Research of multi-restriction energy management of solid rocket
In order to implement depleted shutdown and improve guidance precision in launching process of a solid rocket, the trajectory energy management approaches should be studied. First, the rocket inserting trajectory problem is described. The real velocity and the required velocity calculating model are given. Second, under the multi-restriction conditions, the spline energy management model is given. Third, required velocity is parameterized by a B-spline function. Take required velocity function to initial conditions, terminal conditions and process conditions, the energy management problem can be solved by an optimum approach. The optimum trajectory can be followed up with trajectory tracking control approach, and make the velocity vector track the required velocity vector. The simulation results show that the terminal and process restrictions are met.
ADAPTIVE GUIDANCE WITH TRAJECTORY RESHAPING FOR REUSABLE LAUNCH VEHICLES
Reusable launch vehicle (RLV) designs are influenced by weight and other constraints that rarely allow for significant effector redundancy. Therefore, reconfiguration of the inner-loop control system and outer-loop guidance functions can be necessary to compensate for significant control effector failures, aerodynamic uncertainties, and disturbances such as strong winds. Trajectory reshaping is also important in some situations to judiciously manage vehicle energy on-line to meet the flight objectives. This paper presents an Optimum-Path-To-Go (OPTG) algorithm, which is a general framework to perform the on-line trajectory-command generation task. The methodology was applied to Lockheed's X-33 RLV for the approach- and-landing phase of flight, and a Monte-Carlo simulation analysis was used to demonstrate the benefits of the approach. Random increments to the vehicle drag were inserted in the simulation at various downrange locations. Such variations are representative of mismodeled aerodynamics, speedbrake failure, or significant winds. The X-33 implementation of the OPTG was able to reshape the trajectories to result in a safe landing for greater than 93% of the cases. Without the OPTG capability, safe landing was accomplished for only 29% of the drag variations simulated.
Neurorehabilitation: A Disciplined Disciplining Discipline
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