scholarly journals Adaptive Machining Scheme for Multi-Hole Part with Multi-Position Accuracy Requirements

2021 ◽  
Author(s):  
Zhen Sun ◽  
Pingfa Feng ◽  
Long Zeng ◽  
Shaoqiu Zhang ◽  
Xi Cheng
Keyword(s):  
Position Error ◽  
Experimental Results ◽  
Correction Model ◽  
Topological Relationship ◽  
Position Accuracy ◽  
Compensation Process ◽  
Adaptive Machining ◽  
Hole Position ◽  
Position Correction ◽  
Relationship Of

Abstract The machining of multi-hole parts often has complex correlated position accuracy requirements. When some position accuracies do not meet the requirements, several hole axes need to be adjusted. Previous methods usually correct all deviated axes to their theoretical locations. However, the correction workload is too large and inefficient. This paper proposes an efficient and adaptive hole position correction model for multi-hole part. First, the method establishes the topological relationship of the holes and faces on the part according to the position accuracy requirements of the multi-hole part. Then, the goal is to minimize the number of holes that need to be corrected. In this model, the parallelism of holes, perpendicularity, and other constraints are considered. The simulation and experimental results show that the use of this model can effectively reduce the number of holes that need to be corrected during the compensation of the position error between holes. It improves the efficiency in the subsequent compensation process significantly.

Calibration Methods of Planar Parallel Robot

2011 ◽  
Vol 464 ◽  
pp. 340-343
Author(s):  
Wei Da Li ◽  
Juan Li ◽  
Li Ning Sun
Keyword(s):  
Error Compensation ◽  
Calibration Method ◽  
Parallel Robot ◽  
Position Error ◽  
Experimental Results ◽  
Kinematic Calibration ◽  
Absolute Position ◽  
Position Accuracy ◽  
Calibration Methods ◽  
Means Of Measurement

Kinematic calibration is an effective method of improving robotic absolute position accuracy by means of measurement, identification and compensation etc. This paper investigates the technology of kinematic calibration and error compensation for the 2-DOF planar parallel robot. A multi-step calibration method is presented based on error itterative method and nonlinear optimum method. Experimental results indicate that the proposed method can effectively compensate position error of the robot in Oxy plane, and the absolute position error of the calibrated robot is less than 6μm.

Discussion on Micro-Structure and Transport Properties of Carbon Micro-Coil

2011 ◽  
Vol 399-401 ◽  
pp. 573-576
Author(s):  
Fa Yu Wu ◽  
Yi Yong Wang ◽  
Wei Juan Li ◽  
Yan Wen Zhou ◽  
Jun Wei Zhang
Keyword(s):  
Transport Properties ◽  
Electrical Transport ◽  
Experimental Results ◽  
Helical Conformation ◽  
Micro Structure ◽  
Electrical Transport Properties ◽  
Relationship Of

The micro-structure, the thermal and electrical transport properties, and their corresponding relationship of carbon micro-coils were discussed, based on the experimental results. The disordered micro-structure and the helical conformation of carbon micro-coils were responsible for the characteristic of their transport properties.

scholarly journals Photoreduction of Cr(VI) Ions in Aqueous Solutions by UV/ Photocatalytic Processes

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Chih Ming Ma ◽  
Yung Shuen Shen ◽  
Po Hsiang Lin
Keyword(s):  
Aqueous Solutions ◽  
Reaction Rate ◽  
Removal Rate ◽  
Experimental Results ◽  
Order Kinetic ◽  
Solution Ph ◽  
Relationship Of ◽  
The Relationship ◽  
Photocatalytic Processes ◽  
Order Kinetic Equation

This study discussed the photoreduction of Cr(VI) ions in aqueous solutions by UV/TiO2photocatalytic processes under various operational factors. Experimental results showed that the removal rate of Cr(VI) increased with decreasing solution pH values and with increasing dosages of organic compounds, indicating that the recombination rate of electrons and h+can be retarded in the reaction systems by the addition of the scavenger, thus raising the reaction rate of Cr(VI). The relationship of the chemical reaction rate of Cr(VI), TiO2dosage, and changes of Cr(VI) concentration was expressed by the pseudo-first-order kinetic equation. Comparing the experimental results of two different doping metals in modified TiO2photoreduction systems, the removal rate of Cr(VI) by the Ag/TiO2process is larger, possibly because the electron transferring ability of Ag is superior to that of Cu. However, the photoreduction rates of Cr(VI) by modified UV/TiO2processes are worse than those by a nonmodified commercial UV/TiO2process.

scholarly journals Analysis of Internal and External Determinant Variables towards Profitability of Islamic Banking in Indonesia (2014-2020)

2021 ◽  
Vol 4 (1) ◽  
pp. 18-34
Author(s):  
Febri Ramadhani ◽  
Muhammad Rizkan
Keyword(s):  
Negative Relationship ◽  
Banking System ◽  
Islamic Banking ◽  
Correction Model ◽  
Factors Affecting ◽  
Vector Error Correction ◽  
Vector Error ◽  
Long Run ◽  
Short Run ◽  
Relationship Of

