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The issues in geodynamic research in Northern Eurasia over the past three decades with emphasis on the use of space technologies in geodesy and geodynamics are presented. The main focus is on the GNSS system as the most widespread and effective tool for geodynamic research due to the compactness and relative ease of installation of ground-based tracking equipment, as well as the possibility of its autonomous operation. The importance of precise GNSS positioning for monitoring small-scale geodynamic displacements of the Earth's surface, which requires millimeter-scale measurement accuracy, is emphasized. The issues of development of a precise reference frame for geodynamics and maintaining its long-term consistency based on the International Terrestrial Reference Frame (ITRF) are considered, as well as the problems and prospects of precise satellite geodetic measurements and geodynamic research in the context of the current reduction in interaction with international geodetic data centers. To solve the problems that have arisen, ways are proposed based on arranging a subcontinental-scale system for equalization of raw GNSS measurements. The capabilities of the GNSS network used for solving problems of geodesy and geodynamics are demonstrated by the example of the analysis of the tectonic rigidity of cratons of Northern Eurasia and the impact of motion of adjacent tectonic plates and variations of these motions in the past geological eras on the contemporary geodynamic setting of these cratons. [ABSTRACT FROM AUTHOR]

The key technologies for advanced autonomous vehicles include those relating to perception, decision making, and execution. Path-tracking control in autonomous vehicles is heavily dependent on their positioning system. Therefore, the development of low-cost and reliable positioning systems is crucial to improving perception and decision-making technologies for autonomous vehicles. Although the accuracy of the global positioning system (GPS) is extremely high, it is vulnerable to interference. Further, despite the low positioning accuracy of inertial navigation systems (INSs), their robustness is notably high. Therefore, an integrated navigation information method based on the Adaptive Particle Filter and the Iterative Kalman Filter (APF-IKF) was developed in this study. Firstly, an integrated navigation system model was established. Then, the IKF was adopted to estimate the speed, latitude and longitude errors of the INS. Thirdly, the newest estimated error results were introduced into the APF to optimize the distribution function, and the particle quality was improved. In this process, the APF can filter non-Gaussian noise, preliminarily estimate the error, optimize the result with the IKF and correct the output information of the INS with the final estimated error. Finally, by using differential GPS positioning as the benchmark, we built a real-vehicle test platform with a low-cost and low-precision GPS and inertial units and carried out a series of real-vehicle tests. The experimental results show that compared with the traditional KF method, APF-IKF can significantly improve the positioning accuracy and robustness of the system. [ABSTRACT FROM AUTHOR]

Influenced by a cosmological view of the interconnectedness between heaven and humankind, ancient Chinese astrologers developed the fenye (分野, “field allocation”) system. This theory envisioned correspondence between heaven and earth and was a prevalent regional positioning system in ancient China. However, during the Qianlong era (1736-1796), fenye theory faced skepticism and rejection from official quarters, leading to a significant crisis for this traditional positioning system. With the eastward spread of Western learning, modern European astronomical and geographical knowledge were introduced into China, and Chinese intellectuals began to favor the Western system of latitude and longitude for geographical positioning. In the late Qing period, the gradual popularization of the spherical Earth concept and the latitude and longitude system laid the theoretical foundation for establishing of this system. The public dissemination of latitude and longitude data measured by the imperial astronomical and calendrical institutions, along with mathematicians’ calculations based on historical data and the supplementary measurements conducted by local governments, provided data support for the system’s establishment. By the end of the Qing dynasty, as the knowledge structures and worldviews of Chinese intellectuals transformed, the traditional celestial-terrestrial correspondence in Chinese local gazetteers was phased out, giving way to the latitude and longitude system.

The ability to navigate and precisely locate a visually challenged people within a building is significantly important for a wide variety of location services and public safety. Also, Indoor Localization (IL) for blind people is an open research challenge and the individual localization algorithm failed to achieve accurate location results. To overcome this problem, in this research work, a novel hybrid indoor localization strategy using a WiFi fingerprint database is proposed. It includes two stages such as Offline Phase (OP) and Online Phase (OnP). In the OF, this system employs a Min-Max Normalization approach to normalize the fingerprint database. Then, the Fractional Sparse Fuzzy C-Means Clustering method (FSFCC) is proposed to retrieve the Validation Set (VS) from all the Training Sets (TS) in the ratio of 4:1. In the online stage, the received signal strength indicator (RSSI) data value in dBm is reconstructed and key features such as longitude, latitude, floor ID and building ID are extracted by using Self-Attention-Based Multimodality Convolutional Volcano Eruption Network (Se-AMCVE). Hence, the weight parameters of the proposed network are optimized by applying Volcano Eruption Optimization (VEO). Finally, the accurate estimated location data is the outcome of the proposed network which helps the blind to find the path. The achieved accuracy is 94%, mean positioning error is 3.01 m and floor hit rate is 97.08% which is implemented in the python flask framework. [ABSTRACT FROM AUTHOR]

An analysis of the operation of the piercing mill revealed the need to upgrade the mechatronic rolls positioning system and to introduce an intelligent system to improve the quality of rolled products. The main problem is the formation of defects at the ends of the shells during rolling on a piercing mill. The excess material must be cut off and recycled because more raw materials than required are used for rolling one billet. To eliminate this problem, it is necessary to change the preload of the workpiece during rolling, thereby forming a profile that reduces the undesirable changes at the ends of rolled pipes. The mill currently has foreign equipment which is difficult to purchase. Such difficulties may lead to downtime. Moreover, the unit operates only in manual or semi-automatic mode. The possibility of replacing equipment with domestic analogs is considered. A visualization and control program has been developed. To determine the position of the workpiece in the mill and change the preload of the shell in automatic mode, a neural-network control system has been developed. [ABSTRACT FROM AUTHOR]

