Application of Piecewise Linear Control Allocation to Reusable Launch Vehicle Guidance and Control

摘要

We will demonstrate two applications of the piecewise linear control allocation (PLCA) approach. The first application to be considered is to use the PLCA approach in the inner-loop control law of a re-usable launch vehicle on approach and landing. Body axis angular rates are controlled using a dynamic inversion controller. The vehicle will be subjected to two stuck control effectors, and recovery of the vehicle using only control effector reconfiguration provided by the control allocator and without trajectory reshaping will be demonstrated. The second application that will be demonstrated is constraint estimation for trajectory reshaping and re- targeting. In order to successfully re-target a trajectory when an aircraft has experienced degraded performance due to a failure or damage to the vehicle, the effects of the failure or damage on the lift, drag, and 'trimmability' of the vehicle must be known a priori over the entire flight envelope. We present a method that allows for the effects of a locked or floating control effector to be estimated over the flight envelope.