Evaluation of the Bridge Weigh-in-motion System

Evaluation of the Bridge Weigh-in-motion System
Author:
Publisher:
Total Pages: 96
Release: 1985
Genre: Government publications
ISBN:

This demonstration project allowed Wisconsin Dept. of Transportation to test the overall performance of Bridge weigh in motion equipment as well as develop an entirely new comprehensive and representative truck weight database.

Evaluation of Weigh-in-motion Systems

Evaluation of Weigh-in-motion Systems
Author: Benjamin H. Cottrell
Publisher:
Total Pages: 106
Release: 1992
Genre: Piezoelectric devices
ISBN:

The objective of this research was to evaluate low cost weigh-in-motion systems. The three systems evaluated were (1) a capacitance weigh mat system, (2) a bridge weighing system, and (3) a piezoelectric cable sensor system. All three systems have a two-lane capability. An evaluation was made of (1) the quality of the data, (2) the performance of the equipment, (3) the applications of the equipment and its ease ofuse, and (4) the format of the data and its usefulness. Although objective data were used when possible, the majority of the evaluation is subjective. The quality of the data from each of the three systems is about the same. The piezoelectric cable system provides slightly lower quality data than the other two systems. The equipment of the capacitance weigh mat performed well; that of the bridge system was adequate; and there was concern about the durability of the piezoelectric cable system. Because of the tradeoffs between the capacitance weigh mat system and the bridge system, it is difficult to rank them. The piezoelectric cable system's sensors are permanently installed; therefore, it is not as portable as the other two systems. With regard to the format of the data and its usefulness (which are dependent mostly on the software and not the sensors), the capacitance weigh mat system is flexible and provides individual truck records in two formats, the bridge system provides the most comprehensive tables, and the piezoelectric cable system is limited and depends on other software to generate additional tables. Suggestions are made about how to use the systems and how to improve their performance.

Technologies and Approaches to Reducing the Fuel Consumption of Medium- and Heavy-Duty Vehicles

Technologies and Approaches to Reducing the Fuel Consumption of Medium- and Heavy-Duty Vehicles
Author: National Research Council
Publisher: National Academies Press
Total Pages: 251
Release: 2010-07-30
Genre: Science
ISBN: 0309159474

Technologies and Approaches to Reducing the Fuel Consumption of Medium- and Heavy-Duty Vehicles evaluates various technologies and methods that could improve the fuel economy of medium- and heavy-duty vehicles, such as tractor-trailers, transit buses, and work trucks. The book also recommends approaches that federal agencies could use to regulate these vehicles' fuel consumption. Currently there are no fuel consumption standards for such vehicles, which account for about 26 percent of the transportation fuel used in the U.S. The miles-per-gallon measure used to regulate the fuel economy of passenger cars. is not appropriate for medium- and heavy-duty vehicles, which are designed above all to carry loads efficiently. Instead, any regulation of medium- and heavy-duty vehicles should use a metric that reflects the efficiency with which a vehicle moves goods or passengers, such as gallons per ton-mile, a unit that reflects the amount of fuel a vehicle would use to carry a ton of goods one mile. This is called load-specific fuel consumption (LSFC). The book estimates the improvements that various technologies could achieve over the next decade in seven vehicle types. For example, using advanced diesel engines in tractor-trailers could lower their fuel consumption by up to 20 percent by 2020, and improved aerodynamics could yield an 11 percent reduction. Hybrid powertrains could lower the fuel consumption of vehicles that stop frequently, such as garbage trucks and transit buses, by as much 35 percent in the same time frame.

ICWIM 5, Proceedings of the International Conference on Heavy Vehicles

ICWIM 5, Proceedings of the International Conference on Heavy Vehicles
Author: Bernard Jacob
Publisher: John Wiley & Sons
Total Pages: 534
Release: 2013-03-04
Genre: Technology & Engineering
ISBN: 1118623274

Weigh-in-motion (WIM) is a process of measuring the dynamic tire forces of a moving vehicle and estimating the corresponding tire loads of the static vehicle. This collection of lectures from the International Conference on Weigh-in-Motion details applications such as: collection of statistical traffic data, support of commercial vehicle enforcement, roadway and bridge cost allocation, and traffic management.

Traffic Monitoring Guide

Traffic Monitoring Guide
Author: United States. Federal Highway Administration. Office of Highway Information Management
Publisher:
Total Pages: 220
Release: 1995
Genre: Traffic flow
ISBN:

This guide is designed to provide direction on the monitoring of traffic characteristics. It begins with a discussion of the structure of traffic characteristics monitoring and traffic counting. The next two sections cover vehicle classification and truck weighing. The last section presents the coordinated record formats for station identification, traffic volume, vehicle classification, and truck weight data.

On motion planning and control for truck and trailer systems

On motion planning and control for truck and trailer systems
Author: Oskar Ljungqvist
Publisher: Linköping University Electronic Press
Total Pages: 98
Release: 2019-01-22
Genre:
ISBN: 9176851303

During the last decades, improved sensor and hardware technologies as well as new methods and algorithms have made self-driving vehicles a realistic possibility in the near future. Thanks to this technology enhancement, many leading automotive and technology companies have turned their attention towards developing advanced driver assistance systems (ADAS) and self-driving vehicles. Autonomous vehicles are expected to have their first big impact in closed areas, such as mines, harbors and loading/offloading sites. In such areas, the legal requirements are less restrictive and the surrounding environment is more controlled and predictable compared to urban areas. Expected positive outcomes include increased productivity and safety, reduced emissions and the possibility to relieve the human from performing complex or dangerous tasks. Within these sites, different truck and trailer systems are used to transport materials. These systems are composed of several interconnected modules, and are thus large and highly unstable while reversing. This thesis addresses the problem of designing efficient motion planning and feedback control frameworks for such systems. First, a cascade controller for a reversing truck with a dolly-steered trailer is presented. The unstable modes of the system is stabilized around circular equilibrium configurations using a gain-scheduled linear quadratic (LQ) controller together with a higher-level pure pursuit controller to enable path following of piecewise linear reference paths. The cascade controller is then used within a rapidly-exploring random tree (RRT) framework and the complete motion planning and control framework is demonstrated on a small-scale test vehicle. Second, a path following controller for a reversing truck with a dolly-steered trailer is proposed for the case when the obtained motion plan is kinematically feasible. The control errors of the system are modeled in terms of their deviation from the nominal path and a stabilizing LQ controller with feedforward action is designed based on the linearization of the control error model. Stability of the closed-loop system is proven by combining global optimization, theory from linear differential inclusions and linear matrix inequality techniques. Third, a systematic framework is presented for analyzing stability of the closed-loop system consisting of a controlled vehicle and a feedback controller, executing a motion plan computed by a lattice planner. When this motion planner is considered, it is shown that the closed-loop system can be modeled as a nonlinear hybrid system. Based on this, a novel method is presented for analyzing the behavior of the tracking error, how to design the feedback controller and how to potentially impose constraints on the motion planner in order to guarantee that the tracking error is bounded and decays towards zero. Fourth, a complete motion planning and control solution for a truck with a dolly-steered trailer is presented. A lattice-based motion planner is proposed, where a novel parametrization of the vehicle’s state-space is proposed to improve online planning time. A time-symmetry result is established that enhance the numerical stability of the numerical optimal control solver used for generating the motion primitives. Moreover, a nonlinear observer for state estimation is developed which only utilizes information from sensors that are mounted on the truck, making the system independent of additional trailer sensors. The proposed framework is implemented on a full-scale truck with a dolly-steered trailer and results from a series of field experiments are presented.