Path Angle Research Articles

Cyanobacterial Blooms in City Parks: A Case Study Using Zebrafish Embryos for Toxicity Characterization

Cyanobacteria are photosynthetic prokaryotes that play an important role in the ecology of aquatic ecosystems. However, they can also produce toxins with negative effects on aquatic organisms, wildlife, livestock, domestic animals, and humans. With the increasing global temperatures, urban parks, renowned for their multifaceted contributions to society, have been largely affected by blooms of toxic cyanobacteria. In this work, the toxicity of two different stages of development of a cyanobacterial bloom from a city park was assessed, evaluating mortality, hatching, development, locomotion (total distance, slow and rapid movements, and path angles) and biochemical parameters (oxidative stress, neurological damage, and tissue damage indicators) in zebrafish embryos/larvae (Danio rerio). Results showed significant effects for the samples with more time of evolution at the developmental level (early hatching for low concentrations (144.90 mg/L), delayed hatching for high concentrations (significant values above 325.90 mg/L), and delayed development at all concentrations), behavioral level (hypoactivity), and biochemical level (cholinesterase (ChE)) activity reduction and interference with the oxidative stress system for both stages of evolution). This work highlights the toxic potential of cyanobacterial blooms in urban environments. In a climate change context where a higher frequency of cyanobacterial proliferation is expected, this topic should be properly addressed by competent entities to avoid deleterious effects on the biodiversity of urban parks and poisoning events of wildlife, pets and people.

Analytical solution for the skip trajectory of hypersonic vehicles with time-varying aerodynamic coefficients

Abstract An analytical method is proposed for calculating the altitude and flight path angle of hypersonic vehicles’ skip trajectories under the influence of arbitrary time-varying aerodynamic coefficients. First, a longitudinal plane dynamics equation is established based on the inertial Earth model and the specific kinetic energy is introduced as independent variable to simplify the derivation. Subsequently, the solution is obtained through the perturbation method, where the zero-order analytical solution is based on existing literature, and the first-order linear time-varying system is decoupled through matrix linear transformation. Finally, by comparing numerical integration and analytical solutions with constant aerodynamic coefficients, the precision of this method in dealing with time-varying aerodynamic coefficients is verified, demonstrating its advantages over analytical solutions with constant aerodynamic coefficients.

Variable angle tow-steered fibres based rotating composite beam with rotary oscillations – Parametric excitation/instability analysis

This study is concerned with the stability analysis for various vibrational motions of tow-steered variable angle fibres based composite rotating beam with time varying speed. The formulation combines a higher order theory introducing sine function along with finite element methodology. It satisfies the plane stress condition in width direction of beam. The displacement kinematics are generic in the sense it includes various possible vibrational motions like chord and flap wise motions, torsional and axial vibration behaviours. The equilibrium equations for the proposed problem evolved adopting virtual dynamic work are then transformed into the equations of Mathieu-Hill type considering time varying harmonic rotational speed. Using Bolotin’s procedure coupled with C1 continuity-based beam element, the parametric resonance zones along with boundary limits are numerically evaluated. The eigenvalue type of solution methodology applied for the detailed study is validated for accuracy and computational efficiency against the time domain dynamic response analysis. Based on in-depth analysis, dynamic instability characteristics in terms of resonance range and origin of instability of composite beam subjected to the chord and flap wise, torsional and axial motions are studied considering curvilinear fibre path angles, beam cross section, hub radius, thickness ratio and mean rotary speed.

Optimal Gliding Trajectories for Descent on Mars

In this paper, optimal gliding trajectories are analyzed, formulating an optimal control problem to be solved computationally via nonlinear programming. A multi-objective terminal cost function that minimizes the velocity, altitude, horizontal flight path angle, and the error of a desired terminal point is formulated. The results are validated via Monte Carlo simulations, analyzing the influence of the variations in the lift-to-drag ratios in the atmospheric entry. The results show feasible solutions for minimizing the distance to the desired final point, which have significant practical implications for the controlled gliding entry of a spaceplane on Mars. In this sense, the results also show that the longitudes of the landing points do not change too much for almost all trajectories, while the latitude of these points is in the interval of about 4 degrees for the majority of the trajectories. This suggests that it is possible to implement an optimal control approach with reasonable accuracy for the controlled gliding entry of a spaceplane on Mars, even in the presence of some uncertainties regarding the aerodynamic performance of the spacecraft, such as the lift-to-drag ratio.

