Energy Transfer During Locking of Deployable Flexible Links

摘要

Spacecraft appendages like solar arrays and antennae are lightweight and flexible. These are stowed during launch and deployed only in orbit. Deployment of these appendages is powered by pre-loaded torsion springs at joints which have locking mechanisms. The locking mechanism prevents further rotation of a joint when it reaches the predefined angle. During locking the system loses its rotational degree of freedom and, due to the inherent flexibility, vibration is induced in the system. In this paper the energy lost due to locking during the deployment of two-link and single-link appendages is estimated. The finite element method with Lagrange's equation is used for deriving the equations of motion, and the momentum balance method to obtain the state variables just after locking. Experiments have been carried out and results of both mathematical modeling and experimentation are compared for joint rotation, strain and tip acceleration during motion. Energy transfer after each locking is discussed.