An enhanced anti-disturbance guidance scheme for powered descent phase of Mars landing under actuator fault

Jianwei Xu,Jianzhong Qiao,Lei Guo

doi:10.1177/1729881418759889

Jianwei Xu, Jianzhong Qiao + Show 1 more

Open Access

https://doi.org/10.1177/1729881418759889

Copy DOI

Abstract

As a class of autonomous deep-space exploration robots, Mars lander is simultaneously affected by wind disturbance and actuator fault, which hinders precise landing on Mars. In this article, we propose a composite guidance approach by combining disturbance observer and iterative learning observer together. The Mars wind disturbance is dealt by the disturbance observer providing wind estimation which is rejected through feed-forward channel. Meanwhile, the iterative learning observer is used to estimate the deficiency of actuators. The proposed guidance scheme ensures not only the precision but also the reliability of the Mars guidance system. The stability of the closed-loop system is analyzed. Simulations made in different situations demonstrate the performance of the proposed approach.

Highlights

Landers will inevitably face Mars wind disturbance, which may result in far range away from the prespecified landing point, sometimes it even causes a crush into the ground.[3,4,5]
The main contributions of this article can be summarized as follows: (1) the powered descent guidance model has been established, considering the concurrence of wind disturbance and actuator fault problem; (2) compensating the effect of wind disturbance and autonomously healing actuators fault, disturbance observer (DO) and iterative learning observer (ILO) are combined to achieve a high precision and safe landing; and (3) the closed-loop landing guidance system has been analyzed to guarantee the stability of the proposed approach
It needs to be pointed out that the minus sign in Figure 1 represents that the composite guidance scheme simultaneously rejects wind disturbance and compensates the loss of actuators in the feed-forward path

Summary

Introduction

Powered descent phase is the final regulation phase in Mars landing tasks.[1,2] landers will inevitably face Mars wind disturbance, which may result in far range away from the prespecified landing point, sometimes it even causes a crush into the ground.[3,4,5] Besides, the Mars landing mission needs to endure a long stage including launching from the earth, in-orbit flying, and landing. Few literatures consider the additive wind disturbance and multiplicative actuator fault problem on Mars precision landing. Motivated by this problem, a novel anti-disturbance guidance method integrating disturbance observer (DO) with ILO is proposed to simultaneously improve the landing accuracy and ensure the performance of reliability. The main contributions of this article can be summarized as follows: (1) the powered descent guidance model has been established, considering the concurrence of wind disturbance and actuator fault problem; (2) compensating the effect of wind disturbance and autonomously healing actuators fault, DO and ILO are combined to achieve a high precision and safe landing; and (3) the closed-loop landing guidance system has been analyzed to guarantee the stability of the proposed approach. The “Conclusion” section gives a total conclusion to this article

Problem description

Composite guidance scheme design

Stability analysis

Initial value

Conclusion