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• IDENTIFICATION OF FAULTS IN DRIVES BASED ON OPTIMAL CONTROL METHODS

  А.А. Kabanov, V.А. Kramar, А.V. Zuev, V. F. Filaretov, А.N. Zhirabok

  192-204

  2025-08-04

  Abstract ▼

  The paper exams the problem of identifying faults in the drives of robotic systems, the dy-namics model of which is described by linear differential equations. It is proposed to search for a solution to the fault identification problem based on the solution of an auxiliary optimal control problem for a dynamical system in which the role of an unknown vector function describing emerging faults is performed by some auxiliary control, which should provide a minimum for the residual functional. Based on the solution of the auxiliary optimal control problem, a fault diag-nostic observer is proposed. In this case, the fault itself is found through the solution of the corre-sponding algebraic Riccati equation and the differential equation for the auxiliary variable. Un-like popular approaches to solving the problem of fault identification based on observers operat-ing in a sliding mode, the proposed method allows us to expand the class of systems for which the identification problem can be solved. It is known that the methods of sliding mode observers de-sign impose certain restrictions on the systems under consideration. The proposed approach based on optimal control can also give results for systems with nonlinear dynamics. In this case, methods of approximate solution of optimal control problems based on the representation of the system in linear form with state-dependent coefficients (the so-called State-dependent Riccati Equation, SDRE) are likely to be effective. The improvement of the proposed method in this direction will be the subject of further research. The stated theory is shown on the example of fault identification in a DC drive. Different cases are considered for a system with complete observations (the entire state vector is known) and with incomplete observations. It was shown during the simulation that the quality of faults identification can be improved by selecting the appropriate values of the pen-alty matrices in the residual functional, while it is possible to achieve good diagnostics separately through various channels of faults occurrence. The paper presents recommendations on the choice of penalty matrices. The simulation results confirmed the operability of the diagnostic observers synthesized using the proposed method

• DIGITAL PLATFORM FOR THE CREATION OF DISTRIBUTED CONTROL AND NAVIGATION SYSTEMS FOR UNDERWATER VEHICLES

  V.F. Filaretov, D.A. Yukhimets, A.V. Zuev, A.S. Gubankov, D.D. Minaev

  2021-04-04

  Abstract ▼

  The paper proposes the architecture of a digital platform for the implementation of distributed
  control and navigation systems of underwater vehicles (UV), that perform technological operations
  in an uncertain environment. The proposed digital platform is designed to automate the
  following activities: monitoring the state of underwater infrastructure objects (communication
  lines, pipelines, mining equipment, etc.), cartographic and geodesic works, determining the parameters
  and boundaries of physical fields, zones of distribution of chemical compounds (pollution
  zones) and bioresources, protection of underwater and surface infrastructure objects (underwater
  mariculture farms, borders of water reserves, etc.), tracking moving objects, searching for objects
  of a given type (biological, man-made, etc.), performing underwater technological operations
  (welding, cutting, cleaning, etc.). For this platform, a command system has been developed that
  provides flexible assignment of various types and purposes of UV missions. There are five types of
  digital platform messages: mission order management commands, mission load management
  commands, information messages, mission and group control commands. The concept of building
  distributed control systems of the UV is proposed, which ensures the compatibility of existing onboard
  UV systems with the proposed solution based on the combined hydroacoustic systems of
  global hydroacoustic navigation developed in PAO "Dalpribor" (Vladivostok). These control systems
  consist of two main parts. The first part is the initial on-board information and control system
  of the UV, which ensures its movement to a given point in space at a given speed, receiving
  data from on-board sensors, as well as controlling the operation of on-board equipment. The second
  part – the high level control system, provides the possibility of interaction of the control system
  through an acoustic communication channel with the global hydro-acoustic navigation system
  and the operator's automated workplace. Simulation of the data transfer in CoppeliaSim between
  the operator and the UV within the proposed digital platform have shown that reliable mission
  loading and receiving information about the state of the UV is provided at different speeds and
  under different operating conditions of the acoustic communication channel.

• NON-PARAMETRIC METHOD FOR DETECTING BREAKDOWN OF TIME SERIES USING THE RANDOM WALKS THEORY MECHANISM

  G. F. Filaretov , Z. Bouchaala

  2020-11-22

  Abstract ▼

  The task of the on-line detection of a sudden change in the probability properties of a time series
  is considered, which is usually interpreted as the detecting task of change point the characteristics
  (breakdown) in the observed stochastic process. The actuality of the development of research on this
  topic is noted, which is due to the emergence of ever new applied problems where methods and algorithms
  for breakdown detecting can be successfully used - in particular, when creating monitoring systems
  in industry, ecology, medicine, etc. Two main varieties of methods for breakdown detecting are
  discussed: parametric and nonparametric. It is noted that, although nonparametric methods, ceteris
  paribus, are inferior to parametric methods in terms of efficiency (the speed of breakdown detecting),
  they also have a number of advantages, without requiring, in particular, for their application detailed
  information about the probabilistic properties of the controlled process. This is fundamentally important
  for building monitoring systems, when detailed information about these properties may either be completely
  absent and then it is necessary to conduct a rather laborious preliminary study of it, or to be
  unreliable. An original sequential nonparametric algorithm for detecting discord is proposed based on
  the implementation of the random walk mechanism or, more specifically, using the theory of success
  runs. The operating principle of the control algorithm is explained and its description is given. The results
  of the study of the basic statistical characteristics of the algorithm, including the determination of
  its effectiveness, and results of comparison with known parametric methods, are given. The area of possible
  practical use of the proposed algorithm is highlighted, where its effectiveness remains quite high.
  The prospects of using the proposed algorithm as part of the software and algorithmic support of monitoring
  systems for various purposes are noted.