System for estimating brake-fluid pressure

A motor vehicle, comprising:

• a master cylinder;
• wheel cylinders connected to the master cylinder;
• and
• brake control system, comprising:
• a brake line with a supply line;
• a pump which supplies brake fluid to the supply line;
• branch lines branched from the supply line to the wheel cylinders;
• a pressure controller which allows independent control of brake-fluid pressures within the wheel cylinders;
• and
• an ECU which controls the pump and the pressure control, the ECU comprising an estimate part which estimates the pressures within the wheel cylinders in accordance with a flow amount of brake fluid obtained out of signals indicative of braking conditions, the estimate part being so constructed as to:
• estimate an amount of brake fluid flowing from the supply line to the first wheel cylinder during execution of brake-fluid pressure control of the ECU and when the control is switched to pressure-increase control for the first wheel cylinder having the pressure lower than that in the supply line;
• and
• estimate the pressure within the first wheel cylinder in accordance with the amount of brake fluid as estimated.

A method of controlling a braking device for a motor vehicle with a master cylinder and wheel cylinders, the braking device comprising:

• a brake line with a supply line;
• a pump which supplies brake fluid to the supply line;
• branch lines branched from the supply line to the wheel cylinders;
• and
• a pressure controller which allows independent control of brake-fluid pressures within the wheel cylinders,
• the method comprising:
• estimating the pressures within the wheel cylinders in accordance with a flow amount of brake fluid obtained out of signals indicative of braking conditions,
• wherein it is estimated an amount of brake fluid flowing from the supply line to the first wheel cylinder during execution of brake-fluid pressure control and when the control is switched to pressure-increase control for the first wheel cylinder having the pressure lower than that in the supply line;
• and
• wherein it is estimated the pressure within the first wheel cylinder in accordance with the amount of brake fluid as estimated.