vahid pourgharibshahi - Academia.edu (original) (raw)
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Papers by vahid pourgharibshahi
International Journal of Advanced Robotic Systems, 2012
International Journal of Advanced Robotic Systems, 2012
this paper proposes a new method for designing a reconfigurable controller for descriptor systems... more this paper proposes a new method for designing a reconfigurable controller for descriptor systems which is obtained from the second order dynamics of a robot control situation. Using mathematical tools the equations of robot control situation have been translated to descriptor systems, thus, after this change the controller has been designed for control performances. The proposed reconfigurable controller can recover the nominal closed-loop performances after fault occurrence in the system. The dynamics of descriptor systems contain infinite and finite elements, so a complete response of descriptor systems can be represented by an eigenstructure which involves finite and infinite elements. In this paper eigenstructure assignment is used to design a reconfigurable controller in general such that the reconfigured system can recover the complete response of a nominal system as much as possible. Finally, an example represents the effectiveness of the new method.
This work analyzes the human shoulder complex workspace by introducing a new method to estimate t... more This work analyzes the human shoulder complex workspace by introducing a new method to estimate the intraarticulation location of the glenohumeral (GH) joint. The proposed algorithm is based on the hypothesis of the GH joint remaining fixed during the first 30 degrees of shoulder elevation. This part of any vertical movement is considered to estimate the center of spherical motions CoS) where the humeral head is located.For the experimental results, six subjects performed 5 cycles of 12 different movements in different planes. The data are collected using motion capture, for various landmarks of the shoulder girdle. With the proposed method, estimating the location of GH is possible for any motion of the shoulder girdle complex. In order to complete the kinematic model of the shoulder complex, PCA is used to identify a relation between the shoulder joints. This technique indicates that the shoulder complex can be modeled using two degrees of freedom (DOFs) to locate the spherical GH...
International Journal of Advanced Robotic Systems, 2012
International Journal of Advanced Robotic Systems, 2012
this paper proposes a new method for designing a reconfigurable controller for descriptor systems... more this paper proposes a new method for designing a reconfigurable controller for descriptor systems which is obtained from the second order dynamics of a robot control situation. Using mathematical tools the equations of robot control situation have been translated to descriptor systems, thus, after this change the controller has been designed for control performances. The proposed reconfigurable controller can recover the nominal closed-loop performances after fault occurrence in the system. The dynamics of descriptor systems contain infinite and finite elements, so a complete response of descriptor systems can be represented by an eigenstructure which involves finite and infinite elements. In this paper eigenstructure assignment is used to design a reconfigurable controller in general such that the reconfigured system can recover the complete response of a nominal system as much as possible. Finally, an example represents the effectiveness of the new method.
This work analyzes the human shoulder complex workspace by introducing a new method to estimate t... more This work analyzes the human shoulder complex workspace by introducing a new method to estimate the intraarticulation location of the glenohumeral (GH) joint. The proposed algorithm is based on the hypothesis of the GH joint remaining fixed during the first 30 degrees of shoulder elevation. This part of any vertical movement is considered to estimate the center of spherical motions CoS) where the humeral head is located.For the experimental results, six subjects performed 5 cycles of 12 different movements in different planes. The data are collected using motion capture, for various landmarks of the shoulder girdle. With the proposed method, estimating the location of GH is possible for any motion of the shoulder girdle complex. In order to complete the kinematic model of the shoulder complex, PCA is used to identify a relation between the shoulder joints. This technique indicates that the shoulder complex can be modeled using two degrees of freedom (DOFs) to locate the spherical GH...