Vehicle Battery SOH Estimation Using Assisted Discharge Resistance
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Solution Overview
Problem
Existing methods struggle to accurately measure output degradation of eco-friendly vehicle batteries, making it difficult to determine the timing for inspection, exchange, and recycling.
Innovation Solution
A method and apparatus that utilize a vehicle's driving assistance function to measure battery degradation by determining resistance and voltage values during discharge, enabling accurate estimation of battery health (SOH) through a cell current-resistance table.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional methods (current and resistance or polarization) are used to estimate output degradation, then the estimation process is simple, but the measurement accuracy is insufficient
Solution Approach 1:
The system performs preliminary actions by determining whether the vehicle can drive while discharging the battery at a predetermined current for a predetermined time before measuring voltage. This preparation ensures that measurement conditions are met, allowing for accurate output degradation measurement without requiring complex external testing equipment.
Solution Approach 2:
The battery management system uses the vehicle's own driving assistance function and existing battery discharge capabilities to perform self-diagnosis. The system leverages the vehicle's intrinsic resources (battery, motor, control systems) to measure output degradation, eliminating the need for external testing equipment and reducing system complexity while improving measurement accuracy.
2Measurement precision
If the battery is discharged at a predetermined current for a predetermined time to measure voltage, then output degradation can be accurately measured, but the measurement process requires specific driving conditions
Solution Approach 1:
The system dynamically determines whether the vehicle satisfies conditions for entering a degradation diagnosis mode based on real-time driving status. The measurement process adapts to current driving conditions, allowing the system to perform accurate measurements when conditions are met while maintaining normal operation when they are not, thus balancing measurement precision with operational flexibility.
Solution Approach 2:
The battery management system integrates multiple functions: normal battery management, driving assistance control, and degradation diagnosis. By making the degradation measurement function universal and integrated into the existing battery management system, the system can accurately measure output degradation without requiring separate dedicated equipment or compromising adaptability to different driving scenarios.
3Measurement precision
If multiple voltage measurements are taken at different currents (increasing or decreasing by predetermined rate), then more accurate degradation estimation is achieved, but the measurement time and complexity increase
Solution Approach 1:
The system performs periodic voltage measurements at different currents (increasing or decreasing by a predetermined rate) during normal vehicle operation. By utilizing periodic driving cycles and the vehicle's natural operation patterns, the system can accumulate multiple measurement data points over time without requiring dedicated extended measurement periods, thus improving degradation estimation accuracy while minimizing time loss.
Solution Approach 2:
The degradation measurement process is integrated into continuous vehicle operation rather than being a separate discrete process. The system continuously monitors battery performance and performs voltage measurements at appropriate moments during normal driving, ensuring that the useful action of vehicle operation continues uninterrupted while gathering necessary measurement data efficiently.
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
Accurately measures battery output degradation, facilitating timely inspection, exchange, and recycling by identifying the lowest SOH cell, thus optimizing battery management.
Implementation Method 1
Eco-friendly vehicles, such as a hybrid electronic vehicle (HEV), a plug-in HEV (PHEV), and an electronic vehicle (EV), include built-in batteries corresponding to a storage device for storing electrical energy to drive motors
Implementation Method 2
a sensor unit including a voltage sensor configured to detect a voltage of multiple cells forming a battery
Data Source
AI summary
A method and an apparatus for estimating eco-friendly vehicle battery degradation using a driving assistance function of a vehicle are disclosed. The method for estimating eco-friendly vehicle battery degradation includes: measuring a first voltage of each cell included in the battery during driving of the vehicle while discharging the battery of the vehicle at a preconfigured first current for a preconfigured time, determining a first resistance value of each cell based on the first current and the first voltage, and estimating degradation of the battery based on the first current and the first resistance value.