Attitude Dynamics Research Articles

Bottom-Up Approach to Language Policy and Planning in Kazakhstan

National and world news is constantly accompanied by inter-group dramas which are permeated by the dynamics of language use and attitudes. Conflicts can arise between the state insisting on an official language and the family and community who may support the preservation or revitalisation of heritage languages. Kazakhstan is an example of how languages (official Kazakh, the language of communication Russian and international English) coexist peacefully. Language policy and planning depend on the ability and willingness of individual members of the speech community to adopt a language. Language planning is often seen as a top-down, government-controlled activity. This paper shows that language planning can also be carried out from below. Here, we analyze the main initiatives of grassroots movements in promoting the status of the Kazakh language and the emergence of new bottom-up approaches facilitated by the Internet and present sociolinguistic survey results regarding the roles, importance and prestige of languages for the people of Kazakhstan. The focus of the study reported in this article is to monitor the transformative character of bottom-up approaches to language-policy study in Kazakhstan.

Intelligent PIV Fuzzy Navigation and Attitude Controller for an Octorotor Mini-UAV

In this research, a proportional plus integral plus velocity (PIV) fuzzy gain scheduling flight controller for an octorotor mini-unmanned aerial vehicle is developed. The designed flight controller scheme, with a PIV term, is combined with a fuzzy gain scheduling approach. The tracking controller PIV fuzzy gain scheduling is based on two controllers connected in cascade with a saturation approach. The Newton–Euler equations of motion are applied to obtain a mathematical model for the octorotor mini-unmanned aerial vehicle (mini-UAV). The flight controller approach is applied to obtain coupling moments and forces with interconnected attitude and navigation tracking trajectory. In the design of a flight navigation controller with two layers, the inner layer consists of a PIV fuzzy gain scheduling controller that is applied to the attitude dynamics, obtaining the references for the coupling outer layer PIV fuzzy gain scheduling controller, which manipulates the translational dynamics. The navigation PIV fuzzy gain scheduling controller is saturated for bounding in translational forces to avoid large deviations of commands to Euler angles pitch and roll, and another saturated controller is implemented for the bounded thrust rotor to avoid the excessive angular speed of these rotors. The octorotor mini-UAV flight navigation simulation is performed to validate the tracking control of a sequence of motions in each axis, which is presented as a validation for the proposed control scheme.

Quaternion-Based Adaptive Trajectory Tracking Control of a Rotor-Missile with Unknown Parameters Identification

This paper investigates the adaptive trajectory tracking control problem and the unknown parameter identification problem of a class of rotor-missiles with parametric system uncertainties. First, considering the uncertainty of structural and aerodynamic parameters, the six-degree-of-freedom (6DoF) nonlinear equations describing the position and attitude dynamics of the rotor-missile are established, respectively, in the inertial and body-fixed reference frames. Next, a hierarchical adaptive trajectory tracking controller that can guarantee closed-loop stability is proposed according to the cascade characteristics of the 6DoF dynamics. Then, a memory-augmented update rule of unknown parameters is proposed by integrating all historical data of the regression matrix. As long as the finitely excited condition is satisfied, the precise identification of unknown parameters can be achieved. Finally, the validity of the proposed trajectory tracking controller and the parameter identification method is proved through Lyapunov stability theory and numerical simulations.

Представление о себе и других в условиях транзитивного общества: межпоколенческий анализ

<p>The article examines the problem of the dynamics of psychological attitudes of the individual to himself and to other people in the context of the socio-cultural transformation of the living environment. The example of the Republic of Tuva shows the socio-cultural transformation for different age generations of Tuvans. The article presents the results of an empirical study of the attitude of Tuvans living in a remote area of ​​the Republic of Tuva, of different ages, towards themselves and other people - representatives of the Tuvan and Russian ethnos of different age generations. It is shown that, in the perceptions of Tuvan respondents of different age groups, there are “nuclear” qualities, characteristics, with the help of which representatives of their ethnic group are described in comparison with representatives of the Russian ethnic group.</p>

Comments on “quaternion models of a rigid body rotation motion and their application for spacecraft attitude control”

The commented paper discusses the attitude dynamics representation using quaternions. The main idea of the paper is to eliminate angular velocity from the dynamics equations. The obtained equations are interesting. However, all applications presented in the discussed paper have plain errors in the equations derivations. This affects the main results and conclusions of the paper, which require significant corrections. • Errors in commented paper are outlined. • Quaternion dynamics equations application for the attitude control is discussed. • Control singularity is shown.