Based on the construction of the cable pier foundation of the Xiangluzhou Bridge in Changsha, the key technologies of manufacturing, launching, floating, precise positioning and implantation for double-wall steel cofferdam were studied by comprehensively considering the factors such as geology, hydrology, coastal landform and lifting capacity in the bridge site, and the construction technology to accurately determine large steel cofferdam with vertical segmentation, horizontal looped connection, whole floating transport and platform anchoring system was put forward. The proposed technology can ensure the successful construction for steel cofferdam in the field of deep water shallow cover layer, which was proved by field practice. This paper can provide a reference for similar projects. [ABSTRACT FROM AUTHOR]

To regulate the energy flow in orchard ecosystems and maintain the environment, weeding has become a necessary measure for fruit farmers, and the use of automated mowers can help reduce labor costs and improve the economic efficiency of orchards. However, due to the complexity of the geographic and spatial environment of the orchard, in particular, the loose and undulating road surface, the interference of satellite signals by large trees, etc., which decreases the positioning accuracy and stability of the positioning system of the mower, and the high cost of the sensor also affect the popularization of intelligent mowers for these applications. To address the above problems, this paper constructs a positioning system through a low-cost global navigation satellite system (GNSS), inertial measurement unit (IMU), and odometry, and utilizes the Kalman filter algorithm based on the error state for a combined GNSS/IMU positioning so that the inertial navigation system can maintain a more accurate positioning when the GNSS signals are poor. Considering the side-slip and error accumulation problems of the odometry of the traction mower, the combined GNSS/IMU positioning information is used to optimize the odometry model and improve the navigation and positioning accuracy. To reduce the measurement error of the IMU and the problem of error accumulation, this paper utilizes the nonholonomic constraint (NHC) of a lawn mower to suppress the dispersion of IMU measurement errors and constructs periodic and nonperiodic zero-velocity updating (ZUPT) strategies in combination with the travel paths of lawn mower navigation operations in the region to update the IMU data to improve the positioning accuracy and stability of the positioning system. The experiments show that the average error of the constructed positioning system is controlled within 0.15 m, the maximum error is maintained at approximately 0.3 m, and the positioning system constructed by using low-cost sensors can achieve a positioning accuracy similar to that of the differential global navigation satellite system (DGNSS), which is beneficial for the promotion and application of intelligent mowers in orchards. [ABSTRACT FROM AUTHOR]

The object of research is the reliability of information in information-control systems. The work considers a solution to an important scientific and practical problem – increasing the reliability of information in real-time control systems, in particular in positioning systems on road transport. To solve this task, the use of information redundancy, in particular, parallel information redundancy, is proposed. The paper studies the influence of the probability of occurrence of a controlled event, the majority coefficient, as well as the number and quality of information sensors on the reliability of information in an information control system with parallel information redundancy. For these dependences, the corresponding plots were constructed. The paper shows that a change in the quality of information sensors by 20 % can lead to an increase in the reliability of information by more than 0.5. Also, the paper shows that an increase in the majority index by 1 can lead to a change in the reliability of information by more than 0.3. The paper investigates parallel information redundancy systems with different structures and defines formulas for calculating the probabilistic characteristics of their operation. The mathematical modeling was carried out taking into account the probability of occurrence of the controlled event, which made it possible to determine the tendencies to build information-control systems with parallel information redundancy to control events with variable probability of occurrence. The results obtained are based on the theory of probability. The results reported in this work can be used in the construction of an information and control system with a programmatically variable structure to control the occurrence of an event with a variable probability of occurrence, in particular in positioning systems on road transport. [ABSTRACT FROM AUTHOR]

This paper presents the results of a computer optimising a multibody system using Generative Design methods to select a lower-cost actuator that meets process requirements with its parameters. Optimisation was performed to reduce the mass of the motion apparatus components of the author's CPM device, used for the rehabilitation of patients after knee arthroscopy and total or partial knee replacement. An analysis of the kinematics and dynamics of the multibody mechanism, based on a virtual model, was carried out to identify the requirements for selecting an actuator. The main components of the motion apparatus mechanism were subjected to a series of numerical analyses using selected CAD/CAE tools, with the assumed criterion of varying material and component shapes to ensure that the required strength and accuracy of the mechanism links were maintained, assuming the same functionality. The results of the numerical analyses will be the basis for the selection of the optimum solution, for which a new, lower-cost actuator will be selected. [ABSTRACT FROM AUTHOR]

Scanning electron microscopy (SEM) is a precious tool in materials science and morphology sciences, enabling detailed examination of materials at the nanoscale. However, precise and accurate sample repositioning during different observation sessions remains a significant challenge, impacting the quality and repeatability of SEM analyses. This study aimed to develop and evaluate a LEGO®‐based sample positioning system for SEM analysis. The system was designed to consistently identify and align features across multiple repositioning cycles, maintain accurate positioning along the z‐axis, minimize distortion, and provide repeatable and reliable results. The results indicated a high degree of precision and accuracy in the repositioning process, as evidenced by the minimal displacements, deviations in scaling and shearing, and the highly significant results (p < 0.001) obtained from the analysis of absolute translations and rotations. Moreover, the analyses were consistently replicated across six repetitions, underscoring the reliability of the observed results. While the findings suggest that the LEGO‐based sample positioning system is promising for enhancing SEM analyses' quality and repeatability, further studies are needed to optimize the system's design and evaluate its performance in different SEM applications. Ultimately, this study contributes to the ongoing efforts to develop cost‐effective, customizable, and accurate solutions for sample positioning in SEM, contributing to the advancement of materials science research and all SEM analysis requiring overtime observations of the same sample. Research Highlights: This study focused on the development and evaluation of a novel LEGO‐based sample positioning system specifically designed for SEM analysis.One of the standout features of this system is its ability to consistently identify and align features across multiple repositioning cycles, showcasing its precision and reliability.To further understand the mechanical aspects of the SEM stage, we employed the Rambold Kontroll comparator, which provided a baseline understanding of its mechanical tolerance.The registration process results were particularly noteworthy, as they revealed high accuracy with minimal displacements.Furthermore, the consistent outcomes observed across multiple repetitions emphasize the reliability and robustness of the methods we employed in this research. [ABSTRACT FROM AUTHOR]

