MINISTRY OF EDUCATION AND TRAINING HCM CITY UNIVERSITY OF TECHNOLOGY AND EDUCATION HO NHAT LINH DEVELOPMENT AND OPTIMIZATION OF GRIPPERS FOR CYLINDER SAMPLES USING COMPLIANT MECHANISMS PH. DISSERTATION MAJOR: MECHANICAL ENGINEERING CODE: 9520103 Ho Chi Minh City, July 2023 MINISTRY OF EDUCATION AND TRAINING HCM CITY UNIVERSITY OF TECHNOLOGY AND EDUCATION HO NHAT LINH DEVELOPMENT AND OPTIMIZATION OF GRIPPERS FOR CYLINDER SAMPLES USING COMPLIANT MECHANISMS PH. DISSERTATION MAJOR: MECHANICAL ENGINEERING CODE: 9520103 Supervisor 1: Assoc. Le Hieu Giang Supervisor 2: Dr.
Dao Thanh Phong Reviewer 1: Reviewer 2: Reviewer 3: Ho Chi Minh City, July 2023 I SCIENTIFIC CURRICULUM VITAE I. Full name: HO NHAT LINH 2. Birthday: 01/01/1982 Place of birth: Long An 3. Nationality: Vietnam Sex: Male 4.
Academic degree: Master of Engineering - 2016 5. Office Home 2nd Floor, No.63, Xuan Hong B69/4, My Hoa 2, Xuan street, 12 Ward, Tan Binh District, Thoi Dong Ward, Hoc 1 Address HCMC, Viet Nam Mon District, HCMC, Viet Nam 2 Phone/ (+84) 944.004 fax 3 Email honhatlinh01011982@gmail. Education background (latest): Level Time Institution Major/Specialty HCM University of Mechanical BS. 2005 Technology and Education, Engineering Viet Nam Ho Chi Minh City Mechanical MS.
2016 University of Technology, Engineering Viet Nam II. Work experience Time Organization Position From to II CÔNG TY TNHH VIE-PAN – 06/2005 01/2007 Mechanical Engineer Việt nam CTY TNHH IKEBA SANGYO 01/2007 05/2009 Mechanical Engineer – Nhật Bản CTY TNHH SEKO SANGYO 06/2009 10/2012 Mechanical Engineer – Nhật Bản CTY TNHH NIDEC 12/2012 09/2013 Mechanical Engineer SEIMITSU VIET NAM 09/2013 Present CTY TNHH KOEI VIET NAM Sales engineer III. Dao Thanh Phong Office: Institute for Computational Science, Ton Duc Thang University Email: daothanhphong@tdtu. Le Hieu Giang Office: HCMC University of Technology and Education Email: gianglh@hcmute.vn Commitment: I hereby guarantee that all the above declaration is the truth and only the truth.
I will fully take responsibility if there is any deception. Ho Chi Minh City, July 2023 Signature and Full name Ho Nhat Linh III CONTENTS CONTENTS .IV ORIGINALITY STATEMENT .XI LIST OF ABBREVIATIONS. XII LIST OF SYMBOLS. XIV LIST OF FIGURES.
XVII LIST OF TABLES. XXII CHAPTER 1 INTRODUCTION. Background and motivation. Problem description of proposed compliant grippers.
Objects of the dissertation. Objectives of the dissertation. The scientific and practical significance of the dissertation. Outline of the dissertation.
10 CHAPTER 2 LITERATURE REVIEW. Overview of compliant mechanism. Definition of compliant mechanism. Categories of compliant mechanism.
Compliant joints or flexure hinges. Displacement amplification based on the compliant mechanism. The Scott-Russell mechanism. Displacement sensors based on compliant mechanisms.
Compliant grippers based on embedded displacement sensors. International and domestic research. Research works in the field by foreign scientists. Study on compliant mechanisms by foreign scientists.
Study on robotic grippers and compliant grippers by foreign scientists. Research works in the field by domestic scientists. Research on compliant mechanisms by domestic scientists. Research on robotic grippers and compliant grippers by domestic scientists.
43 CHAPTER 3 THEORETICAL FOUNDATIONS. Design of experiments. Modeling methods and approaches for compliant mechanisms. Pseudo-rigid-body model.
Lagrange-based dynamic modeling approaches. Finite Element Method. Graphic method, Vector method, and Mathematical analysis. Data-driven modeling methods.
Data-driven optimization. Weighting factors in multi-objective optimization problems. 60 CHAPTER 4 DESIGN, ANALYSIS, AND OPTIMIZATION OF A DISPLACEMENT SENSOR FOR AN ASYMMETRICAL COMPLIANT GRIPPER. Research targets of displacement sensor for compliant gripper.
