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Feedback linearization in a six degree-of-freedom mag-lev stage
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Author | Ludwick, Stephen J. Trumper, David L. Holmes, Michael L. |
| Copyright Year | 1996 |
| Description | A six degree-of-freedom electromagnetically suspended motion control stage (the Angstrom Stage) has been designed and constructed for use in short-travel, high-resolution motion control applications. It achieves better than 0.5 nm resolution over a 100 micron range of travel. The stage consists of a single moving element (the platen) floating in an oil filled chamber. The oil is crucial to the stage's operation since it forms squeeze film dampers between the platen and the frame. Twelve electromagnetic actuators provide the forces necessary to suspend and servo the platen, and six capacitance probes measure its position relative to the frame. The system is controlled using a digital signal processing board residing in a '486 based PC. This digital controller implements a feedback linearization algorithm in real-time to account for nonlinearities in both the magnetic actuators and the fluid film dampers. The feedback linearization technique reduces a highly nonlinear plant with coupling between the degrees of freedom into one that is linear, decoupled, and setpoint independent. The key to this procedure is a detailed plant model. The operation of the feedback linearization procedure is transparent to the outer loop of the controller, and so a proportional controller is sufficient for normal operation. We envision applications of this stage in scanned probe microscopy and for integrated circuit measurement. |
| File Size | 577535 |
| Page Count | 16 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_19960052911 |
| Archival Resource Key | ark:/13960/t58d4v50w |
| Language | English |
| Publisher Date | 1996-07-01 |
| Access Restriction | Open |
| Subject Keyword | Cybernetics Controllers Actuators Positioning Degrees of Freedom Digital Systems Oils Control Systems Design Levitation Dynamic Range Feedback Control Floating Real Time Operation Platens Algorithms Signal Processing Capacitance Linearization Analog To Digital Converters Magnetic Suspension Ntrs Nasa Technical Reports Server (ntrs) Nasa Technical Reports Server Aerodynamics Aircraft Aerospace Engineering Aerospace Aeronautic Space Science |
| Content Type | Text |
| Resource Type | Article |
