Micro-positioning platform plays an important role in the field of precision positioning such as microelectronics, robotics and biomedicine. This paper proposes an equal-stiffness and equal-stroke 2D micro-positioning platform, which is driven by piezoelectric actuators. The overall structure of the 2D micro-positioning platform adopts a nested structure and the displacement magnification mechanism adopts two hourglass displacement magnification mechanisms. The displacement magnification ratio of the hourglass displacement magnification mechanism was studied, and its structural parameters were optimized. Static stiffness analysis and simulation analysis of the micro-positioning platform were carried out. The simulation stiffness of the micro-positioning platform in the XY direction is 46873 N/m and 46832 N/m respectively. The experimental prototype of the micro-positioning platform was built. Through the measurement experiment with the prototype, the maximum stroke of the micro-positioning platform in the XY direction is 489 μm and 493 μm respectively; the maximum coupling ratio in the XY direction is 2.38% and 2.70% respectively. The research indicates that the micro-positioning platform had the characteristics of small size, equal long stroke, equal stiffness and low coupling ratio in the XY direction.

The conventional scroll compressor cannot run oil-free because of wear and tear and lubrication problems during operation due to some parts, such as anti-rotation devices. The magnetic drive oil-free scroll compressor (MDOFSC) uses a contactless drive method to avoid this drawback. In order to solve the swing problem of the orbiting scroll during the operation of the MDOFSC, decentralized control and centralized control are used to study the trajectory tracking characteristics. Firstly, the structure and working principle of the MDOFSC are introduced, and the system’s magnetic circuit and differential control principle are analyzed. Then, the dynamic model of the MDOFSC under the condition of non-compressed gas is established, and the coordinate matrix decoupling method is used to analyze the relationship between the degree of freedom of the system and the measurement distance of the displacement sensor. Finally, the system is simulated and experimentally studied under centralized PID control, and the experimental comparison study between decentralized control and centralized control is conducted. The results show that centralized control dramatically improves the trajectory control ability of the system.

The relative position between the laser beam and the nozzle is controlled by laser-focus-controlled magnetic actuators to achieve non-coaxial laser cutting and improve laser cutting efficiency. In this paper, a 3-DOF (degrees of freedom) magnetic actuator is designed to solve the inconsistency of the laser beam focus and the nozzle focus in off-axis laser cutting. A mixed sensitivity robust controller is designed, and its simulation analysis and experimental research are carried out. First, the kinetic mathematical equations are established according to the structure of the actuator. Then, a mixed sensitivity robust controller is designed and analyzed using MATLAB/Simulink. The control performance is simulated and analyzed under 20% parameter variation and pulse disturbance with an uncertain mathematical model and external disturbance, respectively. Finally, the experimental study of the step response of the actuator is carried out. The experimental results show that the step response of the actuator in the Y, X, and θ directions can quickly reach the steady-state value. Furthermore, the steady-state error in the X is 1.6%; the steady-state error in the Y is 0.39%; the steady-state error in the θ is 0.45%. Their errors are all less than 0.025 mm, so they meet the position performance requirements. It can provide technical support for laser off-axis cutting.

During laser processing, optimizing the cutting performance by adjusting the angle or off-axis displacement between the auxiliary gas flow and the laser beam is an effective approach to improving processing quality and efficiency. However, traditional electromechanical actuators suffer from inherent limitations in compactness and multi-degree-of-freedom cooperative control, which restrict their applicability in high-speed and high-precision laser cutting systems. To address these limitations, this paper presents a five-degree-of-freedom magnetic levitation actuator for laser cutting lens control and proposes a multi-degree-of-freedom cooperative control strategy based on backstepping control (BC) to cope with the system’s strong coupling, nonlinearity, and model uncertainty. First, a dynamic model of the actuator system is established, and a corresponding BC is designed. Subsequently, a centralized control framework is developed, and comparative simulations and experiments are carried out between the proposed BC and a conventional PID controller. The experimental results demonstrate that the proposed BC method outperforms the PID controller in terms of multi-degree-of-freedom cooperative control capability and dynamic response, thereby significantly enhancing the overall control performance of the system.