scholarly journals Pose Determination of the Disc Cutter Holder of Shield Machine Based on Monocular Vision

Sensors ◽  
2022 ◽  
Vol 22 (2) ◽  
pp. 467
Author(s):  
Dandan Peng ◽  
Guoli Zhu ◽  
Dailin Zhang ◽  
Zhe Xie ◽  
Rui Liu ◽  
...  
Keyword(s):  
Measurement Method ◽  
Vision System ◽  
Engineering Application ◽  
Optimal Solution ◽  
Maximum Error ◽  
Vital Role ◽  
Disc Cutter ◽  
Accuracy Requirement ◽  
Practical Engineering ◽  
Shield Machine

The visual measurement system plays a vital role in the disc cutter changing robot of the shield machine, and its accuracy directly determines the success rate of the disc cutter grasping. However, the actual industrial environment with strong noise brings a great challenge to the pose measurement methods. The existing methods are difficult to meet the required accuracy of pose measurement based on machine vision under the disc cutter changing conditions. To solve this problem, we propose a monocular visual pose measurement method consisting of the high precision optimal solution to the PnP problem (OPnP) method and the highly robust distance matching (DM) method. First, the OPnP method is used to calculate the rough pose of the shield machine’s cutter holder, and then the DM method is used to measure its pose accurately. Simulation results show that the proposed monocular measurement method has better accuracy and robustness than the several mainstream PnP methods. The experimental results also show that the maximum error of the proposed method is 0.28° in the direction of rotation and 0.32 mm in the direction of translation, which can meet the measurement accuracy requirement of the vision system of the disc cutter changing robot in practical engineering application.

scholarly journals Identification of Random Dynamic Force Using an Improved Maximum Entropy Regularization Combined with a Novel Conjugate Gradient

2017 ◽  
Vol 2017 ◽  
pp. 1-14 ◽  
Author(s):  
ChunPing Ren ◽  
NengJian Wang ◽  
ChunSheng Liu
Keyword(s):  
Maximum Entropy ◽  
Conjugate Gradient ◽  
Regularization Parameter ◽  
Engineering Application ◽  
Optimal Solution ◽  
Identification Problem ◽  
Dynamic Force ◽  
Force Identification ◽  
Mathematical Algorithm ◽  
Practical Engineering

We propose a novel mathematical algorithm to offer a solution for the inverse random dynamic force identification in practical engineering. Dealing with the random dynamic force identification problem using the proposed algorithm, an improved maximum entropy (IME) regularization technique is transformed into an unconstrained optimization problem, and a novel conjugate gradient (NCG) method was applied to solve the objective function, which was abbreviated as IME-NCG algorithm. The result of IME-NCG algorithm is compared with that of ME, ME-CG, ME-NCG, and IME-CG algorithm; it is found that IME-NCG algorithm is available for identifying the random dynamic force due to smaller root mean-square-error (RMSE), lower restoration time, and fewer iterative steps. Example of engineering application shows that L-curve method is introduced which is better than Generalized Cross Validation (GCV) method and is applied to select regularization parameter; thus the proposed algorithm can be helpful to alleviate the ill-conditioned problem in identification of dynamic force and to acquire an optimal solution of inverse problem in practical engineering.

scholarly journals Turbine Blade Three-Wavelength Radiation Temperature Measurement Method Based on Reflection Error Correction

2021 ◽  
Vol 11 (9) ◽  
pp. 3913
Author(s):  
Kaifeng Zheng ◽  
Jinguang Lü ◽  
Yingze Zhao ◽  
Jin Tao ◽  
Yuxin Qin ◽  
...  
Keyword(s):  
Temperature Measurement ◽  
Turbine Blade ◽  
Measurement Method ◽  
Turbine Blades ◽  
Target Surface ◽  
Maximum Error ◽  
Radiation Temperature ◽  
Average Error ◽  
Real Surface ◽  
Wavelength Radiation

The turbine blade is a key component in an aeroengine. Currently, measuring the turbine blade radiation temperature always requires obtaining the emissivity of the target surface in advance. However, changes in the emissivity and the reflected ambient radiation cause large errors in measurement results. In this paper, a three-wavelength radiation temperature measurement method was developed, without known emissivity, for reflection correction. Firstly, a three-dimensional dynamic reflection model of the turbine blade was established to describe the ambient radiation of the target blade based on the real surface of the engine turbine blade. Secondly, based on the reflection correction model, a three-wavelength radiation temperature measurement algorithm, independent of surface emissivity, was proposed to improve the measurement accuracy of the turbine blade radiation temperature in the engine. Finally, an experimental platform was built to verify the temperature measurement method. Compared with three conventional colorimetric methods, this method achieved an improved performance on blade temperature measurement, demonstrating a decline in the maximum error from 6.09% to 2.13% and in the average error from 2.82% to 1.20%. The proposed method would benefit the accuracy in the high-temperature measurement of turbine blades.

