Shape Estimation of Soft Manipulator Using Stretchable Sensor

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Jinho So ◽  
Uikyum Kim ◽  
Yong Bum Kim ◽  
Dong-Yeop Seok ◽  
Sang Yul Yang ◽  
...  
Keyword(s):  
Robot Manipulator ◽  
Soft Robot ◽  
Shape Estimation ◽  
Multiwalled Carbon ◽  
Human Organ ◽  
Teflon Sheet ◽  
Tip Position ◽  
Shape Sensing ◽  
Soft Manipulator ◽  
The Relationship

The soft robot manipulator is attracting attention in the surgical fields with its intrinsic softness, lightness in its weight, and safety toward the human organ. However, it cannot be used widely because of its difficulty of control. To control a soft robot manipulator accurately, shape sensing is essential. This paper presents a method of estimating the shape of a soft robot manipulator by using a skin-type stretchable sensor composed of a multiwalled carbon nanotube (MWCNT) and silicone (p7670). The sensor can be easily fabricated and applied by simply attaching it to the surface of the soft manipulator. In its fabrication, MWCNT is sprayed on a teflon sheet, and liquid-state silicone is poured on it. After curing, we turn it over and cover it with another silicone layer. The sensor is fabricated with a sandwich structure to decrease the hysteresis of the sensor. After calibration and determining the relationship between the resistance of the sensor and the strain, three sensors are attached at 120° intervals. Using the obtained data, the curvature of the manipulator is calculated, and the entire shape is reconstructed. To validate its accuracy, the estimated shape is compared with the camera data. We experiment with three, six, and nine sensors attached, and the result of the error of shape estimation is compared. As a result, the minimum tip position error is approximately 8.9 mm, which corresponded to 4.45% of the total length of the manipulator when using nine sensors.

scholarly journals An Investigation on the Grasping Position Optimization-Based Control for Industrial Soft Robot Manipulator

Machines ◽  
2021 ◽  
Vol 9 (12) ◽  
pp. 363
Author(s):  
Guangcheng Zhang ◽  
Shenchen Li ◽  
Yi Wu ◽  
Mingkang Zhu
Keyword(s):  
Fatigue Damage ◽  
Control Strategy ◽  
Robot Manipulator ◽  
Step Function ◽  
Soft Robot ◽  
Function Type ◽  
Optimal Position ◽  
Challenging Tasks ◽  
Soft Manipulator ◽  
Resultant Stress

Mitigating fatigue damage and improving grasping performance are the two main challenging tasks of applying the soft manipulator into industrial production. In this paper, the grasping position optimization-based control strategy is proposed for the soft manipulator and the corresponding characteristics are studied theoretically and experimentally. Specifically, based on the simulation, the resultant stress of step-function-type channels at the same pressure condition that was smallest compared with those of sine-function- and ramp-function-type channels, hence, a pneumatic network with step-function-type channels was selected for the proposed soft manipulator. Furthermore, in order to improve the grasping performance, the kinematics, mechanical, and grasping modeling for the soft manipulator were established, and a control strategy considering the genetic algorithm is introduced to detect the optimal position of the soft manipulator. The corresponding fabrication process and experiments were conducted to cross verify the results of the modeling and the control strategy. It is demonstrated that the internal pressure of the soft manipulator was reduced by 13.05% at the optimal position, which effectively helped mitigate the fatigue damage of the soft manipulator and prolonged the lifespan.

scholarly journals Additive Manufacturing for Soft Robotics: Design and Fabrication of Airtight, Monolithic Bending PneuNets with Embedded Air Connectors

Micromachines ◽  
2020 ◽  
Vol 11 (5) ◽  
pp. 485 ◽  
Author(s):  
Gianni Stano ◽  
Luca Arleo ◽  
Gianluca Percoco
Keyword(s):  
Additive Manufacturing ◽  
Wall Thickness ◽  
Chamber Wall ◽  
Soft Robotics ◽  
Soft Robot ◽  
Soft Robots ◽  
Bending Performance ◽  
3D Print ◽  
Air Tightness ◽  
The Relationship

Air tightness is a challenging task for 3D-printed components, especially for fused filament fabrication (FFF), due to inherent issues, related to the layer-by-layer fabrication method. On the other hand, the capability of 3D print airtight cavities with complex shapes is very attractive for several emerging research fields, such as soft robotics. The present paper proposes a repeatable methodology to 3D print airtight soft actuators with embedded air connectors. The FFF process has been optimized to manufacture monolithic bending PneuNets (MBPs), an emerging class of soft robots. FFF has several advantages in soft robot fabrication: (i) it is a fully automated process which does not require manual tasks as for molding, (ii) it is one of the most ubiquitous and inexpensive (FFF 3D printers costs < $200) 3D-printing technologies, and (iii) more materials can be used in the same printing cycle which allows embedding of several elements in the soft robot body. Using commercial soft filaments and a dual-extruder 3D printer, at first, a novel air connector which can be easily embedded in each soft robot, made via FFF technology with a single printing cycle, has been fabricated and tested. This new embedded air connector (EAC) prevents air leaks at the interface between pneumatic pipe and soft robot and replaces the commercial air connections, often origin of leakages in soft robots. A subsequent experimental study using four different shapes of MBPs, each equipped with EAC, showed the way in which different design configurations can affect bending performance. By focusing on the best performing shape, among the tested ones, the authors studied the relationship between bending performance and air tightness, proving how the Design for Additive Manufacturing approach is essential for advanced applications involving FFF. In particular, the relationship between chamber wall thickness and printing parameters has been analyzed, the thickness of the walls has been studied from 1.6 to 1 mm while maintaining air tightness and improving the bending angle by 76.7% under a pressure of 4 bar. It emerged that the main printing parameter affecting chamber wall air tightness is the line width that, in conjunction with the wall thickness, can ensure air tightness of the soft actuator body.

