Robust Adaptive Target State Estimation for Missile Guidance

Interceptor missiles have traditionally used PN (Proportional Navigation) for terminal homing guidance. However, modern threats have become faster, more stealthy, and more maneuverable. Terminal homing missile performance requirements have also become more stringent, such as for direct-hit capability. These requirements have led to the development of newer guidance laws to improve terminal homing performance. These newer guidance laws typically use additional information (e.g., target acceleration) not required for PN. The state estimators providing this information must produce accurate estimates, otherwise the performance of the newer guidance laws can degrade to the point where there performance is worse than conventional PN guidance. The accuracy and robustness of the state estimators have been some of the limiting factors for improving terminal homing performance via the use of newer guidance laws. TSC is proposing the development of robust and adaptive state estimators based on the Interacting Multiple Model (IMM) algorithm for use in onboard terminal homing guidance. The IMM algorithm is a self-adjusting variable bandwidth filter, which makes it robust and adaptive to target maneuvers. TSC will develop a six degree-of-freedom missile simulation, develop the IMM estimators, implement a newer guidance law utilizing these state estimates, and conduct a series of Monte Carlo simulations to quantify the performances of the IMM estimators against various types of targets and maneuvers.