Straight-line Movement Research Articles

Adaptive Filter Approach for Enhancing Localization Accuracy in Mobile Robots

This article focuses on improving the positional accuracy of mobile robots. Positional accuracy is crucial for robots to reach target points precisely and efficiently. The study combines data from wheel odometry and LiDAR sensors using an adaptive complementary filter. This method aims to merge the advantages of these two data sources while minimizing their disadvantages. LiDAR sensors can map the environment with high accuracy but suffer from issues such as delayed updates due to processing time and reduced reliability in the presence of moving objects. On the other hand, wheel odometry provides real-time data but is prone to errors caused by mechanical wear and slippage, especially on uneven or slippery surfaces. The adaptive complementary filter dynamically weights the reliability of sensor data to address these challenges. In the study, the proposed method continuously optimizes the robot's position and orientation, enhancing motion accuracy. Experimental results demonstrate that during scenarios such as wheel slippage, the system relies more on LiDAR data to maintain positional accuracy, while during straight-line movements, wheel odometry is prioritized for its reliability. This research presents an effective solution for enabling mobile robots to operate more reliably under real-world conditions.

Task-specific temporal prediction mechanisms revealed by motor and electroencephalographic indicators.

Time prediction is pervasive, and it is unclear whether it is supra-modal or task-specific. This study aimed to investigate the role of motor temporal prediction in preparing to stop a movement following a sensory stimulus. Participants performed a straight-line movement with their finger until a target signal, which occurred after a short or long foreperiod. In one task, participants changed movement direction between trials (multidirectional task), while in the other, they always moved in the same direction (unidirectional task). The motor trajectory and EEG signals were continuously recorded. During the foreperiod, participants slowed down their movement, reflecting preparation to stop. To assess the influence of motor temporal prediction we examined how a given trial influences performance on the subsequent trial (sequential effect) when the movement changes or stays the same (multi- vs. unidirectional). In the unidirectional task, but not in the multidirectional task we found sequential effects on several behavioural parameters. In contrast, sequential effects were observed in both tasks on EEG results. This study revealed a temporal prediction related to motor movement (behavioural indicators), and a temporal preparation while waiting for the target (EEG indicator). These findings highlight the importance of considering various temporal prediction mechanisms.

Advanced Leader-Follower Control Strategies: Integrating Adaptation Laws with Model Predictive Control

This article investigates the intricate dynamics of the leader-follower problem within the framework of model predictive control (MPC). The study focuses on a scenario where a leader, characterized by a differential dynamic model, is diligently followed by a follower vehicle with a distinct differential dynamic model. The follower has full access to the leader's state information, facilitating real-time informed decision-making. A novel adaptation law is introduced to adjust the weighting matrix of the MPC controller, ensuring the follower approaches the leader in the tangent plane manifold by prioritizing the heading angle error. The control strategy is designed to synchronize the follower's trajectory with that of the leader, which performs various maneuvers such as lane changes, abrupt heading angle alterations, and sudden shifts in linear velocity. The leader-follower formation control problem is thoroughly investigated across diverse scenarios, including straight-line movements, circular trajectories, and intricate S-shaped paths. Comprehensive analysis demonstrates the effectiveness of MPC and the proposed adaptation law in achieving precise and adaptable formation control, significantly enhancing the understanding of leader-follower dynamics under varying conditions. This research contributes to the field by offering a robust solution for precise and reliable formation control in dynamic environments, showcasing the potential of MPC in autonomous systems.

