2 AUTOMATIC GRADE CONTROL SYSTEMS

1 st International Conference on Machine Control & Guidance 2008 1 Trimble offers the Connected Construction Site Connecting Office, People and Machines: The New Way to Increase Productivity on Earthmoving and Road Construction Sites Norbert MATTIVI* Trimble Abstract Few will argue that construction is an industry of close tolerances, where precision and accuracy can make or break a contractor s bottom line. At the same time, the pressures of a compressed schedule and tighter budget means jobs must be completed faster and cheaper, while improving profitability. To ensure a smooth completion, all parts of a job need to be integrated from design to project completion to confirmation. To achieve this, contractors are increasingly relying on cutting-edge technology at each phase of the construction process. Trimble offers a broad range of solutions including conventional and 3D grade control systems, site positioning systems as well as construction fleet and equipment management solutions. As part of the Trimble Connected Site strategy, these solutions provide a high-level of process and workflow integration from the design phase through to the finished project delivering significant improvements in productivity throughout the construction lifecycle. Grade control solutions extend from basic systems that rely on string lines and lasers to highly precise three-dimensional solutions. Most of the systems are added to construction equipment as an aftermarket add-on, although some manufacturers, like Caterpillar, are now offering integrated systems at the time of manufacture. Keywords Total Stations, GNSS, Connected Construction Site, Trimble Machine Control 1 LASER-BASED DISPLAY SYSTEMS There are three major categories of systems available. The first are laser-based display systems. These are generally easy-to-use modular systems that are flexible and configured to the machine and site requirements. Used for machine guidance, these laserbased systems are found in a range of earthmoving applications on machines, that include dozers, backhoes, scrapers, skid steers and excavators. Figure 1: Skid Steer with Laser Receiver

3D-Construction Applications II 2 The systems are simple to use and understand. Some contractors start out with a digital linear laser receiver mounted on the front of the machine on top of a heavy-duty mast. Perched above the operator s compartment, a number of the receivers provide 360 degree operation. The receiver is used as a stand-alone battery-powered display system for guidance. With the receiver, the operator has additional valuable information needed to perform grade work faster and more accurately. Spectra Precision Laser Display Systems for grading and excavating allow operators to visually check the grade from the cab while continuing to work, increasing productivity. 2 AUTOMATIC GRADE CONTROL SYSTEMS Add proportional valve controls to the machine s hydraulics and a user interface, and the laser-based display system is quickly upgraded to automatic. If these changes are combined with an electric mast option, the laser receiver can be raised or lowered from within the operator s cab, saving time and effort. The signals from the laser receiver are used to control a proportional hydraulic valve for blade correction, allowing operators to grade faster and more accurately. This type of system is best suited for larger site preparation work. Laser or tracer-based grade control systems have numerous benefits, including reduced stakeout requirements, improved material yields, faster job cycles, eliminating communication errors, rework and idle machine time. Figure 2: GCS400withGL700Laser Trimble conventional grade control systems are flexible, fully upgradeable and can be installed on machines from any manufacturer. To meet specific machine or application requirements, Trimble GCS sensors and software can be easily added. Using the industry-standard Controller Area Network (CAN), the upgradeable wiring harness is designed for plug-and-play flexibility, allowing the system to be upgraded from a single sensor control to a multi-functional GNSS 3D solution. 3 3D GRADE CONTROL Probably the most revolutionary change in earthmoving has come about with the introduction of threedimensional grade control. There are three phases of construction today that are being significantly impacted by the introduction of three dimensional (3D) positioning technologies and the ability to digitally and seamlessly move data from the office to the field and back to the office. They are: 1. Design 2. Grading 3. Checking/Confirming With the advent of digital design data, it is possible to move the same data seamlessly between each construction phase without any loss or distortion of information a tremendous quality control and productivity advantage. Here is a summary of some of the technologies available to contractors:

