Off-Road Vehicle Mass Estimation via Energy Conservation

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Solution Overview

Problem

Off-road vehicles, such as agricultural tractors, present challenges in mass estimation due to noisy and low acceleration signals, which are affected by vibrations, making traditional acceleration-based methods ineffective.

Innovation Solution

A method utilizing sensors to detect velocity, slope angle, and engine quantities, which are processed by an electronic control unit to calculate mass through energy conservation principles, integrating power and energy quantities over time to reduce noise and accurately estimate the vehicle's mass.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If acceleration-based mass estimation is used, then the method is simple and well-known in the automotive industry, but the acceleration signal is too noisy and low compared to over-dynamic signals due to wheel vibrations in off-road vehicles

Engineering Contradiction:
Improvemass estimation precisionVSAvoidacceleration signal noise from wheel vibrations
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent replaces the mechanical acceleration-based measurement system with an energy-based estimation system. Instead of using acceleration sensors that are corrupted by wheel vibrations, the system uses engine torque, fuel consumption rate, and velocity data to calculate mass through energy conservation principles, thereby substituting a noisy mechanical measurement approach with a cleaner energy-based calculation approach.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces energy quantities (engine energy, kinetic energy, potential energy) as intermediary variables to indirectly determine mass. Rather than directly measuring acceleration which is contaminated by vibrations, the system measures engine parameters and energy changes as intermediaries that are not affected by wheel vibrations, then uses these intermediaries to calculate the mass.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of manufacture

If traditional acceleration-based estimation is applied to off-road vehicles, then the procedure is straightforward, but it is not possible to obtain reliable mass values due to the noisy acceleration signal

Engineering Contradiction:
Improvesimplicity of estimation procedureVSAvoidreliability of mass estimation
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent changes the parameters used for mass estimation from acceleration-based parameters to energy-based parameters. Specifically, it uses engine torque, fuel consumption rate, and velocity instead of acceleration, fundamentally changing the measurement parameters to ones that are not corrupted by wheel vibrations while maintaining computational feasibility.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent replaces the acceleration measurement system with an energy-based calculation system that uses engine parameters. This substitution eliminates the reliability issue caused by noisy acceleration signals while keeping the procedure implementable through standard engine sensors and calculations.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Measurement precision

If energy-based mass estimation is used, then the mass can be precisely estimated by integrating power and energy quantities over time, but the calculation becomes more complex requiring multiple sensor measurements and integrations

Engineering Contradiction:
Improvemass estimation precisionVSAvoidcomplexity of energy calculation system
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent makes the electronic control unit perform multiple functions: it not only controls engine operations but also serves as the calculation unit for mass estimation. The same sensors used for engine control (torque, fuel consumption, velocity) are also used for mass estimation, eliminating the need for separate dedicated measurement devices and reducing overall system complexity.

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

Solution Approach 2:

The system uses its own existing sensors and processing capabilities to perform mass estimation without requiring external dedicated measurement equipment. The electronic control unit that already exists for engine management also performs the energy calculations and mass determination, making the system self-sufficient and avoiding additional complexity.

Inventive Principle:
Principle #25Self-service

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

This approach allows for precise mass estimation of off-road vehicles by using energy-related values that are insensitive to acceleration noise, providing a reliable and cost-effective solution.

Implementation Method 1

determine a kinetic energy, a potential energy, an engine energy and a lost energy according to a principle of energy conservation

Methodology Applied
Scientific EffectEnergy conservation: Conservation of Momentum

Implementation Method 2

a first, a second, a third and a fourth sensor (14A-14D) configured to respectively detect a velocity v of the tractor vehicle (1) when driven by the combustion engine (9)

Methodology Applied
Scientific EffectSensor detection:

Data Source

PatentEP3760986B1Method for estimating the mass of an off road vehicle and a related off-road vehicle
Publication Date: 2023.05.03 CNH IND ITALIA SPA
  • EP3760986B1 patent drawingFigure 1~2
  • EP3760986B1 patent drawingFigure 3
  • EP3760986B1 patent drawing

AI summary

Method for estimating a mass (m) of an off-road vehicle (1) comprising: acquiring (30, 40) detection signals (S1,a-S4,a, S1,b-S4,b) from a plurality of sensors (14, 14A-14D), the detection signals being indicative of a velocity (va, vb), a slope angle (αa, αb) and engine quantities (Meng,a, ωeng,a, Meng,b, ωeng,b), the velocity, the slope angle and the engine quantities being measured during the movement of the off-road vehicle; processing (32, 42) the detection signals to determine derived quantities (Eeng, Elosses, Ek, Ep); processing (34, 44-48) the derived quantities; determining (54) the mass of the off-road vehicle from the derived quantities; and storing (56) the mass of the off-road vehicle in a memory, wherein the derived quantities are energy quantities (Eeng, Elosses, Ek , Ep).