Simulating the Effects of a Non-Uniform Gravitational Field on a Space Robot

Abstract

This paper investigates the influence that a nonuniform gravitational field has on the dynamics of a space robot. This is accomplished by obtaining the differential equations of motion of the space robot using three gravitational field potential approximations: a uniform field approximation, a zeroth-order Taylor series expansion of the field about the center of mass of each body, and a second-order binomial series expansion of the gravitational field. The three models are then simulated in a free-fall from identical initial conditions. The results indicate that a zeroth-order series expansion of the gravitational field about the center of mass of each body provides a sufficiently high degree of accuracy without resulting in a significant computational burden.