Indonesia is a country that adheres to a dual banking system, namely conventional and Islamic Banking. The growth rate of Islamic banking in the last three years is higher than conventional banking. However, in total assets, Islamic banking is still far behind conventional banking. Therefore, it is necessary to study further the performance of Islamic banking reflected in its profitability. So, it becomes an alternative input in determining Islamic banking policies. This study aims to know the factors affecting the profitability (ROA) of Islamic Banking in Indonesia. The data used are the 2014-2020 monthly data in the amount of 79 data. The method used in this study is a Vector Error Correction Model (VECM) to determine the effect of long-run and short-run relationships. The results of the study showed that the long-run relationship of the NPF variable affected and was significant positive toward ROA, CAR affected and was significant negative toward ROA, while the inflation variable had a negative relationship and not significant toward ROA. The results of the short-run relationships showed that the NPF and CAR variables positively affected ROA, while the inflation variable did not significantly affect the ROA.

scholarly journals Predicting the Tensile Behavior of Ti-6.6Al-3.3Mo-1.8Zr-0.29Si Alloy via the Temperature-Dependent Crystal Plasticity Method

Materials ◽  
2019 ◽  
Vol 12 (19) ◽  
pp. 3138
Author(s):  
Jun Zhang ◽  
Yang Wang ◽  
Peng Wang ◽  
Junhong Chen ◽  
Songlin Zheng
Keyword(s):  
Crystal Plasticity ◽  
Experimental Results ◽  
Uniaxial Tensile ◽  
Published Data ◽  
Initial Yield Stress ◽  
Polycrystal Plasticity ◽  
Different Temperatures ◽  
Polycrystalline Model ◽  
Critical Resolved Shear Stress ◽  
Relationship Of

Uniaxial tensile flow properties of a duplex Ti-6.6Al-3.3Mo-1.8Zr-0.29Si alloy in a temperature range from 213 K to 573 K are investigated through crystal plasticity modelling. Experimental results indicate that the initial yield stress of the alloy decreases as the temperature increases, while its work-hardening behavior displays temperature insensitivity. Considering such properties of the alloy, the dependence of the initial critical resolved shear stress (CRSS) on temperature is taken into account in the polycrystal plasticity modelling. Good coincidence is obtained between modelling and the experimental results. The determined values of CRSS for slip systems are comparable to the published data. The proposed polycrystalline model provides an alternative method for better understanding the microstructure–property relationship of α + β titanium alloys at different temperatures in the future.

Dimensional Optimization for Minimally Invasive Surgery Robot Based on Double Space and Kinematic Accuracy Reliability Index

2020 ◽  
Vol 3 (2) ◽  
Author(s):  
Yang Jing ◽  
Jin Lingyan ◽  
Shi Xinge ◽  
Zhao Deming ◽  
Hu Ming
Keyword(s):  
Reliability Index ◽  
Position Error ◽  
Optimal Size ◽  
Kinematic Accuracy ◽  
Position Accuracy ◽  
Adjustment Mechanism ◽  
Error Space ◽  
Double Space ◽  
Kinematic Performance ◽  
Dimensional Optimization

Abstract To improve the kinematic performance of the remote center mechanism for surgical robot, a double space index and kinematic accuracy reliability index are proposed to optimize the dimensional sizes of mechanism. First, the influence of the angular error on the position error and the operability of the remote center in the workspace are analyzed. The position error space and operability space index are weighted to establish the double space index. Second, a kinematic accuracy reliability index is established based on the influence of joint clearance on output position accuracy. Finally, the dimensional sizes of remote center adjustment mechanism and double parallelogram mechanism are optimized based on proposed optimization indices. Multipopulation genetic algorithm is used to obtain the optimal size parameters under the corresponding index. The optimized double space index is 56.7%, which is 56.5% higher than before optimization. The optimized kinematic accuracy reliability is 0.91, which is 22.9% higher than before optimization. The kinematic performance of remote center mechanism has been significantly improved after optimization.

Bond investigation of hybrid textile with self-compacting fine-grain concrete

2016 ◽  
Vol 46 (8) ◽  
pp. 1616-1632 ◽  
Author(s):  
Shiping Yin ◽  
Bo Wang ◽  
Fei Wang ◽  
Shilang Xu
Keyword(s):  
Tensile Load ◽  
Experimental Results ◽  
Interfacial Property ◽  
Uniaxial Tensile ◽  
Uniaxial Tensile Test ◽  
Multiple Cracks ◽  
Textile Reinforced Concrete ◽  
Fine Grain ◽  
Resin Impregnation ◽  
Relationship Of