Dynamic Characteristics and Stability Analysis of Two-Dimensional (2D) Electro-Hydraulic Proportional Directional Valve

2015 ◽  
Author(s):  
S. Li ◽  
J. Ruan ◽  
B. Meng ◽  
W. A. Jia ◽  
H. Y. Xie
Keyword(s):  
Dynamic Characteristics ◽  
Magnetic Force ◽  
Engineering Application ◽  
Proportional Valve ◽  
Acceptable Range ◽  
Hydrostatic Force ◽  
Practical Engineering ◽  
Direct Operation ◽  
Electrohydraulic Valve ◽  
Proportional Directional Valve

A 2D electrohydraulic proportional directional valve is proposed, which integrates both direct and pilot operation of the valve. In this valve, the output magnetic force of the proportional solenoid is converted to rotate the spool through a thrust-torsion coupling and thus the pressure in the valve sensitive chamber is varied. The varied pressure exerted on the areas of the spool end produces a hydrostatic force to move the spool linearly, which will rotate the spool reversely. Theoretical analysis is carried to the proposed valve and the effects of the key geometric parameters on the dynamic characteristics of the 2D valve and stability are investigated. Experiments are also designed to access to the characteristics of the valve working under direct and pilot operation. The 2D electrohydraulic valve can work properly for both direct operation and pilot operation. The hysteresis and frequency response are measured and the results are within the acceptable range in practical engineering application required of the directional proportional valve.

scholarly journals Latency optimization for D2D-enabled parallel mobile edge computing in cellular networks

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Yan Cai ◽  
Liang Ran ◽  
Jun Zhang ◽  
Hongbo Zhu
Keyword(s):  
Cellular Networks ◽  
Optimal Solution ◽  
Vital Role ◽  
Base Stations ◽  
Low Latency ◽  
Mobile Edge Computing ◽  
System Delay ◽  
Simulation Results ◽  
And Task ◽  
Parallel Communication

AbstractEdge offloading, including offloading to edge base stations (BS) via cellular links and to idle mobile users (MUs) via device-to-device (D2D) links, has played a vital role in achieving ultra-low latency characteristics in 5G wireless networks. This paper studies an offloading method of parallel communication and computation to minimize the delay in multi-user systems. Three different scenarios are explored, i.e., full offloading, partial offloading, and D2D-enabled partial offloading. In the full offloading scenario, we find a serving order for the MUs. Then, we jointly optimize the serving order and task segment in the partial offloading scenario. For the D2D-enabled partial offloading scenario, we decompose the problem into two subproblems and then find the sub-optimal solution based on the results of the two subproblems. Finally, the simulation results demonstrate that the offloading method of parallel communication and computing can significantly reduce the system delay, and the D2D-enabled partial offloading can further reduce the latency.

Study and Analysis of GA-Based Heuristic Applied to Assembly Line Balancing Problem

2014 ◽  
Vol 13 (02) ◽  
pp. 113-131 ◽  
Author(s):  
P. Sivasankaran ◽  
P. Shahabudeen
Keyword(s):  
Cycle Time ◽  
Assembly Line ◽  
Assembly Line Balancing ◽  
Optimal Solution ◽  
Vital Role ◽  
Line Balancing ◽  
Problem Size ◽  
Minimum Number ◽  
Assembly Line Balancing Problem ◽  
Balancing Efficiency

Balancing assembly line in a mass production system plays a vital role to improve the productivity of a manufacturing system. In this paper, a single model assembly line balancing problem (SMALBP) is considered. The objective of this problem is to group the tasks in the assembly network into a minimum number of workstations for a given cycle time such that the balancing efficiency is maximized. This problem comes under combinatorial category. So, it is essential to develop efficient heuristic to find the near optimal solution of the problem in less time. In this paper, an attempt has been made to design four different genetic algorithm (GA)-based heuristics, and analyze them to select the best amongst them. The analysis has been carried out using a complete factorial experiment with three factors, viz. problem size, cycle time, and algorithm, and the results are reported.

scholarly journals Analysis of influencing factors of flow state concrete mixture performance

2021 ◽  
Vol 2076 (1) ◽  
pp. 012073
Author(s):  
Dandan Shi ◽  
Xing Qin ◽  
Hao Qu
Keyword(s):  
Measurement Method ◽  
Engineering Application ◽  
Performance Testing ◽  
Reducing Agent ◽  
Mineral Admixture ◽  
Raw Material ◽  
Concrete Mixture ◽  
Flow State ◽  
Test Results ◽  
Concrete Mix