scholarly journals Trapezoidal Motion Profile to Suppress Residual Vibration of Flexible Object Moved by Robot

Electronics ◽  
2019 ◽  
Vol 8 (1) ◽  
pp. 30 ◽  
Author(s):  
Hyun Joong Yoon ◽  
Seong Youb Chung ◽  
Han Sol Kang ◽  
Myun Joong Hwang
Keyword(s):  
High Speed ◽  
Robot Manipulator ◽  
Control Algorithms ◽  
Residual Vibration ◽  
Motion Characteristic ◽  
The Relationship ◽  
Being Moved ◽  
Additional Feedback ◽  
Motion Profile ◽  
Deceleration Time

The residual vibration when a robot manipulator is operated at high speed needs to be suppressed. These vibrations are generated by the resonance of a flexible object being moved by the robot, and research on control algorithms and motion profiles is ongoing to reduce them. In this paper, we propose a method to reduce the residual vibration of an object moved by a robot manipulator by optimizing the acceleration/deceleration time calculated using the object’s natural frequency. The relationship between acceleration/deceleration time and the residual vibration in a trapezoidal velocity profile is considered by analyzing the scenario when the jerking motion characteristic of such vibrations occurs. The results of experiments using a commercial robot show that residual vibrations can be reduced by the proposed method without the need for an additional feedback control algorithm while transferring a flexible object over small and large distances.

Vision-Based Tip Position Control of a Single-Link Robot Manipulator

2019 ◽  
Author(s):  
Umesh Kumar Sahu ◽  
Arun Mishra ◽  
Biswajeet Sahu ◽  
Prateek Priyaranjan Pradhan ◽  
Dipti Patra ◽  
...  
Keyword(s):  
Position Control ◽  
Robot Manipulator ◽  
Single Link ◽  
Tip Position

scholarly journals A Survey of Strategies to Modulate the Bone Morphogenetic Protein Signaling Pathway: Current and Future Perspectives

2016 ◽  
Vol 2016 ◽  
pp. 1-15 ◽  
Author(s):  
Jonathan W. Lowery ◽  
Brice Brookshire ◽  
Vicki Rosen
Keyword(s):  
Bone Morphogenetic Proteins ◽  
Bmp Signaling ◽  
Protein Signaling ◽  
Bone Morphogenetic Protein Signaling ◽  
Human Organ ◽  
Morphogenetic Protein ◽  
Organ Systems ◽  
Bmp Pathway ◽  
Wide Perspective ◽  
The Relationship

Bone morphogenetic proteins (BMPs) constitute the largest subdivision of the TGF-βfamily of ligands and are unequivocally involved in regulating stem cell behavior. Appropriate regulation of canonical BMP signaling is critical for the development and homeostasis of numerous human organ systems, as aberrations in the BMP pathway or its regulation are increasingly associated with diverse human pathologies. In this review, we provide a wide-perspective on strategies that increase or decrease BMP signaling. We briefly outline the current FDA-approved approaches, highlight emerging next-generation technologies, and postulate prospective avenues for future investigation. We also detail how activating other pathways may indirectly modulate BMP signaling, with a particular emphasis on the relationship between the BMP and Activin/TGF-βpathways.

Realization of Pressfitting by Impact Manipulation Using an Under-Actuated Manipulator

2008 ◽  
Vol 2 (4) ◽  
pp. 305-311 ◽  
Author(s):  
Shinichiro Shindo ◽  
◽  
Shingo Tomita ◽  
Yasumichi Aiyama
Keyword(s):  
Genetic Algorithm ◽  
Robot Manipulator ◽  
Sweet Spot ◽  
End Effector ◽  
Simple Genetic Algorithm ◽  
Large Force ◽  
The Relationship

Impact manipulation instantaneously generates a large force making it effective for pressfitting. We model pressfitting and analyze it for realization by a robot manipulator, analyzing the relationship between hit speed and pressfitting depth to determine the hit speed required for different pressfitting depths. We use an under-actuated manipulator for hitting the “sweet spot” of the end effector, introducing a simple genetic algorithm to plan manipulator movement to generate the desired hit speed. Results of experiments on pressfitting for driving an under-actuated manipulator verified the feasibility of our proposal.

