a leak is detected in the hydraulic trailer brake circuit if the difference satisfies the threshold.

Provided is a brake apparatus capable of securing a braking force on a vehicle even at the time of a fluid leak. The brake apparatus performs control so as to continue generation of a brake hydraulic pressure to be supplied to a wheel cylinder with use of a second hydraulic source if a fluid leak of brake fluid is determined based on a preset relationship between a hydraulic pressure of a first hydraulic source and a stroke of a brake pedal.