Advanced Materials Research Vols. 211-212

Abstract: Nano-positioning technology has been widely used in many fields, such as microelectronics, optical engineering, and micro-technology equipment and manufacture. This paper presents a one-dimensional positioning system, adopting a PZT piezoelectric ceramic nano-positioning stage designed by multi-objective topological optimal synthesis. In order to obtain better performance, wedge-shaped structure has been applied as a precise pretension for the piezoelectric ceramic. Through finite element simulation and experimental verification, better static performance and smaller kinetic coupling are achieved, with up to 10 μm stroke displacement output and 5 nm resolution. This stage provides a novel, flexible, and efficient way in the design and optimization of the nano-positioning system.

Abstract: Based on the non-linear equivalent spring-damper model in the "two-state model", Impact model with hinge clearance for deployable mechanism of folding wing is set up and deploying dynamics on deployable mechanism of folding wing is simulated including impact force variation caused by the size of clearance and the clearance friction by using ADAMS software. The results show that the random continuous impact force is produced by the influence of clearance; as dimensions of the clearance increase, impact times decrease and amplitudes of impact forces are increased; System energy consumption is speeded up and to some extent times of impacts with clearance and disturbance effects of deployable mechanism is suppressed by friction in the whole deployable process.

Abstract: During trajectory planning, position, velocity and acceleration should satisfy the boundary condition simultaneously, if the interpolation cycle was directly used to discrete velocity, precision loss will occur. In order to solve these problems, a novel double acceleration control algorithm in the deceleration phase is presented and used to deal with linear acc/dec control, based on which a moving-average acc/dec control algorithm is studied, this algorithm can not only meet requirement for velocity and acceleration smooth control, but also realize NC instruction interpretation with high-order differentiability. The simulation results demonstrate that the proposed algorithm is reasonable.

Abstract: The ordinary silk was puffed, the morphological structure of puffed silk was changed by testing, long diameter was shorter, short diameter was thicker, and the length to diameter ratio was changed. The properties of ordinary and puffed silk fabric were tested and compared, some performance of puffed silk fabric improved, means that the puffing treatment of Tussah silk is a useful way which can improve the performance of fabric and develop the silk product.

Abstract: By researching and investigating the structure of capacitive gyroscopes, A novel capacitive micromachined gyroscope is proposed and the structure is designed. The method of electrostatic comber drive, capacitive detection of bar structure is used for the structure, and these make the gyroscope high sensitivity. The main air damping of the drive mode and detection mode is slide film damping, it is possible to make the gyroscope achieve high Q-values at atmospheric pressure. The decoupled gyroscope is designed, too. By large numbers of simulation analysis， frequencies of the first six steps mode are gained, nature frequencies of drive mode and sense mode of gyroscope are a close match, and rationality of the structure is validated. At last, the structure encapsulated is presented.

Abstract: A Generalized Hammerstein Model with Impulse Response for symmetric nonlinear systems was presented in this paper. A hyper-quadratic object function was developed by adding highest order control input term with a symbolic function into the object function, and a constrained multi-step model algorithmic control for the non-minimum phase systems with open-loop stable characterization was established by forcing the control input with saturated limitation. The algorithm with one control policy can guarantee the simulative results without steady state deviation and the control input being converged to a varying region centered in the zero-point. Simulated results validated the constrained model algorithmic control for Generalized Hammerstein Model with impulse response is reasonable and applicable.

Abstract: This paper analyzes grid resources organization, elaborates on the fundamental principles of the Ant Colony Algorithm, and proposes a grid resource discovery method based on the Ant Colony Algorithm. We consider users request ontology as ants, take search resource as food, and food source is the node of search target. The process of ants to find food is similar to the process of discovery grid resources.

Abstract: High temperature box is wildly used in many fields. Alone with the increasing of the requirement temperature, the temperature of it becomes more and more high. But it is difficult to test the temperature when the temperature is greater than 2000°C. In this paper, the thermal field of high temperature box is analyzed by finite element method, the result show that the temperature satisfies the design objects.

Abstract: This paper presents the characteristic equation of out-of-plane instability when a bending beam, which is composed of two beams, is under lateral force and vertical force. It clarifies a method which can calculate the out-of-plane instability load of a structural component with main jib and counterbrace.

Abstract: Curve fitting, or interpolation algorithm is core technology for Computer Numerical Control (CNC) systems. A saddle-shaped curve is formed by intersection of two tubes. The trajectory interpolation of saddle-shaped curve is usually carried out through approximating the curve as segments of straight line for automated CNC welding/cutting. This paper proposes a new saddle curve curve fitting algorithm for automated welding/cutting system with non-Cartesian coordinate system. Simulation of the direct curve fitting algorithm has demonstrated that the algorithm has high curve interpolation precision and high feedrate stability.