scholarly journals Design of a fuzzy safety margin derivation system for grip force control of robotic hand in precision grasp task

2021 ◽  
Vol 18 (3) ◽  
pp. 172988142110180
Author(s):  
Canfer Islek ◽  
Ersin Ozdemir
Keyword(s):  
Grip Force ◽  
Human Performance ◽  
Fuzzy Logic Controller ◽  
Safety Margin ◽  
Surface Friction ◽  
Robotic Hand ◽  
Performance Tests ◽  
Human Beings ◽  
Limit Value ◽  
Grasp Force

In this study, the aim was to grasp and lift an unknown object without causing any permanent change on its shape using a robotic hand. When people lift objects, they add extra force for safety above the minimum limit value of the grasp force. This extra force is expressed as the “safety margin” in the literature. In the conducted study, the safety margin is minimized and the grasp force was controlled. For this purpose, the safety margin performance of human beings for object grasping was measured by the developed system. The obtained data were assessed for a fuzzy logic controller (FLC), and the fuzzy safety margin derivation system (SMDS) was designed. In the literature, the safety margin rate was reported to vary between 10% and 40%. To be the basis for this study, in the experimental study conducted to measure the grip performance of humans, safety margin ratios ranging from 9% to 20% for different surface friction properties and different weights were obtained. As a result of performance tests performed in Matlab/Simulink environment of FLC presented in this study, safety margin ratios ranging from 8% to 21% for different surface friction properties and weights were obtained. It was observed that the results of the performance tests of the developed system were very close to the data of human performance. The results obtained demonstrate that the designed fuzzy SMDS can be used safely in the control of the grasp force for the precise grasping task of a robot hand.

The limits of human performance

2008 ◽  
Vol 44 ◽  
pp. 11-26 ◽  
Author(s):  
Ralph Beneke ◽  
Dieter Böning
Keyword(s):  
Human Performance ◽  
Safety Margin ◽  
Afferent Input ◽  
Metabolic Energy ◽  
Human Organism ◽  
Mechanical Resistance ◽  
As Doping ◽  
Gene And Protein Expression ◽  
Underlying Mechanisms ◽  
Biochemical Research

Human performance, defined by mechanical resistance and distance per time, includes human, task and environmental factors, all interrelated. It requires metabolic energy provided by anaerobic and aerobic metabolic energy sources. These sources have specific limitations in the capacity and rate to provide re-phosphorylation energy, which determines individual ratios of aerobic and anaerobic metabolic power and their sustainability. In healthy athletes, limits to provide and utilize metabolic energy are multifactorial, carefully matched and include a safety margin imposed in order to protect the integrity of the human organism under maximal effort. Perception of afferent input associated with effort leads to conscious or unconscious decisions to modulate or terminate performance; however, the underlying mechanisms of cerebral control are not fully understood. The idea to move borders of performance with the help of biochemicals is two millennia old. Biochemical findings resulted in highly effective substances widely used to increase performance in daily life, during preparation for sport events and during competition, but many of them must be considered as doping and therefore illegal. Supplements and food have ergogenic potential; however, numerous concepts are controversially discussed with respect to legality and particularly evidence in terms of usefulness and risks. The effect of evidence-based nutritional strategies on adaptations in terms of gene and protein expression that occur in skeletal muscle during and after exercise training sessions is widely unknown. Biochemical research is essential for better understanding of the basic mechanisms causing fatigue and the regulation of the dynamic adaptation to physical and mental training.

A Quasi-Static Model for Studying Physical Interaction Between a Soft Robotic Digit and a Human Finger

2018 ◽  
Author(s):  
Mahdi Haghshenas-Jaryani ◽  
Muthu B. J. Wijesundara
Keyword(s):  
Human Performance ◽  
Theoretical Models ◽  
Element Model ◽  
Human Robot Interaction ◽  
Physical Interaction ◽  
Robotic Hand ◽  
Robot Interaction ◽  
Interaction Forces ◽  
Comparison Of The Results ◽  
Human Finger

This paper presents the development of a framework based on a quasi-statics concept for modeling and analyzing the physical human-robot interaction in soft robotic hand exoskeletons used for rehabilitation and human performance augmentation. This framework provides both forward and inverse quasi-static formulations for the interaction between a soft robotic digit and a human finger which can be used for the calculation of angular motions, interaction forces, actuation torques, and stiffness at human joints. This is achieved by decoupling the dynamics of the soft robotic digit and the human finger with similar interaction forces acting on both sides. The presented theoretical models were validated by a series of numerical simulations based on a finite element model which replicates similar human-robot interaction. The comparison of the results obtained for the angular motion, interaction forces, and the estimated stiffness at the joints indicates the accuracy and effectiveness of the quasi-static models for predicting the human-robot interaction.

