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In recent years, knee diseases are spread especially in elderly people. Since performing daily activities such as walking and running, the knee supports the weight of the body, there is more likely to be injured. This issue is more important for elderly people who have weak muscles and almost all elderly people suffer from knee pain. One way to help this people in order to move normally is to use a wearable device to aid the knee. In this article, a passive wearable robot will be designed to improve the strength of the elderly who suffers from the knee pain. The robot uses the compliance elements to increase the power of the knee joint in parts of a cycle. This robot will be developed based on a Stephenson II six-bar mechanism. Using this mechanism has the advantage of producing the similar motion to a knee. In other words, this mechanism produces the linear and rotational motions simultaneously. Additionally, more compliance elements can be added to improve the performance of the wearable robot. The optimal dimensions of the robot will be Through the kinematics analysis and also the derivation of the dynamics equations and the numerical validations of these equations, the performance of the robot will be considered. The performance of the robot mounted on the leg is compared with the human. Obtained results show that the less power is required when a wearable robot is used. This proves the merits of the designed robot to be used for the elderly.

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Recently, robotic systems are widely used in surgery, due to their characteristics such as having high precision, being tireless and making no mistakes. They are especially suitable for operation on hard tissue, as the bone is stationary and does not change shape and therefore preoperative planning of the system is much more straightforward. Nevertheless, proposed robotic systems for surgery on skull bone are still in the research stage. In this study, by considering the requirements of craniotomy surgery, a Remote Center of Motion spherical mechanism is used in design and prototyping of a surgical system. The kinematic equations and Jacobian of the mechanism are calculated analytically and later verified through software simulation. Detailed design and force analysis helped selection and use of appropriate AC servo motors for actuation. An aluminum prototype is fabricated out of CNC machined parts. Performance of different connection methods between PC and the robot were tested and a combination of them is proposed for higher reliability and speed. Finally, a software library is generated in LabVIEW environment to simplify the connection with servo motors and utilization and control of the robotic system.

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Among the pieces are ceramic balls that are special because of the physical and mechanical properties that have been the industry's attention. Ceramic balls are produced by powder metallurgy way. Finally, by grinding, lapping and polishing processes is reached to surface smoothness, roundness and diameter of the desired. Since the required finishing process to ceramic finishing for surface quality and geometry accuracy of the desired is Time consuming and expensive, creating an economical finishing way is an important issue in the application of ceramic balls. In this article, a mechanism for ceramic balls lapping is proposed. Proposed mechanism consist of two lap plates. Lower lap plate has an eccentric v-shaped groove and placed on out of upper lap plate rotation center. Kinematic analysis of proposed mechanism has been done and lapping trajectory has been investigated on the ball surface. The results of kinematic analysis and lapping trajectory show that the proposed mechanism increases removal rate and roundness of the ball. In general, efficiency and productivity of balls lapping process will improve to achieve the desired surface smoothness and roundness. It can increase the speed of operation and reduce the process time by increasing removal rate.

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In this article, the kinematic and dynamic analysis of a multi-bar drum mechanism is discussed using Adams software. At first, the modeling of the mechanism is done in the catia engineering software, and then the model is entered in the Adams software. Then, by determining the appropriate joints, the initial speed is given to the mechanism and THE MOTION OF the mechanism is simulated. A kinematic analysis of the mechanism is performed and results of speed and acceleration of the joints are presented. The performed design and simulation show the effectiveness of the mechanism.