Even the most sophisticated machine needs direction. The optimum control systems eases the burden of human operators while keeping them in the decision making loop. Truck scales may not be the first machinery that comes to mind when discussing sophisticated controls, but these systems employ some of the most advanced software systems available to the transportation industry.
How Truck Scales Work
Truck scales begin with load cells. These mechanisms are the heart of any tuck scale operation whether it’s an in-ground model, or integrated into the truck body. Load cells directly measure the weight of the applied loads. They do this by physically deforming under the resultant pressure. The loads are transmitted to the cells at the points where the cell is directly attached to the truck’s body frame or to the structural framework of an in-ground scale. Scale technology has advanced to the point where onboard truck scales are accurate enough to provide certification for billing from in-motion scales.
The actual measurement of deformation is performed by the transducer located at the heart of the load cell. The load cell itself is constructed of materials with known stress strain characteristics. All materials (metals, plastics, etc.) deform to some degree while subject to a load. Stress is a measure of applied force divided by the cross sectional area of the object being deformed, pounds per square inch (psi) being a typical measurement. The cross section is always perpendicular to the direction of the force. So, a load applied to the top of a cylinder shaped object at its very center would have a stress value dependent on the circular cross section of the cylindrical object.
Strain is a measurement of deformation, and compares initial length paralleled with the direction of the applied load with the resultant lengths along the same axis. The same cylinder would deform to a shorter length (compressive strain) than its initial length as a result of the applied load. A load in the opposite direction would tend to pull the cylinder apart, resulting in increased cylinder length (tensile strain). The materials used in the manufacture of loads cells do not permanently deform. After the load is removed, the load cell returns to its original pre-load dimensions.
It is this strain that gets measured by the transducer. Standard transducers include strain gauges connected to the core or frame of the load cell. The strain induced in the gauge alters the cross-sectional width of the strain gauge. As a result, the electromagnetic characteristics (resistivity and frequency) of the gauge are altered. In turn, an electronic signal or electrical current passing through the gauge responds to the gauges new physical characteristics and gets altered proportionally. In addition to this basic type of load cell there are several variations used for different functions.
Vibrating wire load cells utilize a vibrating wire sensor. This consists of a wire tension mounted between a pair of anchor blocks, one at each end of a cylinder structure. As the main cylinder deforms under applied stress, the distance between the vibrating wire anchors changes, which further changes the vibrating frequency of the tension wires. Initial and changed resonance frequencies are tested by an electromagnetic coil, which in effect “plucks” the wires. A computer in a readout device attached to the load cell via a signal cable translates the frequency resonance change into applied load for purposes of measurement. Having several wires per cell reduces the effects of eccentric loading by averaging the measurements of each wire.
Some load cells utilizing the compression of a working gas or fluid to measure resultant strain. For example, air-pressure load cells measure weight by gauging the increase in air pressure as a result of the applied loads. While this may seem like a less sophisticated approach, better quality air-pressure load cells can measure even minimal weight changes while compensating for environmental factors, like ambient temperature, that can indirectly affect air pressure.
In-ground scales can use a wide variety of load cells including compression cylinders that operate as air pressure load cells, tension linked load cells integrated into heavy-lifting equipment like cranes or pulleys, and general purpose S-Type beams. More specialized load cells include single end beams that are side mounted to the framework of floor scales, platform scales, hopper scales, and tanks scales. Instead of being side mounted, double end shear beams are center mounted for measuring loads on heavy-duty truck and railroad scales.
Scales not built into the truck frame itself are classified as in-ground scales. In-ground does not necessarily mean flat or below grade. The term also applies to tank scales, crane scales, and scales attached to pulleys. For the most part, in-ground scales are those scales comprising a sturdy framework over which a deck is laid for trucks to drive on to be weighed. As a safety measure, the more expensive concrete decks (6–8 in. of precast concrete) used by in-ground scales are roughened to prevent skidding. Easier-to-install flat top steel decks consist of 12-gauge-or-thicker steel plating bolted or welded in place. The underlying frame is designed to confine the load deflection to the frame itself to maximize scale accuracy. To minimize interference with the weight reading by the load cells, the scale frame should have a deflection ratio of at least 1:850.
