scholarly journals A Soft Robot Arm with Flexible Sensors for Master–Slave Operation

2021 ◽  
Vol 10 (1) ◽  
pp. 34
Author(s):  
Yoshie Yamamoto ◽  
Shuichi Wakimoto ◽  
Takefumi Kanda ◽  
Daisuke Yamaguchi

In our study, a soft robot arm consisting of McKibben artificial muscles and a silicone rubber structure was developed. This robot arm can perform bending and twisting motions by ap-plying pneumatic pressure to the artificial muscles. The robot arm is made of flexible materials only, and therefore it has high flexibility and shape adaptability. In this report on the fundamental investigation of the master–slave feedback control of the soft robot arm for intentional operation, we focus on the bending motion of the soft robot arm. Three flexible strain sensors were placed on the soft robot arm for measuring the bending motion. By establishing a master–slave feedback system using the sensors, the bending motion of the soft robot arm followed the operator’s wrist motion detected via the wearable interface device.

Actuators ◽  
2019 ◽  
Vol 8 (2) ◽  
pp. 40 ◽  
Author(s):  
Shota Furukawa ◽  
Shuichi Wakimoto ◽  
Takefumi Kanda ◽  
Hiroki Hagihara

An octopus arm with a flexible structure and no rigid skeleton shows a high degree of freedom and flexibility. These excellent features are suitable for working in an environment having fragile and unknown-shaped objects. Therefore, a soft robot arm resembling an octopus arm can be useful as a harvesting machine without damaging crops in the agricultural field, as a rehabilitation apparatus in the welfare field, as a safe surgery tool in the medical field, and so on. Unlike industrial robots, to consider the applications of the soft robot arm, the instructions for it relating to a task cannot in many cases be given as a numerical value, and the motion according to an operator’s sense and intent is useful. This paper describes the design and feedback control of a soft master-slave robot system. The system is configured with two soft rubber machines; one is a slave machine that is the soft robot arm mimicking the muscle arrangement of the octopus arm by pneumatic artificial muscles, and the other is a master machine that gives the target motion to the slave machine. Both are configured with soft materials. The slave machine has an actuating part and a sensing part, it can perform bending and torsional motions, and these motions are estimated by the sensing part with threads that connect to wire encoders. The master machine is almost the same configuration, but it has no actuating part. The slave machine is driven according to the deformation of the master machine. We confirmed experimentally that the slave machine followed the master machine that was deformed by an operator.


Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1364
Author(s):  
Seulah Lee ◽  
Yuna Choi ◽  
Minchang Sung ◽  
Jihyun Bae ◽  
Youngjin Choi

In recent years, flexible sensors for data gloves have been developed that aim to achieve excellent wearability, but they are associated with difficulties due to the complicated manufacturing and embedding into the glove. This study proposes a knitted glove integrated with strain sensors for pattern recognition of hand postures. The proposed sensing glove is fabricated at all once by a knitting technique without sewing and bonding, which is composed of strain sensors knitted with conductive yarn and a glove body with non-conductive yarn. To verify the performance of the developed glove, electrical resistance variations were measured according to the flexed angle and speed. These data showed different values depending on the speed or angle of movements. We carried out experiments on hand postures pattern recognition for the practicability verification of the knitted sensing glove. For this purpose, 10 able-bodied subjects participated in the recognition experiments on 10 target hand postures. The average classification accuracy of 10 subjects reached 94.17% when their own data were used. The accuracy of up to 97.1% was achieved in the case of grasp posture among 10 target postures. When all mixed data from 10 subjects were utilized for pattern recognition, the average classification expressed by the confusion matrix arrived at 89.5%. Therefore, the comprehensive experimental results demonstrated the effectiveness of the knitted sensing gloves. In addition, it is expected to reduce the cost through a simple manufacturing process of the knitted sensing glove.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Wenjie Yan ◽  
Huei-Ru Fuh ◽  
Yanhui Lv ◽  
Ke-Qiu Chen ◽  
Tsung-Yin Tsai ◽  
...  

