Self-contained guidance systems

Inertial guidance is based on the use of reference coordinates established by applications of Newton's Laws of Motion to self-contained systems. Gyro units carried by servo-powered gimbals give accurate information on preset angular positions that may be used to supply the function of the celestial sphere in conventional navigation. Changes in position are indicated by integration of acceleration components along axes fixed to the gyro-stabilized member. When vehicles moving over or near the earth's surface are involved, the use of Schuler tuning to give vertical indications unaffected by linear acceleration makes accurate long-range inertial guidance possible. Because in all cases only the laws of gravity and classical mechanics are involved, inertial guidance systems are generally free from interference, short of actual physical damage. Systems based on gyro units and accelerometers are made possible only by modern developments in mechanical design, materials, electronics, and servomechanism techniques. Illustrative examples are given and discussed to bring out the nature of the problems involved. Beyond question, the future holds many applications of inertial principles to a wide range of guidance problems.