Control method for electronic hydraulic brake

1 . A control method of an electric hydraulic brake including an auxiliary braking system generating a braking force in a vehicle when a main brake system fails, the control method comprising:

determining whether the main brake system fails;

opening a rear-wheel High pressure Switching Valve (HSV) connecting a rear wheel of the main brake system and a Low Pressure Accumulator (LPA) of the auxiliary braking system when the main brake system is determined to have failed;

determining whether a driver intervenes in braking; and

controlling the auxiliary brake system to generate the braking force in the vehicle.

2 . The control method of claim 1 , wherein the controlling the auxiliary braking system includes:

closing a plurality of Traction Control Valves (TCV) that adjusts opening and closing of a front wheel inlet line of the auxiliary braking system; and

operating an actuator of the auxiliary braking system.

3 . The control method of claim 2 , wherein the controlling the auxiliary braking system further includes controlling a plurality of high pressure switching valves (HSV 1 ) and (HSV 2 ) disposed on a line configured to connect the actuator and an oil chamber of the auxiliary braking system when an intervention time in braking of a driver is less than a preset time.

4 . The control method of claim 3 , wherein the controlling the auxiliary braking system further includes determining a first condition defined as a case in which pressure of a master cylinder of the main brake system is larger than a preset pressure and a second case defined as a case in which an intervention time in braking of the driver is less than a preset time.

5 . The control method of claim 4 , wherein the controlling a plurality of high pressure switching valves (HSV 1 ) and (HSV 2 ) comprises when both of the first condition and the second condition are not satisfied.

6 . The control method of claim 4 , wherein the controlling a plurality of high pressure switching valves (HSV 1 ) and (HSV 2 ) comprises performing pattern control on the plurality of HSVs when one or more conditions of the first condition and the second condition are satisfied.

7 . The control method of claim 3 , wherein the controlling the auxiliary braking system further includes determining a third condition defined as a case in which a pressure increase value of a master cylinder of the main brake system is smaller than a preset pressure increase value and a fourth condition defined as a case in which an intervention time in braking of the driver is less than a preset time.

8 . The control method of claim 7 , wherein the controlling a plurality of high pressure switching valves (HSV 1 ) and (HSV 2 ) comprises closing the plurality of HSVs when one or more conditions of the third condition and the fourth condition are satisfied.

9 . The control method of claim 7 , wherein the controlling a plurality of high pressure switching valves (HSV 1 ) and (HSV 2 ) comprises opening the plurality of HSVs or performing pattern control on the plurality of HSVs when both of the third condition and the fourth condition are not satisfied.

10 . The control method of claim 1 , wherein the opening the rear-wheel HSV comprises keeping the rear-wheel HSV open when the main brake system is determined to have failed.

11 . The control method of claim 1 , wherein the opening the rear-wheel HSV comprises opening the rear-wheel HSV when the main brake system is determined to have failed and there is intervention in braking of the driver.

12 . The control method of claim 11 , wherein the intervention in braking of the driver is determined using one or more of a pedal stroke and a pressure sensor of the main brake system.