1 st International Conference on Machine Control & Guidance 2008 3 3.1 Design phase: survey data converted to a plan Before an earthmoving machine cuts the surface, there is considerable planning, surveying and design for creating the site design and project plan. Civil engineers and designers work with a wide range of powerful design and CAD packages, such as the Autodesk Land Desktop, Inroads, Geopak, MOSS, the Trimble Terramodel software or Trimble Business Center. Technological advances have shifted the design emphasis from the preparation of data for printed plans to the development of a 3D surface model. It is now possible to build a surface model of the entire project and interrogate it in multiple ways prior to grading, heading off potential design problems. As a result, any point observed in the field can be instantly compared to the surface model and grade can be established. Additionally, surface files can be transferred to automatic machine control systems, thereby reducing or even eliminating the need for construction staking. Today we are seeing an ever increasing use of digital data and the digital transfer of data to connect the design engineer, surveyor, and contractor into an integrated work flow. Gone are the days when it was acceptable that the only deliverable is a sheaf of paper plans. Instead, the same digital information created for the site design and project plan can be used for machine control to ensure accurate grading and for site positioning during and after project completion. Figure 3: Design Trimble offers a suite of office software products that provide a wide range of capabilities facilitating job functions from planning and bidding to complete project productivity analysis which are designed to work together. Data changes made in the office or by a field crew are automatically recognized and used to populate the project data base and are routed to all other crews that need the data. Trimble Intelligent Data Tracking means that everyone has the latest and most up to date information at all times, reducing the possibility of making mistakes caused by having out of date models. Here s how it works: Design engineering and CAD software today typically allows the ability to import the original survey data. A 3D site design is generated. Once completed the design data is exported to a format suitable for loading onto the machine grade control system and onto the site controller system. Seamless data flow is critical from the design to construction stakeout or design to machine control without the need for additional data exchange or information reformatting which significantly reduces the potential for error and speeds the process. 3.2 Grading: turning the plan into reality During the construction phase, the earthworks contractor begins the process of converting the designer s electronic designs into reality on the site. On the integrated construction site, design data is available to the machine operator and supervisors right at the site, in the cab of the machine or their vehicle. With the advent of 3D automatic grade control systems, contractors literally can put cutting-edge technology on their cutting edge the blade of their earthmoving machine. This technology uses either the Global Navigation Satellite System (GNSS) or a robotic total station to control the actual position,

3D-Construction Applications II 4 elevation and cross-slope of a machine s blade or bucket relative to the site design that is loaded on the in-cab computer. 1. GNSS Grade Control For bulk earthwork. The GNSS approach takes advantage of a network of satellites encircling our planet. GNSS antennas are mounted on both sides of the machine s blade. A GNSS automatic grade control system can provide 20mm to 30mm accuracy with 20 Hz measuring rate. Figure 4: GCS900 on Komatsu Dozer Figure 5: GCS900 on Hitachi Excavator The Trimble GCS900 Grade Control System provides automatic blade control, configurable earthworks progress monitoring and blade guidance software on the machine. This performance allows the operator to grade, not just simple pads and slopes, but complex design surfaces and alignments at faster speeds. As the machine reaches the design grade it is possible to collect as-built data for Quality Control purposes. Avoidance zones to protect environmentally sensistive or hazardous areas can be implemented in the cab display with audible and visual warnings for the operator. With these capabilities, operators can keep tighter control over safety issues and see precisely where dirt is being moved on site. The Trimble GCS900 Grade Control System for excavators provides real-time information for the excavating of simple or complex slopes and ditches. 2. Universal Total Stations (UTS) For precise finished grade work. The UTS robotic total station automatically tracks a target, which is mounted, on the blade of the machine. The UTS continuously measures the target s position and transmits the data to the in-cab computer, which then determines the desired elevation and slope for that position. A beneficial feature of the UTS instrument is that it has search intelligence, which means that if the sight line between the machine and its target is interrupted the UTS quickly relocates the target automatically. A total station is typically used, when accuracies as tight as +/-5mm are required. Figure 6: GCS900 on CAT Grader with SPS930 Total Station

1 st International Conference on Machine Control & Guidance 2008 5 The Trimble GCS900 Grade Control System using the new Trimble Universal Total Stations and MT900 Machine Target, provides advanced high speed with steep angle tracking for millimeter accuracy grade control for motorgraders and dozers. This allows operators to grade faster in higher gear with maximum machine uptime meaning increased productivity for job completion and a faster return on investment. Here s how it works: The GNSS receiver or robotic total station computes the blade s exact position many times per second. The on-board computer determines the exact position and slope of the blade. It compares this information to the design elevation and computes the cut or fill to grade. This information is graphically displayed on the screen inside the operator compartment in project plan view, crosssection or as text. The cut/fill data is passed to the in cab display, which guide the operator up/down for grade and right/left for a defined alignment (for road work). The cut/fill data is also used to activate hydraulic valves for 3D automatic blade control systems. The system shows exactly where the machine is on the site, and where the blade is relative to the site plan. An advantage of placing grade information within the cab is that operators are empowered to make fast decisions. Operators know where grade is, as well as the locations of design elements, and can work in dust, wind, or darkness. In-field changes can be made quickly. New grade or pad elevation can be set right in the cab without waiting for grade stakes to be set or repositioned. 3.3 Checking phase: making certain While the project is being worked on, there is the need to check and verify finished grade and material thickness meets the design specifications in real-time verification. On the integrated construction site, the grade checkers and supervisors can now take the site design into the field in a digital format to measure material volumes, check grades and material thicknesses, and perform site measurement tasks, such as point, line, and surface stakeout. To provide in-process checking and end of project confirmation, contractors are using solutions such as the Trimble Site Positioning Systems with Trimble SCS900 Site Controller Software. The unit is designed to automate daily construction site tasks so that contractors can easily perform site positioning and make decisions in the field to keep machines running. Figure 7: SPSwithTSC2 Figure 8: SCS900 Screen Snap The new Trimble SPS730 and SPS930 Universal Total Stations with exclusive Trimble MagDrive servo technology provides fast, responsive, and accurate tracking for high performance automatic machine guidance. Unique MultiTrack technology provides the ability to track and lock to a range of targets, including both active targets such as the Trimble MT900 Machine Target and passive targets such as a normal prism. This technology enables unparalleled tracking performance in areas of high vibration or where obstructions exist and reliably locks onto the right reflective surface. Designed for the daily needs of heavy and highway contractors, the Trimble SCS900 Site Controller Software employs dedicated task-specific menus and reports that streamline data management and onsite measurement tasks.

