Machine Management
by Joseph V.R. Paiva PLS, PE, PhD
July 1, 2005
Servicing of machines can be automatically scheduled and managed, providing service personnel with lead time and ensuring they have the correct tools and supplies.
Is monitoring and managing construction machine control a remote possibility?
Construction
machines are costly--to acquire, operate, maintain and even to manage. Use the
wrong machine for the job, run one past its scheduled service hours,
misdiagnose a series of similar failures, rent a machine out only to have it
misused, unused or sitting onsite with its engine idling… and you’ve got
problems. Machine monitoring and remote management help solve some of these
problems.
Various kinds of machine automation are available to assist in machine
management. Machine control ensures that earth is moved according to plan using
a digital terrain model onboard the machine. Machine monitoring systems log the
conditions under which the machine is used, how it is used, and other vital
statistics such as its temperatures, pressures and fluids. Remote machine
management enables using some or all elements of machine control and machine
monitoring to enable cost-effective use of the machine, often in real-time.
Starting Remotely
Many providers’ systems require an initial investment for the hardware installation on each machine to be monitored and managed. If the customer is to do the monitoring and management, a central facility must be established as well, where base maps, data collection, analysis, reporting and decision-aiding software is housed. Subsequently, there is a monthly charge paid to the provider (or third party) that is proportional to the amount of data transmitted and wireless airtime required to receive and send data between the machines and the central system. Data can also be sent between machines, though in some cases this may occur through the central hub. Michael Ritter, general manager for Construction Services at Trimble, says that many customers start with a service plan that provides a real-time position update every 10 minutes and a minute-by-minute report of machine position for the previous 10 minutes. As customers gain experience using the reports to optimize vehicles and personnel, they see benefits of increasing the timeliness of updates. “Even though the machine management services infrastructure costs more to provide the owner real-time data every minute, they learn within weeks that it pays back big time,” Ritter says. “They achieve productivity improvements as if they were sitting in the passenger seat of each vehicle.”
The Maintenance Example
An
example of automatic activity resulting from remote machine monitoring and
management is machine maintenance scheduling. The conventional (manual) way to
perform machine maintenance is to periodically check a machine’s run time meter
against a maintenance schedule. While some owners will service machines before or
after the scheduled interval, knowledgeable users who have tracked performance
and cost know that strictly following the schedule provides economic benefits.
To determine actual engine time of a machine first requires locating the
machine and, if at a remote site, then sending someone to retrieve the
information requested. If service is necessary, the service provider must be
able to deliver the service onsite.
With an automatic management system, the owner can get projected service dates
based on current rates of use of each machine. When a triggering time is
reached, the machine will appear on that day’s or week’s list of machines to be
scheduled for service. If the owner permits the service provider to have access
to this information, the service provider can take the initiative to schedule
onsite service on the proper day, and at the proper time and place. Generally,
some form of interaction, manual or automatic, must take place between the
service provider and owner to determine the machine’s use pattern to schedule
the service for the least disruptive day and time. Because the nature of the
service is known, the service provider can ensure that the correct tools and
supplies are on the service truck.
This system for scheduling the proper servicing location, personnel, tools,
parts and supplies is especially beneficial when there is an equipment failure.
The report of the machine failure is accompanied by various vital statistics
(pressures, temperatures, loads, etc.) as well as fault codes, warnings and
other diagnostic information sent to the central hub for automatic transmittal
to the owner’s chosen location.
Types of Remotely Gathered Information
The onboard control box in Topcon’s System 5 3D-GPS+ grading solution allows for multiple views, indicating machine position and teeth of the bucket relative to design grade. The operator can observe and communicate with other machines working on the same project. This same information is also available in real-time to a controller working from a remote location.
Machine Management Roots
With Komatsu’s Komtrax system, users can locate machines instantly with GPS, get real-time service hour meter readings, plan maintenance by customers’ usage patterns, and track lost or stolen equipment.
Trimble Site Positioning Systems give site foremen, supervisors, grade checkers and site engineers the ability to check and verify that finished grade and material thickness meet the design specifications via in-process checking and real-time verification.
Even though certain aspects of machine control or guidance using stringlines and other aids existed before the application of GPS to construction machines, it is this all-weather 24-hour tool that has offered possibilities for system designers. Though use of GPS to determine position indoors or underground is problematic, it has been, in many cases, the final ingredient in the technology mix to enable realization of many innovators’ dreams. With GPS it is now possible (with a few extra measurements, and perhaps a few additional sensors to detect the relationship between the machine’s movable parts such as stick and boom) to know where the machine’s cutting edge is. Then, and using that same position (in a manner similar to which a mouse’s pointer is used to indicate the point of interest), it is possible to determine on a digital model what the finished surface should be. From manually controlling the machine using the information generated by this process (guidance), the technology quickly progressed with the use of proportional valves in the hydraulic systems of the machines to automate control.
For various reasons, including improved accuracy, a number of optical systems may be used to also determine the machine’s position and relationship to the finished surface. But it is GPS and its freedom from the line-of-sight issues of optical systems that have allowed designers to dream the broadest visions for machine control, and eventually, management.
