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• GENERALIZED CIRCULAR CRITERION FOR THE ABSOLUTE SUSTAINABILITY OF DISTRIBUTED SYSTEMS

  Z. R. Mayransaev, A. B. Chernyshev

  2021-07-18

  Abstract ▼

  Systems control with distributed parameters is one of the complex and important sections of
  cybernetics, like the science of control, information and systems. The need to study and develop
  this scientific discipline is due to the fact that to control many objects you have to take into account
  their geometric parameters, that is, their spatial length. So far, many results have been
  achieved in the field of distributed system theory, but for the most part these results are aimed at
  the study of linear systems. In the course of researching non-linear automatic systems, as one of
  the main tasks, the task of finding possible states of equilibrium of the system under study is
  solved. Research into the sustainability of such systems is also a major challenge. Using the technique
  of decomposition of functions that describe distributed signals in rows, according to the
  general theory of the Fourier series, a class of distributed systems is allocated, in which decomposition by its own vector functions is permissible. Due to this capability, the transmission function
  that describes an object with distributed parameters appears as a combination of transmission
  functions in separate spatial mods. The concept of "generalized coordinates" is introduced to take
  into account the spatial coordinates. For systems with distributed parameters, the spatialamplifier
  gain factor is adopted as a direct non-linear angular angular ratio. A cylindrical criterion
  for the absolute stability of non-linear distributed systems has been developed and formulated,
  based on the generalization of the circular criterion. An illustration of the spatial sector of
  nonlineaivity is given. For the first time, a generalized circular criterion for the stability of distributed
  systems has been developed, taking into account the dependence of non-linear characteristics
  on spatial coordinates. A graphic illustration of this criterion is presented.

• STABILITY OF WALKING MACHINES AND ROBOTS IN UNDERWATER CONDITIONS

  V.V. Chernyshev, I.P. Vershinina, V.V. Arykantsev

  2020-07-10

  Abstract ▼

  When carrying out underwater technical works, walking machines and robots moving along the bottom significantly surpass traditional vehicles in terms of traction and cross-country ability. The exploitation conditions of underwater walking robotic systems - a rough terrain of the seabed, slopes, weakly bearing soil, etc., determine the urgency of the problem of their stability. The paperdiscusses the results of theoretical and experimental studies aimed at ensuring the dynamic stabil-ity of walking machines and robots in underwater conditions. The novelty of the study is provided by the specific features of their operating conditions. The studies are based on the test results of the 6-legged underwater walking device MAK-1. The instability of the walking device may be caused by the gait features. Also, the loss of stability of the walking device can occur when meet-ing with an unrecognized obstacle and when overcoming slopes. Mathematical modeling of the dynamics of statically unstable gait is carried out. The main stages of the phase of movement of the device in an unstable position are analyzed. It is shown that underwater conditions, dynami-cally stable walking of a 6-legged walking device with cyclic movers is also possible in the case of independent legs drives of the right and left side. The methods of autonomous response to a meet-ing with an unrecognized obstacle are considered. Various typical situations that arise when mov-ing along an unorganized surface are analyzed. The methods of self-adaptation and self-management of legs based on fuzzy algorithms, that exclude the occurrence of emergency situa-tions, including rollover, are proposed. The features of overcoming slopes by walking vehicles in underwater conditions are considered. In traditional vehicles movement, rollover or slide downhill is possible. It is shown that on weak soils downhill slide of walking machine is unlikely. This is due to significant deformations of the soil under the supporting elements (feet) of walking machines. A method of increasing the resistance to tipping over when moving a walking device along a slope due to the separate tuning of the conditional clearance of the walking mechanisms is considered. Particular attention is paid to the stability of drilling walking platforms moving along the bottom. Their specificity is the high location of the center of mass. Possible stages of walking platforms rollover are considered. The stabilizing effect of an increased location of the center of floatation is shown. The results of the work can be demanded in the development of walking machines and robots designed for underwater technical works, for new industrial technologies for the develop-ment of the seabed resources, to ensure the antiterrorist and technological safety of underwater infrastructure objects and other works.