Control Performances of a Fine Motion Stage using a Multilayer Electrostatic Actuator without Precise Balls for Lubrication

• Main Author: Md Ghazaly, Mariam
• Format: Conference or Workshop Item
• Language: English
• Published: 2010
• Subjects: TJ Mechanical engineering and machinery; TK Electrical engineering. Electronics Nuclear engineering
• Online Access: http://eprints.utem.edu.my/id/eprint/8970/1/ICMT2010_05.pdf; http://eprints.utem.edu.my/id/eprint/8970/

This paper describes the control performances of a multilayer electrostatic actuator, which is designed for a fine motion stage without precise balls for lubrication. The motion characteristics of the electrostatic actuator without precise balls depend on the input signal to the actuator, which consequently influences the frictional effect. First, the relationship between the working range and the input signal is explained. Next, based on the relationship, the actuator’s control system is designed. The control system includes the PID compensator and the driving signal unit which generates the suitable signal for three driving modes in response to the working range; that is (1) fine driving mode for working range smaller than 120nm, (2) wide driving mode for working range wider than 120nm and (3) dual driving mode. The fine driving mode enables the actuator to be driven with a large holding force for limited working range. To ensure the full working range of the actuator, the wide driving mode is useful. Additionally, to permit the actuator to be driven with a large holding force under the full working range, the dual driving mode was introduced. The actuator exhibits high performances under these three driving modes with the positioning accuracy less than 15nm.