One of the important issues being explored in Industry 4.0 is collaborative mobile robots. This collaboration requires precise navigation systems, especially indoor navigation systems where GNSS (Global Navigation Satellite System) cannot be used. To enable the precise localization of robots, different variations of navigation systems are being developed, mainly based on trilateration and triangulation methods. Triangulation systems are distinguished by the fact that they allow for the precise determination of an object's orientation, which is important for mobile robots. An important feature of positioning systems is the frequency of position updates based on measurements. For most systems, it is 10–20 Hz. In our work, we propose a high-speed 50 Hz positioning system based on the triangulation method with infrared transmitters and receivers. In addition, our system is completely static, i.e., it has no moving/rotating measurement sensors, which makes it more resistant to disturbances (caused by vibrations, wear and tear of components, etc.). In this paper, we describe the principle of the system as well as its design. Finally, we present tests of the built system, which show a beacon bearing accuracy of Δ φ = 0.51 ° , which corresponds to a positioning accuracy of Δ R = 6.55 cm, with a position update frequency of f u p d a t e = 50 Hz. [ABSTRACT FROM AUTHOR]

The key technologies for advanced autonomous vehicles include those relating to perception, decision making, and execution. Path-tracking control in autonomous vehicles is heavily dependent on their positioning system. Therefore, the development of low-cost and reliable positioning systems is crucial to improving perception and decision-making technologies for autonomous vehicles. Although the accuracy of the global positioning system (GPS) is extremely high, it is vulnerable to interference. Further, despite the low positioning accuracy of inertial navigation systems (INSs), their robustness is notably high. Therefore, an integrated navigation information method based on the Adaptive Particle Filter and the Iterative Kalman Filter (APF-IKF) was developed in this study. Firstly, an integrated navigation system model was established. Then, the IKF was adopted to estimate the speed, latitude and longitude errors of the INS. Thirdly, the newest estimated error results were introduced into the APF to optimize the distribution function, and the particle quality was improved. In this process, the APF can filter non-Gaussian noise, preliminarily estimate the error, optimize the result with the IKF and correct the output information of the INS with the final estimated error. Finally, by using differential GPS positioning as the benchmark, we built a real-vehicle test platform with a low-cost and low-precision GPS and inertial units and carried out a series of real-vehicle tests. The experimental results show that compared with the traditional KF method, APF-IKF can significantly improve the positioning accuracy and robustness of the system.

In order to solve the problems of vehicle congestion, high safety risk and difficult dispatching when multiple operational vehicles are travelling during the construction of long tunnels, an intelligent dispatching system with position confirmation, signal transmission and positioning application functions was designed, relying on the oversized diameter shield tunnel project of the airport liaison line of the Shanghai rail transit city line. The construction material priority was analysed and the vehicle dispatching order was determined with the objective of reducing vehicle waiting time, and a vehicle dispatching model was established. Based on the tunnel vehicle positioning system and vehicle dispatching model, an intelligent dispatching system for tunnel vehicles under complex working conditions has been developed and validated for application in the Dou ~ Ling interval tunnel of the airport liaison line project of the Shanghai metro line, efficiency and improve the safety of long-distance tunnel single-lane multi-vehicle driving. [ABSTRACT FROM AUTHOR]

This treatise studies a microoptoelectromechanical accelerometer (MOEMA) with an optical measuring transducer built according to the optical tunneling principle (evanescent coupling). The work discusses the design of the accelerometer's microelectromechanical sensing element (MSE) and states the requirements for the design to achieve a sensitivity threshold of 1 µg m/s2 at a calculated eigenvalue of the MSE. The studies cover the selection of the dimensions, mass, eigenfrequency and corresponding stiffness of the spring suspension, gravity-induced cross-displacements. The authors propose and experimentally test an optical transducer positioning system represented by a capacitive actuator. This approach allows avoiding the restrictions in the fabrication of the transducer conditioned by the extremely high aspect ratio of deep silicon etching (more than 100). The designed MOEMA is tested on three manufactured prototypes. The experiments show that the sensitivity threshold of the accelerometers is 2 µg. For the dynamic range from minus 0.01 g to plus 0.01 g, the average nonlinearity of the accelerometers' characteristics ranges from 0.7% to 1.62%. For the maximum dynamic range from minus 0.015 g to plus 0.05 g, the nonlinearity ranges from 2.34% to 2.9%, having the maximum deviation at the edges of the regions. The power gain of the three prototypes of accelerometers varies from 12.321 mW/g to 26.472 mW/g. The results provide broad prospects for the application of the proposed solutions in integrated inertial devices. [ABSTRACT FROM AUTHOR]

Localization, in both indoor and outdoor settings, represents a problem that has received increased attention lately. This paper presents the development, testing, and validation of an indoor localization system for 1/10 scale vehicles based on the Robot Operating System (ROS) and ArUco marker detection. It has a distributed architecture, consisting of tens of Raspberry Pi (RPi) singleboard computers running ROS nodes and fitted with cameras, that monitor a certain area of the 14x14 m plane. The developed system has been successfully used in three editions of Bosch Future Mobility Challenge, an international student competition, where the participants are required to implement autonomous driving functionalities in an environment resembling a real-life city on small-scale automated vehicles. [ABSTRACT FROM AUTHOR]

