Reduction of the Actuator Oscillations using Adaptive Control in a Damped Beam Model under a Follower Force

Omid Kavianipour, Abdol Khoshnood, Hossein Sadati, Ali Jafari
unpublished
µ€fÀ¯ ĸn» |¸m 3 ÃZ¼‹ , 4 , ½Zfˆ» 1388 Äv¨ , 36-26 «{ Y‚]Y Á µ€fÀ¯ ½Z‡|ÀAE» ¾¼n¿Y ,µ€fÀ¯ ĸn» Ì ½Y€ËY ª-ʇ— ¾Ë|·Y€Ì¿ ÄmYÂy Êf À ÃZ´Œ¿Y{ °» Y{ Ã|AEŸ Ã|ÀˆË¿ cZ^eZ : {ÂÀ‹Ây |Ìn¼·Y|^Ÿ ŠÅZ¯ cZ¿Z‡Â¿ Zŀ´¸¼Ÿ { ʬÌ^˜e µ€fÀ¯ Y Ã{Z¨f‡Y Z] ®Ë €Ìe Z] ÊËY€Ì» dve ÉÁ€Ì¿ \̬ e Ã|ÀÀ¯ Âa Ê¿ZËÁZ¯ |Ì»Y 1 , Ÿ {ÂÀ‹Ây |Ìn¼·Y|^ 2 ÊeY{Z‡ ¾Ìˆu |̇ , 3 ɀ¨ m €¤Y ʸŸ ,) Ä·Z¬» ‰€Ë~a xËZe , Ä·Z¬» d §ZË{ xËZe (Ã|Ì°q : {{€³ µ€fÀ¯ ºfˆÌ‡ ÉY|ËZaZ¿ Ä] €nÀ» |¿YÂe Ê» €] ÃYÂÅZ» ÉZÅ ºfˆÌ‡ { ÁZ‡ ɀË~a ¥Z˜ ¿Y cY€ÌiZe. Ä·Z¬»
more » ... Y cY€ÌiZe. Ä·Z¬» ¾ËY ¥|Å ÊuY€— Á{ €Ìe ®Ë c Ä] ÊËY€Ì» cY€iY Á ½Y€ŒÌa Ã|ÀÀ¯ \̬ e ÉÁ€Ì¿ €iY { ʌ¼y cZ‹Z eY €ÌiZe ɁZˆ·|» Á cZ‹Z eY Ã|ÀÅZ¯ |‹Z] Ê» {YM €‡. Á Ã|ÀÀ¯ \̬ e ÉÁ€Ì¿ €ÌiZe Z] ÃYÂÅZ» ¶»Zu ÉZÅ ºfˆÌ‡ ÉY€] Ã|ÀÀ¯ µ€fÀ¯ ÊuY€— ½ÂÀ¯Ze Äf‹~³ ÉZÅ ŠÅÁ„a { ‡Y Ã|Œ¿ ¹Zn¿Y ÁZ‡ ÊËY€Ì» d. †¿Z¯€ § ,Ã|‹ €f¸Ì § ÊfŒ³Z] ÊËZ‡ZÀ‹ ‰Á Y Ã{Z¨f‡Y Z] ėÂ]€» ɁZˆ·|» Y †a ŠÅÁ„a ¾ËY { d‡Y Ã|‹ Äf §€³ ÀAE] cZ‹Z eY ŠÅZ¯ ÉY€] ʬÌ^˜e ÉZÅ €f¸Ì § Y Á Ã|‹ ÊËZ‡ZÀ‹ ʋZ eY. Ã|ÀÀ¯ µ€fÀ¯ į {Y{ ½ZŒ¿ ɁZ‡ ÄÌ^‹ lËZf¿ Ì» Á Ã|ÀÀ¯ \̬ e ÉÁ€Ì¿ €ÌiZe {ÂmÁ Z] Ã|‹ ÊuY€— d‡Y Ã{Y{ ŠÅZ¯ Y ºfˆÌ‡ ÁZ‡ ʌ¼y cZ‹Z eY Ê]Ây Ä] ÊËY€. ¾ËY ¾ÌÀr¼Å |Å{ Ê» ½ZŒ¿ Y ɀfAE] {€°¸¼Ÿ |À¯ Ê» ÉÁ€Ìa žm€» µ|» É´·Y Y į ½ZË{Y€³ ‰Á Z] ĈËZ¬» { ‰Á. É|̸¯ cZ¼¸¯ : €Ë~a ¥Z˜ ¿Y €] ÃYÂÅZ» , Ã|ÀÀ¯ \̬ e ÉÁ€Ì¿ , ÁZ‡ ÊËY€Ì» , ¸Ì § ,ʋZ eY †¿Z¯€ § ÊËZ‡ZÀ‹ ʬÌ^˜e €f. Abstract: Flexible behaviors in new aerospace structures can lead to a degradation of their control and guidance system and undesired performance. The objectives in the current work are to analyze the vibration resulting from the propulsion force on a Flexible Launch Vehicle (FLV) modeled as a follower force on a free-free beam with proportional damping, study its effects on the oscillation of the actuators, and develop an approach to reduce these oscillations. To pursue these objectives, the stability of the beam model is first studied using the Ritz method. It was determined that the proportional damping consisting of those of internal (material) and external (viscous fluid) result in a change in the critical follower force. The rigid dynamics of a FLV in the pitch channel was then modeled and modified using the vibrational model of the device for the same channel. A new dynamic model and an adaptive control system for the FLV was then developed, allowing the aerospace structure to run on its maximum bearable propulsion force with the optimum effects on the oscillation of its actuators. Simulation results show that such a control model provides an effective way to reduce the undesirable oscillations of the actuators.
fatcat:ulxjvqh73jf2vbia6ehjckipzq