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A new system has recently been developed which is capable of performing highly accurate measurements of buildings at various stages of construction, while supporting complete bi-directional immediate integration with CAD files. The system–devised by the Israeli company EZ2CAD in collaboration with the American electronics company IntelliCon–allows a single operator to measure a building and create a CAD three-dimensional model which can immediately be used by the surveyor in drawing a building layout. Relying on ultrasound and RF transmission between its portable base station and a mobile unit, the new system is not bound by "line of sight" and "open skies" constraints restricting the use of current surveying equipment. In spite of these obvious advantages, the price of the new system is well below that of existing equipment.
Despite this impressive progress, most up-to-date surveying systems, like RTK-GPS and total stations, are still bound by certain limitations. RTK-GPS still requires an "open sky" in order to receive satellite signals and is therefore inhibited in performing measurements taken indoors, near buildings, high walls or under trees. The total station is constrained by line of sight and lighting conditions in the area under measurement. All measurement systems currently in use require holding a "measuring rod" vertically, are relatively expensive, and are tailored for professional surveyors.
To overcome these limitations, a team of Israeli professional surveyors and engineers set out to create a distinctly new device called QuickSurveyor. This device includes two portable units: a base station and a lightweight mobile unit called Rover. The base station is a 50cm high metallic pyramid with three tiny RF and ultrasound inbuilt transmitters/receivers. The Rover is a portable 1m unit shaped like a telescopic rod that can extend up to 3m and is used for measuring high ceilings and other hard to reach places. The Rover unit can also include a palm computer presenting the measurements in real time. Alternatively, the Rover can transmit data to a laptop placed nearby.
In the current prototype stage of development, the Rover operates within an approximately 30m radius from the base station and creates within a few seconds a 3D model of the measured area with an accuracy of about 2cm. In the finished product, the accuracy level should improve to about 5mm (almost the level of accuracy of a total station). The range of the QuickSurveyor might also grow to about 200m in some versions of the commercial device. The current prototype uses a proprietary algorithm and a plug-in software for the industry standard AutoCAD to create real time 3D models, but other CAD applications can also be used, as well as less expensive data collectors and simpler geometrical processing software such as COGO.
The estimated price of the commercial version ranges between $3,00010,000 USD depending on the system configuration. In its forthcoming stages of development, the QuickSurveyor could be adapted to various configurations, tasks and budget ranges:
• High precision reduced range configuration (with QuickSurveyor Direction Finder): up to 25m range and increased accuracy–less than 2mm in space–for monitoring 3D objects positioning, industrial geodesy, etc.
• Extra precision reduced range configuration (2 QuickSurveyor Bases with QuickSurveyor Direction Finder): up to 10m range and increased accuracy–less than 1mm in space positioning–for monitoring, 3D objects positioning, industrial geodesy, etc.
• Low cost reduced range configuration (without QuickSurveyor Direction Finder): up to 20m range and 2cm accuracy in space positioning–for indoor measurements and as-built drawings not requiring high precision.
• Low cost planimetric configuration (4 QuickSurveyor Bases without QuickSurveyor Direction Finder) for positioning in a plane with 7mm accuracy and up to 100m range.
Low cost configurations can be upgraded for high performance operations. In other task-specific and custom configurations available (up to 200m range, automatic switching for best accuracy according to the distance between QuickSurveyor Base and QuickSurveyor Rover) enhanced functionality is expected.
The measuring procedure in the new system is far simpler when compared to other systems currently in use. In an "as-built" application, for instance, the surveyor places the base unit in the center of the measuring area and starts walking with the Rover unit in his hand. By touching a wall, ceiling or floor with the three sensors at the triangle end of the Rover, the surveyor establishes the coordinates defining a flat surface, which is immediately transformed into a 3D model of a room. More sophisticated surfaces can be defined by minimum necessary points using QuickSurveyor application menu and QuickSurveyor Rover pointed rod. A QuickSurveyor operator can add doors and windows to the virtual model by hitting the corners of each opening with a pointed Rover rod. In addition, the unique geometry of the QuickSurveyor Rover makes it possible to have access to points behind obstacles and release an operator as a result of the vertical position of the Rover. The operator can move the QuickSurveyor base from one room to another and at the end of the measuring process the complete set of "as-built" drawings is obtained without spending any office time.
In layout marking-out application, a surveyor can start drawing a basic layout without any preliminary office preparation. On a QuickSurveyor computer an operator opens a site layout plan prepared by an architect on a site topography background. By touching a reference point on the site with the QuickSurveyor Rover, and at the same time marking this point with computer pointing device, the operator establishes coordination between the QuickSurveyor base position on the file and the QuickSurveyor base position on the site. From this point on, every movement of the QuickSurveyor Rover on the site is displayed as a blinking dot on the file background–an obvious advantage for further marking-out.
QuickSurveyor is not an optical device. Hence, a single QuickSurveyor base may support more than one QuickSurveyor Rover, which significantly decreases the working time of the surveyor. QuickSurveyor can be used with limited lighting or even in complete darkness.
By using an RTK-GPS to position a QuickSurveyor base, a surveyor can reach otherwise inaccessible points for RTK-GPS, for example, under trees, in the proximity of buildings, in narrow streets, etc.
A recent presentation of the QuickSurveyor project by EZ2CAD at the summer technology exhibition in Tel-Aviv aroused interest among IDF representatives, who envisaged possibilities of using the QuickSurveyor system for military applications. Such applications are relevant, for example, in situations requiring "as-built" drawings right away in some tasks carried out by engineering military units, or where there is a need for an immediate spatial presentation of a building in order to locate hidden spaces between floors or walls. Construction contractors also showed interest in the QuickSurveyor system and its potential applications for coordinating mechanisms on construction sites (for example, better coordination between crane operators and assembling workers on construction sites).
EZ2CAD, the company developing the QuickSurveyor, is presently at the advanced stages of creating a working prototype. The market for the RTK-GPS is currently estimated at more than three billion dollars a year and is expected to grow above five billion by 2008. The QuickSurveyor, which can be viewed
as a built-in unit within the RTK-GPS system, has a similar global market. As a product in its own right, QuickSurveyor will serve not only as a low price substitute for existing systems but will also complement and improve the performance of currently used equipment. As a consequence, QuickSurveyor will be used not only by professional surveyors, but also by architects, building contractors, interior decorators and appraisers, who have not used surveying equipment up until now due to its complexity and high price.
EZ2CAD Technologies is currently looking for investors for the first stage of R&D as well as for the later stage of creating a commercial product which is scheduled for marketing in about two years’ time.
Author’s note: Special thanks to Chaim Ash, CEO of EZ2CAD, for his assistance.
Iddo Genuth is the science & technology reporter of the Israeli E-journal IsraCast. Send comments to tech@isracast.com. This article was adapted from the original article published in IsraCast on July 3, 2005 (www.isracast.com/tech_news/010705_tech.htm)
A 1.190Mb PDF of this article as it appeared in the magazine—complete with images—is available by clicking HERE