scholarly journals The Optimal Adaptive-Based Neurofuzzy Control of the 3-DOF Musculoskeletal System of Human Arm in a 2D Plane

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Amin Valizadeh ◽  
Ali Akbar Akbari
Keyword(s):  
Rehabilitation Robotics ◽  
Control Technique ◽  
Adaptive Critic ◽  
Correct Operation ◽  
Optimum Trajectory ◽  
Natural Motion ◽  
Neurofuzzy Control ◽  
Human Arm ◽  
Optimized Model

Each individual performs different daily activities such as reaching and lifting with his hand that shows the important role of robots designed to estimate the position of the objects or the muscle forces. Understanding the body’s musculoskeletal system’s learning control mechanism can lead us to develop a robust control technique that can be applied to rehabilitation robotics. The musculoskeletal model of the human arm used in this study is a 3-link robot coupled with 6 muscles which a neurofuzzy controller of TSK type along multicritic agents is used for training and learning fuzzy rules. The adaptive critic agents based on reinforcement learning oversees the controller’s parameters and avoids overtraining. The simulation results show that in both states of with/without optimization, the controller can well track the desired trajectory smoothly and with acceptable accuracy. The magnitude of forces in the optimized model is significantly lower, implying the controller’s correct operation. Also, links take the same trajectory with a lower overall displacement than that of the nonoptimized mode, which is consistent with the hand’s natural motion, seeking the most optimum trajectory.

Dynamics and Control of Robotic Systems Worn by Humans

1991 ◽  
Vol 113 (3) ◽  
pp. 379-387 ◽  
Author(s):  
H. Kazerooni ◽  
S. L. Mahoney
Keyword(s):  
Material Handling ◽  
Robotic Systems ◽  
Control Technique ◽  
Load Force ◽  
Two Dimensional ◽  
Direct Drive ◽  
Human Arm ◽  
Dynamics And Control ◽  
Physical Interfaces ◽  
And Control

This article describes the dynamics, control, and stability of extenders, robotic systems worn by humans for material handling tasks. Extenders are defined as robot manipulators which extend (i.e., increase) the strength of the human arm in load maneuvering tasks, while the human maintains control of the task. Part of the extender motion is caused by physical power from the human; the rest of the extender motion results from force signals measured at the physical interfaces between the human and the extender, and the load and the extender. Therefore, the human wearing the extender exchanges both power and information signals with the extender. The control technique described here lets the designer define an arbitrary relationship between the human force and the load force. A set of experiments on a two-dimensional non-direct-drive extender were done to verify the control theory.

A gesture-based telemanipulation control for a robotic arm with biofeedback-based grasp

2017 ◽  
Vol 44 (5) ◽  
pp. 575-587 ◽  
Author(s):  
Yassine Bouteraa ◽  
Ismail Ben Abdallah
Keyword(s):  
Real Time ◽  
Force Feedback ◽  
Emg Biofeedback ◽  
Control Technique ◽  
Robotic Arm ◽  
Effective Control ◽  
Content Type ◽  
Human Arm ◽  
Gesture Control ◽  
Posture Recognition

