Pub Date : 2024-05-02DOI: 10.1177/09544100241248875
Enbo Sun, Haideng Zhang, Yun Wu, Lifu Zhang
To construct a method for designing a total pressure distortion generator with adjustable, steady, and dynamic components, we experimentally investigated the influences of combinational distortion generator geometrical parameters on the steady and dynamic components of the total pressure distortion based on an indraft wind tunnel. Different types of annular plates and cylindrical rods were installed upstream of a traditional baffle total pressure distortion generator; the total pressure distortion was then measured using rotatable total pressure rakes. The installation of cylindrical rods upstream of the baffle plate could maximally reduce the ratio of steady and dynamic components of total pressure distortion by 30%. Increasing the number and height of the rods, as well as the axial distance between the rod and baffle plate, were effective methods of reducing the steady components of total pressure distortion. Similarly, changing the geometrical parameters of the annular plate was also an effective method for adjusting the ratio of steady and dynamic components of total pressure distortion. The ratio of the steady and dynamic components of total pressure distortion first experienced a decrease and then increased variance law with the increase in the height and circumferential scale of the annular plate. During this procedure, the steady and dynamic components ratio of total pressure distortion could be maximally reduced by 24% and maximally increased by 20%.
{"title":"Influence of combinational distortion generator geometrical parameters on the steady and dynamic components of the total pressure distortion","authors":"Enbo Sun, Haideng Zhang, Yun Wu, Lifu Zhang","doi":"10.1177/09544100241248875","DOIUrl":"https://doi.org/10.1177/09544100241248875","url":null,"abstract":"To construct a method for designing a total pressure distortion generator with adjustable, steady, and dynamic components, we experimentally investigated the influences of combinational distortion generator geometrical parameters on the steady and dynamic components of the total pressure distortion based on an indraft wind tunnel. Different types of annular plates and cylindrical rods were installed upstream of a traditional baffle total pressure distortion generator; the total pressure distortion was then measured using rotatable total pressure rakes. The installation of cylindrical rods upstream of the baffle plate could maximally reduce the ratio of steady and dynamic components of total pressure distortion by 30%. Increasing the number and height of the rods, as well as the axial distance between the rod and baffle plate, were effective methods of reducing the steady components of total pressure distortion. Similarly, changing the geometrical parameters of the annular plate was also an effective method for adjusting the ratio of steady and dynamic components of total pressure distortion. The ratio of the steady and dynamic components of total pressure distortion first experienced a decrease and then increased variance law with the increase in the height and circumferential scale of the annular plate. During this procedure, the steady and dynamic components ratio of total pressure distortion could be maximally reduced by 24% and maximally increased by 20%.","PeriodicalId":54566,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers Part G-Journal of Aerospace Engineering","volume":"44 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2024-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140838362","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-02DOI: 10.1177/09544100241235402
Lu Bai, Defu Lin, Duo Zheng, Tianyu Lu
The direct/aerodynamic force compound control can enhance the maneuverability and response characteristics of missiles, and the dynamic stabilization is the precondition of normal operation for rolling missiles. Aiming at the stability problem caused by the cross-coupling effect of rolling missiles employing direct/aerodynamic force compound control, proposing a typical topological control system structure described by the complex coefficient theory, and deducing the dynamic stability conditions. Firstly, the mathematic model is established based on the kinematics and dynamics theories of rotating airframes and the direct/aerodynamic force compound control mechanism. Then, a three-loop autopilot and the direct/aerodynamic force ratio distribution method are designed to establish the complex summation model of the compound control system by selecting suitable complex variables. Furthermore, deducing the dynamic stability conditions and verifying them by numerical simulations. Finally, the stable regions of the rolling missile in different cases are obtained and found to be influenced by many factors, such as parameters of the autopilot, hybrid force distribution proportion and rolling rate. The derived dynamic stability criterion is effective for evaluating the stability of rolling missiles employing direct/aerodynamic force compound control and the research method used in this paper can provide reference for the stability study of strongly coupled nonlinear systems.
