UNIVERSAL MEASURING MODULE BASED ON A THREE-COMPONENT FERROSONDE SENSOR AND A MAGNETIZATION STATION BASED ON ITS BASIS

The work is devoted to the description of the design of the measuring module (fluxgate magnetic compass) and the magnetovariation station (geophysical device) created on its basis. This station is designed to carry out geomagnetic work in various conditions - both stationary observation points and for work in the field.

Laboratory test results of a new developed low-cost and open-source inclinometer based on MEMS technology

<p>The stationary or in-place inclinometer is the main high-performance solution in landslide monitoring applications due to its capability of tracking real time displacement at different depth and supporting early warning. Despite that and the general need of data for understanding landslide behaviour, the high cost of in-place inclinometers, in most cases, limit or prevent their use. On this basis, we started developing a low-cost and open source, modular MEMS-based inclinometer that uses multiple Arduino boards as processing units. Although MEMS accelerometers have many advantages in comparison with traditional high-precision electromechanical sensors, they are very sensible to temperature variation (i.e. thermal drifting).</p><p>In order to compensating thermal drifting a specific thermal analysis and an associated simple compensation strategy were used. After the mitigation of thermal bias, the electronic devices were designed, built and assembled.</p><p>The developed inclinometer system is composed of two main electronic systems: 1) a multiple electronic device (i.e. a MEMS accelerometer, the IMU reading interface and a communication board) installed within each measuring module; 2) an external master control unit, based on the Arduino platform coupled with a dedicated developed interface board. The master unit reads tilt value from each measuring module through a communication interface. This unit was developed to allow interfacing of additional digital or analog sensors (e.g. water content, rain gauge, etc..), and control additional parameters.</p><p>A steel casing for measuring components was designed and built. For each measuring unit, a squared-section case, consisting of a 30 cm long tube equipped with 4 elements that allow the installation the instrument within a standard inclinometric tubes, was prepared and assembled.</p><p>After system assembling, displacement of the inclinometric column was first simulated by a laboratory test. In particular, we used a supporting frame that allowed to vertically align the modules. The auxiliary frame was specifically designed to drive displacement along a selected axis and to register the maximum displacement at the head of the inclinometric column. In this way, the lower module is kept fixed. This test permitted to obtain a number of different synthetic deformation curves that form a basis for checking the accuracy of the instrumentation measurement. Result obtained highlight the potential use of our system for real monitoring application. The next step will be to install the instrumentation on site to check its operation in real field conditions.</p>

Methodological Support for Applying the Method of Majority Reservation in Measuring Channels

Introduction. For hazardous industries, the reliability of information and measuring equipment must ensure an almost complete absence of failure events, with their probability as low as 10-6. This requirement can be satisfied using various approaches, one of which is reservation. Reservation methods are classified into several types depending on such factors, as the operating mode of an object, failure types, frequency rate, etc. Majority redundancy schemes are rarely used in measuring equipment, particularly in measuring channels, largely because this method was initially aimed at improving the reliability of discrete digital devices. Thus far, no mathematical support for applying the method of majority reservation in measuring channels of analogue values has been developed. This gap determined the relevance of this study.Aim. To develop a methodological support for applying the method of majority reservation with the purpose of improving the level of measurement accuracy.Materials and methods. Both Russian and foreign sources published over the past 40 years on the topic of processing small samples when designing measuring channels for information and measuring systems were reviewed. The nonparametric Mann-Whitney rank test was applied to process small samples. Other research methods included mathematical modelling, as well as the mathematical apparatus of measurement theory andтsystems theory.Results. A measuring module with a redundant structure was simulated. Parametric and nonparametric rank criteria were considered. An algorithm allowing identification of the failure of a channel in a measuring module with a redundant structure was developed. The computational complexity of the developed algorithm is estimated by a polynomial of the second degree.Conclusion. The use of nonparametric rank criteria for processing small samples, as well as diagnostic situations for various combinations of these criteria, supports statistically grounded decision on the state of measuring channels. In the future, this method will be applied for diagnostic control of the serviceability of technological equipment used in fuel combustion, namely in boiler plants and installations for thermal waste destruction.

