Wrench-feasible workspace-based design of hybrid thruster and cable driven parallel robots

Abstract

In this research, the design of general hybrid thruster cable-driven parallel robots (TCDPRs) is studied. TCDPRs combine the actuation advantages of both cables and thrusters(rotors) in order to achieve a larger payload capacity and workspace. The additional forces provided by the thrusters can efficiently increase the available wrench set (AWS), and hence the wrench-feasible workspace (WFW), compared with pure CDPRs. The focus of this work is to study the arrangement of thrusters such that the TCDPR can produce the desired wrench set over a required workspace. The arrangement refers the number, attachment locations, directions and maximum force of the thrusters. By comparing the WFW of both planar and spatial CDPRs with TCDPRs designed using the proposed methods, it is shown that the AWS and hence the WFW can be increased to meet the requirements. Furthermore, the contributions of the thruster force to decrease the maximum required cable forces is also shown in this work. These show that a well-designed thruster arrangement is an effective approach to increasing the CDPR capabilities.