Terrain Types Research Articles

Dimensional optimization of rocker-bogie suspension for planetary rover based on kinetostatics and terramechanics

Dimensional optimization is important for planetary rovers to reach good performance, such as high mobility, stability, and low energy consumption. The paper presents a dimensional optimization for a planetary rover with rocker-bogie suspension. During the optimization process, the influence of dimensions on the actuation requirements is studied based on kinetostatics and terramechanics. The objective function is built considering the average driving torque requirements in the most common type of windblown terrain in Mars called megaripples. The optimal dimension design is reached through the genetic algorithm, and the influences of dimensional parameters on rover performances are studied by drawing performance atlases. This work realizes the consideration of energy consumption in the design phase of a planetary rover. Finally, the results guide the design of a rover prototype and are validated by a series of experiments.

ECOLOGICAL GEOMORPHOLOGY, ITS SUBJECT, HISTORICAL ASPECTS AND METHODS

Paper considers ecological geomorphometry as the scientific area aimed at the study of place and functions of terrain and modern morphogenetic processes in the functioning of other components of natural environment, ecosystems, and in shaping of the conditions for human activities, applying the methods of quantitative spatial analysis. Some terminological issues are considered, as well as a short history of geomorphometry, its main tasks and research methods. In particular, the methods of quantitative analysis of the structure of terrain surface are considered, namely –the detection of the spatial trends, of periodicity, and of the spatial autocorrelation. The capabilities of the method of autocovariogram building and analysis are shown for the purpose of the studies of terrain elements, forms and types, their automatic delineation and classification. The basics of ecologically grounded classification of morphometric variables are considered, as well as the principles of the delineation of complex morphometric variables (topographic ecological indices), which reflect the impact of terrain morphology on ecological processes and ecological factors distributions. The main principles of ecological classification of terrain elements are also considered, together with the automatic delineation of terrain forms and types on the basis of their geometric signatures, that are defined through the distribution of the set of morphometric variables and the parameters of their spatial variability. Paper also reviews former studies by the author in the areas of morphometric analysis of the terrain surfaces of several study areas in Ukrainian Carpathians; the automatic terrain classification and segmentation; the analysis of the relationships between morphometric variables and ecological factors, the character of ground cover and the vegetation. Key words: ecological geomorphometry; topographic surface; morphometric variables; morphotop, autocovariogram; geometric signature.

CALCULATION OF THE PARAMETERS OF THE WIND TURBINE ROTOR TEMPERATURE SENSOR

Today, all the processes associated with technology, mainly operate in autonomous modes, so devices such as a temperature sensor are a must. Since technical progress is taking place in industry and production by leaps and bounds, all equipment most often used in various kinds of processes and work has an automatic principle of operation [1]
 However, for productive work, albeit automated units, it is necessary to comply with all the exact indicators at which the device's performance will be the highest. These indicators include values, namely the required, more precisely, the working pressure, speed, and temperature. To prevent rapid wear and overload of automated equipment, the temperature level must be measured. Of course, this is not done with a simple thermometer or thermometer. For these purposes, special devices are used, such as temperature sensors. Wind power is one of the most important renewable energy solutions. As a rule, wind farms are located far from civilization, in remote regions - in hilly areas, on the sea coast [2]. These types of terrain are chosen because wind energy becomes profitable only under conditions that allow obtaining the maximum amount of wind throughout the year. However, the harsher environment calls for more sophisticated wind turbines, usually consisting of towers, blades, hubs and nacelles. To ensure control over all parts of the wind turbine, companies install controllers near the tower. A wind generator controller, like a PLC, is the brain of any wind generator, providing control over the system as a whole, the ability to generate reports and monitoring. The generator must be controlled and programmed; without a controller, it couldn't work correctly. For this reason, the controllers must be connected to a single system for remote monitoring, power generation reporting, parameter monitoring and diagnostic maintenance [3].This article provides an algorithm for calculating a temperature sensor for its correct selection for a wind generator system, which will subsequently be used for a temperature control system in a generator system.

