Kun Zhang

To enhance the output thrust of a macro–micro precision actuator while maintaining its precision positioning capability, an optimization design method for the macro-motion structure based on Halbach permanent magnet arrays is proposed. By establishing an equivalent magnetic network model of the macro-motion magnetic circuit, the analytical efficiency for the magnetic field distribution is improved. A single-factor analysis method is employed to reveal the influence of key parameters, including axial permanent magnet length, air-gap thickness, and winding thickness, on the maximum output thrust. The Grey Wolf Optimizer is applied to perform comprehensive optimization of the main parameters, yielding a structural dimension combination that maximizes thrust. On the basis of the optimization results, a prototype is fabricated and experimentally tested, and the results show that under a 6A drive current, the macro-motion stage achieves an output thrust of 190.2N, with a relative error of 2.4% compared with the optimized model prediction. Meanwhile, a stroke positioning of 35.32mm is achieved within 25ms, with a maximum nonlinear error of 0.469mm, demonstrating good linearity of displacement output. This method ensures high-thrust output while maintaining rapid precision positioning, providing an effective technical solution for high-load precision drive applications.

To improve the positioning accuracy of macro-micro precision positioning drives, this paper proposes a novel micro-displacement amplification mechanism utilizing a power-function-based flexible hinge. Using the flexible hinge as the basic component, a symmetrical two-stage lever transmission mechanism was designed based on the principle of differential lever amplification. Compared to traditional flexible hinges, power-law flexible hinges can achieve greater deformation displacement under the same input force, while exhibiting lower maximum stress values. Compared to traditional lever-based amplification mechanisms, this mechanism offers higher amplification efficiency and a higher natural frequency. This paper derives the magnification ratio of the mechanism and analyzes the effects of structural parameters on the output displacement and natural frequency. The maximum stress and displacement characteristics of the mechanism were verified through finite element simulation, and experimental validation was subsequently conducted using a magnetostrictive actuator. The results show that the designed amplification mechanism achieves a magnification of 3.953, with a maximum stroke of 186.8 μ m for the microactuator. This mechanism effectively compensates for the positioning errors of the macro-motion platform, achieving a synergistic optimization of long stroke and high precision, and provides a valuable reference for ultra-precision applications.