| 英文摘要 | As some payloads are so heavy, precise, valuable and fragile that they absolutely cannot endure point-to-point or line-to-line touch with the assembly platforms or the transporting vehicles, a four-rope-driven level-adjustment robot is designed to level these eccentric payloads whose density is uneven and centers of gravity are different from their centers of geometry. The robot regulates the payload to level by changing the ropes’ lengths, which may render the rope tension unbalanced. However, the rope tension should be regulated to balance to ensure the safety of the payload as well as the operators. Further, owing to the ropes’ flexibility and coupling, the modeling and control of the robot is challenging and important in both theory and application. In this dissertation, the modeling and control of the robot is studied with the support of the National 863 Program of China “Design of a four-rope-driven level-adjustment robot” (No.2007AA04Z239). Firstly, the background and significance of the four-rope-driven level-adjustment robot is briefly introduced. Also, the research statuses of the existing technologies, which can be used to adjust the payloads’ posture, are comprehensively surveyed. Then, the background and main work of the dissertation is proposed. Secondly, the mechanical structure, control system, and working principle of the robot are elaborated. Meanwhile, a multithread based software, integrating manual control and automatic control together, is designed for the robot. Its architecture, working interface and work flow are expatiated. Thirdly, as it is hard to establish the robot system’s mathematical model directly because of the ropes’ coupling and flexibility, the robot system is divided into two 2D (short for two-dimensional) diagonal subsystems. The mathematical model of the 2D diagonal subsystem is deduced. However, it is hard to deduce the mathematical model’s analytical solution, so a function fitting model is established for the 2D subsystem with the help of genetic algorithm and fuzzy system. Then some features of the 2D diagonal subsystem are obtained to guide the controller’s design. Fourthly, “dimension disaster” is effectively avoided by dividing the robot system into two 2D diagonal subsystems and designing one fuzzy sub-controller for each subsystem respectively. The two sub-controllers cooperate with each other to level the payload and balance the rope tension simultaneously. Fifthly, a... |
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