Driving force control system
Apparatus for controlling negative pressure for a brake booster in a diesel engine
Method and device for brake application Patent #: 5938297
ApplicationNo. 102113 filed on 06/22/1998
US Classes:303/114.3, Including pneumatic power booster303/113.3, Including booster303/115.2Having electric control
ExaminersPrimary: Graham, Matthew C.
Assistant: Williams, Thomas J.
Attorney, Agent or Firm
International ClassB60T 008/44
AbstractAn electrically augmented brake control method in which vacuum booster run-out and pedal force are accurately predicted as a function of master cylinder pressure and engine vacuum, thereby eliminating the expense of dedicated sensors for measuring the same. A mathematical model of the vacuum booster is used to estimate the apply chamber pressure and the operator brake pedal force, based on measured values of engine vacuum (or manifold absolute pressure) and master cylinder pressure. The point of vacuum booster runout can be detected as the point at which the estimated apply chamber pressure reaches atmospheric pressure. In a preferred embodiment, a force-balance approach is used to carry out the estimation in an accurate but simple manner that is especially amenable to real-time control in an automotive on-board micro-controller.
Field of SearchHaving electric control
Having vacuum motor control
Including hydraulic power booster
Having pump pressure control
Braking pressure demand or braking force desire
Including a stroke sensor
With distinct piston or diaphragm exposed to pulsator pressure imparting feel to manual control
Having load deformable means between master working member and motor thrust means adjusting bias of manual control
With control of or by a separate power fluid, etc.
Flow in recirculating circuit controlled