The Human-Machine: Possibilities for Expression in Robotic Dance

2018 ◽  
Author(s):  
Hannah M. Brown
Keyword(s):  
Performing Arts ◽  
Human Performance ◽  
Installation Art ◽  
Scientific Field ◽  
Point Of View ◽  
Human Beings ◽  
The Arts ◽  
Art Works ◽  
Social Applications ◽  
Insight Into

Robots have been a source of both intrigue and anxiety for artists and a lively apparatus for study by scientific researchers for several decades. Though many people view robots as being cold, unemotional, and frightening, there is a growing field in robotics specifically focused on social applications including therapy, elder care, and the arts. Robots have been utilized extensively in installation art works and sculpture, but the performing arts have been somewhat more resistant to them. Machines which have all the technical abilities to perform tasks, such as playing an instrument or executing choreography without fatiguing or making errors, can be threatening to human performers who have honed these abilities and rely upon them for creative expression and their livelihoods. By synthesizing studies in the scientific field of social robotics, philosophical insight into technology and the arts, and case studies of robots used in dance and other art forms, I seek to provide an alternative point of view of robotic integration into performance. Robots do not need to act only as avatars of human beings, they can be effectively utilized in dance to expand upon the capabilities of the human body, act as automatic ‘puppets’ for choreography, integrate into human performance, and be ‘autonomous’ performers in their own right. Robot dancers do not inherently replace or devalue human artists; instead, they can provide complex insight into the understanding of human bodies, emotions, and technology.

Design, Build, and Test of a Permanently Implanted Prosthetic Hand

2002 ◽  
Author(s):  
Matthew Williams ◽  
Wayne Walter
Keyword(s):  
Range Of Motion ◽  
Grip Force ◽  
Point Of View ◽  
Neural Interface ◽  
Normal Operation ◽  
Human Model ◽  
Prosthetic Hand ◽  
Robotic Hand ◽  
Laminin 5 ◽  
Implant Length

The feasibility of a permanently implanted prosthetic hand was evaluated from both an internal biocompatibility and exterior mechanics point of view. A literature review of the issues involved in permanent implantation of a percutanious device was performed in the areas of bone interaction and fixation and neural interface control. A theoretical implant was designed for a 90th percentile male, using a HA-G-Ti composite material to provide a permanent base to which the hand could attach. Using a radial implant length of 1.87 inches and an ulna implant length of 1.32 inches, the simulated implant could withstand a push out force of 10.260 pounds. Using nerve guidance channels and microelectrode arrays, a Regenerative Neural Interface was postulated to control the implant. The use of Laminin-5 was suggested as a method of preventing the lack of wound closure observed in percutanious devices. The exterior portion of a permanent artificial hand was analyzed by the construction of a robotic hand optimized for weight, size, grip force and wrist torque, power consumption and range of motion. Using a novel dual drive system, each finger was equipped with both joint position servos as well as a tendon. Fine grip shape was formed using the servos, while the tendon was pulled taunt when grasping an object. Control of the prosthetic hand was performed using a distributed network of micro-controllers. Each finger’s behavior was governed by a master/slave system where input from a control glove was processed by a master controller with joint servo and tendon instructions passed to lower-level controllers for management of hand actuators. The final weight of the prototype was 3.85 pounds and was approximately 25% larger than the 90th percentile male hand it was based on. Grip force was between 1.25 and 2 pounds per finger, depending on amount of finger flexion with a wrist lifting torque of 1.2 pounds at the center of the palm. The device had an average current draw of 3 amps in both normal operation and tight grasping. Range of motion was similar to that of the human model. Overall feasibility of the device is examined and factors involved in industrial implementation are discussed.

A comparison of the effects of 1-benzylpiperazine and dexamphetamine on human performance tests

1973 ◽  
Vol 6 (3) ◽  
pp. 163-169 ◽  
Author(s):  
C. Bye ◽  
A. D. Munro-Faure ◽  
A. W. Peck ◽  
P. A. Young
Keyword(s):  
Human Performance ◽  
Performance Tests

Importance of Cutaneous Feedback in Maintaining a Secure Grip During Manipulation of Hand-Held Objects

2003 ◽  
Vol 89 (2) ◽  
pp. 665-671 ◽  
Author(s):  
Anne-Sophie Augurelle ◽  
Allan M. Smith ◽  
Thierry Lejeune ◽  
Jean-Louis Thonnard
Keyword(s):  
Internal Model ◽  
Grip Force ◽  
Tangential Force ◽  
Safety Margin ◽  
Background Level ◽  
Load Force ◽  
Initial Contact ◽  
Phase Lag ◽  
Cutaneous Sensation ◽  
Hold Period

