Modeling and simulation study of electromechanically system of the human extremity exoskeleton

In order to design a suitable control scheme for human extremity exoskeleton, the interaction force control scheme which regards human body as the work environment of human extremity exoskeleton was proposed. And then, the electromechanical system of human extremity exoskeleton was simplified, and the modeling and simulation study of the electromechanical system by using Matlab/Simulink module was carried out. The angular deviations between human extremity exoskeleton joints and human body joints were obtained by the simulation. Besides, the torques provided by human body and motors for human extremity exoskeleton joints to bear heavy payload were calculated. The analysis of the simulation calculation results proves that the interaction force control scheme can achieve good man-machine coordinated walking as well as help human body bear heavy payload. Besides, the upper extremity exoskeleton experiment was conducted, and the same conclusion with the simulation study was obtained

Study on barrel vibration characteristics of typical sniper rifle

The firing accuracy of sniper rifle is significantly affected by the barrel vibration induced by shooting load. The barrel vibration is an important parameter needing to be precisely controlled, whose measurement is less studied before. The vertical vibration characteristics of sniper rifle barrel is obtained for the duration of 500 ms with high speed photography system. Both the averaged vibration frequency and maximum amplitude of the measured muzzle are gained. It is found from the test that after the appearance of the maximum value, the vibration amplitude of the muzzle reduces with nearly fixed vibration frequency. In addition, the finite element model is conducted for the barrel vibration regarding sniper rifle. And then the natural frequency as well as the vibration reflection of the barrel under the effort of shooting load is calculated with the model. The model accuracy is well validated for the numerical results are substantially in line with the measurements

Modeling and simulation study of electromechanically system of the human extremity exoskeleton

In order to design a suitable control scheme for human extremity exoskeleton, the interaction force control scheme which regards human body as the work environment of human extremity exoskeleton was proposed. And then, the electromechanical system of human extremity exoskeleton was simplified, and the modeling and simulation study of the electromechanical system by using Matlab/Simulink module was carried out. The angular deviations between human extremity exoskeleton joints and human body joints were obtained by the simulation. Besides, the torques provided by human body and motors for human extremity exoskeleton joints to bear heavy payload were calculated. The analysis of the simulation calculation results proves that the interaction force control scheme can achieve good man-machine coordinated walking as well as help human body bear heavy payload. Besides, the upper extremity exoskeleton experiment was conducted, and the same conclusion with the simulation study was obtained

SRY gene transferred by extracellular vesicles accelerates atherosclerosis by promotion of leucocyte adherence to endothelial cells

Abstract We set out to investigate whether and how SRY (sex-determining region, Y) DNAs in plasma EVs (extracellular vesicles) is involved in the pathogenesis of atherosclerosis. PCR and gene sequencing found the SRY gene fragment in plasma EVs from male, but not female, patients; EVs from male patients with CAD (coronary artery disease) had a higher SRY GCN (gene copy number) than healthy subjects. Additional studies found that leucocytes, the major source of plasma EVs, had higher SRY GCN and mRNA and protein expression in male CAD patients than controls. After incubation with EVs from SRY-transfected HEK (human embryonic kidney)-293 cells, monocytes (THP-1) and HUVECs (human umbilical vein endothelial cells), which do not endogenously express SRY protein, were found to express newly synthesized SRY protein. This resulted in an increase in the adherence factors CD11-a in THP-1 cells and ICAM-1 (intercellular adhesion molecule 1) in HUVECs. EMSA showed that SRY protein increased the promoter activity of CD11-a in THP-1 cells and ICAM-1 in HUVECs. There was an increase in THP-1 cells adherent to HUVECs after incubation with SRY-EVs. SRY DNAs transferred from EVs have pathophysiological significance in vivo; injection of SRY EVs into ApoE −/− (apolipoprotein-knockout) mice accelerated atherosclerosis. The SRY gene in plasma EVs transferred to vascular endothelial cells may play an important role in the pathogenesis of atherosclerosis; this mechanism provides a new approach to the understanding of inheritable CAD in men

