An optimal guidance law for planetary landing

1997 ◽  
Author(s):  
Christopher D'Souza ◽  
Christopher D'Souza
Keyword(s):  
Guidance Law ◽  
Optimal Guidance ◽  
Planetary Landing

Optimal Guidance Law Based on Virtual Sliding Target

2017 ◽  
Vol 30 (3) ◽  
pp. 04016097 ◽  
Author(s):  
Mohiyeddin Mozaffari ◽  
Behrouz Safarinejadian ◽  
Tahereh Binazadeh
Keyword(s):  
Guidance Law ◽  
Optimal Guidance

scholarly journals Fast guidance method of lunar landing based on dynamic programming

2021 ◽  
Vol 39 (1) ◽  
pp. 159-166
Author(s):  
Hongqian Zhao ◽  
Honghua Dai ◽  
Zhaohui Dang
Keyword(s):  
Lunar Surface ◽  
Process Time ◽  
Rescue Mission ◽  
Emergency Rescue ◽  
Whole Process ◽  
Guidance Law ◽  
Optimal Guidance ◽  
Multi Stage ◽  
Process Guidance ◽  
Time Optimal

In this paper, a novel multi-stage trajectory transfer and fixed-point landing time optimal guidance method for the lunar surface emergency rescue mission is proposed. Firstly, the whole process motion and dynamics model for the lunar surface emergency rescue with four stages are established. Then, in the initial orbit transfer phase, the Lambert algorithm based on "prediction + correction" is designed for the non spherical gravitational perturbation of the moon. In the powered descent phase, the Hamiltonian function is used to design a time suboptimal explicit guidance law that can be applied in orbit in real time. Finally, aiming at the multi-stage global time optimal guidance, the whole time process guidance law is obtained by establishing the allowable control set for each stage in the whole process. The simulation results show that compared with the piecewise optimal control method, the present method has better optimization effect and shorter whole process time. It is of great significance to the possible emergency rescue mission of manned lunar exploration in the future.

Design and Instruction Solution of an Optimal Guidance Law for Ship-Air Missile beyond Visual Range

2012 ◽  
Vol 433-440 ◽  
pp. 3831-3836
Author(s):  
Yong Tao Zhao ◽  
Yun An Hu
Keyword(s):  
Control Variable ◽  
Linear Quadratic ◽  
Linear Quadratic Optimal Control ◽  
Guidance Law ◽  
The Earth ◽  
Optimal Guidance ◽  
Quadratic Optimal Control ◽  
Simulation Results ◽  
Visual Range ◽  
Terminal Guidance

For the case of ship-air missile intercepting the low target beyond visual range by ship-ship coordination, the instruction solution model was presented and an optimal guidance law was designed considering the effect of the curvature of the earth. In the midcourse and terminal guidance segment, the optimal guidance law was designed through applying the concept of the pseudo control variable and the theory of the linear quadratic optimal control. The information of the target was described in the launch coordinates through coordinate transformation to realize the instruction solution for the designed guidance law. The simulation results show that the model of the instruction solution is correct and the designed guidance law is feasible.

An Optimal Guidance Law with Velocity Rendezvous Angle Constraint

2015 ◽  
Vol 22 (8) ◽  
pp. 8-11
Author(s):  
徐兴元 XU Xing-yuan ◽  
郭晨鲜 GUO Chen-xian ◽  
潘晓东 PAN Xiao-dong ◽  
宋晓娜 SONG Xiao-na
Keyword(s):  
Guidance Law ◽  
Optimal Guidance

scholarly journals Analysis of the Influence of Trace Point Step-Jump Behavior

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Yao Yang ◽  
Yang Xu ◽  
Pei Wang
Keyword(s):  
Recovery Time ◽  
Sliding Mode ◽  
Initial Step ◽  
Guidance System ◽  
Adjoint Model ◽  
Proportional Navigation ◽  
Guidance Law ◽  
Optimal Guidance ◽  
Fundamental Reason ◽  
Terminal Guidance

To explore the influence of the trace point step-jump behavior on a terminal guidance system, an analysis is performed from the line-of-sight rate (LOS rate) and guidance accuracy views for designing an anti-step-jump guidance law. First, the linear terminal guidance model under the trace point jump circumstance is constructed, and then the fundamental reason for the miss distance is investigated by deriving the upper bound of the LOS rate at the initial step-jump moment. Following this, the novel proposed analytical differential adjoint model is established with the adjoint method, and its validity is demonstrated comparing with the numeric derivative model. Based on the adjoint model, the effects of the ratio coefficient, the time constant, and the jump amplitude on the guidance accuracy are explored. Finally, a novel anti-step-jump guidance law is designed to shorten the recovery time of the overload. The simulations have shown that the faster recovery time and higher accuracy are achieved in comparison with the proportional navigation guidance, optimal guidance, and adaptive sliding mode guidance.

Generalized explicit guidance with optimal time-to-go and realistic final velocity

2019 ◽  
Vol 233 (13) ◽  
pp. 4926-4942
Author(s):  
Sabyasachi Mondal ◽  
Radhakant Padhi
Keyword(s):  
Optimal Solution ◽  
Optimal Time ◽  
Optimal Solutions ◽  
Final Velocity ◽  
Velocity Magnitude ◽  
Guidance Law ◽  
Optimal Guidance ◽  
Input Parameters ◽  
The Cost

This paper presents an approach to compute the optimal time-to-go and final velocity magnitude in the Generalized Explicit (GENEX) guidance. Time-to-go and final velocity magnitude are two critical input parameters in GENEX guidance implementation. Optimal time-to-go selects that optimal solution which yields less cost compared to the costs yielded by other optimal solutions. In addition to it, the input of realistic final velocity lowers the cost further. These developments relax the existing limitations of GENEX, thereby making this optimal guidance law more optimal, effective and generic.

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