scholarly journals An Exploration into Vection During Virtual Helicopter Flight Using Varying Levels of Active Control and Passive Control

2021 ◽  
Author(s):  
Lars Kooijman ◽  
Houshyar Asadi ◽  
Shehab Abdulraqeb ◽  
Wadhah Al-Ashwal ◽  
Shady Mohamed ◽  
...  
Keyword(s):  
Active Control ◽  
Passive Control ◽  
Weather Conditions ◽  
Object Motion ◽  
The Body ◽  
Helicopter Flight ◽  
Skin Response ◽  
Illusory Perception ◽  
Body Core ◽  
Self Motion

The illusory perception of self-motion, which is called vection, is a phenomenon that is traditionally measured in passive participants. Eliciting a compelling vection experience enhances the immersiveness of, and presence in, virtual environments. The investigation of vection during active control has mostly been done through subjective reports using single intensity stimuli for virtual locomotion or driving tasks, however, a vection study on virtual flight with varying difficulty levels appears to be missing from literature. Herein, we aimed to investigate how varying difficulty levels of active control as well as passive control of a virtual aircraft affects subjective vection intensity and objective physiological signals. Participants were visually and audibly immersed in a virtual environment in which either they or an AI controlled a virtual helicopter. Active control was facilitated by means of a stationary helicopter simulator. Galvanic skin response (GSR) and accelerations of the body core were recorded during flight and upon completion of each condition participants rated the intensity of vection and object-motion for 3 sensory modalities separately. Marginally higher vection intensity ratings compared to object-motion ratings were found and vection ratings were lightly affected by control difficulty due to weather conditions. Furthermore, participants reporting higher vection intensity ratings showed elevated changes in GSR compared to participants reporting lower vection intensity ratings. Our results show that vection can be elicited and modulated through active control with varying difficulty levels and including objective measures could elevate our understanding vection during active control tasks.

scholarly journals The A-Effect and Global Motion

Vision ◽  
2019 ◽  
Vol 3 (2) ◽  
pp. 13
Author(s):  
Pearl Guterman ◽  
Robert Allison
Keyword(s):  
Optic Flow ◽  
Object Motion ◽  
The Body ◽  
Body Tilt ◽  
Whole Body ◽  
Global Motion ◽  
Motion Direction ◽  
And Shifts ◽  
Self Motion ◽  
Gravitational Vertical

When the head is tilted, an objectively vertical line viewed in isolation is typically perceived as tilted. We explored whether this shift also occurs when viewing global motion displays perceived as either object-motion or self-motion. Observers stood and lay left side down while viewing (1) a static line, (2) a random-dot display of 2-D (planar) motion or (3) a random-dot display of 3-D (volumetric) global motion. On each trial, the line orientation or motion direction were tilted from the gravitational vertical and observers indicated whether the tilt was clockwise or counter-clockwise from the perceived vertical. Psychometric functions were fit to the data and shifts in the point of subjective verticality (PSV) were measured. When the whole body was tilted, the perceived tilt of both a static line and the direction of optic flow were biased in the direction of the body tilt, demonstrating the so-called A-effect. However, we found significantly larger shifts for the static line than volumetric global motion as well as larger shifts for volumetric displays than planar displays. The A-effect was larger when the motion was experienced as self-motion compared to when it was experienced as object-motion. Discrimination thresholds were also more precise in the self-motion compared to object-motion conditions. Different magnitude A-effects for the line and motion conditions—and for object and self-motion—may be due to differences in combining of idiotropic (body) and vestibular signals, particularly so in the case of vection which occurs despite visual-vestibular conflict.