Evaluation of the strength of the truck tractor’s frame under emergency braking conditions

Authors carried out a theoretical study of the force impact during emergency braking on the strength of the frame of a truck tractor as a part of a road train with a semi-trailer in order to build a model of the dependence of the safety factor index of the frame on the geometric and weight parameters of the car, semi-trailer, transported cargo and the type of the pavement. Using D'Alembert's principle, a generalized calculation scheme of the frame of the semi-trailer and the truck unit after reaching a steady deceleration during emergency braking while maintaining straight-line movement and adhesion of all wheels to pavement was made. Through a static calculation, the dependences for the unknown reactions of the car frame constraints were obtained, its dangerous cross-section was established, and the condition for the static strength of the longeron was determined. Using this condition and the obtained ratios for active and reactive loads, a model of the dependence of the safety margin coefficient of the car frame on the road train parameters was built. By the example of a road train consisting of a KrAZ-6446 truck tractor and a VARZ-6006 semi-trailer the application of the constructed model for evaluating the strength of the car frame and determining the permissible safe zone location of the center of gravity of different weights cargo in the plane of the road train is demonstrated. The method proposed in this work and the built model can be used to study the strength of the frames of truck tractors and semi-trailers of other manufacturers and types and to establish safe schemes for the placement and fastening of loads to ensure the operational reliability of the vehicle and the safety and security of cargo transportation.

Investigation the behavior of different fullerenes on graphene surface

In the present study, the regime of motion of fullerene molecules on graphene substrate in a specific temperature range is investigated. The potential energy of fullerene molecules is analyzed using classical molecular dynamics methods. Fullerene molecules C36, C50, C60, C76, C80, and C90 are selected due to spherical shapes of different sizes and good motion performance in previous studies. Analysis of the motion regime at different temperatures is one of the main objectives of this study. To achieve this aim, the translational and rotational movements of fullerene molecules are studied independently. In the first step of the investigation, Lennard-Jone's potential energy of fullerene molecules is calculated. Subsequently, the motion regime of different fullerenes is classified based on their displacement and diffusion coefficient. Findings indicate C60 is not appropriate in all conditions. However, C90 and C76 molecules are found to be appropriate candidates in most cases in different conditions. As far as a straight-line movement is considered, the deviation of fullerene molecules is compared by their angular velocities. Although C60 has a lower angular velocity due to its symmetrical shape, it may not move well due to its low diffusion coefficient. Overall, our study helps to understand the performance of different fullerene molecules on graphene substrate and find their possible applications, especially as wheels in nanomachine or nanocarrier structures.

Analisis Forecasting Produksi dan Konsumsi Komoditas Sayuran Sawi (Brassica juncea L)

This research aims to determine the estimated trend of mustard greens production and consumption in Bengkulu Province for the next 10 years 2022 - 2031. This research was conducted in Bengkulu Province using secondary data, with analysis using the least squares method. The results of this research show that the predicted trend in the estimated production of mustard greens (Brassica juncea L) in Bengkulu Province in 2022 - 2031 shows a straight line movement from bottom left to top right, that mustard greens production tends to increase, with the average growth being 0.989 percent per year starting from the forecast year for mustard greens (Brassica juncea L) commodities in the next 10 year period for Bengkulu Province, the average growth is 0.989% per year, starting from 2022 amounting to around 32,782 tons, in 2023 amounting to around 32,839 tons, in 2024 amounting to around 32,897 tons, in 2025 totaling around 32,954 tons, in 2026 totaling around 33,012 tons, in 2027 totaling around 33,070 tons, in 2028 totaling around 33,120 tons, in 2029 totaling around 33,185 tons, in 2030 totaling around 33.24 tons, in 2031 amounting to around 33,305 tons. The estimated trend of consumption of mustard greens (Brassica juncea L) in Indonesia in 2022 - 2031 shows a straight line movement from bottom left to top right, that consumption of mustard greens tends to increase, with an average growth of 1.144 percent per starting from 2022 amounting to around 1.65 tonnes, in 2023 amounting to around 1.66 tonnes, in 2024 amounting to around 1.68 tonnes, in 2025 amounting to around 1.69 tonnes, in 2026 amounting to around 1.7 tonnes, in 2027 amounting to around 1.72 tons, in 2028 amounting to around 1.73 tons, in 2029 amounting to around 1.74 tons, in 2030 amounting to around 1.75 tons, and in 2031 amounting to around 1.76 tons.

