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This paper describes a simple, physically-based conceptual model utilizing watershed drainage characteristics for rainfall-runoff simulation. This conceptual physiographic model is essentially based on the work of Najafi (2003), which has led to a model compris-ing the main tributary subwatersheds and a single main channel subwatershed. The Ki-nematic Wave (KW) theory is used to describe flow over the subwatershed plans. The dy-namic wave theory is applied for channel flow computations to compute the watershed re-sponses at the outlet. The proposed model was tested on a natural watershed where the results could be compared with the results obtained by Najafi (2003). The results show the proposed physiographic model has advantages over the former in terms of mathematical formulation and input data preparation as well as computation time requirements.

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The aim of present study is to investigate the kinematics of tool-workpiece’s relative movement in conventional and ultrasonic-vibration assisted turning (UAT). The kinematic analysis of UAT shows that the movement of cutting tool edge relative to the workpiece resulted from the cutting speed, feed speed and tool’s vibration affects the lateral machined surface of workepiece and leaves a repeating pattern of crushed and toothed regions on it. This results in an increase in the surface hardness of the lateral machined surface in comparison with conventional turning (CT). A model of the tool-workpiece’s relative movement has first been developed in the present study. This model predicts a surface hardening effect for the lateral surface in UAT in comparison with CT. Several experiments were subsequently carried out employing a surface micro-hardness testing machine and an optical microscope to verify the predicted results.

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This paper presents the closed-form calibration procedure of a 5-Dof Mitsubishi robot. In this method only the joint angle information is required. But due to the limitation of the robot degrees of freedom it is not possible to attach the end-effector of the robot directly to the ground; however, we can use a bar with two ball end joints for this purpose. By doing this, the robot can move freely in space. The most limiting factor of the closed-loop calibration of robot is that we cannot measure the non-moving joints, and we have to use other joint to estimate the motion of these joints. A novel approach to estimate the non-moving degrees of freedom are presented in the paper that can be extended to other robots. Experimental results validate the proposed method and the deviation of the joint parameters compared with the nominal values of the robot parameters delivered in the catalogue is very limited and are in an acceptable ranges.

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In this paper, the forward kinematic of the special cases of 4- R" R' R' R" R", 4- R" R" R" R' R' and 4- R" R" R' R' R" parallel mechanisms that respectively lead to two 4- R R U R with different geometric structures and one 4- R U U spatial 4-DOF parallel robots has been studied. They are originated from the type synthesis of 4-DOF parallel mechanisms with motion patterns of 3 T1R. Each of them is composed of four kinematic chains and each chain consists of five revolute joints. The directions of revolute joints have been different with each others that create three different geometrical structures. The forward kinematic problem is done in three dimensional Euclidean space and finally, a univariate mathematical expression of degree 344, 462 and 8 is indicated the forward kinematic problem of each parallel robot. Also, the results are compared with simulations.

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This paper involves the investigation of the forward kinematic problem of three 4-DOF parallel robots, named as 4-PRUR1, 4-PRUR2, 4-PUU, performing 3 translations and one rotation, namely Schönflies motion. The foregoing parallel robots are special cases of 3 parallel robots, named as 4-PR′R′R″R″, 4-PR″R″R′R′ and 4-PR″R′R′R″, respectively, arisen from the type synthesis performed for 4-DOF parallel mechanisms with identical kinematic limb structures. Each robot has 4 identical kinematic chains and each chain consists of one prismatic active joint and 4 revolute passive joints. Due to different direction of revolute joints in each limb, 3 different architectures are considered in this paper. The forward kinematic problem is explored in seven-dimensional kinematic space using the so-called Study's parameters and LIA algorithm and eventually, it has been shown that an algebraic expression of degree 4 indicates the forward kinematic of each kinematic chains of parallel robots under study in this paper. Moreover, using homotopy continuation and comparison with resultant method, it reveals that the forward kinematic problem of this robots have up to 236,236 and 2 real solutions, respectively.

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Patients with medial compartment knee osteoarthritis (OA) may exhibit different kinematics during walking according to the disease stage, also most of differences are in the frontal plane. The objective of this study was to compare lower extremity kinematics in frontal plane between medial knee OA patients and control subjects. Three dimensional gait analysis was performed on 25 women (35 to 53 years old): 10 control subjects, 10 mild medial knee OA and 5 moderate medial knee OA patients. Kinematics waveforms were reduced dimensionally by using Principal Component Analysis (PCA). PCA scores were compared between three groups (control, mild OA and moderate OA) with ANOVA and Post-Hoc TukeyHSD statistical analysis. Ankle of mild OA patients had a leaning towards inversion and moderate OA patients had a leaning towards eversion. Patients with mild OA, had smaller range of ankle motion than two other groups (p>0.05). Knee adduction angle increased with progression of OA severity (p>0.05). Range of hip motion in frontal plane decreased with progression of OA severity and this difference was significant between mild and moderate OA groups (p=0.05).