This paper presents an experimental investigation into the influence of bond characteristics between textile and matrix on the mechanical behavior of textile-reinforced concrete (TRC). Two types of tests were performed, i.e. pullout test and uniaxial tensile test. Self-compacting fine-grain concrete was adopted. Two kinds of hybrid textile, consisting of both carbon and E-glass yarns, were specially prepared for this study. The experimental results show that sticking sands on the textile after epoxy resin impregnation can improve the interfacial property between textile and matrix. The specimens with textile of 10 mm × 10 mm mesh have stronger bond strength than those with textile of 25 mm × 25 mm mesh, and can reach the maximum tensile strength of yarns when the initial bond length is between 30 mm and 35 mm. Moreover, sticking sands on the textile can improve the multiple cracks form and the ultimate bearing capacity of TRC under uniaxial tensile load. Specimens with textile of 10 mm × 10 mm mesh have higher first-crack loads than those with textile of 25 mm × 25 mm mesh whether or not the textile surface treatment was conducted, and also have better crack distribution. Finally, based on the experimental results from TRC under uniaxial tensile load, a double linear constitutive equation of stress–strain relationship of carbon fiber yarn is provided in this paper.

scholarly journals Evolution of the turtle bauplan: the topological relationship of the scapula relative to the ribcage

2012 ◽  
Vol 8 (6) ◽  
pp. 1028-1031 ◽  
Author(s):  
Tyler R. Lyson ◽  
Walter G. Joyce
Keyword(s):  
Shoulder Girdle ◽  
Developmental Model ◽  
Model Organisms ◽  
Turtle Shell ◽  
Developmental Origin ◽  
Topological Relationship ◽  
Fossil Data ◽  
Relationship Of ◽  
The Relationship

The turtle shell and the relationship of the shoulder girdle inside or ‘deep’ to the ribcage have puzzled neontologists and developmental biologists for more than a century. Recent developmental and fossil data indicate that the shoulder girdle indeed lies inside the shell, but anterior to the ribcage. Developmental biologists compare this orientation to that found in the model organisms mice and chickens, whose scapula lies laterally on top of the ribcage. We analyse the topological relationship of the shoulder girdle relative to the ribcage within a broader phylogenetic context and determine that the condition found in turtles is also found in amphibians, monotreme mammals and lepidosaurs. A vertical scapula anterior to the thoracic ribcage is therefore inferred to be the basal amniote condition and indicates that the condition found in therian mammals and archosaurs (which includes both developmental model organisms: chickens and mice) is derived and not appropriate for studying the developmental origin of the turtle shell. Instead, among amniotes, either monotreme mammals or lepidosaurs should be used.

Further Investigations of Movement Time between Brake and Accelerator Pedals in Automobiles

1970 ◽  
Vol 12 (6) ◽  
pp. 559-561 ◽  
Author(s):  
Benjamin T. Davies ◽  
John M. Watts
Keyword(s):  
Horizontal Plane ◽  
Movement Time ◽  
Experimental Results ◽  
Brake Pedal ◽  
Seat Height ◽  
Stopping Distance ◽  
High Speeds ◽  
Relationship Of ◽  
Female Subjects

This report presents the results of continued studies into the nonoptimality of the positional relationship of brake and accelerator pedals in contemporary automobiles. Ten female subjects were tested to determine how long it takes to move the foot from the accelerator to the brake pedal under four conditions involving variations in brake pedal height and seat height. Experimental results indicated: (1) a reduction in stopping distance of upwards of 10 ft. could be effected at high speeds, (2) seat height had no effect on movement time of foot from accelerator to brake pedal in the case of female drivers, and (3) movement times for female drivers when compared with previous experiments on male drivers are the same when the brake pedal is 6 in. higher than the accelerator but are 25% slower when the pedals are in the same horizontal plane.

Relationship of Influence Coefficients Between Static-Couple and Multiplane Methods on Two-Plane Balancing

2008 ◽  
Vol 131 (1) ◽  
Author(s):  
John J. Yu
Keyword(s):  
Experimental Results ◽  
Analytical Relationship ◽  
Vibration Modes ◽  
Static Response ◽  
Individual Probe ◽  
Influence Coefficients ◽  
Relationship Of ◽  
Couple Vibration

This paper demonstrates analytical relationship of influence coefficients between static-couple and multiplane methods on two-plane balancing as well as its application. For the static-couple approach, cross-effects are defined between static weights and couple response as well as between couple weights and static response, thus making it possible to offset both static and couple vibration vectors effectively with appropriate combination of static and couple weights. Relationship of influence coefficients between static/couple and individual probe due to static/couple weights is also given. Static, couple, or individual probe influence coefficients due to static or couple weights can be obtained directly without having to place static or couple trial weights if influence coefficients used in the multiplane approach are known. From static and couple influence data as well as cross-effects, influence data for the multiplane approach can be obtained directly as well without having to place any trial weights at either plane. The above findings and conversion equations are obtained analytically and verified by experimental results. Conversion of influence coefficients from multiplane to static-couple format can determine whether static or couple weights are more effective as well as running vibration modes, while conversion from static-couple to multiplane format can determine which balance plane is more effective.

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