Actuator Armature Stop Time Detection via Coil Current Profiling
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Solution Overview
Problem
Electromagnetically driven actuators, particularly in injection valves, face significant tolerances in the ballistic operating mode due to electrical and mechanical influences, leading to inaccuracies in fuel injection control, which is crucial for reducing emissions and fuel consumption.
Innovation Solution
A method for determining the time at which an armature reaches its stop position by applying a dimensioned actuation voltage signal with a boosting and holding phase, acquiring the temporal profile of the current intensity, and comparing it with a reference profile to achieve precise control, allowing for optimized actuation in both measurement and series operating modes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the actuator is operated in ballistic operating mode with partial deflection, then fuel injection control precision is improved, but tolerances due to electrical and mechanical influences increase significantly
Solution Approach 1:
The patent applies feedback by measuring the actual armature position through voltage signal evaluation and comparing it with the desired position. The system continuously monitors the armature movement by evaluating the voltage signal generated during armature displacement and uses this information to determine when the armature reaches the stop position, thereby compensating for tolerances in ballistic operating mode
Solution Approach 2:
The patent replaces mechanical position detection methods with an electrical measurement system. Instead of using mechanical switches or sensors to detect armature position, the system evaluates the voltage signal generated by the coil during armature movement to determine position and stop time, eliminating mechanical tolerance issues
2Measurement precision
If a voltage signal with boosting and holding phases is applied to the coil, then electrical conditions for measurement become stable, but the complexity of the actuation signal increases
Solution Approach 1:
The patent segments the actuation process into distinct phases: a boosting phase to rapidly establish magnetic field and move the armature, and a holding phase to maintain stable electrical conditions for measurement. This segmentation allows each phase to be optimized independently - the boosting phase for rapid response and the holding phase for precise measurement
Solution Approach 2:
The patent applies preliminary action by first establishing the magnetic field through the boosting phase before transitioning to the holding phase for measurement. The system prepares the electrical conditions in advance by applying the dimensioned voltage signal with specific boosting and holding phases, ensuring stable measurement conditions are established before stop time determination begins
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach reduces tolerances and enhances the precision of fuel injection by providing stable electrical conditions for determining the stop time, enabling better control over the injection process and improving fuel quantity accuracy.
Implementation Method 1
an actuator having a coil and a displaceably mounted armature which is driven by a magnetic field which is generated by the coil
Implementation Method 2
The actual movement of the actuating device can be analyzed by evaluating induced voltage signals which are caused by external mechanical influences
Data Source
AI summary
A method is disclosed for operating an actuator having a coil and a displaceably mounted armature driven by a magnetic field generated by the coil, in a measurement operating mode for ascertaining a time at which the armature reaches its stop position after activation of the actuator. The method includes applying to the coil an actuation voltage signal dimensioned such that the expected armature stop time falls in a time window in which a temporally constant voltage is applied to the coil, detecting an intensity profile of the current flowing through the coil within the time window, and determining the armature stop time, based on an evaluation of the detected current intensity profile. A method for operating such an actuator is also disclosed, wherein information about the stop time is obtained in a measurement operating mode and used in a series operating mode for optimized actuation of the actuator.