Safe Landing Research Articles

Dynamics Research and Analysis of landing on the surface of Asteroid

Asteroid detection has been the main research field of deep space exploration, and even in the future years. Countries have carried out missions to flyby and landing on the surface of asteroids, the sampling can help human explore the origins of small bodies, as well as origin of the solar system. While the particular environmental factors such as small size and low gravity of asteroids make the landing more difficult, this paper designs a four-legged inverted triangle soft lander, supplemented by thrust reversers and rope anchors for stable landing. A mathematical model of the lander landing on the surface of target asteroid is established, and the motion and dynamic response of lander in different landing modes is studied, conditions and safe landing range is well defined. Results of the analysis have demonstrated the effectiveness of dynamic landing model for the proposed lander.

Robust control scheme based on an uncertainty and disturbance estimator for a quadrotor with motor failures

AbstractThis paper proposes a new robust fault tolerant control architecture based on a disturbance observer. The control architecture is composed of a nominal controller and a rotor's fault observer capable to identify and estimate motors' degradation performance. Besides, is designed for a quadrotor vehicle and validated in critical and noncritical motors' failures. For both failure cases, each motor performance is analyzed to counteracted the failure and restore the system stability. If the practical stability is not recovered (critical case) a control reconfiguration is performed for safe landing. Experimental tests are carried out in real time to illustrate the effectiveness of the proposed architecture when confronting the stability of the system with aggressive disturbances or uncertainties.

Parachute deployment system for safe recovery of a drone

Unmanned aerial vehicles are becoming a new vision for human beings, from agriculture to military purposes these are playing a key role and the industry is still booming exponentially. Drones have changed the whole perspective of aerial missions. As the wide range of drones is increasing, it’s a need to perform the entire mission in a safe manner. Though even after certain rules and regulations it is observed that flight operations sometimes mislead.Different internal and external factors can cause hardware damage which includes fallacy of GPS error, battery failure, Magnetic Interference, Poor Weather, Disconnected transmissions that can lead to unsafe landing resulting in accidents and financial loss to information and equipment lost. The consequences of a drone crash can vary depending on several factors, including the size and weight of the drone, the location of the crash, and the presence of people or property in the vicinity. Therefore, there is a need other than regulations that in any such cases the drone can have a smooth landing, using a parachute for such types of errors can not only reduce the chances of accidents but also provide a means of backup.The developed method in this research is an efficient way for safe landing of drones using a parachute made of nylon that will be mounted on top of a drone in case of loss of control or any accident that can lead to sudden or delayed loss of control. The CAD model has been developed and CFD simulations are performed and the model has been optimized according to the results of the simulation, and the method is deduced that has been described in the paper. The paper will provide enough resources to an individual that the person can build the customized Parachute Deployment System according to the drone.

Real-Time Safe Landing Zone Identification Based on Airborne LiDAR

Over the past two decades, there has been a growing demand for generating digital surface models (DSMs) in real-time, particularly for aircraft landing in degraded visual environments. Challenging landing environments can hinder a pilot's ability to accurately navigate, see the ground, and avoid obstacles that may lead to equipment damage or loss of life. While many accurate and robust filtering algorithms for airborne laser scanning (ALS) data have been developed, they are typically computationally expensive. Moreover, these filtering algorithms require high execution times, making them unsuitable for real-time applications. This research aims to design and implement an efficient algorithm that can be used in real-time on limited-resource embedded processors without the need for a supercomputer. The proposed algorithm effectively identifies the best safe landing zone (SLZ) for an aircraft/helicopter based on processing 3D LiDAR point cloud data collected from a LiDAR mounted on the aircraft/helicopter. The algorithm was successfully implemented in C++ in real-time and validated using professional software for flight simulation. By comparing the results with maps, this research demonstrates the ability of the developed method to assist pilots in identifying the safest landing zone for helicopters.

