Controlling Attitude Maneuvers of a Flexible Satellite under Low Frequency Vibration by Using Feed-Forward Constant-Amplitude Inputs

Attitude maneuvers of a satellite equipped by using constant-amplitude thrusters are studied. The satellite consists of a rigid main body and two symmetrical flexible solar panels. Under constant-amplitude thrust, large attitude angle oscillations in low frequencies may occur after the maneuver. This attitude oscillation of course will
disturb its pointing to earth. So, this oscillation should be removed or should be reduced to the small value under the maximum permissible pointing errors. To reduce residual attitude angle oscillations, input shaping method is used in this paper. This method determines number and time locations of input pulses to be used to the satellite regarding to the system’s flexibility. As the result, the input consists of a sequence of constant pulses in the suitable directions and time switching locations.
Then, attitude maneuvers of the satellite are simulated numerically. By shaping the inputs, the residual oscillation of attitude angles of the satellite can be suppressed successfully into an expected level.