Mechanical movement data acquisition method based on the multilayer neural networks and machine vision in a digital twin environment[version 1;peer review:2 approved]

Background:Digital twin requires virtual reality mapping and optimization iteration between physical devices and virtual models.The mechanical movement data collection of physical equipment is essential for the implementation of accurate virtual and physical synchronization in a digital twin environment.However,the traditional approach relying on PLC(programmable logic control)fails to collect various mechanical motion state data.Additionally,few investigations have used machine visions for the virtual and physical synchronization of equipment.Thus,this paper presents a mechanical movement data acquisition method based on multilayer neural networks and machine vision.Methods:Firstly,various visual marks with different colors and shapes are designed for marking physical devices.Secondly,a recognition method based on the Hough transform and histogram feature is proposed to realize the recognition of shape and color features respectively.Then,the multilayer neural network model is introduced in the visual mark location.The neural network is trained by the dropout algorithm to realize the tracking and location of the visual mark.To test the proposed method,1000 samples were selected.Results:The experiment results shows that when the size of the visual mark is larger than 6mm,the recognition success rate of the recognition algorithm can reach more than 95%.In the actual operation environment with multiple cameras,the identification points can be located more accurately.Moreover,the camera calibration process of binocular and multi-eye vision can be simplified by the multilayer neural networks.Conclusions:This study proposes an effective method in the collection of mechanical motion data of physical equipment in a digital twin environment. Further studies are needed to perceive posture and shape data of physical entities under the multi-camera redundant shooting.

Research on and Design of Mechanical System with Optimal Cutting Movement Trajectory of Energy-Saving Stone-Sawing Machine

The technique of cutting slabstone with stone-sawi ng machine is analyzed completely. A new kind of cutting movement trajectory is gi ven whose actual cutting efficiency is near to 100%. It can reduce the energy w earing greatly, and the surface quality of the product is improved to the utmost extent. The design mechanism of the optimal cutting movement trajectory system structure is analyzed incisively. At the same time, the principle of the complex movement of horizontal movement and swing is researched. The optimal design scheme of th e cutting movement trajectory system structure is set up. The choice method to g et the superior value of the movement system structure is found. The mathematics function formula is established which exhibits the relationship between the par ameter of the complex movement structure and that of the system movement structu re. By the formula, the precision value of the offset can be figured out. The r ule is adapted to different types of energy-saving stone-sawing machines. The complex movement structure of horizontal movement and swing is designed to f ulfill the cutting movement. It can make the saw frame move up with the hanging pod deviating from the vertical direction. At the same time, the saw frame have a down-movement. Then the sum of the two movements is near to zero, and the saw blade and the stone can keep in touch during the whole horizontal cutting. The result is that the actual cutting efficiency is 100%. Also, when the hanging pod moves to the limited position, the saw frame can keep the original inertia, and continue to swing up. It makes the back-cutting have high energy-storing. The optimal design of the eccentricity balance wheel is done. The mathematics fo rmula for expressing the movement system structure is deduced. The calculation m ethod and formula is set up which is used to get the value of important componen ts such as offset. The choice method and formula of elasticity distortion coeffi cient is set up when the saw frame moves smoothly. It is concluded that the offs et is the key dimension to actualize the optimal cutting movement trajectory. The resolving of the technical problems discussed above offers a theoretic and technical basis for optimal design of energy-saving stone-sawing machines.

The mechanism of retinomotor movements in the retina of banded grouper (Epinephelus awoara)

In order to clarify the mechanism of retinomotor movements in banded grouper, this paper utilizes inhibition factors of microfilaments and microtubules cytochalasin-B and colchicine to study the roles of actin microfilaments and microtubules in the movements of the REP pigment granles and cones. It provides evidences to explain the mechanism of retinomotor movements in fish.

Experimental Verification of the Theory of Non-Force (Information) Interaction

The work is devoted to the demonstration of the possibility of applying the formulas of information handling obtained in the theory of non-force interaction for the natural language processing. These formulas were obtained in computer experiments in modelling the movement and interaction of material objects by changing the amount of information that triggers this movement. The hypothesis, objective and tasks of the experimental research were defined. The methods and software tools were developed to conduct the experiments. To compare different results of the simulation of the processes in a human brain during speech production, there was a range of methods proposed to calculate the estimate of sequence of fragments of natural language texts including the methods based on linear approximation. The experiments confirmed that the formulas of information handling obtained in the theory of non-force interaction reflect the processes of language formation. It is shown that the offered approach can successfully be used to create systems of reactive artificial intelligence machines. Experimental and, presented in this work, practical results constitute that the non-force (informational) interaction formulae are generally valid.

Modern tectonic stress field in the Chinese mainland inverted from focal mechanism solutions

The inversion of modern tectonic stress field in China is made by regions on the basis of focal mechanism data inthe period of 1920-1996. Results of the inversion show that the maximum principal compressive stress σ1 axisstrikes nearly north-south direction in the Tibet Plateau and western Chin4 east-west direction in North China Incentral China, its strikes show a radiate pattern, i.e., north-north east in north part, east-west in central part andnorth-north west in south part. The σ1 axes are often perpendicular to the minimum principal stress σ3 axes, exceptwestern China where the σ1 axes are oblique to the σ3 axes with an acute angle. R is defined by (σ2-σ1)/(σ3-σ1),has the higher values (0.60-0.90) in north part of central China and quickly changes into the lower values(0. 10-0.30) in the Tibet Plateau. Both of the observed and inverted fault planes have strikes varying with locations.Combining stress directions and R value, the stress configuration is divided into 7 groups. Most of the groups showstrike-slip faulting with intermediate R values, which occupies North China and the eastern part of China as well asinner Tibet Plateau. A few of them show reverse faulting with higher R values within western pod of China and thenorth edge of the Tibet Plateau. Normal faulting occurred on the south edge of the Tibet Plateau with smaller Rval nes.

