The high precision motion tracking controller consisting of a linear permanent magnet iron core synchronous motor (LPMICSM) operating on a positioning platform is proposed. First, we address important issues related to the construction and driving theorem of the LPMICSM. Next the general system dynamic model is derived and analyzed. Then, because of the uncertainties and unknown parameters of the underlying system, a discrete adaptive sliding-mode (DASM) controller is proposed to guarantee system stability for both regulation and tracking tasks. Finally, according to the reported experimental results, the satisfactory performances including step regulation and tracking sinusoid, has been achieved. Therefore, the proposed control method is feasible and effective in high-precision motion control of LPMICSM.

In this paper, a novel XY-dimensional submicropositioner, including mechanism, control, and analysis, is successfully presented. The design of the submicropositioner utilizes a monolithic parallel flexure mechanism with built-in electromagnetic actuators and optical sensors to achieve the object of 3-DOF precise motion. From the provided experimental results, there are several main goals that have been achieved in this paper: (1) to integrate the electromagnetic actuator and the parallel flexure mechanism for planar positioning system; (2) to establish the mathematical modeling; (3) to develop an advanced adaptive sliding-mode controller; and (4) to perform extensive experiments to test the realistic performance.

In this paper, a new planar magnetic levitation (maglev) positioning system is proposed, which is capable of executing dual-axis planar motions purely involving magnetic forces. Functionally, such a mechanism behaves like a planar XY table with micrometer precision. Specifically, in this system, a new structure with an adaptive sliding-mode control (ASMC) algorithm is described, which aims to achieve the following three goals: 1) a large moving range (millimeter level); 2) precise positioning (micrometer level); and 3) fast response. The system consists of a moving carrier platform, six permanent magnets (PMs) attached to the carrier, and six electromagnets mounted on a fixed base. After exploring the characteristics of the magnetic forces between PMs and electromagnets, the general 6-DOF dynamic model of this system is derived and analyzed. Then, because of the naturally unstable behavior inherent in maglev systems, the proposed ASMC guarantees satisfactory performance of the maglev system. Experiments have successfully demonstrated the feasibility and effectiveness of the overall system.

In this paper, we extend our previous result (1999, 2000) on designing a single-axis Maglev guiding system to a more involved task of designing a novel dual-axis positioning system. First, important issues related to construction of the mechanism of the dual-axis positioning system are addressed. Then, the dynamics of the dual-axis Maglev guiding system are analyzed. According to the derived analytic model, which is subject to unknown system parameters, an adaptive controller that can control the carrier at the desired target point of each axis with full alignment is presented. From the experiment results, a good performance in terms of regulation of the guiding-axis and tracking of the positioning-axis is achieved. This validates the design of the system hardware and demonstrates the feasibility of the developed controller.

Atomic force microscopy (AFM) is a powerful measurement instrument which can build 3-D topography image of conductive and nonconductive samples at nanoscale resolution. However, due to the scan method of conventional AFM, the induced mechanical resonance of the scanner and the scan in area of uninterest would strictly limit the scan speed. In this study, we improve these problems with our designed AFM system from three aspects. First, the sinusoidal trajectory is applied to lateral scanning of the AFM rather than the traditional raster trajectory, so the scan rate can be increased without inducing vibration of the lateral scanner. Second, with this promising scan trajectory, the internal model principle-based neural network complementary sliding-mode controller and adaptive complementary sliding-mode controller are designed to achieve high precision scanning and to cope with the system parameter uncertainties and external disturbance. Finally, with the aid of an auxiliary optical microscopy and the scanned information during the scanning process, scan path planning can be adopted to focus the scanning on samples such that the total scan time is further shortened. Extensive experimental results are provided to show the appealing performance of the proposed method.