Design and Fabrication of Pneumatic Soft Gripper

2018 ◽  
Author(s):  
Zhonghua Guo ◽  
Zhongsheng Sun ◽  
Xiaoning Li
Keyword(s):  
Compressed Air ◽  
Work Piece ◽  
Soft Body ◽  
Object Shape ◽  
Soft Actuator ◽  
3D Printed ◽  
Experimental Approaches ◽  
Different Shapes ◽  
The Stability ◽  
Gripping Force

In this paper, a pneumatic soft gripper is proposed with inspiration from sea anemone. The gripper is composed of an actuator and several silicone tentacles. With the power of compressed air, the soft actuator expands and folds the tentacles. The gripper wraps tentacles around the object and highly compliant tentacles conforms to the shapes of an object, enveloping and holding it. The physical model is fabricated with 3D printed PLA mold and silicone gel. The gripping mechanics are analyzed according to the experimental gripping operations. On basis of the experimental and analysis result, the compliant gripping is realized while the stability is to be increased. So the tentacle structure is then improved by multi-chamber soft body and vacuum jamming bag. The jamming bag is combined to the end of each tentacle, where the bag is filled with particles to conform to the object shape. Therefore, a reliable constraint is realized between the gripper and the object under vacuum conditions. The bending motion and shaping effect are verified through theoretical and experimental approaches. The important parameters in the vacuum jamming process are also obtained. With such device, soft adaptive bodies enlarges the contact area to adapt to the work-piece where vacuum jamming bags increase the gripping force and stability. It is convenient for universal gripping operation for objects with different shapes.

Computer Vision-Based Object Recognition and Automatic Pneumatic Soft Gripping

2019 ◽  
Author(s):  
Ebrahim Shahabi ◽  
Wei-Hao Lu ◽  
Po Ting Lin ◽  
Chin-Hsing Kuo
Keyword(s):  
Computer Vision ◽  
Object Recognition ◽  
Random Sample ◽  
Low Cost ◽  
Commercial Products ◽  
Object Shape ◽  
Soft Actuator ◽  
3D Printed ◽  
Novel Method ◽  
Random Sample Consensus

Abstract During recent years, soft robotic is a new sub-class of the robots. Soft robotic has several engaging features, such as lightweight, low cost, simple fabrication, easy control, etc. Commercial products such as soft grippers are now available to apply in various fields and applications, for example, agriculture, medicine, machinery, etc. This paper proposes a novel method of grasping in soft robotic fields using computer vision to find the shape, size, and angle of the object to define the best type of grasping mode. Random Sample Consensus (RANSAC) was used to iteratively select randomly sampled 3D points to determine the working plane and identify the randomly placed object. Furthermore, we designed and fabricated a 3D-printed pneumatic soft actuator. The ratio of payload over weight is around 16. Experiments showed the proposed computer vision techniques and pneumatic soft gripper are capable of automatically recognize the object shape and perform soft gripping.

Design of a Force Feedback Chatter Control System

1972 ◽  
Vol 94 (1) ◽  
pp. 5-10 ◽  
Author(s):  
C. Nachtigal
Keyword(s):  
Machine Tool ◽  
Frequency Domain ◽  
Transient Response ◽  
Force Feedback ◽  
Design Procedure ◽  
Experimental Tests ◽  
Work Piece ◽  
Regenerative Chatter ◽  
Chatter Control ◽  
The Stability

The analysis of machine tool chatter from frequency domain considerations is generally accepted as a valid representation of the regenerative chatter phenomenon. However, active control of regenerative chatter is still in its embryonic stage. It was established in reference [2] that a measurement of the cutting force could be effectively used in conjunction with a controller and a tool position servo system to increase the stability of an engine lathe and to improve its transient response. This paper presents the design basis for such a system, including both analytical and experimental considerations. The design procedure stems from a real part stability criterion based on the work by Merritt [1]. Because of the unknown variability in the dynamics of a machine tool system, the controller parameters were chosen to accomodate some mismatch between structure and tool servo dynamics. Experimental tests to determine the stability zone of the controlled machine tool system qualitatively confirmed the analytical design results. The experimental results were consistent in that the transient response tests confirmed the frequency domain stability tests. It was also demonstrated experimentally that the equivalent static stiffness of a flexible work-piece system could be substantially increased.

