Flexure-based electromagnetic parallel-kinematics manipulator system

Abstract

Manipulation between the nano and meso scales at elevated bandwidth with large continuous output force remains as a technological gap in the field of ultra-high precision manipulation over the past decades. Current ultra-high precision manipulators are incompetent of bridging this gap due to their failure in recognizing the inter-dependency between each subsystem, e.g., the positioning mechanisms, the nano-positioning actuators and the control systems etc. This research focuses on the development of a multiple degrees-of-freedom Flexure-Based Electromagnetic Parallel-Kinematics Manipulator (FEPM) targeted with several capabilities, i.e., nanometric resolution, large continuous output force, fast actuating speed, high system stiffness and a large workspace of a few millimeters and degrees, so as to bridge the existing technological gap. Each subsystem is investigated with the inter-dependency between these subsystems being taken into consideration. Consequently, these subsystems are treated as one unified mechatronics system with a common goal, i.e., to realize those targeted capabilities. In this research, a new analytical model, termed semi-analytic model, is formulated to predict the nonlinear deflection of a beam-based flexure joint coupled with various rigid-link lengths. Experimental investigations have shown that this analytical model provides a highly accurate solution with an average deviation of 2.3% when compared to the experimental results. A new magnetic circuit is introduced to address the low output force limitation of a Lorentz-force actuation. Termed Dual-Magnet (DM) configuration, it offers a large effective air gap and increases the magnetic flux density by 40%. Hence, an Electromagnetic Driving Module (EDM) that adopts the DM configurations can achieve a large continuous output force through small input current and a compact-sized module.