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Inspired by the muscle arrangement of the octopus and skeleton of the snakes, a wire-driven serpentine robot arm has been simulated and constructed in this article. The robot links which are connected via flexible beam act as the snake backbone. Instead of using motors at each joint, four sets of wire are employed as octopus muscles to drive the robot arm. For the spatial inverse kinematics, after determining the generalized coordinates of the system, governing algebraic equations of the system including constraint equations of the joints and cables and favorable movements have been determined. For displacement analysis, these equations have been solved using the Newton-Raphson method. Using this method robot workspace has also been determined. For the inverse dynamics of the robot, cables tension force has been considered as external forces. Using Embedding technique with specified constraint matrix, mass matrix and acceleration vectors that are determined from inverse kinematics, cables tension force and torque of motors are specified. To validate the snake robot model, a prototype has been built and programmed for some circular and arcuate routs. Travelled pass by end effector have been obtained. Comparing the results with the desired path, accuracy of the designed robot has been investigated.

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This paper investigates the multi-objective optimization design of planar cable-driven parallel robots by using the evolutionary optimization algorithm. Since in cable-driven parallel robots, the cables should remain in tension in all configurations, the extent of the controllable workspace is considered as one of the design indices. This objective function is of utmost importance to the design of cable-driven parallel robots, since it considers the unidirectional properties of the cables in the analysis. In addition, in order for the robot to have suitable dexterity and accuracy and to be able to manipulate any arbitrary task in all the required directions, various kinematic indices such as global condition number, translational and rotational kinematic sensitivity indices are used. Through analysis of the conflict of these objectives within the workspace of the robot, it is shown that use of multi-objective optimization is an effective method to reach to a suitable trade-off. Furthermore, by applying multi-objective optimization methods such as the non-sorting genetic algorithm and the adaptive weighted particle swarm optimization algorithm, the optimal pareto front for the design parameters for the cable robot is obtained such that to draw a compromise between the robot designs.

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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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A new complete system model of a flapping wing has been derived which consists of all effective parameters. Flapping mechanism can deliver maneuverability as well as low speed flight capability in MAVs. Here a validated aeroelastic model is being developed based on the wing torsional deformation assumption. Based on the proposed model complete parameter study could be performed and consequently the optimization requirements can be extracted. Experimental results of a static test stand have been used for validation. Performance indices, composed of force generated, power consumption and efficiency are depicted in terms of stiffness and kinematic properties. The average behavior is being referred. It is revealed that by changing frequency and speed, the optimum values for stiffness and amplitude are independent. Therefore using suitable kinematics one can utilize specified constant stiffness to optimize the flapping robot flight.

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Kinematic performance indices are used to have an evaluation of the potential efficiency of the robots. Some of these items are designing the optimal structure, trajectory planning, programming, and evaluation of behavior of the robot in positioning and orienting with desired rates or resolution. These indices will be used when the robot has even translational or rotational degrees of freedom (DoF). Due to dimensional incompatibility of the Jacobian entries in the complex DoF’s robots with both types of DoF’s, performance indices such as Jacobian condition index and associate singular values, are not applicable. In this paper, inhomogeneity of Jacobin matrix has been resolved by introducing a new Jacobian matrix which is called Cartesian Jacobian Matrix (CJM). Cartesian Jacobian Matrix maps Cartesian velocity vector of End-Effector (EE) to the joint space velocity vector. As a case study, the suggested method has been used for a Tricept parallel kinematic manipulator. Moreover, considering Local Conditioning Index (LCI) and associated singular values through the workspace have been led to structure optimization of the robot in order to have maximum positioning and orienting rates of EE through the maximum cuboid workspace. The optimization has been performed by Genetic algorithm via GA toolbox of MATLAB 2012 software.

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Kinematic trajectory optimization of the dual-arm cam-lock parallel robot in the different lock configuration has been done in this paper. A different path has been considered for each of lock configuration. The optimal trajectory of each joint has been calculated by minimizing an objective function in whole trajectory. According to the number of redundancy in the different configurations, an initial guess of the variables have been considered. Then the initial guesses have been modified and optimum results have been obtained by using Pontryagin’s minimum principles and determining the governing initial condition on the system. According to the optimal joint variable, optimal trajectory has been obtained for each of the joints. In all of the configurations, optimal performance index has been achieved. Also the direct kinematic equations have been considered as the constraints of the system.

