Analysis of effect of thruster configuration on control error

The control accuracy as well as the propellant consumption is directly affected by the number of thrusters and their configuration. This paper makes a research on the thrust allocation scheme of a spacecraft. On the analogy of GDOP used in satellite navigation system, the concept of thruster configuration dilution of precision (CDOP) is proposed to define the ratio between the thrust allocation error and the error caused by the thruster configuration. The conclusion that the CDOP increases as the number of thrusters is obtained by analysis of matrix theory. Finally, the CDOP concept and the conclusion presented are validated by a simulation, and can provides a reference for the selection of the number of the thrusters and their configuration.