Design and Optimization of a Planar Cable Robot

Abstract

This thesis presents a new approach towards the design of Cable-Driven-Parallel Robots (CDPR). Typically, the design of such robots is not the main concern, whereas in this work, an optimization of the design is carried out to minimize the consumed energy during a given task. First, a simulation of a simple design, using a software called CASPR, is performed to serve as a validation of the developed model. This latter is then used in the optimization algorithm, where the objective function is the sum of the maximum tensions during the performance of the task. The primary goal is to determine the best design that requires the minimum resultant tensions in the cables while the end effector is following a random trajectory within the achievable workspace. The optimization algorithm aims at minimizing the objective function, based on the validated model, under constraints. The algorithm is implemented under Matlab. The positions of the centers of the different pulleys are the main variables of this problem. The optimum locations of the pulleys are the main results of the algorithm. To further validate the model, an experimental setup was built to test the CDDR to follow a simple trajectory. Preliminary experimental results were obtained showing the motion of the end-effector along the desired trajectory. Different tools were used to conduct the optimization and the results were compared. It is concluded that the obtained design is the best in minimizing the required tensions, for the selected tasks.