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76356_a_10_structassemb_e.indd

Structure Assembly The sheer size of airplanes makes structure assembly a demanding task: Large stressed-skin fuselage elements are delicate and flexible, making a large number of holding points and positioning axes neces-sary when aligning and joining the elements to form sections. This, in turn, necessitates control functionality such as is currently only offered by SINUMERIK 840D.
Structure Assembly: Intro
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Requirements at a Glance
Structure assembly, the joining of stressed-skin Despite all the complexity, the processes fuselage elements and the floor grid to form must be simple to program, diagnose and ope- Structure Assembly round or half-round sections is a precision rate. The dimensions of the joining stations 3D-path interpolation task: A number of stressed-skin elements that favor the use of mobile operating units com- of an overdetermined system are each several meters long and high and are municating with the control via wireless con- distorted under their own weight have to be nections. Finally, sufficient safety for people, Precise positioning aligned with tenth-of-a-millimeter precision the machine and the product must be ensured. of many machine axes and placed in a precise position in space with ple handling in all situations respect to one another. The simplest way of do-ing that is with a control system that processes Safe retraction in case of error Cartesian measured data from a laser tracker, Safety for people, machines transforming these, and allowing correction of setpoints in case of deviations. This per-mits precise positioning of machine axes and coordinated 3D path interpolation of multiple single systems. Structure Assembly: Requirements
Our Solution with SINUMERIK 840D 3D-path Interpolation
3D-path interpolation of an
overdetermined system
The core of our solution for structure assembly A SIMATIC-PLC controls the assembly pro- on the outside, where positioners are applied. To be able to control more than the 31 axes is a group of multiple SINUMERIK 840D-NCUs cess that is simply sequentially programmed SINUMERIK 840D controls movements of the that are possible with SINUMERIK, multiple connected using special link modules. For the by the user in SIMATIC S7-Graph.
positioners. Deviations between the measured NCUs can be coupled using link modules. human-machine interface, there is a central The actual positions of up to ten measuring actual positions and the set positions pro- For structure assembly, systems with three machine control panel and mobile operating points ("targets") on the inside of the stressed- grammed in the CAD system can easily be NCUs and more than 90 single axes have units can also be used. The connection of the skin fuselage elements are usually sensed by compensated for and the parts initially aligned already been implemented with negligible NC level with the SIMATIC WinCC visualization a laser tracker and passed on to the control within themselves. velocity losses.
system permits easy part and order manage- system. The elements are fixed and aligned A worldwide unique feature of the ment and archiving of process data. with an appropriate number of holding points SINUMERIK is that path interpolation in Car-tesian space is possible both across channels Control room PC
Portable Operation Station
Laser control system
and NCUs. That way, the work coordinate systems of several stressed-skin fuselage Windows 2000 server, elements and that of the floor grid can easily be aligned with one another. The opti- mized spatial positions of all parts are stored MS Office,Web Navigator server in the control and can be reproduced at any time. For example, the parts can simply be moved apart in continuous-path mode to in- set sealing compound and then precisely re- MPI-Bus (Service) turned to the joining position. By means of the transformation, simple traversing of the Sidewise shell left Sidewise shell right part with a programmed feedrate is possible Laser tracker platform and complicated programming of single Upper longitudinal seam machine axes is obviated. This also permits manual traversing in JOG mode. With absolute encoders on all axes, con- trols and drives are up to date immediately after a power failure (without having to re- peat referencing). Structure Assembly: Solution
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Precise Positioning
Precise positioning of many machine axes
The joining of several stressed-skin fuselage elements using the kinematic transformation (TRAORI) of SINUMERIK 840D is simplified and speeded up. This permits workpiece pro-gramming in Cartesian coordinates instead of in machine axes, which also permits online corrections without subsequent postprocessor runs. For example, the Cartesian measure- ment data sensed by laser tracker in the basic coordinate system (BCS) of the joining station can simply be compared with the program- med set data and the necessary compensa- tory movements in three linear axes (XYZ) and three angles of orientation (ABC) can be calculated using the transformation. With these six degrees of freedom, it is possible to position multiple complete stressed-skin fu- selage elements in three dimensions and put them in any required relative position. Compensation of the position deviation of the positioners from the set position is per- BCS = Basic Coordination System formed in SINUMERIK via a simple zero offset TRC = Tool Center Point (G5x) and by rotating and/or translating the WCS = Workpiece Coordination System individual work coordinate systems (WCS) in LR = Laser tracker N = Normal vector space using the Frame function. The control automatically works out the set points for all 1 = Machine Coordination System 1 (Axes 1-3)2 = Machine Coordination System 2 (Axes 4-6) the machine axes involved. 3 = Machine Coordination System 3 (Axes 7-9)4 = Machine Coordination System 4 (Axes 10-12)5 = Machine Coordination System 5 (Axes 13-15)6 = Machine Coordination System 6 (Axes 16-18) Structure Assembly: Solution
Simple handling in all situations
Safe retraction in case of error
Safety for people, machines and
products
To be able to operate the movements of many MOBIC and the Option WinCC/WebNavigator The kinematic transformations of the con- axes in multiple work coordinate systems connected to SIMATIC WinCC by Industrial Wire- trol permit safe retraction of each part in easily and, above all, safely, the standard ope- less LAN provide a safe solution that is available a precisely defined (vector) direction, ma- rating functions of the machine panel have for many industrial sectors.