Summary Vehicle utilization has increased on a broader scale in today's reality. Because of insufficient emergency services, increased motor traffic has resulted in the rise of traffic collisions, and widespread accidents lead to the demise of lives and property. Generally, the consequence death rate happens each year, originating from delays in rescue activities. However, vehicles are embedded with trend technology. Still, the accident count will rise day by day due to delays in transmitting the information to the concerned person or delays in rescue activities. The proposed work offers an effective solution to the aforementioned issue by assisting low‐power and long‐range (LoRa) architecture with edge node ultrasonic sensors for identifying the abnormalities and to provide an efficient transport ambulance from the unexpected mishap spot to the closest hospital where emergency well‐being can be provided with the help of cloud technology. Also, emergency information can be sent to the cloud immediately, and its response is the way of alerting the surroundings and notifying the appropriate hospital with the aid of a GPS‐enabled LoRa‐shield. Further, comparing the proposed technology with other LPWAN (low‐power wide area networks) in terms of coverage, cost, capacity, and energy consumption proves efficient communication in the development of intelligent vehicular networks towards a smart city. [ABSTRACT FROM AUTHOR]

To effectively position the tunnel emergency situations and improve emergency response efficiency, a tunnel emergency positioning system based on Beidou technology has been designed. The types of emergency events, positioning requirements, and the characteristics of positioning technology in highway tunnels are analyzed. Based on the Beidou beacon, the Beidou emergency terminal, and various communication methods, data integration is achieved on the Beidou emergency resource monitoring platform, integrating multimedia scheduling platform to release and receive unified platform information, and providing personnel, equipment, and other positioning data to on-site rescue personnel and rear command personnel quickly, accurately, and effectively. After testing, the time used on positioning is 60.33 s, the positioning error is ≤ 0.6 m, and the time used on data transmission is 0.19 s, which can meet the emergency rescue needs of the tunnel. [ABSTRACT FROM AUTHOR]

Reconfigurable intelligent surfaces (RIS) are forecasted to assume a pivotal role in future wireless communication systems, largely attributed to their capacity to dynamically alter the propagation environment. This study primarily concentrates on the utilization of large RIS, leading to near-field propagation channels, especially in high-frequency communication systems. This is aimed at resolving the complex issue of single anchor-based localization, particularly under conditions where the line-ofsight (LoS) path is prone to severe blockage and fading. In this context, a millimeterwave localization problem, based on time difference of arrival (TDoA), utilizing orthogonal frequency division multiplexing (OFDM) downlink signaling, has been modeled and simulated. The time of arrivals (ToA) measurements, enriched from each RIS tile, are applied to determine user positions. It is recognized that some ToA readings may possess low signal to noise ratio (SNR), making them unsuitable for inclusion in the estimation. Subsequently, various scenarios for RIS tile selection were examined in this research, with the aim of enhancing localization accuracy. Numerical results substantiate the efficacy of the TDoA-RIS algorithm in improving localization accuracy. This is achieved through different strategies to select the most reliable 50% of ToA measurements for the formulation of the estimation procedure. [ABSTRACT FROM AUTHOR]

This study addressed the issue of the real-time monitoring and control of the transporter in a mountain orchard terrain characterized by varying topography, closed canopy, shade, and other environmental factors. This study involved independent research and the development of a series of electric monorail transporters. First, the application requirements of "Where is the monorail transporter?" were examined, and an accurate location-aware method based on high-frequency radio frequency identification (RFID) technology was proposed. In addition, a location-aware hardware system based on STM32 + RFID + LoRa was designed to determine the position of the monorail transporter on a rail. Second, regarding the application requirements of "Where is the monorail transporter going?", a multimode control gateway system based on Raspberry Pi + LoRa + 5G was designed. An Android mobile terminal can obtain operational information about the transport plane in real time through the gateway system and remotely control its operation. The track-changing branch structure enables multimachine autonomous intelligent avoidance. Based on the experimental results of monorail transporter positioning in mountain orchards under various typical terrains, such as flat surfaces, turning paths, and uphill/downhill slopes, the road section average relative error of the 7ZDGS–250-type monorail transporter was 1.27% when the distance between benchmark positioning tags was set at 10 m on both flat and turning roads, and that of the 7ZDGS–300-type monorail transporter was 1.35% when the distance between benchmark positioning tags was set at 6 m uphill/downhill. The road section relative error of the 7ZDGS–250-type monorail transporter was 21.18%, and that of the 7ZDGS–300-type monorail transporter was 9.96%. In addition, the experimental results of monorail transporter communication control showed that the combination of the multimode control gateway control system and track-changing branch structure can achieve multimachine cooperation and autonomous avoidance function, ensuring that multiple monorail transporters can operate simultaneously without collision. The findings of this study establish the communication link of "monorail transporter-gateway system-control terminal" and form a precise positioning and real-time control scheme applicable to the operating environment of monorail transporters, thereby improving the intelligence and safety of mountain orchard monorail transporters. [ABSTRACT FROM AUTHOR]

The main goal of this paper is to develop a special modular fixture system for machining and drilling parts that hold pneumatic jacks componets. This family of parts is usually made in various dimensions and sizes but with a specific geometric shape. The design requirements of the restrictions, the way of the construction process is considered as the design inputs of this system. Positioning and clamping system have been designed, modeled and simulated for the mass production of a family of these parts with minimal changes in the manufacturing process. The results obtained from the idea of designing such restraints in machining processes show that with its help, it is possible to reduce the design and manufacturing costs of restraints for a group of parts that are similar in appearance but different in size and dimensions. It will significantly reduce and minimize the time of adjusting these equipments during the production process and will increase the productivity and circulation of products. [ABSTRACT FROM AUTHOR]