Trajectory Optimization to Enhance Observability for Bearing-Only Target Localization and Sensor Bias Calibration.

This study addresses the challenge of bearing-only target localization with sensor bias contamination. To enhance the system's observability, inspired by plant phototropism, we propose a control barrier function (CBF)-based method for UAV motion planning. The rank criterion provides only qualitative observability results. We employ the condition number for a quantitative analysis, identifying key influencing factors. After that, a multi-objective, nonlinear optimization problem for UAV trajectory planning is formulated and solved using the proposed Nonlinear Constrained Multi-Objective Gray Wolf Optimization Algorithm (NCMOGWOA). Simulations validate our approach, showing a threefold reduction in the condition number, significantly enhancing observability. The algorithm outperforms others in terms of localization accuracy and convergence, achieving the lowest Generational Distance (GD) (7.3442) and Inverted Generational Distance (IGD) (8.4577) metrics. Additionally, we explore the effects of the CBF attenuation rates and initial flight path angles.

Understanding the Interplay of Battery and Flight Dynamics Using Coupled Battery and Flight Physics Simulations for Electric Aircraft

Electric aviation has been a major focus of research in recent years as the aviation industry has seen significant growth in electric aircraft development. Most of the current literature related to electric aircraft modeling focuses on aircraft design and optimization with less focus given to battery analysis. Many studies utilize battery simplifications such as linear voltage profiles1 or the use of equivalent circuit models2. Similarly, in the emerging field of electric vertical takeoff and landing (eVTOL) aircraft, battery analysis is often reduced to considering just weight and empirical power parameters, failing to capture physical and electrochemical battery behavior and its effect on battery performance characteristics3. These simplifications can often lead to inaccurate battery state estimations and performance prediction. Moreover, the battery packs used for both electric conventional take-off and landing (eCTOL) aircraft and eVTOLs see unique operating requirements that are often significantly more demanding than those seen in electric vehicles (EVs)4. This suggests the need to analyze aircraft battery pack performance limitations in greater detail. However, only a few such studies have been reported in the literature5-6.In this work, we perform coupled simulation studies of longitudinal flight dynamics and physics-based battery dynamics. For modeling battery dynamics, we use the well-known single particle model7. This coupling enables more reliable estimation of battery states and can better inform battery pack design for electric aircraft. The simulations are performed to understand the interplay between battery cell dynamics governed by its design parameters and parameters associated with fixed-wing flight dynamics, such as cruise altitude, flight path angle, and velocity. Additionally, the simulations show how varying these parameters and operating temperature effects the range and endurance of electric aircraft which can be used to determine the optimal aircraft operating parameters for a desired mission profile. Results from this simulation study are compared against an equivalent circuit battery model to highlight the importance of detailed battery analysis in electric aviation. This work will be extended to develop similar coupled physics-based battery models with the state-of-the-art aircraft configurations emerging in the eVTOL field.References M. Kaptsov and L. Rodrigues, Journal of Guidance, Control, and Dynamics, 41, 288 (2018).N. Biju and H. Fang, Applied Energy, 339, 120905 (2023).L. Kiesewetter, K. H. Shakib, P. Singh, M. Rahman, B. Khandelwal, S. Kumar and K. Shah, Progress in Aerospace Sciences, 142, 100949 (2023).X.-G. Yang, T. Liu, S. Ge, E. Rountree and C.-Y. Wang, Joule, 5, 1644 (2021).A. Ayyaswamy, B. S. Vishnugopi and P. P. Mukherjee, Joule, 7, 2016 (2023).M. Wang, S. Kolluri, K. Shah, V. R. Subramanian and M. Mesbahi, IEEE Transactions on Aerospace and Electronic Systems, 59, 1084 (2022).S. Santhanagopalan, Q. Guo, P. Ramadass and R. E. White, Journal of power sources, 156, 620 (2006).

