Dynamic Offset Compensation for Current Sensor Acquisition Systems
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Solution Overview
Problem
Existing methods for compensating offset errors in current measurement acquisition chains are either expensive, limited to specific types of motors, or only provide static compensation, failing to dynamically address measurement drift over time, especially in household appliances.
Innovation Solution
A method that dynamically compensates for offset errors in current sensors by determining periodic operating time ranges and executing a compensation sequence synchronized with the AC mains supply voltage, involving stopping the power supply, measuring the real offset, and using the new offset value to control the actuator, applicable to various types of motors and actuators.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If active compensation process with dedicated circuit is implemented, then offset error compensation is achieved, but device complexity and cost increase
Solution Approach 1:
The patent extracts the compensation function from a separate dedicated circuit and integrates it into the existing microcontroller unit (MCU) that already controls the actuator. The MCU executes compensation algorithms using existing acquisition chain components, eliminating the need for additional hardware circuits while maintaining measurement accuracy.
Solution Approach 2:
The existing MCU is made multi-functional by having it perform both actuator control and offset error compensation. The same acquisition chain components are used for both normal operation and compensation measurements, maximizing resource utilization and avoiding additional complexity.
2Ease of manufacture
If static compensation method is used, then implementation is simple, but measurement drift over time cannot be corrected
Solution Approach 1:
The patent implements periodic compensation where the MCU periodically interrupts current flow through the sensor and remeasures the offset value during actuator idle periods. This periodic action corrects drift over time while keeping the system simple, as it uses the existing acquisition chain without additional hardware.
Solution Approach 2:
The system performs self-compensation by using its own existing resources (MCU, acquisition chain) to detect and correct offset errors. No external dedicated compensation hardware is needed, as the system serves its own calibration needs through software-controlled periodic measurements.
3Measurement precision
If compensation sequence is executed frequently, then measurement accuracy is maintained, but energy consumption and operational disruption increase
Solution Approach 1:
The patent applies partial compensation by interrupting current flow only briefly during idle periods rather than continuously. The compensation sequence is executed for the minimum necessary duration to remeasure offset, then the actuator resumes normal operation, balancing accuracy maintenance with energy efficiency.
Solution Approach 2:
The system performs compensation measurements in advance during idle periods before normal operation resumes. By proactively correcting offset drift during non-critical times, the system maintains accuracy for subsequent measurements without requiring continuous compensation during active operation.
4Measurement precision
If compensation is performed during actuator operation, then dynamic drift is corrected, but actuator operation is disrupted
Solution Approach 1:
The patent schedules compensation sequences periodically during actuator idle periods when no operational current is expected. This timing allows offset remeasurement without disrupting actuator operation, as compensation occurs during natural pauses in the actuator cycle.
Solution Approach 2:
The compensation measurement is extracted from continuous operation by temporarily interrupting current flow only during idle periods. This separation allows the compensation function to be performed without affecting actuator operation during active phases, maintaining both accuracy and operational continuity.
Data Source
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AI summary
The present invention relates to a method for dynamically compensating for the offset error of an acquisition system comprising a current sensor (1) designed to measure or estimate the current passing through an actuator (6) of a electrical apparatus that is electrically supplied by an AC voltage, said acquisition system having a predetermined offset value, said method comprising the following steps: - determining a plurality of periodic temporal operating ranges (PT) of the actuator (6) in order to dynamically apply a compensation sequence (SC) for the offset error of the acquisition system, - executing the compensation sequence (SC) during any one among the plurality of determined temporal operating ranges (PT), the synchronization between the any one of the determined temporal operating ranges (PT) of the actuator (6) and the execution of the compensation sequence (SC) being performed using synchronization means comprising a synchronization module (7) designed to identify reference times (Ref) from the AC supply voltage (AC) of the sector.