The in-ground scales that trucks can drive on can either be installed above grade (with approach ramps) or constructed below grade (with the deck flush with the ground surface). High profiles allow for ease of maintenance while low profiles make approach easier. Above-grade scales tend to be temporary, while permanent below-grade scales are placed in shallow pits. Being at ground surface maximized safety for approaching trucks.
The Function of Scale Software
Scale software translates physical deformation into usable data. Its job is to read and interpret the stains induced to the load cells and evaluate this physical change into an accurate weight measure. The software then takes these individual weight readings and provides useful context in the form of reports for the scale operator to interpret the data. This data primarily consists of weight records showing truck serial number, name of driver, time and date of weighing, accumulated totals, etc. Based on this data, the scale software can automatically issue payment tickets to the driver and prepare monthly billing statements to customers using the scale. More advanced software systems allow for automated truck loading systems and allow for automated truck loading and manage automated truck loading operations. This involves automated control of the actual loading and unloading process.
The hardware systems run by scale software can be extensive. In addition to automated load management systems, the software runs hardcopy printers for priming out reports and issuing load tickets, coordination with the landfill’s management information system, interfacing with radio frequency identification (RFID) chips imbedded in the truck or its load, self-diagnostics that allow for regular calibration of the entire truck scale system, optimizing truck routes and schedules, and higher level administrative reports writing and record keeping.
The point of using scale software to automate the weighing process, reduces—if not completely eliminates—human labor from the operational loop. There would be no need for a scale attendant, and no need for manual updates of truck hauling data. No need for visual confirmation of driver and truck identify, this is accomplished by use of an RFID chip. Regulation of the truck queue can also be performed by scale software, with it automatically operating traffic signals and sensing truck locations. Built-in security codes prevent fraud. The whole package eliminates human error and reduces operational costs.
The Solid Waste Industry
So what does a scale software system have to offer the solid waste industry? Like any other business, a landfill is in business to make money. Landfill operators are continuously faced with increased fuel, equipment, and labor costs. Anything that saves money on the operational budget can give a landfill operator that competitive edge he needs to stay afloat. In addition to the direct cost savings described above, the accurate data recorded by a truck scale system positively affect the rest of the landfill’s operation. Accurate, real-time data of tonnages received and types of loads accepted by the landfill allows the operator to better coordinate disposal and compaction operations out on the working face. The maximizes in-place density of disposed waste, minimizing he need for daily cover, and delays the need for capital expenditures associated with constructing the next disposal cell.
In an evermore competitive industry environment, truck scale data can lead to greater customer satisfaction, even as customer demands for quality service and reduced costs continue to increase. Customer communication is improved with automated billing. The software allows for differentiating between residential and commercial customers, ensuring timely pickups, or at least the prompt notification of blocked dumpsters or missed pickups. Route optimization features would lead to more efficient and timely hauling operations while improving driver safety.
And it’s not just customers who are pressuring landfill operators. The local community groups and government officials exert their influence on the landfills. Both can be the source of legal and political accusations. Both can make demands on an operator that can greatly increase his operating costs over and above those required by legal statutes and regulatory standards. Complete and detailed record keeping is the first line of defense for any landfill operation. That record keeping begins with the data accumulated by, and the reports generated by, scale software systems.
Major Suppliers
Air-Weigh produces the LoadMaxx on-board truck scale that combines advanced hardware and software technology that accurately measures and displays steer and drive axle group weights, gross vehicle weights, and net payload weights. Weight information is shown on an in-dash display monitor and can be simultaneously transmitted to the truck’s database. From there it can be used by other vehicle applications or transmitted directly to the truck’s fleet headquarters. The system can be used by refuse vehicles, dump trucks, cement mixers, and other types of trucks. Additional features include two alarm outputs with warning/overweight thresholds, an optional date/time printer, an optional inclinometer, and enhanced self-test diagnostics.
Carolina Software’s WasteWORKS and WasteWIZARD software solutions are the primary transaction processing systems for facilities that utilize scales. This includes landfills, transfer stations, recycling facilities, mulch yards, etc. WasteWORKS is the core product, on which everything else is based. This provides the facility operators with a point-of-sale ticketing interface for processing vehicles, a fully integrated billing module and comprehensive reporting. WasteWIZARD provides automation and unattended capabilities for the processing of transactions. A vehicle is either automatically scanned with an RFID reader, or a driver is presented with a keypad interface to identify the vehicle and enter additional information about the type of load, etc. The rest of the transaction, including weighing and printing, happens automatically. There are many different combinations of interface solutions and peripheral options available, and these can be customized to provide the most appropriate setup for a particular site’s operational needs.
