PURPOSE: To provide a dead beat pulse method to suppress complex vibration modes of a soft structure such as a solar cell paddle, antenna supporting beam, etc., wherein the vibration is such as generated in the attitude track control made by a thruster of an artificial satellite or the pointing control of a transmission apparatus made by a motor.

CONSTITUTION: 'n' is set on a pulse generator 2 and an n-counter 3 if complex vibration modes are with two frequencies f and f, a string of pulses synchronous with the periods of the two vibration modes of artificial satellite is generated from a switch 4 with the output of pulse generator 1 as trigger. Therein 'n' is the number of pulses included in the string of pulses. The two vibration modes of the soft structure concerned due to reaction generated at the time are canceled for each period of vibration mode. The drive rate and driving amount are adjustable by altering the manner of taking synchronization.