CubeSat attitude determination with decomposed Kalman filters

CubeSats are the cost-effective entry to space research and applications. As mission requirements increase to carry out more complex tasks, the constraints on the satellite challenge how attitude estimation and control systems are designed. Limited energy, sensors, and computational capacity require compromises. In this paper, we propose a Kalman filter architecture to reduce the computational cost of attitude estimation, leveraging the conditional independence structure of its physical model. Our method decomposes attitude dynamics and kinematics, leading to a linear attitude quaternion and a nonlinear angular velocity filter. As accommodating all vector measurements would require a nonlinear filter, we propose the virtual sensor paradigm that transforms the nonlinear observation model into a linear one, without relying on approximations. Our numerical experiments showcase superior error dynamics and robustness to epistemic uncertainty compared to a nonlinear quaternionic filter, and we also investigate performance against star tracker measurement frequency and sensitivity to the angle between Sun and Earth magnetic field measurements.

Connecting livestock disease dynamics to human learning and biosecurity decisions.

The acceleration of animal disease spread worldwide due to increased animal, feed, and human movement has driven a growing body of epidemiological research as well as a deeper interest in human behavioral studies aimed at understanding their interconnectedness. Biosecurity measures can reduce the risk of infection, but human risk tolerance can hinder biosecurity investments and compliance. Humans may learn from hardship and become more risk averse, but sometimes they instead become more risk tolerant because they forget negative experiences happened in the past or because they come to believe they are immune. We represent the complexity of the hog production system with disease threats, human decision making, and human risk attitude using an agent-based model. Our objective is to explore the role of risk tolerant behaviors and the consequences of delayed biosecurity investments. We set up experiment with Monte Carlo simulations of scenarios designed with different risk tolerance amongst the swine producers and we derive distributions and trends of biosecurity and porcine epidemic diarrhea virus (PEDv) incidence emerging in the system. The output data allowed us to examine interactions between modes of risk tolerance and timings of biosecurity response discussing consequences for disease protection in the production system. The results show that hasty and delayed biosecurity responses or slow shifts toward a biosecure culture do not guarantee control of contamination when the disease has already spread in the system. In an effort to support effective disease prevention, our model results can inform policy making to move toward more resilient and healthy production systems. The modeled dynamics of risk attitude have also the potential to improve communication strategies for nudging and establishing risk averse behaviors thereby equipping the production system in case of foreign disease incursions.

Predefined-Time Control of a Spacecraft Attitude with Thrust Booms

A predefined-time attitude controller for electric spacecraft and its thrust booms is investigated by combining a second-order sliding mode control with predefined-time disturbance observer. First, an Eulerian–Lagrangian attitude dynamics model of the electric spacecraft with thrust booms is constructed; meanwhile, the coupling between the spacecraft platform and thrust boom is treated as the disturbance when designing the controller. Next, a predefined-time convergent second-order sliding surface and reaching law are designed to ensure the predefined-time fast convergence. The second-order sliding surface can avoid the chattering problem of controller and improve the anti-disturbance capability of the spacecraft. Furthermore, a novel predefined-time disturbance observer is developed to handle the disturbances, ensuring that the tracking error of the system converges to the equilibrium. At last, the simulation is performed to verify the feasibility and advantages of the proposed algorithm.

