Patent ID: 9701298
Date: 2017-07-11
CPC Classifications: B60T,G01F,G01N

Claim:
1. A method for ascertaining at least one variable regarding a state of a brake fluid in a brake system of a vehicle, the method comprising: determining, by processing circuitry and using sensor signals, a volume flow variable regarding a volume flow Q of the brake fluid, which flows via a simulator separation valve into a simulator of the brake system during an actuation of a brake pedal of the brake system, based on at least one displacement speed variable regarding at least one of: (a) a displacement speed v determining, by the processing circuitry and using sensor signals, a simulator internal pressure variable regarding a simulator internal pressure increased as a result of the volume flow Q into the simulator based on at least one pedal travel variable regarding a pedal travel of the brake pedal; determining, by the processing circuitry, a pressure difference variable regarding a pressure difference Δp, which prevails at the simulator separation valve, through which the volume flow Q flows, based on the simulator internal pressure variable determined for the respective volume flow Q and an admission pressure variable ascertained for the respective volume flow Q regarding an admission pressure prevailing at the simulator separation valve, through which volume flow Q flows, on a side that is facing away from the simulator; determining, by the processing circuitry, the at least one variable regarding the state of the brake fluid in the brake system based on the at least one determined volume flow variable and the at least one determined pressure difference variable; and outputting, by a control device of the brake system, a control signal to control operation of the brake system as a function of the determined at least one variable regarding the state of the brake fluid in the brake system.