In Structural Vibration Control Of Flexible Space, The Wave Absorber

As the percentage of flexible space structures and the requirement for control accuracy continuousely increase,the control of flexible space structures is increasingly important. Focusing on the problem of vibration control of clamped beam,the thesis studied the application of wave absorbing theory to the vibration control. The thesis included two main following parts:1.Based on the dynamics equation of a beam ,the wave model of one was derived ,so did the relation between the power flow of the elastic waves and the vibration energy .At last ,the function of the compensator was attained by applying knowlage about H2.2. Regarding the solarfan of some satellite as the object ,three control systems of the object was simulated,when they were excited by the impulse and sinusoidal force respectively. In addition ,the third one exited by three forces respectively was simulated,which were centrifugal force induced by the rapid capturing the sun and normal tracing the sun ,inertia force induced by the translational maneuver flight on orbit and the impulse moment of locking at the end of the expansion of the solarfan. The three control systems respectively were as follows:(1) The measuring part of the first one was displacement piezoelectric sensor. A pair of piezoelectric sensor/actuator was collocated by each side of the first solar array plate. The compensator was H(s) = 2395-s;(2) The measuring part of the second one was also displacement piezoelectric sensor.A pair of piezoelectric sensor/actuator was collocated by each side of the whole solarfan.Tthe compensator was H(s) = 244s;(3) The measuring part of the third one was velocity piezoelectric sensor.A pair of piezoelectric sensor/actuator was collocated by each side of the three solars array plates near to the body of satellite. The compensator was H (s) = 2370s .The results of simulation showed that attenuation factor of the first order of the third control system was as much as ten times of the value of the system without controller. It can made the attenuation time deduce to one fifteenth of one of the system without control, in addition, it can suppress the vibration of low orders, for instance, the amplitude of the first order can be suppressed to 7 percent of one without controller.