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The Chaboche kinematic hardening model is generally used for modeling the plastic behaviour of material under quasi-static cyclic and monotonic loadings. This model is independent of strain rate and its constants are normally determined through quasi-static tests. Therefore, it cannot predict material behavior under high strain rate condition. On the other hand, the dynamic behaviour of materials even in some cyclic loadings is usually strain rate sensitive. In this investigation, the constants of Chaboche model are identified at various strain rates through quasi-static and dynamic tests and using these constants the effect of strain rate is incorporated in the Chaboche model. Moreover, the stress-strain diagrams at different strain rates are predicted using artificial neural network (ANN) and the results are compared with the experimental data. The results from the strain rate dependent Chaboche model shows reasonable agreement with the experimental data and the prediction from ANN. It is also shown in this work that the constants of Chaboche plasticity model are strain rate dependent and if the neural network is trained properly, it can be used for interpolating between the experimental data

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In this article microhexapod robot is introduced as a micromanipulator. First hexapod which is a parallel mechanism is investigated and also modifications that is needed for the improvement of positioning accuracy and eliminating factors such as clearance and friction in the conventional joints. Doing this, spherical and universal joints are replaced with flexural beam type joints after scaling down the hexapod. Then the degrees of freedom of flexure joints are achieved and after that the instantaneous center of rotation of flexure joints is derived for every finite twist of moving platform and it is shown that the kinematic chain of each pod of microhexapod consists of two spherical joints and a prismatic actuator; but it differs from hexapod in a way the location of the instantaneous center changes with the change of the finite twist of moving platform. Thereafter the velocity kinematics of microhexapod is solved using screw theory. In addition, using the analytical formula, the velocity of actuators was calculated for some case studies; linear motion of moving platform with constant velocity and also constant acceleration and also movement with constant velocity in a circular path. The results are verified with the finite element analysis and shown good agreement.

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In hydroforming process, the curve of internal pressure versus axial feeding is called loading path which is the key to produce a desire product. Finite element simulation of tube hydroforming can be used to study the loading path effect on the final part characteristics. In this research the finite element simulation of pulsating hydroforming process has been done in conjugation with two different work hardening models: an isotropic hardening and a mixed isotropic-nonlinear kinematic hardening model, which is capable to describe the Bauschinger effect. The parameters of both hardening models have been obtained from tensile test data. The result of the both finite element simulations were compared to experimental work. The results show that the mixed hardening model gets better prediction of final product characteristics than isotropic hardening. The differences between the results of two hardening models are from this fact that in a hydroforming process the tensile and compression loads are used and the loads reversal may be occurred. To study the effect of pulsating pressure on tube material characteristic, a three-step bulge test with unloading has been done and the results have been compared to monotonic bulge test. Loading and unloading of internal pressure cause a higher bulge height for a final pressure level compared to monotonic bulge height. The finite element simulation of pulsating hydroforming has been compared to linear hydroforming. The reported bulge heights and thicknesses show an improvement in formability of tubular material in pulsating hydroforming by considering the average pressure level which was applied.

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Finding a stable trajectory is amongst pivotal subjects for bipeds, which are a type of legged-robots. To mimic human gait, biped robots are basically complex because of having numerous Degrees of Freedom. The main goal of this paper is to design a stable trajectory of gaits for a 9 links robot via Zero Moment Point stability criteria. The robot used in this paper is composed of 16 active joints with two toe joint. One of the aspects of human walking to design longer strides is to use a status in which the foot is rotated about its toe joint. Here, a gait type is utilized whereas the entire sole of the support foot firstly touches the ground then rotates about its toe axis as an active joint. To achieve an initial admissible equation for robot motions, a constraint is used for initial guess of pelvis motion. Then, by using a novel algorithm, the trajectory of the joints is calculated. Finally, by considering Zero Moment Point and a trial-error algorithm, the desired trajectory of the biped robot is obtained.

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The sensitivity of the moving platform of parallel mechanisms to the uncertainties in the design and control stages is of paramount importance. The mechanism has to be designed such that the negative effect of the foregoing errors is minimized. The latter issue has encouraged many researchers to derive and propose relevant indices being responsible for outputting a metric representing the kinetostatic performance of parallel mechanisms. Most of such indices entail severe drawbacks in the sense of leading to physically inapplicable interpretation, which was considerably alleviated by the emergence of kinematic sensitivity. Nevertheless, none of the studies heretofore has investigated the influence of the uncertainties in the passive joints on the kinetostatic performance. In other words, the assumption has always been that the aforementioned errors are negligible. This paper proposes a novel formulation for the kinematic sensitivity index, which, apart from that of the active joints, takes the effect of the uncertainties in the passive joints into account, and brings about the advantage that the mechanism can be optimized and improved in terms of kinetostatic performance, together with the workspace. The formulation, for the sake of illustration and verification, is also applied to the 4-bar linkage and 3-RPR parallel mechanisms, as well as the Tripteron robot. The results of the implementation of the proposed kinematic sensitivity index, which takes the effect of the uncertainties in the passive joints into account, show that the values associated with the case-studies considered in this paper fall within the intervals 1-2.4, 0.1-0.9 and 0.6-2.2, respectively.

