Implementation and application of guidance law using aerodynamic data for simulation purposes

This paper describes a new technique for simulating the guidance of a SAM (surface to air missile) without the help of a controller. This analysis is fully automated in a closed loop using the features of commercial software MATLAB. The guidance algorithm is simulated with the help of aerodynamic data. Control law is not used for obtaining the desired deflections of the control surfaces rather reverse aerodynamics are used to calculate the commanded accelerations which are implied by the guidance system. The addition required in aerodynamics coefficients are calculated through reverse aerodynamics which are later on used to calculate the deflections required. These deflections are passed through actuator dynamics to obtain real deflections. The deflections obtained from actuator are then passed to aerodynamic block to calculate the desired aerodynamic forces. The forces update the current information and LOS (line of sight) of the guidance block thus creating a closed loop system. This technique has a unique solution for a unique guidance algorithm thus ensuring the path followed by the SAM is only dependent on guidance algorithm. This enables an efficient way to diagnose which guidance algorithm is suitable for a particular system without getting into the complexity of updating the controller and re-tuning of controller gains.