Ascertaining an offset of an inertial sensor

An electronic control unit for a brake system of a motor vehicle, comprising:

• interfaces for connection of at least one wheel revolution rate sensor and at least one brake operation sensor;
• at least one inertial sensor disposed in a longitudinal direction and an interface to a vehicle data bus;
• and
• a computing unit with instructions for:
• detecting at least a longitudinal acceleration signal, a brake signal and a drive signal;
• analyzing a balance of forces of longitudinal dynamics of the motor vehicle;
• detecting the signals for at least one acceleration process and for at least one braking process, wherein the signals for acceleration processes are detected separately from the signals for braking processes;
• determining an additive displacement from a comparison of the signals detected during acceleration processes or values calculated from the signals detected during acceleration process with the signals detected during braking processes or values calculated from the signals detected during braking processes, wherein analysis of the balance of forces of the longitudinal dynamics is only carried out if a stable driving state, wherein the stable driving state is traveling straight ahead;
• determining a first longitudinal acceleration aacc during an acceleration process using the longitudinal acceleration signal,
• determining a first longitudinal force Facc at least using the drive signal;
• determining a second longitudinal acceleration adec during a braking process using the longitudinal acceleration signal;
• determining a second longitudinal force Fdec at least using the brake signal;
• and
• determining additive displacement axdrift of the longitudinal acceleration according to:
• a
• x
• drift
• =
• a
• acc
• ⁢
• F
• dec
• -
• a
• dec
• ⁢
• F
• acc
• F
• dec
• -
• F
• acc
• .