Wiegand Angle Sensor Initialization for Reliable Pulse Detection
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Solution Overview
Problem
Wiegand-sensor-based rotary angle measuring systems can malfunction due to strong magnetization of the Wiegand wire during transport or mounting, leading to weak voltage pulses and unreliable energy supply in energetically autarkic systems.
Innovation Solution
An initialization method involving an alternating current with decreasing amplitude is applied to the sensor coil, generating a parallel magnetic field that aligns and reduces the magnetization of the Wiegand wire, ensuring reliable magnetization reversal during operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the Wiegand sensor is exposed to a strong magnetic field during transport or mounting, then the Wiegand wire becomes strongly magnetized, but the excitation magnetic field during operation is not sufficient to completely invert the magnetization, resulting in weak voltage pulses and unreliable detection
Solution Approach 1:
The patent applies a preliminary initialization action before normal operation begins. An initialization alternating current is applied to the sensor coil to generate an initialization magnetic field that actively reduces or eliminates residual magnetization of the Wiegand wire caused by transport or mounting. This preliminary action ensures the Wiegand wire starts in a neutral magnetic state, allowing reliable detection during subsequent operation.
2Reliability
If the Wiegand wire is strongly magnetized during transport or mounting, then the excitation magnetic field during operation cannot completely invert the magnetization, but applying a strong initialization current may consume excessive energy
Solution Approach 1:
The patent employs periodic alternating current applied to the sensor coil during initialization. The alternating current changes direction periodically, creating a time-varying magnetic field that actively works to reduce residual magnetization. This periodic action is more effective than a single DC pulse and allows energy-efficient demagnetization by utilizing the alternating nature of the field to overcome magnetic hysteresis.
Solution Approach 2:
The patent changes the parameter of current amplitude over time during initialization. The initialization alternating current has a time-varying amplitude that decreases with time, as stated in the patent. This parameter change allows the system to apply strong magnetic field initially to overcome residual magnetization, then gradually reduce the field strength, thereby reducing total energy consumption while still achieving effective demagnetization.
3Reliability
If a strong initialization current is applied to reduce magnetization, then reliable detection is achieved, but the current amplitude must decrease with time to prevent excessive energy consumption
Solution Approach 1:
The patent explicitly defines that the initialization alternating current has an amplitude that decreases with time. This parameter change is crucial because it allows the system to apply strong magnetic field initially to overcome residual magnetization from transport or mounting, then gradually reduce the field strength. This time-varying amplitude profile ensures reliable demagnetization while preventing excessive energy consumption and defining the initialization process duration.
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
The method effectively eliminates or significantly reduces magnetization caused by transport or mounting, ensuring reliable detection of shaft rotation and preventing system malfunctions.
Implementation Method 1
feeding an initialization alternating current into a sensor coil which, after the mounting, radially surrounds a Wiegand wire. The initialization alternating current is provided with a current direction which alternates with time and with a current amplitude which decreases with time.
Implementation Method 2
If the Wiegand sensor is exposed to a strong magnetic field, for example. during transport or mounting, the Wiegand wire can become so strongly magnetized
Implementation Method 3
a magnetization direction of the Wiegand wire inverts abruptly under the impact of an excitation magnetic field which is sufficiently strong and directed opposite with respect to the magnetization direction of the Wiegand wire. This abrupt inversion of the magnetization of the Wiegand wire generates a short voltage pulse in the sensor coil
Data Source
AI summary
A method for initializing a Wiegand-sensor-based rotary angle measuring system. The method includes mounting the Wiegand-sensor-based rotary angle measuring system at a place of use, and feeding an initialization alternating current into a sensor coil which, after the mounting, radially surrounds a Wiegand wire. The initialization alternating current is provided with a current direction which alternates with time and with a current amplitude which decreases with time.