Structural design of proposed displacement sensor. Mechanical design and working principle of a proposed displacement sensor. Description of structure of displacement sensor. The working principle of a displacement sensor.
Technical requirements of a proposed displacement sensor. Behavior analysis of the displacement sensor. Strain versus stress. Design optimization of a proposed displacement sensor.
Description of optimization problem of a proposed displacement sensor. Definition of design variables. Definition of objective functions. Definition of constraints.
The proposed method for optimizing the displacement sensor. Optimal Results and Discussion. Determining Weight Factor. 111 CHAPTER 5 COMPUTATIONAL MODELING AND OPTIMIZATION OF A SYMMETRICAL COMPLIANT GRIPPER FOR CYLINDRICAL SAMPLES 113 5.
Basic application of symmetrical compliant gripper for cylinder samples. Research targets of symmetrical compliant gripper. Mechanical design of symmetrical compliant gripper. Description of structural design.
Technical requirements of proposed symmetrical compliant gripper. Behavior analysis of the proposed compliant gripper. Design optimization of the compliant gripper. Problem statement of optimization design.
Determination of design variables. Determination of objective functions. Determination of constraints. Proposed optimization method for the compliant gripper.
Optimized results and validations. 139 CHAPTER 6 CONCLUSIONS AND FUTURE WORKS. 165 VIII ORIGINALITY STATEMENT I, Ho Nhat Linh, confirm that this dissertation is the product of my efforts, carried out under the guidance of Assoc. Le Hieu Giang and Dr.
Dao Thanh Phong, to the best of my understanding. The information and findings presented in this dissertation are authentic and have not been previously published. IX ACKNOWLEDGMENTS First of all, I am grateful to my adviser, Assoc. Le Hieu Giang and Dr.
Dao Thanh Phong have supported me with his knowledge and dedication throughout my Ph. studies and provided me with the perspective required to conduct research in the field of Compliant mechanisms. I would want to thank my compliance team members, who will follow me throughout my research career. Also, I would like to thank for the financial support from the HCMC University of Technology and Education, Vietnam, under Grant No.
T2018-16TÐ, and Vietnam National Foundation for Science and Technology Development (NAFOST ED) under grant No. To conclude, I extend my heartfelt appreciation to my spouse and parents for their motivation, assistance, and endurance. Ho Nhat Linh X ABSTRACT Developing a gripper with accurate grasping and positioning tasks has been a daunting challenge in the assembly industry. To meet these requirements, this thesis aims to develop two new types of compliant grippers.
The first gripper with an asymmetrical structure is capable of integrating displacement sensors. The second gripper with a symmetrical structure is served for assembly. The hypothesized grasping objects are small-sized cylinders as the shaft of the vibration motor used in mobile phones or electronic devices ( 0. In the first part, a displacement sensor for self-identifying the stroke of an asymmetric compliant gripper is analyzed and optimized.
Strain gauges are placed in the flexible beams of the gripper and turn it into the displacement sensor with a resolution of micrometers. In addition, static and dynamic equations of the gripper are built via the pseudo-rigid-body model (PRBM) and Lagrange’s principle. To increase the stiffness and frequency, silicone rubber is filled the open cavities of the gripper. Taguchi-coupled teaching learning-based optimization (HTLBO) method is formulated to solve the multi-response optimization for the gripper.
Initial populations for the HTLBO are generated using the Taguchi method (TM). The weight factor (WF) for each fitness function is properly computed. The efficiency of the proposed method is superior to other optimizers. The results determined that the displacement is 1924.15 µm and the frequency is 170.
In the second part, a symmetric compliant gripper consisting of two symmetrical jaws is designed for the assembly industry. The kinematic and dynamic models are analyzed via PRBM and the Lagrange method. An intelligent computational technique, adaptive network-based fuzzy inference system-coupled Jaya algorithm, is proposed to improve the output responses of the gripper. The WF of each cost function is computed.
The results achieved a displacement of 3260 µm. Besides, the frequency was 61. Physical experiments are implemented to evaluate the effectiveness of both compliant grippers. The experimental results are relatively agreed with the theoretical results.
