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In nanopositioning system, the compliant tripod stages have proved to have enormous advantages for out-of-plane (z/tip/tilt) positioning in turns of compactness, simplicity in structure, and economic cost. However, most of the present-day compliant tripod stage undergo manufacturing problems due to a complicate structure, and little study has been carried out to formulate the tri-inputs and tri-outputs relationship, which is essential for precise positioning. Accordingly, this paper presents the quasi-static analysis of a novel compliant tripod stage with an equivalent plane model to achieve precise position analysis for nanopositioning. Three-plane compliant lever mechanisms and cylindrical flexure hinges with high length–diameter ratio are employed, which mitigate couple influence and enable easy fabrication via planar manufacturing processes. The spatial output motions of the compliant tripod stage are first split among inputs of the three-plane compliant lever mechanisms, where the lateral translations of the compliant tripod stage are included. Then the displacement equations of the plane compliant lever mechanism are formulated through Castigliano’s second theorem. The model is further verified by finite element analysis. Finally, an experimental test system is set up and the test results validate the proposed approach.

Shearer height adjusting is a key technology for coalmine unmanned working face. On the basis of establishing Shearer working face mathematical models, this paper determined related parameters influencing the Shearer height adjusting, then analyzed traditional Shearer memory cutting strategy and pointed out its shortcomings. Aiming at changing technical limitations of Shearer height adjusting currently, this paper proposed a new Shearer memory cutting strategy based on GRNN(General Regression Neural Network). According to height adjusting data acquired from Shearer working face, we use MATLAB to analyze the new Shearer memory cutting algorithm, results shows GRNN network approximation error is ±0.02m, and GRNN network prediction error is ±0.025m. The experimental result shows that the new Shearer memory cutting strategy has higher prediction accuracy and better generalization ability.

The compliant double parallel four-bar mechanism is a classical parallel guiding mechanism. Two mathematic models of double parallel four-bar mechanism were built based on pseudo-rigid-body model and elastic beam theory. The elastic beam theory was used to analysis the effect of axial deformation on the displacement of moving plate at large displacement. Effect of compliant guiding beam geometric parameters on moving plate and the accurate of two models were discussed. Results showed that moving plate displacement is proportional to the force. Meanwhile, the axial deformation of guiding beam and its width/thickness ratio of the rectangular cross section have significant effect on the displacement of plate. The displacement of plate increases rapidly with the decrease of cross section width/thickness ratio, in other words, the system sensitivity increase rapidly. Finally, the FEM (finite element method) was used for comparison with the mathematical model, and similar results were obtained. This research has significant practicality for further analysis the displacement of compliant double parallel four-bar mechanism, optimizing the mechanical structure, and improving the comprehensive performance.

In order to approximate the behavior of hysteresis nonlinearity which often severely limits the performance of system and improve the prediction accuracy of classical Preisach model (CPM), a least squares support vector machine (LS-SVM) based model is presented in this paper. According to the geometric characteristics of multi-loop hysteresis, the input voltage sequences was combined with output stroke sequence and expand to a matrix as the input of LS-SVM. Then the multi-valued mapping of hysteresis was transformed to one-to-one mapping which enable LS-SVM to approximate the behavior of hysteresis. The prediction accuracy is improved effectively on the condition of finite samples and the default of CPM was avoided. Results of simulation and experiments show that the proposed hysteresis model can exactly describe and predict the multi-valued hysteresis feature compare with bilinear interpolation and has the better generalization ability.