Electric Vehicle Range Estimation Using Speed-Based Correction
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Solution Overview
Problem
Existing methods for estimating the residual range of electric vehicles are unreliable due to limited sensitivity in battery voltage monitoring and non-linear voltage variation, leading to overestimation of the charge level and late critical alerts.
Innovation Solution
A method that calculates kilometric consumption and uses it to estimate residual range, combined with average vehicle speed to determine residual battery discharge time, applying a corrective coefficient to improve energy estimation precision, focusing on traction consumption and sampling by distance rather than time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the residual range is estimated by analyzing the evolution of residual energy using SOC parameter and battery voltage monitoring, then the estimation method is simple to implement, but the measurement precision is poor leading to overestimation of residual range
Solution Approach 1:
The patent changes the estimation parameters from using SOC and voltage monitoring to using average speed and residual energy. It introduces a corrective coefficient K that depends on residual discharge time, transforming the estimation approach to achieve better precision while maintaining practical implementability through standard vehicle sensors.
2Device complexity
If the battery voltage monitoring is used to determine SOC, then the monitoring system is simple, but the sensitivity is limited due to non-linear voltage variation
Solution Approach 1:
The patent introduces average speed as an intermediary parameter to calculate residual discharge time. Instead of directly using voltage monitoring to determine charge level, it uses speed and energy data to derive discharge time, which then provides a more sensitive indicator of battery state through the corrective coefficient K.
3Ease of operation
If the residual discharge time is calculated based on SOC variation over time, then the calculation method is straightforward, but the reliability is poor due to unreliable SOC estimation
Solution Approach 1:
The patent inverts the traditional approach by not calculating discharge time from SOC variation, but rather calculating it from residual range divided by average speed. This reversal uses more reliable parameters (speed and energy) to determine discharge time, significantly improving reliability while keeping the calculation straightforward.
Data Source
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AI summary
Estimation method of a residual electric vehicle range, the vehicle having a battery pack and at least an electric motor cooperating with a vehicle transmission, the method comprising in a cyclic succession: acquisition of a residual energy (E), calculation of a residual range (A_R) as the ratio given by said residual energy (E) divided by a predetermined kilometric consumption coefficient (DK) and calculation of a residual discharge time (R) of the vehicle batteries as the ratio of said residual range (A_R) divided by a vehicle speed (S), identification of a corrective parameter (K) of said residual energy value (E) and function of said residual discharge time (R), acquisition of said residual energy (E) and correction of the same by means of said corrective parameter (K).