scholarly journals Human upper limb manipulator mass center motion and mass moments of inertia variation

2018 ◽  
Vol 145 ◽  
pp. 04005 ◽  
Author(s):  
Gergana Nikolova ◽  
Daniel Dantchev ◽  
Alexander Kazakoff

Motion control is complicated for people having traumas or neurological diseases. An underlying assumption in our work is that the motion of healthy people is optimal with respect to positioning accuracy, movement response, and energy expenditure. In this paper, a new approach for determination of the human upper limb mass-inertial characteristics is presented by using the 3D geometrical mathematical modeling analysis approach. Two examples will be given to illustrate the main features and advantages of the proposed design concepts. The objective of the work presented in this paper is a determination of the mass properties of a two joints human upper limb manipulator. Results are aimed to have application in an exoskeleton design, the design of manipulation system and external manipulation system, serving people with some motion difficulties, as well as in sport and rehabilitation.

2013 ◽  
Vol 748 ◽  
pp. 759-764
Author(s):  
Nicolae Dumitru ◽  
Raluca Malciu ◽  
Valentin Grecu

The paper presents the determination of the constraint forces acting in the human upper limb joints, using the inverse dynamic analysis procedure based on Lagrange multipliers method. The kinematics parameters time variation laws were established through experiments for the considered driving joints. The constraint forces time variation laws define the database for the dynamic analysis using the finite element method and for dimensioning an exoprosthetic system for later rehabilitation of the human upper limb motion.


1989 ◽  
Vol 41 (3) ◽  
pp. 219-223 ◽  
Author(s):  
K.V.S. Rao ◽  
G.D. Gupta ◽  
V.N. Sehgal

Author(s):  
Arthur V. Jones

With the introduction of field-emission sources and “immersion-type” objective lenses, the resolution obtainable with modern scanning electron microscopes is approaching that obtainable in STEM and TEM-but only with specific types of specimens. Bulk specimens still suffer from the restrictions imposed by internal scattering and the need to be conducting. Advances in coating techniques have largely overcome these problems but for a sizeable body of specimens, the restrictions imposed by coating are unacceptable.For such specimens, low voltage operation, with its low beam penetration and freedom from charging artifacts, is the method of choice.Unfortunately the technical dificulties in producing an electron beam sufficiently small and of sufficient intensity are considerably greater at low beam energies — so much so that a radical reevaluation of convential design concepts is needed.The probe diameter is usually given by


2017 ◽  
Vol 30 (1) ◽  
pp. 273-289
Author(s):  
Anmari Meerkotter

The Constitutional Court (CC) judgment of Lee v Minister of Correction Services 2013 2SA 144 (CC) is a recent contribution to transformative constitutional jurisprudence in the field of the law of delict. This matter turned on the issue of factual causation in the context of wrongful and negligent systemic omissions by the state. In this case note, I explore the law relating to this element of delictual liability with specific regard to the traditional test for factual causation – the conditio sine qua non (‘but-for’) test. In particular, I note the problems occasioned by formalistic adherence to this test in the context of systemic state omissions as evidenced by the SCA judgment in the same matter. I also consider the manner in which English courts have addressed this problem. Thereafter, I analyse the CC’s broader approach to the determination of factual causation as one based on common sense and justice. I argue that this approach endorses a break from a formalistic application of the test and constitutes a step towards an approach which resonates with the foundational constitutional values of freedom, dignity and equality. Furthermore, it presents an appropriate solution to the problems associated with factual causation where systemic omissions are concerned. I then consider the transformative impact of the Lee judgment. In particular, I argue that the broader enquiry favoured by the CC facilitates the realisation of constitutionally guaranteed state accountability, and amounts to an extension of the existing norm of accountability jurisprudence. Hence, I contend that the judgment presents a further effort by the Constitutional Court to effect wholesale the constitutionalisation of the law of delict, as well as a vindicatory tool to be used by litigants who have been adversely affected by systemic state omissions.


