Linear Motor

Linear motors have been widely used in lithography, which are usually realized with optomechanical devices called a wafer scanner. Linear motors can provide both large travel range and precise motion. Nonlinear back lash and contact friction effects are also avoided with direct drive linear motors supported by air bearings or electromagnetic levitation. In this paper, a linear motor using Halbach magnet arrays are used. By using a Halbach magnetic array, the magnetic flux on one side of the array is reinforced while the flux is canceled on the other, allowing for a stronger force for equal current compared with a conventional north-south magnet array configuration. Using Halbach linear motors, long range nano-precision positioning have been designed and demonstrated with the use of laser inteferometer feedback sensing.

Researchers:

  1. Kevin Chu
  2. Yigang Wang

Related Publications:

  1. Yigang Wang, Kevin C. Chu and Tsu -Chin Tsao, "An Analysis and Synthesis of Internal Model Principle Type Controllers", Proceedings of American Control Conference, St. Louis, Missouri, 2009.
  2. Yigang Wang, Kevin C. Chu and Tsu -Chin Tsao, "Adaptive Rejection of Stochastic and Deterministic Sinusoidal Disturbances with Unknown Frequency", Proceedings of American Control Conference, St. Louis, Missouri, 2009.
  3. Yigang Wang, Kevin C. Chu and Tsu -Chin Tsao, "Analysis and Control of Linear Motor for Nanopositioning", ASME Dynamic Systems and Control Conference and Bath/ASME Symposium on Fluid Power & Motion Control Theme: System Engineering, Hollywood, California, 2009.
  4. Yigang Wang, Kevin C. Chu and Tsu -Chin Tsao, "Adaptive Control for Deterministic Trajectory Tracking and Random Disturbance Rejection with Application to Nano Precision Positioning of a Halbach Linear Motor", ASME Dynamic Systems and Control Conference and Bath/ASME Symposium on Fluid Power & Motion Control Theme: System Engineering, Hollywood, California, 2009.
  5. Kevin C. Chu and Tsu-Chin Tsao, "Enhancing Transient Response of Asymptotic Regulation with Disturbance Onset", Proceedings of American Control Conference, San Francisco, CA, 2011.