Development of a 2D spatial displacement estimation method for turbulence velocimetry of the gas puff imaging system on EAST

A gas puff imaging (GPI) diagnostic has been developed and operated on EAST since 2012, and the time-delay estimation (TDE) method is used to derive the propagation velocity of fluctuations from the two-dimensional GPI data. However, with the TDE method it is difficult to analyze the data with fast transient events, such as edge-localized mode (ELM). Consequently, a method called the spatial displacement estimation (SDE) algorithm is developed to estimate the turbulence velocity with high temporal resolution. Based on the SDE algorithm, we make some improvements, including an adaptive median filter and super-resolution technology. After the development of the algorithm, a straight-line movement and a curved-line movement are used to test the accuracy of the algorithm, and the calculated speed agrees well with preset speed. This SDE algorithm is applied to the EAST GPI data analysis, and the derived propagation velocity of turbulence is consistent with that from the TDE method, but with much higher temporal resolution.

Дослідження гальмівної динаміки автопоїзда

The article analyzes the dynamic characteristics of the braking process of a two-link road train during straight and curvilinear movement. It has been proven that the greatest indicator of the efficiency of the braking process of a road train is observed during full loading of all axles, that is, when all wheels are on the verge of blocking at the same time, and the stability of the movement of the road train in the braking mode depends on the proportionality of the braking forces to the value of the normal reactions on each wheel and the nature of the interaction of the links in the support-coupling device. Dependencies for calculating the value of the normal reactions acting on the wheels of the vehicle have been obtained. It was established that when the weight of the semi-trailer changes, the largest additional load occurs on the axle of the semi-trailer, the smallest - on the front axle of the tractor. During braking in the process of straight-line movement, with increased braking intensity, the load on the rear axle of the tractor, as well as the axles of the semi-trailer, is reduced by increasing the load on the front axle of the tractor. It should be noted that simultaneously with the unloading of the axles of the semi-trailer, there is an increase in the load on the support-coupling device of the vehicle, which, in turn, results in an increase in the load on the axles of the tractor. Braking dynamics of a road train in curvilinear movement shows that an increase in the intensity of braking is accompanied by a redistribution of the values of normal support reactions and additional loading of the front axle of the tractor. At the same time, a larger value of the normal reaction is characteristic of the wheels located on the outer circle relative to the center of rotation. This effect is explained by the influence of centrifugal forces. The maximum value of lateral deviation of normal support reactions is observed on the rear axle of the tractor.

INCREASING THE EFFICIENCY OF OPERATION OF TRAILED SOIL TILLAGE MACHINE UNITS

This work deals with issues related to increasing the stability of the movement of machine units. Manoeuvrability is also one of the most important aspects of machinery, especially trailers. The results of the research carried out in the article allow us to find one of the ways to increase the productivity of trailed machine units, reduce operating costs and improve the quality of agricultural work. In order to increase the productivity and efficiency of the use of machine units, it is necessary to increase the working speed, width of grip, rationally use the agricultural machines that are part of the machine units. The result of improving these indicators can be: lower operating costs for performing mechanized work, reducing the metal consumption of the process of creating machines, shortening the time of work. The current state of the problem is briefly considered, the relevance of the research is substantiated, the purpose of the work is formulated, and the main theoretical principles of the operation of machine-tractor units are presented. A review of scientific works on the outlined issues was carried out, the advantages and disadvantages of the use of combined trailed tillage machines were analysed, the problems that arise when using trailed machine-tractor units were identified, tasks and ways to improve the stability of straight-line movement and manoeuvrability of trailed machine-tractor units were outlined, and also considered different criteria for evaluating their straight-line movement stability and manoeuvrability. The main parameters affecting the stability and manoeuvrability of machine units, and especially combined ones, are considered. The design of the traction coupling device, which increases the indicators of stability of movement and manoeuvrability of trailed machine-tractor units, is described, and a kinematic analysis of the operation of the proposed traction coupling device is performed. The theoretical justification of the problem of the stability of tillage machine units, which consists in the occurrence of external disturbances from the reaction of the soil environment on the working bodies, and as a result, the deviation of trailed machines from straight-line movement, is considered. This deviation is eventually stabilized by the traction force and reappears with the opposite sign, resulting in oscillatory processes described by the laws of vibration. It is to compensate for such deviations that a special construction of the traction-coupling device is designed, which ensures the stability of the unit and ultimately increases its efficiency. Keywords: machine unit, towing links, experiment, operation, turning, manoeuvrability, tractor, tillage unit, traction and coupling device.

