Controlling the attitude of linear time-varying model LEO satellite using only electromagnetic actuation

Recently small satellites are used more commonly because of the low launching cost and development of microelectronics. Also lower weight, size, cost and the power consumption of magnetorquer, has made the application of them in controlling attitude of the satellites common. Intensive changes and non-ability of geomagnetic field are some of the problems, which have limited the efficiency of magnetorquers. In this paper a new control method is presented that keeps the attitude of satellite in desired condition only by electromagnetic coils. The distinction of this method is its abilities in comparison with other methods. In this analytic method a direct relation between design parameters, attitude accuracy and external disturbance, is established and the poles of system can be easily and properly placed. Weight and volume of coils are reduced at least to 1/3 and subsequently energy consumption is also decreased. Unlike previous methods that are just allocatable to orbits with inclination angle of about 90 degrees, in this method there is no limitation for inclination of the orbit.