Vol 2 - No 1

Landfill Machine Control: Site Software and System Benefits

Written by Nigel Adams

Created on Monday, 30 January 2012 19:39

A 569Kb PDF of this article as it appeared in the magazine—complete with images—is available by clicking HERE

Welcome to the final part of the series about Landfill and machine control. So far we have covered landfill fundamentals, and an appreciation of landfill machine control from the system and user perspective. This final article will conclude with a look at the office software suite, its implementation and the benefits and payback achievable in utilising landfill machine control.

Any 3D machine control system is data reliant. It's all about the data, whether in the initial survey and data upload or the mapping and data gathering of the work in progress, data flow and management are the key to successful machine control utilisation.

One of the first hurdles that need to be overcome with large scale data management is the gathering of the information. A process that has been utilised by a number of machine control manufacturers is that of "command and control" as a means of managing data flow between office software and operational machinery.

The command and control systems with which I am familiar are network type systems which provide the means to monitor and manage from any location rather than the restrictions imposed by having a simple local point to point based telemetry interface, which whilst sufficient for basic data gathering would not have the capacity to manage the high volume of real time data reporting which are essential in a well managed command and control environment.

So what is it that we want to do with this data within the landfill environment?

Here are a few suggestions:
Provide all machine control systems onsite with correct DTM and update regularly
• As the job progresses the design requirements may change and alter the structure of the DTM. Regular updates can be easily done from a central point ensuring all machines are compliant with latest design needs.

Have the site office (command centre) receive live updates from machine control systems
• Each machine working on site will be updating the DTM as it progresses in filling cells, creating slopes etc., as well as reporting information such as pass counts (the number of machine passes over an area to achieve optimum compactions) and other density critical information.

Have machine control systems communicate with each other in real time
• As well as reporting to the office the site updates it can also be communicated to other onsite machinery. This real time update of work progress and site topology change can be reported to all onsite machines via the office software suite.

Give complete site visibility of all machine movement to everyone --(note : this can offer huge safety benefits)
• Each operator can see not only the position of his machine on the work site, but the location of all the others and can set proximity warnings, avoidance zones to assist in avoiding machine/machine collisions.

Provide the office with information to enable data management and generate documentation and reports.

With regards to the hardware implementation of the telemetry system, the things to consider when providing the above options are:
1. Bandwidth there's a lot of data being transferred and it needs to be done at high speed to achieve real time operation
2. Site conditions
3. Local / National radio frequency restrictions

Issue one requires WLAN capability and can be met by using a suitable high speed data transfer system, I would recommend that you look at a system such as the Mesh Network system produced by Rajant to get a more detailed understanding of the subject. Obviously any chosen network system needs to be able to withstand the operating conditions that it will be subjected to and should meet the same qualifying standards as that of the machine control system.

The site conditions need to be investigated to ensure that the machine control systems have complete wireless coverage. This may require the addition of repeater stations to avoid any RF blackspots. The repeater stations themselves require careful consideration to ensure that they have suitable power supply and charging capabilities (high capacity batteries with solar cell recharging are very common) and are robust to survive the environment (including the occasional lightning strike). Having the station on wheels helps as it allows it to be moved if coverage requirements change.

Having overcome the data transfer issues and with some understanding of the benefits in utilising command and control, what happens to this gathered data?

The office software suite will give instant access to a wide range of reporting activities key to the correct management of a landfill site, including:
• Topographical information of the site as it changes on a real time basis
• Compaction data density achieved
• Compaction data pass counts
• Machine utilisation and efficiency
• Record of waste types and locations
• Programming of avoidance zones
• Air space utilisation
• Estimate of site life and usage

Other activities which can be done from the comfort of the office are:
• Upload DTM information
• Messaging service to operators
• Monitor record of all site activity—a useful tool for the site manager when reviewing an operators performance and guiding him in more efficient use of his machine.

Business Case & Payback Points
The following is a summary of the business case for landfill machine control and the payback points.

