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• TASKS OF CONTROLLING THE EXCHANGE OF PHYSICAL RESOURCES BETWEEN AGRICULTURAL MEANS WITH VARYING DEGREES OF ROBOTIZATION

  A.L. Ronzhin, Ngo Kuok Tien, Vinh Nguyen Van

  2020-07-10

  Abstract ▼

  The problem of controlling the interaction of unmanned aerial vehicles (UAVs) with ground-based robotic service platforms that perform the functions of transporting and transferring physi-cal resources needed to perform agricultural operations on open ground is considered. The com-bined use of heterogeneous ground and air robotic means expands the functional and sensory capabilities of automatic processing of agricultural land. In a number of cases, for example, when servicing energy supply systems and transporting air means, the problem of physical interaction arises between an unmanned aerial vehicle and a ground service robotic platform. The complexity of solving this problem is associated with the problems of landing, fixing and mechanized pro-cessing of batteries and agricultural resources placed on an aircraft on a service platform, as well as managing the sequence of service of a UAV group. Compared with ground equipment, the use of UAVs in agricultural tasks provides a number of advantages: lack of physical contact with the ground and soil compaction, a wider monitoring and processing area, better treatment of crops with liquid means due to the rotation of rotors without the use of additional devices. Available prototypes of service robotic platforms are distinguished by the complexity of internal mecha-nisms, the speed of service, the algorithms for the joint operation of the platform and the aircraft during landing and maintenance of battery. Autonomous UAV landing in modern research is con-sidered not only on a fixed site, but also on a mobile platform that carries out movement in various environments. Based on the results of the analysis of existing approaches, a classification of exist-ing service systems installed on robotic and mechanized platforms has been compiled. The pro-cessing characteristics of some common crops are considered. A list of operations of the agricultural production process, their duration and cost, as well as the possibility of mechanization. It is concluded that the cost of non-mechanized operations is much higher. A method has been devel-oped for assessing the required composition and quantity of equipment for cultivating agricultural land, characterized by a multi-criteria assessment using a linear combination of three main crite-ria for the total processing time, energy consumed, the cost of the equipment involved and providing numerical modeling and optimization of the volume of involved heterogeneous robotic systems. The results of numerical and simulation modeling of the amount of robotic equipment required for processing agricultural land using arbitrary units and approximate ranges of input parameter values are presented. The simulation was performed in the developed AgrobotModeling software, which also implements visualization of the interaction of unmanned aerial vehicles with agricultural ground service platforms and provides decision support on the optimal number of robotic tools needed to process a given agricultural land area.

• MOBILE-CLOUD SYSTEM FOR SOLVING PHOTOGRAMMETRY TASKS IN INDUSTRY

  A.N. Samoylov, Y. M. Borodyansky

  2021-11-14

  Abstract ▼

  With the development of the capabilities of mobile devices and the increase in the availability
  of wireless communication, the possibilities of building industrial automation systems have
  significantly expanded. The quality of digital photography obtained with a smartphone camera
  makes it possible to build mobile systems based on computer vision: for example, photogrammetry
  systems. There are several factors to consider. The first factor is that the tasks of processing digital
  photography for industrial purposes remain resource-intensive and cannot be fully implemented
  only on the basis of a mobile device. Therefore, it is required to transfer the execution environment
  for resource-intensive tasks to third-party computing power available on demand. The second
  factor is the stability and bandwidth of the communication channel - mobile devices are usually
  needed in remote locations where the deployment of desktop computers is not possible. Therefore,
  using a smartphone only as a camera is not always justified, since the transfer of an unprocessed
  image may take a long time or even be impossible. The third factor hindering the widespread
  use of mobile devices in solving photogrammetric problems is the variability and constant
  emergence of new methods of image processing and analysis. It is necessary to centrally create
  and replenish libraries of such modules. Thus, the creation of mobile photogrammetric measuringsystems requires combining the computing power of cloud services and the mobility of smartphones. The article proposes a method for constructing photogrammetric measuring systems
  based on mobile cloud computing, which provides a dynamic balance of the computational load on
  the nodes of the system, as well as the variability of functionality on mobile devices of users

