Oscillating Motor Control via Constant Inductance Measurement
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Solution Overview
Problem
Existing oscillating motor control systems face instability and amplitude regulation issues due to neglecting the non-linear inductance of the motor, especially under varying loads, which leads to increased costs and complexity in implementing look-up tables and software for accurate control.
Innovation Solution
The system determines a measurement time or position where the motor's inductance remains approximately constant across different currents, allowing for precise regulation by using a single constant inductance value, minimizing deviations within a specified current interval, and optimizing measurement times or positions to maintain stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the inductance of the motor is assumed to be constant for control calculations, then the control implementation is simple and cost-effective, but the motor control becomes unstable and the regulation amplitude deviates from the specified value, especially under heavy load
Solution Approach 1:
The patent changes the measurement parameter from general current measurement to specifically measuring the change in current (dI/dt) at an optimized measurement time. By selecting the measurement time such that the inductance remains approximately constant across the current interval, the system maintains control stability while using a simple constant inductance value for calculations, avoiding the need for complex variable inductance models.
Solution Approach 2:
The patent performs preliminary optimization to determine the specific measurement time at which the inductance is approximately constant. This pre-determined measurement time is then used in the control system, allowing the system to benefit from the optimized measurement point without performing real-time optimization or using complex variable inductance calculations during operation.
2Measurement precision
If look-up tables or mathematical equations are used to account for non-linear inductance characteristics, then the motor control accuracy is improved, but the implementation costs increase and the device area required increases
Solution Approach 1:
Instead of using complex look-up tables or mathematical equations to model variable inductance, the patent changes the approach by selecting a specific measurement time at which the inductance is approximately constant. This allows the use of a simple constant inductance value in control calculations, achieving good control accuracy without requiring expensive or large-scale storage components.
Solution Approach 2:
The patent extracts only the essential information needed for control by measuring the change in current (dI/dt) at the optimized measurement time, rather than storing or processing complete inductance characteristic curves. This extraction approach provides sufficient control accuracy while minimizing the resources required for implementation.
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 ensures stable motor control and precise amplitude regulation across varying loads without the need for extensive resources, enabling a cost-effective and space-saving implementation.
Implementation Method 1
a coil operated as an electromagnet in order to cause a rotor connected to a permanent magnet to oscillate
Implementation Method 2
the slope of the variable to be measured should not change too much between the two measuring points
Data Source
Figure 1
Figure 2~3
Figure 4~5
AI summary
The invention relates to an arrangement having an oscillating motor (100), a control circuit (20) for controlling the motor (100), a sensor arrangement (5) for determining an electric characteristic of the motor (100) at a predetermined measuring time (t 1, t 2, t 3) or in a predetermined measuring position (xM 1, xM 2, xM 3) during an oscillation process, and a processor (21) for determining a movement variable of the motor (100) by means of at least the electric characteristic and a constant inductivity value (L cons t) of the motor (100), wherein the control circuit (20) in the operating state controls the motor (100) as a function of the movement variable, and the measuring time (t 1, t 2, t 3) or the measuring position (xM 1, xM 2, xM 3) is predetermined such that the inductivity (L) of the motor (100) remains approximately constant at least in a given current interval (I 1,I 2), even with different currents (/) through the motor (100). By means of a favorable implementation, the non-linearity of the motor inductivity can be taken into consideration, which results in increased stability in the control of the oscillation amplitude.