Robust simultaneous myoelectric control of multiple degrees of freedom in wrist-hand prostheses by real-time neuromusculoskeletal modeling

ABSTRACTTechnological advances in multi-articulated prosthetic hands have outpaced the methods available to amputees to intuitively control these devices. Amputees often cite difficulty of use as a key contributing factor for abandoning their prosthesis, creating a pressing need for improved control technology. A major challenge of traditional myoelectric control strategies using surface electromyography electrodes has been the difficulty in achieving intuitive and robust proportional control of multiple degrees of freedom. In this paper, we describe a new control method, proprioceptive sonomyographic control that overcomes several limitations of myoelectric control. In sonomyography, muscle mechanical deformation is sensed using ultrasound, as compared to electrical activation, and therefore the resulting control signals can directly control the position of the end effector. Compared to myoelectric control which controls the velocity of the end-effector device, sonomyographic control is more congruent with residual proprioception in the residual limb. We tested our approach with 5 upper-extremity amputees and able-bodied subjects using a virtual target achievement and holding task. Amputees and able-bodied participants demonstrated the ability to achieve positional control for 5 degrees of freedom with an hour of training. Our results demonstrate the potential of proprioceptive sonomyographic control for intuitive dexterous control of multiarticulated prostheses.

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Real-time monitoring of adaptive lenses with high tuning range and multiple degrees of freedom

Optics Letters ◽

10.1364/ol.45.000272 ◽

2020 ◽

Vol 45 (2) ◽

pp. 272

Author(s):

Wenjie Wang ◽

Katrin Philipp ◽

Nektarios Koukourakis ◽

Jürgen W. Czarske

Keyword(s):

Real Time ◽

Degrees Of Freedom ◽

Tuning Range ◽

Real Time Monitoring ◽

Multiple Degrees Of Freedom

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Based on a Microcontroller the Real-Time Control System Design of Manipulator of Multiple Degrees of Freedom

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.722.213 ◽

2014 ◽

Vol 722 ◽

pp. 213-216

Author(s):

Rui Yong Duan ◽

Ji Ling Yan

Keyword(s):

Control System ◽

Real Time ◽

Degrees Of Freedom ◽

Time Synchronization ◽

Synchronization Control ◽

Control System Design ◽

Real Time Control ◽

Multiple Degrees Of Freedom ◽

Time Control ◽

Wireless Transmitter

Manipulator of multiple degrees of freedom has been widely used in all kinds of rescue and exploring robots. This paper regard a kind of 6 DOF manipulator controller as the design object.The data acquisition for WDD35D4 sensors is carried by the C8051F020 microcontroller and sent through a wireless transmitter NRF905 after encrypted.Then the wireless transmitter NRF905 of the manipulator receives decryption. Through data processing and the steering gear adjustment, the angle of linear potentiometer corresponds to the angle of steering by 1-1. Then it drives the manipulator to work out and simulate the same motion of mechanical arm controller, and make real-time synchronization control.

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Design, Fabrication, and Testing of a Novel 3D 3-Fingered Electrothermal Microgripper with Multiple Degrees of Freedom

Micromachines ◽

10.3390/mi12040444 ◽

2021 ◽

Vol 12 (4) ◽

pp. 444

Author(s):

Guoning Si ◽

Liangying Sun ◽

Zhuo Zhang ◽

Xuping Zhang

Keyword(s):

Degrees Of Freedom ◽

Dynamic Properties ◽

Three Dimensional ◽

Polyimide Film ◽

Zebrafish Embryos ◽

Multiple Degrees Of Freedom ◽

Electrothermal Actuator ◽

3D Space ◽

Pick And Place

This paper presents the design, fabrication, and testing of a novel three-dimensional (3D) three-fingered electrothermal microgripper with multiple degrees of freedom (multi DOFs). Each finger of the microgripper is composed of a V-shaped electrothermal actuator providing one DOF, and a 3D U-shaped electrothermal actuator offering two DOFs in the plane perpendicular to the movement of the V-shaped actuator. As a result, each finger possesses 3D mobilities with three DOFs. Each beam of the actuators is heated externally with the polyimide film. The durability of the polyimide film is tested under different voltages. The static and dynamic properties of the finger are also tested. Experiments show that not only can the microgripper pick and place microobjects, such as micro balls and even highly deformable zebrafish embryos, but can also rotate them in 3D space.

