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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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In this paper, kinematic and dynamic model of planar cable-driven parallel robots are introduced in general form which are verified for a constrained cable-driven parallel robot in Sim-mechanics. Path planning based on artificial potential field approach is considered to prevent collision between dynamic obstacle, end-effector and cables in order to achieve collision-free path. As well as to reduce energy consumption, cable tension constraints have been involved in optimization of path planning. This method is proposed to control a cable robot. Therefore, obstacles are distributed randomly in order to have a complex environment. By this way, cable tension constraint is studied as one of the most crucial challenges for cable driven robots. Moreover, Fmincon function of Matlab is applied in order to take into account the required constraints and maintain the limits for cables tension. The latter leads to solve the redundancy resolution which is a definite asset in controlling a cable-driven parallel robot. Finally, a four-cables driven parallel robot is controlled by using the so-called computed torque method for tracking the desired and optimized path. The method is explained and obtained results indicate the efficiency of the proposed approach.