Application of Model-Free Control to the Operation of Post-Capture Combined Spacecraft

A model-free control method is applied to the attitude and orbital operation of the post-capture combined spacecraft, which consists of a space robot and debris. The main contribution of this paper lies in the following three aspects. Firstly, the discrete dynamic linearization method of the motion equation for a post-capture combined spacecraft is proposed, and then, the standardized expression form of multiple input and multiple output system for the attitude and orbital dynamics motions of post-capture combined spacecraft are presented. Secondly, the data mapping model of the post-capture combined spacecraft is defined, and based on this, an initial value online optimization method for the data mapping model is provided, which is key for the convergence of model-free control. Finally, a test system based on the ground-based three-axis spacecraft simulator is built to simulate the attitude and orbital operation of post-capture combined spacecraft, and the experimental system is implemented to verify the validation of the model-free control method proposed in this paper. The results show that the model-free control has a good control effect on the attitude and orbit of the post-capture combined spacecraft, even if the configuration of the spacecraft is time-varying.

Spacecraft attitude estimation under attitude tracking maneuver during close-proximity operations

This paper presents a real-time relative three-axis attitude estimation using a camera and two gyros under momentum changes during close-proximity operations. The camera sensor provides quaternion measurements that relate the body frame of the deputy spacecraft with respect to the body frame of the chief spacecraft. The quaternion measurements are coupled with gyro measurements and attitude dynamics model in a multiplicative extended Kalman filter to determine relative attitude and gyro biases under momentum changes. The relative quaternion kinematics is augmented with spacecraft relative motion dynamics to represent the filter process dynamics. The quaternion measurements from a camera sensor and inertial measurement units (IMU) are utilized to the filter measurement model. The fault-tolerant attitude controller actuated by four reaction wheels, which has no unwinding problem is used for attitude tracking maneuvers during close-proximity operations in the presence of external disturbances, uncertain inertia parameter and actuator faults. This controller is combined with the extended Kalman filter to filter noisy measurements and to estimate gyro biases, which leads to a full-state feedback control system. Numerical simulations are performed to verify the effectiveness of the attitude estimation and control systems of the spacecraft with four reaction wheels during close-proximity operations of spacecraft in low-Earth orbit.

МАРКЕТИНГОВІ АСПЕКТИ МЕДИЧНИХ ПОСЛУГ З ВАКЦИНАЦІЇ В УМОВАХ ІНФОРМАЦІЙНО-КОМУНІКАЦІЙНОЇ ПІДТРИМКИ ДЕРЖАВИ

The article analyzes the marketing aspects of the population's attitude to vaccination medical services based on a nationwide survey of respondents. The article analyzes the dynamics of the Ukrainian population's attitude to vaccination based on surveys of respondents in 2016-2020. It was revealed that during this period the share of the population expressing a positive attitude towards vaccination increased. At the same time, there is a positive trend of a decrease in the share of the population that expressed a negative attitude to vaccination, as well as some growth in the category of the population that had a neutral attitude to vaccination. In the process of the research, it was established that an important positive shift in the issue of vaccination of the adult population and children is a decrease among respondents who oppose vaccination in Ukraine, where their share in 2020 decreased to 8.2 percent compared to previous periods. A marketing analysis of respondents who have children in the household and an assessment of their attitude to vaccination in the regions of Ukraine in 2020 was carried out. The percentage of respondents who had the experience of refusing vaccinations for a child was characterized and divided by region (among those who had children under 18 years of age in the household and information about their health status) in 2020. The authors investigated the main reasons for respondents' refusal to receive vaccinations for children in 2018–2020. It was found that one of the main reasons for refusing vaccination was that parents were afraid of complications from the vaccine and that the child was sick during the period when it was necessary to vaccinate children. It is summarized that the implementation of communication and information policy is an important component of immunoprophylaxis for both the adult population and children, which will prevent the outbreak of many types of infectious diseases in the future. Key words: marketing, medical services, population's attitude to vaccination, refusal of vaccinations, communication and information policy of the state, attitudes of respondents.

