Crankshaft Torsion Sensing for Cylinder-Specific Torque Control

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Solution Overview

Problem

Current methods for determining torque in piston engines, particularly internal combustion engines, face challenges in accurately measuring cylinder-specific torques, leading to unreliable engine control and limited condition monitoring capabilities, as they rely on theoretical models or indirect measurements rather than actual, measured variables.

Innovation Solution

The use of magnetosensitive rotation angle sensors, specifically magnetoresistive and magnetoelastic sensors, spaced apart along the crankshaft to directly measure rotation angles and calculate angular offsets, allowing for precise determination of internal torques and twist, which are then used to improve engine control and condition monitoring.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If theoretical modeling methods are used to determine cylinder-specific torques, then device complexity is reduced, but measurement precision and reliability of engine control deteriorate

Engineering Contradiction:
Improvecomplexity of torque determination systemVSAvoidprecision of cylinder-specific torque measurement
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The crankshaft is segmented into multiple measurement sections, with angle sensors positioned at different locations along the crankshaft. This allows independent measurement of torque contributions from different cylinders, enabling precise cylinder-specific torque determination while using a relatively simple sensor-based approach rather than complex modeling

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent replaces complex theoretical modeling systems with a direct mechanical measurement system using angle sensors and crankshaft torsion analysis. This substitution provides actual measured data instead of calculated estimates, improving measurement precision while keeping the physical device relatively simple

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

2Device complexity

If a single angle sensor is used to measure crankshaft rotation, then device complexity is reduced, but the ability to detect torsion-induced deformation and determine internal torques deteriorates

Engineering Contradiction:
Improvenumber of angle sensorsVSAvoidreliability of condition monitoring and damage detection
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The crankshaft is divided into multiple measurement sections with angle sensors positioned at different locations. This segmentation allows the system to measure angular positions at multiple points, enabling detection of relative angular differences that indicate torsion and internal torque, thereby improving condition monitoring reliability

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent uses the crankshaft itself as an intermediary element that transmits mechanical deformation information to the angle sensors. By measuring angular positions at different locations along the crankshaft, the system indirectly detects internal torques and torsion-induced deformation without requiring direct strain gauge measurements, improving reliability of damage detection

Inventive Principle:
Principle #24Intermediary (Mediator)

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 enables reliable, real-time monitoring of torque loads and twist along the crankshaft, facilitating improved engine control, early damage detection, and optimized fuel injection, reducing pollutant emissions and maintaining emission standards.

Implementation Method 1

The first and second angle sensors are magnetosensitive, in particular magnetoresistive and/or magnetoelastic, sensors

Methodology Applied
Scientific EffectMagnetoresistive effect: Magnetoresistance

Implementation Method 2

The first and second angle sensors are magnetosensitive, in particular magnetoresistive and/or magnetoelastic, sensors

Methodology Applied
Scientific EffectMagnetoelastic effect: Magnetoelastic Effects

Implementation Method 3

a crankshaft supported by base bearings, with a number of crank throws and journals, which converts the movement of a piston in one of the cylinders into a rotary motion by means of a connecting rod attached to a crank throw of the crankshaft

Methodology Applied
Scientific EffectMechanical force transmission: Mechanical Force

Implementation Method 4

under torque application to the crankshaft, with torsion-induced deformation of the torque-actuated crankshaft

Methodology Applied
Scientific EffectTorsion:

Data Source

PatentEP3810917B1Method for operating a piston engine, and piston engine
Publication Date: 2023.12.20 ROLLS ROYCE SOLUTIONS GMBH
  • EP3810917B1 patent drawingFigure 1
  • EP3810917B1 patent drawingFigure 2
  • EP3810917B1 patent drawingFigure 3

AI summary

The invention relates to a method for operating a piston engine, in particular an internal combustion engine, and preferably to a method for operating a piston engine with an electric machine, in particular a generator or a motor, preferably as a hybrid drive. According to the invention, it is provided in the method that - a first and a second rotary angle sensor (S1, S2), as magnetosensitive sensors and part of a number of rotary angle sensors (S1, S2, ... , Sn) which are spaced apart from one another, measure a first and second rotary angle of a torsion directly of a crankshaft (10) in such a way that the first (S1) and second (S2) rotary angle sensor are spaced apart from one another over a spacing region (AB) of the crankshaft, wherein the first and second rotary angle are measured in the spacing region (AB), and - an angular offset between the first and the second rotary angle (S1, S2) is determined, which angular offset results from the torsion of the loaded crankshaft (10), and - the spacing region (AB) between the first (S1) and the second (S2) rotary angle sensor is limited along the crankshaft to a real part region of the spacing between the bearing journals, and - the part region comprises a real subgroup of the number of offsets and/or shaft journals, with the result that the angular offset is to be assigned to the real subgroup of the number of offsets and shaft journals.