The paper investigates the task of the analytically  design of an optimal controllers (ADOC)  as defined by A. A. Krasovskij for stable multidimensional objects, which are described by matrix differential equations with polynomial non-linearity from phase coordinates.  The  investigated class of polynomial  control objects has a wide application: these models are used to describe the motion of systems with a very different nature — electromechanical  equipment, chemical reactors, industrial recycling facilities, biological and ecological systems,  etc.

The  most suitable  task  solution  for the ADOC  is the power series method,  which  in comparison  with other methods, allows to finding  control laws in widest range of the  object’s phase  space.  However, its realization  is dealt  with  a large amount  of calculations  and it is less formalized, so it comparatively  hard for programming. In this paper the quasi-optimal controller’s synthesis method is suggested. It can reduce the disadvantages  of the previously mentioned  power series method. It  uses the multidimensional linearization  of polynomial  objects procedure which  implements  extension  of the object state space with new coordinates. These coordinates are the products of the original phase coordinates and the application of the matrix theory with the Kronecker product. The synthesis method can help to find an approximate  ADOC task solution with a high degree of accuracy.  The  method  is very easy to use, because it mainly  based on uses of well-known software for the linear quadratic  task solution in the optimal control.

The  ADOC  task  solution  accuracy  is defined  by the accuracy  of the corresponding degree (k  = 2, 3...)  that  chosen for the object of the quasi-linearized model under study. It must be noted, that the k^th  power polynomial  components  of the control objects described,  is considered  in the k^th   power linearized  model.  Therefore, suggested synthesis method  provides an accurate  solution as a common  power series method, holding its terms to the k^th  power inclusive.  However, the devised synthesis  method  as a rule gives more  accurate  results,  because  it takes  into  account  the  functional  matrix  of the  used quasilinear  model of the object state augmented  vector containing the original object’s phase coordinates products.

Density is one of the most important properties of seawater and is used in various marine research and technology. Traditionally, in the practice of oceanographic research, it is customary to consider density as a dependent  parameter, which is a function of several other parameters taken  as independent.  Usually the following three parameters are used as the independent  parameters: temperature, hydrostatic  pressure  and  salinity.  The  issues  of  temperature  and  hydrostatic  pressure  measuring  in  situ  are  technologically  well developed,  while in the salinity measuring there are still unsolved problems. This is due to the fact that salinity is such a property that it is simply impossible to determine  directly in situ. To  eliminate  the problems associated  with measurements  of salinity, the authors developed  the special new kind  equation.  That  equation  of the new kind  express the density  of sea water through independent  and in situ measured  parameters:  temperature, hydrostatic  pressure and  sound  speed.  The  novelty  of this approach  is that  using of the sound speed as the independent  parameter makes  it possible to exclude measurements  of salinity. The authors developed two such new equations  for the different cases of using. The  first new equation  is intended  for use in technical  applications and reproduces the sea water density in a wide range of the aquatic environment  parameters with a root mean square deviation  of 0.062  kg/m³. The  second more precise new equation  is intended  for scientific applications  and  reproduces the sea water density  in a narrower oceanographic range of parameters with a root mean  square deviation  of 0.0018  kg/m³.

The  object of the study are the principles and methods  of hydroacoustic  reduction  of an autonomous  underwater  vehicle to a carrier. When solving the problem of constructing a hydroacoustic  navigation  system (HNS), the main  systemic issues are the choice of an acceptable method for locating an object in the reduction zone and estimating the options of the proposed navigation system from the point of view of technical implementation. The  feasibility of constructing the equipment  of a highfrequency hydroacoustic  reduction system in the form of a combined  information  and navigation antenna  system combined  in base, in which hydroacoustic  navigation systems with a short base can be used, is justified; as navigation it is suggested to use data signals exchanged  between the docking module  and the autonomous  underwater  vehicle based on the results of measuring the mutual  navigation  options. The  developed  sample of equipment  is part of a multifunctional network  of hydroacoustic communication and should ensure that in a near zone at distances not exceeding 300 m, an autonomous  underwater  vehicle is brought into contact  with the carrier. For this purpose, mutual  determination  of the distance  and  angular  position of the docking module  of the carrier and the autonomous  underwater  vehicle relative to each other is carried out. Determination  of the distance and angular position of the docking module of the carrier and the autonomous  underwater vehicle relative to each other is accompanied  by the transfer of data  between  them  along the hydroacoustic  communication channel.  The  proposed sample of high-frequency hydroacoustic  reduction system (HHRS) equipment  of short-range action is intended  for operation as part of a complex of technical  means  providing underwater  docking of an autonomous  underwater  vehicle with a carrier. The  obtained  quantitative  options of short-based  HNS are the  initial  indicators  of the  first approximation  when  selecting the necessary parameters of the navigation  signal and developing the structure of the AGSS  designed to solve the problem of automatically bringing the autonomous  underwater  vehicle (AU V ) to the docking module  (DM)  of the given carrier.