nually, too. There are switchable operating been expanded and grouped together to form The assembly process is controlled using screens for this on the central machine con- channel selection displays that the operator SIMATIC S7-400. Maximum flexibility and trans- trol panel on each NCU channel and there- can switch between. parency in the configuration and programming fore for each workpiece.
Ease of operation in the control center is is achieved with the graphical sequencer pro- ensured by a SIMATIC WinCC visualization sys- gramming with the SIMATIC S7 Graph enginee- tem at the level above the SINUMERIK grouping ring tool. That way, the sequence of assembly whose core tasks include part and order ma- steps can easily and clearly be structured and nagement and central visualization of routine changed as required, permitting an earlier start The handling of large and heavy workpieces, and alarm messages, as well as archiving of all to assembly. Extensive diagnostic functions sup- in this case on vertical axes, demands spe- process data. Given the massive size of joining port error search and keep downtimes short. cial measures and therefore functionality to stations, use of additional mobile operating protect people and machines. For instance, units is advisable and the Industrial Webpad it must be ensured that each axis is quickly stopped in a controlled manner in case of error or when a slam button is hit and that collisions and damage to expensive parts or equipment are completely ruled out. With SINUMERIK Safety Integrated, these func-tions are already integrated into the control, which saves inflexible and expensive con-ventional relay technology and a whole lot of cabinet space. The main features of the "SINUMERIK Safety Integrated" package are described in chapter A03. Structure Assembly: Solution
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Functionality / Software Optionswith SINUMERIK 840D 2nd Additional Machining Channel and Maximum Memory Expansion3D-Tool Radius CompensationAdvanced Position Control Axial Coupling in Machine Coordinate SystemAxis Synchronisation, Gantry Axis Clearance ControlContinued Machining at the ContourCorner Velocity Adaptation Siemens offers an automation solution that is Cross-mode Action Dynamic Stiffness Control unique worldwide and created for the requirements Electronic Gear UnitEvaluation of Internal Drive Variables of structure assembly Extended Stop and Retract (ESR)Fast Laser Switching Signal, Compile Cycle With the bundled functionality and perfor- Generator Operation mance of SINUMERIK, SIMODRIVE and SIMATIC, Interrupt Routines with High-Speed Retraction from the Contour you can also reach your goals with precision: Laser Clearance Control, Compile Cycle < Software package OEM transformation Laser Switching Signal, High Speed < SIMATIC WinCC Machining Package 5-Axis, TRAORI < Easy configuration, programming and dia- < SIMATIC STEP 7 Master/Slave for Drives gnostics of assembly processes Master Value Coupling and Curve Table Interpolation < Short set-up and therefore short assembly Measurement Level 2 Multi- Channel Sequence Programming < High precision < SINUMERIK 840D < Maximum process transparency Oscillation Functions (block-related, modal and asynchronous) Safe assembly processes in every phase.
Path Velocity Dependent Analog Output < Link modules for connecting multiple NCU Precontrol Acceleration Dependent < SIMODRIVE 611D Program Preprocessing Quadrant Error Compensation < SIMATIC S7-400 Safety Integrated < SIMATIC ET200S distributed peripherals Sag Compensation, Multi Dimensional < SIMATIC Mobile Panel Spline Interpolation for 5-Axis Machining, CompressorSynchronized Actions Level 2 (up to 255 parallel actions) Synchronous Spindle/Multi Edge TurningTemperature CompensationTrailing Axes (Trail)Transformation 7-Axes, OEM-TransformationTransmit/Peripheral Surface Transformation Travel to Fixed Stop with Force Control Volumetric Compensation Weight Compensation Structure Assembly: Benefi t

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