Angle-of-attack and angle-of-sideslip estimation and complementary filter design for civil aircraft

Angle-of-Attack (AOA) and angle-of-sideslip (AOS) are critical flight parameters affecting the flight safety, and their accuracy and reliability directly impact the operating status and performance of some significant airborne systems. To enhance the redundancy and accuracy of AOA and AOS, this article investigates the problem of the airflow angles estimation and complementary filter design for civil aircraft. Specifically, an extended Kalman filter based AOA and AOS estimation method considering acceleration correction is developed to increase the redundancy. Subsequently, a novel inertial AOA and inertial AOS calculation method using attitude angles, azimuth angle, and flight path angle is introduced, and two schemes for designing the discrete complementary filter based on Tustin transform are presented to improve the accuracy. Through simulations, the developed algorithms are verified, and the results illustrate that the AOA estimation error is within ± 0.6°, and the AOS estimation error is within ± 0.3°.

Analytical trajectory prediction of high-eccentricity spacecraft transfer orbits considering J2 perturbation

Using the perturbation method, the problem of high-accuracy rapid prediction for high-eccentricity spacecraft transfer orbit considering the J2 perturbation is solved. First, an auxiliary geocentric coordinate system is constructed based on the main flight plane of the spacecraft, and a generalized dynamics model considering the J2 perturbation is established by introducing the auxiliary longitude as the independent variable in that coordinate system. Since the J2 term is quite small, using the perturbation method, the dynamics model is decomposed into a zeroth-order system and a first-order system, where the solution of the zeroth-order system is just the analytical solution of the Kepler orbit, but the first-order system is complex and thus difficult to solve. The exact solutions for the first-order heading angle and auxiliary latitude are derived successfully. The approximate analytical solutions for first-order speed, flight path angle, and auxiliary longitude are obtained using a collocation method. Finally, Chebyshev polynomials are employed to derive an approximate analytical solution for the first-order flight time. Simulation results affirm the superiority of the proposed analytical solutions over Kozai's mean elements method and Biria's improved intermediary method.

A Design of Model Predictive Control and Nonlinear Disturbance Observer-based Backstepping Sliding Mode Control for Terrain Following

In this study, we propose the terrain following algorithm using model predictive control and nonlinear disturbance observer-based backstepping sliding mode controller for an aircraft system. Terrain following is important for military missions because it helps the aircraft avoid detection by the enemy radar. The model predictive control is used to replace the generating trajectory and guidance with the flight path angle constraint. In addition, the aircraft is affected to the parameter uncertainty and unknown disturbance such as wind near the mountainous terrain. Therefore, we suggest the nonlinear disturbance-based backstepping sliding mode control method for the aircraft that has highly nonlinearity to enhance flight path angle tracking performance. Through the numerical simulation, the proposed method showed the better tracking performance than the traditional backstepping method. Furthermore, the proposed method presented the terrain following maneuver maintaining the desired altitude.

Influence of biceps-triceps ratio on golf swing performance.

This study examines how maintaining a straight leading arm affects the muscle strength balance between the biceps and triceps in golfers and its influence on golf performance. We recruited 20 male participants aged 18-45, including 10 golfers and 10 non-golfers. The participants' average age was 25.6±6.2 years, height 1.8±0.07 m, and weight 75.6±10.2 kg. We measured isometric and isokinetic muscle strength using the Primus RS Dynamometer (BTE Technologies, Hanover, MD, USA) and assessed golf swing performance with the Optishot 2 Golf Simulator (Optishot, Brighton, MI, USA). Golfers exhibited significantly greater triceps strength (P = 0.02) and a lower biceps-to-triceps strength ratio (P = 0.002) than non-golfers. Low-handicap golfers showed more centered and consistent ball impacts compared to mid-handicap golfers. There were no significant differences in swing path and face angles between low- and mid-handicap golfers. Muscle strength and the biceps-to-triceps strength ratio correlated with driving distance, as well as the frequencies of specific swing paths, face angles, and ball impact points, highlighting the complex interplay between muscle balance and swing performance. Greater triceps strength and a lower biceps-to-triceps strength ratio are key for maintaining a straight leading arm, especially in skilled golfers. While increased muscle strength tends to enhance driving distance, it does not necessarily improve accuracy. Consistent ball impact points may indicate higher skill levels. Future research should involve a larger, more diverse participant pool to validate these findings and further explore the complex nature of golf swing performance.

