Recently, flow control using vortex generators (VGs) and a Gurney flap (GF) has received considerable attention, but independently. The purpose of this study is to perform a numerical investigation into the lift augmentation effects of a tiltrotor wing with the combination of VGs and GF. The numerical results were obtained with the Reynolds-averaged Navier-Stokes (RANS) equations, and the turbulence was solved by the Spalart-Allmaras one-equation turbulence model. The separate and joint performances of these two control devices at different angles of attack are determined. It is shown that the combined configuration can provide greater lift augmentation than either device individually. Compared with the baseline wing, the implementation of both devices increases the stall angle of attack from 10° to 22°, and the maximum lift coefficient is improved by 82.33%.
{"title":"Lift Augmentation on a Tiltrotor Wing Using the Combination of Vortex Generators and Gurney’s Flap","authors":"Hao Chen, Siliang Du, Zhong Chen","doi":"10.1155/2023/6646817","DOIUrl":"https://doi.org/10.1155/2023/6646817","url":null,"abstract":"Recently, flow control using vortex generators (VGs) and a Gurney flap (GF) has received considerable attention, but independently. The purpose of this study is to perform a numerical investigation into the lift augmentation effects of a tiltrotor wing with the combination of VGs and GF. The numerical results were obtained with the Reynolds-averaged Navier-Stokes (RANS) equations, and the turbulence was solved by the Spalart-Allmaras one-equation turbulence model. The separate and joint performances of these two control devices at different angles of attack are determined. It is shown that the combined configuration can provide greater lift augmentation than either device individually. Compared with the baseline wing, the implementation of both devices increases the stall angle of attack from 10° to 22°, and the maximum lift coefficient is improved by 82.33%.","PeriodicalId":13748,"journal":{"name":"International Journal of Aerospace Engineering","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2023-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46452429","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}
This paper studies the multiple geosynchronous spacecraft refueling problem (MGSRP) with multiple servicing spacecraft (Ssc) and fuel depots (FDs). In the mission scenario, multiple Ssc and FDs are parked in the geosynchronous Earth orbit (GEO) initially. Ssc start from FDs and maneuver to visit and refuel multiple GEO targets with known demands. These capacitated Ssc are expected to rendezvous with fuel-deficient GEO targets and FDs for the purpose of delivering the fuel stored in FDs to GEO targets. The objective is to find a set of Pareto-optimal solutions with minimum fuel cost and mission duration. The MGSRP is a much more complex variant of multidepot vehicle routing problems mixing discrete and continuous variables. A two-nested optimization model is built. We propose a new multiobjective hybrid particle swarm optimization to solve the outer-loop problem, and the design variables are the refueling sequence, task assignment, time distribution, and locations of FDs. In the inner-loop problem, branch and bound method is used to find the optimal decision variable for a given outer-loop solution. Finally, numerical simulations are presented to illustrate the effectiveness and validity of the proposed approach.
