Employing machine tools with more than three degrees of freedom, is one of the effective methods for increasing the flexibility and accuracy of the machining parts. The milling machines with parallel mechanisms and higher degrees of freedom, have great stiffness and flexibility and also have great capability in the machining of the complicated parts. The calibration of this type of device, allows for increasing the accuracy and repeatability of the produced parts. In this article, a 4DOF milling machine with a parallel mechanism is introduced and necessary tests are performed to detect the movement errors of its rails. Again, the movement errors of the device have been measured by means of a dial indicator on a fixed part of the device using a magnetic base for positioning and linear movement of the device, and the measurement of errors after calibration has shown that the errors of the device have been significantly reduced. And it has increased the accuracy of the movement axes of the milling machine. Furthermore, the straightness of the axes is measured using a dial indicator and the error compensations are done. It is shown that the straightness of each axis with the adjustment of limit switches are improved very well.

One of the principle design stages of the machine tools, especially based on parallel mechanisms is the deflection analysis of its structure under machining forces. In this paper a new four degrees of freedom parallel robot with three translational and one rotational degrees of freedom was investigated to find the best design configuration. At first the kinematics and force analysis of the mechanism as the base of design analysis considering the load distribution on its various components were implemented. Then, deflection of the different components of structure under external torque and forces on the moving platform was obtained. To confirm the force relations and static analysis of the mechanism, the structure of robot by the FEM in ANSYS environment was analyzed. At last, the results of theoretical relations calculated by the MATLAB were compared with the simulated results obtained by the FEM. It was found a good consequently, the agreement between these two of the proposed design method.

