Abstract: A method is used for determining an operating point of a compressor that includes at least one impeller, compressor blades attached to the impeller, a housing and at least two sensors. The method includes calculating a deflection of the compressor blades. An operating point and a surge margin with respect to a surge limit are determined based on the calculating of the deflection by measuring passage times of the compressor blades at a sensor. A signal that is representative of a rotation speed is determined and is associated with the compressor impeller. In a learning or adaptation mode, compressor blade-specific, state-induced and position-induced deviations from an ideal state are determined using compressor blade-specific passage times that are measured and compared with ideal passage times. In a working mode, compressor blade-specific passage times are measured and the compressor blade-specific passage times are corrected using the determined state-induced and position-induced deviations.

Abstract: A method is used for determining an operating point of a compressor that includes at least one impeller, compressor blades attached to the impeller, a housing and at least two sensors. The method includes calculating a deflection of the compressor blades. An operating point and spacing of the blades is determined with respect to a surge limit based on the calculating of the deflection by measuring passage times of the compressor blades at a sensor. A signal that is representative of a rotation speed is determined and is associated with the compressor impeller. In a learning or adaptation mode, compressor blade-specific, state-induced and position-induced deviations from an ideal state are determined using compressor blade-specific passage times that are measured and compared with ideal passage times. In a working mode, compressor blade-specific passage times are measured and the compressor blade-specific passage times are corrected using the determined state-induced and position-induced deviations.

Abstract: A method for estimating the cylinder interior pressure of an internal combustion engine from a cylinder pressure model having at least the input variables load, speed of rotation, and crank angle (Ppressure model), which forms the cylinder interior pressure (Pgas) to be determined, corrected by a pressure correction value (?Pgas). The pressure correction value (?Pgas) is determined from an observation of the alternating moments at the crankshaft. The modeled value of the cylinder interior pressure from the pressure model is obtained as a pre-control value, and corrected with a correction value formed from the measured value of the non-uniformity of rotation.

Abstract: A method for estimating the cylinder interior pressure of an internal combustion engine from a cylinder pressure model having at least the input variables load, speed of rotation, and crank angle (Ppressure model), which forms the cylinder interior pressure (Pgas) to be determined, corrected by a pressure correction value (?Pgas). The pressure correction value (?Pgas) is determined from an observation of the alternating moments at the crankshaft. The modeled value of the cylinder interior pressure from the pressure model is obtained as a pre-control value, and corrected with a correction value formed from the measured value of the non-uniformity of rotation.