Coping with Stress of Uncertainty

The stress of uncertainty is an inherent characteristic of modern life. Phenomenologically, uncertainty is represented by such categories as emotional experiences (usually negative), limited information about the world and about oneself, lack of control over events, unpredictability of choice results, uncertainty in relationships with other people. Coping strategies may include active actions, seeking help from other people, passive waiting, analyzing and searching for information, changing attitudes to the situation, self-regulation, compromise and intuition. The key factors in the manifestation of stress of uncertainty include not only the unpredictability of life events due to limited information about the world, but also an overabundance of contradictory and unverified data. As a rule, uncertainty is associated with negative feelings of anxiety and uncertainty about the future. This corresponds to the concept of distress, which is destructive in nature and has a disorganizing effect on the state and behavior of a person. However, the perception of uncertainty can occur from the position of new opportunities and ways of development within the constructive so-called eustress. It can be assumed that a number of individual personality characteristics allow a person to better adapt and navigate in stressful situations of uncertainty, cope with negative emotions, and also perceive these situations as a field of new opportunities. Individual personality characteristics may act as positive personality resources that perform a buffer function when interacting with subjective uncertainty and predict the dynamics of changing attitudes to situations of uncertainty, which shows a more successful adaptation to stress factors.

Optimization of Spacecraft Thrusters Configuration Under Fault Diagnosability and Recoverability Constraints

This paper investigates the problem of optimal placement (position and orientation) of spacecraft thrusters, under fault diagnosability and fault recoverability constraints. Avionics equipment contamination and plume impingement are also considered. The goal is to find the thrusters configuration with the minimal number of thrusters required for a given spacecraft architecture, so that it is guaranteed that it is possible to equip the control unit with a model-based fault diagnosis and fault-tolerant control solution, able to accommodate any single thruster's fault. This includes total loss of controllability of the faulty thruster. The proposed solution is a model-based solution in the sense that it is based on the spacecraft attitude and translational dynamics. With the help of the zonotope concept and its so-called H-representation, it is shown that this problem can be formulated as a nonlinear constrained optimization problem, which can be solved efficiently using hybrid optimization techniques. The proposed solution is assessed on a generic spacecraft architecture that performs a proximity maneuver.

Intelligent Attitude Fault-Tolerant Control of Space Tumbling Target Fly-Around Based on RBF Neural Network

The flying around monitoring task of space tumbling target is one of the key links of its on-orbit service. Considering the practical constraints of system inertia uncertainty, external disturbance, actuator saturation, and fault in engineering practice, a robust composite controller based on radial basis function (RBF) neural network is proposed. First, in a new line of sight rotation (RLOS) coordinate system, the relative attitude kinematics and dynamics equations between the tracker and tumbling target based on the error quaternion are established; second, the RBF neural network is used to estimate the additive and multiplicative faults of the system, and the fast nonsingular terminal sliding mode surface (FNTSMS) is combined with the active disturbance rejection control (ADRC) technology to design a finite-time fault-tolerant control (FTC) strategy with high accuracy, strong robustness, and anti-saturation based on the RBF neural network. It is proven that the designed robust fault-tolerant controller can ensure that the system state error converges to a small region containing the origin in a limited time under the Lyapunov framework. Finally, the effectiveness and superiority of the control strategy were verified by numerical simulation.