Monitoring surface deformation of permafrost in Wudaoliang Region, Qinghai–Tibet Plateau with ENVISAT ASAR data

Permafrost in Qinghai–Tibet Plateau (QTP) has been suffering from global warming in recent years, characterized by the deepening of the permafrost active layer. Seasonal changes in permafrost are usually reflected as ground surface deformation, which can be monitored by multi-temporal interferometric synthetic aperture radar (MT-InSAR) technology. Owing to the extreme environment in the QTP, there are few ground-based deformational observation data available, and records of permafrost monitoring by MT-InSAR with ground validation are limited. Here we present a study of surface deformation monitoring for permafrost with MT-InSAR technology validated by a large number of in-situ observations compared with the previous published results. In this study, a small baseline subset (SBAS) method was used with ENVISAT ASAR data in WuDaoLiang, QTP, to acquire the surface deformation and to analyze the corresponding characteristics. The results were first validated with 24 GNSS leveling observation points along the Qinghai–Tibet Railway, including numeric validation (e.g., statistics and KS test) between the InSAR derived deformation and the time-interpolated GNSS leveling values, and the variation trend of the two deformation sequences during a permafrost deformation period, at each observation point. Considering both the differences in magnitudes and trends, the deformation at 22 out of 24 points detected by InSAR corresponded well to the GNSS observation series over one year, which indicates the reliability of MT-InSAR for permafrost monitoring. After validation, the amplitudes and linear velocity of the InSAR deformation in this region were calculated and analyzed, together with selected points in different types of terrain. Generally, in the deformation map, most pixels show a trend of periodic and seasonal displacement, uplift in winter and subsidence in summer, with amplitudes of 3–10 mm in most regions. The deformation in mountain areas is less than that of flat lands in amplitude, and shows more randomness in periodic characteristics. Meanwhile, some points with obvious settlement have been detected, probably corresponding with permafrost degradation.

NOAH-H, a deep-learning, terrain classification system for Mars: Results for the ExoMars Rover candidate landing sites

In this investigation a deep learning terrain classification system, the “Novelty or Anomaly Hunter – HiRISE” (NOAH-H), was used to classify High Resolution Imaging Science Experiment (HiRISE) images of Oxia Planum and Mawrth Vallis. A set of ontological classes was developed that covered the variety of surface textures and aeolian bedforms present at both sites. Labelled type-examples of these classes were used to train a Deep Neural Network (DNN) to perform semantic segmentation in order to identify these classes in further HiRISE images.This contribution discusses the methods and results of the study from a geomorphologists perspective, providing a case study applying machine learning to a landscape classification task. Our aim is to highlight considerations about how to compile training datasets, select ontological classes, and understand what such systems can and cannot do. We highlight issues that arise when adapting a traditional planetary mapping workflow to the production of training data. We discuss both the pixel scale accuracy of the model, and how qualitative factors can influence the reliability and usability of the output.We conclude that “landscape level” reliability is critical for the use of the output raster by humans. The output can often be more useful than pixel scale accuracy statistics would suggest, however the product must be treated with caution, and not considered a final arbiter of geological origin. A good understanding of how and why the model classifies different landscape features is vital to interpreting it reliably. When used appropriately the classified raster provides a good indication of the prevalence and distribution of different terrain types, and informs our understanding of the study areas. We thus conclude that it is fit for purpose, and suitable for use in further work.

