Model Predictive Tracking Control With Parameter Estimation for Spin-Stabilized Indirect Fire Symmetric Projectiles

Abstract

Impact point prediction, estimation, and control is a critical component of many smart weapons applications. In this work, I propose a method for estimating and controlling impact points of indirect fire launches for a spin-stabilized symmetric projectile with forward-mounted canard actuators. My method uses an algebraic point mass model to enable parameter estimation for time-varying parameters within a separate linear prediction model that can be leveraged for real-time impact point control. The point mass model also serves as the basis for a reference trajectory for any launch condition and thus eliminates the need for obtaining preloaded reference trajectories. I then use a linear prediction model in conjunction with the parameter estimates to synthesize a linear MPC tracking control algorithm for projectile impact point control. The MPC tracking controller allows incorporation of actuator saturation constraints and is shown to successfully guide a set of indirect fire launches toward a desired downrange target. A comparative case study to existing work in the literature shows that the proposed method results in a 56% reduction in the CEP radius, which is a prescribed radius such that half of the points of a given set lie within the circle, for a set of 50 yaw and pitch launch angle pairs.