Spectral fingerprinting of structural defects in plasma-treated carbon nanotubes

2003 ◽  
Vol 18 (10) ◽  
pp. 2515-2521 ◽  
Author(s):  
Nirupama Chakrapani ◽  
Seamus Curran ◽  
Bingqing Wei ◽  
Pulickel M. Ajayan ◽  
Alvaro Carrillo ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Plasma Etching ◽  
Photoelectron Spectroscopy ◽  
Morphological Changes ◽  
Structural Defects ◽  
Vibrational Modes ◽  
Multiwalled Carbon ◽  
Systematic Analysis ◽  
Treated Carbon ◽  
The Relationship

Controlled introduction of defects into aligned multiwalled carbon nanotubes (MWCNTs) was achieved by time-dependent plasma etching. The subsequent morphological changes in MWCNTs have been fingerprinted using Raman and x-ray photoelectron spectroscopy, by which induction of defects by functionalization was confirmed. We found that the introduction of defects along the nanotube body affects all Raman vibrational modes. A systematic analysis of the relationship between D, D′, D*, and G modes leads us to believe that no one peak can be used as an accurate standard for estimation of defects in nanotubes.

Path Feasibility and Modification Based on the PUMA 560 Workspace Analysis

1994 ◽  
Vol 116 (1) ◽  
pp. 36-43 ◽  
Author(s):  
Kuo-Chiang Shao ◽  
Kuu-young Young
Keyword(s):  
Robot Manipulator ◽  
Industrial Robot ◽  
Practical Application ◽  
Kinematic Constraints ◽  
Workspace Analysis ◽  
Task Requirements ◽  
The Given ◽  
The Relationship ◽  
Robot Workspace

Robot paths are planned according to different industrial tasks. Their kinematic feasibility is restrained by the structure of the given robot manipulator. In order to design feasible paths under kinematic constraints and different task requirements, we propose first to utilize the geometry of the given robot to generate the geometric boundaries of different regions corresponding to kinematic constraints in the robot workspace. Geometric expressions are then derived to describe the relationship about the planned path and the robot workspace. Finally, by applying the developed modification strategies based on different task requirements, feasible paths can be obtained by modifying the infeasible portions of the paths. To demonstrate the proposed feasibility and modification schemes, the PUMA 560 robot manipulator is selected as a case study due to its complexity and practical application. The results are then extended to general wrist-partitioned types of industrial robot manipulators.

Adaptive Control of Large-Scale Soft Robot Manipulators With Unknown Payloads

2019 ◽  
Author(s):  
Jonathan S. Terry ◽  
Justin Whitaker ◽  
Randal W. Beard ◽  
Marc D. Killpack
Keyword(s):  
Adaptive Control ◽  
Large Scale ◽  
Robot Manipulator ◽  
Coupling Model ◽  
Effective Control ◽  
Soft Robot ◽  
Soft Robots ◽  
Pneumatic Actuators ◽  
Integral Controller ◽  
Model Reference Adaptive

Abstract The compliance and other nonlinear dynamics of large-scale soft robots makes effective control difficult. This is especially true when working with unknown payloads or when the system dynamics change over time which is likely to happen for soft robots. In this paper, we present a novel method of coupling model reference adaptive control (MRAC) with model predictive control (MPC) for platforms with antagonistic pneumatic actuators. We demonstrate its utility on a fully inflatable, six degree-of-freedom pneumatically actuated soft robot manipulator that is over two meters long. Specifically, we compare control performance with no integral controller, with an integral controller, and with MRAC when running a nominal model predictive controller with significant weight attached to the end effector.

scholarly journals ANALISA FORWARD KINEMATIC PADA SIMULATOR ARM ROBOT 5 DOF YANG MENGINTEGRASIKAN MIKROKONTROLER ARDUINO-UNO DAN LABVIEW

ROTASI ◽  
2013 ◽  
Vol 15 (2) ◽  
pp. 37
Author(s):  
Munadi Munadi
Keyword(s):  
Robot Manipulator ◽  
Angular Position ◽  
Servo Motor ◽  
End Effector ◽  
Position Errors ◽  
Position And Orientation ◽  
The Individual ◽  
Forward Kinematic ◽  
The Relationship ◽  
Numerical Program

An arm robot simulator has been developed, that capable in simulating a 5 degree of freedom robot manipulator, in which it was equipped with two-finger gripper mechanism at end-effector. This simulator is designed for educational purposes so that many students can easily understand when learning about robot manipulator. The simulator was developed using Ardiuno Uno with LabVIEW through the Firmata interface for controlling the actuators (servo motors). Ardiuno Uno was chosen because it can interact with LabVIEW that will be able to control the angular position of servo motor easily. Angular position errors that occur on the servo motor can be solved by using a numerical program functions and numerical multiply divided on LabVIEW. For analysis, this paper presents the forward kinematics problem which is concerned with the relationship between the individual joints of the arm robot simulator and the position and orientation of the tool or end-effector. The analysis result is carried out in MATLAB.

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