Design and Experimental Validation of an Adaptive Landing Gear for Safe Landing on Uneven Grounds of VTOL UAVs in the Context of Lightweight and Fast Adaptations

Design and Experimental Validation of an Adaptive Landing Gear for Safe Landing on Uneven Grounds of VTOL UAVs in the Context of Lightweight and Fast Adaptations

Management of land resources of rural areas in the context of the paradigm of sustainable development of Ukraine

Aim. To determine the main directions of the formation of innovative agricultural land use of united territorial communities through its multifunctional development in the context of improving the investment climate of rural areas based on the use of innovative levers of their integrated development. The National Security Strategy of Ukraine [1] defines that ensuring environmental and food security belongs to the priority areas of state policy. The land and resource potential of Ukraine is rightly considered the foundation of the national economy. However, the current ecological and economic situation in land use shows that society is not yet sufficiently aware of the real value of land resources. This mainly applies to agricultural lands, since the methods of their use in agricultural production quite often become the root cause of the occurrence of many negative phenomena, which leads to the growth of environmental hazards and manifestations of degradation of productive lands of agricultural landscapes. Methods. Monographic analysis, abstract-logical, comparative and analogues and comparisons, experimental, economic analyses. Results. The article presents the results of scientific research, which were aimed at substantiating priority measures regarding the rational use, protection and reproduction of the productive potential of land resources, ensuring environmental safety in agricultural landscapes. Special attention is paid to the revision of the land resource management strategy in the field of land use, to the deepening of scientific research on the formation of a multifunctional paradigm for the development of rural areas, the implementation of which will ensure rationality, efficiency and environmental friendliness, their use, which will largely determine the level of economic development of the country. Conclusions. The socio-economic trends of the development of rural areas in the context of ensuring the economic and food security of Ukraine were studied. An assessment of the existing socio-economic development potential of rural areas was carried out from the point of view of the prospects of further European integration of our state. The regional aspects of the development of rural areas in the context of increasing their competitiveness in the conditions of the development of the green economy are revealed. Elaborated directions for increasing the efficiency of agricultural land use at the regional level, taking into account the decentralization of territorial development management. A comprehensive system of measures regarding the ecological and economic regulation of the use of land and resource potential by developing a territory organization project with scientific justification of project decisions regarding changes in the structure of agricultural land on the basis of ecologically safe land use has been substantiated and proposed. The theoretical and methodological foundations of organizational and economic support for ecologically balanced agricultural use of land resources in the conditions of transformation of land relations have been analyzed, systematized and deepened. The dynamics of the state of the land fund were studied (on the example of land use in Obukhiv district, Kyiv region, Forest-Steppe zone) with the aim of developing a conceptual structural-logical model of organizational and land-ordering mechanisms for the formation of balanced land use in rural areas for the further development of an innovative ecological and economic model of the organization of the territory of rural land use.

Multiple-Sliding-Surface Guidance and Control for Terminal Atmospheric Reentry and Precise Landing

The development of an effective guidance and attitude control architecture for terminal descent and landing represents a crucial issue for the design of reusable vehicles capable of performing a safe atmospheric planetary entry. The sliding mode control represents a nonlinear technique able to generate an effective real-time closed-loop guidance law, even in the presence of challenging contingencies. This work proposes a multiple sliding-surface guidance control law that is able to drive a lifting vehicle toward safe landing conditions, associated with a desired downrange, crossrange, runway heading, and final vertical velocity at touchdown, even starting from challenging initial conditions. The time derivatives of the lift coefficient and the bank angle are used as the control inputs, whereas the sliding surfaces are defined so that these two inputs are involved simultaneously in the lateral and the vertical guidance. The commanded attitude is pursued by the attitude control system, which employs a feedback nonlinear control law that enjoys quasi-global stability properties. Effectiveness and accuracy of the guidance and control strategy at hand are proven numerically by means of a Monte Carlo campaign, in the presence of stochastic wind and large dispersions on the initial conditions.

Identification of soil parent materials in naturally high background areas based on machine learning

Recently, farmlands with high geological background of Cd derived from carbonate rock (CA) and black shale areas (BA) have received wide attention. However, although both CA and BA belong to high geological background areas, the mobility of soil Cd differs significantly between them. In addition to the difficulty in reaching the parent material in deep soil, it is challenging to perform land use planning in high geological background areas. This study attempts to determine the key soil geochemical parameters related to the spatial patterns of lithology and the main factors influencing the geochemical behavior of soil Cd, and ultimately uses them and machine-learning methods to identify CA and BA. In total, 10,814 and 4323 surface soil samples were collected from CA and BA, respectively. Hot spot analysis revealed that soil properties and soil Cd were significantly correlated with the underlying bedrock, except for TOC and S. Further research confirmed that the concentration and mobility of Cd in high geological background areas were mainly affected by pH and Mn. The soil parent materials were then predicted using artificial neural network (ANN), random forest (RF) and support vector machine (SVM) models. The ANN and RF models showed higher Kappa coefficients and overall accuracies than those of the SVM model, suggesting that ANNs and RF have the potential to predict soil parent materials from soil data, which might help in ensuring safe land use and coordinating activities in high geological background areas.