AbstractThere is an emergent demand for high-flexibility, high-sensitivity and low-power strain gauges capable of sensing small deformations and vibrations in extreme conditions. Enhancing the gauge factor remains one of the greatest challenges for strain sensors. This is typically limited to below 300 and set when the sensor is fabricated. We report a strategy to tune and enhance the gauge factor of strain sensors based on Van der Waals materials by tuning the carrier mobility and concentration through an interplay of piezoelectric and photoelectric effects. For a SnS2 sensor we report a gauge factor up to 3933, and the ability to tune it over a large range, from 23 to 3933. Results from SnS2, GaSe, GeSe, monolayer WSe2, and monolayer MoSe2 sensors suggest that this is a universal phenomenon for Van der Waals semiconductors. We also provide proof of concept demonstrations by detecting vibrations caused by sound and capturing body movements.


2018 ◽  
Vol 3 (1) ◽  
pp. 108-115 ◽  
Author(s):  
Y. Ansari ◽  
M. Manti ◽  
E. Falotico ◽  
M. Cianchetti ◽  
C. Laschi

Robotics ◽  
2018 ◽  
Vol 7 (4) ◽  
pp. 72 ◽  
Author(s):  
Alaa Al-Ibadi ◽  
Samia Nefti-Meziani ◽  
Steve Davis ◽  
Theo Theodoridis

This article presents a novel design of a continuum arm, which has the ability to extend and bend efficiently. Numerous designs and experiments have been done to different dimensions on both types of McKibben pneumatic muscle actuators (PMA) in order to study their performances. The contraction and extension behaviour have been illustrated with single contractor actuators and single extensor actuators, respectively. The tensile force for the contractor actuator and the compressive force for the extensor PMA are thoroughly explained and compared. Furthermore, the bending behaviour has been explained for a single extensor PMA, multi extensor actuators and multi contractor actuators. A two-section continuum arm has been implemented from both types of actuators to achieve multiple operations. Then, a novel construction is proposed to achieve efficient bending behaviour of a single contraction PMA. This novel design of a bending-actuator has been used to modify the presented continuum arm. Two different position control strategies are presented, arising from the results of the modified soft robot arm experiment. A cascaded position control is applied to control the position of the end effector of the soft arm at no load by efficiently controlling the pressure of all the actuators in the continuum arm. A new algorithm is then proposed by distributing the x, y and z-axis to the actuators and applying an effective closed-loop position control to the proposed arm at different load conditions.


Author(s):  
Yunhao FENG ◽  
Tohru IDE ◽  
Hiroyuki NABAE ◽  
Gen ENDO ◽  
Koichi SUZUMORI ◽  
...  

Author(s):  
Azadeh Doroudchi ◽  
Sachin Shivakumar ◽  
Rebecca E. Fisher ◽  
Hamid Marvi ◽  
Daniel Aukes ◽  
...  

Sensors ◽  
2018 ◽  
Vol 18 (8) ◽  
pp. 2673 ◽  
Author(s):  
Chan Park ◽  
Hyunsuk Jung ◽  
Hyunwoo Lee ◽  
Sunguk Hong ◽  
Hyonguk Kim ◽  
...  

Development of flexible strain sensors that can be attached directly onto the skin, such as skin-mountable or wearable electronic devices, has recently attracted attention. However, such flexible sensors are generally exposed to various harsh environments, such as sweat, humidity, or dust, which cause noise and shorten the sensor lifetimes. This study reports the development of a nano-crack-based flexible sensor with mechanically, thermally, and chemically stable electrical characteristics in external environments using a novel one-step laser encapsulation (OLE) method optimized for thin films. The OLE process allows simultaneous patterning, cutting, and encapsulating of a device using laser cutting and thermoplastic polymers. The processes are simplified for economical and rapid production (one sensor in 8 s). Unlike other encapsulation methods, OLE does not degrade the performance of the sensor because the sensing layers remain unaffected. Sensors protected with OLE exhibit mechanical, thermal, and chemical stability under water-, heat-, dust-, and detergent-exposed conditions. Finally, a waterproof, flexible strain sensor is developed to detect motions around the eye, where oil and sweat are generated. OLE-based sensors can be used in several applications that are exposed to a large amount of foreign matter, such as humid or sweaty environments.


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