Design of a computer-based control system using labview for the nemesys electromagnetic launcher facility

The U.S. Naval Research Laboratory has assembled a facility to develop and test materials for the study of barrel lifetime in electromagnetic launchers (EML) for surface-fire support and other missions'. The pulsed power system utilizes 12 500-kJ modules that can be 2 individually triggered to shape the output current pulse. Each bank module consists of four 130 kJ/can 11-kV capacitors from General Atomics Electronics Systems. The switching thyristors and crowbar diodes are from ABB. A series inductor of approximately 80 pH is used to limit the peak current to 100 kA, isolate modules from each other, and ensure the current is delivered to the test system. LabVIEW from National Instruments (NI) was selected as the control software for the EML system. All facility operations are handled through LabVIEW and controlled by a single operator. The software controls the safety systems; programs and monitors the three CCS High Voltage Power Supplies from General Atomics Electronic Systems; and triggers the capacitor banks. Projectile position status inside the barrel is also monitored in 25-ns steps using the PXI-7811R FPGA module. An overview of the EML facility with respect to control issues is presented. In addition to the software code, circuit diagrams of conditioning hardware will also be discussed. Results from test shots will be shown and discussed.