Purpose The idea is to exploit the natural stability and performance of the human arm during movement, execution and manipulation. The purpose of this paper is to remotely control a handling robot with a low cost but effective solution. Design/methodology/approach The developed approach is based on three different techniques to be able to ensure movement and pattern recognition of the operator’s arm as well as an effective control of the object manipulation task. In the first, the methodology works on the kinect-based gesture recognition of the operator’s arm. However, using only the vision-based approach for hand posture recognition cannot be the suitable solution mainly when the hand is occluded in such situations. The proposed approach supports the vision-based system by an electromyography (EMG)-based biofeedback system for posture recognition. Moreover, the novel approach appends to the vision system-based gesture control and the EMG-based posture recognition a force feedback to inform operator of the real grasping state. Findings The main finding is to have a robust method able to gesture-based control a robot manipulator during movement, manipulation and grasp. The proposed approach uses a real-time gesture control technique based on a kinect camera that can provide the exact position of each joint of the operator’s arm. The developed solution integrates also an EMG biofeedback and a force feedback in its control loop. In addition, the authors propose a high-friendly human-machine-interface (HMI) which allows user to control in real time a robotic arm. Robust trajectory tracking challenge has been solved by the implementation of the sliding mode controller. A fuzzy logic controller has been implemented to manage the grasping task based on the EMG signal. Experimental results have shown a high efficiency of the proposed approach. Research limitations/implications There are some constraints when applying the proposed method, such as the sensibility of the desired trajectory generated by the human arm even in case of random and unwanted movements. This can damage the manipulated object during the teleoperation process. In this case, such operator skills are highly required. Practical implications The developed control approach can be used in all applications, which require real-time human robot cooperation. Originality/value The main advantage of the developed approach is that it benefits at the same time of three various techniques: EMG biofeedback, vision-based system and haptic feedback. In such situation, using only vision-based approaches mainly for the hand postures recognition is not effective. Therefore, the recognition should be based on the biofeedback naturally generated by the muscles responsible of each posture. Moreover, the use of force sensor in closed-loop control scheme without operator intervention is ineffective in the special cases in which the manipulated objects vary in a wide range with different metallic characteristics. Therefore, the use of human-in-the-loop technique can imitate the natural human postures in the grasping task.

scholarly journals The importance of sound velocity determination for bathymetric survey

ACTA IMEKO ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 46
Author(s):  
Pier Paolo Amoroso ◽  
Claudio Parente
Keyword(s):  
Sound Velocity ◽  
Acoustic Waves ◽  
Physical Parameters ◽  
Ligurian Sea ◽  
Data Set ◽  
Correct Operation ◽  
Column Temperature ◽  
Bathymetric Survey ◽  
Depth Measurement

Bathymetric surveys are carried out whenever there is a need to know the exact morphological trend of the seabed. For a correct operation of the echo sounder, which uses the principle of acoustic waves to scan the bottom and determine the depth, it is important to accurately determine the sound velocity in water, as it varies according to specific parameters (Density, Temperature, and Pressure). In this work, we want to analyse the role of sound velocity determination in bathymetric survey and its impact on the accuracy of depth measurement. The experiments are conducted on data set provided by “Istituto Idrografico della Marina Militare Italiana” (IIM), the official Hydrographic Office for Italy, and acquired in the Ligurian sea. In our case, the formulas of Chen & Millero (UNESCO), Medwin, and Mackenzie were applied. The introduction of errors on chemical-physical parameters of the water column (Temperature, Pressure, Salinity, Depth) simulating inaccurate measurements, produces considerable impacts on sound velocity determination and subsequently a decrease of the depth value accuracy. The results remark the need to use precise probes and accurate procedures to obtain reliable depth data.

On the role of stiffness and synchronization in human–robot handshaking

2020 ◽  
Vol 39 (14) ◽  
pp. 1796-1811 ◽  
Author(s):  
Domenico Mura ◽  
Espen Knoop ◽  
Manuel G Catalano ◽  
Giorgio Grioli ◽  
Moritz Bächer ◽  
...  
Keyword(s):  
Personality Traits ◽  
Impedance Control ◽  
Robotic Arm ◽  
Robot Arm ◽  
Passive Behavior ◽  
Arm Motions ◽  
Human Arm ◽  
Human Likeness

This article presents a system for soft human–robot handshaking, using a soft robot hand in conjunction with a lightweight and impedance-controlled robot arm. Using this system, we study how different factors influence the perceived naturalness, and give the robot different personality traits. Capitalizing on recent findings regarding handshake grasp force regulation, and on studies of the impedance control of the human arm, we investigate the role of arm stiffness as well as the kinesthetic synchronization of human and robot arm motions during the handshake. The system is implemented using a lightweight anthropomorphic arm, with a Pisa/IIT Softhand wearing a sensorized silicone glove as the end-effector. The robotic arm is impedance-controlled, and its stiffness changes according to different laws under investigation. An internal observer is employed to synchronize the human and robot arm motions. Thus, we simulate both active and passive behavior of the robotic arm during the interaction. Using the system, studies are conducted where 20 participants are asked to interact with the robot, and then rate the perceived quality of the interaction using Likert scales. Our results show that the control of the robotic arm kinesthetic behavior does have an effect on the interaction with the robot, in term of its perceived personality traits, responsiveness, and human-likeness. Our results pave the way towards robotic systems that are capable of performing human–robot interactions in a more human-like manner, and with personality.