The Optimal Control Method of Impulse Response in Prosthetic Leg

2014 ◽  
Vol 915-916 ◽  
pp. 1181-1185
Author(s):  
Xin Yi Xiao ◽  
Han Bin Xiao
Keyword(s):  
Optimal Control ◽  
Active Control ◽  
Impulse Response ◽  
Passive Control ◽  
Control Method ◽  
Control Variable ◽  
The Body ◽  
Control Techniques ◽  
Suspension Systems ◽  
Optimal Control Method

Passive control and semi-active control of vibration in mechanical systems have recently successfully been used in automobiles and airplanes suspension systems. These control techniques are able to guarantee the performances of all vibration structures. Unfortunately, the knowledge and data has not been readily applied to human prosthetics. The information collected can be directly applied to accelerate research into dampening for prosthetics. A focus of this paper is on modeling and controlling vibrations by a given impulse onto prosthetic legs. Simulations of using passive control and idealized skyhook dampening are using Matlab to complete. Through model analysis, control variable, simulation procedures and comparison of two modeling, the models have been refined and with idealized skyhook dampening suspension provide significant improvement of the body characteristics compared with passive suspensions.

Indicators of metabolism and biochemical status of blood in horses of Yakut breed in winter and spring seasons

2020 ◽  
pp. 52-65
Author(s):  
U. Khompodoeva ◽  
R. Ivanov
Keyword(s):  
Classical Method ◽  
Live Weight ◽  
Weather Conditions ◽  
The Body ◽  
Metabolic Energy ◽  
Temperature Changes ◽  
Experimental Animals ◽  
Spring Period ◽  
Biochemical Status ◽  
Adaptive Mechanisms

The results of researches on the peculiarities of metabolism in the body of horses of Yakut breed in the winter and spring periods under the environments of Central Yakutia have been presented in the article. Physiological experiments on the digestibility of the main nutrients of the feed have been carried out in the winter (February) and spring (April) periods under the environments of the physiological yard in the Yakutsk Scientific and Research Institute of Agriculture named after M. G. Safronov with using the classical method. Five mares and five geldings of Yakut breed have been selected for researches. The average live weight of mares was 378–410 kg, geldings 394–403 kg. The experimental animals had average fatness. It has been found a higher intake of energy and the main nutrients of hay as a mono feed in winter compared to the spring period. At the same time pregnant mares in winter have been consumed 103,8±3,12 MJ of metabolic energy per head/day, which was 27,3 % significantly higher than in the spring period – 75,4±2,18 MJ (P ≥ 0,999). Geldings have been consumed in the experiment 67,70±2,85 MJ, which was by 43,7 % higher than in the spring period – 38,05 ± 4,40 MJ of metabolic energy per head/day (P ≥ 0,999). Experimental animals have been housed in stalls; there was no energy expenditure for movement, so the amount of energy consumed in winter indicates the production of heat in the animal’s body. Pregnant mares per 100 kg of live weight have consumed 31,5±4,11 MJ of metabolic energy or 33,3 % more than in the spring period – 21,0±1,98 MJ; geldings have consumed 27,69±1,12, which was 41,78 % significantly higher than in the spring – 16,12 ± 0,75 MJ (P ≥ 0,999). The high intake of metabolic energy into the body of Yakut horses in winter is explained by the manifestation of adaptive mechanisms that affect the effective metabolism for survival, adapted to frequent changes in weather conditions and sharp temperature changes. The established differences in the biochemical parameters of blood serum of horses of Yakut breed are associated with changes in the consumption and digestibility of basic nutrients and energy, depending on the ambient temperature.

scholarly journals A Critical Review of Supersonic Flow Control for High-Speed Applications

2021 ◽  
Vol 11 (15) ◽  
pp. 6899
Author(s):  
Abdul Aabid ◽  
Sher Afghan Khan ◽  
Muneer Baig
Keyword(s):  
Supersonic Flow ◽  
Flow Control ◽  
Active Control ◽  
Critical Review ◽  
High Speed ◽  
Passive Control ◽  
Control Method ◽  
Sudden Expansion ◽  
Control Approach ◽  
Cost Efficient

In high-speed fluid dynamics, base pressure controls find many engineering applications, such as in the automobile and defense industries. Several studies have been reported on flow control with sudden expansion duct. Passive control was found to be more beneficial in the last four decades and is used in devices such as cavities, ribs, aerospikes, etc., but these need additional control mechanics and objects to control the flow. Therefore, in the last two decades, the active control method has been used via a microjet controller at the base region of the suddenly expanded duct of the convergent–divergent (CD) nozzle to control the flow, which was found to be a cost-efficient and energy-saving method. Hence, in this paper, a systemic literature review is conducted to investigate the research gap by reviewing the exhaustive work on the active control of high-speed aerodynamic flows from the nozzle as the major focus. Additionally, a basic idea about the nozzle and its configuration is discussed, and the passive control method for the control of flow, jet and noise are represented in order to investigate the existing contributions in supersonic speed applications. A critical review of the last two decades considering the challenges and limitations in this field is expressed. As a contribution, some major and minor gaps are introduced, and we plot the research trends in this field. As a result, this review can serve as guidance and an opportunity for scholars who want to use an active control approach via microjets for supersonic flow problems.

