Parameter setting and analysis for the artificial potential functions in the application of small celestial bodies landing trajectory planning

Abstract

The targets of landing missions on small celestial bodies usually have high scientific value but complex terrain. Therefore, there are high demands for the landing trajectory planning method with regard to the safety and precise landing. The artificial potential function method is one of the commonly used methods in trajectory planning for small celestial body landing. It is performed by applying attractive force form the target and repulsive force from the obstacles to the moving spacecraft. The attractive and repulsive forces are generated by the corresponding potential functions, which involves several parameters needed to be determined. Improper parameters may lead to low efficiency of trajectory calculation, collision with obstacles or failure of reaching the target. However, the parameters in the artificial potential functions are usually set as empirical values without consideration of different application scenarios. In this paper, the setting methods of the weight matrices 𝑃𝑟 and 𝑃𝑉 in the attractive potential function, the parameter matrix 𝛭 in the Lyapunov function and the parameters 𝑘1 and 𝑘2 in the Gaussian-type repulsive potential function are studied, and several simulation experiments are conducted to verify the parameter values. And suggestions are given on the setting of these parameters. Keywords: artificial potential function, parameter setting, landing trajectory planning.