Anti-Disturbance Multi-Objective H2/ H∞Fusion Scheme for End-Effector Position Estimation of Space Manipulator

This paper is concerned with the end-effector position estimation problem of space manipulators in the presence of disturbances in joint dynamics and non-Gaussian noises with unknown statistic characteristics. A multi-objective H
2
/ H
∞
fusion scheme based on disturbance observers is put forward to achieve simultaneous processing of vibration disturbance and non-Gaussian measurement noises. Firstly, the filtering model is established based on kinematics and multi-sensor measurement, which takes vibration disturbance in joint dynamics and non-Gaussian noise into account. Then, two sub-filters based on disturbance observers are designed to estimate the disturbance and deal with Gaussian noise, which takes full advantage of measurement data of redundant sensors. Subsequently, a main filter is designed to fuse estimates of two sub-filters in a weighted form, where the H
2
/ H
∞
performance indicators are set to constrain the fusion error caused by norm-bounded non-Gaussian noise. The framework composed of the above filters can improve the accuracy and reliability of end-effector position estimation in the space environment. Finally, numerical simulation is conducted to verify the effectiveness of the proposed methods.