Control method for the actuator of a variable valve train
AssigneeBayerische Motoren Werke Aktiengesellschaft
InventorMartin Schaefer
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Abstract
The invention relates to a control method for the electrical actuator of a variable valve train, the actuator being embodied in the form of a worm gear in which a sensor detects a position value (measured position value) of an eccentric shaft, a control difference is generated in a feedback branch with the use of the measured position value, and the electrical actuator is actuated. To suppress interferences in the control system, an observer value is formed that is associated with the position value from the pulse duty factor of the pulse-width modulation. The observer value is composed to a comparison value formed from the measured position value. The detected measured position value is not accepted if the deviation of the observer value from the comparison value exceeds a defined limit.
Claims21
A control method for an electrical actuator of a variable valve train, said actuator being a worm gear operating on an eccentric shaft of the variable valve train, the method comprising the acts of:
- measuring, via a sensor, a position value of the eccentric shaft;
- forming an observer value associated with the measured position value from a pulse duty factor of a pulse-width modulation;
- forming a comparison value from the measured position value;
- comparing the observer value to the comparison value, wherein the measured position value is not accepted if a deviation of the observer value from the comparison value exceeds a defined limit;
- if accepted, generating a control difference signal in a feedback branch using the measured position value;
- and
- activating the electrical actuator as a function of the control difference signal.
Dependencies are inferred from the claim text.