Regions of interest on Ganymede's and Callisto's surfaces as potential targets for ESA's JUICE mission

The JUpiter Icy moons Explorer (JUICE) will investigate Ganymede's and Callisto's surfaces and subsurfaces from orbit to explore the geologic processes that have shaped and altered their surfaces by impact, tectonics, possible cryovolcanism, space weathering due to micrometeorites, radiation and charged particles as well as explore the structure and properties of the icy crust and liquid shell (Grasset et al., 2013). The best possible synergy of the JUICE instruments is required to answer the major science objective of this mission and to fully exploit the potential of the JUICE mission. Therefore, the JUICE team is aiming to define high priority targets on both Ganymede's and Callisto's surfaces to support the coordination of the planning activities by the individual instrument teams. Based on the science objectives of the JUICE mission and the most recent knowledge of Ganymede's and Callisto's geologic evolution we propose a collection of Regions of Interest (RoIs), which characterize surface features and terrain types representing important traces of geologic processes, from past and/or present cryovolcanic and tectonic activity to space weathering processes, which are crucial to understand the geologic evolution of Ganymede and Callisto. The proposed evaluation of RoIs is based on their scientific importance as well as on the opportunities and conditions to observe them during the currently discussed mission profile.

Navigating by touch: haptic Monte Carlo localization via geometric sensing and terrain classification

Legged robot navigation in extreme environments can hinder the use of cameras and lidar due to darkness, air obfuscation or sensor damage, whereas proprioceptive sensing will continue to work reliably. In this paper, we propose a purely proprioceptive localization algorithm which fuses information from both geometry and terrain type to localize a legged robot within a prior map. First, a terrain classifier computes the probability that a foot has stepped on a particular terrain class from sensed foot forces. Then, a Monte Carlo-based estimator fuses this terrain probability with the geometric information of the foot contact points. Results demonstrate this approach operating online and onboard an ANYmal B300 quadruped robot traversing several terrain courses with different geometries and terrain types over more than 1.2 km. The method keeps pose estimation error below 20 cm using a prior map with trained network and using sensing only from the feet, leg joints and IMU.

Echo State Networks for Estimating Exteroceptive Conditions From Proprioceptive States in Quadruped Robots.

We propose a methodology based on reservoir computing for mapping local proprioceptive information acquired at the level of the leg joints of a simulated quadruped robot into exteroceptive and global information, including both the ground reaction forces at the level of the different legs and information about the type of terrain traversed by the robot. Both dynamic estimation and terrain classification can be achieved concurrently with the same reservoir computing structure, which serves as a soft sensor device. Simulation results are presented together with preliminary experiments on a real quadruped robot. They demonstrate the suitability of the proposed approach for various terrains and sensory system fault conditions. The strategy, which belongs to the class of data-driven models, is independent of the robotic mechanical design and can easily be generalized to different robotic structures.

THE PHYSIOGRAPHY OF INDIA: AN OVERVIEW

Physiography is a field of geography that studies the physical patterns and processes of the Earth, such as geomorphology, hydrology, soil, rocks, biogeography, and the effects of tectonic forces on landscapes. This paper aimed to discuss the physiographic characteristics of India due to its diverse geographical features by using a systematic search and collection of publications and secondary data. The characteristics of India's physiography were discussed descriptively and visually. This study highlights the fundamental physiographic divisions, sub-divisions, and socioeconomic functions of each type of terrain in India, including the northern mountain range, northern plains, peninsular plateau, coastal plains, and islands (the eastern and western coastal plains, Andaman and Nicobar islands). This overview concluded that the physiography of India is complex, heterogeneous and could be categorized into four divisions with distinct characteristics. In detail, the Himalayan Range is a mountainous region in the northern part of the country which produced by the fold mountain processes. Meanwhile, the Indo-Gangetic Plain was well recognised for its extensive agricultural activities contributed by the Ganges River. India's diverse landforms had a profound impact on the country's cultural and economical development. On the other hand, this study also demonstrated that the plateau region in the country's southern and central regions was geographically diversified. The different landscapes of India influenced the socioeconomic characteristics of the Indian society and consequently supported national development of India.