scholarly journals Analysis and experiments with a 3D printed walking robot to improve climbing obstacle

2020 ◽  
Vol 17 (3) ◽  
pp. 172988142092528
Author(s):  
Ivan Chavdarov ◽  
Aleksandar Krastev ◽  
Bozhidar Naydenov ◽  
Galia Pavlova
Keyword(s):  
Mobile Robots ◽  
Static Stability ◽  
Walking Robot ◽  
Baseline Model ◽  
Minimum Number ◽  
3D Printed ◽  
Different Shapes ◽  
Original Concept

The purpose of this work is to investigate the possibilities of climbing higher obstacles while maintaining the overall dimensions of a walking robot through design improvements and experiments. An original concept for the design of a walking robot with a minimum number of motors is presented. Geometric and force constraints for overcoming an obstacle and the conditions for maintaining static stability are determined. Experiments for overcoming a vertical obstacle are conducted with a 3D printed model. The 3D printed robot feet with different shapes and materials are used. The results of the experiments are presented graphically as a percentage of success against a baseline model. In this study, a dimensionless index to compare the height of the overcome obstacle and the dimensions of the robot is introduced. It allows to objectively compare the possibilities of overcoming obstacles between various types of mobile robots. Conclusions and guidelines for design improvements are made.

scholarly journals Investigation of Structural Stability for Monolithic Nano Bridges on Micro Apertures

2020 ◽  
Vol 10 (8) ◽  
pp. 2922
Author(s):  
Jinwon Lee ◽  
Changwook Seol ◽  
Le Vu Nam ◽  
Segeun Jang ◽  
Junsoo Kim ◽  
...  
Keyword(s):  
Theoretical Model ◽  
Structural Damage ◽  
Polymeric Membranes ◽  
Aperture Size ◽  
Stability Criteria ◽  
Design Rules ◽  
Thin Membranes ◽  
Experimental Approaches ◽  
The Stability ◽  
Line Patterns

The instability of polymeric membranes with nano- and micro-sized apertures has been regarded as one of the main reasons behind realizing ultra-thin membranes with apertures. As is well known, when the thickness of the membrane gets thinner or the aperture size gets smaller, the possibility of geometrical deformation or structural damage by collapse or fracture increases. Herein, we suggest the design rules for the stability of polymeric membranes possessing 1D nano-line patterns monolithically constructed on micro-aperture supporting layers. The proposed theoretical model, which has been thoroughly demonstrated and analyzed based on both theoretical and experimental approaches, provides stability criteria for lateral collapse and vertical fracture of ultra-thin membranes with apertures.

Research and analysis of stiffness-enhanced soft gripper

2020 ◽  
pp. 1-8
Author(s):  
Hui Tian ◽  
Zhujun Zhang ◽  
Zhihua Yuan ◽  
Xiaochan Liu ◽  
Yuyan Qi ◽  
...  
Keyword(s):  
Soft Part ◽  
Optimization Method ◽  
Element Analysis ◽  
Bending Performance ◽  
Piecewise Constant ◽  
Soft Actuator ◽  
3D Printed ◽  
Large Balloon ◽  
Low Stiffness ◽  
Main Components

In view of the problems of low stiffness, small driving force and large balloon effect existing in the current soft actuator, this paper proposes an optimization method to enhance the overall stiffness of the soft gripper by using rigid components based on the multi-cavity soft pneumatic actuator. This paper introduces the main components of the actuator: the soft part poured by liquid silica gel, and the open rectangular rigid structures by 3D printed. The kinematics model of the finger is established based on the Piecewise Constant Curvature model(PCC). The bending performance of the enhanced stiffness gripper is verified by finite element analysis(FEA): the tip force of actuator increased with the increase of the number of rigid structures when the bending angle is constant. According to the and experimental data, the overall stiffness of soft gripper is increased by the rigid structure without affecting the flexibility of operation. And the maximum weight which can grasp is 3.4 times that of the traditional soft gripper, improved the grasping range of the soft gripper effectively.

