Browsing by Subject "Weigh in motion"

Now showing 1 - 9 of 9
  • Thumbnail Image
    Item
    Development of a Weigh-Pad-Based Portable Weigh-In-Motion System
    (Minnesota Department of Transportation, 2012-12) Kwon, Taek M.
    Installing permanent in-pavement weigh-in-motion (WIM) stations on local roads is very expensive and requires recurring costs of maintenance trips, electricity, and communication. For county roads with limited average daily traffic (ADT) volume, such a high cost of installation and maintenance is rarely justifiable. One solution to bring WIM technologies to local roads is to utilize a portable WIM system, much like pneumatic tube counters used in short-duration traffic counts. That is, a single unit is reused in multiple locations for few days at a time. This way, WIM data is obtained without the cost of permanent in-pavement WIM stations. This report describes the results of a two-year research project sponsored by the Minnesota Department of Transportation (MnDOT) to develop a portable WIM system that can be readily deployed on local roads. The objective of this project was to develop a portable WIM system that would be used much like a pneumatic tube counter. The developed system is battery operated, low cost, portable, and easily installable on both rigid and flexible pavements. The report includes a sideby- side comparison of data between the developed on-pavement portable WIM system and an in-pavement permanent WIM system.
  • Thumbnail Image
    Item
    Development of Data Warehouse and Applications for Continuous Vehicle Class and Weigh-in-Motion Data
    (Minnesota Department of Transportation, 2009-10) Kwon, Taek M.
    Presently, the Office of Transportation Data & Analysis (TDA) at the Minnesota Department of Transportation (Mn/DOT) manages 29 Vehicle Classification (VC) sites and 12 Weigh-in-Motion (WIM) sites installed on various Minnesota roadways. The data is collected 24/7 from all sites, resulting in a large amount of data. The total amount of data is expected to substantially grow with time due to the continuous accumulation of data from the present sites and future expansion of sites. Therefore, there is an urgent need to develop an efficient data management strategy for dealing with the present needs and future growth of this data. The solution proposed in this research project is to develop a centralized data warehouse from which all applications can acquire the data. The objective of this project was to develop software for creating a VC/WIM data warehouse and example applications that utilize it. This project was successfully completed by developing the software necessary to build the VC/WIM data warehouse and the application software packages that utilize the data. The main contribution of this project is that it provides a single access point for querying all of the Mn/DOT’s WIM and VC data, from which many more applications can be developed without concerns of proprietary binary formats.
  • Thumbnail Image
    Item
    Enhanced Capabilities of BullReporter and BullConverter
    (Minnesota Department of Transportation, 2017-09) Kwon, Taek M.
    Bull-Converter/Reporter is a software stack for Weigh-In-Motion (WIM) data analysis and reporting tools developed by the University of Minnesota Duluth for the Minnesota Department of Transportation (MnDOT) to resolve problems associated with deployment of multi-vendor WIM systems in a statewide network. These data tools have been used by the MnDOT Office of Transportation System Management (OTSM) since their initial delivery in 2009. The objective of this project was to expand the current conversion capabilities of BullConverter to include more raw data formats from different companies and the current BullReporter functions to include new analysis and reporting capabilities. Data analysis needs change over time, and the members of the OTSM WIM section identified several new functions that would increase efficiency and improve quality of WIM data. This report describes the new reporting and conversion functions implemented in this project.