To improve the positioning accuracy of unmanned ships, a multi-sensor system including ZigBee, a Global Positioning System (GPS), and BeiDou Navigation Satellite System (BDS) is constructed, and an adaptive multi-sensor data fusion positioning method based on the threshold and hierarchical capacity particle filter (TCPF) is designed. First, the ZigBee-GPS/BDS multi-sensor measurement data is preprocessed to achieve a consistent space–time reference and transformed into the same coordinate system by projection. Then, the fault data is weighted and corrected through the consistency inspection of ZigBee-GPS/BDS multi-sensor positioning data, and the corresponding confidence factor is given according to the confidence distance of the positioning data; furthermore, the confidence factor is associated with stratified sampling. After that, the multi-sensor positioning data is filtered and denoised using a basic particle filter. Finally, a TCPF data fusion algorithm is designed, and the navigation positioning data of the unmanned ship is fused and filtered to obtain its positioning information. Numerical tests show that compared with other filtering algorithms, the mean square root error and standard deviation of the proposed TCPF algorithm decrease by an average of 25.0% and 28.0%, respectively, which verifies its high filtering accuracy and its advantages in suppressing particle degradation and avoiding sample scarcity. The experimental tests show that compared with other fusion algorithms, the proposed TCPF algorithm can not only realize the precise positioning during unmanned ship navigation, but also in the positioning and fault tolerance test, the average positioning error, root-mean-square error, and standard deviation of the former decrease by 36.0%, 38.0%, and 37.0%, respectively, and the corresponding performance indicators of the latter decrease by an average of 20.0%, 19.5%, and 17.5%, which verifies that it has the advantages of high data reliability and good filtering fault tolerance, and helps to improve the positioning accuracy of unmanned ships. [ABSTRACT FROM AUTHOR]

A VecTwin rudder system comprises twin fishtail rudders with reaction fins to increase its performance. With a constant propeller revolution number, the vessel can execute special low-speed maneuvers like hover, crabbing, reverse, and rotation. Such low-speed maneuvers are termed dynamic positioning (DP), and a DP vessel should be fully/overly actuated with several thrusters. This article introduces a novel and experimental VecTwin positioning system (VTPS) without making the ship fully/overly actuated. Unlike the usual dynamic positioning system (DPS), the VTPS is developed for low-speed operations in a calm harbor area. It is designed upon the assumption that the forces due to the interaction between the rudders, the propeller, and the hull are linear with the rudder angles within a range around the hover rudder angle. The linear relationship is obtained through linear regression of the results from several CFD simulations. The VTPS implements a PID controller that regulates the actuator forces to achieve the given low-speed positioning objective. It was tested in combined automatic docking and position-keeping experiments where disturbances from the environment exist. It shows promising potential for a practical application but with further improvements. [ABSTRACT FROM AUTHOR]

Purpose: To examine the effects of acute caffeine supplementation on physical performance during fitness testing and activity during simulated games in basketball players. Methods: A double-blind, counterbalanced, randomized, crossover study design was followed. A total of 14 professional male basketball players ingested a placebo (sucrose) and caffeine (6 mg·kg-1 of body mass) in liquid form prior to completing 2 separate testing sessions. Each testing session involved completion of a standardized 15-minute warm-up followed by various fitness tests including 20-m sprints, countermovement jumps, Lane Agility Drill trials, and a repeated-sprint-ability test. Following a 20-minute recovery, players completed 3 x 7-minute 5-vs-5 simulated periods of full-court basketball games, each separated by 2 minutes of recovery. Local positioning system technology was used to measure player activity during games. Players completed a side-effects questionnaire 12 to 14 hours after testing. Results: Players experienced significant (P < .05), moderate--very large (effect size = -2.19 to 0.89) improvements in 20-m sprint, countermovement jump, Lane Agility Drill, and repeated-sprint-ability performance with caffeine supplementation. However, external workloads completed during simulated games demonstrated nonsignificant, trivial--small (effect size = -0.23 to 0.12) changes between conditions. In addition, players reported greater (P < .05) insomnia and urine output after caffeine ingestion. Conclusions: Acute caffeine supplementation could be effective to improve physical performance during tests stressing fitness elements important in basketball. However, acute caffeine supplementation appears to exert no meaningful effects on the activity completed during simulated basketball games and may promote sleep disturbances and exert a diuretic effect when taken at 6 mg· kg-1 of body mass in professional players. [ABSTRACT FROM AUTHOR]

To regulate the energy flow in orchard ecosystems and maintain the environment, weeding has become a necessary measure for fruit farmers, and the use of automated mowers can help reduce labor costs and improve the economic efficiency of orchards. However, due to the complexity of the geographic and spatial environment of the orchard, in particular, the loose and undulating road surface, the interference of satellite signals by large trees, etc., which decreases the positioning accuracy and stability of the positioning system of the mower, and the high cost of the sensor also affect the popularization of intelligent mowers for these applications. To address the above problems, this paper constructs a positioning system through a low-cost global navigation satellite system (GNSS), inertial measurement unit (IMU), and odometry, and utilizes the Kalman filter algorithm based on the error state for a combined GNSS/IMU positioning so that the inertial navigation system can maintain a more accurate positioning when the GNSS signals are poor. Considering the side-slip and error accumulation problems of the odometry of the traction mower, the combined GNSS/IMU positioning information is used to optimize the odometry model and improve the navigation and positioning accuracy. To reduce the measurement error of the IMU and the problem of error accumulation, this paper utilizes the nonholonomic constraint (NHC) of a lawn mower to suppress the dispersion of IMU measurement errors and constructs periodic and nonperiodic zero-velocity updating (ZUPT) strategies in combination with the travel paths of lawn mower navigation operations in the region to update the IMU data to improve the positioning accuracy and stability of the positioning system. The experiments show that the average error of the constructed positioning system is controlled within 0.15 m, the maximum error is maintained at approximately 0.3 m, and the positioning system constructed by using low-cost sensors can achieve a positioning accuracy similar to that of the differential global navigation satellite system (DGNSS), which is beneficial for the promotion and application of intelligent mowers in orchards.

