scholarly journals Angular Moment and Corrective Forces in Human Walking Processes: Sensor and Actuator Analysis

Proceedings ◽  
2019 ◽  
Vol 31 (1) ◽  
pp. 59
Author(s):  
Jose Joaquín Pérez Maciá ◽  
F. Javier Ferrández Pastor ◽  
J. Manuel García Chamizo
Keyword(s):  
Angular Velocity ◽  
Human Body ◽  
Human Walking ◽  
Gyroscopic Effect ◽  
Normal Movement ◽  
Angular Moment ◽  
Daily Movement ◽  
Points Of Interest ◽  
The Moment

Taking into account the dynamics of a human body in its daily movement, one can study the forces that are generated in its variations with respect to a normal walk. These forces can be reduced, generating an opposite force through some device if one takes into account that their magnitude is not very large in some cases. This paper outlines results obtained from the sensorization of a human body in uniform movement, and changes in angular velocity and moment of a force produced by different inflections in normal movement. The aim was to calculate the moment of a force thanks to the measured angular velocity, and then study the opposition to this movement by using the produced reaction by the conservation of angular moment (gyroscopic effect). The study was carried out through the positioning of different sensors that were placed to analyze points of interest of the movement. In this study, we were able to appreciate changes in the variables to study up to two orders of magnitude at the generated moment, when the movement went from being uniform, which is equivalent to a walk, to the situation of an inflection, for example, a fall or bending over. With the collected data, the prediction of a fall could be studied and perhaps avoided.

scholarly journals Elastic Simulation of Joints with Particle-Based Fluid

2021 ◽  
Vol 11 (15) ◽  
pp. 6900
Author(s):  
Su-Kyung Sung ◽  
Sang-Won Han ◽  
Byeong-Seok Shin
Keyword(s):  
Principal Stress ◽  
Human Body ◽  
Yield Condition ◽  
Maximum Principal Stress ◽  
Human Motion ◽  
The Difference ◽  
The Moment ◽  
External Forces ◽  
Physical Changes ◽  
Elastic Simulation

Skinning, which is used in skeletal simulations to express the human body, has been weighted between bones to enable muscle-like motions. Weighting is not a form of calculating the pressure and density of muscle fibers in the human body. Therefore, it is not possible to express physical changes when external forces are applied. To express a similar behavior, an animator arbitrarily customizes the weight values. In this study, we apply the kernel and pressure-dependent density variations used in particle-based fluid simulations to skinning simulations. As a result, surface tension and elasticity between particles are applied to muscles, indicating realistic human motion. We also propose a tension yield condition that reflects Tresca’s yield condition, which can be easily approximated using the difference between the maximum and minimum values of the principal stress to simulate the tension limit of the muscle fiber. The density received by particles in the kernel is assumed to be the principal stress. The difference is calculated by approximating the moment of greatest force to the maximum principal stress and the moment of least force to the minimum principal stress. When the density of a particle increases beyond the yield condition, the object is no longer subjected to force. As a result, one can express realistic muscles.

Biomechanics of human walking and stability descriptive parameters

2016 ◽  
Vol 2 (1) ◽  
pp. 4
Author(s):  
Arturo Bertomeu-Motos
Keyword(s):  
Human Body ◽  
Center Of Pressure ◽  
Body Movement ◽  
Human Motion ◽  
Human Walking ◽  
Dynamic Motion ◽  
Mechanical Aspect ◽  
Zero Moment

From the time of Aristotle onward, there have been countless books written on the topic of movement in animals and humans. However, research of human motion, especially walking mechanisms, has increased over the last fifty years. The study of human body movement and its stability during locomotion involves both neuronal and mechanical aspect. The mechanical aspect, which is in the scope of this thesis, requires knowledge in the field of biomechanics. Walking is the most common maneuver of displacement for humans and it is performed by a stable dynamic motion. In this article it is introduced the bases of the human walking in biomechanical terms. Furthermore, two stability descriptive parameters during walking are also explained - Center of Pressure (CoP) and Zero-Moment Pint (ZMP).