Myths of the Soviet Era. Refutation and Debunking in the Postcolonial Period

The article deals with the problem of Ukrainian society’s interaction with its own ideas about the Soviet past. In particular, based on the anthropological interpretation of the myth notion (according to which a myth is a story or narrative that has a sacral character for a specific social group or community), three examples of Soviet myths are considered: 1) about Stalin as a great leader; 2) about nationalism; 3) the Soviet narrative about Ukraine’s past. An important aspect of this article is the analysis of the post-Soviet dynamics of these myths, i.e., their transformation in conditions reminiscent of post-colonialism in countries of Africa and Asia, which were colonies of European countries in the past. In particular, the idea of Stalin as a great leader can serve as an example of coexistence of short and extended stories of a myth. This distinction was introduced by Bronisław Malinowski and Maurice Leenhardt to denote myths that have either taken the form of a clear narrative (short story) or exist, in people’s minds, in the form of vague ideas and beliefs (extended story). The analysis of dynamics of attitudes toward Stalin in Ukrainian society throughout 1991–2016 allows us to identify social factors, which determined positive and negative attitudes toward him in the post-Soviet period. In particular, it is shown that upon the 2000s the identity factor is crucial: if a person identifies him- or herself with the Ukrainian nation, his/her attitude towards Stalin is clearly negative. The analysis of both the main narratives about Ukraine’s past and the perception of the nationalism concept in Ukrainian society proves the accuracy of using the post-colonial approach to the understanding of Ukrainian society during 1991–2022. In particular, the theses of Gayatri Chakravorty Spivak and Edward Said that the domination of colonizers in the sphere of culture persists even in the case a nation has already gained political independence, have been confirmed. First, the nation keeps using the language of colonizers, i.e., keeps staying in the field of meanings imposed by colonizers. Such is the fate of the nationalism concept, which until 2014 had been perceived in Ukrainian society mainly in a Soviet way. The co-existence of six narratives about Ukraine’s past, of which only 2 were distinctly Soviet, allows us to understand the mechanisms of decolonization that took place in Ukrainian society before 2014.

Robust Nonlinear Control for the Fully Actuated Hexa-Rotor: Theory and Experiments

This letter addresses a fully-actuated Hexa-rotor’s control under exogenous position and attitude disturbances. For that aim, we propose a nonlinear and robust control based on a backstepping technique for position dynamics and a geometric control for attitude dynamics. We demonstrate that the closed-loop system is globally exponentially stable. To validate the reached stability, we present simulation results using MATLAB/Simulink and software in the loop simulations using the well-known PX4 firmware in a realistic scenario on a virtual environment in Gazebo. Finally, to ultimately demonstrate the effectiveness of our algorithm, we implement it on an own-developed fully-actuated Hexa-rotor platform. Our contributions can be summarized as 1) the design of a robust controller for the fully-actuated Hexa-rotor not presented in the literature, 2) the publication of the controller’s code for the PX4 autopilot software, and 3) drone’s construction and presentation of real flight experiments.

Adaptive Control of Quadrotor Unmanned Aerial Vehicle With Time-Varying Uncertainties

This paper studies the real-time parameter estimation and adaptive tracking control problem for a six degrees of freedom (6-DOF) of quadrotor unmanned aerial vehicle (UAV) as an under-actuated system. A virtual proportional derivative (PD) is proposed to maintain position dynamics. Two adaptive control schemes are designed and compared to maintain the attitude dynamics of UAV while several parameters of UAV are unknown. In the first scheme, a classical adaptive scheme using the certainty equivalence principle is extended and designed for tracing control of the systems with unknown time-varying parameters. To improve the performance of the first scheme, a new control scheme is designed in the second scheme by proposing additional continuous function to handle the unknown parameters. An additional robust term is designed in both schemes to handle the perturbation caused by unknown time-varying parameters. The rigorous analytical proof and numerical simulation analysis are provided to support the efficacy of the proposed controller.

Fertility and Reproductive Attitudes of the Population Before and After the Epidemiological Situation Worse