{"title":"Multiobjective Mission Planning for Multiple Geosynchronous Spacecraft Refueling","authors":"Linjie Kong, Yang Zhou","doi":"10.1155/2023/6623461","DOIUrl":"https://doi.org/10.1155/2023/6623461","url":null,"abstract":"This paper studies the multiple geosynchronous spacecraft refueling problem (MGSRP) with multiple servicing spacecraft (Ssc) and fuel depots (FDs). In the mission scenario, multiple Ssc and FDs are parked in the geosynchronous Earth orbit (GEO) initially. Ssc start from FDs and maneuver to visit and refuel multiple GEO targets with known demands. These capacitated Ssc are expected to rendezvous with fuel-deficient GEO targets and FDs for the purpose of delivering the fuel stored in FDs to GEO targets. The objective is to find a set of Pareto-optimal solutions with minimum fuel cost and mission duration. The MGSRP is a much more complex variant of multidepot vehicle routing problems mixing discrete and continuous variables. A two-nested optimization model is built. We propose a new multiobjective hybrid particle swarm optimization to solve the outer-loop problem, and the design variables are the refueling sequence, task assignment, time distribution, and locations of FDs. In the inner-loop problem, branch and bound method is used to find the optimal decision variable for a given outer-loop solution. Finally, numerical simulations are presented to illustrate the effectiveness and validity of the proposed approach.","PeriodicalId":13748,"journal":{"name":"International Journal of Aerospace Engineering","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2023-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43385762","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}
Hong Xiao, Hongwei Guo, Mingqi Li, Yu Zhang, Rongqiang Liu, Jianguo Tao
The variable-sweep wing is very attractive for cross-speed domain aircraft. The shear-sliding rigid-flexible coupled skin variable-sweep wing and its associated mechanism are designed and optimized. The variable-sweep wing has smooth continuous deformation and rigid-flexible coupling features. The calculation model of the sliding skin patch segmentation strategy is established, and the aerodynamic characteristics of the two-dimensional airfoil before and after the deformation of the wing skin are analyzed. According to the deformation characteristics of sliding skin, the configuration of the associated mechanism is determined, and the kinematic characteristics of the reference points of each skin are calculated. The kinematic simulation verifies the force of the mechanism model at the joint of skin surfaces during the deformation process. Considering the aerodynamic heat at supersonic speed, the heat transfer, heat distribution, and structural thermal modes between the flow field and the skin are calculated based on the finite element method. The dynamic characteristics of the swept wing with different flight speeds and different morphologies are analyzed. The natural frequencies are found to be reduced by about 30% to 50% compared to cold models at supersonic speeds. Based on the results of the thermal fluid-solid coupling calculation, the skeleton structure of the swept wing is optimized, and the skeleton structure with 25% mass reduction and better performance is obtained.
{"title":"A Shear-Sliding Rigid-Flexible Coupled Skin Variable-Sweep Wing Design and Heat-Fluid-Structure Multifield Coupling Analysis","authors":"Hong Xiao, Hongwei Guo, Mingqi Li, Yu Zhang, Rongqiang Liu, Jianguo Tao","doi":"10.1155/2023/7078091","DOIUrl":"https://doi.org/10.1155/2023/7078091","url":null,"abstract":"The variable-sweep wing is very attractive for cross-speed domain aircraft. The shear-sliding rigid-flexible coupled skin variable-sweep wing and its associated mechanism are designed and optimized. The variable-sweep wing has smooth continuous deformation and rigid-flexible coupling features. The calculation model of the sliding skin patch segmentation strategy is established, and the aerodynamic characteristics of the two-dimensional airfoil before and after the deformation of the wing skin are analyzed. According to the deformation characteristics of sliding skin, the configuration of the associated mechanism is determined, and the kinematic characteristics of the reference points of each skin are calculated. The kinematic simulation verifies the force of the mechanism model at the joint of skin surfaces during the deformation process. Considering the aerodynamic heat at supersonic speed, the heat transfer, heat distribution, and structural thermal modes between the flow field and the skin are calculated based on the finite element method. The dynamic characteristics of the swept wing with different flight speeds and different morphologies are analyzed. The natural frequencies are found to be reduced by about 30% to 50% compared to cold models at supersonic speeds. Based on the results of the thermal fluid-solid coupling calculation, the skeleton structure of the swept wing is optimized, and the skeleton structure with 25% mass reduction and better performance is obtained.","PeriodicalId":13748,"journal":{"name":"International Journal of Aerospace Engineering","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2023-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42932514","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 automatic carrier landing process is a significant and complex due to the plant variation of carrier-based aircraft. To reasonably identify the stability interval for specific performance, an adaptive control strategy based on the guardian map approach is proposed. Prescribed performance, namely, stability margin, damping requirements, or flying quality requirements, is analytically formulated using a guardian map. The null space of guardian maps restricts the prescribed performance regarding the poles’ location. The feasible corridor of control parameters is generated based on the null space of guardian maps. Besides, a velocity-adaptive prescribed performance control method is proposed to conduct the attitude control of carrier-based aircraft. Simulation shows that the short-period mode of carrier-based aircraft will be driven from unstable to stable as the velocity decreases. Moreover, simulation results demonstrate the proposed control method and indicate that the attitude loop control of carrier-based aircraft possesses more underdamped responses as the velocity decreases.
