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• CONTROL OF A MULTI-ROBOT SYSTEM BASED ON HIGHER-ORDER SLIDING MODES

  Nandanwar Anuj , L. А. Rybak , D. А. Dyakonov

  72-83

  2025-11-10

  Abstract ▼

  The article addresses the control problem of a second-order multi-agent robotic system with discrete time under network-induced delays. A novel approach to formation control is proposed, based on higher-order sliding mode control and cloud technologies. The interaction between agents is described using graph theory, where the Laplacian matrix  represents the communication channel between agents and the leader. The system dynamics are modeled by motion equations for the position and velocity of each agent. Special attention is paid to the impact of network-induced delays that occur during data transmission from sensors to the controller and from the controller to actuators. A multi-stage state predictor is developed, utilizing prediction methods to compensate for random delays in the network.
  The proposed control algorithm ensures rapid convergence of the system to the desired formation even in the presence of significant network delays. For each agent, a sliding surface and a reaching law are defined, taking into account multiple timestamps. A detailed stability analysis of the closed-loop system confirms the asymptotic stability of the developed control algorithm. Simulation results in MATLAB demonstrate the high efficiency of the proposed approach: a system consisting of five followers and one leader achieves the desired formation in 10.3 seconds and successfully maintains it despite random network delays. Compared to traditional first-order control methods, the new approach shows significantly improved performance, particularly in reducing chattering effects in control signals. The use of cloud technologies enables efficient real-time processing of large data volumes and implementation of complex prediction algorithms without overloading the local computational resources of the agents. The obtained results confirm the potential of the proposed approach for controlling multi-agent systems under real-world network constraints. The work also demonstrates the feasibility of using prediction methods to compensate for random packet losses and communication delays, ensuring reliable control and communication in dynamic, unpredictable scenarios

• DEVELOPMENT OF A FUNCTIONAL DIAGNOSTIC SYSTEM FOR THRUSTERS OF UNDERWATER VEHICLES

  A.V. Zuev, A.N. Zhirabok

  2020-07-10

  Abstract ▼

  The aim of the study is to increase the efficiency of operation of underwater vehicles (UVs) by using systems of functional diagnosis of their thrusters, by providing detection, localization and identification of minor faults. To solve this problem, the article proposes a new method containing two main stages. At the first stage, a bank of diagnostic observers is built to detect and localize emerging faults. At the same time, each observer is constructed according to a special procedure in such a way to be sensitive to different set of possible faults. At the second stage, additional ob-servers working in the sliding mode are synthesized to accurately estimate the fault values. At the same time, in contrast to existing solutions, it is proposed to use a reduced (having a smaller di-mension) model of the original system when constructing these sliding mode observers. This makes it possible to reduce the complexity of the obtained observers in comparison with the known methods, where full-order observers are built. The results of the research showed the efficiency and high quality of all synthesized observers. In all the considered cases, it was possible to detect the occurrence of typical faults, as well as to ensure the identification of their values. Highly reliable UV control systems can be created on the basis of the considered method.

• SYNERGETIC SYNTHESIS OF SLIDING MODE CONTROL FOR VEHICLE’S ACTIVE SUSPENSION SYSTEM

  A.S. Sinitsyn

  2020-07-20

  Abstract ▼

  This article discusses the problem of designing vehicle’s active suspension systems in which
  the actuator is not ideal and is a subject to the influence of hysteresis and dead zone. The main
  goal of this work is to synthesize a control system that reduces the influence of hysteresis and deadzone on the efficiency of the adaptive suspension system. System parameters like hysteresis require
  significant efforts to identify them and, moreover, can vary widely over the life cycle of the system.
  Thus, it is very difficult to take into account hysteresis in the synthesis of the control system, as
  well as the construction of observers. The solution to this problem is use of sliding control systems,
  which to a certain extent are robust to parametric and structural changes in the control object.
  Existing approaches to the synthesis of sliding control systems are based on a linear or linearized
  model of the control object. Thus, the effectiveness of such systems can vary significantly when the
  regulator operates as part of a real, non-linear control object. The proposed sliding mode control
  allows to reducing sensitivity of the system to disturbances due to imperfect actuator, and also
  takes into account the nonlinear structure of the control object. The efficiency of a closed system is
  investigated on a dynamic model built in Simulink package. The proposed controller is compared
  with an adaptive synergetic regulator. Road of class C (according to ISO 8608 classification) was
  selected as a disturbance. To investigate the effectiveness of the proposed control system, the following
  parameters are evaluated: weighted acceleration of the sprung mass; relative motion of
  suspension and tire reaction force. The RMS and maximum values are calculated for each parameter.
  The results of numerical simulations allow to conclude that the use of sliding control
  systems can improve the following adaptive suspension performance indicators: reduce the maximum
  value of the weighted acceleration of the sprung mass by more than two times and reduce the
  maximum load on the tire by more than 20 %.

• INVESTIGATION OF THE IMPACT OF COMPLEX FIRE CONDITIONS ON THE QUALITY OF SURVEILLANCE AND FLIGHT SAFETY OF UAVS

  M.I. Mokrova

  2021-04-04

  Abstract ▼

  Aviation monitoring of fires with the help of unmanned aerial vehicles (UAVs), in particular,
  forest ones, during which the search for various objects of interest is carried out: people, cars,
  etc., is one of the most effective measures to reduce the level of possible losses. In this paper, we
  consider approaches to the formation of algorithms for processing and improving images obtained
  in the process of monitoring the fire situation, based on the use of neural networks, as well as
  image filtering algorithms, in order to search for various objects of interest. Fire monitoring using
  an UAV is a two-criteria task: there is a need to protect the device from the thermal effects of the
  fire as much as possible, as well as to maximize the observability, which can be achieved by reducing
  the altitude of the flight. This paper presents the empirical models developed by the authors for
  the flight safety of an unmanned aerial vehicle and the observability of objects of interest in the
  process of monitoring the fire situation. The proposed models allow us to take into account the
  features of the monitoring conditions, such as the priority of detecting the object of interest to the
  security of the reconnaissance vehicle itself, air humidity, terrain and type of terrain, time of day,
  and so on. An example of the application of the contrast model is considered on the example of the
  search and detection of the "letter"label. On the basis of the conducted experiment on the recognition
  of the mark in the smoke, the analysis of the proposed models is carried out, the quantitative
  results are given. The paper describes the criteria for the optimal choice of the altitude of the
  flight of the device over the observed scene, which are formed on the basis of the base of expert
  assessments, as well as the proposed models of the observability and safety of the UAV flight. Depending
  on the target search task, the optimality criterion for choosing the UAV flight altitude
  over the observed scene may vary.