Search results

1 – 2 of 2
To view the access options for this content please click here
Article
Publication date: 1 August 2005

Li Shuang, Cui Hutao and Cui Pingyuan

In order to succeed in landing asteroids, good accuracy autonomous navigation is absolutely necessary. Aims to describe a new autonomous navigation algorithm.

Downloads
1005

Abstract

Purpose

In order to succeed in landing asteroids, good accuracy autonomous navigation is absolutely necessary. Aims to describe a new autonomous navigation algorithm.

Design/methodology/approach

First, gray images of asteroid surface are acquired by optical navigation camera, and nature feature points are detected and tracked autonomously. Second, the directional vector from spacecraft to the center of each feature point can be computed from the image coordinates in camera focal plane. Then, LIDAR/LRF is directed to three feature points and the distances from spacecraft to feature points are obtained. Last, the relative position vector from spacecraft to the target asteroid is reconstructed base on measurement outputs of navigation cameras and laser light radar (laser range finder).

Findings

Suppose the initial conditions presented in this paper, the autonomous optical navigation position error and velocity error are less than 1 m and 0.1 m/s, respectively; this navigation accuracy can satisfy the requirement of soft landing on asteroids.

Originality/value

Based on feature detection and tracking, an autonomous optical navigation scheme is brought out and the validity is confirmed by computer simulation.

Details

Aircraft Engineering and Aerospace Technology, vol. 77 no. 4
Type: Research Article
ISSN: 0002-2667

Keywords

To view the access options for this content please click here
Article
Publication date: 6 September 2011

Cui Hutao, Cheng Xiaojun, Xu Rui and Cui Pingyuan

The purpose of this paper is to propose an attitude control algorithm for spacecraft with geometric constraints.

Abstract

Purpose

The purpose of this paper is to propose an attitude control algorithm for spacecraft with geometric constraints.

Design/methodology/approach

The geometric constraint is reformulated as a quadratic form when quaternion is used as attitude parameter, then the constraint is proved to be nonconvex and is further transformed to a convex one. By designing a new constraint formulation to satisfy the real constraint in the predictive horizon, the attitude control problem is reshaped to a convex planning problem which is based on receding horizon control.

Findings

The proposed algorithm is more effective in handling geometric constraints than previous research which used single step planning control.

Practical implications

With novel improvements to current methods for steering spacecraft from one attitude to another with geometric constraints, great attitude maneuver path can be achieved to protect instruments and meanwhile satisfy mission requirements.

Originality/value

The attitude control algorithm in this paper is designed especially for the satisfaction of geometric constraints in the process of attitude maneuver of spacecraft. By the application of this algorithm, the security of certain optical instruments, which is critical in an autonomous system, can be further assured.

Details

Aircraft Engineering and Aerospace Technology, vol. 83 no. 5
Type: Research Article
ISSN: 0002-2667

Keywords

1 – 2 of 2