Tire-Type Adaptive Wheel Load Estimation From Wheel Speed Signals
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing wheel load estimation methods face accuracy issues due to variations in tire frequency characteristics, leading to deviations in the linear relationship between integrated gain values and wheel loads, especially when different tire types are used.
Innovation Solution
A wheel load estimation device that acquires tire type information, calculates frequency characteristic ratios, and uses tire-specific relationship specification information to determine load ratios, incorporating tire tags for electromagnetic data storage and external computing for accurate load estimation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a fixed linear relationship is used to estimate wheel load from integrated gain values, then the estimation process is simple, but the accuracy deteriorates when different tire types are used
Solution Approach 1:
The patent applies dynamics by transitioning from a fixed linear relationship to a dynamic relationship that adapts to different tire types. The system stores multiple sets of coefficients corresponding to different tire types and selects the appropriate coefficients based on detected tire type information. This allows the estimation model to dynamically adjust its parameters to match the specific tire characteristics, thereby maintaining high accuracy across various tire types while preserving relatively simple processing logic.
2Measurement precision
If tire-specific relationship specification information is used to improve estimation accuracy, then the measurement precision improves, but the device complexity increases
Solution Approach 1:
The patent applies preliminary action by pre-storing multiple sets of coefficients corresponding to different tire types in the storage unit before actual wheel load estimation is performed. When a tire is installed, the system detects the tire type information in advance and selects the corresponding pre-prepared coefficient set. This preliminary preparation eliminates the need for complex real-time calculations or adjustments, achieving high accuracy while maintaining relatively simple system structure.
Solution Approach 2:
The patent applies copying by creating multiple copies of the coefficient data, each copy corresponding to a different tire type. Instead of developing a single complex model that tries to accommodate all tire types, the system creates simplified copies of the estimation model tailored to each tire type. This allows the system to maintain simple processing logic for each tire type while achieving high overall accuracy.
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
Enhances the accuracy of wheel load estimation by adapting to different tire types, enabling precise detection of tire deflation, overloading, and unbalanced loading conditions.
Implementation Method 1
at least one of the tires includes a tag in which the type information is electromagnetically stored
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A wheel load estimation device includes a tire information acquisition unit, a wheel speed acquisition unit, a frequency characteristic ratio calculation unit, a load ratio calculation unit, and a wheel load calculation unit. The tire information acquisition unit acquires type information specifying a type of a tire. The wheel speed acquisition unit acquires wheel speed information representing a wheel speed of each wheel of a vehicle. The frequency characteristic ratio calculation unit calculates front-rear and left-right frequency characteristic ratios. The load ratio calculation unit calculates front-rear and left-right load ratios. The wheel load calculation unit calculates a wheel load ratio representing a relative wheel load. The load ratio calculation unit calculates the front-rear and left-right load ratios, based on first relationship specification information and second relationship specification information, respectively. The first relationship specification information and the second relationship specification information are determined according to the type of the tire.