Current Sensor Digital Differential Noise Correction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current sensors face degradation in measurement accuracy due to disturbance magnetic fields, particularly in high-current applications like motor driving in electric vehicles, where existing methods struggle with noise correction and re-adjustment costs.
Innovation Solution
A current sensor configuration using two magnetic sensors with analog-to-digital converters to convert output signals into digital form before differential operations, allowing for more appropriate correction processes and effective noise suppression by comparing signal variations and discarding or weighting data based on accuracy thresholds.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If all correction processes are performed using analog signals, then correction accuracy can be enhanced, but the device complexity increases and re-adjustment becomes difficult
Solution Approach 1:
The patent replaces the mechanical/analog adjustment system with a digital signal processing system. Instead of using variable resistance adjustment or laser trimming for correction, the invention uses digital filters and algorithms to perform correction processes after analog-to-digital conversion. This substitution eliminates the need for complex physical adjustment mechanisms while maintaining correction accuracy.
Solution Approach 2:
The patent changes the state of the signal from analog to digital form to enable more flexible correction processes. By converting signals to digital format first, the system can apply various correction algorithms and parameter adjustments through software rather than hardware changes, making the system more adaptable and easier to reconfigure.
2Adaptability or versatility
If analog-to-digital conversion is performed before differential operation, then appropriate correction processes can be enabled, but the device complexity increases
Solution Approach 1:
The patent performs the analog-to-digital conversion before the differential operation and correction processes. This preliminary conversion enables subsequent digital signal processing to be applied to both channels uniformly, facilitating flexible correction algorithms while maintaining system manageability through a systematic processing sequence.
Solution Approach 2:
The analog-to-digital converter acts as an intermediary between the magnetic sensors and the correction processing stages. This intermediary component enables the system to transition from continuous analog processing to discrete digital processing, allowing for more versatile correction algorithms while containing complexity through a well-defined conversion interface.
3Object-affected harmful factors
If differential operation is performed on analog signals, then noise can be suppressed, but measurement accuracy degrades when noise is present in the analog differential value
Solution Approach 1:
The patent substitutes the traditional analog differential operation with a digital approach. By converting signals to digital form first and then performing differential operation in the digital domain, the system can apply sophisticated noise filtering and correction algorithms that are not possible in the analog domain, thereby improving measurement accuracy while maintaining noise suppression capabilities.
Solution Approach 2:
The patent implements feedback mechanisms in the digital processing stage to correct for noise and measurement errors. By having access to the digital representations of both sensor channels, the system can perform feedback-based correction algorithms that compensate for noise present in the analog differential value, thereby maintaining measurement accuracy.
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 configuration enhances measurement accuracy, reduces noise impact, and prevents system malfunctions by autonomously correcting signals and discarding or reducing low-accuracy data, thereby improving the reliability of current measurement in high-current applications.
Implementation Method 1
a first magnetic sensor 11A and a second magnetic sensor 11B which are arranged in a periphery of a current line through which a current to be measured passes and output reversed output signals due to an induction magnetic field from the current to be measured
Data Source
AI summary
A current sensor includes: a first magnetic sensor and a second magnetic sensor; a first analog-to-digital converter which is connected to the first magnetic sensor and converts an output signal of the first magnetic sensor from an analog signal to a digital signal so as to be output; a second analog-to-digital converter which is connected to the second magnetic sensor and converts an output signal of the second magnetic sensor from an analog signal to a digital signal so as to be output; and an operation device which is connected to the first analog-to-digital converter and the second analog-to-digital converter, and outputs an operation value by subjecting the output signal of the first analog-to-digital converter and the output signal of the second analog-to-digital converter to differential operation.