Abstract: A brake by wire system is integrated with a brake transmission solenoid interlock (BTSI) unit to prevent a vehicle transmission from being shifted out of a park mode into a drive mode until a brake system operational state is determined. The BTSI is activated by a supplemental control unit, which generates a transmission release signal generated by a controller in response to simultaneous presence of a brake intent signal from one or more brake pedal sensors and a determination of an operational state of the brake system. The supplemental control unit includes a switch responsive to the transmission release signal to close the BTSI activating circuit and permit release of the transmission. In a split brake system with two brake controllers, the supplemental control unit may include a switch controlled by a logic (OR, AND) circuit or a pair of switches in an equivalent logical circuit configuration.

Abstract: An electrical system architecture for a vehicle brake by wire system provides three electrical power sources: an electric generator, an electric power storage device such as a battery, and a third source which may be either an electric generator or storage device. An electric circuit has a common node and (1) connects the first electric generator to the common node through a first diode, (2) connects the first electric power storage device to the common node through a second diode, (3) connects the electric power source to the common node through one of the first and second diodes, and (4) connects the common node to the electric power inputs of control unit through circuit breaker devices. A sub-circuit within the electric circuit interconnects the first and second diodes, the common node and the first and second circuit breaker devices and isolates them within a zone protected from short circuits to points outside the zone.

Abstract: A brake by wire system is integrated with a brake transmission solenoid interlock (BTSI) unit to prevent a vehicle transmission from being shifted out of a park mode into a drive mode until a brake system operational state is determined. The BTSI is activated by a supplemental brake control unit, which receives a transmission release signal from a brake system controller upon receipt of a brake intent signal from one or more brake pedal sensors after a diagnostic program has determined the brake system operational state. The supplemental brake control unit includes a switch responsive to the transmission release signal to close the BTSI activating circuit and permit release of the transmission. In a split brake system with two brake controllers, the supplemental brake control unit may include a switch controlled by a logic (OR, AND) circuit or a pair of switches in an equivalent logical circuit configuration.

Abstract: An electrical system architecture for a vehicle brake by wire system provides three electrical power sources: an electric generator, an electric power storage device such as a battery, and a third source which may be either an electric generator or storage device. An electric circuit has a common node and (1) connects the first electric generator to the common node through a first diode, (2) connects the first electric power storage device to the common node through a second diode, (3) connects the electric power source to the common node through one of the first and second diodes, and (4) connects the common node to the electric power inputs of control units through circuit breaker devices. A sub-circuit within the electric circuit interconnects the first and second diodes, the common node and the first and second circuit breaker devices and isolates them within a zone protected from short circuits to points outside the zone.

Abstract: A brake apply system includes a pressure charging module having a bore carrying a pumping piston that has a base piston surface and an augmentation piston surface. The pressure charging piston separates the bore into an input chamber adjacent the base piston surface and an output chamber adjacent the augmentation piston surface. A suspension damper is hydraulically connected to the input chamber of the pressure charging module, preferably through a continuously open fluid communication circuit. A wheel brake is hydraulically connected to the accumulator output chamber through a selectively open fluid communication circuit.

Abstract: A brake apply system includes a modulator that has a first bore carrying a power driven dual-effect piston. The piston has a base piston surface and an augmentation piston surface. A wheel brake is hydraulically connected to the modulator through an open fluid communication route that is provided between the wheel brake and the base piston surface. A selectively open fluid communication route is provided between the wheel brake and the augmentation piston surface with a check valve mechanism positioned in the selectively open fluid communication route. An augmentation chamber is defined adjacent the augmentation surface of the dual-effect piston. The modulator includes a second bore carrying a valve mechanism that provides an open flow path between the augmentation chamber and a reservoir when pressure at the wheel brake is relatively high and that significantly restricts the flow path when the wheel brake pressure is relatively low.

Abstract: A braking system including a wheel brake with a dual piston caliper assembly provides a brake by wire add-on system with dual level manual override capabilities. A pressure control block associated with the wheel brake directs fluid pressure generated by the master cylinder to the first and the second pistons of the caliper assembly for operation of the braking system in a manual apply mode. An electro-hydraulic modulator generates operating pressure in the brake by wire mode. The electro-hydraulic modulator communicates with the pressure control block so that fluid pressure generated by the electro-hydraulic modulator is transmitted to a single piston of the caliper assembly and is prevented from being communicated to the first piston of the caliper assembly by a solenoid valve assembly positioned in the pressure control block.