The applicability of Zermelo's equation to indirect and direct optimization of commercial aircraft flights

This paper focuses on the applicability of Zermelo's equation within the context of 3D commercial aircraft trajectory optimization problems. The associated optimal control problem includes two singular controls, specifically aerodynamic path angle and throttle setting, and one regular control, specifically heading angle. Using Pontryagin's maximum principle and the direct adjoining method, we show that the optimal heading angle is defined by Zermelo's equation. The significance of the presented analysis is that Zermelo's equation holds for 3D commercial aircraft flights, even in the presence of standard state-inequality constraints and a more general objective function. With the help of Zermelo's equation, the control problem is initially analyzed for a 3D time-optimal climb-phase scenario, which is solved by an indirect approach. Through the analysis of the switching function, we demonstrate the dependency of the optimal aerodynamic path angle on the optimal heading angle. Next, by tackling a 3D time-fuel-optimal free-routing flight, solved by a direct approach, we show that Zermelo's equation can help reduce the overall dimension of the associated nonlinear programming. To successfully handle the initial guess in both indirect and direct problems, it is proposed a diminutive nonlinear programming technique as a fast and robust initializer. This simple-yet-effective initializer provides sufficient information about the optimal controls and state dynamics required for initializing a direct optimization, as well as the optimal switching times and co-states required for initializing an indirect optimization.

Data-Driven-Method-Based Guidance Law for Impact Time and Angle Constraints

To increase the hit efficiency and lethality of a flight vehicle, it is necessary to consider the vehicle’s guidance law concerning both impact time and angle constraints. In this study, a novel and straightforward impact time and angle control guidance law that is independent of time-to-go and small angle approximations is proposed with two stages using a data-driven method and proportional navigation guidance. First, a proportional navigation guidance-based impact angle control guidance law is designed for the second stage. Second, from various initial conditions on the impact angle control guidance simulation with various initial conditions, the input and output datasets are obtained to build a mapping network. Using the neural network technique, a mapping network model that can output the ideal flight path angle in flight is constructed for impact time control in the first stage. The proposed impact time and angle control guidance law reduces to the proportional navigation guidance law when the flight path angle error converges to zero. The simulation results show that the proposed guidance law delivers excellent performance under various conditions (including cooperative attack) and features better acceleration performance and less control energy than does the comparative impact time and angle control guidance law. The results of this research are expected to supplement those exploring various paradigms to solve the impact time and angle control guidance problem, as concluded in the current literature.

Global sensitivity analysis of stochastic re-entry trajectory using explainable surrogate models

The assessment of casualty risks associated with re-entry necessitates a comprehensive analysis of trajectories and the examination of pertinent safety-related quantities such as the ground impact area and ground reaching velocity. In practical scenarios, the presence of uncertainty in input conditions introduces variability in safety-related quantities. Consequently, employing stochastic re-entry trajectory analysis becomes crucial in overcoming the limitations of conventional deterministic analyses. Conducting sensitivity assessments during the break-up phase is imperative to gain more insights into how to manage the variability of safety-related measures. Therefore, this paper conducted a surrogate-based global sensitivity analysis and employed explainability machine learning techniques to unveil the complexities of the relationship between input uncertainty conditions and three key measures: ground-reaching velocity, falling range, and falling time, with the object of interest being the Apollo-type capsule. A three-step polynomial chaos expansion-based strategy was devised to efficiently approximate the discontinuous relationships. The results show that the relationship is characterized by severe discontinuity that separates two modes: low- and high-ground reaching velocity caused by the presence of two distinct trim points, with precautionary measures that should be taken to prevent the occurrence of the latter. From this set of procedures, three key input conditions that significantly affect the safety-related measures were identified, namely, the altitude, pitch rate, and path angle of the capsule during the breakup. Subsequently, explainability techniques were utilized to give suggestions on how to control the input variability and avoid the high ground reaching velocity mode, aiming to achieve more dependable predictions for the three safety parameters mentioned earlier.

