kinematic models
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Sensors ◽  
2021 ◽  
Vol 21 (23) ◽  
pp. 7884
Author(s):  
Celia Francisco-Martínez ◽  
Juan Prado-Olivarez ◽  
José A. Padilla-Medina ◽  
Javier Díaz-Carmona ◽  
Francisco J. Pérez-Pinal ◽  
...  

Quantifying the quality of upper limb movements is fundamental to the therapeutic process of patients with cerebral palsy (CP). Several clinical methods are currently available to assess the upper limb range of motion (ROM) in children with CP. This paper focuses on identifying and describing available techniques for the quantitative assessment of the upper limb active range of motion (AROM) and kinematics in children with CP. Following the screening and exclusion of articles that did not meet the selection criteria, we analyzed 14 studies involving objective upper extremity assessments of the AROM and kinematics using optoelectronic devices, wearable sensors, and low-cost Kinect sensors in children with CP aged 4–18 years. An increase in the motor function of the upper extremity and an improvement in most of the daily tasks reviewed were reported. In the population of this study, the potential of wearable sensors and the Kinect sensor natural user interface as complementary devices for the quantitative evaluation of the upper extremity was evident. The Kinect sensor is a clinical assessment tool with a unique markerless motion capture system. Few authors had described the kinematic models and algorithms used to estimate their kinematic analysis in detail. However, the kinematic models in these studies varied from 4 to 10 segments. In addition, few authors had followed the joint assessment recommendations proposed by the International Society of Biomechanics (ISB). This review showed that three-dimensional analysis systems were used primarily for monitoring and evaluating spatiotemporal variables and kinematic parameters of upper limb movements. The results indicated that optoelectronic devices were the most commonly used systems. The joint assessment recommendations proposed by the ISB should be used because they are approved standards for human kinematic assessments. This review was registered in the PROSPERO database (CRD42021257211).


2021 ◽  
Vol 8 ◽  
Author(s):  
Sujit Kumar Sahu ◽  
Canberk Sozer ◽  
Benoit Rosa ◽  
Izadyar Tamadon ◽  
Pierre Renaud ◽  
...  

Soft and continuum robots are transforming medical interventions thanks to their flexibility, miniaturization, and multidirectional movement abilities. Although flexibility enables reaching targets in unstructured and dynamic environments, it also creates challenges for control, especially due to interactions with the anatomy. Thus, in recent years lots of efforts have been devoted for the development of shape reconstruction methods, with the advancement of different kinematic models, sensors, and imaging techniques. These methods can increase the performance of the control action as well as provide the tip position of robotic manipulators relative to the anatomy. Each method, however, has its advantages and disadvantages and can be worthwhile in different situations. For example, electromagnetic (EM) and Fiber Bragg Grating (FBG) sensor-based shape reconstruction methods can be used in small-scale robots due to their advantages thanks to miniaturization, fast response, and high sensitivity. Yet, the problem of electromagnetic interference in the case of EM sensors, and poor response to high strains in the case of FBG sensors need to be considered. To help the reader make a suitable choice, this paper presents a review of recent progress on shape reconstruction methods, based on a systematic literature search, excluding pure kinematic models. Methods are classified into two categories. First, sensor-based techniques are presented that discuss the use of various sensors such as FBG, EM, and passive stretchable sensors for reconstructing the shape of the robots. Second, imaging-based methods are discussed that utilize images from different imaging systems such as fluoroscopy, endoscopy cameras, and ultrasound for the shape reconstruction process. The applicability, benefits, and limitations of each method are discussed. Finally, the paper draws some future promising directions for the enhancement of the shape reconstruction methods by discussing open questions and alternative methods.


2021 ◽  
pp. 1-14
Author(s):  
Ke Wu ◽  
Gang Zheng

Abstract Compliant Mechanisms (CMs) are used to transfer motion, force and energy, taking advantages of the elastic deforma- tion of the involved compliant members. A branch of spe- cial type of elastic phenomenon called (post) buckling has been widely considered in CMs: avoiding buckling for better payload-bearing capacity and utilizing post-buckling to pro- duce multi-stable states. This paper digs into the essence of beam's bucking and post-bucking behaviors where we start from the famous Euler–Bernoulli beam theory and then ex- tend the mentioned linear theory into geometrically nonlin- ear one to handle multi-mode buckling problems via intro- ducing the concept of bifurcation theory. Five representative beam buckling cases are studied in this paper, followed by detailed theoretical investigations of their post-buckling be- haviors where the multi-state property has been proved. We finally propose a novel type of bi-stable mechanisms termed as Pre-buckled Bi-stable Mechanisms (PBMs) that integrate the features of both rigid and compliant mechanisms. The theoretical insights of PBMs are presented in detail for future studies. To the best of our knowledge, this paper is the first ever study on the theoretical derivation of the kinematic models of PBMs, which could be an important contribution to this field.