To enable GPS technology for machine control has meant the use of “carrier phase” processing, a technique commonly used in surveying instrumentation, to take the normally 10- to 15-meter accuracy positioning of GPS and derive accuracies on the level of 1 cm. This is achieved using the additional technique of real-time kinematic (RTK) positioning, which necessitates the use of a wireless data link to send correction data to the construction machine from the one or more GPS base stations in the vicinity of the construction work. The wireless data links use a number of different radio technologies to provide these up-to-the-second corrections that keep the machines on track.
Topcon machine control systems are available through Komatsu dealers. This Komatsu GD 655 motor grader, equipped with Topcon’s System Five 3D-GPS+ and Millimeter GPS/LazerZone, will be featured at Technology Roadshows throughout the nation.
Engine and Machine Monitoring
Manufacturers of construction machines, engines and other major electrohydraulics components have been gradually adding capabilities to monitor and report vital statistics during normal operation and during unusual events such as component failures, erratic operation, or operating conditions such as low coolant levels, high oil temperatures and ambient temperature. Dashboard messages are read and assembled for upload into a diagnostic tool and some diagnostic functions are found onboard. These systems help to solve problems and can also help prevent them through tracking and facilitating maintenance.
Machine statistics including engine run time, engine idle time and other performance details were originally designed to be offloaded into a diagnostic machine carried by service technicians. Through the addition of wireless links, it is now possible to access information from any machine within the coverage area of the communications system. Data can be collected in either real-time, at designated intervals, or at any other time upon command. These communications links may be private proprietary systems, or they may use cellular technology or satellite channels.
Collection, Analysis and Decision-making
Regardless of what time interval data is collected from machines, it is the effectiveness of its management that leads to good results. The most effective management systems allow the user to view the collection of equipment in categories designated by the user. This information may be collected by jobsite, equipment type, idle machines, or machines in use where engine idle time exceeds some set threshold. After setting the categories, subcategories and sub-subcategories, etc., the user can sort the reported information to isolate the machines that are most or least troublesome, or most efficiently or inefficiently used. When integrated with maintenance schedules, the job impacts of maintenance downtime can be assessed and decisions can be made about the exact time and location of maintenance and substitution of machines, if necessary. Special conditions like machine faults, warnings and overdue maintenance can be shown within the categories selected or as categories themselves. Temporal analysis looks at patterns over time. Repeated failures of the same type over applicable time spans, whether on the same machine or many, may yield insights into how to minimize those failures.
The Bells and Whistles
CAT’s EquipmentManager lets users choose the most appropriate subscription level for each machine; users can search and categorize information by alert level, group, equipment ID, make and model.
Many of the developments in machine control came from the mining environment; early pioneers of machine control, monitoring and management were drill rigs used to establish blast hole patterns. Once uploaded with the instructions on where and how to drill each hole, the machines navigated to each hole location to complete the job. “When machine management technology arrived in the construction world, the testing in the mines paid off--usually contractors want as much of the functionality as the newly launched management system can provide,” says Murray Lodge, worldwide construction sales manager for Topcon Positioning Systems. “Even though we offer basic systems that provide once-a-day reporting, we find that most want as close as they can get to real-time reporting.”
Remote machine management is available today, and its capabilities continue to grow rapidly. But the potential customer of machine management must invest time and energy to gain a thorough understanding of the opportunities of the various systems, as well as the need for actions that must be taken from the information gathered.
Sidebar: The Systems and Services Providers
Providers
of machine monitoring and management systems and services include machinery
manufacturers such as Caterpillar (www.cat.com), Komatsu (www.komatsuamerica.com), and Case (www.casece.com); communications
specialists such as Orbcomm (www.orbcomm.com) and Qualcomm (www.qualcomm.com); machine components
suppliers such as electrohydraulics player Sauer-Danfoss (www.sauer-danfoss.com); and machine
control manufacturers such as Leica Geosystems (www.leica-geosystems.com), Topcon (www.topconpositioning.com) and Trimble (www.trimble.com). The range of services
offered differs with each provider into many different classes and budgets of
services. Some providers offer specialized information such as anti-theft services
(including LoJack from Caterpillar and Titan Anti-Theft from DPL North America,
www.dplamerica.com), while others
provide a more comprehensive range for effective machine
management.
It is not unusual for users to use a combination of service providers or
service levels from the same provider to match their needs. For example, hour
and location tracking, which is a low-cost service, may be used on the majority
of low-end equipment and more sophisticated information including diagnostics may
be used on the expensive equipment.
More than one developer in the machine control arena is looking at the
possibility of using machine-to-machine data transfer to create a more
intelligent worksite. With this system, it is possible for one machine to
rework the earth and send a “current status” terrain model to other machines
for automatic adjustments.
Joseph V.R. Paiva PLS, PE, PhD
Joe
Paiva is a professional surveyor and professional engineer, and has obtained
his doctorate in civil engineering. He is a published author, speaker and
consultant to developers and marketers of products for the positioning
industry.
Comments (0) Post a Comment
Did you enjoy this article? Click here to subscribe to the magazine.