{"title":"Research on dynamic stability of rolling missiles employing direct/aerodynamic force compound control","authors":"Lu Bai, Defu Lin, Duo Zheng, Tianyu Lu","doi":"10.1177/09544100241235402","DOIUrl":"https://doi.org/10.1177/09544100241235402","url":null,"abstract":"The direct/aerodynamic force compound control can enhance the maneuverability and response characteristics of missiles, and the dynamic stabilization is the precondition of normal operation for rolling missiles. Aiming at the stability problem caused by the cross-coupling effect of rolling missiles employing direct/aerodynamic force compound control, proposing a typical topological control system structure described by the complex coefficient theory, and deducing the dynamic stability conditions. Firstly, the mathematic model is established based on the kinematics and dynamics theories of rotating airframes and the direct/aerodynamic force compound control mechanism. Then, a three-loop autopilot and the direct/aerodynamic force ratio distribution method are designed to establish the complex summation model of the compound control system by selecting suitable complex variables. Furthermore, deducing the dynamic stability conditions and verifying them by numerical simulations. Finally, the stable regions of the rolling missile in different cases are obtained and found to be influenced by many factors, such as parameters of the autopilot, hybrid force distribution proportion and rolling rate. The derived dynamic stability criterion is effective for evaluating the stability of rolling missiles employing direct/aerodynamic force compound control and the research method used in this paper can provide reference for the stability study of strongly coupled nonlinear systems.","PeriodicalId":54566,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers Part G-Journal of Aerospace Engineering","volume":"102 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2024-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140838367","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-02DOI: 10.1177/09544100241248196
Keivan Torabi, Hassan Afshari, Farhad Haji Aboutalebi
The aim of this work is to investigate the flutter characteristics of nanocomposite cantilever trapezoidal plates with non-uniform thickness enriched with either carbon nanotubes (CNTs), graphene nanoplatelets (GNPs), or graphene oxide powders (GOPs) which are distributed functionally graded (FG) in the axial direction. It is assumed that the thickness of the plate and the volume fraction of the nanofillers vary in one direction from the wider clamped edge of the plate to the outer narrower free one. The modeling of the plate is done using the first-order shear deformation theory (FSDT) and the aerodynamic pressure generated by the aerodynamic pressure is modeled using the linear approximation of the piston theory. The material properties of the plate are calculated using the mixing rule (ROM) and the Halpin–Tsai model. The governing equations and boundary conditions at the clamped and free edges of the plate are derived via Hamilton’s principle. An approximate solution is applied using the differential quadrature method (DQM) to calculate the natural frequencies and the damping ratios of the plate. Numerical examples show that it is possible to find an optimal thickness variation profile that provides the greatest aeroelastic stability. It is concluded that by considering the same value for the mass fractions of the nanofillers, the highest aeroelastic stability can be attained by utilizing the GNPs as the reinforcers. It is found that to attain further improvement in aeroelastic stability, most nanofillers should be distributed near the clamped edge and away from the outer free edge.
{"title":"Effects of non-uniformity in thickness and volume fraction of nanofillers on the flutter characteristics of nanocomposite cantilever trapezoidal plates","authors":"Keivan Torabi, Hassan Afshari, Farhad Haji Aboutalebi","doi":"10.1177/09544100241248196","DOIUrl":"https://doi.org/10.1177/09544100241248196","url":null,"abstract":"The aim of this work is to investigate the flutter characteristics of nanocomposite cantilever trapezoidal plates with non-uniform thickness enriched with either carbon nanotubes (CNTs), graphene nanoplatelets (GNPs), or graphene oxide powders (GOPs) which are distributed functionally graded (FG) in the axial direction. It is assumed that the thickness of the plate and the volume fraction of the nanofillers vary in one direction from the wider clamped edge of the plate to the outer narrower free one. The modeling of the plate is done using the first-order shear deformation theory (FSDT) and the aerodynamic pressure generated by the aerodynamic pressure is modeled using the linear approximation of the piston theory. The material properties of the plate are calculated using the mixing rule (ROM) and the Halpin–Tsai model. The governing equations and boundary conditions at the clamped and free edges of the plate are derived via Hamilton’s principle. An approximate solution is applied using the differential quadrature method (DQM) to calculate the natural frequencies and the damping ratios of the plate. Numerical examples show that it is possible to find an optimal thickness variation profile that provides the greatest aeroelastic stability. It is concluded that by considering the same value for the mass fractions of the nanofillers, the highest aeroelastic stability can be attained by utilizing the GNPs as the reinforcers. It is found that to attain further improvement in aeroelastic stability, most nanofillers should be distributed near the clamped edge and away from the outer free edge.","PeriodicalId":54566,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers Part G-Journal of Aerospace Engineering","volume":"64 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2024-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140838504","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-02DOI: 10.1177/09544100241249346