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The emerging technology of biohybrid micro-robots: a review

Bio-Design and Manufacturing ◽

10.1007/s42242-021-00135-6 ◽

2021 ◽

Author(s):

Zening Lin ◽

Tao Jiang ◽

Jianzhong Shang

Keyword(s):

Self Assembly ◽

Degrees Of Freedom ◽

High Energy ◽

Living Cells ◽

Multiple Degrees Of Freedom ◽

The Past ◽

Great Prevalence ◽

Performance Decline ◽

High Energy Efficiency ◽

Living Tissues

Abstract In the past few decades, robotics research has witnessed an increasingly high interest in miniaturized, intelligent, and integrated robots. The imperative component of a robot is the actuator that determines its performance. Although traditional rigid drives such as motors and gas engines have shown great prevalence in most macroscale circumstances, the reduction of these drives to the millimeter or even lower scale results in a significant increase in manufacturing difficulty accompanied by a remarkable performance decline. Biohybrid robots driven by living cells can be a potential solution to overcome these drawbacks by benefiting from the intrinsic microscale self-assembly of living tissues and high energy efficiency, which, among other unprecedented properties, also feature flexibility, self-repair, and even multiple degrees of freedom. This paper systematically reviews the development of biohybrid robots. First, the development of biological flexible drivers is introduced while emphasizing on their advantages over traditional drivers. Second, up-to-date works regarding biohybrid robots are reviewed in detail from three aspects: biological driving sources, actuator materials, and structures with associated control methodologies. Finally, the potential future applications and major challenges of biohybrid robots are explored. Graphic abstract

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Integrated structured light architectures

Scientific Reports ◽

10.1038/s41598-020-80502-y ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Randy Lemons ◽

Wei Liu ◽

Josef C. Frisch ◽

Alan Fry ◽

Joseph Robinson ◽

...

Keyword(s):

Degrees Of Freedom ◽

Temporal Distribution ◽

Multiple Degrees Of Freedom ◽

Beam Combination ◽

Angular Momenta ◽

Field Control ◽

Topological States ◽

Spatio Temporal ◽

Temporal Field ◽

Structural Versatility

AbstractThe structural versatility of light underpins an outstanding collection of optical phenomena where both geometrical and topological states of light can dictate how matter will respond or display. Light possesses multiple degrees of freedom such as amplitude, and linear, spin angular, and orbital angular momenta, but the ability to adaptively engineer the spatio-temporal distribution of all these characteristics is primarily curtailed by technologies used to impose any desired structure to light. We demonstrate a laser architecture based on coherent beam combination offering integrated spatio-temporal field control and programmability, thereby presenting unique opportunities for generating light by design to exploit its topology.

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Observer-based robust integral of the sign of the error control of class I of underactuated mechanical systems: Theory and real-time experiments

Transactions of the Institute of Measurement and Control ◽

10.1177/01423312211031396 ◽

2021 ◽

pp. 014233122110313

Author(s):

Afef Hfaiedh ◽

Ahmed Chemori ◽

Afef Abdelkrim

Keyword(s):

Real Time ◽

Error Control ◽

Degrees Of Freedom ◽

Sliding Mode ◽

Mechanical Systems ◽

Class I ◽

Control Input ◽

Underactuated Mechanical Systems ◽

Control Scheme ◽

And Performance

In this paper, the control problem of a class I of underactuated mechanical systems (UMSs) is addressed. The considered class includes nonlinear UMSs with two degrees of freedom and one control input. Firstly, we propose the design of a robust integral of the sign of the error (RISE) control law, adequate for this special class. Based on a change of coordinates, the dynamics is transformed into a strict-feedback (SF) form. A Lyapunov-based technique is then employed to prove the asymptotic stability of the resulting closed-loop system. Numerical simulation results show the robustness and performance of the original RISE toward parametric uncertainties and disturbance rejection. A comparative study with a conventional sliding mode control reveals a significant robustness improvement with the proposed original RISE controller. However, in real-time experiments, the amplification of the measurement noise is a major problem. It has an impact on the behaviour of the motor and reduces the performance of the system. To deal with this issue, we propose to estimate the velocity using the robust Levant differentiator instead of the numerical derivative. Real-time experiments were performed on the testbed of the inertia wheel inverted pendulum to demonstrate the relevance of the proposed observer-based RISE control scheme. The obtained real-time experimental results and the obtained evaluation indices show clearly a better performance of the proposed observer-based RISE approach compared to the sliding mode and the original RISE controllers.

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