Development of small-scale unmanned hydrofoil boats

Unmanned boats have gained a lot of interest in the maritime community during the last decade. Most hydrodynamic platforms employed for unmanned boats are based on traditional relatively simple hulls. In the present study, small-scale hydrofoil-assisted unmanned boats (0.6–0.7 m in length and 3.5–5.5 kg in mass) have been developed and tested. Design calculations using a hydrodynamic transverse-strip engineering method with semi-empirical correlations were applied to determine suitable dimensions for hydrofoil systems. The boat hulls and hydrofoils were fabricated by laying up carbon-fiber cloth sheets on foam cores or 3-D printed profiles. The boats were instrumented with outboard propulsors and electronic equipment for operations in both remote control and autopilot modes. In addition, an in-situ thrust-measuring module was designed and installed at the hull sterns to gather thrust data at GPS-measured speeds in the range between 0 and 11 m/s. The developed boats proved to be robust platforms capable of going over 600 m distances at high speeds while autonomously following preset paths. The presented methods and results can assist engineers developing unmanned surface vehicles that utilize advanced hydrodynamic concepts.

DIY approach to measuring surface water properties in the estuary

<p>The monitoring of water bodies, specifically complex ones such as estuaries, has been historically limited. Various research efforts were hindered due to the gaps in the technology implementation and accompanied by the price of developed solutions (usually as a black box for the end-user). However, thanks to the growing trend of open source solutions both in hardware and software domain, it has become more available to apply the DIY (do it yourself) approach and build the equipment that one might need. As all frugal innovations tend to emerge from a problem that had an existing commercial solution but was too demanding on resources, the floating measurement system presented in this study was designed to get surface water properties simultaneously in multiple points. Using multiple commercial probes to do such measurements was too expensive. Therefore, we have developed an innovative low-cost drifter based on the Arduino platform as an alternative. Our device is designed to measure position, temperature, and electrical conductivity in multiple drifter realisations or short-term moored measurements. The system consists of a floating container equipped with the following components: an Arduino Mega development board, a power management module, an SD card logging module, a Bluetooth module, a temperature measuring module, a global positioning satellite (GPS) position module, and a newly developed module for measuring electrical conductivity (EC). The applicability was tested at the estuary of River Jadro near Split (Croatia) and obtained spatial data (velocity, temperature, electrical conductivity and salinity) was analysed and compared with analytical models. All used tools are open-source and greatly supported by the worldwide community. Furthermore, we consider this prototype to be one of the first steps toward development of various DIY monitoring systems with a potential for a broader range of applications. We present our work with a purpose to initiate a dialogue with more collaborators interested in developing different variations of custom-built sensors for water properties.</p>

The Influence of Selected External Factors on Temperature of Photovoltaic Modules

The article deals with the impact of selected external factors on the temperature of photovoltaic module surfaces. Primary aim of this research is creation of temperature model for photovoltaic module, which would be usable under the real climatic conditions in Central Europe region. Fully autonomous measuring system was designed and created for temperature monitoring of different parts of photovoltaic modules. The measuring system consists of 24 temperature sensors, voltage inverter, control unit, transfer modules, receiver modules and temperature measuring module. The experiments were performed on photovoltaic modules installed on the roof of the University of Life Sciences in Prague during summer 2018. The temperature of photovoltaic modules significantly depends on the climatic conditions, which were monitored by the weather station. The temperature and the solar radiation dependencies for polycrystalline and monocrystalline photovoltaic modules were obtained in experiments conducted. The temperature relations were measured for different parts of photovoltaic module – active parts of photovoltaic module, frame, non-active parts of photovoltaic module, as well as ambient temperature. Final mathematical description of polynomial graphical dependencies was obtained after application of fitting procedure and regression analysis.