Author(s):  
Romain Desplats ◽  
Timothee Dargnies ◽  
Jean-Christophe Courrege ◽  
Philippe Perdu ◽  
Jean-Louis Noullet

Abstract Focused Ion Beam (FIB) tools are widely used for Integrated Circuit (IC) debug and repair. With the increasing density of recent semiconductor devices, FIB operations are increasingly challenged, requiring access through 4 or more metal layers to reach a metal line of interest. In some cases, accessibility from the front side, through these metal layers, is so limited that backside FIB operations appear to be the most appropriate approach. The questions to be resolved before starting frontside or backside FIB operations on a device are: 1. Is it do-able, are the metal lines accessible? 2. What is the optimal positioning (e.g. accessing a metal 2 line is much faster and easier than digging down to a metal 6 line)? (for the backside) 3. What risk, time and cost are involved in FIB operations? In this paper, we will present a new approach, which allows the FIB user or designer to calculate the optimal FIB operation for debug and IC repair. It automatically selects the fastest and easiest milling and deposition FIB operations.


2021 ◽  
Vol 11 (13) ◽  
pp. 5865
Author(s):  
Muhammad Ahsan Gull ◽  
Mikkel Thoegersen ◽  
Stefan Hein Bengtson ◽  
Mostafa Mohammadi ◽  
Lotte N. S. Andreasen Struijk ◽  
...  

Wheelchair mounted upper limb exoskeletons offer an alternative way to support disabled individuals in their activities of daily living (ADL). Key challenges in exoskeleton technology include innovative mechanical design and implementation of a control method that can assure a safe and comfortable interaction between the human upper limb and exoskeleton. In this article, we present a mechanical design of a four degrees of freedom (DOF) wheelchair mounted upper limb exoskeleton. The design takes advantage of non-backdrivable mechanism that can hold the output position without energy consumption and provide assistance to the completely paralyzed users. Moreover, a PD-based trajectory tracking control is implemented to enhance the performance of human exoskeleton system for two different tasks. Preliminary results are provided to show the effectiveness and reliability of using the proposed design for physically disabled people.


Sensors ◽  
2021 ◽  
Vol 21 (9) ◽  
pp. 3070
Author(s):  
Sebastian Iwaszenko ◽  
Jakub Munk ◽  
Stefan Baron ◽  
Adam Smoliński

Modern dentistry commonly uses a variety of imaging methods to support diagnosis and treatment. Among them, cone beam computed tomography (CBCT) is particularly useful in presenting head structures, such as the temporomandibular joint (TMJ). The determination of the morphology of the joint is an important part of the diagnosis as well as the monitoring of the treatment results. It can be accomplished by measurement of the TMJ gap width at three selected places, taken at a specific cross-section. This study presents a new approach to these measurements. First, the CBCT images are denoised using curvilinear methods, and the volume of interest is determined. Then, the orientation of the vertical cross-section plane is computed based on segmented axial sections of the TMJ head. Finally, the cross-section plane is used to determine the standardized locations, at which the width of the gap between condyle and fossa is measured. The elaborated method was tested on selected TMJ CBCT scans with satisfactory results. The proposed solution lays the basis for the development of an autonomous method of TMJ index identification.


2021 ◽  
Vol 13 (2) ◽  
pp. 621
Author(s):  
Hsin Rau ◽  
Mary Deanne M. Lagapa ◽  
Po-Hsun Chen

The number of consumers with green awareness have grown these days and as a result they have turned to purchase eco-friendly products. For this reason, this study aims to propose a method for eco-design based on the anticipatory failure determination method to develop eco-design products. By using eco-design concepts adopted from the World Business Council for Sustainable Development, the process will limit the failures and issues related to environmental impact in product design. The proposed method for eco-design product in this study follows the following procedure. First, we analyze product failure. Second, we propose the determination of the non-green phenomenon of the failure. Thirdly, we integrate the intensified non-green phenomenon to generate non-green hypotheses and fourthly, we eliminate each non-green phenomenon hypothesis by introducing the contradiction matrix of TRIZ for obtaining solutions. Finally, we assess alternative eco-design solutions by evaluation. To verify the practicality of the new procedure, a washing machine is used as an example for illustration.


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