Evaluation of the technical and economic efficiency of controlled power distribution in transmissions of all-wheel drive trucks

BACKGROUD: Operating conditions of all-wheel drive trucks determine the probability of motion in conditions of uneven distribution of grip and rolling resistance for driven wheels of various axles and sides, which actualizes torque redistribution from an engine to the driven wheels. Reasonable power distribution between driven axles and wheels is important in order to improve the efficiency of all-wheel drive vehicles. AIMS: Evaluation of technical and economic efficiency of controlled power distribution in transmissions of all-wheel drive trucks with hydraulically controlled friction clutches. METHODS: A series of experiments was carried out on the basis of the KAMAZ-65222 with a differential lock control system with hydraulically driven friction clutches and a measuring and recording facility. The technical efficiency of control on differentials when driving in various road conditions was evaluated by the acceleration duration of the vehicle, the average speed of straight-line movement and when performing a maneuver, the parameters of the ground clearance, fuel efficiency and comparative loading of the wheels drive. RESULTS: The experiment confirmed the effectiveness of the algorithm for automatic control of the differential lock in the vehicle transmission in terms of cross-country abilities, workload and fuel efficiency. An increase up to 16.7% of the average speed in difficult road conditions, a decrease of the specific work of rolling resistance overcoming and a decrease in fuel consumption by 7–8% were recorded. CONCLUSION: Evaluation of efficiency of solutions for control on differentials in transmission of an all-wheel drive truck showed a significant increase in dynamic properties, cross-country abilities and fuel efficiency. Automatic change of the lock degree of differentials in the transmission when driving on a curved path and on uneven surface has a positive effect on transmission reliability and fuel efficiency, ensuring stability and maneuverability to remain stable. The expected economic effect is more than 206.3 thousand rubles. per year for one vehicle.

До визначення стійкості руху автопоїзда з частково заповненою цистерною

When designing and manufacturing tanks for the transportation of liquid cargo, it is necessary to take into account the shape of the tank, the level of liquid filling and the natural frequency of splashing of the liquid in the tank, as they are important factors and affect the stability of the movement. Due to the uncertainty of the lateral forces acting in a partially filled tank, the maximum speed of the start of braking, at which the stability of the movement is still ensured, can be taken as the main indicator of the lateral stability of the tank train. When studying the stability of a road train, as a rule, plane-parallel movement of its links is considered. At the same time, it is considered that the normal reactions of the support surface on the starboard and port wheels are the same. Under this condition, stability of movement is considered for a flat model of a road train. However, when the road train is moving with a partially filled tank, the reactions of the support surface on the wheels of the road train links may change significantly. To determine this phenomenon, the equations of the road train were compiled both in plane-parallel motion and in the longitudinal vertical and transverse planes. 
 The integration of the equations of motion is performed for a road train consisting of a DAF XF95 tractor and a tank semi-trailer filled to 50 % (8000 L) and the same road train with the same rigid load. As a result of the integration of the obtained system of equations, it was established that during braking of a road train with a partially filled tank, due to the movement of liquid in the tank itself, a lateral force arises, which depends on a large number of factors that cannot be determined analytically. This force leads to a change in the normal reactions of the support surface on the wheels of the axles and sides of the road train. At the same time, the reaction on the wheels of both sides of the tractor vehicle increases, and on the wheels of the semi-trailer - decreases. This is explained by the effect of liquid cargo on the walls of the tank. At the same time, it is shown that the generalizing parameter that characterizes the stability of the straight-line movement of a road train with a partially filled tank (50 % of the full volume) in the braking mode should be taken as the initial speed at which the tractor and semi-trailer do not exceed the width of the traffic lane. Based on the selected criterion, the initial braking speeds are obtained, at which the stability of the road train is ensured. These velocities, with a coefficient of adhesion of the wheels to the supporting surface in the range of j = 0.6, were 16.1 and 26.9 m/s for the road train with hard and liquid cargo, respectively. Therefore, it is necessary to provide special devices in the tank structures, in particular internal partitions, which would increase the stability of the road train during the braking process.

