Sürdürülebilir Yeşil Kampüs Koleksiyonu / Sustainable Green Campus Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7755
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Master Thesis Design of Hybrid Cable-Constrained Parallel Mechanisms for Walking Machines(Izmir Institute of Technology, 2018) Demirel, Murat; Kiper, Gökhan; Demirel, Murat; Kiper, Gökhan; Carbone, GiuseppeThe objective of this thesis study is to propose novel cable-constrained parallel mechanisms for walking machines. According to the literature, hybrid structured parallel mechanisms can overcome mechanical design, control system and workspace limitations compared to other structures. This thesis study introduces two novel hybrid structured leg mechanisms comprising rigid links and passive cables. Kinematic structure of the proposed mechanisms are (UPU-2Pa)-(UPU-2Pa)and (UU-2Pa)-P. Both designs have a hip, a knee and a foot platform. Two rotational constraints about horizontal axes are added to the moving platforms by using parallelograms with passive cables. The rotational constraint about the vertical axis is provided by rigid links and joints. Thus, the proposed designs have pure translational motion. The detailed analysis of the mechanism design with anchored cables is conducted. A CAD model is constructed and a dynamic simulation for human-like gait trajectory is performed in SolidWorks® environment. Once the computed actuator torques and forces are found suitable, a first prototype is built to check the proposed solution. Considering the problems encountered in this first prototype, a second prototype of the (UU-2Pa)-P mechanism is built. The prototype is operated using a real-time PCI controller and experimental results are presented. The mechanisms presented in this thesis is one of the few cable-constrained parallel manipulator designs in the literature. Such a manipulator design is used for a walking machine for the first time. The prototype and test results are quite satisfactory, so hopefully more detailed research can be conducted on this topic in the future.Conference Object Citation - Scopus: 3Design and Simulation of a Novel Hybrid Leg Mechanism for Walking Machines(Springer Verlag, 2018) Demirel, Murat; Carbone, Giuseppe; Ceccarelli, Marco; Kiper, GökhanThis paper introduces a novel hybrid structure design that is composed of rigid links and cables for a robotic leg with static walking. The proposed mechanism is characterized by actuated hip joints, passive knee joints and an actuated prismatic foot joint. The foot is the moving platform of the proposed mechanism which possesses pure translational motion due to the passive parallelograms with cables. Kinematic analysis has been worked out for evaluating a typical human-like gait trajectory. A 3-D model has been developed and simulation are made in SolidWorks® environment. Simulation results show that the proposed mechanism is able to perform an ovoid walking cycle of a foot point and the computed actuator torques and forces are in a feasible range for a low-cost and easy-operation design. The simulation results will be used for a prototype construction in a future work.