This paper presents the results of a computer optimising a multibody system using Generative Design methods to select a lower-cost actuator that meets process requirements with its parameters. Optimisation was performed to reduce the mass of the motion apparatus components of the author’s CPM device, used for the rehabilitation of patients after knee arthroscopy and total or partial knee replacement. An analysis of the kinematics and dynamics of the multibody mechanism, based on a virtual model, was carried out to identify the requirements for selecting an actuator. The main components of the motion apparatus mechanism were subjected to a series of numerical analyses using selected CAD/CAE tools, with the assumed criterion of varying material and component shapes to ensure that the required strength and accuracy of the mechanism links were maintained, assuming the same functionality. The results of the numerical analyses will be the basis for the selection of the optimum solution, for which a new, lower-cost actuator will be selected.

Infrared sensors incorporating suspended zinc oxide (ZnO) pyroelectric films and thermally insulated silicon substrates are fabricated using conventional MEMS-based thin-film deposition, photolithography, and etching techniques. The responsivity of the pyroelectric film is improved via annealing at 500 °C for 4 h. The voltage response of the fabricated sensors is evaluated experimentally for a substrate thickness of 1 µm over a sensing range of 30 cm. The results show that the voltage signal varies as an inverse exponential function of the distance. A positioning system based on three infrared sensors is implemented in LabVIEW. It is shown that the position estimates obtained using the proposed system are in excellent agreement with the actual locations. In general, the results presented in this study provide a useful source of reference for the further development of MEMS-based pyroelectric infrared sensors. [ABSTRACT FROM AUTHOR]

Due to the limited availability of parking slots in parking areas, drivers often have difficulty finding an empty parking slot. The number of parking slots available at a particular location is usually less than the number of vehicles. Hence, drivers spend a lot of time looking for vacant parking slots, which eventually delays the completion of their tasks, such as paying bills, attending a meeting, or visiting a patient at the hospital, etc. There are a couple of parking guidance systems that have been highlighted by the other researchers, but most of them lack real-time, convenient guidance. This research proposed a smart parking guidance system made of an IoT Raspberry Pi combined with an Android application that makes use of the weighted k nearest neighbours for positioning the vehicle. This was achieved through the use of Wi-Fi signal strength indicator fingerprinting, allowing for real-time navigation and parking detection. In order to achieve real-time parking over the internet, Raspberry Pi hardware and the ThingSpeak IoT cloud with ultrasonic sensors are used in the proposed method. An Android application was involved in this parking detection system, which adopted IoT approaches to estimate the location of users in real-time and provide routes using route-finding techniques to assist drivers in finding their desired parking slots. Data from the sensors was processed and translated into the Raspberry Pi using the Python programming language. They were sent using the Message Telemetry Transport protocol to send parking data to the ThingSpeak IoT cloud in real-time. This data was displayed via the Android app. The user is then able to view each available parking slot, acquire the route, and be directed with high accuracy to the parking slots of their choice. In this study, advanced sensing and communication technologies were used together with the weighted k nearest neighbours algorithm for positioning and wayfinding in order to improve parking guidance accuracy. Based on the experimental results, the proposed system showed a lower average error rate of 1.5 metres in comparison to other positioning techniques, such as GPS, or other similar algorithms for positioning, such as maximum a posteriori, which have shown average errors of 2.3 metres and 3.55 metres, respectively, a potential increase of more than 35% from the previous error rate. [ABSTRACT FROM AUTHOR]

Obtaining the position of ego-vehicle is a crucial prerequisite for automatic control and path planning in the field of autonomous driving. Most existing positioning systems rely on GPS, RTK, or wireless signals, which are arduous to provide effective localization under weak signal conditions. This paper proposes a real-time positioning system based on the detection of the parking numbers as they are unique positioning marks in the parking lot scene. It does not only can help with the positioning with open area, but also run independently under isolation environment. The result tested on both public datasets and self-collected dataset show that the system outperforms others in both performances and applies in practice. In addition, the code and dataset will release later. [ABSTRACT FROM AUTHOR]

Numerous lunar missions are planned for the next decade and the current deep space tracking system could not be sufficient to support all of them, since it has inherent limits in terms of complexity, availability, costs and user capacity. Consequently, new semi-autonomous or autonomous navigation systems are under study for the Moon, using satellites deployed in lunar orbit. In this work, a general and modular architecture for a satellite based navigation system, compatible with the state-of-the-art recommendations, is defined and three different localization methods, exploiting One-Way and Two-Way ranging, are proposed. The Two-Way ranging is proposed with two different implementation techniques: Earth based and user based round trip delay. These solutions were evaluated for two types of constellations that are, at the moment, the most promising for a future lunar navigation system, the Halo and ELFO constellations, by the use of the Cramer–Rao Lower Bound. Moreover, models for measurement errors affecting the lunar navigation system are proposed. The results show that Two-Way localization has slightly better accuracy and availability w.r.t. the One-Way localization, but it has also some limits in terms of capacity and latency. In the author's opinion, the two methods might coexist for different user requirements and services in a future lunar navigation system. • Modular architecture for lunar satellite-based navigation systems. • One-Way and Two-Way localization methods comparison in the Moon navigation system. • Halo and ELFO lunar orbits navigation performance comparison. • Models for errors affecting the measurements in a lunar navigation system. • Cramer–Rao Lower Bound for three localization methods on the Moon. [ABSTRACT FROM AUTHOR]

