Image Number 12 for United States Patent #5954406.
A booster and a pressure amplifying device are provided as devices performing a brake assist. Further a pressure sensor which detects master-cylinder pressure is provided. While the braking is applied to the vehicle, the malfunction of the booster can be detected based on master-cylinder pressure detected by the pressure sensor. If the malfunction of the booster is detected, a pump in the pressure amplifying device is driven as an substitute for the booster. As a result, a required brake assist can be performed to ensure high braking force. Accordingly, the brake control apparatus can enhance safety during vehicle operation.