Applied Mechanics and Materials Vols. 130-134

Abstract: In this paper, we propose a variant of the QAP-based facility layout problem: the fixed-point facility layout problem (FFLP). .Based on Ant Colony algorithm , we design the modified ant algorithm for solving the general facility layout problem (GFLP). In addition, we also design the ant algorithm for FFLP by increasing the operator of data preprocessing. Analyze the impact of the different parameters values on the results by a lot of data testing. Experimental results show that the algorithm has strong capability of global search and rapid speed of convergence.

Abstract: Pipe automatic operating system uses mechanical,hydraulic and control technology, replace manual operation by using mechanical equipment,it is an effective way to make drilling safe,healthy and efficient.In the paper,the general mechanical structure,and working principle of the column pipe automatic transferring system of land rig are introduced.The strength and stability analysis of column are presented.provided a way of strength and stability analysis.

Abstract: The improvement of RB is significant for safety of both the power plant and power grid. This paper, took the 2 × 350MW unit of Inner Mongolia Huaneng Power Plant for instance, researched on three ways to improve water supply RB, like taking a proper sliding pressure curve, improving the water supply system and optimizing the boiler combustion. In the research, we succeeded to maintain main parameters of the unit within a safety range during RB operation, and avoided a unit trip accident causing by one single pump’s fault trip. Therefore, the research’s success settled a good base for the unit’s safe and stable operation.

Abstract: This paper discusses that conventional direct torque control (DTC) system of permanent magnet synchronous motor (PMSM) exists in the stator flux linkage and electromagnetic torque ripple faults, and puts forward a method using variable parameter PI controller and fuzzy controller respectively used to replace PI speed regulator and hysteresis comparator of the conventional direct torque control and constructs a new direct torque control system of permanent magnet synchronous motor. The experiment results showed that the improved system has good dynamic and static performance, less flux and torque ripple．

Abstract: Recently, the dominating difficulty that fault intelligent diagnosis system faces is terrible lack of typical fault samples, which badly prohibits the development of machinery fault intelligent diagnosis. Mainly according to the key problems of support vector machine need to resolve in fault intelligent diagnosis system, this paper makes more systemic and thorough researches in building fault classifiers, parameters optimization of kernel function. A decision directed acyclic graph fault diagnosis classification model based on parameters selected by genetic algorithm is proposed, abbreviated as GDDAG. Finally, GDDAG model is applied to rotor fault system, the testing results demonstrate that this model has very good classification precision and realizes the multi-faults diagnosis.

Abstract: A novel particle swarm optimization algorithm based on chaos searching has been proposed and introduced to optimize the design of beam pumping unit which takes the minimum peak torque factor on the up stroke as the objective function. The optimization for beam-pumping unit have shown the improved particle swarm optimization based on chaos searching algorithm has both advantage of simplify for implement of original particle swarm optimization and advantage of fast convergence, easy to escape local minima for chaos optimization algorithm. The improved optimization has also provided a new method for the design of complex structure.

Abstract: According to research on the leveling principle of the telescopic handler fork, establishing relevant mathematical model to optimize the position of master cylinder with the optimization algorithm of accumulated error, least square method, and multi-objective programming of method of weighting by using the computer language of VB . Then the position of fork got optimization that stabilizes the level of fork of telescopic handler.

Abstract: The chaotic behaviors of the Arneodo’s system are investigated in this paper. Based on the Arneodo's system characteristic equation, the equilibria of the system and the conditions of Hopf bifurcations are obtained, which shows that Hopf bifurcations occur in this system. Then using the normal form theory, we give the explicit formulas which determine the stability of bifurcating periodic solutions and the direction of the Hopf bifurcation. Finally, some numerical examples are employed to demonstrate the effectiveness of the theoretical analysis.

Abstract: In light of the characteristic of thin-wall weld joint in X-ray image, Flaw-edge extraction algorithm and image enhancement algorithm which is based on mathematical morphology are proposed in the study of flaw extraction technique. Therefore, the area of flaw and background can be removed successfully. On this basis, there are two algorithms to identify different flaw types: one is that spatial domain transform to extract flaw edge for clack, the other one is mathematical morphology which is combined with iteration threshold to extract flaw edge for pore; Experimental results show that both of algorithms can implement flaw extraction and segmentation automatically, which is lay a good foundation for flaw feature parameter extraction and recognition.

Abstract: Nonlinear system identification is a main topic of modern identification. This paper presents a new parameter estimation method of MISO (multiple inputs, single output) Hammerstein model by using improved particle swarm optimization (IPSO). The basic idea of the method is that the model identification problem is converted into optimization of nonlinear function over parameter space. And the swarm intelligence method is used to search the parameter space concurrently and efficiently in order to find the optimal estimation of the model parameter. The basic algorithms of IPSO and the parameter control are discussed. Simulation results demonstrate effectiveness of the suggested method. The advantages of IPSO are easy to implement, few parameters to adjust, small population size, quick convergence ability and so on. Especially in high noise disturbance condition, the results of IPSO are also satisfactory.