Abstract Based on the principle of benefiting the durability of concrete, machined sand is used to configure C40 flow concrete, and the engineering application environment and economy are considered. In this paper, the author through the flow state concrete mix ratio design, give the raw material dosage, concrete mixing, finally combined with the workability measurement method, five groups of concrete mix performance testing. According to the test results, the influence of mineral admixture and water reducing agent on the workability of concrete mixture is studied and analyzed, and the reasonable admixture dosage and water reducing rate of water reducing agent and its admixture dosage are finally given.

scholarly journals Experimental Study on Influence of Temperature to Control Performance for Viscoelastic Materials Pounding Tuned Mass Damper

2021 ◽  
Vol 8 ◽  
Author(s):  
Dehui Ye ◽  
Jie Tan ◽  
Yabin Liang ◽  
Qian Feng
Keyword(s):  
Engineering Application ◽  
Tuned Mass Damper ◽  
Frame Structure ◽  
Force Model ◽  
Viscoelastic Materials ◽  
Mass System ◽  
Mass Damper ◽  
Different Temperatures ◽  
Practical Engineering ◽  
Portal Frame Structure

The pounding tuned mass damper (PTMD) is a novel passive damper that absorbs and dissipates energy by an auxiliary tuned spring-mass system. Viscoelastic materials are attached to the interface of the limitation collar in the PTMD so that the energy dissipation capacity can be enhanced. Previous studies have successfully demonstrated the effectiveness of PTMD at room temperature. However, in practice, the PTMD may face a broad temperature range, which can affect the mechanical properties of the viscoelastic materials. Thus, the study of vibration control effectiveness of PTMD at different temperatures is of great significance for its practical engineering application. In this paper, a series of experiments were conducted to investigate the performance of a PTMD in a temperature-controlled environment. A PTMD device was designed to suppress the vibration of a portal frame structure and tested across environmental temperatures ranging from –20°C to 45°C. The displacement reduction ratios demonstrated the temperature robustness of the PTMD. Additionally, the numerical results validated the accuracy of the pounding force model and the performance of PTMD.

Study on Flexural Behavior of Pre-Stressed Concrete Hollow Slabs Strengthen with CFRP

2013 ◽  
Vol 446-447 ◽  
pp. 1413-1416
Author(s):  
Bo Wang ◽  
Juan Han
Keyword(s):  
Experimental Method ◽  
Engineering Application ◽  
Flexural Behavior ◽  
Experimental Basis ◽  
Concentrated Force ◽  
Disaster Area ◽  
Practical Engineering ◽  
Symmetrical Load

The purpose of this paper is to focus on studying its flexural behavior after different damages pre-stressed concrete hollow slab is strengthened with CFRP. By the experimental method, twelve residential pre-stressed concrete hollow slabs are tested under concentrated force at the two points of the symmetrical load in order to analyze both flexural behavior and effects factored by different bonding modes. The conclusion can be drawn that the flexural behavior of pre-stressed concrete hollow slabs strengthened with CFRP is well-tried. It provides design suggestions and reference for pre-stressed concrete hollow slabs strengthened with CFRP, and also provides an experimental basis for the repairing and reinforcing practical engineering application in Wenchuan disaster area.

A Fault-Tolerant Offset Algorithm for Measured Data with Defects

2014 ◽  
Vol 902 ◽  
pp. 344-350
Author(s):  
Xiang Jia Li ◽  
Ning Dai ◽  
Wen He Liao ◽  
Yu Chun Sun ◽  
Yong Bo Wang
Keyword(s):  
High Efficiency ◽  
Fault Tolerant ◽  
Engineering Application ◽  
Measured Data ◽  
Sphere Model ◽  
High Quality ◽  
Fitting Method ◽  
Enveloping Surface ◽  
Practical Engineering ◽  
Offset Surface

Offsetting of measured data, as a basic geometric operation, has already been widely used in many areas, like reverse engineering, rapid prototyping and NC machining. However, measured data always carry typical defects like caves and singular points. A fault-tolerant offset method is proposed to create the high quality offset surface of measured data with such defects. Firstly, we generated an expansion sphere model of measured data with the radius equivalent to the offset length. Secondly, using the computational geometry application of convex hull, we acquire the data of outermost enveloping surface of this expansion sphere model. Finally, we use local MLS projection fitting method to wipe out existing defects, and generate the high-quality triangular mesh surface of the offset model. The offset surface generated by this method is suitable for practical engineering application due to its high efficiency and accuracy.

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