  • Thumbnail Image
    Item
    Enriched Sensor Data for Enhanced Bridge Weigh-in-Motion (eBWIM) Applications
    (Center for Transportation Studies, 2018-11) Kumar, Ravi; Schultz, Arturo; Hourdos, John
    Bridge weigh-in-motion (BWIM) systems, which measure bridge deformation under live loading to estimate weights of passing vehicles, have been in development since Moses first introduced the concept in 1979. Despite advances made since its introduction, important limitations for BWIM systems still exist. A feasibility study was performed to determine if some of the limitations—including poor accuracy with multiple vehicle passage, either in tandem or side-by-side; and inability to accurately capture the passage of a vehicle moving at variable speeds—could be overcome by enriching the dataset available to the BWIM system. Non-contact measurements collected in real time on the topside of the bridge can enrich the dataset, and by taking advantage of these measurements a more accurate and effective enriched bridge weigh-in-motion (eBWIM) system can be developed. Several sensing technologies were reviewed including fiber Bragg gratings, MEMS accelerometers, microwave radar sensors, magnetic sensors, active infrared detectors, and video image vehicle detection systems. Preliminary results indicated that there was no clear candidate for a fully mature sensing system that would satisfy all the criteria in this study. However, microwave radar sensors have a reasonably low cost, are the least intrusive, and perform better in all weather conditions compared to the other sensors. A testbed using radar sensors is proposed to investigate the accuracy of the eBWIM system. If the desired accuracy of the eBWIM system can be achieved, its implementations should prove to be invaluable for enforcing bridge weight limits, studying truck traffic patterns, and managing bridge inventories.
  • Thumbnail Image
    Item
    Improved Approach to Enforcement of Road Weight Restrictions
    (Minnesota Department of Transportation, 2013-11) Alexander, Lee; Phanomchoeng, Gridsada; Rajamani, Rajesh
    This project focused on the enhancement and evaluation of a battery-less wireless weigh-in-motion (WIM) sensor for improved enforcement of road weight restrictions. The WIM sensor is based on a previously developed vibration energy harvesting system, in which energy is harvested from the vibrations induced by each passing vehicle to power the sensor. The sensor was re-designed in this project so as to reduce its height, allow it to be installed and grouted in an asphalt pavement, and to protect the piezo stacks and other components from heavy shock loads. Two types of software interfaces were developed in the project: a) An interface from which the signals could be read on the MnDOT intranet b) An interface through a wireless handheld display Tests were conducted at MnRoad with a number of test vehicles, including a semi tractor-trailer at a number of speeds from 10 to 50 mph. The sensor had a monotonically increasing response with vehicle weight. There was significant variability in sensor response from one test to another, especially at the higher vehicle speeds. This variability could be attributed to truck suspension vibrations, since accelerometer measurements on the truck showed significant vibrations, especially at higher vehicle speeds. MnDOT decided that the final size of the sensor was too big and could pose a hazard to the traveling public if it got dislodged from the road. Hence the task on evaluation of the sensor at a real-world traffic location was abandoned and the budget for the project correspondingly reduced.
  • Thumbnail Image
    Item
    Traffic Data Quality Verification and Sensor Calibration for Weigh-In-Motion (WIM) Systems
    (Intelligent Transportation Systems Institute, Center for Transportation Studies, University of Minnesota, 2012-08) Liao, Chen-Fu; Davis, Gary A.
    Many state departments of transportation have been collecting various traffic data through the Automatic Traffic Recorder (ATR) and Weigh-in-Motion (WIM) systems as outlined in the Traffic Monitoring Guide (TMG) published by USDOT. A pooled fund study led by MnDOT was conducted in 2002 to determine traffic data editing procedures. It is challenging to identify potential problems associated with the collected data and ensure data quality. The WIM system itself presents difficulty in obtaining accurate data due to sensor characteristics, complex vehicle dynamics, and the pavement changes surrounding the sensor over time. To overcome these limitations, calibration procedures and other monitoring activities are essential to data reliability and accuracy. Current practice of WIM calibration procedures varies from organization to organization. This project aims to understand the characteristics of WIM measurements, identify different WIM operational modes, and develop mixture models for each operation period. Several statistical data analysis methodologies were explored to detect measurement drifts and support sensor calibration. A mixture modeling technique using Expectation Maximization (EM) algorithm and cumulative sum (CUSUM) methodologies were explored for data quality assurance. An adjusting CUSUM methodology was used to detect data anomaly. The results indicated that the adjusting CUSUM methodology was able to detect the sensor drifts. The CUSUM curves can trigger a potential drifting alert to the WIM manager. Further investigation was performed to compare the CUSUM deviation and the calibration adjustment. However, the analysis results did not indicate any relationship between the computed CUSUM deviation and the calibration adjustment.
