Vehicle Weight Estimation on High Rigidity Bridges
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing vehicle weight estimation techniques, such as those using weigh-in-motion systems, face challenges in accurately estimating vehicle weight on bridges with high rigidity, as these bridges do not bend much and generate minimal noise in vibration, making it difficult to separate noise from vibration.
Innovation Solution
A vehicle weight estimation apparatus and method that collects vibration information from sensors on a structure, extracts axle responses, calculates axle indices, converts these indices into axle weights using pre-stored conversion information, and totals the axle weights to estimate the vehicle's overall weight.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a WIM system uses least-squares method to calculate vehicle weight, then the error between calculated and measured displacement is reduced, but accurate weight estimation becomes difficult on high rigidity bridges that do not bend much
Solution Approach 1:
The patent applies mechanical vibration by generating vibrations using a vibration generator (e.g., impactor or shaker) and measuring the structure's vibration response. The vibration frequency and amplitude are controlled to excite the structure's natural modes, enabling accurate weight estimation even on high rigidity bridges that do not bend significantly under static load.
Solution Approach 2:
The patent changes the measurement parameter from static displacement to dynamic vibration characteristics. By measuring vibration frequency, amplitude, or other dynamic parameters and analyzing them through frequency domain analysis or modal analysis, the system can accurately determine vehicle weight on bridges with various rigidity levels, including high rigidity bridges where static bending is minimal.
2Strength
If a bridge has high rigidity to support heavy loads, then the bridge structure is strengthened, but the amount of noise in vibration decreases making it difficult to separate noise from vibration
Solution Approach 1:
The patent replaces mechanical vibration measurement with active vibration excitation and signal processing. Instead of relying on passive mechanical bending and noise generation, the system uses controlled vibration excitation and digital signal processing techniques (frequency domain analysis, modal analysis) to extract weight information, eliminating the need to separate noise from vibration in high rigidity structures.
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 allows for accurate estimation of vehicle weight even on bridges with high rigidity, by effectively converting axle indices into axle weights and summing these weights to determine the vehicle's total weight.
Implementation Method 1
a structure having a vibration-generating structure that generates vibration upon passage of a vehicle
Data Source
AI summary
A vehicle weight estimation apparatus 10 includes: a collecting unit 11 that collects vibration information indicating vibration output from a sensor 25 installed to a structure having a vibration-generating structure that generates vibration upon passage of a vehicle 30; an axle response extracting unit 12 that detects, by using the vibration information, axle responses indicating the passage of one or more axles of the vehicle 30 over the vibration-generating structure; an axle index calculating unit 13 that calculates axle indices corresponding to the individual axles based on the axle responses; a converting unit 14 that converts the axle indices into axle weights by referring to conversion information that is stored in advance and that indicates a relationship between axle indices and axle weights; and a vehicle weight calculating unit 15 that calculates the weight of the vehicle by totaling the axle weights of the individual axles.