Elevation-angle based two-ray path loss model for Air-to-Ground wireless channels

Air-to-Ground (A2G) communication is considered as a significant enabler technology in next-generation networks. To make this a reality, a comprehensive understanding of the A2G channels is vital. This paper presents an Elevation Angle (EA) based two-ray mean path loss model for the A2G channels. In particular, we present closed-form expressions for the path loss with respect to the elevation angle and compare the results with ray-tracing simulation results. Our results show that mean path loss for the A2G channels can be accurately characterized by the proposed EA based two-ray model. Our study investigates different altitudes of the aerial terminal, different types of terrains, and two polarizations, wherein the proposed EA-based two-ray model matches well with the ray-tracing simulation results. Furthermore, a comparison of the proposed model with the other known path loss models in the literature is conducted. Finally, this work reveals an interesting relationship between the elevation angle and the signal down-fades, that these signal down-fades appear at approximately the same elevation angles regardless of the platform altitude.

Impact of Weight Carriage on Joint Kinematics in Asian Elephants Used for Riding.

Simple SummaryRiding elephants is one of the most controversial activities in the tourist industry, with concerns over whether load carrying is physically harmful. Here, we used an empirical approach to test how carrying loads up to 15% of the elephant’s body mass affected gait parameters. The maximal angles of fore- and hindlimb joints of elephants walking at a normal, self-selected speed carrying a mahout only were first evaluated and then compared to those walking with a saddle carrying two people plus added weight to reach a 15% body mass load. Data were analyzed using a computerized three-dimensional inertial measurement system. There were no significant differences between movement angles, including flexion, extension, abduction, and adduction of the fore- or hindlimbs between these two riding conditions. Thus, we found no evidence that carrying two people in a saddle causes significant changes in gait patterns or potentially affects musculoskeletal function. More studies are needed to further test longer durations of riding on different types of terrain to develop appropriate working guidelines for captive elephants. Nevertheless, elephants appear capable of carrying significant amounts of weight on the back without showing signs of physical distress.Background: Elephants in Thailand have changed their roles from working in the logging industry to tourism over the past two decades. In 2020, there were approximately 2700 captive elephants participating in activities such as riding and trekking. During work hours, riding elephants carry one or two people in a saddle on the back with a mahout on the neck several hours a day and over varying terrain. A concern is that this form of riding can cause serious injuries to the musculoskeletal system, although to date there have been no empirical studies to determine the influence of weight carriage on kinematics in elephants. Methods: Eight Asian elephants from a camp in Chiang Mai Province, Thailand, aged between 21 and 41 years with a mean body mass of 3265 ± 140.2 kg, were evaluated under two conditions: walking at a normal speed without a saddle and with a 15% body mass load (saddle and two persons plus additional weights). Gait kinematics, including the maximal angles of fore- and hindlimb joints, were determined using a novel three-dimensional inertial measurement system with wireless sensors. Results: There were no statistical differences between movement angles and a range of motion of the fore- and hindlimbs, when an additional 15% of body mass was added. Conclusion: There is no evidence that carrying a 15% body mass load causes significant changes in elephant gait patterns. Thus, carrying two people in a saddle may have minimal effects on musculoskeletal function. More studies are needed to further test longer durations of riding on different types of terrain to develop appropriate working guidelines for captive elephants. Nevertheless, elephants appear capable of carrying significant amounts of weight on the back without showing signs of physical distress.

Flow rate regime of the Western Urals’s rivers

The flow rate is one of the most important elements of the river’s water regime. Establishing patterns in river flow rates’ changes within a year and by season is of great importance for the hydrological forecasts for spring floods, rain floods and hydrological calculations. By now, there are few publications on this area, both in Russia and abroad. The initial data were divided into 5 hydrological seasons – winter and summer low water, rise and fall of spring floods and autumn rain floods. For each season, an analysis of river flow rate over a period (1936-2013) was done. The average flow rate in rivers varied greatly depending on the water regime’ phase and the type of terrain in which the river flows. For all seasons, the amplitude of fluctuations in the flow rate on the plain rivers is less than on the mountain ones. So, in mountain rivers, flow rates vary from 0.04 to 2.42 m/s, and on flat rivers from 0.02 to 1.43 m/s. As well the pairwise and multiple correlation coefficients of flow rates for each morphometric and catchment characteristics were calculated. The highest correlation coefficients were obtained for the dependency between the average flow rate and the watershed elevation (0.30-0.75) and the watershed slope (0.42-0.76). The multiple correlation coefficients between the average flow rate and all catchment’s morphometric characteristics varied from 0.97 to 0.99. Results verification on an independent data demonstrated that the relative error was on average 2%.

