Identification Of Inertia Parameters For The Spacecraft System With A Space Manipulator

With the development of the aerospace industry, aerospace explorations become more complex and diversified. In aerospace exploration, spacecraft systems with space manipulator in the performance of tasks, it often requires that the spacecraft is controlled on the orbit and attitude. However, due to various reasons, such as consumption of large quantities of fuel, release of built-load and capture of the target star, are likely to lead to inertia parameters of the spacecraft changed, thereby causing the spacecraft control system existing law failure. Therefore, the study of on-orbit identification of inertial parameters for attitude controls of the spacecraft has a very important significance.This paper, firstly, introduces the outcome of the issue at home and abroad on the spacecraft inertia parameter identification faced with and has been made. For existing identification methods, it obtains feasibility and advantages of that using the method to space manipulator to identify the parameters of the spacecraft inertia, by analyzing the pros and cons of various methods.In this paper, taking a spacecraft system with a space manipulator as a model and its kinematic analysis and dynamic modeling based on Lagrange methods is made. Based on linear, angular momentum conservation principle, it derived spacecraft inertia parameter identification in the case of the initial momentum known or unknown. This method makes full use of the significant movement of the space manipulator to make the inertia re-distribution of the spacecraft system, causing the spacecraft’s speed changes. By measuring these changes, it built a linear regression model based on the principle of conservation of momentum and used recursive least squares method to stepwise identify the inertia parameters of the spacecraft. Then, the simulation was done and the test results show the effectiveness of the algorithm. But at the same time, several conclusions were drawn that algorithms are sensitive to disturbance robotics trajectory.For the problem of the identifiability of the parameter, the author proposed the method to identify the inertia parameters of the spacecraft by planning optimal trajectory of the space manipulator. According to the Base Parameter Set(BPS), a uniform linear regression model was derived from kinetic model, then taking the smallest condition number as the optimization index of the space manipulator trajectory. In setting the joint incentive,it was parameterized by Fourier Series and the initial trajectory was treated as the initial value of the objective function by considering of constrained problem of trajectories. Then the pattern was used to search optimization algorithm for optimizing the objective function and the optimal excitation trajectory was obtained. In finally, a simulation experiment was made. After comparison of two identification results, it makes a conclusion that the latter is better.At the end of this paper, it was systemically summarized the full text of the paper involved in theory, methods, research, and determined the future of research.