T‌h‌i‌s p‌a‌p‌e‌r p‌r‌o‌p‌o‌s‌e‌s a s‌y‌s‌t‌e‌m‌a‌t‌i‌c a‌l‌g‌o‌r‌i‌t‌h‌m, b‌a‌s‌e‌d o‌n t‌h‌e i‌n‌t‌e‌r‌v‌a‌l a‌n‌a‌l‌y‌s‌i‌s c‌o‌n‌c‌e‌p‌t, i‌n o‌r‌d‌e‌r t‌o o‌p‌t‌i‌m‌i‌z‌e t‌h‌e m‌a‌x‌i‌m‌a‌l s‌i‌n‌g‌u‌l‌a‌r‌i‌t‌y-f‌r‌e‌e c‌i‌r‌c‌l‌e w‌i‌t‌h‌i‌n t‌h‌e w‌o‌r‌k‌s‌p‌a‌c‌e o‌f 3-D‌O‌F p‌l‌a‌n‌a‌r p‌a‌r‌a‌l‌l‌e‌l m‌e‌c‌h‌a‌n‌i‌s‌m‌s. A 3-R‌P‌R p‌a‌r‌a‌l‌l‌e‌l m‌e‌c‌h‌a‌n‌i‌s‌m i‌s c‌o‌n‌s‌i‌d‌e‌r‌e‌d a‌s t‌h‌e c‌a‌s‌e s‌t‌u‌d‌y. T‌w‌o a‌p‌p‌r‌o‌a‌c‌h‌e‌s a‌r‌e p‌r‌e‌s‌e‌n‌t‌e‌d, n‌a‌m‌e‌l‌y, i‌n‌t‌e‌r‌v‌a‌l a‌n‌a‌l‌y‌s‌i‌s w‌i‌t‌h f‌o‌u‌r a‌l‌g‌o‌r‌i‌t‌h‌m‌s a‌n‌d a g‌e‌o‌m‌e‌t‌r‌i‌c c‌o‌n‌s‌t‌r‌u‌c‌t‌i‌v‌e a‌p‌p‌r‌o‌a‌c‌h. A n‌e‌w c‌o‌n‌c‌e‌p‌t i‌n a‌p‌p‌l‌y‌i‌n‌g i‌n‌t‌e‌r‌v‌a‌l a‌n‌a‌l‌y‌s‌i‌s i‌s i‌n‌t‌r‌o‌d‌u‌c‌e‌d, w‌h‌i‌c‌h c‌o‌u‌l‌d b‌e o‌f g‌r‌e‌a‌t h‌e‌l‌p i‌n o‌t‌h‌e‌r o‌p‌t‌i‌m‌i‌z‌a‌t‌i‌o‌n c‌o‌n‌t‌e‌x‌t‌s. T‌h‌e p‌r‌o‌p‌o‌s‌e‌d a‌l‌g‌o‌r‌i‌t‌h‌m i‌n t‌h‌e i‌n‌t‌e‌r‌v‌a‌l a‌n‌a‌l‌y‌s‌i‌s s‌e‌c‌t‌i‌o‌n i‌s d‌i‌v‌i‌d‌e‌d i‌n‌t‌o f‌o‌u‌r s‌u‌b-a‌l‌g‌o‌r‌i‌t‌h‌m‌s, w‌h‌i‌c‌h e‌a‌s‌e‌s t‌h‌e u‌n‌d‌e‌r‌s‌t‌a‌n‌d‌i‌n‌g o‌f t‌h‌e m‌a‌i‌n c‌o‌n‌c‌e‌p‌t a‌n‌d l‌e‌a‌d‌s t‌o a m‌o‌r‌e e‌f‌f‌e‌c‌t‌i‌v‌e a‌n‌d r‌o‌b‌u‌s‌t a‌l‌g‌o‌r‌i‌t‌h‌m t‌o s‌o‌l‌v‌e t‌h‌e p‌r‌o‌b‌l‌e‌m. F‌i‌r‌s‌t, t‌h‌e w‌o‌r‌k‌s‌p‌a‌c‌e o‌f t‌h‌e m‌e‌c‌h‌a‌n‌i‌s‌m i‌s o‌b‌t‌a‌i‌n‌e‌d, u‌s‌i‌n‌g t‌h‌e b‌r‌a‌n‌c‌h a‌n‌d p‌r‌u‌n‌e m‌e‌t‌h‌o‌d. T‌h‌e‌n, b‌y t‌h‌e s‌a‌m‌e t‌o‌k‌e‌n, t‌h‌e s‌i‌n‌g‌u‌l‌a‌r‌i‌t‌y l‌o‌c‌u‌s o‌f t‌h‌e m‌e‌c‌h‌a‌n‌i‌s‌m u‌n‌d‌e‌r s‌t‌u‌d‌y w‌i‌l‌l b‌e o‌b‌t‌a‌i‌n‌e‌d. A‌f‌t‌e‌r‌w‌a‌r‌d‌s, t‌h‌e m‌a‌x‌i‌m‌a‌l s‌i‌n‌g‌u‌l‌a‌r‌i‌t‌y-f‌r‌e‌e c‌i‌r‌c‌l‌e f‌o‌r a c‌o‌n‌s‌t‌a‌n‌t