Europa Clipper Preparatory Photometry to Constrain Surface Properties

Abstract We infer the surface reflectance properties of Europa using multispectral data sets available from previous missions. We use 21 full-disk images of Europa from Voyager’s Imaging Science System, Galileo’s Solid State Imaging, and New Horizons’ Long Range Reconnaissance Imager at differing observation geometries (10°–128° (phase angle)) to compute disk-integrated surface-scattering properties over various geologic units. The derived empirical photometric models will serve the practical goals of data acquisition, aid in the calculation of instrument integration times, and facilitate quick-look data products for images acquired by Europa Clipper and other future missions to Europa. We use the Minneart and Lommel–Seeliger plus Lambert reflectance models to constrain the photometric parameters of Europa’s surface. We find that the surface albedo parameter, B 0, in the Minneart function gradually decreases with increasing phase angles. We also note that the photometric properties of Europa (geometric albedo at 0.47 μm is 0.72 on the leading side and 0.62 on the trailing side) require a significant “Lambert” term (A < 1) in the Lommel–Seeliger plus Lambert reflectance model. We also observe that the photometric parameters are not highly dependent on the geologic terrain type despite their visibly different albedos.

APPLICATION OF EXERGETIC METHOD FOR EVALUATION OF PROCESS PERFECTION IN DIESEL ENGINE SUPERCHARGING SYSTEM

One of the most important trends of the modern combat vehicles is increasing their mobility for the security of the crew and for fast movement in different types of terrain. Compliance with these criteria is ensured by the engine of the armored vehicle. The competitiveness of domestic engines for armored vehicles should be ensured by the creation of new structures, their constant modernization and further improvement of performance. One of such engines is a forced diesel engine 6DN12/2x12 with a capacity of 1100 kW. In order to improve its performance and increase the level of forcing, it is proposed to improve the air supply system of the engine. Evaluating the effectiveness of the system can identify nodes that need changing design parameters. Therefore, such a qualitative analysis also indicates the feasibility and the possibility of further modernization of the system design. The qualitative analysis of the turbocharger is carried out on the basis of exergy method, which allows identifying sources of energy losses in the system design and determines the degree of perfection of processes. The application of the exergy method is due to the purpose of determining the reserves to improve the efficiency of the turbocharger elements, the magnitude of the supplied exergy and exergy efficiency in the nodes of the air supply system. According to the method, an exergy scheme of the supercharging system was constructed, on the basis of which the energy-exergy balance of each compressor unit was derived. The results of the analysis allowed to determine the parameters of the flow of the working fluid in the characteristic sections of the compressor and turbine and exergetic efficiency of the supercharging system. The calculated data obtained by exergetic analysis provide an estimate of the distribution of energy losses and allow determining the areas for further improvement of the air supply system and providing an opportunity to choose such design parameters that achieve the most effective improvement of the system.

RETRACTED ARTICLE: Application of remote sensing image classification based on adaptive Gaussian mixture model in analysis of mountain environment features

The adaptive Gaussian mixture model is a probability model that can be used to represent the probability distribution of K in the overall distribution. The mixed model represents the probability distribution of the overall observed data. This is a mixed distribution composed of K sub-distributions. In the mixed model, in order to calculate the probability of the observation data in the overall distribution, the observation data is not required to provide information about the sub-distribution. The EM algorithm is used to estimate the parameters of a probability model with hidden variables. Large-scale analysis of remote sensing images of various temporal, climate, and terrain types of mountain environmental characteristics is one of the most important issues at present. In this experiment, 6 Landsat TM remote sensing images with different longitudes and latitudes, different land use patterns, different realities, different ranges, different terrains, and different climates were selected as the research objects. Through their comprehensive comparison, the general ones were selected. The supervised classification method (most likelihood method, BP neural network and support vector machine method) classifies Landsat TM remote sensing images. In order to improve the accuracy of remote sensing image classification and the accuracy of land use information extraction, data such as normalized vegetation index and texture features are used to classify the experimental samples. Cluster statistics and filter analysis are used to classify the results. Finally, a confusion matrix is used to evaluate the accuracy of the classification results.

