Showing papers on "Inertial reference unit published in 1970"

Initial alignment of a gimballess inertial navigation system

Abstract: Initial alignment of gyrostabilized platforms is accomplished by gyrocompassing techniques. These cannot be used in the case of strap-down systems (gimballess inertial navigation systems) where the inertial components are "hard mounted." A scheme is proposed whereby initial alignment is accomplished for a strap-down system at standstill, using the gimballess inertial navigation system components only.

Pendulous type inertial reference devices

Abstract: A non-gyroscopic inertial data reference device for aircraft capable of developing pitch angle, roll angle, lateral and longitudinal acceleration information and comprising a gravityresponsive pendulum device compensated for the effects of horizontal acceleration by the use of one or more accelerometers mounted on and free to move with the universally suspended pendulum, said accelerometers providing correction signals to suitable pendulum position torquers that assist in maintaining the pendulum in the true vertical position at all times.

Attitude control of a spacecraft with a strapdown inertial reference system and onboard computer

Abstract: Spacecraft attitude control with strapdown inertial reference system and onboard digital computer

Means for determining heading alignment in an inertial navigation system

Abstract: This invention relates to apparatus for determining the heading alignment of an inertial navigation system by allowing the inertial platform to drift and employing the outputs of the accelerometers on the platform axes to compute the drift rate components, determining the amount and direction of platform drift corresponding to the computed components, and correcting the heading data of said system with the computed data

Rapid initialization of inertial navigation systems through parameter estimation

Abstract: : The accuracy of an aircraft inertial navigation system depends upon the accuracy with which the system is initially aligned. One procedure for initial alignment involves the use of an external reference. This method utilizes equipment which is much too elaborate for normal operational use. An alternate procedure uses the system's inertial sensors in a self-contained method. If sufficient time were available, the self-contained method could achieve accuracies commensurate with the sensor accuracies; however, in an operational environment it is usually necessary to sacrifice some accuracy in the interest of achieving a more rapid initiation. This dissertation investigates the methods presently available for initialization of an inertial platform in an azimuth wander or free azimuth instrumentation and presents a new method for rapid initialization. The paramount problem is the determination of the initial azimuth angle in minimum time in the presence of random gyro drifts, random accelerometer drifts, and measurement noise.