Determination of contact points between workpiece and fixture elements as a tool for augmented reality in fixture design

2019 ◽  
Author(s):  
Vitalii Ivanov ◽  
Ivan Pavlenko ◽  
Oleksandr Liaposhchenko ◽  
Oleksandr Gusak ◽  
Vita Pavlenko
Keyword(s):  
Augmented Reality ◽  
Fixture Design ◽  
Contact Points

Quadratic Sensitivity Analysis of Fixtures and Locating Schemes for Rigid Parts

2000 ◽  
Vol 123 (3) ◽  
pp. 462-472 ◽  
Author(s):  
Johan S. Carlson
Keyword(s):  
Sensitivity Analysis ◽  
Numerical Experiments ◽  
Geometric Constraints ◽  
Fixture Design ◽  
Practical Relevance ◽  
Sensitivity Equation ◽  
Relative Gain ◽  
Contact Points ◽  
Scheme Evaluation ◽  
Error Interaction

The main purpose of locating schemes are to position parts. The locating scheme utilizes tooling elements, referred to as locators, to introduce geometric constraints. A rigid part is uniquely positioned when it is brought into contact with the locators. By using kinematic analysis we derive a quadratic sensitivity equation that relates position error in locators with the resulting displacement of the part held by the locating scheme. The sensitivity equation which depends on the locator positions and the workpiece geometry around the contact points can be used for locating scheme evaluation, robust fixture design, tolerancing and diagnosis. The quadratic sensitivity equation derived in this paper is novel by adequate dealing with locator contact at nonprismatic surfaces, nonsmall errors, locator error interaction effects and locator errors in arbitrary directions. Theory for comparing the relative gain in precision by using the quadratic sensitivity equation instead of the linear is developed. The practical relevance of the quadratic sensitivity equation is tested through numerical experiments.

The Method of Substitutive Circles Family: Application in Catia Design Environment for Gear Shaped Tool Profiling

2014 ◽  
Vol 1036 ◽  
pp. 370-375 ◽  
Author(s):  
Silviu Berbinschi ◽  
Gabriel Frumuşanu ◽  
Virgil Gabriel Teodor ◽  
Nicolae Oancea
Keyword(s):  
Numerical Data ◽  
Rolling Process ◽  
Design Environment ◽  
Complementary Method ◽  
Contact Points ◽  
Rolling Method ◽  
Graphical Algorithm

Tools which generate by enveloping using the rolling method may be profiled using various methods. The substitutive circles family method is a complementary method developed based a specifically theorem, in which is determined a family of circles associated with the blank’s centrode, family which envelop the profile to be generate. The method assumes the determination of the circles family, transposed in the rolling process between the blank and tool centrodes. In this paper is proposed an algorithm for curling surfaces in enveloping, associated with a pair of rolling circular centrodes. The graphical algorithm is based on the representation of the circles family enveloped the blank’s profile. It is generated the circles family transposed on the centrode associated with the gear shaped cutter and is determined a new position of contact points with the blank. The assembly of these points forms the profile of the gear shaped cutter. The numerical data proof the proposed method quality.

Computer-aided determination of occlusal contact points for dental 3-D CAD

2006 ◽  
Vol 44 (5) ◽  
pp. 445-450 ◽  
Author(s):  
Tomoaki Maruyama ◽  
Yasuo Nakamura ◽  
Toyohiko Hayashi ◽  
Kazumasa Kato
Keyword(s):  
Occlusal Contact ◽  
Contact Points ◽  
Computer Aided

Automatic inference on stable robotic assembly sequences based upon the evaluation of base assembly motion instability

Robotica ◽  
1993 ◽  
Vol 11 (4) ◽  
pp. 351-362 ◽  
Author(s):  
D.Y. Cho ◽  
C.K. Shinf ◽  
H.S. Chot
Keyword(s):  
Robotic Assembly ◽  
Fixture Design ◽  
Assembly Sequence ◽  
Inference Method ◽  
New Approach ◽  
Assembly Sequences ◽  
Crucial Information ◽  
Part Motion ◽  
Selection Of

SUMMARYThe consideration of part motion instability is crucial to the determination of assembly sequence since this affects the complexity of fixtures and dexterity of robots. This paper presents a new approach to the inference of robotic assembly sequences, taking into consideration the instability of base assembly motions. Based upon the evaluation of motion instability, the method generates stable assembly sequences by use of the precedence constraint inference method previously developed by the authors. An example assembly of a 10-part electrical relay is given to illustrate the concepts and procedure of the proposed scheme. The results show that the proposed method can be effectively utilized to generate stable assembly sequences, thus providing crucial information on the fixture design and selection of types of assembly robots.

