Abstract: In some textile machines, fabric is an inseparable element for motion and force transmitting. But the existing mechanical simulation software cannot model the fabric. This paper proposes a new cloth simulation method by blurring machinery (rigid) and cloth (soft) boundaries. This approach simulates the soft with tiny rigid bodies, large deformation with small ones. It aims to integrate the cloth modeling to the mechanical simulation system. Finally, we establish a cloth simulation model on the mechanical modeling and simulation platform, which is an embodiment of our integrated concept.
Abstract: Based on the idea of integrated design, a drive-transmission integrated linear electromechanical actuator is developed. The actuator consists of a permanent magnet synchronous motor (PMSM), a ball-screw and shells. By using coaxial assemblage, the ball-screw is inserted into the hole of the hollow motor rotor and the nut of the ball-screw connects with the motor rotor. In order to restrict the ball-screw rotating relatively to the shell, splines machined respectively on ball-screw and the shell come into being a spline pair. A driver based on a DSP processor and IGBTs plus a position feedback resolver forms a precise servo system.
Abstract: A non-iterative design method about high order intermittent mechanisms is presented. The mathematical principle is that a compound function produced by two basic functions, and then one to three order derivatives of the compound function are all zeroes when one order derivative of each basic function is zero at the same moment. The design method is that a combined mechanism is constructed by six bars; the displacement functions of the front four-bar and back four-bar mechanisms are separately built, let one order derivatives of two displacement functions separately be zero at the same moment, and then get geometrical relationships and solution on the intermittent mechanism. A design example shows that this method is simpler and transmission characteristics are better than optimization method.
Abstract: A method of the classifying of ceramic tiles’ color difference is proposed, and the online detection system based on linear array color CCD sensors is designed. After the image of tile grabbed by CCD is transformed to the HIS color model, a series of image processing and analyzing methods are used to calculate the eigenvalue of sample. The minimum distance classifier is used to carry out tiles’ classifying. Experimental results show the method is effective.
Abstract: Because of the disadvantages in evaluating straightness error of the traditional method, such as high algorithm complexity, low evaluating precision, it can’t be appropriate for various instruments. A fast and accurate method called intercept of convex polygon algorithm is put forward to implement least envelope zone for evaluating plane straightness errors. The algorithm is based on the convex-hull theory in computational geometry, the measuring data of various instruments are firstly converted into coordinate value, then constructed the convex polygon by slope factor. The unique point meeting the least condition can be found, and the straightness error can be calculated through shear shift conversion. Experimental results show that the method is simple and easy for automatic data processing by computer, and has features of high precision and high speed.
Abstract: According to needs of aspheric lens grinding and measurement with X/Y/Z 3-axis grinding machines, a CAM system is designed and implemented. The system, based on the parallel grinding geometry model, has realized the function of grinding locus planning, form error compensation, NC program auto-generation, on-machine measurement, grinding wheel on-machine measurement, simulation and technical database. To verify the stability of this CAM system, experiments were performed with three independent machining experiments. The experimental results indicate that the system realized the whole process of aspheric grinding, and it improved the machining efficiency and automation. Especially, this system adopted on-machine form error compensation technology and improved the machining accuracy. By implementing the error compensation integrated in the CAM system, the surface form error of a 430mm×430mm aspheric lens is decreased from PV8.2µm to PV4.1µm. The grinding accuracy was improved 100%.
Abstract: A novel feature extraction method is presented by combining wavelet packet transform with ant colony clustering analysis in this paper. Vibration signals acquired from equipments are decomposed by wavelet packet transform, after which frequency bands of signals are clustered by ant colony algorithm, and each cluster as a set of data is analyzed in frequency-domain for extracting intrinsic features reflecting operating condition of machinery. Furthermore, the robust ant colony clustering algorithm is proposed by adjusting comparing probability dynamically. Finally, effectiveness and feasibility of the proposed method are verified by vibration signals acquired from a rotor test bed.
Abstract: In the last 20 years, China has been in the radical change of urbanization. The cities have been growing fast through continual construction and demolition. This research focuses on the development of several cities in Southern Yangtze of China to investigate the change of the residents in their lifestyle, living attitude during the “demolition’’ and “construction” in the perspective of urban plan and environmental design. Through the experiments of design projects in urban plan and environmental design, solutions would be found for those disharmony problems occurred during the transition process of “demolition” and “construction”. The proposals, from both the tangible and intangible points of view, would be developed for the development of the cities and regroup of residents, as well as the reconstruction of new communities with extension of traditional custom.
Abstract: Surface texture of tribological interfaces has the potential to improve friction and lubrication performance of various mechanical components. This review paper emphasizes on the current status of the research of surface texture, including the features, the effects on tribological performance, the forming techniques, and the modeling and simulation of surface texture. It is intended to help readers to gain a more comprehensive view on surface texture of tribological interfaces.