3D-Construction Applications II 6 Here s how it works: Small, mobile and lightweight, the Trimble Smart GNSS Antenna SPS881 can be mounted on a pole, ATV, or site vehicle and connected to the controller running the SCS900 software via Bluetooth technology eliminating cables completely. The SCS900 software has been designed with the contractor in mind. It takes the complexity out of grade checking and site surveying by simplifying the setup and operation of what has traditionally been surveying equipment. Intended for construction operations, the SCS900 software can measure and provide real-time reporting and in-field TIN surface modeling, contour generation and computation of volumes with shrink and swell factors. All data can be organized and managed through a site, design and work order structure. Instant in-field and data analysis can be generated for stockpile and progress volumes, grade check quality, thickness check quality and stakeout. 4 CONSTRUCTION FLEET AND EQUIPMENT MANAGEMENT Trimble Construction Manager is designed to reduce construction project costs through enhanced equipment utilization, improved safety, theft recovery, and an improved understanding of a construction company s operations. Built specifically for the construction industry, the Trimble Construction Manger solution provides a powerful, yet easy-to-use solution for construction companies to manage equipment such as dump trucks, fuel trucks, graders, loaders and generators. It brings together a variety of information, including location, hours, and external data, to provide an overview of the construction company s equipment, as well as detailed information for in-depth analysis. Users access information about their equipment by viewing the data on a PC enabling them to view the location of a piece of plant or machine in the map view, running on-demand reports and charts, and using the dashboard view (multiple displays on screen simultaneously). With the alerts feature, users can be automatically notified of unexpected activity via email or SMS, which can aid in theft recovery. Users can also schedule reports to be emailed at regular intervals so the right information gets to the right people at the right time, and view a history of the equipment s activity on the map for up to the past 90 days. The system uses GPS-based positioning hardware and widely available GSM/GPRS wireless networks to provide information to a secure data server. The Internet-based Trimble Construction Manager software displays information about the equipment in real-time and facilitates the optimization in deployment of the equipment from one graphical interface. The software provides customized reporting capabilities to address a company's unique business needs and can be used with Microsoft Excel. Using the Trimble Construction Manager, contractors can realize lower operating costs, reduced fuel consumption, improved equipment productivity and utilization, resulting in a rapid return on investment. Figure 9: TCM_Graphic Figure 10: TCM_Dashboard

1 st International Conference on Machine Control & Guidance 2008 7 Trimble Construction Manager is a geolocalization and telematics solution that allows the user to manage all construction equipment in real-time, both on and off site. TCM is designed to manage all equipment types from machines to trucks, to portable equipment and monitor productivity and utilization. It can also aid in theft recovery. Utilization charts immediately identify equipment not meeting expectations, or idling more than they are working, which may lead the construction manager to deploy that equipment at a more appropriate location where they can be better utilized. Actionable business information is essentially what the Trimble Construction Manager solution and Trimble s Connected Site strategy are all about. 5 CONCLUSION - BIG BENEFITS The Connected Construction Site is helping contractors to be more productive, thorough and precise. Digital data is now flowing seamlessly from the site designer s computer through the machine operator s controls and on to the accurate confirmation of a job well done. The hard work of construction has become technologically sophisticated, yet simpler in many ways to complete. And throughout these three phases of construction, contractors are reaping benefits of improved safety, productivity, accuracy and profits. With the construction market becoming more demanding and competitive than ever before, contractors are increasingly turning to sophisticated machine control systems for significant process and productivity advantages, reduced costs and greater efficiency. Trimble Ready machines Thanks to Trimble Construction partnerships with the top construction equipment manufacturers, contractors can now order Trimble Ready machines direct from their equipment manufacturer. Trimble Ready machines are just that, they are ready for the installation of the selected Trimble Grade Control System. All the hard work associated with installation both the installation of the harness and welding has been done by the manufacturer. Trimble has worked closely with industry- leading construction equipment manufacturers Caterpillar, Liebherr, John Deere, and Volvo to offer earthmoving equipment preconfigured for Trimble Grade Control components. *Dipl. Ing. Norbert Mattivi, Friedhofstrasse 3, D-73760 Ostfildern