Negative pressure supply system

Abstract

A negative pressure supply system (2) that supplies a negative pressure to a negative pressure chamber (91) of a brake booster (9) includes: a negative pressure pump (3); a control device (4) that controls the negative pressure pump (3); a first air pressure sensor (5) that detects, as a first negative pressure (P1), an air pressure inside the negative pressure chamber (91) with reference to an atmospheric pressure; a second air pressure sensor (6) that detects an absolute pressure inside the negative pressure chamber (91); and an atmospheric pressure sensor (7) that detects an atmospheric pressure. The control device (4) calculates a second negative pressure (P2) from the detected absolute pressure and atmospheric pressure, and performs control based on the first negative pressure (P1) and the second negative pressure (P2). Figure 1