Modelling, simulation & sensitivity analysis of various types of sensor errors and its impact on Tactical Flight Vehicle navigation

Kinematic accuracy of a Tactical Flight Vehicle (TFV) is a critical parameter required during the Target engagement trajectory. There are high accuracy sensor packages available which provides the accurate measurements; but these measurements often suffer from the inherent errors like bias, misalignment and scale factors. These errors lead to erroneous computation of navigation algorithm and hence the kinematic updates. Thus an accurate analysis of inertial sensor error growth is essential to ensure the effectiveness of the optimal synergy of seeker and inertial measurements, as success is often limited by the error handling capacity of seeker. This paper brought out sensitivity of various sensor error on kinematics update of TFV at the time of seeker handover event during Target engagement trajectory. Studies of Inertial sensors and their associated error modes have been developed resulting in the wide use of these models for TFV guidance algorithms. This model then integrated with 6-Degree of Freedom (DOF) model of flight vehicle to carry out sensitivity studies under various possible Target engagement scenarios. After validating the error model with hardware test results; an exhaustive Monte Carlo simulation studies carried out to analyze the impact of these errors in TFV trajectories. Simulation analysis showed that among all the errors, the sensor misalignment error w.r.t. seeker axis plays critical role in affecting kinematic updates and this need to be taken care while mechanical integration of INS in tactical vehicle. The purpose of studies carried out in this paper is to develop detailed error model and analysis of inertial sensor error growth to provide quantitative specifications on navigation error acceptable at the time of handing over to seeker for terminal guidance.