{"title":"Velocity-Adaptive Prescribed Performance Control for Carrier-Based Aircraft Based on Guardian Maps","authors":"Chenliang Li, Jizhou Lai, Boyi Chen, Yanbin Liu","doi":"10.1155/2023/5541378","DOIUrl":"https://doi.org/10.1155/2023/5541378","url":null,"abstract":"The automatic carrier landing process is a significant and complex due to the plant variation of carrier-based aircraft. To reasonably identify the stability interval for specific performance, an adaptive control strategy based on the guardian map approach is proposed. Prescribed performance, namely, stability margin, damping requirements, or flying quality requirements, is analytically formulated using a guardian map. The null space of guardian maps restricts the prescribed performance regarding the poles’ location. The feasible corridor of control parameters is generated based on the null space of guardian maps. Besides, a velocity-adaptive prescribed performance control method is proposed to conduct the attitude control of carrier-based aircraft. Simulation shows that the short-period mode of carrier-based aircraft will be driven from unstable to stable as the velocity decreases. Moreover, simulation results demonstrate the proposed control method and indicate that the attitude loop control of carrier-based aircraft possesses more underdamped responses as the velocity decreases.","PeriodicalId":13748,"journal":{"name":"International Journal of Aerospace Engineering","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2023-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49342971","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}
Tianyu Gong, Yiqing Li, Feng juan Wei, Shiqichang Wu, Dehua Cao
Bleeding is an effective method to improve the starting performance of the inlet, and the conventional method often adopts the bleeding to longitudinal direction. This article proposes the use of transversal bleeding method to explore the influence on starting capacity by changing the bleeding direction. The paper designs 6 bleeding inlets. By calculating the starting performance, it is found that the projected bleeding rate of the inlet, which is the direct factor influencing the starting performance, would change due to the direction change of bleeding, although designed with the same entrance. For the inlet designed with longitudinal slots and bleeding, it could reach the starting state at Mach 3.6, but it showed the unstart state when they are transversal direction. The same entrance, when inlet is designed by transversal bleeding with longitudinal slots, the starting Mach number would decrease to 3.8. For the changes of aerodynamic capabilities, there would be the “point jump” tendency when reaching starting state, but the same inlets would keep the similar performance when they get the starting state.
{"title":"The Influence of Bleeding Direction on Starting Performance of Three-Dimensional Inward Turning Inlet","authors":"Tianyu Gong, Yiqing Li, Feng juan Wei, Shiqichang Wu, Dehua Cao","doi":"10.1155/2023/9378776","DOIUrl":"https://doi.org/10.1155/2023/9378776","url":null,"abstract":"Bleeding is an effective method to improve the starting performance of the inlet, and the conventional method often adopts the bleeding to longitudinal direction. This article proposes the use of transversal bleeding method to explore the influence on starting capacity by changing the bleeding direction. The paper designs 6 bleeding inlets. By calculating the starting performance, it is found that the projected bleeding rate of the inlet, which is the direct factor influencing the starting performance, would change due to the direction change of bleeding, although designed with the same entrance. For the inlet designed with longitudinal slots and bleeding, it could reach the starting state at Mach 3.6, but it showed the unstart state when they are transversal direction. The same entrance, when inlet is designed by transversal bleeding with longitudinal slots, the starting Mach number would decrease to 3.8. For the changes of aerodynamic capabilities, there would be the “point jump” tendency when reaching starting state, but the same inlets would keep the similar performance when they get the starting state.","PeriodicalId":13748,"journal":{"name":"International Journal of Aerospace Engineering","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2023-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47524970","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}
In this work, the average effects of the Lorentz acceleration on the charged spacecraft’s orbit are studied encounter with relativistic correction. The relativistic correction as function of the orbital elements, and may be time, is formulated. Lagrange planetary equations are used to calculate the perturbations due to considered perturbing forces. The needed conditions to neutralize the effects of the relativistic corrections, using Lorentz acceleration, are derived. Numerical examples for different kinds of orbits are applied.