Regional study of Ganymede’s photometry

In this study, we present a regional photometric study of Ganymede’s surface to improve our understanding of its physical state. We created a comprehensive photometric dataset based on images taken with Voyager’s Imaging Science Subsystem and the New Horizons’ LOng Range Reconnaissance Image. We corrected for inconsistencies in the geometric metadata (camera position and orientation) and in the absolute calibration. We selected 20 regions of interest across the surface in different types of terrains. For each of them, we derived the Hapke model parameters using an inversion process based on a Monte Carlo Markov Chain in the Bayesian framework. Results are used to characterize surface properties in these different areas (single scattering albedo, roughness, shape of the grains from the phase function). We found that most general trends are consistent with past integrated studies. Ganymede has: (i) a slightly darker equatorial trailing hemisphere, (ii) a fairly elevated macroscopic roughness, (iii) a mostly backscattering behavior. However, we see an important diversity in the different regions we surveyed. We found a number of forward scattering regions both in the polar and equatorial regions that could be related to interaction with magnetospheric plasma but also be the sign of endogenic local activity. This gives us valuable insight in the preparation of ESA’s JUCIE mission whose main target will be Ganymede.

A random parameters with heterogeneity in means and Lindley approach to analyze crash data with excessive zeros: A case study of head-on heavy vehicle crashes in Queensland

This study performed statistical analyses to identify likely crash contributing factors for Head-on Fatal and Serious Injury (FSI) collisions involving heavy vehicles (HVs) on the Queensland state road network. Head-on HV collisions are associated with the largest number of fatalities compared to other crash types in Queensland. However, there is limited relevant literature regarding this type of crashes. Recent studies on road safety research have focused on variants of random parameters models to capture unobserved heterogeneity that may influence the occurrence of crashes. Among such models, random parameters with heterogeneity in means has recently provided better results and has become popular. However, this study illustrates a potential limitation regarding the use of these models without explicitly factoring for excessive zero crash observations. To address this potential limitation, a random parameters with heterogeneity in means and a Lindley distribution is introduced in this study to factor for the unobserved heterogeneity using additional variables as well as site-specific variation from excessive zero crash observations. Results showed that a Poisson model with random parameters and heterogeneity in means using a Lindley distribution outperformed multiple alternative state-of-the-art specifications in terms of fit as well as overall prediction ability. The analyses using the proposed modelling approach revealed factors likely to affect the likelihood of Head-on FSI crashes involving HVs in Queensland including volume, segment length, period of analysis, terrain type being rolling, curve (moderate/sharp/very sharp) longer than 50% of the corresponding segment length, rural single carriageway with high (>=100 kph) and medium (>=50 and <100 kph) speed limits, and urban single carriageway. Unobserved heterogeneity regarding the parameter for road curvature was explained using rolling terrain type as an explanatory variable. This study has explained variation in the means of random parameters for a road attribute using the effect of a geometric variable, in which several stakeholders are primarily interested.