Evaluating Overall Performance in High-Level Dressage Horse-Rider Combinations by Comparing Measurements from Inertial Sensors with General Impression Scores Awarded by Judges.

In the sport of dressage, one or more judges score the combined performance of a horse and rider with an emphasis on the technical correctness of the movements performed. At the end of the test, a single score is awarded for the 'general impression', which considers the overall performance of the horse and rider as a team. This study explored original measures that contributed to the general impression score in a group of 20 horse-rider combinations. Horses and riders were equipped with inertial measurement units (200 Hz) to represent the angular motion of a horse's back and the motions of a rider's pelvis and trunk. Each combination performed a standard dressage test that was recorded to video. Sections of the video were identified for straight-line movements. The videos were analyzed by two or three judges. Four components were scored separately: gaits of the horse, rider posture, effectiveness of aids, and harmony with the horse. The main contributor to the score for gaits was stride frequency (R = -0.252, p = 0.015), with a slower frequency being preferred. Higher rider component scores were associated with more symmetrical transverse-plane trunk motion, indicating that this original measure is the most useful predictor of rider performance.

An assessment of the contact rates between individuals when movement is modelled by a correlated random walk

Understanding how individuals come into contact with each other is important in many fields from biology and ecology to robotics and physics. Interaction dynamics are central in understanding how information is spread between agents, how disease spreads through a population, and how group movement or behaviour occurs. However, in many applications, the underlying mode of movement is not considered, and instead, contacts are considered a fraction of all possible contacts amongst a population. This gives rise to the mass-action law which in turn implies a negative quadratic relationship between contacts and individuals. Here we consider how a simple but often used movement model, the correlated random walk, affects the contact rate in a standard Susceptible-Infection (SI) epidemiological model. Via extensive simulation, we show that the contact rate is not always well described by the assumed negative quadratic relationship, I(N-I) (where I is the number of infected at a given time and N the total number of individuals). Instead, we find that a contact rate proportional to {left[I(N-I)right]}^{alpha } with 0<alpha le 1 is a better qualitative fit, where alpha depends upon parameters such as the straightness of the movement and the density of individuals. We highlight that the expected contacts at low densities increase with straight line movement, whereas, at high densities, they increase with more random movement.

Моделювання та аналіз складного руху автономного безпілотного підводного апарата

Ensuring autonomy, maneuverability and organization of movement control along complex trajectories of a maneuverable multi-purpose autonomous unmanned underwater vehicle (AUUV) is a complex scientific research and engineering task, for the solution of which it is necessary to know the behavior of the vehicle in the environment and the influence of the environment on the dynamics of the vehicle. Plots of the distribution of speed, pressure and kinetic energy of turbulence during the complex movement of the AUUV were obtained, in accordance with the chosen trajectories. Simulation and numerical modeling of AUUV under complex motion was carried out. The obtained results were compared with the results of rectilinear movement. showed that the construction of the ABPA model is acceptable both for straight-line movement and for movement along complex trajectories. A comparative analysis of the obtained values of speed, pressure and kinetic energy of turbulence shows the ability of the developed model of the device to perform quick maneuvers in limited areas (turning around, avoiding obstacles, etc.). The selected and designed ABPA model is suitable for further research in order to develop an automatic control system for a maneuverable multi-purpose AUUV.

