Aerotech's A3200 Digital Automation Platform features pulse synchronised output (PSO) with error mapped systems for enhanced accuracy laser machining

Citation

(2005), "Aerotech's A3200 Digital Automation Platform features pulse synchronised output (PSO) with error mapped systems for enhanced accuracy laser machining", Assembly Automation, Vol. 25 No. 3. https://doi.org/10.1108/aa.2005.03325caf.002

Aerotech's A3200 Digital Automation Platform features pulse synchronised output (PSO) with error mapped systems for enhanced accuracy laser machining

Aerotech's A3200 Digital Automation Platform features pulse synchronised output (PSO) with error mapped systems for enhanced accuracy laser machining

Keywords: Control systems, Automation, Lasers

Aerotech's A3200 Digital Automation Platform is a powerful, software only machine control system combining a high-performance, 32 axis motion engine with decentralised drives interfaced via Firewire^® and other machine control function modules such as HMI and soft PLC, for a completely integrated solution. Widely used in semiconductor, data storage, laser processing, automotive, and machine tool industries, the A3200 includes a wide range of advanced motion control commands aimed at increasing and improving the finished quality and throughput performance of demanding production and test applications (Plate 2).

Along with an extended range of advanced commands for motion including electronic gearbox, cam profiling, high speed registration/ position capture and velocity profiling, Aerotech have developed a number of commands targeted to augment application specific performance in combination with its wide range of mechanical positioning systems. An example of such enhanced performance is that of Position Synchronised Output (PSO). Widely used for high performance laser machining applications, PSO allows the precise, on-the-fly synchronisation of the laser's pulse, power level and firing pattern with the exact position of a multi-axis positioning system typically moving the work piece undergoing laser feature generation.

Plate 2

PSO will acquire and analyse the position of all axes of motion on the A3200 using real time encoder feedback and will process a two or three axis vector position to provide an output for laser firing control which is exactly synchronised to the 2D or 3D contoured position.

For extremely high accuracy requirements, PSO can be combined with positioning systems that have been interferometer calibrated and error mapped using Aerotech's HALAR option, where micron level linear errors are analysed and the resulting calibration information is included as a look-up table in the A3200 motion controllers' parameter file. The combination of PSO and HALAR is unique to Aerotech and allows the real time encoder information to be read then error corrected before the vector position is processed, resulting in laser pulse synchronisation that achieves an unsurpassed level of accuracy.

Aerotech's PSO provides a versatile and easy method of interfacing laser firing with high throughput positioning systems and has been broken down into a number of simple commands and parameters to allow for output modes including fixed pulse, analogue, PWM, ramping and bit pixel mapping. Other PSO commands cover encoder position tracking input set-up, definition of distance and firing trigger, pulse sequence and pulse on/ off characteristics as well as a command to define a window for absolute or incremental position window firing. There is also provision for an array to be used to define bitmapped firing, used to fire the laser at only specific axis locations. Interfacing with lasers that allow external control, including CO₂, YAG and Excimer lasers is easily achieved.

Tracking latency varies depending upon the drive product used in conjunction with the A3200; the best performance is achieved with the Aerotech Nservo digital drive with 140ns for a single axis and 220ns for dual and triple axis tracking.

In addition to laser firing applications PSO has been successfully applied to non-destructive testing applications where its ability to provide a fixed pulse spacing along complex contours has been found ideal for ultrasonic, eddy current and X-ray inspection systems.

Aerotech's A3200 Digital Automation Platform is a software based machine control system for IEEE-1394 (Firewire^®) equipped PC's combining synchronised motion control for up to 32 servo axes with fully integrated modules for HMI, machine vision and soft PLC functions. Programming and software development tools allow the Automation 3200 to be programmed in native RS274 G-code and a software development kit may be used to program with ActiveX based components as well as other languages including C, C++, VisualBasic^® and Labviewe. The high speed Firewire interface delivers fully deterministic position and velocity motion updates to all axes with no system degradation as the number of axes increase.

For technical information please contact Simon Smith: Aerotech Limited, Jupiter House, Calleva Park, Aldermaston, Berkshire RG7 8NN. Tel: +44 (0)118 940 9400; Fax: +44 (0)118 940 9401; E-mail: ssmith@aerotech.co.uk