E148 — DAP Dual-Circuit Bidirectional Pressure Control

While the preceding E147 family introduced novel valve-side architecture — inverting the inlet valve wiring to enable check-valve-free, fault-tolerant pressure control — E148 addresses the pressure supply side directly. Together, the two families form a comprehensive system: E147 governs how pressure is distributed and maintained at the wheel brakes; E148 governs how pressure is generated and controlled at source.

In brake-by-wire systems for autonomous driving, the demands for simultaneous, independent pressure control across multiple circuits are increasing sharply — for functions such as torque vectoring, brake-steer, and wheel-selective regenerative braking. A single-stroke pump cannot satisfy these requirements without significant valve complexity.

E148 thus complements E147: where E147 controls how valves distribute pressure at the wheel, E148 controls how the DAP supplies pressure at the source. Both patent families together enable a complete, check-valve-free, simultaneously controllable dual-circuit brake-by-wire architecture.

The 5 invention complexes of E148 cover the core DAP device architecture, the volume-control method via pV characteristics, a simplified dual-chamber variant, an adaptive dual-circuit control method, and simultaneous dual-circuit pressure operation.