• STUDY OF RETRANSMISSION SCHEMES IN WIRELESS SENSOR NETWORKS

  Alalvan Amin Raad Jihad, Shammari Najim Abed Mandila, D.A. Mishchenko, А. А. L’vov, M.S. Svetlov

  2021-12-24

  Abstract ▼

  Wireless sensor networks (WSNs) are being actively implemented in various systems for remote
  observation and monitoring of distributed objects. WSNs have a number of undoubted advantages:
  flexibility, efficiency, relative cheapness, and the possibility of rapid deployment. However,
  the exchange of information and data is carried out in the WSN using wireless communication
  channels, which are subject to inevitable interference and noise, which leads to transmission errors and even to the loss of transmitted data packets. Another challenge, not fully resolved, is the
  uneven distribution of consumed energy within the WSN in the face of stringent requirements for
  energy sources. Currently, there are two most widely used retransmission schemes in the loss of
  transmitted data, namely, hop-by-hop and end-to-end. Most of the well-known studies devoted to
  the issues of reliable data transmission in WSN using these schemes have been carried out experimentally.
  In addition, there are still no analytical methods for evaluating various reliable
  transport solutions, which complicates the analysis of the proposed WSN. Therefore, the aim of the
  proposed work is the development of analytical methods and algorithms for studying the operating
  characteristics of the signal relaying circuits in the WSN. Analytical methods are proposed for
  evaluating retransmission schemes in the WSN, based on a relatively new theoretical basis - the
  network calculus for packet-switched networks, which is a tool for determining the size of the network.
  First, traffic, service and energy cost models are introduced. Based on these models and
  network calculations, the maximum packet transmission delay and energy efficiency of the two
  main types of retransmission schemes: hop-by-hop and end-to-end retransmission, are analytically
  estimated. According to the results of the experiment, the maximum latency and the maximum
  power consumption of these two schemes are compared in several scenarios. In addition, the analytically
  calculated maximum delay is compared with the simulation results. With the proposed
  method, a suitable retransmission scheme can be selected based on the various requirements and
  constraints to be set.

• FEATURES OF THE CIRCUITRY OF OPERATIONAL AMPLIFIERS BASED ON COMPLEMENTARY FIELD-EFFECT TRANSISTORS WITH A CONTROL PN-JUNCTION

  N.N. Prokopenko, V.Е. Chumakov, А.V. Bugakova, А.Е. Titov

  126-135

  2025-08-01

  Abstract ▼

  The systematic component of the offset voltage (Voff) of two-stage BJT and CMOS operational
  amplifiers (Op-Amps) with classical architecture significantly depends on the numerical
  values (difference from unity) of the current transfer coefficient (Ki≈1) of the current mirrors (CM)
  used. This parameter of CM is also influenced by the Earley stress of their dominant active components.
  Current JFET mirrors are today a weak link in modern JFET analog circuitry and they
  are impractical to use in the structure of JFET Op-Amps. The article posed and solved the problem
  of the conditions for the elimination of CM in an Op-Amps based on field-effect transistors
  with a control pn-junction for the case when it is necessary to obtain a small Voff. Variants of practical
  circuits of input (InS) and intermediate (IntS) stages of microelectronic operational amplifiers
  based on complementary field-effect transistors with a control pn-junction (CJFET) are proposed.
  Their main feature is the absence of a current mirror, which, when implemented on a
  CJFET, negatively affects the main parameters of the Op-Amps in terms of the systematic component
  of the offset voltage, the attenuation coefficients of the input common-mode signal, and the
  suppression of noise on the power buses. In this regard, InSs and IntSs circuits are promising,
  which do not use this CJFET functional unit. The circuits of Op-Amps based on the developed InSs
  with an open gain of more than 80 dB and a systematic component of the offset voltage within 300
  μV with low current consumption in a static mode are presented. The relevance of the performed
  studies lies in the need to develop the theory of designing high-precision JFET and CJFET IPmodules
  for use in structures of low-noise analog interfaces of sensors of various physical quantities,
  including those operating in severe operating conditions (exposure to low temperatures and
  radiation) The proposed circuits can be implemented on wide-gap semiconductors (SiC JFET,
  GaN JFET or GaAs JFET).