Current Issue : July - September Volume : 2018 Issue Number : 3 Articles : 6 Articles
This paper expounds the principle and method of calibration and base detection by using the visual measurement system for\ndetection and correction of installation error between workpiece and the robot drilling system. This includes the use of Cognex\nInsight 5403 high precision industrial camera, a light source, and theKEYENCE coaxial IL-300 laser displacement sensor.Thethreebase\nholes method and two-base holes method are proposed to analyze the transfer relation between the basic coordinate system\nof the actual hole drilling robot and the basic coordinate system of the theoretical hole drilling robot. The corresponding vision\ncoordinates calibration and the base detection experiments are examined and the data indicate that the result of base detection is\nclose to the correct value....
The aim of this paper is to present finite element model of a filament-wound\ncomposite tube subjected to three-point bending and bending in accordance\nwith standard EN 15807:2011 (railway applications-pneumatic half couplings)\nalong with its experimental verification. In the finite element model, composite\nreinforcement plies have been characterized by linear orthotropic material\nmodel, while rubber liners have been described by a two-parameter Mooney-\nRivlin model. Force-displacement curves of three-point bending show fairly\ngood agreement between simulation results and experimental data. Reaction\nforces of FE simulation and experiment of standard bending test are in good\nagreement....
During the last decades, the ionic polymer-metal composite (IPMC) received much attention because of its potential capabilities,\nsuch as large displacement and flexible bending actuation. In this paper, a biomimetic flapping air vehicle was proposed by\ncombining the superiority of ionic polymer metal composite with the bionic beetle flapping principle. The blocking force was\ncompared between casted IPMC and IPMC. The flapping state of the wing was investigated and the maximum displacement\nand flapping angle were measured. The flapping displacement under different voltage and frequency was tested. The flapping\ndisplacement of the wing and the support reaction force were measured under different frequency by experiments. The\nexperimental results indicate that the high voltage and low frequency would get large flapping displacement....
Two cylinders arranged symmetrically on a frame have become a major form of steering\nmechanism for articulated off-road vehicles (AORVs). However, the differences of stroke and arm\nlead to pressure fluctuation, vibration noise, and a waste of torque. In this paper, the differences of\nstroke and arm are reduced based on a genetic algorithm (GA). First, the mathematical model of the\nsteering mechanism is put forward. Then, the difference of stroke and arm are optimized using a\nGA. Finally, a FW50GLwheel loader is used as an example to demonstrate the proposed GA-based\noptimization method, and its effectiveness is verified by means of automatic dynamic analysis of\nmechanical systems (ADAMS). The stroke difference of the steering hydraulic cylinders was reduced\nby 92% and the arm difference reached a decrease of 78% through GA optimization, in comparison\nwith unoptimized structures. The simulation result shows that the steering mechanism optimized by\nGA behaved better than by previous methods....
The innovative method of modeling and kinematics simulation in RecurDyn are proposed, taking a Mecanum wheel\nplatform(MWP) for omnidirectional wheelchair as research object. In order to study the motion characteristics and mobile\nperformance of the MWP, the virtual prototype simulation model is established in SolidWorks, and virtual prototype simulation is\ncarried out in RecurDyn.Theexperience of simulation for theMWPin RecurDyn is introduced, and the simulation steps and points\nfor attention are described detailedly. The working states of the mobile system in real environment have been simulated through\nvirtual simulation experiments. Four typical motion models including moving forward, moving laterally, moving laterally in the\ndirection of 45âË?Ë?, and rotation have been simulated in RecurDyn. The simulation results exactly reflect the motion of the MWP.\nBy comparing the simulation results with the theoretical results, there are acceptable errors that are relatively less overall in the\nsimulation results.The simulation results can be used to predict the performance of the platformand evaluate the design rationality,\nand design quality can be improved according to the exposed problem. This paper can provide reference for the simulation of mobile\nplatform by using RecurDyn....
The aim of this paper is to model the steady-state condition of a rotary shaft\nseal (RSS) system. For this, an iterative thermal-mechanical algorithm was\ndeveloped based on incremental finite element analyzes. The behavior of the\nsealâ��s rubber material was taken into account by a large-strain viscoelastic, so\ncalled generalized Maxwell model, based on Dynamic Mechanical Thermal\nAnalyses (DMTA) and tensile measurements. The pre-loaded garter spring\nwas modelled with a bilinear material model and the shaft was assumed to be\nlinear elastic. The density, coefficient of thermal expansion and the thermal\nconductance of the materials were taken into consideration during simulation.\nThe friction between the rotary shaft seal and the shaft was simplified and\nmodelled as a constant parameter. The iterative algorithm was evaluated at\ntwo different times, right after assembly and 1 h after assembly, so that rubber\nmaterialâ��s stress relaxation effects are also incorporated. The results show\ngood correlation with the literature data, which state that the permissible\ntemperature for NBR70 (nitrile butadiene rubber) material contacting with\n~80 mm shaft diameter, rotating at 2600/min is 100�šC. The results show\n107�šC and 104�šC for the two iterations. The effect of friction induced temperature,\nchanges the width of the contact area between the seal and the shaft,\nand significantly reduces the contact pressure....
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