New generation of gimbals systems for aerospace applications

摘要

The research presented in this dissertation focuses on the application of advanced robotic manipulators in the capacity of precision optical instrumentation positioning. A representative of traditional gimbals systems is subjected to analysis through detailed mathematical modeling and controller design and evaluation. Due to limitations of traditional systems in the form of limited non-continuous motion, slow response time, complicated wiring, and difficulties associated with singularities inherent from the mechanical design, a robotic manipulator is suggested as a successor to current designs. The singularity-free full-hemisphere-range Omni-Wrist III robotic manipulator features a wider and continuous range, improved dynamic response, and convenient wiring at a cost of increased kinematic complexity. This dissertation presents the development of the mathematical model of the novel manipulator, including the analysis of the dynamic response and the solution to the inverse and forward kinematic pose problems. Nonlinearities affecting the system performance are modeled. A full decoupling model-following controller is designed and implemented and applied to problems commonly encountered in the field—stabilization and tracking. Customized hardware necessary for implementing the required functionality is designed and implemented, including signal interface circuitry and an advanced inertial measurement unit consisting of a series of accelerometers, gyroscopes, and magnetometers. A Kalman filter is designed and implemented fusing the inertial measurement data into quaternion representation of orientation and utilized in the platform stabilization study. In the process of designing the tracking system, another Kalman filter is implemented in conjunction with the reference model, forcing the reference model output to match the tracked signal. The outcomes of these studies explore the very promising potential of a robotic manipulator similar to the Omni-Wrist III to become the next generation of gimbals systems.