Seismic Control Effect for Nonlinear Benchmark Building Using Passive or Semi-Active Damper

2002 ◽  
Author(s):  
Akira Fukukita ◽  
Tomoo Saito ◽  
Keiji Shiba
Keyword(s):  
Active Control ◽  
Passive Control ◽  
Feedforward Control ◽  
Electrical Power ◽  
Control Device ◽  
Control Effect ◽  
Damping Force ◽  
Active Device ◽  
Seismic Control ◽  
Control Forces

We study the control effect for a 20-story benchmark building and apply passive or semi-active control devices to the building. First, the viscous damping wall is selected as a passive control device which consists of two outer plates and one inner plate, facing each other with a small gap filled with viscous fluid. The damping force depends on the interstory velocity, temperature and the shearing area. Next, the variable oil damper is selected as a semi-active control device which can produce the control forces by little electrical power. We propose a damper model in which the damping coefficient changes according to both the response of the damper and control forces based on an LQG feedback and feedforward control theory. It is demonstrated from the results of a series of simulations that the both passive device and semi-active device can effectively reduce the response of the structure in various earthquake motions.

Control of Vibration Using Compliant Actuators

2017 ◽  
Vol 139 (5) ◽  
Author(s):  
Sannia Mareta ◽  
Dunant Halim ◽  
Atanas A. Popov
Keyword(s):  
Vibration Control ◽  
Active Control ◽  
Passive Control ◽  
Performance Comparison ◽  
Control Performance ◽  
Frequency Bandwidth ◽  
Series Configuration ◽  
Compliant Actuators ◽  
Stiffness And Damping ◽  
Compliant Actuator

This work proposes a method for controlling vibration using compliant-based actuators. The compliant actuator combines a conventional actuator with elastic elements in a series configuration. The benefits of compliant actuators for vibration control applications, demonstrated in this work, are twofold: (i) vibration reduction over a wide frequency bandwidth by passive control means and (ii) improvement of vibration control performance when active control is applied using the compliant actuator. The vibration control performance is compared with the control performance achieved using the well-known vibration absorber and conventional rigid actuator systems. The performance comparison showed that the compliant actuator provided a better flexibility in achieving vibration control over a certain frequency bandwidth. The passive and active control characteristics of the compliant actuator are investigated, which shows that the control performance is highly dependent on the compliant stiffness parameter. The active control characteristics are analyzed by using the proportional-derivative (PD) control strategy which demonstrated the capability of effectively changing the respective effective stiffness and damping of the system. These attractive dual passive–active control characteristics are therefore advantageous for achieving an effective vibration control system, particularly for controlling the vibration over a specific wide frequency bandwidth.

Health indicators of children 10-11 years old at physical education lessons (cycling module)

2021 ◽  
pp. 113-116
Author(s):  
Maryna Prudnikova ◽  
Katerina Mulik
Keyword(s):  
Physical Education ◽  
Physical Fitness ◽  
Health Indicators ◽  
Weather Conditions ◽  
The Body ◽  
Main Role ◽  
Number Of Children ◽  
Grade 5 ◽  
The Future ◽  
Demographic Processes