Sediment mathematical model for sand ridges and sand waves

A new theoretical model is formulated to describe internal movement mechanisms of the sand ridges and sand waves based on the momentum equation of a solid-liquid two-phase flow under a shear flow. Coupling this equation with two-dimensional shallow water equations and wave reflection-diffraction equation of mild slope, a two-dimensional coupling model is established and a validation is carried out by observed hydrogeology, tides,waves and sediment. The numerical results are compared with available observations. Satisfactory agreements are achieved. This coupling model is then applied to the Dongfang 1-1 Gas Field area to quantitatively predict the movement and evolution of submarine sand ridges and sand waves. As a result, it is found that the sand ridges and sand waves movement distance increases year by year, but the development trend is stable.

Temporal variation of gravity field prior to the Ludian Ms6.5 and Kangding Ms6.3 earthquakes

Using mobile gravity data from the central area of Sichuan and Yunnan Provinces, the relationship between gravity variation and earthquakes was studied based on the Ludian Ms6.5 earthquake that occurred on August 3rd, 2014, and the Kangding Ms6.3 earthquake that occurred on November 22 nd, 2014; the mechanism of gravity variation was also explored. The results are as follows：（1） Prior to both earthquakes, gravity variation exhibited similar characteristics as those observed before both the Tangshan and Wenchuan earthquakes, in which typical precursor anomalies were positive gravity variation near the epicenter and the occurrence of a high-gravity-gradient zone across the epicenter prior to the earthquake.（2） A relatively accurate prediction of the occurrence locations of the two earthquakes was made by the Gravity Network Center of China（GNCC） based on these precursor anomalies. In the gravity study report on the 2014 earthquake trends submitted at the end of 2013, the Daofu-Shimian section at the junction of the Xianshuihe and Longmenshan fault zones was noted as an earthquake-risk region with a predicted magnitude of 6.5, which covered the epicenter of the Kangding Ms6.3 earthquake. In another report on earthquake trends in southwestern China submitted in mid-2014, the Lianfeng, Zhaotong fault zone was also classified as an earthquake-risk region with a magnitude of 6.0, and the central area of this region basically overlapped with the epicenter of the Ludian Ms6.5 earthquake.（3） The gravity variation characteristics are reasonably consistent with crustal movements, and deep material migration is likely the primary cause of gravity variation.

Clinical Data-Driven Finite Element Analysis of the Kinetics of Chewing Cycles in Order to Optimize Occlusal Reconstructions Dedicated to Professor Karl Stark Pister for his 95th birthday

The occlusal design plays a decisive role in the fabrication of dental restorations.Dentists and dental technicians depend on mechanical simulations of mandibular movement that are as accurate as possible,in particular,to produce interference-free yet chewing-efficient dental restorations.For this,kinetic data must be available,i.e.,movements and deformations under the influence of forces and stresses.In the present study,so-called functional data were collected from healthy volunteers to provide consistent information for proper kinetics.For the latter purpose,biting and chewing forces,electrical muscle activity and jaw movements were registered synchronously,and individual magnetic resonance tomograms(MRI)were prepared.The acquired data were then added to a large complex finite element model of the complete masticatory system using the functional information obtained and individual anatomical geometries so that the kinetics of the chewing process and teeth grinding could be realistically simulated.This allows developing algorithms that optimize computer-aided manufacturing of dental prostheses close to occlusion.In this way,a failure-free function of the dental prosthesis can be guaranteed and its damage during usage can be reduced or prevented even including endosseous implants.

Experimental investigation on the movement mechanism of top coal in steeply inclined ultra-thick coal seams

The pre-blasting zones have a significant influence on the coal broken and the recovery rate of the top coal caving mining.This paper explores the coal movement mechanism in the top coal with pre-blasting zones based on the geological parameters of Jiangcang No.1 mine in the western of China.The steeply inclined ultra-thick coal seam was mined by using the sublevel top-coal caving mining method.The geo-image process system(GIPS)software was used to track the mark points on the coal and roof.The support was used to record the load on the top of the support during the caving mining process.The results show that the horizontal coal is moved to the shield window and the vertical coal is moved downward in the first level,while that in the second level shows consistency for the integrity of the coal.The vertical displacements of the corresponding points in the first level are lairger than that in the second level.However,the load on the top of the support in the first level is smaller than that in the second level.It indicated that the pre-blasting zones will give a more loosen top-coal and a small degree of difficulty in the top coal caving.

ON THE STRUCTURE AND MOVEMENT MECHANISM OF FLOW WITH HYPERCONCENTRATION OF SEDIMENT

This paper, based on the information obtained from flume experiments and field observations, concerns with the analyses of the flow with hyperconcentration of sediment containing a certain amount of fine particles. Attention is focused on the classification of flow with hyperconcentration of sediment, the properties of the Bingham shear stress τB and rigidity coefficient η, the movement mechanism of fluid within flow-core and non-flow-core regions, the shear stress distribution and so on. Several formulae have been proposed to indicate vertical velocity distribution of 2-dimensional steady and uniform turbulent flow with hyperconcentration of fluid. The formulae can be applied either to the flow of the Bingham fluid or to that of the Newtonian fluid.