Modeling and Vibration Control of a Two-Link Flexible Manipulator with ANSYS APDL

Year 2018, Volume: 20 Issue: 60, 817 - 829, 15.09.2018

Şahin Yavuz

Abstract

In this study, the control of post-motion residual vibrations of a
two-link flexible manipulator is investigated. The manipulator is modeled in
ANSYS by using APDL (Ansys Parametric Design Language). The post-motion
vibration signals are simulated by transient analysis which is performed in
ANSYS based on the finite element theory. Experimental results are also
presented and compared with simulation results. Trapezoidal velocity profiles
are used for the motors. The acceleration, constant velocity and deceleration
time intervals of the trapezoidal velocity profile are determined by
considering the lowest natural frequency of the manipulator structure at the
stopping position. Various starting and stopping positions are considered. The
root mean square (RMS) acceleration values of the vibration signals after
stopping are calculated. It is observed that the residual vibration is
sensitive to the deceleration time.  The
RMS values are lowest if the inverse of the deceleration time is equal to the
first natural frequency.  It is highest
if the inverse of the deceleration time is equal to the half of the first
natural frequency. It is observed that simulation and experimental results are
in good agreement.

Keywords

Flexible Manipulator, Vibration Control, ANSYS APDL

İki Eksenli Esnek bir Manipülatörün ANSYS APDL ile Modellenmesi ve Titreşim Kontrolü

Abstract

Bu çalışmada, iki eksenli esnek bir manipülatörün hareket sonrası artık
titreşimlerinin kontrolü incelenmiştir. Manipülatör ANSYS'de APDL (Ansys
Parametrik Tasarım Dili) kullanılarak modellenmiştir. Hareket sonrası titreşim
sinyalleri, sonlu elemanlar teorisine dayalı olarak ANSYS'de gerçekleştirilen
dinamik analiz ile simüle edilir. Önceki çalışmada elde edilen deney sonuçları
da sunulmuş ve benzetim sonuçları ile karşılaştırılmıştır. Tahrik motorları
için trapez hız profilleri kullanılmıştır. Trapez hız profilinin ivme, sabit
hız ve yavaşlama süreleri, durdurma pozisyonundaki manipülatör yapısının en
düşük doğal frekansı dikkate alınarak seçilir. Çeşitli başlangıç ve durma
pozisyonları değerlendirilmiştir. Hareket bittikten sonra meydana gelen artık
titreşim sinyallerinin karelerinin ortalamasının karekök (RMS) değerleri
hesaplanır. Artık titreşimin yavaşlama süresine duyarlı olduğu gözlemlenmiştir.
RMS değerleri, yavaşlama süresinin tersi ilk doğal frekansa eşitse, en düşük
değer elde edilmektedir. Yavaşlama zamanının tersi ilk doğal frekansın yarısına
eşitse, en yüksek değer elde edilir. Benzetim ve deney sonuçlarının birbirleriyle
uyumlu çıktığı görülmektedir.

Keywords

Manipülatör, Titreşim Kontrolü, ANSYS APDL

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