Gear Estimation Using Clustering for Test Bench Simulation

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Solution Overview

Problem

Current methods for testing internal combustion engines on test benches struggle to accurately simulate real driving conditions, particularly in estimating gear shifts and engine torque, which are crucial for realistic emission and consumption behavior analysis.

Innovation Solution

A method using a clustering algorithm to identify linear relationships between vehicle speed and engine speed from recorded test drive data, allowing for the estimation of gear shifts and other target values without direct measurement, and correcting for outliers and measurement noise to generate a chronological sequence of gears for a realistic test run.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If gear shift information is not directly measured during test drives, then measurement equipment and system complexity are reduced, but the accuracy of test run simulation deteriorates

Engineering Contradiction:
Improvemeasurement system complexityVSAvoidgear shift estimation accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent replaces direct mechanical measurement of gear shifts with a computational approach using clustering algorithms. The system processes measured data (vehicle speed, engine speed, accelerator pedal position) through algorithmic analysis to identify gear shift events, substituting physical sensors with information processing methods.

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

Solution Approach 2:

The patent introduces intermediate calculated parameters (vehicle speed, engine speed ratios, accelerator pedal position) that serve as mediators to indirectly determine gear shift events. These intermediate values bridge the gap between available measurements and the target gear shift information.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If gear shifts are estimated using simple algorithms, then processing time and computational resources are reduced, but the accuracy of test run specification deteriorates

Engineering Contradiction:
Improvedata processing speedVSAvoidgear shift detection accuracy
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The patent employs feedback mechanisms where the clustering algorithm iteratively refines gear shift detection by comparing detected events with expected patterns based on vehicle dynamics. The system continuously adjusts detection thresholds and parameters based on feedback from the measured data characteristics.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent implements dynamic adaptation of detection parameters during data processing. The clustering algorithm adjusts its sensitivity and thresholds based on the actual characteristics of the measured data, allowing optimal performance across different driving conditions and vehicle types.

Inventive Principle:
Principle #15Dynamics

3Reliability

If real driving conditions are simulated on test benches, then emission and consumption behavior accuracy are improved, but the complexity of test run specification increases

Engineering Contradiction:
Improveemission testing accuracyVSAvoidtest run specification complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent enables the test run specification system to automatically generate its own input data by processing measured test drive data through clustering algorithms. The system serves itself by converting raw measurement data into structured test run specifications without requiring manual intervention or complex external configuration.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent transforms raw measurement parameters (vehicle speed, engine speed, accelerator pedal position) into derived parameters (gear shift events, test run specification) through systematic parameter changes and transformations. This automated parameter transformation simplifies the overall testing system while maintaining accuracy.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3721199B1Test stand and method for performing a test
Publication Date: 2022.08.31 AVL LIST GMBH
  • EP3721199B1 patent drawingFigure 1~2
  • EP3721199B1 patent drawingFigure 3
  • EP3721199B1 patent drawingFigure 4~5

AI summary

The aim of the invention is to estimate a gear of a transmission for a test run in a simple manner from other available measured values (MW) of a test drive. This aim is achieved, according to the invention, in that a temporal sequence of vehicle velocity (v) and of an engine speed (N) is used as measured values (MW). From data points (DP) of associated vehicle velocities (v) and engine speeds (N), a number of ranges (Bn) having a linear relationship between the vehicle velocity (v) and the engine speed (N) is identified by means of a clustering algorithm. The clustering algorithm assigns the data points (DP) to the number of ranges (Bn) and calculates a cluster center (CZn) for each range (Bn), each cluster center being interpreted as a gear (Gn). The gear (Gn) associated with the cluster center (CZn) of a range (Bn) is associated with the data points (DP) of said range (Bn) in order to obtain a temporal sequence of gears (Gn), and the determined temporal sequence of the gears (Gn) is used as a set point value (SW) of the test run or is used to determine another set point value (SW) of the test run.