Investigation of aerodynamics of separator delivery from cavity

2020 ◽  
Vol 34 (14n16) ◽  
pp. 2040104
Author(s):  
Fei Xue ◽  
Yuchao Wang ◽  
Peng Bai
Keyword(s):  
Wind Tunnel ◽  
Angular Velocity ◽  
New Technology ◽  
Wind Tunnel Test ◽  
Ejection Velocity ◽  
Supersonic Wind Tunnel ◽  
Velocity Error ◽  
Technical Specifications ◽  
Ejection Mechanism ◽  
The Moment

The ejection test technology is studied in a sub-transonic supersonic wind tunnel using a single cylinder to provide ejection velocity. The angular velocity adjusting device of ejection mechanism is designed, which can adjust the ejection velocity and angular velocity of the model independently. When the ejection cylinder moves downward, the angular velocity adjusting mechanism works at the same time, so that the model has the preset ejection velocity and angular velocity at the moment of leaving the ejection frame. The ejection velocity error is less than 5%, the angular velocity error is less than 10%, and the repetition rate is more than 95%. The new technology has been verified by wind tunnel tests under complex aerodynamic conditions of sub-transonic supersonic and multi-body interference. All parameters have reached or surpassed the existing technical specifications. It has served for model tests many times and met the needs of wind tunnel test research on ejection of embedded weapons in aircraft.

scholarly journals Dependence of the ROT effect on the energy of different light charged particles and on the incident neutron energy

2021 ◽  
Vol 256 ◽  
pp. 00006
Author(s):  
Irina Guseva ◽  
Alexei Gagarski ◽  
Friedrich Gönnenwein ◽  
Yuri Gusev
Keyword(s):  
Angular Distribution ◽  
Angular Velocity ◽  
Compound Nucleus ◽  
Charged Particles ◽  
Ternary Fission ◽  
Incident Neutron ◽  
Incident Neutron Energy ◽  
Trajectory Calculations ◽  
The Moment ◽  
Light Charged Particles

The shift of the angular distribution of different light charged particles in ternary fission of 235U induced by polarized neutrons, the so-called ROT effect, was estimated by modified trajectory calculations, which take into account the rotation of the compound nucleus. In previous publications only α-particles were considered. It is shown here that inclusion of tritons significantly improves the agreement of the energy dependence of the ROT effect with experiment while the inclusion of 5He particles practically does not influence this dependence. In particular, the change in the magnitude of the ROT effect depending on the energy of incident neutrons is correctly predicted. Also, the ROT effect for gamma quanta and neutrons in binary fission is discussed along the same lines, because all mentioned effects are proportional to the effective angular velocity of the compound nucleus at the moment of scission.

scholarly journals CONTINUOUS FREQUENCY METER FOR A REACTION WHEEL

2013 ◽  
pp. 39-43
Author(s):  
Ю. М. Маринич ◽  
Ю. М. Гуменюк ◽  
Ф. О. Іваха
Keyword(s):  
Angular Velocity ◽  
Effective Control ◽  
Control Law ◽  
Reaction Wheel ◽  
Brushless Dc Motors ◽  
Brushless Dc ◽  
Size Characteristic ◽  
Continuous Frequency ◽  
Size Limits ◽  
The Moment

The usage of reaction wheels as executive parts for control systems of angular orientation and stabilization of spacecraft remains the most widespread method of angular control for a satellite. To create highly effective control system rigid demands are pulled out for reaction wheels such as mass-size characteristic, proportionality of reaction momentum to control signal and minimization power losses during energy transformation.The biggest errors in recreation of control law of reaction wheels take place during rotor angular velocity sign change, as in this moment compensation systems do not decrease but increase the influence of back EMF and friction momentum until the moment the information about angular velocity is renovated. When the angular velocity crosses the null pulsation of reaction momentum takes place. This problem is more important for reaction wheels of micro- and nano- level, as their small size limits the number of poles of the magnetic system and thus the number of information renovation points is small.The article is dedicated to the method of formation of quasi-stationary  signal of  rotor rpm of compact reaction-wheel, built on the basis of 2-and 4-pole three-phase brushless DC motors. The proposed approach allows the use of rotor position sensor signals to form a signal of rotor rpm of reaction-wheel and eliminate the error of reproduction of control law for reaction-wheel when the sign of the angular velocity of rotation of the rotor changes.

scholarly journals The effect of using EMS electrical stimulation on some kinematic variables of the floater serve in volleyball

