Electric Vehicle Towing Weight Estimation via Output Difference

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Solution Overview

Problem

Existing technologies for estimating towing weight in electric vehicles are limited by their reliance on longitudinal acceleration without considering the vehicle's output, leading to reduced accuracy and the need for additional acceleration measurement devices, and do not account for road gradients when determining towing weight.

Innovation Solution

An apparatus and method for controlling a towing mode in electric vehicles that estimates towing weight based on the difference between a reference output and a current output, taking into account vehicle speed and gradient, allowing for adjustments in regenerative braking, acceleration, distance-to-empty calculations, and battery temperature management.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If longitudinal acceleration measurement device is used to estimate vehicle weight, then vehicle weight can be estimated, but measurement accuracy deteriorates and device complexity increases

Engineering Contradiction:
Improvetowing weight estimation accuracyVSAvoidacceleration measurement device
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent extracts the towing weight estimation function from complex acceleration measurement systems and isolates it to a dedicated towing weight detector that calculates weight based solely on output difference between reference output and current output. This separates the towing detection function from general vehicle dynamics measurement, reducing overall device complexity while maintaining accuracy for the specific purpose of towing weight estimation.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent creates a virtual model of vehicle output characteristics under normal conditions (reference output) and compares it with actual current output to estimate towing weight. This copying approach uses pre-established output characteristics rather than direct physical measurement, eliminating the need for additional acceleration sensors while achieving accurate towing weight detection through output difference analysis.

Inventive Principle:
Principle #26Copying

2Measurement precision

If vehicle output is not considered in towing weight estimation, then estimation can be performed using existing sensors, but measurement precision deteriorates

Engineering Contradiction:
Improvetowing weight estimation accuracyVSAvoidoutput measurement system
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent merges the towing weight detection function with the existing output detection system. The towing weight detector utilizes the current output signal that is already being measured by the motor control unit, combining multiple functions (output monitoring and towing detection) into a unified system. This integration allows accurate towing weight estimation without requiring separate measurement devices, as the same output detection infrastructure serves dual purposes.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The output detection system is designed to serve multiple functions: monitoring vehicle performance during normal operation and detecting towing weight through comparison with reference output. This multi-functional approach allows the same sensor and processing infrastructure to provide both general vehicle control data and specific towing weight information, eliminating the need for dedicated towing measurement hardware while maintaining high estimation accuracy.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Measurement precision

If road gradient is not considered in reference output detection, then detection system is simpler, but towing weight estimation accuracy deteriorates

Engineering Contradiction:
Improvereference output detection accuracyVSAvoidgradient detection system
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent performs preliminary detection of road gradient using the gradient detector before using it to correct reference output values. By obtaining gradient information in advance and applying it to adjust reference output, the system compensates for the effect of road slope on vehicle output characteristics. This preliminary action ensures that the reference output accurately reflects vehicle performance under current road conditions, thereby improving towing weight estimation accuracy without requiring complex real-time adjustment mechanisms.

Inventive Principle:
Principle #10Preliminary action

4Productivity

If towing weight is not detected, then vehicle control is simpler, but towing mode operation efficiency deteriorates

Engineering Contradiction:
Improvetowing mode operation efficiencyVSAvoidtowing mode control system
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent implements feedback control in towing mode by continuously monitoring detected towing weight and adjusting vehicle control parameters accordingly. The controller uses the towing weight information to dynamically regulate motor output, regenerative braking force, and transmission shifting, creating a closed-loop control system that optimizes towing performance. This feedback mechanism ensures the vehicle operates efficiently under varying towing conditions, adapting control strategies based on actual load information while maintaining manageable system complexity through integrated control architecture.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP3708451B1Apparatus for controlling towing mode of electric vehicle and method thereof
Publication Date: 2022.08.31 HYUNDAI MOTOR CO LTD
  • EP3708451B1 patent drawingFigure 1
  • EP3708451B1 patent drawingFigure 2
  • EP3708451B1 patent drawingFigure 3

AI summary

An apparatus for controlling a towing mode of an electric vehicle is provided. The apparatus includes a first sensor that measures a speed of the electric vehicle and a second sensor that measures a gradient of a road on which the electric vehicle is driven. A controller detects a reference output of the electric vehicle based on the speed and the gradient of the road and detects a towing weight of the electric vehicle based on an excess rate of a current output with respect to the reference output. The towing mode of the electric vehicle is then executed based on the detected towing weight.