Automatically generating explicit equations of motion for multi-body systems

The development of the complex multibody spacecraft raises higher requirement to multi-body dynamics modeling and control technology. The explicit dynamics equations of the system are always needed to analyze system's characteristics and design controllers, but the complexity of system brings difficulty to deriving the equations. In order to solve this problem, the explicit form of dynamics equations' analytical expression was inferred by using Kane's method, the chain structure system's explicit dynamics equations; then, by analyzing this equation, physical meaning and regularities of distribution of each equation item were established; using those regularities, a program that can output the explicit dynamics equations of spacecraft system with tree structure was developed. This program reduces the workload of modeling this type of spacecraft significantly.