Micro-robotic percutaneous targeting of type II endoleaks in the angio-suite

PurposeEndovascular aneurysm repair has emerged as the standard therapy for abdominal aortic aneurysms. In 9–30% of cases, retrograde filling of the aneurysm sac through patent branch arteries may result in persistence of blood flow outside the graft and within the aneurysm sac. This condition is called an endoleak type II, which may be treated by catheter-based embolization in case of continued sac enlargement. If an endovascular access is not possible, percutaneous targeting of the perfused nidus remains the only option. However, this can be very challenging due to the difficult access and deep puncture with risk of organ perforation and bleeding. Innovative targeting techniques such as robotics may provide a promising option for safe and successful targeting.MethodsIn nine consecutive patients, percutaneous embolization of type II endoleaks was performed using a table-mounted micro-robotic targeting platform. The needle path from the skin entry to the perfused nidus was planned based on the C-arm CT image data in the angio-suite. Entry point and path angle were aligned using the joystick-operated micro-robotic system under fluoroscopic control, and the coaxial needle was introduced until the target point within the perfused nidus was reached.ResultsAll punctures were successful, and there were no puncture-related complications. The pre-operative C-arm CT was executed in 11–15 s, and pathway planning required 2–3 min. The robotic setup and sterile draping were performed in 1–2 min, and the alignment to the surgical plan took no longer than 30 s.ConclusionDue to the small size, the micro-robotic platform seamlessly integrated into the routine clinical workflow in the angio-suite. It offered significant benefits to the planning and safe execution of double-angulated deeply localized targets, such as type II endoleaks.

Comprehensive Six-Degrees-of-Freedom Trajectory Design and Optimization of a Launch Vehicle with a Hybrid Last Stage Using the PSO Algorithm

Increased performance with reduced overall cost, and precise design and optimization of launch systems are critical to affordability. In this respect, the use of hybrid motors has increased to ease handling based on motor selection. In the current study, the launch vehicle’s performance is enhanced by incorporating a hybrid rocket motor into the last stage and optimized using particle swarm optimization to develop a six-degrees-of-freedom tool. This modification aims to increase payload placement flexibility, facilitate handling, and reduce costs. Thanks to the interactive subsystems within this research, this innovative study more comprehensively considers the launch vehicle trajectory design problem, allowing the simultaneous consideration of the effect of launch vehicle geometry along with other parameters in the system. In this context, the proposed method is applied to the Minotaur-I launch vehicle, and contributions of the detailed design and optimization are presented. Optimization results show that the percentage differences between these models for the original vehicle were observed to be 11.55% in velocity and 8.02% in altitude. However, there were differences of 10.06% and 48.8%, 15.8% and 23.2%, and 19.5% and 78.9% in altitudes and velocities when the center of gravity and moment of inertia changes were neglected, and constant aerodynamic coefficients were assumed, respectively. In all these cases, it was observed that the flight path angle was not close to zero. Moreover, the same mission was achieved by the launch vehicle with the optimized hybrid last stage and the propulsion performance was increased by about 7.64% based on the specific impulse and total impulse-over-weight ratio.

Whether search directions number affects the efficiency of the path planning algorithm: Taking an improved ACO algorithm with 32 directions for example

An improved Ant Colony Optimization (ACO) algorithm, named IACO, is proposed to address the inherent limitation of slow convergence, susceptibility to local optima and excessive number of inflection in traditional ACO when solving path planning problems. To this end, firstly, the search direction number is expanded from 4 or 8 into 32; Secondly, the distance heuristic information is replaced by an area heuristic function, which deviated from the traditional approach that only considers pheromone information between two points; Then, the influence of path angle and number of turns is taken into account in the local pheromone update. Additionally, a reward and punishment mechanism is employed in the global pheromone update to adjust the pheromone concentrations of different paths; Furthermore, an adaptive update strategy for pheromone volatility factor adaptive is proposed to expand the search range of the algorithm. Finally, simulation experiments are conducted under various scenarios to verify the superiority and effectiveness of the proposed algorithm.

Investigation of effects of hazard geometry and mitigation strategies on community resilience under tornado hazards using an Agent-based modeling approach

A large number of communities are impacted annually by the increasing frequency of tornado hazards resulting in damage to the infrastructure as well as disruption of community functions. The effect of the hazard geometry (center and angle of tornado path as well as the tornado width) is studied herein on how it influences the recovery of physical and social systems within the community. Given that pre-disaster preparedness including mitigation strategies (e.g., retrofits) and policies (e.g., insurance) is crucial for increasing the resilience of the community and facilitating a faster recovery process, in this study, the impact of various mitigation strategies and policies on the recovery trajectory and resilience of a typical US community subjected to a tornado is investigated considering different sources of uncertainties. The virtual testbed of Centerville is selected in this paper and is modeled by adopting the Agent-based modeling (ABM) approach which is a powerful tool for conducting community resilience analysis that simulates the behavior of different types of agents and their interactions to capture their interdependencies. The results are presented in the form of recovery time series as well as calculated resilience indices for various community systems (lifeline networks, schools, healthcare, businesses, and households). The results of this study can help deepen our understanding of how to efficiently expedite the recovery process of a community.