Yuehui Ji, Jingwei Jiang, Junjie Liu, Qiang Gao
During the hypersonic flight process of rigid hypersonic flight vehicles (HFVs), the flight-path angle and angle of attack are usually small and sensitive to flight condition variation, the accurate measurements are difficult, subsequently the formulation of states observers is an urgent issue. A distributed high-gain observer is proposed to reconstruct the admissible system state dynamics based on limited measured output. First, a distributed observer is proposed for the cascade strict-feedback system to ensure the global convergence of the state estimation errors between the estimated state in each local observer and system states, for the prescribed system initial values. Second, the distributed high-gain observer-based nonlinear control is investigated on the longitudinal dynamics of HFVs with partial measurable states. The rigid body system dynamic is divided into the altitude subsystem and the velocity subsystem. In the altitude subsystem, the proposed distributed high-gain observer is formulated to exact estimate the flight-path angle and angle of attack, and then the back-stepping design is proposed for constructing the controllers. The nonlinear dynamic inversion controller is introduced to accomplish the velocity tracking. Finally, simulation examples are served to verify that the proposed output feedback control possesses the superior properties of high tracking performance, fast convergence of state estimation error and easy-implementation.
{"title":"Output feedback control for hypersonic flight vehicles via distributed high-gain observer","authors":"Yuehui Ji, Jingwei Jiang, Junjie Liu, Qiang Gao","doi":"10.1177/09544100241249346","DOIUrl":"https://doi.org/10.1177/09544100241249346","url":null,"abstract":"During the hypersonic flight process of rigid hypersonic flight vehicles (HFVs), the flight-path angle and angle of attack are usually small and sensitive to flight condition variation, the accurate measurements are difficult, subsequently the formulation of states observers is an urgent issue. A distributed high-gain observer is proposed to reconstruct the admissible system state dynamics based on limited measured output. First, a distributed observer is proposed for the cascade strict-feedback system to ensure the global convergence of the state estimation errors between the estimated state in each local observer and system states, for the prescribed system initial values. Second, the distributed high-gain observer-based nonlinear control is investigated on the longitudinal dynamics of HFVs with partial measurable states. The rigid body system dynamic is divided into the altitude subsystem and the velocity subsystem. In the altitude subsystem, the proposed distributed high-gain observer is formulated to exact estimate the flight-path angle and angle of attack, and then the back-stepping design is proposed for constructing the controllers. The nonlinear dynamic inversion controller is introduced to accomplish the velocity tracking. Finally, simulation examples are served to verify that the proposed output feedback control possesses the superior properties of high tracking performance, fast convergence of state estimation error and easy-implementation.","PeriodicalId":54566,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers Part G-Journal of Aerospace Engineering","volume":"47 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2024-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140838777","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The collaboration among swarmed aircraft can provide additional observation to improve the integrity of its onboard navigation systems. But due to the limitation on relative communicating and measuring burdens, adopting all the observations between aircraft in the swarm is inefficient. The geometry of the collaborated partners is a key factor that influences the effectiveness of the navigation integrity augmentation, which needs to be optimized in collaborative integrity augmented navigation. In this paper, the integrity augmented navigation method for aerial swarm based on collaborative partner optimization is proposed. The geometry constructed by the GNSS satellites and the cooperative partners in the aerial swarm are analyzed dynamically, and the augmented integrity protection levels with different collaborative relationships are predicted to distinguish the partner essential for navigation integrity augmentation. Then the collaborative partner makes a key contribution to integrity augmentation adopted in collaborative navigation integrity monitoring, improving the efficiency of the collaborative navigation. The simulation results indicate the effectiveness of the proposed cooperative partnership optimization strategy, as well as the superiority of the proposed method compared with the traditional independent integrity framework in improving the integrity protection level and fault detection capacity.
