Tunnel Business Magazine

DEC 2018

TBM: Tunnel Business Magazine is the market leader for North America. TBM is written for leading professionals in all aspects of tunneling and covers project stories, design elements, contracting strategies, legal issues, new technology and more.

Issue link: http://digital.tunnelingonline.com/i/1067144

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Page 22 of 59

be maintained automatically during the movements, if desired, using auto nozzle control feature, which simplifies the spraying task for human operators. When using point-to-point mode, the operator defines a line between two points. After activation, the spray nozzle auto- matically follows this line. If the nozzle angle is locked, it is au- tomatically retained in position against the tunnel profile. The operator only has to move the boom to the next position needed for spra osition can be fine-tuned and controls overdriven manually if needed. This functionality is useful for spraying large smooth surfaces. The redundant nature of concrete spraying booms enables inclusion of some extra features to assist with boom control. In the current SmartSpray system, one such feature allows the middle point of the boom to be moved in three (3D) directions by the operator using one of the control levers while pressing an activation button. The position of the boom can be controlled in order to avoid collisions or to prevent the boom from being driven to imprac- tical positions. Operator-controlled movements of the middle point do not alter movement of the spraying nozzle. A second feature allows middle joints (two joints) to be made rigid using an on/off switch. These joints remain in the position where they were during coordinated movement of the nozzle, which is useful especially in narrow tunnels. In addition to these boom control featur SmartSpray 1 system has several smaller features, designed to make the operator's everyday tasks easier. Included is a coordi- nated frame in which the control works can be re-oriented by pressing a button. This new orientation is set according to cur- rent orientation of the upper part of the boom. Essentially this only changes interpretation of the control lever signals, which define the velocity demands of the nozzle. It also includes an au- tomatic back and forth rotation and tilting of the spraying noz- zle. Choosing between on/off or proportional steering of nozzle turn and tilt are similar to those in direct manual control state. SmartSpray 2: currently in development and testing When speaking about "robotic spraying", worries concerning incorrect thickness and inconsistent quality of sprayed con- crete arise. These issues have been taken into account from the beginning of the SmartSpray development process. Customers aske elop a system where distance of the nozzle is kept within a certain range from the wall to make sure that fluctuations of nozzle distance do not affecting final quality of the sprayed concrete. At this stage, however, it was still expected that the responsibility for other spraying pa- rameters is left to the operator so that concrete spraying does not fully rely on equipment and technology. It was also request- ed tha elop a system to spray required thickness of concrete, more or less automatically. Development work for this SmartSpray 2 System, with easy profiling ("area spraying"), is ongoing and already in the testing phase. In the near future we will have more elaborate software and measurement system developments available and ready to to offer "semi-automated" spraying with thickness control. TUNNELINGONLINE.COM TBM: TUNNEL BUSINESS MAGAZINE // DECEMBER 2018 F E AT U R E S T O R Y 2 3 Equipment suitable for small, medium and large headings. Delivery & shotcrete application in mining projects around the world.

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