As part of a team led by General Atomics, Foster-Miller was awarded a contract to design and build a large linear motor demonstration system for Navy aircraft carrier launching applications. We had full responsibility for control system hardware and software design and development. This includes the overall system controls, a distributed health monitoring and prognostics system for system health management, and the motor controller that will control the operational functioning of the linear motor. We also played a key role in motor magnetic and mechanical design, and in system simulation.
For the purposes of controller development, we have built a mock-up of the full-scale EMALS system in our lab. Although the mock-up runs at a greatly reduced power level in comparison to the full-scale motor, all of the full-scale control hardware (and the serial communication between various hardware components over fiber optic lines) can be operated within the mock-up. Power electronics of the same design as the full-scale hardware are used to drive a test rig; the switches simply have lower ratings than the ones that are used on the full-scale machine. The overall result is that complete, end-to-end tests of the control system can be performed at Foster-Miller before installation on the full-scale machine.
The desire for high system reliability requires redundant computing hardware. All hardware is ultimately controlled by an overall supervisory control screen with which the user interacts. All of the software has been designed and written so that besides running on the actual full-scale hardware, it can be compiled to run as threads in a desktop machine. All component software can interact via inter-process communication on a single desktop machine in a fashion that closely mimics the operation of the system in hardware. The software is then used to drive a model of the full-scale EMALS motor which runs in another process. This software simulation of the complete system has proven useful in debugging the controller software before moving onto hardware, for defining issues with respect to ease of use and functional flow, and for training users in the operation of the prototype system.