scholarly journals Human arm weight compensation in rehabilitation robotics: efficacy of three distinct methods

2020 ◽  
Vol 17 (1) ◽  
Author(s):  
Fabian Just ◽  
Özhan Özen ◽  
Stefano Tortora ◽  
Verena Klamroth-Marganska ◽  
Robert Riener ◽  
...  
Keyword(s):  
Rehabilitation Robotics ◽  
Human Arm ◽  
Weight Compensation

Movement-related phasic muscle activation. I. Relations with temporal profile of movement

1990 ◽  
Vol 63 (3) ◽  
pp. 455-464 ◽  
Author(s):  
S. H. Brown ◽  
J. D. Cooke
Keyword(s):  
Muscle Activation ◽  
Temporal Structure ◽  
Temporal Properties ◽  
Human Arm ◽  
Acceleration And Deceleration ◽  
Simple Scaling ◽  
Temporal Structures ◽  
Movement Parameters ◽  
Temporal Profiles

1. The role of phasic muscle activation in determining the temporal properties of human arm movements was studied. The experiments show that subjects can modulate the triphasic electromyographic (EMG) pattern to produce movements of varied temporal structures. 2. Subjects performed horizontal forearm movements in which they varied movement accelerations and decelerations. All movements were of the same amplitude, duration, and peak velocity. A phase-plane (velocity vs. position) template of the desired movement was presented to the subject, who had to reproduce the template by appropriate movement of the forearm. 3. The ratio of the durations of acceleration to deceleration (termed the symmetry ratio, SR) was used as a measure of the temporal structure of the movements. Movements with SRs ranging from 0.4 (short acceleration-long deceleration) to 2.0 (long acceleration-short deceleration) were studied. 4. Subjects modulated the components of the triphasic EMG pattern to produce movements with different temporal profiles. As the SR was increased (increasing acceleration duration-decreasing deceleration duration), the following changes occurred: 1) the duration of the initial agonist burst (AG1) increased while its magnitude decreased; 2) the antagonist burst (ANT1) was progressively delayed relative to movement onset. ANT1 magnitude increased while its duration remained constant; and 3) the magnitude of the second agonist burst (AG2) increased and its duration decreased. 5. The triphasic EMG pattern can be modified to produce movements whose velocity profiles are not the same under simple scaling of duration or magnitude. It is concluded that previously described relations between components of the triphasic EMG pattern and movement parameters, such as amplitude, speed, and duration, are secondary to associated changes in their acceleration and deceleration characteristics.

Role of reference materials for the realization of physicochemical properties. Past, present, and future

2000 ◽  
Vol 72 (10) ◽  
pp. 1809-1818 ◽  
Author(s):  
Kenneth N. Marsh
Keyword(s):  
Physicochemical Properties ◽  
Reference Materials ◽  
State Of The Art ◽  
National Standards ◽  
Correct Operation ◽  
Many Instruments ◽  
Ready Availability ◽  
Commercial Sources

Reference materials have long been considered essential for both calibration and checking the correct operation of equipment used for the determination of physicochemical properties. Up until the 1970s, the maintenance of pure reference materials and the means to verify their properties through measurement using state-of-the-art equipment was the prerogative of many national standards laboratories. Over the last 30 years, many of the standards laboratories have either limited or eliminated their activity in maintaining both reference materials and state-of-the-art measuring equipment. One reason is the ready availability of high-purity materials from commercial sources and the ease with which one can now determine purity. A second reason is the ready availability of instruments to measure digitally fundamental quantities such as time, temperature, length, frequency, and voltage accurately has enabled chemical calibration using reference materials to be replaced in many instruments by electrical calibration. At the same time, digitization has enabled the computerization of the whole measurement process. Such automated devices, if not checked with reference materials, can give highly reproducible results but have large systematic errors, leading to poor values. The role of physicochemical reference materials in the past and the present will be outlined, and their status in the future will be explored.

