Dynamic model of a flying manipulator with two highly flexible links

Zohoor, Hassan; Khorsandijou, S M

doi:10.1016/j.apm.2007.07.010

Cited by 31 publications

(4 citation statements)

References 15 publications

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“…Such models should be as concise as possible for implementation of model-based control algorithms. In most researches on dynamics analyses, the modeling approach introduces an accumulation in the dynamics of rigid-flexible multibody systems, 29,30 while the resulting models require heavy computations and cannot be practically used for model based controller implementations. In fact, to avoid accumulation in the dynamic model, there are some approaches which model the entire system by virtual partitioning between the rigid and flexible subsystems.…”

Section: Dynamics Modelingmentioning

confidence: 99%

Adaptive hybrid suppression control of space free-flying robots with flexible appendages

2014

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SUMMARYControl of rigid–flexible multi-body systems in space, during cooperative manipulation tasks, is studied in this paper. During such tasks, flexible members such as solar panels may vibrate. These vibrations in turn can lead to oscillatory disturbing forces on other subsystems, and consequently may produce significant errors in the position of operating end-effectors of cooperative arms. Therefore, to design and implement efficient model-based controllers for such complicated nonlinear systems, deriving an accurate dynamics model is required. On the other hand, due to practical limitations and real-time implementation, such models should demand fairly low computational complexity. In this paper, a precise dynamics model is derived by virtually partitioning the system into two rigid and flexible portions. These two portions will be assembled together to generate a proper model for controller design. Then, an adaptive hybrid suppression control (AHSC) algorithm is developed based on an appropriate variation rule of a virtual damping parameter. Finally, as a practical case study a space free-flying robot (SFFR) with flexible appendages is considered to move an object along a desired path through accurate force exertion by several cooperative end-effectors. This system includes a main rigid body equipped with thrusters, two solar panels, and two cooperative manipulators. The system also includes a third and fourth arm that act as a communication antenna and a photo capturing camera, respectively. The maneuver is deliberately planned such that flexible modes of solar panels get stimulated due to arms motion, while obtained results reveal the merits of proposed controller as will be discussed.

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Section: Dynamics Modelingmentioning

confidence: 99%

Adaptive hybrid suppression control of space free-flying robots with flexible appendages

2014

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“…H is the distance from the natural axis of the beam to the top of the tip, and d is the distance between the lower edge of the cantilever and the centroid of the cross section. If the axial loaded is neglected, the governing equation based on Timoshenko beam theory is written as [11,15]…”

Section: Theoretical Modelmentioning

confidence: 99%

A New Insight into the Flexural Vibration of Rectangular Atomic Force Microscope Cantilevers by Consideration the Contact Position

Sadeghi

Zohoor

2010

JSDD

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The resonant frequency of flexural vibration for an atomic force microscope (AFM) cantilever has been investigated using the Timoshenko beam theory. In this paper the dynamic behavior of vibrational modes based on Timoshenko beam theory by consideration the effects of contact position, the height of the tip, thickness of the beam, and the angle between the cantilever and the sample surface on the nondimensional resonant frequency have been investigated for the rectangular AFM cantilevers. The results show that the frequency is sensitive to the contact position and also decreases by increasing Timoshenko beam parameter or cantilever thickness, the first frequency is sensitive only to the lower normal contact stiffness, but high order modes are sensitive in a larger range of normal contact stiffness. By increasing the height H, for a limited range of normal contact stiffness the sensitivity to the normal contact stiffness increases. Increasing the lateral contact stiffness increases the sensitivity to the normal contact stiffness after critical normal contact stiffness, but when the normal contact stiffness is lower than critical normal contact stiffness, the situation is reversed. Furthermore, by increasing the angle between the cantilever and sample surface, the frequency decreases.

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“…On the other hand, to control a multi-body system with flexible members, having a properly realistic dynamics model is highly important, particularly to develop model-based control algorithms. An accumulation approach has been widely used for control studies [13][14][15][16][17], where the entire system is modelled by virtual partitioning between the rigid and flexible subsystems. A hybrid parallelizable low-order algorithm has been presented for multiple rigid body systems [18].…”

Section: Introductionmentioning

confidence: 99%

Rigid–flexible interactive dynamics modelling approach

Zarafshan

Moosavian

2012

Mathematical and Computer Modelling of Dynamical Systems

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Dynamics modelling of multi-body systems composed of rigid and flexible elements is elaborated in this article. The control of such systems is highly complicated due to severe underactuated conditions caused by flexible elements and an inherent uneven non-linear dynamics. Therefore, developing a compact dynamics model with the requirement of limited computations is extremely useful for controller design, simulation studies for design improvement and also practical implementations. In this article, the rigid-flexible interactive dynamics modelling (RFIM) approach is proposed as a combination of Lagrange and Newton-Euler methods, in which the motion equations of rigid and flexible members are separately developed in an explicit closed form. These equations are then assembled and solved simultaneously at each time step by considering the mutual interaction and constraint forces. The proposed approach yields a compact model rather than a common accumulation approach that leads to a massive set of equations in which the dynamics of flexible elements is united with the dynamics equations of rigid members. The proposed RFIM approach is first detailed for multi-body systems with flexible joints, and then with flexible members. Then, to reveal the merits of this new approach, few case studies are presented. A flexible inverted pendulum is studied first as a simple template for lucid comparisons, and next a space free-flying robotic system that contains a rigid main body equipped with two manipulating arms and two flexible solar panels is considered. Modelling verification of this complicated system is vigorously performed using ANSYS and ADAMS programs. The obtained results reveal the outcome accuracy of the new proposed approach for explicit dynamics modelling of rigid-flexible multi-body systems such as mobile robotic systems, while its limited computations provide an efficient tool for controller design, simulation studies and also practical implementations of model-based algorithms.

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Dynamic model of a flying manipulator with two highly flexible links

Cited by 31 publications

References 15 publications

Adaptive hybrid suppression control of space free-flying robots with flexible appendages

Adaptive hybrid suppression control of space free-flying robots with flexible appendages

A New Insight into the Flexural Vibration of Rectangular Atomic Force Microscope Cantilevers by Consideration the Contact Position

Rigid–flexible interactive dynamics modelling approach

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