{"title":"A collaborative navigation integrity augmentation method with optimal dynamic partner selection","authors":"Rong Wang, Xin Chen, Zhi Xiong, Huiyuan Zhang, Jianye Liu, Xiaoyi Chen","doi":"10.1177/09544100241249625","DOIUrl":"https://doi.org/10.1177/09544100241249625","url":null,"abstract":"The collaboration among swarmed aircraft can provide additional observation to improve the integrity of its onboard navigation systems. But due to the limitation on relative communicating and measuring burdens, adopting all the observations between aircraft in the swarm is inefficient. The geometry of the collaborated partners is a key factor that influences the effectiveness of the navigation integrity augmentation, which needs to be optimized in collaborative integrity augmented navigation. In this paper, the integrity augmented navigation method for aerial swarm based on collaborative partner optimization is proposed. The geometry constructed by the GNSS satellites and the cooperative partners in the aerial swarm are analyzed dynamically, and the augmented integrity protection levels with different collaborative relationships are predicted to distinguish the partner essential for navigation integrity augmentation. Then the collaborative partner makes a key contribution to integrity augmentation adopted in collaborative navigation integrity monitoring, improving the efficiency of the collaborative navigation. The simulation results indicate the effectiveness of the proposed cooperative partnership optimization strategy, as well as the superiority of the proposed method compared with the traditional independent integrity framework in improving the integrity protection level and fault detection capacity.","PeriodicalId":54566,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers Part G-Journal of Aerospace Engineering","volume":"147 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2024-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140838360","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-29DOI: 10.1177/09544100241249327
Zhongjie Meng, Jianwei Ma, Tong Zhang
A fast trajectory tracking controller is designed for the airship, involving dynamic uncertainties of parameters, capable of guaranteeing the prescribed performance of tracking errors, and fast response of the closed-loop system. To achieve the decoupling of velocity control and attitude control of the airship, a new guidance and control integration framework is proposed first. Then, based on the dynamics model established by the spinor method, the lumped disturbance, caused by unknown aerodynamic parameter uncertainties and exogenous disturbances, is estimated online using a high-order finite-time observer. The control performance, namely, overshoot and steady-state performance of tracking errors, is significantly improved by utilizing the prescribed output performance constraints, while the convergence rate is further enhanced by combining the finite-time convergence property of the fast terminal sliding mode control. Simulation results attest to the effectiveness of the strategy in this paper. Compared with the adaptive fast terminal sliding mode control, the strategy effectively utilizes the capability of the actuator within the allowed range and reduces the convergence time by more than half with similar control inputs.
{"title":"Adaptive fast trajectory tracking control for the airship based on prescribed performance","authors":"Zhongjie Meng, Jianwei Ma, Tong Zhang","doi":"10.1177/09544100241249327","DOIUrl":"https://doi.org/10.1177/09544100241249327","url":null,"abstract":"A fast trajectory tracking controller is designed for the airship, involving dynamic uncertainties of parameters, capable of guaranteeing the prescribed performance of tracking errors, and fast response of the closed-loop system. To achieve the decoupling of velocity control and attitude control of the airship, a new guidance and control integration framework is proposed first. Then, based on the dynamics model established by the spinor method, the lumped disturbance, caused by unknown aerodynamic parameter uncertainties and exogenous disturbances, is estimated online using a high-order finite-time observer. The control performance, namely, overshoot and steady-state performance of tracking errors, is significantly improved by utilizing the prescribed output performance constraints, while the convergence rate is further enhanced by combining the finite-time convergence property of the fast terminal sliding mode control. Simulation results attest to the effectiveness of the strategy in this paper. Compared with the adaptive fast terminal sliding mode control, the strategy effectively utilizes the capability of the actuator within the allowed range and reduces the convergence time by more than half with similar control inputs.","PeriodicalId":54566,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers Part G-Journal of Aerospace Engineering","volume":"20 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2024-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140838780","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-27DOI: 10.1177/09544100241249882
Zheng Yin, Zhang He, Wang Yan
This paper examines the problem of fixed-time attitude tracking fault-tolerant for rigid spacecraft without angular velocity measurement, in the presence of uncertainties, external disturbances, and actuator faults. First, a fixed-time observer is established to obtain accurate estimates of the unmeasurable angular velocities, by applying a fixed-time observer, a fixed-time tracking control method is addressed to enable the tracking spacecraft to track the target spacecraft with time-varying attitude in a fixed time. A fixed-time output feedback attitude tracking controller is designed and the fixed time stability of the system is proved. In addition, the simulation results verify the effectiveness of the proposed control strategy.