scholarly journals The Control of Natural Motion in Mechanical Systems

1991 ◽  
Vol 113 (4) ◽  
pp. 547-551 ◽  
Author(s):  
D. E. Koditschek
Keyword(s):  
Cost Function ◽  
Mechanical System ◽  
Mechanical Systems ◽  
Machine Design ◽  
Simple Extension ◽  
Natural Motion ◽  
Navigation Function ◽  
The Many ◽  
Autonomous Machine

This paper concerns a simple extension of Lord Kelvin’s observation that energy decays in a dissipative mechanical system. The global limit behavior of such systems can be made essentially equivalent to that of much simpler gradient systems by the introduction of a “navigation function” in the role of an artificial field. This recourse to the mechanical system’s natural motion helps transform the open-ended problem of autonomous machine design into the more structured problem of finding an appropriate “cost function” in the many situations that the goal may be encoded as a setpoint problem with configuration constraints.

scholarly journals Optimized Model of Experimental Teaching Plan Based on Improved by Clear Theory

2021 ◽  
Vol 275 ◽  
pp. 03031
Author(s):  
Xinfeng Xia ◽  
Weiwei Lv
Keyword(s):  
Fuzzy Theory ◽  
Triangular Fuzzy Number ◽  
University Teaching ◽  
Advantages And Disadvantages ◽  
Experimental Teaching ◽  
The Status ◽  
Optimized Model ◽  
Institute Of Technology ◽  
Beijing Institute

With the continuous advancement of the “Double First-Class” university plan, the status and role of experimental teaching in university teaching has become increasingly prominent. Chosen as one of the “Double First-Class” universities, Beijing Institute of Technology has also carried out a series of experimental teaching reforms, and has produced different reform plans in the laboratory of “Geometrical Accuracy Specifications”, School of Mechanical Engineering. In order to optimize different schemes, the experimental teaching center innovatively proposes an optimized model improved by clear theory. This is a decisionmaking method based on triangular fuzzy number and clear theory. Utilizing the fuzzy theory and clear theory, the advantages and disadvantages of the alternatives can be ranked more accurately, the influence of subjective and objective factors in the process of selecting the alternatives can be reduced, and new methods can be provided for decision makers to choose the best alternative.

scholarly journals Can Vibrational Playbacks Disrupt Mating or Influence Other Relevant Behaviours in Bactericera cockerelli (Triozidae: Hemiptera)?

Insects ◽  
2020 ◽  
Vol 11 (5) ◽  
pp. 299
Author(s):  
Sabina Avosani ◽  
Thomas E. Sullivan ◽  
Marco Ciolli ◽  
Valerio Mazzoni ◽  
David Maxwell Suckling
Keyword(s):  
Mating Success ◽  
Host Plants ◽  
Sexual Communication ◽  
Control Technique ◽  
Bactericera Cockerelli ◽  
Mate Finding ◽  
Vibrational Signals ◽  
Important Pest ◽  
Management Techniques

Behaviours of insects can be manipulated by transmitting vibrational signals to host plants in order to develop pest management techniques. Bactericera cockerelli is an important pest and uses vibrations for mate-finding. In order to design a future control strategy for B. cockerelli, three different bioassays were performed to assess whether vibrational signals could affect relevant behaviours. Single males or pairs were treated with a female playback in test 1 and 2, respectively. In test 3, mixed sex groups received either different disturbance playbacks. The use of a female playback significantly reduced the mating success of males, since they were attracted towards the source of the stimulus. Moreover, test 2 revealed that B. cockerelli females are competitive, since they used their signals to cover the playback and to duet with males, while in test 3, the disturbance playback, consisting of broadband noises significantly reduced male signalling activity. However, none of the treatments of test 3 negatively affected the mating success of males, which tended to mount the other conspecifics present on the same leaf. The role of vibrations in sexual communication and their potential application as control technique for B. cockerelli are discussed as well.

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