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Double click on the images above to see videos of different complex geometry systems
Relatively flat panels can be tested using simple 2 axis machines, but the increasing complexity of components requires more sophisticated scanners. USL can provide systems for both simple and complex applications. These combine highly rigid and accurate mechanical scanners with USL's established PC based instruments, to provide fast and effective testing of composite structures. A unique range of precision probe manipulators is available, with the type selected to suit the specific application. Systems can operate in pulse echo mode (PE) and in through transmission (TT), either in separate scans or simultaneously. When PE and TT scans are combined, the PE scan uses a linear amplifier and the TT uses a logarithmic amplifier. This gives the optimum combination of resolution and dynamic range. Four alternative configurations are illustrated here - the choice is dependent on the range of component shapes to be tested and also on the available floor space.
This illustrates the simplest configuration with two motorised axes, X and Y. The separation of the squirters is set manually, but this can be motorised. This is a "flat-bed" type of system, suitable for flat panels. One advantage of this system is that it can be used to test a large number of small parts simultaneously, because the parts are supported on wires stretched across the scanner. No special fixturing is needed.
This shows a "travelling gantry" system, designed for inspection of flat and single curvature components. The squirters are mounted on horizontal arms, with a single axis manipulator having a "tip" axis. One advantage of a scanner of this type is that the design can be easily adapted to suit almost any length of component - the scanning gantry is identical regardless of the scanner length. Two pairs of squirters can be mounted on the same manipulator, in order to increase the effective scanning index and reduce the inspection time. This is a traditional 5 axis gantry system with vertical Z axis columns. The parts are held in a two axis rotating fixture. Like the travelling gantry unit, this configuration is suitable for flat and single curvature parts. For parts having a significant curvature, the travelling gantry type is preferred, although this requires a larger floor area because of the safety zone which is needed for the horizontal manipulators.
This shows a 10 axis system with horizontally opposed squirter manipulators. This is effectively two completely independent 5 axis scanners, one on each side of the component. This type of system is designed for contour following of dual curvature components. Sophisticated motion control is incorporated to maintain the alignment of the two squirters throughout the scanning volume. A 5 axis motorised, programmable fixture is available for fixing parts to be inspected - this leaves the floor area completely clear for the operator.
6 axis system for pulse echo inspection of conical parts. The system incorporates full contour following for components which are not roto-symmetrical. The component shape is programmed by a "teach and learn" procedure which is partly automated. The circular shape is measured ultrasonically using a time of flight mode - the operator simply has to define the position of successive rings to define the complete surface profile. The inspection generates C scans from multiple gates and the display is shown in the correct aspect ratio. True surface measurements of defect size and position can be made using cursors on the C scan image.
Typical System features Mechanical
Ultrasonics
Some of the software functions for motion control, imaging and processing are shown in the "Software" section. Typical System SpecificationThe following specification for a through transmission system is provided for illustration only, since each system is built to meet the precise requirements of the customer and his applications, within the constraints of the budget where necessary. Axis configuration 9 axes X, Y1, Y2, Z1, Z2, a1, b1, a2, b2 Scanning envelope / axis travel X axis 3000mm Axis drive and resolution X axis DC servo motor / rack and pinion 0.05mm resolution Axis speed X axis 500 - 750mm/sec Motor drive and control system PMAC multi axis motion controller with Baldor DC servo drives. Optical encoders on all axes. Water system Two independent recirculating filtered water systems with UV treatment unit. Continuously variable pump speed, computer controlled to give constant flow rate regardless of nozzle position and angle. Computer system Industrial Pentium PC, 3GHz, 2Gbyte RAM, 120Gbyte disk drive, Rewriteable CD/DVD drive Ultrasonic system Ultrasonic Sciences PM30 Pulser Receiver (0.5 - 35MHz) with remote PPA15 Pulser Preamplifier. ADC100 analogue - digital converter (100Msps) or 500MHz A-D. DSP100 Digital Signal Processor. Simultaneous Pulse Echo operation in linear mode and Through Transmission operation in logarithmic mode. |