Roadway Roughness Detection via Wheel Speed Frequency Analysis
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Solution Overview
Problem
Existing methods fail to accurately and efficiently determine instantaneous roadway roughness while a vehicle is in motion, which affects vehicle dynamics and safety due to its influence on the friction coefficient between the tire and the roadway.
Innovation Solution
A method using rotational speed sensors to detect the wheel speed and analyze the frequency-dependent amplitude response, isolating a roughness characteristic variable from high-frequency oscillations to determine roadway roughness, which can be used to adjust vehicle systems for improved dynamics and safety.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If frequency analysis is performed on rotational speed data to determine roadway roughness, then measurement precision is improved, but device complexity increases due to the need for sophisticated signal processing
Solution Approach 1:
The frequency spectrum is segmented into different frequency ranges, with specific focus on high-frequency oscillations (typically above 5 Hz) that correspond to roadway roughness. By dividing the spectral analysis into distinct frequency bands, the method isolates the relevant roughness information from other wheel motion components, improving measurement precision while managing processing complexity through targeted frequency band analysis.
Solution Approach 2:
The method extracts the high-frequency oscillation component from the overall rotational speed signal by separating it from the basic amplitude response curve. This extraction isolates the roughness-related information from other influences such as tire resonance and basic wheel motion, enabling precise roughness measurement without requiring complex full-spectrum analysis of all signal components.
2Reliability
If real-time roadway roughness determination is implemented, then vehicle dynamics control is improved, but loss of time occurs due to the computational processing required
Solution Approach 1:
The method performs preliminary frequency analysis on rotational speed data to pre-identify the characteristic high-frequency oscillation patterns associated with roadway roughness. By preparing and analyzing the spectral characteristics in advance, the system can quickly determine roughness levels without requiring complex real-time calculations during critical vehicle control moments, thus reducing processing time while maintaining control reliability.
Solution Approach 2:
The patent replaces complex mechanical vibration measurement systems with an electronic signal processing approach that uses standard rotational speed sensors and frequency analysis algorithms. This substitution enables real-time roughness determination through computational methods that are faster and more adaptable than mechanical measurement systems, improving response time while maintaining measurement reliability.
3Device complexity
If only rotational speed sensor data is used to determine roughness, then device complexity is reduced, but measurement precision may be insufficient without additional sensors
Solution Approach 1:
The method enables the rotational speed sensor to serve multiple functions: it not only monitors wheel speed for standard vehicle control but also self-generates the data needed for roadway roughness determination. By analyzing the frequency characteristics of the rotational speed signal itself, the system extracts roughness information without requiring separate dedicated sensors, thus reducing device complexity while maintaining measurement precision through sophisticated signal analysis.
Solution Approach 2:
The rotational speed sensor and its data are utilized for multiple purposes: standard vehicle speed monitoring, wheel slip detection, and roadway roughness determination. This multi-functional use of existing sensor data eliminates the need for additional specialized sensors, reducing system complexity while achieving precise roughness measurements through advanced processing of the universal sensor output.
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
Enables real-time determination of roadway roughness, allowing for enhanced vehicle control and safety by adjusting systems like the braking, drive, and steering systems based on the friction coefficient, improving driving safety and dynamics.
Implementation Method 1
The rotational speed of the wheel is preferably determined with the aid of a rotational speed sensor
Implementation Method 2
a frequency-dependent amplitude response is determined on the basis of the recorded rotational speed with the aid of the frequency analysis
Implementation Method 3
The basic curve of the amplitude response is superimposed with a high-frequency oscillation, which is attributable to excitations as a result of the roadway roughness
Implementation Method 4
A roughness characteristic variable, which represents a measure of the roadway roughness, is ascertained from this high-frequency oscillation using statistical methods
Data Source
AI summary
A method for ascertaining the instantaneous roadway roughness in a vehicle. In the method, the frequency-dependent amplitude response is determined from the wheel speed, and a roughness characteristic variable is ascertained as a measure of the roadway roughness.