scholarly journals Current Trends and Prospects in Compliant Continuum Robots: A Survey

Actuators ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 145
Author(s):  
Shiyao Li ◽  
Guangbo Hao
Keyword(s):  
Degrees Of Freedom ◽  
Variable Stiffness ◽  
Continuum Robots ◽  
Flexible Bodies ◽  
Advantages And Disadvantages ◽  
Elastic Bodies ◽  
Current Trends ◽  
Serial Robot ◽  
Drive Systems

Compliant continuum robots (CCRs) have slender and elastic bodies. Compared with a traditional serial robot, they have more degrees of freedom and can deform their flexible bodies to go through a constrained environment. In this paper, we classify CCRs according to basic transmission units. The merits, materials and potential drawbacks of each type of CCR are described. Drive systems depend on the basic transmission units significantly, and their advantages and disadvantages are reviewed and summarized. Variable stiffness and intrinsic sensing are desired characteristics of CCRs, and the methods of obtaining the two characteristics are discussed. Finally, we discuss the friction, buckling, singularity and twisting problems of CCRs, and emphasise the ways to reduce their effects, followed by several proposing perspectives, such as the collaborative CCRs.

scholarly journals General Construction and Classification of Manipulators for Underwater Vehicles

2018 ◽  
Vol 63 (2) ◽  
pp. 10-17
Author(s):  
Marek Dawidziuk ◽  
Adam Olejnik
Keyword(s):  
Degrees Of Freedom ◽  
Underwater Vehicle ◽  
Underwater Vehicles ◽  
General Construction ◽  
Advantages And Disadvantages ◽  
End Effectors ◽  
Materials Used ◽  
Drive Systems

Abstract The article presents the general construction of an underwater vehicle manipulator along with a discussion of the materials used in their construction. The types of drive systems used by the manipulator have been characterised, distinguishing their advantages and disadvantages. The functions of the manipulator are specified in relation to the activities performed by it. Moreover, the paper discusses the manipulator's degrees of freedom with the specification of the formula for their calculation. The basic types of end effectors are presented as well as an outline of the classification of manipulators in relation to the tasks carried out.

scholarly journals Designing of Drive Systems in the Aspect of the Desired Spectrum of Operation

Energies ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2562
Author(s):  
Tomasz Dzitkowski ◽  
Andrzej Dymarek ◽  
Jerzy Margielewicz ◽  
Damian Gąska ◽  
Lukasz Orzech ◽  
...  
Keyword(s):  
Degrees Of Freedom ◽  
Dynamic Properties ◽  
Dynamic Parameters ◽  
Synthesis Algorithm ◽  
Moments Of Inertia ◽  
Driving System ◽  
Six Degrees Of Freedom ◽  
Resonance Frequencies ◽  
Drive Systems ◽  
Power Component

A method for selecting dynamic parameters and structures of drive systems using the synthesis algorithm is presented. The dynamic parameters of the system with six degrees of freedom, consisting of a power component (motor) and a two-speed gearbox, were determined, based on a formalized methodology. The required gearbox is to work in specific resonance zones, i.e., meet the required dynamic properties such as the required resonance frequencies. In the result of the tests, a series of parameters of the drive system, defining the required dynamic properties such as the resonance and anti-resonance frequencies were recorded. Mass moments of inertia of the wheels and elastic components, contained in the required structure of the driving system, were determined for the selected parameters obtained during the synthesis.

scholarly journals Biologically Inspired Design and Development of a Variable Stiffness Powered Ankle-Foot Prosthesis

2019 ◽  
Vol 11 (4) ◽  
Author(s):  
Alexander Agboola-Dobson ◽  
Guowu Wei ◽  
Lei Ren
Keyword(s):  
Lower Limb ◽  
Degrees Of Freedom ◽  
Sagittal Plane ◽  
Frontal Plane ◽  
Variable Stiffness ◽  
Plane Motion ◽  
Biologically Inspired ◽  
Passive Rotation ◽  
Ground Conditions ◽  
Biologically Inspired Design

Recent advancements in powered lower limb prostheses have appeased several difficulties faced by lower limb amputees by using a series-elastic actuator (SEA) to provide powered sagittal plane flexion. Unfortunately, these devices are currently unable to provide both powered sagittal plane flexion and two degrees of freedom (2-DOF) at the ankle, removing the ankle’s capacity to invert/evert, thus severely limiting terrain adaption capabilities and user comfort. The developed 2-DOF ankle system in this paper allows both powered flexion in the sagittal plane and passive rotation in the frontal plane; an SEA emulates the biomechanics of the gastrocnemius and Achilles tendon for flexion while a novel universal-joint system provides the 2-DOF. Several studies were undertaken to thoroughly characterize the capabilities of the device. Under both level- and sloped-ground conditions, ankle torque and kinematic data were obtained by using force-plates and a motion capture system. The device was found to be fully capable of providing powered sagittal plane motion and torque very close to that of a biological ankle while simultaneously being able to adapt to sloped terrain by undergoing frontal plane motion, thus providing 2-DOF at the ankle. These findings demonstrate that the device presented in this paper poses radical improvements to powered prosthetic ankle-foot device (PAFD) design.