Masennukseen liittyvä sanastotyö

Opinnäytetyön tavoitteena oli laatia suomi–kiina-sanasto, jonka aiheena on masennus. Opinnäytetyön tietoperustassa esitellään sekä masennukseen liittyviä tärkeitä tietoja kuten masennuksen määritelmä, masennuksen syyt, oireet ja hoidot että masennukseen liittyviä kulttuurisia tekijöitä. Sanastotyön kannalta keskeiset käsitteet määritellään myös tietoperustassa. Sanastoon valittiin 100 termiä ja ne ovat opinnäytetyön liitteenä kahtena taulukkona: toisessa on suomenkieliset termit ja määritelmät, ja toisessa on suomenkieliset termit ja kiinankieliset vastineet. Ideana oli, että käyttäjä voi nopeasti ja helposti löytää taulukoista vastineen termille. Vastineiden oikeellisuus tarkistettiin kiinan kielen asiatuntijalta. Sanastossa suuri osa suomenkielisistä termeistä ja määritelmistä poimittiin Masennus-kirjasta, jossa on jo valmiina suomen kielen sanasto ja määritelmät. Loput termeistä haettiin suomalaisilta verkkosivuilta, esimerkiksi Mielenterveystalo ja Duodecim terveyskirjasto. Osa kiinankielisistä vastineista löydettiin suoraan sanakirjoista, luotettavista rinnakkaisesta kirjallisuudesta ja verkkosivuilta, osa vastineista on itse luotuja suomenkielisten määritelmien ja käännösstrategioiden pohjalta. Asioimistulkki tarvitsee paljon erikoisalojen sanastoa, joten tämä sanasto on suunnattu tulkeille, tulkkiopiskelijoille ja terveysalan ammattilaisille. Tarkoituksena on auttaa tulkkeja masennukseen liittyvissä tulkkaustilanteissa ja niihin valmistautumisessa. Opinnäytetyön yhteistyökumppani on STEA:n rahoittama Terkku-hanke (2020–2022). Tästä opinnäytetyöstä voidaan hyötyä materiaalina hankkeen järjestämien tapahtumien yhdessä mielenterveyden edistämiseen monikulttuurissa ympäristössä

An Improved Scale-Adaptive Simulation Model for Massively Separated Flows

A new hybrid modelling method termed improved scale-adaptive simulation (ISAS) is proposed by introducing the von Karman operator into the dissipation term of the turbulence scale equation, proper derivation as well as constant calibration of which is presented, and the typical circular cylinder flow at Re = 3900 is selected for validation. As expected, the proposed ISAS approach with the concept of scale-adaptive appears more efficient than the original SAS method in obtaining a convergent resolution, meanwhile, comparable with DES in visually capturing the fine-scale unsteadiness. Furthermore, the grid sensitivity issue of DES is encouragingly remedied benefiting from the local-adjusted limiter. The ISAS simulation turns out to attractively represent the development of the shear layers and the flow profiles of the recirculation region, and thus, the focused statistical quantities such as the recirculation length and drag coefficient are closer to the available measurements than DES and SAS outputs. In general, the new modelling method, combining the features of DES and SAS concepts, is capable to simulate turbulent structures down to the grid limit in a simple and effective way, which is practically valuable for engineering flows

Optimization of the Control Scheme for Human Extremity Exoskeleton

In order to design a suitable control scheme for human extremity exoskeleton, the interaction force control scheme with traditional PI controller was presented, and the simulation study of the electromechanical system of the human extremity exoskeleton was carried out by using a MATLAB/Simulink module. By analyzing the simulation calculation results, it was shown that the traditional PI controller is not very suitable for every movement speed of human body. So, at last the fuzzy self-adaptive PI controller was presented to solve this problem. Eventually, the superiority and feasibility of the fuzzy self-adaptive PI controller was proved by the simulation results and experimental results

Design and Ground Performance Evaluation of a Multi-Joint Wheel-Track Composite Mobile Robot for Enhanced Terrain Adaptability

The tracked-wheeled mobile robot has gained significant attention in military, agricultural, construction, and other fields due to its exceptional mobility and off-road capabilities. Therefore, it is an ideal choice for reconnaissance and exploration tasks. In this study, we proposed a multi-jointed tracked-wheeled compound mobile robot that can overcome various terrains and obstacles. Based on the characteristics of multi-jointed robots, we designed two locomotion modes for the robot to climb stairs and established the kinematics/dynamics equations for its land movement. We evaluated the robot’s stability during slope climbing, its static stability during stair climbing, and its ability to cross trenches. Based on our evaluation results, we determined the key conditions for the robot to overcome obstacles, the maximum height it can climb stairs, and the maximum width it can cross trenches. Additionally, we developed a simulation model to verify the robot’s performance in different terrains and the reliability of its stair-climbing gait. The simulation results demonstrate that our multi-jointed tracked-wheeled compound mobile robot exhibits excellent reliability and adaptability in complex terrain, indicating broad application prospects in various fields and space missions