Improved Stanley guidance law–based adaptive path-following control of underactuated ship with state-constrained and time-varying drift angle

To improve the following performance in large curve path and time-varying drift angle, a reduced-order extended state observer is added to the Improved Stanley Guidance Law (EISGL). Combining with the dynamic surface control (DSC), an adaptive auxiliary system is simultaneously built to compensate for the effect of the state constraints on the system. A barrier Lyapunov function combined with a prescribed performance function is designed to constrain the heading angle error of path following. Adaptive laws are also designed to approximate errors, estimating perturbation in poor sea condition. Lyapunov stability analysis shows that all signals are semi-global coherent and eventually bounded. In conclusion, the numerical comparison simulation experiments verify that the scheme has a strong anti-jamming capability and achieves good path following in large curve path.

Antenna Arrays of the Glide Slope for Aerodromes in Areas with High Snow Cover Level

The main means of providing instrumental approach of aircraft for landing are beacon landing systems. It forms in space a trajectory (glide path), located, as a rule, at the angle of 3° in relation to the horizontal plane. The dependence of the glide path angle on the height of the snow cover on the underlying surface when using previously known antenna arrays in the glide slope is demonstrated in the paper. A new class of glide slope antenna arrays is proposed in the study. The requirements for the amplitude-phase distribution of currents along the antenna array of the glide slope, at which the glide path angle does not depend on the reflective properties of the underlying surface and the level of snow cover on it, are determined. We propose a procedure for constructing an antenna array with two subarrays, one of which radiates the so-called “Carrier plus sideband” (CSB) signal, and the second emits the “Suppressed carrier sideband only” (SBO) signal. The procedure of constructing an antenna array with two subarrays, one of which radiates the so-called “Carrier plus sideband” (CSB) signal, and the second emits the “Suppressed carrier sideband only” (SBO) signal are provided. In order to ensure the independence of the glide path parameters from the height of the antenna array (glide path angle and slope of the glide path), the combination of five conditions is specified in the article. A special case of the proposed antenna array is an equidistant antenna array, in which the radiating elements of the subarray of the CSB signal and the subarray of the SBO signal are partially combined. We have performed experimental studies with the 4-element equidistant antenna array as a part of a glide slope prototype. We have carried out flight measurements of the glide path angle at the airfield in the foothill with a difficult terrain for about two years: in summer, winter, next summer and next winter. The snow depth at the airport was 35–40 cm in the first winter, and 30–35 cm in the second winter. The experimental results demonstrate that the changes in the glide path angle of the stated period of time does not exceed one angle minute. This value is comparable with the error of the flight experiment. In order to simulate the influence of a higher level of snow cover on the position of the glide path, we have conducted a special experiment. When the snow cover was of 18 cm on the airfield surface, we lowered all four antennas by one meter and measured the glide path zone. The glide path angle remained the same. Flight tests of a prototype landing system with the proposed glide path beacon demonstrated that this landing system provides parameters for the III-rd category. It means that the aircraft approaching for landing and landing are possible at zero visibility.

Numerical Investigation of Low-Noise Landing Conditions for Multirotor Urban Air Mobility Vehicle

A preliminary investigation of the noise abatement landing approach for the multirotor urban air mobility (UAM) vehicle is carried out using the comprehensive multirotor noise assessment (CONA) framework. The key objectives are to identify the low-noise landing condition of multirotor UAM vehicles to reduce ground noise impact near the landing zone. The CONA framework, developed by our research team, has the capability of trajectory-based noise prediction for RPM-controlled multirotor configurations. It uses the parameterized Beddoes wake model with regression analysis to consider the aerodynamic interaction. The noise impact over a wide range of landing conditions is illustrated for the quadrotor UAM vehicle. Three landing conditions are highlighted: vertical descent, high-noise condition, and low-noise condition. The result shows that the low-noise condition avoids intense aerodynamic interaction and reduces the tip Mach number with a high flight path angle and forward speed. This condition can significantly reduce the area affected by UAM noise. In summary, the noise abatement landing approach has a significant noise reduction in the multirotor UAM vehicle, and the landing approach should be designed by considering landing conditions and UAM configurations.