Evaluation of Two Guidance Laws for Controlling the Impact Flight Path Angle of a Naval Gun Launched Spinning Projectile

2006 ◽  
Author(s):  
Kishore Pamadi ◽  
Ernest Ohlmeyer
Keyword(s):  
Flight Path ◽  
Flight Path Angle ◽  
Spinning Projectile ◽  
Naval Gun ◽  
The Impact ◽  
Guidance Laws

Dispersion reduction of artillery rockets guided by flight path steering method

2016 ◽  
Vol 120 (1225) ◽  
pp. 435-456 ◽  
Author(s):  
S. Mandić
Keyword(s):  
Measurement Errors ◽  
Flight Path ◽  
Guidance System ◽  
Lateral Acceleration ◽  
Dominant Factor ◽  
Measurement Unit ◽  
Impact Point ◽  
Angle Correction ◽  
Flight Path Angle ◽  
The Impact

ABSTRACTArtillery rockets are sensitive to disturbances (total impulse variation, wind, thrust misalignment, etc.). As the range of ground-to-ground rockets increases, the accuracy of free flight rockets decreases. Requirements for the increase of the range and minimisation of the impact point dispersions can be solved by adding guidance and control systems to rockets. Based on the differences between the measured flight parameters and the calculated parameters for the nominal trajectory, the flight path angle correction algorithm is obtained by adding the correction to the nominal value. The flight path steering guidance system with lateral acceleration autopilot in the inner loop, is used for the guidance of hypothetical artillery rockets. The guidance algorithm given in this paper eliminates the time correction due to rocket velocity variations. Efficiency of the proposed algorithm is illustrated by numerical simulation. There is no practical influence of the external disturbances on impact point dispersion. It is also shown that the measurement errors of the inertial measurement unit are the dominant factor affecting impact point dispersion of artillery rockets modified by adding a guidance system based on the flight path steering method.

Trajectory shaping guidance law design using constraint-combining multiplier

2021 ◽  
pp. 095441002098637
Author(s):  
Min-Guk Seo ◽  
Chang-Hun Lee ◽  
Tae-Hun Kim
Keyword(s):  
Design Method ◽  
Impact Angle ◽  
State Variables ◽  
Flight Trajectory ◽  
Potential Significance ◽  
Guidance Law ◽  
Terminal Constraints ◽  
The Impact ◽  
Guidance Laws ◽  
Impact Angle Constraint

A new design method for trajectory shaping guidance laws with the impact angle constraint is proposed in this study. The basic idea is that the multiplier introduced to combine the equations for the terminal constraints is used to shape a flight trajectory as desired. To this end, the general form of impact angle control guidance (IACG) is first derived as a function of an arbitrary constraint-combining multiplier using the optimal control. We reveal that the constraint-combining multiplier satisfying the kinematics can be expressed as a function of state variables. From this result, the constraint-combining multiplier to achieve a desired trajectory can be obtained. Accordingly, when the desired trajectory is designed to satisfy the terminal constraints, the proposed method directly can provide a closed form of IACG laws that can achieve the desired trajectory. The potential significance of the proposed result is that various trajectory shaping IACG laws that can cope with various guidance goals can be readily determined compared to existing approaches. In this study, several examples are shown to validate the proposed method. The results also indicate that previous IACG laws belong to the subset of the proposed result. Finally, the characteristics of the proposed guidance laws are analyzed through numerical simulations.

Effects of Descent Flight-Path Angle on Fuel Consumption of Commercial Aircraft

2019 ◽  
Vol 56 (1) ◽  
pp. 313-323 ◽  
Author(s):  
Enis T. Turgut ◽  
Oznur Usanmaz ◽  
Mustafa Cavcar ◽  
Tuncay Dogeroglu ◽  
Kadir Armutlu
Keyword(s):  
Fuel Consumption ◽  
Flight Path ◽  
Commercial Aircraft ◽  
Flight Path Angle

scholarly journals Finite-Horizon Optimal Tracking Guidance for Aircraft Based on Approximate Dynamic Programming

2019 ◽  
Vol 2019 ◽  
pp. 1-12
Author(s):  
Shizheng Wan ◽  
Xiaofei Chang ◽  
Quancheng Li ◽  
Jie Yan
Keyword(s):  
Dynamic Programming ◽  
Approximate Dynamic Programming ◽  
Least Squares Method ◽  
Flight Path ◽  
Finite Horizon ◽  
Dynamic Programming Method ◽  
Reference Trajectory ◽  
Linear Quadratic ◽  
Optimal Tracking ◽  
Flight Path Angle

Referring to the optimal tracking guidance of aircraft, the conventional time based kinematics model is transformed into a downrange based model by independent variable replacement. The deviations of in-flight altitude and flight path angle are penalized and corrected to achieve high precision tracking of reference trajectory. The tracking problem is solved as a linear quadratic regulator applying small perturbation theory, and the approximate dynamic programming method is used to cope with the solving of finite-horizon optimization. An actor-critic structure is established to approximate the optimal tracking controller and minimum cost function. The least squares method and Adam optimization algorithm are adopted to learn the parameters of critic network and actor network, respectively. A boosting trajectory with maximum final velocity is generated by Gauss pseudospectral method for the validation of guidance strategy. The results show that the trained feedback control parameters can effectively resist random wind disturbance, correct the initial altitude and flight path angle deviations, and achieve the goal of following a given trajectory.

Optimal perturbation guidance with constraints on terminal flight-path angle and angle of attack

2019 ◽  
Vol 233 (12) ◽  
pp. 4436-4446
Author(s):  
Penglei Zhao ◽  
Wanchun Chen ◽  
Wenbin Yu
Keyword(s):  
Optimal Control ◽  
Singular Perturbation ◽  
Time Scale ◽  
Angle Of Attack ◽  
Flight Path ◽  
Superior Performance ◽  
Optimal Perturbation ◽  
Optimal Guidance ◽  
Flight Path Angle ◽  
Guidance Problem

This paper presents the design of a singular-perturbation-based optimal guidance with constraints on terminal flight-path angle and angle of attack. By modeling the flight-control system dynamics as a first-order system, the angle of attack is introduced into the performance index as a state variable. To solve the resulting high-order optimal guidance problem analytically, the posed optimal guidance problem is divided into two sub-problems by utilizing the singular perturbation method according to two time scales: range, altitude, and flight-path angle are the slow time-scale variables while the angle of attack is the fast time-scale variable. The outer solutions are the optimal control of the slow-scale subsystem. Thereafter, by applying the stretching transformation, the fast-scale subsystem establishes the relationships between the outer solutions and acceleration command. Then, the optimal command can be obtained by solving the fast-scale subsystem also using the optimal control theory. The proposed guidance can achieve a near-zero terminal acceleration as well as a small miss distance. The superior performance of the guidance is demonstrated by adequate trajectory simulations.

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