عنوان مقاله [English]
Cable driven parallel mechanisms have a vast range of advantages and application due to their minimal mass and inertial effects. Normally they consist an outer fixed frame and an inner mobile platform. In this paper, a completely novel configuration of these mechanisms has been presented. In this configuration outer frame is considered as mobile platform and inner frame has been fixed. The mobile frame is attached to the fixed frame by the 8 cables and moves through the tensioning and lengthening of the cables. This new structure can be applied to the wrist mechanism, motion simulators, power balances, haptic interfaces, and etc. Since the parallel mechanism is a closed system, forward kinematics cannot be solved analytically. Several methods can be used to solve the forward kinematic of parallel mechanisms, including numerical optimization methods, in which the Newton-Raphson numerical method is used here. cables must always be in tension. Hence, a tension optimization algorithm is presented and, by solving this algorithm for all possible positions, the workspace of the mechanism is obtained. The results show that the Newton-Raphson method has an appropriate convergence rate and the tension algorithm is capable of determining the forces of the cables in the desired range.