XI LIST OF ABBREVIATIONS Abbreviation Full name CAD Computer-aided design FEM Finite element method FEA Finite element analysis CG Compliant gripper CM Compliant mechanism PEA Piezoelectric actuator MDS Micro-displacement sensor SR Silicon rubber TM Taguchi method ANOVA Analysis of variance S/N Signal-to-Noise AVONSNR Average value of normalized S/N ratios RSM Response surface methodology PRBM Pseudo-rigid-body model TLBO Teaching learning-based optimization HTLBO Hybrid teaching learning-based optimization GA Genetic algorithm PSO Particle swarm optimization XII Abbreviation Full name AEDE Adaptive elitist differential evolution ANFIS Adaptive neuro-fuzzy inference system technique WF Weight factor DA Displacement amplification MOO Multi-objective optimization MOOP Multi-objective optimization problem NSGA-II Nondominated sorting genetic algorithm II WEDM Wire electrical discharged machining FH Flexure hinge XIII LIST OF SYMBOLS Abbreviation Full name S Safety factor y Yield strength of the material f Frequency E Young’s modulus ε Strain σ Stress y The quality response i The number of experiments q The number of replicates of experiment ‘i’ nd The population size X The vector of design variables xi Design variable UL,i Upper limit of the design variable UL,i Lower limit of the design variable pop The population r Random value TF The teaching factor XIV Abbreviation Full name m(.) Average value of the data set. S/N Signal-to-noise ratio zi Normalized mean S/N i S/N ratio m The number of responses R The resistance G Gauge factor Vo The output of the circuit Vex The excitation voltage of the circuit Fy Force in the y direction S Sensitivity N The number of failure cycles Sut The ultimate strength Se The endurance strength limit M The bending moments dφ/ds The differentiation of deflection W External work Fi Input force XV Abbreviation Full name Fo Output force kPEA The stiffness of PEA Fpreload Preload force of the piezoelectric actuator Ms The entire mass of the gripper Ks The stiffness of the gripper li Length of the ith flexure hinge ti Thickness of the ith flexure hinge W Width of the positioning platform L Length of the positioning platform H Hight of the positioning platform XVI LIST OF FIGURES Figure 1. 1: Some applications of robotic gripper [2]: a) Medicine/biology, b) Material handling, c) Picking, packaging, and shelling, and d) Machine tending robots.2: Several types of grippers in the industry [3]: a) Vacuum grippers, b) Pneumatic grippers, c) Hydraulic grippers, d) Magnetic grippers, and e) Electric grippers. 3: A miniatured vibrating motor: a) Mobile phone, b) Vibrating mobile- phone motor, c) Miniatured motor [13].
1: a) Traditional rigid-body clamp and b) Compliant clamp [16]. 2: Classification of compliant mechanism based on compliance [18]. 3: Classified based on the static deformation of a structure [18]. 4: A compliant active mechanism with two flexible segments [19].
5: A passive compliant mechanism with four rigid links and a flexible link [19]. 6: Four types of typical CM : a) Inverter, b) Compliant platform, c) Microgripper, and d) Positioning stage [20]. 7: Three principal categories of FH arrangements: a) Single-axis; b) Multiple-axis; c) Two-axis [28]. 8: Complex type of FHs: a) Cross hinge, b) Cartwheel hinge, c) Leaf spring, d) Hyperbolic hinge [28].
9: Flexure hinges with notch shape [29]: a) Circular hinge, b) Filleted leaf hinge, c) Elliptical hinge, d) V shape hinge, e) Hyperbolic hinge, f) Parabolic hinge. 10: Actuators: a) Piezoelectric actuators [34]; b) Electrostrictive actuators [35]; c) Magnetostrictive actuators [36]; d) Shape memory alloy (SMA) actuators [37]; and e) Pneumatic actuators [38]. 12: Lever mechanism for in-compliant grippers: a) A hybrid amplifying structure [39]; b) Single lever mechanism [42]; c) Serial lever mechanisms [43]; d) Different lever mechanisms [44]. 13: Schematic of Scott-Russell mechanism: a) The principle of operation; b) Analysis of the amplification ratio.
14: Application of Scott-Russell mechanism in gripper design: a) Micro- gripper with Scott-Russell mechanism [46]; b) A large-range micro-gripper with Scott-Russell mechanism [47]. 15: Schematic of bridge mechanism: a) Displacement of bridge mechanism; b) Amplification factor analysis of a bridge mechanism. 16: Bridge mechanism for compliant grippers: a) Half of the bridge mechanism [49], b) Serial bridge mechanism [50], c) Two stage-bridge mechanism [52], d) Orthogonal bridge mechanism [53]. 17: Commercial displacement sensors: a) Optical displacement sensors [54]; b) Linear proximity sensors [55]; and c) Ultrasonic displacement sensors [56].