Sensorless Control of Linear Motors

Closed-loop control techniques such as those based on inner loop vector current control are well suited to meeting these performance criteria. However, they require flux or armature position knowledge which is usually based on the use of mechanicalfeedback sensors. Mechanical feedback sensors for position or velocity are the most unreliable link in the control system when subjected to harsh conditions such as those found in EMALS. Sensorless control techniques seek to remove the mechanicalfeedback sensors while still maintaining the same level of control performance. This work will extend the state-of-the-art in sensorless control to linear motor system, and in particular to the demanding transient requirements of EMALS. Signal Injectionmethods, meausrement based methods, and advanced state estimators will be assessed and new hybrid sensorless controller for linear motors will be developed to meet or exceed the EMALS requirements. Development of a robust hybrid sensorless controller willhave immediate benefits for both linear motor and rotational motor systems. Servo grade performance without mechanical sensors improves reliability, survivability, and reduces the cost for closed loop control, making it applicable to a wide variety ofindustrial, commercial, and military applications. Prime candidates for this technology include linear motor aircraft launch and arrest systems, linear motor conveyor belt and transport systems for moving factory goods through a production or storagefacility, linear or rotary vehicle and craft propulsion systems, hybrid electric vehicles, fly-by-wire systems, more-electric aircraft, vehicles, and ships, electrification of mining and drilling equipment, and the machine tool and general automationindustry.