2020 ◽  
Vol 19 (3) ◽  
pp. 0150
Author(s):  
Dr. Alaa Aldein Faisal Dr. Adnan Hady
Keyword(s):  
Electrical Stimulation ◽  
Angular Velocity ◽  
Angular Distance ◽  
Maximum Height ◽  
Technical Performance ◽  
Sports Club ◽  
Post Test ◽  
Arm Muscles ◽  
The Moment ◽  
Women's Volleyball

The importance of this study lies in knowing the development of the basic muscles in the performance of the arm by using electrical stimulation and its effect on technical performance, and to infer it through biochemical variables, which are reflected in realistic training and what is the extent of its value and its impact on the achievment of volleyball females players from the category of advancers.                                                                             The study aimed to know :                       -values of some biomechanical variables for the skill of the floater serve  in the women's volleyball .                                                                        - the extent and effectiveness of the effect of using an EMS device on the arm muscles , its development and its reflection on the performance movement of the serve through the kinematic variables and the differences between the pre and post tests.                                               The descriptive approach was used by using the pre and post kinematic analysis. The research sample consisted of females players of the Qaraqosh Sports Club, who were 6 from the category of advancers. The researchers used the EMS device for the arm leading to the serve after imaging and analysis in the pre-test to extract the variables (shoulder angle at the moment of hitting the ball , maximum height of the ball at the  moment of hitting the ball , ball launch velocity , ball launch angle, angular distance , time of movement, angular velocity) After completing the electrical stimulation program and sessions, over a period of five weeks, the same variables were analyzed in a post-test.                              The most important conclusions of the study were - that the use of electrical stimulation EMS helped in the development of the ball’s launch velocity - there were statistical differences in the arithmetic averages in the variables of the angular velocity and the angular distance between the two pre and post tests as a result of the effect of electrical stimulation, which achieved even partially the goal of the research according to the   kinematic view

scholarly journals On-line measurement method of transmission backlash based on angular velocity and double-end angular position information

2020 ◽  
pp. 002029402097325
Author(s):  
Ming Li ◽  
Ruirui Liang ◽  
Yanshun Zhang ◽  
Chuang Peng ◽  
Dong Mu ◽  
...  
Keyword(s):  
Angular Velocity ◽  
Measurement Method ◽  
Angular Position ◽  
Sudden Change ◽  
Position Information ◽  
Line Measurement ◽  
Gear Transmission System ◽  
Position Data ◽  
On Line ◽  
The Moment

Backlash is the inherent characteristic of gear transmission system. It is an important mean to measure and compensate backlash to improve transmission performance. When the driving gear reverses, due to the existence of backlash, the driven gear will still keep its original steering due to inertial motion until the driven gear collision with the driving gear. In this paper, based on the analysis of the tooth gap of the driving gear and the driven gear, an on-line measurement method of the meshing tooth gap combining the angular velocity of the load end with the information of the Angle position of the two axes of the master-slave gear is presented. This method uses the gyroscope at the load end (driven wheel) to monitor the sudden change of angular velocity at the moment of gear reverse impact and re contact, and the signal is used as the judgment basis for the reverse contact moment of the driving gear and driven gear. Then, the angular position data of driving gear and driven gear are fused at the time of reverse rotation and contact impact, and the backlash of the gear is calculated online. Finally, setting up an experimental platform for measuring backlash, and the proposed method is verified. The experimental results show that the proposed method can achieve accurate backlash measurement.

How Human Body Feel Pressure with Woman Dress in Medical Aspect

2013 ◽  
Vol 718-720 ◽  
pp. 586-592
Author(s):  
Meng Na Guo ◽  
V. Kuzmichev
Keyword(s):  
Human Body ◽  
Science Research ◽  
Pressure Sensitivity ◽  
Human Pressure ◽  
Daily Movement ◽  
Clothing Design ◽  
Medical Aspect ◽  
Structure Building ◽  
Traditional Chinese Medicine Theory ◽  
Chinese Medicine Theory

