Torque Calibration via Dual Weight Estimation

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Solution Overview

Problem

Existing methods for estimating engine torque in heavy vehicles, especially those without load sensors, are prone to inaccuracies due to potential manipulation of engine control parameters or non-approved modifications, leading to incorrect weight calculations and safety and efficiency issues.

Innovation Solution

A method that estimates engine torque using a fuel injection table and calculates a first vehicle weight value, then uses an auxiliary brake torque estimation from an auxiliary brake table to calculate a second weight value, comparing the two to detect deviations and potential manipulation, without requiring a separate torque sensor.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If engine torque is estimated based on fuel injection amount using a fuel injection table, then the torque estimation can be obtained without a torque sensor, but the estimation accuracy deteriorates due to potential manipulation of engine control parameters or non-approved modifications

Engineering Contradiction:
Improvetorque measurement systemVSAvoidengine torque estimation accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The system uses feedback by comparing two independently calculated vehicle weight values: one derived from engine torque estimation and acceleration, and another from auxiliary brake torque estimation and deceleration. This feedback mechanism detects deviations caused by parameter manipulation or engine modifications, allowing the system to identify when the fuel injection-based torque estimation has become unreliable.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent introduces an intermediary verification method using auxiliary brake torque estimation as a mediator. Instead of directly trusting the fuel injection table output, the system uses the auxiliary brake system as an independent reference point to verify the engine torque estimation indirectly through weight calculation comparison.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If the estimated vehicle weight is used to set weight-dependent control parameters, then the vehicle can operate efficiently, but safety deteriorates if the weight estimation is inaccurate due to manipulated engine parameters

Engineering Contradiction:
Improvevehicle operational efficiencyVSAvoidvehicle safety
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The system performs preliminary verification by comparing the two weight values before finalizing weight-dependent control parameters. This preliminary action detects potential manipulations or modifications in advance, allowing the system to prevent unsafe operations before they occur by identifying discrepancies between the engine torque-based weight estimation and the auxiliary brake-based weight estimation.

Inventive Principle:
Principle #10Preliminary action

3Measurement precision

If a torque sensor is installed to measure engine torque directly, then the torque measurement accuracy is improved, but the device complexity and cost increase

Engineering Contradiction:
Improveengine torque measurement accuracyVSAvoidsensor system
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

Instead of using a physical torque sensor, the system creates a virtual copy of the torque measurement through calculation. It replicates the torque value by using the relationship between fuel injection amount, engine parameters, and vehicle dynamics (acceleration and deceleration data), providing an indirect but sufficient measurement for verification purposes without physical sensors.

Inventive Principle:
Principle #26Copying

4Productivity

If the vehicle operates with manipulated engine control parameters, then short-term performance may improve, but long-term reliability deteriorates due to undetected overload and excessive wear

Engineering Contradiction:
Improveengine performanceVSAvoidengine service life
Core Design Contradiction:
ProductivityVSDuration of action of stationary object

Solution Approach 1:

The continuous feedback mechanism monitors engine operation by regularly comparing the two independently derived weight values. When manipulated parameters cause deviations beyond acceptable thresholds, the system generates warnings or alerts, providing ongoing feedback that prevents long-term undetected operation with modified parameters, thereby protecting engine service life.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP2652471B1Torque calibration method
Publication Date: 2019.01.23 VOLVO TRUCK CORP
  • EP2652471B1 patent drawingFigure 1

AI summary

Method for verifying an engine torque estimation, comprising the steps of estimating the engine torque based on the amount of fuel injected into the engine, where the engine torque is obtained from a fuel injection table, estimating a first vehicle weight value by a calculation based on acceleration of the vehicle and the estimated engine torque, estimating an auxiliary brake torque by using an auxiliary brake table, estimating a second vehicle weight value by a calculation based on the estimated auxiliary brake torque, and comparing the first vehicle weight value with the second vehicle weight value. The advantage of the invention is that it is possible to detect if an actual engine torque value deviates from the original engine torque value of a vehicle without measuring the engine torque with a separate torque sensor.