Vehicle Power Supply Device Sensor Failure Detection
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Solution Overview
Problem
Conventional vehicle power supply systems fail to accurately detect performance abnormalities in charge/discharge current sensors and require multiple electric load current sensors, leading to system complexity and increased costs.
Innovation Solution
A vehicle power supply device with a state-of-charge estimation unit, operation current estimation unit, and charge/discharge current sensor failure detection unit that estimates operation current for electric loads, allowing for detection of charge/discharge current sensor failures and continued SOC estimation using electric load operation current values, enabling operation at low output and system simplification.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple electric load current sensors are provided for respective electric loads, then charge/discharge current sensor failure can be detected by comparison, but system complexity and cost increase due to additional sensors, wirings, and interface requirements
Solution Approach 1:
The invention extracts the current sensing function from individual electric load sensors and consolidates it into a single charge/discharge current sensor. By estimating the operation current of each electric load through calculation rather than direct measurement, the system eliminates the need for multiple load current sensors while maintaining the ability to detect sensor failures through comparison between actual and estimated values.
Solution Approach 2:
The invention introduces an operation current estimation unit as an intermediary that calculates the expected current consumption of electric loads based on their operational states. This estimation serves as a reference value to detect charge/discharge current sensor failures without requiring direct measurement from multiple sensors, thus reducing system complexity while preserving detection capability.
2Reliability
If multiple electric load current sensors are provided for respective electric loads, then charge/discharge current sensor failure can be detected by comparison, but cost increases due to additional sensors, electric wirings, and receiver-side interface requirements
Solution Approach 1:
The invention removes the need for multiple expensive electric load current sensors by extracting only the essential sensing function to a single charge/discharge current sensor. The operation current estimation unit replaces the function of multiple sensors through calculation, significantly reducing component costs, wiring requirements, and interface complexity.
Solution Approach 2:
Instead of using physical sensors to measure each electric load current, the invention creates a virtual copy of the current measurement through estimation calculations. This virtual current data serves the same functional purpose as physical sensor readings but at a fraction of the cost, eliminating the need for expensive hardware duplication.
3Device complexity
If only output value range checking is used for charge/discharge current sensor failure detection, then detection is simple, but performance abnormalities based on comparison with total current of electric load current sensors cannot be detected
Solution Approach 1:
The invention implements a feedback mechanism where the operation current estimation unit continuously calculates the expected current consumption of electric loads and compares it with the actual charge/discharge current sensor readings. This closed-loop comparison provides real-time feedback to detect not only out-of-range failures but also performance abnormalities, significantly improving detection accuracy while maintaining reasonable system complexity.
Solution Approach 2:
The invention performs preliminary estimation of electric load operation currents before comparing them with actual sensor readings. By pre-calculating the expected current values based on load operational states, the system prepares reference data in advance that enables comprehensive failure detection including performance abnormalities, rather than relying solely on simple range checking after failure occurs.
Data Source
AI summary
In order to detect failure of a charge/discharge current sensor for a battery and estimate and manage the state of charge of the battery when the charge/discharge current sensor has failed, provided are: a state-of-charge estimation unit for estimating the state of charge of the battery; an operation current estimation unit for estimating operation current of an electric load connected to the battery; and a charge/discharge current sensor failure detection unit for determining that failure occurs on the charge/discharge current sensor for detecting charge/discharge current of the battery, when a difference between the charge/discharge current and the operation current estimation value is equal to or greater than a predetermined value, wherein, when failure of the charge/discharge current sensor is detected, the electric load is operated at low output, and the state of charge of the battery is estimated using the operation current estimation value.