Abstract: The space combat environment places high requirements on the pointing accuracy of the platform’s fire control system. A novel approach to improve the control input accuracy of final stage on a space platform fire control mechanism, is presented by using multiplicative measurement model of unit vector. Motivation comes from the situation that the algebra calculation is in contradiction with geometry reality, because of the linearized error of existing additive measurement model. Full correction equation and practical correction equation for the problem are developed. The effects are tested with respect to simulated Gaussian input and sinusoidal input, and the results highlight a non negligible error affecting mirror motion compensation. It is proved that correction equations can be directly utilized by compensation programs. The proposed algorithm is validated by computer simulations of the attitude control correction of a satellite. Numerical tests show the improvements on compensation accuracy.

Key words: space platform, final stage of fire control mechanism, control input correction, multiplicative measurement model