Chassis Dynamometer Tire Angle Sensing Without Conversion Tables

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Solution Overview

Problem

Conventional vehicle testing apparatuses, such as chassis dynamometers, require time-consuming preparation of steering angle conversion tables and have low accuracy in recognizing tire turning angles, necessitating indirect determination based on steering wheel angles.

Innovation Solution

A vehicle testing apparatus with a roller and a roller rotation mechanism, equipped with a displacement sensor that directly measures tire turning angles using a measurement target region in the tire, eliminating the need for advanced preparation and improving accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a steering angle conversion table is used to indirectly determine tire turning angles, then the system can be simplified and does not require direct measurement, but the recognition accuracy of tire turning angles decreases

Engineering Contradiction:
Improvetire turning angle recognition accuracyVSAvoidmeasurement system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces the indirect mechanical/electrical measurement system (steering angle sensor + conversion table) with an optical measurement system (displacement sensor). The displacement sensor directly measures the actual tire turning angle by detecting the position of a marker on the tire, eliminating the need for conversion tables and intermediate calculations, thereby improving measurement accuracy while maintaining system simplicity

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

Solution Approach 2:

The patent introduces a marker as an intermediary element attached to the tire. This marker serves as a visual reference that the displacement sensor can directly track, enabling accurate measurement of tire turning angles without complex mechanical linkages or conversion algorithms. The marker acts as a mediator between the tire and the sensor

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If a steering angle conversion table is prepared for each vehicle model, then the measurement can be performed, but the preparation time and complexity increase when changing vehicles

Engineering Contradiction:
Improvevehicle changeover speedVSAvoidpreparation time for steering angle conversion table
Core Design Contradiction:
ProductivityVSLoss of time

Solution Approach 1:

The displacement sensor directly measures the actual tire turning angle of the specific vehicle being tested, eliminating the need for pre-prepared conversion tables. The system adapts to each vehicle automatically by performing direct measurements, making the measurement process self-service and independent of vehicle-specific calibration data

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent extracts the measurement function from the complex conversion table system and implements it through a simple displacement sensor that directly measures tire position. This extraction removes the time-consuming preparation step of creating conversion tables while maintaining the ability to measure tire turning angles for any vehicle model

Inventive Principle:
Principle #2Taking out (Extraction)

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

The apparatus accurately determines tire turning angles without requiring prior preparation, ensuring high accuracy and consistent geometry between rollers and tires during testing, regardless of the vehicle model.

Implementation Method 1

a displacement sensor detecting an angular displacement on a tire turning angle, using a measurement target region in the tire as a detection target to obtain angle measurement information

Methodology Applied
Scientific EffectOptical measurement:

Data Source

PatentEP4650744A1Vehicle test device and operation control method for vehicle test device
Publication Date: 2025.11.19 TMEIC CORP
  • EP4650744A1 patent drawingFigure 1
  • EP4650744A1 patent drawingFigure 2
  • EP4650744A1 patent drawingFigure 3

AI summary

This disclosure has an object of obtaining a vehicle testing apparatus such as a chassis dynamometer, which does not require advanced preparation on a tire turning angle and can recognize an angular displacement with high accuracy. A displacement sensor (7L, 7R) according to the disclosure detects a tire turning angle of a tire (6L, 6R), using a distance measurement region (90) in the tire (6L, 6R) as a detection target to obtain angle measurement information (S7L, S7R). A controller (15) receives the angle measurement information (S7L, S7R) from the displacement sensor (7L, 7R), determines a steering angle corresponding to the tire turning angle indicated by the angle measurement information (S7L, S7R), and outputs steering angle instruction information (SG) indicating the determined steering angle to a motor drive (19). The motor drive (19) drives a rotation motor (42) of a roller rotation mechanism (3L, 3R) according to the steering angle instruction information (SG).