Inverse dynamics control of parallel manipulators around singular configurations

Özdemir, Mustafa
In this thesis, a technique for the motion of parallel manipulators through drive singularities is investigated. To remedy the problem of unbounded inverse dynamics solution in the neighborhood of drive singularities, an inverse dynamics controller which uses a conventional inverse dynamics control law outside the neighborhood of singularities and switches to the mode based on the formerly derived modified equations inside the neighborhood of singularities is proposed. As a result, good tracking performance is obtained while the actuator forces remain within the saturation limits of the actuators around singular configurations.


Inverse dynamics of parallel manipulators in the presence of drive singularities
Ider, SK (Elsevier BV, 2005-01-01)
At drive singularities of parallel manipulators the actuators lose control of the end-effector in certain directions. It is shown that if certain conditions related to the consistency of the dynamic equations are satisfied by a proper design of the trajectory, the manipulator can pass through the singular positions while the actuator forces and the system motion remain stable. To find the values of the actuator forces in the neighborhood of the drive singularities, the dynamic equations are modified by usin...
Nonlinear Structural Coupling: Experimental Application
Kalaycioglu, Taner; Özgüven, Hasan Nevzat (2014-02-06)
In this work, the nonlinear structural modification/coupling technique proposed recently by the authors is applied to a test system in order to study the applicability of the method to real structures. The technique is based on calculating the frequency response functions of a modified system from those of the original system and the dynamic stiffness matrix of the nonlinear modifying part. The modification can also be in the form of coupling a nonlinear system to the original system. The test system used i...
Inverse dynamics control of flexible joint parallel manipulators
Korkmaz, Ozan; İder, Kemal; Department of Mechanical Engineering (2006)
The purpose of this thesis is to develop a position control method for parallel manipulators so that the end effector can follow a desired trajectory specified in the task space where joint flexibility that occurs at the actuated joints is also taken into consideration. At the beginning of the study, a flexible joint is modeled, and the equations of motion of the parallel manipulators are derived for both actuator variables and joint variables by using the Lagrange formulation under three assumptions regard...
Motion control of constrained systems considering their actuation-related singular configurations
Özgören, Mustafa Kemal (2001-01-01)
In this paper, the constrained motion control of a normally unconstrained mechanical system is investigated. As far as its motion control is concerned, such a system will have a redundancy in its actuators due to the reduction caused in its number of degrees of freedom by the presence of the constraints. Four methods are described in order to determine the actuator and constraint forces. The first three of these methods necessitate using all the actuators and the fourth method is applicable in a case where ...
Invalid joint arrangements and actuator related singular configurations of a system of two cooperating SCARA manipulators
Ozkan, B; Özgören, Mustafa Kemal (2001-06-01)
In this study, the actuator related singular configurations (ASCs) of a system of two cooperating SCARA manipulators, are investigated. The ASC concept was First developed for planar pairs of cooperating manipulators, and it was shown that these ill-conditions could be different from the kinematic: singularities. (Ozkan B, Ozgoren MK. Torque related singular configurations of a planar system of two coodinated manipulators. In: Proceedings of International Machine Design and Production Conference, Sept. 9-11...
Citation Formats
M. Özdemir, “Inverse dynamics control of parallel manipulators around singular configurations,” M.S. - Master of Science, Middle East Technical University, 2008.