2021 ◽  
Author(s):  
Ziyuan Jiao ◽  
Zeyu Zhang ◽  
Xin Jiang ◽  
David Han ◽  
Song-Chun Zhu ◽  
...  
Keyword(s):  

Author(s):  
Jiali Liu ◽  
Yong Xu ◽  
Haorang Shi ◽  
Jie Yang

The cable-driven flexible arm based on the principle of origami is a new type of non-articulated compliant actuator with high integration, high environmental adaptability, large workspace/large deployment ratio. The forward/reverse kinematic models of joint space, operation space and driving space along with trajectory error model of the cable-driven flexible arm were proposed in this paper. The prototype of the flexible arm was developed capable of realizing bending, torsion and expansion/contraction. The simulation and experiment results of the cable-driven foldable flexible arm verified feasibility of the kinematic models and driving method proposed in this paper. Above research achievements lay necessary foundation for the next step to realize the key service functions of grasping/manipulation, three-dimensional precise movement, non-structural environment interaction/adaptation of the flexible arm with variable stiffness, variable configuration and variable size.


2021 ◽  
Vol 2021 ◽  
pp. 293-299
Author(s):  
D.R. Viziteu ◽  
A. Curteza ◽  
M.L. Avadanei

In the past several years, the application of 3D technologies in the textile and clothing design industry has considerably increased and become more accessible to designers and patternmakers. With digitisation in garment engineering and virtual prototype and modelling techniques becoming more mainstream, a new generation of virtual human models starts to develop to fulfil the demand for protective and functional products designed for specific athletes, such as climbers and mountaineers. We must base our work on an improved understanding of the behaviour of the musculoskeletal system to develop garment patterns that minimise discomfort and improve performance under dynamic body deformations and muscle contractions associated with specific movements. For this study, we explored the possibilities of using existing software packages for virtual prototyping based on human kinematic models for functional clothing.


Author(s):  
Enrico M Di Teodoro ◽  
Lorenzo Posti ◽  
Patrick M Ogle ◽  
S Michael Fall ◽  
Thomas Jarrett

Abstract We study the kinematics and scaling relations of a sample of 43 giant spiral galaxies that have stellar masses exceeding 1011 M⊙ and optical discs up to 80 kpc in radius. We use a hybrid 3D-1D approach to fit 3D kinematic models to long-slit observations of the Hα-$\rm{[N\, \small {II}]}$ emission lines and we obtain robust rotation curves of these massive systems. We find that all galaxies in our sample seem to reach a flat part of the rotation curve within the outermost optical radius. We use the derived kinematics to study the high-mass end of the two most important scaling relations for spiral galaxies: the stellar/baryonic mass Tully-Fisher relation and the Fall (mass-angular momentum) relation. All galaxies in our sample, with the possible exception of the two fastest rotators, lie comfortably on both these scaling relations determined at lower masses, without any evident break or bend at the high-mass regime. When we combine our high-mass sample with lower-mass data from the Spitzer Photometry & Accurate Rotation Curves catalog, we find a slope of α = 4.25 ± 0.19 for the stellar Tully-Fisher relation and a slope of γ = 0.64 ± 0.11 for the Fall relation. Our results indicate that most, if not all, of these rare, giant spiral galaxies are scaled up versions of less massive discs and that spiral galaxies are a self-similar population of objects up to the very high-mass end.


2021 ◽  
Vol 15 (5) ◽  
pp. 567-580
Author(s):  
Soichi Ibaraki ◽  
Nikolas Alexander Theissen ◽  
Andreas Archenti ◽  
Md. Moktadir Alam ◽  
◽  
...  

As long as industrial robots are programmed by teach programming, their positioning accuracy is unimportant. With a wider implementation of offline programming and new applications such as machining, ensuring a higher positioning accuracy of industrial robots over the entire working space has become very important. In this paper, we first review the measurement schemes of end effector poses. We then outline kinematic models of serial articulated industrial manipulators to quantify the positioning accuracy with a focus on the extension of the classical Denavit-Hartenberg (DH) models to include rotary axis error motions. Subsequently, we expand the discussion on kinematic models to compliant robot models. The review highlights compliance models that are applied to calculate the elastic deformation produced by forces, namely gravity and external loads. Model-based numerical compensation plays an important role in machine tool control. This paper aims to present state-of-the-art technical issues and future research directions for the implementation of model-based numerical compensation schemes for industrial robots.


2021 ◽  
pp. 100697
Author(s):  
Hamidreza Barnamehei ◽  
Farhad Tabatabai Ghomsheh ◽  
Afsaneh Safar Cherati ◽  
Majid Pouladian

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