A One-dimensional Trajectory Correction Correction Mechanism And Control Algorithms

The trajectory correction projectile has the characteristic of low-cost but high-precision, as an indispensable type existing between the missile and the original projectile. One-dimensional trajectory correction technique can be achieved easily but correct range precision effectively, as the first step of trajectory correction technique.This paper presents a system scheme of the range correction projectile, based on some type of rocket and GPS, which are both widely used. Main works include the following4aspects:(1) An oar-type drag mechanism, whose actuator is power pin-pusher device, is designed. Then, the differences of flow field around the correction shell between the moment of deploying and undeploying drag-fins are researched by means of CFD software FLUENT. The numerical simulation is to provide initial calculation for the strength check of drag-fins, the exterior ballistics and the algorithm of determining the deployment time;(2) The knowledge of Mechanics is applied to check the strength of drag-fins, which provides a theoretical basis for the familiar mechanism design;(3) By utilizing the exterior ballistics theory, the GPS measurement principle and the software Matlab Comprehensively, an adaptive algorithm of determining the deployment time is raised. Grenades, mortar shells and rockets are taken as examples to verify the algorithm;(4) The effect of mass error, drag force error, deployment time error and GPS measurement error on the correction accuracy is analyzed and recursive least squares (RLS) algorithm is introduced to mitigate GPS measurement error.The results of computer simulation and some experiments verify the feasibility of the proposed design of one-dimensional trajectory correction projectiles.