{"title":"Balancing Conditions for the Relativistic Correction Using Lorentz Acceleration","authors":"M. A. Yousef, M. El-Saftawy, A. Mostafa","doi":"10.1155/2023/5593887","DOIUrl":"https://doi.org/10.1155/2023/5593887","url":null,"abstract":"In this work, the average effects of the Lorentz acceleration on the charged spacecraft’s orbit are studied encounter with relativistic correction. The relativistic correction as function of the orbital elements, and may be time, is formulated. Lagrange planetary equations are used to calculate the perturbations due to considered perturbing forces. The needed conditions to neutralize the effects of the relativistic corrections, using Lorentz acceleration, are derived. Numerical examples for different kinds of orbits are applied.","PeriodicalId":13748,"journal":{"name":"International Journal of Aerospace Engineering","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2023-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46892481","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 presented study offers a comprehensive insight in design and application of the Kalman filters for improvement of control efficiency of small unmanned aerial vehicles with fixed wing. The presented control scheme of the UAV includes its model, a servo drive model, and an optimal proportional-integral-derivative (PID) controller for the selected flight speed. Subsequently, process noise and measurement noise components were introduced into the whole constructed UAV model. The process noise was formed by disturbances caused by horizontal and vertical airflow in the atmosphere. The measurement noise contained deterministic and stochastic errors of the inertial measurement unit (IMU) UAV sensors and engine noise. The obtained results showed that the designed optimal Kalman filter was able to eliminate the influence of interfering signals from the control process and increased the phase safety, controllability, and stability of UAV control as a lean design can be applied in real-time control systems like Pixhawk PX4.
{"title":"Reduction of the Influence of Interfering Signals on the Longitudinal Control of UAVs with Fixed Wing","authors":"R. Bréda, Š. Karaffa, R. Andoga, M. Hlinková","doi":"10.1155/2023/9252640","DOIUrl":"https://doi.org/10.1155/2023/9252640","url":null,"abstract":"The presented study offers a comprehensive insight in design and application of the Kalman filters for improvement of control efficiency of small unmanned aerial vehicles with fixed wing. The presented control scheme of the UAV includes its model, a servo drive model, and an optimal proportional-integral-derivative (PID) controller for the selected flight speed. Subsequently, process noise and measurement noise components were introduced into the whole constructed UAV model. The process noise was formed by disturbances caused by horizontal and vertical airflow in the atmosphere. The measurement noise contained deterministic and stochastic errors of the inertial measurement unit (IMU) UAV sensors and engine noise. The obtained results showed that the designed optimal Kalman filter was able to eliminate the influence of interfering signals from the control process and increased the phase safety, controllability, and stability of UAV control as a lean design can be applied in real-time control systems like Pixhawk PX4.","PeriodicalId":13748,"journal":{"name":"International Journal of Aerospace Engineering","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2023-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42749298","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}
A satellite is considered to be moving relative to a nominal elliptical orbit, whose dynamics are usually described by the Tschaunner-Hempel equation (T-H equation). In this paper, we propose to transform the second-order time-varying system represented by the linear T-H equation with a second-order matrix form into a first-order time-varying system. Then, the controllability of the first-order time-varying system is investigated with the matrix sequence method including e = 0 . Meanwhile, we study the observability of the first-order time-varying system with a specific form of measurement. The advantages of the matrix sequence method for controllability and observability analysis are tested by numerical examples, respectively. Dual theory is used to investigate the controllability and observability of the corresponding dual system of the T-H equation. The corresponding conclusions are obtained.