The paper is devoted to the problem of increasing the adequacy of perception of the environment by the mobile robot operator using remote control. A variant of a real-time surround-view system for mobile robot based on the multiple cameras with fisheye lenses and overlapping fields of view is proposed. A prototype of the circular view system has been developed. In this paper, the key features of the architecture and software of the surround-view system are considered. The algorithms for determining the internal parameters of cameras and distortion correction are researched. New models for describing the distortions of wide-angle and fisheye lens are used. Algorithms for finding the external parameters of cameras, as well as homography matrices using invariant descriptors, are implemented. Static homography matrices are used during stitching images into panorama. Various image-stitching techniques based on the overlapped images region blending are investigated and implemented. The methods of projective geometry and augmented reality were studied to obtain a perspective third-person view. A surface variant for projecting panorama of a surround view is proposed. For the implementation of the software selected cross-platform game engine "Unity". Directions for further research are identified.

Recent  advances  in the development  of sensors allowed to obtain robots with torque-sensitive sensors in each joint. At the moment,  these sensors are used only to detect collision. This work shows the possibility of obtaining information  on the collision point and  it type. This  information  can subsequently  be used to select the robot’s behavior  strategy. The  contact point localization  is realized  using two approaches: the analytical  approach and  machine  learning. Analytical  approach is based on finding point on the robot length and  direction of applied external  force where an equivalent  torques will be the same as torques in a real robot. In the machine  learning approach various learning technics were tested. For the collision type identification  a classification  tree was proposed that  distinguish  soft and  hard  collision,  purposeful  and  accidental, single and continuous.  The  algorithm at the first stage detects presence of a collision, and if there is a collision localizes it and identify  its type. The  described algorithms were tested on an industrial  manipulator  Kuka  iiwa LBR  14 R820, ground truth information  about the experiments  was obtained  using a 3D lidar.

The  theme  is topical  because  of the  ongoing Russian  lunar  program.  Four  more  launches  of Luna-25 to Luna-28 are planned  for the next several years. Only  in 8 out of 14 cases, the soft Moon  landing was provided.  This  fact prompts researchers to seek after new ways of solving this problem. The  article deals with a power-efficient  control algorithm that controls landing  engine thrust at the final phase of spacecraft landing  from a given hovering point to the point of contact with the Moon’s  surface.  Initially not supposed to be used for solution of terminal  control tasks, the power-efficient  algorithm can be applied here, which can be explained  by availability  of an auxiliary  system in it that provides reaching specified motion parameters within a specified period. At the final phase of soft Moon landing,  the proposed algorithm treats the spacecraft as a material  point that moves by the attractive force of the Moon  and the opposite vertical force of the landing engine  thrust.  It is supposed  that  to form  the  thrust  the  vertical  velocity  is measured  by a Doppler velocimeter  and  the altitude  by a multibeam  vertical-building radio altimeter, throughout the whole motion interval.  W hen calculating  the parameters of spacecraft motion under the conditions of the Moon’s gravitational field at the final phase of spacecraft contact with the Moon’s  surface by the mentioned  algorithm,  there is a possibility of some overcorrection,  which  is inadmissible. To exclude  it, a well-known approach is used when the motion  is considered  on the assumption  of absence of the Moon’s gravitational  field.  In this  case  the  control  will be implemented  without  overcorrection, but  to obtain  the  actual  engine thrust it is necessary to add the force opposite to the direction of the Moon’s attraction force, acting upon the spacecraft, to the algorithm-generated signal at every control step. The  author has mathematically modeled  the algorithm. The  results of modeling proved the appropriateness of the problem statement and allow finding the boundary  of the algorithm applicability: to exclude  reversing of the landing  engine thrust the initial  spacecraft  hovering altitude  should  be less than  647  m.  The algorithm can also be used for controlling automatic  landing of vertical takeoff  aircraft.

It is shown that with uniform and rectilinear motion of two, three or several free inert bodies in one-dimensional or three-dimensional  space, arbitrary inertial reference systems, including those associated with each of the moving inert bodies, are not substantially  equivalent  in part of the total kinetic energy. In the particular case, if two free inert bodies with masses m₁  and m₂ move relative to each other with a constant velocity v, then in the inertial reference system associated with the first body, the total kinetic  energy of the bodies is equal to E₁₁₂.  In the inertial reference frame associated  with the second body, the total kinetic energy of the bodies is equal to E₂₁₂. In an arbitrary (third) inertial reference frame, the first inert body moves at a speed v₁, the second at a speed v₂. In the third reference system, the total kinetic  energy is E₃₁₂. In terms of kinetic  energy, all three inertial reference systems are not substantially  equivalent.  At the same time, none of these reference systems is unique  or distinguished. If it is necessary to choose a unique or dedicated  inertial reference system, one can proceed from the condition of the minimum of the total kinetic  energy of moving inert bodies in this system. At the same time, a unique  or distinguished  inertial reference system is a relic reference system associated with the center of mass of moving inert bodies and with the epicenter of their initial hypothetical  interaction.  Relic reference systems are calculated.  Inert bodies do not necessarily interact with them initially.  The use of relic reference systems allows you to maintain  a balance between kinetic  energy and the work performed. The number of inert bodies in the calculation of the relic reference system can be arbitrarily large. If the theory of the Big Bang is true, then the world relic inertial reference system is connected with its epicenter, which is the center of mass of the universe.