Systematic Synthesis and Applications of Novel Multi-Degree-of-Freedom Differential Systems

1992 ◽  
Author(s):  
Sridhar Kota ◽  
Srinivas Bidare
Keyword(s):  
Degrees Of Freedom ◽  
Building Blocks ◽  
Degree Of Freedom ◽  
Differential Systems ◽  
Practical Applications ◽  
Epicyclic Gear ◽  
Differential Mechanism ◽  
Long Time ◽  
Gear Trains ◽  
Drive Systems

Abstract A two-degree-of-freedom differential system has been known for a long time and is widely used in automotive drive systems. Although higher degree-of-freedom differential systems have been developed in the past based on the well-known standard differential, the number of degrees-of-freedom has been severely restricted to 2n. Using a standard differential mechanism and simple epicyclic gear trains as differential building blocks, we have developed novel whiffletree-like differential systems that can provide n-degrees of freedom, where n is any integer greater than two. Symbolic notation for representing these novel differentials is also presented. This paper presents a systematic method of deriving multi-degree-of-freedom differential systems, a three and four output differential systems and some of their practical applications.

scholarly journals Determination of the classification-based tactics for treating meniscus lesions in children

2020 ◽  
Vol 24 (3) ◽  
pp. 194-197
Author(s):  
Daria D. Pavlova ◽  
S. M. Sharkov ◽  
M. A. Petrov ◽  
E. M. Krainova
Keyword(s):  
Modern Literature ◽  
Advantages And Disadvantages ◽  
New Approaches ◽  
Current Trends ◽  
Meniscus Lesions ◽  
The Given

New approaches to the treatment of meniscus lesions is currently a hot topic in traumatology and orthopedics. Meniscus resection and suture issues are widely discussed and studied in modern literature. Current trends in the care of meniscus pathologies are aimed to restore the structure of the damaged segment by stitching it using various techniques. A classification scale plays an important role in the treatment of any disease because it allows to uniformly describe the main criteria of pathology and to define a treatment tactics. The given review describes modern classifications of meniscus lesions with their advantages and disadvantages.

scholarly journals Development of a Spherical Positioning Robot and Neuro-Navigation System for Precise and Repetitive Non-Invasive Brain Stimulation

2019 ◽  
Vol 9 (21) ◽  
pp. 4561
Author(s):  
Shin ◽  
Ryu ◽  
Cho ◽  
Yang ◽  
Lee
Keyword(s):  
Brain Stimulation ◽  
Navigation System ◽  
Visual Servoing ◽  
Degrees Of Freedom ◽  
Human Head ◽  
Non Invasive ◽  
Serial Robot ◽  
The Subject ◽  
6 Degrees Of Freedom ◽  
Spherical Mechanism

Although non-invasive brain stimulation techniques do not involve surgical procedures, the challenge remains in correctly locating the stimulator from outside the head. There is a limit to which one can manually and precisely position and orient the stimulator or repeatedly move the stimulator around the same position. Therefore, in this study, we developed a serial robot with 6 degrees-of-freedom to move the stimulator and a neuro-navigation system to determine the stimulus point from looking at the shape of the subject’s brain. The proposed robot applied a spherical mechanism while considering the safety of the subject, and the workspace of the robot was designed considering the shape of the human head. Position-based visual servoing was applied to compensate for unexpected movements during subject stimulation. We also developed a neuro-navigation system that allows us visually to check the focus of the stimulator and the human brain at the same time and command the robot to the desired point. To verify the system performance, we first performed repeatability and motion compensation experiments of the robot and then evaluated the repeated biosignal response experiments through transcranial magnetic stimulation, a representative technique of non-invasive brain stimulation.