o‌r‌i‌e‌n‌t‌a‌t‌i‌o‌n a‌n‌d a p‌r‌e‌s‌c‌r‌i‌b‌e‌d g‌u‌e‌s‌s b‌o‌x i‌s f‌o‌u‌n‌d. F‌i‌n‌a‌l‌l‌y, t‌h‌e m‌a‌x‌i‌m‌a‌l s‌i‌n‌g‌u‌l‌a‌r‌i‌t‌y-f‌r‌e‌e c‌i‌r‌c‌l‌e f‌o‌r a‌l‌l o‌r‌i‌e‌n‌t‌a‌t‌i‌o‌n‌s o‌f t‌h‌e e‌n‌d-e‌f‌f‌e‌c‌t‌o‌r i‌s a‌c‌h‌i‌e‌v‌e‌d. M‌o‌r‌e‌o‌v‌e‌r, a g‌e‌o‌m‌e‌t‌r‌i‌c a‌p‌p‌r‌o‌a‌c‌h, r‌e‌f‌e‌r‌r‌e‌d t‌o a‌s t‌h‌e o‌f‌f‌s‌e‌t c‌u‌r‌v‌e a‌p‌p‌r‌o‌a‌c‌h, i‌s p‌r‌e‌s‌e‌n‌t‌e‌d, w‌h‌i‌c‌h c‌a‌n b‌e i‌m‌p‌l‌e‌m‌e‌n‌t‌e‌d e‌i‌t‌h‌e‌r i‌n C‌A‌D s‌o‌f‌t‌w‌a‌r‌e o‌r i‌n a c‌o‌m‌p‌u‌t‌e‌r a‌l‌g‌e‌b‌r‌a s‌y‌s‌t‌e‌m. T‌h‌i‌s m‌e‌t‌h‌o‌d i‌s q‌u‌i‌t‌e f‌a‌s‌t a‌n‌d c‌a‌n b‌e a‌p‌p‌l‌i‌e‌d t‌o m‌o‌r‌e c‌o‌m‌p‌l‌i‌c‌a‌t‌e‌d m‌e‌c‌h‌a‌n‌i‌s‌m‌s. A‌s i‌t i‌s a g‌e‌o‌m‌e‌t‌r‌i‌c a‌p‌p‌r‌o‌a‌c‌h, i‌t c‌a‌n b‌e e‌a‌s‌i‌l‌y e‌x‌t‌e‌n‌d‌e‌d t‌o h‌i‌g‌h‌e‌r d‌e‌g‌r‌e‌e‌s o‌f f‌r‌e‌e‌d‌o‌m p‌a‌r‌a‌l‌l‌e‌l r‌o‌b‌o‌t‌s.T‌h‌e m‌a‌i‌n c‌o‌n‌t‌r‌i‌b‌u‌t‌i‌o‌n o‌f t‌h‌i‌s w‌o‌r‌k c‌a‌n b‌e r‌e‌g‌a‌r‌d‌e‌d a‌s a c‌o‌m‌b‌i‌n‌a‌t‌i‌o‌n o‌f t‌h‌e m‌a‌x‌i‌m‌a‌l s‌i‌n‌g‌u‌l‌a‌r‌i‌t‌y-f‌r‌e‌e c‌i‌r‌c‌l‌e w‌i‌t‌h t‌h‌e w‌o‌r‌k‌s‌p‌a‌c‌e a‌n‌a‌l‌y‌s‌i‌s, u‌p‌o‌n c‌o‌n‌s‌i‌d‌e‌r‌i‌n‌g t‌h‌e s‌t‌r‌o‌k‌e o‌f t‌h‌e a‌c‌t‌u‌a‌t‌o‌r‌s, a‌s a‌d‌d‌i‌t‌i‌o‌n‌a‌l c‌o‌n‌s‌t‌r‌a‌i‌n‌t‌s t‌o t‌h‌e l‌a‌t‌t‌e‌r p‌r‌o‌b‌l‌e‌m. T‌h‌e r‌e‌s‌u‌l‌t‌s o‌f t‌h‌i‌s p‌a‌p‌e‌r r‌e‌v‌e‌a‌l t‌h‌a‌t t‌h‌e s‌i‌n‌g‌u‌l‌a‌r‌i‌t‌y-f‌r‌e‌e c‌i‌r‌c‌l‌e o‌f a‌n‌y p‌a‌r‌a‌l‌l‌e‌l m‌e‌c‌h‌a‌n‌i‌s‌m c‌a‌n b‌e r‌e‌a‌d‌i‌l‌y o‌b‌t‌a‌i‌n‌e‌d u‌p‌o‌n f‌o‌l‌l‌o‌w‌i‌n‌g t‌h‌e p‌r‌o‌p‌o‌s‌e‌d a‌l‌g‌o‌r‌i‌t‌h‌m, a‌n‌d, a‌s a c‌a‌s‌e s‌t‌u‌d‌y, a 3-D‌O‌F p‌l‌a‌n‌a‌r p‌a‌r‌a‌l‌l‌e‌l m‌e‌c‌h‌a‌n‌i‌s‌m i‌s p‌r‌e‌s‌e‌n‌t‌e‌d.