Design of a Deformable Smart Tire Using Soft Actuator

2019 ◽  
Author(s):  
Vidya K. Nandikolla ◽  
Michael Costa ◽  
Nathan Boyd ◽  
Gilberto Rosales
Keyword(s):  
Force Feedback ◽  
Design Procedure ◽  
Nickel Titanium ◽  
Operating Conditions ◽  
Mechanical Modeling ◽  
Soft Actuator ◽  
Voltage Signal ◽  
3D Printed ◽  
Primary Focus ◽  
Soft Actuators

Abstract The unique functional properties of nickel-titanium Shape Memory Alloys (SMA) enable them to be used as actuators. This research paper demonstrates theoretically and experimentally the feasibility of using SMA in smart tires for a mobile robot. The design procedure for SMA as a coil spring actuator for a soft deformable wheel is described. The primary focus is the mechanical modeling, manufacturing, and system dynamics of a soft deformable wheel. The 3D printed soft tire exploits the capabilities of the SMA actuation using a voltage signal. The printed components are activated and integrated with electromechanical circuit for wireless communication system. The performance of the force feedback control system is evaluated at different operating conditions to demonstrate the shape-changing characteristic of the smart tire. The developed prototype is designed to propel forward and backward on flat and uneven surface. The experimental results obtained demonstrate the potential of SMA as soft actuators, its benefits and limitations as flexible systems.

scholarly journals Control-Oriented Modelling of a 3D-Printed Soft Actuator

Materials ◽  
2018 ◽  
Vol 12 (1) ◽  
pp. 71 ◽  
Author(s):  
Ali Zolfagharian ◽  
Akif Kaynak ◽  
Sui Yang Khoo ◽  
Jun Zhang ◽  
Saeid Nahavandi ◽  
...  
Keyword(s):  
3D Printing ◽  
Dynamic Models ◽  
Three Dimensional ◽  
Input Voltage ◽  
Soft Actuator ◽  
Voltage Variation ◽  
Sophisticated Model ◽  
3D Printed ◽  
Rc Circuit ◽  
Soft Actuators

A new type of soft actuator was developed by using hydrogel materials and three-dimensional (3D) printing technology, attracting the attention of researchers in the soft robotics field. Due to parametric uncertainties of such actuators, which originate in both a custom design nature of 3D printing as well as time and voltage variant characteristics of polyelectrolyte actuators, a sophisticated model to estimate their behaviour is required. This paper presents a practical modeling approach for the deflection of a 3D printed soft actuator. The suggested model is composed of electrical and mechanical dynamic models while the earlier version describes the actuator as a resistive-capacitive (RC) circuit. The latter model relates the ionic charges to the bending of an actuator. The experimental results were acquired to estimate the transfer function parameters of the developed model incorporating Takagi-Sugeno (T-S) fuzzy sets. The proposed model was successful in estimating the end-point trajectory of the actuator, especially in response to a broad range of input voltage variation. With some modifications in the electromechanical aspects of the model, the proposed modelling method can be used with other 3D printed soft actuators.

A Fabrication Free, 3D Printed, Multi-Material, Self-Sensing Soft Actuator

2020 ◽  
Vol 5 (3) ◽  
pp. 4118-4125
Author(s):  
Travis Hainsworth ◽  
Lawrence Smith ◽  
Sebastian Alexander ◽  
Robert MacCurdy
Keyword(s):  
Soft Actuator ◽  
3D Printed
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