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In modern society, the loading and transshipment of large quantities of materials has become the norm. However, the material loading and transshipment process is faced with problems such as low utilization of transportation equipment and slow delivery process. How to efficiently solve the efficiency and safety issues in the material loading and transshipment process has become the main consideration of major transportation companies. The traditional method of relying on experience cannot efficiently and reasonably solve the technical problems of material loading and transshipment in the warehouse assembly. This paper proposes a material loading and transshipment system guarantee scheme based on the tabu search algorithm, using modeling and simulation techniques to achieve Material loading and transfer auxiliary decision-making and comprehensive efficiency analysis and evaluation capabilities provide decision-making support for the optimal use of material loading and transfer equipment and improving material loading and transfer efficiency.

At present, the commonly used algorithm for detecting circles cannot be directly applied in the detection of concentric circles, there are few researches on the special multi - circle detection problems such as concentric circles. In this paper, the color concentric circles are transformed into gray scale images without color space conversion. The minimum envelopment circle is adopted to locate the target area quickly and accurately. Then, combined with the least square ellipse fitting method, each concentric circle is detected and the position of the center of the circle is marked. Finally, the experiment proves that the algorithm in this paper improves the detection efficiency and detection effect compared with the classical algorithm.

The most classic method for finding a circle mark in an image and positioning the center of the circle is the Hough circle detection. However, this method has many problems, such as large amount of computation, low detection accuracy and large memory usage, which cannot meet the requirement of real-time performance. This paper proposes a positioning method based on color and shape features, first by color segmentation area of interest, then use median filter to filter the noise in image, using edge detection and contour to find the outline of the image, finally from the view of the mathematical description of circular shape characteristics, the contour filter, so as to quickly find the center of concentric circles. Experiments show that compared with the improved Hough gradient method, the proposed method has lower complexity, faster calculation speed and can find the marker area more effectively, especially suitable for real-time requirements such as drone vision guidance and accurate landing.

For the airlines, safety is the foundation for their existence and development. Therefore, the management of risks is one of the most important parts of daily airline management. Uncertain factors such as weather changes, aircraft failures, and employee status all contribute to the occurrence of various types of aviation accidents. How to find, manage, and avoid risks through the improvement of management methods, the analysis of operational data and the application of various technical tools is the problems faced by most airlines. Taking Xiamen Airlines as an example, this article thoroughly studies the theory and methods of airline operations assessment and risk management based on the Analytic Hierarchy Process (AHP). Through the research on various elements involved in aviation operations, the comprehensive application of risk management, safety science theories and methods of complex systems and computer modeling, we have proposed the design and implementation of airline operational risk assessment model construction and monitoring systems based on AHP. Thus, timely warnings can be made and control measures can be taken during routine management to improve the company's safety management level and operational support capabilities.

Rate-dependent hysteresis of piezoelectric stack actuators (PSAs) is known to cause oscillations and instabilities. This paper introduces a novel electro-mechanical coupling model that can accurately characterize the high-bandwidth rate-dependent hysteresis of a PSA. The proposed model contains three components to fully represent the output response of the system, namely, an electric model that is used to describe the electric dynamic behaviors of the PSA and its power amplifier, a hysteresis model that is applied to represent the inverse piezoelectric effect, and a mechanical model that is able to characterize the mechanical dynamic behavior of the PSA. It should be noted that, in the mechanical model, the force generated by the inverse piezoelectric effect of piezoelectric wafers is considered a distributed force and the dynamic model of the PSA is regarded as a longitudinal vibration straight bar with a uniform cross section. Through this proposed model, high modeling accuracy is achieved well with high-bandwidth varying frequencies (1–1000 Hz) as well as varying amplitudes. This paper provides a simple and effective novel method for the high-bandwidth modeling of smart material-based actuators with rate-dependent hysteresis nonlinearity.

The process of the adapter separating from the missile plays an important role in the safety and reliability of missile launching, which involves complex dynamics calculations. In order to guarantee the safety of separating the adapter from the missile and successfully launching the missile, this article was concerned with the whole process of the adapter separating from the missile launching system and presented a novel calculation method and visual simulation software to analyze the dynamics process of adapter separation. The dynamics models including the coordinate system, dynamics and kinematic equations, and the forces acting on the adapter are established. The random factors and their distribution law that greatly influence the separation process are analyzed, the confidence intervals of the separation reliability are estimated by using the Monte Carlo method, and an algorithm for calculating the distance between the adapter, missile wing, and tail rudder is proposed. Visual simulation software for analyzing the separation process is designed, which gathers modeling, solving, and analytical processing. Finally, a numerical simulation result is given to verify the validity and correctness of the proposed method and software and analyze the factors affecting the separation reliability of the separating process of adapters for missile launching. The method and software presented in this paper can provide support for the safety design of missile adapter separation.