Previous research has shown that grip and load forces are modulated simultaneously during manipulation of a hand-held object. This close temporal coupling suggested that both forces are controlled by an internal model within the CNS that predicts the changes in tangential force on the fingers. The objective of the present study was to examine how the internal model would compensate for the loss of cutaneous sensation through local anesthesia of the index and thumb. Ten healthy adult subjects (5 men and 5 women aged 20–57 yr) were asked to grasp, lift, and hold stationary, a 250 g object for 20 s. Next, the subjects were asked to perform vertical oscillatory movements over a distance of 20 cm at a rate of 1.0 Hz for 30 s. Eleven trials were performed with intact sensation, and 11 trials after a local ring-block anesthesia of the index and thumb with bupivacain (5 mg/ml). During static holding, loss of cutaneous sensation produced a significant increase in the safety margin. However, the grip force declined significantly over the 20-s static hold period. During oscillatory arm movements, grip and load forces were continuously modulated together in a predictive manner as suggested by Flanagan and Wing. Again, the grip force declined over the 30-s movement, and 7/10 subjects dropped the object at least once. With intact sensation, the object was never dropped; but with the fingers anesthetized, it was dropped on 36% of the trials, and a significant slip occurred on a further 12%. The mean correlation between the grip and load forces for all subjects deteriorated from 0.71 with intact sensation to 0.48 after digital anesthesia. However, a cross-correlation calculated between the grip and load forces indicated that the phase lag was approximately zero both with and without digital anesthesia. Taken together, the data from the present study suggest that cutaneous afferents are required for setting and maintaining the background level of the grip force in addition to their phasic slip-detection function and their role in adapting the grip force/load force ratio to the friction on initial contact with an object. Finally, at a more theoretical level, they correct and maintain an internal model of the physical properties of hand-held objects.

Grasp force optimization in the design of an underactuated robotic hand

2007 ◽  
Author(s):  
Jasper Schuurmans ◽  
Richard Q van der Linde ◽  
Dick H Plettenburg ◽  
Frans CT van der Helm
Keyword(s):  
Robotic Hand ◽  
Force Optimization ◽  
Grasp Force

Applying Clockwise and Counterclockwise Torque Directions in Pinch Grips: A Descriptive Study

2013 ◽  
Vol 465-466 ◽  
pp. 1170-1174 ◽  
Author(s):  
Poh Kiat Ng ◽  
Ka Xuan Chai ◽  
Shiong Lung Leh ◽  
Meng Chauw Bee ◽  
Qiao Hui Boon ◽  
...  
Keyword(s):  
Manufacturing Industry ◽  
Grip Force ◽  
Human Performance ◽  
Descriptive Study ◽  
Manufacturing Firm ◽  
Hand Tool

Hand and finger-related injuries are increasingly common in the manufacturing industry. In relation to this, researchers have conducted various studies and found that a clockwise torque can produce a greater grip force than a counterclockwise torque direction, hence improving the grip control and exertion of an individual. However, there appears to be limited studies that explore this theory in the circumstances of pinch grips. Thus, the aim of this study is to explore the effects of different torque directions on the pinch grips. 6 prototype industrial screw knobs were designed, produced and evaluated by surveying 160 workers from a manufacturing firm. The results show that although the sizes are different, the effort to turn the knobs with a counterclockwise torque direction is still greater than the effort with a clockwise torque direction, which can technically mean that the pinch exertion in a clockwise torque direction is relatively greater. Based on these findings, guidelines can be developed to further improve hand tool designs and the capacity of torque exertions to potentially increase human performance and the effectiveness in tasks at the workplace.

Optimal grasp force for robotic grasping and in-hand manipulation with impedance control

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Xiaoqing Li ◽  
Ziyu Chen ◽  
Chao Ma
Keyword(s):  
Degrees Of Freedom ◽  
Impedance Control ◽  
Difficult Problem ◽  
Contact Forces ◽  
Design Parameters ◽  
Robotic Hand ◽  
Content Type ◽  
Cone Constraint ◽  
Grasp Force ◽  
Grasp Quality

Purpose The purpose of this paper is to achieve stable grasping and dexterous in-hand manipulation, the control of the multi-fingered robotic hand is a difficult problem as the hand has many degrees of freedom with various grasp configurations. Design/methodology/approach To achieve this goal, a novel object-level impedance control framework with optimized grasp force and grasp quality is proposed for multi-fingered robotic hand grasping and in-hand manipulation. The minimal grasp force optimization aims to achieve stable grasping satisfying friction cone constraint while keeping appropriate contact forces without damage to the object. With the optimized grasp quality function, optimal grasp quality can be obtained by dynamically sliding on the object from initial grasp configuration to final grasp configuration. By the proposed controller, the in-hand manipulation of the grasped object can be achieved with compliance to the environment force. The control performance of the closed-loop robotic system is guaranteed by appropriately choosing the design parameters as proved by a Lyapunove function. Findings Simulations are conducted to validate the efficiency and performance of the proposed controller with a three-fingered robotic hand. Originality/value This paper presents a method for robotic optimal grasping and in-hand manipulation with a compliant controller. It may inspire other related researchers and has great potential for practical usage in a widespread of robot applications.

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