Interior Individual Trajectory Simulation with Population Distribution Constraint

Individual trajectory generation plays an important role in simulation tasks, reconstructing fine-grained mobility behaviors that can be used to evaluate epidemic risks, congestion risks, or commercial profit. Previous research works adopt the Newton’s mechanic-based particle model as their core algorithm, such as the Social Force model. However, real-world human mobility behaviors hardly follow the particle models, especially in the interior scenes where interactions between pedestrians and environments matter. In this article, we propose a Social Force-based trajectory simulator for interior scenarios that improve both trajectory quality and generation speed for interior scenarios. First, we introduce prior scene knowledge to guide the generation process, where pedestrians are armed with exploration behaviors that follow the group-level distribution. It provides more flexibility to simulate complicated human behaviors rather than straight-line movements, generating high-quality individual trajectories. Experiments show that the correlation between the aggregated population distribution of generated trajectories and ground-truth distribution is improved by 11.84% by our method. Second, we optimize the algorithm procedure by introducing a caching mechanism for tenderized intermediate values, along with graph-processing-unit-based implementation. Compared with the baseline Social Force model, we reduced the time consumption by 95%. More importantly, based on our simulation paradigm, we quantitatively evaluate several common mobility interventions in our simulation scenario, which can shed light on better policy designs in public spaces.

Detection of vertical load on the base drive with a plug-in drive

When the disc plug is in operation, its straight line movement is considered important. The reason for this is that the plug bodies are angled, all pointing in the same direction, so they will attempt to rotate the plug during operation. To prevent this from happening, the plug incorporates a support disc which, by resting on the base formed by the end housing, ensures that the plug operates horizontally without tilting to the side, i.e. in a straight line movement. Based on this, it was found in theoretical studies that the vertical load applied to the disc connector depends on its parameters. According to the obtained expression, it was shown that the steepness of load on the support disc depends on its radius (diameter), depth of immersion in the bottom, thickness, thickness of the crucible, angles of sharpening and installation relative to the steepness, as well as friction and volume crushing coefficients of the ground.

Investigation of fullerene motion on thermally activated gold substrates with different shapes

In the current study, the regime of motion of fullerene molecules on substrates with different shapes at a range of specific temperatures has been investigated. To do so, the potential energy of fullerene molecules was analyzed using the classical molecular dynamics method. C20, C36, C50, C60, C72, C76, C80, and C90 fullerene molecules were selected due to their spherical shapes with different sizes. In addition, to completely analyze the behavior of these molecules, different gold substrates, including flat, concave, the top side of the step (upward step), and the downside of the step (downward step) substrates, were considered. Specifying the regime of the motion at different temperatures is one of the main goals of this study. For this purpose, we have studied the translational and rotational motions of fullerene molecules independently. In the first step of the investigation, Lennard-Jones potential energy of fullerene molecules was calculated. Subsequently, the regime of motion of different fullerenes has been classified, based on their displacement and sliding velocity. Our findings indicated that C60 is appropriate in less than 5% of the conditions. However, C20, C76 and C80 molecules were found to be appropriate candidates in most cases in different conditions while they were incompetent only in seven situations. As far as a straight-line movement is considered, the concave geometry demonstrated a better performance compared to the other substrates. In addition, C72 indicated less favorable performance concerning the range of movement and diffusion coefficients. All in all, our investigation helps to understand the performance of different fullerene molecules on gold substrates and find their probable application, especially as a wheel in nano-machine structures.