I. General landfill goals improved by system adoption
A. Improved airspace utilization
B. Optimal compaction
C. Achieve desired density

II. Slope & grade management
A. Proper grade and slope design from the cab--reduce or eliminate failed slopes
B. Water management--proper slopes and grade help shed water away from waste reducing contamination or leachate. Secondary processing of leachate is costly, approximately .10.12 cents per gallon. One site I visited processes 25,000 gallons per week or $3000/ week; $156,000/year.
C. Leachate management--engineered slopes help contain leachate and optimize circulation or leachate recycling. This optimizes microbial activity that consumes waste. Some sites need to add water for microbial optimization. Thus, lack of water and leachate management is costly
D. Monitoring of slopes in real time prevent over-fill or under-fill at the outer slopes. Both extremes cost money and this technology provides accurate guidance and status.
E. Road management--better road design for getting trucks in and out. This also means that road base material is accurately applied and optimized.

III. Monitor Lifts
A. Typically 2' lifts are considered an optimized standard. The system monitors lift thickness keeping an operator on target.
B. If a lift is too thick, an operator can back-lay the area and avoid bridging

IV. Idle time for machines
A. If a compactor is not running, it certainly is not achieving density. Remote monitoring of machines and idle reports improve decision making for operator performance, service and maintenance, even reducing the number of machines or their operating hours in a day.

V. Historical playback
A. Provides operator analysis and training opportunity. Operators can watch machine playback back in the office. Helps break bad habits and optimize performance. "This can be an invaluable training tool, " says Scott Beathard, president of GeoShack North America. GeoShack is a leading landfill system provider.

VI. Safety & quality of work
A. The system reduces the need for laborers to be on the work face potentially in harm's way. Technology reduces daily surveys, site stakes, vertical grade markers for active areas, etc.

VII. Avoidance Zones
A. Areas such as gas wells, gas lines, landfill liner, asbestos zones, chipped tires, etc can be marked and stored in the system. If a machine; dozer, compactor, drill, scraper or excavator enters the user designated zones, either horizontally or vertically, an alarm will sound. Positional data is also stored providing historical data for all machine positions.

VIII. Real time surface topography (daily grids)
A. Certification may require surveys and fly overs but the technology renders these procedures nearly obsolete. These costs can exceed $12,000 annually for a midsize landfill.
B. Real time surface deflection information, pass-by-pass offers fill density, volume consumed, compactor performance and remaining cell/ landfill airspace

IX. EPA and other agency policy requirements
A. This technology produces data that is more readily available, more accurate and more comprehensive than ever before making it easier to comply with agency requirements.

X. Flexible System Entry Points and Scalable System Design
A. Entry points include a Landfill GPS System for the site manager (pickup truck, ATV or man-rover) or for a single machine (compactor or dozer.) This offers affordable options easing the cost of adoption and future migration
B. Scalable/Upgradable--a landfill can adopt at an affordable entry point then add additional machines, a site manager system, an office computer system for post analysis and report generation or a mesh wireless infrastructure enabling remote monitoring, remote training and troubleshooting and even remote data management and analysis.

XI. Additional benefits improved by system adoption
A. Fuel savings--Result of optimized pass counts, material hauling and placement and road grading
B. Reduced machine wear--Result of optimized machine performance and scheduled maintenance.
C. Equipment Selection--Proper analysis of waste stream, daily tonnage, water and leachate can inform your equipment selection; the right size compactor, right size dozer and how many pieces of equipment required to properly manage your site.
D. Job Satisfaction--Operators are a competitive lot and proud of their work. System adoption empowers operators to be better raising job satisfaction. This nurtures competition to perform. Operation managers are quick to incentivize properly raising the performance for the entire landfill.

Summary
A solid waste landfill is a complex and dynamic engineering challenge. One site manager told me that managing a landfill was like building a highway on a moving target. The tools provided by a landfill centric GPS system are just that, tools. They provide real time data and feedback that greatly improve decision making. This technology has positively impacted landfill construction and operation and it is evident that adoption will continue to grow.

Nigel Adams is based in the UK, and was formerly the Engineering Director for Prolec. He now owns OnGrade Ltd and focuses his 21 years experience on machine guidance.