{"title":"Controllability Analysis of Linear Time-Varying T-H Equation with Matrix Sequence Method","authors":"Sihui Liu, Qingdao Huang","doi":"10.1155/2023/1981979","DOIUrl":"https://doi.org/10.1155/2023/1981979","url":null,"abstract":"A satellite is considered to be moving relative to a nominal elliptical orbit, whose dynamics are usually described by the Tschaunner-Hempel equation (T-H equation). In this paper, we propose to transform the second-order time-varying system represented by the linear T-H equation with a second-order matrix form into a first-order time-varying system. Then, the controllability of the first-order time-varying system is investigated with the matrix sequence method including \u0000 \u0000 e\u0000 =\u0000 0\u0000 \u0000 . Meanwhile, we study the observability of the first-order time-varying system with a specific form of measurement. The advantages of the matrix sequence method for controllability and observability analysis are tested by numerical examples, respectively. Dual theory is used to investigate the controllability and observability of the corresponding dual system of the T-H equation. The corresponding conclusions are obtained.","PeriodicalId":13748,"journal":{"name":"International Journal of Aerospace Engineering","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2023-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47564729","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}
For the problem of spacecraft attitude actuator failure, an adaptive terminal sliding mode fault-tolerant controller (ATSMFTC) based on the differential manifold SO(3) modelling is designed in this paper. First, SO(3) is used to provide a global and unique description of the spacecraft attitude dynamic model. This modelling method not only avoids the problems of singularity and unwinding that exist in traditional modelling methods but also the SO(3) modelling has a simple formulation of the dynamic equations. Then a left attitude error descriptor function is constructed on SO(3) to design an ATSMFTC. This controller is capable of fast and accurate tracking of the time-varying desired attitude. At the same time, it can react quickly to maintain system stability in case of spacecraft attitude actuator failure. The controller designed based on the left attitude error description system of SO(3) has the features of small computational effort and simple design process. Finally, the numerical simulation of the attitude tracking error verifies the feasibility and high efficiency of the controller designed in this paper.
{"title":"Adaptive Terminal Sliding Mode Fault-Tolerant Control of Spacecraft Based on the Left Attitude Error Function of SO(3)","authors":"Zhongzhong Zheng, Wei Shang, Zhou Liu, Yong Guo","doi":"10.1155/2023/1983417","DOIUrl":"https://doi.org/10.1155/2023/1983417","url":null,"abstract":"For the problem of spacecraft attitude actuator failure, an adaptive terminal sliding mode fault-tolerant controller (ATSMFTC) based on the differential manifold SO(3) modelling is designed in this paper. First, SO(3) is used to provide a global and unique description of the spacecraft attitude dynamic model. This modelling method not only avoids the problems of singularity and unwinding that exist in traditional modelling methods but also the SO(3) modelling has a simple formulation of the dynamic equations. Then a left attitude error descriptor function is constructed on SO(3) to design an ATSMFTC. This controller is capable of fast and accurate tracking of the time-varying desired attitude. At the same time, it can react quickly to maintain system stability in case of spacecraft attitude actuator failure. The controller designed based on the left attitude error description system of SO(3) has the features of small computational effort and simple design process. Finally, the numerical simulation of the attitude tracking error verifies the feasibility and high efficiency of the controller designed in this paper.","PeriodicalId":13748,"journal":{"name":"International Journal of Aerospace Engineering","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2023-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43708132","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}