Preliminary Experimental Research on the Influence of Counterbalance Valves on the Operation of a Heavy Hydraulic Manipulator during Long-Range Straight-Line Movement

The effective use of robotic manipulators is particularly important when carrying out hazardous tasks. Often, for this type of mission, manipulators equipped with a hydraulic drive system are used, and their work results primarily from the implementation of precise movements through their effectors. In heavy manipulators, limiting the uncontrolled movement resulting from high inertia and relatively low stiffness has an impact on the improvement of the control precision. Therefore, the paper presents experimental studies that allow the assessment of the impact of the use of counterbalance valves on the precision and dynamics of a manipulator with a hydrostatic drive system. The tests were carried out for a wide range of effector velocities along a horizontal trajectory, on the basis of which, it was found that it was possible to improve the precision and dynamics of the work of such manipulators due to the precision of the trajectory and pressures in the drive system.

Dead-reckoning elucidates fine-scale habitat use by European badgers Meles meles

BackgroundRecent developments in both hardware and software of animal-borne data loggers now enable large amounts of data to be collected on both animal movement and behaviour. In particular, the combined use of tri-axial accelerometers, tri-axial magnetometers and GPS loggers enables animal tracks to be elucidated using a procedure of ‘dead-reckoning’. Although this approach was first suggested 30 years ago by Wilson et al. (1991), surprisingly few measurements have been made in free-ranging terrestrial animals. The current study examines movements, interactions with habitat features, and home-ranges calculated from just GPS data and also from dead-reckoned data in a model terrestrial mammal, the European badger (Meles meles).MethodsResearch was undertaken in farmland in Northern Ireland. Two badgers (one male, one female) were live-trapped and fitted with a GPS logger, a tri-axial accelerometer, and a tri-axial magnetometer. Thereafter, the badgers’ movement paths over 2 weeks were elucidated using just GPS data and GPS-enabled dead-reckoned data, respectively.ResultsBadgers travelled further using data from dead-reckoned calculations than using the data from only GPS data. Whilst once-hourly GPS data could only be represented by straight-line movements between sequential points, the sub-second resolution dead-reckoned tracks were more tortuous. Although there were no differences in Minimum Convex Polygon determinations between GPS- and dead-reckoned data, Kernel Utilisation Distribution determinations of home-range size were larger using the former method. This was because dead-reckoned data more accurately described the particular parts of landscape constituting most-visited core areas, effectively narrowing the calculation of habitat use. Finally, the dead-reckoned data showed badgers spent more time near to field margins and hedges than simple GPS data would suggest.ConclusionSignificant differences emerge when analyses of habitat use and movements are compared between calculations made using just GPS data or GPS-enabled dead-reckoned data. In particular, use of dead-reckoned data showed that animals moved 2.2 times farther, had better-defined use of the habitat (revealing clear core areas), and made more use of certain habitats (field margins, hedges). Use of dead-reckoning to provide detailed accounts of animal movement and highlight the minutiae of interactions with the environment should be considered an important technique in the ecologist’s toolkit.

Analysis of the stress-strain state of the vehicle frame by finite element method

Analysis of load-bearing structures of vehicles is carried out. The peculiarities of the operation of vehicles and their bearing systems are considered. It is noted that the loads acting on the structure are time-varying; their amplitude and frequency characteristics depend on the real load, the speed of the vehicle, the condition of the road surface and other factors. This can cause a high level of stress in the areas of structural and technological concentrators and result in the occurrence of fatigue cracks and frames destruction in these areas. The researching methods of operational loads and the stress-strain state of frame structures under static and dynamic loads are analyzed. It is noted that the finite element method is the most universal for the implementation of static, modal, harmonic and other types of analyzes of frame structures. The finite element method is used to investigate the stress-strain state of bearing structure of the 2PTS-2 trailer under different static load options. The full-scale CAD model of the trailer and its finite-element model are developed using specialized software SolidWorks. Calculations of the stress-strain state of the trailer frame are carried out for typical types of loads: straight-line movement, turning and lifting of the vehicles body with load. The analysis of the safety factors by stresses is carried out in order to take into account the uncertainties of the frame structure model and the uncertainties of the operational load. It is established that when considering the investigated options for loading of the frame structure, the most dangerous are those related to the unloading of the cargo, which requires further research into the specified processes.