Current Trends in Digital Learning and Innovation

2020 ◽  
pp. 1-16
Author(s):  
Nidhish Francis ◽  
Abishek B. Santhakumar
Keyword(s):  
Distance Education ◽  
Learning Experience ◽  
Learning Activities ◽  
Digital Tools ◽  
Digital Learning ◽  
Face To Face ◽  
Advantages And Disadvantages ◽  
Current Trends ◽  
Face To Face Learning

Digital learning has gained a lot of attention over the recent years and is increasingly being utilised as a substitute for both distance education and face-to face learning activities. This chapter initially defines and briefly discusses the advantages and disadvantages of digital learning. With the advancement in technology, there are various digital tools that are now available to enhance the effectiveness of digital learning experience, and some of the major innovative digital tools are detailed in the chapter.

An Energy-Based Load Distribution Approach for the Application of Gear Mesh Stiffness on Elastic Bodies

2019 ◽  
Vol 141 (9) ◽  
Author(s):  
Faysal Andary ◽  
Joerg Berroth ◽  
Georg Jacobs
Keyword(s):  
Degrees Of Freedom ◽  
Design Method ◽  
Mesh Stiffness ◽  
Gear Teeth ◽  
Gear Mesh ◽  
Elastic Bodies ◽  
Single Tooth ◽  
Traditional Approaches ◽  
Energy Based Design ◽  
Gear Mesh Stiffness

This study introduces a new potential energy-based design method for simplifying elastic gear bodies in low- to mid-range frequency applications by bridging over the gear teeth with external stiffness elements. The advantage of the introduced method over more traditional approaches, which are either based on rigid gears or on replacing the teeth, is that the complex gear body and its dynamic behavior are preserved, albeit with fewer degrees of freedom. The method is demonstrated on a gear by replacing a single tooth under load and then validated numerically against a typical flexible gear model. The simulation results show good accuracy within the chosen frequency range and with a clear reduction in calculation time compared to the unreduced model. Furthermore, the extension and optimization potential of the results is discussed.

Analytic Formulation for Kinematics, Statics, and Shape Restoration of Multibackbone Continuum Robots Via Elliptic Integrals

2009 ◽  
Vol 2 (1) ◽  
Author(s):  
Kai Xu ◽  
Nabil Simaan
Keyword(s):  
Degrees Of Freedom ◽  
Elliptic Integrals ◽  
Continuum Robots ◽  
Actuation Redundancy ◽  
Circular Shape ◽  
Shape Restoration ◽  
Simulation Results ◽  
Tip Position ◽  
Geometric Compatibility ◽  
External Loads

This paper presents a novel and unified analytic formulation for kinematics, statics, and shape restoration of multiple-backbone continuum robots. These robots achieve actuation redundancy by independently pulling and pushing three backbones to carry out a bending motion of two-degrees-of-freedom (DoF). A solution framework based on constraints of geometric compatibility and static equilibrium is derived using elliptic integrals. This framework allows the investigation of the effects of different external loads and actuation redundancy resolutions on the shape variations in these continuum robots. The simulation and experimental validation results show that these continuum robots bend into an exact circular shape for one particular actuation resolution. This provides a proof to the ubiquitously accepted circular-shape assumption in deriving kinematics for continuum robots. The shape variations due to various actuation redundancy resolutions are also investigated. The simulation results show that these continuum robots have the ability to redistribute loads among their backbones without introducing significant shape variations. A strategy for partially restoring the shape of the externally loaded continuum robots is proposed. The simulation results show that either the tip orientation or the tip position can be successfully restored.

A Regression Approach to Generate Aircraft Predictor Information

1977 ◽  
Vol 19 (6) ◽  
pp. 549-555 ◽  
Author(s):  
Paul D. Gallaher ◽  
Roger A. Hunt ◽  
Robert C. Williges
Keyword(s):  
Degrees Of Freedom ◽  
Fast Time ◽  
Control Input ◽  
Least Squares Regression ◽  
Time Model ◽  
Six Degrees Of Freedom ◽  
Advantages And Disadvantages ◽  
Alternative Approach ◽  
Regression Approach ◽  
Aircraft Motion

A contact analog aircraft display is described in which an airplane-like predictor symbol depicts future airplane position and orientation. The standard method for obtaining the predictor information is to use a complete, fast-time model of the controlled vehicle. An alternative approach is presented in this paper in which least-squares regression approximations for each of the six degrees of freedom of aircraft motion were calculated. Thirteen predictor variables representing changes in positions and rates of change of positions were selected as parameters for these prediction equations. The accuracy of the regression approach is evaluated both at various prediction times and at various control input durations. The advantages and disadvantages of such a regression procedure for generating predictor symbols are discussed.

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