Avoiding contingent incidents by quadrotors due to one or two propellers failure.

With the increasing impact of drones in our daily lives, safety issues have become a primary concern. In this study, a novel supervisor-based active fault-tolerant (FT) control system is presented for a rotary-wing quadrotor to maintain its pose in 3D space upon losing one or two propellers. Our approach allows the quadrotor to make controlled movements about a primary axis attached to the body-fixed frame. A multi-loop cascaded control architecture is designed to ensure robustness, stability, reference tracking, and safe landing. The altitude control is performed using a proportional-integral-derivative (PID) controller, whereas linear-quadratic-integral (LQI) and model-predictive-control (MPC) have been investigated for reduced attitude control and their performance is compared based on absolute and mean-squared error. The simulation results affirm that the quadrotor remains in a stable region, successfully performs the reference tracking, and ensures a safe landing while counteracting the effects of propeller(s) failures.

FLInt: single shot safe harbor transgene integration via Fluorescent Landmark Interference.

The stable incorporation of transgenes and recombinant DNA material into the host genome is a bottleneck in many bioengineering applications. Due to the low efficiency, identifying the transgenic animals is often a needle in the haystack. Thus, optimal conditions require efficient screening procedures, but also known and safe landing sites that do not interfere with host expression, low input material and strong expression from the new locus. Here, we leverage an existing library of ≈300 different loci coding for fluorescent markers that are distributed over all 6 chromosomes in Caenorhabditis elegans as safe harbors for versatile transgene integration sites using CRISPR/Cas9. We demonstrated that a single crRNA was sufficient for cleavage of the target region and integration of the transgene of interest, which can be easily followed by loss of the fluorescent marker. The same loci can also be used for extrachromosomal landing sites and as co-CRISPR markers without affecting body morphology or animal behavior. Thus, our method overcomes the uncertainty of transgene location during random mutagenesis, facilitates easy screening through fluorescence interference and can be used as co-CRISPR markers without further influence in phenotypes.

Stochastic simulation of a signal on a photodetector matrix of a laser navigation system

Abstract Algorithms for stochastic simulation of the signal arriving at the photodetector matrix of the aircraft navigation system are constructed. During the operation of the aircraft landing navigation system, the laser beam of the navigation system coincides in its direction with the glide path determining safe landing. Two photodetector units placed on board of the aircraft determine the glide path position in the coordinate system of the aircraft, which allows one to adjust the position of the touch point on the runway in poor visibility conditions. In this case, the estimation of the power and angular distributions of radiation recorded by the receiver of the navigation system is a relevant problem. In addition, it is interesting to study the effect of scattering of various multiplicities on the recorded signal. The algorithms developed here are based on direct statistical modelling (estimation over collisions) and local estimates of the Monte Carlo method. The calculations show that the proposed methods allow us to evaluate the efficiency of the laser navigation system in various conditions.

Vision-Based UAV Landing with Guaranteed Reliability in Adverse Environment

Safe and accurate landing is crucial for Unmanned Aerial Vehicles (UAVs). However, it is a challenging task, especially when the altitude of the landing target is different from the ground and when the UAV is working in adverse environments, such as coasts where winds are usually strong and changing rapidly. UAVs controlled by traditional landing algorithms are unable to deal with sudden large disturbances, such as gusts, during the landing process. In this paper, a reliable vision-based landing strategy is proposed for UAV autonomous landing on a multi-level platform mounted on an Unmanned Ground Vehicle (UGV). With the proposed landing strategy, visual detection can be retrieved even with strong gusts and the UAV is able to achieve robust landing accuracy in a challenging platform with complex ground effects. The effectiveness of the landing algorithm is verified through real-world flight tests. Experimental results in farm fields demonstrate the proposed method’s accuracy and robustness to external disturbances (e.g., wind gusts).

