Analysis, measurement and compensation of mechanical errors of IR-systems mounted on a five axis motion table

摘要

LFK-Lenkflugkoerpersysteme GmbH develops missile systems for a wide field of military purposes. The Hardware-in-the-Loop (HWIL) facility of LFK in Unterschleissheim uses a five axis motion simulation table and an IR scene projection system. The system is designed for test and evaluation of several missile programs due to the dimensions of the five axis table and it's dynamic performance /1/. In a certain cruise missile program there was the need for system tests with nearly all components of the missile as well as special investigations and validation trials for the subsystem consisting of the IR-seeker and the image processing computer. The components had also to pass their qualification tests with the assistance of the HWIL team. These tests and their analysis are focussed to the mechanical accuracy of the gimbals and resolvers of the IR seeker and the tracking accuracy of the image processing computer. Before starting tests in the HWIL it is absolutely necessary to identify errors caused by mechanical tolerances of the test equipment (e.g. mounting of the seeker and the IR projection system) on the five axis motion simulator. Otherwise the obtained test results includes these errors and lead to incorrect system performance evaluation. There are different mechanical errors in mounting which can occur are analysed below. The main problem is caused by possible shifts of the IR-seeker in a plane perpendicular to the optical axis (with gimbals in zero position). Therefore a procedure has been developed using IR test images, a frame grabber and image processing routines to determine the mounting failures. These can be corrected by using mechanical adjustment tools designed and realised for this purpose.