Hydraulic brake pressure control system

A hydraulic brake pressure control system including a master cylinder generating a brake fluid pressure proportional to a brake pedal pressure, a high-pressure supply device generating an increased brake fluid pressure, and a hydraulic circuit including a wheel cylinder device and connecting the wheel cylinder device to both the master cylinder and the high-pressure supply device, the hydraulic circuit performing a master cylinder control to control a wheel cylinder pressure by using the pressure generated by the master cylinder, and performing a brake-by-wire control to control the wheel cylinder pressure by using the pressure generated by the high-pressure supply device, the hydraulic brake pressure control system comprising:

• a master cut valve device provided in the hydraulic circuit for controlling a flow of brake fluid from the master cylinder into the wheel cylinder device;
• a hydraulic circuit sensor device for outputting a signal indicative of the brake fluid pressure in the hydraulic circuit;
• and
• a malfunction position/mode detecting unit for detecting a malfunction position and a malfunction mode in the hydraulic brake pressure control system based on the combination of the signal output by the hydraulic circuit sensor device during the master cylinder control together with the signal output by the hydraulic circuit sensor device during the brake-by-wire control.

A method of detecting a malfunction position and a malfunction mode in a hydraulic brake pressure control system including a master cylinder generating a brake fluid pressure proportional to a brake pedal pressure, a high-pressure supply device generating an increased brake fluid pressure, and a hydraulic circuit including a wheel cylinder device and connecting the wheel cylinder device to both the master cylinder and the high-pressure supply device, the hydraulic circuit performing a master cylinder control to control a wheel cylinder pressure by using the pressure generated by the master cylinder, and performing a brake-by-wire control to control the wheel cylinder pressure by using the pressure generated by high-pressure supply device, the method comprising the steps of:

• providing a master cut valve device in the hydraulic circuit, the master cut valve device controlling a flow of brake fluid from the master cylinder into the wheel cylinder device;
• providing a hydraulic circuit sensor device which outputs a signal indicative of the brake fluid pressure in the hydraulic circuit;
• outputting a signal from the hydraulic circuit sensor device during the master cylinder control;
• outputting a signal from the hydraulic circuit sensor device during the brake-by-wire control;
• and
• detecting a malfunction position and a malfunction mode in the hydraulic brake pressure control system based on the combination of both the signal output by the hydraulic circuit sensor device during the master cylinder control together with the signal output by the hydraulic circuit sensor device during the brake-by-wire control.