Interactive roll stabilization comparative analysis for large yacht: gyroscope versus active fins

The orbital stability of periodic motions of a Hamiltonian system with two degrees of freedom in the case of 3:1 resonance

Ship resistance estimation is one of the most important problems to be solved by naval architects at the early stages of the ship design project. This paper presents a comparison of methods that are used to estimate the resistance value of a vessel, studying the two terms that are the most relevant, the viscous resistance (depending on the form factor) and the resistance to waves, that appears in any floating device. This work focuses on the estimation of the form factor since it is a parameter difficult to estimate in the design early phases, and it is not always available in the measurements provided by real experiments with ship prototypes in towing tanks. Different estimation methods are applied and they are compared with the direct estimation and with the prediction obtained with a feedforward neural network. The results support the suitability of the neural networks to identify these vessel shape and wave related variables.

The problem in this study is about how the radio broadcast business in the era of technological advancements and information, whether radio broadcasts can still maintain their existence and are still in the public interest as an effective means of entertainment and information and what radio broadcast companies do in facing business challenges in the era technological progress and information so that it can survive. The method used in this study is a qualitative research method, taking data sources using a "purposive sampling" technique with a total of 4 (four) informants including the management of radio broadcast companies in 4 (four) radio broadcast companies in the researched Kebumen Regency. Data collection in this study was carried out through observation, documentation and in-depth interviews. Observations and interviews are used to capture primary data relating to how important radio broadcast companies view technological and information progress as challenges that must be faced to maintain the existence of broadcast radio. While the study of documentation is used to capture secondary data that can be raised from various documentation about media data, broadcast radio company profiles and so on. The data analysis technique in this study is an interactive model analysis, including four components, namely data collection, data reduction, data presentation and conclusions or verification. The theory used is the theory of general communication and business communication. The locus of research in four radio broadcast companies in Kebumen District, namely: Bimasakti FM Kebumen, Mas FM Kebumen, RPFM Gombong, and Radio Gong FM Gombong, the results of this study found that advances in technology and information will raise efforts to improve the quality of broadcast radio companies in Kebumen through various ways including the ability to adjust to follow the advances in technology and information carried out by changing the conventional ways of broadcasting in a more modern way with technology-based and internet-based information. The four radio broadcast companies in Kebumen Regency were examined, although in general they had adjusted to the advancement of technology and information in order to maintain their existence. In fact there were still a number of radio broadcast companies that had not implemented streaming broadcasts so that the range that could be received by audiences or listeners was limited and not yet global. Efforts to adjust to the advancement of technology and information must, of course, be accompanied by efforts to improve the quality of human resources broadcast radio companies both internally and externally.
 Keywords: business communication, existence, radio broadcast, streaming, technological progress.

We deal with the problem of orbital stability of pendulum-like periodic motions of a heavy rigid body with a fixed point. We suppose that the geometry of the mass of the body corresponds to the Bobylev-Steklov case. Unperturbed motion represents oscillations or rotations of the body around a principal axis, occupying a fixed horizontal position. The problem of the orbital stability is considered on the basis of a nonlinear analysis.

Investigation of the stability of periodic motions of an autonomous Hamiltonian system in a critical case

Topicality. When solving a number of problems associated with the design of complex control systems [1-3], it often becomes necessary to adjust the motion in the vicinity of the calculated trajectories set at the initial moment of time and belong to some dynamic sets of phase space [2, 3]. In this case, the correction requirements may relate to the individual coordinate of the calculated trajectories and their linear combination. These tasks belong to the class of tasks of stabilization of motion and reduce to the construction of regulatory influences that provide the original system a certain type of stability [1, 2, 4]. This approach is used, for example, in modeling charged particles in order to control them in dynamics in the presence of appropriate sustainability requirements. To construct constructive algorithms, the stability analysis is carried out on a finite time interval, and the initial conditions are given in the structural form [3, 5-7]. The latter allows us to obtain numerical estimates for the stabilization of motion to practical stability in the presence of dynamic constraints on phase coordinates. Analysis of recent research and publications. With the analysis of practical stability and sensitivity of dynamic systems, problems of optimal control of a beam of trajectories are closely related [2, 3, 6]. Thus, numerical algorithms for calculating the optimal areas of practical stability are used to estimate the area of particle capture in the acceleration process. In this case, the field of initial conditions can be in the given structures (sphere, ellipsoid), and the maximum in volume (optimal by inclusion). Then the question is raised about optimization of estimates of such sets due to the proper choice of system parameters [7]. The tasks of constructing regulatory influences that provide the desired stability requirements are an important part of a set of tasks that arise in the design of technical systems, in particular accelerating-focusing [1, 2]. Unlike the classical statements [1], the analysis of the stability of parametric systems [2-4, 6, 7] allows us to study the system's performance in real modes, taking into account the requirements for sensitivity, and to solve such problems numerically from the standpoint of stability [3]. The purpose of the research ─ development of constructive algorithms for solving stabilization problems for practical stability for linear parametric systems with disturbances. Materials and methods of research. The paper uses methods of stability theory, differential equations and control theory. Research results and their discussion. For linear parametric systems of differential equations with perturbations, the sequence of stabilization problems to practical stability in the given domains of dynamic constraints is investigated. Considered cases of known and limited perturbation norm. For structurally-defined areas of initial conditions, numerical estimates of the stabilization of motion to practical stability have been obtained. Conclusions and perspectives of further research. Formation of stabilization problems for practical stability of linear parametric systems with perturbations is formulated. On the basis of practical stability algorithms, numerical criteria for stabilizing the system motion to a certain type of stability were obtained. Such an approach can be extended to the solution of problems of stabilization of motion to asymptotic stability in regions of a more general structure. Keywords: mathematical model, stabilization, regulator, parameters, practical stability, parametric system, dynamic constraints

