The onboard computers that guide GPS-enabled construction machines require CAD files that have been converted to a format the machine can read. Until recently most of these conversions were done by engineering firms, or in-house engineers in larger construction firms. But the vendors of GPS equipment have all recently begun offering what’s called “translation programs” that individual contractors can use to simplify and speed up this process.
Translation programs take digital terrain models produced in CAD file formats such as Drawing files (DWG), Drawing Exchange Files (DXF), Land Extended Markup Language (LandXML) or the DNG files used by the U.S. Department of Transportation’s Microstation program, and converts them to a format readable by the GPS-driven computers inside the operator’s cab.
Once the plans are translated, they are exported to a flash card and inserted into the computer where the operator can view a current version. These translation programs build the views the operator needs to see and insures that everybody on the site is looking at the same data. Traditional engineering programs do some type of conversion feature, but translation programs don’t require extensive CAD or drafting knowledge.
“In a nutshell, these programs are an easy way for somebody who uses GPS machine control to get a plan or AutoCAD file from their engineer or surveyor and quickly create a 3D model to plug into that machine,” says Jason Killpack, product marketing manager for Topcon.
Companies that offer GPS systems each have their own format and you need the software that matches that format. Leica’s SiteSmart translates files to use with GradeSmart 3D or DigSmart 3D. Design with Leica GPS systems is usually done with SiteManager before translation to a machine-readable format. Topcon’s 3D Office translates files for its 3D-MC control boxes, creates Triangulated Irregular Network (TIN) files for export and partners with Pocket 3D, the software component of Topcon’s Grade Management System, which facilitates surface inspection and surface management using graphics combined with printable reports such as quantities and cut/fill mapping.
Trimble’s SiteVision Office translates CAD files for use with their Grade Control Systems and works best when used in conjunction with Trimble’s Terramodel and Visualizer programs. Some companies offer these programs separately or as part of their GPS equipment package. Although translation is a small part of the overall file conversion process, it is an important link between the engineer and the operator.
“Translation programs must balance ease of use and power that speaks the contractor’s language,” says Randy Noland product sales manager for 3D machine control, Topcon. “This translation and partnership allow contractors to realize job progress instantly and, if needed, respond to changes that are inevitable. It is another great tool to keep the job moving and the contractor in the black. All of this works together so the contractor can more easily have the data on his side. Easy access to the same digital data creates more productive and accurate performance from the contractor’s perspective.”
Time, effort and money
Some type of conversion features have existed with traditional CAD design programs, but translation software is relatively new and was designed out of the need to reduce time and the cost of getting machine-readable files to contractors who aren’t trained in CAD programs or don’t want to expend the effort necessary to use CAD to convert files.
“We are realizing that a lot of our customers have CAD programs and it’s not necessary for them to have another extensive design program,” says Reynolds Boyd, product manager for Leica’s Machine Automation division. “They just need something to take the files they already have and get them into the format that the machine needs. These programs reduce the time it takes to get the file from design to machine control by a matter of days and reduce the cost because contractors don’t have to go an outside firm to convert these files. It’s all about getting that design package data and getting it into the machine without jumping through a lot of hoops.”
Views you can use
Another feature is the ability to present the model in several different layers and provide a 3D simulation of how the terrain would appear from inside the cab. This feature is useful for getting a first look at the site from the operator’s point-of-view and provides a way to check the accuracy of the site plan.
“The simulation feature is useful because it represents how the model will look in the cab of the bulldozer,” Killpack says. “It looks like a miniature version of one of our control boxes. You can drive over one of the models before you send it out to the field.”
“Operators know where they are on the site and they have a visual of what they are building,” adds Tim Tometich, GPS project manager for McAninch Construction, a Des Moines, Iowa-based company that has been using Trimble systems since 1999. “They learn how to read plans a lot better, and they are looking at the plans all day long compared to before when they spent about 15 minutes of the day looking at plans. No matter where they go on that site they are looking at the drawings and they are seeing the cuts and fills. It makes them more self-directing.”
According to Greg Stoppel, vice-president of Stoppel Dirt, his use of translation software has cut down on a lot of mistakes before the grading or excavation begins. The Sublette, Kansas-based Stoppel Dirt has been using Trimble’s GCS since 2000 and converts files using SiteVision Office. “Having these plans available helps us find problems before they get to the field,” he says. “When we convert these files, we are finding mistakes in the plans. If you catch the mistakes before the operators ever get their hands on it, they start gaining a tremendous amount of confidence in the terrain model. If they get out there and see mistakes, then they wonder what else is wrong.”
The next step for the evolution of GPS and its software programs lies with what the manufacturers call the “connected site,” where a manager in a remote office will be able monitor the site on a variety of levels. Using some type of interface, this remote site will be able to monitor the vital statistics, productivity and position of any given equipment on the site and update the design files while sending messages about those updates to operators when they are available.
While current GPS technology already allows this to a limited degree, the connected site will tie all of these features together under one umbrella. Some companies will be testing beta versions of connected sites in 2007, but that won’t change the need for translation programs, at least for the foreseeable future.
Boyd also sees a time when DWG or CAD files will be read directly by the cab’s GPS-driven computer. That probably won’t be the case for awhile because of the way CAD files are prepared.
“The goal of the connected site is just getting the data to the machine quickly,” Boyd says. “It won’t change the need for preparing the machine data. Currently you take a flash card, copy the data to it, go out and copy the data to your machine and upload them. Instead of driving a file to the site, the connected site manager would just upload it directly to the site office.”
What’s available now?
Leica introduced SiteSmart this past August. The program makes files readable with its GradeSmart 3D program for bulldozers or graders or the DigSmart 3D for GPS-driven excavators. Leica designed SiteSmart to import any type of program for conversion with few restrictions. SiteSmart can also import files from Leica’s SiteManager. “It is not that SiteSmart can read any file type,” says Reynolds Boyd, product manager for Leica’s Machine Automation division, “but it can read file types that the majority of CAD programs can export. The program is designed to automatically recognize the entities within CAD and convert them.”
Retail price: $800.
Topcon’s 3D Office manages files needed for the 3D-MC system and allows the site designer or engineer to manipulate multiple control, machine and design files. With a direct link, it is also possible to upload or download files using Topcon’s Pocket 3D field software package. Digital terrain models can be imported as DWG, DXF, LandXML and ASCII text files and 3D office itself can design Triangulated Irregular Network (TIN) files for export. For road construction applications, 3D Office offers the use of horizontal, vertical alignments and templates and can create digital terrain models for complicated earthmoving and modeling.
Retail price: $1,000, but can be discounted if bought with a complete machine control or grade management system.
Trimble’s SiteVision Office takes files produced in the Terramodel design program and converts them to formats readable on Trimble’s various GCS packages. This program is most often used in conjunction with Terramodel and Visualizer, but can read files in DWG, DWF or LandXML formats and import files from programs such as Paydirt estimator software, Sitework, AutoCAD, GEOPAK and Insite. With SiteVision you can also run validation checks and view any profile through the data and check spot heights for inconsistencies.
Retail price: Part of a complete Trimble Grade Control purchase.
While AutoDesk’s Civil 3D 2007 program is technically for civil engineering, it does offer some practical uses for site modeling and conversion. The dynamic software offers tools for engineers, surveyors and production drafters and can import files in the DWG, DGN, LandXML and DWF formats. AutoDesk’s partnership with Trimble means Civil 3D can import files from Terramodel, but it is also integrated with the Trimble Link program that allows the export of machine-readable files.
Retail price: $7,495, but can vary depending on the vendor.