Seismic airgun surveys to map petroleum deposits in the seabed may impact behaviour of marine animals over large distances. Understanding whether fish spawning behaviour is affected by this anthropogenic noise source is important because reproductive success may be impacted. The fine-scale behavioural responses of Atlantic cod to airgun exposure over an extended period were investigated using an acoustic telemetry positioning system on a spawning ground in Norway. During 2019 to 2021, 135 spawning cod were equipped with telemetry sensor tags and were exposed to airgun shooting during the spawning periods of 2020 and 2021, with varying received sound levels comparable to a full-scale survey at distances of 5 to >40 km. Cod demonstrated only weak responses to the disturbance from repeated 3-h treatment periods over 5-d, swimming on average slightly deeper during seismic exposure compared to silent control periods. This response varied between individuals. Longer-term effects of seismic exposure on swimming depth were not detected. No changes in swimming acceleration, displacement, or area use occurred. These results suggest that relatively distant seismic surveys do not substantially alter cod behaviour during the spawning period at received sound exposure levels varying between 115 and 145 dB re 1 µPa2s over a 5-d period. [ABSTRACT FROM AUTHOR]

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An alternative positioning system, the Spread Spectrum Sound-based Local Positioning System (SSSLPS), was developed to extend the usage of UAVs in GPS-denied environments, such as greenhouses. To date, it has been proven that the SSSLPS could provide a centimeter-level locational accuracy of static objects and dynamic ground robots. In this research, the ranging and positioning performance of SSSLPS were evaluated with the system mounted on a UAV. Meanwhile, to minimize the Time of Arrival (ToA) estimation error and improve positioning accuracy, a novel Doppler shift compensation algorithm was proposed. Experiments were conducted, and the measurement accuracy was evaluated by comparing the measurement of the motion capture system. The results show a successful detection rate of 90.2% using the proposed algorithm and a position error of 75.9 mm. These results demonstrate that the SSSLPS with spectrum peak algorithm can improve positioning accuracy and enable the SSSLPS to be an accurate positioning system for UAVs in a greenhouse. [ABSTRACT FROM AUTHOR]

In order to meet the requirements of high-precision positioning in offshore complex construction environment far from the coast, it is necessary to assist the offshore survey platform to carry out the survey and positioning. In this paper, a floating state precise positioning method based on the combination of GNSS and total stations is presented, in which a working vessel is used as a carrier and a GNSS receiver and an electronic total station can be set up directly on the deck of the working vessel to effectively control the influence of measurement error caused by wave and current fluctuation to realize the accurate survey and location of the construction plan. A floating-state precise positioning system with the combination of GNSS and total station is developed based on the project cases and the feasibility of the system useing for accurate survey and location of the construction plan with floating state survey is verified by project practice. [ABSTRACT FROM AUTHOR]

The knee is one of the most stressed joints of the human body, being susceptible to ligament injuries and degenerative diseases. Due to the rising incidence of knee pathologies, the number of knee X-rays acquired is also increasing. Such X-rays are obtained for the diagnosis of knee injuries, the evaluation of the knee before and after surgery, and the monitoring of the knee joint's stability. These types of diagnosis and monitoring of the knee usually involve radiography under physical stress. This widely used medical tool provides a more objective analysis of the measurement of the knee laxity than a physical examination does, involving knee stress tests, such as valgus, varus, and Lachman. Despite being an improvement to physical examination regarding the physician's bias, stress radiography is still performed manually in a lot of healthcare facilities. To avoid exposing the physician to radiation and to decrease the number of X-ray images rejected due to inadequate positioning of the patient or the presence of artefacts, positioning systems for stress radiography of the knee have been developed. This review analyses knee positioning systems for X-ray environment, concluding that they have improved the objectivity and reproducibility during stress radiographs, but have failed to either be radiolucent or versatile with a simple ergonomic set-up. [ABSTRACT FROM AUTHOR]

Copyright of Railway Investigation & Surveying is the property of Railway Investigation & Surveying Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

One of the important issues being explored in Industry 4.0 is collaborative mobile robots. This collaboration requires precise navigation systems, especially indoor navigation systems where GNSS (Global Navigation Satellite System) cannot be used. To enable the precise localization of robots, different variations of navigation systems are being developed, mainly based on trilateration and triangulation methods. Triangulation systems are distinguished by the fact that they allow for the precise determination of an object’s orientation, which is important for mobile robots. An important feature of positioning systems is the frequency of position updates based on measurements. For most systems, it is 10–20 Hz. In our work, we propose a high-speed 50 Hz positioning system based on the triangulation method with infrared transmitters and receivers. In addition, our system is completely static, i.e., it has no moving/rotating measurement sensors, which makes it more resistant to disturbances (caused by vibrations, wear and tear of components, etc.). In this paper, we describe the principle of the system as well as its design. Finally, we present tests of the built system, which show a beacon bearing accuracy of Δφ = 0.51°, which corresponds to a positioning accuracy of ΔR = 6.55 cm, with a position update frequency of fupdate = 50 Hz.

This paper presents experimental studies of the force generated on the rotating cylinder implemented as a bow rudder on a large-scale ship model. The research focused on the maneuverability of the unit equipped with a rotating cylinder (RC) in the front part of the model and its future use as a steering device on small draft river barges. The study presented in this paper is a continuation of the research carried out using the small physical model of a river push train in 1:20 geometric scale equipped with two bow RCs and open water tests of separated rotating cylinders carried out in a flume tank. The experimental test setup with RC installed on the model in 1:24 geometric scale allowed to compare the parameters of standard maneuvers performed with the use of RC and without it. The proposed method based on the measurement of the ship model trajectory during maneuvers allowed to compare the hydrodynamic steering force generated by RC with the steering force generated by the conventional stern spade rudder. The results of the experiments compared with empirical models show a similar trend. RC dynamics was tested for rotational speeds up to 570 RPM (revolutions per minute) and ship model velocity up to 1 m/s. The rotating cylinder generated velocity field is presented and phenomena influencing the generated hydrodynamic force are discussed. [ABSTRACT FROM AUTHOR]

