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Parallel mechanisms are widely being used in industrial applications such as machine tool, metrology, earthquake simulator, fly simulator, medical equipment and etc. These mechanisms have some limitations like having erratic workspace, singular points in the workspace and complexity of control systems. These limitations should be studied for suitable usage of parallel mechanisms. In this article, a four degree of freedom parallel mechanism (three linear and one rotation degrees of freedoms) is proposed as machine tool and being studied and its workspace and singularity analysis are done by solving the kinematic relations and using Matlab software. So, at first the inverse and direct kinematic equations of mechanism were solved and then an algorithm is used to determine the workspace and singular points of proposed parallel mechanism. Finally, to investigate the results of workspace analysis the structure has been modeled in Solidworks software and the inverse kinematic relation and the obtained workspace have been validated using the simulation. At the last, to investigate the quality of robot performance and its dexterity in workspace, global condition index of mechanism using Jacobean matrix is calculated for different orientations of moving platform.

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Robotic arms are widely used for 2D desktop applications. In this paper, a new mechanism for a planar robotic arm is presented. In addition to having the benefits of both series of parallel robots, the proposed mechanism also eliminates the disadvantages of both categories. The arm made on the same side as the parallel arms has rigidity, strength and precision, and other positive features of the parallel arms, and on the other hand, like the serial arms, due to the lack of singular points inside the workspace, has a large, symmetrical and also be able to move continuously in the entire workspace. The kinematics relations for the arm are derived, and a controller based on AVR microcontroller & computer for the arm are introduced. The results indicate an improvement in arm performance and the removal of singular points from within the workspace.