{"title":"Velocity-free fixed-time attitude tracking fault-tolerant control for rigid spacecraft based on the homogeneity method","authors":"Zheng Yin, Zhang He, Wang Yan","doi":"10.1177/09544100241249882","DOIUrl":"https://doi.org/10.1177/09544100241249882","url":null,"abstract":"This paper examines the problem of fixed-time attitude tracking fault-tolerant for rigid spacecraft without angular velocity measurement, in the presence of uncertainties, external disturbances, and actuator faults. First, a fixed-time observer is established to obtain accurate estimates of the unmeasurable angular velocities, by applying a fixed-time observer, a fixed-time tracking control method is addressed to enable the tracking spacecraft to track the target spacecraft with time-varying attitude in a fixed time. A fixed-time output feedback attitude tracking controller is designed and the fixed time stability of the system is proved. In addition, the simulation results verify the effectiveness of the proposed control strategy.","PeriodicalId":54566,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers Part G-Journal of Aerospace Engineering","volume":"7 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2024-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140811940","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-20DOI: 10.1177/09544100241248195
Xiaochen Mao, Yingchen Jiao, Hao Cheng, Botao Zhang, Bo Liu
The coupling optimization design for swept-bowed effects and configuration of tandem cascade is conducted in a highly loaded subsonic compressor tandem cascade, in which the novelty lies in considering the spanwise distribution of configuration parameters and exploring the coupling relationship between them and swept-bowed design. Research results show that, compared with the original one, the loss coefficient of the optimal tandem cascade is decreased by 38.7% at the 4° incidence angle and the range of available incidence angle expands by 25%. For the distribution of the configuration parameters, parameters at the hub are significantly different from those near the tip, which confirms the tandem blade design in compressors is complex and needs to consider 3D flow effect. Forward swept and positive bowed design are beneficial for reducing loss at tip and alleviating the blockage, which cannot be achieved by the optimization only for configuration parameters. In terms of the weak coupling relationship between configuration parameters distribution and swept-bowed effects, the former should be considered first in practical engineering.
{"title":"Coupling optimization design of configuration and swept-bowed effects in highly loaded subsonic compressor tandem cascades with tip clearance","authors":"Xiaochen Mao, Yingchen Jiao, Hao Cheng, Botao Zhang, Bo Liu","doi":"10.1177/09544100241248195","DOIUrl":"https://doi.org/10.1177/09544100241248195","url":null,"abstract":"The coupling optimization design for swept-bowed effects and configuration of tandem cascade is conducted in a highly loaded subsonic compressor tandem cascade, in which the novelty lies in considering the spanwise distribution of configuration parameters and exploring the coupling relationship between them and swept-bowed design. Research results show that, compared with the original one, the loss coefficient of the optimal tandem cascade is decreased by 38.7% at the 4° incidence angle and the range of available incidence angle expands by 25%. For the distribution of the configuration parameters, parameters at the hub are significantly different from those near the tip, which confirms the tandem blade design in compressors is complex and needs to consider 3D flow effect. Forward swept and positive bowed design are beneficial for reducing loss at tip and alleviating the blockage, which cannot be achieved by the optimization only for configuration parameters. In terms of the weak coupling relationship between configuration parameters distribution and swept-bowed effects, the former should be considered first in practical engineering.","PeriodicalId":54566,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers Part G-Journal of Aerospace Engineering","volume":"12 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2024-04-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140628650","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-03DOI: 10.1177/09544100241244816
Tsung-Liang Liu, Kamesh Subbarao
The performance of an uncrewed aerial system (UAS) operating nominally in an indoor/outdoor environment depends upon the available power, and how well the system reacts to disturbances and nonlinear dynamic effects. This paper focuses on development of approaches to compensate for nonlinear dynamic effects due to aerodynamics, gyroscopic coupling, and rotor induced rolling effects in deriving aggressive multi-copter trajectories. A thrust constrained multi-copter is adopted for verifying the compensation, that is achieved through an optimal trajectory synthesis formulation. It is shown that the compensation approach yields precise and aggressive trajectory tracking for the multi-copter flight in and out of indoor environments, such as windows and other constrained openings.
