Inertial reference unit

About: Inertial reference unit is a research topic. Over the lifetime, 1306 publications have been published within this topic receiving 22068 citations. The topic is also known as: IRU.

Inertial velocity sensor signal processing circuit and inertial velocity sensor device including the same

Abstract: PROBLEM TO BE SOLVED: To detect a fault even if an inertial velocity sensor element is not operating normally. SOLUTION: The inertial velocity sensor element 11 vibrates according to the frequency and amplitude of a drive electric signal Sd and outputs a vibration electric signal So corresponding to the vibration, and outputs an inertial electric signal Si corresponding to inertial force given to itself. A drive circuit 12 adjusts the frequency and amplitude of the drive electric signal Sd according to the drive electric signal So. An inertial force detection circuit 13 uses a signal (a clock signal CLK1) for analog detection to extract an inertial force component from the inertial electric signal Si. A fault detection circuit 14 determines whether the operation state of the drive circuit 12 is normal or not. Also, the fault detection circuit 14 measures a period (fault state period) where the operation state of the drive circuit 12 is abnormal in synchronization with a clock signal CLK2 from a CR oscillator 15, and outputs a fault detection signal Sa when the fault state period reaches a fault detection period (predetermined period). COPYRIGHT: (C)2009,JPO&INPIT

Method of determining heading by turning an inertial device

Abstract: A method of determining a heading by means of an inertial device (1) providing measurements by means of at least one vibratory gyro (3), the method comprising the steps of : • positioning the inertial device in such a manner that the gyro extends close to a plane that is substantially horizontal; • orienting the inertial device successively in a predetermined number of orientations about a vertical axis, the predetermined number being greater than one; • for each orientation, adjusting the electric angle of the vibratory gyro to a predetermined value, the predetermined value of the electric angle being the same for all of the orientations of the inertial device, and taking a measurement; and • determining the heading from the measurements and an angle between the orientations.

Precise, no-contact, position sensing using imaging

Abstract: A contact free optical motion sensor for an inertial reference system. One or more image acquisition systems are adapted to produce a series of overlapping images of a gas bearing supported spherical inertial sensor assembly. A controller coupled to receive the series of overlapping images applies a delta detection algorithm to the series of overlapping images to determine the distance, the direction of movement of the inertial sensor assembly and the resulting relative position of the gas bearing supported spherical inertial sensor assembly. The controller further calculates the rotational velocity of the inertial sensor assembly based on a time sequence between the received series of image signals and the distance moved.