  • Thumbnail Image
    Item
    Transportation Data Research Laboratory: Data Acquisition and Archiving of Large Scaled Transportation Data, Analysis Tool Developments, and On-Line Data Support
    (Intelligent Transportation Systems Institute, Center for Transportation Studies, University of Minnesota, 2009-02) Kwon, Taek Mu
    This report contains a collection of reports for projects completed in FY 2004 and 2005 at the Transportation Data Research Laboratory (TDRL). First, an archiving technique referred to as the Unified Transportation Sensor Data Format (UTSDF), which allows simple management of large scaled Intelligent Transportation Systems (ITS) sensor generated data, is described. UTSDF was used for the development of a Data Center (DC) at TDRL. Next, data imputation algorithms to estimate missing data are presented. These algorithms were developed during the process of developing an automated on-line Automatic Traffic Recorder (ATR) and short count data system for the Office of Traffic Data & Analysis (TDA) at MnDOT. Utilizing the archived loop data, TDRL also developed a detector fault identification algorithm and software. This algorithm and test results are reported. Another project report involves cross-utilization of Road Weather Information System (RWIS) and traffic data. Several analysis approaches were developed to analyze the actual data. The analysis approaches used and findings are reported. Another project report involves development of a Weigh-in-Motion (WIM) Probe. This tool was developed as a diagnostic tool for the MnDOT's current WIM systems, and is based on a MnDOT problem statement. It is used for identification of signal anomalies and data verification. The details of this project are reported.
  • Thumbnail Image
    Item
    Weigh-in-Motion Sensor and Controller Operation and Performance Comparison
    (Minnesota Department of Transportation, 2018-01) Gupta, Diwakar; Tang, Xiaoxu; Yuan, Lu
    This research project utilized statistical inference and comparison techniques to compare the performance of different Weigh-in-Motion (WIM) sensors. First, we analyzed test-vehicle data to perform an accuracy check of the results reported by the sensor-vendor Intercomp. The results reported by Intercomp mostly matched with our own analysis, but the data were found to be insufficient to reach any conclusions about the accuracy of the sensor under different temperature and speed conditions. Second, based on the limited data from the Intercomp and IRD sensor systems, we performed tests of self-consistency and comparisons of measurements to inform the selection of a superior system. Intercomp sensor data were found to be not self-consistent but IRD data were. Given the different measurements provided by the two sensors, without additional data, we were not able to reach a conclusion regarding the relative accuracy or the duration of consistent observations before needing recalibration. Initial comparisons indicated potential problems with the Intercomp sensor. We then suggested alternate approaches that MNDOT could use to determine whether recalibration was required. Finally, we analyzed ten-month data from the IRD WIM system and four-month data from the Kistler WIM system to evaluate relative sensor accuracy. While both systems were found to be self-consistent within the data time frame, the Kistler system generated more errors than the IRD system. Conclusions regarding relative accuracy could not be reached without additional data. We identified the sorts of measurements that would need to be monitored for recalibration and the methodology needed for estimating future recalibration time.
  • Thumbnail Image
    Item
    Weigh-Pad-Based Portable Weigh-in-Motion System User Manual
    (Minnesota Department of Transportation, 2016-02) Kwon, Taek M.
    A complete portable weigh-in-motion (PWIM) system consists of a pair of weigh-pads (one for upstream and the other for downstream), a controller which translates raw load signals to WIM data, and an optional external battery pack. The weigh-pad dimensions are one foot wide and 24 feet long, covering two lanes. This document describes how to install and remove weigh-pads using the recommended tools and setup of the controller. The operation of controller that includes initial setup and calibration is described step-by-step. The controller stores WIM data in the controller hard disk using a comma separated values (CSV) format; the details of the CSV file naming convention and column formats are described.