The piezo-positioning system with high dynamic performance is urgently needed in the field of precision manufacturing and precision instrumentation. The observed rate-dependent hysteresis presents more challenges and difficulties for accurately modeling the response behavior of the piezoelectric stack actuators over the last several decades. Our previous research shows that the rate-dependent characteristics may be caused by the dynamic characteristics of the power amplifier. In order to achieve the high-bandwidth and high-speed motion control accuracy, we propose an open-loop compensation control method of a piezo-positioning mechanism based on a composite electromechanical dynamic model. The dynamic model can describe the dynamic characteristics of the power amplifier, the inverse piezoelectric effect and the dynamics of the mechanism. Experimental results show that the proposed control method can achieve precise motion control of the piezo-positioning mechanism within 1–800 Hz bandwidth.

With the development of information technology, virtual reality has been widely used in military, commercial, educational and entertainment industries. By applying virtual reality technology to traditional library, this paper establishes a virtual digital library system. The system takes the library of NJUPT as the designing and modeling object, uses Unity3D as the virtual reality engine to develop the virtual library system, realizing scene construction, the virtual roaming, the scene interaction and the book loaning inquiry and other functions of the virtual library. This paper presents a method for selecting books based on the method of "Ray", and designs a Web Service interface to realize communication between virtual reality environment and library management system. The users can obtain immersive experiences in the virtual library, and also can get the location and the situation of the books in the virtual library by VR glasses, PCs and Smart Mobile Phones.

The transfer matrix method for multibody systems is a new method with very high computational speed developed in recent 20 years for studying multibody system dynamics. By combining transfer matrix method for multibody systems, computer graphics, and open-source software, this article puts forward an approach and software MSTMMSim for visualized simulation and design of mechanical system dynamics. The approach includes the following procedures in sequence: design of functional model, design of three-dimensional solid model, design of dynamics model, automated formation of dynamics equations, and software MSTMMSim for visualized simulation and design of mechanical system dynamics. The proposed method and software provide a platform to realize the simulation and design of complex mechanical systems with the following characteristics: (1) automatic deduction of the overall transfer equation, (2) high computational speed, and (3) high visualization and programming of dynamics simulation and design process. The proposed method and software are verified by the practical example of simulation and design of a tank system dynamics using this platform.

As the main body of modern traffic, transport vehicle is the focus of intelligent transportation systems. For three typical vehicles (including the automobile, motorcycle and bicycle), this paper proposes a new transport vehicle recognition system via class dictionary learning. For solving problems in the traditional transport vehicle recognition under sparse recognition framework, our method use SURF feature and class dictionary learning as the core. By the experiment with heterogeneous database, the effectiveness and feasibility of this method has been verified.

The modeling and solving a transcendental eigenvalue problem are important issues in the transfer matrix method for linear multibody systems. Based on the recursive eigenvalue search algorithm for transfer matrix method for linear multibody system, the distributed parallel approach for assembling overall transfer matrix and searching eigenvalues is proposed. This is achieved based on Message Parallel Interface. The influence of the CPU core number as well as the distributed network environment on the final computational time is analyzed through numerical examples of both a non-uniform beam and a multiple launch rocket system. The results indicate that the computational time is significantly reduced by the proposed parallel computing method, so that the computational efficiency on optimization and design of complex multibody systems can be improved.

The hysteresis characteristics resulted from piezoelectric actuators (PAs) and the residual vibration in the rapid positioning of a two-dimensional piezo-driven micro-displacement scanning platform (2D-PDMDSP) will greatly affect the positioning accuracy and speed. In this paper, in order to improve the accuracy and speed of the positioning and restrain the residual vibration of 2D-PDMDSP, firstly, Utilizing an online hysteresis observer based on the asymmetrical Bouc-Wen model, the PA with the hysteresis characteristics is feedforward linearized and can be used as a linear actuator; secondly, zero vibration and derivative shaping (ZVDS) technique is used to eliminate the residual vibration of the 2D-PDMDSP; lastly, the robust model reference adaptive (RMRA) control for the 2D-PDMDSP is proposed and explored. The rapid control prototype of the RMRA controller combining the proposed feedforward linearization and ZVDS control for the 2D-PDMDSP with rapid control prototyping technique based on the real-time simulation system is established and experimentally tested, and the corresponding controlled results are compared with those by the PID control method. The experimental results show that the proposed RMRA control method can significantly improve the accuracy and speed of the positioning and restrain the residual vibration of 2D-PDMDSP.

The complex mechanical systems such as high-speed trains, multiple launch rocket system, self-propelled artillery, and industrial robots are becoming increasingly larger in scale and more complicated in structure. Designing these products often requires complex model design, multibody system dynamics calculation, and analysis of large amounts of data repeatedly. In recent 20 years, the transfer matrix method of multibody system has been widely applied in engineering fields and welcomed at home and in abroad for the following features: without global dynamic equations of the system, low orders of involved system matrices, high computational efficiency, and high programming. In order to realize the rapid and visual simulation for complex mechanical system virtual design using transfer matrix method of multibody system, a virtual design software named MSTMMSim is designed and implemented. In the MSTMMSim, the transfer matrix method of multibody system is used as the solver for dynamic modeling and calculation; the Open CASCADE is used for solid geometry modeling. Various auxiliary analytical tools such as curve plot and animation display are provided in the post-processor to analyze and process the simulation results. Two numerical examples are given to verify the validity and accuracy of the software, and a multiple launch rocket system engineering example is given at the end of this article to show that the software provides a powerful platform for complex mechanical systems simulation and virtual design.