Bone cutting is a complicated surgical operation. It is very important to establish a kind of gradient porous bone model in vitro which is close to human bone for the research of bone cutting. Due to the existing bone cutting researches are based on solid bone model, which is quite different from human bone tissue structure. Therefore, Voronoi method was used to establish a gradient porous bone model similar to real bone tissue to simulate the process of bone drilling in this paper. High temperature and large cutting force during bone drilling can cause serious damage to bone tissue. Urgent research on bone drilling parameters is necessary to reduce cutting temperature and cutting force. The finite element analysis (FEA) of Voronoi bone models with different gradients is carried out, and a Voronoi model which is similar to real bone tissue is obtained and verified by combining the cutting experiment of pig bone. Then orthogonal experiments are designed to optimize the cutting parameters of Voronoi bone model. The range method is used to analyze the influence weights of cutting speed, feed speed and tip angle on cutting temperature and cutting force, and the least square method was used to predict the cutting temperature and cutting force, respectively. The gradient porous bone model constructed by Voronoi method was studied in detail in this paper. This study can provide theoretical guidance for clinical bone drilling surgery, and the prediction model of bone drilling has practical significance.
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Unmanned operating system is applied to various fields. The disadvantages of the single unmanned system, such as its own limitations, poor flexibility, poor ability, low efficiency, cannot be overcome, as the complexity of the tasks continue to increase. As a result, the cooperative operation system of multi-unmanned platforms is gradually regarded as the main trend of the development of unmanned systems. A novel multiple mobile robots co-avoidance scheme and an improved linear formation algorithm are proposed in this paper. The basic principle and programming steps of the algorithm are described in detail. The improved linear formation algorithm is used for simulation studies. The validity and practicability of the line formation algorithm are verified.
In order to reliable data transmission of wireless sensor network (WSN) in indoor environment, the indoor field intensity distribution and transmission characteristics of electromagnetic wave were researched. First of all, the 3D model in specific indoor environment was built by the finite difference time domain method (FDTD).Then, layout of room, different furniture, position of field source and field source frequency had an influence on indoor field intensity distribution that were studied, and the field intensity distribution was simulated by MATALAB. According to simulation of three dimensional field intensity distribution, and it had directly shown that various factors had an influence on the indoor field intensity distribution, thus indoor wireless sensor network nodes can be reasonable deployed by it, the packet loss rate of WSN transmission was reduced from information source, and it provided theoretical basis for further improving WSN information transmission reliability.
Educational laboratories are places for realizing experimentations and they are important for modern engineering education. The problem is what if there are simply not enough devices or time for conducting experimentation in a local lab? Other factors that prevent the use of local lab devices directly by students are inaccessible or dangerous phenomena, or polluting chemical reactions. The new technologies bring additional strategies of learning and teaching, so it becomes a challenge to integrate the information and communication technologies ICT into the engineering sciences learning. Nowadays, there are two types of online labs, virtual and remote labs. Virtual labs that provide simulation environments for experimentations, remote labs are based on conducting the experimentation remotely through the Internet. In this paper, an example of a successful development and deployment of a cloud based remote lab in the field of engineering education, integrated in the Moodle platform, using very low-coast, high documented devices and free software. The remote lab is user friendly for both trainers and students.
Aiming at the problem of automatic identification and evaluation of road damage degree, the road damage identification and degree assessment algorithms based on unmanned vehicles experimental platform are studied. The road crack segmentation extraction method based on adaptive sliding window is studied. On this basis, the road damage crack classifies and identifies according to the crack geometry information and the principle of template matching. The road damage degree assessment algorithm based on fuzzy decision is proposed based on the quantitative analysis of the road crack and the corresponding parameters information. The experimental results demonstrate that the road damage identification and degree assessment algorithms proposed in this paper are effective and stable.
In underwater target detection, because the acoustic environment of the shallow sea is extremely complex, the acoustic detection is becoming more and more difficult. A deployment algorithm of heterogeneous sensor network based on joint probabilistic sensing model is proposed which combine the acoustic detection and magnetic detection to detect underwater targets. Expert system knowledge is used to achieve the deployment of acoustic magnetic underwater sensor network which base on the normal working area of submarine and the frequency of target within system work a certain time. The simulation results show that the algorithm can guarantee higher detection probability, and reduce the energy consumption of network and prolong network lifetime.
Rotameter is one of the most commonly used local indicating type flow measuring instrument. For remote indication and control a secondary transducer like Hall Probe sensor, LVDT etc. is incorporated with the conventional rotameter. In this paper, a modified rotameter with Hall Probe sensor is used as a measuring instrument. The output hall voltage is proportional to the flow rate of the fluid and the change in fluid density may also vary the hall voltage. So this kind of variation shows incorrect flow rate if the density of the float is not taken to a very high value compared to the density of the fluid. But the density float may affect the flow rate measurement and introduce error. In this respect firstly the variation of Hall voltage with respect to liquid density is analyzed and then the measuring system is calibrated using ANN. The ANN calculates the correction factor with respect to the change in liquid density, which results in obtaining the output close to the desired output. The simulation results show that the calibration technique is efficient. 2ff7e9595c
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