The future of Ukraine is children, the future of demographic processes largely depends on their number, their health. The main role in the child's life is played by the dynamic process of growth and biological maturation, where one of the informative indicators is the cardiovascular system. In case of severe discomfort in the body, it is necessary to stop classes and consult a doctor. All physical activity must correspond to the physical fitness and age of the children. The cycling module is designed for 24 hours, according to the schedule, two physical education lessons were paired. For an effective lesson. In the course of the lessons, they mastered theoretical information (10 %), general and special physical training (20 %), technical training (70 %). During physical culture classes using a bicycle, objective factors were taken into account, such as the availability of a sports ground for technical riding, equipment (30 bicycles), and the weather conditions of the region. Over the course of one and a half months, the conducted classes formed the necessary skills for safe cycling, technical skill in children of 10-11 years old, provided the necessary foundation for physical fitness and motivation to go in for sports. The increase in adaptive indices of the heart was 14 % in grade 5-A, 8 % in grade 5-B, and 15 % in grade 5-V of the total number of children in each grade. This indicates that muscular work took place with positive consequences for the functional state of the body of children aged 10-11 years.

A shuffled frog-leaping algorithm based mixed-sensitivity H∞ control of a seismically excited structural building using MR dampers

2017 ◽  
Vol 24 (13) ◽  
pp. 2832-2852 ◽  
Author(s):  
Xiufang Lin ◽  
Shumei Chen ◽  
Guorong Huang
Keyword(s):  
Active Control ◽  
Passive Control ◽  
Structural Parameters ◽  
Mr Damper ◽  
Inverse Model ◽  
Shuffled Frog Leaping Algorithm ◽  
Weighting Functions ◽  
Inference System ◽  
Mr Dampers ◽  
Shuffled Frog Leaping

An intelligent robust controller, which combines a shuffled frog-leaping algorithm (SFLA) and an H∞ control strategy, is designed for a semi-active control system with magnetorheological (MR) dampers to reduce seismic responses of structures. Generally, the performance of mixed-sensitivity H∞ (MSH) control highly depends on expert experience in selecting the parameters of the weighting functions. In this study, as a recently-developed heuristic approach, a multi-objective SFLA with constraints is adopted to search for the optimal weighting functions. In the proposed semi-active control, firstly, based on the Bouc–Wen model, the forward dynamic characteristics of the MR damper are investigated through a series of tensile and compression experiments. Secondly, the MR damper inverse model is developed with an adaptive-network-based fuzzy inference system (ANFIS) technique. Finally, the SFLA-optimized MSH control approach integrated with the ANFIS inverse model is used to suppress the structural vibration. The simulation results for a three-story building model equipped with an MR damper verify that the proposed semi-active control method outperforms fuzzy control and two passive control methods. Besides, with the proposed strategy, the changes in structural parameters and earthquake excitations can be satisfactorily dealt with.

scholarly journals IDENTIFYING THE MENTAL STATUS OF BEDRIDDEN ELDERLY BY THE BODY TEMPERATURE, HEART RATE, AND SKIN CONDUCTIVITY USING AN ARDUINO SENSOR MODULE

2021 ◽  
Vol 5 (12) ◽  
Author(s):  
W.B.P.N. Herath ◽  
R.A.K.I. Ranasinghe ◽  
M.P.C. Sandaru ◽  
I.A.S. Lakmali ◽  
A.G.N.K. Aluthgama ◽  
...  
Keyword(s):  
Heart Rate ◽  
Body Temperature ◽  
Galvanic Skin Response ◽  
Emotional State ◽  
The Body ◽  
Blood Capillary ◽  
Sensor Module ◽  
Skin Response ◽  
Skin Conductivity ◽  
The Relationship

Addressing the emotional and mental health of the bedridden elderly is necessary as they are more likely to be depressed being isolated and dependent on a caregiver for a prolonged time. Several studies have been carried out to identify the mental stress of patients through their skin conductivity. The variations in the sympathetic nervous system reflect the emotional state of a person. This is demonstrated by the Galvanic Skin Response and thus can be used as a denotation of psychological or physiological arousal. Such arousal causes the blood capillary dilation, increment of sweat gland activities making the skin further conductive to electricity. In this study we develop a sensor module composed of a Galvanic Skin Response sensor for the bed ridden elderly and identify the relationship between body temperature, heart rate and GSR of them. The experiment is conducted upon 10 bed ridden elderly aged from 60 – 80 years of the Mihinthale region. The observations demonstrate a correlation between the heart rate, body temperature, skin conductivity and the human physiological states.

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