Amirkabir University of Technology Amirkabir Journal of Mechanical Engineering 2008-6032 52 1 2020 03 20 Solving the Forward Kinematic Problem of Under-Constrained Cable Driven Robots for Online Control Purposes Solving the Forward Kinematic Problem of Under-Constrained Cable Driven Robots for Online Control Purposes 43 56 2706 10.22060/mej.2017.12945.5480 FA Ali Aflakiyan Human and Robot Interaction Laboratory, Faculty of New Sciences and Technologies, University of Tehran, Tehran, Iran Nima Karbasizadeh Human and Robot Interaction Laboratory, Faculty of New Sciences and Technologies, University of Tehran, Tehran, Iran Mahdi Tale Masouleh University of Tehran, School of Electrical and Computer Engineering Ahmad Kalhor School of Electrical and Computer Engineering, Human and Robot Interaction Laboratory, University of Tehran, Tehran, Iran Journal Article 2017 05 30 In this paper, a method is proposed which allows computing the position of the endeffector based on neural networks approach by taking into account external forces applied to the endeffector. As in under-constrained robots kinematics and statics are intrinsically coupled together, and they simultaneously should be considered, the forward kinematic problem of the robot can be made equivalent to an optimization problem. Solving the optimization problem is time consuming and not suitable for practical purposes. Therefore, in order to solve the forward kinematic problem a SimMechanics model based on the robot geometry and dynamic is designed and presented. By means of this method, the forward kinematic problem is solved offline and is used for online purpose. Moreover, an analysis of workspace is performed which reveals that the solution of the forward kinematic problem of the underconstrained cable robots can be calculated uniquely. By resorting to a neural network method, a position control is performed and the proposed method is validated. The comparison of the operated and desired path is shown for a helical trajectory. Maximum error in the assumed workspace is 0.4 percent. Finally, the proposed method was implemented experimentally and the results confirm the efficiency of the foregoing method. In this paper, a method is proposed which allows computing the position of the endeffector based on neural networks approach by taking into account external forces applied to the endeffector. As in under-constrained robots kinematics and statics are intrinsically coupled together, and they simultaneously should be considered, the forward kinematic problem of the robot can be made equivalent to an optimization problem. Solving the optimization problem is time consuming and not suitable for practical purposes. Therefore, in order to solve the forward kinematic problem a SimMechanics model based on the robot geometry and dynamic is designed and presented. By means of this method, the forward kinematic problem is solved offline and is used for online purpose. Moreover, an analysis of workspace is performed which reveals that the solution of the forward kinematic problem of the underconstrained cable robots can be calculated uniquely. By resorting to a neural network method, a position control is performed and the proposed method is validated. The comparison of the operated and desired path is shown for a helical trajectory. Maximum error in the assumed workspace is 0.4 percent. Finally, the proposed method was implemented experimentally and the results confirm the efficiency of the foregoing method. https://mej.aut.ac.ir/article_2706_2e74c2cf88f68a68c84e9509abc7ea56.pdf