Electronic brake management system with manual fail safe

A brake system comprising:

• a brake pedal for operating a brake system actuator;
• a pedal travel sensor for generating a stroke signal representative of the stroke of said brake pedal;
• a brake system sensor for generating a force signal representative of the brake application force applied by a driver to said brake pedal;
• a control unit responsive to a demand signal for controlling said brake system actuator, said demand signal being generated as a blended function of both said stroke, signal and said force signal wherein, during a first part of the stroke of said brake pedal, said stroke signal is weighted greater than said force signal, and wherein, during a second part of the stoke of said brake pedal, said force signal is weighted greater than said stroke signal.

An electro-hydraulic brake system comprising:

• a reservoir of hydraulic brake fluid;
• a pump having a suction port and a discharge port, said suction port being connected in fluid communication with said reservoir;
• a first fluid conduit being connected in fluid communication with said discharge port of said pump;
• a fluid separator unit having a housing with a bore defined therethrough, said bore having a first end and a second end, said first end of said bore being connected in fluid communication with said discharge port of said pump via said first fluid conduit, said fluid separator unit further including a piston slidingly disposed in said bore and a spring disposed to urge said piston toward said first end of said bore;
• a second fluid conduit connected in fluid communication with said second end of said fluid separator unit;
• a vehicle brake connected in fluid communication with said second end of said fluid separator unit via said second fluid conduit;
• a third fluid conduit connected in fluid communication with said vehicle brake;
• a hydraulic master cylinder connected in fluid communication with said vehicle brake via said third fluid conduit;
• an electrically-operated valve disposed in said third fluid conduit, said valve preventing the flow of hydraulic brake fluid between said master cylinder and said vehicle brake when closed, said valve being open to permit the flow of hydraulic brake fluid between said master cylinder and said vehicle brake when said valve is electrically deenergized;
• a fourth fluid conduit connected in fluid communication with said master cylinder and said third fluid conduit;
• a pedal simulator connected in fluid communication with said master cylinder via said fourth fluid conduit;
• an second electrically-operated valve disposed in said fourth fluid conduit, said second valve being closed to prevent the flow of hydraulic brake fluid between said master cylinder and said pedal simulator when said second valve is deenergized, said second valve permitting the flow of hydraulic brake fluid between said master cylinder and said pedal simulator when said second valve is open;
• and
• a damping circuit hydraulically interposed between said master cylinder and said pedal simulator, said damping circuit comprising, in parallel flow paths, an orifice and a check valve such that said damping circuit presents a first cross sectional flow area to fluid flowing from said master cylinder through said damping circuit into said pedal simulator, and presenting a second cross sectional flow area, different from said first cross sectional flow area, to fluid flowing from said pedal simulator to said master cylinder through said damping circuit.