In this paper we consider controllable orbital motion in a neighborhood of the first collinear libration point L 1 of the Sun-Earth system. This libration point is unstable. For a long stay of the spacecraft in this area of space required the control action. We model the motion by equations circular restricted three-body problem. At the same time, we use non-linear approximation of these equations, so-called Hills equations and linearized equations. For solution of the problem of stabilization of motion, we use the model of linear-quadratic optimization. This model offers a standard approach for the construction of stabilizing control laws. In this work, we present an original family of quadratic functionals, which were built with the help of the special linear function of the phase variables, so-called “hazard function”. The increase of module of this function module mean departure of a spacecraft from a neighborhood of the libration point and the decrease of this module corresponds to the stabilization of motion. For the represented family of functionals we have built the Bellman function and showed that the control damps square of hazard function. Numerical simulations of the orbital motion with obtained controls is realized in the nonlinear model of Hills equations and in model of circular three-body problem.

The stationary motion of a gas cavity in an ideal incompressible fluid is studied taking account of surface tension by using a variational equation. Approximate analytical dependences of the dimensionless parameters on the degree of cavity deformation are obtained. It is shown that the variational equation admits of an exact analytical solution. The stability of motion corresponding to the exact solution is proved relative to arbitrary perturbations in the cavity shape. A solution is given for the problem of stationary motion of an elliptical cavity in a gravity viscous fluid and the stability problem is investigated. Dependences are found for the velocity of cavity rise, the Reynolds number, and the Froude number as a function of the cavity size.

With the social development and the continuous progress of science and technology, the mobile robots can greatly improve efficiency, reduce costs, many of these applications can be attributed to the backward path tracking control problem. A controller for backward path tracking of mobile robot with two trailers is addressed in this paper. The paper presents a new approach to stabilizing the system in backward motion by controlling the orientation angles of the two trailers. Nonlinear smooth control laws for orientations of the trailers with asymptotic stability in backward motion are then proposed. The result simulated in Simulink illustrates the effectiveness of the control law and the controller.

The safety-level gap between China and the US in view of the interaction between coal production and safety management

Optimal stabilization of a rigid body motion using rotors system

With the continuous progress and application of robotics technology, the importance of mobile robots capable of adapting to specialized work environments is gaining prominence. Among them, achieving precise and stable control of AGVs (Automated Guided Vehicles) stands as a paramount task propelling the advancement of mobile robotics. Consequently, this study devises a control system that enables AGVs to attain stable and accurate motion through equipment connection and debugging, kinematic modeling of the four-wheel steering AGV, and a selection and comparative analysis of motion control algorithms. The effectiveness of the Stanley-PID control algorithm in guiding the motion of a four-wheel steering AGV is validated through MATLAB 2021a simulation software. The simulation results illustrate the outstanding stability and precise control capabilities of the Stanley-PID algorithm.

This paper describes a set of tools for the reengineering of computer-based systems, in particular software. The toolset is based on an abstract intermediate representation (IR) which incorporates the system software architecture at five level of granularity: program level, task level, package/object instance level, subprogram level and statement level. The toolset provides a graphical user interface that allows various views of a software architecture, including call graph, rendezvous graph, call-rendezvous graph, call-data-rendezvous graph, control flow graph and dependence graphs. The information captured by the toolset is useful in software structure, flow and interaction analysis, tasks commonly performed manually during maintenance and reengineering. This information is also helpful for understanding the software design to guide software transformation, and for porting software to distributed platforms.

The description of the developed computer system possibilities and its use to solve problems of motion safety and stability is given.

In this chapter we will consider the stability of steady motion, in particular, of equilibrium of rigid bodies with cavities partially or completely filled with ideal or viscous fluids. This study is based on the definition of stability and on the ideas developed by Lyapunov in the theory of stability of equilibrium shapes of a rotating fluid48, 55. It has been proved that the problem of the stability of steady motion or of the equilibrium of a rigid body containing a fluid reduces to the problem of minimizing a certain expression56, 57 a solution to which is given54, 58. The results are used for solving a number of problems of stability of motion of bodies containing a fluid.KeywordsFree SurfaceRigid BodyDynamic StabilityRelative EquilibriumSurface Tension ForceThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.