Applied Mechanics and Materials Vols. 48-49

Abstract: To enhance the ship’s seaworthiness and seakeeping capacity, a new prediction algorithm based on Gray RBF neural network is presented to forecast roll motion accurately. The second-order gray model GM(2,1) and RBF network are introduced firstly, then using AGO (accumulated generating operation) to weaken randomness and volatility of raw data, which would affect the accuracy of RBF network. On the other hand, the algorithm flow of GMRBF(2,1) is given. Further more, GMRBF(2,1) is applied in a sample of ship roll sequence and effectively improves large prediction error of second-order gray model. The simulation results prove that the new model is more accurate and stabilizer than traditional models.

Abstract: With the rapid development of autonomous underwater vehicles, image produced from sidescan sonar mounted on these vehicles has attracted more and more attention. Many general super resolution approaches can not get satisfied results after applying to sidescan sonar image for its low levels of contrast. Compressive sensing theory suggested that high resolution image can be recovered from low resolution image with sparse representation. After training two dictionaries for high resolution and low resolution image patches, the sparse representation of given low resolution image can be applied to the dictionary of high resolution patch to get super resolution result image. Sparse representation based image super resolution approach applied to sidescan sonar image is discussed.

Abstract: Based on the plastic damage model for concrete, this paper realizes the simulated construction for the preloading filling spiral case (PSC) in a hydraulic plant. The contact property and state are analyzed with the nonlinear FEM. The distribution of damage and stress with construction are given. The development mechanism of initial gap is studied. The effect of plastic damage on asymmetry displacement is researched. It is concluded that the influence is remarkable.

Abstract: The traditional method of propulsion of Amphibious vehicles in water has tracked the water, propeller and waterjet propulsion. But the propulsive efficiency is very low, the maximum not more than 30%. Biological methods used to promote, through the million years of evolution, its power utilization of the highest, the best way. Bionic propulsion system designed in this paper consists of two umbrella-shaped wing plate in the large travel agency travel back and forth, driven by a straight line, Carried out along the longitudinal reciprocating motion of vehicles in the water under the influence of backward movement of the wing disk automatically open, resulting in tension on the vehicle forward, Forward movement of the wing disc automatically shut down to reduce the flow resistance. In this way, amphibious vehicles, with the wing disc back and forth movement, has been the role of forward traction, so that forward movement of vehicle. In this paper, the same wing disc, wing disc at different angles, different velocity simulation of the situation. Come forward to promote strength and speed, angle of the curve. To promote the device provides the basis for the physical design and manufacture.

Abstract: Using GT-Power software to establish the simulation model of the working process of an engine coupled with the muffler, insertion loss and pressure loss are obtained, simulation results are consistent with the experimental results, which verifies the correctness of simulation model.Therefore, it is important to shorten the vehicle development cycle and reduce cost.

Abstract: According to vehicle suspension structure, a 2-DOF (degrees of freedom) semi-active hydraulic suspension model for 1/4 vehicle is built. Fuzzy control as a result of simple modeling, with high precision control and non-linear adaptive advantages of the vehicle active suspension control strategy, has been a wider application. In this paper, the body’s speed and acceleration were selected for the fuzzy controller inputs, damper output, to realize the semi-active suspension control. Taking some type of vehicle as the simulation object, this paper uses Matlab/Simulink for computer simulation in the same road conditions. And the performance parameters of improving vehicle vertical vibration are compared to the passive suspension. The results show that the semi-active suspension system strategy by fuzzy control can obviously improve the comfortable and safe ride.

Abstract: Cellular automata (CA) models are the idealization of physical systems with assumed discrete space and time and a finite number of discrete state transition of cells. Utilizing the CA model, we can capture and reveal the dynamics of railway traffic system. In this paper, the improved CA models are proposed to demonstrate the dynamic behavior of trains with conflict resolution. We propose the CA models to simulate the railway traffic network in the moving-block system, and reschedule trains by applying such two scheduling strategies as FCFS (first come first served) and FLFS (first leave first served). We analyze the relationship between the total delay and time interval of departure utilizing the proposed models. The simulation results demonstrate the rational conclusion that FLFS can cause less delay than FCFS. The proposed models can facilitate finding which plan can achieve the maximum transport efficiency for the railway network.

Abstract: The paper analyzes the characteristics of an intelligent transportation system (ITS) to explore the impact on urban transport of the ideas from “the Internet of Things (IOT)” before its official appearance, and further outlook for the driving force from smart traffic guided by IOT.

Abstract: In order to make sure a high-accuracy and fast- speed survey, a Soft-sensing model for the roughness of machining surface was built based on the support vector machines using rotate speed n, feed peed vf, and depth of cutting as independent parameters, taking groups of actual machining experiment data as samples.The allowable error ε and the positive aligned c and the kernel function parameter r were optimized by an adaptive genetic algorithm. After being optimized 300 steps, the following results can be gained through the training, testing and application. The average relative error tended to saturation training was 4.0%; the test error was less than 2.6%; the average relative error between the Soft-sensing value for the roughness of machining surface under the numerical control and the test value of the profile and roughness tester for the SV-C3000 super surface of was ranging from 0.4% to 1.25%.

Abstract: By using analysis of the infinity image of the space camera, we intend to obtain the curve of the dynamic modulation transfer function. We extract the pixel gray values at the image edge which distribute as a knife-edge function, and make differential calculation and Fourier transformation of it, and then we can obtain the dynamic MTF curve of the optical system. The value of the curve at the Nyquist frequency is the most important parameter that reflects the image quality. We add push-scanning imaging and environmental effects to the static MTF of space camera and compare the MTF value with the dynamic MTF at Nyquist frequency. The comparison result can help us verify the accuracy of the calculating results and the feasibility of our method.