Sometimes people who are not used to driving or people who panic easily even if they are used to driving do not step down hard enough on the brake pedal during emergency braking to realize the full performance of the brake system. BA is a system that uses the pressure sensor inside the ABS actuator to detect the speed and force with which the brake pedal is being depressed to allow the computer to estimate the emergency braking will of the driver to increase the braking force to contribute to achieving the maximum performance from the braking system. This BA also features set assist timing and assist amount to make braking feel as natural as possible by adjusting the amount of assist as required as shown in the graph in the figure.In the past, pedal stroke sensor is used in vehicles equipped with BA to detect the amount the brake pedal was depressed.
When the Skid Control ECU determines that the driver is emergency braking, the brake assist switching solenoid valve is turned on, a path is created between the master cylinder and the reservoir, and the fluid is sent to the pump. This fluid is drawn by the pump and sent to the wheel cylinder. Relief valve 4 opens to ensure that the wheel cylinder pressure does not exceed the master cylinder pressure by more than a set amount to maintain the pressure difference.