scholarly journals Determination of student opinions in augmented reality

2016 ◽  
Vol 8 (3) ◽  
Author(s):  
Huseyin Bicen ◽  
Erkan Bal
Keyword(s):  
Augmented Reality ◽  
Undergraduate Students ◽  
Teaching Methods ◽  
New Technology ◽  
Rapid Development ◽  
Classroom Teaching ◽  
Student Opinions ◽  
Study Results ◽  
The Impact

The rapid development of the new technology has changed classroom teaching methods and tools in a positive way. This study investigated the classroom learning with augmented reality and the impact of student opinions. 97 volunteer undergraduate students took part in this study. Results included data in the form of frequencies, percentages and descriptive statistics. The results show that, with gamification methods, augmented reality content affected students’ opinions in a positive way. When QR codes are used in the classroom, students feel independent from classroom materials and can access various resources. Moreover, students think that, when augmented reality in the classroom is used, education is more enjoyable. Keywords: Augmented reality; gamification; opinions; students

Designing and loaded tooth contact analysis of an Archimedean worm gear drive focusing for the connecting teeth of the worm wheel by loaded torques

2020 ◽  
Vol 21 (4) ◽  
pp. 405
Author(s):  
Sándor Bodzás
Keyword(s):  
Main Property ◽  
Worm Gear ◽  
Tooth Contact Analysis ◽  
Normal Deformation ◽  
Gear Drive ◽  
Contact Points ◽  
Worm Wheel ◽  
Loaded Tooth Contact Analysis ◽  
Gear Drives

The cylindrical worm gear drives are widely used in different mechanical construction such as in the vehicle industry, the robotics, the medical appliances etc. The main property of them is the perpendicular and space bypass axes arrangement. Quite high transmission ratio could be achieved because of the high number of teeth of the worm-wheel and a little number of threads of the worm. More teeth are connected on the worm-wheel at the same time that is why higher loads and power could be transferred. In this research an Archimedean type cylindrical worm gear drive was designed. After the determination of the geometric parameters the computer-aided models were created for the LTCA analysis. Knowing of the kinematic motions of the elements the contact points of the wrapping surfaces could be determined by mathematical way. The necessary coordinate system's arrangements and matrixes were also determined. Different torques were applied during the LTCA. The changing of the distribution of the normal stress and normal deformation into different directions was followed on each connecting tooth of the worm-wheel by the torques. Based on the results consequences were determined by the created diagrams which contain the torques and the analysed mechanical parameter for each tooth.

Geometric and Kinetic Model Based Computer-Aided Fixture Design Verification

2003 ◽  
Vol 3 (3) ◽  
pp. 187-199 ◽  
Author(s):  
Y. Kang ◽  
Y. Rong ◽  
J. A. Yang
Keyword(s):  
Kinetic Model ◽  
Kinetic Models ◽  
Fixture Design ◽  
Clamping Force ◽  
Design Verification ◽  
Modular Fixtures ◽  
Computer Aided ◽  
Machining Operations ◽  
Tolerance Assignment

Computer-aided fixture design (CAFD) techniques have advanced to the point that fixture configurations can be generated automatically, for both modular fixtures and dedicated fixtures. Computer-aided fixture design verification (CAFDV) is a technique for verifying and improving existing fixture designs. This paper introduces a first comprehensive CAFDV framework which uses both geometric and kinetic models to verify locating completeness, locating accuracy, and fixturing stability. The models can be also used for locating tolerance assignment and the determination of minimum clamping force required in machining operations. The system is integrated with commercial CAD package and applied in industrial real-cases.

Improved Algorithm for Tolerance-Based Stiffness Optimization of Machining Fixtures

2001 ◽  
Vol 123 (4) ◽  
pp. 720-730 ◽  
Author(s):  
Jose´ F. Hurtado ◽  
Shreyes N. Melkote
Keyword(s):  
Model Development ◽  
Fixture Design ◽  
Array Type ◽  
Stiffness Optimization ◽  
Part Surface ◽  
Systematic Determination ◽  
Machining Fixtures ◽  
Mechanical Elements ◽  
Bulk Elasticity

Current fixture design methods rely extensively on heuristics and lack a formal engineering approach to determine the necessary stiffness, dimensions, etc. This paper presents a model for stiffness optimization of machining fixtures based on the tolerance limit specified for the machined part surface. Specifically, the model allows systematic determination of the optimum fixture stiffness needed to keep the contribution of fixture deflection to the machined feature tolerance within a designer-specified level. Based on the stiffness optimization model presented here, the optimum dimensions of the fixture elements can also be determined. The model development relies on rigid body analysis methods, contact mechanics principles, and consideration of bulk elasticity of the fixture. The model is generic enough to be used for the design of dedicated or flexible fixtures consisting of mechanical elements. Two examples, one involving a pin-array type flexible fixture and another involving a dedicated fixture, are presented to illustrate the applicability of the model.

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