Angular Position Detection Using Phase Error Correction
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Solution Overview
Problem
Existing methods for determining the angular position of a rotatable part are prone to errors due to phase errors and amplitude discrepancies in sensor signals, which affect the accuracy of angle detection.
Innovation Solution
The method employs at least two sensors with an angular offset to generate signal curves with a defined phase difference, corrects offset and phase errors through low-pass filtering and linear superimposition, and uses these corrected signals to determine the angular position, allowing for precise angle determination without complex calibration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional angle sensors are used without correction, then the device complexity is low, but the measurement precision deteriorates due to phase errors and amplitude discrepancies
Solution Approach 1:
The patent applies preliminary action by determining offset values and phase error values in advance through low-pass filtering of the sensor signals. These correction parameters are calculated beforehand and stored, then applied to correct the signals during angle determination. This approach improves measurement precision by eliminating phase errors and amplitude discrepancies without requiring complex real-time correction mechanisms.
Solution Approach 2:
The patent introduces intermediary correction parameters (offset values and phase error values) that mediate between the raw sensor signals and the final angle determination. These intermediaries are derived through low-pass filtering and used to adjust the signal curves before calculating the angular position, thereby improving accuracy without directly modifying the sensor hardware or creating complex correction circuits.
2Measurement precision
If complex calibration methods are used to correct phase errors, then the measurement precision improves, but the ease of operation deteriorates
Solution Approach 1:
The patent implements self-service by enabling the system to automatically determine and correct its own measurement errors. The evaluation electronics automatically calculate offset values and phase error values from the sensor signals using low-pass filtering, then apply these corrections without requiring external calibration equipment or manual adjustment. This maintains high measurement precision while simplifying operation, as the system self-corrects during normal operation.
Solution Approach 2:
The patent applies parameter changes by dynamically adjusting the signal curves based on determined offset values and phase error values. The correction process modifies the amplitude and phase parameters of the sensor signals through mathematical operations (low-pass filtering and signal adjustment), enabling accurate angle determination without complex mechanical or hardware adjustments.
3Measurement precision
If real-time signal correction is performed, then the measurement precision improves, but the productivity deteriorates due to increased calculation time
Solution Approach 1:
The patent applies preliminary action by pre-calculating and storing correction parameters (offset values and phase error values) through low-pass filtering of the sensor signals. These parameters are determined in advance and remain valid over extended periods, allowing rapid angle determination without repeated complex calculations. This approach maintains high measurement precision while improving productivity, as the system performs only simple parameter lookups and basic calculations during angle measurement.
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 results in improved error-corrected angle detection, simplifying the correction process and enabling robust, precise angle determination suitable for applications in electric motors.
Implementation Method 1
the disk has regions magnetized one behind the other in the circumferential direction, with adjacent regions having essentially opposite directions of magnetization
Data Source
AI summary
The invention relates to a method and device for determining the angular position of a rotating part, comprising at least one encoder track running in the circumferential direction, wherein at least two sensors are statically disposed having such an angle offset that the associated signal curves (cos/sin) comprise a phase difference when rotating the rotating part, corresponding to an ideal value, such as 90° or the like, except for a phase error, wherein, particularly at least for a period of a signal curve - offset values of the signal curves are determined and corrected (1), - the signal curves are further corrected (3), such that they comprise the same peak values, the phase error is determined (4) and at least one signal curve is correspondingly further corrected (6), and the angle value of the angular position of the rotating part is determined form the two corrected signal curves (7).