Nowadays, experiment and science research on apparel pressure are mainly about knitting wear which is the most closed to human body compared with other garment species. Yet there exists many tightly fitting styles in woman appeal using woven materials that might do harm to human body than the flexible knitting. In this article, we took experiment on western and eastern woman body using ELF system through modern western medicine and ergonomics angle concerning woman dress as the basic categories. 26 points where pressure will be strengthen while daily movement happened were tested, in this way we described the human pressure sensitivity through building the map. Finally, we compared it with traditional Chinese medicine theory. Thus the phenomenon how human body feels pressure was analysis through two perspective of medicine. Moreover, the result of woman body comfortable feelings in different points would be helpful in clothing design and structure building progress of woman apparel.

scholarly journals Yaw-Correcting Postural Changes in Locusts

1970 ◽  
Vol 52 (3) ◽  
pp. 519-531 ◽  
Author(s):  
JEFFEREY M. CAMHI
Keyword(s):  
Angular Velocity ◽  
Head Rotation ◽  
The Body ◽  
Motor Pathways ◽  
Angle Change ◽  
Postural Changes ◽  
The Moment ◽  
Relative Wind

1. Changes in the angle of the relative wind sensed by the facial wind receptors of a locust evoke fast rudder-like movements of the abdomen and legs whose magnitudes are proportional to the change of wind angle. 2. This system is sensitive to the angular velocity of the wind change. 3. Such wind changes also evoke rotations of the head about the long axis of the body. 4. The head rotation induces, through proprioception by the cervical hair receptors, slow, redundant rudder-like movements of abdomen and legs. 5. Control elements for the fast movements of abdomen and legs and for the head rotation appear not to be precisely co-ordinated and seem to include no proprioceptive ‘crosstalk’. 6. All these responses are evoked by wind-angle changes only if the insect is flying at the moment, suggesting that flight closes a neuronal switch. 7. Separate motor pathways seem to be employed for the abdomen's rudder-like response to wind-angle change, head rotation and turn tendency.

scholarly journals Feasibility of continuous action unit parameters for road underlay formation

2021 ◽  
Vol 18 (3) ◽  
pp. 238-250
Author(s):  
V. A. Nikolaev
Keyword(s):  
Angular Velocity ◽  
Traction Force ◽  
Road Construction ◽  
Dynamic Parameters ◽  
Hydraulic Motor ◽  
Continuous Action ◽  
Action Unit ◽  
Turn On ◽  
Two Phases ◽  
The Moment

Introduction. Russia has a large spatial disunity of settlements and other objects. Therefore, it is irrational to use low-productivity technical means of cyclical action in the construction of roads. To increase the pace of road construction, improve quality, reduce energy costs for road construction, where relief allows, it is economically feasible to use a set of units of continuous action. Continuous action units, moving one after another, will consistently perform a set of works, carrying out the full construction of the road by flow method. The complex should have a continuous action unit to form a underlying layer. To create complex units, their theoretical justification is necessary. In order to determine the geometric and dynamic parameters of the loading part of the unit to form the underlying layer, the process of moving the bucket filled with soil before it is unloaded is considered.The method of research. Based on the constructive layout of the loading part of the unit, the process of moving the bucket filled with soil before it is unloaded is divided into the stages: vertical ascent, moving in the direction of the leading star of the upper drive, two phases of the bucket rotation on the leading stars of the upper drive, moving from the moment of the end of the turn on the leading star of the upper drive to the start of the turn on the lower turn. When the bucket moves vertically up, the ground is no for dumped. Graphically, this angle of the bucket is chosen when it moves in the direction of the leading star of the upper drive, at which the ground will not fall out of the bucket. Two phases of the bucket rotation on the leading stars of the upper drive and moving the bucket from the moment of the end of the turn on the leading star of the upper drive to the moment of the turn on the lower turning roller are considered. The necessary parameters dependencies have been deduced.Results. Based on the developed methodology, the geometric and dynamic parameters of the loading part of the unit are defined. In particular, the torque of the top drive, the angular velocity of the drive sprockets, the power required for the top drive, the transmission ratio from the hydraulic motor to the sprockets are calculated. Based on the power transferred, a hydromotor was selected for the upper drive of the unit.Conclusion. The calculations reveal the maximum traction force of all buckets during their travel to discharge the soil, the torque of the top drive, the angular velocity of the top drive sprockets and the power required for the top drive. It is advisable to use for the upper drive of the unit gerotor hydromotor MT-160 and two-stage planetary gearbox. The calculations made it possible to develop the design of the elements of the loading part of the continuous action unit to form the underlying layer of roads.

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