There are many different scenarios where automation can be useful. A facility with two inbound scales and one outbound scale, for example, can dedicate one of the inbound lanes to being an “express” lane. This minimizes the need for additional manpower (a second weigh master) and allows the existing weigh master to concentrate on the customers who need more attention. WasteWIZARD is also great for after-hours traffic. During the day, a site’s weigh masters can use WasteWORKS to process vehicles, and at the end of the day the weigh master can shut down WasteWORKS and open WasteWIZARD. This provides for automatic, unmanned processing during the night when no weigh master is present. And WasteWIZARD system works seamlessly with WasteWORKS. Transactions can be started with WasteWIZARD and finish it with WasteWORKS, and vice versa.
WasteWORKS comes with a long list of features, covering almost every operational scenario for a landfill, transfer station, or recycling facility, but the focus continues to be on creating operational efficiency and streamlining transaction processing. The software is highly configurable, so the operator has the ability to toggle program options on and off. This creates a site-specific transaction processing environment where a ticket can be created with the minimum number of steps, while still collecting the critical data required for a complete, billable, reportable transaction.
WasteWORKS has a wide range of tools for built-in (or stock) reports, custom reports, and automating report delivery. Microsoft’s SQL Reporting Services and Crystal Reports are leveraged for ad-hoc and custom reporting duties, and the WasteWORKS Auto-Email Module allows customers to automate the delivery of reports, tickets, and bills to customers and internal staff.
Mettler Toledo’ DataBridge SS vehicle scale software automates truck scale operations by organizing records, speeding up transactions, simplifying scale operators tasks, and eliminating costly errors. DataBridge can be easily installed on a personal computer that runs on Windows 7 having a minimum 4 GB of RAM, a 2-GHz processor, 10 GB of HDD, video driver support, and DVD ROM. Not only does DataBridge reduce scale operator workload, it speeds up transaction time, while reducing errors associated with manual entry systems.
MotionLink provides integrated solutions for managing all vehicle operation associated with waste management facilities including, data, vehicles, drivers, containers, custom work orders, special requests, route planning, and schedule optimization. The system allows the operator to manage these requests by distributing and completing work without need of a paper trail. Scheduling resources and optimizing routes and schedules is made possible by advanced algorithms and configurable constraints that leverage system data. The results are work orders that schedule resources along the most optimal routes. The data can be used to extrapolate future needs allowing for accurate demand forecasting, shift planning, and manpower allocations.
To monitor the dynamic optimization of work, routes and schedules the system provides for driver and vehicle tracking and monitoring. This includes real time automatic vehicle location and playback along with vehicle health monitoring to manage maintenance needs. The loads themselves can be tracked and subject to data capture via ruggedized tablets and RFID readers. The system operates with geo-fences that provide driver behavior alerts and notifications. Driver notifications can be made with two-way communications (e-mail and SMS text messaging). Overall performance is improve with improved billing accuracy, container, and bid pick up verification via RFID, automated work order completion and verification, comprehensive reports and analytics, and real-time monitoring of performance and productivity. All in all, the end product is useful and actionable business intelligence.
Paradigm Software LLC’s CompuWeigh System is a data management, integrated accounts receivable and aging, truck tracking, transaction, report writing and posting (to external and optional integrated accounting packages), and shift totals management tool. Ease of use is provided by standard user interface that utilizes user controls at the bottom of the page of all edit windows. These controls provide a database interface that allows users to easily search, filter, save, and browse their data.
The search function provides access to specific data relating to the current search field and information based on any field in the database. Filter control allows a user to focus on a particular data type of field (or multiple fields) such as customer zip codes or specific bill cycles. Saving and browsing allows the user to maneuver through the database, moving forward and backward or returning to the starting point within the database with ease.
