Investigation of robust ship course control based on auxiliary loop method

A novel robust control law is investigated on the problem of ship stabilization on the trajectory, which allows one to compensate perturbations in the parameters of the mathematical model of ship dynamics in cases of their changes caused by external conditions, namely: sea waves, currents, wind gusts, etc. To implement the proposed control law, only measured adjustable values are required such as the yaw angle and the control action that is the angle of the rudder of the ship. The synthesized ship course control system was investigated in MATLAB. The law of controlling the ship’s course with unknown parameters and external disturbances in the power supply is proposed. The design of the control law is based on a robust auxiliary loop algorithm and Khalil observers. The simulations illustrate the efficiency of the proposed control law.

Processing and model design of the gamma oscillation activity based on FitzHugh-Nagumo model and its interaction with slow rhythms in the brain

The brain is processing information 24 hours a day. There are millions of processes proceeding in it accompanied by various spectra of rhythms. This paper tests the hypothesis that the slow delta rhythm excites the gamma rhythm oscillations. Unlike other papers, we determine the slow rhythm spectrum not at the hypothesis stage but during the experiment. We design algorithms of filtering, envelope extraction, and correlation coefficient calculation for signal processing. Moreover, we examine the data on all electroencephalogram channels, which allows us to make a more reasonable conclusion. We confirm that a slow delta rhythm excites a fast gamma rhythm with an amplitude-phase type of interaction and calculate a delay between these two signals equal to about half a second.

Data transfer in a decentralized network of robots using a local voting protocol

The construction of an effective intelligent information transmission system in a group of cyber-physical systems is one of the important problems in both practical and theoretical contexts. Such a system for transmitting information for a group is being built for a network consisting of separate robotic complexes. Increasingly, decentralized solutions are used to build effective interaction between group members. As a rule, in networks, decentralization is present in computing software modules, and the data transmission system between nodes is centralized. One of the aspects of such centralization is the need to send data to a specific destination directly or by relaying through other nodes - routing data in the network. In this work, a method of data transmission in a decentralized network between robotic complexes without reference to routing is proposed. The method consists of the exchange of data on the state of the entire network as a whole between the nodes.

Control of vibrational field in an elastic vibration unit with DC motors and time-varying observer

In the paper the problem of feedback control of vibrational fields in a vibration unit is analyzed taking into account the influence of the elasticity of cardan shafts, the drive dynamics, saturation for control torques. In addition, the synthesized rotor synchronization control algorithm uses the estimates of a non-stationary observer, which makes it possible to implement it practically on a two-rotor vibration unit SV-2. The performance of the closed loop mechatronic systems is examined by simulation for the model of the two-rotor vibration unit SV-2.

Synchronization conditions in networks of Hindmarsh-Rose systems

The algebraic connectivity is crucial parameter in studying of synchronization of diffusively coupled networks. This paper studies the synchronization in networks of Hindmarsh-Rose systems, which is one of the most used neuron models. It presents sufficient condition for synchronization in these networks using the Lyapunov function method. This is a simple condition which depends on the algebraic connectivity and on the parameters of the individual system. Numerical examples are presented to illustrate the obtained results.

Simulation studies of beam dynamics in 50 MeV linear accelerator with laser-plasma electron gun

Conventionally, electron guns with thermionic cathodes or field-emission cathodes are used for research or technological linear accelerators. RF-photoguns are used to provide the short electron bunches which could be used for FEL’s of compact research facilities to generate monochromatic photons. Low energy of emitted electrons is the key problem for photoguns due to high influence of Coulomb field and difficulties with the first accelerating cell simulation and construction. Contrary, plasma sources, based on the laser-plasma wakefield acceleration, have very high acceleration gradient but rather broad energy spectrum compared with conventional thermoguns or field-emission guns. The beam dynamics in the linear accelerator combines the laser-plasma electron source and conventional RF linear accelerator is discussed in this paper. Method to capture and re-accelerate the short picosecond bunch with extremely broad energy spread (up to 50 %) is presented. Numerical simulation shows that such bunches can be accelerated in RF linear accelerator to the energy of 50 MeV with output energy spread not higher than 1 % .

A viscosity solution of the Hamilton–Jacobi equation with exponential dependence of Hamiltonian on the momentum

The initial – boundary value problem is considered for the Hamilton-Jacobi of evolutionary type in the case when the state space is one-dimensional. The Hamiltonian depends on the state and momentum variables, and the dependence on the momentum variable is exponential. The problem is considered on fixed bounded time interval, and the state variable changes from a given fixed value to infinity. The initial and boundary functions are subdifferentiable. It is proved that such a problem has a continuous generalized viscosity) solution. The representative formula is given for this solution. Sufficient conditions are indicated under which the generalized solution is unique. Hamilton-Jacobi equations with an exponential dependence on the momentum variable are atypical for theory, but such equations arise in practical problems, for example, in molecular genetics.

Using of the SPSA method to improve the accuracy of the UAV following a given route under the action of wind loads

In the modern world, UAVs (unmanned aerial vehicles) are increasingly used in everyday life in solving civilian tasks. One of the main applications of UAVs is data collection with their reference to a given coordinate system. For example, for the task of aerial photography, it is necessary to accurately link each image to the global coordinate system. In addition to the exact location of coordinates, it is worth the exact movement of a given route, to collect data of exactly those places that are needed. Thus, it is very important to ensure the minimum deviation of the UAV from the given route under the conditions of external disturbances (wind disturbances) acting on it. The article describes a procedure for assessing wind speed and direction for a UAV control system using the SPSA method. The simulation results of the algorithm operation, confirmed during flight tests on an ultralight UAV with an ardupilot autopilot, are presented.

Nonlinear repetitive control of the metal cutting machine feed module with saturated input

The article discusses the methodology for constructing an automatic control system for the feed module of the cutting tool for lathes in the presence of input saturation. The presence of the saturation function is due to restrict unwanted movements of the feed module actuator. The generator for periodic signals, the hyperstability criterion, L-dissipativity conditions and an implicit reference model are used as the solution methods for structural synthesis of the control system. At the stage of simulation, the functioning quality of the developed control system is illustrated.

On global trajectory tracking control of robot manipulators with a delayed feedback

In this paper, the trajectory tracking control problem of a robot manipulator with cylindrical joints is considered by means of a nonlinear PD controller taking into account the delayed feedback structure. The conclusion about stability of a closed-loop system is obtained on the basis of the development of the direct Lyapunov method in the study of the stability property for a non-autonomous functional differential equation by constructing a Lyapunov functional with a semi-definite time derivative.