{"title":"Inverse dynamics based aerodynamic, gyroscopic, and rotor effects’ compensation in constrained trajectory synthesis for multi-copters","authors":"Tsung-Liang Liu, Kamesh Subbarao","doi":"10.1177/09544100241244816","DOIUrl":"https://doi.org/10.1177/09544100241244816","url":null,"abstract":"The performance of an uncrewed aerial system (UAS) operating nominally in an indoor/outdoor environment depends upon the available power, and how well the system reacts to disturbances and nonlinear dynamic effects. This paper focuses on development of approaches to compensate for nonlinear dynamic effects due to aerodynamics, gyroscopic coupling, and rotor induced rolling effects in deriving aggressive multi-copter trajectories. A thrust constrained multi-copter is adopted for verifying the compensation, that is achieved through an optimal trajectory synthesis formulation. It is shown that the compensation approach yields precise and aggressive trajectory tracking for the multi-copter flight in and out of indoor environments, such as windows and other constrained openings.","PeriodicalId":54566,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers Part G-Journal of Aerospace Engineering","volume":"59 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2024-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140584968","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-28DOI: 10.1177/09544100231162735
Yebao Hu, Yongshou Liu, Qing Guo, Jiayin Dai, Jing Wang
The present article shows the reliability and sensitivity of a missile folding rudder calculated by MSC.ADAMS and MATLAB. For folding rudder, mass of the counterweight, maximum of the motive force, preloading force, and stiffness coefficients of the spring 1 and spring 2 are considered when calculating the reliability. Two methods, active learning kriging (ALK) and Monte Carlo simulation (MCS), are introduced to calculate the reliability. The results obtained by ALK and MCS are compared to ensure the accuracy of the reliability. Three failure modes are considered respectively in reliability calculation, including the unfolding time exceeding the specified value, the max load of the lock structure 1 or lock structure 2 exceeding the specified value. Moment-independent sensitivity index is introduced to assess the importance rank of each factor. Both cases with and without gap are discussed to explore the influence of gaps between sleeve and shaft. Comparison of two cases show that gaps could reduce reliability of the folding rudder. The influence of gaps cannot be neglected during the reliability calculated, especially for mechanism with several motion joints like the rudder folding. The works aim to provide valuable guidance for design and optimization of unfolding rudder. In addition, it is a beneficial trial for introducing reliability theory in weapon equipment field.
{"title":"Moment-independent sensitivity analysis of a fold mechanism based on an active learning kriging method","authors":"Yebao Hu, Yongshou Liu, Qing Guo, Jiayin Dai, Jing Wang","doi":"10.1177/09544100231162735","DOIUrl":"https://doi.org/10.1177/09544100231162735","url":null,"abstract":"The present article shows the reliability and sensitivity of a missile folding rudder calculated by MSC.ADAMS and MATLAB. For folding rudder, mass of the counterweight, maximum of the motive force, preloading force, and stiffness coefficients of the spring 1 and spring 2 are considered when calculating the reliability. Two methods, active learning kriging (ALK) and Monte Carlo simulation (MCS), are introduced to calculate the reliability. The results obtained by ALK and MCS are compared to ensure the accuracy of the reliability. Three failure modes are considered respectively in reliability calculation, including the unfolding time exceeding the specified value, the max load of the lock structure 1 or lock structure 2 exceeding the specified value. Moment-independent sensitivity index is introduced to assess the importance rank of each factor. Both cases with and without gap are discussed to explore the influence of gaps between sleeve and shaft. Comparison of two cases show that gaps could reduce reliability of the folding rudder. The influence of gaps cannot be neglected during the reliability calculated, especially for mechanism with several motion joints like the rudder folding. The works aim to provide valuable guidance for design and optimization of unfolding rudder. In addition, it is a beneficial trial for introducing reliability theory in weapon equipment field.","PeriodicalId":54566,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers Part G-Journal of Aerospace Engineering","volume":"140 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2024-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140325291","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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