Introduction. The preservation and growth of the population is a key task of the Russian Federation Demographic Policy Concept until 2025. Nevertheless, in recent years, the achievement of this task has been difficult due to escalation of socio-economic and demographic problems. The purpose of the article is to determine and compare birth rates and reproductive attitudes of the population in various periods after the beginning of the 2000s, which differ in the socio-economic context and the list of demographic policy measures, including under the latest circumstances – the worsening epidemiological situation. Materials and Methods. The study is based on a statistical analysis of time series data indicators for conditional generations that reflect the demographic situation of fertility in Russia and the Komi Republic – crude and total fertility rates, natural population growth (decline), the number of women in reproductive age (15–49 years) in total structure of the female population, the number of women aged 15–24 in the structure of the female population of reproductive ages. Also, the methodological basis of the presented work is based on the results of three sociological studies, conducted by a team of scientists of The Institute for Social Economic and Energy problems of the North of the North Federal Research Center Komi Science Centre UB RAS in 2008, 2013 and 2020 among the population of the Komi Republic. Results. It is revealed that the most successful period of demographic development in Russia was 2013–2016 and in the Komi Republic in 2011–2016, which consists in achieving natural population growth. Further, there was a decrease in the birth rate. It is determined that the situation in the field of population reproduction has worsened in the context of the COVID-19 pandemic in Russia and the Komi Republic. The study reveals that reproductive attitudes in all generations are the best in 2013. The significant success in this period is the growth of reproductive attitudes even among young cohorts. Further in 2020, the expected number of children decreased in all age cohorts. In 2020, the pattern remains – the lowest reproductive orientations are in the two youngest age cohorts of 1996–2000 and 2001–2005 birth. Discussion and Conclusion. The main result of the work was the confirmation on the example of the northern region of Russia the thesis that the growth of the standard of living is accompanied by an increase in the reproductive attitudes of the population and the birth rate, and vice versa. From a theoretical point of view, the usefulness of the article lies in the description of the processes of fertility and the dynamics of the reproductive attitudes of the population, taking into account the changing socio-economic and epidemiological conditions. From a practical point of view, the information obtained can be useful as an assessment of future fertility prospects and confirmation of the high role of the socio-economic well-being of the population in addressing the issue of increasing the level of children in the families.

Observer-based boundary feedback control for attitude tracking of rigid bodies with partially liquid-filled cavities

In the attitude tracking control tasks of rigid bodies with partially filled cavities, liquid sloshing is a crucial characteristic that hinders effective controller design and accuracy improvement. To overcome this problem, we propose a novel boundary feedback control (BFC) scheme based on the PDE-ODE cascade governing the rigid body attitude and internal liquid dynamics. We further develop an innovative PDE-based observer to cope with requirements on the infinite number of unmeasurable boundary states. Thus, using only attitude data, the discussed boundary controller can stabilize the attitude tracking error and the infinite-dimensional internal dynamics. The asymptotic stability of the closed-loop observer-based controller is established via the Lyapunov direct method. Finally, to show its efficacy, the proposed methodology is applied to the attitude tracking problem of a typical liquid-propellant satellite. In summary, the novelty is twofold: (i) due to dealing with the original involved PDE-ODE cascade, the formulated control strategy is more accurate than the relevant studies that have used liquid rigidity and potential ideal flow assumptions; (ii) the observer design approach is much broader than existing ones for nonlinear parabolic-type PDEs.

Dynamics of parental attitudes of women before and after the birth of the first child

The demographic situation against the background of the reproductive attitudes of young people urgently requires research into the dynamics of parental attitudes, especially among women. Identification of potential resource areas and risk zones will make it possible to determine the main directions of psychological work with young people at the pre-parental and parental stages, strengthening the value of families and children among young people. The purpose of the study is to study the dynamics of parental attitudes before and after the birth of the first child. Sample: stage 1 (n = 50) married pregnant young women (first pregnancy in the third trimester, no history of complications); Stage 2 (n = 39): young mothers with a baby from 3 to 5 months. Data collection was carried out in the course of a longitudinal study using psychological testing methods: PARI E.S. Schaefer and R.K. Bella (adapted by T.V. Neshcheret); Ideas about the ideal parent R.G. Ovcharova; Relationship Color Test by A. Etkind. The results showed that women at the stage of early motherhood showed changes in all components of parental attitudes cognitive, emotional, behavioral. The greatest dynamics occur in the emotional sphere, which is characterized by ambivalence of experiences, and in the mothers self-awareness. The systems of attitudes towards the child and the maternal role (attitude towards oneself as mother and motherhood) are gradually differentiated. There is a restructuring of marital interaction and relations with the parental family: rapprochement with ones own mother while distancing from a marriage partner. Thus, at the stage of early parenthood, a woman needs to form the skills of emotional and volitional self-regulation and increase the level of communicative competence, which are of central importance for high-quality relationships with a child and a spouse.