The ability to produce a timely explosive force may affect loading rate at landing

BackgroundSports injuries are strongly associated with the impact loading at landing. The abilities to produce force and adjust timing are simultaneously required to absorb impact loading.AimsHence, we aimed to examine the hypothesis that the ability to produce an explosive force at the right timing is related to the ability to absorb the impact loading at landing.MethodsTwenty-nine healthy young men volunteered to participate in the study. We proposed a new test to measure the rate of force development (RFD) in accordance with the countdown signal. To evaluate the ability to produce explosive force at the right time, we measured the rate of change between the RFD at the standard start signal and the RFD at the countdown signal. Furthermore, to evaluate the ability to land from a jump, we measured the loading rate at single-leg drop landing (20 cm).ResultsWe divided the participants into two groups based on the timing effect: the positive group (participants with increased RFD at the countdown signal, n = 11) and the negative group (participants with decreased RFD at the countdown signal, n = 18). The loading rate was significantly greater (P < .01) in the negative group (47.4 ± 11.2 body weight (BW)/s) than in the positive group (34.7 ± 7.1 BW/s).ConclusionsParticipants with increased RFD at the countdown signal had a lower loading rate at landing. Our results suggest that the ability to produce a timely explosive force may be a determinant of safe landing ability.

Optimalisasi Stabilitas Lereng pada Daerah Sempadan Sungai Santer Kecamatan Gumukmas Kabupaten Jember

The Santer Riverbank which is located in Panggul Melati Hamlet, Kepanjen Village, Gumukmas District, Jember Regency, East Java is still used by the community for agricultural land. This research was conducted to create safe agricultural land for the community. Landslides on this riverbank often occur because it is located on the edge of the river and has a steep slope. In the observation in 2022, there is a collapsed riverbank approximately 20 meters in front of the river embankment. To prevent a longer landslide area, the slopes on the river border are optimized so that residents can still use the land safely. The selected reinforcement is made based on the geometric conditions and the results of the SF value from modeling the existing conditions using the Geostudio program. Appropriate reinforcement based on geometric conditions and SF values ​​is a balancing method. close to the counterweight method, the geometric conditions are more optimal with the SF value increasing from 1.099 to 1.623

A Faster RCNN Airport Pavement Crack Detection Method Based on Attention Mechanism

Airport pavement inspection is an important link to ensure the safe takeoff and landing of aircraft. At present, the airport pavement safety inspection is still dominated by manual inspection. This method has some problems such as low detection efficiency, strong subjectivity, and unable to fully cover. In this context, Faster RCNN network was used for tunnel crack detection, the backbone network of Faster RCNN was modified, the lightweight network MobileNetV2 was used to improve the network training speed, and CBAM attention mechanism was added to improve the feature extraction ability of the model.

Improvement of the organizational and economic mechanism for the formation of environmentally safe land use

The organizational and economic mechanism of ecologically safe land use is an effective tool for the interest of landowners and land users in compliance with the requirements of environmental standards. The use of such a mechanism contributes to the effective management of land resources at various levels. The article proposes an improved structure of the organizational and economic mechanism for the formation of ecologically safe agrarian land use. Given the specifics of land use, two more instrumental blocks of a cross-functional nature, namely: regulatory and land management, are allocated at the same level as the organizational and economic blocks. For each of the named instrumental blocks, specific tools are defined that allow to ensure the formation of ecologically safe land use. It has been established that any organizational and economic mechanism, in a broad sense, is a certain set of action tools and the necessary forms, methods and levers of their functioning, while simultaneously understanding the mechanism exclusively as a set of tools. Implementation of the developed organizational mechanism for the formation of ecologically safe agrarian land use is carried out by improving the structural scheme, the essence and toolkit of which is transformed depending on the tasks and functions of the main instrumental blocks. It is justified that all four instrumental blocks should be based on consideration of four dimensions: legal, spatial, ecological and social.