Currently, intelligent ships are still in the early stages of development in terms of autonomous navigation and autonomous berthing, so almost no source of fault data can be obtained. Conducting an in-depth analysis of the failure modes of intelligent ships is critical to optimizing the design of smart ships and ensuring their normal and safe navigation. In this paper, the fixed-weight Failure Mode Effects and Criticality Analysis (FMECA) is combined with the decision-making trial and evaluation laboratory (DEMATEL) method to analyze the failure modes and effects of intelligent ship positioning systems. This combined method not only overcomes the failure of traditional FMECA methods to differentiate between severity, incidence, and detection rates but also allows the correlation of failure causes to be analyzed, bringing the results of the analysis closer to reality. Through the expert scoring of failure modes, the failure modes of this system are risk-ranked, and the key failure causes of this system are identified. Correlations between the critical failure causes are then considered. According to the analysis results, the high-accuracy attitude sensor was identified as the subsystem with the highest level of risk. Unavoidable, unknown failures and environmental factors were found to be key factors in causing positioning system failures. The conclusions can provide a reference for the design of equipment safety for intelligent ship positioning systems. [ABSTRACT FROM AUTHOR]

Currently, several, more or less, suitable means for detecting, identifying and monitoring the position of housed animals exist. However, these means suffer from various limitations, which could be eliminated with regard to the current technical and technological possibilities. One possible solution could be the use of some wireless technologies from the Internet of Things (Wi-Fi, Bluetooth, Zigbee, etc.). The uninterrupted supervision of individual housed animals would bring important information about the daily routine of individuals and then, based on the deviations from this daily routine, the opportunity to derive their physical and mental state from these deviations would be potentially possible. This article presents a proof of concept of a low-cost monitoring system of the movement of housed animals. The proposed system is able to detect the client's (prototype's) position in the space by means of Wi-Fi (IEEE 802.11 standard) and received signal strength indication (RSSI) technologies. A fingerprint method and a triangulation method of analysing the space are used to calculate the position in space with a resulting accuracy within metres of the real position.

This study addressed the issue of the real-time monitoring and control of the transporter in a mountain orchard terrain characterized by varying topography, closed canopy, shade, and other environmental factors. This study involved independent research and the development of a series of electric monorail transporters. First, the application requirements of “Where is the monorail transporter?” were examined, and an accurate location-aware method based on high-frequency radio frequency identification (RFID) technology was proposed. In addition, a location-aware hardware system based on STM32 + RFID + LoRa was designed to determine the position of the monorail transporter on a rail. Second, regarding the application requirements of “Where is the monorail transporter going?”, a multimode control gateway system based on Raspberry Pi + LoRa + 5G was designed. An Android mobile terminal can obtain operational information about the transport plane in real time through the gateway system and remotely control its operation. The track-changing branch structure enables multimachine autonomous intelligent avoidance. Based on the experimental results of monorail transporter positioning in mountain orchards under various typical terrains, such as flat surfaces, turning paths, and uphill/downhill slopes, the road section average relative error of the 7ZDGS–250-type monorail transporter was 1.27% when the distance between benchmark positioning tags was set at 10 m on both flat and turning roads, and that of the 7ZDGS–300-type monorail transporter was 1.35% when the distance between benchmark positioning tags was set at 6 m uphill/downhill. The road section relative error of the 7ZDGS–250-type monorail transporter was 21.18%, and that of the 7ZDGS–300-type monorail transporter was 9.96%. In addition, the experimental results of monorail transporter communication control showed that the combination of the multimode control gateway control system and track-changing branch structure can achieve multimachine cooperation and autonomous avoidance function, ensuring that multiple monorail transporters can operate simultaneously without collision. The findings of this study establish the communication link of “monorail transporter-gateway system-control terminal” and form a precise positioning and real-time control scheme applicable to the operating environment of monorail transporters, thereby improving the intelligence and safety of mountain orchard monorail transporters.

To improve the positioning accuracy of unmanned ships, a multi-sensor system including ZigBee, a Global Positioning System (GPS), and BeiDou Navigation Satellite System (BDS) is constructed, and an adaptive multi-sensor data fusion positioning method based on the threshold and hierarchical capacity particle filter (TCPF) is designed. First, the ZigBee-GPS/BDS multi-sensor measurement data is preprocessed to achieve a consistent space–time reference and transformed into the same coordinate system by projection. Then, the fault data is weighted and corrected through the consistency inspection of ZigBee-GPS/BDS multi-sensor positioning data, and the corresponding confidence factor is given according to the confidence distance of the positioning data; furthermore, the confidence factor is associated with stratified sampling. After that, the multi-sensor positioning data is filtered and denoised using a basic particle filter. Finally, a TCPF data fusion algorithm is designed, and the navigation positioning data of the unmanned ship is fused and filtered to obtain its positioning information. Numerical tests show that compared with other filtering algorithms, the mean square root error and standard deviation of the proposed TCPF algorithm decrease by an average of 25.0% and 28.0%, respectively, which verifies its high filtering accuracy and its advantages in suppressing particle degradation and avoiding sample scarcity. The experimental tests show that compared with other fusion algorithms, the proposed TCPF algorithm can not only realize the precise positioning during unmanned ship navigation, but also in the positioning and fault tolerance test, the average positioning error, root-mean-square error, and standard deviation of the former decrease by 36.0%, 38.0%, and 37.0%, respectively, and the corresponding performance indicators of the latter decrease by an average of 20.0%, 19.5%, and 17.5%, which verifies that it has the advantages of high data reliability and good filtering fault tolerance, and helps to improve the positioning accuracy of unmanned ships.