초록 ▼

A brake system control apparatus comprising: a fluid brake system including a master cylinder containing a hydraulic fluid having a hydraulic pressure, a hydraulic pump having an output hydraulically coupled to the master cylinder, a motor coupled to and providing motive force to the hydraulic pump,

A brake system control apparatus comprising: a fluid brake system including a master cylinder containing a hydraulic fluid having a hydraulic pressure, a hydraulic pump having an output hydraulically coupled to the master cylinder, a motor coupled to and providing motive force to the hydraulic pump, a current sensing device coupled to the motor and providing an output signal indicative of electric current through the motor; and an electronic controller coupled to the current sensing device comprising a first sampler taking a first sample of the output signal a first time period after a start up of the motor, a second sampler taking a second sample of the output current a second time period after start up of the motor and a divider for determining a ratio of the first and second samples wherein the ratio is indicative of a hydraulic pressure in the master cylinder at the start up of the motor.

대표청구항 ▼

[ We claim:] [1.] In a control apparatus for a fluid brake system including a hydraulically activated wheel brake, a master cylinder containing a hydraulic fluid having a hydraulic pressure, a hydraulic pump having an output hydraulically coupled to the master cylinder, an electric motor coupled to

[ We claim:] [1.] In a control apparatus for a fluid brake system including a hydraulically activated wheel brake, a master cylinder containing a hydraulic fluid having a hydraulic pressure, a hydraulic pump having an output hydraulically coupled to the master cylinder, an electric motor coupled to and providing motive force to the hydraulic pump, and a current sensing device coupled to the electric motor and providing an output signal indicative of electric current through the electric motor, the control apparatus being responsive to an estimated master cylinder hydraulic pressure derived from the output signal of the current sensing device to control the application of hydraulic fluid from the master cylinder to the wheel brake, the improvement comprising:means for sampling and storing an initial peak value of the value of the output signal of the current sensing device at a first time after initiation of operation of the electric motor;means for sampling and storing a second value of the output signal of the current sensing device at a second time after the initiation of operation of the electric motor, the second time being later than the first time and later than a predetermined reference time;means for determining the ratio of the stored second value to the stored first value; andmeans for deriving the estimated master cylinder hydraulic pressure from the determined ratio, whereby the initial peak value of the output signal of the current sensing device compensates the estimated master cylinder hydraulic pressure for environmental and apparatus variations that affect the relationship between the electric current through the motor and the hydraulic pressure of the hydraulic fluid provided by the hydraulic pump.