Phenomenology of plume–surface interactions and preliminary results from the Tianwen-1 landing crater on Mars

The plume–surface interaction (PSI) is a common phenomenon that describes the environment surrounding the landers resulting from the impingement of hot rocket exhaust on the regolith of planetary bodies. The PSI will cause obscuration, erosion of the planetary surface, and high-speed spreading of dust or high-energy ejecta streams, which will induce risks to a safe landing and cause damage to payloads on the landers or to nearby assets. Safe landings and the subsequent scientific goals of deep-space exploration in China call for a comprehensive understanding of the PSI process, including the plume flow mechanics, erosion mechanism, and ejecta dynamics. In addition, the landing crater caused by the plume provides a unique and insightful perspective on the understanding of PSI. In particular, the PSI can be used directly to constrain the composition, structure, and mechanical properties of the surface and subsurface soil. In this study, we conducted a systematic review of the phenomenology and terrestrial tests of PSI: we analyzed the critical factors in the PSI process and compared the differences in PSI phenomena between lunar and Martian conditions; we also reviewed the main erosion mechanisms and the evolution and development of terrestrial tests on PSI. We discuss the problems with PSI, challenges of terrestrial tests, and prospects of PSI, and we show the preliminary results obtained from the landing crater caused by the PSI of Tianwen-1. From analysis of the camera images and digital elevation model reconstructions, we concluded that the landing of Tianwen-1 caused the deepest crater (depth &gt; 40 cm) on a planetary surface reported to date and revealed stratigraphic layers in the subsurface of Martian soil. We further constrained the lower bounds of the mechanical properties of Martian soil by a slope stability analysis of the Tianwen-1 landing crater. The PSI may offer promising opportunities to obtain greater insights into planetary science, including the subsurface structure, mineral composition, and properties of soil.

The Conversion of Muhammad Shaybani Khan (Shakhbakht) from Desht-I-Kipchak and About the First Period His Stay in Maverannahr

In this article, the authors presents brief biographical information about Muhammad Shaybani Khan and his parents based on reliable historical sources. Also the course of his struggle in Maverannakhr for the restoration of the lost rule of his family in Desht-i-Kipchak is considered. Muhammad Shaybani and his brother Mahmud Sultan after the death of their uncle Sheikh Haydar and many wanderers took refuge from the persecution in Maverannahr. It should be said that relations between the Timurid rulers of Maverannahr and the rulers of Desht-i-Kipchak, including the grandfather of Shaybani Khan, Abulkhair Khan, were strengthened by family ties. This became the reason that their guardian of nephews of Abulkhair Khan decided to send Muhammad Sheibani and his brother to this safe land for them – to Maverannahr. The rulers of Maverannahr and Mahmud Khan the Moghul ruler of Tashkent, wanted to use the grandchildren of Abul Khair Khan in their own interests. The main results of the authors of the article were the identification of the purposes and reasons for the migration of Muhammad Shaibani to the territory of Maverannahr and the decision to consolidate this territory.

Эко-НИОКР – 18 лет для охраны птиц на объектах электросетевого комплекса России

Эко-НИОКР – 18 лет для охраны птиц на объектах электросетевого комплекса России

Fusing Dense Features and Pose Consistency: A Regression Method for Attitude Measurement of Aircraft Landing

The aircraft pose is the important measurement indicator related to the safe landing. The existing pose estimation methods are limited by the extraction accuracy of salient sparse points or line features, and it is hard to obtain higher accuracy and robustness, especially at long distance. In this paper, we implement attitude measurement utilizing a pose estimation. The aircraft pose estimation method based on dense features and pose consistency is proposed, which can infer the aircraft pose relative to the camera from the RGB image directly. This method uses the encoder-decoder network to predict the dense 3D coordinates, the surface regions and visible segmentation. Guided by the dense 2D-3D correspondences and surface regions, the aircraft pose is estimated using the pose regression module. To improve the robustness of decoupled pose estimation relative to object detection, this paper proposes a dual-channel regression framework connected with the pose consistency constraint, which enables mutual supervision between different dynamic zoom in (DZI). The experimental results on the aircraft dataset show the superiority of our aircraft pose estimation method significantly. The pose consistency constraints further improve the prediction performance on the aircraft dataset, LINEMOD dataset, and YCB-V dataset. The pose estimation method can be used for real-time measurement of aircraft attitude directly with the mean error of 0.377°, the RMS error of 0.491°, and the rate of 59FPS.