Cycle slip determination plays an important role in high-precision data processing and application of global navigation satellite systems (GNSS). The TurboEdit method consists of the Melbourne-Wubbena (MW) and the geometry-free phase (GF) combination. It can correctly detect and repair cycle slip in most cases. Cycle slip detection (CSD) with GF is disturbed by severe ionospheric delay variations; moreover, CSD or cycle slip repair (CSR) with the MW faces the risk of the disturbance from large pseudorange errors. Hence, cycle slip determination would be difficult under some extreme conditions, e.g., cycle slips occur in low altitude satellite, low sampling rate of dual-frequency observations. To overcome the limitations, a new dual-frequency CSD and CSR method is proposed. The main contents are as follows: (1) compared with the MW method, the Doppler-assisted phase subtraction pseudorange (DAPSP) method that we proposed has no detection blind spot and can effectively reduce the influence of pseudorange noise at high sampling rates; thus, we replace MW by the DAPSP method to improve the detection accuracy. (2) An adaptive threshold model with root mean square (RMS) is established to effectively reduce the missing and false range detection of cycle slip. (3) The sliding polynomial fitting-assisted GF (SPFAGF) is carried out according to the satellite altitude angle. The trend of ionospheric delay and residual multipath effect error between adjacent epochs is extracted and suppressed by SPFAGF. The method combined with DAPSP and SPFAGF (DAPSP-SPFAGF) overcomes the situation that the TurboEdit method cannot effectively detect under extreme conditions. The experimental results of Beidou dual-frequency observation data show that the TurboEdit method and the DAPSP-SPFAGF method can perform CSD and CSR in most cases. At the sampling rate of 1 s, the detection speed of DAPSP-SPFAGF method is significantly faster than TurboEdit method. The number of false positives about CSD is reduced from 68 to 0. At the sampling rate of 30 s and under the condition of the observed satellite altitude angle below 30°, the false alarm rate of the DAPSP-SPFAGF method is 0, but the TurboEdit method’s false alarm rate is 71.2%. So DAPSP-SPFAGF method is prior to the TurboEdit method at the high sampling rates or under extreme conditions, especially it can accurately detect and repair cycle slip and reduce the false positives and false alarm rate.
{"title":"A Modified Cycle Slip Detection Method with GNSS Doppler Assistance and Optimizing by Adaptive Threshold and Sliding Polynomial Fitting","authors":"Kezhao Li, Yunyan Shen, Xiaokui Yue, Yingxiang Jiao, Kai Wang, Zhe Yue, Keke Xu","doi":"10.1155/2023/9421399","DOIUrl":"https://doi.org/10.1155/2023/9421399","url":null,"abstract":"Cycle slip determination plays an important role in high-precision data processing and application of global navigation satellite systems (GNSS). The TurboEdit method consists of the Melbourne-Wubbena (MW) and the geometry-free phase (GF) combination. It can correctly detect and repair cycle slip in most cases. Cycle slip detection (CSD) with GF is disturbed by severe ionospheric delay variations; moreover, CSD or cycle slip repair (CSR) with the MW faces the risk of the disturbance from large pseudorange errors. Hence, cycle slip determination would be difficult under some extreme conditions, e.g., cycle slips occur in low altitude satellite, low sampling rate of dual-frequency observations. To overcome the limitations, a new dual-frequency CSD and CSR method is proposed. The main contents are as follows: (1) compared with the MW method, the Doppler-assisted phase subtraction pseudorange (DAPSP) method that we proposed has no detection blind spot and can effectively reduce the influence of pseudorange noise at high sampling rates; thus, we replace MW by the DAPSP method to improve the detection accuracy. (2) An adaptive threshold model with root mean square (RMS) is established to effectively reduce the missing and false range detection of cycle slip. (3) The sliding polynomial fitting-assisted GF (SPFAGF) is carried out according to the satellite altitude angle. The trend of ionospheric delay and residual multipath effect error between adjacent epochs is extracted and suppressed by SPFAGF. The method combined with DAPSP and SPFAGF (DAPSP-SPFAGF) overcomes the situation that the TurboEdit method cannot effectively detect under extreme conditions. The experimental results of Beidou dual-frequency observation data show that the TurboEdit method and the DAPSP-SPFAGF method can perform CSD and CSR in most cases. At the sampling rate of 1 s, the detection speed of DAPSP-SPFAGF method is significantly faster than TurboEdit method. The number of false positives about CSD is reduced from 68 to 0. At the sampling rate of 30 s and under the condition of the observed satellite altitude angle below 30°, the false alarm rate of the DAPSP-SPFAGF method is 0, but the TurboEdit method’s false alarm rate is 71.2%. So DAPSP-SPFAGF method is prior to the TurboEdit method at the high sampling rates or under extreme conditions, especially it can accurately detect and repair cycle slip and reduce the false positives and false alarm rate.","PeriodicalId":13748,"journal":{"name":"International Journal of Aerospace Engineering","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2023-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44354615","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：