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.

A system and method for generating a pressure-volume curve for a hydraulic system in a vehicle. The system includes a plunger coupled to the hydraulic system, a pressure sensor configured to detect a pressure of the hydraulic system, and an electronic controller configured to access a prior pressure-volume curve from a memory, generate a signal to move the plunger, receive a pressure from the pressure sensor, generate a new pressure-volume curve based upon the received pressure and a position of the plunger, compare the new pressure-volume curve to the prior pressure-volume curve, in response to the new pressure-volume curve and the prior pressure-volume curve differing by at least a threshold value, replace the prior pressure-volume curve with the new pressure-volume curve in the memory, and actuating the hydraulic system based upon the stored pressure-volume curve.

A motor vehicle brake system having at least four hydraulically actuatable wheel brakes, including an electrically actuatable inlet valve for each wheel brake. A master brake cylinder actuable by a brake pedal is separably hydraulically connected via an isolation valve to a brake supply line to which the inlet valves are connected, and an electrically controllable pressure-providing device having a pressure space hydraulically connected to the brake supply line. An electrically actuatable circuit isolation valve inline with the brake supply line. With the circuit isolation valve closed the brake supply line is hydraulically separated into first and second line sections. The first line section connected to two of the inlet valves, and the second line section connected to the remaining inlet valves. The pressure space is hydraulically connected to the second line section. The circuit isolation valve is normally open, wherein the pressure chamber of the master brake cylinder is connected to the first line section via the isolation valve.

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 system and method for testing a tractor trailer is disclosed. The system includes a housing having connections for establishing an electrical and pressure connection to the electrical system and ABS of a tractor trailer, respectively, a circuit board that generates electrical signals and pressure signals corresponding to the connections, an electronic device for displaying the electrical signals and pressure signals, a wireless transceiver for transmitting the electrical signals and pressure signals to the electronic device, and a memory for storing the transmitted electrical signals and pressure signals. The method includes connecting the tractor trailer electrical system and ABS connections to the housing, powering on the tractor trailer, querying an electrical signal and/or pressure signal of the electrical system and ABS, wirelessly transmitting the electrical signal and/or pressure signal to an electronic device, and displaying the electrical signal and/or pressure signal on the electronic device.

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, and generate an inspection form based on the received information and the determined status.

A motor vehicle brake system having at least four hydraulically actuatable wheel brakes, including an electrically actuatable inlet valve for each wheel brake. A master brake cylinder actuable by a brake pedal is separably hydraulically connected via an isolation valve to a brake supply line to which the inlet valves are connected, and an electrically controllable pressure-providing device having a pressure space hydraulically connected to the brake supply line. An electrically actuatable circuit isolation valve inline with the brake supply line. With the circuit isolation valve closed the brake supply line is hydraulically separated into first and second line sections. The first line section connected to two of the inlet valves, and the second line section connected to the remaining inlet valves. The pressure space is hydraulically connected to the second line section. The circuit isolation valve is normally open, wherein the pressure chamber of the master brake cylinder is connected to the first line section via the isolation valve.

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 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 for determining a leakage in a hydraulic brake system in a vehicle includes evaluating a suspected leakage in the hydraulic brake system and taking into account an actuation of an automated hand brake during the evaluation of the suspected leakage. The hydraulic brake system has a hydraulic footbrake and the automated hand brake has an electromechanical actuator. The hydraulic footbrake and the automated hand brake are configured to act on the same brake piston.