The Spinning Rocket Simulator: An Experimental Design Project For Teaching And Research

An experimental apparatus is being developed to simulate the dynamics and control of spinning, thrusting bodies with internal mass motion. An interdisciplinary team of undergraduate engineering students is executing the first phase of development as a senior design project at Oral Roberts University under the direction of faculty advisors. The apparatus will enhance instruction in dynamics and control systems by providing demonstrations of fundamental dynamical principles and experimentation with spacecraft attitude control concepts. In addition, the apparatus will be used to conduct research in the dynamics and stability of spinning rockets with internal mass motion, and the passive and active control of such vehicles. Introduction Undergraduate engineering students need learning opportunities that more closely resemble the challenges they will face in industry and graduate school. Successful teamwork and communication in engineering design, especially between the engineering disciplines, are essential skills that should be practiced at the undergraduate level. This approach is facilitated in the Oral Roberts University Engineering and Physics Department since students work closely with those of other disciplines. The ABET accredited undergraduate degree in general engineering allows for mechanical or electrical emphasis, Undergraduate degrees in computer engineering, bioengineering, and engineering physics are also conferred within the same department. The two-semester senior design project experience typically involves a team of students from several of these areas with an engineering design problem requiring work in multiple disciplines. This paper describes the initial phase of one such project and the benefits derived for both the students and the university. The long term goal of the project is to develop an experimental apparatus to accurately model the dynamics and control of nonrigid, spinning bodies under thrust. An initial concept for such an apparatus has been proposed by Meyerl. The first phase consists of the development of three interdependent and essential elements: a general spacecraft model with variable inertias, a hemi-spherical air bearing to support the model, and the sensor systems necessary to track the orientation of the model during test. This last element is required for future phases to allow accurate modeling of the thrust force. Completion of the first phase allows laboratory simulation of the rotational dynamics of a rigid body in space over a wide range of inertia properties. In addition, the motion is sensed and recorded for analysis. At this stage, the apparatus is useful for demonstrating fundamental concepts of three dimensional rigid body dynamics that are typically difficult for students to visualize, and hence grasp. The completion of future phases will provide a vehicle for laboratory experimentation and research in the dynamics and control of nonrigid, spinning bodies under thrust, validating and extending the work of Halsmer and Mingori2.