Verification of a Fully Numerical Entry Guidance Algorithm

2016 ◽  
Author(s):  
Ping Lu ◽  
Christopher Brunner ◽  
Susan Stachowiak ◽  
Gavin F. Mendeck ◽  
Michael Tigges ◽  
...  
Keyword(s):  
Entry Guidance ◽  
Guidance Algorithm

Analytical predictor–corrector entry guidance for hypersonic gliding vehicles

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Huatao Chen ◽  
Kun Zhao ◽  
Juan L.G. Guirao ◽  
Dengqing Cao
Keyword(s):  
Feedback Control ◽  
Velocity Variation ◽  
Analytical Relation ◽  
Aerodynamic Load ◽  
Quasi Equilibrium ◽  
Bank Angle ◽  
Entry Guidance ◽  
Guidance Algorithm ◽  
Predictor Corrector ◽  
Guidance Problem

AbstractFor the entry guidance problem of hypersonic gliding vehicles (HGVs), an analytical predictor–corrector guidance method based on feedback control of bank angle is proposed. First, the relative functions between the velocity, bank angle and range-to-go are deduced, and then, the analytical relation is introduced into the predictor–corrector algorithm, which is used to replace the traditional method to predict the range-to-go via numerical integration. To eliminate the phugoid trajectory oscillation, a method for adding the aerodynamic load feedback into the control loop of the bank angle is proposed. According to the quasi-equilibrium gliding condition, the function of the quasi-equilibrium glide load along with the velocity variation is derived. For each guidance period, the deviation between the real-time load and the quasi-equilibrium gliding load is revised to obtain a smooth reentry trajectory. The simulation results indicate that the guidance algorithm can adapt to the mission requirements of different downranges, and it also has the ability to guide the vehicle to carry out a large range of lateral maneuvers. The feedback control law of the bank angle effectively eliminates the phugoid trajectory oscillation and guides the vehicle to complete a smooth reentry flight. The Monte Carlo test indicated that the guidance precision and robustness are good.

Verification of a Fully Numerical Entry Guidance Algorithm

2017 ◽  
Vol 40 (2) ◽  
pp. 230-247 ◽  
Author(s):  
Ping Lu ◽  
Christopher W. Brunner ◽  
Susan J. Stachowiak ◽  
Gavin F. Mendeck ◽  
Michael A. Tigges ◽  
...  
Keyword(s):  
Entry Guidance ◽  
Guidance Algorithm

scholarly journals Adaptive entry guidance for the Tianwen-1 mission

Astrodynamics ◽  
2022 ◽  
Vol 6 (1) ◽  
pp. 17-26
Author(s):  
Minwen Guo ◽  
Xiangyu Huang ◽  
Maodeng Li ◽  
Jinchang Hu ◽  
Chao Xu
Keyword(s):  
Trajectory Design ◽  
Accuracy Control ◽  
Initial State ◽  
Control Phase ◽  
Guidance Law ◽  
Flight Path Angle ◽  
Entry Guidance ◽  
Event Trigger ◽  
Control Authority ◽  
Guidance Algorithm

AbstractTo meet the requirements of the Tianwen-1 mission, adaptive entry guidance for entry vehicles, with low lift-to-drag ratios, limited control authority, and large initial state bias, was presented. Typically, the entry guidance law is divided into four distinct phases: trim angle-of-attack phase, range control phase, heading alignment phase, and trim-wing deployment phase. In the range control phase, the predictor—corrector guidance algorithm is improved by planning an on-board trajectory based on the Mars Science Laboratory (MSL) entry guidance algorithm. The nominal trajectory was designed and described using a combination of the downrange value and other states, such as drag acceleration and altitude rate. For a large initial state bias, the nominal downrange value was modified onboard by weighing the landing accuracy, control authority, and parachute deployment altitude. The biggest advantage of this approach is that it allows the successful correction of altitude errors and the avoidance of control saturation. An overview of the optimal trajectory design process, including a discussion of the design of the initial flight path angle, relevant event trigger, and transition conditions between the four phases, was also presented. Finally, telemetry data analysis and post-flight assessment results were used to illustrate the adaptive guidance law, create good conditions for subsequent parachute reduction and power reduction processes, and gauge the success of the mission.

scholarly journals Skip Re-Entry Trajectory Detection and Guidance for Maneuvering Vehicles

Sensors ◽  
2020 ◽  
Vol 20 (10) ◽  
pp. 2976
Author(s):  
Hongqiang Sun ◽  
Shuguang Zhang
Keyword(s):  
Analytical Relationship ◽  
Quasi Equilibrium ◽  
Bank Angle ◽  
Control Solution ◽  
Entry Guidance ◽  
Path Constraints ◽  
Path Constraint ◽  
Guidance Algorithm ◽  
Feedback Data ◽  
Altitude Estimation

The re-entry trajectory of maneuvering vehicles with medium to high hypersonic lift-to-drag ratios is generally planned using quasi-equilibrium flight conditions known from Space Shuttles. They may exhibit an oscillation re-entry phenomenon termed skip re-entry when related components or sensors fail. However, conventional re-entry guidance only considers quasi-equilibrium flights and ignores the possibility of the occurrence of an unexpected skip trajectory; this may lead to the failure of the re-entry mission due to a lack of a corresponding guidance strategy. However, the detection of a skip trajectory is the necessary reference for the decision-making of calling a related guidance algorithm that helps improve the safety of vehicle re-entry. Herein, a skip re-entry detection and trajectory control solution is proposed to play an emergency role in the cases of skip re-entry. Firstly, the oscillation frequency characteristics of the linearized re-entry motion equation of a vehicle are analyzed, and an approximate analytical relationship is constructed for skip altitude estimation. Then, the residual deviation between the altitude feedback data and the estimated skip altitude is calculated and compared with the threshold to determine the occurrence of skip re-entry. In addition, a method for controlling the skip re-entry trajectory with the range extension is developed by controlling the bank angle with a fixed angle of attack profile, satisfying the path constraint requirements. The results indicate that the method effectively performs skip re-entry detection and that it can help extend the range of the vehicles in abnormal re-entry scenarios, keeping the flight within the path constraints and guiding it to the expected location.

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