In addition to user access, the system allows for data management and reporting. Account Edit allows updates and revisions to data associated with individual customers (company name, address, phone number, types of waste hauled to the site, specific rates, account defaults, accounting limits, and ability to add notices that appear on the scale display screen) allowing each customer to be set up with unique rates and billing configurations. Customer communications are facilitated by the ability to create letters, forms, and envelopes, allowing mail merge directly from within the software. It further helps organize mailers to inform customers of changes operations, rates, etc.
In addition to customer Account Edit, the system allows for the management of a parallel truck form via Truck Edit. This allows the operator to control and track the use of individual vehicles. Truck specs are provided including the tare weight. System default criteria can be assigned to particular trucks to speed up their processing at the scale house. Records of truck tare weights can be updated by a simple operation within the system based on a customer defined tare expiration date, requiring trucks to obtain new tare weights at specified intervals. The system can assign truck specific functionality such as default values, assignment of RFID tags, and display notes to inform the driver and system operator of issues associated with that particular truck.
The Transaction Edit window details all information about the transaction as it occurred at the scale house. Within this display are all of the data entry field associated with the transaction being processed. Modifications can be made (within established parameters and appropriate rights) by the system user. It also provides a signature capture module that displays the driver signature to the system user. Feedback is also provided that ensures that the transaction has been reported to accounting.
Lastly, the Reporting section provides the user with a virtually unlimited number of reporting capabilities where the user can create reports at will. These adhoc reports can be created from any field in the database and allows the user to input selection criterion and sorting for each report. In addition to detailed reports, summary total reports are also available from within the application.
Qv21 Technologies, Inc. produces its LogisticsFramework dispatch/logistics software (which performs scale calculations as a feature) software package with unique features specific to the waste management industry. Its database management capabilities include the ability to track trailer numbers from transfer station or landfills, track and record municipal solid waste tonnage, track transfer station weight contracts, and flag any underweight loads. Demurrage, a charge payable to the owner of the truck in respect of failure to load or discharge the truck within the time agreed, can be entered at the transfer station or landfill. Scale ticket information can be captured in real time without manual inputs, and the ticket entry recorded at the landfill by the driver simultaneously with his dispatcher.
Vulcan On-Board Scales produces a refuse body scale system without mounting brackets designed to work with all refuse bodies that tip to dump. It can also be modified for units that tip only for service. The scale system measures gross vehicle, net payload, and individual commercial pickup weights. It comes with the Vulcan V600 meter, 15-inch super-beam end connectors, six lead VSL Vulcoder. The V600 works with existing Vulcan load cells and sensors and can interact with applications that require more than two channels, set points, recording weight information, or operators who wish to mix tractors and trailers. The V600 meter includes a serial interface, which allows communication of data to on-board computers, GPS systems, printers, and other devices. In addition, set point module options provide the ability to trigger events when programmed weigh points are reached.
Cardinal Scale offers one of the most diversified truck scale hardware and software product lines in the industry. An innovator who built the first all steel truck scale, Cardinal makes a wide variety electronic and hydraulic truck scales with concrete, steel, and pit type decks. Operating systems include wireless truck scales for data transmittal to peripheral equipment. Sizes range from models used at standard loading docks to the Yukon off-road scale for heavy-duty mining industry applications.
Their WinVRS weight recording system can be configured for use at power plants, sand and gravel quarries, concrete mix plants, asphalt plants, warehouses, recycling facilities, transfer stations, and landfill operations. Weight records recorded on PCs include vehicle and customer histories, material loads, and driver information. Its file utilities menu allows data export to other applications and files. The WinVRS-TOUCH version includes touch screen capabilities with larger fonts and buttons for convenient touch screen navigation. This high-speed software ensures that truck queues are minimized as it keeps traffic moving in and out of a facility.
Capable of communicating with up to 20 weight indicators, their WinDDE weight software can record measurements and send this data spreadsheets, databases, and automated industrial controls. Using standard serial ports of Ethernet, it can send data to Microsoft Excel, Microsoft Access, Wonderware InTouch, Automation Direct, Lookout Direct, and Rockwell Automation RSView.
Core Computing Solutions Inc. provides EnCORE, a software package designed for billing, route management, and productivity tracking. Combined with eMobile for Android, it provides a system that covers billing, routing, inventory, scales, live dispatching, collections, fleet management, paperless DVIR, paperless routes, route performance, and online payments. Since the system can use The Cloud, purchasing%