Vehicle Weight Estimation Using Accelerometer and History

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Solution Overview

Problem

Existing methods for estimating a vehicle's weight are inadequate for stationary vehicles and those traveling on soft or uneven surfaces, leading to incorrect gear choices and potential engine stalling, especially after unloading or loading operations.

Innovation Solution

A method that calculates a first weight of the vehicle, detects unloading/loading using accelerometer signals, and estimates a second weight based on the vehicle's operating history, allowing for accurate weight estimation even when stationary or on challenging surfaces without additional sensors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If weight estimation is based on force equation F = m·a, then weight can be estimated when vehicle is in motion, but weight cannot be estimated when vehicle is stationary

Engineering Contradiction:
Improveweight estimation accuracyVSAvoidapplicability to stationary vehicles
Core Design Contradiction:
Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The system performs preliminary weight estimation when the vehicle is in motion using the force equation, stores this information in memory, and then uses it for weight estimation when the vehicle is stationary. This preliminary action allows the system to have weight data available even when the vehicle is not moving.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The control unit acts as an intermediary that stores weight information in memory and uses it to bridge the gap between motion-based weight estimation and stationary conditions. The stored weight data serves as a mediator that allows weight estimation without direct force measurement when stationary.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If gear choice is based on estimated weight before loading/unloading, then gear selection can be made, but incorrect gear choice results due to weight change after loading/unloading

Engineering Contradiction:
Improvegear selection speedVSAvoidgear choice accuracy
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The system continuously monitors vehicle operating conditions and updates weight estimation based on detected loading or unloading events. This feedback mechanism ensures that the weight information used for gear selection reflects the current actual weight, improving gear choice accuracy while maintaining rapid gear selection capability.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The weight estimation system is dynamic and adapts to changing vehicle conditions. When loading or unloading is detected, the system updates the weight estimation in real-time, making the gear selection process adaptive to current vehicle state rather than relying on static pre-loading weight data.

Inventive Principle:
Principle #15Dynamics

3Adaptability or versatility

If weight estimation is performed on soft or uneven surfaces, then weight can be estimated in more conditions, but rolling resistance varies greatly making calculation difficult

Engineering Contradiction:
Improveapplicability to various surfacesVSAvoidweight estimation accuracy
Core Design Contradiction:
Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The system changes the approach from direct force-based calculation to using accelerometer data combined with stored weight information. This parameter change allows weight estimation to proceed even when rolling resistance is highly variable, as the method relies on acceleration measurements and historical weight data rather than direct force calculations that would require accurate rolling resistance values.

Inventive Principle:
Principle #35Parameter changes

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

Enables accurate weight estimation for stationary vehicles and those on soft or uneven surfaces, preventing engine stalling and ensuring correct gear choices by using existing accelerometers and historical weight data, thus improving safety and reducing wear on vehicle components.

Implementation Method 1

weight estimation are based on the vehicle's acceleration and on information from any air suspension system with which the vehicle may be fitted

Methodology Applied
Scientific EffectAccelerometer: Accelerometer

Implementation Method 2

its estimation usually involves using the force equation F = m·a, which is not applicable when the vehicle is stationary and its acceleration is therefore zero

Methodology Applied
Scientific EffectForce equation:

Data Source

PatentEP2591251B1Method and device for estimation of weight of a vehicle
Publication Date: 2020.09.09 SCANIA CV AB
  • EP2591251B1 patent drawingFigure 1~2
  • EP2591251B1 patent drawingFigure 3
  • EP2591251B1 patent drawingFigure 4

AI summary

The present invention relates to a method and a device for estimation of a weight of a vehicle. The method for estimating the weight comprises the steps of calculating at least a first weight m1 of the vehicle, detecting whether unloading/loading of the vehicle has taken place, and estimating a second weight m2 of the vehicle on the basis of information about its previous weight. The invention further relates to a computer programme and a computer programme product, to use of a weight estimated according to the invention, and to a motor vehicle comprising at least one such device.