In this article, controlling the end-effector forces is accomplished using a command system with six degrees of freedom. The command system can use a joystick implemented on a parallel mechanism. The follower robot’s end-effector is controlled by the command system and is capable of traversing the reference path with the specified force. To demonstrate this, several paths on different planes are considered and the robot’s end-effector is seen to traverse each assigned path by applying a constant force. It is also possible to identify obstacles and avoid them with this system. The control system is designed so that while approaching an obstacle, the robot’s end-effector does not collide with it. Hence, a general-purpose robot can be navigated with better performance and it can be used as a surgical robot, a robot for carrying sensitive materials or other applications. In such operations, to adjust the contact forces after a collision of the end-effector with the surface, this control system produces the appropriate control feedback. This feedback gives the operator a sense of the forces at the end-effector position and increases the operator manipulation and maneuvering skill.

Fused deposition modeling (FDM) is one of the most common 3D printings technologies. Low cost and the ability to produce models using wide range of thermoplastic makes this process suitable for rapid prototyping and manufacturing some commercial parts. The mechanism of this printer is 4-DOF parallel machanism with one additional degree of freedom resulting from rotation of printer bed about z-axis. In order to generate tool path for 5-DOF printer, a CAM software was developed with python. For controling the printer, control software was designed based on open-source marlin framework. Since original framework only supports 3-axis printers, source code needed to be changed such as extending source code to support 5-axis and adding machanism inverse kinematics. By using this 5-Dof mechanism, the prints of complicated parts without using the support are possible.

Abundant chevron folds were produced in well-bedded red thin layers radiolarites in Kermanshah area. Various fold hinge area structures were produced due to competency contrast and change of thickness in radiolarian shale and thick-bedded limestone intercalation in radiolarite sequence. Different styles of folding exist in massive to thick-bedded limestone and shale where they are inter-bedded with radilarites. Unique thin layers of the radolarite layers were folded in parallel shape but change of folds shape and mechanism were produced where thick bedded limestone or thin layers of radiolarian shale intercalations exist. Fold accommodation faults were generated in cases during folding. Geometry and style of folding indicate that deformation in radiolarites was produced by parallel folding due to buckling mechanism with southwest vergence. Thrust faults were generated during later stages, displacing some parts of the folded radiolarites.

Fracture intensity-controlling factors, which include folding mechanism, lithology and thickness of layers, have been investigated in the Asmari Formation of the Kuh-e- Asmari using field studies and satellite images. Parameters such as structural position, spacing and vertical extension of the fractures in the limestone and argillaceous limestone units of different thicknesses in the Asmari Formation sequence in Kuh-e Asmari anticline were studied. The existence of large amounts of low-strength and high-porous clay minerals in the argillaceous limestone has resulted in the overall low strength of the rock, which eventually led to lower intensity of fractures in argillaceous limestone than of that in limestone. Variations in the fracture intensitiesin these two rock types showed that the thickness of the units does not much affect the fracture intensity. Hinge-parallel and hinge-perpendicular fractures resulted flexural-slip folding and outer-arc extension in the hinge area of the fold exhibit the largest development, and exert the highest effect on wellbore instabilities. Results show that the maximum fracture intensity is in the hinge area of the fold, and that folding mechanism is the most important factor in controlling the intensity of the fractures.

In this paper, a heuristic solution approach to the single source capacitated facility location problem is considered. As a first step, a local search method is designed to perform quick simple moves in the solution structure. Then, the greedy manner of the local search is combined by Simulated Annealing meta-heuristic. Such a careful combination would allow escaping local optima with the aim of more diversified search capabilities. The method, then makes use of acceleration mechanisms to enhance search process. Here, we combine the algorithm with two different acceleration mechanisms namely consecrating mechanism and parallelizing mechanism. Such a combination will define two different versions of the mentioned search strategy based on simulated annealing meta-heuristic. Computational results obtained over the existing standard benchmark instances, not only demonstrate the superiority of the proposed method over the best existing ones, but also announce the method as an effective practical tool to tackle the problem.