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This paper presents implementation of position control for planar cable-driven parallel robots using Visual servoing. The main contribution of this paper contains three objectives. First, a method is used toward kinematic modeling of the robot using four-bar linkage kinematic concept, which could be used in online control approaches for real-time purposes due to decreasing of the unknown parameters and computation time. In order to track the position of End-Effector, an online image processing procedure is developed and implemented. Finally, as the third contribution, two different controllers in classic and modern approaches are applied in order to validate the model with plant and obtain the most promising controller. As classic controller, pole placement approach is suggested and results demonstrate weaknesses in modeling the uncertainties although they represent acceptable performance. Due to the latter incapability, sliding mode controller is utilized and experimental tests represent effectiveness of this method. Result of the latter procedure is an inimitable operation on the desired task however, it suffers from chattering effect. Moreover, results of these controllers confirm accommodation between the model and robot. The whole procedure imposed, could be applied for any kind of cable-driven parallel robot.

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Iran with more than 11000 historical & monuments constructions is introduced one of the oldest civilizations in the word. Moreover, most of major earthquake in the world is referred to Iran , that is a serious threat for historical building that because during these constructions usually seismic loads are not considered, therefore it is necessary to identify these buildings behaviour in front of this natural hazard (earthquake), and doing necessary actions to strengthening the buildings and even reconstruct them in some cases. One of these splendid constructions is historical Tabriz citadel or Arge- Alisha Tabriz. Remained Citadel Alisha is a U shape plan with average 33 meters height, 51.2 meters width, 21.1 meters length. Arge Tabriz is situated in a city that is a high earthquake prone area. Thus because of different faults in this area and Arge- Alisha’s historical & cultural significance, this safety assessment of this building is unavoidable. Historical masonry structures have complex geometry that because of erosion, humidity and their materials mechanical properties has changed a lot. Usually, there is not enough exact information about compose materials of internal parts of the walls. On the other hand, because these constructions are cultural monuments of a country doing destructive tests for recognizing materials mechanicals properties is against international laws. Therefore producing a numerical model for construction analysis seems difficult, and if applicable solving it by software using FEA programs is time consuming. Simplified Kinematic Limit Analyses (SKLA) is a powerful method for historical building safety assessment analysis and its usage for retrofitting purpose that is permissible by O.P.C.M. 3431 Italian ordinance in both of the linear and nonlinear. In this research linear analysis is used for SKLA analysis. Because of masonry buildings have a rigid box behaviour, often local collapse mechanism (part of structure) is more important than its global collapse mechanism .this method assume that is collapse local, and large part of the structures are collapsed during earthquake. To identify probable collapse mechanism, we can use collapse of similar structure in the past earthquakes events. In this paper a research has been about this method (SKLA) capabilities for Tabriz Alisha Citadel seismic safety analysis. The results show that it doesn’t have enough safety against earthquake prone loads in the site. The analysis of both methods is more or less similar. Non linear time history response analysis results includes: displacement, stresses, wall’s collapse time, while SKLA only used for seismic safety assessment in different mechanisms. This method advantages such as, no need to exact information about materials mechanical properties and any destructive and non destructive test cause this method to be a powerful tool for evaluating seismic safety of historical buildings especially for huge and complex geometry structures. If we choose behaviour factor of structure 2 based on Italian ordinance, 3 mechanisms will not be active, although capacity and demand of the structure in three mechanisms have close value that indicates getting close to mechanism formation threshold.

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One important problem investigated in reverse engineering (RE) field is finding the best surface to approximate point cloud data. Swept surface is a surface type that in addition to various applications in CAD/CAM software, satisfies the whole standards required for use in RE software. The most important problem in utilization of swept surfaces for RE purposes is the finding of the areas belonging to it out of point cloud data. Through an algorithm presented in this paper, a method has been introduced to find these areas automatically. Currently, this process is performed by user intervention. In this paper, using kinematic surface formulation and slippable motion concept, a general method to find swept surfaces with any arbitrary central curve and profile is introduced. To this end, point cloud data are processed regarding slippable motion criterion using iterative segmentation algorithm, then by presenting an effective algorithm and employing the concept of hierarchical classification and drawing the dual graph, swept-surface-related areas are found. The introduced method is implemented in several models with different conditions for validation. It is observed that the results have good agreement with real model condition, showing the efficiency of this method in finding the swept surface.