Рост и состояние смешанных древостоев лесных насаждений Каменной Степи

By now, a vast amount of experimental material has been accumulated in the field of protective afforestation of the Central Chernozem Region of Russia, which allows estimating the stability and longevity of various trees and shrubs in different environmental conditions. Good growth and high vitality of woody vegetation largely depend on growing conditions and are determined primarily by the relationship between species (individuals within a species) when they are placed in the forest area and the type of terrain. The researchdifferent combinations in tree and shrub mixing schemes and unequal location by types of terrain. The study was carried out in mature (115–118-year-old) forest strips laid out by the staff of the Kamennaya Steppe experimental forestry G.F. Morozov and N.A. Mikhailov on the territory of the Kamennaya Steppe (Voronezh region, Talovsky district) using archival materials, scientific works of the authors of this article and the employees of the Department of Agroforestry. A comparative analysis of the materials of forest survey work carried out in protective forest plantations created according to the tree-shrub type of mixing on different types of terrain revealed an excess of biometric indicators of tree species growing on the upland type of terrain over those on the slope. It is shown that the initial percentage of participation of English oak is a significant, but not always decisive factor in the creation of oak plantations. They can also be grown with a smaller proportion of this species in the culture, but in this case, timely thinning will be of paramount importance. Over time, there have been significant changes in the composition of plantations, the number of trees and their valuation indicators. There are no viable ash and elm specimens left in the upper tier of the stands. They are severely damaged by stem pests. Certain tree species are damaged by the following pests: common ash by large ash bark beetle (Hylesinus crenatus) and ash bark beetle (Hylesinus fraxini); elm species by cambium-feeding beetles (large elm bark beetle (Scolytus scolytus), European elm bark beetle (Scolytus multistriatus), and pygmy elm bark beetle (Scolytus pygmaeus); English oak by gold pit oak splendour beetle (Chrysobothris affinis), oak borer (Agrilus angustulus), longhorn beetle (Plagionotus detritus), and European oak bark beetle (Scolytus intricatus). The predominant number of trees of all tree species belongs to the categories of limited viable and inviable.

Design and Control Method of a Planar Omnidirectional Crawler Mechanism

AbstractOmnidirectional mobility is a popular method of moving in narrow spaces. In particular, the planar omnidirectional crawler previously developed by the authors can traverse unstable and uneven terrain with a large contact area. A novel point is that the proposed system is unique in its ability to carry heavy loads in all directions without getting stuck because of the large pressure-receiving area between the crawler and the ground. This work will facilitate omnidirectional motion, which has important implications for the use of robots in spaces such as not only factories, distribution centers, and warehouses but also soft soil in disaster sites. The objective of the present study was to establish a design and control method for an omnidirectional crawler mechanism that can conduct holonomic and two-axis cross-driving. Only two motors are set on the crawler base for translation in the X- and Y-directions, and two large crawler units are arranged for turning. We design a small crawler that has higher traversing ability with a derailment prevention mechanism and tapered track. Further, the relationship between the motor rotational speed as input and crawler velocity as output was verified for control. In addition, it was demonstrated experimentally that the proposed crawler could travel across various types of rough terrain in a target direction.

A New Approach for the Analysis of Deep Convective Events: Thunderstorm Intensity Index

In this study, an investigation of a new thunderstorm intensity index (TSII) derived from lightning data is performed, along with its relationship to rain, wind, hail and waterspouts as well as instability indices (CAPE, LI, KI, and DLS). The study area is located in the northeastern Adriatic and includes various terrain types in a relatively small area (coastal, flatlands, hills and valleys, and mountain regions). The investigated period covers 11 years (2008–2018). The mathematical algorithm standing behind the TSII is based on the well-established methodology of lightning jump, allowing us to recognize areas where intensification in thunderstorms occurred. Our results suggest that these areas (with a positive TSII) experience significantly higher rain intensities and have higher total amounts of precipitation compared with areas where thunderstorms did not generate a TSII. Moreover, 76% of thunderstorm hail cases were associated with the presence of a TSII within a 15 km distance. The maximum reported wind speed also has higher values on a day with a TSII. Out of 27 waterspout events associated with lightning, 77% were related to a TSII. Due to the good spatial (3 km × 3 km) and high temporal (2 min) resolution of lightning data, the TSII can recognize even a local and short-lived intense system that is often misread by radars and satellites due to their inferior temporal resolution. The TSII is designed to be used as a climatological and diagnostic variable that could serve in lieu of more established data sources (e.g., station measurements and observations, radar imagery, etc.) if they are unavailable.