@techreport{oai:jaxa.repo.nii.ac.jp:00045033, author = {大坪, 孔治 and 小口, 美津夫 and 新田, 慶治 and 森, 英彦 and OTSUBO, Koji and OGUCHI, Mitsuo and NITTA, Keiji and MORI, Hidehiko}, month = {Aug}, note = {The inertial guidance system used in a satellite launching vehicle basically consists of an onboard guidance computer system and an inertial sensor unit which contains three accelerometers and three gyros. It is necessary for an onboard guidance computer to have functions for computing current position, velocity and attitude of the vehicle, so called navigation computation using outputs from the inertial sensors, and also a function for computing the guidance command to guide the vehicle to an orbit injection point. These computations must be carried on in the real time. In order to satisfy these requirements, it is necessary to develop onboard guidance software which is not only processed in the real time but also has a high navigation accuracy. In this paper a new algorithm for a strapdown inertial guidance system which satisfies the requirements is presented. A high accuracy flight trajectory analysis program for satellite launch vehicles was also developed for the purpose of evaluating the performance of the onboard guidance software and it is combined in the evaluation software system. A summary of the composition and functions of the evaluation system is presented. Evaluation results indicating the degree of navigation accuracy are also shown. As evaluation parameters, processing cycle time of output data from inertial sensors and navigation computation cycle time are given in the ranges from 20 to 2000 milliseconds. Simulation results show that a cycle time of less than 100 milliseconds must be chosen for the sensor data processing cycle and of less than 1000 milliseconds for the navigation computation cycle to keep navigation errors within 1 m/s in velocity and 1km in altitude. Evaluation results for the accuracy of a closed loop guidance algorithm derived from the optimum control law are also shown. To establish the real time processing, many algorithms of the onboard guidance software are simplified, and the effects of those simplified algorithms on navigation accuracy are also shown., 資料番号: NALTR0775000, レポート番号: NAL TR-775}, title = {ストラップダウン方式を用いた慣性誘導システム-搭載ソフトウェアシステムとその評価-}, year = {1983} }